Title of Invention	A VALVE CLUSTER WITH A SAFETY VALVE
Abstract	Abstract of the Disclosure A valve cluster (6) comprises several electrically operated control valves, which, each are joined simultaneously with at least one common supply duct (1) and a common venting duct (3 and 5). By way of at least one feed duct (32 and 33) the common supply duct (1) is supplied with the pressure medium required for the operation of the valve cluster (6). An additional safety valve (15) renders possible a selective turning on or turning off of the duct connection between the at least one feed duct (32 and 33) and the common supply duct (2). It is thus able to assume a venting position when the connection is turned off in which it vents the common supply duct (1) to the atmosphere. Figure 2

Title of Invention

A VALVE CLUSTER WITH A SAFETY VALVE

Abstract

Abstract of the Disclosure A valve cluster (6) comprises several electrically operated control valves, which, each are joined simultaneously with at least one common supply duct (1) and a common venting duct (3 and 5). By way of at least one feed duct (32 and 33) the common supply duct (1) is supplied with the pressure medium required for the operation of the valve cluster (6). An additional safety valve (15) renders possible a selective turning on or turning off of the duct connection between the at least one feed duct (32 and 33) and the common supply duct (2). It is thus able to assume a venting position when the connection is turned off in which it vents the common supply duct (1) to the atmosphere. Figure 2

Full Text	--A VALVE CLUSTER WITH A SAFETY VALVE-- The invention relates to a valve cluster comprising a plurality of electrically actuated control valves which respectively are simultaneously connected with at least one common supply duct and with at least one common venting duct and are able to control the connection of such ducts with, respectively at least one individual power duct able to be connected with a load, at least one feed duct for the feed of pressure medium intended for the at least one common supply duct and a safety valve connected between the at least one £eed duct and the at least one common supply duct for selectively opening or closing the duct connection. A valve cluster of this type disclosed in the patent publication EP 1 041 325 El comprises several control modules each joined with a respective control valve which are collected together in a module arrangement. By way of a common supply duct extending through the module arrangement all control valves may be simultaneously supplied with pressure medium. The venting of the control valves takes place by way of one or two common venting ducts also extending through the module arrangement. The common supply duct is placed downstream from a closing valve able to be utilised as a safety valve and which is in a position of disconnecting the common supply duct from a feed duct supplying the pressure medium, when a trouble condition occurs. The valve cluster is then more or less disconnected from the pressure medium line. If however disconnection takes place with the valve cluster still at full supply pressure, the pressure medium shut off in the valve cluster may still cause undesired switching functions of the control valves. One object of the present invention is to design a valve cluster having improved safety functions as regards turning off. In order to achieve this object the valve cluster is so designed that the safety valve is able to be switched into a venting position in which it vents the at least one common supply duct and simultaneously shuts off the feed duct. It is in this manner that with the feed duct shut off the pressure medium located in the at least one common supply duct (at the time of shutting off) of the valve cluster is not simply trapped but let off into the atmosphere. The valve cluster is therefore deprived of pressure on the supply side so that even swithing operations, still taking place, of the control valves do not entail undesired functions at the connected loads. Furthermore it is now possible without any risk to perform servicing work on the valve clusters and for example to replace a defective control valve. The safety valve may without any difficulty be designed so that it automatically switches into the venting position when for example the electricity supply and/or the supply pressure should fail. Advantageous developments of the invention are defined in the dependent claims. In order to get the valve cluster ready for operation again following venting it may be designed with at least two feed ducts which are joined, in the open position of the safety valve, simultaneously in parallel with the common supply duct of the valve cluster. The pressure medium may then flow at a high rate to the valve cluster. The venting of the at least one common supply duct may for example occur exclusively through at least one of the at least one common feed duct of the valve cluster. This means that no additional venting position is necessary in the valve cluster. If the valve cluster, as is frequently the case with valve clusters, has or have two common venting ducts for the control valve, the safety valve can be so designed that for venting the at least one common supply duct both common venting ducts of the valve cluster are employed There is furthermore the possibility of providing, in addition to the at least one common duct of the valve cluster, at least one independent additional venting duct by way of which the at least one common supply duct may be vented. In this case there is then a possibility of influencing, by having a suitable design of the safety valve, the venting operation so that such venting takes place exclusively through the independent additional venting duct or - as might be termed a high speed venting operation - in parallel via the at least one common venting duct of the valve cluster and the additional venting duct independent thereof. The latter possibility means that an extremely high venting cross section is available. The safety valve is preferably designed to be electrically activated. It may receive its electrical operating signals individually or also by way of an electrical concatenation means possibly fitted as a standard feature. Preferably the safety-valve in this case so designed that it is maintained in the electrically deactivated state by spring means in the venting position. In order to switch into the turned on position the safety valve is electrically activated and its valve member is deflected against the spring force. If during operation the electrical power supply should fail, the safety valve is immediately and reliably moved into the unproblematical venting position. In the case of a preferred design of the safety valve the venting flow passes through a plenum in the spool of the safety valve. This renders possible a particularly advantageous arrangement of the duct circuitry. The safety valve can arranged at or fitted in any suitable position of the valve cluster. In any case it will be on board the valve cluster so that compact dimensions are possible without external safety components. In the case of a particularly advantageous embodiment the safety valve is a component of a self-contained safety module, which is collected together with control modules respectively comprising at least one control valve to constitute a module arrangement. In this case the safety module is a member of a chain of control modules,, for example as the terminating module or also as an intermediate module. The latter possibility makes it possible to have an intermediate supply, at practically any point, of the pressure medium necessary for the operation of the valve cluster. Preferably the valve cluster comprises a modularly designed fluid distributor with individual fluid distribution modules which with the formation of the control modules with the control valves and with the formation of the safety module are provided with a safety valve, are provided with a safety valve and which, are able to be fitted together in a modular manner. The fluid distributing modules preferably each comprise two individual power ducts joined with the respectively associated control valve for driving a load. The fluid distributing module of the safety valve preferably also has two individual fluid ducts extending through it, of which at least one constitutes a feed duct for the common supply duct. In accordance with the above described modified design the second fluid duct may be employed as a parallel-connected further feed duct or as an additional venting duct. Should it not be required at all, it may be stoppered. In the following the invention will be described in detail with reference to the accompanying drawings. Figure 1 shows a preferred embodiment of the valve cluster in accordance with the invention in a perspective representation with, the terminating element of the fluid distributor of the valve cluster removed. Figure 2 is a section taken through the valve cluster of figure 1 on the section line II - II adjacent to the safety valve. Figure 3 shows the safety valve, employed in the arrangement of figures 1 and 2, in a longitudinal part and in the venting position. Figure 4 shws the safety valve of figure 3 in the turned on position assumed in normal operation. Figure 5 represents a modification of the safety valve in the same fashion as in figure 3 and in the venting position. Figure S represents the safety valve of figure 5 in the turned on position. The valve cluster generally referenced 6 with a preferred design comprises a fluid distributor 8 extending in the direction of a longitudinal-axis 7, which on a mounting face 12 carries several electrically operated control valve 13. The control valves 13 are arranged one after the other in a row direction 14 indicated by a double arrow and coinciding with the longitudinal axis 7. The mounting face 12 also bears a safety valve 15 also included in the row of safety valves 13. The safety valve 15 terminates the row of control valves in the particular working embodiment at one end. The fluid distributor 8 has at least one supply duct 1 extending through it in the longitudinal direction, which is common to all control valves 13. In parallel to this common or shared supply duct 1 a first and a second venting duct 3 and 5 extend, which like the common supply duct 1 respectively open at the mounting face 12 at multiple positions so that each control valve 13 is connected with each of the common supply ducts 1 and with each of the venting ducts 3 and 5. In addition the common supply duct 1 and the two venting ducts 3 and 5 open at a component mounting area 16 on the mounting face 12 at which the safety valve 15 - is detachably secured for example by a screw connection. Accordingly both the common supply duct 1 and also the first and the second common venting duct 3 and 5 communicate with each control valve 13 and also with the safety valve 15. Furthermore each control valve 13 communicates with two power ducts 17 and IS, individually assigned to it, which extend through the fluid distributor 8 athwart the longitudinal axis 7 and respectively at one end open at the mounting face 12 for the associated control valve 13 and at the other end open on the outside of the longitudinal side of the fluid distributor 8 at a connection face 22. At the connection face 22 the power ducts 17 and 18 can be joined with fluid lines (not illustrated in detail) leading to the loads to be operated, for example by fluid power. During routine operation of the valve cluster 6 the common supply duct 1 provides a pressure medium, more particularly, compressed air at a supply pressure. This pressure medium comes from a pressure source P connected with the valve cluster 6. The control valves 13 are able to be electrically operated and may be set in respectively different switching positions, in which they selectively connect the connected individual power ducts 17 and 18 with the common supply duct 1 or with one of the two common venting ducts 3 and 5. As a rule there is in chis case a so-called 5/2 switching function. The operating signals required for the electrical operation of the control valves, such signals including both control signal and also operation power, pass by way of an electrical concatenating means 23 extending in the row direction 14 to electrical connections {not illustrated) of the control valves 13. They stem from an electronic means, which may be mounted on board the valve cluster 6 and/or placed externally. The control valves are preferably pilot valves, each having an electrically operated pilot valve means, as for example a solenoid valve means. Each pilot valve means may be composed of one or two electrically operated pilot valves. The two common venting ducts 3 and 5 open clear of the mounting face 12 at the outer face of the fluid distributor 8 and are joined by way ox openigs with the atmosphere. This may be either directly or by the intermediary of mufflers or by way of s duct to the atmosphere at some remote point. The fluid supply to the common supply duct 1 is able to be controlled by the safety valve 15 arranged on board the valve cluster 6. As regards details the safety valve 15 possesses an outlet port 24 connected with the shared supply duct 1. Moreover it has two venting ports 25 and 25, of which the first one (25) is connected with the common venting duct 3 and of which the second one (25} in the connected with the common venting duct 5 at all times. For this purpose the safety valve 15 has further valve ports 27 and 28 individually connected one first and, respectively, second fluid distributing duct 2 and 4. The same also preferably open at the mounting face 22 of the fluid distributor 8 where connection means (not illustrated) may be provided to render possible the connection of a fluid duct leading to the outside. in the case of all working examples the one, first fluid distribution duct 2 constitutes a feed duct 32 constantly connected with the pressure source ?. The second fluid distribution duct 4 is in the working example of the figures 2 through 4 also a feed duct 33, which in a circuit arrangement parallel to the other feed duct 32 is constantly connected with the pressure source P. In the working embodiment illustrated in figures 5 and 6 on the contrary the second fluid distribution duct 4 functions as an additional venting duct 34 in addition to the common venting ducts 3 and 5. Its opening provided at the mounting-face 22 communicates in operation of the valve cluster 6 directly or by the intermediary of a fitted muffler with the adjacent atmosphere or with a venting line leading at some other point to the atmosphere. In the case of all working examples the common supply duct 1 is exclusively supplied with the pressure medium necessary for the operation of the valve cluster 6 via the at least one feed duct 32 and 33. No further supply of fluid, not controlled by the safety valve 15, is provided to the common supply duct 1. A standard feed opening present on the fluid distributor B {not illustrated in detail) for the common supply duct 1 is shut off, for example by means of a stopper. However it can be employed, when the valve cluster 6 is to be utilized without a safety valve 15 or without using functionality of the safety valve 15 present. All working examples of the valve cluster 5 share the common feature that with the aid of the safety valve 15 the connection between the at least one feed duct 32 and 33 and the common supply duct 1 connected with the safety valve 15 may be selectively turned on or disconnected. With the duct connection turned on the safety valve 15 will in the working example assume the turned on position depicted in figures 4 and 6. In accordance with figure 4 in this case the two feed ducts present 32 and 3 are simultaneously joined with the common supply duct 1. In accordance with figure 6 there is a flow connection between the common supply duct 1 and the single feed duct 32. In the disconnected state of the duct connection illustrated in fig-ares 3 and 5 the common supply duct 1 is disconnected in a fluid-tight manner from the respectively associated feed duct 32 and, respectively, 33. At the same time it is nevertheless vented to the atmosphere owing to the safety valve 15 assuming a venting position. In the working embodiment illustrated in figures 2 through 4 this is due to the turned on connection between the common supply duct 1 and the first common venting duct 3 - In the working embodiment illustrated in figures 5 and 6 the common supply duct 1 is simultaneously vented both via second common venting duct 5 and also via the additional venting duct 34. Irrespectively of the type of venting the common supply duct 1 will accordingly be freed of pressure in the venting position of the safety valve 15 and the entire valve cluster 6 will be freed of pressure. Consequently even if owing to electronic control or owing to manual operation a control valve 13 should be caused to implement a switching operation, such operation can not entail any damaging movement of a connected load. The reduction of the pressure obtaining inside the valve cluster to atmospheric pressure furthermore renders possible a safe removal of the safety valves 13 for repair or substitution purposes. In the working embodiment illustrated in figure 2 through 4 the second common venting duct 5 is not employed for the venting process controlled by the safety valve 15. The control valve 15 is in this case so designed that the second venting port 26 will remain closed irrespectively of the position of the spool 35 of the safety valve 14. It would however be certainly conceivable for the safety valve 15 to be so designed that both common venting ducts 3 and 5 are employed in the venting position for venting the common supply duct 2. Furthermore it would also be possible, departing from the design in accordance with figure 5, for both common venting ducts 3 and 5 and also the additional venting duct 34 to be simultaneously utilized for venting the common supply duct 1, or also only the additional venting duct 34 present, the two common venting ducts 2 and 5- then not partaking in the venting function of the safety valve. A design would also be possible in which the additional venting duct 34 does not communicate with an individual fluid distributor duct 4 but rather directly leads to a free outer face of the housing 36 of the safety valve 15 in order to render possible, from this position and bypassing the fluid distributor 8, venting to the atmosphere. Irrespectively of its further possible design the safety valve 15 is preferably configured for electrical activation. It possesses an electrical interface 37 for the supply of the operation signals required for its actuation. Such signals may be supplied individually or however via the electrical concatenation means 23 which is present and which is comparable with the electrical operation of the control valves 13. The safety valve 15 is in the working example in each case a pilot controlled multiway valve. It comprises an electrically actuated pilot valve 38, as for example a solenoid valve, whose activation state sets the currant operational state of the safety valve 15. The safety valve 15 comprises a valve spool 35 as already described and preferably in the form of a piston, which is able to be shifted in its longitudinal direction between two positions which in one case are the venting position and in the other case are in the turned on position. At one end the valve spool 3 5 has an axially orientated actuating face 42 which delimits a pilot chamber 43 connected with a pilot control duct_ 44 as indicated in dots. The pilot control duct 44 is supplied with a pressure medium at a pilot pressure, which in the working examples is fed from a pilot feed duct 45 extending inside the fluid distributor 8. The pilot feed duct 45 may be supplied with pressure medium either independently of the common supply duct 1 or from it. Alternatively it would also be possible to connect the pilot control duct 44 in the interior of the safety valve 15 with the output port 24. The pilot valve 38 is placed on the pilot duct 44. it is able to selectively open or close the passage through the pilot duct '44. In the turned off state it simultaneously provides for venting of the pilot chamber 43. When the pilot duct 44 is turned on the pilot pressure is present in the pilot chamber 43, such pressure acting on the actuating face 42 and exerting a setting or servo force on the valve spool 3 5 so that the latter is switched into the open position appearing in figures 4 and 6. The setting force 46 consequently always obtains in the open position in order to override an oppositely acting return force 47 of a spring means 48, which constantly urges the valve spool into the venting position indicated in figure 3 and 5. The spring means 48 has one end bearing against the valve spool 35 and the other end bearing directly or indirectly on the valve housing 36 of the safety valve 15. In order to economize in size the spring means 48 may move into an axial recess in the valve spool 35. Instead of the mechanical spring means 43 present in the working embodiments other actuating means could be present in order to produce the return force 47. The invention also contemplates a pneumatic spring, for example. Whatever its design the spring means 48 does have the advantage that it shifts the valve spool 3 5 into the venting position when the pilot chamber 43 is free of pressure, be it owing to a system-related drop in pressure or owing to failure of the electrical supply. The valve spool 3 5 extends in a valve spool socket 52 in the valve housing 36, such socket being divided up by a seal means 53 axially into several portions. The seal means 53 surrounds the valve spool 3 5 coaxially and is preferably arranged in a fixed manner in relation to the valve housing. It can more particularly comprises a plurality of annular seals arranged with a clearance between them which are able to come into sealing contact with different portion of its outer periphery in a fashion dependent on the axial position. The above mentioned various portions are connected with the above mentioned ports 24 through 28. In order to perform the desired switching function the valve spool 35 is multiply stepped in an axial direction on its basically cylindrical outer periphery. Accordingly there is an axial sequence of portions with a larger and a smaller diameter. Dependent on the position of the valve spool 35 and the resulting sealing contact or absence thereof with the sealing means 53 accordingly individual ports 24 and 28 are connected with each other as indicated above or are separated from each other. In the working embodiment illustrated in figures 5 and 6 the valve spool 35 is only contacted by the flow at the outer periphery. In order in the venting position to have a simultaneous connection of the common supply duct 1 both, with the second common supply duct 5 and also with the additional venting duct 34 the valve spool 3 5 has a relatively long waisted portion 54 extending in the venting position along all ports 24, 26 and 28. In the working embodiment illustrated in figures 2 through 4 the valve spool 36 has a special feature to the extent that it has a plenum 55 via which the pressure medium is let off in the venting position. The plenum 55 opens at two axially spaced positions via respectively at least one and preferably several transfer openings 56 and 5? to the outer periphery of the valve spool 35. In the venting position the transfer openings 56" and 57 are so placed that some (56) thereof communicate with the output port 24 and the others (57) communicate with the first venting port 25. It is in this manner that the venting flow may be conducted through the shut off valve port 2 7 without affecting it. At this point it is to be noted that the output port 24 is preferably axially flanked on the one side i>y a further valve port 27 and axially on the other side by the other further valve port 28. These two further valve ports 27 and 28 are followed axially outwardly in one case toy the first venting port 25 and in the other case by the second venting port 26. The safety concept of the invention may be realized in the case of a non-modular fluid distributor 8 as well. It is particularly advantageous however in connection with a modular fluid distributor 8, as is indeed the case with the working example here presented. In the present case the fluid distributor 8 is divided up in the row direction into several juxtaposed fluid distributor modules 58 and 59. In this case first fluid distribution modules 58 are fitted with the control valves 13 and inter alia are fitted with the individual power ducts 17 and 18. A second fluid distribution module 5 9 bears the safety valve 15 and has the two fluid distribution ducts 2 and 4. Owing to the modular design the common supply duct 1 and the common venting ducts 3 and 5 are divided up into duct portions of the individual fluid distribution modules 58 and 59, which are complementary to each other. The first fluid distribution modules 58 together with the control valves 13 seated on them each form a respective control module 62. In the working each of these control modules 62 has a first fluid distribution module 58 and juxtaposed two control valves 13. The safety valve 15 represents, together with the second fluid distribution module 59, a safety module 63. In the working embodiment as illustrated the safety module 63 is mounted at one end of the module arrangement. However it can quite readily be so mounted in the row of control modules 62 that it is axially flanked on either side by at least one control module. Since the supply of pressure medium to the valve cluster S takes place by way of the safety module £3, it is therefore possible to realize supply from one side or end in addition or as an alternative to have an intermediate feed of pressure medium to the valve cluster 6. The safety module 53 may constitute a connection module or an intermediate module of the module arrangement. If the safety valve 15 and the control valves 13 have compatible pneumatic interfaces, which allow fitting to identically formed component mounting faces of the fluid distributor 8, there is the possibility of using each fluid distribution module as an alternative to the provision of a control module 62 or the provision of a safety module 63. Instead of the design modifications indicated with a mechanical or pneumatic spring return means the safety valve 15 could also be implemented in the form of a pulse valve, in the case of which both switching positions are predetermined by a respective electrically operated pilot valve. An advantage of this design lies in the fact that for maintaining the turned on position no continuous actuation or electrical energization of the respective pilot valve 38 is necessary. The position of switching is then held following failure of the electrical supply however Claims 1. A valve cluster comprising a plurality of electrically actuated control valves (13) which respectively are simultaneously connected with at least one common supply duct (1) and with at least one common venting duct (3 and 5) and are able to control the connection of such ducts (1, 3 and 5) with respectively at least one individual power duct (1 and 18) able to be connected with a load, at least one feed duct (32 and 33) for the feed of pressure medium intended for the at least one common supply duct (1) and a safety valve (15) connected between the at least one feed duct (32 and 33) and the at least one common supply duct {1} for selectively opening or closing the duct connection, characterised in chat tins safety valve (15) is able to be switched into a venting position venting the at least one common supply duct (32 and 33) and simultaneously disconnecting the feed duct (1) ■ 2. The valve cluster as set forth in claim 1, characterized in that it includes at least two feed ducts (32 and 33) connected with the safety valve and which in the venting position of the safety valve (15) are shut off and in a turned on position of the safety valve (15) are simultaneously connected with the common supply duct (1). 3. The valve cluster as set forth in claim 1 or in claim 2 characterised in that the safety valve (15) in its venting position connects the at least one common supply, duct (1) with at least one common venting duct (3 and 5) communicating with the atmosphere. 4. The valve cluster as set forth in claim 3, characterized in that in the venting position a single common venting duct (3) is connected with the at least one common supply duct (1) . 5. The valve cluster as set forth in any one of the claims 1 through 4, characterized in that the safety valve (15) in its venting position joins the at least one common supply duct (1) with an additional venting duct (34) which is independent of the at least one common venting duct (3 and 5). 6. The valve cluster as set forth in claim 5, characterized in that in the venting position of the safety valve (15) the common supply duct is joined both with at least one common venting duct (5) and also with the additional venting duct (34). 7. The valve cluster as set forth in any one of the claims 1 through 6, characterized in that the safety valve (15) is designed to be electrically activated. 8. The valve cluster as set forth in claim 7, characterized in that the safety valve (15) is a piloted valve controlled by at least one electrically actuatable pilot valve (38). 9. The valve cluster as set forth in claim 7 or in claim 8, characterized in that the safety valve is continuously urged toward the venting position by an actuating means more particularly in the form of a spring means (4S). 10. The valve cluster as set forth in any one of the claims 1 through 9, characterized in that the safety valve (15) includes a valve spool (35) able to be positioned selectively in the venting position or in a turned on position connecting the common supply duct (1) with at least one feed duct (32 and 33). 11. The valve cluster as set forth in any claim 10, characterized in that the valve spool (35) has a plenum (55} through which, the pressure medium can be let off in the venting position. 12. The valve cluster as set forth in any one of the claims 1 through 11, characterised in that the safety valve (15) is a component of a self-contained safety module (63) of the valve cluster (6). 13. The valve cluster as set forth in claim 12, characterized in that the control valves (13) are components of juxtaposed control modules (62) lined in a row direction (14), the safety module (63) being incorporated in the row of control modules (62) . 14. The valve cluster as set forth in claim 12, characterized in that the safety module (63) is in the form of a terminal module terminating the row of control modules (62) or in the form of an intermediate module intermediately placed in the row of control modules (62) . 15 The valve cluster as set forth in. claim 13 or claim 14. characterized in that the safety module (63) includes a fluid distribution module (59) fitted with the safety valve (15), such distribution module being placed in series with further fluid distribution modules (58) bearing the control valves (13), the common supply and venting ducts (1, 3 and 5) extending through all fluid distribution modules (58 and 59) and the at least one feed duct (32 and 33) extending in the fluid distribution module (59) of the safety valve (15) and opening at an outer face (22) not covered by an adjacent fluid distribution module. 16. The valve cluster as set forth in claim 15, characterized in that the fluid distribution modules (58) assigned to the control valves (13) have in each case at least two individual power ducts (17 and 18) extending through them. 17. The valve cluster as set forth in claim 15 or claim 16, characterized in that the fluid distribution module (59) of the safety valve (15) has two individual fluid ducts (2 and 4) extending through it, of which at least one constitutes a feed duct (32 and 35) for the common supply duct (1).

Full Text

--A VALVE CLUSTER WITH A SAFETY VALVE--
The invention relates to a valve cluster comprising a plurality of electrically actuated control valves which respectively are simultaneously connected with at least one common supply duct and with at least one common venting duct and are able to control the connection of such ducts with, respectively at least one individual power duct able to be connected with a load, at least one feed duct for the feed of pressure medium intended for the at least one common supply duct and a safety valve connected between the at least one £eed duct and the at least one common supply duct for selectively opening or closing the duct connection.
A valve cluster of this type disclosed in the patent publication EP 1 041 325 El comprises several control modules each joined with a respective control valve which are collected together in a module arrangement. By way of a common supply duct extending through the module arrangement all control valves may be simultaneously supplied with pressure medium. The venting of the control valves takes place by way of one or two common venting ducts also extending through the module arrangement. The common supply duct is placed downstream from a closing valve able to be utilised as a safety valve and which is in a position of disconnecting the common supply duct from a feed duct supplying the pressure medium, when a trouble condition occurs. The valve cluster is then more or less disconnected from the pressure medium line. If however disconnection takes place with the valve cluster still at full supply pressure, the pressure medium shut off in the valve cluster may still cause undesired switching functions of the control valves.
One object of the present invention is to design a valve cluster having improved safety functions as regards turning off.
In order to achieve this object the valve cluster is so designed that the safety valve is able to be switched into a

venting position in which it vents the at least one common supply duct and simultaneously shuts off the feed duct.
It is in this manner that with the feed duct shut off the pressure medium located in the at least one common supply duct (at the time of shutting off) of the valve cluster is not simply trapped but let off into the atmosphere. The valve cluster is therefore deprived of pressure on the supply side so that even swithing operations, still taking place, of the control valves do not entail undesired functions at the connected loads. Furthermore it is now possible without any risk to perform servicing work on the valve clusters and for example to replace a defective control valve. The safety valve may without any difficulty be designed so that it automatically switches into the venting position when for example the electricity supply and/or the supply pressure should fail.
Advantageous developments of the invention are defined in the dependent claims.
In order to get the valve cluster ready for operation again following venting it may be designed with at least two feed ducts which are joined, in the open position of the safety valve, simultaneously in parallel with the common supply duct of the valve cluster. The pressure medium may then flow at a high rate to the valve cluster.
The venting of the at least one common supply duct may for example occur exclusively through at least one of the at least one common feed duct of the valve cluster. This means that no additional venting position is necessary in the valve cluster. If the valve cluster, as is frequently the case with valve clusters, has or have two common venting ducts for the control valve, the safety valve can be so designed that for venting the at least one common supply duct both common venting ducts of the valve cluster are employed
There is furthermore the possibility of providing, in addition to the at least one common duct of the valve cluster, at least one independent additional venting duct by way of which the at least one common supply duct may be vented. In this case there is then a possibility of influencing, by having a suitable design

of the safety valve, the venting operation so that such venting takes place exclusively through the independent additional venting duct or - as might be termed a high speed venting operation - in parallel via the at least one common venting duct of the valve cluster and the additional venting duct independent thereof. The latter possibility means that an extremely high venting cross section is available.
The safety valve is preferably designed to be electrically activated. It may receive its electrical operating signals individually or also by way of an electrical concatenation means possibly fitted as a standard feature. Preferably the safety-valve in this case so designed that it is maintained in the electrically deactivated state by spring means in the venting position. In order to switch into the turned on position the safety valve is electrically activated and its valve member is deflected against the spring force. If during operation the electrical power supply should fail, the safety valve is immediately and reliably moved into the unproblematical venting position.
In the case of a preferred design of the safety valve the venting flow passes through a plenum in the spool of the safety valve. This renders possible a particularly advantageous arrangement of the duct circuitry.
The safety valve can arranged at or fitted in any suitable position of the valve cluster. In any case it will be on board the valve cluster so that compact dimensions are possible without external safety components.
In the case of a particularly advantageous embodiment the safety valve is a component of a self-contained safety module, which is collected together with control modules respectively comprising at least one control valve to constitute a module arrangement. In this case the safety module is a member of a chain of control modules,, for example as the terminating module or also as an intermediate module. The latter possibility makes it possible to have an intermediate supply, at practically any point, of the pressure medium necessary for the operation of the valve cluster.

Preferably the valve cluster comprises a modularly designed fluid distributor with individual fluid distribution modules which with the formation of the control modules with the control valves and with the formation of the safety module are provided with a safety valve, are provided with a safety valve and which, are able to be fitted together in a modular manner. The fluid distributing modules preferably each comprise two individual power ducts joined with the respectively associated control valve for driving a load. The fluid distributing module of the safety valve preferably also has two individual fluid ducts extending through it, of which at least one constitutes a feed duct for the common supply duct. In accordance with the above described modified design the second fluid duct may be employed as a parallel-connected further feed duct or as an additional venting duct. Should it not be required at all, it may be stoppered.
In the following the invention will be described in detail with reference to the accompanying drawings.
Figure 1 shows a preferred embodiment of the valve
cluster in accordance with the invention in a perspective representation with, the terminating element of the fluid distributor of the valve cluster removed. Figure 2 is a section taken through the valve cluster of figure 1 on the section line II - II adjacent to the safety valve. Figure 3 shows the safety valve, employed in the arrangement of figures 1 and 2, in a longitudinal part and in the venting position. Figure 4 shws the safety valve of figure 3 in the turned
on position assumed in normal operation. Figure 5 represents a modification of the safety valve in the same fashion as in figure 3 and in the venting position. Figure S represents the safety valve of figure 5 in the turned on position. The valve cluster generally referenced 6 with a preferred design comprises a fluid distributor 8 extending in the direction

of a longitudinal-axis 7, which on a mounting face 12 carries several electrically operated control valve 13. The control valves 13 are arranged one after the other in a row direction 14 indicated by a double arrow and coinciding with the longitudinal axis 7. The mounting face 12 also bears a safety valve 15 also included in the row of safety valves 13. The safety valve 15 terminates the row of control valves in the particular working embodiment at one end.
The fluid distributor 8 has at least one supply duct 1 extending through it in the longitudinal direction, which is common to all control valves 13. In parallel to this common or shared supply duct 1 a first and a second venting duct 3 and 5 extend, which like the common supply duct 1 respectively open at the mounting face 12 at multiple positions so that each control valve 13 is connected with each of the common supply ducts 1 and with each of the venting ducts 3 and 5.
In addition the common supply duct 1 and the two venting ducts 3 and 5 open at a component mounting area 16 on the mounting face 12 at which the safety valve 15 - is detachably secured for example by a screw connection. Accordingly both the common supply duct 1 and also the first and the second common venting duct 3 and 5 communicate with each control valve 13 and also with the safety valve 15.
Furthermore each control valve 13 communicates with two power ducts 17 and IS, individually assigned to it, which extend through the fluid distributor 8 athwart the longitudinal axis 7 and respectively at one end open at the mounting face 12 for the associated control valve 13 and at the other end open on the outside of the longitudinal side of the fluid distributor 8 at a connection face 22. At the connection face 22 the power ducts 17 and 18 can be joined with fluid lines (not illustrated in detail) leading to the loads to be operated, for example by fluid power.
During routine operation of the valve cluster 6 the common supply duct 1 provides a pressure medium, more particularly, compressed air at a supply pressure. This pressure medium comes from a pressure source P connected with the valve cluster 6. The control valves 13 are able to be electrically operated and may be

set in respectively different switching positions, in which they selectively connect the connected individual power ducts 17 and 18 with the common supply duct 1 or with one of the two common venting ducts 3 and 5. As a rule there is in chis case a so-called 5/2 switching function.
The operating signals required for the electrical operation of the control valves, such signals including both control signal and also operation power, pass by way of an electrical concatenating means 23 extending in the row direction 14 to electrical connections {not illustrated) of the control valves 13. They stem from an electronic means, which may be mounted on board the valve cluster 6 and/or placed externally.
The control valves are preferably pilot valves, each having an electrically operated pilot valve means, as for example a solenoid valve means. Each pilot valve means may be composed of one or two electrically operated pilot valves.
The two common venting ducts 3 and 5 open clear of the mounting face 12 at the outer face of the fluid distributor 8 and are joined by way ox openigs with the atmosphere. This may be either directly or by the intermediary of mufflers or by way of s duct to the atmosphere at some remote point.
The fluid supply to the common supply duct 1 is able to be controlled by the safety valve 15 arranged on board the valve cluster 6.
As regards details the safety valve 15 possesses an outlet port 24 connected with the shared supply duct 1. Moreover it has two venting ports 25 and 25, of which the first one (25) is connected with the common venting duct 3 and of which the second one (25} in the connected with the common venting duct 5 at all times.
For this purpose the safety valve 15 has further valve ports 27 and 28 individually connected one first and, respectively, second fluid distributing duct 2 and 4. The same also preferably open at the mounting face 22 of the fluid distributor 8 where connection means (not illustrated) may be provided to render possible the connection of a fluid duct leading to the outside.

in the case of all working examples the one, first fluid distribution duct 2 constitutes a feed duct 32 constantly connected with the pressure source ?.
The second fluid distribution duct 4 is in the working example of the figures 2 through 4 also a feed duct 33, which in a circuit arrangement parallel to the other feed duct 32 is constantly connected with the pressure source P. In the working embodiment illustrated in figures 5 and 6 on the contrary the second fluid distribution duct 4 functions as an additional venting duct 34 in addition to the common venting ducts 3 and 5. Its opening provided at the mounting-face 22 communicates in operation of the valve cluster 6 directly or by the intermediary of a fitted muffler with the adjacent atmosphere or with a venting line leading at some other point to the atmosphere.
In the case of all working examples the common supply duct 1 is exclusively supplied with the pressure medium necessary for the operation of the valve cluster 6 via the at least one feed duct 32 and 33. No further supply of fluid, not controlled by the safety valve 15, is provided to the common supply duct 1. A standard feed opening present on the fluid distributor B {not illustrated in detail) for the common supply duct 1 is shut off, for example by means of a stopper. However it can be employed, when the valve cluster 6 is to be utilized without a safety valve 15 or without using functionality of the safety valve 15 present.
All working examples of the valve cluster 5 share the common feature that with the aid of the safety valve 15 the connection between the at least one feed duct 32 and 33 and the common supply duct 1 connected with the safety valve 15 may be selectively turned on or disconnected.
With the duct connection turned on the safety valve 15 will in the working example assume the turned on position depicted in figures 4 and 6. In accordance with figure 4 in this case the two feed ducts present 32 and 3 are simultaneously joined with the common supply duct 1. In accordance with figure 6 there is a flow connection between the common supply duct 1 and the single feed duct 32.

In the disconnected state of the duct connection illustrated in fig-ares 3 and 5 the common supply duct 1 is disconnected in a fluid-tight manner from the respectively associated feed duct 32 and, respectively, 33. At the same time it is nevertheless vented to the atmosphere owing to the safety valve 15 assuming a venting position. In the working embodiment illustrated in figures 2 through 4 this is due to the turned on connection between the common supply duct 1 and the first common venting duct 3 - In the working embodiment illustrated in figures 5 and 6 the common supply duct 1 is simultaneously vented both via second common venting duct 5 and also via the additional venting duct 34.
Irrespectively of the type of venting the common supply duct 1 will accordingly be freed of pressure in the venting position of the safety valve 15 and the entire valve cluster 6 will be freed of pressure. Consequently even if owing to electronic control or owing to manual operation a control valve 13 should be caused to implement a switching operation, such operation can not entail any damaging movement of a connected load. The reduction of the pressure obtaining inside the valve cluster to atmospheric pressure furthermore renders possible a safe removal of the safety valves 13 for repair or substitution purposes.
In the working embodiment illustrated in figure 2 through 4 the second common venting duct 5 is not employed for the venting process controlled by the safety valve 15. The control valve 15 is in this case so designed that the second venting port 26 will remain closed irrespectively of the position of the spool 35 of the safety valve 14.
It would however be certainly conceivable for the safety valve 15 to be so designed that both common venting ducts 3 and 5 are employed in the venting position for venting the common supply duct 2.
Furthermore it would also be possible, departing from the design in accordance with figure 5, for both common venting ducts 3 and 5 and also the additional venting duct 34 to be simultaneously utilized for venting the common supply duct 1, or also only the additional venting duct 34 present, the two common

venting ducts 2 and 5- then not partaking in the venting function of the safety valve.
A design would also be possible in which the additional venting duct 34 does not communicate with an individual fluid distributor duct 4 but rather directly leads to a free outer face of the housing 36 of the safety valve 15 in order to render possible, from this position and bypassing the fluid distributor 8, venting to the atmosphere.
Irrespectively of its further possible design the safety valve 15 is preferably configured for electrical activation. It possesses an electrical interface 37 for the supply of the operation signals required for its actuation. Such signals may be supplied individually or however via the electrical concatenation means 23 which is present and which is comparable with the electrical operation of the control valves 13.
The safety valve 15 is in the working example in each case a pilot controlled multiway valve. It comprises an electrically actuated pilot valve 38, as for example a solenoid valve, whose activation state sets the currant operational state of the safety valve 15.
The safety valve 15 comprises a valve spool 35 as already described and preferably in the form of a piston, which is able to be shifted in its longitudinal direction between two positions which in one case are the venting position and in the other case are in the turned on position.
At one end the valve spool 3 5 has an axially orientated actuating face 42 which delimits a pilot chamber 43 connected with a pilot control duct_ 44 as indicated in dots. The pilot control duct 44 is supplied with a pressure medium at a pilot pressure, which in the working examples is fed from a pilot feed duct 45 extending inside the fluid distributor 8. The pilot feed duct 45 may be supplied with pressure medium either independently of the common supply duct 1 or from it. Alternatively it would also be possible to connect the pilot control duct 44 in the interior of the safety valve 15 with the output port 24.
The pilot valve 38 is placed on the pilot duct 44. it is able to selectively open or close the passage through the pilot

duct '44. In the turned off state it simultaneously provides for venting of the pilot chamber 43.
When the pilot duct 44 is turned on the pilot pressure is present in the pilot chamber 43, such pressure acting on the actuating face 42 and exerting a setting or servo force on the valve spool 3 5 so that the latter is switched into the open position appearing in figures 4 and 6.
The setting force 46 consequently always obtains in the open position in order to override an oppositely acting return force 47 of a spring means 48, which constantly urges the valve spool into the venting position indicated in figure 3 and 5. The spring means 48 has one end bearing against the valve spool 35 and the other end bearing directly or indirectly on the valve housing 36 of the safety valve 15. In order to economize in size the spring means 48 may move into an axial recess in the valve spool 35.
Instead of the mechanical spring means 43 present in the working embodiments other actuating means could be present in order to produce the return force 47. The invention also contemplates a pneumatic spring, for example. Whatever its design the spring means 48 does have the advantage that it shifts the valve spool 3 5 into the venting position when the pilot chamber 43 is free of pressure, be it owing to a system-related drop in pressure or owing to failure of the electrical supply.
The valve spool 3 5 extends in a valve spool socket 52 in the valve housing 36, such socket being divided up by a seal means 53 axially into several portions. The seal means 53 surrounds the valve spool 3 5 coaxially and is preferably arranged in a fixed manner in relation to the valve housing. It can more particularly comprises a plurality of annular seals arranged with a clearance between them which are able to come into sealing contact with different portion of its outer periphery in a fashion dependent on the axial position. The above mentioned various portions are connected with the above mentioned ports 24 through 28.
In order to perform the desired switching function the valve spool 35 is multiply stepped in an axial direction on its basically cylindrical outer periphery. Accordingly there is an axial sequence of portions with a larger and a smaller diameter.

Dependent on the position of the valve spool 35 and the resulting sealing contact or absence thereof with the sealing means 53 accordingly individual ports 24 and 28 are connected with each other as indicated above or are separated from each other.
In the working embodiment illustrated in figures 5 and 6 the valve spool 35 is only contacted by the flow at the outer periphery. In order in the venting position to have a simultaneous connection of the common supply duct 1 both, with the second common supply duct 5 and also with the additional venting duct 34 the valve spool 3 5 has a relatively long waisted portion 54 extending in the venting position along all ports 24, 26 and 28.
In the working embodiment illustrated in figures 2 through 4 the valve spool 36 has a special feature to the extent that it has a plenum 55 via which the pressure medium is let off in the venting position.
The plenum 55 opens at two axially spaced positions via respectively at least one and preferably several transfer openings 56 and 5? to the outer periphery of the valve spool 35. In the venting position the transfer openings 56" and 57 are so placed that some (56) thereof communicate with the output port 24 and the others (57) communicate with the first venting port 25. It is in this manner that the venting flow may be conducted through the shut off valve port 2 7 without affecting it.
At this point it is to be noted that the output port 24 is preferably axially flanked on the one side i>y a further valve port 27 and axially on the other side by the other further valve port 28. These two further valve ports 27 and 28 are followed axially outwardly in one case toy the first venting port 25 and in the other case by the second venting port 26.
The safety concept of the invention may be realized in the case of a non-modular fluid distributor 8 as well. It is particularly advantageous however in connection with a modular fluid distributor 8, as is indeed the case with the working example here presented.
In the present case the fluid distributor 8 is divided up in the row direction into several juxtaposed fluid distributor

modules 58 and 59. In this case first fluid distribution modules 58 are fitted with the control valves 13 and inter alia are fitted with the individual power ducts 17 and 18. A second fluid distribution module 5 9 bears the safety valve 15 and has the two fluid distribution ducts 2 and 4. Owing to the modular design the common supply duct 1 and the common venting ducts 3 and 5 are divided up into duct portions of the individual fluid distribution modules 58 and 59, which are complementary to each other.
The first fluid distribution modules 58 together with the control valves 13 seated on them each form a respective control module 62. In the working each of these control modules 62 has a first fluid distribution module 58 and juxtaposed two control valves 13. The safety valve 15 represents, together with the second fluid distribution module 59, a safety module 63.
In the working embodiment as illustrated the safety module 63 is mounted at one end of the module arrangement. However it can quite readily be so mounted in the row of control modules 62 that it is axially flanked on either side by at least one control module. Since the supply of pressure medium to the valve cluster S takes place by way of the safety module £3, it is therefore possible to realize supply from one side or end in addition or as an alternative to have an intermediate feed of pressure medium to the valve cluster 6. The safety module 53 may constitute a connection module or an intermediate module of the module arrangement.
If the safety valve 15 and the control valves 13 have compatible pneumatic interfaces, which allow fitting to identically formed component mounting faces of the fluid distributor 8, there is the possibility of using each fluid distribution module as an alternative to the provision of a control module 62 or the provision of a safety module 63.
Instead of the design modifications indicated with a mechanical or pneumatic spring return means the safety valve 15 could also be implemented in the form of a pulse valve, in the case of which both switching positions are predetermined by a respective electrically operated pilot valve. An advantage of this design lies in the fact that for maintaining the turned on

position no continuous actuation or electrical energization of the respective pilot valve 38 is necessary. The position of switching is then held following failure of the electrical supply however

Claims
1. A valve cluster comprising a plurality of electrically
actuated control valves (13) which respectively are simultaneously
connected with at least one common supply duct (1) and with at
least one common venting duct (3 and 5) and are able to control
the connection of such ducts (1, 3 and 5) with respectively at
least one individual power duct (1 and 18) able to be connected
with a load, at least one feed duct (32 and 33) for the feed of
pressure medium intended for the at least one common supply duct
(1) and a safety valve (15) connected between the at least one feed duct (32 and 33) and the at least one common supply duct {1} for selectively opening or closing the duct connection, characterised in chat tins safety valve (15) is able to be switched into a venting position venting the at least one common supply duct (32 and 33) and simultaneously disconnecting the feed duct (1) ■
2. The valve cluster as set forth in claim 1, characterized in that it includes at least two feed ducts (32 and 33) connected with the safety valve and which in the venting position of the safety valve (15) are shut off and in a turned on position of the safety valve (15) are simultaneously connected with the common supply duct (1).
3. The valve cluster as set forth in claim 1 or in claim 2 characterised in that the safety valve (15) in its venting position connects the at least one common supply, duct (1) with at least one common venting duct (3 and 5) communicating with the atmosphere.

4. The valve cluster as set forth in claim 3, characterized in that in the venting position a single common venting duct (3) is connected with the at least one common supply duct (1) .
5. The valve cluster as set forth in any one of the claims 1 through 4, characterized in that the safety valve (15) in its venting position joins the at least one common supply duct (1) with an additional venting duct (34) which is independent of the at least one common venting duct (3 and 5).
6. The valve cluster as set forth in claim 5, characterized in that in the venting position of the safety valve (15) the common supply duct is joined both with at least one common venting duct (5) and also with the additional venting duct (34).
7. The valve cluster as set forth in any one of the claims 1 through 6, characterized in that the safety valve (15) is designed to be electrically activated.
8. The valve cluster as set forth in claim 7, characterized in that the safety valve (15) is a piloted valve controlled by at least one electrically actuatable pilot valve (38).
9. The valve cluster as set forth in claim 7 or in claim 8, characterized in that the safety valve is continuously urged toward the venting position by an actuating means more particularly in the form of a spring means (4S).

10. The valve cluster as set forth in any one of the claims 1 through 9, characterized in that the safety valve (15) includes a valve spool (35) able to be positioned selectively in the venting position or in a turned on position connecting the common supply duct (1) with at least one feed duct (32 and 33).
11. The valve cluster as set forth in any claim 10, characterized in that the valve spool (35) has a plenum (55}

through which, the pressure medium can be let off in the venting position.
12. The valve cluster as set forth in any one of the claims 1 through 11, characterised in that the safety valve (15) is a component of a self-contained safety module (63) of the valve cluster (6).
13. The valve cluster as set forth in claim 12, characterized in that the control valves (13) are components of juxtaposed
control modules (62) lined in a row direction (14), the safety module (63) being incorporated in the row of control modules (62) .
14. The valve cluster as set forth in claim 12, characterized
in that the safety module (63) is in the form of a terminal module
terminating the row of control modules (62) or in the form of an
intermediate module intermediately placed in the row of control
modules (62) .
15 The valve cluster as set forth in. claim 13 or claim 14. characterized in that the safety module (63) includes a fluid distribution module (59) fitted with the safety valve (15), such distribution module being placed in series with further fluid distribution modules (58) bearing the control valves (13), the common supply and venting ducts (1, 3 and 5) extending through all fluid distribution modules (58 and 59) and the at least one feed duct (32 and 33) extending in the fluid distribution module (59) of the safety valve (15) and opening at an outer face (22) not covered by an adjacent fluid distribution module.
16. The valve cluster as set forth in claim 15, characterized in that the fluid distribution modules (58) assigned to the control valves (13) have in each case at least two individual power ducts (17 and 18) extending through them.
17. The valve cluster as set forth in claim 15 or claim 16, characterized in that the fluid distribution module (59) of the

safety valve (15) has two individual fluid ducts (2 and 4) extending through it, of which at least one constitutes a feed duct (32 and 35) for the common supply duct (1).

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Patent Number

268681

Indian Patent Application Number

5218/CHENP/2008

PG Journal Number

37/2015

Publication Date

11-Sep-2015

Grant Date

11-Sep-2015

Date of Filing

29-Sep-2008

Name of Patentee

FESTO AG & Co. KG

Applicant Address

RUITER STRASSE 82, D-73734 ESSLINGEN

Inventors:

#	Inventor's Name	Inventor's Address
1	BOGDANOWICZ, GRZEGORZ	IN DEN STEINEN 17/5, 73760 OSTFILDERN,
2	BRENNER, JACKOB	BAUMREUTE 54, D-73730 ESSLINGEN

PCT International Classification Number

F15B13/00

PCT International Application Number

PCT/EP07/00605

PCT International Filing date

2007-01-25

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	102006010844.2	2006-03-09	Germany