Title of Invention

"A DEVICE FOR THE PRELOAD ADJUSTING OF A SHOCK ABSORBER"

Abstract

A device for the preload adjusting of a spring of a shock absorber, comprising an annular body extended in at least one portion ending in a cam- shaped profile, where the said body presents radial grooves defining a toothed section capable of being engaged by a wrench to operate said device, while the said cam shaped profile is capable of coupling with some projections of said shock absorber to block it into position, characterized in that it comprises at least one collar of an essentially annular form, provided next to at least one extremity of said toothed section, where said collar is capable of maintaining said wrench in a working position as needed for the preload adjusting of said spring of said shock absorber.

Full Text

This invention refers to a device for the preload adjusting of a shock absorber spring. The proposed solution has especially been developed for two-wheeled vehicles or motorcycles, it is however clear that such a solution may be utilized for the preload adjusting of any spring-type shock absorber. A shock absorber, in particular for two-wheeled vehicles, is generally constituted by a rod hinged to the chassis of a vehicle, and inserted in a sliding manner inside a cylinder, by interposing a spring. The cylinder is in turn hinged to a structure firmly attached to a wheel of the same vehicle. The cylinder carries projections used to position a device for adjusting the preloading and the position of the shock absorber spring. The devices for adjusting the preloading of a shock * absorber spring are generally formed by a die-cast, produced from a tubular element fitted with an edge profiled in the shape of a cam, while the opposite edge is profiled in the shape of a circle. When the die-cast is mounted on a vehicle, the edge of the cam is associated with the projections, while the spring of the shock absorber is mounted against the opposite edge. The cam-shaped edge of the die-cast is profiled so as to define various spring preloading positions, while engaging in the appropriate projections of the shock absorber body. The tubular element of the die-cast is fitted with a toothed profile capable of engaging with a wrench, of a standard type and generally supplied with the vehicle's set of on-board tools. By using this wrench, the die-cast may be rotated so as to move it from one preloading position to another, depending on the requirements. The conventional device for preload adjusting is maneuvered by the wrench inserted in the toothed section of the die-cast. The adjusting operation, however, frequently turns proves to be difficult. To make it possible to insert the wrench in the toothed section, the same must in fact allow for a certain play of its extremity while being inserted into the toothed section. In practice, the wrench hooks up with the toothed section* in a poor manner, and much time, patience and manual ability are required to perform the preload adjusting operation. This must be added to the fact Jthat given the construction of the die cast, even the application of a very moderate force in a direction parallel to the axis of the shock absorber may suffice ^to cause the accidental slippage of the wrench, with possibly harmful consequences for the operator. This causes the conventional preload adjusting device to even be dangerous. In fact, if the wrench accidentally comes loose, the operator unavoidably bumps against some part of the chassis, receiving cuts or bruises. The general purpose of this invention is to eliminate the technical shortcomings of the presently available devices, by producing a preload adjusting device of a shock absorber spring capable of performing the adjusting operation in a substantially simple, quick and safe manner. A particular first purpose of the invention is to create a preload adjusting device to avoid the unhooking of the wrench whenever a certain force, even if very minor, is applied parallel to the axis of the shock absorber. A particular second purpose of the invention is to create a preload adjusting device of an essentially safe type, thus avoiding or at least reducing the risks inherent in the conventional adjusting devices. Not the last purpose of the invention is to create a preload adjusting device of a shock absorber spring capable of achieving the mentioned purposes by an essentially simple, safe and reliable technical solution. These and other purposes, according to this invention, are achieved by creating a preload adjusting device of a shock absorber according to claim 1. Other characteristics of this invention are further defined in the subsequent claims. The preload adjusting device according to this invention is advantageously economical and does in particular not imply any substantially increased costs with respect to those of conventional solutions. The device according to this invention may moreover be operated by using conventional wrenches. This not only avoids cost increases and difficulties in finding suitable wrenches, but renders the operating devices according to the invention perfectly interchangeable with those of a conventional type. Any profiles of the wrench, which may already be needed for the traditional adjusting device and vary from vehicle to vehicle in case of particular sizes, may be simplified thanks to the better hooking-up and positioning of the wrench. In practice, the device according to the invention provides for restraining the wrench in the direction of .^ the shock-absorber's axis. This restraining action is achieved on one side, at one extremity of the toothed section, by a first collar provided on the die-cast, while at the opposite end of the toothed section the restraining action is achieved by a second collar similar to the first. In a second embodiment, the restraining action at one end is achieved by a steel washer in the seat of the spring itself. Further characteristics and advantages of a preload adjusting device for a shock absorber spring according to this invention will be more clearly evident from the following description of an exemplifying and non-limiting nature, referred to the simplified attached drawings, in which: Figure 1 shows a shock absorber mounting a preload adjusting device of a spring according to the invention, Figure 2 shows a perspective view of a first embodiment of a device according to the invention, Figure 3 is a plan view of the device shown in Figure 2, Figure 4 shows a section of the device of the present invention along the line IV-IV of Figure 3, Figure 5 shows an elevated lateral view of the device of Figure 2, Figure 6 shows an extended plan view of a cam-shaped profile of the device according to the invention, Figure 7 shows an elevated lateral view of a second embodiment of the device acceding to the invention, Figure 8 shows a cross-section of the device according to the invention shown in Figure 7, and Figure 9 shows a section of an adjusting device according to the invention, with its associated operating wrench. With reference to the mentioned figures, a preload adjusting device of a shock absorber spring is shown and identified in its overall form by the reference number 11. The shock absorber 11 is constituted by a rod 12 hinged to the chassis of a vehicle (not shown for simplicity) . The rod 12 slides inside a cylinder 14 with an interposed spring 13. The cylinder 14 has a free extremity with a pivot joint 16 connecting directly or indirectly to a wheel of the vehicle (not shown for simplicity). Next to the pivot joint 16, the cylinder 14 carries two projections 18, placed symmetrically on two diametrically opposed portions of the cylinder 14. A preload adjusting device 20 abuts against the two projections 18. At'one end of the shock absorber 11, the device 20 blocks the spring 13 and allows its preload adjusting, while the opposite end of the spring 13 is blocked at the extremity of the rod 12. '• In a first embodiment, the device 20 comprises an annular body 24 extended in a cam-shaped and also annular portion 26. The portion 26 is axially symmetric in the sense that its planar extension (Figure 6) presents two identical parts, each shaped like a ramp with four hollows 28 and defining one of the spring's preloading positions. The body 24 is fitted with radial grooves 30, which define a toothing profile capable of being engaged by a wrench 32 so as to operate the device 20. Each groove 30 is closed at only one of its extremities by elements 34 projecting from the body 24, attached to the opposite extremities of each pair of adjacent grooves 30. Each element 34 presents a portion 36 inserted into one of the grooves 30 and firmly attached to another portion 38 emerging from the grooves 30 and extended like an annular sector, essentially all the way up to extremities of the portions 38 of the elements 34, which are positioned at the opposite extremities of the adjacent grooves 30. The" elements 34 are preferably produced in a single piece with the annular body 24 and define two collars 40, at the two extremities of the toothed section of the y body 24 constituted by the grooves 30. * The operation of the preload adjusting device of a shock absorber spring according to the invention is essentially as follows. The device 20 is inserted into the cylinder 14 blocked in position by the projections 18 inserted into two hollows 28 of the cam-shaped profile 24. When the preload of the spring 13 of the shock absorber 11 is to be changed, it suffices to rotate the device 20 by engaging the projections 18 in various hollows 28, so as to increase and/or decrease the preload. This operation is performed by inserting the wrench 32 between the collars 40 defined by the projections 34, while engaging one extremity of the same wrench 32 in one of the grooves 30. It therefore suffices to act on the wrench 32 to rotate the device 20. , This operation is favored by the collars 40 formed by the projecting elements 34, with restrain the wrench 32 and prevent it from slipping out of the grooves 30. A second embodiment of the device 20 according to the invention is shown in the Figures 7 and 8, where identical reference numbers denote identical or similar parts or* elements. The device 20 in this embodiment presents an annular body 24 extended in a cam-shaped and also annular portion 26. The body 24 presents the hollows 30 which define a toothed section capable of being engaged by the wrench 32. Some elements 34 are firmly attached to the alternating extremities of the grooves 30, next to the cam-shaped portion 26, so as to define a collar 40 similar to those already described above. On the opposite side, however, the device 20 lacks any collar firmly attached to its body 24. When the device 20 is mounted, however, a steel washer is inserted at the front portion of the body 24, so as to define a second collar 42 delimiting the toothed section formed by the grooves 30. The operation of the preload adjusting device of a shock absorber spring according to this embodiment of the invention is substantially similar to that previously described. In particular, the washer defining the collar 42 is inserted in an interposed manner between the spring 13 and the front portion of the body 24, so as to function as a collar and restrain the wrench 32 during the operations performed in adjusting the shock absorbers 11. In a further embodiment of the device 20 according to the Invention, the body 24 is fitted with one or two extended annular elements, each of which runs along an edge of the body 24 and defines some continuous collars. The proposed solution solves, at substantially the same cost, the functional and operating safety problems of handling the spring adjustment of the shock absorbers installed on the present vehicles. % Moreover, this solution simplifies the problems of handling associated not with the design of the shock absorber, but with the encumbrance of the components present in the area surrounding the shock absorber (such as the chassis, filter cartridge, etc.). The above description clearly outlines the characteristics and advantages of the preload adjusting device of a shock absorber spring as a subject of this invention. In particular, they are represented by its considerable safety and economics, apart from its considerable adjusting speed and simplicity. It is finally clear that numerous variants may be applied to the preload adjusting device of a shock absorber spring as a subject of this invention, without thereby abandoning the principles of novelty inherent in the inventive idea, just as it is clear that in the practical implementation of the invention, the materials, shapes and sizes of the details shown may be of any type, depending on the requirements, and that the same may be substituted by others of a technically equivalent type. WE CLAIM: 1. A device (20) for the preload adjusting of a spring (13) of a shock absorber (11), comprising an annular body (24) extended in a cam-shaped profile, where the said body (24) fitted with radial grooves (30) defining a toothed section capable of being engaged by a wrench (32) to operate said device (20), while the said cam shaped profile is capable of coupling with some projections (18) of said shock absorber (11) to block it into position, characterized in that it has at least one collar (40, 42) of an annular form, provided next to at least one extremity of said toothed section, where said collar (40, 42) is capable of maintaining said wrench (32) in a working position as needed for the preload adjusting of said spring (13) of said shock absorber (11). 2. A device (20) as claimed in claim 1, wherein said cam-shaped profile is axially symmetrical. 3. A device (20) as claimed in claim 2, wherein said cam-shaped profile presents in a planar extension, two identical parts, each shaped like a ramp with hollows (28), each of which defines a preload position of said spring (13). 4. A device (20) as claimed in claim 1, wherein each of said grooves (30) is closed only at one of its extremities, by elements (34) projecting from said body (24), attached to the opposite extremities of each pair of adjacent grooves. 5. A device (20) as claimed in claim 4, wherein each of said projecting elements (34) presents a first portion (36) inserted into one of said grooves (30), to said first portion is firmly attached a second portion (38) emerging from said grooves (30) and extended essentially like an annular sector. 6. A device (20) as claimed in claim 5, wherein said second portion (38) of each of said projecting elements (34) extends up to the extremities of other second portions (38) of projecting elements (34) placed at the opposite extremities of said adjacent grooves (30). 7. A device (20) as claimed in claim 5, wherein said projecting elements (34) are produced in a single piece with said annular body (24) and define two collars (40, 42) at the two extremities of said toothed section of said body (24), where said toothed section is constituted by said grooves (30). 8. A device (20) as claimed in claim 4, wherein some projecting elements (34) are firmly attached at the alternating extremities of said grooves (30), next to said portion ending with a cam-shaped profile, so as to define said collar (40), while at the opposite side on said shock absorber (11) is inserted at least one washer against a frontal portion of said body (24), so as to define a second collar (42) delimiting said toothed section formed by said grooves (30). 9. A device (20) as claimed in claim 1, wherein it blocks one spring (13) at one extremity of said shock absorber (11), and that it allows some preload adjusting, while an opposite extremity of said spring (13) is blocked at the extremity of rod (12). 10. A device (20) as claimed in claim 1, wherein said body (24) is fitted with at least one of annular elements, each of which runs along the edge of said body (24) and defines a continuous collar. 11. A device (20) for the preload adjusting of a spring (13) of a shock absorber (11), substantially as herein described and as illustrated in the accompanying drawings.

Documents:

1294-del-1999-abstract.pdf

1294-del-1999-claims.pdf

1294-del-1999-correspondence-others.pdf

1294-del-1999-correspondence-po.pdf

1294-del-1999-description (complete).pdf

1294-del-1999-drawings.pdf

1294-del-1999-form-1.pdf

1294-del-1999-form-13.pdf

1294-del-1999-form-19.pdf

1294-del-1999-form-2.pdf

1294-del-1999-form-3.pdf

1294-del-1999-form-5.pdf

1294-del-1999-form-6.pdf

1294-del-1999-gpa.pdf

1294-del-1999-petition-137.pdf

1294-del-1999-petition-138.pdf

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