Title of Invention	"AN OVERLOAD PROTECTION DEVICE FOR A LPG CYLINDER EXTRACTION UNIT"
Abstract	An overload protection device for a LPG cylinder extraction unit comprising an extraction arm mounted on a mounting block. The extraction arm comprising at least two formed plates with the rear ends formed into hooking ends, said plates being separated by a spring and provided with a triggering finger. The mounting block consisting of a holding groove and a holding hook to engage the hooking ends of the extraction arm, a pivoting release trigger in interaction with the triggering finger, spring pins to pre-load the holding hook and the release trigger respectively and an ejection spring pin in communication with the triggering finger. In normal condition the extraction arm is connected to the mounting block. In overload condition the extraction arm is detached from the mounting block and the overload is thus eliminated.

Title of Invention

"AN OVERLOAD PROTECTION DEVICE FOR A LPG CYLINDER EXTRACTION UNIT"

Abstract

An overload protection device for a LPG cylinder extraction unit comprising an extraction arm mounted on a mounting block. The extraction arm comprising at least two formed plates with the rear ends formed into hooking ends, said plates being separated by a spring and provided with a triggering finger. The mounting block consisting of a holding groove and a holding hook to engage the hooking ends of the extraction arm, a pivoting release trigger in interaction with the triggering finger, spring pins to pre-load the holding hook and the release trigger respectively and an ejection spring pin in communication with the triggering finger. In normal condition the extraction arm is connected to the mounting block. In overload condition the extraction arm is detached from the mounting block and the overload is thus eliminated.

Full Text	The present invention provides an overload protection device for a LPG cylinder extraction unit. Background of the Invention: In modern LPG filling Plants the LPG cylinders are filled on systems known as filling carrousels. These are an assemblage of several individual cylinder filling machines mounted on the periphery of a large rotating circular frame. Empty LPG cylinders are fed onto the filling machines by external inlet conveyor. Filled cylinders are ejected onto an external exit conveyor. One method of ejection of the cylinders from the carrousel is by using an extraction unit containing an extensible extraction arm. This unit is mounted near the exit conveyor. The extraction arm is made to extend into the carrousel and then retract to pull out the filled cylinders onto the exit conveyor. This extension and retraction being repeated each time a filling machine arrives opposite the extraction unit. It occasionally happens that the extraction arm does not retract out at the correct moment because of malfunction or mis-adjustment of the control system or because of other causes. If the extraction arm is delayed in retraction then a potentially serious overload situation is created. The driving and inertial forces of the entire carrousel are impressed onto the extraction arm and on the filling machine with which it has collided. These forces are sufficiently large to damage the filling machine and the extraction unit. Though this kind of malfunction is uncommon. Its consequences are serious enough that it is desirable to have some device to limit the force impressed on the filling unit and the extraction arm. Object and summary of the Invention: The object of the present invention is to provide a device to limit the loads that can be reached in the event of a malfunction. A further object of the invention is to provide such load limiting by automatically detaching the extraction arm from the extraction unit if excessive force is applied on it. Another object of the invention is to provide adjustability of the force at which the arm detaches. Another object of the invention is to minimize downtime by making it easy to reattach the extraction arm quickly without special tools. To achieve the above objectives, the present invention provides an overload protection device for a LPG cylinder extraction unit comprising: an extraction arm (10) consisting of: • at least two formed plates (11 & 12) riveted together at one end (13); with the rear ends of said plates formed into hooking ends (14 & 15); • a spring (20) to separate said plates (11 & 12); and • one of said plates is provided with a triggering finger (23), a mounting block (50) for mounting said extraction arm (10), consisting of: • a holding groove (52) and a holding hook (51), to engage the hooking ends (14 & 15) of the extraction arm; • pivoting release trigger (53) in interaction with the triggering finger (23); • spring pins (61 & 62) to pre-load the holding hook (51) and the release trigger (53) respectively; • an ejection spring pin (54) in communication with the triggering finger (23); the arrangement between the extraction arm (10) and the mounting block (50) being such that: in normal condition the extraction arm is connected to the mounting block such that the holding hook (51) of said mounting block (50) is restrained from pivoting open under the influence of spring pin (61) and the ejection spring (54) is compressed by the triggering finger (23); and in overload condition the extraction arm (10) is detached from the mounting block (50) such that the spring (20) in said arm is compressed causing said triggering finger (23) to actuate the trigger (53) and rotate it against the action of spring (62) until the holding hook (51) is disengaged and released from hooking end (14) of the extraction arm, thereby detaching the extraction arm (10) and eliminating the overload. In overload condition, the ejection spring pin (54) forces the extraction arm (10) to rapidly separate from the mounting block once it is detached from the mounting block (50). The two plates (11 & 12) being separated by the spring (20) is provided with retaining pin (21) to limit the separation of said plates. The force exerted by spring (20) is adjusted by adjustment nut (22). Brief Description of the Accompanying Drawings: The invention will now be described with reference to the accompanying drawings. Fig. la, lb and 1c shows the general arrangement of the extraction unit and its position with respect to the carrousel. Fig. 2a and 2b shows the extraction arm mounted on a mounting block on the tip of the extraction unit. Fig. 3 shows the case in which an overload is being impressed on the extraction arm. Fig. 4 shows the extraction arm detaching from the mounting block under the action of the overload. Fig. 5 shows the extraction arm being reattached to the mounting block. Detailed Description: Description of the extraction operation. The explanation in this section is intended to clarify the extraction operation to make the purpose and action of this invention easier to understand Fig la shows the arrangement of the extraction unit with respect to the carrousel. The carrousel is a large rotating circular ring (200) with several filling machines (210) mounted on its periphery. Each filling machine fills one cylinder (220) at a time. For clarity This cylinder is not shown in fig la. This cylinder is visible in top view in Fig. lb and lc. The extraction unit is a machine external to the carrousel and mounted on the ground adjacent to the carrousel. An exit conveyor (300) is also provided next to the extraction unit to carry away the extracted cylinders. When the control system of the extraction unit senses that a filling machine with a filled cylinder is approaching it extends an extraction arm (10) into the space between the filling machines. As the carrousel rotates it carries the filling machine and the filled cylinder (220) towards the extraction arm. When the control system of the extraction unit senses that the filling machine is in the correct position for extraction it retracts the extraction arm. The retracting arm carries the cylinder with it, pulling it out of the filling machine and onto the exit conveyor as shown in Fig. lc. Detailed Description of the Invention: Fig 2a and 2 b show the invention in the normal condition. The invention consists of: An extraction arm constructed of two formed plates (11) & (12) loosely riveted together at (13) with the rear ends of the plates formed into hooking ends (14) & (15). The arm contains a spring (20), a retaining pin (21) and an adjustment nut (22). The arrangement of the parts being such that the spring (20) acts to separate the plates (11) & (12) and the retaining pin (21) acts to limit the separation. The plate (12) contains a triggering finger (23). A mounting block (50) with a holding hook (51) fixed pivotably on it, a holding groove (52), pivoting release trigger (53), an ejection spring pin (54), and springs pins (61) & (62) to preload the holding hook and release trigger respectively. In the normal condition shown in Fig. 2a, the extraction arm is connected to the mounting block. The hooking ends (14 & 15) are engaged with the holding hook (51) and holding groove (52) on the mounting block. In this condition the ejection spring pin (54) is compressed by the triggering finger (23). Fig. 3 shows the situation where the arm is being subjected to an overload by the cylinder (220). The cylinder has contacted the plate (12) of the arm and is forcing it to move against the preload of spring (20). An overload condition is when the force exerted by the cylinder exceeds the preload of spring (20). In Fig. 3 this condition has caused the spring (20) to compress and the plate (12) to pivot around (13). This motion of plate (12) is forcing the triggering finger (23) on the plate to press against trigger (53) and rotate it against the action of spring (62). The point of release is reached when the trigger has rotated sufficiently that it disengages the holding hook (51). When this happens the hook is no longer restrained from pivoting open under the influence of spring pin (61). The hook (51) then suddenly snaps open to release its hold on the hooking end (14) of the extraction arm. This detaches the arm from the block (50). Once the extraction arm is detached, the ejection spring pin (54) forces it to rapidly separate from the mounting block and fall off. Fig. 4 shows the arm separating from the block. After the arm has separated from the block no force can be transmitted through it. The overloading is therefore immediately eliminated. The force required to trigger the detachment of the arm is adjustable by changing the preload provided by spring (20). This is readily achieved by turning the adjusting nut (22) to change the compression of the spring. Fig. 5 shows the extraction arm being reattached. To reattach the arm the operator has to reset the holding hook (51) by pushing it towards trigger (53) until the position shown in Fig. 5 is reached. The operator can then pick up the arm, engage the hooking end (15) of the arm to the groove (52) and apply force to the arm to snap hooking end (14) into the holding hook (51). This action also compresses the ejection spring pin (54). In practice this reattachment operation takes only a few seconds and does not require any tools or special maintenance skills. Production can be restarted immediately after the arm is reattached. An important feature of this device is that it uses no fracturing force limiters like shear pins. The use of such limiters would increase the time required to reattach the arm and restart production. I claim: 1. An overload protection device for a LPG cylinder extraction unit comprising: an extraction arm (10) consisting of: • at least two formed plates (11 & 12) riveted together at one end (13); with the rear ends of said plates formed into hooking ends (14 & 15); • a spring (20) to separate said plates (11 & 12); and • one of said plates is provided with a triggering finger (23), a mounting block (50) for mounting said extraction arm (10), consisting of: • a holding groove (52) and a holding hook (51), to engage the hooking ends (14 & 15) of the extraction arm; • pivoting release trigger (53) in interaction with the triggering finger (23); • spring pins (61 & 62) to pre-load the holding hook (51) and the release trigger (53) respectively; • an ejection spring pin (54) in communication with the triggering finger (23); the arrangement between the extraction arm (10) and the mounting block (50) being such that: in normal condition the extraction arm is connected to the mounting block such that the holding hook (51) of said mounting block (50) is restrained from pivoting open under the influence of spring pin (61) and the ejection spring (54) is compressed by the triggering finger (23); and in overload condition the extraction arm (10) is detached from the mounting block (50) such that the spring (20) in said arm is compressed causing said triggering finger (23) to actuate the trigger (53) and rotate it against the action of spring (62) until the holding hook (51) is disengaged and released from hooking end (14) of the extraction arm, thereby detaching the extraction arm (10) and eliminating the overload. 2. An overload protection device for a LPG cylinder extraction unit as claimed in claim 1, wherein in overload condition, the ejection spring pin (54) forces the extraction arm (10) to rapidly separate from the mounting block once it is detached from the mounting block (50). 3. An overload protection device for a LPG cylinder extraction unit as claimed in claim 1, wherein the two plates (11 & 12) being separated by the spring (20) is provided with retaining pin (21) to limit the separation of said plates. 4. An overload protection device for a LPG cylinder extraction unit as claimed in claim 1, wherein the force exerted by spring (20) is adjusted by adjustment nut (22).

Full Text

The present invention provides an overload protection device for a LPG cylinder extraction unit.
Background of the Invention:
In modern LPG filling Plants the LPG cylinders are filled on systems known as filling carrousels. These are an assemblage of several individual cylinder filling machines mounted on the periphery of a large rotating circular frame.
Empty LPG cylinders are fed onto the filling machines by external inlet conveyor. Filled cylinders are ejected onto an external exit conveyor.
One method of ejection of the cylinders from the carrousel is by using an extraction unit containing an extensible extraction arm. This unit is mounted near the exit conveyor.
The extraction arm is made to extend into the carrousel and then retract to pull out the filled cylinders onto the exit conveyor. This extension and retraction being repeated each time a filling machine arrives opposite the extraction unit.
It occasionally happens that the extraction arm does not retract out at the correct moment because of malfunction or mis-adjustment of the control system or because of other causes.
If the extraction arm is delayed in retraction then a potentially serious overload situation is created. The driving and inertial forces of the entire carrousel are impressed onto the extraction arm and on the filling machine with which it has collided. These forces are sufficiently large to damage the filling machine and the extraction unit.
Though this kind of malfunction is uncommon. Its consequences are serious enough that it is desirable to have some device to limit the force impressed on the filling unit and the extraction arm.
Object and summary of the Invention:
The object of the present invention is to provide a device to limit the loads that can be reached in the event of a malfunction.

A further object of the invention is to provide such load limiting by automatically detaching the extraction arm from the extraction unit if excessive force is applied on it.
Another object of the invention is to provide adjustability of the force at which the arm detaches.
Another object of the invention is to minimize downtime by making it easy to reattach the extraction arm quickly without special tools.
To achieve the above objectives, the present invention provides an overload protection device for a LPG cylinder extraction unit comprising:
an extraction arm (10) consisting of:
• at least two formed plates (11 & 12) riveted together at one end (13); with the rear ends of said plates formed into hooking ends (14 & 15);
• a spring (20) to separate said plates (11 & 12); and
• one of said plates is provided with a triggering finger (23),
a mounting block (50) for mounting said extraction arm (10), consisting of:
• a holding groove (52) and a holding hook (51), to engage the hooking ends (14 & 15) of the extraction arm;
• pivoting release trigger (53) in interaction with the triggering finger (23);
• spring pins (61 & 62) to pre-load the holding hook (51) and the release trigger (53) respectively;
• an ejection spring pin (54) in communication with the triggering finger (23);
the arrangement between the extraction arm (10) and the mounting block (50) being
such that:
in normal condition the extraction arm is connected to the mounting block such that
the holding hook (51) of said mounting block (50) is restrained from pivoting open
under the influence of spring pin (61) and the ejection spring (54) is compressed by
the triggering finger (23); and
in overload condition the extraction arm (10) is detached from the mounting block
(50) such that the spring (20) in said arm is compressed causing said triggering finger

(23) to actuate the trigger (53) and rotate it against the action of spring (62) until the holding hook (51) is disengaged and released from hooking end (14) of the extraction arm, thereby detaching the extraction arm (10) and eliminating the overload.
In overload condition, the ejection spring pin (54) forces the extraction arm (10) to rapidly separate from the mounting block once it is detached from the mounting block (50).
The two plates (11 & 12) being separated by the spring (20) is provided with retaining pin (21) to limit the separation of said plates.
The force exerted by spring (20) is adjusted by adjustment nut (22).
Brief Description of the Accompanying Drawings:
The invention will now be described with reference to the accompanying drawings.
Fig. la, lb and 1c shows the general arrangement of the extraction unit and its position with respect to the carrousel.
Fig. 2a and 2b shows the extraction arm mounted on a mounting block on the tip of the extraction unit.
Fig. 3 shows the case in which an overload is being impressed on the extraction arm.
Fig. 4 shows the extraction arm detaching from the mounting block under the action of the overload.
Fig. 5 shows the extraction arm being reattached to the mounting block.
Detailed Description:
Description of the extraction operation.
The explanation in this section is intended to clarify the extraction operation to make the purpose and action of this invention easier to understand
Fig la shows the arrangement of the extraction unit with respect to the carrousel.

The carrousel is a large rotating circular ring (200) with several filling machines (210) mounted on its periphery. Each filling machine fills one cylinder (220) at a time. For clarity This cylinder is not shown in fig la. This cylinder is visible in top view in Fig. lb and lc. The extraction unit is a machine external to the carrousel and mounted on the ground adjacent to the carrousel. An exit conveyor (300) is also provided next to the extraction unit to carry away the extracted cylinders.
When the control system of the extraction unit senses that a filling machine with a filled cylinder is approaching it extends an extraction arm (10) into the space between the filling machines. As the carrousel rotates it carries the filling machine and the filled cylinder (220) towards the extraction arm.
When the control system of the extraction unit senses that the filling machine is in the correct position for extraction it retracts the extraction arm. The retracting arm carries the cylinder with it, pulling it out of the filling machine and onto the exit conveyor as shown in Fig. lc.
Detailed Description of the Invention:
Fig 2a and 2 b show the invention in the normal condition.
The invention consists of:
An extraction arm constructed of two formed plates (11) & (12) loosely riveted together at (13) with the rear ends of the plates formed into hooking ends (14) & (15). The arm contains a spring (20), a retaining pin (21) and an adjustment nut (22). The arrangement of the parts being such that the spring (20) acts to separate the plates (11) & (12) and the retaining pin (21) acts to limit the separation. The plate (12) contains a triggering finger (23).
A mounting block (50) with a holding hook (51) fixed pivotably on it, a holding groove (52), pivoting release trigger (53), an ejection spring pin (54), and springs pins (61) & (62) to preload the holding hook and release trigger respectively.

In the normal condition shown in Fig. 2a, the extraction arm is connected to the mounting block. The hooking ends (14 & 15) are engaged with the holding hook (51) and holding groove (52) on the mounting block. In this condition the ejection spring pin (54) is compressed by the triggering finger (23).
Fig. 3 shows the situation where the arm is being subjected to an overload by the cylinder (220).
The cylinder has contacted the plate (12) of the arm and is forcing it to move against the preload of spring (20).
An overload condition is when the force exerted by the cylinder exceeds the preload of spring (20).
In Fig. 3 this condition has caused the spring (20) to compress and the plate (12) to pivot around (13).
This motion of plate (12) is forcing the triggering finger (23) on the plate to press against trigger (53) and rotate it against the action of spring (62).
The point of release is reached when the trigger has rotated sufficiently that it disengages the holding hook (51). When this happens the hook is no longer restrained from pivoting open under the influence of spring pin (61). The hook (51) then suddenly snaps open to release its hold on the hooking end (14) of the extraction arm. This detaches the arm from the block (50).
Once the extraction arm is detached, the ejection spring pin (54) forces it to rapidly separate from the mounting block and fall off.
Fig. 4 shows the arm separating from the block.
After the arm has separated from the block no force can be transmitted through it. The overloading is therefore immediately eliminated.

The force required to trigger the detachment of the arm is adjustable by changing the preload provided by spring (20). This is readily achieved by turning the adjusting nut (22) to change the compression of the spring.
Fig. 5 shows the extraction arm being reattached.
To reattach the arm the operator has to reset the holding hook (51) by pushing it towards trigger (53) until the position shown in Fig. 5 is reached. The operator can then pick up the arm, engage the hooking end (15) of the arm to the groove (52) and apply force to the arm to snap hooking end (14) into the holding hook (51). This action also compresses the ejection spring pin (54). In practice this reattachment operation takes only a few seconds and does not require any tools or special maintenance skills. Production can be restarted immediately after the arm is reattached.
An important feature of this device is that it uses no fracturing force limiters like shear pins. The use of such limiters would increase the time required to reattach the arm and restart production.

I claim:
1. An overload protection device for a LPG cylinder extraction unit comprising: an extraction arm (10) consisting of:
• at least two formed plates (11 & 12) riveted together at one end (13); with the rear ends of said plates formed into hooking ends (14 & 15);
• a spring (20) to separate said plates (11 & 12); and
• one of said plates is provided with a triggering finger (23),
a mounting block (50) for mounting said extraction arm (10), consisting of:
• a holding groove (52) and a holding hook (51), to engage the hooking ends (14 & 15) of the extraction arm;
• pivoting release trigger (53) in interaction with the triggering finger (23);
• spring pins (61 & 62) to pre-load the holding hook (51) and the release trigger (53) respectively;
• an ejection spring pin (54) in communication with the triggering finger (23);
the arrangement between the extraction arm (10) and the mounting block (50) being
such that:
in normal condition the extraction arm is connected to the mounting block such that
the holding hook (51) of said mounting block (50) is restrained from pivoting open
under the influence of spring pin (61) and the ejection spring (54) is compressed by
the triggering finger (23); and
in overload condition the extraction arm (10) is detached from the mounting block
(50) such that the spring (20) in said arm is compressed causing said triggering finger
(23) to actuate the trigger (53) and rotate it against the action of spring (62) until the
holding hook (51) is disengaged and released from hooking end (14) of the extraction
arm, thereby detaching the extraction arm (10) and eliminating the overload.
2. An overload protection device for a LPG cylinder extraction unit as claimed in claim 1, wherein in overload condition, the ejection spring pin (54) forces the extraction arm (10) to rapidly separate from the mounting block once it is detached from the mounting block (50).

3. An overload protection device for a LPG cylinder extraction unit as claimed in claim
1, wherein the two plates (11 & 12) being separated by the spring (20) is provided
with retaining pin (21) to limit the separation of said plates.
4. An overload protection device for a LPG cylinder extraction unit as claimed in claim 1, wherein the force exerted by spring (20) is adjusted by adjustment nut (22).

Documents:

356-DEL-2005-Abstract-(24-07-2012).pdf

356-DEL-2005-Claims-(24-07-2012).pdf

356-del-2005-Claims.pdf

356-DEL-2005-Correspondence Others-(24-07-2012).pdf

356-del-2005-Correspondence-others.pdf

356-DEL-2005-Description (Complete)-(24-07-2012).pdf

356-del-2005-Description (Complete).pdf

356-del-2005-Drawings.pdf

356-DEL-2005-Form-1-(24-07-2012).pdf

356-del-2005-Form-1.pdf

356-DEL-2005-Form-13-(24-07-2012).pdf

356-del-2005-Form-18.pdf

356-DEL-2005-Form-2-(24-07-2012).pdf

356-del-2005-Form-2.pdf

356-DEL-2005-Form-3-(24-07-2012).pdf

356-del-2005-Form-3.pdf

356-DEL-2005-GPA-(24-07-2012).pdf

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Patent Number

260716

Indian Patent Application Number

356/DEL/2005

PG Journal Number

21/2014

Publication Date

23-May-2014

Grant Date

19-May-2014

Date of Filing

18-Feb-2005

Name of Patentee

YUNUS PATEL

Applicant Address

508, ASIAN GAMES VILLAGE, NEW DELHI-110 049, INDIA

Inventors:

#	Inventor's Name	Inventor's Address
1	YUNUS PATEL	508, ASIAN GAMES VILLAGE, NEW DELHI-110 049, INDIA

PCT International Classification Number

F16K 1/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA