Title of Invention

AN IMPROVED OLEO-PNEUMATIC SHOCK ABSORBER FOR LAND VEHICLES AND THE LIKE

Abstract

An oleo-pneumatic shock absorber for land vehicles that consists of a twin tube comprising an outer housing an inner tube. A canister is attached to the outer tube at its bottom end, The inner tube is fitted with a base valve and has got inseted in its a pistion rod fitted with a pistion. The top open end of the outer tube is sealed with a sealing device including a seal shield. A hollow screw having a seal at its one end and female threads at its other end is provided on the cap, another screw with male threads is provided to engae the female threads on the hollow screw. The collapsible chamber inserted in the canister is sealed with a circlip.

Full Text

1 3 DEC 2004 THE PATENTS ACT, 1970 (39 OF 1970) COMPLETE SPECIFICATION (SECTION 10) AN IMPROVED OLEO-PNEUMATIC SHOCK ABSORBER FOR LAND VEHICLES AND THE LIKE ENDURANCE SYSTEMS (INDIA) PRIVATE LIMITED, a Company incorporated under the Indian Companies Act, 1956, of E-92, M.I.D.C Industrial Area, Waluj, Aurangabad - 431 136, in the State of Maharashtra, India. The following specification describes the nature of this invention and the manner in which it is to be performed :- 1 3 DEC 2004 This invention relates to an improved oleo-pneumatic shock absorber for land vehicles and the like. The conventional oleo-pneumatic shock absorber for land vehicles and the like, known in the art, are of three types namely : the oleo-pneumatic twin tube shock absorber wherein the gas/air is injected after filling the oil in the shock absorber, the oleo-pneumatic mono tube shock absorber wherein a floating separator is provided inside the mono tube to separate the gas/air from the oil filled in the shock absorber and the oleo-pneumatic mono tube canister attached shock absorber wherein the gas/air is filled in a collapsible chamber enclosed in the canister that is separated from the oil filled in the mono tube canister attached shock absorber. Each of these types of oleo-pneumatic shock absorbers is fitted in the land vehicles for dampening the shocks exerted to the vehicle due to road conditions. The conventional oleo-pneumatic twin tube shock absorber consists of an outer tube housing an inner tube fitted with a piston rod assembly and a base valve assembly. High-pressure gas/air is injected in the shock absorber from the oil seal fitted on the top end of the outer tube. The gas/air and oil filled in the shock absorber have no separator between them and the gas/air and the oil are in constant contact with each other Due to clearance, although very minute, between the oil seal and the piston rod by virtue of relative movement between both, the gas/air filled in the shock absorber escapes through the oil seal and reduces the pressure inside the shock absorber The reduction of gas/air pressure inside the shock absorber lowers the dampening force in compression. The escaped gas/air cannot be re-charged. Also due to constant movement of the piston, while dampening the exerted shocks, the oil and the gas/air, being in direct contact with each other get emulsified. Since the emulsion has a very low density as compared to the oil filled in the shock absorber it results in heavy loss of dampening force when it passes through the piston valve or base valve. The continuous escape of the gas/air filled in the shock absorber over a period of time lowers the dampening force in compression and emulsification effects of oil ultimately reduces the performance of the shock absorber of this type to an unacceptable limit. 2. The second conventional oleo-pneumatic mono tube shock absorber consists of a single tube that is first put in the high-pressure gas/air medium A floating separator is inserted in the tube to separate the gas/air from the oil. The oil is filled in the tube, piston rod assembly and sealing assembly are inserted in the tube and open end of the tube is sealed. There is no base valve in the mono tube shock absorber hence the dampening force in compression is generated through the gas/air pressure inside the tube, Due to leakage of gas/air, over a period of time, across the sealing area of the floating separator, the escaped gas/air reaches the oil chamber of the shock absorber. The escaped gas/air comes in direct contact with the oil filled in the shock absorber and due to constant movement of the piston, while dampening the exerted shocks, the oil and the escaped gas/air get emulsified. Since the emulsion has a very low density as compared to the oil filled in the shock absorber it results in heavy loss of dampening force when it passes through the piston valve. Further due to clearance, although very minute, between the oil seal and the piston rod by virtue of relative movement between both, the escaped gas/air also leaks through the oil seal and reduces pressure inside the tube. The escaped gas/air can never be re-charged. The absence of the base valve in the mono tube, the continuous escape of gas/air filled in the shock absorber over a period of time, from the sealing area of the floating separator and also from the oil seal, the emulsification of the oil with gas/air and the fall in dampening force in compression ultimately reduces the performance of the shock absorber of this type drastically In the third conventional oleo-pneumatic canister attached mono tube shock absorber, the mono tube is attached to the canister. A collapsible chamber is enclosed in the canister and sealed with a circlip. The oil is filled in the mono tube attached to the canister, piston rod assembly and sealing assembly are inserted in the tube and the open end of the tube is sealed. High-pressure gas/air is filled in the collapsible chamber enclosed in the canister attached to the mono tube of the shock absorber There is no base valve in the mono tube shock absorber hence the dampening force in compression is generated through the gas/air pressure filled in the collapsible chamber enclosed in the canister. The gas/air filled in the collapsible chamber enclosed in the canister eliminates the contact of the gas/air with the oil filled in the shock absorber hence the emulsification of oil and gas/air is eliminated securing the density of the oil intact. However the gas/air filled in the collapsible chamber enclosed in the canister 3 escapes over a period of time and reduces the pressure inside the shock absorber. The escaped gas/ air can however be re-charged. The absence of base valve in the mono tube and the reduction of gas/air pressure inside the shock absorber, over a period of time, lowers the dampening force in compression ultimately reduces the performance of the shock absorber of this type drastically. It is an object of this invention to provide an oleo-pneumatic shock absorber for land vehicles and the like which obviates the aforesaid drawbacks and increases the life of the shock absorber. The improved oleo-pneumatic shock absorber for land vehicles and the like, according to the present invention, consists of a twin tube comprising an outer tube housing an inner tube, the inner tube is fitted with a base valve and has got inserted in it a piston rod fitted with a piston, the top open end of the outer tube is sealed with a sealing device including a seal shield, a canister is attached to the outer tube at its bottom end, characterized in that a collapsible chamber having a cap is provided inside the canister, a hollow screw having a seal at its one end and female threads at its other end is provided on the cap, another screw with male threads is provided to engage the female threads on the hollow screw and the collapsible chamber inserted in the canister is sealed with a circlip. According to a preferred embodiment of this invention the seal provided on the hollow screw is made of rubber or the like material. The oil is filled in the inner tube fitted with a base valve, the outer tube and the canister attached to the outer tube of the shock absorber. The piston rod fitted with a piston and sealing device are inserted in the inner tube and the open end of the outer tube is sealed with the sealing device that includes a seal shield. High-pressure gas/air is filled in the collapsible chamber enclosed in the canister through a gas/air filling nozzle by piercing the seal provided in the hollow screw fitted in the cap of the collapsible chamber after unscrewing the screw with the male threads engaged in the female threads on the hollow screw. The oil filled in the shock absorber does not come in contact with the gas/air filled in the collapsible chamber; the emulsification of oil is eliminated securing the density of the oil intact. The gas/air filled in the 4 collapsible chamber that escapes over a period of time can be easily recharged through gas/air filling nozzle by piercing the seal provided in the hollow screw after unscrewing the screw with male threads from the female threads on the hollow screw. The seal provided in the hollow screw when damaged due to frequent piercing to recharge the gas/air can be replaced. Having recharged the gas/air re-screwing the screw with the male threads in the female threads on the hollow screw seals the collapsible chamber. The dampening force in compression is generated through the base valve provided in the inner tube that is supplemented by the gas/air pressure to absorb and dampen the shocks in compression due to bad road conditions. As shown in the accompanying drawings, Figure 1 is the cross sectional view and illustrates the twin tube canister attached oleo-pneumatic shock absorber for land vehicles and the like, according to the present invention that consists of an outer tube (1) that houses an inner tube (2). A piston rod (4) fitted with the piston (5) is inserted in the inner tube (2) fitted with a base valve (6). The top open end of the outer tube (1) is sealed with a sealing device (7) including a seal shield. A canister (3) is attached to the outer tube (1) at its bottom end. A collapsible chamber (8) having a cap (9) is provided inside the canister (3). A hollow screw (12), provided with a seal (11), preferable made of rubber or the like material, at its one end and female threads at its other end, is provided on the cap (9) through an "O"-ring (15). Another screw (12) with male threads is provided in the female threads on the hollow screw (12) through an "O"-ring (14). The collapsible chamber (8) fitted with the cap (9) is inserted in the canister (3) and sealed with a circlip (13). Figure 2 is the enlarged cross sectional view and illustrates the portion marked "X X" in Figure 1. The advantages of the oleo-pneumatic shock absorbers for land vehicles and the like, according to this invention, having a canister attached to the outer tube and the base valve attached to the inner tube of the shock absorber are the base valve provided in the inner tube dampens the shocks in compression. Secondly, the shocks are further dampened in compression progressively due to gas/air pressure filled in the collapsible chamber provided in the canister attached to the outer tube of the shock absorber. Thirdly, the oil filled in the shock absorber does not come in contact with 5" the gas/air filled in the collapsible chamber; the emulsification of oil is eliminated securing the density of the oil intact. Fourthly, the escape of the gas/air filled in the collapsible chamber provided in the canister over a period of time, can be re-charged through gas/air filling nozzle by piercing the seal provided in the hollow screw after unscrewing the screw with male threads from the female threads on the hollow screw Having recharged the gas/air re screwing the screw with male threads in the female threads on the hollow screw seals the collapsible chamber. Fifthly the seal provided in the hollow screw when damaged due to frequent piercing to recharge the gas/air, can be replaced. Sixthly, when the efficiency of the shock absorber is reduced below permissible limits, the performance can be corrected by recharging the gas/air and/or replacing the seal at minimum costs without incurring the heavy costs of replacing the entire shock absorber. These advantages thus not only enhance the performance but also increase the life of the shock absorbers for land vehicles and the like. Since many apparently different embodiments of the present invention could be made without departing from the scope and spirit thereof as will be apparent to those skilled in the art, it is intended that the description of the invention herein be interpreted as being illustrative only and not limiting in any manner 6 We claim: 1. An improved oleo-pneumatic shock absorber for land vehicles and the like, according to the present invention, consists of a twin tube comprising an outer lube housing an inner tube, the inner tube is fitted with a base valve and has got inserted in it a piston rod fitted with the piston, the top open end of the outer tube is sealed with a sealing device including a seal shield, a canister is attached to the outer tube at its bottom end characterized in that a collapsible chamber having a cap is provided inside the canister, a hollow screw having a seal at its one end and female threads at its other end is provided on the cap, another screw with male threads is provided to engage the female threads on the hollow screw and the collapsible chamber inserted in the canister is sealed with a circlip. 2. The oleo-pneumatic shock absorber as claimed in claim 1, wherein the seal provided on the hollow screw is made of rubber or the like material. 3. The oleo-pneumatic shock absorber for land vehicles and the like substantially as herein described and illustrated in the accompanying drawings. Dated this 13th day of December 2004. 1 3 DEC 2004 THE PATENTS ACT, 1970 (39 OF 1970) COMPLETE SPECIFICATION (SECTION 10) AN IMPROVED OLEO-PNEUMATIC SHOCK ABSORBER FOR LAND VEHICLES AND THE LIKE ENDURANCE SYSTEMS (INDIA) PRIVATE LIMITED, a Company incorporated under the Indian Companies Act, 1956, of E-92, M.I.D.C Industrial Area, Waluj, Aurangabad - 431 136, in the State of Maharashtra, India. The following specification describes the nature of this invention and the manner in which it is to be performed :- 1 3 DEC 2004 This invention relates to an improved oleo-pneumatic shock absorber for land vehicles and the like. The conventional oleo-pneumatic shock absorber for land vehicles and the like, known in the art, are of three types namely : the oleo-pneumatic twin tube shock absorber wherein the gas/air is injected after filling the oil in the shock absorber, the oleo-pneumatic mono tube shock absorber wherein a floating separator is provided inside the mono tube to separate the gas/air from the oil filled in the shock absorber and the oleo-pneumatic mono tube canister attached shock absorber wherein the gas/air is filled in a collapsible chamber enclosed in the canister that is separated from the oil filled in the mono tube canister attached shock absorber. Each of these types of oleo-pneumatic shock absorbers is fitted in the land vehicles for dampening the shocks exerted to the vehicle due to road conditions. The conventional oleo-pneumatic twin tube shock absorber consists of an outer tube housing an inner tube fitted with a piston rod assembly and a base valve assembly. High-pressure gas/air is injected in the shock absorber from the oil seal fitted on the top end of the outer tube. The gas/air and oil filled in the shock absorber have no separator between them and the gas/air and the oil are in constant contact with each other Due to clearance, although very minute, between the oil seal and the piston rod by virtue of relative movement between both, the gas/air filled in the shock absorber escapes through the oil seal and reduces the pressure inside the shock absorber The reduction of gas/air pressure inside the shock absorber lowers the dampening force in compression. The escaped gas/air cannot be re-charged. Also due to constant movement of the piston, while dampening the exerted shocks, the oil and the gas/air, being in direct contact with each other get emulsified. Since the emulsion has a very low density as compared to the oil filled in the shock absorber it results in heavy loss of dampening force when it passes through the piston valve or base valve. The continuous escape of the gas/air filled in the shock absorber over a period of time lowers the dampening force in compression and emulsification effects of oil ultimately reduces the performance of the shock absorber of this type to an unacceptable limit. 2. The second conventional oleo-pneumatic mono tube shock absorber consists of a single tube that is first put in the high-pressure gas/air medium A floating separator is inserted in the tube to separate the gas/air from the oil. The oil is filled in the tube, piston rod assembly and sealing assembly are inserted in the tube and open end of the tube is sealed. There is no base valve in the mono tube shock absorber hence the dampening force in compression is generated through the gas/air pressure inside the tube, Due to leakage of gas/air, over a period of time, across the sealing area of the floating separator, the escaped gas/air reaches the oil chamber of the shock absorber. The escaped gas/air comes in direct contact with the oil filled in the shock absorber and due to constant movement of the piston, while dampening the exerted shocks, the oil and the escaped gas/air get emulsified. Since the emulsion has a very low density as compared to the oil filled in the shock absorber it results in heavy loss of dampening force when it passes through the piston valve. Further due to clearance, although very minute, between the oil seal and the piston rod by virtue of relative movement between both, the escaped gas/air also leaks through the oil seal and reduces pressure inside the tube. The escaped gas/air can never be re-charged. The absence of the base valve in the mono tube, the continuous escape of gas/air filled in the shock absorber over a period of time, from the sealing area of the floating separator and also from the oil seal, the emulsification of the oil with gas/air and the fall in dampening force in compression ultimately reduces the performance of the shock absorber of this type drastically In the third conventional oleo-pneumatic canister attached mono tube shock absorber, the mono tube is attached to the canister. A collapsible chamber is enclosed in the canister and sealed with a circlip. The oil is filled in the mono tube attached to the canister, piston rod assembly and sealing assembly are inserted in the tube and the open end of the tube is sealed. High-pressure gas/air is filled in the collapsible chamber enclosed in the canister attached to the mono tube of the shock absorber There is no base valve in the mono tube shock absorber hence the dampening force in compression is generated through the gas/air pressure filled in the collapsible chamber enclosed in the canister. The gas/air filled in the collapsible chamber enclosed in the canister eliminates the contact of the gas/air with the oil filled in the shock absorber hence the emulsification of oil and gas/air is eliminated securing the density of the oil intact. However the gas/air filled in the collapsible chamber enclosed in the canister 3 escapes over a period of time and reduces the pressure inside the shock absorber. The escaped gas/ air can however be re-charged. The absence of base valve in the mono tube and the reduction of gas/air pressure inside the shock absorber, over a period of time, lowers the dampening force in compression ultimately reduces the performance of the shock absorber of this type drastically. It is an object of this invention to provide an oleo-pneumatic shock absorber for land vehicles and the like which obviates the aforesaid drawbacks and increases the life of the shock absorber. The improved oleo-pneumatic shock absorber for land vehicles and the like, according to the present invention, consists of a twin tube comprising an outer tube housing an inner tube, the inner tube is fitted with a base valve and has got inserted in it a piston rod fitted with a piston, the top open end of the outer tube is sealed with a sealing device including a seal shield, a canister is attached to the outer tube at its bottom end, characterized in that a collapsible chamber having a cap is provided inside the canister, a hollow screw having a seal at its one end and female threads at its other end is provided on the cap, another screw with male threads is provided to engage the female threads on the hollow screw and the collapsible chamber inserted in the canister is sealed with a circlip. According to a preferred embodiment of this invention the seal provided on the hollow screw is made of rubber or the like material. The oil is filled in the inner tube fitted with a base valve, the outer tube and the canister attached to the outer tube of the shock absorber. The piston rod fitted with a piston and sealing device are inserted in the inner tube and the open end of the outer tube is sealed with the sealing device that includes a seal shield. High-pressure gas/air is filled in the collapsible chamber enclosed in the canister through a gas/air filling nozzle by piercing the seal provided in the hollow screw fitted in the cap of the collapsible chamber after unscrewing the screw with the male threads engaged in the female threads on the hollow screw. The oil filled in the shock absorber does not come in contact with the gas/air filled in the collapsible chamber; the emulsification of oil is eliminated securing the density of the oil intact. The gas/air filled in the 4 collapsible chamber that escapes over a period of time can be easily recharged through gas/air filling nozzle by piercing the seal provided in the hollow screw after unscrewing the screw with male threads from the female threads on the hollow screw. The seal provided in the hollow screw when damaged due to frequent piercing to recharge the gas/air can be replaced. Having recharged the gas/air re-screwing the screw with the male threads in the female threads on the hollow screw seals the collapsible chamber. The dampening force in compression is generated through the base valve provided in the inner tube that is supplemented by the gas/air pressure to absorb and dampen the shocks in compression due to bad road conditions. As shown in the accompanying drawings, Figure 1 is the cross sectional view and illustrates the twin tube canister attached oleo-pneumatic shock absorber for land vehicles and the like, according to the present invention that consists of an outer tube (1) that houses an inner tube (2). A piston rod (4) fitted with the piston (5) is inserted in the inner tube (2) fitted with a base valve (6). The top open end of the outer tube (1) is sealed with a sealing device (7) including a seal shield. A canister (3) is attached to the outer tube (1) at its bottom end. A collapsible chamber (8) having a cap (9) is provided inside the canister (3). A hollow screw (12), provided with a seal (11), preferable made of rubber or the like material, at its one end and female threads at its other end, is provided on the cap (9) through an "O"-ring (15). Another screw (12) with male threads is provided in the female threads on the hollow screw (12) through an "O"-ring (14). The collapsible chamber (8) fitted with the cap (9) is inserted in the canister (3) and sealed with a circlip (13). Figure 2 is the enlarged cross sectional view and illustrates the portion marked "X X" in Figure 1. The advantages of the oleo-pneumatic shock absorbers for land vehicles and the like, according to this invention, having a canister attached to the outer tube and the base valve attached to the inner tube of the shock absorber are the base valve provided in the inner tube dampens the shocks in compression. Secondly, the shocks are further dampened in compression progressively due to gas/air pressure filled in the collapsible chamber provided in the canister attached to the outer tube of the shock absorber. Thirdly, the oil filled in the shock absorber does not come in contact with 5" the gas/air filled in the collapsible chamber; the emulsification of oil is eliminated securing the density of the oil intact. Fourthly, the escape of the gas/air filled in the collapsible chamber provided in the canister over a period of time, can be re-charged through gas/air filling nozzle by piercing the seal provided in the hollow screw after unscrewing the screw with male threads from the female threads on the hollow screw Having recharged the gas/air re screwing the screw with male threads in the female threads on the hollow screw seals the collapsible chamber. Fifthly the seal provided in the hollow screw when damaged due to frequent piercing to recharge the gas/air, can be replaced. Sixthly, when the efficiency of the shock absorber is reduced below permissible limits, the performance can be corrected by recharging the gas/air and/or replacing the seal at minimum costs without incurring the heavy costs of replacing the entire shock absorber. These advantages thus not only enhance the performance but also increase the life of the shock absorbers for land vehicles and the like. Since many apparently different embodiments of the present invention could be made without departing from the scope and spirit thereof as will be apparent to those skilled in the art, it is intended that the description of the invention herein be interpreted as being illustrative only and not limiting in any manner 6 We claim: 1. An improved oleo-pneumatic shock absorber for land vehicles and the like, according to the present invention, consists of a twin tube comprising an outer lube housing an inner tube, the inner tube is fitted with a base valve and has got inserted in it a piston rod fitted with the piston, the top open end of the outer tube is sealed with a sealing device including a seal shield, a canister is attached to the outer tube at its bottom end characterized in that a collapsible chamber having a cap is provided inside the canister, a hollow screw having a seal at its one end and female threads at its other end is provided on the cap, another screw with male threads is provided to engage the female threads on the hollow screw and the collapsible chamber inserted in the canister is sealed with a circlip. 2. The oleo-pneumatic shock absorber as claimed in claim 1, wherein the seal provided on the hollow screw is made of rubber or the like material. 3. The oleo-pneumatic shock absorber for land vehicles and the like substantially as herein described and illustrated in the accompanying drawings. Dated this 13th day of December 2004.

Documents:

1015-mum-2003-abstract.doc

1015-mum-2003-abstract.pdf

1015-mum-2003-cancelled pages(25-05-2007).pdf

1015-mum-2003-claims.doc

1015-mum-2003-claims.pdf

1015-MUM-2003-CORRESPONDENCE(23-1-2012).pdf

1015-mum-2003-correspondence(ipo).pdf

1015-mum-2003-correspondence.pdf

1015-mum-2003-description(cancelled).pdf

1015-mum-2003-description(granted).doc

1015-mum-2003-description(granted).pdf

1015-mum-2003-drawing.pdf

1015-mum-2003-form 1.pdf

1015-MUM-2003-FORM 13(26-7-2012).pdf

1015-MUM-2003-FORM 13-(26-7-2012).pdf

1015-MUM-2003-FORM 15(23-1-2012).pdf

1015-mum-2003-form 19.pdf

1015-mum-2003-form 2(granted).pdf

1015-mum-2003-form 2(provisional).pdf

1015-mum-2003-form 2(title page).pdf

1015-mum-2003-form 26.pdf

1015-mum-2003-form 4.pdf

1015-mum-2003-form 5.pdf

1015-mum-2003-form-2(garanted).doc

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