US4451978A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for making a pneumatic counterbalance
Assignee: Maremont Corp
•
Filing: 1982-09-16
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Granted: 1984-06-05
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Expires: 2002-09-16
Abstract
Abstract A pneumatic spring counterbalance extensible link including a closed end cylinder with an end connector a piston and rod assembly within the cylinder and maintained therein by the crimped over end portion of the cylinder retaining a rod bushing and rod to cylinder seal. The cylinder is pressurized prior to assembly of the complete piston and rod into the cylinder. The piston assembly includes orifice by-pass means either in the piston periphery or in a piston ring, and the piston may include a fail-safe provision in the event the orifice is clogged. A crimping die assembly is used in assembling and completing final assembly of the counterbalance components while simultaneously maintaining the link in a pressurized environment, utilizing sealed arrangement between the crimping dies to maintain pressurization of the interior of the dies and the counterbalance components prior to assembly of the components. A dual force embodiment of the counterbalance unit is disclosed and utilizes a floating sealed piston below the main piston and rod assembly entrapping pre-charged gas in the space between the floating piston and the closed end of the cylinder.
Inventors
- 👤 George C. Ludwig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 00:41
CPC Classifications
F; F16; F16F; F16F9/00; F16F9/32; F16F9/58; F16F9/585; F16F9/02; Y; Y10; Y10T; Y10T29/00; Y10T29/53; Y10T29/53313; Y10T29/53322; Y10T29/53335; Y10T29/53343; Y10T29/53383; Y10T29/53387; Y10T29/53443
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
255 words
An apparatus to make a pneumatic counterbalance spring link from a pre-assembly of a closed end cylinder with the other end open and a second pre-assembled piston assembly which includes a piston shaft with a free end, a piston fixed on the other end of the shaft, and an abutment bushing and an annular seal means on the shaft with the seal means between the bushing and the piston comprising: a crimping die set adapted to be secured in a press and having at least one upper die assembly with means to releasably secure the piston assembly by the free end of the shaft, said die set also including means to hold the cylinder assembly in said press; means including the press and said die set to enable coaxial alignment and final assembly of the piston assembly and the cylinder assembly with the piston, the seal means and the bushing being inserted in the cylinder; said die set also having means providing a sealed cavity between the cylinder and said upper crimping die assembly with the piston assembly secured therein; means to introduce gas under at least several atmospheres of pressure into said sealed cavity prior to that increment of closure movement of the press which results in insertion of the seal means into said cylinder; means in said upper crimping die assembly adapted to engage and cause inward crimping of the cylinder open end during further, continued movement of said press following that increment of press movement which inserts the bushing into the cylinder.
Claim 2
Independent Claim
255 words
An apparatus to make a pneumatic counterbalance spring link from a pre-assembly of a closed end cylinder with the other end open and a second pre-assembled piston assembly which includes a piston shaft with a free end, a piston fixed on the other end of the shaft, and an abutment bushing and an annular seal means on the shaft with the seal means between the bushing and the piston comprising: a crimping die set adapted to be secured in a press and having at least one upper die assembly with means to releasably secure the piston assembly by the free end of the shaft, said die set also including means to hold the cylinder assembly in said press; means including the press and said die set to enable coaxial alignment and final assembly of the piston assembly and the cylinder assembly with the piston, the seal means and the bushing being inserted in the cylinder; said die set also having means providing a sealed cavity between the cylinder and said upper crimping die assembly with the piston assembly secured therein; means to introduce gas under at least several atmospheres of pressure into said sealed cavity prior to that increment of closure movement of the press which results in insertion of the seal means into said cylinder; means in said upper crimping die assembly adapted to engage and cause inward crimping of the cylinder open end during further, continued movement of said press following that increment of press movement which inserts the bushing into the cylinder.
Claim 3
Dependent Claim
22 words
An apparatus as defined in claim 1, wherein the means to introduce gas under pressure includes passage means in said die set.
Claim 4
Dependent Claim
28 words
An apparatus as defined in claim 2, wherein said passage means enabling introduction of gas under pressure into said sealed cavity is located in the upper die assembly.
Claim 5
Independent Claim
325 words
An apparatus to make a pneumatic counter-balance spring link or the like from a pre-assembly of a closed end cylinder with the other end open and a second pre-assembled piston assembly which includes a piston shaft with a free end, a piston fixed on the shaft, and an abutment bushing and an annular seal means on the shaft between the free end and said piston with the seal means between the bushing and the piston comprising: a crimping die set with upper and lower hollow telescoping die assemblies adapted to be secured in a press; one die assembly having means to releasably secure the piston assembly by the free end of the shaft and the other die assembly having means to hold the cylinder assembly; means including said press and said die assemblies to move both die assemblies and the counterbalance unit pre-assemblies toward each other with the piston assembly coaxially aligned with the cylinder assembly and moving toward entry into the open end of the cylinder assembly, said die assemblies having means to seal said die assemblies upon initial engagement and during subsequent movement toward each other to provide a sealed cavity within said engaged die assemblies which will contain the counterbalance link pre-assemblies; means to introduce gas under at least several atmospheres of pressure into said sealed cavity prior to further closure movement of the die assembly, which results in insertion of the seal means of the piston pre-assembly into said cylinder; means in said die assemblies adapted to cause inward crimping of the cylinder open end by further movement of the die asemblies after said die assemblies have moved together to a position where the bushing of the piston pre-assembly has been moved into the cylinder by movement of the die assemblies; means enabling separation of said die assemblies; and means operable after crimping to vent pressure from said sealed cavity before reverse movement of said die assemblies opens the sealed cavity.
Claim 6
Independent Claim
325 words
An apparatus to make a pneumatic counter-balance spring link or the like from a pre-assembly of a closed end cylinder with the other end open and a second pre-assembled piston assembly which includes a piston shaft with a free end, a piston fixed on the shaft, and an abutment bushing and an annular seal means on the shaft between the free end and said piston with the seal means between the bushing and the piston comprising: a crimping die set with upper and lower hollow telescoping die assemblies adapted to be secured in a press; one die assembly having means to releasably secure the piston assembly by the free end of the shaft and the other die assembly having means to hold the cylinder assembly; means including said press and said die assemblies to move both die assemblies and the counterbalance unit pre-assemblies toward each other with the piston assembly coaxially aligned with the cylinder assembly and moving toward entry into the open end of the cylinder assembly, said die assemblies having means to seal said die assemblies upon initial engagement and during subsequent movement toward each other to provide a sealed cavity within said engaged die assemblies which will contain the counterbalance link pre-assemblies; means to introduce gas under at least several atmospheres of pressure into said sealed cavity prior to further closure movement of the die assembly, which results in insertion of the seal means of the piston pre-assembly into said cylinder; means in said die assemblies adapted to cause inward crimping of the cylinder open end by further movement of the die asemblies after said die assemblies have moved together to a position where the bushing of the piston pre-assembly has been moved into the cylinder by movement of the die assemblies; means enabling separation of said die assemblies; and means operable after crimping to vent pressure from said sealed cavity before reverse movement of said die assemblies opens the sealed cavity.
Claim 7
Dependent Claim
84 words
An apparatus as defined in claim 4 wherein said upper die assembly includes an open ended but otherwise pressure tight cavity with space to accommodate and retain the piston sub-assembly within the cavity and the lower die assembly includes a second open ended but otherwise fluid tight cavity including means to accommodate and retain the cylinder sub-assembly in coaxial alignment with the piston subassembly, and one of said die assemblies includes passage means in fluid communication with said means to introduce gas under pressure.
Claim 8
Dependent Claim
47 words
An apparatus as defined in claim 5, wherein a portion of said lower die assembly is shaped to pass coaxially into the cavity of said upper die assembly and carries a seal ring to effect a gas tight seal between the cavities of each said die assembly.
Claim 9
Dependent Claim
60 words
An apparatus as defined in claim 5 wherein said upper die assembly includes a coaxially nested crimping die insert and an inner sleeve bushing insert the latter adapted to closely receive the shaft of the piston assembly and to engage and maintain the piston assembly bushing spaced away from said crimping die in a direction toward the lower die assembly.
Claim 10
Dependent Claim
43 words
An apparatus as defined in claim 7, wherein the upper die assembly above said nested inserts includes a blind bore which is adapted to receive the shaft of the piston assembly and a magnet is located at the base of said blind bore.
Claim 11
Dependent Claim
32 words
An apparatus as defined in claim 7, wherein both of said inserts are radially slotted to enable through passage of a flat connector link fastened to the end of the piston shaft.
Claim 12
Dependent Claim
28 words
An apparatus as defined in claim 5, wherein said passage means enabling introduction of gas under pressure into said sealed cavity is located in the lower die assembly.
Claim 13
Dependent Claim
28 words
An apparatus as defined in claim 5, wherein said passage means enabling introduction of gas under pressure into said sealed cavity is located in the upper die assembly.
Claim 14
Dependent Claim
80 words
An apparatus as defined in claim 4, wherein the upper die assembly includes a first sleeve member with an interior passage; said lower die assembly includes a second sleeve member which can coaxially move into the passage of said first sleeve member upon operational movement of said die assemblies; and adjustable abutment means on the exterior of said lower die assembly providing a positive abutment limit stop for said upper die assembly, at the end limit of the work stroke.
Claim 15
Dependent Claim
57 words
An apparatus as defined in claim 12, wherein the upper end of said second sleeve member has an external groove, and an O-ring seal is retained in said groove and will engage and seal the two sleeve members upon and after occurrence of the initial telescoping relationship when the die assemblies are operatively moved toward each other.
Claim 16
Dependent Claim
48 words
An apparatus as defined in claim 4, wherein means are provided in fluid communication through one of said die assemblies to introduce a predetermined quantity of oil for lubrication into the open end of said cylinder while said die cavity is sealed and prior to final high pressurization.
Claim 17
Dependent Claim
29 words
An apparatus as defined in claim 14, wherein said means to introduce oil is in fluid communication through the wall of said upper die assembly into the sealed cavity.
Claim 18
Independent Claim
294 words
An apparatus to make a pneumatic counterbalance spring link or the like from a pre-assembly of a closed end cylinder with the other end open and a second pre-assembled piston assembly which includes a piston shaft with a free end a piston fixed on the shaft, and an abutment bushing and an annular seal means on the shaft between the free end and said piston with the seal means between the bushing and the piston comprising: a crimping die set with upper and lower hollow telescoping die assemblies adapted to be secured in a press; one die assembly having means to releasably secure the piston assembly by the free end of the shaft and the other die assembly having means to hold the cylinder assembly; means including said press and said die assemblies to move both die assemblies into an initial engagement to provide a sealed cavity within and between said die assemblies which will contain the counterbalance link pre-assemblies; means to introduce gas under at least several atmospheres of pressure into said sealed cavity before the seal means of the piston pre-assembly is forced into the end of the cylinder pre-assembly and prior to the further closure movement of the die assembly, which results in insertion of the seal means of the piston pre-assembly into said cylinder; means in said die assemblies adapted to cause inward crimping of the cylinder open end by further movement of the die assemblies after said die assemblies have moved together to a position where the bushing of the piston pre-assembly has been moved into the cylinder; means enabling separation of said die assemblies; and means operable after crimping to vent pressure from said sealed cavity and before reverse movement of said die assemblies opens the sealed cavity.
Claim 19
Independent Claim
294 words
An apparatus to make a pneumatic counterbalance spring link or the like from a pre-assembly of a closed end cylinder with the other end open and a second pre-assembled piston assembly which includes a piston shaft with a free end a piston fixed on the shaft, and an abutment bushing and an annular seal means on the shaft between the free end and said piston with the seal means between the bushing and the piston comprising: a crimping die set with upper and lower hollow telescoping die assemblies adapted to be secured in a press; one die assembly having means to releasably secure the piston assembly by the free end of the shaft and the other die assembly having means to hold the cylinder assembly; means including said press and said die assemblies to move both die assemblies into an initial engagement to provide a sealed cavity within and between said die assemblies which will contain the counterbalance link pre-assemblies; means to introduce gas under at least several atmospheres of pressure into said sealed cavity before the seal means of the piston pre-assembly is forced into the end of the cylinder pre-assembly and prior to the further closure movement of the die assembly, which results in insertion of the seal means of the piston pre-assembly into said cylinder; means in said die assemblies adapted to cause inward crimping of the cylinder open end by further movement of the die assemblies after said die assemblies have moved together to a position where the bushing of the piston pre-assembly has been moved into the cylinder; means enabling separation of said die assemblies; and means operable after crimping to vent pressure from said sealed cavity and before reverse movement of said die assemblies opens the sealed cavity.
Claim 20
Dependent Claim
93 words
An apparatus as defined in claim 16, wherein said upper die assembly includes an open ended but otherwise pressure tight cavity with space to accommodate at least the shaft end part, bushing and seal means of the piston subassembly within the cavity, and the lower die assembly includes a second open ended but otherwise fluid tight cavity including means to accommodate at least the cylinder subassembly in coaxial alignment with the piston subassembly, and one of said die assemblies includes passage means in fluid communication with said means to introduce gas under pressure.
Claim 21
Dependent Claim
47 words
An apparatus as defined in claim 17, wherein a portion of said lower die assembly is shaped to pass coaxially into the cavity of said upper die assembly and carries a seal ring to effect a gas tight seal between the cavities of each said die assembly.
Claim 22
Dependent Claim
61 words
An apparatus as defined in claim 17, wherein said crimping means is in said upper die asembly and includes crimping die insert means to closely receive the shaft of the piston assembly and to engage and maintain the piston assembly bushing spaced away from the end portion of the cylinder as that end portion is being crimped by said die assemblies.
Claim 23
Dependent Claim
48 words
An apparatus as defined in claim 19, wherein the upper die assembly above said crimping die insert means includes a blind bore which is adapted to receive the shaft of the piston assembly and means are located in said blind bore to engage and retain the piston pre-assembly.
Claim 24
Dependent Claim
28 words
An apparatus as defined in claim 17, wherein said passage means enabling introduction of gas under pressure into said sealed cavity is located in the lower die assembly.
Claim 25
Dependent Claim
28 words
An apparatus as defined in claim 17, wherein said passage means enabling introduction of gas under pressure into said sealed cavity is located in the upper die assembly.
Claim 26
Dependent Claim
50 words
An apparatus as defined in claim 16 or 17, wherein means are provided in fluid communication through one of said die assemblies to introduce a predetermined quantity of oil for lubrication into the open end of said cylinder while said die cavity is sealed and prior to final high pressurization.
Claim 27
Dependent Claim
22 words
An apparatus as defined in claim 23, wherein said means to introduce oil is in fluid communication through said upper die assembly.
Claim 28
Dependent Claim
67 words
An apparatus as defined in claim 16, wherein the upper die assembly includes a first sleeve member with an interior passage; said lower die assembly includes a second sleeve member which can coaxially move into the passage of said first sleeve member upon operational movement of said die assemblies; and work stroke limiting means provide an end limit for the work stroke movement of said die assemblies.
Claim 29
Dependent Claim
57 words
An apparatus as defined in claim 25, wherein the upper end of said second sleeve member has an external groove, and an O-ring seal is retained in said groove and will engage and seal the two sleeve members upon and after occurrence of the initial telescoping relationship when the die assemblies are operatively moved toward each other.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-06-05 | 1987-12-05 | 1988-06-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-06-05 | 1991-12-05 | 1992-06-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-06-05 | 1995-12-05 | 1996-06-05 | $7700.00 | Window Closed / Lapsed |