US5072501A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for restoring lost fluid pressure particularly in riveting machines
Assignee: Far SNC Di Generali Giacomo & C
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Filing: 1990-11-05
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Granted: 1991-12-17
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Expires: 2010-11-05
Abstract
Abstract In a conventional hydropneumatic gun, blind rivets are pulled and clinched by a single-acting spring-loaded hydraulic cylinder, with force applied by a power unit connected up to a supply of compressed air and incorporating a plunger proportioned and reciprocated in such a way as to actuate the hydraulic cylinder with non-compressible oil displaced under pressure from a master cylinder; the device, which permits of making up any loss in hydraulic pressure, comprises a reservoir connected with the master cylinder, a system by which a reserve supply of the same hydraulic oil held in the reservoir is kept suitably pressurized, and a ball check located between the reservoir and the master cylinder that opens to connect the cylinders to the reserve supply each time the plunger returns to its at-rest position, in readiness to clinch the next rivet.
Inventors
- 👤 Cariati Vincenzo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:12
CPC Classifications
B; B21; B21J; B21J15/00; B21J15/10; B21J15/105; Y; Y10; Y10T; Y10T29/00; Y10T29/53; Y10T29/53709; Y10T29/53717; Y10T29/53726; Y10T29/5373; Y10T29/53739; Y10T29/53743; Y10T29/53748
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
204 words
A device for restoring lost fluid pressure in riveting machines comprising: a fluid power tool assembly for exerting a force on a rivet in response to displacement of a non-compressible fluid under pressure; a propulsion unit for supplying a non-compressible fluid under pressure to said fluid power tool assembly including a master cylinder having a chamber connected with said fluid power tool assembly, said chamber containing a non-compressible fluid, a powered pneumatic cylinder connected with said master cylinder, and a plunger having an axial dimension and one end reciprocally located within said pneumatic cylinder and an opposing end reciprocably located within and in fluid-tight association with the chamber of said master cylinder, wherein said powered pneumatic cylinder when actuated moves said plunger to effect displacement of said non-compressible fluid and to power said power tool assembly; and fluid pressure restoration means for restoring fluid pressure lost during operation of the fluid power tool assembly including a reserve chamber or reservoir interconnectable with the chamber of said master cylinder, said reserve chamber or reservoir containing a non-compressible fluid, and mechanically actuated non-return means located along the axial dimension of said plunger and between said reserve chamber or reservoir and the chamber of said master cylinder.
Claim 2
Independent Claim
204 words
A device for restoring lost fluid pressure in riveting machines comprising: a fluid power tool assembly for exerting a force on a rivet in response to displacement of a non-compressible fluid under pressure; a propulsion unit for supplying a non-compressible fluid under pressure to said fluid power tool assembly including a master cylinder having a chamber connected with said fluid power tool assembly, said chamber containing a non-compressible fluid, a powered pneumatic cylinder connected with said master cylinder, and a plunger having an axial dimension and one end reciprocally located within said pneumatic cylinder and an opposing end reciprocably located within and in fluid-tight association with the chamber of said master cylinder, wherein said powered pneumatic cylinder when actuated moves said plunger to effect displacement of said non-compressible fluid and to power said power tool assembly; and fluid pressure restoration means for restoring fluid pressure lost during operation of the fluid power tool assembly including a reserve chamber or reservoir interconnectable with the chamber of said master cylinder, said reserve chamber or reservoir containing a non-compressible fluid, and mechanically actuated non-return means located along the axial dimension of said plunger and between said reserve chamber or reservoir and the chamber of said master cylinder.
Claim 3
Dependent Claim
83 words
A device for restoring lost fluid pressure as in claim 1, further comprising a contact rod having one end fixed in relation to the propulsion unit and a projecting end extending along an axial bore within said plunger, said rod and plunger being capable of relative axial movement in mutually fluid-tight association, wherein said reservoir chamber or reservoir connects permanently with said axial bore and interconnects with the chamber of said master cylinder upon said contact rod energizing and deactivating said non-return means.
Claim 4
Dependent Claim
38 words
A device for restoring lost fluid pressure in riveting machines as claimed in claim 2, wherein said contact rod comprises an axially hollow interior permanently connecting said reserve chamber or reservoir with said axial bore of said plunger.
Claim 5
Dependent Claim
88 words
A device for restoring lost fluid pressure in riveting machines as claimed in claim 1, wherein said reserve chamber comprises a cylindrical reserve chamber or reservoir including a fixed end wall and an opposing movable end wall, said movable end wall having an access vent therethrough, wherein said opposing movable end wall is capable of axial movement in fluid-tight association within said cylindrical reserve chamber or reservoir in relation to said fixed end wall, and a spring for biasing said movable end wall toward said fixed end wall.
Claim 6
Dependent Claim
123 words
A device for restoring lost fluid pressure in riveting machines as claimed in claim 4, further comprising pressurizing means for pressurizing the fluid within the reserve chamber or reservoir, including a rod extending along the axial dimension of said cylindrical reserve chamber or reservoir, one end of said rod extending through said fixed end wall and being connected with a restraint cap, and an opposing end of said rod extending through said movable end wall and being connected with a retraining head, said spring being located between said restraint cap and said fixed end wall, wherein said spring draws said rod through said fixed end wall and urges said retaining head in fluid-tight association with said vent located through said movable end wall.
Claim 7
Dependent Claim
98 words
A device for restoring lost fluid pressure in riveting machines as claimed in claim 5, further comprising at least one peripheral stop projecting from the external surface of said restraint cap to engage with catch means during movement of said rod, and wherein said two end walls are set apart at a maximum distance one from the other upon compression of said spring and engagement of said catch means with said peripheral stop, for separating said retaining head from said movable end wall and affording access to said reserve chamber or reservoir through said vent of non-compressible fluid.
Claim 8
Dependent Claim
60 words
A device for restoring lost fluid pressure in riveting machines as claimed in claim 6, further comprising a limiter ring located external to said movable end wall in fixed relation to said reserve chamber or reservoir, wherein said limiter ring limits movement of said movable end wall upon engagement of the projection of the restraint cap by the detent means.
Claim 9
Dependent Claim
72 words
A device for restoring lost fluid pressure in riveting machines as claimed in claim 1, wherein said pneumatic cylinder of said propulsion unit comprises a cylindrical barrel capped at one end by an end cover and accommodating a coaxially disposed piston connected to said end of said plunger located within said pneumatic cylinder, wherein said reserve chamber or reservoir of said fluid pressure restoration means is embodied integrally with the end cover.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-12-16 | 1995-06-17 | 1995-12-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-12-16 | 1999-06-17 | 1999-12-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-12-16 | 2003-06-17 | 2003-12-17 | $7700.00 | Window Closed / Lapsed |