Patent US3905635A successfully refreshed from Google Patents.
US3905635A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Material grasping clamp assembly
Assignee: Eaton Corp
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Filing: 1973-01-10
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Granted: 1975-09-16
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Expires: 1993-01-10
Abstract
Abstract A clamp assembly for material handling vehicles includes a hydraulic system which provides a first pressure for moving the clamp assembly before material is grasped between the clamp members of the assembly and a second increased pressure to the clamp assembly once material is grasped therebetween. A main piston operating at the first pressure actuates closure of the clamp members until the material is grasped therebetween at which time a secondary piston operates at the first pressure to increase the pressure on the main piston to the second increased pressure to positively retain the material between the clamp members at the increased second pressure.
Inventors
- 👤 Ernst S Esser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 04:49
CPC Classifications
B; B66; B66F; B66F9/00; B66F9/06; B66F9/075; B66F9/20; B66F9/12; B66F9/18; B66F9/184; F; F15; F15B; F15B11/00; F15B11/02; F15B11/028; F15B11/032; F15B11/0325; F15B2211/00; F15B2211/20; F15B2211/205; F15B2211/2053; F15B2211/20538; F15B2211/21; F15B2211/214; F15B2211/30; F15B2211/305; F15B2211/30505; F15B2211/50; F15B2211/505; F15B2211/50509; F15B2211/50536; F15B2211/70; F15B2211/705; F15B2211/7051; F15B2211/7053
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
242 words
A material grasping clamp assembly for a material handling vehicle comprising: a pair of opposed clamp members with at least one of said clamp members being movable toward the other to retain variable size material matter between said pair of clamp members; means for mounting said clamp members to said material handling vehicle; means for moving said clamp members relatively toward one another at one pressure prior to retaining of material between said pair of clamp members to effect speedy closure of said clamp assembly and applying a second increased pressure to said clamp members thereafter to retain material therebetween; said moving means further including a direct acting fluid motor having a main piston movable at one speed within a main cylinder cavity under the action of said first pressure, a secondary piston movable within a secondary cavity independent of the first cavity and having a shaft received within a cavity in said main piston upon application of said first pressure to said secondary piston, a pump communicating with said main cylinder cavity and said secondary cavity to produce said first pressure on said main piston and said secondary piston, and a sequence valve assembly connected between said pump and said secondary cavity to provide said first pressure to said secondary piston whenever said clamp members retain said material between them, the relationship of the working areas of said pistons being such as to produce said increased pressure on said main piston.
Claim 2
Dependent Claim
242 words
A material grasping clamp assembly for a material handling vehicle comprising: a pair of opposed clamp members with at least one of said clamp members being movable toward the other to retain variable size material matter between said pair of clamp members; means for mounting said clamp members to said material handling vehicle; means for moving said clamp members relatively toward one another at one pressure prior to retaining of material between said pair of clamp members to effect speedy closure of said clamp assembly and applying a second increased pressure to said clamp members thereafter to retain material therebetween; said moving means further including a direct acting fluid motor having a main piston movable at one speed within a main cylinder cavity under the action of said first pressure, a secondary piston movable within a secondary cavity independent of the first cavity and having a shaft received within a cavity in said main piston upon application of said first pressure to said secondary piston, a pump communicating with said main cylinder cavity and said secondary cavity to produce said first pressure on said main piston and said secondary piston, and a sequence valve assembly connected between said pump and said secondary cavity to provide said first pressure to said secondary piston whenever said clamp members retain said material between them, the relationship of the working areas of said pistons being such as to produce said increased pressure on said main piston.
Claim 3
Dependent Claim
32 words
A material grasping clamp assembly as set forth in claim 1 including a passageway extending into the cavity of said main piston to communicate pressure from said cavity to said main piston.
Claim 4
Dependent Claim
39 words
A material grasping clamp assembly as set forth in claim 1 including a pilot check valve connected between said pump and said main piston to prevent said second pressure on said main piston from being transmitted to said pump.
Claim 5
Dependent Claim
178 words
A pressure device for actuating material handling jaws to close upon said material at a first pressure and to positively retain it at a second pressure comprising: a pressure source for providing said first pressure; a main piston assembly providing linear motion to close said jaws upon said material in response to said first pressure; means for intensifying the pressure on said main piston assembly to said second pressure to positively retain said material including a secondary piston assembly movable by said first pressure to increase the pressure to said main piston assembly to said second pressure; and means for actuating said intensifying means in response to the closure of said jaws upon said material including a sequence valve, connected between said pressure source and said main and said secondary piston assemblies, to apply said first pressure of said pressure source to said main piston assembly while said material handling jaws are closing upon said material and to apply said first pressure of said pressure source to said secondary piston assembly once said jaws close upon said material.
Claim 6
Dependent Claim
178 words
A pressure device for actuating material handling jaws to close upon said material at a first pressure and to positively retain it at a second pressure comprising: a pressure source for providing said first pressure; a main piston assembly providing linear motion to close said jaws upon said material in response to said first pressure; means for intensifying the pressure on said main piston assembly to said second pressure to positively retain said material including a secondary piston assembly movable by said first pressure to increase the pressure to said main piston assembly to said second pressure; and means for actuating said intensifying means in response to the closure of said jaws upon said material including a sequence valve, connected between said pressure source and said main and said secondary piston assemblies, to apply said first pressure of said pressure source to said main piston assembly while said material handling jaws are closing upon said material and to apply said first pressure of said pressure source to said secondary piston assembly once said jaws close upon said material.
Claim 7
Dependent Claim
123 words
A pressure device as set forth in claim 4 wherein: said main piston assembly includes a housing with a main piston sealably movable within a first cavity of said housing and having a shaft portion sealably extending from said housing; said secondary piston assembly includes a secondary piston sealably movable within a second cavity of said housing and having a shaft portion sealably extending into said first cavity of said housing to maintain the pressure integrity of said first and second cavity of said housing; and said sequence valve connecting said pressure source only to said first cavity while said jaws are closing upon said material and connecting said pressure source to sAid second cavity only when said jaws close upon said material.
Claim 8
Dependent Claim
78 words
A pressure device as set forth in claim 5 wherein: said shaft portion of said main piston assembly is formed to have a hollow portion communicating with said first cavity; said main piston of said main piston assembly is formed to sealably accept the shaft portion of said secondary piston; and said shaft portion of said secondary piston movably extends through said main piston and into the hollow portion of said shaft portion of said main piston assembly.
Claim 9
Dependent Claim
30 words
A pressure device as set forth in claim 6 wherein said housing includes an exhaust chamber located between said first and said second cavity and communicating with an exhaust reservoir.
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) | 1978-09-15 | 1979-03-17 | 1979-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-15 | 1983-03-17 | 1983-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-15 | 1987-03-17 | 1987-09-16 | $7700.00 | Window Closed / Lapsed |