Patent US3917248A successfully refreshed from Google Patents.
US3917248A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pneumatic holding or clamping device
Assignee: Individual
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Filing: 1974-05-20
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Granted: 1975-11-04
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Expires: 1994-05-20
Abstract
Abstract A holding or clamping device of the type comprising two pressure cylinders adapted to produce a first preliminary weak holding force and subsequently a greater holding force is provided with a sensor pin adapted to bring about a switch over from operation of the first cylinder to the second cylinder. The sensor pin is so loaded that it will only bring about the switching over when it strikes a hard object such as metal but is not actuated when it comes into contact with the human hand. The valve on actuation by the sensor pin closes the connection between the two chambers of the principal cylinder, which is constantly acted upon by pressure, and vents the rear side of the principal piston simultaneously.
Inventors
- 👤 Max Mayer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 22:51
CPC Classifications
F; F15; F15B; F15B15/00; F15B15/20; F15B15/204; B; B25; B25B; B25B5/00; B25B5/06; B25B5/061; B25B5/16
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
169 words
A pneumatic holding device for workpieces, comprising: a first holding cylinder of narrower cross-section; a first chamber defined in and by said first cylinder; a vent from said first chamber; a second cylinder of larger cross-section; a first piston sealingly located in and movable along and through said second cylinder; said first piston dividing said second cylinder into second and third chambers; a first conduit across said first piston and communicating between said first and said second chambers; a second conduit across said first piston and communicating between said second and said third chambers; a fluid inlet to said third chamber; a valve movable for selectively opening one of said first and second conduits while closing the other of said first and second conduits, and vice versa; an abutment sensor extending out of said pneumatic holding device and being connected with said valve for causing the aforesaid movement thereof, in a manner such that application of pressure to said abutment sensor shifts said valve to close said second conduit.
Claim 2
Dependent Claim
169 words
A pneumatic holding device for workpieces, comprising: a first holding cylinder of narrower cross-section; a first chamber defined in and by said first cylinder; a vent from said first chamber; a second cylinder of larger cross-section; a first piston sealingly located in and movable along and through said second cylinder; said first piston dividing said second cylinder into second and third chambers; a first conduit across said first piston and communicating between said first and said second chambers; a second conduit across said first piston and communicating between said second and said third chambers; a fluid inlet to said third chamber; a valve movable for selectively opening one of said first and second conduits while closing the other of said first and second conduits, and vice versa; an abutment sensor extending out of said pneumatic holding device and being connected with said valve for causing the aforesaid movement thereof, in a manner such that application of pressure to said abutment sensor shifts said valve to close said second conduit.
Claim 3
Dependent Claim
74 words
The pneumatic holding device of claim 1, further comprising a second piston in and extending along said first cylinder, and having a cross-section less than said narrower cross-section of said first cylinder, thereby defining said first chamber between said first cylinder and said second piston; said abutment sensor being connected with said second piston for moving same; said valve communicating with said second piston thereby to be moved by movement of said second piston.
Claim 4
Dependent Claim
17 words
The pneumatic holding device of claim 2, wherein said first cylinder is positioned within said second cylinder.
Claim 5
Dependent Claim
119 words
The pneumatic holding device of claim 2, wherein said valve comprises a valve body and a valve chamber, said valve chamber being formed in said first piston; said valve body being movable in said valve chamber; a first valve seat in said valve chamber; said first cylinder extending into and terminating at an end in said first piston; said first valve seat being near said first cylinder end; a second valve seat in said valve chamber, located opposite said first valve seat, and formed in said first piston; said valve closing said second conduit when said valve body is against said second valve seat and opening said second conduit when said valve body is against said first valve seat.
Claim 6
Dependent Claim
26 words
The pneumatic holding device of claim 4, further comprising a compression spring between said valve body and said second piston for forcing them in opposite directions.
Claim 7
Dependent Claim
25 words
The pneumatic hoding device of claim 5, further comprising a compression spring normally biasing said first piston in a direction away from said abutment sensor.
Claim 8
Dependent Claim
89 words
The pneumatic holding device of claim 6, further comprising a pressure plate connected with and movable with said first piston; said abutment sensor projecting through and being freely movable with respect to said pressure plate, such that application of pressure to said abutment sensor moves same inward of said pressure plate and closes said valve body against said second seat, thereby venting said second chamber through said first chamber and permitting build up of pressure in said third chamber, thereby to shift said first piston through said second cylinder.
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) | 1978-11-03 | 1979-05-05 | 1979-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-03 | 1983-05-05 | 1983-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-03 | 1987-05-05 | 1987-11-04 | $7700.00 | Window Closed / Lapsed |