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US3583201A Expired / Lapsed US ⏱️ 0.0 years remaining

Hydraulic overload bolster

Assignee: EW Bliss Co Inc
•
Filing: 1969-01-29
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Granted: 1971-06-08
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Expires: 1989-01-29
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Abstract

Abstract An overload relief system is provided for a press bolster comprising a ram portion and a cylinder portion. The cylinder portion defines a cavity adapted to receive the ram portion, and the cylinder and ram portions together define a pressure chamber. The pressure chamber is sealed and pressurized, and the relief system functions to relieve the pressure in the chamber in the event of a press overload condition.

Inventors

  • 👤 Stephen Topaz

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-03 13:52
CPC Classifications
B; B30; B30B; B30B15/00; B30B15/06; B30B15/28; B30B15/281; B30B15/284

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 120 words
A press bolster comprising a ram portion; a cylinder portion, said cylinder portion defining a cavity adapted to receive said ram portion; said cylinder and ram portions defining a pressure chamber therebetween; means for sealing said pressure chamber; means for pressurizing the chambers; and means to relieve the pressure in the chamber in the event of an overload condition; said cylinder portion defining an upwardly facing cavity comprising a bottom wall and an annular sidewall, said bottom wall comprising a dome-shaped upper surface so that the maximum thickness of the bottom wall is aligned with the axis of said cavity; the ram including a piston having a downwardly shaped concave face generally parallel with the cylinder portion domeshaped upper surface.
Claim 2
Dependent Claim 120 words
A press bolster comprising a ram portion; a cylinder portion, said cylinder portion defining a cavity adapted to receive said ram portion; said cylinder and ram portions defining a pressure chamber therebetween; means for sealing said pressure chamber; means for pressurizing the chambers; and means to relieve the pressure in the chamber in the event of an overload condition; said cylinder portion defining an upwardly facing cavity comprising a bottom wall and an annular sidewall, said bottom wall comprising a dome-shaped upper surface so that the maximum thickness of the bottom wall is aligned with the axis of said cavity; the ram including a piston having a downwardly shaped concave face generally parallel with the cylinder portion domeshaped upper surface.
Claim 3
Dependent Claim 93 words
The bolster according to claim 1 wherein said pressurizing means comprises pump means, first connection means connecting said pump means to the pressure chamber, a check valve in said connection means, first pressure switch means on the side of said check valve remote from said pressure chamber adapted to set the preload pressure for said pressure chamber, second pressure switch means on the side of said check valve adjacent said pressure chamber adapted to actuate said means to relieve the pressure in the chamber, said last-mentioned means being connected directly with said chamber.
Claim 4
Dependent Claim 22 words
The bolster according to claim 2 wherein the connections leading to said pressure chAmber penetrate one or more walls of the bolster.
Claim 5
Dependent Claim 20 words
The bolster according to claim 3 further including bleeder valve means connected to said pressure chamber through said ram portion.
Claim 6
Dependent Claim 34 words
The bolster according to claim 1 wherein said ram portion has a T-shaped cross section elevation view comprising an annular shoulder portion encompassing said piston and defining with the piston the bolster upper surface.

References Cited (Backward Citations)

US2890669A Cited
US2936055A Cited
DE1177006B Cited
US2998238A Cited
US3426873A Cited
US3481171A Cited
US3487772A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1974-06-07 1974-12-07 1975-06-08 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1978-06-07 1978-12-07 1979-06-08 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1982-06-07 1982-12-07 1983-06-08 $7700.00 Window Closed / Lapsed

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