Patent US1844303A successfully refreshed from Google Patents.
Patent US3633696A successfully refreshed from Google Patents.
US3633696A
Expired / Lapsed
US
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Load cell
Assignee: United States Steel Corp
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Filing: 1970-10-15
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Granted: 1972-01-11
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Expires: 1990-10-15
Abstract
Abstract A load cell comprises two pistons reciprocable with respect to each other and to a surrounding cylinder. Conventional rolling seals seal the pistons and cylinder to each other providing two opposed fluid-pressure chambers acting on different piston areas. Mutually engageable seating surfaces on the pistons constitute elements of regulating valves for balancing fluid pressures in the chambers when a load is applied. Then a difference in chamber pressures indicates the weight of the load.
Inventors
- 👤 William K Kleysteuber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 08:05
CPC Classifications
G; G01; G01G; G01G5/00; G01G5/003; G01L; G01L1/00; G01L1/02
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
318 words
A load cell comprising a body member having an axial opening therethrough open at the top, and a bottom closure member for said opening; a first elongated piston reciprocal inside said body member with a first space between the outer wall of said piston and said axial opening, said piston having an axial opening therein, a pressure receiving bottom surface spaced from said bottom closure member, and a load rEceiving top surface; a second elongated piston reciprocal inside said first piston with a second space between the outer wall of said second piston and said axial opening of said first piston, said second piston having an axial opening therethrough; first sealing means for closing the lower end of said first space to provide a first chamber between said first sealing means and said bottom closure member; second sealing means for closing the top ends of said first and second spaces; a port through the wall of said first piston between said first and second sealing means for connecting said first and second spaces to provide a second chamber between said first and second sealing means, said second chamber having a bottom area smaller than the top area of said first chamber; an inlet port to said second chamber for admitting fluid under pressure into said first chamber; inlet valve means responsive to downward movement of the first piston when a load is placed on said load-receiving surface for admitting pressurized fluid from said second chamber into said first chamber until the downward force on said bottom area equals the upward force on said top area; exhaust valve mans responsive to the upward movement of the first piston when a load is removed from said load-receiving surface for exhausting said fluid from said first chamber; and means for measuring the difference in fluid pressure between said first and second chambers when a load is placed on said loadreceiving surface.
Claim 2
Dependent Claim
318 words
A load cell comprising a body member having an axial opening therethrough open at the top, and a bottom closure member for said opening; a first elongated piston reciprocal inside said body member with a first space between the outer wall of said piston and said axial opening, said piston having an axial opening therein, a pressure receiving bottom surface spaced from said bottom closure member, and a load rEceiving top surface; a second elongated piston reciprocal inside said first piston with a second space between the outer wall of said second piston and said axial opening of said first piston, said second piston having an axial opening therethrough; first sealing means for closing the lower end of said first space to provide a first chamber between said first sealing means and said bottom closure member; second sealing means for closing the top ends of said first and second spaces; a port through the wall of said first piston between said first and second sealing means for connecting said first and second spaces to provide a second chamber between said first and second sealing means, said second chamber having a bottom area smaller than the top area of said first chamber; an inlet port to said second chamber for admitting fluid under pressure into said first chamber; inlet valve means responsive to downward movement of the first piston when a load is placed on said load-receiving surface for admitting pressurized fluid from said second chamber into said first chamber until the downward force on said bottom area equals the upward force on said top area; exhaust valve mans responsive to the upward movement of the first piston when a load is removed from said load-receiving surface for exhausting said fluid from said first chamber; and means for measuring the difference in fluid pressure between said first and second chambers when a load is placed on said loadreceiving surface.
Claim 3
Dependent Claim
52 words
A load cell according to claim 1 in which said exhaust valve means includes a base down conical inner portion mounted on the bottom of said body member and a first frustoconical outer surface in the interior of the lower end of said second piston adapted to engage said conical inner portion.
Claim 4
Dependent Claim
29 words
A load cell according to claim 2 in which said conical section is threadedly mounted for vertical movement to adjust the height of said first piston when at rest.
Claim 5
Dependent Claim
56 words
A load cell according to claim 1 in which said inlet valve means includes a first frustoconical base up outer surface in the interior of the lower end of said first piston and a second frustoconical inner surface on the exterior of the lower portion of said second piston adapted to engage said first frustoconical surface.
Claim 6
Dependent Claim
93 words
A load cell according to claim 1 in which said first sealing means includes a first rolling seal between the upper end of said body member and the outside of the upper end of said first piston and a second rolling seal between the inside of the upper end of said first piston and the outside of the upper end of said second piston, and said second sealing means includes a third rolling seal between the lower end of said body member and the lower end of the outside of said first piston.
Claim 7
Dependent Claim
58 words
A load cell according to claim 5 in which said body member has an internal flange at the top thereof with said first rolling seal between said internal flange and said first piston and said first piston has an external flange at the bottom thereof with said third rolling seal between said external flange and said body member.
Claim 8
Dependent Claim
36 words
A load cell according to claim 1 which includes a compression spring mounted on one end to said first piston and on the other end to said second piston to urge said inlet valve means closed.
Claim 9
Dependent Claim
56 words
A load cell according to claim 7 includes an internal flange at the upper end of said first piston inside said second chamber and said spring is mounted between said internal flange and an external flange at the lower end of said second piston with the upper face of said external flange is said second chamber.
Claim 10
Dependent Claim
24 words
A load cell according to claim 7 in which said load receiving surface includes a load-sensing platform mounted on top of said first piston.
Claim 11
Dependent Claim
24 words
A load cell according to claim 9 in which said compression spring is mounted between said platform and the top of said second piston.
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) | 1975-01-10 | 1975-07-12 | 1976-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-10 | 1979-07-12 | 1980-01-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-10 | 1983-07-12 | 1984-01-11 | $7700.00 | Window Closed / Lapsed |