Simplified hydraulic load cell construction

Claim 2

A hydraulic load cell of simplified construction comprising, in combination: A. a cylinder member having a pressure chamber in its base, B. a diaphragm extending across said chamber, C. a piston member reciprocally mounted in said cylinder, D. means providing lateral support for said piston member adjacent said diaphragm, and E. an Annular upper bridge ring disposed for pivotal deflection between said cylinder and said piston members, said upper bridge and ring supported at a position spaced from said diaphragm by shoulder support means comprising a first shoulder around said piston member facing the top of said cell and underlying the inner diameter edge of said upper bridge ring, the upper surface of said upper bridge ring adjacent said inner diameter edge being unsupported, and a second shoulder around said cylinder surface facing the bottom of said cell and overlying the outer diameter edge of said upper bridge ring, the under surface of said upper bridge ring adjacent said outer diameter edge being unsupported.

Claim 3

A hydraulic load cell simplified construction comprising, in combination: A. a cylinder member having a pressure chamber in its base, B. a diaphragm extending across said chamber, C. a piston member reciprocally mounted in said cylinder, D. an annular lower bridge ring resting over said diaphragm and dispose between said cylinder member and said piston member and, E. an annular upper bridge ring having arcuate inner and outer diameter edges being disposed for pivotal deflection between said cylinder and piston members, a. said upper bridge ring being supported by first shoulder around said piston member facing the top of said cell and underlying the inner diameter edge of said upper bridge ring, the upper surface of said upper bridge ring adjacent said inner diameter edge being unsupported, and by a second shoulder around said cylinder facing the bottom of said cell and overlying the outer diameter edge of said upper bridge ring, the under surface of said upper bridge ring adjacent said outer diameter edge being unsupported.

Claim 4

A hydraulic load cell simplified construction comprising, in combination: A. a cylinder member having a pressure chamber in its base, B. a diaphragm extending across said chamber, C. a piston member reciprocally mounted in said cylinder, D. an annular lower bridge ring resting over said diaphragm and dispose between said cylinder member and said piston member and, E. an annular upper bridge ring having arcuate inner and outer diameter edges being disposed for pivotal deflection between said cylinder and piston members, a. said upper bridge ring being supported by first shoulder around said piston member facing the top of said cell and underlying the inner diameter edge of said upper bridge ring, the upper surface of said upper bridge ring adjacent said inner diameter edge being unsupported, and by a second shoulder around said cylinder facing the bottom of said cell and overlying the outer diameter edge of said upper bridge ring, the under surface of said upper bridge ring adjacent said outer diameter edge being unsupported.

Claim 5

A hydraulic load cell ad defined in claim 2 wherein said first and second shoulders are respectively integral with said piston and cylinder members.

Claim 6

A hydraulic load cell as defined in claim 2 wherein said arcuate inner and outer diameter edges have a radius equal to one-half the width of said upper bridge ring.

Claim 7

In a hydraulic load cell comprising a cylinder member having a pressure chamber in its base, a diaphragm extending across said chamber, a piston member reciprocally mounted in said cylinder, and an annular lower bridge ring resting over said diaphragm and disposed between said cylinder member and said portion member, the improvement comprising an annular upper bridge ring disposed for pivotal deflection between said cylinder and said piston members and being supported therein without clamping by shoulder means comprising a first shoulder around said piston member facing the top of said cell and underlying the inner diameter edge of said upper bridge ring, the upper surface of said upper bridge ring adjacent said inner diameter edge being unsupported, and second shoulder around said cylinder facing the bottom of said cell and overlying the outer diameter edge of said upper bridge ring, the under surface of said upper bridge ring adjacent said outer diameter edge being unsupported.

Claim 8

In a hydraulic load cell comprising a cylinder member having a pressure chamber in its base, a diaphragm extending across said chamber, a piston member reciprocally mounted in said cylinder, and an annular lower bridge ring resting over said diaphragm and disposed between said cylinder member and said portion member, the improvement comprising an annular upper bridge ring disposed for pivotal deflection between said cylinder and said piston members and being supported therein without clamping by shoulder means comprising a first shoulder around said piston member facing the top of said cell and underlying the inner diameter edge of said upper bridge ring, the upper surface of said upper bridge ring adjacent said inner diameter edge being unsupported, and second shoulder around said cylinder facing the bottom of said cell and overlying the outer diameter edge of said upper bridge ring, the under surface of said upper bridge ring adjacent said outer diameter edge being unsupported.

Claim 9

In a hydraulic load cell as defined in claim 5 having a protective flexible boot secured over said piston cylinder members to prevent intrusion of contaminants, the further improvement comprising a supplementary shield comprising an annular elastomeric sheet adhesively secured to the top surfaces of said piston and cylinder members over said upper bridge ring and serving to prevent the intrusion of contaminants should said boot fail.

Claim 10

A hydraulic load cell as defined in claim 5 including a passage means through said cylinder member and communicating with said pressure chamber, said passage means functioning both as a means for filling said pressure chamber with hydraulic fluid as a connection for an external pressure-sensitive indicating instrument.

Claim 11

A hydraulic load cell as defined in claim 5 wherein said first and second shoulders are respectively integral with said piston and cylinder members.

Claim 12

A hydraulic load cell as defined in claim 5 wherein said upper bridge ring has arcuate surfaces on the inner and outer diameter edges thereof to facilitate pivotal deflection and prevent binding.

Claim 13

A hydraulic load cell as defined in claim 9 wherein the radius of each of said arcuate surfaces is equal to one half the width of said upper bridge ring.

Claim 14

A hydraulic load cell as defined in claim 9 and further including arcuate surfaces on the inner and outer diameter edges of said lower bridge ring, said arcuate surfaces each having a radius equal to one-half the width of said lower bridge ring to facilitate pivotal deflection and prevent binding.

Claim 15

A hydraulic load cell as defined in claim 5 including a recess in said piston member, a resilient cylinder supported on the bottom of said recess and in substantially contiguous contact with the sidewall thereof, a first load block freely supported on the bottom of said recesses within said resilient cylinder, a loading head located above said piston, a second load block freely supported on the lower surface of said loading head over said first load block, and rolling ball disposed in said recess within said resilient cylinder in position to contact both said first and second load blocks during cell operation.

Claim 16

A hydraulic load cell as defined in claim 12 wherein the height of said resilient cylinder is substantially less than the depth of said recess to permit side-to-side motion of said loading head.

Claim 17

A hydraulic load cell as defined in claim 12 wherein said the height of said resilient cylinder is substantially equal to the depth of said recess and contiguously surrounds at least a portion of said second load block to inhibit side-to-side motion of said loading head.