Weighing apparatus

Claim 2

A weighing apparatus comprising relatively stationary rigid support means, a pair of flexure spring members mounted in cantilever fashion on said support means in vertically spaced essentially parallel relation, means rigidly interconnecting the free ends of said flexure members and maintaining said free ends in fixed spaced apart relation, a load-receiving structure supported by the free ends of said flexure members, said flexure members having intermediate portions that are free to be flexed by the weight of a load applied to said load-receiving structure to provide for a relatively small, essentially vertical displacement of the assembly of said load-receiving structure and said interconnecting means by a distance that is substantially proportional to the weight of the applied load, said loadreceiving structure being adapted to receive a load at locations where it places said flexure members respectively in tension and in compression whereby said interconnecting means is angularly displaced a small distance relative to said support means and about a predetermined essentially horizontal axis, and transducer means comprising coacting, signal-producing parts respectively connected to said support means and said assembly of said loadreceiving structure and said interconnecting means, said coacting signal-producing parts being relatively movable by the weightrepresenting displacement of the assembly of said load-receiving structure and said interconnecting means to measure the weightrepresenting displacement of said assembly at a predetermined location that is at least closely adjacent to a predetermined center of integrity where no signal-producing relative motion is imparted to said parts by the angular displacement of said interconnecting means relative to said support means.

Claim 3

The weighing apparatus defined in claim 1 wherein the signal-producing part connected to said assembly is carried by said assembly without supporting any part of the load applied to said load-receiving structure.

Claim 4

The weighing apparatus defined in claim 1 wherein each of said flexure members is a plate, wherein said interconnecting means firmly clasps each of the free ends of said flexure members between opposing surfaces to maintain said free ends in substantially parallel relation, and wherein said center of integrity is in a plane transversely intersecting the longitudinal flexure axes of said flexure members and passing through the interfaces between the clamped free flexure member ends and said intermediaTe portions that are flexed by application of a load to said load-receiving structure.

Claim 5

The weighing apparatus defined in claim 3 wherein said center of integrity is in a plane extending parallel to said flexure members and containing the neutral flexure axis of the assembly of said flexure members.

Claim 6

The weighing apparatus defined in claim 4 wherein said center of integrity is contained in a plane medially intersecting said flexure members.

Claim 7

The weighing apparatus defined in claim 3 wherein said center of integrity is substantially coincident with said horizontal axis.

Claim 8

The weighing apparatus defined in claim 3 wherein the signal producing part that is connected to said assembly is so mounted that it does not support any part of the load applied to said load-receiving structure.

Claim 9

The weighing apparatus defined in claim 7 wherein said signal producing parts are respectively fixed to and supported by said interconnecting means and said support means.

Claim 10

The weighing apparatus defined in claim 7 wherein said transducer comprises a transformer, and wherein said signal producing parts respectively comprise a transformer core and a transformer winding means respectively fixed to and supported by said interconnecting means and said support means, the displacement of said core relative to said winding means being effective to correspondingly vary an electrical signal that is supplied at an output of said winding means.

Claim 11

The weighing apparatus defined in claim 9 comprising a relatively thin wire mounting said core, and adjustment means fixing said wire to said interconnecting means and being manipulatable to selectively longitudinally adjust the position of said core relative to said winding to correspondingly vary said signal.

Claim 12

The weighing apparatus defined in claim 10 wherein said wire has a thermal coefficient of expansion that, in response to temperature changes, longitudinally varies the position of said core relative to said winding means by a magnitude sufficient to essentially compensate for temperature induced variations in the modulus of elasticity of said flexure members.

Claim 13

The weighing apparatus defined in claim 10 comprising spring means anchored to said support means and said interconnecting means for biasing said assembly and the free ends of said flexure members in a direction opposing the weight of a load applied to said load-receiving structure, and means for selectively adjusting the biasing force exerted by said spring means to thereby selectively vary the angle at which said plane intersects and each of said flexure members.

Claim 14

The weighing apparatus defined in claim 3 wherein said interconnecting means comprises rigid coacting clamping members defining said opposing surfaces and clamping each of said free ends along its entire width.

Claim 15

The weighing apparatus defined in claim 2 comprising stop means for limiting weight-representing displacement of said assembly to a relatively minute magnitude.

Claim 16

The weighing apparatus defined in claim 14 wherein said stop means comprises a sleeve, means coaxially received by said sleeve for fixing said sleeve to said support means, said sleeve extending between said support means and said interconnecting means and having one end received with a relatively small clearance in an opening in said interconnecting means, said interconnecting means being abuttable with said one end of said sleeve to limit the weight-representing displacement of assembly to said relatively minute magnitude.

Claim 17

A weighing apparatus for weighing off-center loads and comprising relatively rigid support means, a pair of flexure beam members mounted in cantilever fashion on said support means in vertically spaced apart essentially parallel relation, means rigidly interconnecting the free ends of said flexure members and maintaining said free ends in fixed parallel spaced apart relation, said interconnecting means including coacting structural members firmly clamping each of said free ends along Substantially its entire width between opposing clamping surfaces, a load receiving structure mounted on said interconnecting means, with the assembly of said load receiving structure and said interconnecting means being supported for load-induced displacement only on the free ends of said flexure members, the intermediate portions of said flexure members extending between said free ends and the opposite flexure member ends that are mounted on said support means being free to be flexed by the weight of a load applied to said load-receiving structure to provide a relatively minute, essentially vertical weight-representing displacement of said assembly by a distance that is substantially proportional to the weight of the applied load, said load receiving structure being adapted to receive a load at off-center locations where it places said flexure members respectively in tension and in compression to cause said flexure members to respectively stretch and buckle, whereby said interconnecting means is angularly displaced a small distance relative to said support means and about an essentially horizontal axis, transducer means comprising first and second coacting signal-producing parts respectively connected to said assembly and said support means, said coacting signal producing parts being relatively movable by the weight-representing displacement of said assembly to measure the weight-representing displacement of said assembly at a predetermined location that is at least closely adjacent to a predetermined center of integrity where no signal-producing relative motion is imparted to said signal-producing parts by the angular displacement of said interconnecting means relative to said support means, said center of integrity lying in a plane that extends transversely of said flexure members and substantially passes through the interfaces between said free ends and said intermediate portions of said flexure members, and means so mounting said first signal-producing part that the load applied to said load-receiving structure is supported independently of said first signal-producing part.

Claim 18

A weighing apparatus for weighing off-center loads and comprising relatively rigid support means, a pair of flexure beam members mounted in cantilever fashion on said support means in vertically spaced apart essentially parallel relation, means rigidly interconnecting the free ends of said flexure members and maintaining said free ends in fixed parallel spaced apart relation, said interconnecting means including coacting structural members firmly clamping each of said free ends along Substantially its entire width between opposing clamping surfaces, a load receiving structure mounted on said interconnecting means, with the assembly of said load receiving structure and said interconnecting means being supported for load-induced displacement only on the free ends of said flexure members, the intermediate portions of said flexure members extending between said free ends and the opposite flexure member ends that are mounted on said support means being free to be flexed by the weight of a load applied to said load-receiving structure to provide a relatively minute, essentially vertical weight-representing displacement of said assembly by a distance that is substantially proportional to the weight of the applied load, said load receiving structure being adapted to receive a load at off-center locations where it places said flexure members respectively in tension and in compression to cause said flexure members to respectively stretch and buckle, whereby said interconnecting means is angularly displaced a small distance relative to said support means and about an essentially horizontal axis, transducer means comprising first and second coacting signal-producing parts respectively connected to said assembly and said support means, said coacting signal producing parts being relatively movable by the weight-representing displacement of said assembly to measure the weight-representing displacement of said assembly at a predetermined location that is at least closely adjacent to a predetermined center of integrity where no signal-producing relative motion is imparted to said signal-producing parts by the angular displacement of said interconnecting means relative to said support means, said center of integrity lying in a plane that extends transversely of said flexure members and substantially passes through the interfaces between said free ends and said intermediate portions of said flexure members, and means so mounting said first signal-producing part that the load applied to said load-receiving structure is supported independently of said first signal-producing part.

Claim 19

The weighing apparatus defined in claim 16 wherein said first and second coacting signal-producing parts are respectively mounted on said interconnecting means and said support means, and wherein said interconnecting means is configured to at least partially receive said signal producing parts with sufficient clearance to provide for the relative weight representing motion between said signal-producing parts.

Claim 20

The weighing apparatus defined in claim 17 wherein one of said coacting structural members extends between the free ends of said flexure members and has an opening formed therein for at least partially receiving said signal-producing parts.

Claim 21

The weighing apparatus defined in claim 17 wherein said transducer comprises a transformer, and wherein said first and second signal producing parts respectively comprise a core and winding means coaxially receiving said core, the center of said core being at least closely adjacent to said center of integrity.