Constant moment weigh scale with floating flexure beam
First Claim
1. Floating beam weigh scale apparatus comprising a base, a load receiving member spaced from the base, first and second pivot members disposed between the base and load receiving .[.members,.]. .Iadd.member, .Iaddend.load transmitting means interconnecting the pivots, the base, and the load receiving member to produce moments in the pivots of opposite sense and about spaced axes, a substantially rigid beam connected to and extending between the pivots, and means carried by the beam for producing a signal related to the bending stress therein over the elastic bending range thereof.
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Accused Products
Abstract
A weigh scale apparatus in which forces caused by the applied load are transformed into moments of opposite sense and applied to opposite ends of a substantially rigid beam. Deflection of the beam is measured by centrally disposed strain gage resistors to produce an electrical signal quantity proportional to the applied load. The conversion of applied load to moments of opposite sense is accomplished by a pair of spaced parallel pivot members which are suspended by straps between the load receiving pan and the base such that the pivots tend to rotate in opposite directions. The beam is mechanically connected between the pivots such that it is subjected to the bending moment over substantially its entire length. A split scale device is provided by a composite pan, one portion of which is connected to the pivots directly and another portion of which is connected to the pivots through long lever arms to provide moment multiplication. A vibrator device for dithering the pivots is provided. .Iadd.
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Citations
17 Claims
- 1. Floating beam weigh scale apparatus comprising a base, a load receiving member spaced from the base, first and second pivot members disposed between the base and load receiving .[.members,.]. .Iadd.member, .Iaddend.load transmitting means interconnecting the pivots, the base, and the load receiving member to produce moments in the pivots of opposite sense and about spaced axes, a substantially rigid beam connected to and extending between the pivots, and means carried by the beam for producing a signal related to the bending stress therein over the elastic bending range thereof.
- 14. circuit to produce a visual indication of the magnitude thereof. 16. Apparatus as defined in claim 14 further including at least two temperature responsive compensating resistors connected to opposite terminals of said bridge circuit to compensate the bridge circuit for
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15. temperature variations. 17. In a weigh scale:
- a load pan, a pair of spaced members, means connecting the pan to said members to produce in said members turning moments of opposite sense and related to loads applied to the pan, a beam of rigid material connected between said spaced members and of substantially greater length than thickness, and means for detecting the extent of bending of said beam as an indication of the
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17. weigh scale. .Iadd.19. Floating beam weigh scale apparatus comprising:
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a base; a load receiving member spaced from the base; first and second elongated, torsionally rigid pivot members disposed between the base and the load receiving member; a substantially rigid beam having its ends connected substantially centrally of and to the pivot members so that the beam extends between the pivot members; load transmitting means spaced from the beam for interconnecting the pivot members, the base and the load receiving member to produce turning moments in said pivot members of opposite sense and about spaced axes, said turning moments being transmitted to the ends of the beam through the lengths of the pivot members to create bending stress in the beam without applying direct forces to the beam; and means carried by the beam for producing a signal related to the bending stress therein over the elastic bending range thereof..Iaddend. .Iadd.20. Apparatus as defined in claim 19 wherein the load transmitting means comprises torsionally compliant straps connected in opposing pairs to the ends of the pivot members, one such strap of each pair being connected between the base and a pivot members, and another such strap of each pair being connected between the pivot member and the load receiving member, said pairs of straps operative to produce the turning moments in the pivot members. .Iaddend. .Iadd.21. In a weigh scale; a load pan; a pair of spaced elongated and torsionally rigid members; a beam of rigid material having its ends connected substantially centrally of and between said spaced members and being of substantially greater length than thickness; means spaced from the beam connecting the pan to said members to produce turning moments therein of opposite sense and related to loads applied to the pan, said turning moments being transmitted to the ends of the beam through said members to create bending stress in the beam without applying direct forces to the beam; and means for detecting the extent of bending of said beam as an indication of the load applied to the pan. .Iaddend. - View Dependent Claims (16)
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Specification