Load cell of integral unitary construction containing a solid disc-shaped measuring section

• US 4,423,793 A
• Filed: 10/23/1981
• Issued: 01/03/1984
• Est. Priority Date: 10/23/1981
• Status: Expired due to Fees

• Current Assignee: Interface Incorporated
• Original Assignee: Interface Incorporated
• Inventors: Caris, Richard F.
• Primary Examiner(s): MILLER JR, GEORGE
• Application Number:
  US06/314,310
• Time in Patent Office: 802 Days
• Field of Search: 177/211, 73/862.65, 73/862.66, 338/5
• US Class Current: 177/211
• CPC Class Codes: G01L 1/2218 the supports being of the column type, e.g. cylindric, adapted for measuring a force along a single direction

Abstract

A load cell of integral unitary construction wherein strain gages are mounted on the peripheral surface of a solid disc-shaped measuring body and are responsive to shear strain induced in the solid measuring body by an applied load. The load receiving and load cell supporting ends are incorporated into the integral unitary structure.

Claims

1. A load cell formed as an integral unitary structure for measuring axially applied loads which comprises

(a) a body of resilient material having first and second ends and containing an axis extending therebetween in the direction of the applied load;

(b) a first pair of spaced diametrical openings located within said body and residing within a first plane, perpendicular to said axis said openings being orthogonal one to the other;

(c) a first pair of opposing slots interconnecting adjacent openings of said first pair and extending inwardly to said axis;

(d) a second pair of diametrical openings located within said body and residing within a second plane, perpendicular to said axis said openings being orthogonal one to the other, said second plane being axially spaced from said first plane;

(e) a second pair of opposing slots interconnecting adjacent openings of said second pair and extending inwardly to said axis, said second pair of slots being rotated about said axis from said first pair of slots, and

(f) means for sensing strain induced in the peripheral surface of said load cell.

2. The load cell of claim 1 wherein said means for sensing strain induced in the peripheral surface of said load cell comprises strain gage means mounted on the outer surface of said cylindrical body and located between adjacent openings in said first and second planes.

3. The load cell of claim 1 wherein the slots of the first and second pairs have an arcuate length which does not exceed ninety degrees, said pairs having a relative rotation therebetween of ninety degrees about said axis.

4. The load cell of claim 1 wherein the slots of said first and second pairs are rotationally oriented about said axis so as to prevent overlap in the axial direction.

5. The load cell of claim 4 further including a load receiving surface integral with said first end and a basal surface integral with said second end.

6. In a load cell of the type wherein strain responsive means is located on the outer surface thereof to indicate the magnitude of an applied axial load, the improvement which comprises:

(a) a disc-shaped measuring body through which the axis of the applied load extends, said body having first and second opposing surfaces orthogonal to said axis;

(b) said first surface having at least two diametrically opposed raised portions thereon which extend inwardly toward said axis;

(c) said second surface having at least two diametrically opposed raised portions thereon which extend inwardly toward said axis, the raised portions of said second surface being rotated about said axis with respect to the raised portions of said first surface;

(d) means for applying a load to the disc-shaped measuring body on the opposed raised portions on the first surface;

(e) means for supporting the disc-shaped measuring body on the opposed raised portions on the second surface; and

(f) the applied load causing a strain in the outer surface of the disc-shaped measuring body, said strain being sensed by strain responsive means located on said outer surface.

7. The improvement of claim 6 wherein the raised portions of said first and second surfaces are arcuate segments.

8. The improvement of claim 7 wherein the raised portions of said first and second surfaces are integral with a load receiving member and a basal support member respectively.

9. The improvement of claim 8 wherein said first and second surfaces each include a pair of orthogonal depressions extending thereacross through said axis, each of said pair of depressions being aligned with the pair on the opposing surface whereby the raised portions of said surfaces are thereby spaced from each other.