Shear measuring flexure isolated load cells

• US 4,009,608 A
• Filed: 01/12/1976
• Issued: 03/01/1977
• Est. Priority Date: 01/20/1975
• Status: Expired due to Term

• Current Assignee: Alfred Newman Ormond
• Original Assignee: Alfred Newman Ormond
• Inventors: Ormond, Alfred Newman
• Primary Examiner(s): Gill, James J.
• Assistant Examiner(s): Ciarlante, Anthony V.
• Application Number:
  US05/648,454
• Time in Patent Office: 414 Days
• Field of Search: 73/141 A, 73/88.5 R, 177/211, 177/229
• US Class Current: 177/211
• CPC Class Codes: G01L 1/2231 the supports being disc- or ring-shaped, adapted for measuring a force along a single direction
• CPC Class Codes: G01L 1/26 Auxiliary measures taken, or devices used, in connection with the measurement of force, e.g. for preventing influence of transverse components of force, for preventing overload

Abstract

Horizontally loaded load cells are isolated by using an integrally formed flexure in the load cell body. Two or more of these cells can be secured to a platform to form a platform scale and the flexure isolation prevents the introduction of interaction terms resulting from extraneous torsion forces or moments from off-center loading on the platform.

Claims

1. In combination, at least two shear measuring load cell bodies, each having first and second end portions, one of said end portions including load responsive strain gage means and the other including integrally formed flexure means, and a platform for carrying a load generally normal to the plane of the platform, said load cell bodies being secured between peripheral points of said platform and a stationary structure such that a straight line passing through said first and second end portions is parallel to the plane of said platform, said flexure means substantially isolating extraneous moments from said load responsive strain gage means so that only a force component normal to the plane of said platform is measured, said one end portion including a cut-out window having an integrally formed diagonal bar lying in a plane normal to the plane of the platform and parallel to said straight line, said strain gage means comprising strain gages fixed to opposite sides of said bar, said flexure means comprising oppositely directed slots in said other end portion of said body defining therebetween a first flexure web lying in a plane perpendicular to said straight line and to the plane of said platform, and a cut-out portion defining opposed flanges having a second flexure web therebetween lying in a plane including said straight line and normal to said first flexure web and the plane of said platform, said second flexure web isolating extraneous torsion forces from said strain gages.

2. In combination, at least two shear measuring load cell bodies, each having first and second end portions, one of said end portions including load responsive strain gage means and the other including integrally formed flexure means, and a platform for carrying a load generally normal to the plane of the platform, said load cell bodies being secured between peripheral points of said platform and a stationary structure such that a straight line passing through said first and second end portions is parallel to the plane of said platform, said flexure means substantially isolating extraneous moments from said load responsive strain gage means so that only a force component normal to the plane of said platform is measured, said one end portion including a cut-out window having integrally formed crossed bars lying in a plane normal to the plane of the platform and parallel to said straight line, said strain gage means comprising strain gages fixed to opposite sides of said bars, said flexure means comprising oppositely directed slots in said other end portion of said body defining therebetween a first flexure web lying in a plane perpendicular to said straight line and to the plane of said platform, and a cut-out portion defining opposed flanges having a second flexure web therebetween lying in a plane including said straight line and normal to said first flexure web and the plane of said platform, said second flexure web isolating extraneous torsion forces from said strain gages.