Strain gage scale

• US 4,433,741 A
• Filed: 04/12/1982
• Issued: 02/28/1984
• Est. Priority Date: 04/12/1982
• Status: Expired due to Fees

• Current Assignee: Black & Decker Incorporated (Stanley Black & Decker, Inc.)
• Original Assignee: General Electric Company
• Inventors: Ryckman, William D. Jr.
• Primary Examiner(s): Hartary, Joseph W.
• Application Number:
  US06/367,360
• Time in Patent Office: 687 Days
• Field of Search: 177/211, 177/DIG. 9, 177/199, 177/238, 177/244
• US Class Current: 177/199
• CPC Class Codes: G01G 19/44 for weighing persons
• CPC Class Codes: G01G 21/23 Support or suspension of weighing platforms G01G21/24 takes precedence
• CPC Class Codes: G01G 3/1402 Special supports with preselected places to mount the resistance strain gauges; Mounting of supports

Abstract

In a strain gage weighing scale with a load platform, a plurality of foot structures support the platform. The invention is an improvement in each foot structure of a sandwich with a bottom support plate, a pair of spaced first cylindrical roller fulcrums on the plate, a floating beam plate on the first fulcrums and spaced above and coextensive with the bottom plate. A pair of differently spaced and equally offset second cylindrical roller fulcrums on the beam plate support the platform. Suitable strain gages are secured to the beam any place between the closer pair of fulcrums. The entire sandwich is held together by a deformable plastic housing that secures the plates and fulcrums together and is barb-connected to the platform. The strain gages are connected to conventional converting structure measuring the change in resistance under load and calibrated to read weight. The deformable plastic housing holding the sandwich is an integral molding with structural details reducing friction between the parts. The overall result is a lower profile scale for common household use.

Claims

1. In a strain gage weighing scale with a load platform, a plurality of individually spaced foot structures supporting said platform, an improvement in each foot structure of a sandwich construction comprising,

a bottom support plate,

a pair of spaced first fulcrums on said plate,

a floating beam plate on said first fulcrums and spaced above and substantially coextensive with said bottom plate,

said plates being substantially flat, square, hard metallic plates and interchangeable in said sandwich,

a pair of differently spaced and equally offset second fulcrums on said beam plate supporting said platform,

strain gage means secured to said beam plate between the closer pair of fulcrums,

means connected to said gage means converting the gage resistance change under load to read the weight of the load,

an integral, deformable plastic housing supporting and securing the plates and fulcrums together,

the sides of said plastic housing including a plurality of vertical barbs,

elongated slots in said platform receiving said barbs locking said sandwich together against said platform, and

a support cup on the bottom of said housing conformed to flatten under load along and against the support plate thus spreading the barbs along said slots to remove friction therebetween while maintaining said sandwich together on and against said support plate.

2. Apparatus as described in claim 1 wherein said scale overall outline is formed to receive four foot structures in a quadrate pattern peripherally spaced around the outline.

3. Apparatus as described in claim 2 wherein said plastic housing has paired bearing and locating grooves therein fixing each fulcrum in the sandwich.