Bathroom scale

• US 4,765,422 A
• Filed: 06/01/1987
• Issued: 08/23/1988
• Est. Priority Date: 10/26/1985
• Status: Expired due to Fees

• Current Assignee: Robert Krups Stiftung & Company KG Heresbachstrasse
• Original Assignee: Robert Krups Stiftung & Company AG
• Inventors: Hoffmann, Erich
• Primary Examiner(s): MILLER JR, GEORGE
• Application Number:
  US07/056,852
• Time in Patent Office: 449 Days
• Field of Search: 177/165, 177/211, 204/192.21, 338/2
• US Class Current: 177/211
• CPC Class Codes: G01G 19/44 for weighing persons
• CPC Class Codes: G01G 23/163 involving digital counting
• CPC Class Codes: G01G 3/1402 Special supports with preselected places to mount the resistance strain gauges; Mounting of supports

Abstract

A scale wherein a platform is mounted on and is movable and/or deformable with reference to a base in response to the application of a load, such as the weight of a person standing on the platform. A strain gauge is mounted on a plate-like carrier on the base or directly at the underside of the platform, and its resistor is a thick film conductor whose resistance changes proportionally with the magnitude of the load which is applied to the platform. Such change of resistance is used to change the position of a pointer with reference to a scale which is calibrated to indicate the magnitude of the applied load.

Claims

1. A scale, particularly a bathroom scale, comprising a base member;

a platform member which is mounted on the base member so that at least a portion thereof is displaced with reference to the base member in response to the application of a load thereto; and

a strain gauge mounted on one of said members and including an electrical resistor which is placed under strain in response to the application of a load to said platform to thereby change its resistance to an extent which is a function of the magnitude of the load, said resistor including a thick film conductor and said one member including a body of steel and an insulator between said body and said thick film conductor.

2. The scale of claim 1, further comprising two spaced-apart supports for said platform member on said base member, said thick film conductor extending substantially all the way between said supports.

3. The scale of claim 1, wherein said body comprises a carrier disposed between said members and supporting said platform member so that the carrier undergoes deformation in response to the application of a load to said platform member and the extent of deformation of said carrier is proportional to the magnitude of the applied load, said insulator being provided on said carrier and said thick film conductor being provided on said insulator.

4. The scale of claim 1, wherein said platform member has a side facing said base member and said thick film conductor is provided at said side of said platform member.

5. The scale of claim 1, further comprising zero point selector means including a microprocessor connected with said conductor and provided on said one member.

6. The scale of claim 1, further comprising a scale which is calibrated to indicate the magnitude of the load upon said platform member, a mobile pointer adjacent said calibrated scale, and means for moving said pointer with reference to said calibrated scale including an energy source and amplifier means in circuit with said conductor.

7. The scale of claim 1, wherein said conductor contains a silver palladium alloy.

8. The scale of claim 1, wherein said conductor has an undulate shape.