Browse Prior Art Database

BI-HELICAL BATTERY CONTACT

IP.com Disclosure Number: IPCOM000006128D
Original Publication Date: 1991-Apr-01
Included in the Prior Art Database: 2001-Dec-06
Document File: 1 page(s) / 72K

Publishing Venue

Motorola

Related People

Wolfgang W. Ritter: AUTHOR [+2]

Abstract

This invention provides a design for an economical battery contact that is capable of maintaining appropriate contact pressure through a relatively large range of motion while allowing insertion and rotation of a battery along various angles perpendicular to the contact's mounting axis.

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MOTOROLA INC. Technical Developments Volume 12 April 1991

BI-HELICAL BATTERY CONTACT

by Wolfgang W. Ritter and John Lewis Dascanio II

  This invention provides a design for an economical battery contact that is capable of maintaining appropriate contact pressure through a relatively large range of motion while allowing insertion and rotation of a battery along various angles perpendicular to the contact's mounting axis.

  Battery contacts complete an electrical circuit via a mechanical linkage. Small personal electronic devices generally have either an axial or a side loading battery access. The usual mechanical linkage, depending on the type of battery access, is formed from some combination of flat springs, compression springs, (conic helix), and torsion springs. One objective of the linkage should be that the contact maintain electrical continuity during mild shock and vibration and that the contact not be damaged (stressed beyond yielding) during severe shock. Other objectives should be to compensate for all of the individual piece-part tolerances, for variations in the manufacturing processes, and be an economical solution that contributes towards a competitive product.

  A common problem resulting from the manufacture of disposable and rechargeable batteries is that the overall tolerances for length are very large, relative to the tolerances for injection molded plastic OT even die cut and formed metal pieces of similar overall dimensions (e.g., 2.045 for a typical N&Cad versus +.003 for small injection molded parts). Batteries can also change in length as they are exposed to the shock induced by dropping (e.g., .02 - .03 reduction in length, typical). If a product adds the versati...