MAGNETICALLY ACTUATABLE REED SWITCH ASSEMBLY

• US 3,622,926 A
• Filed: 03/12/1970
• Issued: 11/23/1971
• Est. Priority Date: 03/12/1970
• Status: Expired due to Term

• Current Assignee: George Risk
• Original Assignee: George Risk
• Inventors: Risk, George
• Primary Examiner(s): Gilheany, Bernard A.
• Assistant Examiner(s): Envall, Jr., R. N.
• Application Number:
  US05/018,941
• Time in Patent Office: 621 Days
• Field of Search: 335/205,206,303
• US Class Current: 335/205
• CPC Class Codes: H01H 36/004 push-button-operated, e.g. for keyboards

Abstract

A reed switch assembly of the type comprising a pair of spacedapart flexible magnetically permeable electrically conductive reeds adapted to contact each other when brought into proximity to magnetic flux. Herein, the magnetic flux is supplied from a permanent magnet formed of permanently magnetized particles distributed throughout a structurally continuous flexible resinous matrix, said permanent magnet-means being annularly Cshaped and resiliently constrictable and being employed in the switch assembly under conditions of unrelieved constricted stresses.

Claims

1. A magnetically actuatable reed switch assembly to control the flow of electrical current between at least two distinctly separated reeds, said magnetically actuatable reed switch assembly comprising:

A. A pair of magnetically permeable flexible elongate electrically conductive reeds disposed in substantially colinear relationship along a longitudinal axis, said flexible reeds being normally separated by a finite spatial gap at a first reed free end, at least one of said reeds being sufficiently flexible that said reeds will be brought closer together when subjected to magnetic flux;

B. A transversely C-shaped and transversely resiliently constrictable magnet means substantially surrounding said reeds, said magnet means being adapted to reciprocate along the longitudinal axis and including a first station therefor relatively remote from the first reed free end at which first station said reeds remain spatially separated and further including a second station therefor located nearer to said first reed free end at which said second station the magnetic flux of the said permanent magnet means diminishes the interreeds spatial gap, the first and second stations being longitudinally separated by a finite distance, said magnet means having two transverse ends of opposite magnetic polarities including a '"'"''"'"''"'"''"'"'North'"'"''"'"''"'"''"'"' pole and a '"'"''"'"''"'"''"'"'South'"'"''"'"''"'"''"'"' pole, and C-shaped magnet means under conditions of unrelieved constriction stresses being supported against the transverse floor plate of a transversely rigidly dimensioned longitudinally reciprocatable support means;

C. A housing surrounding said longitudinally reciprocatable support means for the magnet means, said housing including a rearward end and an open forward end; and

D. A pushbutton disposed within and extending forwardly from the housing open forward end, said pushbutton extending rearwardly into the housing and being longitudinally reciprocatably actuatably engaged with the support means, the longitudinal reciprocatability for the pushbutton being at least equal to said interstations finite distance.

2. The magnetically actuatable reed switch assembly of claim 1 wherein the said pair of reeds are supported within an elongate envelope of relatively magnetically impermeable material;

wherein the resiliently constrictable C-shaped magnet means comprises permanently magnetized particles distributed throughout a structurally continuous matrix of a resiliently flexible resinous material;

wherein the support means comprises a centrally open floor plate positioned substantially normal to the longitudinal axis and an integrally connected circular upright annular wall portion having a uniform upright height, said annular wall having a circular upright inside surface spaced a constant radial distance from the longitudinal axis;

wherein the constricted magnet means has a C-shaped upright outer wall in continuous contact with the support means upright inside surface;

wherein the upright pushbutton is tubular surrounding the longitudinal axis and attached to the support means floor at the central opening thereof, the pushbutton bore having an upright length exceeding the interstations finite distance; and

wherein an upright helical spring surrounds the longitudinal axis for resiliently normally urging the support means and the magnet means toward one station.

3. The reed switch assembly of claim 2 wherein the major volumetric fraction of the magnet means comprises the resinous matrix whereby said magnet means can be readily altered in peripheral length;

and wherein the helical spring is disposed rearwardly of the magnet means.

4. A plurality of the magnetically actuatable reed switch assemblies of claim 3 banked together in a keyboard installation, each of said reed switch assemblies being identical in every structural and dimensional detail except that the gravimetric mass for the C-shaped resiliently constrictable magnet means differs so greatly from one reed switcH assembly to the other that such gravimetric mass differential is readily visually apparent to the naked eye.