ACCELERATION SWITCH WITH MAGNETIC PERMEABLE METAL SLEEVE FOR SHUNTING MAGNETIC FIELD

• US 3,737,599 A
• Filed: 10/26/1971
• Issued: 06/05/1973
• Est. Priority Date: 10/26/1971
• Status: Expired due to Term

• Current Assignee: Bernard R. Zuvela
• Original Assignee: Bernard R. Zuvela
• Inventors: Zuvela, Bernard R.
• Primary Examiner(s): Scott, J. R.
• Application Number:
  US05/192,219
• Time in Patent Office: 588 Days
• Field of Search: 200/61.45R,61.45M,61.52,61.53 335/205
• US Class Current: 200/61.45R
• CPC Class Codes: H01H 35/147 the switch being of the reed switch type

Abstract

An acceleration switch utilizes a permanent magnet with a pole enclosing a magnetically permeable shield and a magnetically permeable ball. The field of the magnet is normally shunted by the shield and ball to weaken the magnetic field existing at a magnetic reed switch. In response to the acceleration, the ball leaves the sleeve and diminishes the shunting effect of the sleeve, so that the field at the reed switch increases and actuates the switch. Directional sensitivity of the acceleration switch is provided by the shape of the cavity within which the ball moves. A winding may be provided about the reed switch for testing switch operation or selectively inhibiting the actuation of the switch.

Claims

1. An improved acceleration switch having a housing with a permanent magnet fixed within a passage therein, a magnetically permeable ball disposed in said passage so as to be moveable between a first position adjacent one pole of said magnet and a second position remote from said magnet pole, and a magnetic reed switch actuated by a change in magnetic flux occurring upon movement of said ball away from said magnet pole, wherein the improvement comprises a magnetically permeable sleeve disposed within said passage which encloses said magnet pole to shunt the magnetic field of the permanent magnet through said sleeve and ball when said ball is in its first position whereby, when said ball is in its said first position, the magnetic field intensity at said reed switch is insufficient to actuate said reed switch and, when said ball moves toward its said second position, said magnetic field intensity at said reed switch increases to actuate said reed switch.

2. An acceleration switch according to claim 1, and including a winding about said reed switch operable, upon the application thereto of the first input signal, to actuate said reed switch and operable, upon the application thereto of a second input signal, opposite the first, to inhibit switch actuation upon ball movement toward its said second position.

3. Apparatus according to claim 1, and in which said passageway portion within which said ball is disposed is laterally tapered inwardly toward said magnet pole and is oval in cross section.

4. Apparatus according to claim 2, and in which the passageway portion within which said ball is disposed is tapered inwardly toward said magnet pole and is oval in cross section.

5. An improved acceleration switch having longitudinal and selectively limited lateral but not vertical sensitivity including a housing with a permanent magnet fixed within a passage therein, a magnetically permeable ball disposed in said passage so as to be moveable between a first position adjacent one pole of said magnet and a second position remote from said magnet pole, and a magnetic reed switch actuated by a change in magnetic flux oCcurring upon movement of said ball away from said magnet pole, where the improvement comprises a passageway portion within which said ball is disposed and which is laterally tapered inwardly toward said magnet pole and is oval in cross section.

6. In an acceleration switch having a housing with a permanent magnet fixed within a passage therein, a magnetically permeable ball disposed in said passage so as to be moveable between a first position adjacent one pole of said magnet and a second position remote from said magnet pole, and a magnetic reed switch actuated by a change in magnetic flux occurring upon movement of said ball away from said magnet pole, the method of increasing the rate of change of magnetic flux at said reed switch with ball movement comprising enclosing said magnet pole with a magnetically permeable sleeve disposed in said passage so as to decrease the magnetic field intensity at said reed switch when said ball is in its first position by shunting said magnetic field through said sleeve and said ball.