Mechanically-powered electric generator for instant-photographic camera and other apparatus

• US 4,101,792 A
• Filed: 08/29/1974
• Issued: 07/18/1978
• Est. Priority Date: 07/17/1973
• Status: Expired due to Term

• Current Assignee: Westinghouse Electric Company LLC (Brookfield Asset Management Incorporated)
• Original Assignee: Westinghouse Electric Company LLC (Brookfield Asset Management Incorporated)
• Inventors: Bratkowski, Walter V., Shoupp, William E.
• Primary Examiner(s): Duggan, Donovan F.
• Application Number:
  US05/501,560
• Time in Patent Office: 1,419 Days
• Field of Search: 310/15, 310/30, 310/29, 354/135
• US Class Current: 310/15
• CPC Class Codes: G03B 15/0447 Energy sources; Batteries; Capacitors
• CPC Class Codes: G03B 9/70 with flash-synchronising contacts
• CPC Class Codes: H02K 35/00 Generators with reciprocating, oscillating or vibrating coil system, magnet, armature or other part of the magnetic circuit arrangements for handling mechanical energy structurally associated with generators H02K7/00, e.g. H02K7/06

Abstract

A compact electric generator that is powered by a tensioned spring and adapted to serve as an integral and permanent source of electric energy for a photographic camera or other apparatus. The generator includes a permanent magnet, a pole piece and a reciprocally-movable armature that define a magnetic circuit. The permanent magnet is also movable with respect to the pole piece and armature and is so oriented, when the generator is cocked, that the field strength of the magnetic circuit is sufficient to permit the pole piece to magnetically "capture" the armature and hold it in a predetermined position against the action of the tensioned spring. The generator is tripped by displacing the permanent magnet and thus weakening the field strength of the magnetic circuit. This permits the tensioned spring to overcome the magnetic "lock" on the armature and rapidly propel the latter away from the pole piece. The resultant sudden change in the flux density of the magnetic circuit induces a voltage pulse in an associated wire coil.

Claims

1. A mechanically-powered generator for producing a pulse of electrical energy, said generator being of the recockable type and comprising the combination of;

a permanent magnet and a pole piece that are movable relative to one another and constitute parts of a magnetic circuit,

an armature that is movable toward and away from said pole piece and also constitutes part of said magnetic circuit, said armature being magnetically attracted to said pole piece and in magnetically captured relationship therewith when the electric generator is cocked and ready for use,

a winding of insulated wire disposed is inductive relationship with said magnetic circuit and oriented to generate a voltage pulse in response to a change in the flux density of the magnetic circuit produced by the movement of said armature relative to said pole piece,

means for tripping the cocked electric generator comprising means for displacing said permanent magnet and pole piece relative to one another a sufficient distance to effect a concomitant decrease in the field strength of the magnetic circuit, and

means for controllably storing mechanical energy and, in response to the actuation and operation of said tripping means, converting the stored mechanical energy into a force that acts on said armature and is so oriented and of such magnitude that the weakened magnetic attractive force on the armature is overcome and the position of said armature relative to the pole piece is thereby rapidly shifted and causes a voltage pulse to be generated by the wire winding.

2. The electric pulse generator of claim 1 wherein said mechanical-energy storage means comprises a spring that is retained in tensioned condition by the armature and pole piece when said generator is cocked and the armature is in magnetically-captured relationship with said pole piece.

3. The electric pulse generator of claim 1 wherein;

said armature is in physical contact with the pole piece when in magnetically-captured relationship therewith, and

said armature, permanent magnet and wire winding are held in operative relationship with one another by means that limits the movement of the armature away from said pole piece when the cocked generator is tripped.

4. The electric pulse generator of claim 1 wherein;

said pole piece, armature and permanent magnet are held in operative relationship by a metal casing that constitutes part of said magnetic circuit, and

said mechanical-energy storage means comprises a spring.

5. The electric pulse generator of claim 4 wherein;

said spring is disposed between said pole piece and armature,

said pole piece is immovably fastened to the metal casing, and

said permanent magnet is movably secured to said metal casing.

6. The electric pulse generator of claim 1 wherein;

said mechanical-energy storage means comprises a coil spring that is disposed between said pole piece and a part of said armature, and

said coil spring is retained in compressed tensioned condition by the armature and pole piece when the electric generator is cocked and said armature is in magnetically-captured relationship with said pole piece.

7. The electric pulse generator of claim 6 wherein;

said wire winding comprises a wire coil is of annular configuration, and

said pole piece is disposed in the opening of said wire coil.

8. The electric pulse generator of claim 2 wherein;

said pole piece, armature and permanent magnet are held in operative relationship by a casing, and

said armature is returned to magnetically-captured and cocked relationship with said pole piece against the action of said spring by a cam that is rotatably secured to said casing and, when rotated, engages and moves the armature toward the pole piece.

9. The electric pulse generator of claim 8 wherein a second permanent magnet is disposed adjacent said armature and immovably secured to said casing.

10. The electric pulse generator of claim 9 wherein;

said permanent magnets are aligned with one another on opposite sides of the armature, and

said casing is composed of metal and constitutes part of said magnetic circuit.

11. The electric pulse generator of claim 1 wherein;

said permanent magnet is movable and said pole piece is immovably secured to means that holds the generator components in operative relationship,

said armature and permanent magnet are adjacent one another and define an air gap in the magnetic circuit, when the generator is in cocked condition, and

the decrease in the field strength of the magnetic circuit effected by said tripping means is achieved by displacing the permanent magnet in a direction relative to said armature which increases said air gap.

12. The electric pulse generator of claim 11 wherein;

a second permanent magnet is disposed adjacent said armature in fixed spaced relationship therewith, and

said permanent magnets are in substantial alignment with each other and with said armature, when the generator is in cocked condition,

said armature being located between said permanent magnets and thereby providing a pair of air gaps.