Portable piezoelectric electric generating device

• US 4,091,302 A
• Filed: 04/15/1977
• Issued: 05/23/1978
• Est. Priority Date: 04/16/1976
• Status: Expired due to Term

• Current Assignee: Shiro Yamashita
• Original Assignee: Shiro Yamashita
• Inventors: Yamashita, Shiro
• Primary Examiner(s): Budd, Mark O.
• Application Number:
  US05/788,015
• Time in Patent Office: 403 Days
• Field of Search: 310/328, 310/329, 310/339, 58/23 BA, 58/41 B, 58/82 A, 58/46, 58/116 R, 58/28 R, 58/28 D, 58/23 R
• US Class Current: 310/339
• CPC Class Codes: H02N 2/18 producing electrical output from mechanical input, e.g. generators for measurement devices G01

Abstract

A portable electric generating device particularly for an electronic timepiece comprises an oscillatable weight rotatably supported for rotation in either direction by changes in position of the device, rotation converting means for converting oscillation of the oscillatable weight into rotation in one direction and a rotatably energy storing wheel comprising a hub portion driven by the rotation converting means, a coaxial rim portion having on its periphery a plurality of circumferentially spaced teeth and springs connecting the hub portion with the rim portion. A pallet engageable with the teeth restrains rotation of the rim portion of the energy storing wheel until predetermined energy has been stored in the springs whereupon the rim portion of the energy storing wheel is rotated by the springs until again stopped by the pallet. Operation of the pallet is controlled by a cam wheel driven by the rotation converting means. Piezoelectric elements are mounted on the pawls of the pallet in a position to be struck by the teeth of the energy storing wheel whereby electric energy is generated. The piezoelectric elements are connected through a rectifier to a secondary cell and to output terminals of the generating device. Alternatively, a piezoelectric element is mounted in position to be struck by a projecting portion provided on the pallet.

Claims

1. A portable electric generating device comprising an oscillatable weight rotatably supported for rotation in either direction by changes in position of said device, rotation converting means for converting oscillation of said oscillatable weight into rotation in one direction, a rotatably supported energy storing wheel comprising an input portion driven by said rotation converting means, an output portion and elastic means connecting said input and output portions, control means for restraining rotation of said output portion of said energy storing wheel until predetermined energy has been stored in said elastic means and then releasing said output portion, a piezoelectric element, and means energized by rotation of said output portion of said energy storing wheel to strike said piezoelectric element and thereby generate electrical energy.

2. A portable electric generating device according to claim 1, in which said means for sriking said piezoelectric element comprises at least one tooth on said output portion of said energy storing wheel.

3. A portable electric generating device according to claim 2, in which said control means comprises a pallet having pawls engageable with said tooth of said output portion of said energy storing wheel.

4. A portable electric generating device according to claim 3, in which said piezoelectric element is disposed on at least one of said pawls in position to be struck by said tooth.

5. A portable electric generating device according to claim 3, in which said piezoelectric element is mounted in position to be struck by said pawl.

6. A portable electric generating device according to claim 3, in which said control means further comprises a cam wheel driven by said rotation converting means and having cam means for actuating said pallet.

7. A portable electric generating device according to claim 1, in which said energy storing wheel comprises a barrel drum having a hub portion driven by said rotation converting means, a rim portion coaxial with said hub portion and spring means connecting said hub portion with said rim portion.

8. A power supply for an electronic watch having a case, comprising a portable generating device mounted in said watch case and comprising an eccentric weight rotatably supported for oscillation by changes in position of said watch, rotation converting means for converting oscillation of said weight into rotary movement in one direction, a rotatably supported energy storing wheel comprising an input portion driven by said rotation converting means, an output portion and elastic means connecting said input and output portions, control means for restraining rotation of said output portion of said energy storing wheel until predetermined energy has been stored in said elastic means and then releasing said output portion, a piezoelectric element, means energized by rotation of said output portion of said energy storing wheel upon release by said control means to strike said piezoelectric element and thereby generate electric current, means connected with said piezoelectric element for rectifying said current, a secondary electric cell and means for connecting said rectifying means with said cell to charge said cell.

9. A power supply according to claim 8, in which said energy storing wheel comprises a barrel drum comprising a hub portion driven by said rotation converting means, a rim portion coaxial with said hub portion and having circumferentially spaced teeth thereon, and spring means connecting said hub portion with said rim portion.

10. A power supply according to claim 9, in which said control means comprises a pallet having pawls engageable with said teeth of said energy storing wheel.

11. A power supply according to claim 10, in which said piezoelectric element is mounted on a pawl of said pallet in position to be struck by said teeth of said energy storing wheel.

12. A power supply according to claim 10, in which said piezoelectric element is mounted in position to be struck by said pallet.

13. A power supply according to claim 10, in which said control means further comprises a cam wheel driven by said rotation converting means and having cam means for actuating said pallet.