Movement detecting device

• US 5,065,012 A
• Filed: 01/17/1990
• Issued: 11/12/1991
• Est. Priority Date: 01/17/1989
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Moriyama, Norio, Kawakami, Kazuhiko
• Primary Examiner(s): Nelms, David C.
• Application Number:
  US07/466,206
• Time in Patent Office: 664 Days
• Field of Search: 250/231.13, 250/231.14, 250/231.15, 250/231.16, 250/231.17, 250/231.18, 250/237 G, 356/395, 33/707
• US Class Current: 250/231.14
• CPC Class Codes: G01D 5/34715 Scale reading or illumination devices

Abstract

A movement detecting device having a light transmitter 44 and a spaced light receiver 46, with a moving plate 32 containing slit apertures therein being positioned between the transmitter and receiver for interrupting the light path between the transmitter and the receiver in dependence upon the motion of the moving plate. So as to improve the clarity of light detection, stationary apertured plates 56U, 56D are unitarily formed and are positioned on respective sides of the moving plate and adjacent a respective one of the transmitter or receiver. The stationary apertured plates 56U, 56D may be formed from a single sheet of material (FIG. 18), or from two separate sheets connectingly joined by a flanged pin (FIG. 12), or a combination thereof. The unitarily formed stationary apertured plates 56U, 56D may be directly molded into a support housing (38, 60, 62 in FIG. 8) with locating holes 64, 66 for the light transmitter 44 and light receiver 46, or may be formed in a molded sub assembly (FIG. 5) prior to moulding into a support housing (FIGS. 4 and 7).

Claims

1. In a movement detecting device comprising a light transmitter and a light receiver spaced therefrom, a first stationary apertured plate having an aperture therein is associated with the light transmitter and a second stationary apertured plate having an aperture therein is associated with the light receiver, said first and second stationary apertured plates being amounted in a body and an apertured movable plate interposed between the first and second stationary apertured plates, the improvement wherein the first and second stationary apertured plates are unitarily connected together so that the apertures in each said first and second apertured plate are aligned with one another prior to mounting in said body whereby light from the transmitter may be accurately received by the light receiver.

2. A device according to claim 1 wherein the first and second stationary apertured plates are integrally formed from a single sheet of material.

3. A device according to claim 1 wherein said first and second stationary apertured plates are formed into a U-shape.

4. A device according to claim 3 wherein at least one pin having a flange defining the spacing between the first and second apertured plates is provided.

5. A device according to claim 1 where the first and second apertured plates are two discrete stationary apertured plates which are unitarily secured together by at least one pin having a flange defining the spacing between said apertured plates.

6. A device according to claim 5 wherein a portion of said at least one pin is swaged over part of an outer surface of each apertured plate to thereby secure said aperture plates together.

7. A device according to claim 5 wherein securing means are provided for securing said apertured plates to said pin, said securing means including one of a weld, epoxy adhesive, and at least one pressure ring located about the pin for forcing said apertured plates on to said flange.

8. A device according to claim 4 wherein each said apertured plate is substantially rectangular in shape and two pins are located at adjacent corners of each said apertured plate.

9. A device according to claim 1 wherein the first and second apertured plates each have outwardly turned flanges extending away from the opposing apertured plate.

10. A device according to claim 9 wherein the flanges have cut outs therein for assisting in bonding the apertured plate associated therewith to the body, which said body is molded over said flanges.

11. A device according to claim 1 wherein the first and second apertured plates have a plurality of holes in the major surfaces thereof for relaxing strain when said first and second apertured plates are molded into said body.

12. A device according to claim 1 wherein a sub assembly is formed by said unitarily assembled first and second apertured plates and a molded body over the outer surface of said first and second apertured plates.

13. A device acording to claim 12 wherein said body has location apertures for locating the light transmitter and the light receiver respectively.

14. A device according to claim 12 wherein the sub assembly is molded in a support housing.

15. A device according to claim 1 wherein more than one light transmitter and associated light receiver is provided, each light transmitter and light receiver having associated sets of apertures in the first and second stationary apertured plates and said movable plate.

16. A device according to claim 1 wherein the movable plate is pivoted to be at least partially rotatable about an axis.

17. A device according to claim 16 wherein the spacing between the first and second apertured plates is only sufficient to permit movement of said movable plate.

18. A movement detecting device comprising a light transmitter and a light receiver spaced therefrom, a first stationary apertured plate having an aperture therein associated with the light transmitter and a second stationary apertured plate having an aperture therein associated with the light receiver, said first and second stationary apertured plates being unitarily connected together so that the apertures in each said first and second apertured plate are aligned with one another, said first and second apertured plates forming a subassembly, a body molded over the outer surface of said first and second apertured plates, and an apertured movable plate interposed between the first and second stationary apertured plates whereby light from the light transmitter may be accurately received by the light receiver.

19. An internal combustion engine ignition distributor having a movement detecting device comprising a light transmitter and a light receiver spaced therefrom, a first stationary apertured plate having an aperture therein associated with the light transmitter and a second stationary apertured plate having an aperture therein associated with the light receiver, said first and second stationary apertured plates being mounted in a body and an apertured movable plate interposed between the first and second stationary apertured plates, said first and second stationary apertured plates being unitarily connected together so that the apertures in each said first and second apertured plate are aligned with one another prior to mounting in said body whereby light from the transmitter may be accurately received by the light receiver.

20. A fluid regulating flow detector having a movement detecting device comprising a light transmitter and a light receiver spaced therefrom, a first stationary apertured plate having an aperture therein associated with the light transmitter and a second stationary apertured plate having an aperture therein associated with the light receiver, said first and second stationary apertured plates being mounted in a body and an apertured movable plate interposed between the first and second stationary apertured plates, said first and second stationary apertured plates being unitarily connected together so that the apertures in each said first and second apertured plate are aligned with one another prior to mounting in said body whereby light from the transmitter may be accurately received by the light receiver.