Motion sensor

• US 6,198,396 B1
• Filed: 11/30/1998
• Issued: 03/06/2001
• Est. Priority Date: 09/11/1998
• Status: Expired due to Fees

• Current Assignee: Mine Safety Appliances Company (MSA Safety, Inc.)
• Original Assignee: Mine Safety Appliances Company (MSA Safety, Inc.)
• Inventors: Frank, Peter A.
• Primary Examiner(s): Wu, Daniel J.
• Assistant Examiner(s): PHAM, TOAN NGOC
• Application Number:
  US09/201,229
• Time in Patent Office: 827 Days
• Field of Search: 340/573.1, 340/309.15, 340/540, 340/686.1, 340/686.4, 340/687, 340/689, 340/529, 200/61.52, 200/51.09, 200/61.71, 200/239, 200/240, 200/275, 200/277, 200/279, 200/DIG.29, 200/61.45 R
• US Class Current: 340/573.1
• CPC Class Codes: G01P 13/00 Indicating or recording presence, absence, or direction, of movement electric switches H01H; counting moving objects G06M7/00
• CPC Class Codes: G08B 21/0415 detecting absence of activity per se
• CPC Class Codes: G08B 21/0446 worn on the body to detect changes of posture, e.g. a fall, inclination, acceleration, gait

Abstract

A motion sensor having an electrically-conductive ball and at least a second ball to damp the motion of the electrically-conductive ball. Both balls are confined within a housing. A plurality of electrical contact elements are disposed within the housing. During movement, the electrically-conductive ball successively forms electrical connection with the electrical contact elements within the housing. The motion sensor also includes detection circuitry in electrical connection with the electrical contact elements to detect if the electrically-conducting ball is moving.

Claims

1. A movement sensor for detecting motion in any direction comprising:

a first ball which is electrically conductive;

a second ball to damp the motion of the electrically-conductive ball without substantially affecting the sensitivity of the movement sensor to motion in any direction;

a housing to confine the movement of the first ball and the second ball;

a plurality of electrical contact elements within the housing, the electrically-conductive ball being capable, during movement within the housing, of successively, forming electrical connection with the electrical contact elements within the housing regardless of the orientation of the housing;

detection circuitry in electrical connection with the electrical contact elements to detect if the electrically-conducting ball is moving.

2. The motion sensor of claim 1 wherein the second ball is formed from an electrically-nonconductive material.

3. The motion sensor of claim 2 wherein the housing comprises a substantially cylindrical structure, the structure comprising a side wall and a first end wall.

4. The motion sensor of claim 3 wherein the electrical contact elements comprise a first set of electrical contact elements and a second set of electrical contact elements disposed on the side wall, the electrical contact elements being spaced around an inner circumference of the structure with the electrical contact elements of the first set interspaced with the electrical contact elements of the second set.

5. The motion sensor of claim 4, further comprising a first terminal carried by the end wall, the electrically-conductive ball being capable, during movement within the structure, of successively, electrically connecting the electrical contact elements of the first set and the second set with the first terminal.

6. The motion sensor of claim 5, further comprising an alarm signal generating circuit coupled to the electrical contact elements and to the terminal to produce an alarm signal in response to lack of motion of the electrically-conductive ball.

7. The motion sensor of claim 6 wherein the variation in the settling time for the balls is less than approximately five seconds.

8. The motion sensor of claim 1 wherein the electrically-conductive ball is made from a noncorrosive material.

9. The motion sensor of claim 1 wherein the second ball has an outer layer formed from an electrically-nonconductive material.

10. The motion sensor of claim 1 wherein the variation in the settling time for the balls is less than approximately five seconds.

11. A movement sensor for detecting motion in any direction comprising:

a first ball which is electrically-conductive;

a plurality of additional balls to damp the motion of the electrically-conductive ball without substantially affecting the sensitivity of the movement sensor to motion in any direction;

a plurality of electrical contact elements within a housing, the electrically-conductive ball being capable, during movement within the housing, of successively forming electrical connection with the electrical contact elements within the housing regardless of the orientation of the housing;

detection circuitry in electrical connection with the electrical contact elements to detect if the electrically-conducting ball is moving.

12. The motion sensor of claim 11 wherein the plurality of additional balls are formed from an electrically-nonconductive material.

13. The motion sensor of claim 12 wherein the housing comprises a substantially cylindrical structure, the structure comprising a side wall and a first end wall.

14. The motion sensor of claim 13 wherein the electrical contact elements comprise a first set of electrical contact elements and a second set of electrical contact elements disposed on the side wall, the electrical contact elements being spaced around an inner circumference of the structure with the electrical contact elements of the first set interspaced with the electrical contact elements of the second set.

15. The motion sensor of claim 14, further comprising a first terminal carried by the end wall, the electrically-conductive ball being capable, during movement within the structure, of successively, electrically connecting the electrical contact elements of the first set and the second set with the first terminal.

16. The motion sensor of claim 15, further comprising an alarm signal generating circuit coupled to the electrical contact elements and to the terminal to produce an alarm signal in response to lack of motion of the electrically-conductive ball.

17. The motion sensor of claim 16 wherein the variation in the settling time for the balls is less than approximately five seconds.

18. The motion sensor of claim 11 wherein the electrically-conductive ball is made from a noncorrosive material.

19. The motion sensor of claim 11 wherein the plurality of additional balls have an outer layer formed from an electrically-nonconductive material.

20. The motion sensor of claim 11 wherein the variation in the settling time for the balls is less than approximately five seconds.