Claims
- 1. In an arrangement for moving a barrier with respect to an opening in a wall, a safety arrangement comprising:motor driven apparatus for extending and retracting a cable attached to the barrier; first cable guide for retaining the cable at substantially first predetermined distance from the wall; second cable guide spaced apart from the first cable guide for retaining the cable at second predetermined distance from the wall; cable tension sensing apparatus contacting the cable between the first and the second cable guide apparatus for generating a signal when slack is detected in the cable; and a controller responding to the signal from the cable tension sensing apparatus for controlling movement of the barrier.
- 2. A safety arrangement in accordance with claim 1, wherein the motor driven apparatus comprises a cable take up/pay out drum, and the first cable guide comprises a perimeter of the drum.
- 3. A safety arrangement in accordance with claim 2, wherein the barrier is raised and lowered by the motor driven apparatus, and the second cable guide is disposed on the wall beneath the cable drum.
- 4. A safety arrangement in accordance with claim 3, wherein the first and the second predetermined distances are substantially the same.
- 5. A safety arrangement in accordance with claim 4, wherein the cable tension sensing apparatus comprises a spring biased contact arm contacting the cable from between the cable and the well.
- 6. A safety arrangement in accordance with claim 5, wherein the cable tension sensing apparatus comprises a signal generator for generating a signal when the contact arm is urged a predetermined distance from the wall by the bias spring.
- 7. A safety arrangement in accordance with claim 6, wherein the signal generator comprises electrical switch contacts.
- 8. A safety arrangement in accordance with claim 5, wherein the motor driven apparatus comprises a torsion shaft driven by a motor to rotate the cable drum.
- 9. A safety arrangement in accordance with claim 8, wherein the torsion shaft has a longitudinal axis, and the contact arm pivots about the longitudinal axis of the torsion shaft.
- 10. A safety arrangement in accordance with claim 3 comprising obstruction sensing apparatus.
- 11. A safety arrangement in accordance with claim 10, comprising circuitry responsive to sensing of an obstruction for controlling the motor to raise the barrier upon sensing an obstruction.
- 12. A safety arrangement in accordance with claim 11, wherein the cable tension sensing apparatus is connected to the obstruction sensing apparatus.
- 13. A safety arrangement in accordance with claim 11, wherein a signal generated by the cable tension sensing apparatus emulates obstruction signals generated by the obstruction sensing apparatus.
- 14. A safety arrangement in accordance with claim 3 comprising a sliding apparatus moved by the cable tension sensing apparatus for blocking a barrier being raised without use of the motor.
- 15. A safety arrangement in accordance with claim 3 comprising a barrier blocking apparatus for blocking a barrier being raised without use of the motor and a user operated override to disable blockage of barrier movement by the blocking apparatus.
- 16. A safety apparatus in accordance with claim 15 comprising a spring responsive to lack of cable tension by moving the barrier blocking apparatus into blocking engagement with the barrier.
- 17. A safety apparatus in accordance with claim 16 comprising user operated apparatus operating against the spring to move the barrier blocking apparatus out of blocking engagement with the barrier.
- 18. In an arrangement for moving a barrier with respect to an opening in a wall, a safety arrangement comprising:motor driven apparatus for extending and retracting a cable attached to the barrier; a cable guide for retaining the cable at a predetermined distance from the wall; attachment apparatus for connecting the cable to the barrier to be moved; cable tension sensing apparatus contacting the cable between the cable guide apparatus and the attachment apparatus for generating a signal when slack is detected in the cable; and a controller responding to the signal from the cable tension sensing apparatus for controlling movement of the barrier.
- 19. A safety arrangement in accordance with claim 18, wherein the motor driven apparatus comprises a cable take up/pay out drum, and the cable guide comprises a perimeter of the drum.
- 20. A safety arrangement in accordance with claim 19, wherein the barrier is raised and lowered by the motor driven apparatus, which is energized by the controller.
- 21. A safety arrangement in accordance with claim 20, wherein the cable under tension is substantially parallel to and spaced at the predetermined distance from the wall.
- 22. A safety arrangement in accordance with claim 21, wherein the cable tension sensing apparatus comprises a spring biased contact arm contacting the cable from between the cable and the wall.
- 23. A safety arrangement in accordance with claim 22, wherein the cable tension sensing apparatus comprises a signal generator for generating a signal when the contact arm is urged away from the wall by the bias spring responsive to lack of cable tension.
- 24. A safety arrangement in accordance with claim 23, wherein the signal generator comprises electrical switch contacts.
- 25. A safety arrangement in accordance with claim 24, wherein electrical switch contact opens when the contact arm moves away from the wall.
- 26. A safety arrangement in accordance with claim 25, wherein the controller is responsive to switch contact opening by controlling the motor to reverse movement and raise the barrier.
- 27. A safety arrangement in accordance with claim 25, wherein the controller is responsive to switch contact opening by blocking the barrier to prevent raising from its lowered/closed position.
Parent Case Info
This application claims the benefit of Provisional Application No. 60/286,472 filed Apr. 25, 2001.
US Referenced Citations (12)
Foreign Referenced Citations (1)
Number |
Date |
Country |
2 634 815 |
Jul 1988 |
FR |
Provisional Applications (1)
|
Number |
Date |
Country |
|
60/286472 |
Apr 2001 |
US |