Safety control for power operated equipment

• US 4,965,909 A
• Filed: 05/19/1989
• Issued: 10/30/1990
• Est. Priority Date: 10/04/1988
• Status: Expired due to Fees

• Current Assignee: Bettcher Industries Incorporated
• Original Assignee: Giorgio Grasselli, Timothy J. Mccullough
• Inventors: Grasselli, Giorgio, McCullough, Timothy J.
• Primary Examiner(s): Little, Willis
• Application Number:
  US07/354,890
• Time in Patent Office: 529 Days
• Field of Search: 17/21, 17/50, 17/52, 192/130, 192/131 R, 2/2, 2/16, 2/20, 2/154
• US Class Current: 192/131.00R
• CPC Class Codes: F16P 3/12 with means, e.g. feelers, which in case of the presence of a body part of a person in or near the danger zone influence the control or operation of the machine F16P3/08 takes precedence

Abstract

A safety control system for power operated equipment ensures operator safety by immediately disconnecting or reversing the power drive from a power driven rotating member such as a circular blade of a meat trimming knife or a toothed feed shaft of a meat skinning machine, upon a metal conductive glove worn by the operator, contacting the blade or toothed shaft or other electrically isolated portion of the equipment. The operator'"'"'s glove is electrically connected to a safety switch which immediately disconnects or reverses the power drive from the rotating member upon the glove completing a circuit upon contact with the electrically isolated portion of the equipment. A moisture impervious dielectric plastic glove preferably is worn by the operator to prevent the moisture in the meat from conducting current between the metal glove and isolated machine portion until the plastic glove is cut and contact made with the metal glove. A switch requires manual actuation to connect the power drive to the rotatable member. The metal gloves are connected to the safety switch by electrodes secured to the operator'"'"'s wrists in close proximity to the metal gloves. In a second embodiment the gloves are connected to the safety switch by a pair of metal electrodes mounted on the operator'"'"'s garment adjacent the thigh areas which contact another pair of electrodes provided by a pair of pivotally mounted conductive arms which extend outwardly from the power operated equipment.

Claims

1. A safety control system for power operated equipment of the type having a rotating metal component including:

(a) a reversible electric motor operatively connected to the metal component for rotating said component;

(b) control means for operatively connecting the motor to the rotating metal component;

(c) electrical conductive gloves adapted to be worn by an operator of the power operated equipment;

(d) moisture impervious dielectric gloves adapted to be worn by the operator over the electrical conductive gloves; and

(e) said control means further including safety switch means electrically connected to the conductive gloves and rotating metal component for reversing the direction of rotation of the motor and the direction of rotation of the rotating metal component to prevent injury to the operator if at least one of the operator'"'"'s conductive gloves contacts the rotatable metal component.

2. The control system defined in claim 1 in which an electrode is attached to each of the operator'"'"'s wrists and is electrically connected by conductors to the safety switch means and is in close proximity to the conductive gloves for electrically connecting said gloves to the safety switch means.

3. The control system defined in claim 1 in which the control means includes a manually actuated operator control switch for operatively connecting the electric motor to the metal component for rotating said component.

4. The control system defined in claim 3 in which the control means includes means for preventing energizing of the electric motor by the manually actuated operator control switch unless the electrical conductive gloves are being worn by the operator.

5. The control system defined in claim 1 in which the metal component is a shaft having a plurality of teeth mounted thereon for removing skin from a piece of meat in a meat skinning machine.

6. The control system defined in claim 5 in which the shaft is rotated in the reverse direction for less than one complete revolution upon contact of at least one of the conductive gloves or other part of the operator'"'"'s body with the rotatable metal component.

7. The control system defined in claim 1 in which the control means includes a time delay circuit to prevent reconnection of the electric motor to the rotatable metal component for a predetermined time period after disconnection of the electric motor by the safety switch means.

8. The control system defined in claim 4 in which the meat skinning machine further includes a base and brackets for rotatably mounting the shaft on said base;

and in which the brackets are electrically insulated from the base by intervening pads of a dielectric material and are electrically connected to the rotating metal component whereby contact of said brackets by at least one of the conductive gloves prior to contact with said rotating metal component also will operatively disconnect the electric motor from said metal component.

9. The control system defined in claim 1 in which the conductive gloves include stainless steel wires externally exposed for direct contact with the rotatable metal component and internally exposed for direct contact with the operator'"'"'s hand to provide continuous electrical contact between said metal component and the safety switch means upon contact of at least one of the conductive gloves with said metal component.

10. The control system defined in claim 1 including dielectric platform means for supporting the operator and for electrically isolating said operator from the power operated equipment and from other electrically grounded elements.

11. The control system defined in claim 1 in which first electrode means externally exposed on a lower portion of a garment adapted to be worn by an operator of said equipment contacts second electrode means projecting outwardly from said equipment for electrically connecting the conductive gloves to the safety switch means.

12. A safety control system for power operated equipment of the type having a rotating metal component including:

(a) a reversible electric motor operatively connected to the metal component for rotating said component;

(b) control means for operatively connecting the motor to the rotating metal component;

(c) electrical conductive gloves adapted to be worn by an operator of the power operated equipment;

(d) said control means further including safety switch means electrically connected to the conductive gloves and rotating metal component for reversing the direction of rotation of the motor and the direction of rotation of the rotating metal component to prevent injury to the operator if at least one of the operator'"'"'s conductive gloves contacts the rotatable metal component; and

(e) first electrode means externally exposed on a lower portion of a garment adapted to be worn by an operator of said equipment for contacting second electrode means projecting outwardly from said equipment for electrically connecting the conductive gloves to the safety switch means.

13. The control system defined in claim 12 in which the first electrode means is a pair of metal mesh pads mounted on the garment and located adjacent the thighs of the operator when the garment is worn by the operator.

14. The control system defined in claim 12 in which each of the mesh pads are connected to a respective one of the conductive gloves by an electrical conductor extending along a respective arm of the garment and terminating in a connector at a cuff area of the garment.

15. The control system defined in claim 12 in which the second electrode means is a pair of electrical conductive arms pivotally mounted on the power operated equipment.

16. The control system defined in claim 12 in which the control means includes a time delay circuit to maintain the electric motor energized for a predetermined time period after the first and second electrodes are moved out of contact with each other.

17. A safety control system for power operated equipment of the type having a rotating metal component including:

(a) an electric motor operatively connected to the metal component for rotating said component;

(b) control means for operatively connecting the motor to the metal component for rotating said component;

(c) electrical conductive gloves adapted to be worn by an operator of said equipment;

(d) said control means including safety switch means electrically connected to the conductive gloves; and

(e) first electrode means externally exposed on a garment adapted to be worn by an operator of said equipment for contact with second electrode means projecting outwardly from said equipment for electrically connecting the conductive gloves to the safety switch means.

18. The control system defined in claim 17 in which the first electrode means is a pair of metal mesh pads mounted on the garment adapted to be located adjacent the thighs of the operator when the garment is worn by the operator.

19. The control system defined in claim 18 in which each of the mesh pads are connected to a respective one of the conductive gloves by an electrical conductor extending along a respective arm of the garment and terminating in a connector at a cuff area of the garment.

20. The control system defined in claim 19 in which each of the conductive gloves is provided with a connector adapted to be releasably engaged with the connector in the garment for electrically connecting the mesh pads to the conductive gloves.

21. The control system defined in claim 19 in which the mesh pads and electrical conductors are removably attached to the garment.

22. The control system defined in claim 21 in which the mesh pads and electrical conductors are removably attached to the garment by hook and pile fabrics.

23. The control system defined in claim 19 in which the mesh pads are located internally of the garment and are externally exposed by a plurality of conductive buttons connected to the pads and projecting through the garment.

24. The control system defined in claim 17 in which the second electrode means is a pair of electrical conductive arms pivotally mounted on the power operated equipment.

25. The control system defined in claim 24 in which a curved metal contact plate is mounted on an extended end of each of the conductive arms for engagement with the mesh pads on the operator'"'"'s garment.

26. The control system defined in claim 25 in which pivotally mounted ends of the conductive arms are connected by a link so that said arms move in unison.

27. The control system defined in claim 24 in which the conductive arms are pivotally mounted on dielectric pivot posts electrically isolating said arms from the power operated equipment.

28. The control system defined in claim 17 in which the control means includes a time delay circuit to maintain the electric motor energized for a predetermined time period after the first and second electrode means are moved out of contact with each other.

29. The control system defined in claim 17 in which the control means includes means for preventing the electric motor from being energized unless the first and second electrodes are in contact with each other and the conductive gloves are being worn by the operator.

30. The control system defined in claim 17 including dielectric platform means for supporting the operator and for electrically isolating said operator from the power operated equipment and from other electrically grounded elements.

31. A safety control system for an electrically driven knife of the type having a handpiece with an annular rotatable cutting blade driven by a flexible drive cable which is driven by an electric motor located remote from the handpiece, said control system including:

(a) control means having a clutch for connecting the flexible drive cable to an output shaft of the electric motor;

(b) electrical conductive gloves adapted to be worn by an operator of the handpiece;

(c) safety switch means electrically connected to the conductive gloves and cutting blade for disengaging the clutch to stop rotation of the cutting blade by the drive cable if at least one of the operator'"'"'s conductive gloves contacts the cutting blade of the handpiece; and

(d) moisture impervious dielectric gloves adapted to be worn by the operator over the electrical conductive gloves.

32. A safety control system for power operated equipment of the type having a rotating metal component including:

(a) an electric motor operatively connected to the metal component for rotating said component;

(b) control means for operatively connecting the motor to the metal component for rotating said component;

(c) electrical conductive gloves adapted to be worn by an operator of said equipment;

(d) said control means including safety switch means electrically connected to the conductive gloves; and

(e) electrical conductor means on a garment adapted to be worn by an operator for releaseably electrically connecting the conductive gloves with the safety switch means.

33. A safety control system for power operated equipment of the type having a rotating metal component including:

(a) a reversible electric motor operatively connected to the metal component for rotating said component;

(b) control means for operatively connecting the motor to the rotating metal component;

(c) electrical conductive gloves adapted to be worn by an operator of the power operated equipment;

(d) said control means further including safety switch means electrically connected to the conductive gloves and rotating metal component for reversing the direction of rotation of the motor and the direction of rotation of the rotating metal component to prevent injury to the operator if at least one of the operator'"'"'s conductive gloves contacts the rotatable metal component; and

(e) dielectric platform means for supporting the operator and for electrically isolating said operator from the power operated equipment and from other electrically grounded elements.