Machine guarding system having a sensing mat with status indicator lights

• US 7,119,704 B2
• Filed: 10/19/2004
• Issued: 10/10/2006
• Est. Priority Date: 10/19/2004
• Status: Active Grant

• Current Assignee: Tapeswitch Corporation (Inductotherm Group)
• Original Assignee: Tapeswitch Corporation (Inductotherm Group)
• Inventors: Grzan, John, Keats, Robert
• Primary Examiner(s): Lieu, Julie Bichngoc
• Application Number:
  US10/968,508
• Publication Number:
  US 20060082465A1
• Time in Patent Office: 721 Days
• Field of Search: 340/635, 340/665, 340/666, 340/668, 200/86.5, 200/86.R
• US Class Current: 340/665
• 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
• CPC Class Codes: F16P 3/144 using light grids
• CPC Class Codes: H01H 3/141 Cushion or mat switches
• CPC Class Codes: H01H 9/182 Illumination of the symbols or distinguishing marks H01H9/181 takes precedence

Abstract

A machine guarding system generally includes a switch mat in electrical communication with a machine being guarded. The switch mat is adapted to be placed on a floor adjacent the machine being guarded and includes a pressure actuated switch mechanism which causes power to the machine to be terminated when a pressure is applied to the switch mat. The switch mat further includes a status indicator display disposed on a surface of the switch mat which is illuminated based on a status of the machine being guarded. In a preferred embodiment, the machine guarding system further includes a machine control unit for controlling power to the machine being guarded. The switch mat is in electrical communication with the machine control unit, wherein the switch mechanism causes the machine control unit to terminate power to the machine when a pressure is applied to the switch mat. The machine control unit also illuminates the indicator display based on a status of the machine being guarded.

Claims

1. A machine guarding system comprising a switch mat in electrical communication with a machine being guarded, said switch mat being adapted to be placed on a floor adjacent the machine being guarded and including:

a pressure actuated switch mechanism, said switch mechanism causing power to the machine being guarded to be terminated when a pressure is applied to said switch mat; and

a status indicator display disposed on a surface of said switch mat, said indicator display being illuminated based on a status of the machine being guarded.

2. A machine guarding system as defined in claim 1, further comprising a machine control unit for controlling power to a machine being guarded, said switch mat being in electrical communication with said machine control unit, wherein said switch mechanism causes said machine control unit to terminate power to the machine when a pressure is applied to said switch mat and said machine control unit illuminating said indicator display based on a status of the machine being guarded.

3. A machine guarding system as defined in claim 2, wherein said status indicator display comprises a plurality of light emitting diodes (LEDs).

4. A machine guarding system as defined in claim 3, wherein said light emitting diodes (LEDs) comprise a first color illuminated by said machine control unit to indicate a safe condition of the machine being guarded and a second color illuminated by said machine control unit to indicate a dangerous condition of the machine being guarded.

5. A machine guarding system as defined in claim 4, wherein said switch mechanism causes said machine control unit to illuminate said first color light emitting diode (LED) when said pressure is applied to said switch mat and when power is terminated to the machine being guarded to indicate said safe condition.

6. A machine guarding system as defined in claim 4, wherein said machine control unit includes a flasher for alternately illuminating said first color light emitting diode (LED) and said second color light emitting diode (LED) to indicate an interim condition of the machine being guarded.

7. A machine guarding system as defined in claim 6, wherein said machine control unit includes a timer and a switch for activating said timer, said timer initiating a timing sequence when activated by said switch, wherein said flasher alternately illuminates said first and second color light emitting diodes (LEDs) to indicate said interim condition and said timer ending said timing sequence after a pre-determined amount of time, wherein said machine control unit provides power to the machine being guarded and illuminates said second color light emitting diode (LED) to indicate said dangerous condition of the machine being guarded.

8. A machine guarding system as defined in claim 1, further comprising a guard cage substantially surrounding the machine being guarded, said guard cage defining a machine work area and an entrance to said machine work area and said switch mat being placed at said entrance to said machine work area for detecting intrusion into said machine work area.

9. A machine guarding system as defined in claim 1, comprising a plurality of switch mats surrounding the machine being guarded and electrically connected to each other, said plurality of switch mats defining a machine work area.

10. A method for guarding a machine work area against intrusion comprising the steps of:

providing a switch mat on a floor adjacent the machine work area being guarded, said switch mat including a pressure actuated switch mechanism and a status indicator display;

terminating power to a machine in the machine work area when a pressure is applied to said switch mechanism of said switch mat; and

illuminating said indicator display of said switch mat based on a status of the machine work area.

11. A method for guarding a machine work area as defined in claim 10, wherein said step of illuminating indicator display of said switch mat comprises the step of illuminating a plurality of light emitting diodes (LEDs).

12. A method for guarding a machine work area as defined in claim 11, wherein said step of illuminating said indicator display of said switch mat comprises the steps of illuminating a first color light emitting diode (LED) to indicate a safe condition of the machine work area and illuminating a second color light emitting diode (LED) to indicate a dangerous condition of the machine work area.

13. A method for guarding a machine work area as defined in claim 12, wherein said first color light emitting diode (LED) is illuminated when a pressure is applied to said switch mechanism and power is terminated to the machine in the work area to indicate said safe condition.

14. A method for guarding a machine work area as defined in claim 12, further including the step of alternately illuminating said first and second color light emitting diodes (LEDs) to indicate an interim condition of the machine work area.

15. A method for guarding a machine work area as defined in claim 14, further including the steps of:

initiating a timing sequence to begin said step of alternately illuminating said first and second color light emitting diodes (LEDs) to indicate said interim condition;

ending said timing sequence after a pre-determined amount of time;

illuminating said second color light emitting diode (LED) to indicate said dangerous condition of the machine work area after said timing sequence has ended; and

providing power to the machine in the machine work area after said timing sequence has ended.

16. A switch mat comprising:

a support frame;

a flexible plate member supported in said support frame;

a pressure actuated switch mechanism disposed between said support frame and said plate member, wherein pressure applied to said plate member actuates said switch mechanism; and

a status indicator display disposed on a surface of one of said support frame or said plate member, said status indicator display being illuminated upon actuation of said switch mechanism, wherein said status indicator display comprises a plurality of light emitting diodes (LEDs) including a first color illuminated to indicate a safe condition and a second color illuminated to indicate a dangerous condition.

17. A switch mat as defined in claim 16, wherein said first color light emitting diode (LED) is illuminated upon actuation of said switch mechanism.

18. A switch mat as defined in claim 16, wherein said support frame includes a ramp portion, said status indicator display being disposed on a top surface of said ramp portion.

19. A switch mat as defined in claim 16, further comprising a flasher for alternately illuminating said first and second color light emitting diodes (LEDs) to indicate an interim condition.