Logic control with test mode for fast-acting safety system

• US 20030058121A1
• Filed: 09/13/2002
• Published: 03/27/2003
• Est. Priority Date: 09/24/2001
• Status: Active Grant

• Current Assignee: Sawstop Holding LLC
• Original Assignee: SD3, LLC
• Inventors: Fanning, David A., Gass, Stephen F.
• Granted Patent: US 7,197,969 B2
• Time in Patent Office: Days
• US Class Current: 340/686.5
• CPC Class Codes: B27G 19/00 Safety guards or devices specially adapted for wood saws; Auxiliary devices facilitating proper operation of wood saws
• 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: Y10S 83/01 Safety devices
• CPC Class Codes: Y10T 83/091 Responsive to work sensing means
• CPC Class Codes: Y10T 83/175 With condition sensor

Abstract

Woodworking machines including cutting tools and motors adapted to drive the cutting tools are disclosed. The machines also include a detection system adapted to detect a dangerous condition between the cutting tool and a person, and a reaction system adapted to perform a specified action upon detection of the dangerous condition. The machines further include a control system adapted to test the operability of at least a portion of the detection system and/or the reaction system. The control system is adapted to disable the motor if the tested portion is inoperable. The control system also includes a test mode to test whether the detection system is working, to test whether various materials would be detected by the detection system, and/or to test whether various materials would trigger the reaction system.

Claims

1. A machine having an operative structure configured to perform a task, where the operative structure includes a cutting tool adapted to move in at least one motion, and where the machine comprises:

a detection system adapted to detect the occurrence of an unsafe condition between a person and the cutting tool;

a reaction system adapted to mitigate the unsafe condition; and

a control system adapted to monitor the detection system and control actuation of the reaction system, where the control system includes a test mode feature configured to allow a user to test whether the detection system is operating.

2. The machine of claim 1, where the test mode feature is further configured to allow a user to test whether a particular material would be perceived by the detection system as a person in a dangerous condition.

3. The machine of claim 2, where the particular material is green wood.

4. The machine of claim 2, where the particular material is water soaked wood.

5. The machine of claim 1, where test mode feature is configured to allow a user to test whether the detection system is operating by the user touching the cutting tool.

6. The machine of claim 1, where the reaction system is disengaged while the test mode feature is enabled.

7. The machine of claim 1, where the control system includes a logic controller configured to perform the test mode.

8. The machine of claim 1, where the control system is configured so that the test mode feature is enabled by a user performing a specified action.

9. The machine of claim 1 further comprising a warning signal to inform the user when the test mode feature is enabled.

10. A machine having an operative structure configured to perform a task, where the operative structure includes a cutting tool adapted to move in at least one motion, and where the machine comprises:

a detection system adapted to detect the occurrence of an unsafe condition between a person and the cutting tool;

a reaction system adapted to mitigate the unsafe condition; and

a control system adapted to monitor the detection system and control actuation of the reaction system, where the control system includes a test mode feature configured to allow a user to test whether a particular material would be perceived by the detection system as a person in a dangerous condition.

11. The machine of claim 10, where the particular material is green wood.

12. The machine of claim 10, where the particular material is water soaked wood.

13. The machine of claim 10, where test mode feature is configured to allow a user to test whether a particular material would be perceived by the detection system as a person in a dangerous condition by having the user touch the cutting tool with the particular material.

14. The machine of claim 13, where the test mode feature is configured so that the user may touch the cutting tool with the particular material while the cutting tool is not moving.

15. The machine of claim 13, where the test mode feature is configured so that the user may touch the cutting tool with the particular material while the cutting tool is moving.

16. The machine of claim 10, where the reaction system is disengaged while the test mode feature is enabled.

17. The machine of claim 10, where the control system includes a logic controller configured to perform the test mode.

18. The machine of claim 10, where the control system is configured so that the test mode feature is enabled by a user performing a specified action.

19. The machine of claim 10 further comprising a warning signal to inform the user when the test mode feature is enabled.

20. A machine having an operative structure configured to perform a task, where the operative structure includes a cutting tool adapted to move in at least one motion, and where the machine comprises:

a detection system adapted to detect the occurrence of an unsafe condition between a person and the cutting tool;

a reaction system adapted to mitigate the unsafe condition; and

control system adapted to monitor the detection system and control actuation of the reaction system, where the control system includes test mode means for allowing a user to test the detection system.