Translation stop for use in power equipment

• US 20060032352A1
• Filed: 10/24/2005
• Published: 02/16/2006
• Est. Priority Date: 09/18/2000
• Status: Active Grant

• Current Assignee: Sawstop Holding LLC
• Original Assignee: SD3, LLC
• Inventors: Huebner, Randall J., Fanning, David A., Gass, Stephen F., Fulmer, J. David
• Granted Patent: US 8,065,943 B2
• Time in Patent Office: Days
• US Class Current: 83/58
• CPC Class Codes: B23D 47/10 actuated by fluid or gas pressure
• CPC Class Codes: B23D 59/001 Measuring or control devices, e.g. for automatic control of work feed pressure on band saw blade measuring in general G01; controlling in general G05
• CPC Class Codes: B27G 19/02 for circular 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: Y10T 83/04 Processes
• CPC Class Codes: Y10T 83/081 With randomly actuated stopping means
• CPC Class Codes: Y10T 83/088 Responsive to tool detector or work-feed-means detector
• CPC Class Codes: Y10T 83/773 Work-support includes passageway for tool [e.g., slotted table]

Abstract

Woodworking machines are disclosed having a blade adapted to cut workpieces, and an actuating mechanism operable to move the blade toward the workpiece. The machines also include a detection system configured to detect one or more dangerous conditions between a user and the blade, and a reaction system configured to stop the movement of the blade toward the user upon detection of a dangerous condition by the detection system.

Claims

1. A method of operating an up-cut chop saw, where the saw includes a work surface adapted to support a workpiece, a spinnable blade configured to cut a workpiece on the work surface by moving from below the work surface to at least partially above the work surface, a motor to spin the blade, an actuation device to trigger the blade to move upward, a detection system adapted to detect a dangerous condition between a person and the blade by imparting a signal to the blade and monitoring that signal for a predetermined change indicative of the dangerous condition, and a reaction system adapted to take some action to mitigate possible injury if the detection system detects the dangerous condition, where the saw includes a power switch to supply power to the detection system, the method comprising:

turning on the switch to supply power at least to the detection system, whereupon the detection system then imparts the signal to the blade and starts monitoring the signal for the predetermined change indicative of the dangerous condition;

supplying power to the motor to spin the blade;

placing a workpiece on the work surface;

operating the actuation device to trigger the blade to start moving upward from below the work surface toward a position at least partially above the work surface; and

if the predetermined change is detected, then triggering the reaction system to take some action to mitigate possible injury.

2. The method of claim 1, where the dangerous condition is contact between a person and the blade.

3. The method of claim 1, where the dangerous condition is proximity between a person and the blade.

4. The method of claim 1, where the predetermined change indicative of the dangerous condition is a predetermined rate of change.

5. The method of claim 1, where the action taken by the reaction system is to decelerate the blade.

6. The method of claim 5, where the reaction system decelerates the blade by moving a brake into contact with the blade.

7. The method of claim 1, where the action taken by the reaction system is to retract the blade.

8. The method of claim 7, where the reaction system retracts the blade below the work surface within 10 milliseconds after the detection system detects the dangerous condition.

9. The method of claim 1, where the action taken by the reaction system is to stop the upward movement of the blade.

10. The method of claim 1, where the limitation of supplying power to the motor occurs only if the detection system is imparting the signal to the blade.

11. The method of claim 1, where the limitation of supplying power to the motor occurs only if the detection system is monitoring the signal to the blade.

12. The method of claim 1, where the saw includes a second switch to supply power to the motor, and where the limitation of supplying power to the motor occurs by turning on the second switch.

13. The method of claim 1, where the actuation device moves the blade with a fluid-actuated cylinder.

14. The method of claim 1, where the reaction system retracts the blade with a fluid-actuated cylinder.

15. The method of claim 1, where the reaction system retracts the blade with a cam.

16. The method of claim 1, where the reaction system retracts the blade with an eccentric.

17. The method of claim 1, where the saw includes a guard and where the dangerous condition is contact between a person and the guard.

18. The method of claim 17, where the saw includes a control system that allows the reaction system to operate only if the blade is spinning.

19. The method of claim 1, where the dangerous condition is contact between a person and a portion of the work surface.

20. The method of claim 1, where the work surface includes an opening through which the blade is raised, and where the dangerous condition is contact between a person and a portion of the work surface adjacent the opening.