Retraction system for use in power equipment

• US 20020017181A1
• Filed: 08/13/2001
• Published: 02/14/2002
• Est. Priority Date: 08/14/2000
• Status: Active Grant

• Current Assignee: Sawstop Holding LLC
• Original Assignee: SD3, LLC
• Inventors: Jensen, Joel F., Fanning, David A., Gass, Stephen F., Johnston, Andrew L., Kim, Sung H., DʼAscenzo, David S.
• Granted Patent: US 7,509,899 B2
• Time in Patent Office: Days
• US Class Current: 83/58
• CPC Class Codes: B23D 47/08 of devices for bringing the circular saw blade to the workpiece or removing same therefrom
• CPC Class Codes: B23D 55/08 of devices for guiding or feeding strap saw blades
• 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: B27B 5/38 Devices for braking the circular saw blade or the saw spindle; Devices for damping vibrations of the circular saw blade, e.g. silencing B23D47/005 takes precedence
• 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: 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: F16P 3/148 using capacitive technology
• CPC Class Codes: Y10S 83/01 Safety devices
• CPC Class Codes: Y10T 83/081 With randomly actuated stopping means
• CPC Class Codes: Y10T 83/089 Responsive to tool characteristic
• CPC Class Codes: Y10T 83/613 Work guard
• CPC Class Codes: Y10T 83/7693 Tool moved relative to work-support during cutting
• CPC Class Codes: Y10T 83/773 Work-support includes passageway for tool [e.g., slotted table]
• CPC Class Codes: Y10T 83/7788 Tool carrier oscillated or rotated
• CPC Class Codes: Y10T 83/8773 Bevel or miter cut

Abstract

Woodworking machines are disclosed having movable cutting tools for cutting workpieces in a cutting region. The machines include a detection system adapted to detect one or more dangerous conditions between a person and the cutting tools, and a reaction system associated with the detection system. The reaction system is configured to retract the cutting tool at least partially away from the cutting region upon detection of a dangerous condition by the detection system.

Claims

1. A woodworking machine having a cutting region for cutting workpieces, comprising:

a movable cutting tool for cutting workpieces in the cutting region;

a detection system adapted to detect one or more dangerous conditions between a person and the cutting tool; and

a reaction system associated with the detection system and the cutting tool, where the reaction system is configured to retract the cutting tool at least partially away from the cutting region upon detection of at least one of the dangerous conditions by the detection system.

2. The machine of claim 1, where the detection system is adapted to detect accidental contact between a person and the cutting tool, and where the reaction system is configured to retract the cutting tool at least partially away from the cutting region upon detection of such contact by the detection system.

3. The machine of claim 1, where the detection system is adapted to detect dangerous proximity between a person and the cutting tool, and where the reaction system is configured to retract the cutting tool at least partially away from the cutting region upon detection of such proximity by the detection system.

4. The machine of claim 1, where the cutting tool includes a rotatable blade having angular momentum when rotating, and where the reaction system is configured to retract the blade by using, at least partially, the angular momentum of the blade.

5. The machine of claim 4, where the reaction system includes a brake mechanism configured to stop the rotation of the blade upon detection of the at least one dangerous condition by the detection system.

6. The machine of claim 1, where the reaction system is configured to retract the cutting tool away from the cutting region within approximately 14 milliseconds after the at least one dangerous condition is detected.

7. A woodworking machine comprising:

a frame adapted to support workpieces in a cutting region;

a movable cutting tool supported by the frame and configured to cut workpieces in the cutting region;

a motor configured to drive the cutting tool;

a detection system configured to detect one or more dangerous conditions between a person and the cuffing tool; and

a brake mechanism including at least one braking component configured to engage and stop movement of the cutting tool upon detection of at least one of the dangerous conditions by the detection system, where engagement of the braking component with the cutting tool tends to urge the cutting tool in a direction away from the cutting region.

8. The machine of claim 7, where engagement of the braking component with the cutting tool causes the cutting tool to move out of the cutting region.

9. The machine of claim 7, where the rotating cutting tool has angular momentum, and where the braking component is configured to transform at least a portion of the angular momentum of the cutting tool into a force on the cutting tool in a direction away from the cutting region.

10. The machine of claim 7, further comprising a rotatable shaft pivotally coupled to the frame, and where the cutting tool is mounted to rotate about the shaft and pivot toward and away from the cutting region, and where the engagement of the braking component with the rotating cutting tool causes the cutting tool and shaft to pivot away from the cutting region.

11. The machine of claim 7, where the detection system is configured to detect accidental contact between a person and the cutting tool, and where the braking component is configured to engage and stop movement of the cutting tool upon detection of such contact by the detection system.

13. The machine of claim 12, further comprising means for rotationally driving the cutting means during cutting, and means for stopping rotation of the cutting means in response to detection of accidental contact between a person and the cutting means.

14. The machine of claim 13, where the rotating cutting means has angular momentum, and where the means for stopping rotation of the cutting means uses at least a portion of the angular momentum to retract the cutting means away from the person.

16. The method of claim 15, where the cutting tool rotates and has angular momentum, and where the step of retracting includes using at least a portion of the angular momentum of the cutting tool to retract the cutting tool away from the person.

17. The method of claim 16, where the cutting tool has one or more teeth adapted to cut workpieces, and where the step of retracting includes moving a braking component into the teeth of the rotating cutting tool.

18. The method of claim 15, further comprising the step of stopping movement of the cutting tool in the event accidental contact between a person and the cutting tool is detected.

12. A woodworking machine, comprising:

cutting means for cutting workpieces;

means for detecting accidental contact between a person and the cutting means; and

means for retracting the cutting means away from the person in response to such detection of accidental contact.

15. A method for minimizing potential injuries from a woodworking machine having a movable cutting tool, the method comprising:

detecting accidental contact between a person and the cutting tool; and

retracting the cutting tool away from the person in the event accidental contact between the person and the cutting tool is detected.