Power equipment with detection and reaction systems

• US 7,895,927 B2
• Filed: 05/19/2010
• Issued: 03/01/2011
• Est. Priority Date: 10/01/1999
• Status: Expired due to Fees

• Current Assignee: Sawstop Holding LLC
• Original Assignee: SD3, LLC
• Inventors: Gass, Stephen F.
• Primary Examiner(s): PRONE, JASON D
• Application Number:
  US12/800,607
• Publication Number:
  US 20100236663A1
• Time in Patent Office: 286 Days
• Field of Search: 83D/IG.1, 83/58, 83/62, 83/621, 83/72, 83/767, 837/88, 835/81, 834/712, 834/771, 834/772, 835/221.2, 835/26, 833/971, 835/221.21, 144/154.5, 144/356, 144/384, 144/391, 144/427, 144/286.5, 297/08, 292/54, 294/13, 324/550, 324/424, 408/5, 56/109, 56/113, 192/192.A, 192/129.R, 192/130, 102/202.7, 89/15.6, 137/68.12, 137/72, 137/76, 188/5, 188/6, 188/110, 188/189, 169/57, 169/59, 169/42, 169/DIG.3, 74/2, 403/2, 403/28, 411/2, 411/39, 411/390, 335/1, 335/242, 335/132, 318/362, 241/32.5, 337/239, 337/148, 337/1, 337/5, 337/10, 337/17, 337/140, 337/170, 337/190, 337/237, 337/401, 337/290, 337/404, 337/405, 218/2, 218/154, 307/639, 307/328, 307/115, 307/326, 307/142, 307/117, 307/126, 307/131, 451/409, 280/806, 297/480, 187/69, 187/77, 187/89, 187/189, 187/216, 187/166, 187/72.3
• US Class Current: 83/62.1
• CPC Class Codes: B23D 47/025 of tables
• 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 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: B26D 7/24 arranged to disable the operating means for the cutting member
• CPC Class Codes: B27B 13/14 Braking devices specially designed for band sawing machines, e.g. acting after damage of the band saw blade
• 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: B27G 19/06 for band or strap 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 3/14 the means being photocells or other devices sensitive without mechanical contact
• CPC Class Codes: F16P 3/148 using capacitive technology
• CPC Class Codes: G05B 9/02 electric
• CPC Class Codes: Y10S 83/01 Safety devices
• 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 83/089 Responsive to tool characteristic
• CPC Class Codes: Y10T 83/091 Responsive to work sensing means
• CPC Class Codes: Y10T 83/141 With means to monitor and control operation [e.g., self-regulating means]
• CPC Class Codes: Y10T 83/162 : With control means responsive to replaceable or selectable information program
• CPC Class Codes: Y10T 83/175 : With condition sensor
• CPC Class Codes: Y10T 83/178 : Responsive to work
• CPC Class Codes: Y10T 83/541 : Actuation of tool controlled in response to work-sensing means
• 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 83/7697 : Tool angularly adjustable relative to work-support
• CPC Class Codes: Y10T 83/7726 : By movement of the tool
• CPC Class Codes: Y10T 83/7734 : With guard for tool
• CPC Class Codes: Y10T 83/7788 : Tool carrier oscillated or rotated
• CPC Class Codes: Y10T 83/85 : Signal; e.g., alarm
• CPC Class Codes: Y10T 83/8773 : Bevel or miter cut

Abstract

Woodworking machines and safety methods for use with those machines are disclosed. The machines include a detection system adapted to detect one or more dangerous conditions and a reaction system associated with the detection system. The reaction system can include an explosive to trigger the system, and also can be configured to retract a cutting tool at least partially away from a cutting region upon detection of a dangerous condition by the detection system.

Claims

1. A method of operating a woodworking machine, where the woodworking machine has a work surface defining a cutting region and a cutting tool that extends at least partially into the cutting region, the method comprising:

moving the cutting tool;

detecting a dangerous condition between a person and the cutting tool; and

retracting the cutting tool below the work surface within approximately 14 milliseconds after the dangerous condition is detected by the detection system.

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

3. The method of claim 1, where the dangerous condition is proximity of a person to the cutting tool.

4. The method of claim 1, further comprising firing an explosive to cause the retracting of the cutting tool.

5. The method of claim 1, further comprising stopping the retracting of the cutting tool.

6. The method of claim 1, further comprising providing a stop to limit the retracting of the cutting tool.

7. A woodworking machine comprising:

a work surface defining a cutting region;

a cutting tool positioned to extend at least partially into the cutting region;

a detection system adapted to detect a dangerous condition 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 below the work surface within approximately 14 milliseconds after the dangerous condition is detected by the detection system.

8. The woodworking machine of claim 7 where the dangerous condition is contact between a person and the cutting tool.

9. The woodworking machine of claim 7 where the dangerous condition is proximity of a person to the cutting tool.

10. The woodworking machine of claim 7 further comprising a stop to limit the retraction of the cutting tool.

11. The woodworking machine of claim 10 where the stop includes an impact-absorbing material.

12. The woodworking machine of claim 7, where the reaction system includes an explosive.