Power equipment with systems to mitigate or prevent injury

• US 8,490,527 B2
• Filed: 09/01/2011
• Issued: 07/23/2013
• Est. Priority Date: 08/14/2000
• Status: Expired due to Fees

• Current Assignee: Sawstop Holding LLC
• Original Assignee: SD3, LLC
• Inventors: Gass, Stephen F., D'Ascenzo, David S.
• Primary Examiner(s): Alie, Ghassem
• Application Number:
  US13/199,548
• Publication Number:
  US 20120067181A1
• Time in Patent Office: 691 Days
• Field of Search: 83/58, 83/59, 83/621, 833/671, 834/71, 835/81, 83D/IG.1, 83/72, 83/768, 834/73, 833/57, 834/712, 83/526, 835/46, 835/64, 835/90, 836/65, 834/713, 834/85, 834/83, 834/90, 834/91, 835/221.7, 835/44, 337/10, 337/17, 337/70, 337/140, 337/148, 337/170, 337/190, 337/737, 403/2, 403/28, 411/7, 411/39, 411/390, 335/142, 72/2, 292/790, 292/DIG.66, 307/116, 307/142, 307/131
• US Class Current: 83/58
• 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 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 vibration-damping of sawing machines or devices working with circular saw blades B23D47/005
• 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: Y10T 83/04 Processes
• CPC Class Codes: Y10T 83/081 With randomly actuated stopping means
• CPC Class Codes: Y10T 83/083 With means to permit subsequent hand operation
• CPC Class Codes: Y10T 83/089 Responsive to tool characteristic
• CPC Class Codes: Y10T 83/536 Movement of work controlled
• CPC Class Codes: Y10T 83/613 Work guard
• CPC Class Codes: Y10T 83/7684 With means to support work relative to tool[s]
• CPC Class Codes: Y10T 83/7726 By movement of the tool
• CPC Class Codes: Y10T 83/773 Work-support includes passageway for tool [e.g., slotted table]
• CPC Class Codes: Y10T 83/8773 Bevel or miter cut

Abstract

Woodworking machines are disclosed having cutting tools for cutting workpieces. The machines include a detection system adapted to detect one or more dangerous conditions between a person and the cutting tool. The machines also include a mechanism having a moveable component adapted to move upon detection of the dangerous condition by the detection system. Movement of the moveable component contributes to one or more of the following actions to mitigate or prevent injury to the person: deceleration of the cutting tool, retraction of the cutting tool, and placement of a barrier over at least a part of the cutting tool. An actuator is adapted to move the moveable component at a high acceleration when the dangerous condition is detected.

Claims

1. A method of mitigating a dangerous condition between a person and a cutting tool of a woodworking machine, the method comprising:

detecting the dangerous condition; and

using stored energy to start moving a moveable component within approximately 3 milliseconds after the dangerous condition is detected in such a manner that movement of the moveable component contributes to one or more of the following actions;

deceleration of the cutting tool, retraction of the cutting tool, and placement of a barrier over at least a part of the cutting tool.

2. The method of claim 1, where the limitation of using stored energy moves the moveable component 1/32nd of an inch within approximately 3 milliseconds.

3. The method of claim 1, where the limitation of using stored energy comprises releasing a spring.

4. The method of claim 1, where the limitation of using stored energy comprises triggering an explosive.

5. The method of claim 1, where the cutting tool is a circular blade, where the woodworking machine is a table saw, where the table saw includes an arbor block supporting the blade, where the moveable component is the arbor block, where the table saw further includes a sector gear, where the arbor block is releasably coupled to the sector gear, where releasing the arbor block from being coupled to the sector gear allows the arbor block to move to retract the blade, and further comprising releasing the arbor block from the sector gear.

6. A method of mitigating a dangerous condition between a person and a cutting tool of a woodworking machine, where the woodworking machine includes an arbor block supporting the cutting tool, the method comprising:

detecting the dangerous condition; and

using stored energy to start moving the arbor block within approximately 3 milliseconds after the dangerous condition is detected in such a manner that movement of the arbor block contributes to retraction of the cutting tool.