Power equipment with detection and reaction systems

• US 9,522,476 B2
• Filed: 08/20/2010
• Issued: 12/20/2016
• Est. Priority Date: 10/01/1999
• Status: Expired due to Term

• Current Assignee: Sawstop Holding LLC
• Original Assignee: SD3, LLC
• Inventors: Gass, Stephen F.
• Primary Examiner(s): PRONE, JASON D
• Application Number:
  US12/806,829
• Publication Number:
  US 20110072942A1
• Time in Patent Office: 2,314 Days
• Field of Search: 83D/IG.1, 83/58, 83/62, 83/621, 83/63, 83/72, 83/767, 837/88, 835/81, 834/712, 834/771, 834/772, 835/221.2, 835/26, 833/971, 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, 340/679, 340/680, 340/686.1, 340/687, 340/686.3, 340/686.6
• US Class Current: 1/1
• 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 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: 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 table saw comprising:

a support structure;

an arbor block pivotally attached to the support structure;

a rotatable arbor supported by the arbor block;

a circular blade supported by the arbor;

electronics that detect contact between a person and the blade, where the electronics are connected to the blade through a capacitive coupling, where the electronics include an oscillator that generates an oscillating signal, where the oscillating signal is imparted on the blade through the capacitive coupling; and

an explosive triggerable by the electronics to cause the arbor block to pivot to mitigate possible injury from the contact.

2. The table saw of claim 1, where the support structure includes a trunnion structure and an elevation plate supported by the trunnion structure, and where the arbor block is pivotally attached to the elevation plate.

3. The table saw of claim 1, further comprising a bearing supporting the arbor in the arbor block, where the bearing is isolated electrically from the arbor block.

4. The table saw of claim 1, where the electronics includes a controller.

5. The table saw of claim 1, further comprising a shielded cable connecting the electronics to the capacitive coupling.

6. A table saw comprising:

a support structure including a trunnion structure and an elevation plate supported by the trunnion structure;

an arbor block pivotally attached to the elevation plate;

a rotatable arbor;

a bearing supporting the arbor in the arbor block;

a circular blade supported by the arbor;

a detection circuit connected to the blade through a capacitive coupling, where the detection circuit includes an oscillator that generates an oscillating signal, where the oscillating signal is imparted on the blade through the capacitive coupling, where the detection circuit includes a controller that detects a change in the oscillating signal on the blade indicative of contact between a person and the blade, and where the detection circuit generates a detection signal when the change in the oscillating signal on the blade is detected;

a firing circuit connected to the detection circuit to receive the detection signal, where the firing circuit includes a capacitor, and where the firing circuit discharges current from the capacitor upon receiving the detection signal; and

an explosive or fusible member connected to the firing circuit to receive the current discharged from the capacitor and cause the arbor block to pivot to mitigate possible injury from the contact.

7. The table saw of claim 6, further comprising a shielded cable connecting the detection circuit to the capacitive coupling.