Table saw with improved safety system

• US 7,908,950 B2
• Filed: 01/04/2010
• Issued: 03/22/2011
• Est. Priority Date: 08/14/2000
• Status: Expired due to Fees

• Current Assignee: Sawstop Holding LLC
• Original Assignee: SD3
• Inventors: Kim, Sung H., D'Ascenzo, David S., Jensen, Joel F., Fanning, David A., Gass, Stephen F., Johnston, Andrew L.
• Primary Examiner(s): Alie; Ghassem
• Application Number:
  US12/655,694
• Publication Number:
  US 20100192741A1
• Time in Patent Office: 442 Days
• Field of Search: 834/771, 833/971, 83D/IG.1, 835/81, 836/66, 83/621, 83/72, 834/713, 83/62, 834/73, 834/88, 834/90, 83/58, 83/767, 834/81, 834/712, 834/78, 834/85, 834/87, 834/89, 835/74, 838/21, 838/23, 838/27, 838/28, 839/54, 836/65, 835/22, 83/11, 83/22, 835/44, 834/91, 834/76, 835/26, 835/46
• US Class Current: 83/58
• CPC Class Codes: B23D 45/06 with a circular saw blade arranged underneath a stationary work-table
• 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: 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: 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 83/7697 Tool angularly adjustable relative to work-support
• 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 83/7788 Tool carrier oscillated or rotated
• CPC Class Codes: Y10T 83/8773 Bevel or miter cut

Abstract

A table saw having an adjustable blade, a detection system to detect contact between a person and the blade, and a brake mechanism to engage and stop the blade upon detection of contact between the person and the blade is disclosed. The saw includes a brake positioning system that adjusts the position of the brake mechanism to maintain the brake mechanism in an operative position relative to the blade as the position of the blade is adjusted. The saw also may include a retraction system that urges the blade downward, away from a user, upon detection of contact between a person and the blade. The retraction system may include a releasable gear. The saw may be constructed so that the blade is adjustable up and down around a pivot point downstream of the blade relative to the feed direction.

Claims

1. A table saw comprising:

a table defining a work surface;

a rotatable blade extendable up through the work surface, where the blade is configured to rotate about a rotation axis;

an elevation mechanism adapted to change the elevation of the blade relative to the table;

a detection system adapted to detect a dangerous condition between a person and the blade; and

a brake adapted to engage and decelerate the blade when the detection system detects the dangerous condition between the person and the blade, where the brake changes elevation relative to the table by pivoting around an axis substantially parallel to the rotation axis when the elevation mechanism changes the elevation of the blade relative to the table.

2. The table saw of claim 1 where the elevation mechanism is adapted to change the elevation of the blade by pivoting the blade up and down around an axis substantially parallel to the rotation axis.

3. The table saw of claim 1 where changing the elevation of the blade changes the elevation of the brake.

4. The table saw of claim 1 where the elevation mechanism is adapted to change the elevation of the blade by pivoting the blade up and down around an axis substantially parallel to the rotation axis and where pivoting the blade up and down changes the elevation of the brake.

5. The table saw of claim 1 where the elevation mechanism is adapted to change the elevation of the blade by pivoting the blade up and down around an axis substantially parallel to the rotation axis and where pivoting the blade up and down pivots the brake up and down.

6. The table saw of claim 1 where the elevation mechanism includes an arbor block adapted to pivot around a pin extending substantially parallel to the rotation axis, and further comprising a brake positioning mechanism adapted to mount the brake to the arbor block so the brake moves pivots with the arbor block.

7. The table saw of claim 1 where the dangerous condition is contact between a person and the blade.

8. The table saw of claim 1 where the dangerous condition is proximity between a person and the blade.

9. A table saw comprising:

a frame including a table defining a work surface;

a rotatable blade coupled to the frame and extendable up through the work surface, where the blade is configured to rotate about a rotation axis;

an elevation mechanism adapted to change the elevation of the blade relative to the table;

a detection system adapted to detect a dangerous condition between a person and the blade; and

a brake adapted to decelerate the blade upon detection of the dangerous condition; and

brake positioning means for pivoting the brake up and down around an axis substantially parallel to the rotation axis to maintain the brake in an operative position relative to the blade as the elevation of the blade relative to the table is changed.

10. The table saw of claim 9 where the dangerous condition is contact between a person and the blade.

11. The table saw of claim 9 where the dangerous condition is proximity between a person and the blade.