Miter saw with improved safety system

• US 20060230896A1
• Filed: 06/02/2006
• Published: 10/19/2006
• Est. Priority Date: 10/01/1999
• Status: Active Grant

• Current Assignee: Sawstop Holding LLC
• Original Assignee: SD3, LLC
• Inventors: Gass, Stephen F.
• Granted Patent: US 7,347,131 B2
• Time in Patent Office: Days
• US Class Current: 83/76.800
• 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

A miter saw is disclosed having a base, a blade supported by the base, a detection system adapted to detect a dangerous condition between a person and the blade, and a reaction system associated with the detection system to cause a predetermined action to take place upon detection of the dangerous condition. The blade is rotatable, and moves into a cutting zone to cut a workpiece. The predetermined action may be to stop the blade from rotating, to create an impulse against movement of the blade into the cutting zone, or to cause the blade to move away from the cutting zone.

Claims

1. A miter saw comprising:

a base adapted to support a workpiece during cutting;

a motor;

a rotatable, circular blade driven by the motor, where the blade includes teeth around its periphery;

a pivot arm assembly associated with the base and supporting the blade, where the pivot arm assembly is adapted to pivot toward and away from the base to move the blade toward and away from the base; and

a safety system having a detection subsystem adapted to detect the occurrence of an unsafe condition between a person and the blade, and a reaction subsystem adapted to mitigate the unsafe condition, where the reaction subsystem includes a brake mechanism adjacent the blade, and where at least a part of the brake mechanism is adapted to pivot into the teeth of the blade to engage the blade.

2. The miter saw of claim 1, where the unsafe condition is contact between a person and the blade.

3. The miter saw of claim 1, where the unsafe condition is proximity between a person and the blade.

4. The miter saw of claim 1, where the brake mechanism includes a brake pawl and where the brake pawl is adapted to pivot into the teeth of the blade.

5. The miter saw of claim 4, where the blade is substantially planar, and where the brake pawl is adapted to pivot around an axis generally perpendicular to the plane of the blade.

6. The miter saw of claim 1, where the blade is substantially planar and where at least a part of the brake mechanism is adapted to pivot into the teeth of the blade around an axis generally perpendicular to the plane of the blade.

7. The miter saw of claim 1, further comprising a pivot pin supporting a part of the brake mechanism adapted to pivot into the teeth of the blade.

8. The miter saw of claim 1, further comprising a support arm holding at least a portion of the brake mechanism adjacent the teeth of the blade.

9. The miter saw of claim 1, where the brake mechanism includes a brake pawl adapted to pivot into the teeth of the blade, and further comprising at least one support arm holding the brake pawl adjacent the teeth of the blade.

10. The miter saw of claim 9, where the blade is substantially planar, and where the brake pawl is adapted to pivot around an axis generally perpendicular to the plane of the blade.

11. The miter saw of claim 10, further comprising a pivot pin positioned generally perpendicularly relative to the plane of the blade and supported at least partially by at least one support arm, and where the brake pawl is adapted to pivot on the pivot pin.

12. A miter saw comprising:

a base adapted to support a workpiece during cutting;

a motor;

a rotatable, circular, generally planar blade driven by the motor, where the blade includes teeth around its periphery;

a pivot arm assembly associated with the base and supporting the blade, where the pivot arm assembly is adapted to pivot toward and away from the base to move the blade toward and away from the base; and

a safety system having a detection subsystem adapted to detect the occurrence of an unsafe condition between a person and the blade, and a reaction subsystem adapted to mitigate the unsafe condition, where the reaction subsystem includes a brake configured to pivot into the teeth of the blade around an axis generally perpendicular to the plane of the blade.

13. The miter saw of claim 12, where the unsafe condition is contact between a person and the blade.

14. The miter saw of claim 12, where the unsafe condition is proximity between a person and the blade.

15. The miter saw of claim 12, further comprising a pivot pin supporting the brake.

16. The miter saw of claim 12, further comprising at least one support arm holding the brake adjacent the teeth of the blade.

17. The miter saw of claim 16, further comprising a pivot pin positioned generally perpendicularly relative to the plane of the blade and supported at least partially by at least one support arm.

18. The miter saw of claim 17, where the brake is adapted to pivot on the pivot pin.

19. A miter saw comprising:

a base adapted to support a workpiece during cutting;

a fence on the base;

a motor;

a rotatable, circular blade driven by the motor, where the blade includes teeth around its periphery;

a pivot arm assembly associated with the base and supporting the blade, where the pivot arm assembly is adapted to pivot toward and away from the base to move the blade toward and away from the base; and

a safety system having a detection subsystem adapted to detect the occurrence of an unsafe condition between a person and the blade, and a reaction subsystem adapted to mitigate the unsafe condition, where the reaction subsystem includes brake means for pivoting into the teeth of the blade to stop the rotation of the blade if an unsafe condition is detected by the detection subsystem.

20. The miter saw of claim 19 where the brake means is supported by support arm means for holding the brake means adjacent the teeth of the blade.