Brake mechanism for power equipment

• US 7,024,975 B2
• Filed: 08/13/2001
• Issued: 04/11/2006
• Est. Priority Date: 08/14/2000
• Status: Expired due to Term

• Current Assignee: Sawstop Holding LLC
• Original Assignee: SD3, LLC
• Inventors: McDonald, Anwyl M., D'Ascenzo, David S., Jensen, Joel F., Gass, Stephen F., Johnston, Andrew L.
• Primary Examiner(s): Ashley, Boyer D.
• Assistant Examiner(s): Alie, Ghassem
• Application Number:
  US09/929,241
• Publication Number:
  US 20020017180A1
• Time in Patent Office: 1,702 Days
• Field of Search: 188/82.7, 188/82.74, 188/82.77, 188/82.9, 188/371, 188/376, 188/377, 56/104, 56/113, 307/142, 307/115, 307/639, 307/328, 307/320, 307/116, 307/131, 83D/IG.1, 835/44, 833/97, 834/771, 834/73, 834/713, 834/78, 833/971, 83/61, 83/621, 83/63, 83/46, 83/72, 83/75, 83/767, 83/768, 83/769, 833/59, 833/68, 833/70, 833/71, 83/58, 834/91, 835/26, 834/712, 834/85, 835/221.2, 834/87, 835/46, 835/81, 835/90, 836/65, 834/90, 834/772, 833/57, 833/98, 834/71, 835/01, 839/32, 403/2, 443/90, 44/2, 44/35, 144/384, 144/391, 144/427, 144/154.5, 144/356, 192/124.R, 192/133, 192/148, 192/144, 192/142.R, 192/138, 192/137, 340/280, 303/87, 303/81, 292/290, 292/DIG.66, 411/390, 411/2, 411/29
• US Class Current: 83/62.1
• 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 5/00 Arrangements for operating and controlling machines or devices for cutting, cutting-out, stamping-out, punching, perforating, or severing by means other than cutting
• CPC Class Codes: B26D 7/22 Safety devices specially adapted for cutting machines safety devices in general F16P
• 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: 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 83/089 Responsive to tool characteristic
• 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 83/773 Work-support includes passageway for tool [e.g., slotted table]
• 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 83/8773 Bevel or miter cut

Abstract

Woodworking machines are disclosed having cutting tools adapted to cut 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 brake mechanism having one or more braking components adapted to engage and stop the cutting tool in response to the detection of a dangerous condition.

Claims

1. A woodworking machine comprising:

a rotatable blade having one or more teeth;

a detection system associated with the blade and configured to detect one or more dangerous conditions; and

a brake mechanism configured to stop the rotation of the blade if one of the dangerous conditions is detected, where the brake mechanism includes at least one brake pawl configured to pivot into the teeth of the blade.

2. The machine of claim 1, where the brake pawl is plastic.

3. The machine of claim 2, where the brake pawl is metal.

4. The machine of claim 1, where the brake pawl is aluminum.

5. The machine of claim 1, further comprising a spring configured to urge the brake pawl into the teeth of the blade, and where the brake pawl includes at least one engagement member adapted to be engaged by the spring to position the spring relative to the brake pawl.

6. The machine of claim 5, further comprising a restraining mechanism configured to releasably hold the brake pawl spaced-apart from the blade against the urging of the spring, and where the brake pawl includes a mounting structure for connecting the restraining mechanism to the brake pawl.

7. The machine of claim 6, where the mounting structure is spaced-apart from the engagement member.

8. The brake system of claim 1, wherein the brake pawl is self locking against the blade upon contact with the teeth.

9. A woodworking machine comprising:

a cutting tool having one or more teeth;

a motor configured to drive the cutting tool;

a detection system adapted to detect one or more dangerous conditions between a person and the cutting tool; and

a brake mechanism including a brake pawl movable into contact with the cutting tool so that a tooth-engaging portion of the brake pawl binds against the teeth of the cutting tool to stop movement of the cutting tool when the detection system detects at least one of the dangerous conditions;

where the tooth-engaging portion of the brake pawl is formed of metal.

10. The machine of claim 9, where the one or more teeth are formed of a material having a lesser hardness than the tooth-engaging portion so that the tooth-engaging portion bites into the teeth.

11. The machine of claim 9, where the tooth-engaging portion is formed of aluminum.

12. The machine of claim 11, where the one or more teeth are formed of a material having a greater hardness than aluminum so that the teeth bite into the tooth-engaging portion when the tooth-engaging portion binds against the teeth.

13. A woodworking machine, comprising:

a movable cutting tool for cutting workpieces;

at least one motor configured to drive the cutting tool;

a detection system configured to detect one or more dangerous conditions between a person and the cutting tool; and

a brake mechanism configured to stop movement of the cutting tool upon detection of one of the dangerous conditions by the detection system;

where the brake mechanism includes one or more metal braking components configured to move into contact with, and bind against, the cutting tool to stop movement of the cutting tool, and where the braking components include one or more ridges adapted to at least partially bite into the cutting tool.

14. A woodworking machine, comprising:

a movable cutting tool having one or more teeth;

a motor configured to drive the cutting tool;

a detection system configured to detect one or more dangerous conditions between a person and the cutting tool; and

a brake mechanism including at least one brake pawl configured to engage the cutting tool upon detection of one of the dangerous conditions by the detection system, and to pivot tightly into, and bind against, the teeth to stop the movement of the cutting tool.

15. The machine of claim 14, where the brake pawl is configured to be pulled into binding engagement with the cutting tool by the teeth of the cutting tool.

16. A woodworking machine comprising:

a rotatable blade having one or more teeth;

a detection system associated with the blade and configured to detect one or more dangerous conditions; and

brake means for stopping the rotation of the blade if one of the dangerous conditions is detected, where the brake means includes brake pawl means for pivoting into the teeth of the blade.

17. A woodworking machine comprising:

a rotatable blade having one or more teeth, where the blade is generally planar;

a detection system associated with the blade and configured to detect one or more dangerous conditions; and

a brake mechanism configured to stop the rotation of the blade if one of the dangerous conditions is detected, where the brake mechanism includes at least one brake pawl configured to pivot into the teeth of the blade around an axis generally perpendicular to the plane of the blade.