Power tool safety mechanisms

• US 7,373,863 B2
• Filed: 01/08/2004
• Issued: 05/20/2008
• Est. Priority Date: 07/11/2001
• Status: Expired due to Term

• Current Assignee: Black & Decker Incorporated (Stanley Black & Decker, Inc.)
• Original Assignee: Black & Decker Incorporated (Stanley Black & Decker, Inc.)
• Inventors: Webster, Matthew, O'Banion, Michael, Ceroll, Warren A.
• Primary Examiner(s): Ashley; Boyer D.
• Assistant Examiner(s): PRONE, JASON D
• Application Number:
  US10/753,845
• Publication Number:
  US 20040226424A1
• Time in Patent Office: 1,594 Days
• Field of Search: 83D/IG.1, 83/58, 83/761, 83/621, 83/62, 83/63, 833/70, 834/772, 83/72, 83 766- 769, 340/660, 340/686.6, 192/129.R, 192/125.R, 192/116.5, 342109-112, 318/362, 700/253, 700/255
• US Class Current: 83/63
• 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 47/10 actuated by fluid or gas pressure
• 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: B23Q 11/06 Safety devices for circular cutters
• CPC Class Codes: B26D 7/24 arranged to disable the operating means for the cutting member
• CPC Class Codes: B27B 5/32 Devices for securing circular saw blades to the saw spindle
• 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 19/02 for circular saws
• CPC Class Codes: B27G 21/00 Safety guards or devices specially designed for other wood-working machines auxiliary devices facilitating proper operation of said wood-working machines
• CPC Class Codes: F16P 3/06 in which body parts of the operator are removed from the danger zone on approach of the machine parts
• 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 3/141 using sound propagation, e.g. sonar
• CPC Class Codes: F16P 3/144 using light grids
• CPC Class Codes: F16P 3/148 using capacitive technology
• CPC Class Codes: Y10S 83/01 Safety devices
• 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 83/091 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 83/178 : Responsive to work
• CPC Class Codes: Y10T 83/541 : Actuation of tool controlled in response to work-sensing means
• CPC Class Codes: Y10T 83/606 : Interrelated tool actuating means and guard means

Abstract

A sensing mechanism (12) for detecting user contact with an active portion (26) of the power tool (10) is provided. In addition, a safety mechanism (14) for preventing prolonged user contact with the active portion (26) of a power tool (10) is provided. The safety mechanism (14) is configured to actuate upon receipt of a signal from the sensing mechanism (12). According to a first aspect, the safety mechanism (14) is arranged to rapidly displace the active portion (26) away from a user extremity. Alternatively, according to a second aspect, the safety mechanism (14) is arranged to rapidly urge an extremity of the user away from the active portion (26) of the power tool (10).

Claims

1. A safety mechanism for engaging an active portion of a power tool comprising:

a depth sensor that monitors a depth of a workpiece being fed into the active portion of the power tool and is adapted to detect a sudden depth change based on said monitoring;

an engaging member pivotally coupled to a portion of the power tool;

a biasing member normally biasing said engaging member into engagement with the active portion of the power tool; and

a release mechanism retaining said engaging member in a first position against said biasing member and operable to release said engaging member based on said sudden depth change detected by said depth sensor, thereby permitting said biasing member to bias said engaging member into the active portion of the power tool.

2. The safety mechanism of claim 1 wherein said release mechanism includes a fuse member interconnected between said engaging member and a portion of the tool.

3. The safety mechanism of claim 2 wherein said release mechanism further comprises a controller operable to apply current to said fuse member thereby causing said fuse member to fail.

4. The safety mechanism of claim 3 wherein said fuse member includes a wire.

5. A safety mechanism for engaging an active portion of the power tool comprising:

a depth sensor that monitors a depth of a workpiece proximate to the active portion and is operable to detect a sudden depth change based on said monitoring;

an engaging member pivotally coupled to a portion of the power tool;

a biasing member normally biasing said engaging member into engagement with the active portion of the power tool; and

a release mechanism retaining said engaging member in a first position against said biasing member and operable to release said engaging member, thereby permitting said biasing member to bias said engaging member into the active portion of the power tool, wherein said depth sensor is disabled upon release of said engaging member.

6. The safety mechanism of claim 5 wherein said release mechanism includes a fuse member interconnected between said engaging member and a portion of the tool.

7. The safety mechanism of claim 6 wherein said release mechanism further comprises a controller operable to apply current to said fuse member thereby causing said fuse member to fail.

8. The safety mechanism of claim 7 wherein said fuse member includes a wire.