# US 2008/0184857 A1 · Brake cartridges for power equipment

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- Number: US 2008/0184857 A1
- Document ID: US20080184857A1
- Status: Published application
- Kind: A1
- Application number: 12/079,820
- Filed: 2008-03-27
- Published: 2008-08-07
- Earliest claimed: 2003-08-20
- Assignees: Sd3, LLC
- Inventors: Stephen F. Gass; J. David Fulmer; David A. Fanning
- Web page: https://patentgrep.com/patent/US20080184857A1

## CPC

- F16D 63/00: Brakes not otherwise provided for; Brakes combining more than one of the types of groups F16D49/00 - F16D61/00
- B27B 5/381: {with at least one brake member contacting saw blade portions}
- B27G 19/008: {with sensing of human contact or proximity with the blade}
- B27G 19/022: {with blades dropping below a table in reaction to dangerous situation}
- F16D 2127/008: {Trigger mechanisms}
- Y10T 83/089: Responsive to tool characteristic
- Y10T 83/613: Work guard
- Y10T 83/7726: By movement of the tool
- Y10T 83/773: Work-support includes passageway for tool [e.g., slotted table]
- Y10T 83/7788: Tool carrier oscillated or rotated
- Y10T 83/8773: Bevel or miter cut
- F16D: COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
- B27B: SAWS FOR WOOD OR SIMILAR MATERIAL; COMPONENTS OR ACCESSORIES THEREFOR (saws specially adapted for pruning or debranching A01G3/08; sawing apparatus specially adapted for felling trees A01G23/091; features not restricted to a particular type of wood saw B23D, e.g. attaching saw blades B23D51/00; machine tool frames, beds, pillars or like members, in general B23Q1/01)
- B27G: ACCESSORY MACHINES OR APPARATUS FOR WORKING WOOD OR SIMILAR MATERIALS; TOOLS FOR WORKING WOOD OR SIMILAR MATERIALS (tools for grinding B24D; sawing tools B27B33/00; tools for slotting or mortising machines B27F5/02; tools for the manufacture of wood shavings, chips, powder or the like B27L11/00); SAFETY DEVICES FOR WOOD WORKING MACHINES OR TOOLS
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

Safety systems for power equipment and components and brake cartridges for use in those safety systems are disclosed. The safety systems, components and brake cartridges are specifically applicable for woodworking equipment such as saws. An exemplary brake cartridge includes a housing and a braking component configured to engage a moving part of the power tool upon occurrence of a predetermined event. The brake cartridge may further include a switch configured so that proper installation of the cartridge in the power tool triggers the switch.

## Claims

### Claim 1

A brake cartridge for use in safety systems for power tools, the cartridge comprising:
a housing;
a brake pawl associated with the housing and adapted to pivot relative to the housing;
a spring at least partially enclosed in the housing and adapted to pivot the brake pawl relative to the housing when the spring expands;
a fuse wire adapted to hold the spring in compression;
circuitry enclosed in the housing and adapted to fuse the fuse wire to release the spring;
a plug associated with the housing and adapted to engage a corresponding plug in the power tool; and
means for determining whether the cartridge is properly installed in a power tool.

### Claim 2 (depends on 1)

The brake cartridge of claim 1, where the means for determining further comprises switch means for indicating the cartridge is properly installed when the switch means is activated, and switch contactor means for activating the switch means when the cartridge is properly installed in the power tool.

### Claim 3 (depends on 2)

The brake cartridge of claim 2, where the means for determining further comprises aperture means for receiving a rotatable key, where rotation of the key causes the switch contactor means to activate the switch means.

### Claim 4 (depends on 3)

The brake cartridge of claim 3, where the aperture means is configured to allow the key to rotate only when the cartridge is properly installed in the power tool.

### Claim 5

A brake cartridge for use in safety systems for power tools, where the brake cartridge includes a housing and a braking component configured to engage a moving part of the power tool upon occurrence of a predetermined event, and where the brake cartridge further includes means for determining whether the cartridge is properly installed in a power tool.

### Claim 6

A brake cartridge for use in safety systems for power tools, where the brake cartridge includes a housing and a braking component configured to engage a moving part of the power tool upon occurrence of a predetermined event, and where the brake cartridge further includes a switch configured so that proper installation of the cartridge in a power tool triggers the switch.

### Claim 7 (depends on 6)

The brake cartridge of claim 6 where the switch is a tactile switch.

### Claim 8 (depends on 6)

The brake cartridge of claim 6 further comprising a switch contactor.

### Claim 9 (depends on 6)

The brake cartridge of claim 6 where the switch includes a contact button and where the brake cartridge further comprises a switch contactor configured to contact the contact button.

### Claim 10 (depends on 9)

The brake cartridge of claim 9 where the switch contactor is configured to move into and out of contact with the contact button.