# US 4,395,171 A · Chuck key

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- Number: US 4,395,171 A
- Document ID: US4395171A
- Status: Granted
- Kind: A
- Application number: 06/232,174
- Filed: 1981-02-06
- Granted: 1983-07-26
- Earliest claimed: 1980-02-08
- Inventors: Gunter H. Rohm
- Web page: https://patentgrep.com/patent/US4395171A

## CPC

- B25B 33/005: {Chuck keys}
- Y10T 279/3437: Safety feature; e.g., ejector, interlock
- Y10T 408/94: Tool-support
- B25B: TOOLS OR BENCH DEVICES NOT OTHERWISE PROVIDED FOR, FOR FASTENING, CONNECTING, DISENGAGING, OR HOLDING
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A chuck key as a tubular body extending along an axis and having an axially forwardly directed end formed with an array of teeth centered on the axis. A crosspiece extends diametrically through the body at the end opposite its toothed end. A pin is displaceable axially in the bore of the body between a front position projecting axially forwardly from the body beyond the teeth and in a rear position withdrawn axially backwardly in the body. A spring braced between the pin and the body urges the pin into the front position. An operating member is movable radially relative to the body and has an outer end that projects radially from the body. Interengaging formations on this member and on the pin displace the pin against the force of the spring from the rear to front position on depression of the end of the member radially inwardly. Thus the thumb of the hand grasping the crosspiece can push in the operating member to extend the pin for fitting of the key to a chuck. When the operating member is released the pin automatically retracts to ensure that the key disengages from the chuck.

## Claims

### Claim 1

A chuck key comprising:
a body extending along an axis and having an axially forwardly directed end formed with an array of teeth centered on said axis, said body being formed with a bore opening axially forwardly at said forward end;
a crosspiece extending generally radially from said body and fixed thereon remote from said forward end;
a pin displaceable axially in said bore of said body between a front position projecting axially forwardly from said body beyond said teeth and a rear position withdrawn axially backwardly in said body;
a spring braced between said pin and said body and urging said pin into said rear position;
an operating member mounted to be movable radially relative to said body and having an outer end projecting radially from said body; and
means including a pair of interengaging formations on said member and on said pin for displacing said pin against the force of said spring from said rear to said front position on depression of said one end of said member radially inwardly.

### Claim 2 (depends on 1)

The key defined in claim 1 wherein said operating member is mounted to be movable transversely of said axis and of said crosspiece.

### Claim 3 (depends on 2)

The key defined in claim 2 wherein said pair of formations includes one formation on said member and another formation on said pin, both of said formations being flat and inclined to said axis.

### Claim 4 (depends on 3)

The key defined in claim 3 wherein said member is a diametrally extending rod having two such outer ends and two such one formations, said pin having two such other formations.

### Claim 5 (depends on 4)

The key defined in claim 4 wherein said rod is formed with a V-shaped notch having a pair of flanks forming said faces of said one formations.

### Claim 6 (depends on 5)

The key defined in claim 5 wherein said pin has a V-shaped rear end having a pair of flanks forming said faces of said other formations.

### Claim 7 (depends on 4)

The key defined in claim 4 wherein said crosspiece is substantially perpendicular to said member and said member is between said crosspiece and said pin, said member having a side turned toward said crosspiece and formed with an elongated groove having a pair of ends, said crosspiece being spaced from both of said ends in the undepressed conditions of said member.

### Claim 8 (depends on 4)

The key defined in claim 4 wherein both outer ends of said member extend substantially the same distance from said body in the undepressed position of said member.

### Claim 9 (depends on 2)

The key defined in claim 2 wherein said crosspiece has a crosspiece axis intersecting and perpendicular to said axis of said body and said member has a member axis intersecting and perpendicular to said axis of said body, said member and crosspiece axes being offset by about 90.degree. to each other about the axis of said body.