# US 8,740,227 B2 · Force increasing self-locking drill chuck and self-locking mechanism thereof

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- Number: US 8,740,227 B2
- Document ID: US8740227B2
- Status: Granted
- Kind: B2
- Application number: 12/689,278
- Filed: 2010-01-19
- Published: 2010-07-22
- Granted: 2014-06-03
- Earliest claimed: 2009-01-19
- Assignees: Shandong Weida Machinery Co., Ltd.
- Applicants: Zexin Zhou; Guijie Li
- Inventors: Zexin Zhou; Guijie Li
- Web page: https://patentgrep.com/patent/US8740227B2

## CPC

- B23B 31/123: {with locking arrangements (locking arrangements for chucks with simultaneously-acting jaws moving radially actuated by one or more spiral grooves B23B31/16041)}
- B23B 31/1238: {Jaws movement actuated by a nut with conical screw-thread}
- B23B 2231/38: Keyless chucks for hand tools
- Y10T 279/17632: Conical sleeve
- Y10T 279/32: Means to prevent jaw loosening
- Y10T 279/34: Accessory or component
- B23B: TURNING; BORING (arrangements for copying or controlling B23Q)
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

The present invention discloses a self-locking mechanism for use in a drill chuck, comprising: clutch tooth sleeves, fixedly connected with the chuck body of the drill chuck and forming teeth; an oval deformation ring, having a substantially circular first shape and a substantially oval second shape, wherein the oval deformation ring has teeth on the side wall, with the teeth engaging with the teeth of the clutch tooth sleeve when the oval deformation ring is in the second shape; and a control sleeve, for controlling the conversion of the oval deformation sleeve between the first shape and the second shape. The present invention also discloses a force increasing self-locking drill chuck with said self-locking mechanism. The self-locking mechanism according to the present invention can be used in drill chucks of multiple structures, and provides a brand-new thought for the designs of the self-locking mechanisms of drill chucks.

## Claims

### Claim 1

A drill chuck, characterized in comprising,
a chuck body (11), comprising therein multiple equally distributed slanting holes along the circumference;
multiple jaws (13), slideably provided within the slanting holes of the chuck body (11), and having threads at a rear end;
a split-body nut (12), rotatably provided around the chuck body (11) and joining the threads of the jaws (13); and
a nut sleeve (2), closely put around the split-body nut (12);
characterized in further comprising:
a connecting sleeve (04), rotatably mounted within a connecting hole (111) of the chuck body (11) and connected with a driving shaft of a power machine;
a self-locking mechanism, comprising: a clutch tooth sleeve (10, 10″), fixedly connected with the chuck body (11) of the drill chuck, and provided with teeth (101); an oval deformation ring (09, 09″), having a substantially circular first shape and a substantially oval second shape, wherein the oval deformation ring (09, 09″) has teeth (091) on side wall, with the teeth (091) of the oval deformation ring (09, 09″) engaging with the teeth (101) of the clutch teeth sleeve (10, 10″) when the oval deformation ring (09, 09″) is in the second shape; and a control sleeve (08), for controlling the conversion of the oval deformation sleeve (09, 09″) between the first shape and the second shape, wherein the clutch tooth sleeve (10″) of the self-locking mechanism is formed with a handling portion at an outer surface, and the control sleeve (08) includes a handling portion (84) between the clutch tooth sleeve (10″) and the connecting sleeve (04); and
an intermediate sleeve (05), rotating synchronously with the connecting sleeve (04) and connected fixedly with a rear portion of the oval deformation ring (09″).

### Claim 2 (depends on 1)

The drill chuck according to claim 1, characterized in further comprising:
a friction ring (07), rotatably mounted between a bearing (16) of the split-body nut (12) and a support stand (112) of the chuck body (11).

### Claim 3 (depends on 2)

The drill chuck according to claim 2, characterized in that the oval deformation ring (09″) is provided thereon with a driving jaw (099) engaging with a tooth groove (073) of the friction ring (07),
the friction ring (07) includes a key side wall (071, 072) for restricting the rotation angle of a driving key (097, 098) of the oval deformation ring (09″).