Chuck mechanism for dental handpiece and dental handpiece using the mechanism

Patent metadata

Field	Value
Publication number	US-10004571-B2
Application number	US-201213353139-A
Country	US
Kind code	B2
Filing date	Jan 18, 2012
Priority date	Jan 25, 2011
Publication date	Jun 26, 2018
Grant date	Jun 26, 2018

Abstract

A chuck mechanism for a dental handpiece holds a columnar rotary tool for dental care rotatably with an annular rotor of the dental handpiece. The columnar rotor tool is concentrically detachable to the annular rotor which is rotatably attached to a head part of the dental handpiece. The chuck mechanism has an annular chucking member with a cylindrical base part into which the annular rotor is integrally fitted and an elastic chucking piece having a chucking pawl for engaging with a locking groove formed at a base end of the rotary tool. The chuck mechanism enables the rotary tool to be easily removed from the annular rotor by elastically deforming the elastic chucking piece against elastic force of the elastic chucking piece to disengage the chucking pawl from the locking groove.

First claim

The invention claimed is:

1. A chuck mechanism in combination with a columnar rotary tool for use in a dental handpiece, the chuck mechanism holding the columnar rotary tool, the combination comprising:
the columnar rotary tool having a shank part and a locking groove, the shank part having a base end side and a tip side, the locking groove positioned nearer the base end side of the shank part than the tip side; and
the chuck mechanism having an annular rotor, and an annular chucking member mounted to the annular rotor, the annular chucking member including
a cylindrical base part that fits with and surrounds the annular rotor; and
a plurality of chucking pieces, each chucking piece including
an abutting part extending in an axial direction from the cylindrical base part, the abutting part being elastically deformable in a radial direction such that a radially inner main surface of the abutting part elastically abuts against a portion of an outer circumference of the shank part in the radial direction, the portion of the outer circumference of the shank part being positioned between the locking groove and the tip side of the shank part, and
a chucking pawl projecting radially inward from a tip end of the abutting part such that the chucking pawl elastically engages the locking groove of the columnar rotary tool,
wherein the radially inner main surface of the abutting part faces in a direction that is perpendicular to a center axis of the columnar rotary tool.

2. The chuck mechanism in combination with the columnar rotary tool according to claim 1 , the chuck mechanism further comprising a pair of chucking pieces diametrically opposing each other.

3. The chuck mechanism in combination with the columnar rotary tool according to claim 1 , the chuck mechanism further comprising a tubular rotor outer member fitted to an external area of the cylindrical base part of the annular chucking member,
wherein the columnar rotary tool has a rotary tool base part that engages an inner surface of the tubular rotor outer member such that the columnar rotary tool and the tubular rotor outer member are not rotatable relative to each other.

4. The chuck mechanism in combination with the columnar rotary tool according to claim 3 , the chuck mechanism further comprising a bearing attached on a radially outward part of the tubular rotor outer member,
wherein the annular rotor is rotatably fitted to a head part of the dental handpiece via the bearing.

5. The chuck mechanism in combination with the columnar rotary tool according to claim 4 , wherein the bearing is fitted to a corresponding region where the chucking pawl and the locking groove are engaged.

6. The chuck mechanism in combination with the columnar rotary tool according to claim 3 , the chuck mechanism further comprising:
a working body movable along an axis of the tubular rotor outer member,
wherein the working body and the tubular rotor outer member are not rotatable relative to each other, and
wherein the working body has an operation part for deforming one of the plurality of chucking pieces via movement of the working body.

7. The chuck mechanism in combination with the columnar rotary tool according to claim 6 , wherein the working body has a short cylindrical part and a flat canopy part for covering one end of the short cylindrical part, and
wherein the short cylindrical part is provided with the operation part and a locking part for attaching the working body to the tubular rotor outer member movably in an axial direction of the axis of the tubular rotor outer member.

8. A dental handpiece, comprising:
the chuck mechanism in combination with the columnar rotary tool of claim 1 , wherein the chuck mechanism is provided at a head part;
a hand-held piece body;
the head part connected to a front end of the hand-held piece body;
a rotary drive portion built in the hand-held piece body;
a rotation transmitting portion for transmitting rotary force from the rotary drive portion to the columnar rotary tool; and
a manual button for releasing the chuck mechanism,
wherein the columnar rotary tool is held via the chuck mechanism and is constructed such that it rotates together with the annular rotor about an axis by rotary force transmitted from the rotation transmitting portion.

9. A chuck mechanism in combination with a columnar rotary tool for use in a dental handpiece, the chuck mechanism holding the columnar rotary tool, the combination comprising:
the columnar rotary tool having a shank part and a locking groove, the shank part having a base end side and a tip side, the locking groove positioned nearer the base end side of the shank part than the tip side; and
the chuck mechanism having an annular rotor, and an annular chucking member mounted to the annular rotor, the annular chucking member including
a cylindrical base part that fits with and surrounds the annular rotor; and
a plurality of chucking pieces, each chucking piece including
an abutting part extending in an axial direction from the cylindrical base part, the abutting part being elastically deformable in a radial direction such that a radially inner main surface of the abutting part elastically abuts against a portion of an outer circumference of the shank part in the radial direction, the portion of the outer circumference of the shank part being positioned between the locking groove and the tip side of the shank part, and
a chucking pawl projecting radially inward from a tip end of the abutting part such that the chucking pawl elastically engages the locking groove of the columnar rotary tool,
wherein the radially inner main surface of the abutting part is located between the chucking pawl and the cylindrical base part, and
wherein the radially inner main surface of the abutting part faces in a direction that is perpendicular to a center axis of the columnar rotary tool.

Assignees

• Tanaka Hitoshi
• Ono Hiroyuki
• Nakayama Shozo
• J Morita Mfg Corp

Inventors

• Tanaka Hitoshi
• Ono Hiroyuki
• Nakayama Shozo

Classifications

• A61C1/142

  Operating tool blocking means · CPC title

• A61C1/141 Primary

  in an angled handpiece · CPC title

• A61C1/144

  constricting the operating tool, e.g. chuck · CPC title