Patent Application
20050029753
1. Field of the Invention
The present invention relates to a drill chuck, more particularly to a drill chuck with a jaw control mechanism.
2. Description of the Related Art
Referring to
One disadvantage of the conventional drill chuck 1 resides in that counterclockwise rotation of the drilling shank 15 for removal of tightened screws can result in loosening of the drilling shank 15, which, in turn, results in axial movement of the pressing member 13 away from the bit-receiving opening 113 in the chuck body 11 and hence radial movement of the jaws 12 away from one another, thereby dropping the bit 16 from the chuck body 11.
Therefore, the object of this invention is to provide a drill chuck with a jaw control mechanism so as to overcome the aforesaid disadvantage of the prior art.
Accordingly, a drill chuck of the present invention is adapted to be connected to a power drill, and includes: a chuck body defining a rotation axis, and formed with a bit-receiving opening and a mounting end opposite to the bit-receiving opening; a plurality of spring-biased jaws disposed in the chuck body, having top ends, and axially and radially displaceable within the chuck body so as to clamp a drilling bit inserted into the chuck body through the bit-receiving opening; a coupling unit which is securely mounted on the mounting end of the chuck body and which defines an axial threaded portion extending axially and outwardly of the chuck body; and a jaw control mechanism mounted securely and adjustably on the coupling unit, and including a driving member that threadedly engages the axial threaded portion of the coupling unit so as to be adjustable along the axial threaded portion, a pressing member disposed within the chuck body and seated on the jaws, and a pushing unit that is associated with and that is driven by the driving member and that extends axially through the mounting end of the chuck body to abut against the pressing member in such a manner that tightening of the driving member relative to the pressing member results in axial movement of the pushing unit to abut against the pressing member, which, in turn, results in movement of the jaws toward one another so as to be adapted to securely clamp the drilling bit thereamong.
Other features and advantages of this invention will become more apparent in the following detailed description of the preferred embodiment of this invention, with reference to the accompanying drawings, in which:
Referring to FIGS. 3 to 5, the preferred embodiment of a drill chuck according to the present invention is adapted to be connected to a power drill 100 through a driving shank 70 so as to be driven thereby, and is shown to include a chuck body 10, a jaw unit 20, a coupling unit 80 and a jaw control mechanism 90.
As illustrated, the chuck body 10 defines a rotation axis, and is formed with a bit-receiving opening 103 and a mounting end 105 opposite to the bit-receiving opening 103.
The jaw unit 20 includes three jaws 21 and three urging members 22. The jaws 21 are disposed in the chuck body 10 and cooperatively define a gap 28 thereamong. Each of the urging units 22 is disposed between an adjacent pair of the jaws 21 so as to push the jaws 21 to abut against an inner face of the chuck body 10 in such a manner that the jaws 21 are axially and radially displaceable within the chuck body 10 (see
The coupling unit 80 is securely mounted on the mounting end 105 of the chuck body 10, and defines an axial threaded portion 82″ that extends axially and outwardly of the chuck body 10.
The jaw control mechanism 90 is mounted securely and adjustably on the coupling unit 80, and includes a driving member 91, a pressing member 30, and a pushing unit 92. The driving member 91 threadedly engages the axial threaded portion 82″ of the coupling unit 80 so as to be adjustable along the axial threaded portion 82′. The pressing member 30 is disposed within the chuck body 10, and is seated on the jaws 21. The pushing unit 92 is associated with and is driven by the driving member 91, and extends axially through the mounting end 105 of the chuck body 10 to abut against the pressing member 30 in such a manner that tightening of the driving member 91 relative to the driving member 91, i.e., axial movement of the driving member 91 toward the pressing member 30, results in axial movement of the pushing unit 92 to abut against the pressing member 30, which, in turn, results in radial movement of the jaws 21 against the urging action of the urging members 21 toward one another, thereby minimizing the gap 28 among the jaws 21. As such, the drilling bit 60 can be clamped securely among the jaws 21 (see
In this preferred embodiment, the coupling unit 80 includes a chuck-connecting member 81 and a coupling tube 82. The chuck-connecting member 81 is mounted securely on the mounting end 105 of the chuck body 10, and has an end flange 815 that abuts against the mounting end 105 of the chuck body 10. The chuck-connecting member 81 is further formed with a plurality of rod-extension holes 813 which are angularly spaced apart from one another relative to the rotation axis of the chuck body 10 and which extend through top and bottom faces 811,812 of the chuck-connecting member 81. The coupling tube 82 extends co-axially and integrally from the chuck-connecting member 81, and is formed with an external thread 821 defining the axial threaded portion 82″ of the coupling unit 80. The driving shank 70 is fastened securely to an inner thread 823 of the coupling tube 82 and is adapted to be connected to the power drill 100 (see
The jaw control mechanism 90 further includes a bearing retention seat 94 disposed between the driving member 91 and the coupling disc 920 of the pushing unit 92, and a bearing unit 93 sandwiched between the driving member 91 and the bearing retention seat 94. The driving member 91 is annular in shape, and has an inner thread 911 threadedly engaging the external thread 821 of the coupling tube 82, and an annular outer surface 912 formed with a plurality of axially extending engaging grooves 913. A rotatable sleeve 95 is sleeved on the driving member 91, encloses the mounting end 105 of the chuck body 10, and has an inner face 951 formed with a plurality of axially extending tongues 952 which project radially and inwardly therefrom to respectively engage the engaging grooves 913 in the driving member 91 so as to permit co-rotation of the driving member 91 with the rotatable sleeve 95.
An annular cap 83 is co-axially sleeved on the coupling tube 82. The outer surface of the rotatable sleeve 95 is provided with anti-slip knurls 934 to facilitate gripping of the same so as to drive the rotatable sleeve 95 in order to the tightening and loosening actions of the driving member 91 relative to the chuck body 10.
With the inclusion of the driving member 91 and the pushing unit 92 in the drill chuck of the present invention and since the driving shank 70 is not directly in contact with the pressing member 30 in the chuck body 10, the aforesaid disadvantage of the prior art is accordingly overcome.
With this invention thus explained, it is apparent that numerous modifications and variations can be made without departing from the scope and spirit of this invention. It is therefore intended that the invention be limited only as indicated in the appended claims.
