METHOD OF MANUFACTURING CLAMPING JAWS, CLAMPING JAW AND DRILL CHUCK

Abstract

A method of manufacturing clamping jaws for drill chucks, in which a pin is provided made from a blank, on which are formed a row of teeth furnished for engaging in a thread associated with the drill chuck and, axially offset on the side of the pin opposite the row of teeth, a clamping surface extending at an angle to the axis of the pin; in which at least one of the steps of quenching, carburizing, nitriding, and annealing is carried out to improve the material properties of the pin; and in which additional hardening is subsequently carried out in at least one region of the clamping jaws. The invention also relates to a clamping jaw and to a drill chuck having such clamping jaws.

Claims

1. A method of manufacturing a clamping jaw for a drill chuck, the method comprising: providing a pin from a blank; forming a row of teeth furnished for engaging in a thread associated with the drill chuck; and forming a clamping surface extending at an angle to an axis of the pin and on a side of the pin opposite the row of teeth and axially offset, wherein at least one of the steps of quenching, carburizing, nitriding, or annealing is carried out to improve the material properties of the pin, and wherein additional hardening is subsequently carried out in at least one region of the clamping jaws.

2. The method according to claim 1, wherein at least one clamping bevel is formed in the clamping surface, and wherein a vicinity of the clamping bevel is hardened by laser hardening.

3. The method according to claim 1, wherein a material harder than a material of the pin is applied to the clamping surface by a laser welding process, for use as a clamping bevel.

4. The method according to claim 3, wherein the harder material is applied to the clamping surface by a powder deposition welding process.

5. The method according to claim 4, wherein the powder for the powder deposition welding process comprises hard metal.

6. The method according to claim 4, wherein the powder to be applied by the powder deposition welding process is formed by a powder mixture containing at least two constituents with properties that differ in terms of toughness and hardness after deposition.

7. The method according to claim 2, wherein the clamping bevel is formed to run parallel to a tool shank that will be clamped.

8. The method according to claim 1, wherein the blank is provided by cutting to length a round bar of steel.

9. A clamping jaw comprising: a steel cylindrical pin on which is formed a row of teeth for engaging in a thread associated with a drill chuck; a clamping surface formed axially offset on a side opposite the row of teeth that, in the assembled state, runs parallel to an axis of a drill chuck; and a clamping bevel formed as a single unit on the clamping surface with a hardness greater than that of the cylindrical pin.

10. A drill chuck comprising a plurality of clamping jaws according to claim 9.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0016] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawing which is given by way of illustration only, and thus, are not limitive of the present invention, and wherein the sole figure is a perspective view of a clamping jaw.

DETAILED DESCRIPTION

[0017] The FIG. 1 shows a clamping jaw 1 that is made from a blank obtained by cutting to length a round bar of steel; this steel has a carbon content of more than 0.4% or is imparted this carbon content by carburization. On the blank, which is formed by a cylindrical pin 2, a row of teeth 3 is formed, which is intended to engage in a thread associated with the drill chuck. Moreover, axially displaced on the side of the cylindrical pin 2 opposite the row of teeth 3, there is a clamping surface 4 that is inclined to the axis of the pin and on which, in the exemplary embodiment shown, two clamping bevels 5 are formed parallel to the tool shank that will be clamped.

[0018] In order to improve the material properties of the cylindrical pin 2, different steps may be carried out alternatively or cumulatively, namely the steps of quenching, carburizing, nitriding and tempering, so that the clamping jaw 1 obtains the desired properties, namely a high degree of toughness in the vicinity of the row of teeth 3 and a deformability in the elastic region of the base material.

[0019] On the clamping surface 4 of the parts of the clamping jaw 1 intended for contact with the tool or the workpiece, however, the greatest possible hardness is desired, so the clamping bevels are furnished with greater hardness than the cylindrical pin 2.

[0020] This is achieved by hardening the clamping bevel 5 or, in the exemplary embodiment shown, the two clamping bevels 5, by laser hardening. Alternatively, it is also possible that a material harder than the material of the cylindrical pin 2 is applied to the clamping surface 4 by a laser welding process for use as a clamping bevel 5, and may in particular be applied by a powder deposition welding process and the powder for the powder deposition welding process is formed from a hard metal or from a powder mixture by containing at least two constituents having properties that differ with regard to their toughness and hardness after being applied.

[0021] Such a clamping jaw 1 has at least the advantageous properties of a clamping jaw 1 furnished with hard-metal inserts, but may be manufactured at a much lower cost, so that the use of these clamping jaws 1 in a drill chuck retains its wear resistance.

[0022] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.