High speed drill holders
AssigneeWestwind Air Bearings Ltd.
InventorMichael C Tempest
Life of this patent
Estimating the term…
Abstract
A collet for carrying a high-speed drill which comprises a collar (2) arranged to enclose a drill shank (1), an outer rim support (8) arranged for attachment to a drill, and a clamping mechanism between the collar and the outer rim support (8). The clamping mechanism is arranged to provide clamping forces between said outer rim support (8) and said collar so that said collar tightly grips a drill shank (1), as a consequence of centrifugal forces and of off center sprag effect forces.
Claims10
A drill holder for carrying a high-speed drill, said drill holder comprising a collar arranged to enclose a drill shank, an outer rim support arranged for attachment to a drill, and a clamping mechanism between the collar and the outer rim support, said clamping mechanism being arranged to provide clamping forces between said outer rim support and said collar so that said collar tightly grips a drill shank, as a consequence of centrifugal forces and off-center sprag effect forces, said collar, outer rim support and clamping mechanism being integrally formed from a single piece of material, said clamping mechanism including siamesed pairs of connecting arms of rotationally opposed but similar shape so that the sprag forces will act in either direction of rotation.
A drill holder for carrying a high-speed drill, said drill holder comprising a collar arranged to enclose a drill shank, an outer rim support arranged for attachment to a drill, and a clamping mechanism between the collar and the outer rim support, said clamping mechanism being arranged to provide clamping forces between said outer rim support and said collar so that said collar tightly grips a drill shank, as a consequence of centrifugal forces and off-center sprag effect forces, said collar, outer rim support and clamping mechanism being integrally formed from a single piece of material, said clamping mechanism including a plurality of connection arms arranged around a principal rotary axis of the drill holder and each arm being offset with respect to a direction radial to said axis of rotation.
A drill holder for carrying a high-speed drill, said drill holder comprising a collar arranged to enclose a drill shank, an outer rim support arranged for attachment to a drill, and a clamping mechanism between the collar and the outer rim support, said clamping mechanism being arranged to provide clamping forces between said outer rim support and said collar so that said collar tightly grips a drill shank, as a consequence of centrifugal forces and off-center sprag effect forces, said collar, outer rim support and clamping mechanism being integrally formed from a single piece of material, said clamping mechanism including a plurality of connection arms arranged around a principal rotary axis of the drill holder, each connection arm in said plurality thereof being joined to the outer rim support via a respective integral hinge and each connection arm having at a distal end a jaw with a leading edge, each of the jaws forming part of said collar, and the plurality of connection arms being arranged so that for each arm, a line passing through the respective integral hinge and the respective leading edge does not pass through said principal rotary axis.
A method of manufacturing a drill holder for carrying a high-speed drill, said drill holder comprising a collar having an integral surface arranged to enclose a drill shank, an outer rim support arranged for attachment to a drill, and a clamping mechanism between the collar and the outer rim support, said clamping mechanism being arranged to provide clamping forces between said outer rim support and said collar so that said collar tightly grips a drill shank, as a consequence of centrifugal forces and off-center sprag effect forces, the collar, outer rim support and clamping mechanism being integrally formed from a single piece of material, the method comprising the steps of:
- finishing the internal surface of said collar by bore grinding whilst the collar is continuous;
- and
- after said finishing step, separating the collar into a plurality of jaws which are movable relative to one another.
Dependencies are inferred from the claim text.