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.

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 cenrifugal forces and of off center sprag effect forces.

Abstract: A rotatable mirror assembly is described comprising a spherical housing (1) rotatable about an axis (A). The housing contains a mirror (2) bonded in the rear end of the housing. The housing at the front of mirror (2) has a flange (3) while a second enlarged flange (4) is formed at the rear of the mirror (2) the front of the mirror (2) has a sloping end face (5) at an angle of 45.degree. of the rotary axis (A) which fives toward an opening (6) in the side of the housing (1). The opening (6) in a first embodiment is closed by an optically flat sapphire window (7) bonded into the opening (6) and in a second embodiment has a curved lens (17) mounted in the aperture. The improved assemblies reduce noise generation of high speed rotating mirrors and prevent the deposit of small particles of dust on the mirror surface.

Abstract: An air bearing comprising a static shaft having a circumferential surface in a form which when developed into a substantially flat plane takes the form of a series of shallow sinusoidal waves having at least three wave peaks, wherein one of the peaks carries a groove extending longitudinally parallel to the shaft axis and which bearing further comprises a hollow support member mounted for rotation around the static shaft.

Abstract: An inclined mirror is provided in a cylindrical housing which has an open end and a closed end. An optical planar glass plate or window is mounted at the open end of the cylindrical housing. A laser beam enters the housing through the window and is reflected off the inclined mirror. The reflected beam leaves the housing through a side aperture in the housing. The cylindrical housing is rotated to scan the beam through a range of angles. Rotation of this optical system induces astigmatism in the beam due to the deformation of the inclined mirror at high rotational speed. If the window is tilted so that the entering laser beam is no longer normal to the window surface, then the window will induce a degree of astigmatism in the laser beam. The angular position of the window can be adjusted relative to the inclined mirror, thus compensating for the dynamic astigmatism due to rotation.

Abstract: An air bearing having a non-circular bearing having a longitudinal bearing axis, and a plain cylindrical horizontal shaft rotatably mounted in the bearing, wherein the bearing surface when developed into a flat plane, has a shallow sinusoidal wave form including at least three wave peaks, one of the peaks having a groove therein, extending longitudinally, parallel to the bearing axis.

Abstract: A centrifugal spindle is described comprising a hollow shaft (1) having a collet (2) at one end for gripping a tool shank (12) and a centrifugal loading means (3) housed within the shaft (1). The loading means comprises two coaxial pistons (4,5) spaced from each other and linked by flexible connecting members (6) and intermediate bob weights (7). One piston (4) is secured axially to the hollow shaft (1) while the other piston is secured to the collet so that rotation of the shaft (1) causes the weights (7) to move radially outwards under centrifugal force to draw the piston (5) and collet (2) into the hollow shaft (1) gripping the tool shank (12). The collet may have spring loaded jaws forcing them into the closed position.