Patent GB-1444965-A (GB)
Title: Apparatus for cutting workpieces electromechani
IPC: B24B49/00
Filed: 1973-08-03
Abstract: 1444965 Severing TELEDYNE Inc 3 Aug 1973 37086/73 Heading B3D [Also in Division G3] Apparatus for cutting workpieces, such as metal barstock or the like 20, comprises first and second cutting wheels 48, 48<SP>1</SP> which are mounted for rotation in a common plane and have parallel axes of rotation, the wheels being mounted so that their edges are substantially tangent to a straight common cutting path 50 with the wheels on opposite sides of the path and their axes of rotation offset from each other in a direction parallel to the cutting path, means 34, 34<SP>1</SP> for advancing the axes of the wheels towards the workpiece in a direction parallel to the cutting path, sensing means 62, 62<SP>1</SP> for determining the location of the edges of the wheels, and drive means 18, 181 responsive to the sensing means for maintaining the axes of the cutting wheels at such positions that the edges of the wheels remain tangent or substantially tangent to the cutting path. The barstock workpiece 20, the end of which is to be cut-off is supported by a pair of V-blocks 22 on a dolly 24 movable along rails 26 relative to a bed 12. A pair of columns 14, 141 are movable along guideways on the bed in the direction of the arrow 16, and each column supports a frame 30, 30<SP>1</SP> for vertical movement, each frame rotatably carrying a cutting wheel 481, 48<SP>1</SP>, driven by a D.C. motor 32, 32<SP>1</SP>. The columns are positioned on the bed so that the edges of the wheels are tangent to the path 50, and the frames are offset vertically so that the axes 54, 54<SP>1</SP> of the wheels are spaced a distance A in the vertical direction to provide a gap 56 between the wheels. The frames 30, 30<SP>1</SP> are movable along the columns to feed the wheels into the workpiece by rotation of lead screws 40, 40<SP>1</SP> through gearing 38 by motors 36 which are controlled by signals H 1 , H 2  from contacts 90, 90<SP>1</SP> on the frames movable over resistive elements 92, 92<SP>1</SP> on the columns. The signals H 1 , H 2  are compared to each other in a network 96 and with a minimum signal H to maintain the offset A greater than a predetermined minimum. The edges of the wheels 48, 48<SP>1</SP> are sensed by pneumatic or photo-electric detectors 62, 62<SP>1</SP>, the outputs of which are applied to motors 66, 66<SP>1</SP> driving lead screws 70, 70<SP>1</SP> to cause the detectors to follow the edges of the wheels as they wear. The movement of the detectors causes a corresponding movement of contacts 72, 72<SP>1</SP> over resistive elements 74, 741 to provide diameter signals D1, D2. The columns 14, 14<SP>1</SP> have contacts 78, 78<SP>1</SP> which move over resistive elements 80, 80<SP>1</SP> on the bed and produce column position signals S 1 , S 2 . The diameter signals D 1 , D 2  and position signals S 1 , S 2  are compared in networks 82, 82<SP>1</SP> which produce error signals that are fed through amplifiers 87, 87<SP>1</SP> to motors 44, 44<SP>1</SP> driving ball and lead screw mechanisms 46, 46<SP>1</SP> for moving the columns on the bed to positions in which the edges 48, 48<SP>1</SP>, of the wheels are again tangent to the path 50, thereby compensating for the wear of the wheels.