Abstract: A control arrangement for plate cutting apparatus capable of making a cut which curves in, and is angled with respect to, the local plane of a plate, which arrangement comprises a programme representation defining a curve and relating an angle to that curve, and first and second sensor devices arranged to be responsive respectively to representations of the curve and corresponding angle, and arranged to send signals capable of controlling relative movement between the plate and a cutting device, and angular movement between the line of cut and the local plane of the plate respectively, in accordance with this programme.

Abstract: An interactive graphics system in which plotting, digitizing and other related capabilities are performed is described in which complex graphics may be generated, edited and developed at a plurality of terminals, independently, with a minimum of hardware and in which precision control of the motion of a plotting table at each location is achieved in response to simplified input commands. Additionally, a novel floating cursor is described by which an operator may control the motion of the carriages of a plotting table or other positioning system actuated during plotting on the table, and digitize various coordinate locations with corresponding storage in a central computer of such locations, all by manually positioning the cursor at the desired locations. The floating cursor is connected with an energy sensor and both the cursor and the sensor are mechanically movable relative to or independently of the carriage.

Abstract: A photo-copying device for controlling displacement of the working member of a metal gas-cutting machine following the line of the contour being copied, comprising a photoelectric transducer which provides circular scanning of the line of the contour being copied by means of an optical scanning beam for detecting the points of intersection of said beam with said contour line, the path of said beam in the contour plane being a circumference with its center lying approximately on said contour line, the optical scanning beam moves along said path at a constant angular speed and intersects said contour line at two points; a source of reference signals in the form of sine and cosine voltages; a first and a second drives for moving said photoelectric transducer along the X and Y axes, respectively; a third and a fourth drives for displacing said working member of the gas-cutting machine along its guides which are taken to be X and Y axes; a first and a second converters for converting instantaneous values of a cosi