Patent GB-1302882-A (GB)
IPC: H02K15/02
Filed: 1969-12-12
Abstract: 1302882 Punching L SCHULER GmbH 12 Dec 1969 [12 Dec 1968] 60750/69 Heading B3W In a press for producing stacks of laminations for conical armature motors comprising a shaft (not shown) for supporting a sheet metal blank,  a punching tool (not shown) displaced radially relative to the axis of the shaft and means for adjusting the radial distance between the shaft and the punching tool by different increments, a programming device is operative to determine the sequence in which the displacement increments are selected dependent on the theoretical number of blanks required to form a stack of laminations of the required height compared with the actual number of blanks, due to variations in the thickness of the blanks. As shown, Fig. 6, the shaft is moved by means of a ratchet 21 rotated by a pawl 23 actuated by a lever 25, 24 pivoted to a link 33. The link 33 is pivotally connected to piston rods 29, 30 of cylinders 27, 28 respectively, the disposition of the pivot point 34 along the link 33 causing the shaft carrying a blank to be moved radially towards or away from the punch by a small increment if piston-rod 30 is actuated, by a medium increment if piston-rod 29 is actuated and a large increment if both rods are actuated. In a modification the pivot point 34 is central of the length of link 33 and the piston-rods are of different lengths. Figs. 8-10 illustrate single or composite cylinders for achieving the same range of feed increments. The programming device may be a ring counter which has a counting cycle of preselectable length and a pulse generator which applies a given number of pulses to the ring counter for each cycle of the press, the ring counter at the completion of each count cycle producing an output signal which is fed to means for controlling two solenoid valves respectively controlling the supply of fluid to pipes feeding the cylinders 27 and 28. The press is arranged so that the shaft is moved a medium increment between every cycle of the press until an output signal from the counter which for any given stack of laminations will only call for either large or small increments. The preselection of the count cycle may be by means of a manual input or by means of a decade switch operating a preselector which controls an input control which interrogates a reader, e.g. a punched tape reader, and feeds the figures received to a buffer store, which in turn acts on a preselector device built into the ring counter. The pipes supplying fluid to the cylinders 27  and 28 are also connected to the manual input and to the buffer store so that the solenoid valve actuating the cylinder 27 is normally actuated and a signal applied to one pipe or the other at the beginning of the punching of a stack of blanks decrees whether at an output signal from the ring chamber the other solenoid valve is opened instead of or in addition to the one actuating cylinder 27. For setting up the count cycle in the ring counter a table indicating the necessary frequency of a feed increment other than the medium one, when 10 and 100 pulses are generated per press cycle, and whether it is to be small or large one can be used. Where three presses are used respectively for punching stator slots, for separating the stator ring from the rotor and for punching rotor slots, a single programming device is preferably used to control the feed increments of successive blanks relative to the punching tools of all three presses.