GB825439A - A device for automatically setting a machine element to a pre-opted position either in linear or angular measure - Google Patents

Abstract

825,439. Machine-tool details. BERLINER MASCHINENBAU AKTIENGESELLSCHAFT VORM. L. SCHWARTZKOPFF. March 18, 1957 [March 28, 1956], No. 8771/57. Class 83 (3). Means in a machine for automatically setting an element to a predetermined position (e.g. a drill-slide 16 or an indexing - table), comprises adjustable stop members 2 on a longitudinallydisplaceable rail 1, and a contact finger 15, which is connected with the element, and which can be automatically intercepted by a preselected stop member. The stops 2 are mounted for relative adjustment on a bar 1 movable on rails 3 by a screw-and-nut drive 4, 5. The screw 5 is rotated by a motor 10 through reversing gears 6 and magnetic clutches 7, 8. The rail 1 can be moved up to a distance equal to treble the space between the stops, the distance being indicated on a revolution counter 9 and limited by switches 12, 14. The stops 2 co-operate with a contact finger 15 carried by the machine slide 16, or attached thereto by a link 19 and a slide 17 moving on a bar 18. The finger 15 is normally displaced from the line of stops, but can be moved laterally to contact a preselected stop, whereupon a microswitch 22 is actuated through a lever 21 to stop the slide. The lateral movement of the finger is effected by an electromagnet 20 which is actuated when a carbon brush 30 contacts a segment 29 which has been energized by the setting of a control lever 24. In operation, the slide 16 is moved hydraulically under electrical control, so that a drill on the slide 16 is positioned over a centre which is to form a reference zero. The bar 1 is then moved until a dog 11 thereon actuates a switch 13. The finger 15 is next moved into operative position, the rail 1 is moved until the finger 15 is actuated by a stop 2 to stop the motor 10, and the revolution counter is set to zero. Dimension setting levers 24-28 are also set to zero, and the slide can then be traversed either to the left or the right by an amount set by the levers. The first lever determines the direction of traverse of the machine slide, and selects the stop member which is to be contacted by the finger. The initial movement of the slide is such that the finger always approaches the selected stop from the same side, to eliminate back-lash. Thus, in certain cases, the slide movement is reversed before being stopped. The slide is automatically clamped in its adjusted position. In a modification, the finger 15 is deflected laterally by oblique faces on the stops. In the case of a table which is to be indexed, the stops are arranged in a circle.