A Tracer Assembly for a Copying Machine Tool.

摘要

1,176,676. Copy milling. NASSOVIA WERKZEUGMASCHINENFABRIK G.m.b.H. 16 Nov., 1967, No. 52257/67. Heading B3K. [Also in Division G3] A tracer assembly for a copying machine tool, of the kind in which the tracer leads the tool to anticipate changes in direction, includes a control head having a rotary member and co-operating stationary member in which the rotary member is urged off centre with respect to the stationary member by a bias force to a distance corresponding to the lead distance, the axis of rotation of the rotary member lying oblique to the tracing plane for all tracing directions. The tracer for a copy-milling machine comprises a tracer pin 16 held by a holder 10 which is axially slidably mounted in a tracer bar 7 but which may be locked thereto by a bolt 27. On the upper end of the bar 7 is mounted a stationary member 28 which may be frustoconical, cylindrical or ball-shaped. Deflection of the tracer in the three co-ordinate directions X, Y, Z is detected by levers 4, 5, 6 and transmitted thereby to hydraulic control valves 1, 2, 3 which respectively control the tool and tracer feed movements in these directions. Deflection of the tracer in any one of these directions can be prevented by means of locking bolts 17, 18 or 19, thereby determining the tracing plane. Thus, e.g. insertion of bolt 17 in hole 171 prevents deflection in the X axis direction and tracing is carried out in the Y, Z plane. End switches 55, 56 operable by the tool or work slides at the end of a tracing line control the insertion and withdrawal of the locking bolts 17, 18 or 19 as necessary to alter the tracing plane, resulting automatically in a delivery movement of the tracer the extent of which is controlled by a path metering switch; operation of the latter switch again alters the positions of the locking bolts and reverses the tracer connections to start the tracer moving back on a line parallel to the original tracing direction. The control head includes a rotary member 29 mounted for rotation on an oblique axis 281 and having spring-loaded rollers 341, 361 adapted to bear on the stationary member with two supporting rollers 41, 42, Fig. 3, disposed on either side of rollers 361. A lever 36 which carries roller 361 operates a switch S through a rod 38 in dependence upon the extent and direction of eccentricity of the rotary and stationary members to cause rotation of a drive motor 30 in the appropriate direction to maintain the desired angular relationship between the biasing force and the tangent at the point of contact with the pattern. Other types of signal transmitter can be used in place of the hydraulic valves 1, 2, 3 and the control head employed may be hydraulic instead of electrical.