Patent GB-1214703-A (GB)
Title: An improved lapping machine
IPC: B24B37/10
Filed: 1968-04-11
Abstract: 1,214,703. Lapping. H. F. BOVENSIEPEN, [trading as PETER WOLTERS KRATZENFABRIK UND MASCHINENFABRIK]. 11 April, 1968 [15 April, 1967], No. 17650/68. Heading B3D. A lapping machine comprises (i) a lap rotatable about a predetermined axis and having a lapping surface, (ii) at least one work-accommodating adapter on said lapping surface, and (iii) locating means for holding said adapter against rotation with the lap about said axis, said locating means comprising (a) first stop means engaging said adapter at a point located at a first distance from said axis, and (b) second stop means engaging said adapter at a point located at a second distance from said axis, said second distance exceeding said first distance, one of said stop means being cylindrical and being adjustable with reference to said adapter in a direction substantially at right angles to said lapping surface so as to vary the axial spacing from said lapping surface of the position of contact of said one stop means with said adapter. A lapping machine, Figs. 1 and 2, has a lap 3 secured to a carrier 2 rotated about a vertical axis. A shaft 5 is keyed to the carrier 2 coaxially therewith and supports a disc-shaped inner stop member 6 rotated therewith by a key 16; the disc 6 is vertically adjustable on the shaft 5 and is secured in adjusted position by a screw 17. The frame 1 supports three pivots 8 defining pivot axes for arms 7. Each arm can be secured in adjusted angular position and its free end carries a shaft 9 for a roller-shaped outer stop member 10 constituting, or mounted on, the outer race of an antifriction bearing. Three ring-shaped adapters 11 not on the lapping surface, each accommodating a plate-like workholder 13 having apertures for workpieces 12. A weight 14 may be placed on the work-holder 13 and a cushion 15 of felt or the like interposed therebetween. A stud 26 on the weight 14 engages a groove 27 in the adapter 11 to prebent relative angular movement. In operation, the adapters 11 are rotated by the disc 6. If wear is greatest on the inner part of the lapping surface the operator adjusts the disc 6 upwardly, e.g. to position 25, resulting in a tendency to tilt the adapters to lift their inner parts off the lapping surface; if wear is greatest on the outer part of the lapping surface the operator adjusts the disc 6 downwardly, e.g. to position 24. Alternatively, the axial positions of the rollers 10 may be adjusted. Additionally the distance between the disc 6 and one or more of the rollers 10 may be adjusted. In a modification, Fig. 3, the disc-shaped inner stop member 21 is freely rotatable on an adjusting sleeve 18 rotating with the shaft 5 by a key 20. A shaft 19 carried by the sleeve 18 is threaded at 19b to engage internal threads in the shaft 5, so that manipulation of the knob 19a adjusts the disc 21 vertically. In a further modification, Figs. 4 and 5, a pivot 8 supports an arm 7 carrying a roller 28 and also supports an arm 29 carrying a housing 33 in which is a shaft 30 having a head 31 for a shaft 32 carrying a roller 10. Rotation of the shaft 30 is prevented by a pin 36 and groove 37 and the shaft 30 is urged axially by a spring 34. The arms 7, 29 are adjustable angularly about the pivot 8 and preferably also vertically.