GB1081449A - Improvements in profile forming apparatus - Google Patents

Abstract

1,081,449. Grinding; copy-milling. LIGHTNING FASTENERS Ltd. Sept. 16, 1965 [Nov. 20, 1964], No. 47368/64. Headings B3D and B3K. A profile forming apparatus comprises a tool-holder support 1 and guide means 15 to allow for reciprocation of a tool-holder 18 relative to the support, the holder rotatably holding a rotary cutting tool, such as a grinding wheel or milling cutter, with its rotational axis extending in a predetermined direction Y-Y relative to the holder, which is pivotal about an axis A-A normal to the direction Y-Y, the guide means, in any pivotal position of the holder and during pivotal movement, permitting reciprocating movement of the holder relative to the pivotal axis along a path which lies in a plane containing the pivotal axis. The axis A-A passes through one end of a link 9 of a pantograph mechanism and is coincident with a pivot 8, the mechanism having further links 51, 53, 54, 55, 56 and 57, the pivot connecting the links 56, 57 being formed with a stylus for following the profile of a template 62. The mechanism also has links 58, 59 and is mounted on a pivot 60 on the machine, such as a grinding or milling machine, the pantograph causing movement of the stylus to effect movement of the tool 61 and to move the tool so that when the stylus is pivoted so as to be normal to a portion of the surface of the template, the tool takes up a corresponding angular position. The tool-holder 18 consists of a pair of brackets 27 having bearings for a shaft to which is secured the tool 61 and a pulley 31. The brackets are carried by a member 23 which is adjustable both parallel to and perpendicular to the axis of the tool by a pair of cross slides 24, 25, Fig. 1 (not shown), mounted on a plate 20. A pair of guide sleeves 16 are secured to the plate and are engaged by guide rods 15 depending from a bridge 14 mounted for adjustment about a pivot 12 on a block 2 which, at one end, is secured to a brace 6 connected to a platform 7 and, at the other end is secured by dowels to a block holder 3, the latter, and the platform 7, being secured to the pivot shaft 8 in the link 9. The plate 20 is connected by a rod 44, which is slidable in the bridge 14, to a casing 47, Fig. 3, having a worm 38 on a shaft carrying a pulley 36, the worm meshing with a wheel 39 secured to a disc 40 having an eccentrically disposed pin 41 joined to one end of a rod 42, the other end of which is connected to a pin 43 on the bridge 14. A belt 30 is entrained around both pulleys 31, 36, a pulley 34 mounted on the bridge 14, and a pulley 32 on a motor 33 carried by the platform 7. When the motor is operated, the tool 61 is rotated and the worm 38 rotates the wheel 39 to cause reciprocation of the casing 47 which is connected by the rod 44 to the holder 18 which is thereby reciprocated along the guide rods 15. The bridge is initially adjusted about the pivot 12 to bring the rods 15 parallel to the axis A-A and the tool is adjusted by the cross slides to be tangent to the axis so that when the stylus is moved over the template, the tool produces the profile on a workpiece 63, such as a metal blanking die, as it is rotated and reciprocated. Thereafter, the bridge can be adjusted about the axis of the pivot 12 so that the guide rods 15 are at an angle a, Fig. 5 (not shown), to the axis A-A, reciprocation of the tool as the stylus is moved over the template forming a clearance on the previously-formed surface.