GB829101A - Improvements in magnetic workholders - Google Patents

Abstract

829,101. Magnetic workholders. PANTON, J. R., and WEBB, A., [trading as PANTON & WEBB.]. April 25, 1957 [Jan. 26, 1956], No. 2573/56. Class 60. [Also in Group XXXV] A magnetic workholder comprises a block 1 of permanent magnets 9 mounted in a housing 2 for movement relative to the top work holding surfaces thereof by means of a spindle 16 which is mounted transversely in the housing and is provided with an eccentric portion 15 engaging the arms 14 of a U-shaped member 13 provided at one end of the magnetic block, whereby the block is moved to render the surface alternately operative and inoperative. The block 1, which consists of alternate magnets 9 and magnetic flux transmitting pieces 10 insulated from each other by members 11, and member 13, are held together by a bolt 12, and are slidable between the upper and lower plates 4, 7 of the housing 2 ; the upper plate 4 consists of pole pieces 5 separated by non-magnetic material 6. In the operative position, the magnets 9 and pieces 10 are aligned with the pole pieces 5 so that flux from each magnet passes through a pole piece, the work, a second pole piece, the piece 10 and lower plate 7 back to the magnet, and in the inoperative position, as shown in Fig. 2, the pole pieces provide a direct path from the magnets to the pieces 10. The means for actuating the spindle 16 which is generally flush with the side walls of the housing comprises a boss 20, Fig. 3, provided with a handle 21, a transverse key 22 to fit a groove 17 in the spindle, and an axially-projecting bolt 24 arranged to be screw-threaded into an axial bore 18 in the spindle. An extension rod may be fitted between the end of the spindle and the boss 20 so that the workholders may be operated when a workpiece overlaps the plate 4. Similar rods may connect a plurality of workholders . together for simultaneous operation by a boss member 20 and handle 21 from one side of the workholders.