GB586463A - Collet chucks - Google Patents

Abstract

586,463. Chucks. HINES, R. E. Sept. 22, 1944, No. 18170. [Class 83 (iii)] A collet chuck comprises a supporting body adapted to be secured to the arbor of a lathe and formed with an axial bore having a radially extending annular seat for engaging a collet, a collet mounted in said bore and having a frustoconical slotted portion at its forward end, a closing member slidably mounted on the body and having a complementary inner frustoconical surface for engaging the frusto-conical surface on the collet and actuating means for moving the closing member axially of the body to close the collet, said means including a plurality of fingers pivotally mounted on the body for engaging a radially extending portion of the closing member. The collet supporting body 12 is a close frictional fit within a body 14 having a radially extending flange 20 screwed to a threaded collar 28 which is screwed on to the end of the lathe spindle 34. Alternatively, the members 12 and 14 may be integral. A collet 43 is supported within the bore of the body 12 and abuts at its rear end against an annular shoulder 40 of the body 12 by which the collet is held against axial movement during the rearward collet-closing movement of the member 55. The member 55 is slidably mounted on the body 12 and at its front end is formed with a frusto-conical bore engaging the similar external frusto-conical front portion of the collet. At its rear end the member 55 is formed with a radial flange 58 having a thrust surface 59 adapted to be engaged by the surfaces 74 of fingers 62, three of which are pivotally mounted at 69 in radial slots formed in a cage member 61. The rear end of the member 61 is in screw-threaded engagement with the body 14 to which it may be locked in adjusted position by a set-screw 66. The collet is normally opened by its own resilience, but may be closed to grip the work 63 by a rearward movement of the member 55, caused by an inward movement of the fingers 62 under the cam action of a conical surface 98 formed on an actuating member 87 which may be moved axially of the chuck body by means of rollers engaging within a circumferential groove 100. The rollers are mounted at the ends of the arms of a yoke operated by a hand lever.