GB190903022A - Improvement in Chucks. - Google Patents

Abstract

3022. Morrow, A. P. Feb. 8. Chucks.-In a chuck, means are provided for quickly relaxing the grip of the jaws on the initial rotary movement of the case. The case A has a smooth interior bore into which fits a sectional head B, relative rotary motion only being allowed by a ball race D ; the jaws C are retained in slides in the casing A by a screw cap A<1> and rotate with the case. A coupling-section B' is formed in two parts, one part b being a screw shell adapted to screw into the head B, and the other part being a head b<1> which screws by a coarse thread G into the portion b, the head b<1> having an end b<2> adapted to hold the ends of the jaws in dovetail grooves and so retract or advance them. The motion of b<1> relatively to b is limited by a pin g wbich can rotate in slots f in the head b until it reaches the ends of the slot initially-releasing the jaws ; on further rotation of the case A the jaws are wholly retracted. Instead of the ball bearings D, pins screwed into the case A may be used, or instead of the double head for retracting the jaws, a single head I is used, and the jaws are mounted so as to be rotatable with the case A<2> round the head L, the initial movement of the case being allowed to loosen the jaws by pins i moving in cam slots K in a screwed sleeve I'. Another device for releasing the jaws is shown in Fig. 10, wherein the part p<1> is bolted on to a pin which is retained in the screwed portion N by an enlarged head engaging a recess, and initial relative motion being allowed by a cam projection n engaging a cam slot; or a device as shown in Fig. 11 may be employed, where the relative motion is limited by the balls S engaging cam grooves in the head R.