GB597008A - Improvements relating to power boring and turning mills - Google Patents

Abstract

597,008. Boring and turning mills ; milling-machines. GROSSMAN, A. Aug. 8, 1945, No. 20330. [Class 83 (iii)] [Also in Group XXIII] A boring, milling or grinding machine comprises a rotating work-holding chuck, a tool holder linearly moveable in a plane through the axis of the chuck and a rotary tool mounted on the holder with its axis of rotation offset from the axis of the chuck and angularly adjustable on the holder round the axis of the chuck. The work, such as an annulus 12, is held in a chuck 11 rotating about a vertical axis A and a slide 17, that is vertically, pivotally and horizontally adjustable on an overhanging frame 13, carries a turret 18. By means of an adaptor plate 20 and a bolt 25, a right-angled bracket 23 is pivotally mounted on the bottom face of the turret and carries an electric motor 27 adjustably pivoted about a horizontal axis and driving a shaft 28 and grinding wheel 29. With the axis B of attachment of the bracket 23 collinear with the axis of rotation of the chuck, the grinding wheel is adjustable round an arc having the axes A and B as centre ; if adjusted to lie on a diameter CC, Fig. 3, the horizontal traverse across the frame 13 is equal to the depth of cut achieved or, if adjusted to lie on a chord EE, the depth of cut achieved is reduced in the proportion of the cosine of the angle between the chord EE and a radius AG, thus increasing the accuracy of adjustment. For taper grinding, the turret slide 17 is tilted and the angle measured with the aid of a sine bar placed on a lip 21 of the adaptor plate and bearing against a ridge 22 so that it is parallel to the traversing slide.