GB946192A - Grinding apparatus - Google Patents

Abstract

946,192. Grinding machines. SHEFFIELD CORPORATION. Aug. 29, 1962 [Sept. 13, 1961], No. 33196/62. Heading B3D. A grinding machine comprises a grinding wheel supported by a metallic hub to which a high-frequency generator imparts axial vibrations, the arrangement being such that the wheel is situated substantially in a nodal plane of the vibratory field so as to convert the axial vibrations to radial vibrations within the wheel. The wheel G, Fig. 1, is supported for vertical adjustment over the work W mounted on cross-slides 16, 18. Coaxial with the wheel hub 122, and abutting it as shown in Fig. 3 is a driving hub 20 which is mounted between separate, vibration-insulated, bearings 40, 78, Fig. 2, and is associated with a generator unit in the form of an ultrasonic transducer T 2 ; the latter is connected to the energy source by slip rings 96, 98 and housed in a casing 66 through which the rotational drive is transmitted to the wheel hub 122 by a pulley 92 and a stud coupling the vibratory hub 20 to the wheel. In the arrangement shown in Fig. 3, the wheel G is supported by a nylon bearing 130 in the plane of the abrasive portion of the wheel but, as shown in Figs. 8 and 9, alternative forms of hub may be used from which this bearing is omitted. In the embodiment of Fig. 8, an annular groove 147 is provided of such dimensions that a nodal point is at 148. The outward flare 152 of the embodiment of Fig. 9 transmits the axial vibrations received at 26 into radial vibrations which reach the wheel periphery. In each wheel construction the abrasive portion is forced on and bonded to a slightly-tapered hub periphery; a tight but removable fit is provided by a metal ring 156, Fig. 9, this ring being bonded to the abrasive portion and secured on the hub by a further ring 158. In the arrangement of Fig. 1 the work W is also mounted for ultrasonic vibration by a transducer T 1 , but it may be mounted directly on the cross-slide 16.