Patent GB-968558-A (GB)
Title: Dynamically actuated balancing means
Inventor: BACKER WILLIAM RICHARD
IPC: G01M1/36
Filed: 1962-04-11
Abstract: 968,558. Dynamic balancing apparatus. NORTON CO. March 29, 1963 [April 11, 1962], No. 14054/62. Heading G1X. [Also in Division B3] Dynamically actuated balancing apparatus comprises a rotatably mounted spindle assembly 23 arranged to support a rotatable member, such as a grinding wheel 36, and having releasable restraining means for maintaining the member concentric with the spindle assembly, balancing means 175 immobilised when the rotatable member is constrained by the restraining means and operable to balance the member mounted on the spindle assembly when the restraining means is released, and an actuating means 29 selectively operable between first and second positions in which the member is constrained and released, respectively, by the restraining means, the actuating means having a resilient supporting means 101 to yieldably support the member when the restraining means is released. As applied to a grinding machine, the spindle assembly 23 is mounted in bearings 21, 22 in openings 17, 18 of a head 31, movable on guideways 11, 12. The assembly is axially reciprocated by a mechanism 41 and has two parts 24, 25, part 25 supporting the grinding wheel and being movable relative to the part 24 from a first position in which tapered surfaces 26, 27 of the parts retain the part 25 concentric with the part 24 to a second position in which the surfaces are separated for the balancing operation. The movement of part 25 relative to part 24 is effected by actuating means 29 comprising a hydraulic piston 107 which slides in a cylinder 111 and is connected to one end of a rod 101 forming the resilient supporting means, the other end of the rod having a tapered portion 156 which is retained in engagement with the part 25 by a nut 173. The said other end also rotatably supports three balancing weights 175 which, in the normal position of the spindle parts, have pointed screws 176, 176<1>, 176<11> engaging notches in a locking ring 181 restrained from movement relative to the part 24 by flexible cables 193. In the normal position of the parts, the tapered surfaces 26, 27 of the parts 24, 25 engage each other and a cylindrical surfaces 151 of the rod 101 is received within a surface 153 in the member 24. When it is desired to balance the grinding wheel at the end of a grinding cycle, an electro-hydraulic circuit is operated to supply hydraulic fluid to a chamber 118 of the cylinder 111 to move the piston 107 and rod 101 to the left and disengage the surface 26 from surface 27 and surface 151 of rod 101 from the surface 153 so that the wheel 36 is free to oscillate under the restraint of the yieldable rod 101. At the same time, the points of the screws 176, 176<1>, 176<11> are disengaged'from the notched disc so that the weights 175 can move to positions balancing the wheel as described in U.S.A. Specification 1,967,163. Thereafter,the hydraulic supply to the cylinder 111 is reversed to retract the rod 101 so that the screws engage the notched disc 181, the surface 151 of the rod engages the surface 153, and finally the surface 27 on part 25 engages surface 26 on part 24 to accurately locate the spindle parts. The spindle is rotated by a drive comprising pulleys 32, 33 and belts 34 and the rod 101 is rotatable in the piston 107 of the hydraulic actuator 29, the cylinder of which is prevented from rotating by an arm 131 engaging a forked member 133 on the head 31. In an alternative embodiment, the end of the rod 101 extending through the wheel 36 is supported in bearings in a sleeve which, during grinding, engages a cylindrical surface of a support but during balancing is moved by the rod from engagement with the surface to permit oscillation of the wheel on the resilient rod 101. U.S.A. Specifications 1,584,717 and 1,808,401 also are referred to.