GB602641A - Improvements in or relating to grinding machine - Google Patents

Abstract

602,641. Trueing grinding-wheels. SHEFFIELD CORPORATION. Nov. 2, 1945, No. 29095. Convention date, Nov. 20, 1944. [Class 60] A grinding-machine, having a rotatable grinding-wheel mounted on a support, a crusher wheel for forming the grinding wheel, said crusher wheel being rotatably mounted on a holder, a holder support on which said holder is mounted for movement in a direction towards and from the grinding wheel, is characterised by the fact that said holder is yieldingly mounted on said holder support and that means is provided for moving one of said supports to cause engagement of said wheels and movement of said yieldingly mounted holder on the holder support, and means automatically operable as a result of said yielding movement for positively adjusting the wheels one towards the other to force said wheels one into the other at a comparatively slow feeding rate. An annularly ribbed crushing roller 11, for forming a ribbed grinding wheel 10, is freely mounted in a bracket 15 adjustably bolted to a holder 18 slidably guided on a support 20 slidable on a housing 19, a spring 34 being interposed between the lower part of the slide 20 and a projection 35 on the holder 18. Fixed to the rear of the slide 20 is an internally threaded boss 27 engaged by a threaded shaft 28. This shaft is driven, by a motor 49 through gearing 50, 51, 52 and a clutch hub 54 keyed to the said shaft 28, so that the slide 20, and thus the crusher wheel, is moved rapidly down towards the grinding wheel 10. When the crusher wheel contacts the grinding wheel the slide 20 continues to move and compresses the spring 34, the consequent relative motion of the holder 18 and the slide 20 moves a lever 38 to close a limit switch which operates a solenoid 41 to straighten a toggle linkage 43 to move a finger 44 which locks the slide 20 and the holder 18. Also as a result of the closing of the limit switch, and by means of a system of switches and a timing motor, the grinding wheel is driven at a slower speed, by switching over to another driving motor, and the clutch hub 54 is lowered to be driven from the motor 49 through a worm wheel 60 so that the crusher wheel is fed at a slower speed for a predetermined time. The clutch is then auto. matically disengaged to stop further feed of the crusher wheel for a few turns of the grinding wheel and the crusher wheel is rapidly withdrawn, the clutch 54 engaging a clutch plate 53 and the motor 49 being reversed, the holder 18 being unlocked from the slide 20 as a pin 46 breaks the aligned arrangement of the toggle arm 43. Cooling liquid is automatically supplied when the wheels engage the supply being stopped when the crushing action is completed. A cover 73 over the grinding wheel is automatically withdrawn out of the path of the crusher wheel.