Patent GB-357622-A (GB)
Title: Improvements in or relating to grinding or abrading machines
IPC: B24B47/06
Filed: 1930-06-18
Abstract: 357,622. Grinding. CINCINNATI GRINDERS, Inc., 3058, South Street, Cincinnati, Ohio, U.S.A.-(Assignees of Einstein, S., Booth, C., and Haas, F. S. ; 3058, South Street, Cincinnati, Ohio, U.S.A.) June 18, 1930, No. 18669. Convention date, June 26, 1929. [Class 60.] Round holes, enlarging and trueing.-An internal grinding-machine adapted automatically by electrical and hydraulic mechanism to place workpieces in a chuck to move the work to grinding position, apply the feed, and when the work is to size eject the work and replace it, consists of a bed 30 having thereon ways 31, 32, the ways 31 , having mounted thereon a slide 33 carrying a grinding-wheel 37 driven by an electric motor 34, the slide being reciprocated by a fluid pressure cylinder 39 and piston 38 by the action of dogs 42, carried by the slide, on a reversing lever 40. On the ways 32 is mounted a table 43 reciprocated by a piston 160 in a cylinder 159 and controlled by a valve 158 to move the work into and out of grinding position. The work 44 is fed, whilst the wheel 37 lies wholly in contact therewith, by movement of a table 46, mounted for transverse movement on the table 43, by means of a cam 47 engaging a cam-follower 48 carried by the table 46. On the table 46 is mounted a swivel table 49 adjustable by worm gearing and on the table 49 is a head 53 carrying a chuck with clamp fingers 55 driven through bevel and worm gearing from a shaft in the machine bed. The table 46 is moved rearwards to disengage the work from the wheel 37 by a piston 71, acting in a cylinder 70 and engaging a sleeve 60 of the table 49 in opposition to the action of the cam 47. The follower 48 is carried by a nut 73 engaging a screw 74 on the table 46, and the cam 47 is carried by a sleeve oscillatable in the table 43 by an arm 78 moved by a piston 81 in a cylinder 82 carried by a bracket 83, and under control of a valve 85 operated by solenoids 89, 90. In order to compensate for wear of the wheel 37, the table 46 is fed by movement of a shaft 91 carried in the bracket 83 and rotatably carrying a gear 97 driven from a rack on the piston 81 through a double gear 99, the gear 97 also being integral with a disc 96 having thereon a spring- pressed pawl adapted to engage a ratchet wheel which rotates the shaft 91, and through bevel gears the screw 74; a knock-out screw acting on the pawl serves to set the amount of rotation of the shaft 91 to give the required feed to compensate for wear of the wheel. The machine operates as follows. An arm 122 carried by a rock shaft 123 is depressed manually, fingers 124, 125 on the arm engaging a work-piece 44 in a shoot 127 and moving the piece 44 down to alignment with the chuck fingers 55 which are normally held open by a spring 126. The arm is then moved axially inwards by a spring and cam to place the work within the chuck, where it engages a head 133 rotatable on a rod 134 and moves this rod and a piston 135 thereon outwards; a switch 137 also is closed to actuate a solenoid 139 moving a valve 140 which admits fluid to the cylinder 141 to move the piston 135 to the left, thus causing a conical part 145 of the head 133 to press the fingers 55 to grip the work. The piston also, through a lug 142, closes a switch 143 to operate a solenoid 147 to move a valve 148 to move a piston 151, which, through rack gearing, rotates the shaft 123 to lift the arm 122, thereby also closing a switch 155 of the circuit a solenoid 157, moving the valve 158 to cause the piston 160 to move the table 43 and the work into operative position ; the work may be rotated continuously or stopped when retracted, by a switch 161 opened by the table. When the table reaches the working position, a dog thereon engages a trip 163, and through a link 164 moves an arm within the casing 224 closing a switch 176 to operate the valve of piston 81 and thereby apply feed by means of the cam 47, and at the same time oscillating a shaft to move the valve 158 to neutral position, thus stopping movement of the table 43. The feeding of the work is continued until the work is to size as determined by a device consisting of a casing 185 on the table 83 carrying a spindle 186 with a head 188 thereon carrying a pivoted arm with a contact point 190 adapted to contact with the grinding-wheel, and set in definite relation to the axis of the work. The lever, when it is swung by contact with the grinding-wheel, closes the circuit of the solenoid 90, reversing the valve 85 and thus the piston 81 so that the table 46 is retracted by piston 71 ; the circuit of a solenoid 197 also is closed to reverse valve 158 so that the table 43 is moved to carry the work from the grinding-wheel. The table moves until a dog engages the trip 163 thus moving the table valve to neutral, and at the same time closing a switch 199 of solenoid 201 reversing the valve 140 moving the piston 135 forward to release and eject the work ; the lug 142 then closes switch 203 to actuate the valve 148 to operate the arm 122 to carry a new work-piece into position; the valve 148 is then moved to neutral position. The gauging device is moved away from the working position during ejection and insertion of the work by rotation of the support 186 by a pinion 214 actuated by a rack bar 215 moved by the worktable, and brought to operative position by a spring 217. Cooling fluid is provided by a pipe having therein a valve which is closed during the inoperative periods of the machine. The grinding- wheel may be fed instead of the work.