Patent GB-1108341-A (GB)
Title: Improvements in or relating to automatic cutter grinding machine
Inventor: MITSUI MIKIZO
IPC: B24B3/02
Filed: 1965-04-05
Abstract: 1,108,341. Valves. TOYODA KOKI KABUSHIKI KAISHA. 5 April, 1965, No. 14287/65. Heading F2V. [Also in Division B3] An automatic cutter grinding machine comprises a hydraulic cylinder 5, Fig. 1, for subjecting a traverse motion to a wheel head 1, a hydro-motor 6 for subjecting an indexing motion to a cutter 4, and a rotary valve 10 having two rotary discs 24, 24<SP>1</SP>, one of the discs being adapted to control the hydro-motor successively in a predetermined order including a negatively directional drive for the indexing, and the other of the discs being adapted to control the hydraulic cylinder successively in a predetermined order after the hydro-motor has ended a cycle of motion for the indexing. The wheelhead 1 carries a grinding wheel 1<SP>1</SP> driven by an electric motor and is mounted on a column 1<SP>11</SP> movable along a table 7 by the hydraulic cylinder 5. The cutter 4 is mounted on a workhead 2 containing the hydro-motor 6 for indexing the cutter, a stop finger 3 being mounted on an arm 3<SP>1</SP> adjacent the cutter for engaging the blades thereof to determine the indexed positions of the cutter; during indexing, a blade moves past the finger arid is then reversed to engage the finger. The valve 10, Fig. 2, has a shaft 21 which is rotated by a worm-and-wheel mechanism 17, 18 from a pulley 14 driven by a motor when clutch teeth 19, 19<SP>1</SP> on the wheel 18 and an axially-movable part 20 keyed to the shaft are engaged. The shaft 21 is also keyed to the rotary discs 24, 241 which are disposed one on each side of a distributer 25 in chambers 27, 27<SP>1</SP> in body parts 15, 15<SP>1</SP>. Each disc has two perforations 41, 42 and 51, 52, perforations 41, 42 in disc 24 co-operating with arcuate channels 61, 62, 71, 72, Fig. 3 (not shown) in body part 15<SP>1</SP>, and perforations 51, 52 co-operating with arcuate channels 63, 64, 73, 74, Fig. 4 (not shown) in body part 15, the channel arrangement in the parts being identical but displaced through 90 degrees. Certain of the channels are interconnected as shown by the dotted lines in Figs. 3 and 4. Body part' 15<SP>1</SP> has ports 93, 94 leading to hydro-motor 6 and body part 15 has ports 91, 92 leading to the hydraulic cylinder 5. The distributer 25 has an inlet port 81 connected to a source of hydraulic pressure and an outlet port 85 connected to exhaust. Port 81 is connected to inner annular grooves 66, 76 which are in the faces of the distributer and co-operate with the perforations 42 and 52 in the rotary discs, while port 85 is connected to outer annular grooves 65, 75 which are in the faces of the distributer and co-operate with the perforations 41, 51 in the rotary discs. In operation, the worm 17 is rotated by an electric motor driving the pulley 14, and when the part 26'is moved inwardly, the clutch teeth 19, 19<SP>1</SP> transmit drive from the wheel 18 to the shaft 21 and the rotary discs 24, 24<SP>1</SP>. During the first quarter of a revolution of the discs, fluid from port 81 is directed to port 93 and the hydro-motor 6 to rotate the cutter 4 and move a fresh cutter blade past the finger 3: fluid is also directed from port 81 to port 92 and the cylinder 5 to maintain the wheelhead 1 in a rearmost position. When the discs are in their second quarter of revolution, the port 81 is connected to port 94 and the opposite side of hydro-motor 6 to reverse the direction of rotation of the cutter until the blade engages the finger 3 and is also maintained in communication with port 92 to keep the wheelhead in its rearmost position. In the third quarter of the revolution of the discs, the wheelhead is advanced by connecting the port 81 to port 91 and the opposite end of cylinder 5, the port 94 remaining connected to port 81 so that hydromotor 6 keeps the blade against the finger. Movement of the discs to the fourth quarter reconnects port 81 to port 92, port 91 being connected to exhaust port 85, to cause cylinder 6 to return the wheelhead to its rearmost position, the connections to hydro-motor 6 remaining the same to keep the blade in contact with the finger while the wheelhead is retracted. A flow control valve 13 is provided for adjusting the position and/or length of stroke of the wheelhead, a second flow control valve 11 is provided for adjusting the amount of indexing movement, and a third flow control valve 12 acts to absorb shock when a blade abuts the finger.