| 摘要 |
865,930. Copy-milling. CINCINNATI MILLING MACHINE CO. July 2, 1959 [Nov. 10, 1958], No. 22740/59. Class 83 (3). A copying-machine comprises a source of pressure P for actuating an hydraulic motor 13 for traversing a tool and a tracer relatively to a work-piece and a pattern, means to maintain a lower pressure on one side (113) of the .motor, additional means 75, 76 connecting the other side of the motor to the source when the tracer is in a particular position, and further means 78, 77 disconnecting that side of the motor from the source and connecting it to discharge when the tracer is moved to another position. In a copymilling machine, a table 12 is moved by a piston 34 and a tool slide 20 is moved by a piston 35. The table and slide may be controlled by hand wheels 24 and 25 and the tool 27 may be moved vertically by hand wheels 28. The tracer mechanism 33 is slidable on a bracket 31 movable vertically on a cross-slide 30 mounted on the tool-slide 20. The tracer 47, Fig. 2, is secured by a screw 48 in a member 46 mounted to tilt in a ball mounting 51. The valve has a lower portion controlling the piston 35 and an upper portion controlling the piston 34. In the lower portion, there are discharge ports 68, 69, a pressure port 67, and a pair of piston-operating ports 70, 71, so that when the valve is moved in either direction the pressure port 67 is connected to one or other side of the piston. In the upper portion, there are a pair of piston-operating ports 76, 77, a pressure port 75 and a discharge port 78. In the position of the valve shown in Fig. 3, the piston 35 is not moved but pressure is applied to one side of the piston 34 through line 105. The other side of the piston is always connected to a reduced pressure in a line 108. When the valve is moved upwardly or downwardly the piston 34 is first stopped and then is reversed in its movement being moved by the reduced pressure. In a modification, Fig. 6, the upper portion of the valve body has a pistonoperating port 177, a pair of discharge ports 175, 178 and a pressure-port 176, and the valve member has a bore 168. |
