| 摘要 |
698,163. Milling. GIDDINGS & LEWIS MACHINE TOOL CO. Dec. 10, 1951 [Dec. 15, 1950], No. 28862/51. Class 83 (iii). [Also in Group XXX] A machine tool having a tool-head 32 movable linearly in a horizontal path between columns 26 comprises a track 36 overlying the path of movement of the head, and suspension means mounted on a trolley 38 which traverses the track 36. As applied to a planer-type milling machine, the track 36 extends between the columns 26 which support the cross-beam 28. The columns each carry an angle-piece 42 to guide a counterweight 46. Three cable-and. pulley systems are provided, the actual counter. weighting system comprising a cable 72 which is attached at each end to the ends of the beam 28 at 74, 76 and passes around a pulley 82 on each counterweight and around a pulley 90 on the head 32. Thus, horizontal movement of the head does not alter the positions of the counterweights and the trolley 38 tends to follow the movement of the head. A second cable-and-pulley system maintains the trolley 38 centralized over the head 32. One cable 100 is attached to the trolley at 102, passes over pulleys 104, 106, 108, 110, 116, 118 and 120 and is secured to the head at 122. A second cable 100a extends in an opposite manner from a point 102 on the trolley to a point 122 on the opposite side of the head. The two cables 100, 100a may be replaced by a single cable. The third cable system maintains the tension in the latter system. It comprises cables 140 each attached at one end to the cross-beam 28 and, at the other, to a tension-adjusting screw 132. Each cable passes round a pulley 136 carried by each block on which each pulley 110 is mounted. In a modification, the second and third systems, that is those including the cables 100, 100a and 140, are replaced by a single system comprising two cables each attached at one end to the back of the tool-head and at the other to the top of the head. If the tool-head is pivotally mounted, the cables 100, Fig. 11, may be attached to a slide 213 which is mounted on a block 200 secured to the tool-saddle 50 and is connected to the head by a pin-and-slot device 208, 204. Thus, when the head is tilted, the cables are moved an amount corresponding to the movement of the pulley 90. |
