| 摘要 |
1,245,726. Mechanical presses. L. SCHULER G.m.b.H. 3 March, 1970 [4 March, 1969], No. 10128/70. Heading B5F. [Also in Division F2] In a press comprising a vertically reciprocable ram 2 driven through at least one pair of crank wheels 13, 14 (Figs. 1, 2) and connecting rods 18, 19, each pair of crank wheels 13, 14 is disposed coaxially and the wheels of each pair are rotated in opposite directions. In Figs. 1, 2 a pinion 4 on a main drive shaft 3 meshes with a first gear 5 which meshes with a second gear 6. The gears 5, 6 are rigid with pinions- 9, 10 respectively, the pinions 9, 10 meshing with the crank wheels 13, 14 respectively. The rods 18, 19 are connected to the ram 2 at offset positions, enabling a retarded downward movement and an accelerated upward movement of the ram to be obtained. Fig. 3 shows a modification in which a pair of two-armed levers 26, 27 are journalled on eccentrics 24, 25 provided on crank wheels 21, 22 respectively. One arm. of each lever 26, 27 is pivoted to a connecting rod 29 or 31 and the other arm to a constraining link 32 or 34 pivoted to the press frame. In a variant of the Fig. 3 embodiment the links 32, 34 are connected to the pivots 28, 30 instead of to the other lever arms. |
