| 摘要 |
1,101,650. Torsion bars; cams. PITNEY-BOWES Inc. 15 Aug., 1966 [26 Aug., 1965], No. 36423/66. Headings F2K and F2S. In an electrically powered business machine, e.g. a postage meter, in which a small electric motor 2 is incapable of delivering the shortinterval high torque requirements of a camshaft 10 but which, for the most part of each operational cycle, delivers a steady low-torque output above the load requirements of the camshaft 10, the available energy during the period of low-torque demand is stored in an energy accumulator mechanism in the form of a torsion bar 36 of constant general triangular crosssection and is given up to the cam-shaft 10 during the high-torque demand, e.g. when the machine is carrying out a printing operation. The cam-shaft 10, which is rotatably mounted in standards 8, 12 mounted on a base-plate, is connected to the shaft 4 of the motor 2 by a worm 6 and wheel 18, and carries a number of cams and pulleys 20, 22, 24 &c. It also has fixed thereto a cam 66 with a spirally formed surface ranging from R 1 to R 2 , Fig. 5, and with a depression 68. The torsion bar 36, which has concentrically rounded corners 40a-40c, is fixed at one end to a sheet metal wall 42 by means of a metal plate 44, which is riveted to the plate 42 and has an opening shaped to the cross-section of the torsion bar 36, and a backing ring 46. The other end of the bar is secured to the outer end of a bushing (50), Fig. 4, not shown, which is rotatably mounted in a bearing (48) in the standard (8) and which carries a lever arm (62) with a cam-follower roller (64) which accomplishes the twisting of the torsion bar. During an operational revolution of the cam-shaft, as the cam 66 is rotated counterclockwise, the spiral surface acts upon the roller 64 to twist the bar, in a clockwise direction, to a maximum at R 1 . The bar releases its energy as the cam depression 68 moves into line with the roller 64 so the torque input to the shaft 10 is sufficient to handle the transient high-torque requirements. Before the end of the operation the wheel 64 moves to low-torque position R 2 . The distance from each flat surface of the bar 36 to a diametrically opposite arcuate surface is approximately nine-tenths of the diameter of a circumscribed circle having its circumference coincident with the curved surface of the arcuate corners. The three flat sides are of equal length and the corners 40a- 40c are of the same radii and length. |
