| 摘要 |
940,865. Cam mechanism. G. JESSE. June 18, 1962 [June 20, 1961], No. 23301/62. Heading F2K. [Also in Division F1] Mechanism for varying the stroke of a piston 40 of a proportioning pump comprises a cylindrical bush 18 connected to the piston 40 and provided with two cam slots 19 disposed in opposite walls, a cylindrical bore 17 in a casing 11 within which the bush is rotatable and axially displaceable, a driving connecting rod 20 having mutually aligned gudgeon pins 24 which slidingly engage the cam slots 19, and a stroke-governing disc 27 having an elongated diametrical groove 29 which is engaged by a pin 25 projecting from the bush 18 and passing through an aperture 26 in the wall of the bore 17. The periphery of the disc 27 is toothed and operatively engaged by a worm 34 on a spindle 35 which may be rotated by a hand wheel 38 to vary the angular location of the groove 29. If zero stroke is required, the wheel 27 is turned so that the groove 29 lies at right-angles to the axis of the bush 18, as shown in Fig. 7. With the slot extending parallel to the axis of bush 18, as shown in Fig. 5, maximum stroke is effected. The connecting rod 20 is driven from an eccentric on a shaft 15 which also drives a diametrically opposed similar mechanism. The eccentric may be replaced by a crank. |
