APPARATUS IN WHICH ROTATING MOTION IS CONVERTED TO RECIPROCATING LINEAR MOTION, THE RECIPROCATING LINEAR MOTION INCLUDING A FIRST STROKE AT A LOWER VELOCITY THAN THE RETURN STROKE

摘要

1,200,277. Actuating devices; reciprocating drive. U.S. INDUSTRIES Inc. 12 Dec., 1968, No. 59268/68. Headings B3B and B3L. [Also in Division F2] A quick-return motion for driving a linearly reciprocating member 1, such as a ram head or a chuck of a planer or shaper, comprises a threeelement epicyclic gear having a sun 12, planets in a carrier 9, and an annulus 11, one element being driven by a rotary input, a second element driving a rotary wheel 7, 7SP1/SP which is drivingly connected to the member 1 and the third element being oscillated in synchronism with the reciprocation of the member 1 so that the wheel 7, 7SP1/SP is slowed during the working stroke of the member 1 and accelerated during the return stroke, relative to its mean angular velocity. Identical intermeshing gear-wheels 7, 7SP1/SP carry crankpins 6, 6SP1/SP coupled by connecting rods 5, 5SP1/SP to the member 1. In Fig. 1, the planet carrier 9 drives the gear-wheel 7SP1/SP via a pinion (8), (Fig. 2, not shown), and a rack 20 rigid with the member 1 meshes a pinion 21 rigid with the sun 12 to oscillate the latter as the member 1 reciprocates. A shaft (15) carrying the annulus 11 may be braked, or clutched to a belt-driven flywheel (13). In a modification, Fig. 3, not shown, a change-speed gear provides two transmission ratios between the rack (20SP1/SP) and the sun 12, and has a third setting in which the sun is held stationary. In Figs. 5, 6, the planet carrier 9 drives the gearwheel 7 via gears 41, 40. A gear sector 45 coaxial with the gear-wheel 7SP1/SP meshes a pinion 21 rigid with the sun 12, and is oscillated by means of an auxiliary connecting rod 50 on the crankpin 6SP1/SP, the small end 47 of the rod 50 being pivoted to a radius rod 48 and a link which is pivoted at 52 to the sector 45. A change-speed gear may be provided between the sector 45 and the sun 12.