Improvements in Hydraulic Machines for Rivetting, Punching, Shearing and the like.

摘要

28,384. Piat, A. Dec. 24. Riveting; punching; shearing.-Hydraulic machines of various types are controlled by a single lever, and the liquid is under compression during one stroke only. Fig. 10 shows the invention applied to an electrically driven riveting-machine. A nut 19, driven through bevel gearing, and provided with a ball thrust-bearing 37, engages a screwed extension 18 of a pump plunger 16. The pump cylinder 17 is connected to a cylinder 2, containing a heading-ram 3, kept in contact with the liquid in the cylinder by a spring 8, rod 9, and arm 91. A screw stop is provided, not shown in the Figure, to limit the stroke of the ram to the minimum necessary for closing. A small reservoir 14 provides for the change in the volume of the liquid required, when the stroke of the ram is altered, and for any leakage that may occur. Communication is effected between the cylinder 2 and the reservoir 14 by a valve held tightly on its seat by the bydraulic pressure, a safety-valve 141 being provided to limit the pressure on the piston to a predetermined amount. A control-lever 38 pivoted at 381 carries a slide 39, on which inclines 40 are adjustably mounted, and a cam arm 41, engaging a roller 421 which operates a band brake 43, the arm 44 serving as a flywheel foi the motor. The lever 38 is shown in the off position, and a movement of the lever first releases the brake strap, and then operates a reversing-rheostat 47. The plunger 16 carries a roller 401 which engages one of the inclines 40, restores the lever 38 to the off position, and prevents its further motion except in the reverse direction, thus acting as a safety locking-device. In a belt-driven machine, the lever 38 operates the belt-shipper. Modifications are described showing various arrangements of the parts as adapted for belt-driven, portable, and suspended types. In small hand-power machines, the plunger cylinder is in one with, or is directly attached to, the ram cylinder ; the nut 19 is fixed to the framing, and the screwed extension 18 of the plunger is provided with a feather-way, and is driven by bevel gearing 23, 28, Fig. 2. Two cranks 34, loose on fixed shafts 29, are provided, one, not shown, forming part of a flywheel. Screws 32 in the crank-arms, carrying pinions 31 engaging fixed bevels 30, traverse nuts 35 attached to the handles, so that the leverage obtained is continuously increased during the closing of the rivet.