Other

Jbd Corporation

James D Cunningham

James E Smith

A high impact device, as for producing an impact of 1,000 foot pounds or more, includes a ram which is engageable by a pair of rotating flywheels. The ram may impact a tool, as of a chisel type adapted for demolition purposes, or having a enlarged head for percussion purposes, or other types or purposes. By terminating the engagement of the flywheels with the ram prior to its impact against a tool or similar object, the vibration normally associated with a demolition or percussion device is avoided. Such termination of engagement also reduces reverse shocks and conserves the energy of the rotating flywheels. In one embodiment, the flywheels are moved inwardly and outwardly of the ram through a linkage connected to a solenoid, with each flywheel supported between a pair of arms and alignment of the axis of each flywheel with the side of the corresponding ram being maintained by a torque tube extending between the arms. A guide for the ram extends into a tool housing, and the ram has an enlargement to engage a hole in an upper plate to limit upward movement and on downward movement to engage a metal ring placed above a pair of resilient rings, for resilieintly terminating downward movement of the ram, if necessary. In another embodiment, one flywheel is fixed, although adjustable laterally, while the other flywheel is pivotally mounted and moved by a hydraulic cylinder with each flywheel being rotated by a hydraulic motor. A heavy coil spring is engaged by the ram on its upward stroke and returns the energy, normally dissipated, to the ram to start it down so that the ram is moving downwardly when engaged by the flywheels. A sensor activated on the upward stroke of the ram may control the inward movement of the movable flywheel while a sensor activated on the downward stroke of the ram may control the withdrawal of the movable flywheel from the ram path. Each sensor control is correlated with the lag time in the movement of the ram from the activating position to a position at which the flywheels should engage the ram and a position when the upper end of the ram is just below the flywheels, respectively.

High impact device and method

A pair of rotating flywheels which engage a ram for moving a tool which impacts a part, such as a nail to be driven, are rotated in opposite directions from a single motor or other rotating means, through a pair of substantially identical gears, one of which drives one flywheel and the other of which drives the other flywheel. The drive connection between the respective gears and each of the flywheels may include a belt and pulley arrangement, so that each flywheel may be driven directly by the respective belt but the flywheels are pivoted toward and away from the ram so that when the flywheel moves toward the corresponding side of the ram, the connection between the belt and the corresponding pulley will tend to slacken. A special flywheel pulley has an inner V-shaped groove and parallel side walls for guiding the belt into the groove when full tension occurs. A pair of sockets for receiving pivot pins for the respective flywheels are connected by a bar which is integral with a corresponding end plate and not only withstand precession forces but also tensile forces. A friction surface on the ram, particularly when the flywheel peripheries are polished steel, is a fabric layer of natural fiber, such as long fiber cotton cloth, impregnated by and molded in polyurethane, i.e. a natural fiber embedded in a medium hard plastic or rubber. A bumper has a pyramidal socket to engage a corresponding end of the ram on its return.

Impact devices

One or both of a pair of oppositely rotating bodies, such as motor driven flywheels, are mounted for pivotal movement against the side of a ram. One or more tension rods connect pivot shafts or members for equalizing precession and similar forces of rotating bodies, rather than housing. Pulsed solenoids produce force increased by force multiplying device, such as pivoted links or cable arrangement, which has greatest mechanical advantage when solenoid pull is weakest at start, but decreases as solenoid pull increases. Ram has entrance taper on one or both sides. Ram is returned by nylon sheathed bundle of elastomer cords which are looped around ram from both sides and stretch proportionally along their length. Removable guide rods engage holes in side wings of ram. Safety device is actuated by rod, moved through engagement with work piece, for closing safety switch in solenoid circuit. Alternatively, a block engages a ram wing to prevent impact stroke, but is removed by a similar rod. Alternatively, a stop block is placed between motor housings to prevent movement against ram until work piece is engaged and similar rod moves spring pressed pivoted link to withdraw stop block.

Electrically operated impact tool

This invention relates to an electric impact tool characterized by a pair of electric motor-driven counterrotating flywheels, at least one of which is movable relative to the other from a retracted inoperative position into an extended operative one closely adjacent the other flywheel whereby a ram is squeezed therebetween and impelled forward at high speed against a workpiece. The nosepiece of the tool frame is retractable although normally extended due to the spring bias urging it and the movable flywheel to which it is mechanically linked into disengaged position. These elements cooperate with one another and with a manually-actuated trigger such that the latter must be depressed and the nosepiece retracted in order to engage the high energy friction clutch defined by the flywheels so as to operate the ram. A flywheel speed control is provided for matching the ram impact to the workload. The nosepiece also includes an energy absorbing cushion effective to dissipate the excess energy carried by the ram at the end of its work stroke so as to prevent damage to the structure against which the nosepiece is pressed.

Growing community of inventors

Boulder, CO, United States of America

James D Cunningham