Black Decker Inc.

The Black and Decker Manufacturing Company

Bernhard Palm

The invention is directed to a power driven tool for reciprocating a cutting element such as a saw-blade or the like and includes a motor housing and a drive motor mounted in the motor housing. A gear case is connected to the motor housing and the shaft arrangement is mounted in the gear case. The shaft arrangement includes a shaft slideably mounted in the gear case for reciprocating movement. The shaft is adapted to receive the cutting element thereon. A U-shaped channel yoke is mounted to the drive shaft in such a manner that the walls of the drive shaft laterally support the U-shaped channel yoke at the base of the yoke. An eccentric drive connects the U-shaped channel yoke with the drive motor for reciprocating the shaft arrangement. A method of assembling the shaft arrangement includes the step of cutting two slots in the base of the channel yoke to define three bridges one adjacent the other bridging the gap between the leg walls of the yoke. The channel yoke is then inserted into the notch-like cut-out of the shaft so as to cause the channel yoke to engage the annular wall of the shaft in the slots at the bottom region of the cut-out. In this way, the center bridge of the channel is disposed between the inner walls of the shaft. The channel yoke is then brazed to the shaft at the interface between the channel yoke and the shaft.

Power driven tool having a reciprocating shaft arrangement and method of

A clamp arrangement for clamping saw blades to the blade holder of a power driven saw includes a seating surface formed on the end portion of a blade holder of the power driven saw for receiving the saw blade thereon. A collar surrounds the end portion of the blade holder and the shank portion of the saw blade. A threaded annular member threadably engages the collar and presses the saw blade against the seating surface and the end portion of the blade holder is, in turn, pressed against the inside wall surface of the collar. A clear passage through the annular member facilitates access to the shank portion of the saw blade held between the annular member and the seating surface whereby the shank portion can be easily removed from between the annular member and the receiving surface with the aid of an instrument passed through the clear passage in the event the blade should break off at the shank.

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Fallston, MD, United States of America

Bernhard Palm