Abstract: A wedging clamp assembly is provided for retaining a saw blade. A housing defining a vertical cavity therein is included in the assembly. The cavity includes a top end and a bottom end tapered with respect to the top end. Extending through a bottom end of the housing is a saw blade passageway included in the bottom end of the cavity. Disposed inside the cavity is a saw blade retention mechanism. A piston is further disposed within the cavity. The saw blade retention mechanism is configured for lockingly retaining a saw blade upon insertion into the passageway, thus, causing the piston to be biased against the bottom end of the cavity. At least one locking element is further included in the saw blade retention mechanism, and such locking element is disposed in the cavity for engaging the bottom tapered end. A wedging clamping force exerted by the at least one locking element is applied to the saw blade, and such force renders the saw blade immobile relative to the housing.

Abstract: A handheld machine tool, for example a circular saw, has a disk-shaped tool which is driven in rotation in a housing which holds a drive motor and a tool shaft carrying the tool. The tool can be clamped between a clamping nut, a clamping screw, and two supporting flanges. One supporting flange can be rotated easily relative to the tool shaft without use of auxiliary tools and is supported with an extensive friction at the tool. This supporting flange can be dependably clamped or loosened without tools. The machine tool further has an adjusting device which is coupled with that supporting flange to displace the latter axially toward the tool when that supporting shaft is rotated relative to the tool shaft due to rotational driving. The adjusting device therefore clamps the tool with an increasing force and tries to displace that supporting flange axially away from the tool automatically when the tool is stopped and accordingly reduces the clamping force.

Abstract: The blade holder includes a mounting portion for attachment to the reciprocating plunger of a power saw. The blade holder also includes an integral exposed portion provided with a slot for receiving a substantial portion of the shank of the blade. The slot is dimensioned with respect to the blade shank such that an edge of the blade shank projects from the slot. The exposed portion of the blade holder includes an external surface in opposed relationship with the slot. A resiliently biased wedging washer engages the exposed edge of the blade and the external surface for holding the blade in place.

Abstract: In the first embodiment, the distal end of a reciprocating plunger of a power saw includes a longitudinally extending cavity receiving a block-like wedge member. A planar wall of the cavity and a planar face of the wedge member are arranged for substantial coextensive engagement with respective opposed faces of the saw blade. A spring in the cavity engages the wedge member for urging the same outwardly of the cavity. A pin extends through the wedge and has its opposite ends received in slots in opposed walls of the plunger. These slots are inclined with respect to the longitudinal axis of the plunger and cooperate with the pin to form a cam to urge the planar surfaces into clamping engagement with the blade under the influence of the spring. The blade may be released by forcing the wedge inwardly of the cavity under finger pressure. In a second embodiment, a similar block-like wedge member cooperates with a U-shaped member mounted on the plunger.

Abstract: An automatic shaft lock for use in power tools with one end that carries implements such as screwdriver heads, drill bits and the like, permits use of the tool manually, i.e., without power. The locking mechanism allows rotation of the shaft by the motor but locks rotation of the shaft when torque is applied at the implement end or to the housing so as to allow manual use of the tool. In the preferred embodiment, a locking ring is concentric with an end of the spindle that is connected to the implement and also with an end of the output shaft driven by the motor. A wedging pin wedges against the locking ring to prohibit rotation of the spindle and the output shaft except when the spindle is driven by the output shaft which, when driven in either direction, traps the pin in a non-wedging position.