Abstract: Intermittent screw thread geometry with a rapid step-wise lead feature when external threads are engaged with internal threads of reflective geometry. In an embodiment, thread segments are alternated with unthreaded segments of equal arc length along a helical path of a single-start thread form which results in an odd number of alternating thread/gap features along the helical path per revolution of the thread body. When such external intermittent threads engage internal intermittent threads of reflective geometry, an external thread body can be axially advanced or retracted through an internal thread body in a rapid step-wise fashion by turning the external thread body in either the clockwise or counterclockwise direction, or in both directions alternately, with respect to the internal thread body when a net axial force is applied to the external threaded body with respect to the internal thread body in the desired linear direction of travel.

Abstract: A workpiece change for use in a machine tool that comprises a tool spindle for clamping tools for machining workpieces, comprises two wheels arranged parallel to one another and rotatable about an axis of rotation into at least two prominent angular positions. Two swivel tables for clamping workpieces are arranged between the wheels and are each mounted on the wheels to swivel about a swivel axis which runs parallel to the axis of rotation. In each prominent angular position, one of the swivel tables is located in its working position in which clamped workpieces can be machined with the tools. Both wheels are supported at their rim.

Abstract: A person support apparatus comprises a lower frame, a support, and an upper frame. The support is coupled to the lower frame. The upper frame has a head section and a foot section and defines a longitudinal axis passing through the head section and the foot section and a lateral axis substantially perpendicular to the longitudinal axis. The upper frame includes a tilt mechanism pivotably coupling the upper frame to the support. The tilt mechanism includes a base and a rocker nested within the base. The base and the rocker are pivotable with respect to one another about a pivot axis that passes through the base and the rocker and is substantially parallel the longitudinal axis. The upper frame is pivotable about the pivot axis with respect to the lower frame.

Abstract: A modular workpiece holding apparatus comprising a first portion including a first base and a first jaw member supported by the first base and, additionally, a second portion including a second base positionable relative to the first base at a selected distance relative to the first base, wherein the selected distance is selected by the operator of the modular apparatus. The modular apparatus can further include a movable second jaw member and a drive member extending between the first base and the second base, wherein the second jaw member comprises a connector movable between an engaged position in which the second jaw member is operably engaged with the drive member and a disengaged position in which the second jaw member is operably disengaged from the drive member. The drive member extends between the first and second portions when the portions are positioned on a foundation plate at the selected distance.

Abstract: A vise includes a screw rod extended through an adjustable and a fixed jaw. The adjustable jaw is internally provided with a cam sleeve having a centered cam-shaped bore and two opposite arms outward projected therefrom. The cam-shaped bore is slightly larger than an outer diameter of the screw rod, and provided at one lateral surface with a small length of screw threads. When the screw rod is turned clockwise, it brings the cam sleeve to rotate at the same time while moves in the cam-shaped bore to mesh with the screw threads in the bore, causing the cam sleeve to axially move along the screw rod and finely shifts the adjustable jaw relative to the fixed jaw. And, when the screw rod is turned counterclockwise, it disengages from the screw threads in the cam-shaped bore, allowing the cam sleeve to freely and quickly move along the screw rod.

Abstract: A woodworker's vise that includes a fixed jaw adapted to be mounted to a workbench or the like and a moveable jaw assembly adapted to move with respect to the fixed jaw. The moveable jaw assembly includes an inner jaw, a front support and preferably a pin mounting the inner jaw to the front support in a manner that permits the inner jaw to pivot and to slide vertically relative to the front support. The woodworker's vise also includes a rapid-acting nut assembly disposed about the spindle that includes a pair of cam surfaces for causing engagement and disengagement of the assembly and the spindle.

Abstract: A quick acting threaded fastener assembly using two identical half nuts with alternating internal threaded and grooved portions which are either threadedly engaged or slidably aligned with a threaded rod which has corresponding alternating external threaded and landed portions. The screw and nut combination provides quick release and tightening features which facilitate opening and closing clamping jaws or pads on vises, clamps, adjustable wrenches and other devices otherwise requiring many turns of long screws.

Abstract: The clamp includes a member having an anvil at one end and a threaded bore at another end with a longitudinal bore axis directed at the anvil. A rod having threads and longitudinal splines is threadingly disposed within the threaded bore. The rod has a first end, preferably with a handle, and a second end, preferably with a shoe, facing the anvil. A gear matingly engageable with the splines on the rod is rotatably held to the member by a fastener through a central bore. The gear intertwines with the splines on the rod, such that movement of the gear in one direction rotates the rod to threadingly move the rod through the bore along the longitudinal axis of the rod. A second embodiment of the clamp includes a member having an anvil at one end and a bore at another end with a longitudinal bore axis directed at the anvil. A rod having a plurality of threads and a pair of longitudinally extending, generally smooth surfaces is disposed within the bore.

Abstract: A clamping apparatus is actuated to clamping position by a reciprocating elongated member having a clutch mechanism which either permits or does not permit reciprocation of the elongate member according to the rotative position of the elongate member in the clutch and a screw means for advancing the clamping face when the unit formed by the clutch in engagement with the elongate member is rotated. The clutch is designed so that it does not disengage until after a workpiece is unclamped.