Abstract: The conventional exercise device for performing sit-ups includes a base and a strap for holding the feet of the user on the base. The number of consecutive sit-ups performed by an exerciser can be dramatically increased by using an exercise device including a frame, and footrests, calf supports, thigh supports and a seat on the frame, with each of such elements being adjustable in terms of position and inclination on the frame.

Abstract: A book mold for producing a plurality of flat footwear soles simultaneously includes opposed top and bottom molds, each of which includes a pair of mold cavities; and an intermediate mold defined by a plate connected to one end of the bottom mold by a piano hinge. The intermediate mold is closed on the bottom mold, and the top mold is clamped on the intermediate mold using a clamping cylinder. Thermoplastic material is injected into the mold cavities through a port defined by a square slot in the intermediate mold, resulting in a large sprue in the intermediate mold. The soles remained attached to the intermediate mold, and when the mold is opened all soles are removed rapidly.

Abstract: A toe binding for a cross country ski includes a rectangular plastic block for mounting on the ski, with a T-shaped groove in the top of the block for receiving a similarly shaped toe piece. One end of the toe piece is molded into or otherwise permanently attached to the sole of a cross country ski boot, the T-shaped front end of the toe piece extending forwardly. The toe piece is retained in the block by pins slidably mounted in the block for intersecting the groove above the toe piece. The pins are biased across the groove by a leaf spring, and can be moved out of the groove by a handle connected to the spring and pivotally connected to the block by a lever, the handle having a notch for receiving the tip of a ski pole, whereby the handle, lever, spring and pins can be moved.

Abstract: An exercise device for the hands and wrists includes an elongated cylindrical body, with a sleeve rotatably mounted on each end thereof and a cord, one end of which is fixedly connected to the body between the sleeves. A weight is mounted on the other end of the cord. By alternately squeezing, rotating and releasing the ends of the body, i.e. by squeezing, rotating and releasing one sleeve and then the other sleeve, the cord is coiled around the center of the body to raise the weight.

Abstract: A pneumatic jet injector for needleless injection of a liquid medicine into the skin includes a pistol-shaped casing including a barrel, a handle and a trigger; a compression chamber in one end of the casing for a gas which is partially liquefied under pressure; a first piston movable in the casing against the gas; a charging liquid in the handle which is pumped against the first piston using the trigger and a second piston in the handle; a piston rod movable in the barrel with the first piston for creating a partial vacuum in the barrel for drawing medicine into the barrel through an inlet containing a one-way valve; a discharge orifice in one end of the barrel for discharging medicine into the skin of a user; and a safety catch in the handle for locking the first and second pistons in the loaded or charged position, and for releasing the pistons whereby at least a portion of the liquid in the compression chamber becomes gaseous moving the piston rod against the medicine to discharge the medicine through the

Abstract: A marine propulsion apparatus including a flexible, elongated plate, with a flexible tube attached to each side of the plate, or a flexible plate through which fluid can be passed. In use, the plate is cantilevered to a boat. When water is passed through the tubes at a sufficiently high velocity, the tubes and plate undulate with a downstream propagating wave component, resembling the swimming motions of a slender fish. The result is a forward propulsion of the boat.