Abstract: The invention relates to a two-wheeled exercise device that serves to support the feet or legs of the exerciser spaced above an appropriate support surface, in a manner that they can be moved freely along the support surface. The exercise device has a substantially unitary cross member and a pair of wheels rotatably connected thereto, for rotation about an axis extended between the cross member ends. Holding forms on the cross member are laterally spaced apart and between the wheels, to hold the feet of legs just below the knees of the exerciser.

Abstract: The disclosed exercise device has a frame, wheels connected to the frame operable to support the frame for movement along a generally flat horizontally disposed support surface, and structures the frame includes foot retainers to receive and hold the legs of the exerciser, generally at or near the feet, relative to the frame, with the exerciser's toes generally pointing in the same direction. The exercise device is used by the exerciser assuming a substantially rigid bridged position on a generally horizontal support surface, supported at the head end primarily on his/her hands and at the feet end primarily on his/her legs via the exercise device. The exerciser then can move his/her body at the waist and/or hips and/or knees and/or elbows and/or shoulders, with the hands stationary, to move the frame device along the support surface toward and away from the hands, or moving the hands along hand over hand on the support surface, to move the frame device along the support surface in following the hands.

Abstract: A portable device adapted to be secured to a generally horizontal board, vis a bench in a locker room or the like, operable to assist an exerciser in doing situps and related exercises. The device has a single flexible board strap and a pair of flexible leg straps secured to the board strap. The board strap is of sufficient length to be wrapped around the board, extending transverse to the length thereof; and means are provided to secure the ends of the board strap together to hold the board strap firmly wrapped in place relative to the board. Each leg strap is formed of two pieces having adjacent end portions that are disposed on opposite faces of the board strap, and that are overlapped and secured together as by stitches adjacent the opposite side edges of the board strap.

Abstract: Sensitive control of the rate of flow of a fluid under pressure over a wide range of pressures and over a wide range of pressure differentials is effected by a valve comprising a pair of telescoping piston and regulator elements movable relative to each other against the biasing action of a spring when the fluid pressure upon the valve exceeds a predetermined level, the relative motion of the two elements (the upstream piston element and the downstream regulator element) resulting in a degree of closure of ports in the downstream regulator element which depends on the degree to which the pressure differential across the valve differs in magnitude from a pre-selected pressure differential. A critical relationship of the areas of piston ports, regulator ports and fixed-area exit orifice is defined which gives novel and unexpected flow-rate control over wide pressure differentials across the valve.

Abstract: An improved hydraulic flow-control valve with critical dimensional characteristics which assure laminar flow rather than turbulent flow through the valve thus reducing or eliminating valve "hunting" or chattering and increasing sensitivity of the valve to pressure changes and assuring accurate and totally predictable fluid flow control over a wide range of differential pressures across the valve.