Abstract: The present invention is a pressure sensing and measurement device that eliminates errors due to compliance and lack of sensitivity. The cell uses a pressure receiving means (such as a flexible diaphragm) to detect an impinging object, a means to counteract the pressure caused by the impinging object (such as internal hydraulic pressure), and a detector to measure the amount of internal pressure used to counteract the impinging force. Since the cell is internally pressurized to a point equal to a value equal to the external pressure, the diaphragm is undeflected and may avoid the problems inherent in simple diaphragm systems (such as bridging and insensitivity).

Abstract: The grip portion of a tennis racket comprises a pair of flat surfaces disposed in parallel relationship relative to each other and relative to a flat plane containing the head of the racket. Each of the flat surfaces is subtended by an obtuse angle having its vertex at a geometric center of the grip portion. A pair of at least substantially arcuate surfaces are each subtended by an acute angle and intersect the flat surfaces to define four perceptible edges about the grip portion, with each of the arcuate surfaces being defined by a radius having its center at the geometric center of the grip portion and further having a length of about 0.75 inches.

Abstract: An offshore structure which is able to withstand the ice forces imposed thereon by impinging ice sheets and other larger masses of ice wherein the structure has an upper conical portion coaxially positioned relative to a lower conical portion. The walls forming both the upper and lower portions are inclined at an angle to the horizontal to receive ice masses moving into contact with the structure. The angle of inclination from the horizontal of the upper portion is greater than the angle of inclination of the lower portion, and the cross-sectional diameter of the upper conical portion is no greater than that at the top of the lower conical portion.

Abstract: A racket for tennis and like games which includes a handle having a substantially oval cross-section, with two flat opposite planar surfaces of dimension such that the grasp of the hand on the racket is more accurately aligned to control the orientation of the plane of the head than is the case with existing rackets. The handle may be constructed to receive a rigid hollow grip portion so that the grip portion may be quickly replaceable to change grip size or surface characteristics.

Abstract: A method and apparatus for reducing ice forces on a marine structure erected in a body of water which becomes frozen through natural weather conditions. The structure has a low-ice-adhesional wall forming its perimetrical surface in the zone where natural ice will freeze onto or impinge against the structure. Enclosed chambers are built within the structure and may be in heat-transmitting relationship with the outer wall. Heat is applied to the chambers to heat and maintain the outer wall at a temperature above the melting point of the natural ice occurring in the water around it. In a preferred embodiment, the marine structure is formed with a heated wall which slopes upwardly and inwardly in the area of ice contact to provide a ramp-like surface upon which a sheet of ice will be forced with reduced friction as it moves against the structure. Thus, an edge of the sheet of ice will be prevented from strongly adhering to the structure either initially or subsequently.