Abstract: A hand operated apparatus for reducing the size of racket handles such as used in tennis rackets is described. A base in which racket handles are secured has raised opposed sides, the edges of the sides defining a guide plane. The guide plane is parallel to the center line of the handle secured within the base. A frame, having an adjustably extendable blade means, is adapted for slideable contact with the edges so that the blade means removes material from the racket handle in a plane parallel to the center line of the handle. A control means is provided for adjusting the depth of cut of the blade means. By repeated operation, uniform depth cuts can be made on each face of a racket handle to maintain symmetry.

Abstract: The load of a compressor of a refrigeration unit is determined and from this determination a standard condenser head pressure is determined. This standard condenser head pressure is compared with measured condenser head pressure. If there is a null comparison, then the air conditioner is operating properly. If the condenser head pressure as measured varies beyond a band from the predetermined condenser head pressure for the load, it is symptomatic of less than optimum operating efficiency. Compressor load is determined as a function of the condenser cooling fluid temperature at the inlet and outlet from the condenser, or one of these temperatures and the power required by the compressor.