Abstract: The shower spa fixture is mounted between an inlet pipe and a shower head and includes a container for mixing a stream of water with additives. A portion of the stream of water passing from the inlet pipe to the shower head is diverted into the container. The container includes a replaceable cartridge which has a first additive in a first chamber and a second additive in a second chamber. The diverted stream of water mixes with the first additive in the first chamber, passes through a screen to the second chamber, and mixes with the second additive in the second chamber. The diverted stream containing additives is then returned to the main stream of water which exits the shower head. The amount of additives added to the main stream of water is controlled by a control valve. The present invention provides an improvement over known arrangements by providing two additives which are kept separate from one another preventing a chemical reaction between the additives which would cause a loss of potency.

Abstract: An automatic bias control for substantially eliminating crossover distortion in power amplifiers. The bias current is measured in terms of a voltage developed across a resistor in series with the output device. This voltage is processed by a bias control function consisting of a summing circuit, a peak minimum detection circuit, a voltage reference and a mixing circuit added to the output stage in a controlled feedback loop. Elements of these circuits include operational amplifiers. The bias control system is compatible with other feedback loops in the amplifier so that transient and drift control are achieved and no instabilities are introduced. The bias control operates in the presence of widely varying high level signals.

Abstract: A computer input device for positioning a cursor on a computer video screen. With this device information is put into the computer by the penmanship motion of the hand holding a stylus in the fashion of a writing instrument so that only finger motion is required for data input. Device replaces the arm-to-eye coordination of the mouse with hand-to-eye coordination such as that used in ordinary penmanship. Rather than encoders driven by a turning ball or wheels, a resistance array with wiper contacts produces variable resistances which are converted into variable voltages that are a function of position of the stylus.

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: A tool holder for cutting tools used on metal cutting lathes which allows for easy adjustment of the tool position with respect to the work to be cut. Provides a simple and rapid means of tool change and adjustment while eliminating the need for extra tools for making the adjustment. Utilizes a manually adjustable collet for positioning and a simple, single lever control for clamping and releasing the tool.

Abstract: A swimming pool cleaning apparatus comprising a quick connect-disconnect handle, an ovate frame, a collecting net structure with an inner and outer section, and a blade-like edge on the forward portion of the frame. The collecting net structure contains an open inner net contained in a closed outer net; the inner net allows easy ingress of debris into the outer net while retarding its escape if the direction of net motion is reversed. The blade-like edge of moderately flexible material attached to the front of the net increases the efficiency of collection of debris close to the bottom walls of the pool. Construction of the apparatus is modular and allows easy replacement of worn parts without discarding serviceable parts; repairs can be made without the use of tools. The ease of assembly and disassembly allows the net to be stored and shipped in a disassembled state and is reflected in reduced handling costs.