Abstract: A kaleidoscope includes three or four highly polished plain, front-surface mirrors assembled in the form of a prism with a cross section that is an equilateral triangle, a square or a rhombus with the angles between sides of 60.degree. and 120.degree., having a length 8 to 15 times the linear dimensions of its cross section. An optically opaque cylinder encloses the mirror assembly with opaque end caps providing alignment of the positions for the ends of the mirrors and electric light means for illuminating objects being viewed.

Abstract: In an electrocardiographic system there is a multielement electrode at two skin locations for providing an ECG signal of negligible magnitude between elements because of the close spacing while the pair of elements are sufficiently separated so that the motion of one element is at least partially independent of the motion of the other. Parallel ECG signals are obtained from different elements of two multielement electrodes. The difference between the signals is detected by logical circuitry to produce a signal indicating baseline shift.

Abstract: An external magnetic field retains a layer of magnetic liquid as a protective covering over an element, such as in slide wire potentiometers and in pressure measuring diaphragms.

Abstract: An automatic smoking device includes a beverage can having a smoking bowl seated in the top centered above a platform beneath a fan chamber carrying a flat rotating fan blade about 11/4" long by 1/2" high facing a stem at the same height that fits in an opening in the can wall and is an alligator clip insulating boot. The platform separates the flat rotating fan blade above from an electric motor below whose shaft carries the flat rotating fan blade. The compartment below the platform also encloses a battery for powering the motor and a push-button switch for coupling current from the battery to the motor when the switch is pushed to rotate the fan blade.

Abstract: A pin is connected between the two legs of the game racket frame in the handle portion near the end. This assembly is placed in a mold with an insert between the legs abutting the pin and initially effectively blocking any string from being looped around the pin and emerging through the bottom of the handle portion. Handle molding material is introduced into the mold to form the handle. The material around the pin is then routed out forming a channel open at the bottom of the handle portion for receiving the handle string that may be readily looped about the pin.

Abstract: A microwave detector comprises a tapered ridged horn that terminates in a ridged waveguide formed with a slot extending through a broad wall of the waveguide and through the ridge that accommodates a stripline positioned so that a pair of diodes are connected across the gap between the ridge and the broad wall and brought out through stepped conductors dimensioned to function as low pass filters.

Abstract: An unsulfonated cross-linked polystyrene, silicic acid and a binder comprise a tobacco smoke filter for removing essentially all nitrosamines and secondary amines from the tobacco smoke passing through the tobacco filter attached to the normally unlighted end of the cigarette.

Abstract: Food temperature vessel or other utensil comprising a thermochromic layer at a surface thereof indicating temperature of the food content of the vessel within a safe range above 60.degree. and below 70.degree. C. corresponding to achievement of safety conditions by raising the food content above the minimum temperature of the range to produce reversible protein denaturation in certain microorganisms to limit sporulation, and below a limit corresponding to irreversible protein denaturation and tissue injury of the tongue, lips or throat tissues of the user on the upper end of the range. The thermochromic layer goes through a transition from red to black across the range.

Abstract: A color marker container has a wall with holes separated by twice the marker diameter, into which the markers may be inserted, the wall around each hole being colored the same as one of the markers, the names of the colors being imprinted on the wall near the openings.

Abstract: Conducting plates of opposite electrical potential are alternately disposed and spaced apart and immersed in a dielectric fluid in a chamber. Gas is supplied to the bottom of the chamber and passes through the fluid and over the plates. A partial vacuum is maintained in the region above the surface of the dielectric, from which the gas is extracted.

Abstract: A louspeaker system having a woofer, tweeter and crossover network has a closed box resonance of 81.5 Hz which frequency is above the half-power point of 65 Hz of the system that includes active equalization of the vented box woofer in the region below 81.5 Hz with an inexpensive two-pole one-transistor circuit.

Abstract: A standard size tennis racket has a flex of substantially 1.2 centimeters at the throat, 2.4 centimeters at the head center and 5.8 centimeters at the tip when a force of substantially thirty pounds is applied to the racket tip with the racket cantilevered from the handle end. A weight between 15 and 25 grams is located on one side on the frame at the midpoint of the strings, and a weight of between 15 and 25 grams is placed at the end of the handle, the weights being concentrated in as small an area as possible, the total weight of the racket counting the side weight only being substantially the same as a conventional unweighted racket. For a 27 inch racket, the weights are selected to establish a center of gravity between 123/4 inches and 13 inches from the end of the handle and the center of percussion between 22 and 221/2 inches from the end of the handle determined by using a pivot point 43/4 inches from the end of the handle.

Abstract: A film holder receives film chips for developing and enters through an input opening where a transport mechanism carries it into a developer tray having a thermistor for providing a signal representative of the developer temperature. This signal is used to control the development time to be inversely proportional to temperature. At the end of the development cycle the transport mechanism lifts the film holder from the developer tank, carries it to the fixing tank and deposits it in the fixing tank. At the end of the next development cycle, the transport mechanism lifts the film holder from the fixing tank, transports it to the wash tank and deposits it in the wash tank. At the end of the next development cycle, the transport mechanism lifts the film holder from the wash tank and deposits it in the drying chamber where forced hot air dries the developed fixed washed film chips. They may be removed through an exit door.

Abstract: A multiple driver loudspeaker system comprises two angularly spaced rear rectangular baffles each nearly filled with four closely spaced full-range small loudspeakers with a port tube passing through the center of each rear baffle and the junction therebetween. A front baffle carries a small centrally located loudspeaker. The front loudspeaker is backed by a cavity that is vented through the port tube at the intersection between the rear baffles. Each of the remaining loudspeakers is backed by a cavity with the four cavities associated with each rear baffle being vented through the associated port tube through channels located at the front of each cavity. Two bullets are cantilevered from the front baffle rearward and essentially concentric within the respective centrally located ports. The volume of each of the nine cavities is substantially the same.

Abstract: A plug and socket connection includes helical guides at the socket for guiding mating helical pins on the plug through orifices to connection contacts protected by the orifices in the socket. The projection of each helical guide about the socket axis subtends an angle that is substantially equal to 360.degree. divided by the number of helical guides.

Abstract: A water conditioning system for fish growing tanks includes several receptacles connected to said tank and to one another in series by risers with cascade-like staggered compressed gas inlets thus obtaining rising water levels from ever one to the next receptacle, the last of which is connected by a return pipe to the growing tank.

Abstract: A kit for shrink wrap framing includes a light rigid backing board having one face coated with positionable pressure-sensitive mounting adhesive and a release sheet, a rectangular shrink-wrap envelope about 1/4 inch larger than the backing board on all four sides, with a 1-inch flap along one short side coated with pressure sensitive adhesive and a release strip, plastic corner reinforcements and double-faced foam suqares or foam tape. The user peels the release sheet from the face of the board, presses the artwork to be mounted against the exposed adhesive area, inserts the plastic corner reinforcements into the four corners of the board, inserts the board into the shrink film envelope, removes the release paper frpom the envelope flap, seals the envelope flap and exposes the assembly to heat, such as from a gun-type hair dryer until the shrink film is tightly wrapped around the enclosed assembly.

Abstract: A triggered before disarmed alarm system especially useful in connection with an automobile alarm uses CMOS circuitry and appropriate supply filtering having one hex-inverter integrated circuit as the only active component beside the output transistor. Diodes couple a negative immediate trigger, positive and negative delayed triggers and a disarm potential to various ones of the six inverters to render the output transistor conductive and signify an alarm condition only when an alarm condition is signified by a sequence of inputs consistent with unauthorized entry.

Abstract: The invention provides a toy of the type consisting of a box wherein there is a tracing device making it possible to draw forms on a translucent screen previously coated with an opaque pulverulent powder by applying a stiletto on to said screen, a toy wherein the base of said box carries at least two stirrups hinged about bearings, said stirrups co-operating with screws operating the downwards and upwards motions of said stirrups which actuate one of the rods carrying the stiletto so as to move it away from the screen or bring it closer to same, said screws being integral with driving studs arranged on the upper surface of the box.