Abstract: An improved transport system for a motion picture projector which permits either intermittent or continuous drive of a film advancement sprocket. The transport is capable of use selectively with film having, for example, either two or four perforations per picture frame. During normal operation of the projector, the sprocket is intermittently driven to advance the film through a gate while a shutter interrupts the projection light. For automated film rewind through the projector, the sprocket is driven at a continuous speed which is preferably higher than the average speed in which the film is intermittently advanced through the projector.

Abstract: A skipping exercise device is disclosed. The device comprises a rectangular frame formed from a lightweight synthetic resinous material to define two long sides and two short sides. The two long sides are each hinged at points equidistant from a first short side located from such first short side between one-ninth and one-third the length of the long sides. An abrasion resistant sleeve is positioned over such first short side and, optionally, a rotatable handle is positioned over the second short side.

Abstract: An optical electronic ignition system for industrial internal combustion engines. Light reflective markers on an optical timing disc rotated by the engine are sensed by a timing module to generate an electric pulse for initiating each spark. Each pulse simultaneously energizes optical scanners in separate distributor modules for each combustion chamber. Only the scanner scheduled to fire by reflective alignment of a separate distribution marker located elsewhere on the timing disc will trigger a related capacitive discharge ignition circuit associated with the related combustion chamber. More than one scanner may be scheduled for simultaneous firing. A single conductor carries both uniform capacitor charging current and trigger signals to the capacitive discharge ignition circuit associated with each combustion chamber. An inductive loop in the low voltage lead to an ignition coil in a capacitive discharge ignition circuit provides a signal for operating a timing light.

Abstract: An electronic vacuum modulator is disclosed for controlling air flow to a throttle valve modulator mechanism for limiting the maximum speed of an engine and, optionally, for also limiting the maximum vehicle speed. An electric signal having a frequency proportional to engine speed is converted into an electric signal which smoothly and progressively controls a solenoid valve as the engine speed increases over a narrow range at a predetermined maximum engine speed. The valve is controlled such that the modulator mechanism progressively closes a carburetor throttle valve in the engine to limit the engine speed by limiting the available power. Optionally, a vehicle speed signal also is converted into an electronic signal which smoothly and progressively controls the solenoid valve as the vehicle speed increases over a narrow range at a predetermined maximum vehicle speed.

Abstract: An improved variable speed pulley for adjusting the drive ratio between two shafts interconnected through two pulleys and a V-belt. The variable speed pulley has a hub which is attached through to one shaft with a collet. A number of keys of generally square cross sections with two opposed chamfered corners are located at each end of the hub in V-shaped axially directed keyways spaced around the periphery of the hub and in correspondingly spaced V-shaped keyways around interior openings through each of two sheave halves to permit axial movement of the sheave halves on the hub. Bushings retain the four keys within each sheave half. The bushings and the keys are of a compliant material to prevent fretting corrosion. The keys engage the bushings to prevent the bushings from rotating with respect to the sheave half and hub. A helical spring located within a spring housing is compressed between each sheave half and an adjacent one of two retainer rings located in grooves near each end of the hub.

Abstract: An improved piston assembly for high-power internal combustion engines such as supercharged diesel engines. The piston includes separate head and skirt portions. An elongated bearing member having an external journal surface is formed across the bottom of the piston head. A wrist pin, which is attached to or integral with a connecting rod, defines a generally tubular shaped bearing member having an internal bearing surface in which the piston head bearing member is journaled to permit rotational movement between the connecting rod and the piston head. The external journal surface on the piston head is supported by the wrist pin along its entire length to prevent any flexing of the wrist pin when high compressive forces are applied to the piston head. The skirt is connected to the wrist pin by thrust bearings which engage an external journal surface on the wrist pin substantially along its entire length to permit rotational movement between the piston head and the piston skirt.

Abstract: A balanced bridge chopper circuit including four metal oxide semiconductor field effect transistors (MOSFETs) is driven by a remote oscillator connected through an isolator to modulate low-voltage low-frequency input signals at their remote source into a square wave A.C. output signal that can be conducted to a common point where it is amplified and demodulated for better linear measurement of said low-voltage signals. The oscillator is connected through the isolator to the bridge circuit in such a manner that opposing pairs of the bridge transistors are simultaneously conducting. The isolator may comprise a novel photovoltaic isolation device or it may consist of an isolation transformer or of other types of electrical isolation devices.

Abstract: An improved roll former for imparting a predetermined symmetrical curve to an advancing elongated metal strip in a tube mill. The roll former includes two identical rollers, each having a contoured surface for contacting and shaping one half of the metal strip. Each roller is mounted on a shaft which extends substantially perpendicular to a form radius in a central region of the section being formed by such roller. The shafts are mounted for simultaneous pivotal adjustment in both the same direction about a point and in opposite directions about such point to compensate for camber in the strip and to receive different sized rollers.

Abstract: A spark plug having an internal auxiliary spark gap in series with an ignition noise suppressor in a center electrode is disclosed. One side of the series gap is formed by a conductive ball which also supports the suppressor.

Abstract: An improved medical restraining board for temporarily restraining, for example, a patient's forearm and wrist during intravenous administration of fluids. The arm board includes an elongated flat rigid support member which is padded on at least one side with a substantially flat sheet of flexible material having a plurality of spaced enclosed gas-filled pockets formed therein. The support member and padding are enclosed within an outer cover formed from a porous hydrophobic material, preferably of porous spun-bonded polyethylene fibers. In a modified embodiment, the support member and padding are enclosed within a microporous sealed inner cover and the outer cover is disposable and has a moisture-absorbent lining.

Abstract: An improved modular breadboard for temporarily mounting and interconnecting electrical components to form an electronic circuit. The breadboard includes two panel assemblies which are mounted on leg brackets to extend parallel and spaced apart. Modules mounting preselected circuit components or circuit subassemblies are releasably locked between the panel assemblies with spring loaded fingers on one or both of the panel assemblies. The modules and the panel assemblies are provided with a plurality of solderless spring terminals and binding posts for temporarily connecting wires and circuit components to form the experimental circuit.

Abstract: An improved straight flow check valve construction is disclosed for use as intake and discharge valves in fluid compressors and other similar applications. The valve includes a valve inlet block and a valve outlet block which are attached together at generally planar abutting surfaces. A valve stop insert is positioned therebetween in a recess formed in the inlet block. At least one pair of valve ports extends through the inlet block, the valve stop insert and the outlet block and such ports are shaped to have elongated parallel cross sections in a plane perpendicular to the ports. Each port is closed by a separate valve plate. The valve plates for each pair of ports are mounted in the inlet block between the two ports for pivoting between closed and open positions and a single elongated V-shaped spring extends between the two valve plates for simultaneously biasing both valve plates to the closed positions. When the valve plates are in the open positions, the ports are streamlined.

Abstract: An improved combined environmental control and fire protection system for a building is disclosed. Water is circulated from cooling apparatus including a closed circuit cooling tower and, when necessary, refrigeration apparatus through supply lines to air handling indirect heat exchangers, lighting fixtures and other heat sources for absorbing heat. The water then circulates through return lines to the cooling apparatus. Automatic sprinkler heads are connected to at least the return lines for fire protection. A pressure sensor detects any drop in water pressure in the circulating system caused by the opening of one or more sprinkler heads and switches the system to a fire protection mode. The pressure sensor opens a valve to connect a pressurized water supply tank to the sprinkler heads. Check valves and motorized valves controlled by the pressure sensor protect the heat exchangers, lighting fixtures and other heat sources from high pressures when the system is operating in a fire protection mode.

Abstract: An improved high voltage pulse power supply for a spark plug test fixture. AC line voltage is applied through a voltage step-down transformer, a half wave rectifier and an electronic switch to the primary winding of a conventional ignition coil. During the rise time of positive half cycles, the rectified voltage is applied through the electronic switch to the ignition coil primary. As the positive half cycle begins to fall towards the zero crossover, the electronic switch is opened. The magnetic field collapse in the ignition coil produces a high voltage negative pulse which is applied to a spark plug under test. The peak voltage of the negative pulse is adjusted by controlling the peak current in the ignition coil primary.

Abstract: An improved method and structure for forming wiring channels in a concrete floor. Parallel trenches are formed in a concrete floor slab when the slab is poured. A metal cover placed over each trench has a metal U-shaped channel attached thereto for dividing the trench into at least two and preferably three separate wire raceways with the center raceway completely shielded by the channel and cover. Access boxes are selectively positioned over knockouts in the cover plate. Metal channels are positioned to extend perpendicular to the trenches for forming main distribution ducts. A concrete surface is then poured over the slab to extend flush with the tops of the access boxes and the main distribution ducts and a cover plate is attached to enclose the main distribution ducts. The resulting floor structure has embedded therein parallel wiring raceways spaced across the floor with spaced accesses into each raceway and main distribution ducts interconnecting the parallel raceways.

Abstract: Improved apparatus for injecting vapors, such as water vapor in the form of low temperature-low pressure steam, into the intake manifold of an internal combustion engine. A controlled flow of air is drawn through a vapor generator by the intake manifold vacuum and the resulting air-vapor mixture is discharged through a nozzle into the intake manifold. The vapor generator contains a level controlled body of liquid for forming the vapor. Air enters the generator at the bottom of the liquid and rises through the liquid past a heater and a dispersion member which disperses the air into small bubbles. The heater is operated from the engine cooling system and heats the air and liquid sufficiently for generating steam at the subatmospheric pressures available from the intake manifold. The resulting steam-air mixture is injected into the intake manifold for controlling combustion. In a modified embodiment, liquid is also injected directly into an engine carburetor during acceleration.

Abstract: An improved spark plug for use in an internal combustion engine having a capacitive discharge ignition system. The spark plug includes a conventional metal shell supporting an insulator having a center electrode bore extending therethrough. A center electrode mounted in the insulator bore includes an electrode tip which defines a spark gap with a ground electrode. An auxiliary spark gap is formed within the insulator bore immediately above the tip. A low resistance inductive suppressor is mounted above the auxiliary spark gap and has an end attached to a terminal for connection to the capacitive discharge ignition system.

Abstract: An infrared solar energy collector is disclosed. The collector comprises a heat absorber which in a first embodiment is a tube through which a heat transfer fluid is circulated. The heat absorber is disposed within a larger glass tube. In a modified embodiment, the heat absorber is in the form of a heat pipe which conducts heat to a heat transfer fluid circulated through a manifold. A wick carrying a volatile fluid may also surround the heat pipe. Absorbed heat evaporates the fluid which is in turn condensed on the cooler manifold. Either the entire interior of the glass tube surrounding the heat absorber is under reduced pressure, or an annular region between the surrounding glass tube and a second, larger diameter surrounding glass tube is under reduced pressure. An energy director such as a reflector within the enclosing glass tube directs solar energy on the heat absorber.

Abstract: An improved method for making leak-proof connections to fuel tanks and other hollow articles rotationally molded from synthetic resinous materials, and particularly from relatively soft materials such as polyethylene. Prior to molding the article in a conventional rotational mold process, one or more male or female studs or similar threaded fittings are bolted to or otherwise temporarily held against the interior surface of the mold at a location which corresponds to the location for the leak-proof connections in the finished article. When a number of threaded fittings are located relatively close together or are spaced around an opening in an article, the fittings are preferably interconnected by wires or other metal support members which is embedded in the finished article. The support member strengthens the connection and also maintains a fixed spacing between the fittings. The article is then rotationally molded such that the fitting is embedded in the wall of the finished article.

Abstract: A motion picture projector having an improved electric transport system for incrementally advancing film through a light gate. A constant, but adjustable, velocity rotating shutter periodically interrupts the projected picture to permit advancing the film through the light gate to the next frame. As the shutter moves to a position blocking the projected picture, a shutter position detector generates a signal for triggering a control circuit which drives an electric servomotor to rotate a film drive sprocket. The servomotor is driven to rotate the sprocket to advance the film one frame and then to hold the sprocket in a fixed position to prevent any motion of the film while the picture is projected. Power is applied from a non-linear control circuit to the servomotor. Error signals applied to the servomotor are of a peak magnitude when the servomotor is stopped with the film framed in the light gate so that small position errors drive the servomotor to the desired position with a maximum torque.