Abstract: An automatic system for exposing and handling double-sided printed circuit boards without scuffing either side, which effects precise positioning of the circuit boards at exposure stations, and which holds the circuit boards firmly clamped on a planar stage during exposure. The system includes a first apparatus to expose one side of each circuit board, and a second apparatus to expose the other side thereof. Air-bearing and mechanical-engagement means cooperate with each other to float and actuate the circuit boards from one station to the other, and coarse and fine positioning means are provided at each station to effect accurate locating of the boards thereat followed by vacuum clamping onto the exposure stage. Means are provided for automatically inverting each board as it moves from the first exposure station to the second, the inverting means incorporating air-bearing and mechanical-actuating means to insure that there is no scuffing at the inverting station.

Abstract: To adjust the characteristic sounds produced by electric guitars and other musical instruments, the present apparatus and method provide for varying the resistive loading on the electromagnetic pickups of such instruments. This changes the shape of the peak of the resonance curve caused by the self-resonance of the electromagnetic pickup. A predetermined fixed resistance is maintained in the circuit at all times, such that when a control element is at a certain known position, the output curve from the pickup will be substantially flat and, furthermore, the apparent volume generated by the instrument will not be reduced substantially. To change volume, a volume-control potentiometer is provided. In the preferred form, a single control element not only adjusts the characteristic sounds produced by electric guitars or other musical instruments having electromagnetic pickups, but also provides roll-off of higher frequencies at some desired region within the audio spectrum.

Abstract: In an apparatus and method for effecting automatic handling of circuit boards prior to exposing them, pins are provided that effect highly accurate location of the circuit board at an exposure station. The pins are extended through slots provided in the circuit board, at least one slot being perpendicular to the others.Each pin is noncircular, being sufficiently small to be inserted through an associated slot when the pin is in one rotated position, but being sufficiently large that rotation of the pin about its axis will cause it to bind with the walls of the slot, so that further pin rotation is prevented. The pins are inserted into the slots when in the non-binding rotated positions, following which the pins are rotated so as to bind with the slot walls, and thereby move the board to a precisely known position relative to the axes of the pins. Thereafter, exposure of the board is effected.

Abstract: A tool for retrieving or placing test or process elements from and into a pressurized container has a relatively short run in/run out shaft that carries a connector for attachment to and rotation of a holder that mounts a test probe, test coupon, or the like, in the container. The run in/run out shaft is driven by a pair of concentric drive cylinders, rotation of the shaft being achieved by a longitudinally slotted rotation drive cylinder, and longitudinal motion of the shaft being achieved by rotation of a spirally slotted cam cylinder. The arrangement provides a shorter length tool and eliminates gears and close-fitting drive elements that are subject to wear and damage from trash that may be contained in the fluid of the system.

Abstract: High strength composite tape is prepared for laying in side-by-side strips upon a work surface by precutting the strips to a predetermined length and mounting the strips upon a carrier belt in longitudinally spaced relation to one another, so that the pressure foot of the machine applying the tape to a work surface may press to the end of one tape strip without pressing the end of the following tape strip. Improved laying of the tape is achieved by stretching a strip of tape entirely across the area on which the tape is to be laid before pressing any part of the tape against the work surface, and then pressing the tape against the surface while the tape is stretched across and adjacent the work surface. The tape is held and stretched across the work surface on supply and take up reels on opposite sides of the work surface, so that the reels need not move along the tape with the moving pressure foot.

Abstract: A fly-fishing reel has a rotatable spool provided with a click gear engaged by a pivoted pawl which can apply resistance to rotation of the spool in opposite directions by independently adjustable spring means. A pair of exteriorly exposed adjustment knobs are each provided with an eccentric pin extending into the reel housing to slide a plate which carries a pretensioned spring engaged with one of the opposite radial sides of the pawl. By rotating the knobs, the slides move linearly to vary the contact point of the springs with the pawl and thereby regulate the moment arm of the force resisting rotation of the pawl and thus the click gear and spool to which is engaged. Since the adjustments are independent, the resistances to rotation of the spool may be varied as to degree and to which direction of rotation they apply. The slides mount the springs in a manner to limit the degree to which the springs may follow movements of the pawls.

Abstract: The laser beam of a flying spot scanner is turned on and off to write data under control of a reference clock that generates clock signals determined by the position of the writing beam. To detect position of the writing beam a reference beam is scanned in synchronism with the writing beam along and through a coding mask to a strip of retroreflective material fixed adjacent the mask. The reference beam is retroreflected through the mask back through the scanning optics to a fixed detector that produces an output determined by the scanning coded reference beam. Unwanted reflections from the mask surface are separated by tilting the mask. Reading of a document having a pattern of opaque and transparent areas is accomplished by retroreflecting a scanning laser reading beam from a body of retroreflective material adjacent to but spaced from one surface of the document.

Abstract: The plug shell and receptacle of an electrical connector have registration keys and keyways that are alignable in a single rotational position. A coupling ring mounted for rotation on a plug shell has a mating set of keys and keyways that must be aligned with the registration elements of the plug shell and receptacle for insertion of the receptacle into the plug shell. After such insertion has been accomplished, the coupling ring is rotated to further draw the receptacle and plug shell together and to prevent axial separation of the plug shell and receptacle. In order to positively prevent precocking of the coupling ring prior to insertion of the receptacle into the plug shell, a locking finger is resiliently pivoted to the plug shell, having one part entering a locking recess of the coupling ring and a second part entering the plug shell bore into which the receptacle is to be inserted.

Abstract: A mastic applicator or "flat box" for use in application of mastic to tape drywall joints includes a container for storing and dispensing mastic. The container has a pressure plate which both supports the apparatus from a handle and applies pressure to force the mastic from an opening that extends across the direction of motion of the tool. To distribute and contour the mastic a flexible blade assembly extends along the rearmost edge of the opening and is positively driven through a range of infinitely adjustable positions by a means of a lever and camming linkage arrangement. The entire adjustment mechanism is itself adjustably mounted so as to selectively adjust the entire adjustment range.

Abstract: An all metal-welded flush electrical resistance probe for measuring corrosion of a fluid in a pipe avoids problems of sealing dissimilar materials by using a thin, metallic test disc that is welded around its periphery to the open end of a probe body which also mounts a reference element. The very thin test element is backed up by a solid supporting medium within the probe body, and resistance of the test disc is measured between a point at the disc periphery and a point nearer to the disc center.

Abstract: A mixing chamber designed for ready disassembly is described in which a generally spherical-shaped outer container encloses an inner sphere. Entry and exit openings are provided on opposite sides of the outer sphere, so that breath specimens pass through the chamber between the outer surface of the inner sphere and the inner surface of the outer sphere and undergo thorough mixing with low back pressure over a wide flow range. The interior volume can be increased by using a hollow inner sphere with an opening through the wall thereof to permit the inner sphere to fill with breath specimen also.

Abstract: An anti-backflow valve for installation in a blower discharge line of a therapy tub aeration system has an air inlet, an air outlet, and an auxiliary outlet in its housing. A spring-loaded check valve member within the housing precludes fluid flow outwardly through the air inlet. Also within the housing is a combined pressure relief and float valve mechanism which opens the outlet passage in response to a pressure in the housing greater than a predetermined relief pressure or the presence of water in the housing above a predetermined level. An initial backflow of water in the discharge line closes the check valve member, the float and relief mechanism limiting the air pressure building caused by a continued backflow and permitting water to enter the housing through the air inlet when the housing is vented. After reaching the predetermined level in the housing, the entering water is discharged through the auxiliary outlet passage.

Abstract: A motor generator set that is used to provide clean, noise-free power to a load, such as a computer, is upgraded to a complete uninterruptible power supply by the addition of a logic controlled, battery powered inverter that is readily connected in the main power supply line to the motor generator. The emergency power inverter operates only when normal utility power fails, and employs the ability of the motor generator set to handle brief power outages to power the load for the brief time needed to decouple the main line power supply and couple the inverter to the motor generator. An oscillator that clocks trigger pulses for the inverter tracks motor voltage frequency and phase until power is supplied to the motor from the standby inverter. Switching to the emergency power inverter is accomplished by detecting both reverse power and zero current.

Abstract: To convert a conventional nonpulsating air/water mixer for a therapy tub, swimming pool, spa or the like to a pulsating mixer, an inexpensive pulsator fitting is used to replace the central eyeball portion of the mixer's outlet and mounting fitting. The pulsator fitting has at least one cross bar positioned to block the mixer's aerated water jet, and a small cylindrical rotor journaled on the cross bar. The rotor extends from the cross bar coaxially into the mixer body's outlet passage in the path of the aerated jet. The jet strikes a central portion of the upstream rotor end, travels through an angulated rotor passage, and exits the downstream rotor end at an angle relative to the rotor axis and at a point spaced apart from it, causing the rotor to spin. As the rotor spins, the exiting aerated jet rotates and is repetitively and intermittently blocked by the cross bar, thereby pulsing the jet.