Abstract: An apparatus for converting a conventional rectangular HVAC duct to a flat oval shaped duct where a conventional rectangular duct fitting is provided with a converting means to convert the opening from rectangular to a flat oval. The converting means is formed by a pair of arcuate members defining semi-circular edges and having recesses to receive portions of parallel members. The apparatus utilizes two sheet metal pieces which are formed in arcuate contours that connect between flat edges of parallel sheets to form the oval shape.

Abstract: An automatic adjusting threshold microphone squelch system for use in aircraft or other high noise environments including digital drop-out timer and voice detector connected directly to an analog composite signal processor. The processor is comprised of two channels including a microphone audio channel and an aircraft noise detection channel. The channels, driven from a common microphone, are arranged in parallel with the noise detector feeding its noise-dependent output forwardly to a variable-threshold microphone audio post-amplifier. The composite audio from this amplifier is automatically maintained below a first digital "zero" level when voice is absent while containing peaks above a second digital "one" level when audio is present. This composite audio directly feeds the digital detector/timer without further wave-shaping or other signal processing.

Abstract: A reclosable cover for converting a two-piece electrical wire and cable duct system into a one-piece reclosable duct. The cover is fabricated from a dual-durometer plastic co-extrusion having a flexible hinge portion extruded of a resilient lower durometer plastic material. A clip assembly formed along one edge of the cover includes a modified U-shaped channel to receive and clamp the top end of a duct channel sidewall. Flexible fins are provided within this channel to further locate and retain the duct cover. A generally V-shaped hinge support member and dual ridges provide enhanced hinge integrity and an interference engagement therebetween to provide a cover `remain-open` function. The clip assembly and support member share common elements to thereby improve on the space and cost efficiency of the duct cover.

Abstract: A safety razor has a handle, a head on the handle on which a razor blade or blade holder is mountable, a reservoir for water or other suitable lubricating liquid for shaving and an outlet for supplying the liquid from the reservoir to the blade, whereby the liquid is available for the skin during shaving.

Abstract: A dimmer oscillator for a high frequency luminous tube power supply including a frequency shiftable high frequency oscillator, a variable duty cycle low frequency oscillator operatively connected to the high frequency oscillator for controlling the high frequency oscillator between a first normal output operating frequency and a second higher frequency. A low pass filter within the high frequency supply whereby the supply output to a luminous tube load is reduced, when the oscillator is operating at the second higher frequency, to a low intensity ionization maintenance level. An integrator between the low and high frequency oscillators whereby the transition between the first nominal and second higher operating frequencies is smoothed to reduce acoustic noise and false GFI and OVP triggering. A frequency control diode between the low and high frequency oscillators to limit the lower frequency excursion, and to maintain oscillation of, the high frequency oscillator.

Abstract: A method and structure for the integral reinforcement of HVAC ducting including the steps of laying out one or more planar sheet metal blanks having portions defined therein dedicated for integral rib reinforcement; placing relief slots in the dedicated portions of the blank corresponding to the seams and folding lines; forming the integral reinforcement rib from the dedicated blank material; bending the blanks along fold lines and assembling the rectangular duct; and placing rib corners over the reinforcing rib ends at the corners of the duct. Alternatively, the step of cutting the reinforcing rib at the fold lines may be substituted for the step of placing slots in the blank. The completed structure includes reinforcing ribs circumferentially positioned around the duct or on the planar duct surfaces, the ribs being formed of, and integral to, the duct itself. Pre-manufactured rib corners serve to seal and strengthen the reinforcement ribs as required.

Abstract: Apparatus and method for reforming a visor of a baseball type cap including a flexible member to be positioned adjacent the visor and having retention plates along the sides or center thereof that form visor receiving slots to position and retain the visor during reforming. Clips may be used in lieu of slots to retain the visor. Straps or similar elongated devices are affixed to the sides of the flexible member and are tensioned to draw said sides together thereby imparting an increased angular contour to the visor. Latches on the straps hold the desired tension and visor contour until the visor has assumed the new contour set. The method may include moisturizing the visor and may be performed iteratively to permit various intermediate contours to be sampled or as required to provide the desired semi-permanent visor set.

Abstract: A low cost and portable scalar network analyzer for the simultaneous measurement of forward and reflected scalar scattering parameters of devices under test. Plural UHF oscillators of similar construction are mixed to produce a wideband test instrument having good stability characteristics. A dual-diode biased RF detector with feedback, including an in-loop adjustable gain buffer stage, provides enhanced linearity, over a wide dynamic range, and at low cost. The forward transfer parameter measurement arrangement further includes a selectable attenuation/gain PIN-diode switched stage to accommodate the widely varying gain/attenuation characteristics of devices under test.

Abstract: An alcohol/water fuel vaporizer for use in an internal combustion steam engine. The vaporizer comprises an exhaust gas chamber through which engine exhaust is passed and a vapor chamber for the generation and retention of pressurized fuel vapor. The exhaust gas chamber includes a plurality of baffles to direct the flow of the gas against a crown sheet, the latter sheet being heated thereby. The crown sheet forms the dividing partition between the vapor and exhaust gas chambers. A fuel preheater is positioned in the vapor chamber through which engine coolant is passed. A plurality of switchable fuel injectors in the vapor chamber controllably admit and spray fuel onto the preheater and crown plate in response to engine power demands and vapor chamber pressure.

Abstract: An elongate plastic bag clamp or cable tie defined by a main strap portion, said strap having a plurality of teeth at a tip end thereof and a low profile strap engaging and locking head integrally formed at the other end thereof. The teeth are evenly spaced and oriented perpendicularly to the longitudinal axis of the strap. Further, the teeth are contoured, having a greater height along the center region thereof, to facilitate camming and locking engagement with the head. The head includes a pair of sidewalls extending from the strap and a plurality of semi-flexible retention bars rigidly affixed to, and spanning between, the sidewalls. Each retention bar is deformable in its center region under the camming influence of the strap teeth thereby to permit the passage and locking thereof.

Abstract: Intercom apparatus having stereo amplifiers adapted for connection to one or more headsets. A plurality of headset output and microphone input connections are provided. Each microphone input includes a separate microphone switch and audio detector whereby only microphone inputs having voice audio thereon are activated. Stereo entertainment and aircraft radio audio inputs are provided. An aircraft radio audio detector is interfaced, along with the various microphone audio detectors, to entertainment partial mute circuitry whereby the presence of a voice or radio audio signal lowers the amplitude of the entertainment input. Microphone and aircraft radio partial mute circuitry are interfaced through a priority selector switch with respective microphone and radio signal detectors.