Abstract: Synthetic continuous filament yarn is woven with a sacrificial filling and thus formed into a prefabric, selected portions of the prefabric are dyed, the prefabric is optionally crimped either before or after dyeing, the prefabric is immersed into a dilute solution which, when concentrated will destroy the sacrificial filling, and the prefabric is then conducted through a heating and drying operation, boiling off the water and concentrating the solution, then substantially completely destroying the sacrificial filling and freeing the warp yarns as a free warp of intermittently colored yarns.

Abstract: A microphone is described for operating in dirty environments where a layer of dirt or mud may accumulate over the vibratile surface of microphone. The microphone is designed with its vibratile diaphragm having a mass greater than 0.4 gm/sq cm of diaphragm area so that an added layer of dirt over its surface will not cause any significant change in the sensitivity of the microphone over its prescribed frequency range of operation.

Abstract: Drawn but undyed synthetic continuous filament yarn is formed into a prefabric, selected portions of the prefabric are dyed while leaving other selected portions free of any dye, the prefabric is raveled, the resulting partially dyed yarn is formed into a partially dyed prefabric, and this partially dyed prefabric is then substantially completely over-dyed to produce a novel over-dyed fabric.This method produces a novel form of crimped and drawn continuous filament synthetic polymeric yarn, a substantial portion of which is undyed, and the balance of which consists of random, intermittent dyed lengths consisting of at least two different colors (A and B) intermittently and randomly arranged along the length of the yarn.

Abstract: A molded rubber tubular member includes a grommet-like flange at its open end for permitting the structure to be attached to a panel. A recessed nest portion is provided at the opposite end of the tubular member into which is inserted a transducer whose diaphragm serves as a closure at the end of the tubular member. The assembly serves as a flexible shock mount for the transducer and also as an acoustic amplifier which increases the acoustic sensitivity of the transducer by 10 to 20 dB in a selective frequency band within the audible range.

Abstract: A method and apparatus for automatically switching a circuit to regulate artificial light in an area. The artificial light is turned on by a person entering the area and reflecting an ultrasonic wave pattern toward a receiver. The light is turned off by a person moving into contactless proximity of a capacitance comparison circuit which utilizes the capacitance of the human body as one of the circuit elements. The ultrasonic circuit operates at different levels of sensitivity, depending upon the existing available light in the area, such as during daylight hours. Optionally, a capacitance comparison circuit may be utilized for both turning on and turning off of the artificial light.

Abstract: An ultrasonic transducer employs a ceramic disc which, when excited by a d-c pulse, vibrates in its planar resonant frequency mode. The sensitivity is selectively increased for the second positive half cycle of the transient oscillation of the disc and a method is described for using the selectively improved transient response to greatly increase the precision of measurement of the time interval for a transient pulse of ultrasonic energy to travel the distance between an ultrasonic transmitter and an ultrasonic receiver.

Abstract: Aqueous base soft drink concentrate formulations of various strengths consisting of flavoring and coloring, an artificial sweetener selected from the group consisting of saccharin, or sodium saccharin, and up to about 50% of total sweetener in the form of sugar, depending on strength of the concentrate, along with a preservative, and from more than 1 up to about 7 volumes of carbon dioxide per volume of concentrate. The carbonated concentrates are utilized to prepare a palatable carbonated soft drink by mixing one part of concentrate to from 1 to 5 parts of ice water, depending on strength of the concentrate formulation.

Abstract: A normally closed wafer thin switch, particularly intended for pilferage type burglar alarms, comprising a flat base plate of insulating material having an opening therein and a pair of leaf spring contacts attached to one peripheral portion of the plate and extending over the opening. Free ends of the contacts normally engage each other to complete a circuit. A raised tab on a first of the contacts overlies an opposite peripheral portion of the plate whereby, when an object is placed on or against the switch, the tab is depressed against the plate, causing opening of the switch.

Abstract: A method and apparatus for the continuous manufacture of plastic bags from an extruder which includes a differential tachometer which senses the speed of the film in two locations so that the film drive can be adjusted to compensate for the shrinkage of the film and to eliminate tension in the film. Welding and perforating blades are provided which contact the travelling film and travel with the film to complete their weld and perforations before returning to their initial positions. One type of welding and perforating device uses a pair of opposed blocks which come together around the film and travel with the film while the perforating blade pierces through the film and the weld is being completed. A timing cam coupled to the film drive determines the spacing of the welds and perforations and thus the length of each bag produced.

Abstract: A comprehensive analysis of the effect of air turbulence on the acoustic performance of an ultrasonic intruder alarm system indicates that air turbulence does not cause Doppler frequency shifts in the received signal in the frequency region 2 - 100 Hz, as has been universally assumed in prior art systems but that air turbulence can only produce amplitude modulations in the received signal over this frequency region. It is also disclosed that changes in air velocity, or accelerations of the air flow, cause only very low Doppler frequency shifts in the signal, below 2 Hz for a 20 kHz carrier, and only moving targets can produce higher Doppler frequency shifts. A processing system is disclosed which is immune to false alarms in the presence of air turbulence without sacrificing threshold sensitivity and without introducing long time delays in the signal processing circuit as has been necessary in prior art systems.

Abstract: Electroacoustic transducers are nested to provide a centrally vibrating portion and a peripherally vibrating portion. The phases of the two transducers may be adjusted with respect to each other in order to provide a variety of beam patterns.

Abstract: The invention describes a low cost transducer construction utilizing a vibratile diaphragm to form a closure for a cylindrical tubular housing. The sound radiating surface of the diaphragm is of a concave shape to achieve an increased diaphragm thickness at its periphery. The concave diaphragm design permits the precise adjustment of the resonant frequency of large quantities of mass produced transducers by machining the surface of the thick rim portion of the diaphragm. Greater precision in the adjustment of the resonant frequency is achieved with this design because the frequency change is less critically dependent on the amount of material removed than is the case with a conventional flat diaphragm surface as used in prior art designs.

Abstract: An electroacoustic transducer uses a bilaminar vibratile element having at least two plate members which are bonded together in face-to-face relationship, at least one of the plates being made from a piezoelectric material. The bilaminar plate is supported within a frame-like structure by resilient pads which attach the bilaminar plate at its nodal points to the surface of the supporting frame.

Abstract: A high speed continuous knitting machine wherein the cylinder has a substantially circular cam track for the needle butts having a substantially uniform slope and disposed at an oblique angle relative to the axis of the cylinder, and also including cam controlled axially moveable sliders disposed between the needles for assisting in castoff, which sliders are moved in a direction opposite to the direction of movement of the needles.

Abstract: This invention provides an expendable velocimeter probe. High frequency transmitting and receiving transducers are mounted opposite to one another in axial alignment on the probe body and on a frame in front of the body. The mounting includes means for accurately adjusting the distance between the transducers in order to provide low cost, but highly reliable, means for calibrating the velocimeter during large scale manufacture of the instruments.