Abstract: An improved method of manufacturing electroacoustic transducers which emp vibratile transducer elements includes an automatic method of measuring the motional impedance vs. frequency characteristics of a plurality of transducer elements and an automatic method of segregating the transducer elements into separate groups which are selected in accordance with the similarities of the measured motional impedance characteristics of the elements. The separate groups of selected transducer elements are then processed by changing a mechanical dimension of the elements in each separate group by a different specified amount which adjusts the motional impedance vs. frequency characteristic of each separate group to the same specified desired value. The processed transducer elements are then assembled into complete transducers, thereby achieving improved uniformity in the performance characteristics of the transducers which is obtained at relatively low cost.

Abstract: A transducer of the flexural resonant vibratile rectangular type is described in which a housing includes a square frame-like mounting structure with a square opening for receiving the vibratile plate assembly. V-shaped projecting ribs from the center of the inner sides of the square opening provide locating points for precisely positioning the periphery of the square vibratile plate assembly concentrically with the square opening. A second set of four V-shaped ribs are located at right angles to the ribs projecting from the inner sides of the square opening and lie in a plane to provide support for the face of the vibratile plate assembly. All of the V-shaped ribs are located near the nodal regions of the vibratile plate and present minimal area of contact with the vibratile plate.

Abstract: An improved transducer utilizes an acoustic delay line to adjust the phase f the acoustic output from the out-of-phase portion of a free resonant flexural disc so that it is constructively added to the acoustic output generated from the remaining portion of the resonant flexural disc. The improved transducer combines an acoustic coupler with the housing structure of the transducer for the purpose of increasing the radiation resistance load on the vibratile disc to achieve increased acoustic output from the transducer.

Abstract: An improved transducer utilizes an acoustic delay line to reverse the phase f the sound vibrations generated by the peripheral area of a bi-laminar vibratile disc operating at its free fundamental resonance mode. When the diameter of the vibratile disc is dimensioned within specific limits in comparison with the wavelength of sound being radiated at the frequency of operation, the radiation efficiency of the transducer is significantly increased over the efficiency of the same vibratile disc operating in the prior art manner with an acoustic shield placed over the peripheral area of the disc to prevent destructive interference from the out-of-phase sound radiation generated by the peripheral area.

Abstract: An apparatus for printing transparencies, such as 35 mm transparencies, onto instant-developing film is disclosed which is suitable for use in the amateur market. The device includes use of short-focal length lenses so that it may be of compact construction, and a previewing mechanism to assure that the image to be printed is in focus.

Abstract: Improved ultrasonic cleaning of large surfaces is achieved by modifying conventional transducers of either the cylindrical or piston vibratile type so that the transducer vibratile element is brought in closer proximity to the surface being cleaned. For efficiently cleaning the wall surface of a circular water-filled tank, such as a toilet bowl, a ceramic disc operating in the planar resonant mode is provided with an acoustic transmission line comprising a solid annulus bonded to the periphery of the ceramic. The radial dimension of the annulus is equal to one-half wavelength of sound in the material at the frequency of operation. The annulus serves as an acoustic transmission line to extend the peripheral vibrating surface of the ceramic to a region closer to the wall of the tank. The transmission line also increases the radiating area of the transducer which achieves increased sonic power density in the vicinity of the wall surface.

Abstract: A device for use in maintaining a poster or like sheet decorative material in a flat configuration by removably engaging narrow marginal edge portions thereof, and as a result no portion of the decorative insignia on the poster being concealed from view when supported by the device. The device when not in use may be dismantled and the components thereof stored side-by-side in a compact configuration until again needed.

Abstract: Drive and steering mechanism for a vehicle embodying a frame supported by a pair of transversely spaced wheels separately connected to a pair of transverse shafts rotatable about a common axis with adjacent ends being rotatable relative to each other. A sleeve mounted non-rotatably on adjacent ends of the shafts is movable axially of the shafts to a first position in contact with both ends of the shafts so that both shafts rotate as a unit and to a second position in engagement with only one of the adjacent ends. Drive means connected to one of the shafts rotates the same while the sleeve is in the second position and rotates both shafts while the sleeve is in the first position.

Abstract: This invention discloses a mold design which limits the maximum pressure that can be developed inside a closed cavity containing a polarized ceramic as a result of the volume expansion of the molding compound during the curing cycle. The pressure control is achieved by interposing a spring member between the mold and the pressure source which closes the mold. The spring will deflect slightly to absorb any volume expansion of the molding compound during the curing cycle, thus preventing any significant increase in pressure in the cavity and thereby preventing depolarization of the ceramic.

Abstract: A process and system for the segregation and separation of mixed office-paper-waste material which comprises: shredding the waste material to a uniform size; forming a fluidized bed of the shredded waste material in a vertical column by an upwardly flowing, high-volume, low-pressure air stream, to divide the material into distinct layers in the column; and separating and removing the layers from the column with lateral airflow.

Abstract: This invention discloses an improved process for applying electrodes to the surfaces of thin ceramic discs which permits the coating of the entire disc with a conducting film and then automatically removes the conducting film from the peripheral edge of the disc as it is rolling down an inclined plane while being held within a guide slot. The bottom of the guide slot is provided with a moving abrasive belt which automatically removes the conducting film from the peripheral edge of the disc as it passes over the belt. The inventive process will permit the advantageous use of plated electrodes such as electroless nickel without entailing the costly expense of masking the edges of the discs before plating.

Abstract: An insert for the receiver of an intake manifold for an internal combustion engine. The receiver receives air/fuel mixture from a carburetion system, usually from a plurality of carburetor barrels, and runners exit from the receiver to conduct the mixture to respective cylinders. The insert, which can be of a selectible or adjustable contour, serves to direct the flow of mixture to the various runners in accordance with the demands of the respective cylinders. Correct selection of insert contour and size enables an individual manifold configuration to be adapted to the unique airflow pattern and volumetric requirements of an individual engine, rather than to an average engine, and also to specific performance ranges, rather than to a wider average performance range. The insert can also be movably mounted to provide for various load conditions. The invention comprehends the combination of the insert and a manifold.

Abstract: A mathematical analysis reveals the existence of circular motion in the head of a rotating phasor which represents the received signal in a Doppler intrusion alarm system in the presence of a moving target. The circular motion is virtually nonexistent when a moving target is absent regardless of the presence of environmental disturbances such as air turbulence and noise transients. The mathematical revelations are confirmed by a considerable amount of experimental data representing hundreds of thousands of measurements under various environmental conditions. The invention makes use of these new findings in combination with a new signal processing system which incorporates a circle detector for recognizing the presence of circular motion in the head of a rotating phasor when it occurs in the received signal, thus permitting absolute detection of a moving target even in the presence of environmental disturbances, such as air turbulence, while the system remains immune to false alarms due to these disturbances.

Abstract: A movie camera is provided with an automatic focusing adjustment mechanism which is responsive to a control signal which is generated by an ultrasonic range finder attached to the camera. The camera is automatically kept in focus as the distance of the subject from the camera is varied.

Abstract: A coin-operated vending machine accepts any combination of valid coins which are deposited and automatically returns the correct change when the merchandise is dispensed. The amount of change represents the difference between the total value of the accepted coins and the price of the selected merchandise. A digital data processing circuit is employed for recognizing the validity and denomination of all deposited coins and any unacceptable coin that falls outside the established tolerance limits for a genuine valid coin is automatically rejected and immediately returned.

Abstract: An improved depth sounder combines a multi-beam ultrasonic transducer with a multi-range selector switch with provisions for automatically selecting a particular beam pattern for a particular range setting. The relationship between beam patterns and depth ranges is uniquely chosen to provide equal areas of insonification at each full scale range setting. The inventive system also provides an additional scale on the multi-scale range dial which shows the diameter of the insonified region in the vicinity of the reflecting target in addition to the target depth.

Abstract: A soccer practice net and goal structure is disclosed which is particularly useful in the training of players for the game of soccer. This soccer practice net can be used as a goal structure for games between teams on a large playing area or readily converted to a ball-returning practice net for use in a limited playing area such as a residential backyard by one or more players.

Abstract: Chain link fence straightener apparatus usable to restore bent chain link fence sections or segments without removal thereof from the fence, and including lower and upper tine means arranged on an upright post supported by a ground engageable base member, such upper tine means being movable vertically on a carriage vertically shifted along the post through means of a rack gear on the post and pinion gear means on the carriage, said lower and upper tine means being of substantial horizontal span to engage a plurality of links of the fence at various points along the fence. In preferred form the rack gear on the post is made up of a length of hardened steel chain links and is readily removable and adjustable in tension by means of a threaded anchor bolt at its lower end.

Abstract: A plurality of ultrasonic flow meter measurement probes are located at spaced intervals along the length of a pipeline carrying a fluid and each probe measures the rate of flow of the fluid at each location along the line. If a leak develops at any point along the pipeline the nearest probe located upstream from the leak will read higher than the measurement being made by the nearest downstream flow meter probe. The difference in readings between the adjacent probes will be an indication of the magnitude of the leak and when the difference exceeds a preset threshold limit an alarm will sound and a coded command signal will be transmitted from the data monitoring center to initiate the immediate closing of the nearest upstream and downstream shut-off valves in the vicinity of the leak. This procedure will immediately isolate the damaged section of the pipe and prevent uncontrolled leakage of the fluid into the environment.

Abstract: A baffle structure for use with an electroacoustic transducer in a sound ranging system eliminates secondary reflections between the transducer and target, thus eliminating false target errors that occur in conventional sound ranging systems due to phantom target indications caused by multiple reflections between the transducer and target.