Abstract: An apparatus and method for locating the vertical axis of symmetry of a sace of horizontal circular cross-section. The apparatus has a plumb structure that establishes a vertical line of sight, and a horizontal translating structure that preselectedly locates the plumb in the two horizontal dimensions. The plumb has at least three arms whose ends are constrained to lie on a circular perimeter which, because the arms are fixed to the plumb, is horizontally disposed. The translating structure and the arms are manipulated so that the end of the arms touch the surface, constraining the line of sight to be colinear with the axis of symmetry. A laser can make the axis visible. The apparatus and method are useable to locate the focal axis and focus of a parabolic antenna.

Abstract: A projection lens, for enlarging and projecting an image displayed on a liquid crystal display panel onto a transmission type screen provided at a display window of a projector case, is arranged so that its optical axis is perpendicular to the optical axis of projection toward the transmission type screen. At least one mirror, for reflecting an image projected through the projection lens toward the transmission type screen, is arranged between the projection lens and the transmission type screen. The liquid crystal display panel is arranged such that its optical axis is perpendicular to the optical axis of the projection lens. At least one mirror, for reflecting an image displayed on the liquid crystal display panel toward the projection lens, is arranged between the liquid crystal display panel and the projection lens.

Abstract: A psychrometer having transducers producing two electrical signals respectively representing dry bulb temperature and wet bulb temperature, and an electrical circuit operating to derive a signal representing relative humidity in accordance with the formula: ##EQU1## where RH is the relative humidityt is the dry bulb temperaturet' is the web bulb temperature and.alpha.,.beta.,.gamma.,.alpha.',.beta.', and .gamma.' are constants.The constants are chosen to give accurate results over the desired operating range of the psychrometer.

Abstract: A pressure difference type liquid level meter for measuring the quantity of an object liquid includes a liquid receptacle containing the object liquid, a pressure transmitting device including a pressure transmitting liquid for transmitting a pressure from the object liquid to a pressure difference detector so as to compare the transmitted pressure with a reference pressure, and an isothermal device for maintaining at least part of the pressure transmitting liquid at a predetermined temperature.

Abstract: A surveying target having a housing with one open side, encloses a high intensity gas discharge flash tube. A light absorbing surface in the housing bounding the back and sides of said flash tube prevents reflection of light, thereby maintaining a relatively discrete outline. A light transparent cover member on said open side for passing light from said high intensity gas discharge tube toward an observer. A transmitter and receiver, and including resettable code devices are provided for limiting responsive operation only to transmitters transmitting a preassigned code and a corresponding receiver for detecting said preassigned code. A light transparent cover member filters light from said lamp of a predetermined wave length. A surveying system using an optical instrument for binocular visioned observers is also disclosed.

Abstract: A combined hole size gauge and oversized hole marker having either first and second sensing members (42, 44) or a single dimensionally graduated size sensing member (14) which when inserted into a hole (40) in a workpiece (38) allows the user to determine whether the hole is of at least minimum size and if it is of greater than maximum size. If the hole is oversized, a marker adjacent the oversized hole size sensing member (44) or the greater portion of the single dimensionally graduated size sensing member (18) is permitted to contact the workpiece (38) and leave an indication that the corresponding hole is oversized.

Abstract: A liquid level detecting device comprises a vibrator for vibrating a sample vessel containing a sample solution, and a piezo-electric element provided on a suction member having an opening for sucking the sample solution. Changes in the output voltage of the piezo-electric element are read out as the suction member is moved vertically, contact of the lower end of the suction member with the sample solution is detected based on the changes in the output voltage, and the liquid level of the sample solution is detected. Or, the liquid level detecting device comprises a vibration transmitting plate for holding a nozzle member to a suction member, a vibrator for vibrating the nozzle member at a predetermined frequency, a frequency control circuit for changing the frequency of vibration, and a detector for detecting extreme values of the output voltage of the vibrator corresponding to changes in the frequency. The liquid level is detected based on changes in the extreme values.

Abstract: A quick release mounting arrangement for a portable gauging sensor utilizes three locating surfaces to establish a positive, repeatable mounting for the releasable sensor at any desired number of locations on a gauging fixture. A landing pad at each mounting location provides a depressed cavity in a first face for receipt of a first locating surface carried by the sensor housing, and the landing pad further provides a grooved surface in a second face for receipt of the second and third locating surfaces carried by the sensor body. At least one of the three locating surfaces is movable under spring tension to provide a quick connect/disconnect feature to the sensor mounting arrangement.

Abstract: A bow string peep sight comprises a disk having a string hole for receiving a bow string to be kept in a position perpendicular to the disk. Outside the string hole the disk is provided with a transparent sighting area having the shape of a sector of a circle ring concentric to the string hole and extending over an angle of between 120.degree. and 270.degree.. When the bow is drawn the disk is tilted, thereby revealing to the archer a single sighting opening outwardly appearing to be limited by two elliptic arcs. The sighting hole is made sufficiently small to ensure an exact aiming. Owing to the great angular distance between the ends of the sighting area, the single sighting opening is formed independent of the twist of the bow string.

Abstract: An apparatus for measuring the steering angle of a steerable vehicle wheel comprises first and second electric angle measurement instruments interconnected by an elastic tensile member and electronic circuitry connected to the angle measurement instruments. The first angle measurement instrument is attached to the wheel by a pivotal measuring arm at a generally perpendicular axis to the wheel. The second angle measurement instrument is attached to a measuring base by a pivotal measuring arm and is arranged approximately along the axis of rotation of the wheel. The electronic circuitry receives signals issued by the angle measurement instruments and processes these signals to generate a steering angle signal. A display device is provided and is connected to the electronic circuitry. The apparatus can also be used to measure the track differential angle for each steerable wheel of the vehicle.

Abstract: A bubble level with a hollow metal section has a circular window, in which a cylindrical level tube for a vertical level can be inserted with a positive interlock in the axial direction and can be fastened with a material interlock. A level support is inserted into the hollow section in the axial direction. The support has a cylindrical seat aligned with the window, to receive a level holder that bears a level. An interlock device is disposed between the level support and the level holder. By means of this interlock device, the level holder is mounted axially fixed, but rotatable until it is fastened by the material interlock.

Abstract: A precision calorimeter which comprises a heater, an agitator and a detection bath which are disposed in a temperature controlled bath and in which gaps formed between them are filled with a liquid; and a detection unit placed in the detection bath, a gap formed therebetween being filled with a liquid; the detection unit being comprised of a detection element, a pipe for passing a sample therethrough provided with a mixer and a reference heater which are arranged between metallic pieces.

Abstract: A screen-forming sphere is made of a front translucent half-sphere and of a rear half-sphere which is opaque except in a central region. An image projector is situated behind the screen and has a front face comprising a platen mounted in front of the optic of the image projector. The platen contains a rotary polarization filter rotated by a first motor. The filter is occultable by a rotary flap mounted on spindles rigidly connected to two rotary vertically aligned disc members which rotate in synchronism under action of a second motor.

Abstract: Apparatus and method are provided for use in determining information relating to the plane of rotation of an object, particularly a vehicle wheel. The apparatus includes a probe that is maintained at the same contact point relative to the wheel during the rotation of the wheel. The position of the probe is monitored and position-related data is analyzed by a processing system. The processing system implements a least squares method for defining the plane of rotation utilizing a number of the position-related data points, which were obtained during rotation of the wheel. In one embodiment, the probe is connected to a pivotable wobble plate for use in maintaining a predetermined position of the probe relative to the wheel during rotation thereof. A carriage assembly also acts to maintain the predetermined position of the probe. In another embodiment, instead of a carriage assembly, rotatable arms and counter-weight are employed so that the probe moves as a direct result of rotation of the wheel.

Abstract: A photographic cropper comprises a pair of opposable right-angle portions, each of which contains alternating transversely spaced strips of oppositely magnetized material extending parallel to edges of that portion. The right-angle portions are continuously adjustable relative to each other in the direction of the strips and are relatively adjustable in a direction perpendicular to the strips in equally spaced steps corresponding to the spacing between similarly magnetized strips of each portion.

Abstract: In a mixing projector, a guide element for the slide magazine extends transversely with respect to the optical axes of the objective lens systems of the optical assembly. Disposed between the two projector units for projecting the respective slides is a main slider member which is displaceable parallel to the optical axes of the optical assembly, for transportation of slides between the magazine and a slide turning mechanism which turns the respective slides through 90.degree.. Transverse slider members then provide for transportation of the turned slides into and out of the positions thereof for projection through the objective lenses of the optical assembly.

Abstract: An environmental chamber for providing thermal stress screening is comprised of a plurality of modular components which may be quickly assembled and disassembled for ease of maintenance and repair. In particular, a heater/cooling unit is coupled by means of a plurality of quick release lockable fasteners to a plenum module. The plenum module in turn is coupled by means of additional quick release lockable fasteners to a blower module. The plenum module in turn is comprised of a heater plenum which communicates with a blower plenum. Gas is drawn into the heater plenum and passed over heating coils which are disposed into the heating plenum from the heating/cooling module. The gas is then communicated to a blower plenum. Cryogenic nitrogen gas is constantly bled through a small (0.015") hole of the liquid nitrogen valve body and is selectively provided to the blower plenum from the heating/cooling module.

Abstract: Carpenter's tool particularly a wedge or spacer for indexing the desired spacing between adjacent planks. The device consists of an angle brace placed on top of the decking and a wedging plate which extends downwardly as an index between the planks for measured spacing prior to nailing the outside plank to a joist or the like.

Abstract: A liquid level sensing apparatus for detecting leaks in storage tanks. A buoyancy member is at least partially immersed in the liquid, suspended from a pivoted, counterbalanced, parallelogram support arrangement with a radio frequency target sensing element for electrical readout of displacement. Two such apparatus are incorporated in a system with a provision for measuring a portion of the liquid of the tank in isolation from the remainder, in order to provide for temperature compensation.

Abstract: A dual purpose instrument having parts to measure the width of the nose and parts to measure the vertical distance from the underside of the chin to the underside of the nose, for use in making dentures.