Abstract: A keyboard device has a key, a support for the key, the key being rotatably mounted on the key support, a hammer, a support for the hammer, the hammer being rotatably mounted on the hammer support, a resilient member for urging the key to swing in a direction which is the same as the direction of swinging of the key when the key is depressed and for urging the hammer to swing in a direction which is opposite to the direction of swinging of the hammer when the key is depressed. The resilient member has a first end coupled to the key and a second end coupled to the hammer.

Abstract: A microfilm projection apparatus is disclosed which is usable for a plurality of zoom lenses having different magnification ranges from each other. In the zoom lenses attached, the zoom lens selected from the plurality of zoom lenses to be used is identified. A plurality of specific magnifications corresponding to each zoom lens are memorized. When the zoom lens is set in place, the specific memorized magnifications corresponding to the selected zoom lens are indicated. The magnification of the zoom lens is set to the desired magnification designated from the specific magnifications.

Abstract: A camera system in which a balancer is installed on one side of the camera and is linked to the camera body by two arms so that the photographer's hand can be inserted through a space defined by the camera body, the balancer and the arms. The balancer has substantial weight so as to balance the camera during hand held operation. Batteries are installed in the balancer and a flash unit may be incoporated therein. The arms may be rigid or may be a flexible belt. The balancer is preferably spaced from the camera body by an adjustable distance. Electrical contact is provided between the balancer and the camera body through the arms.

Abstract: A sound absorptive structure for installation on room wall structure to reduce low frequency wave energy and enhance room acoustics. A fibrous, sound absorptive member is of curved section and terminates in tapered side edges for inserted engagement with wall mounted strips. The structure may be segmented with partitions between the segments. Alternatively T-shaped divider strips may interconnect adjacent segments. A further modification utilizes a flat base for wall attachment with end portions of the base folded perpendicularly to the base to provide closures for the ends of a sound member. Intersections between segments of a sound absorptive structure may be accomplished by corner mounted box structures or may be mitered for endwise abutment with one another. Openings in the room wall structure increase the volume of the present wall mounted structure.

Abstract: A mirror assembly forming part of an overall arrangement for insuring that the lens of a camera supported by a tripod or the like is parallel with a flat surface supporting an object to be photographed is disclosed herein. This mirror assembly includes a mirror member having a mirrored body including a mirrored surface and a view hole through its mirrored body and mirrored surface. It also includes means for connecting the mirror member to the camera. One such means comprises a T-mount designed to temporarily replace the lens. Another means utilizes a combination of an adaptor ring and a retaining ring. Still another means utilizes the adaptor ring alone.

Abstract: Stereo electroacoustical transducing apparatus for providing acoustical reproduction in a room at least partially bounded by a room bounding surface including a floor, sidewalls, and a ceiling, the apparatus including a nonlocalizable woofer module that is mounted outside of the room and communicates with an opening in the room bounding surface, upper frequency drivers located within the room, and electronics for providing audio electrical signals to the nonlocalizable woofer module and the upper frequency drivers.

Abstract: In order to reduce the noise the exhaust of an internal-combustion engine, especially for off-road vehicles, there is utilized an absorption silencer comprising: a housing (1) made up of a plurality of mountable elements (10, 18), built from heat-resisting material and intended to be fitted and fixed in a removable way on the perforated exhaust pipe (50). Stuffing material (13) of deadening and heat-resisting material is interposed using two annular joints, a front one (20) and a rear one (21) built from partially elastic and highly heat-resisting material such as silicone or viton, and which also ensure the housing seal to the exhaust gases.Advantageously, said the housing (1) is built from heat-resisting material, such as nylon or PPS, according to the rotary molding process.

Abstract: An improvement in single and double reed mouthpieces for musical instruments comprising a pair of rounded or flat elongate protrusions along portions of the lay surfaces of the mouthpiece body on opposite sides of the vibrating portion of the reed, for reducing a player's lip pressure on the vibrating portion of the reed.

Abstract: A stringed instrument construction including a neck attached to an annular housing and having its acoustic components such as soundboard and rim mounted concentrically in the housing. Rather than having multiple tensioning hooks and brackets to tighten around the perimeter of the soundboard as in a banjo, this instrument employs an annular threaded connection between the acoustic components and the housing. A gear and pinion aparatus is used to facilitate turning the inner threaded portion within the external housing. There is no need for coordinator rods therefore the acoustic components can resonate more freely, providing better sound. The neck is connected to the housing at a radiused interface which enables ample adjustment of the neck's angle. The neck features a track mounted self adjusting capo, and an optional track mounted single string capo.

Abstract: A muffler for use with an internal combustion engine or the like having improved attenuation capabilities. The muffler of the disclosure comprises at least two separate passages interconnected in series with a single or multiple output exhaust manifold and a single or multiple tail pipe of an engine exhaust system. At least one of the passages has a length greater than the other or others. The total cross-sectional area of the passages is approximately equal to or greater than the cross-section of the single or multiple exhaust manifold and single or multiple tail pipe to eliminate back pressure and maintain column inertia. In an embodiment, a housing encloses the passages and the overall appearance is that of a conventional muffler. In still another embodiment, at least one of the passages within the housing are perforated with a plurality of apertures. These apertures can be all of the same dimension or can be of different cross-sectional areas.

Abstract: A camera has a front cover with an inner wall and an opening for a movable lens barrel. An immovable annular member is spaced from the inner wall of the front cover. A light interception member, with elastic end projections and inner lips, is disposed in the space between the inner wall of the front cover and the annular member. The end projections of the light interception member contact the inner wall of the front cover and inner lips are in slidable contact with the movable lens barrel.

Abstract: A sound barrier member for enabling a sound barrier providing good prevention of sound transmission sound reflection. The sound barrier member comprises an enclosure in a generally panel like configuration having a rectangular outer perimeter adapted to engage with other similar members to produce a sound barrier. The enclosure is formed by a front panel (10) and a rear panel unit (16) defining an enclosed space therebetween, with the front panel (10) having a plurality of openings (12) in a desired shape and array allowing sound transmission into the enclosed space. A sound absorbing material (25) is positioned in the enclosed space overlying at least the openings in the front panel (10) and being spaced forwardly of the rear panel unit (16).

Abstract: A speaker diaphragm is formed by heat-pressurized molding a composite structure of fabric cloth and resin sank into the fabric cloth. The fabric cloth is woven from high strength and high elasticity polyethylene fiber which has at least tensile modulus of 4,500 kg/mm.sup.2 (500 g/d).

Abstract: A full closed type diaphragm apparatus having a complete light shut-off function comprises seven blade members made of thin plate and having respective pivot points rotatably supported in succession in a rotational direction about an optical axis and respective free end portions oriented in the rotational direction, and a rotating apparatus to simultaneously rotate the blade members by the same angle in the rotational direction about their respective pivot points. The blade members include at least one long blade member and a plurality of short blade members.

Abstract: A mount for a pinhole lens camera includes a plate for mounting to a wall or cabinet and an approximately hemispherical shell rotatable relative to the plate. The shell is held at a fixed rotational position relative to the plate with clamp or the like. The camera is held in a tube assembly which is adjustable along a radial slot in the shell in a manner that the entrance pupil of the camera lens, in front of the lens, remains fixed at a point on the center normal line of the plate when the direction of the camera axis is changed. The tube assembly is fixed in position in the slot by clamping with a washer and clamping nut.

Abstract: A muffler system for a working vehicle, particularly a lawn mower, comprising a main muffler body connected to an exhaust manifold of the engine, and a curved muffler cover covering the main muffler body from below. An exhaust pipe extends from the main muffler body laterally outwardly of the vehicle body, and defines an exhaust outlet for discharging exhaust gas in a direction away from a front wheel and the ground. Cooling air is blown by a cooling fan from the engine into the muffler cover. The muffler cover defines air exhaust openings for directing the cooling air forwardly of the vehicle body.

Abstract: A lap top keyboard is provided having an outwardly curved center for user comfort and efficiency. The lap support on an underside of the keyboard is recessed, allowing the keyboard to extend downward to an outside of the user's thighs.

Abstract: The present invention relates to an acoustical diffusor device which is made up of a plurality of specially designed and shaped cinder or concrete blocks which may be assembled together through the use of mortar to provide a diffusor of desired shape and configuration. Each diffusor includes a plurality of wells, the depths of which are determined through the use of number theory sequences, such as the quadratic-residue sequence developed by Karl Frederick Gauss. These surface irregularities are unique in that they provide a flat power spectrum and constant scattered energy in the diffraction directions.

Abstract: A fluid friction controller that includes an outer member having a first friction control surface and an inner member having a second friction control surface. The control surfaces coact to define an elongated orifice that diverges from its entrance toward its exit. The length of the orifice is related to the angle of divergence so that the flow of a fluid passing therethrough remains attached to the control surfaces and the dynamic pressure in the flow does not exceed the static pressure at any point along the length of the orifice.

Abstract: The present invention is a peg type score keeping game board which is two game boards in one and is specifically suited by design to facilitate card games such as the game GIVE-A-WAY and CRIBBAGE.