Abstract: A power driven drum beater is controlled by means of a foot pedal. The pedal device serves to close an electrical circuit for the actuation of a pivoted solenoid actuated beater mounted on a rod. The foot pedal is further pivotable enabling an electrical contact on the underside thereof to be brought into a desired position along a resistance selector for driving the beater with variable speed or intensity and at a variable rate.

Abstract: A system for adjusting the tonal quality of piano hammers or similar objects consists of incorporating a tensioning device into the device for attaching the string-engaging cover to the hammer so that the stiffness of the cover may be varied. The cover itself may consist of an elastic rubber-like material.

Abstract: An acoustic system for disposition proximate to an acoustical boundary comprising at least one acoustic transducer for directing acoustic energy away from the boundary and an acoustic reflector surface extending, without substantial acoustic discontinuity, from proximate to the center of the transducer to the boundary.

Abstract: An omni-directional sound system having means to create a high compression zone of low-frequency sound and a speaker-baffle assembly rotatable in said zone and emanating high-frequency sound. A feature includes a grill assembly to create the compression zone. One embodiment includes two rotating speaker-baffle assemblies vertically spaced and another embodiment includes a pair of speaker-baffle assemblies rotating side-by-side. Another includes a speaker array directed to a common zone with a rotating speaker-baffle in that zone. Another embodiment includes a compact system having a drive motor arranged in the stationary speaker cone and directly connected to rotate the speaker-baffle.

Abstract: This apparatus is a unitary photographic lettering and display typography composing device and has as its objective the creation and mechanical combining of two adjacent master and slave photo typographic systems into one unitary, simultaneously controlled photographic, daylight operating lettering composing device that can produce display headings, captions and sub-heads in either English or foreign languages, on a full sheet of photographic paper. Because of its constantly yellow-illuminated character image that develops into a black character image instantly upon exposure to white light and its visible spacing control, its transverse and longitudinal motion adjustability of the photographic paper, it also lends itself to the composition of Semitic and Oriental languages, border designs, overall background pattern tint effects and engineering symbols.Each character is constantly projected in the master unit from a yellow safety light source and is visually spaced to the desired position.

Abstract: A drumstick for use with a musical percussion instrument integrally formed from a thermoplastic nylon matrix material and other suitable reinforcing agents such as chopped fiberglass or carbon fibers. The drumstick body is hollow and includes a plurality of longitudinally disposed internal ribs for increasing stiffness and a vibration dampener disposed within to eliminate structural vibrations or reverberations which may be caused if a drumstick is struck against a solid surface such as the rim of a drum.

Abstract: A stereoscopic camera system is disclosed which includes an insertable film cartridge. An optical system in the camera includes mirrors which are arranged to reflect images from the lenses along coincident axes through aperture plates for exposing sensitized film carried by the cartridge. The cartridge includes a housing forming a supply chamber for containing a roll of the film. Another chamber is provided in the housing for enclosing a take-up spool which is adapted to be driven for advancing the film along a transport track formed about the rim of the housing. A pair of pressure plates are mounted in the housing adjacent the portions of the film which are to be exposed by the light images. Means is provided for yieldably urging the pressure plates against the film so that the latter is maintained in flat relationship against the aperture plates.

Abstract: A course correction calculator for use in light aircraft includes two arms pivotally connected together and each independently pivoted over a map supported on a base. The pivot connecting the two arms is slidable longitudinally along one of the arms and the other of the arms is slidable longitudinally relative to one of two pivot points. A protractor is provided at the pivot connecting the two arms to indicate the angle between them and hence course correction when the two independent pivots are at the departure and destination points on the map and the mutual pivot is at the aircraft's position on the map.

Abstract: A toy cash register having vertically slidable plastic indicator targets and plunger-type actuating keys which are integral with the targets and with interconnecting parts including hinging portions. When raised, the targets are held up by resilient fingers formed on and integral with a rockable plastic latch plate which is swingable to release the targets. The working and locating parts, formed primarily of plastic, interlock with each other and with supporting portions of a metal housing structure so that the need for separate fasteners is virtually eliminated.

Abstract: Muffler having a metal wool outlet barrier has central corepiece comprising a helically ribbed and slotted tube which immobilizes the mass of metal wool and uniformly delivers exhaust fluid thereto.

Abstract: This invention relates to musical instruments and in particular to attachments for application to guitars to change the tone of the latter.

Abstract: A system for instruction in the manipulation of the chord portion of a keyboard of a musical instrument in 3-4 or 4-4 time includes uniquely written music which provides a student with an identity of the root note of each chord to be played and the timing (but not necessarily the identity) of the corresponding chord triad to follow the root note. In conjunction with the music, an apparatus senses the depression of the root note key by the student, provides a sustained confirming identification of that note, and provides the identity (but not the timing) of the triad notes. The indication is retained until a different note key is depressed. The apparatus is useful independently of the written music or keyboard instrument to demonstrate the 5-2-1 system of fingering chords as set forth in U.S. Pat. No. 3,335,630.

Abstract: In a photographic camera of the type having a box-like camera housing and a cover door having a main cover portion which is hinged at one end to the camera housing and a lens support portion on the other end of the main cover portion, a two-part light-tight bellows is provided which couples the cover door with the camera housing in a manner permitting movement of the cover door between a closed position wherein the main cover portion is substantially parallel to one wall of the camera housing and an open position wherein the main cover portion is extended outwardly from the housing at an oblique angle and the lens support portion is substantially parallel to the one wall of the camera housing. When the door is closed, the two-part bellows is collapsed with one part folded flat against the main cover portion of the door and the other part folded flat against the lens support portion of the cover door.

Abstract: An embedded type speaker has the speaker body mounted on a wall by inserting the speaker within a mounting opening within the wall. A grill is detachably mounted in overlying fashion in front of the speaker body with the grill consisting of an annular grill frame having circumferentially spaced sound communicating holes at the peripheral portion and a large central opening therein. A support strip extends transversely across the central opening of the grill frame from one side of the frame to the other. A grill sheet overlies the grill frame to close off the central opening and has the same appearance and is preferably formed of the same material as that overlying the wall surface, facing in the same direction as the speaker. A packing is provided between the peripheral portion of the grill sheet and the periphery of the grill frame and a connecting member couples the center of the grill sheet to the center of the support strip.

Abstract: An apparatus for adjusting the light source position of a light source assembly comprises a lamp socket for mounting a lamp at an eccentric position thereon, and a sleeve secured to a lamp housing for mounting the lamp socket so as to be slidable along the axis and rotatable about the axis of the sleeve. By axially sliding the lamp socket relative to the sleeve or by rotating the lamp socket about the axis, the position of the lamp can be optimally adjusted relative to a condenser which is mounted on the lamp housing.

Abstract: A stethoscope having a head wherein a diaphragm sound chamber is disposed within a housing which allows for the head to be used as a diaphragm sound chamber or a bell sound chamber without removal of the stethoscope head from the patient.

Abstract: A fan silencer having an external shell of annular cross section and a cylindrical central core mounted on a rigid frame. The external shell and the inner core each contain noise absorbing insulation, and have easily removable wall sections to allow fast and easy replacement of said insulation and cleaning of said wall sections.

Abstract: The device of this invention has a housing disposed to fit over the nine keys or push-buttons, numbered 1 through 9 of a push-button array of a calculator or push-button telephone, or the like. Push-button operating means are provided with U-shaped members for receiving human digits. Three of such push-button operating means are disposed along columnar openings in the housing and are resiliently held in a position which corresponds to the second row of the three rows of push-buttons in a standard array. A push-button is movably secured to the U-shaped member and extends therethrough to a finger element. When the push-button is depressed, the finger element to which it is connected depresses the push-button in the center row of the array. When the human finger is pushed against one of the concave-shaped walls of the U-shaped member, the push-button operating means moves along the column to one of the other rows. Within the housing is a wheel which is resiliently connected to the push-button operating means.

Abstract: This invention relates to a selection mechanism for a postage meter in which a single Thomas-type mutilated drum actuator is rigidly mounted on a hollow cylindrical drive shaft on which is also mounted the postage meter printing head, and comprises a series of selection bars lying longitudinally of the drive shaft and angularly therearound, each of which bars is set by a suitable manual positioning means, such as a selection wheel, each such bar carrying a yoke to position a driven gear of a first register to be driven by the actuator, a like series of auxiliary setting bars, each of which is rigidly yoked to the respective first setting bar and which carries a yoke for setting a register drive gear of another register of a postage meter. The main setting bar, at its forward end, is provided with gear teeth which drive a gear train that meshes with a rack carried by the actuator drive shaft to set the mechanism in the print wheel.

Abstract: Resonant acoustic beams modes are generated by an acoustic energy source and a plurality of reflectors disposed along a path.