Abstract: Disclosed is a modified striking mechanism for use in pianos and related instruments having strings or their equivalent to produce musical notes and keys to select the notes. The mechanism includes a hammer assembly, a lever driving the hammer, coacting gear means for imparting motion to the hammer and features a novel escapement action for use therewith. Additionally disclosed are improvements including an escapement action adapted for use with conventional piano striking mechanisms, a novel damper assembly, a mechanism for activation by the soft pedal of the piano, a tension adjustment mechanism for varying the amount of force necessary to strike a key, and novel balance rail and capstan lever assemblies.

Abstract: A stroboscopic tuning device for a stringed musical instrument that is mounted on the musical instrument adjacent to the strings to be tuned. A solid state circuit employs a frequency generator, such as a piezoelectric crystal oscillator or a tuning fork oscillator, to operate the stroboscopic light source at a preselected frequency. In the use of the device, a string is plucked, and when the vibratory motion of the plucked string is either the fundamental frequency or the harmonic frequency of the preselected operating frequency of the stroboscopic light source, the string will appear to an operator to be in a nonvibrating condition. At that time, the string is tuned or adjusted to the desired tone.

Abstract: An improved banjo drumhead having a circumferential body rim and a separate tone ring which receives the head membrane stretched over it, the tone ring being supported relative to the body rim by a number of cantilevered support columns extending from the body rim, the head membrane being stretched over the tone ring and affixed to the body rim so that the only mechanical connection between the tone ring and the body rim is the plurality of cantilevered support columns permitting the tone ring to achieve independent vibrational movement relative to the body rim.

Abstract: A removable tonal pitch indicator for a kettledrum having a foot lever-actuated adjustably tensioned drumhead or tympanum. The indicator provides a visual indication of the tonal pitch of the tympanum and includes a reciprocally movable marker which is moved upwardly or away from the tympanist to indicate a higher pitch and downwardly or toward the tympanist to indicate a lower tonal pitch of the tympanum. The desired direction of movement of the marker is attained by enclosing a relatively stiff cable in a sheath. The cable is attached to the marker and is anchored below the lever device while the sheath cooperates between the indicator housing and the lever device. Sufficient curvature is provided in the sheath/cable combination so that the movement of the lever device changes the curvature of the sheath/cable combination thereby forcing the cable to move the marker in a direction counter to the movement of the lever device.

Abstract: The application discloses a new silencer for internal combustion engines. This silencer comprises an internal resilient tube capable to vibrate longitudinally and permeable to the exhaust gas and an external sheath. An end piece closes the internal tube. Spacers are secured to the internal tube and another end piece provided with apertures is secured to the end of the external sheath. The exhaust gases exit from the internal tube through the space comprised between the spacers and the external sheath towards said apertures in the other end piece.

Abstract: A keyboard for a piano, organ, or similar instrument in which the keys are arranged in groups of three, each having a pair of flat keys with a raised key inset between. The flat keys are on a common plane in the manner of the white keys of a conventional keyboard, the raised keys being short in length and spaced between the front edge of the flat keys and the back board of the instrument. In one form of the keyboard a second set of raised keys is positioned adjacent the backboard and mechanically coupled to the basic set of raised keys, so that either raised key in a pair may be used to play a particular note for the convenience of fingering. Four groups of three keys represent the twelve tones of the chromatic scale and a related notation system identifies each tone clearly, without the need for sharp and flat symbols. The keys also have a physical relationship to the note positions in the musical notation, which simplifies playing.

Abstract: A sound-damping housing suitable for use with a piece of sound-generating equipment. The housing has inner and outer housing parts, the former forming a chamber for receiving the piece of sound-generating equipment, with the two housing parts forming between themselves a second chamber for receiving a sound-damping liquid. This second chamber surrounds the receiving chamber, and suitable provision is made for allowing the piece of sound-generating equipment to be inserted into and withdrawn from the receiving chamber. By virtue of this arrangement, the sound-damping housing and the piece of sound-generating equipment may be transported separately from each other. Moreover, the liquid need not be introduced into the sound-damping housing until after the same has been transported to the place where it is to be installed, thus making it easier for the sound-damping housing to be transported.

Abstract: An exhaust apparatus for internal combustion engines comprises an outer pipe having an enlarged intermediate portion and at least one end portion having nearly the same diameter as the exhaust pipe from the engine for connection thereto, an inner pipe of approximately the same diameter as the exhaust pipe, a plurality of helical passages provided between the inner and outer pipes and sets of fins arranged inside the inner pipe at each end to impart vortical flow of gases passing through the inner pipe and to accelerate the gases through the helical passages and absorb them from the engine, the end portion of the outer pipe being connected with the exhaust pipe by means of an encircling clamping ring.

Abstract: A sound-attenuating inlet duct is provided for a gas turbine engine wherein the inlet duct includes a casing defining, in serial flow relationship, a minimum area throat of predetermined axial extent, a diffuser and a cylindrical section. Sound-absorbent acoustic material is disposed upon the inner walls of the duct in the cylindrical section. A first amount of acoustic attenuation is provided by accelerating the motive fluid to high subsonic velocities through the throat. A second amount of acoustic attenuation is provided by locally accelerating the motive fluid in the vicinity of the acoustic material, thereby imparting a velocity component to the acoustic waves which is normal to the acoustic material, thereby enhancing absorption. By sizing the various sections of the inlet duct in a unique predetermined relationship the effects of the two sources of acoustic attenuation may be made additive.

Abstract: An apparatus in which a latent image of an original document is recorded on a photosensitive member. A light image of the original document is projected through a normally non-deformed transparent member onto the photosensitive member. An operator actuatable control deforms the transparent member producing a plurality of spaced grooves therein. The light image transmitted through the grooved portion of the transparent member is phase shifted with respect to the light image transmitted through the non-grooved portion thereof. In this way, the operator may deform the transparent member producing a modulated light image, or permit the transparent member to remain in the non-deformed condition so as not to modulate the light image.

Abstract: A microfiche or microfilm editing device in which a microfilm or microfiche to be edited is supported on a frame arranged to be driven in an x and y axis directions according to a program, the movements being relative to a copy axis. Also movable in relation to the copy axis is a microfiche holding means arranged to be driven by actuators in a similar fashion to the first microfiche or microfilm and according to a further program. In order to illuminate the image to be transferred to the first film to the second film a light source condenser and at least one light transfer block is arranged to project light along the copy axis. Several light transfer blocks may be mounted on a rotatable turret so that different blocks may be provided for different microfiche or microfilm standards.The editing device is arranged so that microfiches can be updated according to a set program or alternatively microfilm can be changed to microfiche or microfiches and one standard can be changed to microfiches of another standard.

Abstract: A string post for a musical instrument of the type which extends perpendicular to the instrument head and is adapted to be rotated manually to tighten a string wrapped therearound, the string post having a constantly decreasing diameter from the outer end thereof to a plane closely adjacent the instrument head so as to urge a string wrapped therearound toward and into contact with the instrument head.

Abstract: A supporting and pivot device for use in a keyboard of a musical instrument. The device is preferably made of plastic and is wedge-shaped having a pair of adjacent slots, one of said slots being adapted to securely receive a pin by virtue of the resilient deflection of one wall of the receiving slot towards the other slot. The lever of the keyboard is pivotably secured to the support frame through the device and secured pin.

Abstract: An instrument for tuning musical instruments where a low difference frequency is derived between the instrument to be tuned and a reference frequency. The difference frequency signal is shaped to a pulse train of constant amplitude and width pulses. The pulses are integrated with respect to time, and an indicating meter indicates when the instrument is precisely in tune or small sharp or flat deviations therefrom.

Abstract: A tone enhancing element incorporated within the mouthpiece of a reed type musical instrument, such as a saxophone or clarinet, has two steps projecting into the air flow-through passage of the mouthpiece at a point opposite the opening over which the reed is mounted. The first step in from the outward end of the mouthpiece is the lower of the two, projecting into the passage less than the second step. The element may be a removable element that can be taken out for cleaning, for example, or it may be an integral portion of the mouthpiece structure.

Abstract: A noise barrier having a large magnitude of transmission loss is disclosed which is formed of a cell-box-type noise barrier comprising (A) a hollow cell-type block having a perforated sound-absorbing plate disposed on the side confronting the source of noise and a sound-insulating plate disposed on the opposite side relative to said perforated sound-absorbing plate and incorporating therein a sound-absorbing material and (B) a free-spacing plate disposed opposite said sound-insulating plate across a space and held in position by the medium of an elastic member, with a free air layer intervening between said free-spacing plate and said sound-insulating plate. Also disclosed is a method for insulating noise by providing a free-spacing plate at a distance from a noise source in such a way as to create a free air layer.

Abstract: In a piano pedal assembly adapted to control the duration and amplitude of musical tones or notes generated by a piano, the individual pedals of the assembly when attached to the piano, are maintained in their normal position under pressure and adapted when depressed to pivot about a pin. The assembly is mounted on a support such as a base plate, and a pair of pedal mounting blocks having a cylindrical opening, for securing opposite sides of the pivot pin, are mounted within openings in the base plate. The pedal mounting blocks are formed from a low friction material such as Nylon or Teflon and function to provide and maintain precise registration of the individual pedals within the assembly. The piano pedal assembly utilizes fewer and less complex parts and components than prior art assemblies whereby the assembly time and fabrication cost of pedal assemblies are substantially reduced.

Abstract: The invention is a teaching and practicing aid for music students which graphically displays the relationship of the dominant, tonic, and subdominant scales in a particular key signature and as they relate to the diatonic scale in that key signature, the device structurally comprising a backing sheet optionally having the scale tones of a diatonic scale named in a row along the bottom, and three preferably reversible panels disposed in staggered horizontal slits cut in the backing sheet, these panels having portions visible above the slit with indicia thereon indicating by fingering number or scale tone name musical notes representing chords or scales, these notes being spaced proportionally to the key spacing of a piano keyboard. There is an optional insert card having two selectively displayable portions which represent the left and right hand, respectively, with the fingers thereof numbered in accordance with conventional elementary teaching techniques.

Abstract: A synthetic material drumstick of the type commonly employed in the playing of various percussion instruments such as drums, cymbals, and the like, wherein the drumstick is fabricated from fiberglass reinforced polyester resin rod stock material machined to a specified dimensional configuration, which configuration, in combination with the material employed, provides a drumstick of significantly high durability characteristics.

Abstract: A self-contained unit for the re-stringing of a bow for a musical instrument as a replacement for the traditional horse hair comprises a hank of reorientated monofilaments each containing at least a substantial proportion of polyvinyl chloride and having a diameter in the range of 0.15 to 0.40 mm. The adjacent free ends of the monofilaments are bonded together to form an enlargement at each end of the hank and these are preferably trapped mechanically in recesses at the ends of the bow although they can be glued in position in the traditional manner if required. When the unit is fitted mechanically the frame of the bow has at one end a recess with a restricted mouth fitted with a spring-loaded member for jamming the mouth under the spring force, but capable of yielding inwardly to permit the introduction of an enlargement at the end of the unit, and at the other end it has an adjustable frog formed with a recess provided with a longitudinally slidable cover.