Abstract: An elastomer muffler for the exhaust of a pneumatic percussive tool, which comprises an outer and an inner side wall. The cross-sections of the side walls are C-shaped and the side walls are longitudinally unified for forming a cavity therebetween. The muffler is detachably mounted to the tool by resilient snap action. To advantage, the muffler may be used in connection with a pusher leg arrangement for a rock drill. The muffler, then, is mounted on the pusher leg and the inlet mouth thereof is arranged substantially concentrically with the axis of the hinge connection between the pusher leg and the rock drill but spaced axially from said hinge connection. The exhaust port of the rock drill is also substantially concentrically with the hinge connection but spaced axially therefrom.

Abstract: A diaphragm type stethoscope for conveying sounds from within a patient's body to the ears of a medical examiner. A heating element is mounted within the hollow head of the stethoscope substantially adjacent the diaphragm member thereof for selectively heating the diaphragm member. A source of electrical power is preferably fixedly attached to the head of the stethoscope in electrical communication with the heating element to selectively activate the heating element.

Abstract: A stringed musical instrument particularly a ukelele employing simple rotatable friction pegs in the machine head, is provided with a tension-receiving member for the strings disposed between the instrument nut and the machine head. Each string is looped in a circle about the member and it is found there is a marked reduction in the tendency for the instrument to detune under the string tension. The member may be constituted by a screw or a rod mounted by the instrument neck and about which the respective string is looped. With a wooden-necked instrument each member may be constituted by a wood screw screwed directly into the neck.

Abstract: An earpiece which takes the form of a pouch made of a plastics foil which surrounds a less pliant plastics tube in an airtight manner and is filled with a sluggishly moving jelly-like paste.A not readily movable compression ring provided with a funnel shaped portion which is clear of the tube ensures that the pouch is filled in such a way that during use the pouch perfectly engages with the inner wall of the auditory canal.

Abstract: A high efficiency, compact muffler apparatus for use with internal combustion engines comprises a tubular muffler housing internally divided into first, second and third longitudinal chambers by first and second transverse wall partitions. An exhaust inlet duct base axially through the upstream housing end into the first chamber and an exhaust outlet duct extends axially through the downstream housing end through the third chamber to the downstream side of the second partition. A pair of diametrically spaced, internal ducts, open at both ends, project longitudinally, out of alignment with the inlet and outlet ducts, through the two wall partitions from the first chamber, wherein upstream duct ends overlap the inlet duct, through the second chamber and into the third chamber. Several longitudinal, opposing rows of small tubular, aperture-defining elements project from each of the internal ducts in the region of the second chamber.

Abstract: A head piece, for grasping by a musician, having a stem joined thereto, the stem having elongated teeth which are formed thereon and disposed radially with respect to the longitudinal axis of the stem and head piece. A ratchet body having a bore therethrough is placed over a spindle, and the spindle is threaded into the head piece such that the spindle and head piece are rotatable as a unit. The ratchet body has elongated teeth formed thereon which are radially disposed about the bore of the ratchet body and which mesh with the teeth formed on the stem. The meshing teeth allow rotation of the head piece and spindle in one direction only with respect to the ratchet body, thereby causing a string of a musical instrument attached to the spindle to be wound about the spindle and secured in a taut condition.

Abstract: The invention relates to silencers for damping sound waves created in gases, comprising a series of thin-walled, tubular damping units and an inner tube for conducting gases through the end walls of the units, the tube having openings communicating with the chambers defined in each unit. In accordance with the invention each damping unit is surrounded by an outer tube which is connected in a gas-tight fashion through two end walls with the cylindrical surface of the damping unit, and the space between the cylindrical surface and the outer tube is divided into at least two chambers communicating with the inner tube through a transversely-extending branch pipe.

Abstract: A planar diaphragm, preferably for loudspeakers where, on the rear face side there is an asymmetrically shaped sound producing portion, surrounded by marginal and channel shaped portions to assure that sound waves generated by said sound producing portion will not trespass said portion, and said marginal portion is provided plugs of different density than said diaphragm, to modify the vibratory characteristic of the sound producing portion and thereby improve the response curve.

Abstract: A chord inversion coordination aid comprises a plurality of dials of increasing diameter and each representing a particular chord type and having a peripheral array of the scale tone names of the chord in its root and inverted positions arranged in sectors, whereby upon aligning various sectors of the discs a given chord progression can be arranged according to the most easily played chord inversions. The dial may be centrally pivoted behind a cover sheet having a window therein to expose the dial sectors, and a pad of staff paper may be mounted on the cover sheet.

Abstract: This disclosure pertains to a novel wind instrument having a range of two octaves. Seven lettered note keys, starting with C, each can be individually depressed to produce a tone. An octave bar, when simultaneously depressed, produces the corresponding tone in the next higher octave. Scale programming buttons, when once depressed, select a sharp, natural, or flat tone which is now produced when depressing the lettered note key, in accordance with the composition's key signature. Means are provided to quickly reset the program by first making all lettered note keys natural and upon further simple manipulation, selection of the new scale program may be obtained. To avoid disturbing the program set by the scale buttons, a group of buttons provides tones in an accidental register which, upon their depression, will produce accidental notes not included in the main key.

Abstract: A longitudinally extending body is provided with a longitudinally extending slot or opening. A hollow tubular member is secured adjacent one end of the body and is provided with a slot across its end which coincides with the slot in the body. Reed means are secured at one end to the body and extend longitudinally of the slot in the body and the tubular member, with the reed means having a portion extending laterally therefrom adjacent the hollow tubular member for manual vibration of said reed means relative to said body and member. The other end of the hollow tubular member is open to be positioned adjacent the mouth of the user for providing desired notes and tonal effects when the reed is manually vibrated. Clamp means on the body are movable longitudinally therealong for engagement with the reed at a predetermined or selected position to vary the length of the reed and thereby the pitch of the notes created by the vibration of the reed means.

Abstract: A motor vehicle headlamp system has an adjusting mechanism which causes the dipped beam briefly to be raised and deflected sideways, to improve vision, when the main beam is extinguished.

Abstract: The lighting structure disclosed is particularly useful for operational areas where the reflection is poor and which are subject to the risk of explosion and fire damp. The novel lighting structure comprises a casing containing power supply means and a fluorescent tube. The power supply means is a constant current transformer with power factor compensation and a rubber-like mass encases the transformer and tube connector terminals to conceal all live electrical parts except for the light emitting portion of the tube.

Abstract: Optical metronomes with a spot or column of light shining through the sheet of music simultaneously in all staves or alternatively in all measures utilizing individual lamps, fiber optics, or lamps located in reflecting channels. Lights illuminate successively and are controlled by motor-driven perforated shields, contact arms, or an oscillator and gating circuitry.

Abstract: A loudspeaker comprises a frame, a cone assembly which includes a cone body having an outer periphery spaced away from the frame, and a flexible annular surround connecting the periphery of the cone body to the frame. The surround has an inner peripheral flange secured to the outer periphery of the cone body, an outer peripheral flange secured to the frame, and an arched web between the two flanges and spanning the gap between the cone body and the frame. The radial cross-section of the arched web has a varying radius of curvature with a greater radius at the bases thereof than at the apex. The preferred cross-sectional configuration is a parabola. The arched web decreases in thickness from the bases thereof toward the apex so that the minimum thickness is located at the apex of the arch and the maximum thickness is located at the bases of the arch. The surround is made of a solid resilient material having a durometer of less than about 55, preferably a rubber such as butyl.

Abstract: A rocking footpedal mechanism for driving a tambourine or similar percussion instrument in fore-and-aft oscillation about a pivotal arrangement below the tambourine, the pivotal arrangement and the tambourine-holding shank are so located at one end of the footpedal as to cause the tambourine to strike the leg above a musician's foot operating the footpedal, simulating conventional hand-striking of the tambourine, while leaving the musician's hands free; double action provides positive control of both half-cycles of tambourine oscillation and the pivotal arrangement is preferably spring mounted to provide secondary oscillations when desired.

Abstract: An adapter for a reflex camera formed by an adjustable image reflector that is positionable on the camera with respect to its view finder.

Abstract: A unitary retainer for a cymbal on a stand. The combination employs a conventional stand for supporting a cymbal at the suitable height for playing by a drummer in a band. The essence of the invention is a one-piece retainer secured to the cymbal rod. The unit employs a threaded cymbal base with an integral drive nut; a sloping, flared shoulder; and the cymbal neck extending into flexible arms and a flared retaining head for passing through the hole in a cymbal and flaring to a fully extended dimension for retaining the cymbal on the stand.

Abstract: The invention is a plectrum or pick for a guitar or other stringed musical instrument played with a pick. In particular, the invention is a pick and pick holder conformable to the contours of the forearm of a wrist amputee, the invention also providing a method for making the present prosthetic pick structure.

Abstract: A speaker enclosure for a stereophonic sound system is disclosed. The speaker is mounted in a chamber, the enclosure of which is connected to a tube of relatively long length and of circular cross-section. The construction is such that phase-inversion occurs so that the sound emanating from the rear of the speaker reinforces sound from the front of the speaker. The construction also substantially suppresses standing waves.