Abstract: The object of the invention is to provide a slide calculator to make the determination of flash-to-subject working distances (WD) easy and accurate for amateur and professional photographers. Light sources other than flash can be used. The calculator uses known factors such as lens f-stop, film speed, light ratio, flash guide number (GN), flash power setting and filter exposure factors to determine working distances even when using multiple flashes simultaneously. The indicia on the slides and the indicia adjacent the appropriate windows on the panels are arranged in a predetermined manner and relationship to each other to permit the desired working distance to be determined accurately. Working distances for several flashes (each flash having a different purpose) can be determined and their affect on each other is compensated for in the calculations. Then the several flashes can be used in combination to achieve a desired lighting effect with correct exposure.

Abstract: A hearing aid apparatus comprises a pair of cup shaped members positionable behind the ears of a user and being connected by means of a headband. The cup shaped members form sound reflective surfaces which direct sound waves into the user's ears to thus increase his or her hearing capacity. A modified embodiment of the invention utilizes foam padding in a rear portion of the cup shaped members, and this padding causes a gentle forward bending of the user's ears to further increase hearing ability. Additionally, the cup shaped members may be provided with through-extending apertures which permit limited air flow within the members. The air flow through the apertures prevents humidity and heat buildup within the members which could affect sound reflection capabilities. The apertures are of a cone shape with the large open end directed towards the interior sections of the members.

Abstract: Adjustable packing strips (3, 4) are held on the inside of a carrying sheet (6) covered with sound-absorbing material (5), and are slidable by adjustment elements (7, 9), which can be actuated and fastened from the outside, within an adjustment chamber isolated against the sounds of a sound-emitting body (2) to project the packing strips beyond the peripheral edge (6A) of the carrying sheet (6).

Abstract: A stethoscope chestpiece has a body member, a tubular shaft, and an indexing detent. The body has a plurality of microphones each of which has a opening at its apex and a central recess. The tubular shaft is rotably secured within the central recess and has an opening in its wall that aligns selectively with one of the openings from the microphones. The sound conveying detent is mounted transversely within the shaft and aligned with the opening in the shaft wall. The indexing detent has a hollow cylindrical element and spring. The hollow cylindrical element has an open bottom and a seat end having an opening. The seat end is beveled and extends beyond the opening in the shaft wall to engage the body. When the seat end is aligned with a selected one of the openings from the microphones it seats to hold the opening from the microphone in alignment with the opening in the seat end to create a sound passageway into the tubular shaft.

Abstract: The acoustic transducer system includes an electroacoustic transducer and a flexural oscillator plate which is coupled to the electroacoustic transducer. The flexural oscillator plate is so constructed that at the system operating frequency it is stimulated to flexural oscillations of a higher order at which on the flexural oscillator plate node lines form between which antinode zones oscillating alternately in opposite phase lie. To influence the sound radiation of the flexural oscillator plate a sonic beam shaper is provided. The sonic beam shaper has soundwave barriers which are impermeable for soundwaves and which lie spaced from the flexural oscillator plate and acoustically decoupled therefrom in front of first antinode zones oscillating in equal phase with each other, and soundwave-permeable regions which lie between the soundwave barriers in front of the remaining second antinode zones oscillating in opposite phase to the first antinode zones.

Abstract: A device for improving the hearing acuity of a user directionally, including a pair of reflectors to be supported behind the user's ears so as to increase the effective area of the outer ear and reflect an increased amount of sound energy into the user's ears from a position in front of the user. The reflectors are supported alternatively on a headband or a cap equipped with horizontally extending straps which permit adjustment of the location of each reflector, and the reflectors are attached to the headband or straps by a respective base plate to which each reflector is attached pivotably so that the reflectors can be adjusted to optimum positions.

Abstract: A device for allowing for spoken communication between a pregnant woman and her fetus. The device has a speaking tube component connected at one of its ends to a mouthpiece component and at its other end to a stomach-piece, megaphone-type component. The speaking tube component is made of flexible and soft plastic to allow for reconfiguration to suit the size and stage of pregnancy of the woman. The stomach-piece component has a canted annular edge surface to allow flush positioning against the stomach. The pregnant woman speaks into the mouthpiece, the sounds being amplified and sent to the megaphone-type component positioned against the abdomen so the fetus may hear.

Abstract: An acoustic filter adapted to be fitted on a pipe for the purpose of absorbing pressure waves. The acoustic filter has a body constituted by a cylinder, an inlet and outlet end, a locking ring fitted in a groove located at the inlet and outlet ends, coupling means within the locking rings for coupling the filter to a pipe. A holder tube fitted with diffuser rings for connecting the coupling means. A deformable bag made from a flexible material is mounted between the inlet and outlet ends, shaped like a cylindrical sleeve and surrounds the holder tube and diffuser rings. The bag defines with an inner wall of the cylinder a chamber for receiving a pressurized gas.

Abstract: A muffler for work vehicle V-type internal combustion engines is disclosed, which is mounted in a horizontal sideway position, with its axis placed perpendicularly with the longitudinal vehicle axis, kept a proper distance from the chassis or vehicle body so that it is disposed in full exposure to the atmosphere for proper cooling. A pair of spaced inlet ports are provided in the muffler, at locations adjacent to opposite ends thereof for receiving the exhaust gases from the engine through a pair of parallely extending, parallel exhaust pipes directly interconnected between the combustion chambers of the two cylinders and the muffler inlet ports, without using the conventional intermediate flexible corrugated connectors.

Abstract: A remotely operated cash box assembly comprises a box-like structure having a front wall portion, a rear wall portion and two side wall portions. Rotatably mounted between the front wall portion and the rear wall portion is a spring urged cover member. A solenoid actuated latch mechanism mounted to the front wall portion engages a latching surface on the cover member latching the cover member upon movement of the cover member to a position engaging the front wall portion. Energizing of the solenoid releases the cover member for movement to a position adjacent the rear wall portion opening the cash box assembly. Located within the cash box assembly is a cash tray having separate compartments for coins and bills in which the bill compartments are orientated in an upward direction to facilitate the removal and depositing of bills in the tray.

Abstract: A muffler is provided with a pair of internal plates stamp formed to define an array of tubes therebetween. An external shell, which may be stamp formed, surrounds and encloses at least selected portions of the internal plates. The array of tubes stamp formed in the internal plates includes at least two tuning tubes. One tuning tube terminates at a tuning aperture in one of the two internal plates, while the other tuning tube terminates at an aperture stamp formed in the other of the two internal plates. Thus, one tuning tube will communicate with a low frequency resonating chamber on one side of the pair of internal plates, while the other tuning tube will communicate with a low frequency resonating chamber on the opposite side of the assembled internal plates.

Abstract: A sound transducer, particularly an earphone, is buttoned into a sound opening of an in-the-ear hearing aid housing by means of an elastic hose part seated on a sound connector of the sound transducer. The elastic hose part is slightly pre-stressed in longitudinal direction and the sound transducer is provided with an elastic abutment that elastically compensates the prestress.

Abstract: Hydraulic clatter damping device consisting of a piston mechanically connected to a valve spindle and sliding within a closed composite chamber (20) consisting of two sub-chambers arranged on either side of the piston, namely, a large sub-chamber (23) in the upper part and a compression chamber (24) in the lower part, both chambers being filled with the same hydraulic fluid under pressure, the piston being provided with a hollow deformable body filled with a gaseous fluid, being rigidly connected to its free face in the large sub-chamber and contracted during rest by the pressure prevailing in the sub-chambers. The sub-chambers communicate with a thin-walled nozzle (26), the chamber containing the hollow body comprising a visual communication means which permits its upper face to be observed. The invention relates to the manufacture of safety valves and other safety components.

Abstract: An exhaust muffler is provided. The muffler may be formed from a pair of internal plates that are secured in registration with one another and are formed to define an array of tubes through which the exhaust gages may travel. Selected portions of the tubes in the internal plates may be formed to include perforations. The muffler may further include at least one external shell formed to define at least one chamber which may at least partly surround the perforations in the internal plates. At least one inlet or outlet may lie on the seam between the formed plate members. However, at least one inlet or outlet may also be provided through a portion of the muffler spaced from the seams. The inlet and/or the outlet may be angularly aligned to the longitudinal axis of the muffler and may further be angularly aligned to one another.

Abstract: A silencer to be mounted on the air intake of a cooling fan of an electric motor in a vacuum cleaning system. The silencer comprises a cylindrical housing closed at one end and opened at the other end. The housing is provided with perforations around its periphery adjacent the closed end. A sleeve made of sound absorbing material lines the inside of the housing without obstructing the perforations.

Abstract: A muffler is provided including a pair of internal plates formed to define an array of tubes. At least one external shell is formed to define at least one chamber which will surround and enclose a selected portion of the array of tubes. Selected portions of certain tubes will be formed to include perforations. Portions of certain tubes will further undergo cross-sectional changes to control the flow of exhaust gases through the muffler. Certain channels between adjacent chambers of the external shell will be disposed to extend substantially continuously from peripheral portions of the adjacent chambers formed in the external shell. In certain embodiments, a controlled communication is provided between a low frequency resonating chamber and an adjacent expansion chamber. In other embodiments, additional formed layers are provided to enhance either heat or noise insulation.

Abstract: An air intake noise suppressor for reducing noise generated by intake air sucked into an internal combustion engine. An intake pipe is provided with a resonance pipe, which extends forwards within the intake pipe as penetrating through a rear end wall of the intake pipe, communicates with the interior of the intake pipe through an opening at its front end, extends backwards from the rear end wall externally of the intake pipe and has its rear end closed, and the resonance pipe is fixedly locked to the intake pipe at its portion penetrating through the rear end wall and in the proximity of the opening at the front end. Since the resonance pipe is accommodated within the intake pipe over a considerable length and only its rear end portion projects backwards from the intake pipe, a surplus space is almost not necessitated for mounting the resonance pipe, and yet the resonance pipe itself can be made sufficiently long.

Abstract: A protective keyboard enclosure assembly consisting of an upper section that mounts over a lower section and conforms to the size and shape of an electronic keyboard it houses and shields. The upper section allows a keyboard operator to push keys through a transparent, flexible, durable membrane which is readily interchangeable. The keyboard enclosure assembly protects this very sensitive electronic keyboard from any kind of harmful elements and potentially dirty hands and fingers of an operator all of which especially prevail in an industrial or manufacturing plant.

Abstract: A loudspeaker is disclosed having an enhanced response at bass frequencies. The loudspeaker includes a tubular enclosure having a pair of outwardly directed, opposing loudspeaker drivers mounted over each end. A port is provided through the enclosure midway between the drivers and is coupled to the exterior of the loudspeaker by a perpendicularly projecting duct. The length and cross-sectional area of the duct, as well as the enclosure, are selected to describe an acoustic cavity having a predetermined mechanical resonance. The opposing nature of the drivers, spaced apart by the continuous curved walls of the enclosure, reduces spurious resonances within the enclosure. In addition, the resultant T-shaped configuration of the loudspeaker maintains the loudspeaker substantially stationary in a moving vehicle without the need for auxiliary fastening devices.

Abstract: A simulated rock speaker cabinet in the form of a natural rock has build-up portions of modeling clay which include a pattern of small diameter holes to form speaker grills at longitudinally spaced positions. A chicken wire ring provides structural reinforcement to the speaker cabinet. The artificial rock cabinet may be molded of various hydrolitic cements, magnesite cement, a suitable catalytic plastic resin to which pigment or other colorants may be added along with glass or rock chips, to provide the simulated rock cabinet with an external appearance which corresponds to various natural rocks. The speaker cabinet has speakers and the various electronic components of the speaker system housed within the speaker cabinet and may be coated with water-proofing and weather-proofing material with the speakers molded into the wells and facing the grills. An end plug may be adhesively sealed to the opening within the base of the speaker cabinet and suitably sealed by Hydrostone or other cementous material.