Abstract: A process and apparatus for selecting or designing a product, such as a muffler, having a complex, content-free sound output which is less stressful or more pleasing. The process includes the steps of sensing at least one physiological response of a subject (21) while the subject listens to an initial content-free sound output, repeating the sensing step for a new content-free sound output, comparing the physiological responses, and selecting the sound output for use in selecting or designing the product which output produces the physiological response that is the least stressful or most pleasing to the subject. The apparatus includes an audio playback device (15), a sound recording (16) of the initial sound, a sound recording (16) of the new sound, and physiological monitoring apparatus (17) suitable for attachment to and monitoring of the physiological responses of the test subject (21) to the playback of the sound recordings.

Abstract: A process and apparatus for selecting or designing a product, such as a muffler, having a complex, content-free sound output which is less stressful or more pleasing. The process includes the steps of sensing at least one physiological response of a subject (21) while the subject listens to an initial content-free sound output, repeating the sensing step for a new content-free sound output, comparing the physiological responses, and selecting the sound output for use in selecting or designing the product which output produces the physiological response that is the least stressful or most pleasing to the subject. The apparatus includes an audio playback device (15), a sound recording (16) of the initial sound, a sound recording (16) of the new sound, and physiological monitoring apparatus (17) suitable for attachment to and monitoring of the physiological responses of the test subject (21) to the playback of the sound recordings.

Abstract: An electrophysiological monitoring apparatus for designing a workstation (21, 21p). The monitoring apparatus preferably is a surface electromyography apparatus which includes pairs of electromyography electrodes sensors (31a, 31b; 32a, 32b; 33a, 33b) with appropriate grounding formed for attachment to a worker (24), a signal processor (37) connected to the electrodes and formed to process output signals from the electrodes and produce muscle loading profiles (101, 111, 121, 131) therefrom. The apparatus further includes a workstation (21, 21p) having an adjustable physical geometry capable of variation so as to change the manner of movement of the worker's muscles during performance of the task. The apparatus (21, 37) is used in a method to select a workstation configuration most desirable for extended use by the worker. The optimized overall workstation (21p) may be customized and used to train an individual worker (24) to lower his or her muscle loading profiles during performance of the task.

Abstract: A process and apparatus for selecting or designing a product, such as a muffler, having a sound output which is less stressful or more pleasing. The process includes the steps of sensing at least one physiological response of a subject (21) while the subject listens to an initial sound output, repeating the sensing step for the new sound output, comparing the physiological responses, and selecting the sound output for use in selecting or designing the product which output produces the physiological response that is the least stressful or most pleasing to the subject. The apparatus includes an audio playback device (15), a sound recording (16) of the initial sound, a sound recording (16) of the new sound, and physiological monitoring apparatus (17) suitable for attachment to and monitoring of the physiological responses of the test subject (21) to the playback of the sound recordings.

Abstract: An electrophysiological monitoring apparatus for designing a workstation (21, 21p) for use in performing a task. The monitoring apparatus preferably is a surface electromyography apparatus which includes pairs of electromyography electrodes sensors (31a, 31b; 32a, 32b; 33a, 33b) with appropriate grounding formed for attachment to a worker (24), a signal processor (37) connected to the electrodes and formed to process output signals from the electrodes and produce muscle loading profiles (101, 111, 121, 131) therefrom during performance of the task by the worker. The apparatus further includes a workstation (21, 21p) having an adjustable physical geometry capable of variation so as to change the manner of movement of the worker's muscles during performance of the task. The adjustable workstation (21, 21p) and surface electromyography apparatus (37) are used in a method to select a workstation configuration most desirable for extended use by the worker.

Abstract: A process and apparatus for selecting or designing a product, such as a muffler, having a sound output which is less stressful or more pleasing. The process includes the steps of sensing at least one physiological response of a subject (21) while the subject listens to an initial sound output, repeating the sensing step for the new sound output, comparing the physiological responses, and selecting the sound output for use in selecting or designing the product which output produces the physiological response that is the least stressful or most pleasing to the subject. The apparatus includes an audio playback device (15), a sound recording (16) of the initial sound, a sound recording (16) of the new sound, and physiological monitoring apparatus (17) suitable for attachment to and monitoring of the physiological responses of the test subject (21) to the playback of the sound recordings.

Abstract: A muffler (10) having a casing (21), an inlet opening (22) and an outlet opening (26). An initial partition (30) forms an expansion chamber (28). The casing (21) has mounted and formed therein a partition array (34) that includes a divider partition (36), a first intermediate partition (38), and a second intermediate partition (40). Partition array (34) is positioned in a main sound attenuation chamber (46). A collector partition (42) having a collector opening (44) is positioned between array (34) and opening (26). A pre-outlet chamber (48) is formed by collector partition (42) prior to outlet (26).

Abstract: A muffler assembly (10) for use with internal combustion engines discharging hot exhaust gases. The muffler assembly includes an elongated casing (15) having an inlet opening (12) at one end and an outlet opening (13) at an opposite end. A sound attenuating partition assembly including a conically converging, perforated, dispersion shell (33) and a transverse wall (45) are provided inside the muffler casing (15). The dispersion shell (33) tapers inwardly by an amount resulting a cross sectional area (A.sub.3) between the dispersion shell (33) and casing (15) at the transverse wall (45) which is at least equal to the area (A.sub.1) of the inlet opening (.sub.12). The combined area (A.sub.4) of the perforations (46) in the dispersion shell (33) upstream of the transverse wall (45) also is at least about equal to the area (A.sub.1) of the inlet opening (12). A perforated retaining shell (17) is provided positioned internally of the casing radially outwardly of the dispersion shell (33).

Abstract: A muffler for an internal combustion engine or the like including a casing (21) having an inlet opening (28), an outlet opening (29), a first partition (43) secured in the casing (21) to divide incoming exhaust gases, and a second partition (46) secured in the casing (21) downstream of the first partition (43), which second partition (46) has an opening (39) through which the divided exhaust gases are converged and joined together for exiting the casing (21). The improvement in the muffler assembly which produces both sound attenuation and lower operating back pressure is to provide an intermediate partition (51) secured in the casing between the first and second partitions (43,46) which is formed to permit substantially uninterrupted or unimpeded flow of exhaust gases past the intermediate partition, while a forwardly facing concaved surface (52) reflects sound components in a direction away from the opening (39) in the second partition (46).

Abstract: A compact, high performance exhaust assembly (50) for an internal combustion engine (20) or the like having a balanced chamber (52). Two substantially parallel inlet exhaust pipes (38, 40) are mounted to a first wall (74) of the chamber (52) and are axially aligned with, but independent of, two output exhaust pipes (54, 56) similarly mounted to a opposing second wall (76) of the chamber (52). Exhaust gas is discharged through the inlet pipes (38, 40), preferably in an out-of-phase relationship or alternating from one inlet pipe to the other. The exhaust gas passes a short distance through the chamber (52) and out of aligned outlet pipes (54, 56). The majority of the exhaust gas flows directly through the chamber (52) without significant expansion. The exhaust assembly (50) increases the power output of the engine.

Abstract: A header assembly for an internal combustion engine including a pair of header pipes having discharge ends, a collector mounted on the discharge ends and having a housing directing exhaust gas pulses from both of the pipes to an outlet. The collector is formed to produce the flow of exhaust pulses in a manner fluid coupling out-of-phase exhaust gas pulses in each of the pipes to the others by an amount sufficient to increase horsepower of the engine at substantially all normal operating speeds. The header pipes proximate the inlet to the header collector are formed for discharge of gases along a common interface or boundary of substantial transverse length to effect fluid coupling. Additionally, the collector is free of channeling or protrusions to permit unconstrained transverse expansion of the pulses across the adjacent header pipe. A method of increasing engine horsepower by fluid coupling together header pipes also is described.

Abstract: A compact, sound-attenuating muffler for an internal combustion engine or the like. The muffler has a divergently tapered partition located near the inlet of the muffler for dividing the exhaust gases into two pulse streams with similar sound frequencies to achieve sound attenuation when the streams are converged back together. The diverging partition creates a low-pressure volume or region on the partition's downstream side where unignited fuels may accumulate. The partition is formed with a passageway to provide communication of live fire from the inlet of the muffler to the low-pressure volume for ignition of any unignited fuel. A method of communication of live fire from the inlet of the muffler to the low-pressure volume on the downstream side of the diverging partition in the muffler also is described.

Abstract: A tangle-free tether post assembly for tether animals which includes a post having a lower end adapted to be buried in the ground, and upper end formed to project above the ground. A tether securement assembly is mounted on the upper end of the post at a spaced distance above the ground. The tether securement assembly is positioned vertically above a rotatable sleeve which also is mounted on the post so that the combination of securement assembly and sleeve rotation ensures tangle-free tethering of animals. A ground anchor also is provided on the tether post assembly which may be used to anchor the assembly and remove the same from the ground without digging up the post.

Abstract: A compact, sound-attenuating muffler for an internal combustion engine is disclosed in which the muffler includes a stream dividing partition positioned proximate the inlet of the muffler to divide the incoming exhaust gases into two streams of substantially equal volume. The stream dividing partition directs the streams laterally of the inlet in directions diverging from each other, and the muffler sound-attenuating assembly further includes corridor defining partitions receiving the streams from the stream dividing partition and maintaining the streams in corridors as coherent substantially eddy-free streams. The corridor defining partitions further direct the streams laterally to converge towards each other for discharge of the coherent streams against each other from opposed directions in a common volume inside the muffler casing. Further sound attenuation is accomplished by a common channel receiving the streams after they are intersected or discharged against each other.

Abstract: A compact, sound-attenuating muffler for a high-performance internal combustion engine is disclosed in which the muffler casing has an elongated transverse cross-section with a height dimension of only slightly larger than the height dimension of the inlet exhaust pipe and a width dimension in the range of about 2 to 41/2 times the height dimension. The muffler includes a divergently tapering planar first partition which causes gases to be expanded only in a horizontal plane toward the side walls of the muffler and further includes a second partition formed to contract or converge the gases in a horizontal plane toward a central opening. The first partition has a cup-shaped back surface so that contraction of the gases around the back side of the first partition is highly effective in attenuating sound, and both partitions are sloped in a direction toward the outlet from the muffler so as to minimize the generation of back pressure, which is not substantially greater than the back pressure in a straight pipe.

Abstract: A muffler for dissipating the sound component in exhaust gases from an internal combustion engine or the like is disclosed which has an enhanced useful life. The muffler includes a partition positioned across an incoming stream of exhaust gases. The partition is formed with stream dividing or splitting means which positively divides the stream into portions that can be more evenly directed throughout the muffler. This prevents destructive preferential flow of gases within the muffler. Additionally, shielding of sound absorption material in the muffler is accomplished by selecting the pattern of perforations to reduce the contact of such material with high velocity gases.

Abstract: A lightweight muffler and method for muffling a noise component of a stream of gases is disclosed. The muffler includes a chamber in which gases are directed side-by-side streams flowing in opposite directions. The streams are in contact with each other for the generation of sound dampening eddy currents in the chamber, but such contact does not break down the continuous, low resistance flow of gases through the muffler. The chamber is advantageously formed as an expansion chamber in which gases: enter one end of the chamber as an annular stream concentric with the inlet pipe to the muffler, travel along the inlet pipe to the other end of the chamber, are reversed, and travel as a concentric annular stream of greater diameter in the opposite direction down the length of the chamber for discharge into a passageway leading to the outlet tube of the muffler.

Abstract: A dehydrator comprises an enclosure having a door pivotally mounted on a front side thereof to normally close a chamber defined in the enclosure. A tubular manifold is disposed in the chamber and defines an inlet passage therein which communicates with the chamber via a plurality of orifices formed in the manifold. The fan is mounted on the enclosure for pumping air into the inlet passage formed in the manifold and a resistance-type heater is disposed in the passage to heat the air to a predetermined temperature level. The heated air is thus discharged through the orifices, formed in the manifold, to dehydrate foodstuffs disposed on racks removably mounted in the chamber of the enclosure. In carrying forth the method of this invention, the heated air is substantially uniformly circulated in the chamber and about foodstuffs disposed therein and such air is discharged from the chamber at a controlled flow rate while simultaneously maintaining a predetermined back pressure on the air in the chamber.