Abstract: A compact safety control apparatus and method for powered lawnmowers having a cable-actuated clutch between the motor and blade thereof is provided which includes a "dead man" function along with an operating mechanism requiring two distinct steps for engaging the clutch and initiating rotation of the lawnmower blade. The control apparatus preferably comprises a shiftable lever and a separate, shiftable "dead man" bail, along with an operating mechanism including a coupler positioned on the lever and movable into engagement with an end fitting on the actuating cable by means of a plate shiftable with the bail; when the coupler is initially positioned by movement of the bail, the lever is shifted to move the cable and thereby engage the clutch, whereupon the cable is releasably locked in position by interengagement of respective shoulders on the cable fitting and plate. Subsequent release of the bail releases the locking shoulders, thereby disengaging the clutch.

Abstract: A tension regulator in a double twister comprising a tenser body including a plurality of stages and ring tensers freely fitted in the respective stages of the tenser body. The tension regulator is mounted on the top end of a cop placed at the center of a stationary disk.

Abstract: A combustor for a gas turbine engine includes a metal engine block including a wall portion defining a housing for a combustor having ceramic liner components. A ceramic outlet duct is supported by a compliant seal on the metal block and a reaction chamber liner is stacked thereon and partly closed at one end by a ceramic bypass swirl plate which is spring loaded by a plurality of circumferentially spaced, spring loaded guide rods and wherein each of the guide rods has one end thereof directed exteriorly of a metal cover plate on the engine block to react against externally located biasing springs cooled by ambient air and wherein the rod spring support arrangement maintains the stacked ceramic components together so that a normal force is maintained on the seal between the outlet duct and the engine block under all operating conditions.

Abstract: An air-fuel ratio control apparatus for an internal combustion engine comprises a carburetor for controlling the air-fuel ratio of the fuel-air mixture supplied to the engine, a thermal reactor in which the exhaust gas from engine is caused to undergo reaction with secondary air supplied to the reactor, an oxygen sensor disposed in an exhaust gas passage between the reactor and three-way catalyst, a negative pressure generator for producing a negative pressure corresponding to the output from the oxygen sensor, a detector for detecting a low and a high speed operation region of the engine, and means for controlling a low speed fuel system and a main fuel system, respectively, of the carburetor in response to the negative pressure in such a manner that the fuel-air mixture is enriched with the secondary air supply being concurrently increased in the low speed operation region of the engine, while in the high speed operation range the fuel-air mixture having an approximately stoichiometric air-fuel ratio is sup

Abstract: An exhaust gas purifying system for internal combustion engines includes a three-way catalyst disposed in the exhaust system of the engine, and secondary air is supplied to the exhaust system through an air control valve under the control of an air-fuel ratio control circuit. The air-fuel ratio control circuit produces a control signal which increases or decreases stepwisely at every reception of a clock signal depending on whether the air-fuel ratio in the exhaust system is above or below a stoichiometric air-fuel ratio. The air control valve is of the proportional electromagnetic type and controls the secondary air passing therethrough in proportion to the control signal.

Abstract: An electric stepping motor, operated by command signals from a computer or a microprocessor, rotates a rotary control member of a distributor valve, for sequencing hydraulic pressure and hence flow to the cylinders of an axial piston hydraulic machine. A group of the cylinders are subjected to pressure and flow and the remaining cylinders are vented to a return line. Rotation of the rotary control valve member sequences pressurization by progressively adding a cylinder to the forward edge to the pressurized group and removing a cylinder from the trailing edge of the pressurized group. The double ended pistons of each new pressurized group function to drive a wobble plate into a new position of equilibrium and then hold it in such position until another change in the makeup of the pressurized group. These pistons also displace hydraulic fluid from the opposite cylinder head which serves as the output of a pumping element.

Abstract: A buoyancy prime mover that converts the potential energy of a gas buoyant within a liquid into rotating mechanical energy comprises a plurality of rigid or collapsible buckets joined by one or more chains with rotatable sprockets and shafts to form a continuous loop so that when the buoyant gas is trapped within the buckets, the buckets rise through the liquid and rotate the chain and sprockets to generate power.

Abstract: A system is disclosed for converting a standard buoy design into an electrical power producing apparatus. The vertical arms slide in sleeves attached to the buoy body and terminate in feet in the form of flat discs. As the buoy bobs and pivots in the water, the resistance of the feet to motion cause the arms to reciprocate, operating pneumatic piston pumps within the buoy. These piston pumps power pneumatic turbines which activate generators for producing electrical power. The moving parts of the linkages connecting the arms to the pumps are protected by a plastic casing which keeps out sea water. The casing includes facets which act as sails. Annular wipers are provided between the arms and sleeves within which the arms reciprocate, so as to prevent sea water from seeping therebetween.

Abstract: A lubricating system for automotive components includes an oil reservoir to supply an initial charge of lubricating oil upon cold starting of the engine, with provision to maintain the reservoir in a full attitude after the engine lubricating oil has warmed and is freely circulating, thereby preserving a charge of oil available for the next cold starting of the engine.

Abstract: A process for the conversion of aqueous hydrogen sulfide, bisulfide ion, and sulfide ion in condensed geothermal steam to form less volatile and environmentally less objectionable sulfur compounds comprises reacting such steam components with hydrogen peroxide catalyzed by various iron or nickel compounds. The hydrogen peroxide and catalyst are added to steam condensate after it has been used and before it is returned to a cooling tower where it may be added to other cooling water in a geothermal steam power system. The conversion process prevents the buildup of harmful, contaminating sulfur compounds on system components in the liquid stream and also prevents the release of certain otherwise voltatile components to the atmosphere.

Abstract: The condensate of a closed cycle power plant that uses an organic working fluid for lubricating the bearings of the turbine is cooled to a temperature below the condenser temperature by an auxiliary cooler before being supplied to the bearings. This subcooling of the lubricating liquid increases its viscosity to a value which causes the minimum thickness of the lubricating film in the bearings to be increased significantly. By increasing the minimum film thickness, the filtering demands on the lubricating condensate are reduced and the surface finish of the journals and bearings is less critical permitting the journals and bearing to be finished by standard precision grinding techniques. In a specific embodiment of the invention, a cannister housing the turbine/generator is provided with a sump for collecting liquid working fluid which is delivered to the bearings through a cooler.

Abstract: A cryogenic vacuum pump has an expander module suspended from the vacuum chamber of an electron microscope by a metal bellows which dampens the vibrations transmitted to the electron microscope from the expander module. A weight mounted on the expander module and disposed around the bellows counters the lifting force of the atmospheric pressure acting on the expander module and protects the bellows. The expander module is maintained in a centered position by vibration damping isolators disposed symmetrically around the expander module and which are attached to a support extending down from the vacuum housing. In one embodiment the isolators are bar magnets which repel magnetic ring attached to the expander module. In another embodiment the isolators are ladders in which the rungs are wire cables tensioned between a side members attached respectively to the expander module and to the support.

Abstract: A heat pump system uses a non-reversing refrigeration circuit having a water-cooled condenser and a counterflow chiller fed by a thermostatic expansion valve to permit operation at close to zero superheat. To protect the compressor in the refrigeration circuit from possible flood-back at this low superheat, a combination suction-liquid heat exchanger-suction accumulator is employed. A hold-back valve serves to maintain constant compressor suction pressure regardless of evaporator pressure fluctuations caused by changing chiller fluid temperatures. The system is designed to operate in four distinct modes: (1) water source heat pump heating; (2) direct solar heating; (3) air source heat pump heating; and (4) heat pump cooling. To switch the refrigeration circuit to heat pump mode from the cooling mode or vice versa, four three-way valves and three fluid pumps are selectively operated. The fluid circuit of the system consists of two separate coils in an air-handling unit.

Abstract: A method and system of converting low-temperature energy into high-temperature energy comprises steps of concentrating a high-boiling liquid diluted with a low-boiling liquid through evaporation of the low-boiling liquid; condensing the vapor of the low-boiling liquid through its absorption into an intermediate heat medium liquid, while cooling, evaporating the diluted intermediate heat medium, and absorbing the vapor generated in the last step into the concentrated high-boiling liquid thereby generating dilution heat and phase-change heat. The intermediate heat medium has the property that the difference between the saturation temperature thereof and the saturation temperature of the high-boiling liquid becomes small under a low pressure and the difference between the saturation temperatures of both the liquids becomes large under a high pressure.

Abstract: Ice making apparatus having one or more corrugated freezing plates with substantially vertical channels in which water flows to form ice cubes. Angled penetration lugs are secured to one surface of each freezing plate at vertically spaced intervals along the bent portions of the freezing plate defining the channels, and the refrigeration line is in contact with each of the penetration lugs so that ice cubes are formed evenly in vertically spaced relation along each of the channels defined by the bent portions of the freezing plate. The penetration lugs are bent at substantially the same angle as the bent portions of the freezing plate, and the lugs are bent or wrapped around the refrigeration line to maximize penetration. A thermostat is positioned at an angle adjacent one of the channels and near a cube to be formed that is below the uppermost cube.

Abstract: A water heating system for residential use is provided having a heat pump solely for producing heat energy to heat water. The system includes an insulated storage tank interconnected in a water system and the tank may be provided with secondary heating means such as electric resistance elements for effecting heating of the water in the event that the heat pump is unable to produce sufficient heat as a consequence of ambient environment temperature conditions or if the heating demands exceed the heat pumps capability. A water circulating conduit is connected with the tank and is coupled with the heat pump by a heat exchanger. Positive circulation of water in the conduit is obtained by a pump interconnected therein. A temperature regulating flow control valve may be included in the circulating conduit to result in the water leaving the circulating conduit and either returning to the tank or entering the water system at the maximum desired temperature.

Abstract: The invention pertains to an environmental protection system and method for withdrawing and charging refrigerants, particularly fluorocarbon refrigerants, with respect to refrigeration systems as used for refrigeration, dehumidifying, air conditioning and the like without contamination of the atmosphere. Refrigerant is evacuated from a refrigeration system through a closed circuit into a closed disposal or storage container, and in an embodiment of the invention direct evacuation pumping of the refrigerant may be proceeded by drawing the majority of the refrigerant from the refrigeration system by means of a preliminary vacuum tank connected in series with a refrigerant disposal container. Additionally, the invention contemplates combining a refrigerant charging circuit with the refrigerant evacuation circuit in order to provide complete refrigeration system servicing without the release of refrigerant to the atmosphere.

Abstract: An apparatus for producing and dispensing a cold product comprises a scraper member operable to scrape a forming wall which is maintained near or below freezing temperature. A substance comprising the product in fluid form is directed to the scraper member and sprayed onto the forming wall during relative movement between the piston member and the wall where it forms a thin layer and the scraper removes the formed product. A cleansing fluid is selectively supplied in one instance to cleanse the apparatus between different substances dispensed, and in another instance, to cleanse and sanitize the apparatus.

Abstract: A warp knitting machine is disclosed as including slider needles, each of which has a needle shank of channel form with a hook head and a slider that covers the hook opening of the needle shank by means of a cover member fitted on the slider shank, such cover member is shorter than the hook opening of the needle shank, and the slider has such a cross-section that it carries the stitch in each instance without being supported on the needle shank and/or the hook head.

Abstract: The frame of a creel includes vertical support columns rigidly interconnected at their upper ends by a framework arranged so as to permit the frame to be positioned astride a circular-knitting machine with the columns disposed around the machine itself and with the framework at a height such as not to interfere with the movement of personnel about the machine. A vertically-movable slide is associated with each column, the slides being rigidly interconnected by a peripheral bobbin-carrier support structure. A driving device is provided for raising and lowering all the slides in unison in order to raise the peripheral structure to an upper position at a height at which it does not interfere with the movement of personnel about the machine and to lower it, respectively, to a lower position in which the structure surrounds the machine and is located at a height such as to allow manual access to bobbins which are on the bobbin-carrier.

Abstract: A latching system for a luggage article comprises a pair of spaced swiveling latches mounted on the interior of a front wall of the article, the latches being connected together for swiveling movement in unison between latching and unlatching positions by means of an endless drive cable. The latches are operated by a single manual actuator including a swiveling lever connected to one of the latches by a lost motion connection which allows the lever to be returned to a rest position after moving the latches into their latching or unlatching positions. A combination lock is provided for locking the actuator lever in the rest position except when the lock is on combination.

Abstract: An improved door lock construction comprising a lock bolt formed in U-shape operable in association with an actuating mechanism, an interlocking device, a dog device and a hold-release device assembled in a box type housing to be mounted on the inner side of the door, capable of locking the door on closing and further locking with a key.

Abstract: A locking mechanism for ranges utilizes a bar extending transverse to the longitudinal axis of the knob operated shafts controlling the operation of the individual valves of a gas range or the individual switches of an electric range. A plurality of arms are pivotably secured to the bar, each having fingers directed and biased towards the longitudinal axis of each shaft. Each shaft is rotatable and carries an opening at a discrete location in the surface thereof. Rotating the shaft to a position corresponding to deenergizing the associated heating element of the range into an off position permits the free end of the finger to enter the opening, preventing further rotation of the shaft when the bar is slidably positioned into a locked position by the operation of a key operated lock.

Abstract: A cash register tray for currency and coins having its own pivotal cover and lock whereby the tray can also be used as a portable cash box. A spring and electromagnet within the tray itself control opening and closing functions.

Abstract: The invention relates to a cylindrical lock of the type comprising a barrel journalling in the bore of a body.In the lock to which the invention relates, the peripheral surface of the barrel and the surface of the bore in the body comprise an assembly consisting of an elastic longitudinal tongue and a shoulder which are respectively integral with the said two surfaces and which are arranged in such a manner that the said elastic tongue interacts with the said shoulder to lock the barrel so that it cannot move longitudinally in relation to the body.Application to the car industry.

Abstract: A vehicle door lock (106) and latch (104) assembly is provided whereby a key may be used to lock the door (100) and to prevent rotation of the outside door handle (108). A lock handle (116) is provided inside the vehicle door (100) for overriding the key lock (110) to permit the inside and outside handles (114,108) to operate to open the door. Both the key lock (110) and the lock handle (116) when turned operate a linkage (172,168) which is connected to the locking cam (158) enabling the locking cam (158) to be moved between its locked and unlocked positions. Even with the lock handle (116) and the key lock (110) in the locked position, the inside handle (114) can be turned to move the locking cam (158) to the unlocked position and to open the door (100). The outside handle (108) can now be used to open the door also. The outside handle (108) can also be released for operation by turning the key in the key lock (110) to the unlocked position.

Abstract: A sheet metal tool as two relatively movable tool sections, one of which is rovided adjacent its sheet metal-shaping face with a sheet metal holder which is movable relative to that face. Also movable relative to that face is a pressure-distributing unit composed of two spaced parallel plates which are maintained at a predetermined distance by spacers, this unit serving as an abutment for the sheet metal holder.

Abstract: An apparatus for cold forming stabilizer blades from elongated members by holding an elongated member while being bent or twisted to form a stabilizer blade. A mandrel is provided for receiving first and second sleeves so that a force applied by a toggle arrangement causes the first and second sleeves to rotate in opposite directions to bend the elongated member to form a stabilizer blade.

Abstract: A method and an apparatus, FIG. 1, for manufacturing sections (9,10,11), preferably for manufacturing beam preforms.The method is characterized in that a blank (7) with rectangular or square cross-section is forged between a pair of web tools (1,2), in that the web tools (1,2) are moved to and from each other for forming a web portion (9) on said blank (7), and is forged against flange tools (3,4), in that the tools are moved to and from the web tools (1,2) in a direction perpendicular to the direction of movement of the web tools. The blank portion located between the web tools (1,2) and respective flange tool (3,4) is upset to form flange portions (10,11) between the flange tool (3,4) and respective sides (1',2',1",2") of the web tools (1,2).The method further is characterized in that the blank (7) successively and in steps is fed in between the web tools (1,2) and successively and in steps is deformed by means of said tools (1,2,3,4).

Abstract: Apparatus for the automatic removal of a sample from a production line comprises a rotary removal arm connected to a vacuum source for bringing the sample into a position opposite a diametral bore in a rotary disc. The disc is intended to bring the sample into a transfer position. The disc may be associated with devices for checking the pressure drop and weight of the sample. The sample may be reintroduced back into the production line.

Abstract: The disclosed apparatus is intended for use in determining the breathing characteristics of a structure such as a home, office building, or business establishment. After establishing the initial breathing characteristics, it is possible through the use of disclosed apparatus to seal the structure so as to achieve breathing characteristics which are consistant with the intended use of the structure.

Abstract: An improved test section 16 for a supersonic or hypersonic wind tunnel 10 is disclosed wherein the model tested is shielded from the noise normally radiated by the turbulent tunnel wall boundary layer. A vacuum plenum 23 surrounds spaced rod elements 28 making up test chamber 16 to extract some of the boundary layer as formed along the rod elements during a test to thereby delay the tendency of the rod boundary layers to become turbulent. Novel rod construction involves bending each rod slightly prior to machining the bent area to provide a flat segment 29 on each rod for connection with the flat entrance fairing 31. Rods 28 and fairing 31 are secured to provide a test chamber incline on the order of 1.degree. outward from the noise shield centerline to produce up to a 65% reduction of the root-mean-square (rms) pressure over previously employed wind tunnel test sections at equivalent Reynolds numbers.

Abstract: In a device for measuring the breath volume of patients, a pair of temperature sensitive sensors are arranged in a tube-like housing of a respiration conduit of a respirator. The sensors are spaced from one another in flow direction and an air resistance member is arranged between them in such way that at least in one of the opposite air flow directions one of the sensors is in a position sheltered from the air flow by the air resistance member. Both of the sensors are connected with electronic circuits respectively and a current supply for holding the temperatures of the sensors on constant high levels. A calorimeter unit is connected to the circuits measuring the current supply necessary to compensate the temperature decrease of the sensors caused by the cool respiration flow. The air throughput is calculated in dependence on the measured current supply.

Abstract: The present invention is part of a liquid gaging system and comprises an apparatus for monitoring a quadrature signal from a capacitor sensor. Included is a capacitive sensor for providing a liquid measurement signal related to a liquid in a tank, the liquid measurement signal comprising a capacitive signal and a quadrature signal. The invention also includes apparatus for monitoring the quadrature signal through null detection of the capacitive signal, the null detection being implemented through a rebalance approximation sequence. The apparatus for monitoring is connected to the sensor.

Abstract: The present invention is directed to liquid-level indicating windows, especially suitable for reservoirs for master cylinder, which are characterized in that a container for housing a liquid is provided with a hole bored therein to which the liquid-level indicating window is made fit. The body of the liquid level device projects outside the container and the liquid-level indicating window has on its inside wall, at the liquid-level indicating section, a sign portion which is different from the other portions of the liquid-level indicating section in the light-path length and which is made of a material almost the same in refractive index as the liquid to be contained in the container.

Abstract: An improved rotational speed governor characterized by a non-linear response to speed changes, includes a control arm, the angular position of which changes in response to the rotational speed of the governor, the control arm carrying a weight held to a fixed position with respect to the control arm at speeds less than a first predetermined speed and displaced from said control arm by centrifugal force at speeds greater than that predetermined speed to effect a non-linear pivotal displacement response to the control arm.

Abstract: The RF output of a voltage controlled oscillator (VCO) 11 is periodically gated by gate 15 to a transducer 18 which produces acoustic waves in bolt 19. The reflected acoustic waves are converted to electrical signals by transducer 18 and gated by a gate 20 to mixer 31. Mixer 31 also receives the output from VCO 11 and produces an output which is filtered by low pass filter 32. The output of filter 32 is a DC signal proportional to the phase difference change from a fixed phase difference between the two input signals to mixer 32. This DC signal is sampled at an instant and held by circuit 33 in response to the "P" signal. The output of circuit 33 is integrated by integrator 34 and then applied to VCO 11 to change the frequency of VCO 11 such that the phase difference between the two inputs to mixer 31 remains at said fixed phase difference. The frequency of VCO 11 is a measure of the change in strain of bolt 19.

Abstract: A measurement circuit and calibration technique for temperature compensating a half-bridge-high-temperature strain gage, capable of providing data which is independent of cable resistance variations.The need for a compensating resistor is eliminated and the cable conductors are removed from the measurement circuit. The output signal is easily and accurately converted to a measurement of strain without the need for auxiliary measurement required with prior art circuitry.

Abstract: The flow velocity or flow rate of a fluid containing electrical charges or magnetic dipoles is sensed by receiving a noise signal generated by movement of the charges or dipoles, and determining the mean frequency of the received signal.

Abstract: A liquid sampling apparatus includes a sample carrier supporting a plurality of sample containers arrayed in a generally spiral pattern for successive passage through a sampling station at which a sampling tube removes a small quantity of liquid from each container. A receptacle for containing a wash liquid is located adjacent the sampling station, and the wash liquid is supplied to the sampling tube between the taking of successive samples in order to cleanse the sampling tube.

Abstract: A carriage drive system for a metal working machine wherein the carriage supports the metal working tool. The carriage drive comprises a worm gear rotatably engaged with a rack arrangement, driven by a motor and gear box on the carriage. The rack arrangement comprises a pair of rack sections opposed to one another along the sides of the worm gear. The carriage drive is pivotably supported on the carriage by a pivot pin which permits slight rocking and self centering motion in the carriage drive as it propels the carriage on its ways.

Abstract: A power transmission having a single Ravigneau-type planetary assembly, having a single carrier with two sets of planet gears, two sun gears, and one ring gear. A first sun gear is connected by a first set of planet gears to the ring gear; the ring gear itself is directly and rigidly connected to an output shaft. A speed-varying module is connected in driving relation to the input shaft and in driving relationship to the first sun gear. The speed varying means may comprise a pair of hydraulic units hydraulically interconnected so that one serves as a pump while the other serves as a motor and vice versa, one of the units having a variable stroke and being connected in driving relation to the input shaft, the other unit, which may have a fixed stroke, being connected in driving relation to the first sun gear. The input shaft is also connectable by a first clutch to the carrier and by a second clutch to the second sun gear.

Abstract: This transmission differential gear of the type comprising a cage enclosing a pair of driven bevel sun gears and a plurality of sun gear driving planet pinions mounted for loose rotation on pins fitted in corresponding bores formed through the cage walls, comprises an annular member encircling the cage and adapted to partially close the outer ends of these bores. The differential gear is intended more particularly for road vehicles.

Abstract: A neutral safety switch is moved to a closed position upon shifting of an automatic transmission to a neutral position but moved to an open position when the automatic transmission is shifted to a drive position. An air pressure responsive switch is moved to a closed position when air brake pressure is reduced to set alternative brakes and is in series with a bell, buzzer, light or other signal producing device. A control device is controlled by the neutral safety switch, so as to close one circuit, whereby an ignition control may be utilized to start the engine with the transmission in neutral position, but to close an alternative circuit, whereby the signal device will be activated with the alternative brakes set, when the neutral safety switch is moved to open position.

Abstract: A device for driving a screw, pin, rivet or the like into a threaded or drilled hole is disclosed which is adapted to operate a nozzle comprising a pair of nozzle halves to pinch it. When driving a screw by means of the device as a screw driver, a thrust sleeve is displaced forwards by operating an E-shaped control lever on a stationary cylinder and thereby the nozzle halves are depressed at their rear parts so that they are opened. Then the screw to be driven is located in position midst the nozzle halves kept open and thereafter the control lever is restored to the original position. A press block is displaced forwards by means of a spring in the thrust sleeve and expands the nozzle halves, causing the nozzle to be opened to firmly hold the screw.

Abstract: A method and apparatus for cutting bread is disclosed. The apparatus includes a conveyor which conveys bread through a positioner to a circular, vertically disposed, rotatably mounted cutting blade. The positioner positions the bread with respect to the cutting blade to control the size and configuration of the pieces of bread cut by the cutting blade. A displacement member separates the upper portions of the cut pieces of bread, thus causing the pieces to separate and drop downwardly with the cut face of each piece of bread facing upwardly.

Abstract: In order to be able to cut short workpieces by means of a multiple blade circular sawing machine a separate depresser member is provided for each saw blade. This depresser member has a slot which extends in the longitudinal direction of this member and through which the respective saw blade projects. A depresser member is so connected to an associated displacer head that together therewith it is displaceable to a defined position and is fixable in this position. Furthermore, at least one presser roller is provided in each depresser blade on both sides of the saw blade in the sawing region and the workpiece to be sawn is pressed thereby against a conveyor chain.

Abstract: Automatic hollow punch search device and relevant control, for die-cutting machines, particularly for footwear production, in which a mobile head is associated to means to move it to and fro, both horizontally and vertically, above a fixed faceplate on which the material to be cut is placed, together with a hollow cutting punch. The movement means are automatically piloted by a drive circuit interlocked to manual starting means which provides means to carry out a complete head movement operating sequence from its positioning above the hollow punch to its lowering and return to the starting point after cutting.

Abstract: A horizontal bandsaw machine provided with a detecting means for detecting the cross-sectional length of the workpiece being cut during a cutting operation and an actuating means which is controlled by the detecting means to move either or each of the guide means for guiding the bandsaw blade toward and away from the other.

Abstract: A process and apparatus are provided for recording electric signals corresponding to piano key operation and for reproducing the piano key operation. The process includes switching a discrete frequency oscillator corresponding to each piano key, algebraically adding the outputs of each oscillator, filtering the algebraic sum of the oscillator outputs through a low pass filter, recording the filtered signal, reproducing said filtered signal through a high pass filter, detecting each frequency in the high pass filtered signal, and energizing an electromechanical device so as to actuate the piano key which had switched the discrete frequency oscillator.