Abstract: A four part guard assembly for the rotating drive connection between a drive motor and a pump. The guard assembly being rigidly and removably secured to the frame of the pump and extending to a point short of the drive motor and encompassing the drive connection therebetween. The sleeve is of two part construction removably secured together to permit removal of one part for gaining access to the drive connection for field servicing maintaining the remaining components in assembled condition.

Abstract: A method for preparing a field which has crop residue rows for subsequent row crop planting comprises cutting a plurality of furrows between crop residue rows and lifting and turning over the soil from the furrows into ridges, and simultaneously scraping over a plurality of crop residue rows and transferring the residue into the furrows which are being simultaneously cut, and wherein the former step forms the ridges on surfaces that are simultaneously being cleared by the latter step. The method is accomplished by tillage apparatus including a horizontal frame, a plurality of furrow cutting moldboards affixed to the frame and being curved to lift and turn over the soil cut from the furrows into ridges, and a plurality of trash boards affixed to the frame diagonally to the crop rows and in alternate relation to the moldboards and being curved to transfer the crop residue removed thereby into the furrows being simultaneously cut by the moldboards.

Abstract: A helical duct separator particularly suited for use in the suspension preheater of a cement calcining plant to separate raw cement meal from kiln-off gases in which the meal is suspended comprises a hollow elongated continuous duct having its longitudinal axis disposed along a downwardly inclined helical path, an inlet opening in a vertical plane for receiving a horizontal stream of gas with entrained meal, a downwardly inclined upper wall and a concave outer sidewall in the path of the gas stream to deflect the gas stream into a downwardly inclined helical path, a horizontal bottom wall adjacent the outlet end of the duct, a meal exit opening in the bottom wall and a gas exhaust opening in a horizontal plane in the upper wall adjacent the outlet end of the duct.

Abstract: Method for gasifying cellulosic material comprises feeding cellulosic material into the uphill end of an inclined rotary kiln; transporting a bed of cellulosic material through the kiln and continuously tumbling the bed; withdrawing fuel gas from the uphill end of the kiln so it flows countercurrent to the bed and removes moisture in the drying zone and thermally decompose volatiles in the devolatilization zone; admitting air overbed in the devolatilization zone and only underbed in the gasifying zone; and controlling the mass flow rate of air into the devolatilization and gasifying zones respectively as predetermined percentages of that rate of which is stoichiometric to the cellulosic material fed into the kiln to thereby limit temperature rise, prevent agglomeration and minimize entrainment of solid particles.

Abstract: Roller grate apparatus for simultaneously transporting and transferring heat to or from a bed of material particles has elongated cylindrical parallel horizontal rollers rotatably driven in the same direction; filler bars disposed in the nip between adjacent rollers and together with the rollers forming a generally flat surface with constantly moving portions which continually tumble the material particles and urge them thereacross in a direction transverse to the roller axes; gas passage apertures in the rollers which permit a heat transfer gas stream to pass through the rollers; a heat transfer chamber spanning the rollers; and a fan for blowing a heat transfer gas stream through the chamber and the material bed being transported by the rollers.

Abstract: Roller grate material bed conveying and heat transfer apparatus which provides plural bed depths has cylindrical horizontal rollers driven in the same direction with gas passage apertures in the rollers and filler members in the nip between adjacent rollers. Means are provided to pass heat transfer gas streams through the bed as the rollers urge the material particles in a direction transverse to the roller axes and continually tumble the particles so that all surfaces thereof are exposed to the gas streams. A first plurality of rollers are positioned in a first generally horizontal plane to receive the material fed to the apparatus, and a second plurality of rollers downstream from the first rollers are at elevations lower than the first horizontal plane and preferably are driven at slower speed than the first rollers to thereby increase the material bed depth downstream from the first horizontal plane as the material particles are hardened by heat and can withstand greater bed depth without crushing.

Abstract: A system for indicating area traversed by a vehicular implement has a ground speed sensor for generating ground speed pulses at a frequency which is a function of the implement ground speed; a pulse generator for deriving fixed width pulses from said ground speed pulses; an integrator for accumulating the fixed width pulses to derive a positive slope dc signal whose instantaneous magnitude is an analog of distance traveled by the implement; a comparator for comparing the analog signal to a reference signal whose magnitude is an inverse function of the width of path traversed by the implement and for providing an output signal when the former becomes equal to the latter, whereby the output signal indicates that the implement has traversed an area equal to the distance traveled multiplied by the path width; and a counter for registering and displaying the number of output signals as an indication of area traversed.

Abstract: In a moving matrix magnetic separator in which a matrix device moves relative to a processing device and a seal assembly seals a longitudinal section of the matrix device to an associated processing device, the seal assembly including a sealing surface on one of the devices and a seal on the other, the improvement comprising said seal including a base portion extending generally longitudinally in the direction of motion of the matrix device; first and second salient, resilient lip portions extending from the base portion toward an associated sealing surface in the gap between the matrix device and the processing device, and extending generally longitudinally to the direction of motion of the matrix device and spaced from each other transversely to the direction of motion of the matrix device and forming a channel therebetween; a pressurized purge fluid chamber formed by the channel and the associated sealing surface; and means for supplying purging fluid to the purge fluid chamber formed by the channel and li

Abstract: A relatively quiet vibrating screen has a rotatable eccentric mass drive supported on the screen body by isolator mounts which transmit vibratory forces at shaker frequency unrestrained to the screen body and attenuate forces at higher harmonics of shaker frequency that would otherwise excite wall panels of the screen body into resonance, thereby reducing the noise level of the screen.

Abstract: A fork lift truck has a safety system for inhibiting further raising of the carriage or further forward tilting of the mast when an excessive tilting moment is acting on the truck and permits override of the safety system so that the overload can be relieved by the operator under certain conditions without requiring the assistance of a second truck.

Abstract: A closed-loop height control for the header of a combine harvester permits adjustment of height setpoint and deadband from the operator's platform without stopping the combine. A variable capacitance is rotated in accordance with minimum clearance between header and ground to generate a continuous electrical header height signal which is compared to a setpoint signal indicative of desired header height to derive a height error signal whose value is at a null level when actual header height is equal to desired height indicated by the setpoint signal and which deviates in both magnitude and direction from the null level as a function of the variation between actual header height and setpoint height. Raise and lower command signals are derived in response to a predetermined deviation of the height error signal in opposite directions respectively from the null level by first and second Schmitt trigger circuits having switching levels which respectively are greater than and less than the null value.

Abstract: Tap changer voltage regulating apparatus permits a tap changer selector contact to engage an open-circuited new tap without arcing and has a half-tap voltage auxiliary winding which permits halving the voltage being interrupted and doubling the number of steps and also has an auxiliary switch which initially connects the selector contact on the new tap in series with a circulating current-limiting inductor and the load to prevent load circuit interruption and then opens the previous tap circuit so that circulating current is interrupted at reduced voltage and then short circuits the inductor to complete the tap change, whereby the inductor is energized only momentarily.

Abstract: A power circuit arrangement for a power conditioning system adapted to supply variable frequency, variable magnitude voltage to an electromagnetic device such as an electric motor having a center-tapped winding includes first and second inverting thyristors connected to the respective winding ends and connected in series with a transistor chopper across a unidirectional source so that the inverting thyristors may be gated on alternately at a relatively low modulation frequency while the chopper is time ratio controlled at a higher carrier frequency to selectively vary the voltage applied to the winding; a capacitor in shunt to the chopper which is overcharged due to winding leakage reactance when the chopper is turned off to reverse bias and "soft" commutate the thyristors when they are not conducting load current; a free-wheeling thyristor connected between the winding center tap and the chopper and poled to form a low-impedance free-wheeling path for winding current in series with the inverting thyristors w

Abstract: A fork lift truck has an overload protective circuit which is responsive to an excessive tilting moment acting on the truck, as a result of a load on the raised carriage, to disable the mast tilting motor and carriage elevating motor from shifting the load supporting carriage in a direction which would increase the forward tilting moment and also has a crowbar circuit which, upon failure of the protective system to respond properly to such excessive tilting moment, opens an electrical circuit that also results in inhibiting the mast tilting and carriage elevating motors from further raising the carriage or further forward tilting of the mast on the overloaded truck, thereby providing enhanced protection against faulty operation resulting from component failure. One embodiment permits the truck operator to selectively simulate an overload and thereby initiate testing for component failure in the overload protective system.

Abstract: An adjustable speed AC electric motor drive has a static inverter energized from a unidirectional power source through a semiconductor series chopper and eliminates a filter between chopper and inverter and controls the fundamental inverter output frequency as a function of an analog speed reference signal and also pulse width modulates the series chopper at a constant frequency as a function of the speed reference signal and synchronizes the series chopper to the fundamental inverter freqency to provide variable voltage and variable frequency power to the motor. The drive has a shunt chopper at the output of the series chopper and switches it to the opposite conductive state from the series chopper so that it coacts with the feedback diodes to form substantially continuous, low impedance, bidirectional free-wheeling paths for motor current and provides constant harmonic content current to the motor with reduced ripple.

Abstract: A gas insulated circuit breaker is provided having a plurality of circuit interrupters disposed in a single enclosure. Each interrupter is provided with its own high pressure container located within the sealed enclosure; the high pressure container also operates as an insulating support for the associated interrupter. A single actuating rod passing through the interrupters operates the contacts and blast valves of all the interrupters simultaneously. Service means are provided for the insertion and withdrawal of the interrupters into and out of the enclosure.

Abstract: A DC contactor providing increased magnetic efficiency, reduced contact bounce, and shorter arc time has a movable contact carrier bar pivotally mounted relative to a clapper armature so as to prevent tilting about its longitudinal axis and eliminate rotational bounce; a pre-loaded contact pressure spring which resiliently urges the contact carrier bar against the armature; an armature retainer spring which resiliently urges the pivoted end of the armature backward and downward against the yoke so as to displace dirt accumulated in the pivot area and prevent jamming of the armature; a generally hyperbolic magnetic pull characteristic with the knee at approximately the one-half armature travel position and the magnetic pull at the two-thirds armature travel position being approximately twice the magnetic pull at the knee to thus provide relatively high magnetic pull per ampere in the region above the knee; the magnet gap between armature and core at the point of contact engagement being less than that at the k

Abstract: A chopper motor-controller for regulating a lift truck traction motor incorporates means for detecting faults which may cause the truck to run out of control, such as the high speed bypass contacts which shunt the semiconductor power switch being welded closed, and for disabling the controller in response thereto and also has time delay means for preventing a directional contactor from closing in on a fault before the fault detecting means can operate to disable the controller. The disclosed controller may alternatively be connected to require the operator to relax the accelerator foot pedal when starting or changing direction or to permit change of direction while the foot pedal is depressed.

Abstract: The contacts of a DC contactor operating in a contaminated atmosphere are prevented from welding as a result of jamming of the armature by a thin nonmagnetic shim which is mounted on the armature so that it is disposed in the closed magnetic circuit and retains a dirt-shielding gasket above the armature pivot area so that falling dirt cannot accumulate between armature and yoke where it might, absent the gasket, interfere with closing of the armature and thus result in reduced contact pressure and increased heating of the contacts.

Abstract: An overload protective system continuously monitors the forward overturning moment on a counterbalanced lift truck and prevents further raising of the carriage or further forward tilting of the mast when the overturning moment is excessive.