Abstract: A pulverized solid fuel is injected into a shaft furnace by being entrained in a stream of pressurized air, the resulting fuel-air mixture subsequently being further mixed with heated air being delivered to the furnace via a tuyere. The air used to entrain the pulverized fuel is diverted from the cold air supply to a mixing station, which is used to control the temperature of the hot air supplied to the furnace via the tuyere, and this diverted air is pressurized prior to the pulverized material entrainment.

Abstract: The disclosure teaches a mobile dust collector which comprises a housing structure mounted on a trailer. The housing structure includes a filter chamber and a fan chamber. An opening in the side wall of the filter chamber communicates outside air with the filter chamber, and a plurality of filter bags disposed in the filter chamber make up the filter of the dust collector. A fan is disposed in the fan chamber, and the interior of the filter chamber is communicated with the fan. Wheels at the back of the trailer are adapted to rollingly support the trailer, and a removable support is disposed at the front end of the trailer for supporting the trailer when it is in a stationary condition. In operation, the housing structure stands in an upright position. Means are included for self erection of the housing structure.

Abstract: A calibration test stand and method is presented for calibration of hydraulically powered torque wrenches. A hydraulic wrench to be powered by a pump is directly calibrated with the pump so that the pressure level of the pump can be accurately set to obtain the desired output torque level.

Abstract: An activation device is presented for a tactile keyboard of the type having a molded monolithic plastic layer of tactile elements. The actuator is a thermocompressively molded monolithic plastic layer which incorporates a matrix of geometrically designed strikers, the actuator layer being interposed between the keys and the molded monolithic plastic layer of tactile elements in a keyboard assembly.

Abstract: A ball bearing hammer actuator comprises a hammer lever which is connected at the one end to the hammer and which is connected at the other end to a shoe which is slidable in relation to guide surface having a U-shaped cross section. The guide surface is provided for by a portion of the frame which has a generally U-shaped cross section. The shoe of the ball bearing hammer actuator includes a body having a generally rectangular shape which is designed to fit within the U-shaped guide. The shoe fits within the guide with a small clearance, the clearance allowing for use of ball bearings. Two edges of the body of the shoes include elongated recesses. The recesses receive a plurality of bearing balls therein. The bearing balls protrude from the bottom of the shoe and the sides of the shoe. The bearing balls are in contact with the walls and the floor of the U-shaped guide. A spring mechanism urges the shoe upwardly.

Abstract: Material to be deposited on the hearth of a shaft furnace serially passes through a pair of temporary storage containers positioned above the furnace. The uppermost storage container is in the form of a bin open to the ambient atmosphere while the lower storage container is provided with valves at either end whereby it may be hermetically sealed and subsequently brought to furnace pressure. The lower storage container is loaded while at ambient pressure, by releasing furnace charge material previously delivered to the upper storage container into the lower container and subsequently by delivering material directly to the lower container from a conveyor system through the lower container. The upper container is refilled with material while the lower container is at furnace pressure and is discharging its contents into the furnace.

Abstract: A keyboard has a planar surface with depressions formed therein. Switch devices of the type which provide tactile feedback are aligned with the depressions. Exertion of downward force on the base of the depressions will cause switch contacts to be closed with a snap-action to generate an information bearing signal.

Abstract: A power supply, including a static inverter, which is suited for the periodic energization of a flash tube. The static inverter may be turned off during periods when a capacitive load charged thereby is being discharged through the flash tube. The power supply has the capability of causing two successive ionizations of a flash tube within a short time period and may include both over-current and over-voltage protection in the form of sensing circuits which disable the static inverter.

Abstract: A damper adjusting mechanism is presented wherein the damper is opened and closed by adjusting a rod. This rod is adjusted by the use of grooves which are latched onto the stove's front wall. These grooves are protected from creosote build-up by a shield.

Abstract: A flexible electrical connector for borehole telemetry apparatus is presented wherein the electrical connector includes an elongated metal tube having an intermediate section coiled around the exhaust shroud of a mud turbine. Electrical conductors are housed within the metal tube, and the tube is internally pressurized with oil, the pressure of the oil being maintained equal to the drilling mud pressure by a bellows exposed to the drilling mud.

Abstract: A mounting base is presented for an operating motor for a valve. The mounting base has split locking clamps which mount over the valve stem and are locked in place by clamping bolts.

Abstract: A keyboard has first and second nested planar members with depressions formed thereon. The upper member is transparent. The lower member may be color coded and carry replaceable key indicia in the depressions.The laminated overlay nested planar members are disposed adjacent to a conventional elastomeric diaphragm switch assembly having an upper layer of shaped protrusions abutting the lower most inner surfaces of the second or lower member depressions. Frame structure of variable form assists in retaining the laminated overlay members in fixed relationship to the elastomeric diaphragm switch assembly.

Abstract: The invention relates to an electronic device for measuring the time interval between the occurrence of any two successive ones of a plurality of similar events, specifically, the time interval between footsteps in jogging, running or walking, or the leg or arm motion associated with bicycling, rowing, swimming, cross-country skiing or the like, and for providing bio-feedback information to a user in the form of an alarm signal when: the measured interval is less than a predetermined low limit; the measured interval is greater than a predetermined high limit. The device includes a transducer for producing a signal at the detection of the occurrence of each event. The signals are fed to both a timing circuit and a detection circuit. The timing circuit measures the time interval between two successive events, and the detection circuit determines if the measured interval is between the high and low limits. If it is not, a signal is fed to an output circuit which then provides an audible alarm.

Abstract: The profile of material deposited on the hearth of a pressurized furnace is controlled by means of a charging installation including a lower charging bell which has, suspended therefrom, a variable geometry distributor which may be controlled to select the point of deposition of material delivered to the furnace. The charging bell cooperates with an intermediate storage hopper, positioned within a hermetically sealable casing, whereby the hopper may be alternately filled with material and emptied by permitting the material to fall onto the distributor via an annular opening defined when the bell is lowered.

Abstract: A heater cable with coaxial inner and outer conductors and an intermediately disposed resistance heater. The heater is spaced from the inner conductor by radially extending alternating conductive and non-conductive separators with current being delivered to the heater by the conductive separators. The heater is deformed so as to contact the outer conductor at spaced locations to thereby define plural parallel heating circuits.

Abstract: An isolation and flow control valve in a furnace charging installation, installed in a discharge conduit of a storage hopper which may be alternately at ambient pressure for loading and furnace pressure for discharging, is characterized by a valve member which is caused to move serially in two directions during opening and closing. The movement is produced by an actuator mechanism including a pivot arm and a cam system and results in movement axially with respect to the conduit for seating and unseating and generally transverse to the conduit axis for controlling material flow through the conduit.

Abstract: A tactile snap-action element for use in keyboards, the element comprising an arcuately shaped invertible first dome and a second dome shaped actuating protrusion extending from the invertible second dome, the actuating dome protrusion being integral with the invertible dome and being non-invertible. The element is operated by an actuation force which acts directly or indirectly through the non-inverting second dome to invert the first dome and to provide tactile feedback. The keyboard includes a plurality of keys, each key comprising an element, a conductive circuit associated with the first dome and movable with the inversion of the first dome to electrically contact a second conductive circuit associated with the element.