Abstract: An automatic trim circuit for hydrofoil craft which compensates for offsets in the system due to manufacturing and assembly tolerances and wear of parts. This is achieved by integrating an error signal derived by comparison of a reference signal with an actual position signal and applying the integrated output, after amplification, to one or more servo systems which actuate the control surfaces of the hydrofoil craft.

Abstract: A method and apparatus to heat a forced-air supply utilizing hot waste gases in a flue. A flue closure housing is supported by a frame that is arranged to surround an opening in the chimney. The housing supports a heat exchanger having side walls formed of plates with a space between the plates being sealed by end walls to form a flow space for a forced-air supply. The heat exchanger is sealed to a flue closure plate forming part of the flue closure housing. The heat exchanger receives a supply of cold air from a motor-driven blower coupled to a header. Heated air from the heat exchanger is directed by a hot-air discharge header through an opening in the flue closure housing.

Abstract: Method and apparatus for printing a design with a stencil screen including a resilient membrane formed by reversely-bent portions in the screen between a desired pattern defined by a paint-pervious opening in the screen and edge portions of the screen. The reversely-bent portions of the screen are filled with an elastomeric material and extend beyond the bent portions of the screen. A coating of an elastomeric material may be applied to the outside areas of the reversely-bent portions of the screen and adhered to the elastomeric material in the pocket of the screen by permeating the screen openings.

Abstract: A process for producing a coal-water mixture includes classifying a coal feedstock to form first and second coal feed streams each comprised of differently-classified coal particles. Separate surge vessels receive the coal particles to form separate feed streams. The distribution of coal particles in a liquid medium forming each coal feed stream is determined and an electrical signal is delivered to the microprocessor for controlling the portions of each stream which are mixed together in the presence of a dispersing agent and a stabilizing agent to form a coal-water mixture. The coal-water mixture is comprised of at least 65% by weight coal particles and this may be increased to about 82% by controlling the distribution of coal particles in the liquid medium forming each of the coal feed streams.

Abstract: A control system for longwall mining roof supports which are controlled in dependence on the position of the mining machine at any time. All of the roof supports are connected to a central computer via common conductors. Each of the roof supports includes a control unit having a code corresponding to the number of that support. This code serves as an address and enables the central computer to transmit its control command signals positively, in response to the mining machine position signals, through an appropriate address control unit for a particular roof support. In order to enable roof supports to be actuated manually also, the control units of all of the roof supports are connected to the central computer by two common conductors, one of which carries an automatic enable signal and the other of which carries a manual enable signal.

Abstract: An improved coke oven gas washing process for removing hydrogen sulfide is proposed wherein the coke oven gas is treated in a hydrogen sulfide scrubber by counterflow with an aqueous ammonia wash water. A stream of aqueous weak ammonia liquor is cooled and sprayed through nozzles in the mid-region of the hydrogen sulfide scrubber. A quantity of aqueous ammonia liquor, corresponding to the quantity which is sprayed through the said nozzles, is withdrawn from the hydrogen sulfide scrubber at a level below the nozzles and is introduced into the top of the said hydrogen sulfide scrubber. Ammonia vapor released at the nozzles has a higher partial pressure than the ammonia partial pressure of the coke oven gas in the region of the nozzle. The aqueous ammonia liquor from the deacidifier is the source of the cooled aqueous ammonia liquor which is introduced through the nozzles.

Abstract: A device for interconnecting two sections of a longwall mining machine secured to the side wall of a face conveyor, characterized in that lugs project outwardly from the sides of adjacent end portions of the respective track sections and receive an oval chain link securing element which extends around the lugs and bridges the joint between the respective track sections.The chain link element has horizontally-extending portions interconnecting semicircular end portions which extend around the lugs, the horizontally-extending portions being such that elongation of the interconnecting device is limited as is the separation between adjacent end portions. This insures that the clearance between ends of adjacent track sections is sufficient to provide for the correct tooth spacing on a drive rack to accommodate the driving wheel of a mining machine.

Abstract: Apparatus for removing charging hole covers and for cleaning sealing surfaces is carried by a charging car that is movable along an oven roof of a battery of horizontal coke oven chambers. The apparatus includes a support member carried by guides for vertical movement on the charging car. A pivot head is carried by a shaft to pivot about a first axis on the support member. The first axis is inclined at an angle of 45.degree. to vertical. A magnetic gripper is carried by a shaft to rotate about a second axis on the pivot head. A charging hole frame cleaner includes a cleaning tool carried by a shaft to rotate about a third axis on the pivot head. The second and third axes are disposed in a plane at an angle to one another on opposite sides of the first axis and coplanar with the first axis.

Abstract: An animal pen comprises a plurality of frame members interconnected to provide an animal receiving structure having a front end and a rear end, a door adjacent the rear end for entry of the animal head first into the pen, an advancing means mounted on the main frame for movement forwardly of the frame to engage the rear of the animal to urge the animal forwardly in the structure, a first hydraulic ram to actuate the advancing means mounted between the advancing means and the main frame, and a yoke comprising a pair of closure members mounted in the frame for movement forwardly and inwardly of the frame to close around a front of the animal, and a linkage between the closure members, a second hydraulic ram between the linkage and the main frame to actuate the closure members.

Abstract: An electrical power supply and liquid supply arrangement for a mining machine, particularly a longwall mining machine, wherein extended lengths of a power supply cable and liquid supply conduit are disposed within a housing structure extending along one side of the course of travel of the mining machine. A side arm on the mining machine extends through a slot in a face plate of the housing structure and carries at its outer end a junction box within which power cables leading from the mining machine can be connected to or disconnected from an external power cable. Clamped to the aforesaid junction box is the liquid supply conduit which can be selectively coupled to, or uncoupled from, a mating supply conduit leading to the interior of the mining machine. The arrangement permits connection or disconnection of the power supply and water supply members to or from the mining machine without any disassembly of the machine itself.

Abstract: A cable is pulled in a duct or along an overhead support line according to a method and through the use of a tape comprised of warp and weft threads. Indicia printed on the web is used to indicate the length of the course of travel for the cable along which the web extends. The width of the web is sufficient to affix indicia on the surface thereof. The web has an elongation of 10% or less at a break strength which is in excess of 750 pounds of pull force. The pull strength of the woven web is about 2900-3000 pounds. The web is comprised of strands of parallel filaments of yarn consisting of aromatic polyamide fibers. Insulated conductors are incorporated in the tape as two of many warp threads according to a second tape embodiment for conducting a tension signal along the tape. After a length of the course of travel is measured with the tape, one end of the tape is connected to the leading end of a cable while the remaining end of the tape is connected to a winch.

Abstract: Coke oven chamber doors form heat-resistant plugs having a construction to prevent damage when the plugs are removed and replaced. Each plug consists of an external door-body plate and internal steel plates. The ends of the internal plates overlap each other for relative movement. The lowermost plate is secured at its lower end and the uppermost plate is secured at its upper end. This provides a specific longitudinal dimension of the overlapping plates.

Abstract: Straightened rods are withdrawn singly from a table by a carousel apparatus and advanced against a stop which is then withdrawn. Solenoid-coil induction-heating apparatus then raises the end of the rod to forging temperature and retains it at such temperature until the forge operator is ready to use it. Apparatus then operates to deliver the rod with heated end to the operator, and to deliver another single rod to the induction-heating apparatus.

Abstract: The drag pattern and the cope pattern for a standard AAR coupler yoke are each mounted on a pattern plate to form an oblique angle of about 1.degree. between the mounting surface of the pattern plate and a plane parallel to a longitudinal center plane of the pattern. The patterns each include core print surfaces for establishing the position of one unitary core which is used in a sand mold to form surfaces in the coupler yoke at the front end portion thereof. The drag pattern includes pattern surfaces to mold sand to form the surfaces surrounding the draft gear pocket on the upper and lower straps and the rear draft gear seat at the rear end portion of the yoke. The draft gear seat is generally planar and perpendicular with each inside wall of top and bottom straps.

Abstract: A pair of pliers is provided with a slot in each jaw to receive the tongue member of a special purpose plier cap member having a unique working face. The cap member may be quickly assembled, removed and replaced. The cap members have a tongue which engages a pair of rods secured across the jaw slots and also have a finger-like projection which engages an arcuate recess at the base of the slot. The cap members are retained by engagement of the finger-like projection in the arcuate recess and by engagement of grooves in the cap member tongue with the bars which are secured across the jaw slot.

Abstract: Hydrogen sulfide is first removed by ammoniacal liquor from coke oven gas in the bottom part of a gas scrubber. In the top part of the scrubber, two consecutively-arranged fine scrubbing stages remove hydrogen sulfide by treating the gases, in the upper stage, with a caustic soda solution or a caustic potash solution. Beneath the upper scrubbing stage is the second fine scrubbing stage fed with a subflow of an aqueous carbonate solution collecting at the outlet of the upper fine scrubbing stage and a subflow of cooled, regenerated carbonate solution discharged from the hydrogen-sulfide/hydrogen-cyanide stripper. From the hydrogen-sulfide/hydrogen-cyanide stripper, a second subflow is admixed with coal liquor for removing fixed ammonia therefrom in a separator. The separator produces water vapor with carbon dioxide vapors that are delivered to the hydrogen-sulfide/hydrogen-cyanide stripper for regenerating the aqueous carbonate washing solution.

Abstract: The stack cooler comprises a substantially vertical circular chamber with walls from refractory blocks or bricks. The chamber comprises an upper prechamber and disposed below it the quenching chamber proper, where the prechamber is provided with an upper conical section with a central charging opening. Gas exhaust discharge openings are provided in the transition region between prechamber and quenching chamber over the complete circumference at a distance from each other, which are joining to an annular collection channel running in the masonry. The masonry comprises an outer layer and an inner layer separate from the outer layer over the conical section and also over the cylindrical section disposed below the conical section. The inner layer adjoins at its lower end the masonry work of the wall in the area of the quenching chamber via support walls running between the gas exhaust discharge openings.

Abstract: A firearm capable of firing different-sized cartridges by the use of a detachable chamber having a plurality of bores extending therethrough. Each bore is adapted to receive a different-sized cartridge. The chamber is carried on a firearm receiver and can be positioned such that any one of the aforesaid bores in the chamber is aligned with the axis of the receiver.

Abstract: An audio pickup for musical instruments employing a condenser-type microphone mounted on a suction cup which is pressed against the sounding board or the like of the instrument.

Abstract: A coal-leveling apparatus includes a leveling rod supported by a pressing machine for movement through a leveling opening into a mushroom-shaped gas-collecting space to level the coal charged in the coking chamber of a coke oven. The leveling rod includes a head element that carries two support members that can move on pivot levers between an operative position wherein the support members are extended from the head element for support by upwardly-inclined wall surfaces in the mushroom-shaped gas-collecting space. In the inoperative position, the support members are retracted toward both sides of the head element. An actuating rod extends through the leveling rod to the head element. In one embodiment, the actuating rod can be moved in opposite directions of its length. An end of each of the first pivot levers is connected to the actuating rod and the opposite ends of the first levers are connected to second pivot levers.