Abstract: A heat extractor system for a furnace, said furnace including a burner with a chimney that is connected but is normally not in operation. Instead, the furnace is connected to a vent in parallel with the chimney through a draft-inducing arrangement including a water spray in which water is heated and circulated to a point where the heat from the water is utilized. Due to the parallel arrangement of the vent and chimney, if the vent fails to operate, it will function in a fail-safe manner, with the combusted gases from the burner leaving through the chimney.

Abstract: A universal joint has a cross formed by two mutually perpendicular pairs of coaxial trunnions, each pair of trunnions being rotatably received in bearings which in turn are coaxially retained in the bearing caps of one of two yokes. The yokes are subdivided into half sections which each include one of the bearing caps. The half sections of each yoke are separably interconnected with a juncture therebetween defined by confronting mating surfaces. Interengaging elements are provided at the juncture for preventing the thus interconnected half sections from shifting in relation to each other in directions which disturb the coaxial alignment of the bearings.

Abstract: A shaft is rotatably journalled in a bearing assembly. The shaft has a sleeve fixed thereon at a location axially adjacent to the bearing assembly, and a ring depends from the sleeve into a supply of liquid lubricant contained in an underlying sump. Rotation of the shaft and sleeve causes the ring to rotate about its own axis, and the rotating ring carries lubricant upwardly from the sump, with the thus carried liquid ultimately being returned to the sump by a combination of centrifugal and gravitational forces. A dam is interposed between the underside of the sleeve and the ring depending therefrom to direct a substantial and continuous flow of the returning lubricant to the bearing assembly.

Abstract: A method and apparatus for imparting a three-dimensionally curved configuration to a straight elongated element wherein one end of the element is removably supported with its axis coincident with a reference axis. The element is partially pre-bent away from the reference axis into conformity with a two-dimensional first guide path. Thereafter, the pre-bent element is bent into conformity with a three-dimensional helical second guide path.

Abstract: Hydraulic control apparatus serves to operate roof support props of a mineral mining installation. An automatic setting arrangement with a valve device ensures the props become set against the roof with a high uniform force by connecting a prop pressure chamber to a pressure fluid source once a threshold pressure is exceeded signifying the prop has been extended. To disable the automatic setting arrangement during prop retraction the valve device thereof is provided with a control piston which is subjected to pressure during retraction to oppose the action of another control piston which responds to the threshold pressure.

Abstract: A slide plate screen changer has a housing defining a material flow passage and a transverse slide plate passage in which is mounted a movable screen plate. Seal rings on the upstream and downstream sides respectively of the screen plate prevent leakage of material from the flow passage. One of the seals is adjusted by means of a threaded bushing which surrounds the flow passage and which protrudes axially from one end of the housing where it is fully accessible to torque exerting tools.

Abstract: A housing is disclosed for an insect killing assembly of the type having an elongated light source protruding downwardly from a mounting shelf. The light source is surrounded by an electrically conductive grid supported by legs depending from the lower surface of said shelf. The light source and the grid are energized by an A.C. source via circuit components including a voltage augmenting transformer carried on the top surface of the shelf. The housing includes an open-ended enclosure surrounding the insect killing assembly. The enclosure is defined by a pair of separable half-sections which are each provided with an array of holes through which insects may pass as they are attracted by the light source onto the energized grid. A removable base closes the lower end of the enclosure. A one-piece water impervious cover is detachably mounted to the upper end of the enclosure. The cover cooperates with the half sections and the mounting shelf to isolate the circuit components from external moisture.

Abstract: A book-type ornament adapted to be suspended from a Christmas tree bough or other like support has a plurality of pliant inner sheets folded on themselves to provide pages. A pliant outer sheet is folded on itself to provide top and bottom cover portions, with the pages being arranged therebetween, and with the fold lines of the inner and outer sheets being parallel and adjacent to one another. A flexible elongated element is received in aligned openings located at the fold lines of the inner and outer sheets. This element extends exteriorly of the fold line of the outer sheet to form a loop for suspending the ornament. Planar outer elements overlie the exterior surfaces of the cover portions. The outer elements, which are dimensioned to expose the fold line of the outer sheet, have inturned peripheral flanges overlapping the edges of the cover portions.

Abstract: Apparatus for, and a method of, driving a tunnel utilizes a drive shield to support the forward end of the tunnel where debris material is removed. At the rear end of the drive shield, a lining is created to cover the exposed tunnel wall. This lining is produced by simply spraying concrete rearwardly directly between the space between multi-part formwork and the tunnel wall itself. The formwork may overlap with the drive shield. The formwork is advanced to follow the progress of the drive shield by removing part of the formwork from the rear and re-siting this part at the front end.

Abstract: A mineral mining installation includes a longwall conveyor and a plurality of roof support units positioned side-by-side on the goaf side of the conveyor. The conveyor is braced longitudinally by a block bracing system having a plurality of hydraulic bracing rams each of which is disposed at an acute angle to the conveyor. The bracing rams act between the conveyor and floor girders of the roof support units. Each bracing ram is attached to a respective floor girder by means of a bracket. Each bracket has first and second bracket parts welded together, the first bracket part comprising means for connecting the bracket to its floor girder, and the second bracket part forming an extension of the first bracket part and carrying a pivot joint member for pivotally supporting the cylinder of the associated bracing ram. The first bracket part is a standard cast member, to which second bracket parts of differing lengths can be welded.

Abstract: A mineral mining installation comprises a mine roof support assembly and apparatus for drilling bores. The roof support assembly comprises a plurality of roof support units positioned side-by-side, and the drilling apparatus comprises a drilling device which is movably guided on a track associated with the roof support assembly. Each of the roof support units has at least one roof bar. The track is arranged on the underneath sides of the roof bars of the roof support units. The drilling device is pivotally mounted on a trolley which is movably guided on the track.

Abstract: An apparatus and method for unscrambling and separating a plurality of elongated elements randomly deposited in a pile at a receiving station, and for delivering the elements individually to a discharge station is disclosed wherein small batches of the elements are removed from the pile at the receiving station into the first of a plurality of element separating stations arranged successively between the receiving station and the discharge station. Thereafter, the elements in each batch are shifted from one separating station to the next. This shifting occurs alternately in a forward direction towards the discharge station, and then in a reverse direction back towards the receiving station, with selected properly aligned elements in the separating stations being rearwardly bypassed and forwardly shifted.

Abstract: A fluidized bed die container holding a lubricant compound receives material which is to be reduced in a die. Pressurized air entering the bed beneath the lubricant agitates the particles to fluidize them so that contact is continually assured between the lubricant and the material, and the pressurized air is used to help cool the die.

Abstract: A roof support unit for a longwall mineral mining installation has a roof shield supported above a floor sill. A first hydraulic ram is provided for advancing the roof support unit. The roof shield is provided with a forward extension which is advanceable by means of a second hydraulic advance ram. A hydraulic control arrangement, which includes the two hydraulic advance rams is provided for controlling the advance of the roof shield extension in dependence upon the working stroke of the first hydraulic advance ram. The control arrangement is such that the amount of hydraulic fluid supplied to one of the pressure chambers of the second hydraulic advance ram is dependent upon the amount of hydraulic fluid expelled from one of the pressure chambers of the first hydraulic advance ram during the working stroke of the first hydraulic advance ram.

Abstract: An electrically powered log splitter has a frame carrying a pair of mutually spaced fixed splitting components with a carriage mounted movable splitting component movable in opposite directions therebetween. A reversible electric drive motor is mechanically connected to the carriage to propel the carriage in opposite directions. A control switch is electrically connected between a power source and the drive motor. The switch has a first closed setting at which the drive motor is energized to move the carriage and its movable splitting component in one direction toward one of the fixed splitting components, a second closed setting at which the drive motor is energized to move the carriage and its movable splitting component in the opposite direction towards the other of the fixed splitting components, and a third normally open setting at which the drive motor is deenergized to halt movement of the carriage.

Abstract: A bird feeder has a seed storage compartment at least partially defined by a side wall. Improved feeding ports are provided in the side wall through which birds may extract seeds from the storage compartment. Each feeding port comprises an opening in the side wall which is partially occluded by one or more resilient finger members. The finger members are arranged to prevent a free flowing escape of seeds from the storage compartment, and are flexible to accommodate forcible extraction of seeds from therebetween.

Abstract: In a rolling mill wherein hot rolled rod is directed along a downwardly curved path into a vertical laying head which forms the rod into a series of rings, a method of and apparatus for propelling the rod through the laying head. The rod is passed between a pair of adjustable driven pinch rolls located in advance of the downwardly curved path. An initial closing force is exerted on the pinch rolls to establish an initial parting prior to entry of a rod front end therebetween. The initial parting is sized to produce at least some rod deformation while providing a driving relationship between the pinch rolls and the rod. The initial closing force is greater than the momentary surge in separating force accompanying impact of a rod front end with the pinch rolls. The initial parting is maintained until the rod front end has negotiated the downwardly curved path and has passed through the laying head, at which time the initial closing force is released.

Abstract: A pouring reel has a rotatable tube with a bottom and an upstanding cylindrical side wall open at the top. Pin members are arranged in a circular row concentrically within the side wall. The pin members are pivotally adjustable between vertical positions cooperating with the tub side wall to define an annular coil forming chamber, and inoperative positions inclined inwardly from the side wall. Pivotal adjustment of the pin members from their inoperative to their operative positions is achieved by inserting a carrier into the tub. The carrier has a base which extends across and forms the bottom of the coil forming chamber, and a central core which carries contact membrs arranged to urge the pin members into their operative positions.

Abstract: A blade assembly for a tractor or other like vehicle of the type adapted for movement over snow covered terrain, having a horizontally extending first blade with second blades mounted at the opposite ends thereof for pivotal movement about vertical axes. Top plates are fixed relative to and extend forwardly from the first and second blades. The second blades are pivotally adjustable between open positions extending angularly outwardly from the first blade, and closed positions extending angularly inwardly from the first blade to cooperate therewith in defining an enclosure. The enclosure has a bottom opening defined by the lower edges of the blades, and a top opening which is smaller than the bottom opening and which is defined at least in part by the top plates.