Abstract: A multiple-mandrel ring rolling machine for producing a ring from a ring blank having a plurality of elongated mandrel rolls rotatably mounted on a rolling platform fixedly mounted to a frame for rotation relative thereto is disclosed. The mandrel rolls are axially displaceable relative to the rolling platform between a first position above the rolling platform for rolling a ring blank and a second position below the rolling platform.

Abstract: A method and apparatus of manufacturing a metal casing, particularly for accessories, such as steel casings, and preferably gate valves which can be employed in installations requiring high safety measures and testing with testing heads, the casings having large nominal widths and particularly usable in nuclear reactors and the like, comprising, permanently deforming a bloom into a tubular body having one open end and an opposite closed end, deforming at least a portion of the tubular body to form at least two diametrically opposed sides thereof which are planar on their interior and exterior surfaces, forming a port in at least one of the planar ends having a diameter less than that of the diametrically opposed sides to leave an approach area around the port and connecting a pipe connection to the port by a single welding seam which can be tested with a testing head which can approach the seam in the approach area. A casing made in accordance with the method is also disclosed.

Abstract: A gear is disclosed with a heavy loading capacity which has teeth roots between adjacent gear teeth and contact area patterns on the face of each gear tooth. Each tooth root includes a concave fillet running substantially in a direction of the rolling element generator line of the gear. The top of each tooth is substantially equidistant and a mirror image of the tooth root fillet.

Abstract: A rotation-elastic, shock and vibration damping clutch, comprises, an outer ring part with an inner ring part arranged within the outer ring part and with each ring having a generally axially extending aperture therethrough at a plurality of circumferentially spaced locations. An elastic pressure pad of arc-shaped cross-section extends between the inner and outer ring portions and has respective ends abutting against the respective sides of the ring portions around each of the apertures. At least one non-elastic rope extends through the elastic pressure pad and is advantageously embedded therein and it extends through each of the apertures and is evenly distributed around the circumference of the rings. Each ring is held by a spring member at its passage through the apertures, which spring member is located in a recess defined on the opposite side of the ring from the elastic pad.

Abstract: An apparatus for generating a control current flow in a pool, comprises, a continuously operable electric motor which has a rotatable drive shaft which is connected to an electrically operated clutch. A rotatable propeller drive shaft is disposed alongside the clutch and is engageable with the clutch upon actuation thereof to rotate a propeller affixed thereto to produce a current flow in the pool. The device includes means for sensing the level of the water and for operating the clutch either directly upon changes of level or after a time delay so that it selectively engages and disengages from the propeller drive shaft. The engagement for rotation of the propeller at selected intervals in accordance with the level of the pool produces a wave flow within a few minutes.

Abstract: An excess pressure valve particularly for props having telescopic parts which are extensible or retractable by fluid under pressure used in underground mining operations, comprises a valve housing having a bore therethrough with a connection end connectable to the fluid under pressure and an opposite opened end. A tubular sleeve is slidable in the bore and has a passage therethrough for the fluid under pressure and it has an annular inlet end face facing the connection end and an opposite annular pressure end face which opposes a piston which is also slidable in the bore between the sleeve and the opened end. The fluid under pressure maintains the sleeve and the piston in slightly spaced relationship so that there is a small space therebetween which is sealed by an annular pressure seal.

Abstract: A machine tool comprises a main support with a machine stand on the main support carrying a headstock alongside a workbench which is mounted advantageously for movement toward and away from the headstock. The construction includes a tool magazine support mounted on the main support and the tool magazine and the headstock are mounted for relative movement in two distinct planes. In addition, the tool magazine carries a rotatable tool magazine disk having a plurality of recesses in its periphery each of which accommodates a tool carrier. The tool magazine disk is supported by the rotation in a third plane distinct from the first and second planes, and cam means are provided between the tool carrier and the tool magazine disk which are effective to lock the carrier to the disk and/or to the headstock in accordance with whether the tool carrier with the tool is to be inserted on the headstock or to be stored in the tool carrier disk.

Abstract: A shield timbering frame for timbering mines adjacent a mining face, comprises a horizontal floor-engaging skid and a breaking shield extending obliquely over the skid which is connected to the skid by a pair of longitudinally spaced, lemniscate guide rods. A roof cap member has an inner end which is pivoted to the upper end of the breaking shield and it is also braced by a piston and cylinder combination which is articulated to the breaking shield intermediate the length thereof and to the roof cap intermediate its length. At least one hydraulic ram is mounted on the skid and is engaged with the roof cap between the connection of the roof cap to the breaking shield and the connection to the additional support. The hydraulic ram is madeup of at least three telescopically interengageable extensible and retractable parts and includes pressure valve means to provide a substantially equal support pressure on the roof cap in various positional orientations of the roof cap.

Abstract: A method of heating metal workpieces so as to minimize scale formation and decarburization using an electroinduction heater, comprises placing the workpiece in the vicinity of the induction heater, reducing the air present in the vicinity of the workpiece to provide a reduced air atmosphere, and heating the metal by an electroinduction heater in the reduced air atmosphere. The air is advantageously displaced by a protective gas and this is done before the workpiece is heated to a temperature of 350.degree. C. A device for carrying out the heating, comprises a thermally insulated hood which has an interior heating cavity which opens downwardly and which is made gas-proof at its sides and top. A thermally insulated bottom fits into the opening of the hood and substantially fills the cavity and it is provided with a support area for the workpiece which, when the bottom is inserted, is positioned alongside the electroinduction heater.

Abstract: A fluid pressure operated press has a drive piston which is movable in a cylinder and has a drive surface side and an opposite return surface side which is connected with a ram which operates on a workpiece. An accumulator is connected to the respective cylinder spaces disposed on the respective drive and return surface sides through a control so as to effect the movement of the piston in a drive direction by admission of a fluid pressure source and pressure from an accumulator in a selected amount to the cylinder space on the drive surface side. The return of the drive piston is effected by applying a fluid pressure to the return surface side. A difference in the areas of the return surface side of the drive piston and the combination of the drive surface side with a central area surface associated with the drive surface side, defines an effective piston area.

Abstract: A shield type support for use in underground mining comprises a floor construction with one or more pressure operated extensible and retractable rams mounted on the floor and connected at their upper end to a roof-member. The roof-member is articulated at one end to a breaking shield which has an opposite end which is supported by lemniscate guide rods. The lemniscate guide rods are carried on a support which is mounted for adjustable movement on a column supported on the floor. In addition, this support also advantageously carries an additional adjusting element in the form of a telescopically retractable and extensible ram connected between the support and the roof structure at a spaced location from the other rams.

Abstract: A press which has a short ram stroke in which the ram is movable in a single plane in a working direction and return direction, particularly for high speed cutting presses, comprises, a press frame with a ram carried by the press frame which is supported by springs which are rigidly connected to the ram and to the press frame and hold the ram resiliently for movement in the working and return direction but rigidly in all other planes.

Abstract: A positioning device for positioning a part, such as, a movable part of a machine tool, relative to a fixed part of the machine tool, comprises, a transmitter adapted to be secured to one of said fixed and movable parts and having spaced apart first and second transmitter surfaces and a differential transmitter adapted to be secured to the other of the first and second parts and having first and second heads adapted to be positioned in alignment with the respective first and second transmitter surfaces, so that the heads produce a control signal in accordance with the amount of the heads aligned with the surfaces. Control means are connected to the respective heads and to means for moving a machine part to position the machine part in accordance with the coverages of the heads on the first and second surfaces.

Abstract: A multilayer vessel or tube comprises an inner core tube and a plurality of supporting layer tubes around said inner core tube which have degassing bores. A blind layer is provided between the core tube and the innermost supporting layer tube and a plurality of core plugs rest on the core tube and are provided in a number corresponding to the number of degassing bores. The blind layer has an opening therethrough and is longitundinally split into segments and a parting channel is formed between every adjacent two segments. A core plug is positioned in central alignment with the parting channel in an opening of the blind layer. One of the supporting layers is welded only by its upper portion to the supporting layer and the core plug has a bore communicating directly or indirectly with the atmosphere. A degassing pipe is threaded into a threaded bore defined in the core plug and the core plug is provided with grooves which extend transversely along its underside, which rests on the core tube.

Abstract: A coupling gear for connecting two side-by-side, longitudinally extending shiftable skids of a divided footwall skid of a lemniscate shield timbering frame for actuation by a fluid pressure operated piston and cylinder combination which is adapted to be connected thereto, comprises, a double crank joint which includes first and second outer crank pins extending transversely between the skids with bracket means adapted to be positioned on the respective skids for rotatably supporting the outer crank pins on the respective skids and, wherein, the crank pins have outer ends rotatably supported in the bracket means and opposite inner ends and including first and second longitudinally extending, substantially parallel crank arms, one of which has a first end connected to the inner end of the first outer crank pin and the other of which has a first end freely rotatable on the second outer crank pin and with a central crank pin having a first end freely rotatable in the first crank pin arm opposite end and an opposi

Abstract: A ring rolling machine for rolling a ring blank engaged over a mandrel roll which has an outside diameter smaller than the inside diameter of the mandrel roll comprises a rotatable main roll having an annular curved surface. The main roll is rotated about a fixed axis which is spaced at a fixed distance from the mandrel. Its curved surface is divided into a loading zone having a radius less than the spacing from said main roll access to the ring blank, a rolling zone having a variable radius curved with a continuously increasing value and a rounding zone extending between the rolling zone and the loading zone which is of substantially constant radius.

Abstract: A timbering device connected to a longwall conveyor disposed toward the mining face of an excavation for progressively timbering frames from the gobbing side toward the mining face side comprises first and second skids which are adapted to be shifted over the floor. The guide piece is pivoted to one of the skids adjacent the gobbing side thereof and it has a guide slot extending toward the mining face. A push rod has one end connected to the longwall conveyor and an opposite end having a slide portion which is slidable in the guide piece guide slot. A thrust drive piston has a gobbing side end pivotally connected to the slide piece portion of the push rods and has an opposite mounting face end which is pivotally connected to a bracket carried under one of said skids. The sliding plane control device is carried by the pusher rod.

Abstract: A hydraulic mine prop comprises a cylindrical top ram portion and a bottom ram portion which is telescopically engageable in said top ram portion and has an upper piston portion in sliding sealing engagement with the interior of said top ram portion. A ram head closes the top of said ram portion and a valve seat body is disposed between the ram head at a spaced location therefrom adjacent the top of the top ram portion and defines a vent space therebetween. The valve seat body also encloses a pressure space between itself and the piston and a passage is defined through the valve body within a valve seat portion thereof which communicates the pressure space to the vent space. The passage is closed by a spring-biased valve which may open against the biasing force of the spring.

Abstract: A canopy and shield structure for supporting a shield adjacent a working face in a seam-like mine deposit, comprises a floor skid which is connected through an extensible and contractable prop at the working face end to the working face end of a canopy adapted to be positioned in parallel relation to the roof strata. The working space is covered at the waste removal end by a shield which includes a lower two-arm lever portion which is pivotally mounted on the skid and an upper portion which is pivotally connected to the longer arm of the two-arm lever adjacent the upper end thereof and is also pivotally connected to the canopy. The two-arm lever is driven by a hydraulic drive motor and a parallel linkage is connected between the upper shield part and the canopy in order to provide a guidance of the canopy in a direction substantially perpendicular to the strata.

Abstract: A canopy and shield structure for supporting a shield adjacent a working face in a seam-like mine deposit, comprises a floor skid which is connected through an extensible and retractable prop at the working face end to the working face, and of a canopy, which is adapted to be positioned in parallel relation to the roof strata. The working space is covered at the waste removal end by a shield which includes a lower portion pivotal on the floor skid, and an upper portion which is rigidly connected to the canopy at the opposite end of the canopy from the working face end. The shield is connectable to an extensible and retractable prop and a lemniscate guidance mechanism, so that the upper part of the shield may be moved upwardly and downwardly along its longitudinal axis. The upper part also carries an opening for the passage of a blast pipe which is supported on roller means carried by the canopy.