Abstract: A lining element (10) for mounting onto an inner surface of a drum mantle (56) in a grinding mill, comprising an elongated lifter member (12) of a wear resistant material adapted to be axially oriented with respect to the drum mantle and to project radially into the drum, and an elongated single-piece support member (26) of an elastomeric material adapted to resiliently support the elongated lifter member over a full length thereof above the inner surface of the drum mantle. The support member is extended peripherally in a rearward direction with respect to an operational forward direction of rotation of the drum into contact with a subsequent lining element (10) to be mounted onto the inner surface, and to cover entirely therebetween the inner surface of the drum mantle.

Abstract: A grinding mill liner having inward and outward layers. The outward layer is formed of a relatively soft, shock-absorbent material and the inward layer is formed of a relatively hard, impact and abrasion resistant material. A plurality of magnets are embedded in the inward layer. A pair of pole pieces are positioned on opposed sides of each magnet and embedded in the inward layer. The pole pieces extend above the magnet, protecting it from the impact forces to which the liner is subjected during operation of the grinding mill. The pole pieces also focus the magnetic field forces emanating from the magnet. The magnets are arranged in rows, with adjacent poles of adjacent pairs of magnets within each row having alternate polarity; and, with adjacent poles of adjacent pairs of magnets in adjacent pairs of the rows having alternate polarity. The rows are parallel to one another and extend transversely to the direction in which material flows across the liner during operation of the grinding mill.

Abstract: An improved lifter and a method of repairing a damaged lifter employed in a rotary drum debarker of the type which removes the bark of logs by introducing logs into a rotating drum wherein the the logs tumble and flail against one another so that the bark is removed by the tumbling and rubbing action of one log against another. A plurality of lifters are arranged around the interior surface of the drum so that the point or vertex of the lifter is facing toward the axis of rotation of the drum. The lifters are provided with cleats on the vertex of the lifter in the direction of rotation of the drum to protect the lifter from excessive wear. In addition the cleat lifts the logs higher in the drum which improves the tumbling action. Damaged lifters may be repaired by the addition of the cleat to the vertex of the lifter.

Abstract: A paper shredder, particularly a small paper shredder, includes a shell-like lower housing part which includes the cutting rollers with their bearing plates at the end faces and the stripping elements, and an upper housing part which is provided with a material inlet slot and can be placed on the lower housing part. The bearing plate on the drive side for the cutting rollers simultaneously forms the single-piece bottom of an also shell-like gear housing which can be closed by means of a cover. The entire cutting mechanism including gear housing, cutting rollers and stripping elements is mounted in the area of the bearing plates on the end faces through vibration-damping elements in the lower housing part.

Abstract: The objective of this invention is to provide a sliding mechanism for the toggle block of a jaw crusher that enables the position of the toggle block to be adjusted easily and quickly. This invention is a novel sliding mechanism for the toggle block of a jaw crusher, in which the toggle block supports one end of a toggle plate connected at the other end to the bottom end of the swing jaw: The toggle block is comprised of an upper block and lower block, joined by an elastic body, sandwiched between an upper support member and lower support member that are joined to the machine frame. The toggle block slides back and forth with the application of an external force.

Abstract: A liner for a corrugated debarking drum having a continuously undulating outer wall with an interior surface including an axially extending concave portion includes an elastomeric compressible body having an inner surface adapted to be positioned over the concave portion and an outer surface opposite the inner surface and a support secured to the body and adapted to be bonded to the interior surface without perforating the outer wall.

Abstract: A conical gyratory grinder-crusher having a rigidly supported outer frustroconically shaped grinding-crushing member and an inner conical grinding member supported on a wobble mechanism which is in turn adjustably supported by air bellows so as to adjust the spacing between the inner and outer grinding-crushing members defining the grinding-crushing cavity, and therefore the particle size of the ground material. The bottom of the grinding-crushing cavity is closed by a flexible member. The flexible member seals the bottom of the grinding-crushing cavity. A slurry of fines or ground material is discharged from the grinder-crusher through grate discharge outlets provided in the lower portion of the inner conical grinding-crushing member.

Abstract: A protection arrangement for a hopper seal in a conical crusher having a material feed hopper located within the upper portion of the crusher bowl, over the crusher bowl liner. The protection arrangement preventing material and liquid flowing from the hopper into the crusher bowl from flowing against and abrading components of the hopper seal. The protection arrangement including an upwardly extending lip on the bowl liner which is received within a discharge hole in the bottom of the hopper.

Abstract: An adapter for mounting a liner to a first mill having an inner diameter with a first contour. The liner has a back face with a second contour shaped for mating with a second mill. The adapter includes a top face and a bottom face. The top face supports the back face of the liner. The bottom face has a contour formed for mating with the contour of the first mill.

Abstract: A rotary grinding mill is disclosed including a hopper for holding a product to be milled, a mixing chamber having a grain inlet and a separate air inlet for mixing grain and air prior to grinding, a grinding mechanism for grinding the grain and a discharge port for disposing of grain flour received from the grinding mechanism. Connected to the discharge port is a container separate from the grinding mill which may be used not only to collect ground product, but also to store the ground product for later use. In accordance with one aspect of the invention, the container is connected to the grinding mechanism by an arcuate connector for developing a helical flow path of air within the container. In accordance with another aspect of the invention, a motor which drives the grinding mechanism, and a rotor of the grinding mechanism, are structurally isolated from the grinding mill so as to minimize vibration and noise within the grinding mill.

Abstract: A cone crusher having a main frame, a crusher head interconnected with the main frame, a crusher bowl positioned adjacent to the first crusher member, and a double-acting hydraulic lift interconnected with both the main frame and the second crusher member. A force transfer member extends downward relative to the crusher bowl. The hydraulic lift includes an upper end interconnected with the main frame and a lower end interconnected with the force transfer member, thereby providing a downward clamp force on the force transfer member to compliantly clamp the crusher bowl to the main frame in an operating position. The hydraulic lift can provide an upward lift force on the force transfer member to move the second crusher member from the operating position to a clear position.

Abstract: A chopper has a rotatable cutting tool provided with a plurality of cutting teeth, a stopping body having a surface which faces the cutting teeth and guides the chopping product. The surface extends substantially in an axial direction of the cutting teeth and is arranged at a distance from the cutting teeth. The cutting teeth during a cutting process are in operative connection with the chopping product. A rotatably supported pressing roller which is arranged in a distance-free manner relative to the cutting tool and forms a gap between the pressing roller and the cutting tool, while the stopping body having a working side which extends in the gap between the pressing roller and the cutting tool.

Abstract: Grain is fed from a hopper to a horizontally oriented adjustable speed steam heated auger driven by a variable speed drive. The auger is long enough (approximately twenty inches) that temperature controlled steam fed to a plurality of inlets along the auger as related to the rate of grain movement through the auger heats the grain therein to approximately three hundred degrees fahrenheit. Then it is dropped through a grain outlet opening into a high velocity cold air stream temperature shocking the hot grain causing a sudden contraction of grain outer layers causing them to crack and loosen from the grain core. The grain is then fed through tubes to space between a rotatable internally rubber (or soft plastic) sheet layer sheathed inner surface outer mill member fitted to and rotatable about a truncated cone member having outer surface metal channel members angled approximately forty five degrees adjacent at the top and diverging at the bottom.

Abstract: A gyrasphere crusher includes a crusher frame, a crushing head, and a crusher bowl which is selectively locked to and released from the crusher frame via operation of a bowl lock assembly including a clamping ring or locknut and an inflatable bladder device. The bladder device, which preferably is formed from a plurality of discrete bladder segments mounted on an axial end of the locknut, applies sufficient clamping forces to the locknut when it is fully inflated to prevent rotation of the locknut and bowl, and can be partially deflated to permit precisely controlled rotation of the bowl and thus adjustment of the crushing gap under load. The bladder operated bowl lock assembly is simple, reliable, and operates at a fraction of the pressures typically required for conventional mechanically applied/fluid-pressure released lock assemblies.

Abstract: The lifting element (16) consists of a parallelepipedal block of elastomer designed to be fixed to the internal wall of a grinding mill and forms part of the lining of the latter. Its face (24) exposed to the grinding elements includes cavities (26) to allow the grinding elements to be embedded therein.

Abstract: In a grinding mill, a polymeric filler material is molded into the rectangular or prismatic recesses in a metallic or ceramic lining. In a grinding mill where longitudinally extending elongate ribs of the lining have two different radial thicknesses or heights, with relatively narrow bars and relatively thick bars alternating with one another, the filler material is initially cast to have a cylindrical or undulating inner surface. Where the surface is cylindrical, the filler material is worn away during use of the grinding mill and gradually conforms to the alternating narrow and thick bars to assume an undulating inner surface. Supplemental lifter bars may be embedded in the grid and rubber filler material during the casting process. Where the lining is assembled from elongate wedge-shaped metallic or ceramic bas and spacers, the bars and spacers are provided in modular forms with the spacers as wing-like extensions on the bars. Ceramic or other hard particles are embedded in the filler material.

Abstract: An apparatus for breaking solid objects includes a box-shaped support (6) open at the top and at the bottom, a substantially horizontal rotor (6) mounted in the box and carrying at least one knife which turns with it while passing between backing knives, an active face of which is turned toward the rotor, and preferably has teeth, the backing knives being movable independently of each other and having their own return means, for example by oscillating the backing knives on a pivot parallel to the rotor. The knives may be set in forced oscillation, and may be individually removable.

Abstract: The invention relates to a lifter bar intended to be mounted internally in a rotating mill drum for grinding ore and minerals. According to the invention, the upper portion of the lifter bar has a carcass of metal, comprising an elongated forward wall element facing in the direction of movement of the wear element, an elongated rear wall element and between these two wall elements transverse wall elements, the wall elements of the carcass defining between them a plurality of spaces, which are at least partially filled with a filler of another material than any of the components of the mill charge, and of greater abrasive specific volume loss than the metal of the carcass.

Abstract: A side feed type of roller mill having a housing, a rotating table provided in the housing, and a feed inlet chute extending obliquely downwardly through an upper side wall of the housing and having a lower end exposed over the rotating table. The feed inlet chute includes a cylindrical chute body and a liner mounted inside the chute body. The liner is formed of a flexible elastic material, so that the inner surface of the liner is irregularly deformed as accompanying peristalsis and vibration by both the own weight and the gliding/falling forces of a feed material passing through the chute and the elastic restoring force of the liner itself. Accordingly, a deposit layer of the feed material formed on the inner surface of the liner can soon be autonomously removed by the deformation of the liner without interruption of the operation of the roller mill. Thus, stable and efficient pulverization can be continuously performed.

Abstract: A two-piece hammer for use in a shredder comprises a work engaging piece made from a hard, wear resistant material and a supporting piece made from a softer, relatively ductile material having a relatively high tensile strength. The two pieces are secured together by a removable fastener, with a resilient member being interposed between the work engaging piece and a supporting flange of the supporting piece to dampen the transmission of impact forces from the work engaging piece to the supporting piece. The supporting piece comprises an aperture which is adapted to receive a support pin of the shredder when the hammer is mounted in the shredder.

Abstract: A grinding mill dishcarge apparatus cone is a multi-component arrangement with an outer segment having a coated rigid frame, an inner segment with a coated rigid frame, which inner segment has a wear plate of a high abrasion-resistant metal mountable upon the inner segment for ease of removal and replacement, and the outer segment being removable for rebuilding after extended wear and previous replacement of the inner segment.

Abstract: A wear member for use in quarry chutes and the like utilizes a plurality of wear strips with a layer of resilient material therebetween. The resilient material may be a natural rubber or synthetic material as urethane. A bottom mounting plate engages a T-shaped base plate mounted to the chute to hold the wear member in an array on the chute surface.

Abstract: A vibrating jaw crusher which includes a housing, in the inside of which there are operatively mounted a pair of working jaws. The pair of jaws includes at least one movably mounted jaw. The working surfaces of the rigid and the movable jaws are shaped in the form of a convex and a concave broken (polygonal) line, respectively. The movable jaw is driven by means of a vibrator. The movable jaw is supported by means of elastic elements connected to the top and the bottom end of the jaw. In a preferred embodiment of the invention the rigid and the movable jaws are fastened by means of an axle at their top ends, while their bottom ends are supported by means of elastic elements, which are shaped as rubber pads.

Abstract: A process and an apparatus for mechanically removing a sulphur containing layer from lumped lime, wherein the lumped lime is accelerated from a bottom member by a mechanical impulse and projected from the bottom member against a processing surface having profiles provided over partial sections thereof to remove the sulphur containing layer, when the lumped lime returns to the bottom member and the process is repeated along a conveying path for the lumped lime for a determined length of time, or for as long as it takes to achieve the desired removal of the sulphur containing layer.

Abstract: A wear resistant lining element for a rotary grinding mill. The element, which is made of elastomeric material, is provided on its leading side with respect to rotation with a hard wear layer made, for example, of steel. The hard wear layer is backed and supported by the elastomeric material of the element to which it is secured by chemical and/or mechanical bonding. With this arrangement, the elastomeric component cushions the hard wear layer and provides damping during grinding impact and minimizes cracking of the hard layer and scrap loss.

Abstract: A vertical wet stirred ball mill is provided according to this invention, wherein a slurry raw material fed from the top of the mill body is stirred together with a grinding medium in said mill body under pressure and the material is gradually exhausted from the bottom of said mill body as it is milled. A spring-loaded conical separation valve is fitted at an exhaust port of said body. The separation valve retracts when the pressure within the mill body is increased due to plugging, thereby the annular clearance around the separation valve is enlarged to increase the amount of exhaust, leading to elimination of the plugging.

Abstract: A paper shredding device for separating and shredding a carbon paper sheet from a credit card invoice slip having a first original copy separated by a carbon paper sheet from a second copy has a rectangular housing which encloses a rotationally driven cutter roller and a pair of adjacent idling anvil rollers. An insertion slot is formed in an end wall of the housing and communicates with an internal channel. A pair of vertically spaced perforated vacuum plates form ceiling and floor portions of the channel adjacent the insertion slot. Upper and lower receptacles are provided and each communicate via a slot with the internal channel. In use, the original copy and the second copy are directed respectively to the upper and lower receptacles and the carbon paper sheet is directed through the internal channel to the cutter roller for shredding. A microswitch is provided for actuating the vacuum plates and cutter roller upon insertion of a credit card invoice into the insertion slot.

Abstract: A shredder (1) is surrounded by a revolving screen (3) which also acts as an elevator. Said shredder outputs the shredded material in the interior of said screen (3), which allows the exit of the smaller material through the holes and lifts the remaining material depositing it once more at the input of the shredder (1). According to the present invention the bottom surface of the drum faces a fixed wall (8) placed at such a distance that it determines the third dimension of the material which passes through.

Abstract: A vertical spindle type grinding mill for example for crushing coal comprises upper and lower rings 1, 2 together defining a track for rolling grinding members 3 and yokes 7, 4 bearing against the upper and lower rings 1, 2 for resisting forces tending to separate them. A drive is provided via main shaft 8, for effecting relative rotation between the rings. At least one yoke, preferably the lower yoke 4, bears against its associated ring 2 via interposed elastomeric material 6. This reduces the risk of brittle fracture when using hard relatively brittle alloys for the manufacture of the upper and lower rings so that they have increased wear resistance.

Abstract: A cylindrical grinding mill liner plate support comprising a base portion; means for securing the base portion to the shell of the grinding mill; replaceable corner bumpers detachably secured to each interior longitudinal edge of the base portion; and at least one side panel assembly, detachably secured to at least one side of the base portion. A cylindrical grinding mill liner comprising a plurality of liner plate supports placed in parallel courses along the longitudinal axis of the grinding mill which converts the heretofore circular cross-section of the hollow milling space into a polygonal, preferably square, cross-section.

Abstract: A vertical shaft impact crusher having a rotor mounted for rotation about a vertical axis on a vertical shaft supported by a central bearing, and an impeller mounted on that shaft so that rock fed into the crusher is caught by the spinning impeller and thrown against an adjacent breaker means, and is broken; wherein the crusher is provided with a guard ring means and a dust shell means mounted telescopically and concentrically to each other with the vertical shaft to restrict the entrance of rock dust and rock fragments into the rotor shaft and bearing; and an annular flexible curtain mounted in spaced relationship to the interior of the crusher housing to dissipate material velocities and reduce operational noise.

Abstract: An improved multiple disk refiner of the type employing a rotatable hub which is mounted for rotation within a housing, and a plurality of spaced refiner rotor disks and additional disks in interleaved relation with each other and defining passages through which a stock suspension to be refined can be passed. Relative rotational movement occurs between the rotor disks and the additional disks. The invention is particularly concerned with an improved rotor structure which is mounted on the hub for rotation therewith, and resilient coupling means which connect the rotor with the rotor disks. The coupling means include a resiliently deformable elastomer which is arranged to deform in a shearing mode thereby permitting increased axial deflection of the rotors and operation at a higher intensity level.

Abstract: A sectional liner for use on the interior of a ball mill liner or rotary pulverizer. The sectional liner has a rubber base that is undulating or sinuate in contour. Means are provided in the rubber base to facilitate the securing of the base to the shell of a ball mill. The rubber base may or may not be covered with a layer of fiberglass which in turn is covered with an exterior surface of polyurethane. Ceramic tiles are embedded in the polyurethane being aligned in rows with a clearance space between the tiles filled with polyurethane. The ceramic tiles, polyurethane, and rubber are all bonded together during the cure cycle to form a one piece replaceable sectional liner for ball mills.

Abstract: The invention relates to a shredding apparatus for use in shredding a material mass into a plurality of discrete particles. The principal components includes a shredding screen and wiper blades. The wiper blade include a semi-rigid blade having its lower end in firm contact with said shredding screen. Reciprocating means is fixed to the shredding screen means to provide reciprocating motion of the shredding screen relative to said wiper blade. The reciprocating means produces a length of travel of said shredding screen at least equal to the space between an adjacent pair of wiper blades. Each of said wiper blades are parallel to each other and to a first set of spaced parallel bars. A second set of spaced parallel bars are substantially perpendicular to the first set of spaced parallel bars thereby forming a plurality of openings having a predetermined cross-sectional area substantially equal to the required cross-sectional area of said discrete particles.

Abstract: A closure member (11) for opening and closing an outlet orifice (30) in a stationary cover (32) of a drum (1) drivable in rotation in a processing machine, in which the material being treated is conveyed upwards towards the outlet aperture, which is provided generally at the lower region of the drum. Closure member (11) is movably fitted to the cover (32) and is at least partly closable.

Abstract: An agitator mill comprising a grinding vessel (3) which encloses a grinding area, a storage vessel (37) which contains grinding bodies (28), and a device (8) for feeding grinding bodies (28) from the storage vessel (37) into the grinding area. This device (8) essentially consists of a housing (11) attached to the grinding vessel (3) and a rotatable worm (13) situated therein. When the worm (13) is rotated, the grinding bodies (28) may be fed trouble-free as required into the grinding area, even if re-used grinding bodies (28) are concerned which have been worn out of true and have varied diameters.

Abstract: An impact mill in which the pins of the milling tools are provided with pocket-forming vanes which are oriented substantially radially or tangentially with respect to the rotation circle of the respective tool and, downstream of the pin forming the tool, a streamlined profile is provided to reduce vortex formation and turbulence and thereby improve the energetic efficiency of the mill.

Abstract: Presented is a method and means for use in cleaning the inside surfaces of a waste disposal unit. The device does not interfere with the grinding action of the disposal unit, nor is the device forming the subject matter of this invention subjected to the grinding action of the disposal unit while in use. Additionally, the device may include appropriately scented oils effective to make the inside of the disposal unit pleasantly aromatic.

Abstract: A wear-resistant rubber product adapted to be used as, for example, a lifter in grinding mills, comprises at least two prefabricated parts (11, 12) interconnected with one another by means of a binder layer having a thickness of at least 2 mm and consisting of in situ cast and cured polyurethane. The wear-resistant rubber product is manufactured by placing the prefabricated cured rubber parts (11, 12) at a distance of at least 2 mm from one another and by introducing, preferably injecting a reacting urethane rubber composition with excess isocyanate groups into the gap (13) to cause said prefabricated parts on either side of said gap to be contacted subtantially simultaneously by the said urethane rubber composition.

Abstract: A nut blanching arrangement in which nuts to be blanched are passed between first and second spaced, counter-rotating rollers. Each roller is provided with a plurality of hollow elastic tubular rings extending around its outer circumference. The tubular rings on the first roller are longitudinally aligned with respect to the tubular rings on the second roller such that each four adjacent tubular rings, two on each roller, form an opening through which the nuts pass during the blanching operation. In this arrangement, the nuts passing between the counter-rotating rollers are forced between the grooves of adjacent tubular rings such that the rings encapsulate and compress the nuts as they pass therebetween. The counter-rotating rollers are rotated at slightly different speeds such that during the blanching operation, the slight differential in the roller speeds causes the outer skin of the peanut to peel away from the nut meat.

Abstract: The invention comprises resilient lining panels formed preferably from polyurethane of certain specified hardness and provided with leading and trailing sides between which a material-engaging surface is formed which has a smoothly curved wave configuration cresting nearer the trailing than the leading side, the leading side terminating in a relatively thin wedge-shaped flange which is overlaid with a thicker clamping flange on the trailing side, and a metallic clamping member is positioned within the panels, extending between opposite ends thereof, and having flat ribs extending laterally and oppositely from a channel arrangement into at least the overlapping flanges of the trailing side of the panel to effect firm clamping against the flange on the leading side of each panel.

Abstract: A particle grinder includes a container having at least one opening in a wall thereof; a sound isolation layer covers a major portion of the exterior surface of the container and an elogated fastening device passes through the opening, fastening the sound isolation layer to the container. The fastening device includes a bolt and a nut threadable onto the bolt. A first sleeve composed of substantially non-deformable material surrounds the elongated fastening device at least partially within a region of the opening, and a second and resilient sleeve surrounds the first sleeve, at least partially and normally projects exteriorly therebeyond. A clearance exists normally between the sleeves and the sound isolation layer abuts an exterior portion of the second sleeve. A resilient seal is disposed around the periphery of a portion of the fastening device, and between the first sleeve, and the container.

Abstract: An agitator-type ball mill has a circumferential wall which bounds a working chamber having an axis and includes two radially spaced jackets which form therebetween a gap for receiving a heat-exchange medium. The jackets are releasably connected with one another so that they can be separated from each other by displacement in an axial direction. A flexible member is arranged in the gap between the jackets, connected with one of the jackets, and forms a substantially helical passage in the gap. The heat exchange medium flows through the thus-formed helical gap. The flexible member may be formed by a band which is inserted in a helical groove provided in one jacket and extends radially into the gap so as to abut against the other jacket with prestress.

Abstract: A method and arrangement for support of contact elements for material treating applications are disclosed in which a hardenable liquid bonding material is flowed into a space provided between surface areas of support and contact elements, the material being allowed to harden to provide a solid element which acts in compression to resiliently oppose relative movement of the elements. The space preferably has a cross-sectional configuration such that a wedging action is developed in response to relative movement of the elements. The holding element may be effectively burned out for removal and replacement of the contact element.

Abstract: A method is described for sequential replacement of the lining in a rotating mill according to wear of the lining. Generally, such a lining consists of adjacent zones parallel to the rotational axis of the mill, the height of these zones varying periodically in the peripheral direction of the mill. According to the invention rubber beams of equal width are used, and for the replacement operation completely fresh beams of only one height are employed, this height representing the highest one of only a few preselected categories of beams. Upon removal of worn beams, these are reassorted according to the selected categories and those beams worn-out and unfit for even the lowest category are discarded. Thus, the reassorted beams not rejected can be reused properly positioned so as to maintain a suitable variation of the beam height in the peripheral direction of the mill, and only one height of fresh beams need to be held in stock.

Abstract: The disclosure is directed to an improved liner assembly for an ore grinding mill. The liner assembly is of the segmented type, comprising a first plurality of holder segments which are mounted directly to the shell of the mill, and a second plurality of wear segments which are mounted to the shell in overlying relation to the holder segments, which are thus virtually unexposed to the ore comminution process and wear very slowly. The wear segments are formed with a plurality of downwardly projecting bosses which are received in similarly configured recesses formed within the holder segments. Mounting openings or bores are formed in the wear segments, extending from the top grinding surface to the center of each boss to receive a mounting bolt that extends through both segments and projects externally of the shell to receive a threaded lock nut. These mounting openings are countersunk so that the heads of the mounting bolts securing the wear segments are substantially recessed from the grinding surface.

Abstract: Method and apparatus for separating fibers from agglomerated masses thereof is disclosed, and achieved by paired rolls having roll surfaces with randomly disposed protuberances thereon, such protuberances being initially deformed randomly as the roll surfaces approach complete conjugacy and being further deformed as the roll surfaces move into complete conjugacy to induce shearing and tearing action on the agglomerated fiber masses therebetween to separate discrete fibers therefrom. The roll surfaces are characterized by each having the elastomeric roll surface thereof with a Poisson ratio different from the Poisson ratio of the other.

Abstract: A wall of elastomeric material having at least one inner cavity for a pressure fluid. The wall is compression prestressed in the portion thereof closest to the surface which is subjected to wear in the use of the wall.