Abstract: A 3-D printing apparatus is configured to make a modeling material form a 3-D object layer by layer. The 3-D printing apparatus includes a printing assembly and a cleaning unit. The printing assembly includes a feeding tube, a nozzle and a driving wheel set disposed between the feeding tube and the nozzle to drive the modeling material transferred to the nozzle from the feeding tube and then exiting from the printing assembly via the nozzle so as to form a 3-D object layer by layer. The cleaning unit has a brush, in which the brush leans against on the driving wheel set to clean out the residual modeling material while the driving wheel set rotates relatively to the cleaning unit.

Abstract: A method of shaping plastics material pre-forms into plastics material containers is provided, in which the plastics material pre-forms are expanded inside a blow mould with the aid of an expansion agent and a stretch rod to form the plastics material containers, and in which at least the blow mould and/or the stretch rod is or are sterilized if necessary at least in part with sterilization agent, wherein, to sterilize the outer side of the stretch rod, the stretch rod is displaced at least in part into the blow mould, and the sterilization agents are brought from a discharge element arranged outside the stretch rod to the exterior face of the stretch rod.

Abstract: An apparatus for transforming plastic preforms into containers may include at least one blow mould which forms a cavity, inside which the plastic preforms can be transformed into containers. The apparatus may include a pressure application device for applying a medium to the plastic preforms in order to expand the preforms against an inner wall of the blow mould delimiting the cavity. The apparatus may include a stretching rod for stretching the plastic preforms in the longitudinal direction. The apparatus may include a cleaning device for cleaning regions of the blow mould. The cleaning device may include at least one outlet opening for a cleaning medium for cleaning the blow mould, and this outlet opening is arranged at least at times inside the blow mould.

Abstract: An object is to provide a method and an apparatus for lapping strip-shaped food dough onto a transporting unit without repeatedly applying tension or relaxation. A method of lapping food dough in which strip-shaped food dough being continuously conveyed is lapped onto the transporting unit configured to transport the food dough in a direction intersecting a conveyance direction of the food dough.

Abstract: An apparatus for transforming plastic preforms into containers, includes at least one blow mould which forms a cavity, inside which the plastic preforms can be transformed into containers. The apparatus includes an opening and closing mechanism for opening and closing the blow mould, and a cleaning device for cleaning regions of the blow mould. The cleaning device includes at least a first cleaning element for cleaning an inner wall of the blow mould, which cleaning element is arranged at least at times outside the blow mould.

Abstract: A blow molding machine for producing plastic bottles, particularly PET bottles, including a plurality of blow molding stations, which have assigned thereto valve blocks with control valves and blowing nozzles for introducing or discharging blowing air; and a cleaning-in-place (CIP) system for cleaning the blow molding machine. Since the valve blocks are configured such that they can be included in the CIP process, the system components, such as the blowing nozzle, which are particularly important for the production of PET bottles in terms of hygiene, can be cleaned and sterilized without disassembly.

Abstract: A machine for making cotton candy includes a shell, a sugar-spinning unit and a scraping unit. The sugar-spinning unit includes a heater located in the shell for heating and melting sugar, a bowl located around the heater, a lid located on the bowl, and a primary motor for spinning the heater and the bowl to spin the molten sugar. The scraping unit includes a holder located in the shell, a stopper connected to the holder, a lever pivotally connected to the holder, a first scraper attached to the lever, a second scraper pivotally connected to the holder, a hook connected to the second scraper, a spring for connecting the lever to the second scraper, a difference motor, and a crank including an end connected to a mandrel of the difference motor and an opposite end connected to a pin movably inserted in a slot defined in the lever.

Abstract: An apparatus for forming desired patterns on ceramic tile from a slurry comprising: a means for preparing a slurry; at least one slurry holding tank for holding at least one type of slurry; at least one pattern forming tray; at least one means for connecting said at least one tank to at least one pattern forming tray and a filter pressing unit; wherein the pattern forming unit dispenses a predetermined type, amount, colors of slurry at a predetermined order into the pattern forming tray to form a desired pattern, said slurry with desired pattern is pressed with the filter pressing unit to form ceramic tiles or slabs with a desired pattern running though its entire thickness.

Abstract: Extrusion dies may be cleaned, especially of so-called die drips, by passing a wire over the die orifices in the vicinity of the exit face of the extrusion die. The operation of the extrusion operation is not affected by the passing of the wire through the stream(s) of the extrudate, and so the extrusion operation need not be shut down for the cleaning process. The process is especially useful for cleaning dies through which polymers are extruded.

Abstract: A gas-assisted mold surface heating system is disclosed, which comprise: an air supply, for providing air with a flow rate larger than 300 L/min; a heater, for heating air to a temperature higher than 400° C.; a mold, configured with a mold cavity, an inlet and an outlet; and an air storage tank; wherein, the inlet is connected to the heater through a pipeline for allowing the air from the air supply to flow into the cavity after being heated by the heater and thus to be for heating up the surface of the mold cavity while the heated air is being enabled to flow out of the cavity through the outlet and into the air storage tank. With the aforesaid system, surface temperature of the mold cavity can be raised to a point higher than a glass transmission point in a short period of time.

Abstract: A spinneret format, an electric-field reversal format and a process for post-treatment of membranes formed from electro-spinning or electro-blowing are provided, including a cleaning method and apparatus for electro-blowing or blowing-assisted electro-spinning technology.

Abstract: Apparatus for producing an object by sequentially forming thin layers of a construction material one on top of the other responsive to data defining the object, the apparatus comprising: a plurality of printing heads each having a surface formed with a plurality of output orifices and controllable to dispense the construction material through each orifice independently of the other orifices; a shuttle to which the printing heads are mounted; a support surface; and a controller adapted to control the shuttle to move back and forth over the support surface and as the shuttle moves to control the printing heads to dispense the construction material through each of their respective orifices responsive to the data to form a first layer on the support surface and thereafter, sequentially the other layers; wherein each printing head is dismountable from the shuttle and replaceable independently of the other printing heads.

Abstract: An apparatus for transforming plastic preforms into containers may include at least one blow mould which forms a cavity, inside which the plastic preforms can be transformed into containers. The apparatus may include a pressure application device for applying a medium to the plastic preforms in order to expand the preforms against an inner wall of the blow mould delimiting the cavity. The apparatus may include a stretching rod for stretching the plastic preforms in the longitudinal direction. The apparatus may include a cleaning device for cleaning regions of the blow mould. The cleaning device may include at least one outlet opening for a cleaning medium for cleaning the blow mould, and this outlet opening is arranged at least at times inside the blow mould.

Abstract: A spinneret format, an electric-field reversal format and a process for post-treatment of membranes formed from electro-spinning or electro-blowing are provided, including a cleaning method and apparatus for electro-blowing or blowing-assisted electro-spinning technology.

Abstract: A system for moulding three-dimensional products from a mass of one or more food starting materials which are suitable for consumption, in particular human consumption, has a production device having a frame, a mould member provided with at least one mould cavity, the frame supporting the mould member, mass feed means for feeding the mass to the one or more mould cavities of the mould member. The system also has at least one cleaning device for cleaning one or more parts of the production device which come into contact with the mass. The mould member is removable from the frame. The system has a storage device for storing a plurality of mould members, which may be provided with an identification, has recognition means for recognizing the identification of a mould member, and may have a memory for storing at least one history of a mould member.

Abstract: In an injection molding machine 1 for supplying clean air 10 to a die 8 in a direction perpendicular to a direction that opens/closes the die 8, in order to effectively pass the clean air 10 through an opened space in the die 8 so as to prevent dust from depositing on a die cavity surface or a molded product when the die 8 is opened and a ventilating hole 12 is provided in a safety door 11 provided so as to be in parallel with the die opening/closing direction.

Abstract: Apparatus for forming a dough strand from a preferably large-volume dough mixture (28) has a receptacle (2) for holding this dough mixture, which is provided at the bottom with a discharge opening (4) for the dough. Connected to this discharge opening are two shafts (6) arranged so as to be parallel to one another and driven in opposite directions in order to effect a downward movement of the dough. The shafts (6) are provided with profiles acting on the dough which are formed by star arms (5). The shafts (6) are arranged so as to be fixed and are driven in a timed manner for the rotary movement. The star arms (5), of which there is an even number for each shaft (6), in the position directed towards one another block the downward flow of dough therethrough over the major part of the axial length of the shaft (6).

Abstract: An apparatus for scraping a lip of an extrusion die includes a scraping surface pressed against the lip. The scraping surface is movable along the lip of the die to clean debris, such as hardened thermoplastic, from the surface of the lip. The scraping surface may be removable and/or replaceable. A method of cleaning the extrusion die includes pressing the scraping surface against the lip of the extrusion die and traversing the scraping surface along the lip in a controlled manner.

Abstract: Apparatus for molding blocks with laterally projecting, undercut side features includes a mold box having split mold parts defining a mold cavity open at the top and bottom. A top plate having an opening aligned with a cavity overlies the mold parts. Moldable block material is charged into the cavity from a feed box, and the material is compacted and shaped between a lower pallet and upper stripper head. The mold parts are retractable beneath the top plate to release the block for stripping through the bottom of a mold. A plurality of fluid outlets in the top plate cleanse the mold surfaces of the block material between mold cycles.

Abstract: The rotary tablet press comprises a housing, in which a compression unit (14) is detachably mounted. The compression unit (14) comprises a die table (15) with punches (17, 18), a feeding device for the supply of material to be compressed into the dies (16), and a tablet discharge device for removal of compressed material in the form of tablets. The compression unit (14) encloses each die opening and its corresponding first punch end (21, 22) in a chamber, the feeding device and the tablet discharge device are enclosed, the feeding device communicates with an inlet for detachable connection with an external supply channel, and the tablet discharge device communicates with an outlet.

Abstract: An apparatus for scraping a lip of an extrusion die includes a scraping surface pressed against the lip. The scraping surface is movable along the lip of the die to clean debris, such as hardened thermoplastic, from the surface of the lip. The scraping surface may be removable and/or replaceable. A method of cleaning the extrusion die includes pressing the scraping surface against the lip of the extrusion die and traversing the scraping surface along the lip in a controlled manner.

Abstract: The rotary tablet press comprises a housing, in which a compression unit (14) is detachably mounted. The compression unit (14) comprises a die table (15) with punches (17, 18), a feeding device for the supply of material to be compressed into the dies (16), and a tablet discharge device for removal of compressed material in the form of tablets. The compression unit (14) encloses each die opening and its corresponding first punch end (21, 22) in a chamber, the feeding device and the tablet discharge device are enclosed, the feeding device communicates with an inlet for detachable connection with an external supply channel, and the tablet discharge device communicates with an outlet.

Abstract: Apparatus for molding blocks with laterally projecting, undercut side features includes a mold box having split mold parts defining a mold cavity open at the top and bottom. A top plate overlies the mold parts and is formed with an opening aligned with a cavity. Moldable block material is charged into the cavity from a feed box, and the material is compacted and shaped between a lower pallet and upper stripper head which are moved to close the bottom and top of the cavity during vibration of the mold. The mold parts are retractable beneath the top plate to release the block for stripping through the bottom of a mold. A plurality of fluid outlets in the top plate communicate with problem areas of the recessed mold parts which are prone to accumulate residual block material. Pressurized clean-out fluid, such as air is directed through the outlets onto such problem areas to cleanse the mold surfaces of the block material between mold cycles.

Abstract: A device for wiping the surfaces or rotors used to portion mixed materials. The device removes adhering materials, such as cookie dough, from the cutting or metering surfaces. Typical application is for use in large automated bakeries or cookie manufacturers wishing to transport larger slabs or chunks of cookie dough from a mixer to machines which portion the dough prior for baking or freezing. The device has a wiper located proximate to the rotors. The device then moves the wiper along the rotors to release the adhering materials.

Abstract: An apparatus for producing dentures having a synthetic resin base comprises a flask tank provided with a tank closure which is opened when a flask is brought into and out of the tank and when resin is to be injected into the flask and which is closed when wax is to be removed. The flask tank has a wax pattern heater and is formed with fluid channels adapted to communicate with a resin injecting gate of the flask for successively supplying cleaning hot water, drying air and separating agent to the interior of the flask therethrough.

Abstract: A dough sheeting system having a cutter assembly for pulling and cutting elongated chunks of dough from a hopper containing dough is disclosed. A receiving surface is disposed beneath the cutter assembly. A motor advances the receiving surface in a direction of dough feed. A calendar assembly receives dough output by the receiving surface and outputs a sheet of dough. A level sensor monitors the height of accumulated dough at the input of the calendar assembly and produces a signal when the input exceeds a predetermined level. The motor is responsive to the signal from the level sensor to stop advancing the receiving surface when the level exceeds the predetermined level. A movement sensor monitors the advancement of the receiving surface to actuate the cutter assembly to pull and cut a chunk of dough when the surface has advanced a predetermined distance from the position at which the surface was positioned when a prior chunk of dough was delivered to the surface.

Abstract: A resin sealing and molding apparatus for electronic parts includes, a cleaning UV application mechanism for removing mold surface contaminants adhering to or accumulating on the mold surfaces. The UV application mechanism is mounted to be freely reciprocative to a retracted position not inhibiting an operation for supplying unsealed lead frames and resin tablets to each resin molding unit part and an operation for taking out sealed lead frames, and to a deployed or operating position close to the mold surfaces in each resin molding unit. Using this UV application mechanism especially in conjunction with a suction device, the mold surface contaminants, such as a; mold release agent contained in a resin material or volatile gas generated by heating, that adhere to or accumulate on the mold surfaces of each resin molding unit are efficiently and reliably removed.

Abstract: A hollow mounting hub is used to mount the tool to an extruder head and a plunger with a stop at one end extends longitudinally through the hub. The plunger reciprocates the plunger between a retracted position in which the plunger is housed in the hub and an extended position in which the plunger protrudes from the hub so that it may abut with extrudate lodged in an extruder head. Extrudate is dislodged in an extended position of the plunger with the stop remote from the mounting hub.

Abstract: An apparatus is provided for molding lead frames. The apparatus has a mold formed by two mold halves. An assembly for introducing a lead frame into one of the mold halves, an assembly for carrying encapsulating material into the cavities of the mold and an assembly for removing an encapsulated product from the mold are arranged on a carriage movable along a guide relative to the mold halves.

Abstract: A pelletizer particularly useful for pelletizing water-dispersible melt-extrudate, among other materials, delivered from an extruder through a die positioned in communication with the interior of the pelletizer housing. The pelletizer includes a rotor disposed inside the housing and knives mounted around the periphery of the rotor. The knives pelletize the melt-extrudate as the rotor rotates. A fluid supply system selectively delivers a fluid, such as air, to the knives when the knives are at a selected location in the housing. The selected location is preferably just past the inlet and can extend in a circumferential direction around the housing in the area of the housing which is near the outlet. The circumferential extent can vary according to the configuration of the knives and the fluid supply system.

Abstract: Apparatus is disclosed for producing thin polymeric film and includes a source (17) of a solution of polymer and solvent; a casting member (10) having an outer surface (12) for receiving a cast layer (18) of polymer and solvent, the layer having a transverse width; a casting die (16) for casting the layer of polymer and solvent onto the outer surface, the die including a transverse slot (20) with adjacent upstream and downstream lips (22, 24) between which the polymer and solvent flow during casting, the lips having lengths approximating the transverse width of the layer; and a device (11 ) for moving the outer surface past the casting die.

Abstract: An indirect extrusion press wherein a cleaning ring can be clamped with certainty by clamp members. The indirect extrusion press has a die stem, a container, a cleaning ring removably fitted at an end portion of the die stem for cleaning the inner face of the container, a loose die removably mounted at the end of the die stem, and a handling apparatus including first and second pairs of clamp members for clamping therebetween and handling the cleaning ring and the loose die, respectively. The cleaning ring has a circumferential groove formed on an outer periphery thereof. Each of the first pair of clamp members for clamping the cleaning ring therebetween has a projection formed thereon for engaging the circumferential groove of the cleaning ring.

Abstract: An apparatus for molding electronic components. The single-strip molding apparatus has a mold die formed from two mold halves which are movable relative to each other and can be closed upon one another. A leadframe for the component to be molded is placed into a recess in one of the mold halves. Molding material is heated and forced under pressure into the recess containing the leadframe. After the component is molded the mold is opened and the upper half of the mold is cleaned by a combined cleaning-discharge unit. Upon the return stroke of the cleaning-discharge unit, the molded component is removed and the lower half of the mold is cleaned.

Abstract: An electronic component is molded into a resin seal by first compressing a resin tablet to increase its density by removing air contained in the tablet. The compressed or molded resin tablet is supplied into a pot (3) wherein the tablet is melted by heat. The melted resin is injected under pressure into cavities (5a, 5b) through a transfer path (9), whereby electronic components (10) set in these cavities (5a, 5b) are seal molded. This method substantially prevents air from being mixed into the melted resin and also avoids the formation of a void within and on the surface of a resin sealed molding of the electronic components (10) encapsulated in the resin.

Abstract: Herein disclosed is a pressurized slip casting apparatus which includes an upper mold carried vertically movably on a replacer which is made horizontally movably on a horizontal rail; and a lower mold for receiving the upper mold in alignment, when the upper mold descends, to cast a slip under pressure inbetween thereby to prepare a green body of a sanitation fixture or the like. Dehydrating assembly is carried vertically movably on the replacer. A spongy member is attached to the lower end of the dehydrating assembly for absorbing the water from the inside of the lower mold. A push plate is arranged at the side of the lower mold for pushing the spongy member to dehydrate the same.

Abstract: A turret type soap molding machine has a cleaning station at which soap residue is removed from mold cavities. The cleaning station includes reciprocating brushes for cleaning the surfaces of the mold cavities.

Abstract: A CM block machine for casting masonry blocks includes a mold cavity formed between a mold box and a mold core containing one or more plungers selectively extending laterally into the cavity along a second axis which is normal to the axis of casting so as to form openings extending through portions of the block in the direction of the second axis. The plunger(s) is disposed in a cartridge housing contained within the mold core. An oversized vibrating ring wiper mounted in the cartridge housing engages the external periphery of the plunger to prevent CM material from entering the cartridge during plunger retraction. The plunger includes an annular relief chamber formed in a side wall thereof to provide an additional volume of air from within the cartridge to an air passage communicating with the plunger end face to prevent vacuum from impeding plunger retraction.

Abstract: A system for cleaning the bottom of a filled mold in a fixed surface molding process including providing a cleaning spatula in sliding contact with the surface of the mold while the mold is stationary and a device for raising the spatula above the mold when the spatula is returned to its intial position. A hopper is provided for receiving material removed by the spatula during the cleaning sweep.

Abstract: A separator manufacturing apparatus includes a transfer roller (2) with a plurality of annular shaping grooves (1) having a predetermined shape in cross section which are formed in the outer circumferential surface of the transfer roller in its circumferential direction, a resin feeding device (4) with nozzles (3) feed a hot-melt type resin to the annular shaping grooves (1) of the transfer roller (2), a base paper feeding device (5) to feed a continuous paper (W) at a predetermined speed to the outer circumferential surface of the transfer roller (2) supplied with the resin to thereby form by transfer a plurality of ribs (9) on a surface of the continuous paper (W), and a fault detecting device (6, 36, 46) to detect the shape and /or a dimension of the rib (9) formed by transfer. A resin drop receiving device (53) or an annular shaping groove cleaning device (63) may be provided so that maintenance of the transfer roller (2) can be easy.

Abstract: A food product forming device is provided with a dispensing nozzle through which the food product, in slurry form, is continually fed to the outlet end thereof where a sleeve including a cut off sleeve and an outer forming tube are mounted about the exterior of the nozzle so as to be movable towards and away from the dispensing end of the nozzle; the sleeve is provided with passages for receiving and distributing a discharging fluid to the food engaging portion of the sleeve to assist in discharging the food product from the lower end thereof.

Abstract: A method and apparatus for cleaning at least selected surfaces of a mold apparatus to remove plastic residue and surface contaminates and impurities to enable the molds to be used in a continuous in-line type process for encapsulating lead frame assemblies or similar semi-conductor circuits. After the molds are separated and the large pieces of excess plastic are broken away, they are transported to a vacuum chamber and electrically coupled as, or at least proximate, the cathode. The vacuum chamber is evacuated and an inert ionizable gas such as argon is admitted. An electrical field is established between the anode and cathode to create a plasma or glow discharge causing the gas to ionize. The positive ions are accelerated by the electrical field toward the cathode and bombard at least selected areas of the mold portion to be cleaned for removing surface contaminates and producing an extremely clean surface to enable the mold portion to be used again and again in a continuous cyclical or in-line process.

Abstract: An apparatus and method for forming components having one or more inner cavities wherein material forming the component is laid up about a number of eutectic salt mandrels corresponding to the inner cavities. The mandrels are melted and the laid up material compressed during the formation of the component by hydraulic pressure transmitted through the molten mandrels.

Abstract: A device for the continuous application of spin finishes to a spinneret as well as a process of said application are described. The device has a flat distribution body which can be attached and detached to the exit face of a spinneret. Holes are provided in the body corresponding to the spinneret orifices for melt spinning of filaments. Also the device includes a fastening member for pressing the distribution body on to the exit face of the spinneret. This member has a feeding orifice for the spin finish.The device may also include seals arranged above and below the distribution body. The distribution body may be sieve-like or consist of a perforated foil or of a foil having channel-like recesses linked with each other and an inlet orifice for the spin finish. The foil may have raised portions that serve as baffles and that are arranged in a pattern between the individual recesses.

Abstract: An injection molding device for molding shaped bodies of natural or synthetic rubber comprising a heatable mold for shaping and vulcanizing therein the bodies to be molded and an elongated feed duct communicating with the mold via an injection nozzle. Plasticized material is fed into the duct by a plasticizing device and injection is effected by a piston-type injection device, both communicating with the duct. There is provided in the duct a valve which in its closed position blocks ingress of plasticized material into the duct but opens the duct for ingress of the material to be pressed by the injection means into the mold via the nozzle. The valve head is axially displaceable in the duct and mounts a member so dimensioned that in the open position of the valve it fully closes the nozzle opening, thereby pushing any residual plasticized material into the mold and in the closed position is completely withdrawn from the nozzle opening.

Abstract: Cup handles made from clay have their seams removed by the handle being pushed along a passage of appropriate cross-section in a sponge. The sponge is washed after use by the introduction of water into the passage and by squeezing the sponge. The invention provides for the outer surface of the sponge to be treated all over to render it at least substantially impermeable to water. In use, when the sponge is squeezed, water is expelled only from the passage, and thus the uncontrolled flow of water encountered with sponges having permeable outer surfaces is avoided. Rigid plates may cover those parallel faces of the sponge into which the ends of the passage open, the plates having slots aligned with the ends of the passage. The sponges may be incorporated in a handle de-seaming machine operating cyclically.

Abstract: A spinneret cleaning device for removing deposits quickly, reliably and uniformly has an adjustable force flat plane cleaning blade.

Abstract: A process for molding a cheese piece of a desired shape comprises filling a mold having a hollow interior of the desired shape with softened, uncured cheese, cooling the mold to harden and partially cure the cheese, and then opening the mold to release the cheese piece under the surface of a cold brine so that the fluid pressure of the brine prevents the shape of the partially cured cheese piece from being distorted. An apparatus for automatically performing the described method is disclosed.

Abstract: A T-shaped extrusion die for forming transparent, uniformly thick and edge beads-free synthetic resins with a high efficiency, comprising a die body having a manifold for containing a supply of the synthetic resin in molten state and a slot-like passage for the molten resin, adjustable lips for forming a slot-like discharge orifice, inner deckles useful mainly for varying the edge thickness of the resulting extruded film, support rods for supporting the inner deckles, and inner deckle rods for regulating the width of the resulting extruded film, the inner deckles being moved by moving the support rods in the manifold in sliding contact with the surface thereof to vary the edge thickness of the resulting film, the inner deckle and inner deckle rod being kept somewhat away from each other thereby to permit free movement of the latter even under a high molten resin pressure. In one embodiment, a remover for an oxidized or scorched resin is disclosed.

Abstract: Equipment for filling molds with colored mortars to obtain cement tiles or the like, having a pattern, includes a filling station having a pair of mold partitions which can be raised and lowered with respect to the molds and which can be rotated horizontally through 180.degree. between a first position, in which a partitioned unit is aligned with a mold, which may be a multiple mold, to be filled, and a second position in which a mold unit is in an outer washing position. A batching unit is raisable and lowerable on the mold, and includes several small tanks for the colored mortars, discharge tubes emerging from the bottoms of the tanks, and batching cups that can slide in a sealed manner along the tubes and which are moved along the tubes between a position submerged in the mortar of the small tanks and a raised and emergent position, in which the mortar contained therein is discharged into the respective tube.

Abstract: A manufacturing bench for molded construction elements is disclosed comprising molds whose bottom walls are defined by an elongated table and whose lateral walls are constituted at least in part by flexible blades placed edgewise on the table which are held taut. The lateral walls are longitudinally displaceable.