Abstract: A substrate transfer method for use in a substrate processing apparatus including a first processing unit that performs a first process on a substrate, a second processing unit performing a second process on the substrate, and a substrate transfer mechanism that transfers the substrate between the first and the second processing unit, includes: detecting misalignment of the substrate when the substrate is unloaded from the first processing unit; and correcting the misalignment of the substrate based on a detected result. Further, the substrate transfer method includes loading the misalignment-corrected substrate to a targeted position in the second processing unit.

Abstract: A method is provided of manufacturing semiconductor devices formed on a semiconductor wafer, including placing the wafer in a semiconductor container and conveying the container to a semiconductor manufacturing apparatus. An opening of the container is opposed to an opening of the apparatus such that an opener of the apparatus holds a lid of the opening the container. A key of the opener is inserted to a latch groove of the lid, and the key is rotated to contact a latch of the lid. The openings are connected such that a velocity differential pressure ratio obtained by dividing the maximum velocity when the opener holding the lid horizontally moves away from the opening of the container, by the differential pressure between the inside pressure and the outside pressure of the apparatus, is set to be 0.06 ((m/s)/Pa) or less, and then the wafer is processed.

Abstract: A device and method to feed metal bars associated with a work machine including at least a drawing member for the metal bars. The device includes loading members to load one or more metal bars to the work machine, and one or more containing members in which the metal bars are disposed in respective bundles. The device also includes deflector members disposed downstream of the containing members and upstream of the drawing member, and movable laterally in independent manner with respect to the containing members, so as to be able to condition the position of at least a head portion of each of the metal bars picked up, relative to their lying position in the containing members, so as to displace them sideways one by one, or in groups, with respect to a nominal axis (X) in which the metal bars lie stationary in the respective containing member.

Abstract: An automatic wafer storage system and a method of controlling the system are disclosed. The automatic wafer storage system includes an analysis module and a storage unit. The analysis module estimates the locations between an idle equipment, a transport tool, and the storage unit, so as to control the storage unit and the transport tool to move to the best location for the transport tool to receive wafers from the storage unit. After that, the transport tool carries the wafers to the idle equipment for processing.

Abstract: An automatic transport system includes: an overhead rail module having a plurality of transport rail sets, the transport rail sets each defining a bay; a plurality of overhead hoist transport vehicles movably disposed in the overhead rail module; and a control module electrically connected to the overhead hoist transport vehicles, the control module being used to control the number of the overhead hoist transport vehicles in the bays. Via this arrangement, the control module keeps some overhead hoist transport vehicles staying in each bay, thereby preventing one of the bays from having no overhead hoist transport vehicle to immediately use. This invention further provides a control method of the automatic transport system.

Abstract: An improved apparatus and method is provided for storing semiconductor wafer carriers, and for loading wafers or wafer carriers to a fabrication tool. The apparatus preferably provides an elevated port for receipt of wafer carriers from an overhead factory transport, allows for local interconnection among a plurality of the inventive apparatuses, and enables independent loading of the factory load port and the tool load port. An inventive wafer handling method which divides a lot of wafers into sublots and distributes the sublots among tools configured to perform the same process is also provided.

Abstract: A method for reloading workpieces includes providing a manipulator having a connecting base and a plurality of grasping assemblies arranged on the connecting base, providing a plurality of original workpieces and a plurality of machined workpieces positioned in a plurality of machining positions, grasping the original workpieces by at least one grasping assembly, with at least one grasping assembly vacant, grasping one machined workpiece by one vacant grasping assembly, rotating the connecting base, so that one original workpiece is placed in one machining position by one grasping assembly, further rotating the connecting base until another vacant grasping assembly is opposite to another machining position, and repeating grasping the machined workpieces from the machining positions and placing the original workpieces on the machining positions until a last original workpiece is placed on one machining position. The manipulator used in the present method for reloading workpieces is also provided.

Abstract: A mini clean room for preventing wafer pollution includes a robot arm, a clean room body slidably disposed on the robot arm and at least one lock unit which is rotatably connected with the clean room body. During operation, the robot arm extends out of the clean room body to carry a wafer waiting to be processed, and then moves back into the clean room body which can provide an isolated and protected space for the wafer to avoid that the wafer is polluted. The present invention also discloses a method of using a mini clean room for preventing wafer pollution.

Abstract: Systems, computer program products, and methods useful for handling or managing microplates are provided.

Abstract: The invention relates to a method for transferring heavy loads, such as sheet-like objects, particularly anodes and cathodes, in electrolysis, the transfer apparatus comprising a lifting device (1) to which a stationary control housing (3) is attached; along the slide surfaces (6) of said control housing (3), there moves a control frame (5), and in said control frame there are arranged control shafts (7) along which a gripping element (8) is movable by the control surfaces (16) of said gripping element (8), so that the stationary control housing (3) is suspended from the lifting device (1) by means of at least three fastening elements (2) articulated at both ends.

Abstract: The invention relates to a device and a method for processing flat substrates (2), such as circuit boards or the like to be printed, wherein the substrate (2) can be fed resting on a transport device on two opposite side edge regions (4), can be first lifted from below for the purpose of processing by means of supports (7) and pressed against corresponding hold-down pieces (10) in the side edge regions (4), and can be clamped on the corresponding side edges (11) of the substrate (2) in this position, resting on the supports (7), between two clamping strips (13), whereupon the hold-down piece (10) can be lowered to the side away from the substrate (2) and the clamping strip (13) and further below the region of the upper side (16) of the substrate (2) thus located, whereupon full-surface processing can take place.

Abstract: An alignment tool is used to ensure proper alignment of a component on a rotating gear relative to a non-rotating platter. The alignment tool includes a first arm member coupled to a locating feature on the gear, and a second arm member that is coupled to the first arm member such that the second arm member is movable relative to the first arm member. When the first arm member is coupled to the locating feature, the second arm member locates off the platter to verify proper alignment. The second arm member is cannot be fitted to the platter when there is improper alignment.

Abstract: A system for manufacturing free-standing films from work pieces. The system includes a racetrack structure being configured to transfer at least one work piece and one or more accelerator-based ion implanters coupled to the racetrack structure via an end station. Each of the accelerator-based ion implanters is configured to introduce particles having an energy of greater than 1 MeV to implant into a surface of the work piece loaded in the end station to form a cleave region in the work piece. The system includes one or more cleave modules coupled to the racetrack structure configured to perform a cleave process to release a free-standing film from the work piece along the cleave region. Additionally, the system includes an output port coupled to each cleave module to output the free standing film detached from the work piece and one or more service modules each connected to the racetrack structure.

Abstract: A substrate processing apparatus includes a main load unit, a buffer load unit, and a transfer unit. Containers each accommodating substrates are placed on the main load unit and the buffer load unit. The buffer load unit is disposed above the main load unit and movable into and outward from a process module. Therefore, more containers can be placed in the substrate processing apparatus without increasing the footprint of the substrate processing apparatus, and thus it is possible to reduce equipment idle time during which standby substrates wait before being processed, thereby improving productivity.

Abstract: A two-piece reinforced container is provided. The container includes an outer structure and an inner structure. The outer structure includes front and rear panels that are coupled to each of a first side panel and a second side panel via at least one corner panel. The corner panels extend from the front panel, the rear panel, the first side panel, and the second side panel at a substantially oblique angle. The inner structure includes front and rear panels that are coupled to each of a first side panel and a second side panel via at least one corner panel. The corner panels extend from the front panel, the rear panel, the first side panel, and the second side panel at a substantially oblique angle.

Abstract: Methods, apparatuses and systems are provided that may be used in performing controlled environment processes on substrate items within in at least one chamber A plurality of substrate items may be arranged at each of a plurality of horizontal levels within a vertically oriented stack of a substrate item holding assembly and moved into a reactor chamber and/or other like chamber and processed.

Abstract: A method of transferring air cargo loading units (12) between a publicly accessible operational zone (A) and a security-sensitive apron zone (B), including a stationary transfer and security checking system (10) which comprises a first transfer device (22), a second transfer device (24), and a cargo lock (14) in between, the cargo lock (14) including a lock chamber (16) which is connected to the first transfer device (22) via a cargo entrance gate (18) and to the second transfer device (24) via a cargo exit gate (20), includes the following method steps: a) the air cargo loading units (12) are delivered by a road or rail transport means (28) via the publicly accessible operational zone (A); b) the cargo entrance gate (18) is opened with the cargo exit gate (20) in the closed condition; c) the air cargo loading units (12) are transported into the lock chamber (16) by means of the first transfer device (22); d) the lock chamber (16) is separated from the publicly accessible operational zone (A) by closing th

Abstract: A system and method is provided for transporting wafers in wafer carriers to a fabrication tool. The system provides an incoming carrier location adapted to receive a wafer lot carrier containing a wafer lot, a divider mechanism adapted to divide and place the wafers into a plurality of sublot carriers wherein each sublot carrier includes a fewer number of wafers than the wafer lot carrier, and a transfer mechanism adapted to transfer the plurality of sublot carriers. Inventive wafer handling methods, which divide a wafer lot into wafer sublots and distributes the sublots among tools configured to perform processes on the wafers is provided. Apparatus adapted to divide the wafer lot into sublots are also provided, as are other aspects.

Abstract: An end effector for a robot having an array of suction cups includes an air control valve connected to each suction cup. Each valve can be individually operated so that specific zones of suction cups may be activated while others are dormant. The dormant suction cups are closed to the sub-atmospheric pressure, so that leakage of air through unused suction cups is avoided, while only the suction cups of the selected zone perform the picking of the work products. This allows the end effector to provide accurate and constant sub-atmospheric pressure to the work products during the picking process.

Abstract: The invention relates generally to a roofing shingle apparatus and more particularly to an improved such apparatus for high speed shingle making generally when handling a double shingle line (one line overlaid on the other with the high side of each line on opposite sides to make a single mostly even thickness) in a more compact arrangement from the cutter to the stackers and catchers, but not limited to a slower single line of shingle making that uses a flipper at the discharge of the catcher shuttle and not limited to a four wide overlaid to four thicknesses of shingles in one line and scissor cut, not described in detail herein, before entering a single line delivery belt section.

Abstract: A substrate transfer apparatus comprising: a plurality of floating-transfer guide plates adjacent to each other, each of guide plates having a plurality of floating gas ejecting holes; a gas supplying source; a tray to mount a substrate to be transferred, and that is floated by the floating gas; and a transfer arm for transferring the floated tray from the guide plate to the adjacent other guide plate, wherein the tray includes both side edges, and a contact/engagement portion formed at the respective both side edges for the transfer arm, each of the transfer arms including a base portion that can horizontally reciprocate along a rail provided so as to be parallel to the transfer direction, a guide portion provided to the base portion, that can horizontally reciprocate in a direction orthogonal to the transfer direction, and an arm portion provided to the guide portion, that can horizontally reciprocate in the direction parallel to the transfer direction.

Abstract: A laboratory storage and retrieval system and a method to handle laboratory sample tubes are disclosed. The laboratory storage and retrieval system for storing sample tubes and retrieving stored sample tubes comprises a rack handler section (12) and a storage section (14), the rack handler section (12) comprising a transport system and a determination unit, wherein the transport system receives and transports incoming primary racks (PR) containing sample tubes (S) to the determination unit for determining at least one given parameter of the sample tubes (S) relating to predetermined sort criteria in order to have the transport system unload the sample tubes from the analysed primary rack (PR) and resort the unloaded sample tubes into appropriate storage racks (SR) depending on the determined sample tubes' sort criteria parameter for storage in the storage section (14) in the storage racks.

Abstract: Devices and methods for successively transporting a plurality of cards arranged in a row, in particular GSM chip cards, between at least one feed path and a first tray element which can be displaced perpendicular to the orientation of the feed path, by means of at least one transfer station within a card processing device, wherein the transfer station comprises at least two transport elements for picking up and depositing individual cards, said transport elements being able to be rotated about a respective axle running perpendicular to the plane of the feed path and of the first tray element, wherein the transport elements can be moved back and forth along the orientation of the first tray element and a second tray element which can be displaced in the direction of the first tray element.

Abstract: The invention relates to methods and apparatus in which a plurality of ALD reactors are placed in a pattern in relation to each other, each ALD reactor being figured to receive a batch of substrates for ALD processing, and each ALD reactor comprising a reaction chamber accessible from the top. A plurality of loading sequences is performed with a loading robot. Each loading sequence comprises picking up a substrate holder carrying a batch of substrates in a storage area or shelf, and moving said substrate holder with said batch of substrates into the reaction chamber of the ALD reactor in question.

Abstract: A device for providing support to an LCD and its corresponding components during various manufacturing steps. A first carrier section is positioned on a work surface and is then loaded with an LCD as well as drivers to be bonded to the tabs of the LCD. Once the desired work has been performed a second carrier section is mated with the first carrier section and a closing means is utilized to position the two carrier sections in a closed position. Once the two carrier sections have been placed in a closed position about the LCD and other components, the entire piece may be safely removed from its position on the work surface for further processing, storage, etc. Exemplary embodiments also relate to a method of providing support to an LCD and its corresponding components during various manufacturing steps.

Abstract: A method of operating a production line comprises the steps of supporting equipment in the production line on a plurality of crawlers comprising at least one rolling track and a structural support for supporting the equipment. A first plurality of lifting magnets coupled to an interior surface of said at least one rolling track is configured to oppose a second plurality of lifting magnets coupled to an exterior surface of said structure support to lift the structural support, such that the structural support floats between and within said at least one rolling track. The magnetic fields experienced by the first and second plurality of lift magnets are adjusted to translate the at least one rolling track, such that the crawlers move along the production line.

Abstract: A shuttle is disclosed in which a large-sized substrate is prevented from sagging under its weight or from slipping. The shuttle includes a body, support pins supporting sides of the substrate, and shuttle arms provided to sides of the body to rotate in an axial direction and move in a right-to-left direction. The support pins are coupled with the shuttle arms, respectively. A pair of center supports support center parts of sides of the substrate not supported by the support pins. The center supports are movably coupled to a main frame in a front-to-rear direction. A driving unit moves and rotates the shuttle arms in the right-to-left direction. The driving unit moves the center supports in the front-to-rear direction using the main frame. A vacuum instrument assembly is provided to each of the support pins to securely hold the substrate by a vacuum force.

Abstract: A carrier for a semiconductor device includes a body having an opening formed therein to receive the semiconductor device and a pair of rollers to hold the semiconductor device between the rollers in the opening.

Abstract: In stacking tray supplying for receiving in a stacked state a plurality of trays that are received in a state in which components to be mounted onto a board are aligned, two tray stages are provided rotationally transferably on a concentric circle. In a state in which one is positioned in a feeding tray placement position and the other is positioned in a standby tray placement position, components are fed from the tray stage positioned in the feeding tray placement position. When a component depletion state occurs, the tray stages are rotationally transferred to switchover the mutual placement positions, by which waste of time required to component feeding is reduced.

Abstract: A plate handling system for a sampling device with a drawtube that includes a vertical actuation system that adjusts the vertical distance between the drawtube and a sample tray, a horizontal linkage system that positions a sample tray in a horizontal plane, and a drive system that drives the rotational motion of the horizontal linkage system. The horizontal linkage system includes a base arm that rotates about a base joint, and a sample arm that rotates about a sample arm joint on the base arm.

Abstract: A modular paint line includes a plurality of modular stations positioned in series and defining a transportation path. At least one of the modular stations includes an immersion tank. The paint line also includes means for moving at least a first carrier in a forward transport direction along the transportation path while maintaining at least a second carrier in a stationary position, above the immersion tank, along the transportation path. The aforementioned means includes an article transportation system having a plurality of carrier tracks.

Abstract: A biological reaction apparatus for receiving at least one substrate having a sample located in a sample region, and a separate cover, such that a reaction chamber is formed between the cover and substrate over the sample region, wherein the apparatus includes a locating means to locate the substrate; a cover locating means for locating and moving the cover with respect to the substrate; a fluid dispensing means for dispensing fluid into the reaction chamber; and a draining mechanism; wherein the draining mechanism includes wicking means.

Abstract: A substrate processing apparatus includes a main load unit, a buffer load unit, and a distribution unit. The main load unit is disposed at a front side of the process module for receiving a plurality of containers each accommodating substrates. The buffer load unit receives a plurality of containers, and the distribution unit transfers a container between the main load unit and the buffer load unit. The substrate processing apparatus includes the buffer load unit as well as the main load unit, and the distribution unit is used to transfer a container between the main load unit and the buffer load unit. Therefore, substrates can be transferred to the substrate processing apparatus with less time, and thus productivity can be improved.

Abstract: A method and apparatus for producing and/or machining panels. The apparatus includes a transport device for transporting a panel along a transport path and a machining device for machining the panel as it moves via the transport device. The transport device includes a plurality of positioning devices arranged one behind the other and spaced apart by a distance along the transport path. Each positioning device includes upper and lower abutment mechanisms arranged opposite one another and on opposite sides of a panel plane, and being spaced apart by a distance. An adjusting device is used for setting the distance between the upper and lower abutment mechanisms. An actuating arrangement is structured and arranged to actuate the adjusting device of at least two of the plurality of positioning devices. An arrangement is used for independently adjusting each of the upper and lower abutment mechanisms of at least one of the plurality of positioning devices.

Abstract: A coating system comprises a swing station including a swing module and an arrangement of chambers. The arrangement of chambers comprises a lock chamber and a first coating chamber. The lock chamber is configured as a combined lock-in/lock-out chamber. The arrangement of chambers has a first substantially linear transport path indicated by dashed lines, and a second substantially linear transport path indicated by dashed lines. The arrangement of the paths establishes a dual track. The system includes a transport system for moving a substrate through the arrangement of chambers, along the first transport path and/or along the second transport path as indicated by arrows. One or particularly both chambers comprise transfer means for transferring the substrate/carrier from the first path to the second path by a lateral movement and/or from the second path to the first path.

Abstract: Introduction of substrates into vacuum environment is accomplish by gradually reducing the number of substrates being transferred simultaneously as the clean and evacuated environment is progressed. Cassettes are maintained in clean atmospheric environment and do not enter the vacuum environment. Several vacuum locks are linearly staggered so as to introduce progressively higher level of vacuum environment. The number of substrates transported through this arrangement is a portion of the number of substrates present in each cassette. The staggered vacuum locks lead to a series of processing chambers, wherein a yet smaller number of substrates, e.g., one or two, are transported.

Abstract: A cassette stocker includes a plurality of cassette storage shelves positioned adjacent a cleanroom wall above a cassette docking station, and a cassette mover to carry a cassette between the shelves and the docking station. An interstation transfer apparatus includes an overhead support beam and a transfer arm adapted to carry a cassette between processing stations.

Abstract: While a vicinity of a bottom surface-side region of a pressure-sensitive adhesive sheet, corresponding to an adhesion region of a semiconductor chip, is sucked and held, a plurality of protruding portions of a removing member are brought into contact with the bottom surface of the semiconductor chip through the adhesive sheet at the adhesion region. Also, the adhesive sheet is sucked in between the respective protruding portions so as to change an adhesive surface bond of the semiconductor chip to the adhesive sheet to point bonding. Further, the removing member is moved along the bottom surface of the semiconductor chip so as to change the position of the point bonding and decrease the adhesive bonding force to the adhesive sheet. Then, the semiconductor chip is removed from the adhesive sheet.

Abstract: A plurality of substrates is transported to accurate positions, while mounted on one hand of a transport robot. When the substrates are to be transported from a transporting chamber into a processing chamber, a first mounting portion of a hand is located immediately above a first processing position provided in the processing chamber; and the substrate placed on the first mounting portion is lifted up. Then, a second mounting portion is located immediately above a second processing position by finely moving the hand. Next, the substrate on the second mounting portion is lifted up. When the hand is pulled out from between the substrates and the first and second processing positions and the substrates are lowered, the substrates are accurately arranged on the first and second processing positions. When the substrates are mounted on the hand in an order reverse to the above, the substrates in the processing chamber can be accurately mounted on the first and second mounting portions and be carried out.

Abstract: A control system for transferring a sample from a source vessel to a target vessel generally includes a vessel unit, a primary transfer unit, an x-drive, a y-drive, a z-drive and a control unit for controlling the drives. The vessel unit includes a support plate for supporting the source vessel and the target vessel thereon and the transfer unit includes at least one transfer device for transferring the sample from the source vessel to the target vessel. The x-, y- and z-drives reciprocally translate one of the support plate and the transfer device in a respective x-direction, y-direction and z-direction, wherein the x, y and z directions define a three axis Cartesian coordinate system.

Abstract: A storage device processing system that includes at least one automated transporter, at least one rack accessible by the at least one automated transporter, and multiple test slots housed by the at least one rack. Each test slot is configured to receive a storage device for testing. The storage device processing system includes a conveyor arranged in a loop around and being accessible by the at least one automated transporter. The conveyor receives and transports the storage device thereon. The at least one automated transporter is configured to transfer the storage device between the conveyor and one of the test slots of the at least one rack.

Abstract: In order to make it possible to reduce the occurrence of physical damage to wafers during conveyance, a state is established in which wafers W are contained in a wafer cassette 1 standing approximately vertically, and the wafer cassette 1 is conveyed, in this state in which the wafers W are contained in the wafer cassette 1 standing approximately vertically, so that the planes of the wafers W are approximately parallel to the direction of conveyance. Since the wafers are kept in the state of standing approximately vertically, it is possible to reduce the occurrence of bending, as happens when they are held horizontally.

Abstract: A forklift assembly is mounted to a robotic bomb disposal vehicle. The forklift assembly includes at least one fork, and may be coupled via a receiver hitch to the vehicle. In one embodiment, the receiver hitch is positioned between articulating arms located on the vehicle, permitting vertical movement of the forks. An explosive countermeasure is positioned on the forks. With the countermeasure so positioned, the vehicle may be caused to travel proximate a vehicle suspected of having an explosive device therein. The countermeasure may then be lowered onto the ground at a desired position proximate the suspect vehicle, and the robotic bomb disposal vehicle withdrawn from the site.

Abstract: Converting systems including stacking and casing modules are provided. Stacking modules permits rapid and reliable stacking of boxes having a wide variety of shapes and sizes, such as straight-line and auto-bottom boxes. Stacks may be formed with layers arranged in varying orientations, having varying numbers of boxes. Casing modules operate to load one or more stacks of product, which again may have varying shapes and sizes, into cases.

Abstract: A method and apparatus for welding motor vehicle body component subassemblies at a weld station. First and second pallets are arranged for reciprocal movement between a load/unload station and the weld station and the pallets are alternately moved from a load/unload station to the weld station while the other pallet is moved from the weld station to a load/unload station. Each pallet has a plurality of substations for receipt of component subassemblies and, while each pallet is at the load/unload station, the component subassembly at each substation is moved to the next successive substation and a further component is added to the moved component.

Abstract: In order to ensure reliable feeding in particular of a clinch nut (M) from a ready position (16) into a processing position, the processing tool designed as a press-in tool (2) has a guide element (14), through which the clinch nut (M) is pressed into the processing position by means of a punch (8) against an elastic holding force exerted by the guide element (14). The guide element (14) is designed in particular as a slotted bush and is arranged as an insert in a hold-down (12).

Abstract: The present invention is related to a method for transferring substrates. The method comprise simultaneously transferring two substrates, by means of a transfer unit, between first support plates disposed to be vertically spaced apart from each other and second support plates arranged abreast in a lateral direction. The transfer unit comprises a top blade and a bottom blade converted to a folded state where they are vertically disposed to face each other and an unfolded state where they rotate at a preset angle in opposite directions. The transfer unit place/take a substrate on/out of the first support plates under the folded state and place/take a substrate on/out of the second support plates under the unfolded state.

Abstract: An improved apparatus and method is provided for storing semiconductor wafer carriers, and for loading wafers or wafer carriers to a fabrication tool. The apparatus preferably provides an elevated port for receipt of wafer carriers from an overhead factory transport, allows for local interconnection among a plurality of the inventive apparatuses, and enables independent loading of the factory load port and the tool load port. An inventive wafer handling method which divides a lot of wafers into sublots and distributes the sublots among tools configured to perform the same process is also provided.

Abstract: A cluster apparatus for processing a substrate includes a load-lock chamber to receive a substrate, a transfer chamber adjacent to the load-lock chamber, one or more processing chambers each having a side facing the transfer chamber, and a robot in the transfer chamber to unload the substrate from or load the substrate into at least one of the one or more processing chambers or the load-lock chamber. A rotating stage is included in the load-lock chamber to support and rotate the substrate to a desired orientation.

Abstract: A testing device to test a plate for electronic circuits, comprising transport members able to transport the plate along an axis of feed (Y), at least from an entrance station to a testing station defining a testing plane (P?), and testing members, disposed in correspondence with the testing station. The testing device also comprises an alignment station defining an alignment plane (P), disposed upstream of the testing station, and alignment members, disposed in correspondence with the alignment station, able to dispose the plate in an aligned position, in which the plate is disposed symmetrical both with respect to the axis of feed (Y) and also with respect to a first axis (X) substantially transverse and co-planar to the axis of feed (Y).