Abstract: A sealing device for a raisable-curtain warehouse door, the door comprising a curtain and a rigid frame having two vertical lateral uprights, 1,2 interconnected at their top ends by a downwardly-open channel-section cross-member 3 having a web 4, and two flanges, 5,6 and housing mechanical members for operating the curtain, the curtain being capable of being lowered or raised between the uprights. The highest portion of the curtain is situated at a certain distance below the web of the cross-member, below any mechanical members that may be below the cross-member, and a cover, 15;35 having two parallel longitudinal edges, namely a top edge and a bottom edge, is fastened via its top edge to the bottom edge of one of the flanges of the cross-member, and is maintained in an orientation such that its bottom edge is placed against the top portion of the curtain so as to provide continuous closure between the cross-member and the curtain.

Abstract: A rolling shutter for a roof or wall window includes an apron, a shaft for rolling up and unrolling the apron, and two spaced lateral supports fixed with respect to the window for rotatably supporting the shaft. Two parallel side parts are rotatably supported in the two supports for rotation about an axis extending parallel to the shaft. The two side parts include guides for guiding the apron in rolling-up and unrolling movements thereof. The guides have rear extensions facing the shaft. An upper trim extends between the two side parts and is connected thereto for covering the apron from above. The rear extensions of the guides are spaced in all rotational positions of the two parts, from the shaft axis a distance substantially corresponding to a maximum radius of the shaft. The guides and the shaft define a space such that the apron can move freely therein without being damaged.

Abstract: A roll-up or curtain type door is disclosed which is for use in large doorways, the door having an improved support apparatus, an improved spring mounting mechanism, and a unique bearing block which also functions to support the door as it is rolled up. The roll-up door has a substantially stronger hollow hexagonal barrel assembly which is less susceptible to flexural stress, and a spring mounting arrangement which allows the springs to shrink or grow longitudinally as the door is rolled up or down. The barrel assembly is mounted on pivoting support means allowing the barrel assembly to move away from and toward the guide tracks as the door is rolled up and down, whereby the variation in diameter of the barrel assembly does not affect the performance of the door.

Abstract: A shutter assembly for a bay window to close an opening by moving a shutter curtain upward from a containing space in the bottom of the bay window and to open it by way of a downward movement of the curtain under the influence of a coil spring. The basic driving system for the shutter is located either in the roof or in the lower containing space of the bay window. Various devices are disclosed including a seal for sealing the space between the leading member of the curtain and the roof of the bay window, a structure for installing the driving motor, a structure for detachable connection of the driving shaft, hainging members used to raise and lower the curtain, a structure for supporting the winding drum on the driving shaft, as well as features to allow maintenance of the shutter assembly.

Abstract: An articulated door covers storage bays of a beverage body. The articulated door is formed by engaging a plurality of polymeric panel sections into a sequence such that a hinge is formed between adjoining panel sections. Each hinge allows adjacent panel section to be positioned at varying angles with respect each other. A resilient sealant bond between adjacent panel sections is made at spaced locations along each hinge. The articulated door is guided between an open position and a closed position by a door guiding track comprised of a left channel facing a right channel across a door opening. The sequence of panel sections is slidably positioned in the door guiding track by having a left end of each panel section extending into the left channel and a right end of each panel section extending into the right channel.

Abstract: The present invention relates to a shutter which is capable of ventilating air in a building. There is provided a slat, which has a through-hole covered with a net, in the upper section of the shutter; there is provided a slat, which is capable of adjusting the amount of ventilating air, in the lower section of the shutter. With this combination, fresh air is able to enter the building from the lower slat and air inside is able to flow out from the upper slat when the lower slat makes possible to ventilate.

Abstract: A drive mechanism for an industrial door. A rotatable drive member is operably connected to the door and rotation of the drive member in one direction through operation of a motor will move the door to the closed position while rotation of the member in the opposite direction will move the door to the open position. A clutch mechanism interconnects the motor and the drive member and is movable between an engaged and disengaged position. The clutch mechanism is biased to the engaged position, and by manually pivoting an actuating member that is connected to the clutch mechanism, the clutch mechanism can be moved to the disengaged position, and is retained in the disengaged position until manually released. A switch is operably connected to the motor, and when the actuating member is pivoted to a position to disengage the clutch, the switch will be actuated to shut off power to the motor.

Abstract: A manually operated roll door. The door comprises a flexible door panel that is coiled on a drum located above the header of a doorway in a building, and the door panel is manually movable between an open position where the door panel is coiled on the drum, to a closed position where it encloses the doorway. A latch mechanism is associated with the door panel and automatically latches the door panel in the closed position. A handle is attached to the lower end of the door panel and the handle is connected to the latch mechanism in a manner such that an upward pull on the handle to open the door panel will simultaneously release the latch mechanism. A counterbalancing weight is operably connected to the door panel and partially counterbalances the weight of the door panel to aid in manually moving the door panel to the open position.

Abstract: A rolling security shutter system is provided with improved structure for resolving security, alignment and tracking problems in rolling shutters employing an interconnected set of slats. Problems of insecure mounting and interfitting of housing assembly elements precisely enough that there is no misalignment or binding of the slats as the shutter is opened and closed are resolved inpart by integrally cast single element sideframes mounted by means of mounting bars interfitting into integrated guided slot brackets. The slats are guided into alignment with the tracks by means of frictionally inserted guides held by the sideplates. Connection of slats to the roller core by a flexible spring panel improves salt to track alignment and security against forced entry. Hood strengthening support structural mounts register housing members for better slot alignment and strength and ease of dismount. Improved spring clip slat reinforcement bar retainers assure slat rigidity and alignment.

Abstract: A cabinet includes a rigid housing having an opening at the forward side thereof with vertical guide tracks defined at opposite sides of the opening. A roller subassembly is mounted in the upper portion of the housing over the opening and is driven in rotation about a horizontal axis by a motor. A segmented glass curtain made up of contiguous, elongated, parallel glass slats of rectangular configuration closes the opening in the housing. Each glass slat is supported in metal corner brackets interconnected so that adjacent longitudinal edges of adjacent slats are in close proximity, and the slat ends project into the guide tracks. Flexible cables interconnect the corner brackets to maintain the spacial relationship of the slats. Ends of the cables are connected to the roller subassembly and the curtain is rolled up on the roller subassembly to open the opening in the housing.

Abstract: A cover for an open-bodied truck is movable between retracted and extended positions. A pair of guides are mounted on the side walls of the open body, and a cover assembly includes a plurality of rectangular panels linked to one another and extending across the open body. End portions of the panels are slidably mounted in the guides. A drive mechanism is provided for translating the cover assembly between the retracted and extended positions, and an enclosure is mounted at the forward end of the open body for receiving and storing the cover assembly in its retracted position. The tailgate of the open body is maintained in a closed and locked condition when the cover assembly is in its fully extended position.

Abstract: An apparatus configured for maintaining a barrier in a position against a trans-barrier force less than a predetermined magnitude. The barrier has associated structures for cooperating with the apparatus to define the position in which the barrier is maintained.The apparatus comprises a guide follower attached to the barrier and operatively interactive with the associated structures for defining the barrier position. The guide follower of the apparatus comprises a first portion attached to the barrier and a second portion operatively interactive with the associated structures. The first portion and the second portion are in an interfitting relation and define at least one pair of mating surfaces, each of which mating surfaces is transverse to the barrier and oriented to allow sliding disengagement of the first portion and the second portion in response to application of a trans-barrier force to the barrier in excess of a predetermined magnitude.

Abstract: A rolling shutter for wall or roof openings, especially in connection with a turnable roof window comprises a rolling shutter web composed of a plurality of rolling shutter elements pullable from one another for forming light gaps, a rolling shutter shaft for winding and unwinding of the rolling shutter web, supports for rotatably supporting the rolling shutter web, two parallel side walls connected with the supports for guiding lateral ends of the rolling shutter webs, an actuating device having a mechanism for an opening movement of the rolling shutter web and a pulling device engaging a free front end of the rolling shutter web and supporting or performing its closing movement, the rolling shutter elements including a front rolling shutter element and a rear rolling shutter element, a pulling rope connecting the front rolling shutter element and the rear shutter element, the pulling rope being fixedly connected with the rear rolling shutter element and being connected with the front rolling shutter element

Abstract: An improved slat assembly and curtain for a rolling door assembly employing the improved slat are provided. The slat assembly has a primary slat with a lower bead having a downwardly facing cavity which is used to retain an elastomeric sealing strip which seals the space between adjacent interlocked slats in the curtain. The slat assembly may be provided with a backer slat and material filling a void between the primary slat and backer slat to improve the thermal insulation and/or acoustical insulation and absorption properties of the slat assembly and curtain.

Abstract: Disclosed herein is a sheet shutter which is a shutter of the type in which a sheet-form shielding material is lifted and lowered to be used as a partition of the entrance or passage of factory, warehouse or the like. The sheet shutter comprises (a) a pair of sheet guides erected parallel with a predetermined spacing therebetween, each sheet guide having an uppr end; (b) a sheet case provided between the upper ends of the sheet guides; (c) a take-up drum rotatably supported within the sheet case, the take-up drum having an interior space; (d) a flexible sheet having a top edge and both of side edges, the both side edges being guided by the sheet guides in such a manner that the flexible sheet is lifted and lowered, and the top edges being attached to the take-up drum; and (e) a motor for rotationally driving the take-up drum, and motor being fixed to the sheet case and accommodated in the interior space of the take-up drum.

Abstract: A safety device, particularly intended to be used in roll-up doors to cause reversal of the door closing movements in case an obstacle obstructs the path of movement of the door. The device comprises at least a couple of photoelectric cells which are arranged at a certain distance from the closing edge of the door leaf in alignment with the door leaf on a support arm which is displaceable in the direction of closing of the door.

Abstract: In a tambour door opening/closing apparatus, a tambour door is moved along a longitudinal axis between open and closed positions under restraint of a frame guiding opposed sides of the door. A constant spring is mounted to the tambour door and has a section thereof extending generally along the longitudinal axis to assist in moving the tambour door between the opened and closed positions. A fixed rod is mounted between the frames guiding both sides of the door and a spool is rotatably mounted on the rod with the spring being coiled around the spool and the exposed end of the constant spring is attached to the tambour door. A track assembly is mounted on each side of the frame for guiding the movement of the tambour door and includes a substantially straight portion extending substantially the length of the opening and a loop portion with a coiled track for forming coils of the tambour door.

Abstract: A roll-up or curtain type door is disclosed which has modular components which are interchangeable for use on either side of the door, thereby reducing significantly the number of parts which must be manufactured for the door. The number of hardware items is also reduced significantly by designing components which slide together in a secure locking fashion, resulting in better ease of assembly and installation. In one embodiment, the roll-up door of the present invention is used to secure a storage unit with shelves.

Abstract: A power assist device for raising and lowering an independent band spring door is disclosed. The present invention includes a prime mover, an operator controlling the prime mover, a band spring cage, and a roller chain gear set mechanically connecting the operator to the band spring cage so that there is no back lash in the gear set.

Abstract: A security door system using a roll-up door fabricated of curtain sections reinforced by extruded metal cross beams. The system is designed for installation in a closet doorway or the like to provide security for valuables which may be stored in the closet or to keep dangerous implements, such as guns, away from children in a household, and the like. The door has a slide lock with a re-lock assembly for back up in the event that the primary key lock is broken. The door is designed for shipment in kit form and includes a number of door track sections with mating splices for joining the sections together. The design and construction of the system provide a low cost solution to the problem of developing secure storage within a residence, school, business establishment or the like in a unit which is aesthetically pleasing in design and is inexpensive to purchase and install.

Abstract: A retractable truck bed cover comprising a plurality of relatively narrow slats (12--12) which are rotatably interfitted together along their longitudinal edges by means of mating elements (26,28) so that the cover is flexible in its longitudinal direction. The slats include wheels (64) which extend from the opposite end edges thereof and which are mounted for rotation. The wheels are received into opposing side rails (36,38) which are mounted along the top edges of the truck bed. A cover retracting mechanism (18) is positioned adjacent the cab of the truck, and includes two vertical end pieces (100,102), on facing surfaces of which is located a shallow spiral track (108), which receives the wheels (64) of the succession of slats comprising the cover, permitting the cover to be conveniently rolled up upon itself.

Abstract: A roll shutter for roof windows, particularly of the hinged casement-type construction, including a roll shutter draw mechanism having two cords, one end of each of which is attached to the lower end of the roll shutter plating. The ends of the two cords are connected to a common cord which after being guided over stationary diverting elements is guided to a drivable spool. In addition, the roll shutter draw mechanism includes a length compensating device having a diverting element which can slide against the force of an elastic member and over which the two cords are guided in tandem. The length compensating device has at least one additional diverting element which can slide together with the slidable diverting element, and the cords are guided in their path from one slidable diverting element to the next by passing over a stationary diverting element.

Abstract: The invention provides a roll up closet door in a tubular housing. Spring or electrical roll up and roll down assist mechanics are included and the door housing is extendable to fit a variety of household closet door widths.

Abstract: A security door system using a roll-up door fabricated of curtain sections reinforced by extruded metal cross beams. The system is designed for installation in a closet doorway or the like to provide security for valuables which may be stored in the closet or to keep dangerous implements, such as guns, away from children in a household, and the like. The door has a slide lock with a re-lock assembly for back up in the event that the primary key lock is broken. The door is designed for shipment in kit form and includes a number of door track sections with mating splices for joining the sections together. The design and construction of the system provide a low cost solution to the problem of developing secure storage within a residence, school, business establishment or the like in a unit which is aesthetically pleasing in design and is inexpensive to purchase and install.

Abstract: A windstrap secured to a lightweight, pliable, roll-type overhead door across the width thereof reinforces the door structure maintaining it in position across a doorway when the door is in the lowered, extended position and isolating the two areas on respective sides of the door when there is a pressure differential therebetween such as due to wind.

Abstract: A shutter assembly of the type capable of being rolled upon itself and accordingly positionable between a stored position on a rotatable shaft, preferably within a housing, and a covering position relative to an opening, such as a window, door, etc. in a building. The shutter assembly includes a barrier structure comprising a primary portion and at least one separable barrier segment spaced from a free end of a primary portion and positionable at various locations along the track assembly in covering relation to various portions of the building opening. The folding awing uses the shutter assembly components as well as a folding hinged track assembly which allows variable positioning of the awning.

Abstract: A shutter control apparatus is disclosed for providing an auxiliary power source to drive a shutter motor. A double-pole, double-throw switch selectively connects an electric shutter motor to a primary electrical source of power or, when the primary source of power is interrupted, is switched to connect a self contained auxiliary power source to the shutter motor so as to permit extension and retraction of the shutter door.

Abstract: Awning with a canopy consisting of several strips (18) extending in the direction of extension which are rolled up on one and the same canopy roller.The longitudinal edges of the strips (418, 518, 618) can overlap one another, and the strips (418, 518) can be attached on the canopy roller (13, 113), offset with respect to one another in the circumferential direction thereof, while being connectible to one another along their longitudinal edges by the use of a fastening device such as a bristle trim or the like (23, 24), or with the edges adjacent each other without overlapping, whereby the edges can be released or separated by the application of wind pressure.

Abstract: Trailer doorposts are provided with removable tracks for rollers of vertically sliding doors. The tracks are provided with removable plastic inserts upon which the rollers travel. Weather stripping on the inside faces of the outer end wall of the tracks provide a seal between the doors slidable in the tracks.

Abstract: A rolling door drive assembly including a chassis, a final drive unit rotatably mounted to the chassis for operating the door, a motor fixed with respect to the chassis, a drive device interconnecting the motor and the final drive unit, a housing defining a mounting channel on the assembly remote from the final drive unit, the mounting channel extending transversely to the axis of rotation of the final drive unit and adapted to receive part of a mounting bracket, and a mounting member extending into the mounting channel in a direction parallel to the axis for engagement with the mounting bracket.

Abstract: A deployment and retraction arrangement for a slot cover which is adapted to cover or seal a longitudinally extending slot or space present between at least two adjacent located membranes or panels. More particularly, the arrangement is a rollable deployment and retraction arrangement for selectively deploying and retracting a slot cover employed for covering a slot or space present intermediate two adjacent membranes or panels so as to, preferably, prevent any FR leakage through the slot during radar operation of the panels.

Abstract: A rolling shutter for being pivotably mounted on a roof window. The rolling shutter is provided with an apron, a shaft on which the apron is wound and from which it is unwound, another shaft for winding and unwinding the apron, a guide located between the two shafts, and a damping element; the damping element serves to maintain the rolling shutter in the position to which it is pivoted. The guide reverses the winding direction of the apron between the two shafts.

Abstract: A roller shutter is described which has a roller (13) arranged with its axis vertical, so that the shutter curtain (10) is extended laterally in use. The weight of the curtain (10) is supported in the extended condition from a top track (14) having internal running surfaces (35) co-operating with roller wheels (34) of a top chain (29), to which the articulated laths (11) of the curtain are, in turn, attached. Constant tensioning means (18-25) are provided for the curtain, which can follow a straight, angled or curving path. The bottom chain (9) of the curtain may have depending skirts (42), interfitting (at 43, 45) to reduce fire penetration. A lead-in guide (50) of the roller housing (12) has a lifting ramp (53) co-operating with ball glides (38) of the bottom chain to lift the curtain (10) gently onto, and off, the top track (14) running surfaces (35) on leaving and re-entering the housing (12).

Abstract: An improved rolling steel door of the type having interlocking steel slats, each slat being hinged to the slat above and below it. An improved method of holding the slats in vertical alignment with one another utilizes a pin affixed to the lower end of each slat. The pin has an enlarged head which abuts the edge of the adjacent slat. A spring module is readily removable from the rolling steel door assembly to facilitate the replacement of a broken or inoperative spring.

Abstract: In a roller blind with an armor (3) comprising lamellae (4, 4') which may be moved in guiding rails (5) at the side over a deployment length and which can be rolled on or off a take-up roll (2) disposed in a roller-blind housing (1), the free end of a material or coarse-screen blind (6), which is rolled up under the tension of a spring on a roll (7) that in turn is accommodated in a blind housing (8), is fastened to the last lamella (4') at the free end of the armor (3) and the blind housing (8) is disposed below the last lamella (4') of the armor (3). Moreover, the blind housing (8) can be moved over the deployment length (L) of the armor (3), can be locked in position at any height by means of a locking mechanism (10, 11) and, when not in the locked position, is pressed by the tension of a spring in set contact with the last lamella (4').

Abstract: An enclosure assembly including a frame having guides for positioning a plurality of stiff elongate panels across an opening through the frame one above another in edge-to-edge relationship and for affording edgewise movement of the panels along the guides through the top of the frame to an open position. The panels are attached together by lengths of non porous flexible material attached along the adjacent edges of each pair of adjacent panels so that the lengths of flexible material form into a generally cylindrical projections from the sides of the adjacent panels when the panels are supported on each other. The lengths of non porous flexible material are tensioned between the panels to lift the lower panels when the uppermost panel is lifted in the guides by rotating a plate like spindle at the top of the frame to wrap on the panels and move the panels to the open position.

Abstract: A roller shutter has louvers which are pivotal about respective axes between their opening and closing positions by movement of respective chains parallel to the axes of pivot pins upon which the louvers are journaled and which interconnect links of the chain. Screw formations between the pivot pins and the links translate the linear displacement of the links into pivotal movement of the louvers. The adjoining edges of adjacent louvers can hook together.

Abstract: A shutter is provided which is moved up and down by the use of the urging force of a take-up spring for turning a take-up shaft that winds up a number of slats and the weight of the slats. These slats are mutually coupled vertically expandably and a number of slits are formed in expandable portions of individual slats. The shutter includes a slit open/close means for expanding and contracting the slats to open/close the slits.

Abstract: A door operator for an overhead garage door having a reversible electric motor and a gear train driving the door. Limit stops are provided, one for the "up" limit and another for the "down" limit. Each of the limit stops is independently zero setable to cut off current to the motor at a pre-selected position.

Abstract: The present invention relates to a roll shutter for hinged casement type roof windows, which includes two guide rails (14) for the roll shutter bars (12), which guide rails (14) run parallel to each other and are connected to the shutter and is provided with a roll shutter activation device which includes a first and a second control cable (40 and 42) as well as a third control cable (50). The first and the second control cables (40 and 42) are led to a connection point (47) and are attached to each other. The connection point (47) is also connected with the third control cable (50) which is guided from a spool (26) on the winding shaft (24) of the roll shutter, through an activation loop (59) accessible to the user and an adjoining buffer loop (43) to the connection point (43). The length of the buffer loop (43) is at least as large as the displacement path of the roll shutter (10) between its completely open and completely closed positions.

Abstract: An operator for a rolling door having a curtain barrel shaft rotatable for actuating the door and including a drive gear adapted for connection to one end of the curtain barrel shaft and a second gear adapted for connection to one end of an idler roller. The idler roller in use engages one surface of the door and extends horizontally across the top of the door opening. A third gear is rotatably mounted in the region of the drive gear and the second gear and an electric motor is provided to rotate this third gear. In one version of the invention there is a moveable fourth gear in meshing engagement with the third gear and driven thereby. The fourth gear can be swung from a first position where it is in meshing engagement with the second gear to a second position where it is in meshing engagement with the drive gear. A chain loop connectable to the door is driven when the second gear and the idler roller rotate and it is provided to close the door even under pressure.

Abstract: A rolling shutter characterized by an array of edge-adjacent, parallel shutter slats and full shutter width, clear shutter segments or links articulately interconnecting respective pairs of adjacent shutter slats. The links are telescopically movable in the slats to permit relative movement of the slats between spaced-apart and juxtaposed positions. When spaced apart, the slats form therebetween a gap which exposes the clear link which permits passage of light over substantially the full extent of the gap. The clear links also provide a double hinge-like joint between adjacent slats. The shutter slats are also uniquely reinforced and have an improved exterior appearance.

Abstract: A sliding door, which includes a winding tube, which is mounted on a winding shaft for winding up and unwinding a hanging door for opening and closing-off an opening, and a take-up and tensioning mechanism which is disposed between the free end of the hanging door and the winding shaft and which has traction members which are guided about guide pulleys. The take-up and tensioning mechanism for the hanging door includes take-up or tensioning pulleys, which are freely rotatably mounted on the winding shaft on both sides of the winding tube, and pretensioned leg springs which are disposed between the pulleys and the winding shaft.

Abstract: A rolling shutter includes a winding and/or unwinding shaft for a sectional structure consisting of blades provided with a catch mechanism engageable by a driving mechanism rotatably rigid with a second shaft disposed downstream of the winding shaft and held by lateral flanges of the shutter housing. The shutter further includes guide rails slidably engaged by the lateral ends of the blades. The second shaft includes at either end a driving mechanism having a backlach consistent with the variable pitch existing between the catch mechanism of two adjacent blades. The driving mechanism is adapted to be actuated by a motor for causing the rotation of the winding shaft in one or the other direction.

Abstract: This control system for a roller-blind or the like comprising swivel blades coupled to a master blade carrying at one end a stud adapted, during its downward movement, to travel in a slide groove disposed behind a rocker and, during its upward movement, to engage both the slide groove, and the rocker, this control system comprises a microcomputer having stored in its non-volatile memory a control program of which the instruction groups are adapted to control the stud movements and the blind movement in relation to four predetermined stop points with respect to the rocker.

Abstract: A rolling firedoor having a closure drum on which a closure is wound, and a chaindrive for rotating the drum to raise or lower the closure. The chaindrive is disconnected from the drum during a fire. Means are provided for reconnecting the chaindrive to the drum from the ground so that the door can be raised in an emergency.

Abstract: This invention relates to a panel shutter mechanism for covering and uncovering the opening of a building, wherein in one position the panels constituting the shutter are arranged in the same plane so as to cover the opening when each of the panels is supported by guide rails uprightly placed on both edges of the opening, and the panels locked in place by a locking mechanism, and in the other position the panels are rolled up so as to leave the opening uncovered, wherein each of the panels is housed side-by-side in a housing located above the upper ends of the guide rails.

Abstract: A windable curtain or blind in which individual bands are wound or unwound on a winding tube. A torpedo device including first and second driving screws acts to reduce input rotational motion resulting from motion of a manual belt. When the belt is fully unwound the individual bands are rotated by means of a rack coupled to the second driven screw to control lighting and ventilation.

Abstract: A barrel ring for use in rolling closures comprising at least two ring sections. One of the ring sections defines a part-circular outer surface. Another of the ring sections defines a part-spiral outer surface. The ring sections are joined together end-to-end to form a barrel ring with the part-spiral surface, at one end, merging smoothly into the part-circular surface.A method for producing the barrel ring is also disclosed.

Abstract: A cover arrangement for a servicing hole comprises a band of a plurality of supporting bars pivotably connected with one another by chains. The band can be drawn into an open position and pushed into a closed position by a reversing motor driving chain wheels which engage with the chains at the band. Guide means at both ends of each supporting bar move along a horizontal U-shaped path which is continuously surrounded by a guiding web structure ensuring that the band is positively guided and cannot buckle even during its pushing motion.