Abstract: The machine (1) includes at least one assistance subassembly (10) having: an endless chain or belt (16); a plurality of thrust members (20) connected to the chain or belt (16) in succession and projecting from the chain or belt (16), and a drive device (21) of this chain or belt (16), several thrust members (20) are brought into the path (3) of the sliders (8) connected to the grippers (4) for gripping the film (F), so that at least one of the thrust members (20) comes to bear against at least one of these sliders (8) and exerts a thrust on this slider to assist the displacement of this slider along the rail (5e) on which this slider moves.

Abstract: Clipping both right and left side edge parts of a sheet or film by right and left pitch-variable clips having flow-directional clip pitches variable along with travel movements, respectively, having positions (AR, AL) for initiation of enlargements of flow-directional clip pitches changed between right clips and left clips, and enlarging flow-directional clip pitches along with travel movements of clips to thereby make an oblique stretch.

Abstract: A clip support member 30 has a first shaft member 51 cantilevered by guide rollers 56 and 56 for a guiding along a reference rail with a recessed channel 101, the clip support member 30 being provided with a slider 40 having a second shaft member 52 cantilevered by guide rollers 57 and 57 for a guiding along a pitch setting rail 120 with a recessed channel 121, the clip support member 30 supporting a clip 20 at an end thereof, where it has the first shaft member 51, whereto one end of a main link member 53 and one end of a sub-link member 54 are pivotally connected, to constitute a reference linkage at the clip 20 end.

Abstract: Clipping both right and left side edge parts of a sheet or film by right and left pitch-variable clips having flow-directional clip pitches variable along with travel movements, respectively, having positions (AR, AL) for initiation of enlargements of flow-directional clip pitches changed between right clips and left clips, and enlarging flow-directional clip pitches along with travel movements of clips to thereby make an oblique stretch.

Abstract: A clip 20 is provided on a clip support member 30, and one end of a main link member 53 and one end of a sub-link member 54 are pivotally connected to a first shaft member 51 at the clip 20 side of the clip support member 30 to constitute a reference linkage at the clip 20 side.

Abstract: A process for stretching films is described. The process preferably stretches films in a uniaxial fashion. Preferably, optical films are stretched including multilayer optical films. Other aspects of the invention include a roll of stretched film and an apparatus for stretching films.

Abstract: Disclosed are an apparatus and method for simultaneously biaxially stretching a film (e.g., a continuous web of film). The apparatus includes upper and lower rails, for guiding a pair of endless links that each has link units for grasping side edges of the film. The endless links have upper and bottom rollers for being guided by (e.g., rolling on) the rails. The upper and bottom rollers are guided respectively by the upper and lower rails in different zones of the apparatus, the endless links being lifted and guided by the upper rail in one zone and being supported and guided by the lower rail in another zone. Since rolling, rather than sliding, friction occurs during movement of the endless links, amount of lubricant needed is decreased and dirt in the system due to large amounts of lubricant used, can be reduced.

Abstract: A method is disclosed of temporarily speeding up delayed carriages on a return side of an endless loop of driven carriages in a linear motor web tenter.

Abstract: A tenter clip is provided for gripping a web of thermoplastic film between the curved surface of a toggle arm and an anvil surface which is tapered at each of its ends. The surface configurations of the toggle arm and anvil define effective surfaces for gripping the film while allowing the film to stretch under these surfaces. Beads are formed at the edges of the web during stretching. These beads wedge into substantially V-shaped gripping regions defined by the toggle arm and anvil to assist in the stretching operation.

Abstract: A tentering frame is equipped with a tentering chain for the simultaneous treatment of a film web in two directions or in a so-called biaxial manner. The film web is carried by endless tentering chains which hold the film web edges by grippers carried by tentering clamps secured to the tentering chain. The chains have tiltable chain link plates and chain links, whereby the on-center spacing between neighboring clamps is continuously adjustable or variable for changing the chain pitch. In order to reduce the normal pitch when the chain is stretched out as much as possible, and in order to achieve a more efficient pitch adjustment in a larger adjustment range, each tentering clamp is carried by a single shaft which simultaneously functions as one of the two chain pins or chain axles that link two neighboring chain links to each other.

Abstract: A thermoplastic film web is subjected to a defined shrinking in a treatment apparatus with two mirror-symmetrically arranged tentering chains. For this purpose, each chain is equipped with tentering clamps that have a variable on-center spacing or pitch in the travel direction of the tentering chains, and which additionally are position adjustable in a direction other than the travel direction. The entire clamp body or clamp elements may be position variable in a direction other than the travel direction. In operation, the pitch is first reduced in the inlet and/or heating zone of the treatment apparatus. Simultaneously, the clamping position of the individual clamps or clamping element is changed, e.g. by tilting or lifting. The clamp position change takes up extra film web length resulting from the pitch change, whereby the film web assumes throughout its width a corrugated configuration. Then, the film web is cross-stretched.

Abstract: A process and apparatus for producing a web achieves relaxation of the web in the machine direction during and/or after heat-treating, by changing the shape of the side edge of the web in the longitudinal plane from a substantially non-linear zone to a substantially linear zone.

Abstract: Tentering clamps for an endless tentering chain are formed so that two clamp bodies slideably mounted on at least one common guide bar can move toward each other and away from each other for adjusting the pitch. The guide bar or bars have entraining stop elements so positioned that an axial pulling force that moves the tentering chain, is transmitted through the guide bar or bars. The pitch is adjusted with the help of at least one, preferably two, toggle link mechanisms carrying a control roller engaging a guide rail. When the toggle links of the toggle link mechanism are straightened out in the travel direction of the tentering chain, the toggle link mechanism is substantially relieved of the axial tension force or load because the load passes through the guide bars (10) and the clamp bodies forming a pair. A plurality of such compound tentering clamp body pairs are linked by chain link plates and respective linking chain journal pins (23).

Abstract: In order to achieve a controlled longitudinal shrinkage of a film web, an adjusting mechanism including a threaded spindle with a cross-piece is provided between neighboring clamping bodies along the tentering chain. The cross-piece is equipped with control rollers that are radially arranged around the longitudinal axis of the threaded spindle and spaced from one another by an angular spacing of, for example, 90.degree. between neighboring control rollers. The control rollers intermittently engage a control rail that has operational segments of a multiple leads screw guide track.

Abstract: A tentering machine having a compliant drive link allows for a considerable rate of stretch in a tentered fabric, web or film without the distortion or bowing frequently observed with the tentering machines of the prior art. The tentering machine includes two conveyor tracks adjacent to and facing one another, each conveyor track having a number of fabric edge holders slidingly directable thereabout. A fabric, web or film, grasped on opposite edges by the fabric edge holders, is conveyed thereby through the tentering machine in the space between the two conveyor tracks. Widthwise stretching occurs where the conveyor tracks of the tentering machine have sections on each side of the fabric which diverge from one another, while the two conveyor tracks may be parallel to each other on the two sides of the fabric in applications where prevention of shrinkage is of interest. The fabric edge holders on each conveyor track are run at a substantially common speed by drive chains.

Abstract: A tentering chain is equipped with a mechanism for the stepless, continuous adjustment of the chain pitch which is the on-center spacing between two neighboring chain link journal bolts or pins. Such chains are used for this simultaneous, biaxial treatment of synthetic material films or webs. For this purpose, the chains carry tenter bodies with hooks or clamps for gripping the film edge. The tenter bodies carry guide rollers which engage guide rails along the travel path of the tentering chain. In order to dimension the tenter body with its gripping elements as small as possible, while still permitting a large shrinking or stretching of the film web, the chain link journal bolts or pins are mounted in the respective tenter body for an adjustment of the pin position in a direction of the chain travel. In all positions of the journal pin or pins these pins extend perpendicularly to the longitudinal direction of the chain.

Abstract: An assembly for a stretching frame has a rectangular cross section rail, a multiplicity of carriages displaceable along the rail and formed with shanks which have offset pairs of rollers engaging the surface of the rail perpendicular and parallel to the plane, and couplings on the shanks located substantially in the median plane between the surfaces of the rail perpendicular to the frame for engagement by respective transport devices.

Abstract: An apparatus for simultaneously treating film webs biaxially is described. Film edges are clamped into tentering clamps running around in an endless track. The individual tentering clamps are interconnected with one another by an upper and a lower chain, whereby the connection between two successive tentering clamps is respectively established by two chain links loosely interconnected with each other. The loose chain links can be brought in pairs into a lengthwise extending arrangement or into a kinked arrangement and vice versa, with the aid of control rails arranged outside of the chain track cooperating with a chain link formed as a bellcrank. In this manner the spacing between two successive tentering clamps is shortened or alternatively lengthened. Thus, it is possible to achieve a lengthwise variation in the film web being treated, and especially to adjust a fine shrinking ratio.

Abstract: The present invention refers to a temple for holding or for laterally tensioning a woven fabric, in particular on weaving looms, comprising endless guide means having displaceably arranged therein members provided with needles for engagement with said woven fabric, said guide means extending and being arranged in such a way that the needles of at least two members are simultaneously in engagement with the edge of the woven fabric and that, in the course of the needling-in operation, the needles brought into engagement with the woven fabric, are located at a greater distance from the longitudinal axis of the width of woven fabric than in the course of the de-needling operation. The failures occurring in the case of such a temple are now eliminated by providing an appropriate amount of play between the individual members and by guaranteeing at the same time that the members are returned to the point of needling-in in an appropriate manner.

Abstract: A link device for stretching a sheet material consists of pantograph-like link member units having a sub-link held substantially at a right angle to the running direction and rollers fitted to said sub-link. Due to the low running resistance of the rollers and the pantograph-like structure composed of long and short links, an endless guide-rail can be introduced in the stretching apparatus for a sheet material and the running of the chain can be stabilized, thereby resulting in a high-speed stable stretching operation. Reduction of the running resistance makes it easy to adjust the stretching ratios according to the desired stretching conditions.

Abstract: A device is disclosed for a variable speed carrier with power input from a chain drive to a sprocket on the carrier and power output to cones affixed to the sprocket and running on a pair of rails of variable spacing.

Abstract: A simultaneous biaxial stretching machine for thermoplastic film webs, said machine having two transport rails arranged on both borders of the film web, on which transport rails gripping devices for the gripping of the borders of the film web are guided, each coupled with one another by flexible connecting elements and having a roller moving mechanism, the gripping devices being guided at constant small distance in a preheating zone, divergently and at an increasing mutual distance within a stretching zone, and in parallel or convergently within a fixing zone. Each gripping device has an extension arm, oriented rectangularly to the moving direction of the gripping device, the extension arm having a slide, guided therein. Each gripping device, in addition, has a deflection roller for the deflection of the connecting element, coming from the adjacent gripping device.

Abstract: An apparatus is disclosed for the fabrication of a biaxially stretched flat film of thermoplastic material, particularly of polypropylene, with improved properties for a process in which the material is first partially pre-stretched in a longitudinal direction and, thereafter, simultaneously biaxially (longitudinally and laterally) stretched, the apparatus comprising stretching rollers for effecting partial longitudinal stretching of the film, the rollers being arranged upstream of an assembly for effecting simultaneous biaxial stretching of the film. The speed of the stretching rollers is infinitely variable so as to influence the total degree of film-stretching only by changing the speed of the rollers. The rollers used for longitudinal pre-stretching are arranged at the inlet section of the biaxial stretching assembly.

Abstract: Web-stretching apparatus wherein the web, gripped by web-gripping devices mounted to carriages which run on guide rails, is stretched by increasing the distance between adjacent gripping devices by altering the degree of extension of an articulated chain to which the carriages are attached.

Abstract: In an apparatus for the biaxial, simultaneous stretching of a flat film web from particularly polypropylene, the edges of the film web 1 are engaged by grippers 3, which in the stretching zone 9 are driven by divergent threaded spindles 5, and at least part of the stretching in longitudinal direction is effected, by means of a progressive pitch of the threaded spindles, simultaneously with part of the transverse stretching. Subsequent to the progressive pitch a thread with degressive pitch is provided, preferably at the end of the threaded spindles, effecting shrinkage of the previously stretched film web in longitudinal-direction, while preferably simultaneously the film web is further stretched in transverse direction. The shrinking of the film web takes place over about 5 to 10% of the spindle length at up to 10% of the previously produced longitudinal stretching, to the longitudinal stretching degree desired in the finished film.

Abstract: A biaxial web stretching machine has diverging tong conveying screws and the screws are provided with double or triple threads to provide relatively high speed tong movement with a relatively low speed of screw rotation.

Abstract: An apparatus for longitudinally stretching a web comprising a pair of spaced apart rotatable members. Associated with each member are a plurality of angularly spaced primary clamps, each radially movable outward, during member rotation, from a primary web engaging position, in which the primary clamps initially engage the edges of the web being transported between the members, for longitudinally stretching the clamped web. Further associated with each member is a plurality of angularly spaced secondary clamps, each angularly interposed between primary clamps and radially movable outward during member rotation from a secondary web engaging position, which is spaced radially outward from the primary web engaging position. The secondary clamps engage the intermediate edges of the web extending between primary clamps, thereby minimizing edge scalloping of the web during continued stretching thereof in unison with engaged primary clamps.