EP0079607A1 - Continuous press, in particular a samming machine for manufacturing and processing leather - Google Patents

Abstract

In the case of continuous presses for leather production and leather processing, in particular in the case of dewing machines, there is a need for a preceding, laborious stretching and spreading process of the leather in order to avoid wrinkles. In the case of continuous presses with a pair of press rollers (W1, W2), an outreach device (ARV) acting transversely to the leather direction of passage (P1) is arranged in the area of the roller inlet gusset (EZ), which extends between an open position (OST) which releases the leather and an Working position (AST) is adjustable with stretching tools (RW1, RW2) attacking the leather. This enables a perfect introduction of the leather under visual control and with correction options. The small distance between the end section (EA) of the stretching tool and the roller press zone (PRZ), which can be achieved especially with stationary, plate-shaped stretching tools, promotes wrinkle suppression during the pressing process.

Description

The invention relates to a continuous press, in particular a continuous wilting machine for leather production and leather processing, with at least one pair of rollers under mutual pressure, the continuous path of the leather pieces to be processed preferably being provided with at least one suction and / or conveyor belt. Continuous presses of this type and, in particular, wilting machines are generally known and are used for the pressing processes required in various stages of leather production and leather processing, in particular those for removing liquid from the leather. These operations and the associated machines are of great importance with regard to their effectiveness and performance for the quality of the leather or for the efficiency of the entire manufacturing process.

Wilting is generally required at least twice within the leather manufacturing process, with the first wilting due to the nature and the water content in leather makes special demands. In any case, however, wrinkles in the leather should be avoided as far as possible during the pressing process or wrinkles that are present should be eliminated as far as possible before the pressing process. To do this, a stretching process is generally required before wilting. In the case of the instantaneous wilting machines, this stretching, which may have to be carried out repeatedly, was carried out in a separate operation and with correspondingly separate devices before the wilting. In addition, the use of knife cylinders, which press the leather to be de-wedged against the infeed conveyor belt or suction belt, is known in such weaning machines. These knife cylinders essentially only result in a more even contact of the leather on the infeed belt, but do not actually represent an outstretching device. In any case, no substantial stretching and spreading effect transverse to the direction of leather passage and thus no significant reduction in the formation of wrinkles is achieved. In particular, the adhesive effect between suction or transport belts of the usual type on the one hand and the leather pressed against them on the other hand prevents a relative movement between the leather and the belt transversely to the direction of passage and thus an effective stretching and spreading process.

The object of the invention is therefore to create a continuous wilting machine which, without special work steps, enables a stretching and spreading process of effectiveness which precedes wilting in a single leather pass. The fiction According to the solution to this problem is characterized in a continuous wilting machine of the type mentioned by at least one, arranged in the region of the inlet gusset of the pair of rollers, at least partially acting transversely to the direction of the stretching device, between an open position releasing the leather and a working position with the leather attacking stretching tools is adjustable.

Such an arrangement of a stretching device acting transversely to the direction of leather movement in the area immediately in front of the roller press zone results in an intensive spreading of the leather, which is due to the small distance of this stretching and spreading zone from the subsequently running press zone during the actual wilting and pressing process preserved. The unavoidable, more or less strong contraction of the leather up to the entrance into the roller press zone, which is inevitable when the stretching devices are connected at a greater distance, is avoided and an excellent wrinkle freedom is achieved during the pressing process. At the same time, the adjustability of the stretching device between the working position and the open position enables the leather to be introduced in a loosely spread manner and free of coarse folds into the working area of the stretching device and the run-in area of the rollers.

According to a preferred embodiment of the invention, the stretching device has, on at least one surface side of the leather, a stretching tool which is stationary or moves in opposite directions with respect to the continuous movement and engages in the inlet gusset of the pair of rollers in the working position. This engagement arrangement of the stretching tool in the roller inlet gusset enables a particularly small distance between the outlet of the stretching device and the inlet into the roller press zone. A largely wrinkle-free pressing and wilting process can also be achieved with leather, which tends to contract and wrinkle to a greater extent. In this context, it offers particular advantages, according to one embodiment of the invention, to arrange the open position of the outstretching device in relation to the working position to be set back against the direction of flow. This enables a comparatively wide open position, as is desired for an optimal insertion process, even with larger roll diameters, in particular with a larger top roll diameter, while on the other hand a deep engagement of the stretching tool in the roll inlet gusset is maintained in the working position.

In principle, rotating, roller-shaped stretching tools come into consideration for the stretching device, which rotate on their working side in opposite directions to the continuous movement of the leather. However, is the inevitable diameter and _H öhenausdehnung such stretching rotating tools to the desired, deep engagement in the roller inlet gusset and thus a small distance between the stretching tool and the roller press zone. An essential development of the invention therefore provides that the stretching device has at least one plate-shaped stretching tool, the rear end portion of which, viewed in the direction of passage, is arranged in the working position within the roller inlet gusset. Such a stretching tool allows a design with very low thickness or ' Expansion in height and in particular with an end section which tapers out in cross section and can thus engage in the inlet gusset in the working position until just before the roller press zone.

The stretching device can be provided on both surface sides of the leather with interacting stretching tools, in particular with complementary stretching elements interacting with teeth. However, a further development of the continuous press according to the invention which is particularly favorable in terms of production expenditure and also particularly advantageous in terms of handling is characterized in that the stretching device on one surface side of the leather has a pressure-resilient abutment which is provided with the leather-slidable surface and is preferably soft-deformable and pressure-flexible has the stretching tool arranged on the opposite surface side of the leather. Such an abutment is preferably on the underside of the leather running in a horizontal plane. The slippery surface quality of the abutment with respect to the leather, which is pressed by the opposite stretching tool, is essential for the stretching and spreading, because as a result the required relative movement between the leather and the abutment, in particular transverse to the direction of passage, is not impaired. A rigid abutment with a slidable surface is sufficient for numerous applications or leather properties, whereby the stretching elements of the opposite tool have a sufficient coating effect on the leather solely due to the frictional engagement with the leather surface or the compressibility of the leather. However, this coating effect can, if necessary, be supported and reinforced by the abovementioned, soft-deformable and pressure-resilient nature of the abutment.

Another essential development of the invention provides that a stretching tool abutment of the aforementioned type is connected to a feed table for the leather to be processed or is designed as such a feed table. In this case, this feed table is movably supported between a preparation and support position which is advanced in the opposite direction of travel and a feed position which is moved back in the direction of travel and engages in the roller inlet gusset. Such a design enables one Significant relief and simplification of the feeding and inserting process by the operator or an automatic feeding device, because the insertion can be carried out in a comparatively freely accessible and favorable for the preparatory spreading of the leather and under visual control.

In this context, the combination of the feed table and extension abutment or lower tool means an advantageous constructional simplification and a considerable space saving with regard to the machine parts arranged in the inlet area. In principle, however, such a table arrangement on the feed side can also be used independently of the presence of an extension tool, that is to say in connection with other continuous presses for leather production and leather processing. The subject of the invention therefore also extends to this independent application of the aforementioned feed table arrangement. In this context, a feed conveyor belt for pieces of leather to be processed can also be provided with particular advantage in the area of the preparation and resting position of the feed table, which facilitates operation and early placement of the next leather piece before the feed table returns to its original position, ie an increased working speed.

• Fig. l eine Durchlauf-Abwelkmaschine mit integrierter Ausreckvorrichtung in einem schematischen Vertikalschnitt quer zur Walzenanordnung, und zwar mit in Offenstellung befindlicher Ausreckvorrichtung,
• Fig. 2 eine Darstellung gemäss Fig. 1, jedoch mit in Arbeitsstellung befindlicher Ausreckvorrichtung,
• Fig. 3 eine Durchlauf-Abwelkmaschine mit integrierter Ausreckvorrichtung, jedoch mit abgewandelter Ausführung eines Reckwerkzeuges,
• Fig. 4 eine perspektivische Ansicht der Arbeitsseite eines plattenförmigen Reckwerkzeuges,
• Fig. 5 ein Ausreck-Widerlager mit drucknachgiebiger Polsterung im Querschnitt, und zwar im Arbeitszustand mit ausliegendem Leder und im Angriff befindlichem Reckwerkzeug, und
• Fig. 6 einen Teil-Querschnitt einer Ausreckvorrichtung mit zwei gegensinnig wirkenden und zueinander komplementären Reckwerkzeugen.

Further features and advantages of the invention are explained on the basis of the exemplary embodiments shown schematically in the drawings. Herein shows:

• 1 shows a continuous wilting machine with an integrated stretching device in a schematic vertical section transverse to the roller arrangement, specifically with the stretching device in the open position,
• 2 shows a representation according to FIG. 1, but with the stretching device in the working position,
• 3 shows a continuous wilting machine with an integrated stretching device, but with a modified version of a stretching tool,
• 4 is a perspective view of the working side of a plate-shaped stretching tool,
• Fig. 5 is a stretching abutment with resilient padding in cross-section, in the working state with exposed leather and a stretching tool under attack, and
• Fig. 6 is a partial cross section of a stretching device with two counter-acting and complementary stretching tools.

The continuous press shown in FIGS. 1 and 2 is a wilting machine with two rollers W1 and W2 which are mounted axially parallel and are under vertical, mutual pressure, and which have a pressing or squeezing zone PRZ within the continuous path DB of the leather pieces L to be processed, indicated by dash-dotted lines form. On the side of each of the two rollers W1 and W2, a suction or transport belt B1 and B2 is guided through the press zone PRZ. These are, for example, conventional, endlessly circulating felt belts guided over corresponding deflection and drive rollers. The direction of leather passage, according to which the rollers W1 and W2 with the associated belts B1 and B2 are driven by a conventional type of unit (not shown) is indicated by the arrow P1.

The rollers Wl, W2 with the associated suction or transport belts form an inlet gusset EZ, into each of which the front edge of the leather piece to be processed is inserted in order to be gripped by the converging belts B1, B2 and conveyed into or through the press zone PRZ . A stretching device ARV is connected upstream of the inlet gusset EZ, which essentially consists of a stretching tool RW1 arranged above the continuous path DB and an abutment WL arranged below the continuous path for the stretching tool. The stretching tool RW1 extends - in one piece or in adjacent sections - over the working width of the roller arrangement and is not conventional by means of itself Guides and drive means shown in more detail are adjustable according to the double arrow P2 between an open position OST according to FIG. 1 and a working position AST according to FIG. 2. In the open position, the inlet area of the stretching device ARV and the inlet gusset EZ of the roller arrangement are released for inserting the front section of a piece of leather or for its entry into the press zone PRZ. The open position with respect to the working position is set back in the opposite direction of travel according to arrow P1, so that on the one hand a sufficient height position and a large access opening are available for the leather insertion, while on the other hand the end section EA of the stretching tool RW1 is shown in FIG. 2 can reach deep into the EZ gusset. As already stated in the introduction, this results in the advantage of a small distance between the end of the stretching device and the entry into the press zone PRZ of the pair of rollers.

In the working position AST of the stretching tool RW1, the abutment WL is pressed upwards by a pressing device APV arranged below the inlet run of the belt B2, ie against the leather in the stretching device and above it against the stretching elements of the overhead stretching tool. This working pressure is from the pressing device via a pressure plate DR, which compensates for any Positional inaccuracies of the stretching tool and changes in thickness of the leather is provided with a swivel bearing LG. The same arrangement can also be used in the event that a second stretching tool RW2 with stretching elements complementary to the opposite stretching tool RW1 is provided instead of the abutment WL below. The structure of such stretching tools and abutments is shown in more detail below.

1 and 2, the abutment WL or the correspondingly arranged lower stretching tool RW2 is parallel to the through path DB according to arrow P3 between a preparation and support position VST (FIG. 1) and an infeed position EST (FIG. 2) sliding feed table ZT designed. Moreover, in the position of the _Z VST uführtisches and above the latter a smaller, continuously revolving feed belt ZB with corresponding guide and deflection rollers and a drive, not shown, are provided. When a piece of leather to be processed is placed with its upper strand OT sloping in the direction of flow, this feed belt picks up the front section of the leather piece, which is initially to be roughly spread out, and conveys it so far in the direction of passage that its front edge in the area in front of the inlet gusset EZ on the inlet side of the belt B2 arrives (Fig. 1). The feed table is then moved in the same direction in the direction of travel from its position VST located below the feed belt ZB the band B2 advanced until it assumes its infeed position _E ST (Fig. 2). The feed table takes the front section of the leather, which lies on the abutment WL or the lower stretching tool RW2, with it to the front. When the infeed position is reached, the front edge of the leather piece reaches the infeed gusset EZ and in the entrance area of the press zone PRZ of the pair of rollers. The leather is then gripped by the converging bands B1, B2 and drawn into the press zone. At the same time, the upper stretching tool RW1 is lowered and advanced according to arrow P2 from its open position OST to the working position AST. The contact pressure of the leather between the upper stretching tool RW1 and the lower abutment WL or the appropriately arranged stretching tool RW2 thus takes effect. The leather is now continuously drawn through the stretcher ARV, the subsequent leather sections being evenly and already loosely spread over the upper run OT and the discharge point LST of the feed belt into the inlet area of the stretcher.

3 differs from the embodiment explained above - apart from the omission of a feed belt for the leather pad - by the use of a rotating stretching tool RW3 instead of a stationary, plate-shaped stretching tool on the top of the leather. The roller-like trained and with ledge The stretching tool RW3 provided with its underside rotates in the opposite direction to the direction of travel Pl and, by suitable inclination of the strip-shaped stretching elements, exerts a corresponding brushing action on the leather which is directed transversely to the direction of travel and parallel to the leather plane. Apart from the significant advantage of the greater relative coating speed between the stretching elements and the leather surface, such a design is subject to the restriction that on the underside of the leather no complementary stretching tool attacking with corrugations on the leather, but only a smooth abutment WL can be used.

The stretching tool RW3 is adjustable between an open position OST and a working position AST, similar to the above embodiment according to arrow P2. In the open position, as in the previous embodiment, the correct entry of the leather into the effective area of the stretching device and the introduction of the leather front edge into the inlet gusset EZ and the press zone PRZ must be checked. An intervention to correct any wrinkles formed is also possible in the open inlet area.

In contrast to the above embodiment, when using a roller-shaped stretching tool RW3 according to FIG. 3, the transition area is of equivalent design between the stretching device and the roller press zone cannot be reached. As can be seen from FIG. 3, even a comparatively small roller diameter of the stretching tool _R W3 does not allow a similar approach to the embodiment according to FIGS. 1 and 2 between the exit region of the stretching device and the inlet region of the press zone, because the roller diameter limits the engagement of the stretching tool in the inlet gusset puts. The design with a fixed, in particular plate-shaped and at its rear edge tapering stretching tool is therefore generally associated with significant advantages.

The structure of the overhead stretching tool RW1 can be seen in detail from FIG. 4. A plate PL is formed underneath the hollow profile-like support body TR, the surface area of which essentially determines the extension zone. And the rear end section EA engages in the inlet gusset EZ of the pair of rollers according to FIG. 2. On the underside of the plate PL, strip-shaped or knife-shaped stretching elements REL are arranged in a divergent manner in the direction of passage Pl, which run obliquely in opposite directions on both sides of the conveyor track center M. These stretching elements grip frictionally and because of the compressive deformability of the leather lying on a firm, smooth abutment surface or in connection with a cushion-like abutment also form-fitting with corresponding corrugations on the leather. When the leather glides in relation to the free longitudinal edges the stretching elements result in the desired stretching and spreading effect in the direction transverse to the direction of passage and parallel to the leather plane.

The above-mentioned corrugation of the leather with partially positive engagement of the stretching elements on the leather is indicated for a cushion-like abutment WL (in connection with a displaceable feed table ZT) in FIG. 5 in a schematic vertical cross-section. The same applies to stretching tools RW1 and RW2 arranged opposite one another with complementarily arranged stretching elements REL and correspondingly stronger corrugation and stretching effect as shown in FIG. 5. In all cases, it is important that the elements of the stretching device that come into contact with the leather have a relative to the Identify leather with a sufficiently slippery surface finish so that the relative movement required for the stretching process is not excessively impeded. In the exemplary embodiments shown, this can be easily achieved because a structural separation is created between the pressing and suction elements that come into contact with the leather on the one hand and the stretching elements that move relative to the leather.

Claims (14)

1. Continuous press, in particular continuous wilting machine, for leather production and leather processing, with at least one pair of rollers under mutual pressure, whereby the continuous path of the leather pieces to be processed is preferably provided with at least one suction and / or conveyor belt, characterized by at least one in the area of the inlet gusset (EZ) of the pair of rollers (W1, W2) arranged, at least partially acting transversely to the direction of travel (Pl) stretching device (ARV), which between the open position of the leather-releasing open position (OST) and a working position (AST) with the leather Stretching tools (RWl, RW2, RW3) is adjustable. 2. Continuous press according to claim 1, characterized in that the open position (OST) of the stretching device (ARV) with respect to the working position (AST) is arranged set back against the direction of flow (Pl). 3. Continuous press according to claim 1 or 2, characterized in that the stretching device (ARV) on at least one surface side of the leather with respect to the continuous movement (Pl) resting or moving in opposite directions, in the working position (AST) in the inlet gusset (EZ) of the pair of rollers (Wl, W2) engaging stretching tool (RW1, RW2). 4. Continuous press according to claim 2 or 3, characterized in that the stretching device (ARV) at least one pair of elongated or resting with respect to the continuous movement, elongated and divergent with respect to the direction of passage (P1) arranged, sliding elements acting on the leather (REL) having. 5. Continuous press according to claim 3 or 4, characterized in that the stretching device (ARV) has at least one plate-shaped stretching tool (RW1, RW2), the rear end portion (EA) seen in the direction of flow in the working position (AST) within the roll inlet gusset ( EZ) arranged. is. 6. Continuous press according to claim 4 or 5, characterized in that a stretching tool (RW1, RW2) with complementary stretching elements (REL) is provided on both surface sides of the leather. 7. Continuous press according to one of the preceding claims, characterized in that the stretching device (ARV) on one surface side of the leather is provided with a surface that is slidable with respect to the leather, preferably soft-deformable and / or pressure-compliant abutment (WL) for at least one on the opposite surface side of the leather arranged stretching tool (RW1). - 8. Continuous press according to claim 7, characterized in that the abutment (WL) for the opposite stretching tool (RW1) is designed as a soft elastic cushioning plate against pressure. 9. _D urchlaufpresse according to any one of the preceding claims, in particular according to claim 7 or 8, characterized in that the Ausreckvorrichtung (ARV) below the pass line (DB) of the arranged one to be processed leather pieces, the roll inlet pocket (SR) upstream pressing device (APV ) for the stretching elements attacking the leather. 10. Continuous press according to claim 9, characterized in that the pressing device (APV) is arranged below the feed-side, resiliently guided strand of the leather continuous path (DB) forming a suction and / or transport belt (B2), which is flexible and transverse to the direction of passage (Pl) is in pressure-transmitting sliding or rolling contact with this belt. 11. Continuous press, in particular wilting machine for leather production and leather processing, with at least one pair of rollers under mutual pressure, the continuous path of the leather pieces to be processed being guided through the press zone of the pair of rollers, preferably with the roller press zone running on at least one surface side of the leather Suction and / or conveyor belt, in particular according to one of the preceding claims, characterized in that in the region upstream of the roller press zone
the leather continuous path (DB) is arranged at least one feed table (ZT) and that this feed table between a preparation and support position (VST) which is advanced in the opposite direction to the direction of travel (Pl) and a position in the roller inlet gusset (EZ ) engaging inlet position (EST) is movably mounted. ₉ 12. Continuous press according to one of claims 6 to 8 and according to claim 11, characterized in that the feed table (ZT) is provided with at least one abutment (WL) for at least one opposite stretching tool (RWl). 13. Continuous press according to claim 11 or 12, characterized in that in the area of the preparation and support position (VST) of the feed table (ZT) at least one feed conveyor belt (ZB) is arranged for pieces of leather to be processed. 14. Continuous press according to claim 13, characterized in that the feed table (ZT) in its preparation and support position (VST) is at least partially arranged below the discharge point (LST) of the feed belt (ZB).

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