GB2038234A - Apparatus for processing hides - Google Patents

Abstract

Apparatus for processing tanned hides or simulated hides to stretch or emboss the hides comprises an endless belt 10 driven with intermittent motion between opposed pressing members 3, 5 of a press. The hides are carried on a surface of a steel belt which is either smooth and chromium plated for stretching or patterned for embossing. Loading and withdrawal stations are provided externally of the press. The press may comprise a fixed member 3 whose surface comprises a replaceable layer, and a heated, movable member 5. The apparatus may include heating means 16, a device for measuring the hide area and comprising emitters 22 and receivers 24 for energy beams, and a stamping device 28 for marking on the hides indicia representing the measured area. <IMAGE>

Description

SPECIFICATION Apparatus for processing hides This invention relates to an apparatus for processing tanned or simulated hides.

In the stretching or embossing of hides, the hides may be laid manually on conventional hydraulic presses with parallel beds. However, this manual process is carried out under difficult conditions both because of the press and because of the obstructions caused by safety devices which are incorporated in the working zone to prevent accidental injury to operating personnel. These difficulties lead to a method of working which gives low operation efficiency and requires considerable physical effort.

Sometimes personnel will try to avoid the safety devices to improve their output and this becomes a frequent source of accidents.

Various methods have been proposed to overcome these difficulties, and these will now be discussed.

One method comprises feeding hides to alternate working surfaces (DUPLO) and is applicable to conventional presses. It consists of two tables connected in series and mounted on a sliding bench, to enable the work to be carried out on one working surface while feeding on to the other. The advantages of this method are the elimination of conventional safety systems, and the ease of inserting the hide. In contrast, there are the disadvantages of considerable masses in movement, with consequent high down times or waiting times, and the impossibility of rationally utilising the area of the working surface.

Another method comprises feeding the hides by means of a continuously-movable conveyor belt of wool felt or rubber. This method enables the press to be fed from a distance without any impediment, thus reducing down times and increasing the useful area, by means of the rational positioning of the hide to be processed. The advantages consist of working continuity and high conveying efficiency. The disadvantages are the considerable deterioration of the conveyor belt, the long time required for replacing the rubber belt with the felt belt and vice versa, frequent stoppages of the press due to the adhesion of the hides to the bed of the press (which is only partly prevented by the use of chemical additives in the stage prior to stretching), and the impossibility of preheating the hide before processing.

According to the invention thereis provided appar atus for processing hides, comprising a press having opposed pressing members, an endless belt driven with intermittent motion between the pressing members of the press, said belt having a surface on which the hides are carried, means defining a loading station at which hides are loaded onto the belt, and means defining a discharge station at which hides are removed from the belt.

In a preferred embodiment of the invention, the endless belt has its active conveying run at the top, with a lapped, or possibly machined, working sur face facing upwards. The surface of the pressing member facing the working surface of the belt is provided with a replaceable layer by which it can be adapted to the precise material being processed.

The apparatus can provide conventional stretching between parallel pressing members and, by means of a stepwise feed system using a belt constructed of stainless steel or with a chromium plated surface, can attain a very high production rate by virtue of the elimination of down times and the rational positioning ofthe hide.

The endless belt operates stepwise and this enables the hide to be positioned under static conditions, i.e. when the belt is at rest.

The hide is preferably loaded with its "grain" side in contact with the working surface of the belt at a temperature slightly lower than the operating temperature, and is retained on this surface for a time equal to two steps of the machine, so ensuring that the hide has a thermal gradient which is ideal for preparing the surface resins or pigments for the stretching operation. It is also possible to allow the hide to remain adhering to the belt after pressing. As the hide cools while it is still adhering, the resultant hide is more shiny.

An area measuring device for the hides can be combined with the belt, and comprises a transverse row of light energy beam emitters and receivers, which utilise the refraction and reflection differences between the hide surface and belt surface.

An embodiment of the invention, will now be described by way of example only, with reference to the accompanying diagrammatic drawings, in which: Figure 1 is an overall perspective view of hide processing apparatus in accordance with the invention; Figure 2 is a longitudinal section of the apparatus; and Figures 3 and4 are enlarged details of Figure 2.

The apparatus shown in the drawings comprises a bridge structure 1 which carries an upper fixed bed 3 of a conventional hydraulic press. A movable bed 5 of the press is controlled by a large hydraulic cylinder system 7 for force application and by a small hydraulic cylinder 8 for rapid raising of the bed 5. The bed 5 is heated in a controlled manner in order to obtain the ideal temperature for stretching or embossing of the hide.

The active surface of the bed 3 comprises a replaceable layer 9 of a material appropriate for the particular process, for example a layer of felt, a layer of rubber, or a combination of the two. The upper surface of the movable bed 5 is smooth, and co-operates either with a smooth metal sheet for stretching purposes, or with a metal sheet matrix for embossing the hides.

The reference numeral 10 indicates an endless flexible steel belt, which extends between rollers 12 and 14, and has an outer surface which can be smooth and chromium plated for stretching, or can comprise various relief and hollow patterns for forming embossing impressions in the hides. The belt 10 is driven intermittently in the direction of the arrow f1, such that successive zones of the upper run of the belt can be moved between a loading station indicated by the arrow Fc, a pressing station be tween the two beds 3 and 5, and a discharge station indicated by the arrow Fs.

In a position upstream of the press, the belt 10 with the hide extended on it can be preheated by heating means 16 in contact with the belt 10.

Alternatively, the belt 10 can be heated by noncontact heating means, such as infra-red heaters.

The belt 10 is stretched between the rollers 12 and 14, one of which (as shown, the roller 12) is mounted on a slidable support 18 biased in a direction away from the other roller by resilient means 20. In this arrangement, the roller 12 can be moved towards the roller 14 against the bias of the resilient means 20 when the cylinders 7, 8 liftthe belt 10 against the layer 9 of the fixed bed 3. It should be noted that, in a modification (not shown) the movable bed of the press can alternatively be disposed above the upper run of the belt 10, but this can lead to disadvantages because of the possibility that drops of oil may fall onto the hides in transit.

One of the rollers (as shown, the roller 14) can be mounted in such a manner that its axis of rotation can be inclined relative to the axis of the roller 12, in the horizontal plane containing the axes of rotation ofthetwo rollers 12, 14, in orderto correct any tendency of the belt to move sideways. The inclination of the axis of the roller 12 is controlled by a transistor-controlled servo motor 20 which is responsive to the position of an edge of the belt 10.

A measuring device for the hide area can be provided at the press outlet, or in some other position adjacent to the working zone. Such a device comprises a transverse row of emitters 22 and a transverse row of corresponding receivers 24 for respective energy beams, each beam being reflected from the belt 10 in the absence of a hide, and not reflected if a hide is present at the point of reflection.

The small distance between the individual emitterreceiver pairs and the frequency with which the individual readings are made during the transit of the hide enable the hide area to be measured with sufficient accuracy. The device is analagous to previously measuring devices using an endless conveyor in the form of parallel wires, with the emitters disposed on one side and the receivers on the other side of the hides fed on the wires.

However, there is the advantage over these previously proposed devices of taking the measurement without any further handling of the hides which are already on the stretching bed.

A stamping device 28, advantageously slidable both longitudinally and transversely on guides 30 and 32, can be installed downstream of the measuring device in order to stamp the hides in a required position with the size of the area measured by the measuring device. The stamping device can be of the thermoprinting type.

In the loading station, the operator has time to spread out the hide to be stretched or embossed while a previously spread hide is being pressed in an adjacent zone, the stretching hide then being able to be discharged or withdrawn in a further subsequent zone. This eliminates down times and enables the hide stretching operation to be carried out in a comfortable and safe manner, as the loading position is external to the distant from the working zone.

The stretched or embossed hide can be easily removed in the discharge station, the zone of which is completely free from any obstructions. Thus withdrawal is easy even if the presence of dyes or other additives has caused the grain surface of the hide to adhere to the matrix (smooth or patterned), which is represented by the conveyor belt 10.

The hide is positioned during periods when the belt is at rest and the machine is not working, and this makes the operation easierforthe operator, consequently increasing productivity. The surface continuity enables the useful stretching surface to be utilised rationally without any length limits, and independently of the size of the press structures.

The apparatus enables the hide to be preheated before pressing, as the belt 10, when working normally reaches the loading position (arrow Fc) still at a suitable temperature for preheating the hide, but if necessary using auxiliary heating or conditioning means. This means that the pressing time is considerably reduced relative to the time at present necessary in apparatus in which a stage of application and initial contact between the hide and press structures is required.

Claims (8)

1. Apparatus for processing hides, comprising a press having opposed pressing members, an endless belt driven with intermittent motion between the pressing members of the press, said belt having a surface on which the hides are carried, means defining a loading station at which hides are loaded onto the belt, and means defining a discharge station at which hides are removed from the belt.

2. Apparatus as claimed in claim 1, wherein the endless belt has an upper horizontal run passing between the pressing members, the hides being carried by an upper surface of the belt, one of said pressing members is located above the belt and has a downwardly-facing surface, and means defining a replaceable layer is provided on said downwardlyfacing surface.

3. Apparatus as claimed in claim 2, wherein the said one pressing member is a stationary member, and the other pressing member is a movable member operative to raise the upper run of the belt, said apparatus further comprising means defining a movable mounting for one of said rollers, said mounting being movable against a resilient bias when the belt is raised.

4. Apparatus as claimed in any one of claims 1 to 3, further comprising heating means for preheating the belt prior to its passage between the pressing members.

5. Apparatus as claimed in any one of claims 1 to 4, further comprising means for measuring the area of the hides carried by the belt, and marking means responsive to the measuring means for marking on the hides indicia representing the measured area.

6. Apparatus as claimed in any one of claims 1 to 5, wherein the said surface of the belt on which the hides are carried is smooth.

7. Apparatus as claimed in any one of claims 1 to 5, wherein the said surface of the belt on which the hides are carried consists of a patterned matrix.

8. Apparatus for processing hide substantially as hereinbefore described with reference to the accom panying drawings.