Fur processing apparatus with two scraper roller units

FIELD OF THE INVENTION

The present invention relates to the field of processing of fur, such as mink fur, and more specifically the invention provides a skinning or fleshing apparatus for scraping fat and flesh of a leather side of a fur.

BACKGROUND OF THE INVENTION

Processing of fur, e.g. mink fur, often includes a process of removing fat and flesh residues from the back side of the fur by means of a skinning or fleshing apparatus with rotating scraper rollers that remove the fat and flesh during contact with the back side of the fur under pressure.

An example of a fleshing apparatus is disclosed in EP 2 093 299 B1 by Pamutec. This apparatus has an elongated mandrel on which the fur is mounted with its fur side facing inwards. Several rotating scraper rollers and brushes inside the apparatus serve to remove fat and flesh and thus clean the fur while the mandrel is projected through the rotating scraper rollers which are pressed against the fur on the mandrel.

Another example of a fleshing appartus is disclosed in WO 2011/116771, upon which the preamble of claim 1 is based.

However, it is a problem that fat and flesh is not completely removed in such apparatus, and thus the fur can suffer from spots due to fat residues penetrating the pores of the skin from the flesh side to the fur side during the subsequent drying process. Thus, to improve the quality of the fur, it is important to remove as much fat as possible in the scraping process.

SUMMARY OF THE INVENTION

Following the above description, it may be seen as an object of the present invention to provide a fur processing device which can scrape the flesh side of the fur effectively free from fat and flesh residues, so as to improve the resulting fur quality.

The invention provides a fur processing apparatus, according to claim 1.

Such fur processing apparatus is advantageous for fleshing or scraping of fur, such as mink fur, since the problem of fat and flesh residues is reduced compared to prior art apparatuses. This provides furs of higher quality.

Still, the apparatus can perform the complete scraping process automatically without the need for any manual operation involved other than placing the fur on the mandrel when it is in its initial position.

Preferred embodiments comprise a material dispenser arranged to apply an amount of particles, such as sawdust, to the fur between the first scraper unit and the second scraper unit, seen in a direction of forward movement of the mandrel. Further, the apparatus may comprise a set of scraper plates, such as made of rubber or a polymeric material or metal, arranged to scrape the fur, wherein the set of scraper plates are arranged between the first scraper unit and the material dispenser, seen in a direction of forward movement of the mandrel.

The apparatus may comprise a second material dispenser arranged to apply an amount of particles, such as sawdust, to the fur after the second scraper unit, seen in a direction of forward movement of the mandrel.

The apparatus comprises a mandrel support serving to support the mandrel in a horizontal direction to decrease a bending of the mandrel upon engagement of the at least one scraper roller of the first scraper unit. The mandrel support may be in the form of a wheel or roller mounted below the mandrel and in contact with the mandrel so as to support its downward bending during engagement with the scraper rollers. Hereby, a higher pressure can be applied to the scraper rollers, thus providing a more efficient scraping, especially of the head part of the fur. The mandrel support may comprises a roller arranged to support the mandrel, wherein the mandrel support is arranged between the base of the mandrel and the first scraper unit. E.g. the roller may be positioned around midway between the base of the mandrel and the first scraper unit, however a good effect can be obtained also with the mandrel support in other positions along the mandrel. The roller may be mounted on an air or pneumatic cylinder, hereby allowing the roller to be disengaged. The mandrel support may have a fixed position in a length direction of the mandrel, however in other embodiments the mandrel support may be mounted to be movable in a length direction of the mandrel, such as the mandrel suppor being mounted on a sliding arrangement which is fixed to a frame of the apparatus. Especially, the mandrel support may be movable together with movement of the mandrel, e.g. the mandrel support may be mounted so as to synchronously follow the forward and backward movement of the mandrel.

In preferred embodiments, the first scraper unit comprises a set of horizontal scraper rollers, and a set of vertical scraper rollers. The apparatus preferably further comprises a second scraper unit comprising a set of horizontal scraper rollers, and a set of vertical scraper rollers. Especially, the scraper rollers of the second scraper unit are of the same type as the scraper rollers of the first scraper unit, however the scraper rollers of the second scraper unit may be of a different type than the scraper rollers of the first scraper unit, such as scraper rollers with a different diameter, a different material, a different number of teeth, and/or different size of the teeth. Such difference in type of scraper roller between the first and second scraper unit may provide an improved scraping quality, since it is possible to select a type of scraper roller for the first scraper unit which is suited to remove large amount of fat and flesh, whereas the type of scraper roller for the second scraper unit may be specially designed to remove minor pieces of fat and flesh.

In one embodiment, the horizontal scraper rollers of the second scraper unit are positioned before the vertical scraper rollers of the second scraper unit, seen in a direction of forward movement of the mandrel. Hereby, it is possible to reduce the length of the machine by such as 15 cm, due to the tail part of a mink fur placed only on the horizontal part of the mandrel, is then being scraped with a shorter stroke of the mandrel. This means a higher efficiency of the machine.

Preferably, the mandrel has a rectangular cross section, at least on its front part, where the mandrel is arranged for the fur to be placed. However, it is to be understood that the invention may also be used with mandrels of other cross sections, such as triangular, or pentagonal or the like. Preferably, the scraper units have scraper rollers angularly arranged to match the cross section of the mandrel, so as to scrape all sides of the fur when placed on the mandrel.

In a specific embodiment, the mandrel has a rectangular cross section, and a scraping arrangement comprises a sequence of: a first scraper unit with four rotating scraper rollers, followed by a set of scraping plates, such as four scraping plates, followed by a first sawdust dispenser, followed by a second scraper unit with four rotating scraper rollers, and followed by a second sawdust dispenser. After the second sawdust dispenser, the apparatus preferably has a fur removing arrangement for pulling off the fur from the mandrel, before the mandrel returns to its initial position for processing a new fur.

The apparatus may comprise a clamping arrangement arranged to clamp a head or nose part of fur to the mandrel, preferably to the frontal tip of the mandrel, during scraping. Such arrangement is advantageous, since it allow a firm fit of the fur to the mandrel, thus allowing a high scraping pressure to be used. Especially, it is preferred that the clamping arrangement is capable of firmly clamping furs where a head part is at least partly damaged. Preferably, the clamping arrangement is automatically engaged upon activating the fur processing. It is to be understood that different types of clamping shapes can be used, depending on the type of fur.

In preferred embodiments, the first and second scraper units are housed within one common casing. E.g. a sawdust suction system may be included inside the casing so as to ensure that only a minimum amount of sawdust dispensed inside the casing is spread to the environment. However, in other embodiments, the second scraper unit comprising two or four scraper rollers may be provided as an add-on kit for mounting outside a casing. Possibly, such kit further includes a sawdust dispenser to apply sawdust or other material to the fur after the second scraper unit.

The method for scraping a fur, such as a mink fur, comprises

• mounting the fur on a mandrel with the fur side facing inwards,
• moving the mandrel forward so as to scrape the fur with a first scraper unit with at least one rotating scraper roller,
• applying an amount of particles, such as sawdust, to the fur, and
• moving the mandrel further forward so as to scrape the fur with a second scraper unit with a plurality of rotating scraper rollers.

In preferred embodiments, the method comprises

• mounting the fur on a mandrel with the fur side facing inwards,
• moving the mandrel forward so as to scrape the fur with a first scraper unit with at least one rotating scraper roller,
• moving the mandrel forward such that the fur is scraped by a set of scraping plates,
• applying an amount of particles, such as sawdust, to the fur, and
• moving the mandrel further forward so as to scrape the fur with a second scraper unit with a plurality of rotating scraper rollers, and
• applying a second amount of particles, such as sawdust, to the fur.

The scraper roller comprises an essentially cylindrical body with two opposite end surfaces and a toothed outer surface extending between the end surfaces, wherein the end surfaces define planes, which extend perpendicularly to an axies of revolution of the scraper roller, and wherein the toothed outer surface comprises teeth, each of which extends along a continuous path between said end surfaces, and wherein said continuous path of each of the teeth is non-parallel to the axis of revolution. In the prior art, teeths of scraper rollers extend in a v-formation, i.e. along a discountinuous path.

It has been found that fat and flesh is more efficiently conveyed away from the scraper roller by the provision of teeth which extend along a continuous path, which is non-parallel to the axis of rotation. Hence, the rotation of the scraper roller imparts a movement of the fat and flesh between the teeth in a linear direction, whereby the fat and flesh is conveyed and pushed out of the interstices between the teeths. Such scraper roller has been found to be particularly beneficial in respect of scraping of the forelegs of mink fur, as the legs are forced outwardly whereby improved scraping results have been achieved.

BRIEF DESCRIPTION OF THE FIGURES

Embodiments of the invention will be described in more detail in the following with regard to the accompanying figures. The figures show one way of implementing the present invention and is not to be construed as being limiting to other possible embodiments falling within the scope of the attached claim set.

• Fig. 1 shows a side view of a partly open skinning machine embodiment with two units each having four rotating scraper rollers,
• Fig. 2 shows a side view of another skinning machine embodiment comprising a set of scraping plates and two sawdust dispensers as well as a mandrel support to help reduce bending of the mandrel during scraping,
• Fig. 3 shows a side view of yet another embodiment, similar to the one of Fig. 2 except that the order ot the scraper rollers of the second scraper unit is reversed, such that the horizontal scraper rollers are placed before the vertical scraper rollers, and
• Fig. 4 shows a side view of a further embodiment of a skinning machine;
• Fig. 5 shows an embodiment of a scraper roller according to the present invention, and
• Fig 6 shows an embodiment of a scraper roller according to the prior art.

DETAILED DESCRIPTION OF AN EMBODIMENT

Fig. 1 shows a skinning machine. The machine has an elongated mandrel M with a rectangular cross section is arranged for receiving a mink fur with the head end arranged at the tip of the mandrel M, i.e. to the right on Fig. 1. The mandrel M is shown in its initial position where it is prepared for a fur to be mounted. During operation, the mandrel M is driven along its longitudinal axis, i.e. in the direction indicated by the bold arrow, so as to process the fur by a scraper arrangement with rotating scraper rollers arranged to remove remaining fat and flesh pieces on the leather side of the fur.

The scraper arrangement has two scraper units with scraper rollers with an intermediate sawdust dispenser SD arranged to sawdust onto the fur. The first unit of scraper rollers by which the fur is processed when the mandrel M is driven forwards, has four scraper rollers, of which only three are visible, namely two horizontal scraper rollers S1_1, S2_1 which are placed on opposite sides of the mandrel M during operation, and two vertical scraper rollers of which only the nearest one S3_1 is visible. The not visible vertical scraper roller is placed behind S3_1, and during operation the two vertical scraper rollers S3_1 are placed on opposite sides of the mandrel M. The fours scraper rollers S1_1, S2_1, S3_1 are thus placed to cover all sides of the fur when placed on the rectangular mandrel M. Fat and flesh removed by the scraper rollers S1_1, S2_1, S3_1 is pumped away by a motor driven pump FP. After processing by the first scraper unit, the fur is provided with sawdust from the sawdust dispenser SD, and subsequently, when the mandrel M is driven further forward, the fur is processed by a second scraper unit to remove the last pieces of fat and flesh as well as the sawdust which serves to absorb fat. Three out of the four scraper rollers of the second scraper unit are visible S1_2, S2_2, S3_2. An immobilzed fat scraper SF is provided downstream of scraper rollers S 1_1 and S 2_1.

All 8 scraper rollers are driven by respective electric motors.

Fig. 2 shows a skinning machine according to the invention. It has the same type of mandrel M as described for the embodiment of Fig. 1. However the mandrel is herein provided with a mandrel support (MS). Further, the two embodiments are also similar with respect to the first scraper unit SU1 with two horizontal and two vertical scraper rollers, and the second scraper unit SU2 also with two horizontal and two vertical scraper rollers.

Fig. 3 shows another embodiment which is similar to the one shown in Fig. 2, except for the order of the scraper rollers of the second scraper unit SU2. I Figs. 1 and 2, the horizontal scraper rollers S2_2, S3_2 of the second scraper unit SU2 are positioned after the vertical scraper rollers S1_2 of the second scraper unit SU2, seen in a direction of forward movement of the mandrel M. In Fig. 3, the horizontal scraper rollers S2_2, S3_2 of the second scraper unit SU2 are positioned before the vertical scraper rollers S1_2 of the second scraper unit SU2, seen in a direction of forward movement of the mandrel. Hereby, the length of the machine can be reduced for processing the same size of fur, and the efficiency of the machine can also be increased.

However, this embodiment has a set of two or four scraping plates SP of rubber or a polymeric material or metal, which scrape the fur, when the mandrel M is projected forwards so that the fur passes the scraping plates SP. The scraping plates SP are placed between the first and second scraper units SU1, SU2.

A first sawdust dispenser SD is arranged to apply sawdust to the fur after the scraping plates SP, but before the skin enters the second scraper unit SU2.

Further, a second sawdust dispenser SD2 is arranged to apply sawdust to the skin after having passed the second scraper unit SU2.

The main feature of the present invention is seen on the embodiment of Fig. 2, namely a mandrel support MS serving to reduce horizontal bending of the mandrel M upon engagement with the scraper rollers of the first scraper unit SU1. Hereby, it is possible to provide a more efficient scraping of the head part of the skin, since it is possible to use a higher scraping pressure on the scraper rollers of the first scraper unit SU1. In Fig. 2 the mandrel support MS is shown in the form of a wheel or roller supporting the mandrel M placed below the mandrel M so as to support it in a horizontal direction. The wheel or roller is mounted on an air or pneumatic cylinder to provide a mandrel support which can be removed or disengaged by activating the cylinder, and the opposite end of the air or pneumatic cylinder is mounted on the non-moving frame of the machine. However, it is to be understood that the mandrel support MS may alternatively be mounted movably in a length direction, e.g. so as to follow the forward movement of the mandrel M.

It is to be understood that the apparatus may comprise a fur removing arrangement arranged to remove the fur from the mandrel after sawdust has been applied thereto by the second sawdust dispenser SD2. Subsequently, the mandrel is moved backwards in its length direction to its initial position, ready for a new fur to be mounted and processed.

The apparatus may include a control system arranged to control, either manually or automatically according to a control algorithm, a pressure to be applied to the scraper rollers during scraping. Especially, the control system may be arranged to apply different scraping pressures to different zones of the fur, such as individual pressures for two, three or more different zones of the fur.

The mandrel may include a heating arrangement arranged to heat the mandrel and thus also heat the fur during processing. The apparatus may further include a washing arrangement arranged to wash the mandrel during its return to its initial position.

Fig. 4 shows an example of a further embodiment of skinning machine. As in the embodiment of Fig. 1, an elongated mandrel M with a rectangular cross section is arranged for receiving a mink fur with its head end arranged at the tip of the mandrel M, i.e. to the right on Fig. 4. The machine operates in a similar manner as the machine of Fig. 1.

The scraper arrangement has two scraper units with scraper rollers with an intermediate sawdust dispenser SD arranged to sawdust onto the fur. The first unit of scraper rollers by which the fur is processed when the mandrel M is driven forwards, has four scraper rollers, of which only three are visible, namely two horizontal scraper rollers S1_1, S2_1 which are placed on opposite sides of the mandrel M during operation, and two vertical scraper rollers of which only the nearest one S3_1 is visible. The not visible vertical scraper roller is placed behind S3_1, and during operation the two vertical scraper rollers S3_1 are placed on opposite sides of the mandrel M. The fours scraper rollers S1_1, S2_1, S3_1 are thus placed to cover all sides of the fur when placed on the rectangular mandrel M. Fat and flesh removed by the scraper rollers S1_1, S2_1, S3_1 is pumped away by a motor driven pump. After processing by the first scraper unit, the fur is provided with sawdust from the sawdust dispenser SD, and subsequently, when the mandrel M is driven further forward, the fur is processed by a second scraper unit to remove the last pieces of fat and flesh as well as the sawdust which serves to absorb fat. Three out of the four scraper rollers of the second scraper unit are visible S2_2, S3_2, and S4_2.

In the embodiments of Figs. 1 and 4 alike, a second sawdust dispenser may be provided downstream of the last set of scraper units S 2_2, S 3_2 and S 4_2 in order to achieve a further drying effect upon the fur.

In summary, embodiments of the invention provide a fur processing apparatus, such as for processing mink fur, with two scraper units each with a plurality of rotating scraper rollers arranged to remove fat and flesh of a leather side of a fur when placed on a mandrel which is then projected forward in its length direction. The two scraper units are preferably laterally separated such that an intermediate sawdust dispenser can apply sawdust to the fur after the scraping by the first scraper unit. Further, a set of scraping plates may be arranged between the first scraper unit and the sawdust dispensing. A second sawdust dispenser may be arranged to apply sawdust to the fur after scraping by the second scraping unit. A mandrel support is provided to support the mandrel in order to reduce its bending upon engagement of the first scraper unit, thereby allowing a higher pressure to be applied to the scraper rollers.

The mandrel M preferably has a closed, planar outer surface in order to avoid fat and flesh entering cavities or depressions therein. The mandrel is preferably solid in order to allow it to be suspended at one end only and yet to be able carry its own weight.

Generally, the mandrel M may be driven at constant or at variable speed. It has been found that the removal of flesh and fat from the neck region of mink fur is more troublesome that the removal of flesh and fat from the remaining body part of mink fur. Accordingly, the mandrel may be driven at a variable speed, so that the neck region of the mink fur is conveyed past the scraper rollers at a lower speed than the body part of the mink fur. In one example, the aparatus is operable such that the speed of the mandrel is increased steadiy throughout the mandrel's movement. For example, the speed may be varied from about 1.5 to about 6 m/s, or such as from between 2 and 4.5 m/s. The speed variation may be selected by an operator of the apparatus through an appropriate user interface.

The scraper rollers may advantageously be suspended in such a way that they are firmly pressed against the mandrel and hence against the fur to be scraped. In embodiment of the present invention, the pressure by which the scraper rollers are pressed against the mandrel is variable in such a way that a first, high pressure is excerted in the neck region of the fur, i.e. at the foremost front part of the conical section of the mandrel. A slightly lower pressure may be provided at the rearward conical section of the front part of the mandrel, i.e. in the region of the forelegs of the fur. A third even lower pressure may be provided at the back part of the fur, i.e. at the non-conical main section of the mandrel.

The pressure, by which the scraper rollers are pressed against the mandrel and hence the fur is preferably controlled by suitable means, such as electric actuators or pneumatic cylinders providing a controlled biasing force of the scraper rollers towards the mandrel. In the case of pneumatic cylinders, control signals may preferably be provided as pressure signals provided from a control unit through air conduits to the pneumatic cylinders. The control unit continuously regulates the biasing pressure in response to a pressure or force measurement obtained from an appropriate sensing device. Whereas, in the prior art, the control units have been provided at a distance of some meters from the pneumatic cylinders, in preferred embodiments of the present invention, the control unit is provided closer to the pneumatic cylinder, most prefrably at a distance of at most 2 meters therefrom in order to reduce the control reaction delay when the control signals travel through the air conduits. It has surprisingly been found that such reduction of the distance between the pneumatic cylinders and the control unit and hence of the length of the air conduits for pressure control signals improves scraping quality. In the prior art, uneven scracping results have been observed, notably at the neck region of mink fur. A firm belief has existed in the art that such uneveness was due to uneven surface structures of the mandrel. However, the present inventors have found that the reduction of the control signal delay significantly improves the eveness of the scraping results. In other words, the reduction of the length of air conduits for pressure control signals and hence inaccurate biasing pressure control has surprisingly been found to constitute a major cause of unven scraping results.

In one embodiment of the invention, the control unit is placed diretly at the pneumatic cylinders with air conduits for pressure control signals having a length of at most 20 cm or even with the pneumatic cylinders being attached directly to the control unit with no air conduits therebetween.

Fig. 5 shows scraper roller for a fur processing apparatus according to the invention. The scraper roller comprises an essentially cylindrical body with two opposite end surfaces and a toothed outer surface extending between the end surfaces. Each of the teeth of the outer surface extends along a continuous path between the end surfaces of the roller, and the continuous path of each of the teeth is non-parallel to the axis of revolution.

Fig. 6 shows a prior art scraper rollers, the teeth of which extend in a v-formation, i.e. along a discountinuous path.

Fat and flesh is efficiently conveyed away from the scraper roller by the provision of teeth which extend along a continuous path as shown in Fig. 5, as the rotation of the scraper roller imparts a movement of the fat and flesh between the teeth in a linear direction, whereby the fat and flesh, notably that of the forelegs of mink fur and the forelges themselves are conveyed and pushed out of the interstices between the teeths. To the contrary, the v-formation of Fig. 6 causes fat and flesh to assemble in interstices between teeth at the valleys of the v's.

Although the present invention has been described in connection with the specified embodiments, it should not be construed as being in any way limited to the presented examples. The scope of the present invention is set out by the accompanying claim set. In the context of the claims, the terms "comprising" or "comprises" do not exclude other possible elements or steps. Also, the mentioning of references such as "a" or "an" etc. should not be construed as excluding a plurality. The use of reference signs in the claims with respect to elements indicated in the figures shall also not be construed as limiting the scope of the invention. Furthermore, individual features mentioned in different claims, may possibly be advantageously combined, and the mentioning of these features in different claims does not exclude that a combination of features is not possible and advantageous.