The present invention relates to an apparatus for processing the skin side of a tubular pelt by scraping the skin side by means of rotating helical scraping rollers.

BACKGROUND

A fresh pelt taken from a furred animal such as a mink normally has a layer or residues of fat, tendons and/or flesh that is firmly attached to the skin side of the pelt. Before the pelt can be used for further processing, such layers or residues must be removed from the skin side.

A prior art apparatus for processing such pelts to remove layers or residues of fat, tendons and/or flesh on the skin side is described in Danish patent specification DK 156 669. This apparatus comprises a single scraper roller with V-shaped scraping elements to scrape the skin on each side of a mandrel, on which a tubular pelt is arranged with the skin side facing outwards.

The area beneath the front leg skin parts, i.e. the skin parts that used to cover the animal's front legs are difficult to process completely and a residue of fat may be left from the processing by the primary scraping rollers which may cause damages to the pelt as the fat may influence the fur side of the pelt negatively.

Danish patent specification DK 173 611 describes an apparatus for processing pelts on a mandrel. The apparatus comprises several scraper rollers that, while scraping the skin side of the pelt, cause the pelt to rotate about its longitudinal axis in order to obtain a complete scraping of the entire surface of the skin side.

European patent specification EP 2 093 299 discloses an apparatus for processing pelts which comprises two scraper rollers engaging the same part of the pelt but driven in opposite directions of rotation to obtain an improved scraping behind and beneath the front legs by achieving both a friction force against a thick end of a mandrel on which a pelt is arranged and a friction force against the thin end of the mandrel.

WO 2012/019606 Al discloses an apparatus for scraping the skin side of a tubular pelt, where the relative motion of the mandrel and the scraper rollers is slower when the scraper roller processes the first part of the skin side of the tubular pelt for improved scraping of the area around the front legs and the neck of the pelt. Additionally or alternatively, the means for biasing the scraper rollers against the skin side may be equipped with a damper arrangement for damping the movement of the scraper rollers towards and away from the skin side, which is also intended to improve the scraping quality in particular around the front legs. Also, two scraper rollers on the same side of the mandrel are disclosed, where both scraping rollers apply a force to the pelt in the direction towards the thicker end of the mandrel. DK 177 165 discloses an apparatus for processing of the skin side of a tubular pelt which apart from primary scraping rollers comprises at least one further treatment means having a direction of treatment that deviates at least 175° from the relative direction of movement of the mandrel and with one or more axes of rotation that deviates from the direction of rotation of the primary scraping roller.

It is an object of the present invention to provide an improved apparatus for processing the skin side of a tubular pelt where the cleaning of the skin side is satisfactory. BRIEF DESCRIPTION OF THE INVENTION

The present invention relates to an apparatus for processing the skin side of a tubular pelt, the apparatus comprising an elongated tapering mandrel of a substantially rectangular cross-section for supporting the pelt with its skin side turned outwards, the mandrel having a thinner, free end from which the tubular pelt is drawn over the mandrel and a thicker end, a scraping device comprising a first pair of primary scraping rollers arranged on opposing sides of the mandrel, a second pair of primary scraping rollers arranged on other opposing sides of the mandrel and being substantially perpendicularly oriented with respect to the first pair of primary scraping rollers, and a first pair of secondary scraping rollers arranged to engage the skin side of a pelt on the same, opposing sides of the mandrel as the first pair of primary scraping rollers, the scraping device further comprising rotation means for rotating said primary scraping rollers and secondary scraping rollers during processing of a pelt so as to engage a skin side of the pelt, and moving means for conducting a relative movement between the scraping device and the mandrel in the longitudinal direction of the mandrel, wherein a scraping roller of the first pair of primary scraping rollers and a scraping roller of the first pair of secondary scraping rollers, which are arranged to engage the skin side of a pelt on the same side of the mandrel, each has a plurality of scraping edges extending substantially helically along the longitudinal direction of the scraping rollers, and wherein said two scraping rollers are arranged to impose force components transversal to the longitudinal direction of the mandrel acting in the same direction on the skin side of a pelt during their engagement with the skin side of a pelt.

This configuration ensures a turning or stretching of at least a side of the pelt around the mandrel during processing of the pelt by means of the apparatus, so that the part of the skin side of the pelt at or near the corners of the mandrel will be shifted to a side of the mandrel by said force components and thus be subjected to a more throughout processing. The repetition of the application of a force component in the same direction ensures that the effect is obtained satisfactory. The force components parallel to the mandrel imposed by the two scraping rollers of the first pair of primary scraping rollers on the skin side of a pelt during their engagement with the skin side of a pelt are preferably both directed towards the thicker end of the mandrel so that said force components assist in maintaining the pelt stretched towards the thicker end of the mandrel. Likewise, the force components parallel to the mandrel imposed by the each of the secondary scraping rollers on the skin side of a pelt during their engagement with the skin side of a pelt is preferably directed towards the thicker end of the mandrel so that said force components assist in maintaining the pelt stretched towards the thicker end of the mandrel.

It is preferred in one embodiment of the present invention that the other scraping roller of the first pair of primary scraping rollers and the other scraping roller of the first pair of secondary scraping rollers, which are arranged to engage the skin side of a pelt on the same side of the mandrel, each has a plurality of scraping edges extending substantially helically along the longitudinal direction of the scraping rollers, wherein said two scraping rollers are arranged to impose force components transversal to the longitudinal direction of the mandrel acting in the same direction on the skin side of a pelt during their engagement with the skin side of a pelt.

In one embodiment of the present invention, the two scraping rollers of the first pair of primary scraping rollers are provided with a plurality of scraping edges extending substantially helically along the longitudinal direction of the scraping rollers and are arranged to impose force components transversal to the longitudinal direction of the mandrel acting in the same direction on the skin side of a pelt during their engagement with the skin side of a pelt. With this configuration, the tendency of the first mentioned scraping rollers of the first pair of primary scraping rollers to rotate the pelt on the mandrel is countered by the action of the last mentioned scraping rollers of the first pair of primary scraping rollers.

According to an alternative embodiment of the present invention, the two scraping rollers of the first pair of primary scraping rollers are provided with a plurality of scraping edges extending substantially helically along the longitudinal direction of the scraping rollers and are arranged to impose force components transversal to the longitudinal direction of the mandrel acting in opposing directions on the skin side of a pelt during their engagement with the skin side of a pelt. With this configuration, the first pair of primary scraping rollers will in operation of the apparatus together imposes a rotational force (i.e. a torque) on the pelt around the longitudinal axis of the mandrel. The torque imposed by the first pair of primary scraping rollers will turn the pelt a fraction as the sides of the skin side of the pelt are scraped by the first pair of primary scraping rollers so that the part of the skin side of the pelt near the four corners of the mandrel will be angularly displaced to the sides of the mandrel, where two opposing corner parts will be scraped by the first pair of primary scraping rollers and the other two corners parts of the skin side of the pelt will in turn be scraped by the second pair of the primary scraping rollers and thus the whole skin side of the pelt is satisfactory processed by the scraping rollers.

Furthermore, the two scraping rollers of the second pair of primary scraping rollers may be arranged to impose force components transversal to the mandrel acting in opposite directions on the skin side of a pelt during their engagement with the skin side of a pelt, so that the second pair of primary scraping rollers will tend to rotate the pelt in the opposite direction around a longitudinal direction of the mandrel than the first pair of primary scraping rollers whereby a twisting of the pelt is reduced or avoided. The magnitudes of said force components of the scraping rollers of the second pair of primary scraping rollers transversal to the mandrel are preferably substantially equal.

The force components parallel to the mandrel imposed by the two scraping rollers of the second pair of primary scraping rollers on the skin side of a pelt during their engagement with the skin side of a pelt both are preferably directed towards the thicker end of the mandrel.

The first pair of primary scraping rollers and the second pair of primary scraping rollers are in a preferred embodiment arranged adjacent to each other in a longitudinal direction of the mandrel. It is furthermore preferred that one or both of the second pair of primary scraping rollers are provided with essentially V-shaped or U-shaped scraping edges.

The apparatus may further comprise a tail scraping roller provided with a plurality of scraping edges of a substantially symmetrical configuration, so that said tail scraping roller will impose a substantially zero resulting force component on the skin side of a pelt in a longitudinal direction of the tail scraping roller during its engagement with the skin side of a pelt, the tail scraping roller being arranged to scrape a skin part of the tail of the pelt, the apparatus further comprising rotation means for rotating said tail scraping roller during processing of a pelt. Hereby, the skin side of the tail will be properly processed because it will be fully scraped by a scraping roller of a symmetrical configuration as opposed to a scraping roller having helical scraping edges, which may just turn the tail part of the pelt to the side to be directed transversal to the mandrel without being properly scraped. Said tail scraping roller of a substantial symmetrical configuration has preferably a configuration of the scraping edges selected from the group consisting of V-shaped, U-shaped and straight scraping edges of which the configuration of V-shaped scraping edges is preferred. Said tail scraping roller constitutes preferably one of the second pair of secondary scraping rollers. In a preferred embodiment, both of the second pair of secondary scraping rollers are provided with scraping edges of a V-shaped configuration.

Said moving means consists in a preferred embodiment of the present invention of mandrel drive means for driving the mandrel in a longitudinal direction thereof during processing of a pelt.

BRIEF DESCRIPTION OF THE FIGURES

An embodiment of the present invention is shown in the accompanying drawing of which Fig. 1 is a schematic perspective view of a first embodiment of an apparatus according to the present invention,

Fig. 2 is a perspective view of a second embodiment of an apparatus according to the present invention, and

Fig. 3 is a side view of a mandrel and helical scraping rollers for illustration of the forces imposed on a pelt on the mandrel by the helical scraping rollers. DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION

The furred animal, in this example a mink, has been skinned and the fresh pelt 3 has been turned inside out and drawn onto the mandrel 1 with the fur side towards the surface of the mandrel 1 and the skin side, also known as the flesh side, outwards and ready for being processed by the scraping device 5. This processing is intended to remove flesh residues, fat, tendons and other material from the skin side of the fur. The pelt 3 comprises the skin part of e.g. the tail 6 and the skin parts 32 of the pelt 3 that have covered the front legs of the animal. The pelt 3 is in the drawing arranged with the tail 6 and consequently the back side of the pelt 3 on top of the mandrel 1 , the front leg skin parts 32 on the side of the mandrel 1 and the belly side of the pelt 3 on the lower side of the mandrel 1.

A scraping apparatus for scraping the skin side of tubular pelts according to the present invention, in particular mink pelts is shown in Fig. 1 , comprising a tapered, horizontal mandrel 1 having a thinner front end 2 from which the pelt 3 is drawn onto the mandrel 1 and a thicker end 4 which is connected to mandrel moving means (not shown) for moving the mandrel 1 in a longitudinal direction thereof towards the scraping device 5 during the processing of a pelt 3 and back to the starting position of the mandrel 1 in a return stroke. The mandrel 1 is of a square cross-sectional shape and the scraping device 5 is designed for processing each of the four sides of the pelt 3 drawn onto the mandrel 1. The scraping device 5 is arranged stationary on a frame (not shown) of the apparatus and comprises four primary scraping rollers 7, 8, 9, 10 arranged in two pairs, a first pair 7, 8 arranged on the opposing vertical side of the mandrel 1 for scraping of the vertical sides of the skin side of the pelt 3 arranged on the mandrel 1 and a second pair 9, 10 for scraping of the horizontal sides of the skin side of the pelt 3. Each primary scraping roller 7, 8, 9, 10 is driven by an individual motor 11, 12, 13, 14. The primary scraping rollers 7, 8, 9, 10 are provided with helical scraping edges 15, 16, 17, 18 arranged so that all four primary scraping rollers 7, 8, 9, 10 impose a force on the pelt 3 in the direction towards the thicker end 4 of the mandrel 1 whereby the pelt 3 is stretched on the mandrel 1 and remains stretched during the processing of the pelt 3. The first pair 7, 8 of the primary scraping rollers are formed and driven as shown in Fig. 1 so that one scraping roller 7 furthermore imposes an upwardly force component to the skin side of the pelt 3 and the other scraping roller 8 imposes a downwardly force component to the skin side of the pelt 3 so that the first pair 7, 8 of primary scraping rollers together imposes a rotational force (i.e. a torque) on the pelt 3 in a clock-wise direction as indicated by an arrow on Fig. 1. The second pair of primary scraping rollers 9, 10 has scraping edges 17, 18 formed oppositely, so that the second pair of scraping rollers 9, 10 impose forces transverse to the longitudinal direction of the mandrel 1 to provide a torque on the pelt that is opposite to the torque imposed by the first pair 7, 8 of the primary scraping rollers, i.e. in the counter clock- wise direction as indicated by the corresponding arrow in Fig. 1. The torque imposed by the first pair 7, 8 of primary scraping rollers will turn the pelt 3 a fraction clockwise as the left and right side of the skin side of the pelt 3 are scraped so that the part of the skin side of the pelt 3 near the four corners of the mandrel 1 will be angularly displaced to the sides of the mandrel, where said corner parts of the skin side of the pelt 3 at the two sides of the mandrel 1 will be scraped by the first pair 7, 8 of primary scraping rollers. The corners parts of the skin side of the pelt 3 displaced to the upper and lower sides of the mandrel 1 will in turn be scraped by the second pair 9, 10 of the primary scraping rollers, so that the whole skin side of the pelt is satisfactory processed by the primary scraping rollers 7, 8, 9, 10. The torques are of substantially the same magnitude, so that the pelt 3 after being processed by means of both pairs of primary scraping rollers 7, 8, 9, 10 will be displaced angularly to substantially the original position of the pelt 3 without a twist to the pelt.

The apparatus is further equipped with secondary scraping rollers 21, 22, 23, 24 displaced in the longitudinal direction of the mandrel 1 with respect to the primary scraping rollers 7, 8, 9, 10 to improve the scraping of the skin side of the pelt 3 further. The secondary scraping rollers comprises a first pair of scraping rollers 21, 22 which are arranged on opposing sides of the mandrel 1 corresponding to the first pair of primary scraping rollers 7, 8 and a second pair of secondary scraping rollers 23, 24 which are arranged on the other opposing sides of the mandrel 1 corresponding to the second pair of primary scraping rollers 9, 10. Each secondary scraping roller 21, 22, 23, 24 is driven by an individual motor 25, 26, 27. The secondary scraping rollers 21, 22, 23, 24 are in the shown embodiment provided with helical scraping edges 28, 29, 30, 31 which are arranged similarly to the primary scraping rollers 7, 8, 9, 10 so that all they impose a force on the pelt 3 in the direction towards the thicker end 4 of the mandrel 1. The first pair 21, 22 of the secondary scraping rollers are formed and driven as shown in Fig. 1 so that one scraping roller 21 furthermore imposes an upwardly force component to the skin side of the pelt 3 and the other scraping roller 22 imposes a downwardly force component to the skin side of the pelt 3, the first pair 21, 22 thus imposing a torque on the pelt 3 in a clockwise direction as indicated by an arrow on Fig. 1 and the second pair 23, 24 of secondary scraping rollers has scraping edges 30, 31 formed oppositely, so that the scraping rollers 23, 24 impose a torque on the pelt which is in the opposite direction of the torque imposed by the first pair 21, 22 of the secondary scraping rollers, i.e. in the counter clock-wise direction as indicated by the corresponding arrow in Fig. 1. The impact from the secondary scraping rollers 21, 22, 23, 24 on the pelt 3 will be similar to the impact from the primary scraping rollers 7, 8, 9, 10 as described previously. In an alternative embodiment as shown in Fig. 2, one or both of the second pair 23, 24 of secondary scraping rollers are instead provided with scraping edges 30' of a V- shaped configuration which will provide for a satisfactory scraping of the skin side of the pelt 3 without imposing a torque on the pelt 3. Such scraping rollers 23, 24 provided with scraping edges 30' of a V-shaped configuration which will stretch the pelt 3 on the mandrel 1 away from the corners of the mandrel 1 and towards the centre of the plane sides of the mandrel 1 and ensure that the part of the pelt 3 near and at the corners of the mandrel 1 will be processed by both sets of primary scraping rollers 7, 8, 9, 10 and thus be sufficiently cleaned for the following processing of the pelt 3, starting with the drying of the pelt 3. In particular, the provision of a scraping roller with scraping edges of a V-shaped configuration at the side of the mandrel 1 where the tail part 6 of the pelt 3 will be arranged ensures that this part of the pelt 3 is sufficiently cleaned as the scraping roller imposes a substantially zero resulting force on the pelt 3 in the direction transverse to the longitudinal direction of the mandrel 1 and the tail part 6 will thus be sufficiently cleaned by such scraping roller, whereas a scraping roller having helical scraping edges may force the tail part 6 to be turned to be oriented substantially transverse to the longitudinal direction of the mandrel 1 and therefore be insufficiently scraped. That may in turn leave excessive fat or meat residues on the tail part 6 that during drying of the pelt 3 can cause a reduction of the quality of the pelt 3. Similar results could be achieved by a roller having scraping edges of a U-shaped configuration or a straight configuration, i.e. extending substantially parallel to the centre axis of the scraping roller. In another alternative embodiment, one or both of the second pair 9, 10 of the primary scraping rollers are additionally or alternatively provided with scraping edges of a V-shaped, U-shaped or straight configuration. In Fig. 3, the mandrel 1 together with one 7 of the first pair of primary scraping rollers and one 21 of the first pair of secondary scraping rollers are shown as seen from the right side. The scraping edges 15, 28 of the scraping rollers 7, 21 impose forces F7, F21 on the skin side of the pelt 3 having respective angles a and β to the longitudinal direction of the mandrel 1 so that the force F7 imposed by one scraping roller 7 has a component towards the thicker end 4 of the mandrel 1 and an upwards component, whereas the other scraping roller 21 imposes a force F21 with a component towards the thicker end of the mandrel 1 as well as an upward component. The angles a and β may be different and the magnitude of the forces F7, F21 may also be uneven, but in a preferred embodiment of the present invention, the angles a and β as well as the magnitude of the forces F7, F21 of imposed by the two scraping rollers 7, 21 on the skin side of the pelt are substantial identical. The mandrel 1 is during operation moved in the direction indicated by the arrow MD in the longitudinal direction of the mandrel 1 towards its thinner end 2.

LIST OF REFERENCE NUMERALS

1 Mandrel

2 Thinner front end of mandrel

3 Pelt

4 Thicker end of mandrel

Scraping device

6 Skin part of the tail

7, 8 Scraping rollers of first pair of primary scraping rollers

9, 10 Scraping rollers of second pair of primary scraping rollers

11, 12, 13, 14 Motors for driving the primary scraping rollers

14' Motor for driving the tail scraping roller

15, 16, 17, 18 Helical scraping edges of the primary scraping rollers

21, 22 Scraping rollers of the first pair of secondary scraping rollers

23, 24 Scraping rollers of the second pair of secondary scraping rollers

25, 26, 27 Motors for driving the secondary scraping rollers

28, 29, 30, 31 Helical scraping edges of the secondary scraping rollers

V-shaped scraping edges of a secondary scraping roller

Skin parts of the pelt that have covered the front legs of the animal

F7 Force imposed by one primary scraping roller on the pelt

F21 Force imposed by one secondary scraping roller on the pelt

MD Direction of movement of the mandrel Angle between force imposed by a primary scraping roller on the pelt and the longitudinal direction of the mandrel

Angle between force imposed by a secondary scraping roller on the pelt and the longitudinal direction of the mandrel