i DK 177520 B1
APPARATUS FOR PROCESSING OF PELTS HAVING FRONT LEG SCRAPING ROLLERS
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 scraping rollers particularly 5 designed for scraping the area of the skin side of the pelt where that covered the front legs of the furred animals.
Background A fresh pelt taken from a furred animal such as a mink normally has a layer or 10 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, 15 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.
20 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.
25 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.
30 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 DK 177520 B1 2 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.
5 WO 2012/019606 A1 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.
10 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.
15 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.
20
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, in particular around the skin parts that have covered the front legs of the furred animal.
25
Brief description of the invention
The present invention relates to an apparatus for processing the skin side of a tubular pelt, in particular a mink pelt, the apparatus comprising an elongated tapering mandrel for supporting the pelt with its skin side turned outwards and the fur side 30 turned inwards against the surface of the mandrel, the mandrel having a thinner, free end from which the tubular pelt is drawn over the mandrel and a thicker end, a DK 177520 B1 3 scraping device comprising two front leg scraping rollers each having a plurality, such as 7 to 12 scraping edges and being arranged to engage a skin side of a pelt on opposing sides of the mandrel, and rotation means for rotating the front leg scraping rollers, moving means for conducting a relative movement between the scraping 5 device and the mandrel in the longitudinal direction of the mandrel, wherein the plurality of scraping edges extend substantially helically along the longitudinal direction of the front leg scraping rollers, and wherein the two front leg scraping rollers are arranged to impose force components transversal to the mandrel acting in the same direction on the skin side of a pelt during their engagement with the skin 10 side of a pelt so as to reduce or eliminate the tendency of such forces to rotate the pelt on the mandrel as known from the aforementioned Danish patent specification DK 173 611.
The front leg scraping rollers are furthermore preferably arranged so that the force 15 components parallel to the mandrel imposed by the two front leg scraping rollers on the skin side of a pelt during their engagement with the skin side of a pelt both are directed towards the thicker end of the mandrel whereby the whole pelt remains stretched on the mandrel and damages on the pelt or insufficient processing of the skin side due to unequal stretching of the pelt at the two sides are avoided.
20
It is particularly preferred that the helical scraping edges of the two front leg scraping rollers have opposite directions of turn, i.e. left-handed helical and right-handed helical. Hereby, the front leg scraping rollers may be rotated in opposite directions on opposing sides of the mandrel with parallel axes of rotation and impose forces on the 25 skin side of the pelt when in engagement with the skin side that have equal-sized components in the same direction perpendicularly to the longitudinal direction of the mandrel and equal-sized components in the direction towards the thicker end of the mandrel.
30 In a particularly preferred embodiment of the present invention, the moving means consists of mandrel drive means for driving the mandrel in a longitudinal direction 4 DK 177520 B1 thereof during processing of a pelt while the scraping device is kept substantially stationary.
The scraping device according to the present invention preferably comprise a first set 5 of primary scraping rollers arranged on opposing sides of the mandrel and a second set of primary scraping rollers arranged on other opposing sides of the mandrel and being substantially perpendicularly oriented with respect to the first set of primary scraping rollers, the scraping device further comprising primary rotation means for rotating said primary scraping rollers during processing of a pelt so as to engage a 10 skin side of the pelt. The skin side of the pelt may thereby be processed by being scraped on all side of a substantially rectangular or square cross-section of the mandrel by means of the primary scraping rollers, which in a preferred embodiment each are equipped with a plurality of scraping edges being substantially V-shaped.
15 The V shape of the primary scraping rollers' scraping edges has several advantages. Firstly, the scraping edges prevent the pelt from rotating on the mandrel. Among other things, this results in increased control over the scraping of the pelt. The V shape also means that the pelt on the mandrel can be stretched towards or away from a plane that passes through the centre axis of the mandrel in the longitudinal 20 direction of the mandrel so that areas around edges or curves on the mandrel are processed, depending on how the primary scraping rollers are turned. The scraping rollers with the V-shaped scraping edges are arranged preferably so that the points of contact between the scraping rollers and the pelt for each of the scraping edges, during operation, stretches the pelt towards a plane that passes through the centre 25 axis of the mandrel in the longitudinal direction of the mandrel. Thus, e.g. the parts of the skin arranged on edges of the mandrel for example in embodiments where the mandrel comprises substantially plane surfaces, e.g. a square formed tapering mandrel with four edges extending in the longitudinal direction of the mandrel the skin parts at or near the edges are adequately scraped.
30 DK 177520 B1 5
In an alternative embodiment, the set of primary scraping rollers that are arranged to process the skin side of the pelt on the same opposing sides of the mandrel as the front leg scraping rollers are processing may be equipped with scraping edges that extent substantially helical along the longitudinal direction of said primary scraping 5 rollers so that they are arranged to impose force components transversal to the mandrel acting in the same direction in the skin side of the pelt during their engagement with the skin side, wherein that force is in the opposite direction of the force imposed by the front leg scraping rollers. Hereby, the pelt is stretched in the opposite direction by this set of primary scraping rollers and the scraping of the 10 edges of the skin side of the pelt, i.e. the area at the edges of the mandrel, may be improved. It is particularly preferred that the helical scraping edges of the two primary scraping rollers of this set have opposite directions of turn, i.e. left-handed helical and right-handed helical. Hereby, the primary scraping rollers may be rotated in opposite directions on opposing sides of the mandrel with parallel axes of rotation 15 and impose forces on the skin side of the pelt when in engagement with the skin side that have equal-sized components in the same direction perpendicularly to the longitudinal direction of the mandrel and equal-sized components in the direction towards the thicker end of the mandrel.
20 The apparatus may also comprise biasing means for selectively biasing the scraping edges of the front leg scraping rollers into engagement with the skin side of a pelt supported on the mandrel.
The shape of the scraping edges of the primary as well as the front leg scraping 25 rollers are preferably shaped for defining a contour substantially complementary to the cross-sectional contour of the mandrel.
The helical scraping edges of the front leg scraping rollers form preferably an angle (a) with the axis of rotation of the respective scraping roller in the range of 30 to 65°, 30 preferably in the range of 35 to 55° to ensure an actual lifting of the front leg of the DK 177520 B1 6 pelt and an efficient scraping of the area around and in particular beneath the front leg.
The present invention also relates to the use of an apparatus as described herein, 5 wherein the tubular pelt is arranged on the mandrel so that the force components transversal to the mandrel imposed by the two front leg scraping rollers on the skin side of the pelt during their engagement with the skin side of the pelt both act from a belly side of the pelt towards a back side of the pelt, whereby the front leg scraping roller will process the skin side of the pelt particularly well under and behind skin 10 parts of the fur that have covered the front legs of the animal as these skin parts will be lifted by the action of the front leg scraping rollers.
The scraping roller is made from an elastic material, such as a natural or artificial rubber, and it is preferred that the roller is moulded in a polyester type polyurethane 15 having a hardness between Shore 60A and Shore 95A.
The scraping edges of the front leg scraping roller form preferably a substantially cylindrical surface so as to match the outer shape of a mandrel having a rectangular or quadratic cross-section.
20
Also, the present invention relates to a pair of scraping rollers as described herein, wherein helical scraping edges of the two scraping rollers have opposite directions of turn, i.e. left-handed helical and right-handed helical scraping edges.
25 These scraping rollers are the preferred ones for being a part of the apparatus described herein and for being used as disclosed herein.
Brief description of the figures
An embodiment of the present invention is shown in the accompanying drawing of 30 which DK 177520 B1 7
Fig. 1 is a schematic perspective view of an apparatus according to the present invention,
Fig. 2 is a perspective view of a set of front leg scraping rollers according to the 5 invention,
Fig. 3 is a side view of a mandrel with a tubular pelt thereon and one of the front leg scraping rollers shown, 10 Fig. 4 is a top view of a mandrel with a tubular pelt thereon and both of the front leg scraping rollers shown, and
Fig. 5 is a partial side view of one of the front leg scraping rollers.
15 Detailed description of an embodiment of the invention 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 20 (not shown) for moving the mandrel 1 in a longitudinal direction thereof towards the scraping device 5 during the processing of a pelt 6 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 6 drawn onto the mandrel 1.
25
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 to 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 30 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.
DK 177520 B1 8
The primary scraping rollers 7, 8, 9, 10 are provided with V-shaped scraping edges 15, which will stretch the pelt 3 on the mandrel 1 away from the comers of the mandrel 1 and towards the centre of the plane sides of the mandrel 1. Since the two pairs of primary scraping rollers 7, 8, 9, 10 are displaced in the longitudinal direction 5 of the mandrel 1, the V-shape of the scraping edges 15 will ensure that the part of the pelt 3 near and at the comers 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. All four primary scraping rollers 7, 8, 9, 10 impose a force on the pelt 3 in the direction towards the 10 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 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 15 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 16 and the skin parts 6a, 6b of the pelt 3 that have covered the front legs of the animal. The area beneath the front leg 20 skin parts 6a, 6b are difficult to process completely and a residue of fat may be left from the processing by the primary scraping rollers 7, 8, 9, 10 which may cause damages to the pelt as the fat may influence the fur side of the pelt negatively. Therefore, the pair of front leg scraping rollers 17, 18 have been provided for a separate scraping of the area around and in particular beneath the front leg skin parts 25 6a, 6b, i.e. in the direction towards the belly side of the pelt 3. The front leg scraping rollers 17, 18 are driven by individual motors 20, 21.
The pelt 3 is in the drawing arranged with the tail 16 and consequently the back side of the pelt 3 on top of the mandrel 1, the front leg skin parts 6a, 6b on the side of the 30 mandrel 1 and the belly side of the pelt 3 on the lower side of the mandrel 1.
DK 177520 B1 9
The front leg scraping rollers 17, 18 are provided with helical scraping edges 19, 19’ as shown in Figs. 2, 3 and 5, where it is clear from Fig. 2 that the helical scraping edges 19, 19’ are turned in opposite direction on the two front leg scraping rollers 17, 18, so that one roller 17 has a left-hand turn of the scraping edges 19 whereas the 5 other roller 18 has a right-hand turn of the scraping edges 19’. The purpose of the helical scraping edges 19, 19’ is that they will provide the front leg skin parts 6a, 6b with a force in the direction towards the back side of the pelt 3 and lift these skin parts 6a, 6b so that the front leg scraping rollers 17, 18 obtain access to process the area beneath the skin parts 6a, 6b and remove the fat and other impurities, resulting 10 in a more satisfactory overall result of the processing of the skin side of the pelt 3 by the apparatus. The helical scraping edges 19, 19’ have an angle of 41° with the axis of rotation.
The two front leg scraping rollers 17, 18 are of similar diameter and are driven with 15 the same rotational speed so that the force they impose on the skin side of the pelt 3 will have a component transversal to the longitudinal direction of the mandrel 1, in the case shown in the upwards direction, which are of the same magnitude of and have the same direction so that both front leg skin parts 6a, 6b are lifted and the pelt 3 will not rotate on the mandrel 1. This could be achieved with identical front leg 20 scraping rollers 17, 18, of which one is turned upside down with respect to the other, but with the present embodiment, the two rollers 17, 18 are formed with mirrored directions of turn of the helical scraping edges 19, 19’ so that both can impose a force on the skin side of the pelt 3 having an upwards component as well as a component in the longitudinal direction of the mandrel 1 towards the thicker end 4 of 25 the mandrel 1 whereby the pelt 3 remains stretched on the mandrel 1 and damages on the pelt 3 or insufficient processing of the skin side due to unequal stretching of the pelt 3 at the two sides in case the two front leg scraping rollers 17, 18 rotate in different directions. A side view of the mandrel 1 with a pelt 3 arranged and one of the front leg scraping rollers 17 is shown in Fig. 3 with the axis of rotation 22 of the 30 roller 17 indicated and a diagram of the forces imposed by the roller 17 on the skin side of the pelt 3 during processing. The helical scraping edges 19 are turning left- DK 177520 B1 10 handed on the roller 17 and the roller 17 is rotated counter clockwise when seen from above as in Fig. 4 and the scraping edges 19 will thus impose an upward force component as well as a component towards the thicker end 4 of the mandrel 1.
5 The front leg scraping rollers 17, 18 are in the example shown in Fig. 1 arranged to engage the skin side of the pelt 3 prior to the processing by the two pairs of primary rollers 7, 8, 9, 10, but it should be clear that the pair of front leg scraping rollers 17, 18 could as well be arranged between the two pairs of primary rollers 7, 8, 9, 10 or so that they would engage the skin side of the pelt 3 after the primary rollers 7, 8, 9, 10 10 have processed the pelt 3.
The apparatus also comprises biasing means (not shown) for selectively biasing the scraping edges 19, 19’ of the front leg scraping rollers 17, 18 into engagement with the skin side of a pelt 3 supported on the mandrel 1. The biasing means are 15 preferably arranged so that the front leg scraping rollers 17, 18 only engages the skin side of the pelt 3 in the region in which the front legs 6a, 6b are situated and are withdrawn from the engagement when the front legs 6a, 6b have passed the front leg scraping rollers 17, 18, whereas other biasing means (not shown) are arranged to bias the primary scraping rollers 7, 8, 9, 10 into engagement with the skin side of the pelt 20 3 along the whole length of the pelt 3.
List of reference numerals 1 Mandrel 2 Thinner front end of mandrel 25 3 Pelt 4 Thicker end of mandrel 5 Scraping device 6a, 6b Skin parts of the pelt that have covered the front legs of the animal 7, 8 Scraping rollers of first pair of primary scraping rollers 30 9,10 Scraping rollers of second pair of primary scraping rollers 11, 12, 13, 14 Motors for driving the primary scraping rollers DK 177520 B1 11 15 V-shaped scraping edges 16 Skin part of the tail 17, 18 Front leg scraping rollers 19, 19’ Scraping edges of the front leg scraping rollers 5 20,21 Motors for driving the front leg scraping rollers 22 Axis of rotation of a front leg scraping roller a Angle between scraping edge of a front leg scraping roller and the axis of rotation thereof 10