DK179849B1 - Curved gripping elements for gripping a pelt - Google Patents

Curved gripping elements for gripping a pelt Download PDF

Info

Publication number
DK179849B1
DK179849B1 DKPA201870055A DKPA201870055A DK179849B1 DK 179849 B1 DK179849 B1 DK 179849B1 DK PA201870055 A DKPA201870055 A DK PA201870055A DK PA201870055 A DKPA201870055 A DK PA201870055A DK 179849 B1 DK179849 B1 DK 179849B1
Authority
DK
Denmark
Prior art keywords
gripping
pelt
curvature
gripping element
radius
Prior art date
Application number
DKPA201870055A
Other languages
Danish (da)
Inventor
Pedersen Kurt
Original Assignee
Eikon Technologies Holding S.À.R.L.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Eikon Technologies Holding S.À.R.L. filed Critical Eikon Technologies Holding S.À.R.L.
Priority to DKPA201870055A priority Critical patent/DK179849B1/en
Priority to PL428664A priority patent/PL428664A1/en
Application granted granted Critical
Publication of DK179849B1 publication Critical patent/DK179849B1/en
Publication of DK201870055A1 publication Critical patent/DK201870055A1/en

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C14—SKINS; HIDES; PELTS; LEATHER
    • C14B—MECHANICAL TREATMENT OR PROCESSING OF SKINS, HIDES OR LEATHER IN GENERAL; PELT-SHEARING MACHINES; INTESTINE-SPLITTING MACHINES
    • C14B15/00—Mechanical treatment of furs
    • C14B15/04—Fur dressing
    • C14B15/06—Fur-stretching devices
    • C—CHEMISTRY; METALLURGY
    • C14—SKINS; HIDES; PELTS; LEATHER
    • C14B—MECHANICAL TREATMENT OR PROCESSING OF SKINS, HIDES OR LEATHER IN GENERAL; PELT-SHEARING MACHINES; INTESTINE-SPLITTING MACHINES
    • C14B1/00—Manufacture of leather; Machines or devices therefor
    • C14B1/26—Leather tensioning or stretching frames; Stretching-machines; Setting-out boards; Pasting boards

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Shaping By String And By Release Of Stress In Plastics And The Like (AREA)

Abstract

The present invention relates to gripping means, stretching apparatus and a method of stretching a pelt on a pelt board. The gripping means comprises a set of gripping elements comprising a first gripping element and a second gripping element, each having a gripping surface wherein a longitudinal extend of said gripping surface of said first gripping element in a direction parallel to a longitudinal centre axis of the pelt board is of a convex shape configured to correspond to a concave shape of said gripping surface of said second gripping element, such that when said gripping surfaces are in an opposing arrangement and a pelt is arranged between the gripping surfaces, the pelt can be gripped by the gripping surfaces by mutual displacement of the gripping surfaces, said gripping surface of said first gripping element comprises a surface curvature at a first point (P1) having a first radius of surface curvature (R1), and said gripping surface of said second gripping element comprises a surface curvature at a second point (P2) having a second radius of curvature (R2), said first point (P1) and said second point (P2) are opposing points in said opposing arrangement, wherein said first radius of the surface curvature (R1) is smaller than said second radius of the surface curvature (R2) by 10-40 %, such as by 15-35 % or such as by 20-30 %.

Description

CURVED GRIPPING ELEMENTS FOR GRIPPING A PELT
The invention relates to gripping means comprising curved gripping elements for gripping a pelt to be stretched, an apparatus for stretching a pelt on a pelt board comprising curved gripping elements and a method of stretching said pelt.
BACKGROUND
It is common practise to stretch pelts along the longitudinal of the pelts before drying them in order to obtain a desired size of the pelt and a wrinkleless leather part of the pelt. For pelts of bred furred animals, in particular mink and fox, the pelt is usually stretched on a pelt board, by fastening a lower part of the pelt and applying a stretch force in a direction opposite the nose-end of the pelt. The individual pelt is stretched with individual force to an individual length depending on the size and the sex of the animal and other qualities of the un-stretched pelt. The pelt is thereafter secured to the pelt board prior to drying the pelt.
Danish patent No. DK 169 525 discloses a machine for stretching of pelts on pelt boards, where a first stretch force is applied to stretch the pelt and, in case it is detected that the pelt length is close to the next higher classification size, a second, higher stretch force is applied to the pelt.
International patent application No. WO 02/44428 discloses a further development of this machine by adding a vibrating movement to the pelt during the stretching thereof, whereby an increased stretching of the pelt is achieved without causing damages to the pelt.
In the international patent application No. WO 2005/028682 a device for stretching of pelts is disclosed, where holding elements are provided to grip, engage and fasten the pelt along the whole periphery of the lower end of the pelt, thereby applying the stretch force more uniformly to the pelt and allowing for an increased stretching thereof.
In the international patent application No. WO 2012/126467 Al, the maximum force with which the apparatus stretches the pelt is determined for the individual pelt from the length of the pelt prior to stretching thereof. It is also disclosed to decrease the stretching force to reduce the length of the stretched pelt to the nearest shorter classification size length and thereby improving the quality of the pelt.
The international patent application no. WO 2015/024788 describes a stretching apparatus for stretching a pelt in the longitudinal direction thereof by controlling the stretching operation so as to reduce the speed which with the pelt is stretched during stretching of the pelt.
In the international patent application no. WO2017149074 and in the European patent application no. EP3135776, a stretching apparatus comprising a holding device and a fastening device comprising a gripping mechanism is described. The tubular contour of the rear end of the pelt is pinned between gripping elements and opposing holding elements of the gripping mechanism.
The object of the present invention is to improve the stretching of the pelts, in particular stretching of mink pelts, and furthermore increase the number of pelts that are stretched to an optimal length without damage to the pelt.
BRIEF DESCRIPTION OF THE INVENTION
The inventor has found that during the stretching process, pelts may be fixed by gripping means in a more efficient way such that the pelt may be stretched by a larger stretching force without damaging the pelt. The increased efficiency of the gripping means leads to an increased exploitation of the stretching potential of the pelt which in turn increases the value of the pelt.
The first aspect of the invention relates to gripping means for an apparatus for stretching a pelt on a pelt board, wherein said gripping means comprises a set of gripping elements comprising a first gripping element and a second gripping element, each gripping element comprising a gripping surface, wherein a longitudinal extend of said gripping surface of said first gripping element in a direction parallel to a longitudinal centre axis of the pelt board is of a convex shape configured to correspond to a concave shape of said gripping surface of said second gripping element, such that when said gripping surfaces are in an opposing arrangement and a pelt is arranged between the gripping surfaces, the pelt can be gripped by the gripping surfaces by mutual displacement of the gripping surfaces, said gripping surface of said first gripping element comprises a surface curvature at a first point (P1) having a first radius of surface curvature (R1), and said gripping surface of said second gripping element comprises a surface curvature at a second point (P2) having a second radius of curvature (R2), said first point (P1) and said second point (P2) are opposing points in said opposing arrangement, wherein said first radius of the surface curvature (R1) is smaller than said second radius of the surface curvature (R2) by 10-40 %, such as by 15-35 % or such as by 20-30 %.
Due to the curved surface shape of the gripping surface the overall contact area for gripping the pelt is increased compared to a flat linear surface. This means that a larger compressive force can be applied on the pelt, without increasing the average pressure applied to the pelt, as the force is distributed over a larger surface area.
The correspondence between the surface shapes of the gripping surfaces may mean that the first surface has a gripping surface which is curved e.g. of a surface shape curving outwards along a first direction, the second surface may have a gripping surface of a similar surface shape but curving inwards along said first direction.
The radii of curvatures are generally calculated based on the radius of an osculating circle in a given point, e.g. the radius of curvature of the first gripping element at the first point P1 is the radius of an osculating circle in said first point P1. An osculating circle of the curve at a point P is the circle that has the same tangent as the curve at that point P and the same curvature. The osculating circle may be regarded as the best fit circle that approximates the curve at the point P, e.g. the radii of curvature may be based on a calculation of the best fit circle to a surface curve of the first gripping element and the second gripping element at the first point P1 and second point P2, respectively.
Said first radius of the surface curvature of said first gripping element (R1) is 10-40 %, such as by 15-35 % or such as by 20-30 % smaller than said second radius of the surface curvature of said second gripping element (R2).
Advantageously, this allows for the first gripping element to engage with the second gripping element, such that parts of the first surface and second surfaces are somewhat overlapping e.g. such that the second surface may be somewhat enclosing a part of the first surface. Preferably the gripping surfaces may be shaped such that the gripping surface of the first surface can come into contact with the gripping surface of the second surface.
Furthermore, the larger radius of curvature of the second gripping element allows the pelt to be readily fitted between the first gripping element and the second gripping element and placed along the opposing gripping surfaces of the second gripping element and first gripping element without being trapped and damaged at edges thereof as the pelt is gripped.
In one or more embodiments, the surface shapes of the first and second gripping elements may be regarded as a protrusion and a cavity with surface shapes corresponding to one another, but with the main difference that the radius of surface curvature in the cavity i.e. second gripping element is larger than the radius of surface curvature of the protrusion i.e. the first gripping element at two opposing points on said gripping surfaces.
In one or more examples, the second radius of curvature (R2) may be 2.8 mm measured at second point (P2), said second point (P2) is in the present example located at a point on the gripping surface corresponding to the valley of the surface e.g. the apex or a vertex of a parabola shaped surface curvature. The radius of the surface curvature of the first gripping element (R1) at said first point (P1) is in the present example between 1.7 - 2.5 mm (10-40% smaller) or such as between 1.8 2.4 mm (15-35 % smaller) or such as 2.0 - 2.2 mm (20-30 % smaller), where said first point (P1) is located at the apex of said gripping surface of the first gripping element.
The gripping elements may be arranged with gripping surfaces opposing one another in a direction defined in a transverse plane, the transverse plane being defined by a first (a1) and third axis (a3) arranged perpendicular to one another. A second axis (a2) being perpendicular to the transverse plane. The gripping means may be configured such that the longitudinal centre line of a pelt board arranged with said gripping means preferably extends parallel to the second axis (a2).
In one or more embodiment, the opposing points (P1, P2) may be located on a first line (l) located in a transverse plane defined by the third (a3) and the first axis (a1).
The gripping elements may be configured to be displaceable at least in said transverse plane, such as e.g. along said first line (l) being perpendicular to the longitudinal extent of the pelt board and pelt. The displacement may be undertaken by displacing the first gripping element or the second gripping element or both gripping elements. Alternatively or additionally, the mutual displacement may be provided by a pivoting movement of one or both gripping elements, such that the gripping surfaces and the points (P1), (P2) are brought into an opposing arrangement, preferably such that after the mutual displacement the opposing points are located on said first line (l).
In one or more embodiments, the surface shape of the gripping surfaces of the first gripping element and the second gripping element gradually curves such that the surfaces comprises no sharp edges, such as a 90 degree edge, sharp enough to introduce damages to the pelt upon gripping and stretching the pelt. Preferably, the curvatures at discrete points along the gripping surfaces are gradually changing relative to neighbouring curvatures along the gripping surfaces of both the first gripping element and second gripping element.
Preferably, the set of gripping elements are to be arranged in a pinning machine such that the gripping surfaces provide a gradual sideways displacement of the pelt sandwiched between the surfaces upon gripping said pelt.
In one or more embodiments, the generally smooth surface shape of the gripping elements, e.g. a gradual change in curvature along the gripping surfaces allows for a better interaction between pelt and gripping surfaces in which the pelt may be sufficiently displaced along the curved surfaces as the gripping surfaces engage with the pelt, such that the gripped part may not be unnecessarily over-stretched in some sections e.g. at edges of the gripping surfaces, which may introduce damages to the pelt.
The depth of the curved surface shapes of the gripping surface is preferably of at least 1.5 mm, such as at least 1.75 mm or such as at least 2 mm, which may correspond to the overlap of the outward curvature and inward curvature along said first direction upon engagement of the first gripping element with the second gripping element e.g. in to a closed, gripping position.
The gripping surface of said second gripping element may be configured to be used such that it is directed towards the skin side of the pelt, while said gripping surface of said first gripping element may be configured to be used such that it is directed towards the fur side of the pelt.
The gripping surface may be defined as the part of the surface of the element, arranged to face the pelt, when arranged with said pelt, and providing a continuously curving surface generating either an outward or inward curved surface towards or away from the pelt, respectively.
At least a part of the surface shape of the gripping surface of the second gripping element and/or first gripping element may be symmetrical about a second line (l, ex) extending through the apex i.e. the valley and/or the tip of the curved gripping surfaces, said second line (l, ex) being perpendicular to the tangent line to the curves at the apex points of the gripping surfaces. Preferably, at least a part of surface being adjacent to the apex is symmetrical about the second line (l, ex).
In one or more embodiments, the radius of surface curvature may be larger for the second gripping element than the first gripping element at any opposing surface points (P1, P2) on the curved gripping surfaces.
The gripping elements may be shaped to be able to be displaced such that the surface of the second gripping element and the surface of the first gripping element come into direct contact with each other. In one or more embodiments, the apex of the first gripping element and the apex of the second gripping element may be aligned on the same line and generate a point of contact upon full engagement.
In one or more embodiments, the gripping surface of the second gripping element is of said second radius of curvature (R2) at any point (P2) located within a surface segment covering at least 30 % such as at least 40 % of the gripping surface centred about the apex point (P2, min).
In one or more embodiments, the radius of curvature (R1, R2) at said points (P1, P2) are varying by less than 20 % or such as by less than 10 % between neighbouring first points (P1) and/or between neighbouring second points (P2) within the gripping surfaces. In other embodiments the radius of curvature is approximately constant in all points within the gripping surface. The neighbouring points are defined as being located directly adjacent to one another, such as with a maximum separation distance corresponding to the resolution of the measuring technique for obtaining the radius of curvature.
In one or more embodiments, the gripping surface of the second gripping element comprises said second radius of curvature (R2) at any point (P2) located within a surface segment defined as the part of the gripping surface located between the apex point (P2, min) of the curvature and an edge point (P2, edge) defined at an angle (A2) up to 90 degrees, such as up to 75 degrees or such as up to 55 degrees from a second line (l, ex) extending perpendicular to a tangent line at the apex point (P2, min) and measured from the centre of curvature (C2) for the apex point (P2, min).
In the present embodiment, the surface segment may be defined within an angle (A2) measured from the centre of curvature (C2). The centre of curvature (C2) is the point that is at a distance from the surface curve at the apex point (P2, min) equal to the radius of curvature, such that the segment extends from the apex point (P2, min) to points on the surface at said angle (A2) both below and above a line extending through the apex point (P2, min).
Alternatively, the surface segment may be defined as the surface between two discrete points of intersection between the gripping surface and a second chord (c2), wherein said second chord is arranged perpendicular to a normal line to the curve at a minimum point (P2, min) of said gripping surface of the second gripping element and furthermore arranged at a second distance (h2) from minimum point (P2, min) of said gripping surface. The first distance (h1) and second distance (h2) are measured along a line extending parallel to the second line (l2) through the maximum point at apex, i.e. the tip (P1, max) and the minimum point at the apex, i.e. the valley (P2, min), respectively.
In a similar fashion, the gripping surface of the first gripping element may comprise said first radius of curvature (R1) at any point (P1) located within a surface segment defined as the part of the gripping surface located between two points of intersection of the gripping surface of the first gripping element and a first chord (c1) arranged perpendicular to the second line (l, ex) and at a first distance (h1) inwards from the apex e.g. the tip of first gripping surface.
In one or more embodiments, the first distance (h1) and/or the second distance (h2) may be of an extent corresponding to 0.25% - 0.75% of the radius of surface curvature at the apex of the first gripping element and/or the valley of the second gripping element, respectively.
In one or more embodiments, at least 30 %, such as 35 %, or such as 40 % of the surface segment of the second gripping element and/or the first gripping element is of a radius of curvature (R1, R2) which is substantially constant.
Of all points within the segment at which the radius of curvature can be determined, at at least 30 % of those points, the calculated radius of surface of curvature is approximately constant. The shape of the surface segment can be interpreted as a surface part of a circle, such as the surface of a semi-circle or quarter-circle. The surface segment may be defined in a longitudinal plane defined by the second axis (a2) and a line extending perpendicular to the second axis (a2), said second axis is generally corresponding to be parallel to the longitudinal extent of the pelt when the gripping means are arranged in a pinning machine.
In one or more embodiments, said first radius of surface curvature (R1) of said first gripping element in said first point (P1) is in the range of 0.5-3.5 mm, such as in the range of 1.2 - 2.8 mm.
In one or more embodiments, said second radius of surface curvature (R2) of said second gripping element in said second point (P2) is in the range of 1.5-4.5 mm such as in the range of 2.2 - 3.8 mm.
In one or more embodiments, the gripping surface of the first gripping element and or the second gripping element is of a circular surface shape.
In one or more embodiments, the curvature of the gripping surfaces of the first gripping element and or the second gripping element may be a circular curvature.
This may provide a uniform radius of curvature along the surface, eliminating any abrupt geometrical changes which the pelt may have a difficulty to adapt to while providing a firm grip. Furthermore, if the curved surface of the second gripping element provides a lateral displacement which is too deep, the pelt may not be displaced properly inside the second gripping element. If the curved surface of the second gripping element provides a displacement which is too narrow, a larger compression force may need to be applied in order to properly fasten the pelt, introducing risks of breaking or damaging the pelt.
In one or more embodiments, said gripping means are arranged to grip a mink pelt for stretching said mink pelt. The gripping means may be particularly suited for mink pelts.
In one or more embodiments, said gripping elements extend around the pelt board in a substantially transverse plane extending perpendicular to the longitudinal extend of the pelt board such that the elements are of a collective extent being at least 70-98 %, preferably 80-95 % of the circumference of the pelt board.
For example, a pelt board for a male mink pelt is typically of a circumference of 250 mm at the lower end of the pelt board. The gripping elements may in this case have an extent along the circumference of the pelt which in total corresponds to e.g. 0.7 times 250 mm, which equals at least 175 mm. This total extent may be divided between two or more pairs of gripping elements, each pair comprising a first and second gripping element arranged in an opposing manner.
The width of a set of gripping elements may be measured as the extent of the set of elements in the transverse plane, such as the circumferential width of the set gripping elements as they curve in the transverse plane. The circumferential width of a set of gripping elements, measured at the gripping surface arranged to face towards the pelt board may be above 45 mm, such as above 50 mm, but below 60 mm. One or more sets of gripping surfaces may be arranged to grip a different circumferential extent of the pelt than other sets of gripping surfaces.
In one or more embodiments, the gripping means comprises a plurality of gripping elements, such as four sets of gripping elements. The gripping elements may be of a collectively circumferential extent corresponding to an extent covering e.g. 70 % of the circumference at a lower end of the pelt board when the gripping elements and the pelt board are arranged in pinning machine. Due to the efficiency of the gripping elements in gripping said pelt effectively using a high compressive force, without damaging the pelt, only a small part, such as approximately 70 % of the circumference of the tail end of the pelt needs to be gripped by the gripping means. This allows for the pelt to be gripped more easily is less pelt is needed to be introduced between the gripping surfaces which in turn provides for a more efficient stretching process.
The tubular pelt may generally be larger in circumferential extent than the corresponding part of the pelt board, meaning that the pelt may fold over itself between the gripping which cause creases in the pelt upon gripping said pelt. Furthermore, this may result in an uneven stretching of the pelt. Advantageously, by allowing the gripping means to engage with only parts of the periphery of the pelt, the occurrence of creases within the pelt can be significantly reduced as it is not necessary for circumference of the pelt to the circumferential extent of the opposing gripping surfaces or the pelt board. Parts of the pelt between the gripping surfaces may be aligned with the gripping surfaces while the remaining parts may hang freely.
In one or more embodiments, the second gripping element may be adapted to be placed near the inner side of the pelt, and furthermore comprise a gripping surface directed toward the skin side of the pelt and comprising a surface shape generating a cavity. The corresponding first gripping element, adapted to be arranged on the fur side of the pelt, may comprise a gripping surface directed towards the fur side and comprising a surface shape protruding towards said cavity. These surface shapes may be similar, e.g. such as the same along a width (W) of the set of gripping elements measured in the transverse plane.
In one or more embodiments, the transverse shape in the transverse plane of the inner element is arranged to curve about the second axis (a2) and may preferably be of a shape similar to a pelt board suitable for use with said gripping elements and for being arranged adjacent to the gripping element in question. This correspondence in shape is advantageous as it allows for an easy introduction of the innermost gripping element in the narrow space between the pelt board and the skin side of the pelt. The innermost element may then be tightly aligned with the pelt board and any major gaps between the gripping element and the pelt board in the transverse plane, due to different shapes, is eliminated. Similarly, the outermost gripping element may also be of a transverse shape similar to the transverse shape of the part of the pelt board said element is to be arranged adjacent to. The outermost gripping element is preferably also of a similar transverse shape as a corresponding innermost gripping element so as to grip the pelt along the majority of the transverse extent of the inner surfaces.
In one or more embodiments, said gripping surface of the second gripping element comprises a saddle-shaped curvature, at said second point (P2), so that the gripping element curve laterally about the longitudinal extend of the pelt board when said gripping element and pelt board are arranged in said apparatus.
In one or more embodiments, said gripping surface of the first gripping element comprises a saddle-shaped curvature, at said first point (P1), so that the gripping element curve laterally about the longitudinal extend of the pelt board when said pelt board is arranged in the apparatus.
In one or more embodiments, the arrangement of gripping elements may be opposite to the previously mentioned arrangement i.e. the first gripping element may be adapted to be arranged on the skin side of the pelt and have gripping surface protruding toward the gripping surface of the second gripping element adapted to be arranged near the fur side of the pelt and comprising a corresponding surface shape in form of a cavity for engagement with the protruding part of the gripping surface of the first gripping element.
In one or more embodiments, the edge of the curved gripping surface of the second gripping element may be chamfered or have a rounded shape, preferably such that the edge may be of a lateral circular, elliptical or parabolic curvature.
Advantageously, the curved edge eliminates any localized areas of high, possibly damaging, pressures when the gripping elements engage with the pelt, while simultaneously, providing the required surface area and geometry in order to properly fasten the pelt, and withholding the pelt during stretching.
The second aspect of the invention relates to an apparatus for stretching a pelt on a pelt board, wherein the apparatus comprises a pelt board holder for holding one end part of the pelt board, pelt holders comprising gripping means arranged to grip at least a part of the lower periphery of the pelt when arranged on the pelt board, driving means for displacing the pelt board holder and the pelt holders in a longitudinal direction of the pelt board, so as to stretch the pelt, wherein the gripping means comprises a first gripping element and a second gripping element arranged on opposite sides of the pelt and substantially opposing each other in a direction transverse to the longitudinal extend of the board, wherein at least one of said first or second gripping element is configured to be displaceable toward said opposing gripping element so as to grip said pelt wherein each opposing first and second gripping element comprises a gripping surface being arranged towards said pelt, said gripping surface of the first gripping element comprises a surface curvature at a first point (P1), having a first radius of curvature (R1) and said second gripping element comprises a surface curvature at a second point (P2), having a second radius of curvature (R2), and wherein said first radius of surface curvature (R1) of said first gripping element is smaller than said second radius of surface curvature (R2) of said second gripping element by 10-40 %, such as by 15-35 % or such as by 20-30 %.
An apparatus for stretching a pelt on a pelt board is also known as a pinning machine. The gripping elements may be configured to be displaceable at least in a transverse direction being perpendicular to the longitudinal extent of the pelt board and pelt. Alternatively, the mutual displacement may be provided by a pivoting movement of e.g. the outer gripping element, such that the gripping surface of the outer gripping element is moved towards the gripping surface of the inner gripping element.
In one or more embodiments, said first and/or second gripping elements are configured to be displaceable toward an opposing gripping element so as to grip said pelt. In one or more embodiments, said first gripping element is configured to be displaceable toward said second gripping element so as to grip said pelt. It may be only necessary that only one gripping element is displaceable in the gripping action.
The longitudinal centre line of the pelt board is aligned along the second axis (a2), while the first axis (a1) and the third axis (a3) are defined perpendicular to the second axis (a2) and define the transverse plane. In one or more embodiments when the gripping elements are arranged with a pelt board, the first axis (al) may be defined as extending parallel to the line along which the width of the board is measured, the largest width being the largest extent of the board in the transverse plane. The third axis (a3) may be defined parallel to the line along which the thickness of the board is defined. The surface curvature may be a lateral surface curvature in the sense that it provides a displacement of the surface towards a lateral direction being substantially perpendicular relative to the longitudinal centre line of the board. The surface curvature may point in any direction in the transverse plane defined by the first (a1) and the third axis (a3).
A gradual lateral displacement of the pelt has shown to effectively hold the pelt in a fixed position throughout the stretching process. The pelt is compressed and thereby fastened by opposing gripping surfaces which, due to the shape of the second gripping element and first gripping element, the pelt may be generally directed both along the longitudinal and lateral directions relative to the pelt board, such that the pelt is efficiently gripped and fastened during the stretching process. The curved surface provides a larger gripping area for direct contact with said pelt. Furthermore the curved surface allows for a more uniform distribution of force, than edged surfaces and thereby reduces the risk of damaging the pelt upon gripping. Overall, a larger force may thereby be applied to the pelt, without reaching damaging pressures, and in turn a larger stretch force may be utilized in the stretching process.
In one or more embodiments, said first point (P1) and said second point (P2) are points on a first line (l) extending along and parallel to the direction of mutual displacement of the opposing gripping elements. The first line (l) may preferably be located in the transverse plane defined by the first (a1) and the third axis (a3).
In one or more embodiments, the first gripping element may be the outer gripping element and the second gripping element may be the inner gripping element. The inner gripping element may be arranged nearest the pelt board, with a gripping surface directed towards the skin side of the pelt, when a pelt may be arranged on a pelt board an in the apparatus. The outer gripping element may be arranged with the gripping surface of the outer gripping element directed towards the fur side of the pelt, when a pelt is arranged on a pelt board an in the apparatus. The inner and outer gripping elements may be arranged in the apparatus such that the gripping surface of the inner gripping element may be opposing the gripping surface of the outer gripping element in a direction transverse to the longitudinal extend of the board.
Preferably, said gripping surface of said outer gripping element is of a shape configured to correspond to the shape of said gripping surface of said inner gripping element, such that when said gripping surfaces are in an opposing arrangement in the apparatus and a pelt is arranged between the gripping surfaces, the pelt can be gripped by the majority of the surface of the gripping surfaces by mutual displacement of the gripping surfaces towards each other.
The depth of the curved surface shapes of the gripping surface, measured from the edge of the surface curve to the apex of the curve along a line parallel to the normal line at the apex, e.g. the maximum distance of displacement of the surface provided by the surface curvature is preferably of at least 1.5 mm, such as at least 1.75 mm or such as at least 2 mm. The vertical extent of the curved surface, measured parallel to the second axis (a2) of the curved gripping surface of the second gripping element is preferably larger than the curved gripping surface of the vertical extent of the first gripping element. The vertical extend may be between 1-3 mm for the gripping surface of the first gripping element and the vertical extent may be between 2-4 mm for the gripping surface of the second gripping element.
The second gripping element comprises a larger radius of curvature, preferably provided such that it curves inwards from an upper/lower edge of the curved gripping surface, towards the second axis (a2), i.e. away from the skin side of the pelt, when the second gripping element is arranged as the inner gripping element in the apparatus. This curve of the gripping surface may result in a cavity, causing a lateral displacement of the surface away from the pelt.
The first gripping element comprises a smaller radius of curvature than the second gripping element and it is preferably provided such that it curves outward from an upper/lower edge of the curved gripping surface, towards the second axis (a2), i.e. towards the fur side of the pelt, when the first gripping element is arranged as the outer gripping element. This curve in the gripping surface may result is a protrusion, or bulging surface causing a lateral displacement of the gripping surface towards the pelt.
The gripping means may comprise one or more sets of gripping elements with corresponding gripping surfaces. The sets of gripping elements may be evenly distributed about the second axis (a2) or the set of gripping elements may be distributed symmetrically about the first axis (a1) and/or the third axis (a3). One or more sets of gripping surfaces may grip a different circumferential extent of the pelt than other sets of gripping surfaces.
In one or more embodiments, the second gripping element(s) may comprise gripping surfaces having a plurality of discrete surface curvatures curving inwards away from said pelt according to the present invention, e.g. cavities. The first gripping element(s) may comprise gripping surfaces having a plurality of discrete surface curvatures curving outwards towards said pelt according to present invention e.g. protrusions, and opposing surface curvatures of the inner gripping element(s). The pelt may then experience several lateral displacements in succession as viewed in a direction along the second axis (a2).
The opposing first and second points at which the radius of surface curvature is defined for each gripping surface may be chosen along any part of the gripping surface having a curvature. The second radius of curvature may fulfil the requirements according to the invention, i.e. be larger than the first radius of curvature, at any second point (P2) along the gripping surface. Generally, the curvature at the second point (P2) is compared with the curvature opposing first point (P1) of the first gripping element along a first line (l) extending in the transverse plane defined by the first (a1) and third axis (a3).
The pelt board holders may comprise an opening for accommodating a protruding part of the pelt board, such that the pelt board can be placed in an upright position.
The pelt board may comprise an elliptical shaped cross-section in the transverse plane perpendicular to the longitudinal centre axis of board. The pelt board may comprise to half-shells in arranged in a mirror configuration about the longitudinal centre axis. The outer gripping element preferably is of a similar transverse shape as inner gripping element so as to grip the pelt along the majority of the transverse extent of the inner surfaces.
In one or more embodiments, said gripping means is of the gripping means according to any of the previously described embodiments and aspects of the invention. The apparatus may comprise any embodiments and advantages of the gripping means as described in relation to the first aspect of the invention.
The apparatus may be particularly suitable for stretching mink pelts and the gripping means may be adapted to grip a tail end of a mink pelt for stretching said mink pelt.
In one or more embodiments, the driving means may comprise an electric or a pneumatic actuator. The electric actuator is easy to control and the applied force may be adjusted by adjusting the current fed to the driver.
The transverse shape of the first gripping element and/or second gripping element in the transverse plane as it curves about the longitudinal centre axis of the board is preferably of a shape similar to the outer transverse shape of the part of the pelt board being adjacent to the gripping element in question.
The transverse shape of second gripping element and the first gripping element about the longitudinal centre axis, provides a gripping surface which in a vertical direction along the board from the tip/valley of the gripping surfaces of the first gripping element/second gripping element curves away from the longitudinal centre axis of the board, while in the transverse direction, in the transverse plane, the surfaces curve towards the longitudinal centre axis of the board, thereby creating a saddlecurvature at those points.
The first and second gripping elements may be arranged in an opposite configurations, i.e. where none of the gripping surfaces are of a saddle-shape.
The third aspect of the inventions relates to a method of stretching a pelt arranged on a pelt board supported at an end part by a pelt board holder, the method comprising the steps of gripping the lower periphery of the pelt by means of the gripping means according to any of the previous embodiments of the first aspect of the invention, mutually displacing the pelt board holder and the pelt holders in a longitudinal direction of the pelt board by driving means so as to stretch the pelt.
The gripping means, the apparatus and the method for stretching are particular suitable for the stretching of mink pelts.
In one or more embodiments, the pelt is drawn over the pelt board and when placed in the pinning machine the gripping means are located adjacent to the tail end of the pelt, in an open configuration corresponding to a configuration in which a gap is provided between the gripping surfaces of the first and second gripping element, so that the tail end of the pelt can be arranged between the first and second gripping element. The gripping element may then be placed in a closed position in which the gap between the gripping surfaces of the first and second gripping element is decreased as the elements are displaced towards each other, either by displacing one gripping element or by displacing both such that the first gripping element cooperates with the second gripping element and such that the gripping force is applied to the pelt arranged between the elements. Thereby the pelt is fastened between the first and second gripping element.
The gripping surface of the first element and the gripping surface of the opposing second element are displaced towards each other, such that both surfaces come into contact with the pelt, i.e. one of the surfaces are in contact with the skin side of the pelt and the opposing gripping surface in contact with the fur side of the pelt. The elements are further displaced towards each other such that the gripping elements press on the pelt and the thereby fastens the pelt between the gripping surface of the first element and the gripping surface of the opposing second element.
The pelt board holder may be e.g. displaced in a direction towards the head of the pelt, while the gripping means remains in a fixed position, thereby stretching the pelt on the pelt board. Alternatively, the gripping means may be displaced in a direction away from the head of the pelt, while the pelt board holder remains in a fixed position, thereby stretching the pelt on the pelt board.
The method may be executed using a plurality of pairs of gripping elements, wherein each pair comprises a first and a second gripping element arranged in an opposed manner. All pairs may be arranged to grip different part of the lower tail end of the pelt.
The gripping means may comprise of four sets of gripping elements i.e. four first and four second gripping elements. The sets of gripping elements may be arranged about the centre axis of the board when arranged in the apparatus, such as in a symmetrical manner about the centre axis.
The displacement of the gripping element may be provided by a driver such as an electric or pneumatic actuator. The displacement of the pelt board holder and the gripping means may also be provided by an electric or a pneumatic actuator.
As the pelt is in a stretched configuration, the pelt is fastened by fastening means at a lower end of the pelt, e.g. by a strip or by a placing a bag over the pelt which provides a press force on the pelt. Thereafter the gripping means are placed in an open position, releasing the applied pressure on the tail end of the pelt. The pelt remains in the stretched configuration due to the fastening means applied.
The present invention also relates to the use of a gripping means in an apparatus for stretching a pelt according to any of the embodiments in the first aspect of the invention in order to stretch said pelt.
Moreover the present invention relates to the use of an apparatus according to any of the embodiments according to the second aspect of the invention for stretching a pelt.
BRIEF DESCRIPTION OF THE DRAWING
Aspects of the present disclosure will be described in the following with reference to the figures in which:
Fig. 1 is a schematic front view of a stretching apparatus with gripping means and a pelt arranged on a pelt board.
Fig. 2 is a perspective view of set of gripping elements comprising a protrusion and a cavity.
Fig. 3 is another perspective view of the embodiment shown in Fig. 2, where the protrusion is engaging with the cavity.
Fig. 4 is a perspective view of a gripping element comprising a gripping surface generating a cavity.
Fig. 5 is a perspective view of a part of a gripping element comprising a gripping surface generating a protrusion.
Fig. 6a is a side view of opposing gripping surfaces of the gripping means arranged in an open position.
Fig. 6b is a side view of a pelt arranged between the gripping surfaces of the gripping means, in an open position.
Fig. 6c is a side view of a pelt arranged between the gripping surfaces of the gripping means, in a closed, gripped position.
Fig. 7 is a top view of the apparatus with four sets of gripping elements around a pelt board.
DETAILED DESCRIPTION OF THE EMBODIMENT
Fig. 1 illustrates gripping means 9 for a stretching apparatus 1 according to embodiments of the invention, seen in perspective. A pelt 2 is shown drawn over a pelt board 4, and the pelt board is positioned in a pelt board holder 5. In the present example the pelt board 4 is held by engagement of a protruding part of the pelt board 4 with an opening in the pelt board holder 5, but alternative pelt board holders 5 may also be utilized. The pelt board 4 shown comprises an upper end 4a, which is positioned near the head end of the pelt and a lower end 4b, which is positioned near the tail end of the pelt 2. The pelt 2 is preferably a tubular pelt having an inner side 3a and an outer side 3b. The gripping means 9 comprises at least two sets of gripping elements 10, 11, each set having a first gripping element 10 and a second gripping element 11 according to invention, one arranged on the inside of the pelt 2a and one arranged at the outside of the pelt 2b. After gripping said pelt 2, the apparatus 1 is configured to be able to stretch said pelt 2 by mutually displacing the pelt board 4 and the pelt board holder 5 such the tip of the board 4 and the gripping means 9 are displaced away from each other thereby applying a stretching force on said pelt 2. The operation of the stretching apparatus 1 is executed by control means 8 in corporation with driving means 7 for driving said displacement. As indicated in the Figure, the first axis (a1) is defined parallel to the widest extend of the pelt board 4, i.e. along the width of the pelt board 4 when arranged in the apparatus 1 as shown in Fig. 1. A second axis (a2) is defined along the longitudinal extend of the board 4 parallel to the longitudinal centre line of the board 4 when arranged in the apparatus 1. A third axis (a3) is defined along the thickness of the board 4 when arranged in the apparatus, and being perpendicular to the first (a1) and second axis (a2). The transverse plane is defined by the first axis (a1) and the third axis (a3).
As seen in Fig. 1, the gripping means 9 are arranged to grip said pelt 2 near the tail end of the pelt 2b. In Fig. 2 an embodiment of the gripping means 9 are shown as seen in perspective. The figure shows a single set of gripping means 9, having an inner gripping element, configured to be positioned between the pelt board 4 and the inner side of the pelt 3a, and comprising a gripping surface facing a gripping surface of the opposing outer gripping element. The outer gripping element is configured to be positioned adjacent to the outer side of the pelt 3b. As can be seen in the present example, the inner gripping element corresponds to a second gripping element 11 having a gripping surface of the second element 11a, while the outer gripping element corresponds to a first gripping element 10 having a gripping surface of the first element 10a. Both gripping surfaces 10a, 11a comprises a surface curvature 12 substantially complementing one another, such the gripping surfaces 10a, 11a may engage with one another in the process of gripping said pelt 2. In the present example, the shape of the gripping surfaces are configured to be able to engage with one another, as the shape of the gripping surface inner, second gripping element provides a cavity 15, while the shape of the gripping surface of the outer, first gripping element provides a protrusion 13, configured to fit at least partially inside the cavity 15.
Fig. 2 shows the gripping elements 10, 11 arranged in an open position which is configured to provide a gap between the gripping surfaces of the elements 10a, 11a which is large enough to allow a part of the tail end of the pelt 2b to be placed between the gripping surfaces 10, 11a. Fig. 3 shows a different arrangement of the gripping elements 10, 11 shown in Fig. 2, namely a closed position of the gripping elements 10, 11, where the protrusion 13 and the cavity 15 of the gripping elements 9 are engaging with each other. As can be seen in the present example, the inner gripping element corresponds to a second gripping element 11, while the outer gripping element corresponds to a first gripping element 10 having a gripping surface with a radius of surface curvature (R1) at a first point (P1) being smaller than a radius of surface curvature (R2) at a second point (P2) on the gripping surface of the second gripping element 11. In the present example, as indicated in Fig. 3, the radius of curvature (R1) in the apex point (P1, max) of the protrusion 13 is calculated as the radius of an osculating circle in the apex point (P1, max). The osculating circle of the curve, as indicated in Fig. 3 by dashed circle, is the circle that has the same tangent as the curve at the apex point (P1, max) and the same curvature. Similarly, the radius of curvature (R2) measured at the apex point (P2, min) of the cavity 15 is calculated as the radius of an osculating circle indicated in Fig. 3 by a dashed circle. In the present example the radius of curvature (R1) of the protrusion is 2 mm, while the radius of curvature (R2) of the cavity is 2.8 mm, resulting in the radius of curvature of the protrusion (R1) being 27 % smaller than the radius of curvature of the cavity (R2). The osculating circles each have a centre of the circle corresponding to the centre of curvature (C1, C2). The radii are a measure of the distance between the centre of curvature of the osculating circle and the periphery of the osculating circle. The comparison between radii of curvatures (R1, R2) in points on the gripping surfaces 10a, 11a are undertaken for opposing points located on a first line (l) extending in the transverse plane. In the present example, the opposing points are the apex points (P1, max), (P2, min) and the surface curvatures may be substantially constant above and below the apex points (P1, max), (P2, min) e.g. mirrored about a second line (l, ex) defined as extending in the transverse plane through the apex points (P1, max), (P2, min) of the surface curves.
Fig. 4 shows a perspective view of the inner gripping element as shown in Fig. 2 and Fig. 3, corresponding to a second gripping element 11 according to an example of the invention. The second gripping element 11 comprises a gripping surface 11a having a surface curvature 12 creating a cavity 15 as a lateral displacement of the gripping surface 11a. The apex line 16 of the cavity 15 is shown in Fig. 4 by a dashed line. The apex line 16 of the cavity as shown is made up of the most laterally displaced point on the curved gripping surface 11a for each obtainable cross-section in a longitudinal plane. The surface curvature 12 curves in different directions depending on whether the surface curvature 12 is inspected along a longitudinal direction or along a transverse direction. The different directional curvatures provide a saddleshaped curvature 12a of the gripping surface 11a. Correspondingly, a matching part of a first gripping element 10, in the present example has a gripping surface 10a comprising an outward rounded shape with a saddle-shaped curvature 12a as shown in Fig. 5, such that when the gripping surfaces10a, 11a are combined for gripping a pelt 2, the gripping force is advantageously distributed along the majority of the gripping surfaces 10a, 11a and not concentrated in discrete points of contact, which may result in unwanted high pressures on the pelt 2. In the present example, the part of the first gripping element 10 comprising the rounded shape can be attached by fastening through an opening 20 to the remainder of the first gripping element 10, so as to provide a first gripping element 10 as shown in Fig. 2 and Fig. 3, where the rounded shape provides a protrusion 13 extending toward the corresponding cavity
15. Upon fastening by extending suitable fastening means through the opening 20, the protrusion 13 can be loosely fitted to remainder of the first gripping element 10, being substantially stationary. The loose fit of the protrusion 13 is advantageous as it enables the gripping element 10 to adapt and adjust to difference in thickness within the area of the pelt 2, gripped by the gripping elements 10, 11.
The protrusion 13 has an apex line 14 corresponding to the tip of the protrusion 13 along the length of the protrusion 13. The radius of curvature (R1) for each point (P1, max) on the apex line 14, may vary between neighbouring points (P1, max) with less than 10% such as with less than 5% or be substantially constant. Similarly, the radius of curvature (R2) for each point (P2, min) on the apex line 16 may vary between neighbouring points (P2, min) with less than 10% such as with less than 5% or be substantially constant. The surface curvatures 12 of the gripping surfaces 10, 11a may also be composed of a number of linear segments joined together end to end, such as a polygon shape, in order to create the overall surface curvature 12. In such examples, the radius of curvature (R1), (R2) for each linear element would be infinite, but instead the radius of curvature (R1), (R2) should be measured along a curve resulting from a best fit to said polygon surface shape. The same method of calculation should be applied if the surface shape of gripping surfaces 10a, 11a have a linear section at the apex points (P1, max), (P2, min) of the surface curvatures 12.
Fig. 6a shows a longitudinal cross section defined by the second axis (a2) and the third axis (a3), wherein a first line (l) extends in the transverse plane and through opposing points (P1), (P2) on opposing gripping surfaces 10a, 11a. Upon mutual displacement of the gripping elements 10, 11 the distance between opposing points (P1), (P2) are decreased and the gripping elements 10, 11 may be arranged to be displaced so that the opposing points (P1), (P2) come into contact. Alternatively, in one or more examples the displacement may not exclusively be along the first line (l), but instead be caused by a pivoting movement, where the points (P1), (P2) are brought into opposing arrangement on the first line (1) near the end of the displacing movement of the gripping surfaces, upon gripping engagement with the pelt. The second axis (a2) generally extends parallel to the centre axis of the tubular pelt 2, to be stressed or the pelt board 4 on which the pelt 2 may preferably be located. Fig. 6a shows an example of a part of a first gripping element 10, having a gripping surface 10a which has a surface curvature 12, protruding outwards towards a second gripping element 11. The second gripping element 11 also comprises a gripping surface 11a, which has a surface curvature 12, providing a lateral displacement of the gripping surface 11a, in the sense that an indentation, groove or cavity 15 is created in the gripping element 11. The cavity 15 has a surface curvature 12 corresponding to the opposing surface curvature 12 of the first gripping element 10, but the surface curvature 12 of the cavity 15 generally has a larger radius of curvature (R2) at points (P2) on the surface compared with opposing radius of surface curvatures (R1) of the second gripping element 11 at points (P1) on the gripping surface 11a.
In one or more examples, at all second points (P2) within a surface segment of the gripping surface 11a of the second element 11 has a radius of surface curvature (R2) which is larger by 10-40 %, such as by 15-35 % or such as by 20-30 % than the radius of surface curvature (R1) of the opposing first point (P1) on the gripping surface 10a of the first gripping element 10. Similarly, a surface segment 17 on the gripping surface 10a of the first gripping element 10 may also be defined which fulfils the above condition. The surface segment 17, 18 of the gripping surface of the second gripping element 11 or the first gripping element 10 may be defined in different ways.
E.g. For the first gripping element 10, the surface segment 17 may defined as the part of the gripping surface 10a located between two points of intersection between the gripping surface 10a of the first gripping element 10 and a first chord (c1) arranged parallel to the second axis (a2) and arranged at a first distance (h1) inwards from the apex point (P1, max), i.e. tip of the surface, in a direction extending in the transverse plane, such as along the third axis (a3) as shown in Fig. 6a. The first distance (h1) may be e.g. half of the radius of curvature (R1) at the apex point (P1, max).
In another example of a definition of the surface segment, depicted in relation to the second gripping element 11 in Fig. 6a, the surface segment of the surface curvature 12 of the cavity 15 may be defined by first determining a centre of curvature C2 for the osculating circle 19b at the apex point of the cavity (P1, min). The surface segment 18 is defined for the surface extending upwards or downwards, initially extending in a longitudinal direction from the apex point (P1, min), to a point at an angle (A) measured from the centre of curvature (C2). In the present example, the surface segment 18 extends to the surface point at an angle (A) both above and below the apex point (P2, min). The angle (A) may be approximately 45 degrees. In one or more examples, the surface segment 17, 18 may additionally defined the section of the gripping surface in which the surface curvature is substantially constant, or varying by less than 10 % or 5 % between neighbouring points. In one or more examples, the surface curvature 12 of the gripping surfaces 10a, 11a may be a circular, elliptical or parabolic curvature.
Fig. 6b and Fig. 6c shows a longitudinal cross section as in Fig. 6a, but with a pelt 2 arranged between the gripping elements 10, 11. In Fig. 6b, the gripping elements 10, 11 are in an open position, where the pelt 2 can be inserted between the gripping surfaces 10a, 11a of the gripping elements 10, 11. The apex lines 14, 16 of the gripping surfaces 10a, 11a may be opposing and aligned on a second line (l, ex) extending through the two extremes. Furthermore, the gripping surfaces 10a, 11a may be substantially symmetric in shape about the apex lines 14, 16. Fig. 6c shows a closed position of the gripping elements 10, 11, after a mutual displacement of the gripping elements 10, 11 towards each other. In the present example, the closed position is obtained by displacing the first gripping element 10 towards the second gripping element 11. The second gripping element 11 may preferably be situated between the inner side of the pelt 3a and the pelt board 4.
In the closed position the gripping surfaces 10a, 11a overlap and the pelt 2 is displaced laterally perpendicular to the second axis (a2) and fixed between the gripping surfaces 10a, 11a.The lateral displacement improves the fixing ability of the gripping means 9 upon stretching of the pelt along the second axis (a2). The curved surfaces provide a larger contact area, meaning larger compressive force can be utilized without damaging the pelt 2.
In one or more examples, the gripping surfaces 10a, 11a of said gripping elements 10, 11 may comprise discrete surface parts each having a surface curvature 12. The gripping surface 10a, 11a of an element 10, 11 may comprise an outward curved surface in a first part and an inward curved surface in a second part each part may be arranged to corporate with corresponding opposing parts of a gripping surface 10a, 11a of an opposing gripping element 10, 11. Said parts may be arranged in succession in the vertical direction along the second axis (a2) and correspondingly along the longitudinal extend of the pelt 2. Some parts of the same gripping surface 10a, 11a may thereby be of said second radius of curvature (R2) while other parts may be of a first radius of curvature (R1) and respectively arranged to corporate with opposing parts of an opposing gripping surface 10a, 11a having a first radius of curvature (R1) and a second radius of curvature (R2).
Fig. 7 shows a part of the pinning machine 1 in cross-sectional view defined by the first axis (a1) and third axis (a3). The pinning machine 1 is shown to comprise pelt holders 6 comprising gripping means 9 having four sets of gripping elements 10, 11.
The pinning machine 1 is furthermore shown with a pelt board 4 arranged in the middle of the apparatus 1 and surrounded by the gripping elements 10, 11. In the present example, the gripping mechanism is undertaken by displacing the outer gripping elements, being first gripping elements 10, towards the inner gripping elements, being second gripping elements 11 along a direction parallel to the third axis (a3). As shown in Fig. 7 the second gripping elements 11 is of a shape configured to substantially correspond to the outer shape of the pelt board 4, so that the elements can be closely aligned with the pelt board surface 4, and easily fitted between a pelt 2 arranged on the pelt board 4 and the pelt board 4. The second gripping elements 11 extend a distance along the surface of the pelt board 4 in the cross-section shown. Collectively the circumferential extend of the second gripping elements 11 corresponds to about 75 % of the circumferential extend of the pelt board 4 at the lower end of the pelt board 4b. Between the second gripping elements 11, the pelt is allowed to hang freely. The gripping surfaces 10a of the first gripping elements 10 are slightly loosely fitted in the apparatus 1 via the openings 20, such that upon engagement with the pelt 2 and the second gripping element 11, the first gripping element 10 may adapt to e.g. a difference in thickness of the pelt 2 adjacent to the transverse extend of the gripping element 10. In the transverse plane, as both gripping surfaces 10a, 11a curve about the longitudinal second axis (a2), a saddle curvature 12a is created at points on the apex lines 14, 16 of the gripping surfaces 10a, 11a about the second axis (a2).
In one or more examples, the gripping means 9 may comprise four outer gripping elements 10, 11 and a single inner gripping element 10, 11, where the single inner gripping element 10, 11 is configured to cooperate with each of the outer gripping elements 10, 11. E.g. the inner gripping element 10, 11 may comprise a second gripping element 11 extending a full circle about the centre axis of the pelt board 4, which is arranged to cooperate with first gripping elements 10 on the outer elements. The first gripping elements 10 are in the present example arranged to be directed towards different parts of the circumference of the inner gripping element 11.
REFERENCE NUMBERS AND SIGNS
Stretching apparatus/Pinning machine
Pelt
2a Nose end of the pelt
2b Tail end of the pelt a Inner side of the pelt
3b Outer side of the pelt
Pelt board
4a upper end of the pelt board
4b lower end of the pelt board
Pelt board holder
Pelt holders
Driving means
Control means
Gripping means
First gripping element
10a Gripping surface of the first gripping element
Second gripping element
11a Gripping surface of the second gripping element
Surface curvature, e.g. parabolic, circular curvature etc.
12a Saddle-shaped curvature
Protrusion
Apex line of gripping surface of the first gripping element
Cavity
Apex line of gripping surface of the second gripping element
Surface segment of the first element
Surface segment of the second element
19a First osculating circle
19b Second osculating circle
Opening l First line
l, ex Second line
a1 First axis
a2 Second axis/longitudinal centre axis of the board
a3 Third axis
P1 First point on the gripping surface of the first gripping element
P1, max First point at apex of the gripping surface, e.g. protrusion
P2 Second point on the gripping surface of the second gripping element
P2, min Second point at apex of the gripping surface, e.g. cavity
R1 First radius of curvature in first point P1
R2 Second radius of curvature in second point P2
A1 First angle
A2 Second angle
h1 First distance
h2 Second distance
c1 First chord
c2 Second chord
C1 Centre of curvature for first apex point (P1, max)
C2 Centre of curvature for second apex point (P2, min)

Claims (17)

PatentkravPatent claims 1. Gribemidler (9) til en indretning til at strække en pels (2) på en tane (4), hvor gribemidlet (9) omfatter et sæt gribeelementer (10, 11) omfattende et første gribeelement (10) og et andet gribeelement (11), hvor hvert gribeelement (10, 11) omfatter en gribeflade (10a, 11a), hvor en langsgående udstrækning af det første gribeelements (10) gribeflade (10a) i en retning parallelt med en langsgående midterakse (a2) af tanen (4) har en konveks form, der er udformet til at svare til en konkav form af det andet gribeelements (11) gribeflade (11a), således at når gribefladerne (10a, 11a) er i en modstående anbringelse, og en pels (2) er anbragt mellem gribefladerne (10a, 11a), kan pelsen (2) gribes af gribefladerne (10a, 11a) ved indbyrdes forskydning af gribefladerne (10a, 11a), det første gribeelements (10) gribeflade (10a) har en overfladekrumning på et første punkt (P1) med en første overfladekrumningsradius (R1), og det andet gribeelements (11) gribeflade (11a) har en overfladekrumning på et andet punkt (P2) med en anden krumningsradius (R2), hvor det første punkt (P1) og det andet punkt (P2) er modstående punkter i den modstående anbringelse, hvor den første overfladekrumningsradius (R1) er mindre end den anden overfladekrumningsradius (R2) med 10-40 %, såsom 15-35 % eller 20-30 %.Gripping means (9) for a device for stretching a fur (2) on a tane (4), wherein the gripping means (9) comprises a set of gripping elements (10, 11) comprising a first gripping element (10) and a second gripping element ( 11), each gripping element (10, 11) comprising a gripping surface (10a, 11a), a longitudinal extension of the gripping surface (10a) of the first gripping element (10) in a direction parallel to a longitudinal central axis (a2) of the tane (4). ) has a convex shape designed to correspond to a concave shape of the gripping surface (11a) of the second gripping element (11), so that when the gripping surfaces (10a, 11a) are in an opposite position, and a fur (2) is arranged between the gripping surfaces (10a, 11a), the fur (2) can be gripped by the gripping surfaces (10a, 11a) by mutually displacing the gripping surfaces (10a, 11a), the gripping surface (10a) of the first gripping element (10) has a surface curvature at a first point (P1) with a first surface curvature radius (R1) and the gripping surface (11a) of the second gripping element (11) has a surface curvature g at a second point (P2) with a second radius of curvature (R2), where the first point (P1) and the second point (P2) are opposite points in the opposite position, where the first surface curvature radius (R1) is less than the second surface curvature radius (R2) by 10-40%, such as 15-35% or 20-30%. 2. Gribemidler (9) ifølge krav 1, hvor det andet gribeelements (11) gribeflade (11a) har den anden krumningsradius (R2) ved et hvilket som helst andet punkt (P2), der er placeret i et overfladesegment (18) dækkende mindst 30 % såsom mindst 40 % af gribefladen (11a) centreret omkring gribefladens (11a) toppunkt (P2, min).Gripping means (9) according to claim 1, wherein the gripping surface (11a) of the second gripping element (11) has the second radius of curvature (R2) at any other point (P2) located in a surface segment (18) covering at least 30% such as at least 40% of the gripping surface (11a) centered around the apex of the gripping surface (11a) (P2, min). 3. Gribemidler (9) ifølge et af de foregående krav, hvor krumningsradiussen (R1, R2) ved punkterne (P1, P2) varierer med mindre end 20 % eller såsom mindre end 10 % mellem første punkter (P1) og/eller mellem anden punkter (P2) i gribefladerne (10a, 11a).Gripping means (9) according to one of the preceding claims, wherein the radius of curvature (R1, R2) at the points (P1, P2) varies by less than 20% or such as less than 10% between the first points (P1) and / or between the second points (P2) in the gripping surfaces (10a, 11a). 4. Gribemidler (9) ifølge et af de foregående krav, hvor det andet gribeelements (11) gribeflade (11a) har den anden krumningsradius (R2) ved et hvilket som helst punkt (P2), der er placeret i et overfladesegment (18), der defineres som den del af gribefladen (11a), der er placeret mellem toppunktet (P2, min) og et kantpunkt (P2, kant), der defineres i en vinkel (A2) på op til 90 grader, såsom op til 75 grader eller såsom op til 55 grader fra en anden linje (l, ex), der strækker sig vinkelret på en tangent ved toppunktet (P2, min) og måles fra krumningscentret (C2) for toppunktet (P2, min).Gripping means (9) according to one of the preceding claims, wherein the gripping surface (11a) of the second gripping element (11) has the second radius of curvature (R2) at any point (P2) located in a surface segment (18). , defined as the part of the gripping surface (11a) located between the vertex (P2, min) and an edge point (P2, edge) defined at an angle (A2) of up to 90 degrees, such as up to 75 degrees or such as up to 55 degrees from another line (1, ex) extending perpendicular to a tangent at the vertex (P2, min) and measured from the center of curvature (C2) of the vertex (P2, min). 5. Gribemidler (9) ifølge et af kravene 2-4, hvor mindst 30 %, såsom 35 % eller såsom 40 % af overfladesegmentet (17, 18) af det andet gribeelement (11) og/eller det første gribeelement (10) har en krumningsradius (R1, R2), der er i det væsentlige konstant.Gripping means (9) according to one of claims 2-4, wherein at least 30%, such as 35% or such as 40% of the surface segment (17, 18) of the second gripping element (11) and / or the first gripping element (10) have a radius of curvature (R1, R2) which is substantially constant. 6. Gribemidler (9) ifølge et af de foregående krav, hvor den første overfladekrumningsradius (R1) af det første gribeelement (10) i det første punkt (P1) ligger i området 0,5-3,5 mm, såsom i området 1,2-2,8 mm.Gripping means (9) according to one of the preceding claims, wherein the first surface curvature radius (R1) of the first gripping element (10) in the first point (P1) is in the range 0.5-3.5 mm, such as in the region 1 , 2-2.8 mm. 7. Gribemidler (9) ifølge et af de foregående krav, hvor den anden overfladekrumningsradius (R2) af det andet gribeelement (11) i det andet punkt (P2) ligger i området 1,5-4,5 mm såsom i området 2,2-3,8 mm.Gripping means (9) according to one of the preceding claims, wherein the second surface curvature radius (R2) of the second gripping element (11) in the second point (P2) is in the range 1.5-4.5 mm as in the region 2, 2-3.8 mm. 8. Gribemidler (9) ifølge et af de foregående krav, hvor gribefladen (10a) af det første gribeelement (10) og eller det andet gribeelement (11) har en cirkulær overfladeform.Gripping means (9) according to one of the preceding claims, wherein the gripping surface (10a) of the first gripping element (10) and or the second gripping element (11) has a circular surface shape. 9. Gribemidler (9) ifølge et af de foregående krav, hvor gribemidlerne (9) er indrettet til at gribe en minkpels (2) til at strække minkpelsen (2).Gripping means (9) according to one of the preceding claims, wherein the gripping means (9) are arranged to grip a mink fur (2) to stretch the mink fur (2). 10. Gribemidler (9) ifølge et af de foregående krav, hvor gribeelementerne (10, 11) strækker sig omkring tanen (4) i et i det væsentlige tværgående plan, som strækker sig vinkelret på den langsgående udstrækning af tanen (4), således at elementerne (10, 11) har en fælles udstrækning, der er mindst 70-98 %, fortrinsvis 80-95 % af tanens (4) omkreds.Gripping means (9) according to one of the preceding claims, wherein the gripping elements (10, 11) extend around the tane (4) in a substantially transverse plane which extends perpendicular to the longitudinal extension of the tane (4), thus that the elements (10, 11) have a common extent which is at least 70-98%, preferably 80-95% of the circumference of the tan (4). 11. Gribemidler (9) ifølge et af de foregående krav, hvor gribefladen (11a) af det andet gribeelement (11) har en saddelformet krumning ved det andet punkt (P2), således at gribeelementet (11) krummer lateralt omkring tanens (4) langsgående udstrækning, når gribeelementet og tanen (4) er anbragt i indretningen (1).Gripping means (9) according to one of the preceding claims, wherein the gripping surface (11a) of the second gripping element (11) has a saddle-shaped curvature at the second point (P2), so that the gripping element (11) curves laterally around the tan (4) longitudinal extent when the gripping element and the tan (4) are arranged in the device (1). 12. Gribemidler (9) ifølge et af de foregående krav, hvor gribefladen (10a) af det første gribeelement (10) har en saddelformet krumning ved det første punkt (P1), således at gribeelementet (10) krummer lateralt omkring tanens (4) langsgående udstrækning, når tanen (4) er anbragt i indretningen (1).Gripping means (9) according to one of the preceding claims, wherein the gripping surface (10a) of the first gripping element (10) has a saddle-shaped curvature at the first point (P1), so that the gripping element (10) curves laterally around the tan (4) longitudinal extent when the tan (4) is placed in the device (1). 13. Indretning (1) til at strække en pels (2) på en tane (4), hvor indretningen (1) omfatter en taneholder (5) til at holde en endedel af tanen (4), pelsholdere (6), som omfatter gribemidler (9), der er indrettet til at gribe mindst en del af pelsens (2) nedre periferi, når den er anbragt på tanen (4), drivmidler (7) til at forskyde taneholderen (5) og pelsholderne (6) i en langsgående retning af tanen (4) for at strække pelsen (2), hvor gribemidlet (9) omfatter et første gribeelement (10) og et andet gribeelement (11), der er anbragt på modsatte sider af pelsen (2) og i det væsentlige er modsat hinanden i en retning på tværs af tanens (4) langsgående udstrækning, hvor mindst et af det første eller andet gribeelement (10, 11) er udformet til at være forskydeligt mod det modstående gribeelement (10, 11) for at gribe pelsen (2), hvor hvert modstående første og andet gribeelement (10, 11) har en gribeflade (10a, 11a), der er anbragt mod pelsen (2), hvor det første gribeelements (10) gribeflade (10a) har en overfladekrumning ved et første punkt (P1) med en første krumningsradius (R1), og det andet gribeelement (11) har en overfladekrumning ved et andet punkt (P2) med en anden krumningsradius (R2), og hvor det første gribeelements (10) første overfladekrumningsradius (R1) er mindre end det andet gribeelements (11) anden overfladekrumningsradius (R2) med 10-40 %, såsom 15-35 % eller 20-30 %.Device (1) for stretching a fur (2) on a tane (4), the device (1) comprising a tane holder (5) for holding an end portion of the tane (4), fur holders (6) comprising gripping means (9) arranged to grip at least a part of the lower periphery of the fur (2) when it is placed on the tan (4), drive means (7) for displacing the tan holder (5) and the fur holders (6) in a longitudinal direction of the tan (4) to stretch the fur (2), the gripping means (9) comprising a first gripping element (10) and a second gripping element (11) arranged on opposite sides of the fur (2) and substantially are opposite each other in a direction transverse to the longitudinal extent of the tan (4), where at least one of the first or second gripping element (10, 11) is designed to be displaceable against the opposite gripping element (10, 11) for gripping the fur ( 2), each opposing first and second gripping element (10, 11) having a gripping surface (10a, 11a) arranged against the fur (2), the gripping element (10) of the first gripping element (10) surface (10a) has a surface curvature at a first point (P1) with a first radius of curvature (R1), and the second gripping element (11) has a surface curvature at a second point (P2) with a second radius of curvature (R2), and where it first surface curvature radius (R1) of the first gripping element (10) is less than the second surface curvature radius (R2) of the second gripping element (11) by 10-40%, such as 15-35% or 20-30%. 14. Indretning (1) ifølge krav 13, hvor gribemidlet (9) er af gribemidlerne (9) ifølge et af kravene 1-12.Device (1) according to claim 13, wherein the gripping means (9) is one of the gripping means (9) according to one of claims 1-12. 15. Fremgangsmåde til at strække en pels (2), der er anbragt på en tane (4), der ved en endedel er understøttet af en taneholder (5), hvilken fremgangsmåde omfatter trinnene med at gribe den nedre periferi af pelsen (2) ved hjælp af gribemidlerne (9) ifølge et af kravene 1-12, indbyrdes at forskyde taneholderen (5) og pelsholderne (6) i en langsgående retning af tanen (4) ved hjælp af drivmidler (7) for at strække pelsen (2).A method of stretching a fur (2) disposed on a tane (4) supported at an end portion by a tane holder (5), the method comprising the steps of gripping the lower periphery of the fur (2). by means of the gripping means (9) according to one of claims 1-12, mutually displacing the tane holder (5) and the fur holders (6) in a longitudinal direction of the tane (4) by means of drive means (7) for stretching the fur (2) . 16. Anvendelse af gribemidler (9) i en indretning (1) til at strække en pels (2) ifølge et af kravene 1-12 for at strække pelsen (2).Use of gripping means (9) in a device (1) for stretching a fur (2) according to one of claims 1-12 for stretching the fur (2). 17. Anvendelse af en indretning (1) ifølge et af kravene 13-14 til at strække en pels (2).Use of a device (1) according to one of claims 13-14 for stretching a fur (2).
DKPA201870055A 2018-01-25 2018-01-25 Curved gripping elements for gripping a pelt DK179849B1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
DKPA201870055A DK179849B1 (en) 2018-01-25 2018-01-25 Curved gripping elements for gripping a pelt
PL428664A PL428664A1 (en) 2018-01-25 2019-01-25 Curved gripping elements for gripping of the raw hide

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DKPA201870055A DK179849B1 (en) 2018-01-25 2018-01-25 Curved gripping elements for gripping a pelt

Publications (2)

Publication Number Publication Date
DK179849B1 true DK179849B1 (en) 2019-07-31
DK201870055A1 DK201870055A1 (en) 2019-07-31

Family

ID=67384416

Family Applications (1)

Application Number Title Priority Date Filing Date
DKPA201870055A DK179849B1 (en) 2018-01-25 2018-01-25 Curved gripping elements for gripping a pelt

Country Status (2)

Country Link
DK (1) DK179849B1 (en)
PL (1) PL428664A1 (en)

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB138930A (en) * 1919-02-13 1920-09-09 Erberto Durio Improved process of and apparatus for stretching skins or the like
FI6367U1 (en) * 2004-06-11 2004-08-27 Norcar Bsb Ab Oy Tana
DK177149B1 (en) * 2011-03-22 2012-02-20 4M Globe Man Ltd Apparatus and method for extending a skin before attaching to a tane
DK177976B8 (en) * 2013-07-10 2021-04-22 Jasopels As Apparatus and method for stretching a pelt on a pelt board

Also Published As

Publication number Publication date
DK201870055A1 (en) 2019-07-31
PL428664A1 (en) 2019-07-29

Similar Documents

Publication Publication Date Title
KR101290912B1 (en) Stretch-forming machine and method
US9453267B2 (en) Machine and method for stretching a pelt before fastening to a pelt board
EP1678331B1 (en) Method and machine for non-destructive stretching and fastening of a pelt on a pelt board
US20130319452A1 (en) Hair iron
DK179849B1 (en) Curved gripping elements for gripping a pelt
WO2014103195A1 (en) Wire gripper
JP2009107317A (en) Clip and film forming machine
US20090101027A1 (en) Screen Printing Device
CN202181413U (en) Device for balancing tension change in warp yarn at weaving machine
CN101959438A (en) Hair shaping device
JP2015020068A5 (en)
HRP920989A2 (en) Method and machine for softening and stretching laminar products, particularly tanned hides.
US1761888A (en) Method and means for upsetting sheet metal
US9820545B2 (en) Hair straightening/curling method and apparatus
KR101689438B1 (en) Tensile test system
DK201900027U1 (en) Arch-shaped gripping elements for gripping a fur
CN108698350B (en) Tread support device for use in retreading processes
US20020062675A1 (en) Method and device for producing a double-curved sheet-like object by means of stretch-forming
KR200230588Y1 (en) Tread Semi-finished Product Feeder with Center Retention
KR101329214B1 (en) Bead former unit for tire manufacture
US1757548A (en) Vise
KR20210091717A (en) A device that bends long and thin workpieces without wrinkling
US2147039A (en) Measured stretch, tension distributing machine
EP3421617A1 (en) Apparatuses and methods for stretching a pelt on a pelt board
SE329256B (en)

Legal Events

Date Code Title Description
PAT Application published

Effective date: 20190726

PME Patent granted

Effective date: 20190731