A combination weigher with a mounting structure, a method of mounting a screw feeder, and a mounting structure

Abstract

The present disclosure provides a combination weigher comprising a screw feeder configured to convey objects by rotation about a rotation axis extending in an axial direction and being rotated by a motor by a mounting structure. The mounting structure comprises a male part and a female part. One of the male part and the female part comprises a pin structure and the other one of the male part and the female part comprises a receiving slot. The receiving slot is designed for allowing the pin structure to slide therein when the male part slides into the female part. The receiving slot extends from an open end via an intermediate zone to a closed end and defines at least a first section and a second section extending in different directions from the intermediate zone. The first section extends from the intermediate zone to the open end, and the second section extends from the intermediate zone to the closed end. The intermediate zone is defined within a first end-wall, a second end-wall, and a ceiling connecting the first end-wall and the second end-wall. The first end-wall and the second end- wall are non-parallel. The first section is in communication with a first zone part of the intermediate zone and the second section is in communication with a second zone part of the intermediate zone.

Description

[0001] A COMBINATION WEIGHER WITH A MOUNTING STRUCTURE, A METHOD OF MOUNTING A SCREW FEEDER, AND A MOUNTING STRUCTURE

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to a combination weigher, a mounting structure for mounting a screw feeder to a combination weigher, and a method of mounting a screw feeder.

[0004] BACKGROUND OF THE INVENTION

[0005] Combination weighers such as the one shown with position number 100 in figure 1 are commonly used in the food and feed industry for generating portions of food products and feed products fulfilling a pre-defined weight target. Such a combination weigher comprises a dispersion unit 101 configured to receive food or feed items from an infeed unit typically positioned above the weigher. A plurality of conveyance units 102 extend radially away from the dispersion unit for receiving food or feed items from the dispersion unit. A plurality of weighing hoppers 103 are associated with the conveyance units for receiving food or feed products therefrom. The weighing hoppers are operated by a control unit by repeatedly monitoring the weight in each of the weighing hoppers for finding an optimal weight combination in two or more weighing hoppers such that a target weight is obtained.

[0006] Subsequently, the food or feed products are dropped from the selected two or more weighing hoppers into a discharge chute, and further into a bag, tray, or the like.

[0007] Such conveyance units consist of trenches and screw feeders 104 arranged therein, where the screw feeders are mechanically attached to motor units and are configured to advance the received food or feed products from an infeed end in the trenches to an outfeed end of the trenches via a rotational movement of the screw feeders 104 and into the associated weighing hoppers, e.g., via a collecting hopper.

[0008] When mounting the screw feeders 104 to the motor units it is often necessary to use tools, and the mounting process can be time consuming. W02020 / 079217, incorporated herein by reference, discloses a mounting device with a structure which moves a pin structure automatically into a mounting slot by operation of the motor. SUMMARY OF THE INVENTION

[0009] It is an object of embodiments of the disclosure to provide easy, fast, and convenient, preferably tool-free mounting of screw feeders on motor units, and to ensure a stable fixation during use to reduce unintended dismounting of the screw feeder.

[0010] For these and other objects, the disclosure, in a first aspect, provides a combination weigher comprising a screw feeder configured to convey objects by rotation about a rotation axis extending in an axial direction and being driven by a motor via a mounting structure, said mounting structure comprising a male part and a female part, the male part having an outer diameter being essentially the same or less than an inner diameter of the female part,

[0011] - where one of the male part and the female part comprises a pin structure and the other one of the male part and the female part comprises a receiving slot,

[0012] - where the receiving slot is designed for allowing the pin structure to slide therein when the male part slides into the female part, where the receiving slot extends from an open end via an intermediate zone to a closed end,

[0013] - where the receiving slot defines at least a first section extending e.g. between opposite first and second sidewalls and a second section extending e.g. between third and fourth sidewalls in different directions from the intermediate zone, the first section extending from the intermediate zone to the open end, the second section extending from the intermediate zone to the closed end, and

[0014] - the intermediate zone being defined within a first end-wall, a second end-wall, and a ceiling connecting the first end-wall and the second end-wall, the first end-wall and the second end-wall being non-parallel, and where the first section is in communication with a first zone part of the intermediate zone and the second section is in communication with a second zone part of the intermediate zone.

[0015] This may provide an easy mounting and demounting of the screw feeder e.g., for cleaning and / or maintenance, by rotation of the male part and the female part relative to each other.

[0016] One of the male and female part may form part of, or may be removably attached to the screw feeder, whereas the other one of the male and female part may be rotated by the motor. The receiving slot may be formed along an outer surface of the male part or along an inner surface of the female part. The pin structure may correspondingly be arranged on an inner surface of the female part or on an outer surface of the male part to thereby allow the pin structure to slide in the receiving slot when the male part slides into the female part. The first end-wall may have a first ratio between an X-component extending in the axial direction, and a Y component extending perpendicularly to the axial direction, whereas the second end-wall may have a second ratio between a X-component extending in the axial direction, and a Y component extending perpendicularly to the axial direction, where the second ratio may be smaller than the first ratio, whereby a first angle between the first endwall and the ceiling may be smaller than a second angle between the second end-wall and the ceiling. This may facilitate movement of the pin from the first section via the intermediate section to the second section.

[0017] The first section may extend between opposite first and second sidewalls, at least one having a stepped layout comprising alternating segments with a different ratio between a component in the axial direction and components transverse to the axial direction. The stepped layout may at least partly hinder the pin structure from unintended removal from the receiving slot.

[0018] One of the first and second sidewalls may have a stepped layout and the other one of the first and second sidewalls may have a continuous layout, where the continuous layout is nonstepped. By providing a continuous layout of one of the sidewalls, such as a smooth layout, movement of the pin structure along this surface may facilitate movement of the pin structure from the open end towards the intermediate zone.

[0019] The first sidewall may have a stepped layout, and the first end-wall may have a stepped layout, wherein the first sidewall may extend in continuation of the first end-wall to form a common stepped wall. The common stepped wall may extend from the open end to the ceiling, which may further hinder the pin structure from unintended removal from the receiving slot.

[0020] The stepped layout may define a pattern comprising a plurality of alternating A and B sections, each A and B section having an X-component extending in the axial direction and a Y-component extending in a direction transverse to the axial direction, wherein an A ratio being a ratio between the Y-component and the X-component of an A section is different from a B ratio being a ratio between the Y-component and the X-component of a B section. This may provide a gradient which may increase the hinderance of unintended removal of the pin structure.

[0021] At least a plurality of the A sections may be identical, and at least a plurality of the B sections may be identical. However, some of the A sections and / or some of the B sections may be different to change the gradient of the first end-wall and / or the first sidewall, e.g., to increase a distance between the stepped wall and the second section. The pattern may be a repetitive pattern at least along a part of the common stepped wall. As an example, the pattern may be repetitive on opposite sides of a stepped section in which at least one or more A sections are different or in which at least one or more B sections are different.

[0022] The first section may have a first X-component extending in the axial direction, and the second section may have a second X-component extending in the axial direction, where the second X-component may be shorter than the first X-component. This may provide a second section being shorter than the first section.

[0023] Additionally, or alternatively the first section may have a first Y-component extending in a direction transverse to the axial direction, and the second section may have a second Y- component extending in a direction transverse to the axial direction, where the second Y- component is shorter than the first Y-component. This may provide a second section being shorter than the first section.

[0024] The ratio between the first Y-component and the first X-component may be different from the ratio between the second Y-component and the second X-component.

[0025] The second section may be defined between a driving surface, an oppositely arranged locking surface, and the closed end connecting the driving surface and the locking surface. During operation of the combination weigher, the pin structure may be arranged in the second section which may form a partially enclosed space defined by the driving surface, the locking surface, and the closed end. Rotation of the screw feeder by the motor 208 be achieved, when arranging the pin structure in contact with the driving surface which may push the pin structure, whereby the screw feeder may be rotated. When stopping the motor to thereby terminate rotation of the mounting structure, the pin structure may continue its movement and may move towards the locking surface which may stop movement of the pin structure.

[0026] To facilitate insertion of the pin structure into the second section, a length of the driving surface may be longer than a length of the locking surface.

[0027] The driving surface and the locking surface may be substantially parallel. The locking surface may terminate in a guide surface extending transverse to the locking surface, such as in a direction towards the first end-wall. This may increase the opening into the second section to facilitate movement of the pin structure from the intermediate zone to the second section.

[0028] The guide surface and the second sidewall may extend transverse to each other and may be joined at a pointed edge, whereby the thickness of a wall area formed between the guide surface and the second sidewall may decreased towards the pointed edge. This may further facilitate movement of the pin structure to the second section of the receiving slot.

[0029] The first section and the second section extend in different directions from the intermediate zone. The first section may extend at an angle in the range of 20-60 degrees from the axial direction, whereas the second section may extend at an angle in the range of 20-60 degrees from the axial direction in the other direction relative to the axial direction. The first section may extend at an angle between 75 and 100 degrees to the second section to facilitate movement of the pin structure from the open end to the closed end during rotation of the male and female parts relative to each other.

[0030] One of the male part and the female part may comprise an additional pin structure and the other one of the male part and the female part may comprise an additional receiving slot.

[0031] The additional receiving slot may be designed for allowing the additional pin structure to slide therein, when the male part slides into the female part. By providing two sets of a receiving slot and a corresponding pin structure, the mounting structure may be stronger, e.g., in relation to transfer of torque.

[0032] To increase stability of the mounting structure, the additional pin structure and the additional receiving slot may be displaced 180 degrees relative to the pin structure and the receiving slot, as this may improve balance of the mounting structure.

[0033] The first zone part of the intermediate zone and the second zone part of the intermediate zone may be separated by a plane extending through a pointed edge extending between and thus separating the first and the second sections. The pointed edge may facilitate easier movement of the pin structure between the first and second sections.

[0034] The first section defines a centre-line extending between geometric centre points of cross sections of the first section perpendicular to the rotation axis. With this definition of a centreline, the centre-line may extend helically wounded around the rotation axis, e.g. such that an angle between the centre-line and the rotation axis is between 20 and 60 degrees.

[0035] In one embodiment, the one of the male part and the female part may comprise a pin structure and the other one of the male part and the female part comprises an additional receiving slot, i.e. two receiving slots. These two receiving slots could be identical, or one could form a mirrored layot of the other of the two receiving slots, with our without identical dimensions. By mirrored layout is herein meant that the first and second sections extends in a mirrord way relative to the other receiving slot. The receiving slot and the mirrored receiving slot do not necessarily have identical dimensions, but they extend in different direction relative to the rotation axis, e.g. at opposite angles relative to the rotation axis. The mirrored layout allows the pin to slide into one of the receiving slots during rotation in one direction and into the other receiving slot during rotation in an opposite direction.

[0036] In a second aspect, the disclosure provides a screw feeder for a combination weigher, said screw feeder comprising an auger-shaped transport portion, e.g., a centerless auger shape, and comprising a male part, where the male part comprises a receiving slot,

[0037] - where the receiving slot extends from an open end via an intermediate zone to a closed end,

[0038] - where the receiving slot defines at least a first section and a second section extending in different directions from the intermediate zone, the first section extending from the intermediate zone to the open end, the second section extending from the intermediate zone to the closed end, and

[0039] - the intermediate zone being defined within a first end-wall, a second end-wall, and a ceiling connecting the first end-wall and the second end-wall, the first end-wall and the second end-wall being non-parallel, and where the first section is in communication with a first zone part of the intermediate zone and the second section is in communication with a second zone part of the intermediate zone.

[0040] Alternatively, the screw feeder may comprise an auger-shaped transport portion, e.g., a centerless auger shape, and a male part, where the male part comprises a pin structure arranged for sliding in a receiving slot which may be formed at a corresponding female part. The female part may engage a motor for driving the screw feeder.

[0041] In a third aspect, the disclosure provides a screw feeder for a combination weigher, said screw feeder comprising an auger-shaped transport portion, e.g., a centerless auger shape, and a female part, where the female part comprises a receiving slot,

[0042] - where the receiving slot extends from an open end via an intermediate zone to a closed end, where the receiving slot defines at least a first section and a second section extending in different directions from the intermediate zone, the first section extending from the intermediate zone to the open end, the second section extending from the intermediate zone to the closed end, and

[0043] - the intermediate zone being defined within a first end-wall, a second end-wall, and a ceiling connecting the first end-wall and the second end-wall, the first end-wall and the second end-wall being non-parallel, and where the first section is in communication with a first zone part of the intermediate zone and the second section is in communication with a second zone part of the intermediate zone. Alternatively, the screw feeder may comprise an auger-shaped transport portion, e.g., a centerless auger shape, and a female part, where the female part comprises a pin structure arranged for sliding in a receiving slot which may be formed at a corresponding male part. The male part may engage a motor for driving the screw feeder.

[0044] In a fourth aspect, the disclosure provides a male part for a mounting structure for mounting a screw feeder to a combination weigher, said male part having an engagement structure for engagement with a motor for rotating the screw feeder via the male part, where the male part comprises a receiving slot,

[0045] - where the receiving slot extends from an open end via an intermediate zone to a closed end,

[0046] - where the receiving slot defines at least a first section and a second section extending in different directions from the intermediate zone, the first section extending from the intermediate zone to the open end, the second section extending from the intermediate zone to the closed end, and

[0047] - the intermediate zone being defined within a first end-wall, a second end-wall, and a ceiling connecting the first end-wall and the second end-wall, the first end-wall and the second end-wall being non-parallel, and where the first section is in communication with a first zone part of the intermediate zone and the second section is in communication with a second zone part of the intermediate zone.

[0048] Alternatively, the male part may have an engagement structure for engagement with a motor for driving the screw feeder via the male part, where the male part may comprise a pin structure arranged for sliding in a receiving slot which may be formed at a corresponding female part.

[0049] In a fifth aspect, the disclosure provides a female part for mounting structure for mounting a screw feeder to a combination weigher, said female part having an engagement structure for engagement with a motor for rotating the screw feeder via the female part, where the female part comprises a receiving slot,

[0050] - where the receiving slot extends from an open end via an intermediate zone to a closed end,

[0051] - where the receiving slot defines at least a first section and a second section extending in different directions from the intermediate zone, the first section extending from the intermediate zone to the open end, the second section extending from the intermediate zone to the closed end, and

[0052] - the intermediate zone being defined within a first end-wall, a second end-wall, and a ceiling connecting the first end-wall and the second end-wall, the first end-wall and the second end-wall being non-parallel, and where the first section is in communication with a first zone part of the intermediate zone and the second section is in communication with a second zone part of the intermediate zone.

[0053] Alternatively, the female part may have an engagement structure for engagement with a motor for driving the screw feeder via the female part, where the female part may comprise a pin structure arranged for sliding in a receiving slot which may be formed at a corresponding male part.

[0054] In a sixth aspect, the disclosure provides a method of operating a combination weigher according to the first aspect of the disclosure, where the pin is slided from the open end to the intermediate zone of the receiving slot during rotation of the female part relative to the male part in a first direction of rotation, and slided from the intermediate zone to the second section by a further rotation of the female part relative to the male part in the first direction.

[0055] It should be understood that a skilled person would readily recognise that any feature described in combination with the first, second, third, fourth, and fifth aspects of the disclosure could also be combined with the sixth aspect of the disclosure, and vice versa.

[0056] The combination weigher according to the first aspect of the disclosure, as well as the screw feeder, the male part, and the female part according to the second to fifth aspects are very suitable for performing the method steps according to the sixth aspect of the disclosure. The remarks set forth above in relation to the combination weigher, the screw feeder, the male part, and the female part are therefore equally applicable in relation to the method.

[0057] BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 illustrates an example of a combination weigher,

[0059] Figure 2 illustrates a part of a combination weigher,

[0060] Figures 3-4 illustrate different views of a male part of a mounting structure,

[0061] Figures 5A and 5B two different male parts in an end view,

[0062] Figure 6 illustrates two unfolded receiving slots (not to scale),

[0063] Figure 7 illustrates a male part with an engagement structure, Figures 8-9 illustrate different views of a screw feeder,

[0064] Figures 10 - 12 illustrate two receiving slots in a mirrored layout in an unfolded view and in perspective views, respectively, and

[0065] Figures 13 - 14 illustrate a helically wounded layout of the centre-line of the first receiving section.

[0066] DESCRIPTION OF EMBODIMENTS

[0067] Figure 1 illustrates an example of a combination weigher 100 which is commonly used in the food or feed industry for generating portions of food or feed products fulfilling a pre-defined weight target. The combination weigher 100 comprises a dispersion unit 101 configured to receive food or feed items from an infeed unit (not shown) typically positioned above the combination weigher. A plurality of conveyance units 102 extend radially away from the dispersion unit 101 for receiving food or feed items from the dispersion unit. A plurality of weighing hoppers 103 are associated with the conveyance units 102 for receiving food or feed products therefrom. The weighing hoppers 103 are operated by a control unit (not shown) by repeatedly monitoring the weight in each of the weighing hoppers for finding an optimal weight combination in two or more weighing hoppers such that a target weight is obtained. Subsequently, the food or feed products are dropped from the selected two or more weighing hoppers into a discharge chute, and further into a bag, tray, or the like.

[0068] Such conveyance units 102 consist of trenches and screw feeders 104 arranged therein, where the screw feeders 104 are mechanically attached to motor units (not shown) and are configured to advance the received food or feed products from an infeed end in the trenches to an outfeed end of the trenches via a rotational movement of the screw feeders 104 and into the associated weighing hoppers 103, e.g., via a storage hopper in which the food objects are collected.

[0069] Figure 2 illustrates a part of a combination weigher 200. The combination weigher 200 may comprise a plurality of screw feeders 204 of which only one is shown. The screw feeder 204 is configured to convey objects by rotation about a rotation axis 209 extending in an axial direction which is indicated by the arrow 211. Each screw feeder 204 could be arranged in a trench 206 extending outwardly from a dispersion unit (not shown). The trench 206 may be tilted along the axial direction A to facilitate conveyance of the objects in the axial direction A. The screw feeder 204 is rotated by a motor 208 schematically illustrated by the dotted line and the box 208. A separate motor may be arranged for driving each screw feeder 204. The screw feeder 204 could be mounted to the motor 208 by a mounting structure 210, where the mounting structure 210 comprises a male part 210A and a female part 210B.

[0070] In Figure 2, the screw feeder 204 comprises a centerless auger-shaped transport portion 212 and the female part 210B of the mounting structure 210. The male part 210A could comprise an engagement structure 214 (see also Figure 7) to engage the male part 210A to the motor 208 for driving the screw feeder 204.

[0071] Alternatively, the screw feeder 204 may comprise an auger-shaped transport portion 212, particularly a centerless auger shaped portion, and the male part 210A of the mounting structure 210. The female part 210B may alternatively comprise an engagement structure 214 (see also Figure 7) to engage the female part 210B to the motor 208 for driving the screw feeder 204.

[0072] The male part 210A has an outer diameter being essentially the same or less than an inner diameter of the female part 210B to facilitate insertion of the male part 210A into the female part 210B. The clearance between the female part 210B and the male part 210A may be small to provide a good bearing strength and to provide the ability to absorb torque transverse to the rotation direction. The clearance may e.g., be less than 3 mm, i.e., the inner diameter of the female part 210B is at most 3 mm larger than the outer diameter of male part 210A. The clearance may be less than 1 percent of the diameter of the male part 210A which may allow the male part 210A to be carried by the female part 210B which thereby may absorb radial forces and moments transverse to the rotation axis. Consequently, the screw feeder 204 may be carried alone by a motor via the mounting structure 210.

[0073] The small clearance may be established along an insertion section (not shown) along which the male part 210A is inserted into the female part 210B. To provide good stability, the insertion section may have a length exceeding the outer diameter of the male part 201A. It may e.g., have a length being 2, 3, 4, or 5 times the outer diameter of the male part 210A.

[0074] One of the male part 210A and the female part 210B comprises a pin structure 216 (see e.g. Figures 8-9) and the other one of the male part 210A and the female part 210B comprises a receiving slot 218 (see e.g. Figures 3-4).

[0075] Figures 3-4 illustrate different views of a male part 210A of a mounting structure 210. The male part 210A comprises a receiving slot 218 which could be arranged along an outer surface hereof. The receiving slot 218 is designed for allowing the pin structure 216 (see Figures 8-9) to slide therein when the male part 210A slides into the female part 210B. This may be achieved by rotating the male part 210A and the female part 210B relative to each other. The receiving slot 218 extends along an outer circumference of the male part 210 from an open end 222 via an intermediate zone 224 to a closed end 226 (see also Figure 6).

[0076] The receiving slot 218 defines at least a first section 228 and a second section 230. The first section is defined between first and second sidewalls 242, 244, and the second section is defined between third and fourth side walls 245, 247. The first section and the second section extend in different directions from the intermediate zone 224. The first section 228 extends from the intermediate zone 224 to the open end 222, whereas the second section 230 extends from the intermediate zone 224 to the closed end 226. When the male part 210A slides into the female part 210B, the pin structure 216 slides in the receiving slot 218 from the open end 222 in the first section 228 to the intermediate zone 224 and further to the closed end 226 in the second section 230. Since the second section 230 extends from the intermediate zone 224 in a direction being different from the direction in which the first section 228 extends from the intermediate zone 224, the second section 230 may provide a locking effect preventing or at least reducing the risk of unintentional disengagement between the male part 210A and the female part 210B of the mounting structure 210.

[0077] The first section 228 and the second section 230 extend in different directions from the intermediate zone 224. The first section 228 may extend at an angle in the range of 20-60 degrees from the axial direction, whereas the second section 230 may extend at an angle in the range of 20-60 degrees from the axial direction in the other direction relative to the axial direction. The first section 228 may extend at an angle between 75 and 100 degrees to the second section 230.

[0078] The intermediate zone 224 is defined within a first end-wall 232, a second end-wall 234, and a ceiling 236 which connects the first end-wall 232 and the second end-wall 234. The first end-wall 232 and the second end-wall 234 are non-parallel which may facilitate sliding of the pin structure 216 (see Figures 8 and 9) from the first section 228 of the receiving slot 218 to the second section 230 of the receiving slot 218. The first section 228 is in communication with a first zone part 238 of the intermediate zone 224, whereas the second section 230 is in communication with a second zone part 240 of the intermediate zone 224. The first and second zone parts 238, 240 of the intermediate zone 224 are in communication with each other, and are not separated by a separating wall element. Likewise, is the first and second sections 228, 230 in communication with the first and second zone part 238, 240 of the intermediate zone 224 without being separated by a separating wall element.

[0079] The first end-wall 232 and the second end-wall 234 are connected by the ceiling 236 and extend in different directions from the ceiling 236 to form angles between the ceiling 236 and the first and second end-walls 232, 234, respectively, preferably each being at least 90 degrees. A first angle between the ceiling 236 and the first end-wall 232 is smaller than a second angle between the ceiling 236 and the second end-wall 234.

[0080] This may alternatively be expressed by the X and Y component of the end-walls. I.e., the first end-wall 232 has a first ratio between an X-component extending in the axial direction, and a Y component extending perpendicularly to the axial direction. The second end-wall 234 has a second ratio between a X-component extending in the axial direction, and a Y component extending perpendicularly to the axial direction. Where the second ratio is smaller than the first ratio.

[0081] The first section 228 extends between opposite first and second sidewalls 242, 244. The first sidewall 242 has a stepped layout comprising alternating segments 246 with a different ratio between a component in the axial direction and components transverse to the axial direction. The second sidewall 244 has a continuous layout, i.e., a non-stepped layout.

[0082] Both the first sidewall 242 and the first end-wall 232 could have a stepped layout. Additionally, the first sidewall 242 could extend in continuation of the first end-wall 232 to thereby form a common stepped wall. The stepped layout may define a pattern comprising at least a plurality of alternating A and B sections, where each A and B section may have an X- component extending in the axial direction and a Y-component extending in a direction transverse to the axial direction. An A ratio being defined as a ratio between the Y- component and the X-component of an A section may be different from a B ratio being a ratio between the Y-component and the X-component of a B section. The stepped layout may comprise more than two different sections are illustrated. Figures 3 and 4 illustrate a plurality of convex sections, a plurality of concave section, and a plurality of substantially plane sections.

[0083] Each of the A sections may be of the same size and shape, and each of the B sections may be of the same size and shape. However, as illustrated in Figures 3 and 4 at least a plurality of the A sections, but not all, are identical, and at least a plurality of the B sections, but not all, are identical. In Figures 3 and 4, the some of the sections in the area of the second section 230 are different.

[0084] Figure 6 illustrates an unfolded view of the receiving slot 218 and the additional receiving slot 218A. The receiving slot 218 and the additional receiving slot 218A may be identical with the only exception that they may be displaced 180 degrees relative to each other. To simplify the illustration of the two slots 218, 218A, some of the reference numbers are added to the illustration of the receiving slot 218, whereas other are added to the illustration of the additional receiving slot 218A in the figure. In Figure 6, the pattern comprises A sections of the same size and shape, and B sections are of the same size and shape. Alternatively, at least some of the A and / or B sections may be of a different shape and / or size. This may be particularly relevant in the abutting area X, where a corner of the second section 230 of one of the receiving slot 218 and the additional receiving slot 218A is close to the first side wall 242 of the other one of the receiving slot 218 and the additional receiving slot 218A, as this may endure a sufficient material thickness in the abutting area X.

[0085] Figures 3 and 4 illustrate the second section 230 being defined between a driving surface 248, an oppositely arranged locking surface 250, and the closed end 226, where the closed end 226 connects the driving surface 248 and the locking surface 250. The driving surface 248 could be longer than the locking surface 250. During operation of the combination weigher 200, the pin structure 216 could be arranged in the second section 230. Rotation of the screw feeder 204 by the motor 208 may be achieved, when the pin structure 216 is arranged in contact with the driving surface 248 which may push the pin structure 216, whereby the screw feeder 204 can be rotated. When stopping the motor 208 and thereby terminating rotation of the male part 210A, the pin structure 216 (not shown in Figure 3 and 4) may continue its movement and may move towards the locking surface 250 which may stop movement of the pin structure 216. The driving surface 248 and the locking surface 250 could be arranged substantially in parallel.

[0086] The locking surface 250 may terminate in a guide surface 252 extending transverse to the locking surface 250 at an angle which may e.g., be in the range of 100-160 degrees. By providing the guide surface 252 at an angle relative to the locking surface 250, movement of the pin structure 216 into the second section 230 may be facilitated.

[0087] The guide surface 252 and the second sidewall 244 could be arranged so that they extend transverse to each other at an angle which may e.g., be in the range of 20-80 degrees. They may be joined at a pointed edge 254. This may provide an un-interrupted wall extending from the open end 222 to the closed end 226, which un-interrupted surface may comprise the second sidewall 244 being continuous, the guide surface 252, and the locking surface 250. The un-interrupted surface which may be continuous without steps may facilitate positioning of the pin structure 216 in the second section 230 when rotating the male part 210A and the female part 210B relative to each other in one direction.

[0088] If the pin structure 216 (not shown in Figure 3 and 4) continues its movement and moves towards the locking surface 250, when stopping the motor 208, the locking surface 250 may be prevented from stopping the pin structure 216, e.g., if food or feed products get stuck between the auger 212 (see Fig. 2) and the trench 206 (see Fig. 2), which may introduce a force on the auger 212. The reaction to such a force may consequently be that the pin structure 216 may continue its movement into the intermediate zone 224. When colliding with the first end-wall 232 being stepped, the angle the stepped section may ensure that the pin structure 216 is bounced back towards the second end-wall 234. As the second end-wall 234 may be arranged at an obtuse angle relative to the ceiling 236, movement of the pin structure 216 back into the second section 230 may be facilitated.

[0089] As illustrated in Figures 3 and 4, the male part 210A may comprise an additional receiving slot 218A, where the additional receiving slot 218A is designed for allowing an additional pin structure 216A to slide therein when the male part 210A slides into the female part 210B. As illustrated in Figure 9, the female part 210B may comprise the additional pin structure 216A. The additional pin structure 216A and the additional receiving slot 218A may be displaced 180 degrees relative to the pin structure 216 and the receiving slot 218.

[0090] Figures 5A and 5B illustrate two different male parts 210A in an end-view. The male-part 210A illustrated in Figure 5A is for clockwise rotation around (indicated by the letter R) the rotation axis when seen from an outer end 256 at which the receiving slot 218 and the additional receiving slot 218A extends from the open end 222. The male-part 210A illustrated in Figure 5B is for counter-clockwise rotation (indicated by the letter L) around the rotation axis when seen from an outer end 256 at which the receiving slot 218 and the additional receiving slot 218A extends from the open end 222.

[0091] The combination weigher 200 may comprise a plurality of screw feeders 204 each being mounted to a motor by a mounting structure 210. Each mounting structure 210 comprises a male part 210A and female part 210B, and each screw feeder 204 may comprise an auger 212 and either a male part 210A or female part 210B. One combination weigher 200 may comprise a plurality of screw feeders 204 which are all configured for clockwise rotation around their respective rotation axis, thereby applying male parts 210A as illustrated in Figure 5A.

[0092] Another combination weigher 200 may comprise a plurality of screw feeders 204 which are all configured for counter-clockwise rotation around their respective rotation axis, thereby applying male parts 210A as illustrated in Figure 5B. In a further alternative, a combination weigher 200 may comprise a plurality of screw feeders 204 of which some are configured for clockwise rotation around their respective rotation axis and of which other are configured for counter-clockwise rotation around their respective rotation axis, thereby applying male parts 210A as illustrated in Figure 5A and applying male parts 210A as illustrated in Figure 5B. In the latter case, every second screw feeder 210 may be arranged for clockwise rotation, whereas every other may be arranged for counter-clockwise rotation. Figure 6 illustrates an unfolded receiving slot 218 (not to scale). The receiving slot 218 defines at least a first section 228 and a second section 230 which extend in different directions from the intermediate zone 224. The first section 228 extends from the intermediate zone 224 to the open end 222, whereas the second section 230 extends from the intermediate zone 224 to the closed end 226.

[0093] The intermediate zone 224 is defined within a first end-wall 232, a second end-wall 234, and a ceiling 236 which connects the first end-wall 232 and the second end-wall 234. The first section 228 is in communication with a first zone part 238 of the intermediate zone 224, whereas the second section 230 is in communication with a second zone part 240 of the intermediate zone 224. The dotted lines are for illustration of the first and second zone parts 238, 240 only.

[0094] The first end-wall 232 and the second end-wall 234 are connected by the ceiling 236 and extend in different directions from the ceiling 236 to form angles between the ceiling 236 and the first and second end-walls 232, 234, respectively, where each preferably are at least 90 degrees.

[0095] The first section 228 extends between opposite first and second sidewalls 242, 244. The first sidewall 242 has a stepped layout comprising alternating segments 246. The second sidewall 244 has a continuous layout, i.e. , a non-stepped layout..

[0096] Fig. 6 illustrates a dotted centre-line 60 which is formed by interconnecting geometric centre points of cross sections of the first section perpendicular to the rotation axis 209. Fig. 6B illustrates such a cross section perpendicular to the rotation axis and with indication of the geometric centre point 61. The dotted centre-line 62 is in a similar manner formed by interconnecting geometric centre points of cross sections of the second section perpendicular to the rotation axis.

[0097] Figure 7 illustrates a male part 210A with an engagement structure 214 for engagement with a motor 208 (see Figure 2) for driving the screw feeder 204 (see Figures 2, 8, and 9). The male part 210A is similar to the male parts 210A illustrated in Figures 3, 4, and 5A, and the reference numbers refer to the same features as in these figures. The engagement structure 214 may be formed integrally with the remaining part of male part 210A or may be a separate element which is attached to the remaining part of the male part 210A, e.g., by respective inner and outer threading, by welding, or by other process.

[0098] Figures 8-9 illustrate different views of a screw feeder 204 for a combination weigher 200 as illustrated in Figure 2. The screw feeder 204 comprises a centerless auger-shaped transport portion 212 and a female part 210B. In Figures 8 and 9, the female part 210B comprises a pin structure 216 and an additional pin structure 216A (see Figure 9) configured to slide in a receiving slot 218 and an additional receiving slot 218A, respectively (see Figures 3, 4, 5A, and 5B).

[0099] The pin structure 216 and the additional pin structure 216A are arranged on an inner surface 258 of the female part 210B to facilitate sliding hereof in a receiving slot 218 and an additional receiving slot 218A arranged on an outer surface 220 of a male part 210A.

[0100] In Figure 10 illustrates diagrammatically two unfolded receiving slots 218, 218'. Both receiving slots 218 define at least a first section 228, 228' and a second section 230, 230' which extend in different directions from the intermediate zone 224, 224'.

[0101] The pattern of receiving slot 218 is similar to that illustrated in Fig. 6, and the receiving slot 218' is a mirrored image of 218 in the mirror plane 1001. Herein, we refer to this receiving slot 218' as having a mirrored layout meaning that it extends in an oppostite helical pattern compared to the other receiving slot 218. They do not necessarily have identical dimensions, but they extend at opposite angles relative to the rotation axis 209.

[0102] In one embodiment, the one of the male part and the female part which comprises the receiving slot, comprises both the receiving slot 218 and the receiving slot 218'. This allows automatic movement of the pin structure towards the closed end in a selected one of the receiving slots 218, 218' depending on the direction of rotation of the motor and screw feeder.

[0103] Figs. 11 and 12 illustrate perspective views of the mirrored layout of the two receiving slots 218, 218'.

[0104] Fig. 13 illustrates diagrammatically, that the centre-line 60 of the first section 228 extends helically wounded around the rotation axis. The centre line is also illustrated in the diagram of Fig. 6 and it is formed by interconnecting geometric centre points of cross sections of the first section perpendicular to the rotation axis 209. Due to the helical shape of the centre line, the first section extends at an angle to the rotation axis. This angle is indicated in Fig. 13 with p, and it would typically be between 20 and 60 degrees.

[0105] Fig 14 illustrates the corresponding centre line 62 of at least a first portion of the second section 230. This centre line extends at an angle of 75-100 degreees to the centre line 60 of the first section.

Claims

CLAIMS1. A combination weigher comprising a screw feeder configured to convey objects by rotation about a rotation axis (209) extending in an axial direction (211) and being rotated by a motor via a mounting structure, said mounting structure comprising a male part 210A and a female part 210B, the male part having an outer diameter being essentially the same or less than an inner diameter of the female part, where one of the male part and the female part (210A, 210B) comprises a pin structure (216) and the other one of the male part and the female part comprises a receiving slot (218, 218A, 218'),- where the receiving slot is designed for allowing the pin structure to slide therein when the male part slides into the female part,- where the receiving slot extends from an open end (222) via an intermediate zone (224) to a closed end (226),- where the receiving slot defines at least a first section (228) extending between opposite first and second sidewalls (242, 244) and a second section (230) extending between opposite third and fourth sidewalls (245, 247), the first section and the second section extending in different directions from the intermediate zone, the first section extending from the intermediate zone to the open end, the second section extending from the intermediate zone to the closed end, and- the intermediate zone being defined within a first end-wall (232), a second end-wall (234), and a ceiling (236) connecting the first end-wall (232) and the second endwall, the first end-wall and the second end-wall (234) being non-parallel, and where the first section is in communication with a first zone part of the intermediate zone and the second section is in communication with a second zone part of the intermediate zone.

2. The combination weigher according to claim 1, wherein- the first end-wall has a first ratio between an X-component extending in the axial direction, and a Y component extending perpendicularly to the axial direction,- the second end-wall has a second ratio between a X-component extending in the axial direction, and a Y component extending perpendicularly to the axial direction, and- the second ratio is smaller than the first ratio.

3. The combination weigher according to claim 1 or 2, wherein the first section extends between opposite first and second sidewalls, at least one having a stepped layout comprising alternating segments with a different ratio between a component in the axial direction and components transverse to the axial direction.

4. The combination weigher according to claim 3, wherein one of the first and second sidewalls has a stepped layout and the other one of the first and second sidewalls has a continuous layout.

5. The combination weigher according to claim 4, wherein the first sidewall has a stepped layout, and the first end-wall has a stepped layout, wherein the first sidewall extends in continuation of the first end-wall to form a common stepped wall.

6. The combination weigher according to any of claims 3-5, wherein the stepped layout defines a pattern comprising a plurality of alternating A and B sections, each A and B section having an X-component extending in the axial direction and a Y-component extending in a direction transverse to the axial direction, wherein an A ratio being a ratio between the Y- component and the X-component of an A section is different from a B ratio being a ratio between the Y-component and the X-component of a B section.

7. The combination weigher according to claim 6, wherein at least a plurality of the A sections are identical, and wherein at least a plurality of the B sections are identical.

8. The combination weigher according to claim 6 or 7, wherein the pattern is a repetitive pattern at least along a part of the common stepped wall.

9. The combination weigher according to any of the preceding claims, wherein the first section has a first X-component extending in the axial direction, the second section has a second X-component extending in the axial direction, and the second X-component is shorter than the first X-component.

10. The combination weigher according to any of the preceding claims, wherein the first section has a first Y-component extending in a direction transverse to the axial direction, the second section has a second Y-component extending in a direction transverse to the axial direction, and the second Y-component is shorter than the first Y-component.

11. The combination weigher according to claim 9 and 10, wherein the ratio between the first Y-component and the first X-component is different from the ratio between the second Y- component and the second X-component.

12. The combination weigher according to any of the preceding claims, wherein the second section is defined between a driving surface, an oppositely arranged locking surface, and the closed end connecting the driving surface and the locking surface, wherein a length of the driving surface is longer than a length of the locking surface.

13. The combination weigher according to claim 12, wherein the locking surface terminates in a guide surface extending transverse to the locking surface.

14. The combination weigher according to claim 13, wherein the guide surface and the second sidewall extend transverse to each other and are joined at a pointed edge.

15. The combination weigher according to any of claims 12-14, where the driving surface and the locking surface are substantially parallel.

16. The combination weigher according to any of the preceding claims, where one of the male part and the female part comprises an additional pin structure and the other one of the male part and the female part comprises an additional receiving slot, where the additional receiving slot is designed for allowing the additional pin structure to slide therein when the male part slides into the female part.

17. The combination weigher according to claim 16, where the additional pin structure and the additional receiving slot are displaced 180 degrees relative to the pin structure and the receiving slot.18 The combination weigher according to any of the preceding claims, wherein the first zone part of the intermediate zone and the second zone part of the intermediate zone are separated by a plane extending through a pointed edge (254) separating the first and the second sections.

19. The combination weigher according to any of the preceding claims, wherein the first section defines a centre-line extending between geometric centre points of cross sections of the first section perpendicular to the rotation axis, wherein the centre-line extends helically wounded around the rotation axis.

20. The combination weigher according to any of the preceding claims, where one of the male part and the female part (210A, 210B) comprises a pin structure (216), such as one pin structure, and the other one of the male part and the female part comprises two receiving slots (218, 218B, 218').

21. The combination weigher according to claim 20, wherein the receiving slots are identical (218, 218B).

22. The combination weigher according to claim 20, wherein one of the two receiving slots is a mirrored layout of the other of the two receiving slots (218, 218').

23. A screw feeder for a combination weigher, said screw feeder comprising an auger-shaped transport portion and a male part, where the male part comprises a receiving slot,- where the receiving slot extends from an open end via an intermediate zone to a closed end, where the receiving slot defines at least a first section and a second section extending in different directions from the intermediate zone, the first section extending from the intermediate zone to the open end, the second section extending from the intermediate zone to the closed end, and- the intermediate zone being defined within a first end-wall, a second end-wall, and a ceiling connecting the first end-wall and the second end-wall, the first end-wall and the second end-wall being non-parallel, and where the first section is in communication with a first zone part of the intermediate zone and the second section is in communication with a second zone part of the intermediate zone.

24. A screw feeder for a combination weigher, said screw feeder comprising an auger-shaped transport portion and a female part, where the female part comprises a receiving slot,- where the receiving slot extends from an open end via an intermediate zone to a closed end,- where the receiving slot defines at least a first section and a second section extending in different directions from the intermediate zone, the first section extending from the intermediate zone to the open end, the second section extending from the intermediate zone to the closed end, and- the intermediate zone being defined within a first end-wall, a second end-wall, and a ceiling connecting the first end-wall and the second end-wall, the first end-wall and the second end-wall being non-parallel, and where the first section is in communication with a first zone part of the intermediate zone and the second section is in communication with a second zone part of the intermediate zone.

25. A male part for a mounting structure for mounting a screw feeder to a combination weigher, said male part having an engagement structure for engagement with a motor for rotating the screw feeder via the male part, where the male part comprises a receiving slot,- where the receiving slot extends from an open end via an intermediate zone to a closed end,- where the receiving slot defines at least a first section and a second section extending in different directions from the intermediate zone, the first section extending from the intermediate zone to the open end, the second section extending from the intermediate zone to the closed end, and- the intermediate zone being defined within a first end-wall, a second end-wall, and a ceiling connecting the first end-wall and the second end-wall, the first end-wall and the second end-wall being non-parallel, and where the first section is in communication with a first zone part of the intermediate zone and the second section is in communication with a second zone part of the intermediate zone.

26. A female part for a mounting structure for mounting a screw feeder to a combination weigher, said female part having an engagement structure for engagement with a motor for rotating the screw feeder via the female part, where the female part comprises a receiving slot,- where the receiving slot extends from an open end via an intermediate zone to a closed end,- where the receiving slot defines at least a first section and a second section extending in different directions from the intermediate zone, the first section extending from the intermediate zone to the open end, the second section extending from the intermediate zone to the closed end, and- the intermediate zone being defined within a first end-wall, a second end-wall, and a ceiling connecting the first end-wall and the second end-wall, the first end-wall and the second end-wall being non-parallel, and where the first section is in communication with a first zone part of the intermediate zone and the second section is in communication with a second zone part of the intermediate zone.

27. A method of operating a combination weigher according to any of claims 1-22, where the pin is slided from the open end to the intermediate zone of the receiving slot during rotation of the female part relative to the male part in a first direction of rotation, and slided from the intermediate zone to the second section by a further rotation of the female part relative to the male part in the first direction.

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