CONVEYOR CHAIN LINK AND CONVEYOR CHAIN COMPRISING SUCH A CHAIN LINK AND CONVEYOR SYSTEM

Abstract

Conveyor chain link (1) provided with an upper body (2) and a lower body (3), where the chain link (1) is provided with an upper bearing surface (17), a front end (4) and a rear end (5), where the rear end (5) is provided with a first leg (6) and a second leg (7) arranged spaced apart from each other with a distance corresponding to the width of the front end (4), where the chain link (1) is adapted to be connected to an adjacent chain link (1) through a pivot member (12), where the front end (4) of the upper body (2) is provided with a plurality of front teeth (18) and front notches (19), where the rear end (5) of the upper body (2) is provided with a plurality of rear teeth (20) and rear notches (21), where the length of the teeth (18, 20) differs over the width of the chain link (1), where the ratio between the width of the chain link (1) and the number of teeth (20) of the rear end (5) is less than 10 mm/tooth. The advantage of the invention is that a conveyor chain link that will allow small objects to be conveyed on a conveyor chain is provided.

Claims

1-15. (canceled)

16. Conveyor chain link (1) provided with an upper body (2) and a lower body (3), where the chain link (1) is provided with an upper bearing surface (17), a front end (4) and a rear end (5), where the rear end (5) is provided with a first leg (6) and a second leg (7) arranged spaced apart from each other with a distance corresponding to the width of the front end (4), where said first leg (6) has a first protrusion (8) facing outwards from the first leg (6) and where the second leg (7) has a second protrusion (9) arranged opposite the first protrusion (8) and facing outwards from the second leg (7), where the first protrusion (8) is provided with a first through hole (10) and the second protrusion (9) is provided with a second through hole (11) being coaxial with the first through hole (10), where the lower body comprises an opening (13) adapted to hold a pivot member (12), where the first and the second through holes (10, 11) are adapted to hold a connecting pin (16), where the front end (4) of the upper body (2) is provided with a plurality of front teeth (18) and front notches (19), where the rear end (5) of the upper body (2) is provided with a plurality of rear teeth (20) and rear notches (21), where the length of the teeth (18, 20) differs over the width of the chain link (1), and wherein the ratio between the width of the chain link (1) and the number of teeth (20) of the rear end (5) is less than 10 mm/tooth.

17. Conveyor chain link according to claim 16, wherein the front end (4) is provided with eight teeth (18).

18. Conveyor chain link according to claim 16, wherein the length of an outermost rear tooth (36) is shorter than a second outermost rear tooth (35).

19. Conveyor chain link according to claim 16, wherein the chain link (1) is symmetric to a centre plane (22) and that the chain link (1) is provided with a left section (43) and a right section (44), where the right section (44) is provided with a first front tooth (26), a second front tooth (27), a third front tooth (28) and a fourth front tooth (29).

20. Conveyor chain link according to claim 19, wherein the outer front side edge (41) of the fourth front tooth (29) is continuously inclined from the tip (45) of the fourth front tooth (29) to the side edge (42) of the chain link (1).

21. Conveyor chain link according to claim 19, wherein at least one of the second front tooth (27), the third front tooth (28) or the fourth front tooth (29) is provided with a side edge that is either bent in different segments (46, 47; 48, 49; 50, 51; 52, 53) or curved.

22. Conveyor chain link according to claim 16, wherein the chain link (1) is 83 mm wide.

23. Conveyor chain link according to claim 16, wherein the pitch of the chain link (1) is 33.5 mm.

24. Conveyor chain link according to claim 16, wherein the ratio between the pitch of the chain link (1) and the number of teeth (20) of the rear end (5) is less than 3.5 mm/tooth.

25. Conveyor chain link according to claim 16, wherein the upper bearing surface (17) is provided with a material that differs from the material of the body (2, 3).

26. Conveyor chain (60), wherein the conveyor chain (60) comprises a plurality of conveyor chain links (1) according to claim 16, where each conveyor chain link (1) is connected to an adjacent conveyor chain link (1) by a pivot member (12) arranged in the pivot opening (13) in the lower body (3) and a connecting pin (16) arranged through the first through hole (10), the second through hole (11), a transverse through hole of the pivot member (12), and transverse pivot openings (14) of the lower body (3).

27. Conveyor chain (60) according to claim 26, wherein the conveyor chain (60) has a horizontal turning radius of less than 300 mm.

28. Conveyor chain (50) according to claim 26, wherein the conveyor chain (60) has a vertical turning radius of less than 200 mm with the bearing surface (17) facing inwards towards the centre of the curvature.

29. Conveyor chain (60) according to claim 26, wherein the conveyor chain (60) prevents a circular object with a diameter of 6 mm or more to enter between two adjacent chain links (1) when the conveyor chain is bent in any direction.

30. Conveyor system, wherein the conveyor system comprises at least one conveyor chain (60) according to claim 26, a conveyor beam holding the conveyor chain (60), and a drive unit arranged to drive the conveyor chain (60).

Description

BRIEF DESCRIPTION OF DRAWINGS

[0039] The invention will be described in greater detail in the following, with reference to the embodiments that are shown in the attached drawings, in which

[0040] FIG. 1 shows a view of a chain link according to the invention,

[0041] FIG. 2 shows an upper view of a chain link according to the invention,

[0042] FIG. 3 shows a lower view of a chain link according to the invention,

[0043] FIG. 4 shows an upper view of a straight conveyor chain according to the invention,

[0044] FIG. 5 shows an upper view of a conveyor chain in a horizontal bend according to the invention, and

[0045] FIG. 6 shows a side view of a conveyor chain in a vertical bend according to the invention.

MODES FOR CARRYING OUT THE INVENTION

[0046] The embodiments of the invention with further developments described in the following are to be regarded only as examples and are in no way to limit the scope of the protection provided by the patent claims. References such as longitudinal, horizontal, vertical, right, left etc. refer to directions of a conveyor in normal use, conveying objects in a horizontal plane.

[0047] FIGS. 1 to 3 show an example of a conveyor chain link according to the invention, and FIGS. 4 to 6 show an example of a conveyor chain according to the invention. The conveyor chain link is intended to be used in endless conveyor chains for conveying objects on a chain conveyor. With the design of the chain link, a conveyor chain that can carry small objects through sharp bends is obtained. This simplifies the transport of small objects and allows for compact conveyor systems. In this application, a small object is an object having a diameter of 6 mm. Objects having a larger diameter can of course also be conveyed by such a conveyor chain.

[0048] In FIGS. 1 to 3, a conveyor chain link 1 that can form part of a conveyor chain is shown. The chain link has an upper body 2 with an upper bearing surface 17 adapted to carry objects that are to be conveyed. The upper bearing surface is preferably shaped like a substantially flat surface for supporting objects. The upper bearing surface may be made in the same material as the body of the chain link, or may be provided with a different material having a higher friction value, such as rubber or a soft plastic. The upper bearing surface is provided with a front side and a rear side. The front side is provided with a plurality of front teeth 18 and front notches 19 arranged adjacent to the front side, and the rear side is provided with a plurality of rear teeth 20 and rear notches 21 arranged adjacent to the rear side. The notches and the teeth are arranged to mesh with the corresponding front and rear teeth and notches of adjacent chain links. The chain link 1 comprises a centre plane 22 that is parallel to the travelling direction of a conveyor chain and a transverse plane 23 that is perpendicular to the centre plane 22 and to the travelling direction of a conveyor chain. The centre plane divides the conveyor chain link 1 in a left section 43 and a right section 44, where left and right refers to the normal travelling direction of a conveyor chain with the front end 4 of the conveyor chain link directed in the travelling direction.

[0049] The conveyor chain link is further provided with a lower body 3 provided with a front end 4 and a rear end 5. The front end 4 is provided with a circular opening 13 that is arranged to hold a pivot member 12, which is provided with a transverse through hole. The through hole of the pivot member is adapted to hold a connecting pin 16. The sides of the front end is further provided with transverse pivot openings 14 through which the connecting pin will extend. The rear end 5 has a first leg 6 and a second leg 7 arranged at a certain distance from each other, with the legs bifurcating out from the front end 4. The distance between the first leg and the second leg is such that the front end of a chain link fits between the first and second legs of an adjacent chain link when mounted in a conveyor chain.

[0050] The first leg 6 has a first protrusion 8 arranged substantially perpendicular to the centre plane 22 and facing outwards from the first leg. The protrusion is advantageously utilized as transport facilitating means, i.e. used as engagement means for cooperation with a drive wheel or the like, for example interacting with a cogwheel of a conveyor drive unit. The protrusion is further advantageously adapted to function as a sliding surface bearing on a slide rail in the return path of a conveyor chain. The first protrusion 8 has a first through hole 10, which may have a circular or a non-circular cross-section, e.g. a substantially triangular shape, even though other shapes are also plausible. The second leg 7 has a second protrusion 9 arranged opposite to the first protrusion 8 and facing outwards from the second leg. The second protrusion 9 has a second through hole 11 substantially coaxial with the first through hole 10 of the first protrusion 8 and of the same cross-section. The protrusions extend uniformly such that the protrusions resemble a tube shaped protrusion. A connecting pin 16 adapted to connect two adjacent chain links will extend through the first and second through holes, the transverse pivot openings of the front end and the transverse through hole of the pivot member. The connecting pin may either be secured by the transverse through hole or the first and second through holes 10, 11.

[0051] The upper body 2 comprises a plurality of teeth and notches, in the shown example eight front teeth 18 and seven front notches 19 arranged adjacent the front side. The upper body further comprises and nine rear teeth 20 and eight rear notches 21 arranged adjacent the rear side. The ratio between the width of the chain link and the number of teeth at the rear side is less than 10 mm/tooth, and more preferably less than 9.5 mm/tooth. The width of a chain link is defined by the distance between the two parallel outer side edges 42 of the rear part of the chain link. With this ratio, it can be ensured that a sufficient dense conveyor chain can be obtained by the chain links. In the shown example, the width of the chain link is 83 mm. A wider chain link requires more teeth to obtain the same teeth density. It is also possible to provide the upper body with nine front teeth and ten rear teeth. More teeth for the same width will mean that each tooth must be narrower, which causes problems when the chain links are injection moulded. The conveyor chain link is preferably made from a material having a low coefficient of friction, such as an acetal plastic and/or polyamide.

[0052] The pitch of the chain link, i.e. the distance between the front pivot point and the rear pivot point of the chain link, is 33.5 mm. The ration between the pitch of the chain link and the number of teeth at the rear side is less than 3.5 mm/tooth. This will provide a conveyor chain that can travel through sharp curves but that still provides a relatively dense chain in the bends. The purpose of a chain link is to provide a conveyor chain that will stop objects with a diameter smaller than 6 mm to enter between two conveyor chains in a curve, when the chain is bent to its maximum.

[0053] Since the conveyor chain link is symmetrical, only the right section 44 will be described in detail. The rear side is provided with a central rear tooth 25, a first rear tooth 33, a second rear tooth 34, a third (or second outermost) rear tooth 35 and a fourth outermost rear tooth 36. Between the central rear tooth 25 and the first rear tooth 33, a first rear notch 37 is provided. Between the first rear tooth 33 and the second rear tooth 34, a second rear notch 38 is provided. Between the second rear tooth 34 and the third rear tooth 35, a third notch 39 is provided, and between the third rear tooth 35 and the fourth or outermost rear tooth 36, a fourth rear notch 40 is provided. The extension of the rear teeth except for the fourth or outermost rear tooth, i.e. the distance from the transverse plane 23 to the tip of the teeth is substantially the same, with the extension of the fourth or outermost tooth being shorter. The distance from the centre of a notch to the transverse plane 23 decreases outwards from the first rear notch 37, i.e. the depth of each notch increases outwards from the centre plane.

[0054] The front side is provided with a first front tooth 26, a second front tooth 27, a third (or second outermost) front tooth 28 and a fourth or outermost front tooth 29. Between the two first front teeth 26, a central notch 24 is provided. Between the first front tooth 26 and the second front tooth 27, a first front notch 30 is provided. Between the second front tooth 27 and the third front tooth 28, a second front notch 31 is provided, and between the third front tooth 28 and the fourth or outermost front tooth 29, a third front notch 32 is provided. The extension of the front teeth, i.e. the distance from the transverse plane 23 to the tip of the teeth increases outwards from the first tooth 26, where the first front tooth 26 is the shortest and the fourth or outermost front tooth 29 is the longest. The distance from the centre of a notch to the transverse plane 23 decreases slightly outwards from the centre plane.

[0055] In order to allow for a conveyor chain that can travel through sharp curves, the shape of a tooth or a notch must not be symmetrical. Especially one or more of the outer teeth may be provided with side edges that are curved or broken. In the shown example, the outer side edge of the second front tooth 27 is provided with an outer first edge segment 46 and an inner second edge segment 47 having different inclinations with regards to the centre plane 22. The inner side edge of the third front tooth 28 is provides with an outer third edge segment 48 and an inner fourth edge segment 49 having different inclinations with regards to the centre plane 22. The outer side edge of the third front tooth 28 is provides with an outer fifth edge segment 50 and an inner sixth edge segment 51 having different inclinations with regards to the centre plane 22.

[0056] The side edges of the second rear tooth 34 and the third rear tooth 35 are also provided with differently inclined edge segments in the same way. This will allow the teeth and notches of two adjacent chain links to be closer to each other when a conveyor chain bends, which will further help to prevent smaller objects to enter between two chain links. The outer side of the upper body 2 is provided with a rear side edge 42 that is parallel to the centre plane 22, and a front side edge 41 that is continuously inclined from the rear side edge to the tip of the fourth or outermost front tooth 29. The shape of the fourth or outermost rear tooth 36 and the fourth or outermost front tooth 29 will also help to prevent objects from entering between tow chain links when a conveyor chain bends.

[0057] A plurality of conveyor chain links 1 are attached to each other as shown in FIGS. 4 to 6 in order to create a conveyor chain 60. Such a conveyor chain is adapted to travel in a conveyor beam provided with slide rails. One or more conveyor chains with conveyor beams make up a conveyor system, which also comprises curves and may comprise other functional elements, such as diverters, stops, drive units, handling stations etc. The conveyor system is used for moving objects between different stations in e.g. a factory. Such conveyor systems are well known in the art.

[0058] FIG. 4 shows a conveyor chain 60 arranged to travel in a straight moving direction 61. The free area between two chain links is in the shown example, with an 83 mm wide chain, approximately 400 mm.sup.2, where the bearing surface of the upper body is approximately 2370 mm.sup.2. The ratio between the bearing surface and the free area is preferably larger than 5. The distance between the teeth and notches of two adjacent chain links in the longitudinal direction ensures that the conveyor chain can travel in an upward curve, i.e. in a vertical direction. A smaller distance will limit the radius of the vertical curve.

[0059] FIG. 5 shows a bent conveyor chain arranged to travel in a horizontal curve. The conveyor chain is designed with a horizontal turning radius of minimum 250 mm. Since the chain links are symmetrical, the curves may bend both to the right and to the left. When the conveyor chain is bent, the free area between two chain links remains the same as for a straight conveyor chain, but the distance between the teeth and notches at the inside and outside of the curve changes. At the inside, the distance between the teeth and notches decreases, and the tip of a tooth may even bear on the bottom of a notch. At the outside, the distance between the tip of a tooth and the bottom of a notch increases. However, due to the spacing of the teeth and notches, a small object is still prevented to extend into the space between two chain links. It will thus be possible to convey objects with a diameter of 6 mm through the curve in a reliable manner.

[0060] FIG. 6 shows a side view of a conveyor chain arranged to travel in vertical curve, with the bearing surface 17 facing inwards, towards the centre of the vertical curve. The conveyor chain is designed with a vertical turning radius of less than 200 mm. In this way, sharp upwards bends may be used in the conveyor system. In the upward curve, the teeth and the notches will mesh such that small objects are prevented from entering between two adjacent chain links. An upward curve is always straight.

[0061] The invention is not to be regarded as being limited to the embodiments described above, a number of additional variants and modifications being possible within the scope of the subsequent patent claims. The chain link may have any size and may be made from any suitable material.

REFERENCE SIGNS

[0062] 1: Conveyor chain link [0063] 2: Upper body [0064] 3: Lower body [0065] 4: Front end [0066] 5: Rear end [0067] 6: First leg [0068] 7: Second leg [0069] 8: First protrusion [0070] 9: Second protrusion [0071] 10: First through hole [0072] 11: Second through hole [0073] 12: Pivot member [0074] 13: Opening [0075] 14: Transverse pivot opening [0076] 16: Connecting pin [0077] 17: Upper bearing surface [0078] 18: Front teeth [0079] 19: Front notches [0080] 20: Rear teeth [0081] 21: Rear notches [0082] 22: Centre plane [0083] 23: Transverse plane [0084] 24: Central front notch [0085] 25: Central rear tooth [0086] 26: First front tooth [0087] 27: Second front tooth [0088] 28: Third front tooth [0089] 29: Fourth front tooth [0090] 30: First front notch [0091] 31: Second front notch [0092] 32: Third front notch [0093] 33: First rear tooth [0094] 34: Second rear tooth [0095] 35: Third rear tooth [0096] 36: Fourth rear tooth [0097] 37: First rear notch [0098] 38: Second rear notch [0099] 39: Third rear notch [0100] 40: Fourth rear tooth [0101] 41: Front side edge [0102] 42: Rear side edge [0103] 43: Left section [0104] 44: Right section [0105] 45: Tip [0106] 46: First edge segment [0107] 47: Second edge segment [0108] 48: Third edge segment [0109] 49: Fourth edge segment [0110] 50: Fifth edge segment [0111] 51: Sixth edge segment [0112] 52: Seventh edge segment [0113] 53: Eighth edge segment [0114] 60: Conveyor chain [0115] 61: Moving direction