caster and transport device with one caster

Abstract

Caster (1), e.g., swivel caster, for transport equipment (T), with a wheel (2) rotatably mounted in a fork (G) about an axis of rotation (x), wherein the fork (G) has a support foot (13, 14) with a support surface (15, 16) on each side of the wheel (2), and with at least one groove (25) formed on the support foot side between the support feet (15, 16), characterized in that the wheel (2), with respect to a vertical section, has a stationary central part (22) forming a groove base (26) and two disc-like running parts (17, 18) arranged laterally to the central part (22), that the central part (22) has a mounting section (31), wherein a mounting surface (32) of the mounting section (31) and the support surfaces (15, 16) of the support feet (13, 14) face in the direction of the axis of rotation (x) are aligned with each other and that the contact surface (32) and the support surfaces (15, 16) extend transversely to the axis of rotation (x) with a radius of curvature (s),which corresponds to at least 1.5 times the radius (r) of the wheel (2).

Description

field of technology

[0001] The invention relates to a castor, for example a steering castor, for transport equipment, with a running wheel mounted in a fork so as to be rotatable about a rotation axis, wherein the fork has a support foot with a support surface on each side of the running wheel, and with at least one groove formed on the support foot side between the support feet.

[0002] The invention further relates to a transport device, for example a shopping trolley, with a roller. State of the art

[0003] Casters of the type in question are known for transport devices, as well as for transport devices, for example in the form of shopping carts with such casters. Reference is made, for example, to DE 29 514 898 U1 and WO 2017 / 001263 A1. Such casters are particularly designed both for use on conventional floor surfaces and for use on so-called moving walkways. Such moving walkways typically have a grooved surface. The groove of the caster formed between the support feet engages with the grooved surface when the transport device is arranged on such a moving walkway. As a result, the support feet of the caster come to rest on the upper side of the grooved webs, so that the transport device is held in place by the resulting friction between the support feet and the surface of the moving walkway.In this arrangement of the roller on the passenger moving walkway, the running wheel, which is mounted on a rotatable bearing, preferably does not absorb any supporting forces.

[0004] EP 1 918 127 A2 discloses a roller in which the central part is stationary and forms a groove base. Disc-like running parts are provided laterally to the central part. FR 3008025 A1 discloses a roller in which the central part is firmly connected to disc-like running parts and is designed to rotate as a running part. Support feet are provided laterally to the central part, allowing the roller to achieve secure footing on a grooved passenger moving walkway. Summary of the invention

[0005] In view of the above-described prior art, one object of the invention is to provide an improved design of a castor, for example a steering castor, for transport devices and a transport device provided with such a castor.

[0006] This object is achieved in the subject matter of claim 1, wherein the impeller, based on a vertical section, has a fixed central part forming a groove base and two disc-like running parts arranged laterally to the central part, that the central part has a seating section, wherein a seating surface of the seating section and the support surfaces of the support feet are aligned with one another in the direction of the axis of rotation, and that the seating surface (32) and the support surfaces (15, 16) extend transversely to the axis of rotation (x) with a radius of curvature (s) which corresponds to at least 1.5 times the radius dimension (r) of the impeller (2).

[0007] Furthermore, this object is achieved with regard to a transport device in the subject matter of claim 9.

[0008] According to the proposed design, an improved roller and an improved transport device with such a roller are provided. The disc-like running parts, which are spaced apart from one another by the central part in the direction of the rotation axis and, during normal use, freely rotatable relative to the fixed central part and relative to the fixed fork about the rotation axis, provide appropriate support on a floor surface during normal use of the roller. The intended spacing of the running parts from one another is preferably such that it allows meshing engagement with the grooved surface of a passenger moving walkway.

[0009] The fixed central section defines only one groove, which extends between the two disc-like running parts. Furthermore, a groove formed in this way on the roller can, viewed in the direction of the rotation axis, extend over the area of ​​several grooved webs of the moving walkway when the roller or a transport device equipped with such a roller is arranged on a passenger moving walkway, for example, over the area of ​​two, three, four, or five grooved webs.

[0010] The fixed central part advantageously forms a support section which, during normal use of the roller or transport device, rests on the upper side of the grooved webs together with the support surfaces of the support feet when the roller or transport device is arranged, for example, on a moving walkway. Due to the formation of this additional support section in the created fixed central part, the overall support surface of the roller is enlarged, which advantageously leads to improved frictional locking of the roller or the transport device equipped with the roller on such a moving walkway.

[0011] This also makes it possible to achieve a favorable adaptation of the three frictional engagement surfaces provided by the proposed invention to the conditions of the substrate on which the frictional engagement is to be established.

[0012] In the course of use of the roller, one or more of the friction surfaces may become worn.

[0013] In the frictional engagement position, a linear support of the roller can occur via the friction engagement surfaces on the grooved surface of the moving walkway. In particular, due to normal wear during use of the roller, but also due to the normal load on the roller, a possibly flat support surface can also develop on one or more friction engagement surfaces, correspondingly extending in alignment with the rotational axis as well as transversely to it.

[0014] According to a further development, the central part, with the exception of a partial area forming the mounting section, can have a cylindrical outer surface. In this regard, a circular-cylindrical outer surface is preferred, which has a radius relative to the axis of rotation that is selected to be smaller than the corresponding radius of the disc-like running parts. Thus, the radius of the cylindrical section of the central part can correspond to approximately 0.7 to 0.95 times, and furthermore approximately 0.8 to 0.9 times, the running part radius.

[0015] The contact surface and the support surfaces extend transversely to the axis of rotation with a radius of curvature that corresponds to at least 1.5 times the radius of the impeller. The radius of curvature can be up to approximately three times the radius of the impeller. Thus, the contact surface in the center section and the support surfaces each have a cambered surface.

[0016] It is further preferred that the support section, in particular its support surface, be formed from a softer plastic than the remaining part of the overall stationary central section. The support foot, in particular its support surface, can also, as is also preferred, be formed from a softer plastic material than the remaining part of the fork on which the support foot is formed.

[0017] Thus, the softer plastic for forming the contact section or the contact surface and / or for forming the support foot or its support surface can comprise a polyurethane with a hardness of preferably approximately 38 to 42 Shore D. In a further embodiment, the softer plastic can have a hardness of approximately 40 Shore D, for example.

[0018] The remaining part of the middle part and / or the fork is preferably made of a harder plastic than the contact section or the contact surface and / or the support foot or the support surface, more preferably of a plastic comprising, for example, polyurethane, optionally of polypropylene or a glass fiber reinforced polyamide, with a hardness of, for example, approximately 57 to 63 Shore D. In further detail, the remaining part of the middle part and / or the fork can have a hardness of, for example, approximately 60 Shore D.

[0019] The ranges or value ranges or multiple ranges specified above and below also include all intermediate values ​​with regard to the disclosure, in particular in 1 / 10 increments of the respective dimension, and therefore possibly also dimensionless. For example, the specification 38 to 42 Shore D also includes the disclosure of 38.1 to 42 Shore D, 38 to 41.9 Shore D, 38.1 to 41.9 Shore D, etc., the disclosure of 0.7 to 0.95 times, also the disclosure of 0.8 to 0.95 times, 0.7 to 0.85 times, 0.8 to 0.85 times, etc. This disclosure can serve, on the one hand, to delimit a stated range limit from below and / or above, but alternatively or additionally, to disclose one or more singular values ​​from a respectively specified range. Short description of the drawings

[0020] The invention is explained in more detail below with reference to the accompanying drawing, which illustrates an exemplary embodiment. It shows: Fig. 1 a roller in perspective view; Fig. 2 a transport device in the form of a shopping cart in side view with castors according to the invention; Fig. 3 the roller in side view; Fig. 4 the front view against the roller according to arrow IV in Fig. 3; Fig. 5 the bottom view against the roller according to arrow V in Fig. 3; Fig. 6 the roller in exploded perspective view; Fig. 7 the section along the line VII-VII in Fig. 4; Fig. 8 the section along the line VIII-VIII in Fig. 4; Fig. 9 the section along the line IX-IX in Fig. 3. Description of the embodiments

[0021] Shown and described is a castor 1 designed as a steering castor, which essentially has a running wheel 2, which in the installed state is held between two fork halves 3 and 4 of a fork G, and a fastening pin 5 for fastening the castor 1 to a transport device T, for example in the form of a shopping cart according to the illustration in Fig. 2. The fastening pin 5, which is essentially vertically aligned in the normal state of use, can also be designed as a screw, and together with its longitudinal body axis forms the steering axis y, which is essentially vertically aligned in the state of use.

[0022] In the use state, the fork halves 3 and 4 each form a bearing shell half 6 and 7 on the upper side, for receiving an upper plain or roller bearing 8.

[0023] The two fork halves 3 and 4 are preferably each formed as a plastic injection-molded part. As is also preferred, the fork halves 3 and 4 can be essentially mirror-imaged.

[0024] As can be seen, a fork leg 9 extends from the upper bearing shell half 6 or 7 in the state of use, on the end region of which, facing away from the bearing shell half 6, 7, a hub 10 is formed in the direction of the fork leg 9 of the other fork half 4, 3.

[0025] As can be seen from the illustration in Fig. 3, the hub 10 can be provided on the outside of the wall with a non-circular section in the form of, for example, a hexagonal section 11 extending in the direction of a central axis of the hub 10.

[0026] A disc-shaped cover 12 (so-called thread guard) can be formed integrally and of the same material on the fork legs 9 of the fork halves 3 and 4. This can also be manufactured, for example, using a two-component injection molding process. These covers 12 cover, for example, Fig. 1 the broad side of the wheel 2 which is rotatably mounted between the fork legs 9.

[0027] With regard to the further design of the fork G, in particular the design and arrangement of the fork halves 3 and 4 with the bearing shell area accommodating the bearing 8, reference is also made to DE 10 2019 118 980 A1. The content of this patent application is hereby incorporated in its entirety into the disclosure of the present invention, also for the purpose of incorporating features of this patent application into the claims of the present invention.

[0028] A support foot 13, 14 is preferably formed integrally with the cover 12 and, if appropriate, with the cover 12, respectively, and optionally of the same material. Corresponding to the fork leg 9 and the cover 12, the support foot 13, 14 is also mounted on the fork halves 3 and 4 in a non-rotating manner. In the normal use position of the roller 1, the support foot 13, 14 is directed essentially vertically downwards. A support surface 15, 16 forms the lower end.

[0029] The support foot 13 or 14 can taper continuously and continuously in the direction of the support surface 15 or 16, with reference to a side view as shown in Fig. 3 lateral boundaries of the support foot 13 or 14 can, if necessary, run tangentially into the edge of the plate-like cladding.

[0030] The disc radius of the fairing 12 can correspond to approximately 0.5 to 0.8 times the impeller radius r, furthermore approximately two thirds.

[0031] The impeller 2 is essentially formed by two disc-like running parts 17 and 18 arranged at a distance from one another in the direction of the axis of rotation x, which is predominantly horizontally oriented during normal use. These can, as is also preferred, be of essentially the same design.

[0032] The running parts 17 and 18 determine the radius for the impeller 2 and form a running surface 19 on the respective circumferential surface.

[0033] The axial distance a between the mutually facing surfaces of the running parts 17 and 18 corresponds approximately to 4 to 6 times, further approximately 5 times, the width b of a running surface 19 of a running part 17 or 18, viewed in the axial direction.

[0034] Each running part 17 or 18 is rotatably mounted on the hub 10 of the associated fork half 3, 4 or the associated fork leg 9 via a centrally mounted roller bearing 20, 21.

[0035] A stationary central part 22 is provided between the running parts 17 and 18. This central part has a non-circular receiving opening 23, in the illustrated embodiment a hexagonal opening viewed in a plane transverse to the rotation axis x. The hub 10 of the respective fork halves 3 and 4 engages in this opening, preferably in a form-fitting manner, whereby the central part 22 is held in a rotationally fixed manner between the fork halves 3 and 4.

[0036] The central part 22 essentially has a cylindrical outer surface 24, with a central part radius t which is selected to be smaller than the radius r of the running parts 17 and 18 flanking the central part 22. Thus, the central part radius t can correspond to approximately 0.9 to 0.98 times the running wheel radius r.

[0037] According to the above-described arrangement and the given dimensions, a groove 25 is formed between the running parts 17 and 18, which is laterally delimited by the running parts 17 and 18, the groove base 26 of which is formed by the outer surface 24 of the central part 22.

[0038] In the usual condition of use, as shown in the illustrations according to the Fig. As shown in Figures 1 to 5 and 7 to 9, the fork halves 3 and 4 are connected in the region of their hubs 10. A screw 27 can be used for this purpose, which penetrates one hub 10 of one fork half and can engage the hub 10 of the other fork half. Openings 28 provided for this purpose in the fork legs 9 can be closed by plugs 29.

[0039] The upper bearing 8 can be further secured to the fork halves 3 and 4 via a metal ring 38, which, in normal use, encompasses the bearing shells 6 and 7 of the fork halves 3 and 4. A cap 30, in particular a plastic cap, is also preferably provided, which protectively covers the bearing 8. The aforementioned fastening pin 5 protrudes outward through this cap 30.

[0040] In the normal downward-facing state of use, the central part 22 forms a support section 31. This section, viewed in the direction of the rotation axis x, is aligned with the support surfaces 15 and 16 of the support feet 13 and 14. In the area of ​​the support section 31, the central part 22 deviates from its otherwise circular-cylindrical configuration.

[0041] The mounting section 31 and the support feet 13 and 14, or the sections of the mounting section 31 and the support feet 13 and 14 forming the mounting surface 32 of the mounting section 31 and the support surfaces 15 and 16, are preferably formed from a softer plastic than the remaining part of the fork G, in particular the remaining part of the fork legs 9 or the cover 12, and further than the remaining part of the middle part 22. A material-to-material connection can be provided between the softer plastic, in particular forming the support surfaces 15 and 16 and the mounting surface 32, and the harder plastic of the middle part 22 or the fork G, or alternatively or in combination with this, a form-fitting connection. Furthermore, production using a two-component injection molding process is possible in this regard.

[0042] The softer plastic can comprise a polyurethane with a hardness of, for example, 38 to 42 Shore D, more preferably about 40 Shore D, while the harder plastic of the remaining sections of the middle part 22 and fork G can comprise, for example, PA6-GF (a glass fiber reinforced polyamide) and / or polypropylene and have a hardness of, for example, 57 to 63 Shore D, preferably about 60 Shore D.

[0043] The support surfaces 15 and 16 as well as the contact surface 32 can be seen in a cross-section as shown in the Fig. 7 and Fig. 8 with a radius of curvature s that can be approximately 1.5 to 3 times, or even approximately 2 times, the impeller radius r. Starting from the rotation axis x, this results in a convex curvature of the respective surface, with a reduced degree of curvature compared to the running surface 19 of the running parts 17 and 18.

[0044] Particularly before the first use of the roller 1, the support surfaces 15 and 16 and the contact surface 32 can, as is also preferred, essentially overlap when projecting these surfaces toward a plane transverse to the rotation axis x. The contact surface 32 extends transversely to the circumferential surface of the central part 22, viewed in the direction of the rotation axis x, across the entire width of the central part 22, which width corresponds approximately to the distance a between the running parts 17 and 18. The width of the contact surfaces 32 can furthermore essentially correspond to the width c of the support surfaces 15 and 16 viewed in the same direction.

[0045] With reference to a projection of the above-described surfaces into a common horizontal plane, the lengths d of the support surfaces 15, 16 and the contact surface 32 are also approximately equal when viewed transversely to the orientation of the rotation axis x (compare Fig. 5).

[0046] Due to the above-described design and arrangement of the support surfaces 15, 16 and the contact surface 32, these are radially set back from the running surface 19 of the running parts 17 and 18.

[0047] The result is the arrangement of such rollers 1 on a transport device T, such as a shopping cart according to Fig. 2, and when the transport device T is moved over a normal flat floor 33, the running wheels 2 roll over the running surface 19 of the running parts 17 and 18. The support surfaces 15 and 16 as well as the contact surface 32 are spaced from the floor 33 (compare Fig. 4).

[0048] When arranged, for example, on a passenger moving walkway 34, which preferably has webs 35 that are spaced parallel to one another, of equal height and run longitudinally in the conveying direction, and longitudinal grooves 36 between the webs 35, the running wheel 2 dips into the longitudinal grooves 36 between the webs 35 with the sections of the running parts 17 and 18 that project vertically downwards beyond the support surfaces 15 and 16 and the contact surface 32. The distance a between the running parts 17 and 18 in the direction of the axis of rotation x is adapted to the usual grid of web 35 and longitudinal groove 36 in passenger moving walkways 34.

[0049] The vertical distance h between the support plane E resulting from the running surfaces 19 of the running parts 17 and 18 when supported on a conventional floor 33 and the support plane F resulting from the support surfaces 15 and 16 as well as from the contact surface 32, in particular in their downwardly facing zenith areas, is smaller than the depth of the longitudinal grooves 36 viewed in the same direction (cf. Fig. 9). This distance h can correspond to approximately 0.4 to 0.7 times the groove depth.

[0050] This results in an arrangement of a transport device T equipped with such rollers 1 on a passenger moving walkway 34, a support of the rollers 1 via the support surfaces 15 and 16 of the support feet 13 and 14 as well as via the central contact surface 32 of the contact section 31 viewed in the direction of extension of the rotation axis x. Due to the given choice of material in the area of ​​the frictional engagement surfaces (support surfaces 15, 16 and contact surface 32) resting on the webs 35 of the passenger moving walkway 34, a frictional fixing of the transport device T also results.

[0051] The preferred oversize of the distance h compared to the depth of the longitudinal groove 36 allows a wear area of ​​the support feet 13 and 14 or of the contact section 31, corresponding to the difference between the distance h and the groove depth.

[0052] During the use of the roller 1 and the associated wear or abrasion in the area of ​​the support surfaces 15 and 16 as well as the contact surface 32, the effective frictional engagement surface of the respective parts can increase transversely to the rotational axis x, so that a deviation from the course along a curvature line of the respective surface can occur.

[0053] As further explained in Fig. 1, a support part 37 can be formed in the area of ​​the bearing shells 6 and 7, partially covering the running wheel 2 or the running parts 17 and 18 as well as the central part 22 in a roof-like manner, for example for arranging a braking device or for arranging a device cleaning the groove 25, for example in the form of a scraper or the like. List of reference symbols 1 roller 2 wheels 3 fork halves 4 fork halves 5 mounting pins 6 bearing shell 7 bearing shell 8 warehouses 9 fork legs 10 Hub 11 Hexagonal section 12 Cladding 13 Support foot 14 Support foot 15 Support surface 16 Support surface 17 Running part 18 Running part 19 Tread 20 roller bearings 21 roller bearings 22 Middle section 23 Receiving opening 24 exterior area 25 grooves 26 groove base 27 Screw 28 Opening 29 plugs 30 cap 31 touchdown section 32 contact surface 33 Floor 34 passenger moving walkway 35 jetty 36 longitudinal groove 37 Bracket part 38 metal ring a distance b width c Width d length h distance s radius of curvature r impeller radius t Middle part radius x axis of rotation y steering axle E Support level F support level G Fork T Transport device

Claims

[1] Castor (1), e.g. steering castor, for transport equipment (T), with a running wheel (2) mounted in a fork (G) so as to be rotatable about an axis of rotation (x), the fork (G) having a support foot (13, 14) with a support surface (15, 16) on each side of the running wheel (2), and with at least one groove (25) formed on the support foot side between the support feet (15, 16), characterized byin that the impeller (2), based on a vertical section, has a fixed central part (22) forming a groove base (26) and two disc-like running parts (17, 18) arranged laterally to the central part (22), in that the central part (22) has a seating section (31), wherein a seating surface (32) of the seating section (31) and the support surfaces (15, 16) of the support feet (13, 14) are aligned with one another in the direction of the axis of rotation (x), and in that the seating surface (32) and the support surfaces (15, 16) extend transversely to the axis of rotation (x) with a radius of curvature (s) which corresponds to at least 1.5 times the radius dimension (r) of the impeller (2). [2] Roller (1) according to claim 1, characterized by that the central part (22), with the exception of a partial area which forms the mounting section (31), has a cylindrical outer surface (24). [3] Roller (1) according to one of the preceding claims, characterized bythat the attachment section (31) is made of a softer plastic than the remaining part of the middle part (22). [4] Roller (1) according to one of the preceding claims, characterized by that the support foot (13, 14) is made of a softer plastic than the remaining part of the fork (G). [5] Roller (1) according to one of claims 3 or 4, characterized by that the softer plastic is a polyurethane with a hardness of 38 to 42 Shore D. [6] Roller (1) according to one of claims 3 to 5, characterized by that the softer plastic has a hardness of 40 Shore D. [7] Roller (1) according to one of claims 3 to 6, characterized by that the remaining part of the middle part (22) and / or the fork (G) is made of a plastic with a hardness of 57 to 63 Shore D. [8] Roller (1) according to claim 7, characterized bythat the remaining part of the middle part (22) and / or the fork (G) has a hardness of 60 Shore D. [9] Transport device (T), for example a shopping trolley, with a roller (1) according to one of claims 1 to 8.

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