Wheel brake for double suitcase swivel caster

Abstract

A brakeable swivel caster (1) for suitcases, comprising a caster housing (3) pivotable in a direction of travel (L) via pivot means (10) and two wheels (7) rotatably mounted on the caster housing (3) on a horizontal wheel axle (5), wherein the pivot means are arranged in front of the wheel axle (5) when viewed against the direction of travel (L), and comprising a brake device which is adjustable between a brake position in which the brake device exerts a braking force on at least one wheel (7) and a freewheel position in which the brake device releases the wheels (7), characterized in that a brake pedal (11) for generating the braking force is pivotably mounted on the caster housing (3) via a parallel to the wheel axle (5),The pedal axle (15) is mounted between the wheels (7) and is positively locked to the roller housing (3) in the freewheel position and in the braking position via locking means (16), and at least one brake shoe (14) arranged on the brake pedal (11) exerts a braking force parallel to the wheel axle (5) directly on one side of at least one wheel (7) in the braking position.

Description

[0001] The invention relates to a brakeable swivel caster, comprising a caster housing pivotable in a direction of travel by means of pivoting means and two wheels rotatably mounted on the caster housing on a horizontal wheel axle, wherein the pivoting means are arranged in front of the wheel axle when viewed against the direction of travel, and comprising a braking device which is adjustable between a braking position in which the braking device exerts a braking force on at least one wheel and a freewheeling position in which the braking device releases the wheels.

[0002] Swivel casters have become the preferred type of wheel for luggage such as suitcases. In particular, steerable double casters are frequently used. Besides minimal cost, smooth rolling, and durability, suitcase wheels must also meet specific requirements regarding shock absorption and noise reduction. Furthermore, the design of the wheels, and especially the wheels themselves, is important, particularly for high-priced suitcases. It is also advantageous if the wheels are replaceable, as this ensures the luggage's continued proper functioning over a long period of use and counteracts any negative effects caused by worn wheels (such as increased noise, reduced rolling performance, or a less pleasant feel when handling the luggage).Particularly due to the now very smooth running of high-quality suitcase wheels, the problem arises of the luggage rolling away unintentionally, for example on sloping surfaces when queuing in queues, which are increasingly common due to the barrier-free and accessible development of airports and train stations, or in public transport when buses or trains start or stop.

[0003] Depending on the coefficient of friction of the wheels and the floor surface, even commercially available braked and fully lockable suitcase wheels can slip if the wheels don't have sufficient traction, depending on the weight of the load and the condition of the surface. Conversely, it can be disadvantageous if the traction and braking force are so great that the suitcase tips over once a certain force is applied.

[0004] A braked swivel caster is described by way of example in DE 39 13 722 A1. The braking device is designed for a caster housing which laterally encompasses the two wheels in a fork-like manner with two arms. The braking device for the swivel caster described there is relatively complex, whereby the caster can not only be braked by frictional force, but its rotational movement can also be blocked. The braking force is generated by a braking force directed radially downwards onto the wheels.

[0005] Another braked swivel caster is known from ES 1 047 165 U. The braking device is also designed for a caster housing that laterally encompasses the two wheels in a fork-like manner with two arms. The braking device features a brake pedal with a vertical partition in the shape of a slightly inverted truncated cone, arranged between the wheels. The brake pedal is pressed into holes formed in the arms of the caster housing by means of two molded-on cams. The partition has a slight thickening that limits its downward movement when it rests on the wheels. In this swivel caster, braking is achieved by the partition penetrating between the two wheels and pressing against the arms of the caster housing, thereby braking the wheels.With this type of design, fatigue can occur relatively early in the mounting and bearing of the brake pedal on the roller housing, as the forked roller housing and the brake pedal itself are regularly forced apart when the brake pedal is actuated. Furthermore, in this design, the braking mechanism acts primarily in the upper part of the wheels, so that the wheels are forced apart at the top and thus inevitably compressed at the bottom. This results in positive camber, which reduces the contact area of ​​the wheels and therefore their grip on the ground. Additionally, the forked roller housing with the forked brake pedal makes replacing the wheels more difficult.

[0006] In both state-of-the-art swivel casters, the caster housing surrounds the wheels in a fork-like manner, thus obscuring the design of the wheels, which is undesirable.

[0007] The invention is based on the objective of providing a design of a braked swivel caster that is as simple and cost-effective to manufacture as possible, achieves an effective braking effect that is both low-wear and durable, and also allows for the simplest possible replacement of the wheels.

[0008] The object of the invention is achieved by the features of the characterizing part of claim 1. The braking device has a brake pedal for generating the braking force, which is pivotably mounted on the roller housing via a pedal axle running parallel to the wheel axle and arranged between the wheels, and is positively locked to the roller housing by means of detents in the freewheel position and in the braking position. At least one brake shoe arranged on the brake pedal exerts a braking force directly on one side of at least one wheel in the braking position, parallel to the wheel axle. This enables a very simple to manufacture and at the same time stable and durable braking device. In addition, the wheels can be easily replaced without having to loosen or remove the braking device. The wheels are also not concealed by the roller housing or the braking device, thus offering an attractive design option with regard to...This is made possible by the design of the wheels (especially the front surface of the wheels – wheel hubs / caps). Furthermore, this allows for braking without completely locking the wheels. If the downward force of the suitcase, depending on its weight and the forces acting upon it, is greater than the holding force of the brake, this allows the suitcase to roll away slowly while simultaneously preventing it from tipping over.

[0009] In an advantageous embodiment of the invention, the pedal axle is arranged behind a vertical plane extending through the wheel axle when viewed against the direction of travel. In particular, the brake shoes are arranged such that their centers, viewed in the circumferential direction of the wheel, lie behind a vertical plane extending through the wheel axle when viewed against the direction of travel L. This specific arrangement of the axles and brake shoes relative to each other makes it difficult or impossible for the brake pedal to release itself when the wheels rotate in the direction of travel.

[0010] Furthermore, in the braking position, the brake mechanism can push the wheels apart on the side opposite the direction of travel and indirectly compress them on the side facing the direction of travel. This provides additional braking power, as the wheels are positioned in opposite directions. The braking effect is similar to the snowplow position used in skiing. Moreover, this positioning of the brake pads reduces or prevents positive or negative camber of the wheels in the braking position, which in turn ensures the flattest and most complete contact area of ​​the wheels with the ground, thus maximizing traction and distributing the pressure evenly across the entire possible contact area / wheel width. This complete contact area (even in the braking position) ensures that the weight of the suitcase is distributed across the entire possible contact area of ​​the wheels.

[0011] In a preferred embodiment, the roller housing and the brake pedal have cooperating locking means that positively lock the brake pedal in both the braking position and the freewheeling position with a defined holding force. The locking means generate haptic and / or acoustic feedback regarding the actuation of the brake pedal.

[0012] Preferably, the brake pedal is designed as a two-component injection-molded part, wherein a first component forms a mounting tab for attaching the brake pedal to the roller housing, and a second injection-molded component forms the brake shoes. The resulting reduction in the number of individual parts enables simple manufacturing and assembly of the unit. Particularly preferably, the brake pedal has a through-opening in the area of ​​the brake shoes, and the brake shoes are formed together as a single-piece injection-molded component with a material bond through the through-opening. This allows for simple manufacturing of the brake shoes and a particularly robust design. It is especially advantageous if the brake shoes are made of a plastic whose Shore hardness is higher, in particular up to 10 times higher, preferably 5 times higher, than the Shore hardness of the plastic used for the wheels.This means that the wear caused by the frictional force of the brake shoes will mainly occur on the side surfaces of the wheels, whose effective area is considerably larger than that of the brake shoe.

[0013] Further advantageous embodiments of the invention will become apparent from the following description of the figures and the dependent subclaims.

[0014] They show: Fig. 1 a three-dimensional view of an embodiment of a brakeable swivel caster according to the invention, Fig. 2 an exploded view of the brakeable swivel caster according to the invention Fig. 1, Fig. 3 a rear view of the brakeable swivel caster according to the invention Fig. 1 in the direction of travel, Fig. 4 a three-dimensional view of an embodiment of a brake pedal according to the invention and an embodiment of brake shoes according to the invention, Fig. 5 a side interior view of the brakeable swivel caster according to the invention Fig. 1, in which one wheel has been removed, in freewheel position, Fig. 6 a side interior view of the brakeable swivel caster according to the invention Fig. 1, in which one wheel was removed, in braking position, and Fig. 7 A sketchy top view of a brakeable swivel caster according to the invention in the braking position.

[0015] In the various figures of the drawing, identical parts are always labelled with the same reference symbols.

[0016] The following description claims that the invention is not limited to the exemplary embodiments and not to all or several features of the described combinations of features; rather, each individual partial feature of the exemplary embodiment(s) is also significant for the subject matter of the invention, independent of all other partial features described in connection therewith, both on its own and in combination with any features of another exemplary embodiment.

[0017] Fig. Figure 1 shows a three-dimensional view of an exemplary embodiment of a brakeable swivel castor 1 according to the invention. Fig. Figure 2 shows an exploded view of this embodiment, in which the individual parts of the brakeable swivel castor 1 according to the invention are visible. Fig. Figure 3 shows a rear view in the direction of travel L.

[0018] The swivel caster 1 has a roller housing 3. The roller housing 3 includes, in particular, a receiving opening 2 for receiving at least one wheel bearing 6. A horizontally extending wheel axle 5 is rotatably mounted in the roller housing 3 by means of the wheel bearing 6. A wheel 7 is attached to each of two outer sides of the roller housing 3 via the wheel axle 5. The wheels 7 can be attached to the wheel axle 5, in particular, by means of a rivet, screw, or snap-fit ​​connection.

[0019] The wheels 7 comprise, in particular, a rim 8 and a tread 9 applied to the rim 8. The tread 9 is preferably made of TPU material. Advantageously, the wheel 7 has a hubcap attached laterally to the rim 8.

[0020] To ensure that the swivel caster 1 automatically aligns itself in a direction of travel L during movement, the caster housing 3 has pivoting means 10 arranged offset from the wheel axis 5. The pivoting means 10 are arranged in front of the wheel axis 5, opposite to the direction of travel L. Preferably, the pivoting means 10 comprise a vertical receiving bore in the caster housing 3, in which a pivot axis (not shown) is rotatably mounted and by means of which the caster housing 3 can be attached to a case.

[0021] The roller housing 3 preferably also has a horizontally extending through-opening 4 for attaching a brake device. The brake device is adjustable between a braking position, in which the brake device exerts a braking force on at least one wheel 7, and a freewheeling position, in which the brake device releases the wheels 7.

[0022] According to the invention, a brake pedal 11 is pivotably mounted on the roller housing 3 for generating the braking force via a pedal axle 15 running parallel to the wheel axle 5 and arranged between the wheels 7. For this purpose, the brake pedal 11 has, in particular, a fork-shaped mounting bracket 13 that laterally engages the roller housing 3 with two legs between the wheels 7. The legs of the mounting bracket 13 each have, in particular, a horizontal through-hole that is aligned with the through-opening 4 of the roller housing 3, and through which the pedal axle 15 is inserted to fasten the brake pedal 11 to the roller housing 3. The pedal axle 15 can, in particular, be designed as a riveted connection.

[0023] Furthermore, the brake pedal 11 has a preferably wave-shaped actuating surface, particularly in the radially outer area of ​​the steering wheel 1, via which the brake pedal 11 can be moved from the freewheel position to the brake position by means of a toe.

[0024] Advantageously, the brake pedal 11 is ergonomically shaped in such a way that by applying force to a lower first step area, the brake pedal 11 can be retracted into the caster 1 and by applying force to an upper second step area, the brake pedal 11 can be extended out of the caster 1.

[0025] Advantageously, the pedal axis 15 is arranged centrally on the brake pedal 11, in particular centrally to the actuating surface, such that actuation of the brake pedal 11 at the end pointing towards the pivot means 10 of the roller housing 3 moves the brake pedal 11 into the freewheel position and actuation of the brake pedal 11 at the end facing away from the pivot means 10 of the roller housing 3 moves the brake pedal 11 into the brake position.

[0026] The brake pedal 11 has a brake shoe 14 on the side facing a wheel 7, which in the braking position exerts a braking force parallel to the wheel axle 5 directly on one side of the adjacent wheel 7.

[0027] The brake shoes 14 are formed in particular on opposing side surfaces of the brake pedal 11 facing the running wheels 7.

[0028] The brake pedal 11 is advantageously designed as a two-component injection molded part, wherein a first component forms a base body with mounting tab 13 for attachment to the roller housing 3 and the actuating surface, and a second component forms the brake shoes 14.

[0029] Advantageously, the base body of the brake pedal 11 forms a core attachment 12, in particular made of PA material, which is preferably overmolded with TPU material for the brake shoes 14.

[0030] Fig. Figure 4 shows a three-dimensional view of an advantageous embodiment of the brake pedal 11 and the brake shoes 14, which are formed as an overmolding 14a of the brake pedal 11. For better illustration, the overmolding 14a is shown separately. The brake pedal 11 has a core projection 12 on each of its two side faces. Advantageously, a through-injection opening 12a is arranged in the core projections 12, extending through the brake pedal 11 from one end face of a core projection 12 to the end face of the other core projection 12. Preferably, a groove 12b is formed around each core projection 12 in the side face of the brake pedal 11. The core projections 12 are overmolded with the overmolding 14a, which forms the brake shoes 14. Advantageously, the overmolding 14a extends through the injection opening 12a and thus connects the two brake shoes 14. The overmolding 14a engages particularly advantageously in the groove 12b.Such a design enables a very stable and durable design of the brake shoes 14.

[0031] Fig. Figure 5 shows a side interior view of the brakeable swivel castor 1 according to the invention with the brake pedal 11 in freewheel position. Fig. Figure 6 shows the same internal view of the steering wheel 1 with the brake pedal 11 in the braking position. To make the positions of the brake pedal 11 easier to see, the front wheel 7 (in the direction of view) has been removed from the view.

[0032] The pedal axle 15 is preferably arranged behind a vertical plane E1 extending through the wheel axle 5 when viewed against the direction of travel L. Advantageously, the pedal axle 15 is arranged above a horizontal plane E2 extending through the wheel axle 5. Particularly preferably, the pedal axle 15 is arranged circumferentially to the wheels 7 such that it lies in a plane E3 with the wheel axle 5, which forms an angle α of at most -45° with the horizontal plane E2 extending through the wheel axle 5. In the illustrated embodiment, the angle α is 20°.

[0033] Preferably, the brake shoes 14 are arranged such that their centers M, viewed in the circumferential direction of the wheel 7, lie behind the vertical plane E1 passing through the wheel axle 5 when viewed against the direction of travel L. In particular, the centers M of the brake shoes 14 lie behind the pedal axle 15 when viewed in the direction of travel L.

[0034] In the free-running position according to Fig. In the 5, the brake shoes 14 of the brake pedal 11 are positioned radially outside the wheels 7. Specifically, in the freewheel position, the brake shoes 14 are positioned circumferentially to the wheels 7 such that they lie in a plane E4 with the wheel axle 5, which forms an angle β of at most +15° with the horizontal plane E2 passing through the wheel axle 5. In the illustrated embodiment, the angle β is 4°.

[0035] In the braking position according to Fig. 6. The brake shoes 14 of the brake pedal 11 are axially clamped between the two wheels 7. For this purpose, the brake pedal 11 together with the brake shoes 14 has a thickness extending in a direction parallel to the wheel axis 5, which is greater than the lateral distance between the wheels 7 (see also Fig. 3).

[0036] In particular, the brake shoes 14 are positioned between the wheels 7 in the braking position such that their centers M, viewed in the circumferential direction of the wheels 7, lie below a horizontal plane E2 extending through the wheel axle 5. Preferably, the brake shoes 14 are positioned between the wheels 7 in the braking position such that they lie in a plane E4 with the wheel axle 5, which forms an angle γ of at most +45° with the horizontal plane E2 extending through the wheel axle 5. In the illustrated embodiment, the angle γ = 23°.

[0037] Fig. Figure 7 shows a schematic top view of an embodiment of the brakeable swivel caster according to the invention in the braking position. In this position, the brake shoes 14 press the wheels 7 apart on the side opposite the direction of travel L and indirectly together on the side in the direction of travel L, whereby the wheels 7 are positioned relative to each other in the direction of travel L at an angle Ω of 1° to 4°, preferably 2° to 3°. In particular, this inclination relative to the direction of travel L is set by tolerances in individual components of the swivel caster 1, preferably by the tolerances of the diameter of the wheel axle 5 and the wheel bearing 6 of the wheel 7 and / or the design of the riveting of the wheel axle 5 and / or the interference of the brake shoes 14.

[0038] As in Fig. 5 and Fig.As can be seen in Figure 6, the brake pedal 11 is advantageously held in the freewheel position by means of a positive locking mechanism on the roller housing 3. In particular, the roller housing 3 has at least one integrally formed locking projection 16 for this purpose. The locking projection 16 is arranged on at least one side of the roller housing 3 facing a wheel 7, preferably integrally formed. Advantageously, the roller housing 3 comprises a locking projection 16 on each side. The locking projection 16 is particularly curved such that it forms a positive locking connection with an end face of a leg of the brake pedal 11 in the freewheel position. Preferably, the locking projection 16 is curved in the direction of the legs of the brake pedal 11.

[0039] The brake shoes 14 are particularly advantageous if they are made of a plastic, in particular TPU, whose Shore A hardness is greater, in particular up to 10 greater, preferably 5 greater, than the Shore A hardness of a plastic, in particular TPU, of the wheels 7. The Shore A hardness is determined according to DIN ISO 48-4:2021-02.

[0040] Therefore, preferably in the braking position, a clamping action is created between the TPU brake pedal 11 and the TPU wheel rims of the wheels 7. Advantageously, the brake shoes 14 are smooth, i.e., without tread, which generates high surface pressure. At the same time, this makes it more difficult for the brake shoes 14 to tilt against the wheel rim material. Ideally, the TPU materials are selected with respect to their coefficients of friction such that the wheels can slip beyond a certain threshold of the force acting on the luggage without the brake pedal 11 disengaging from the braking position. This can, in particular, prevent the luggage from tipping over under high forces, especially on inclined surfaces exceeding 38°.

[0041] Advantageously, the core elements 12 of the brake shoes 14 are made of PA solid material that is harder relative to the brake shoes 14, thereby reducing or even avoiding spring action and any fatigue that may have occurred in the material of the brake shoes 14.

[0042] The invention is not limited to the embodiments illustrated and described, but also encompasses all embodiments that have the same effect within the meaning of the invention. It is expressly emphasized that the embodiments are not limited to all features in combination; rather, each individual feature can also have inventive significance independently of all other features. Furthermore, the invention is not yet limited to the combination of features defined in claim 1, but can also be defined by any other combination of specific features from all disclosed individual features. This means that, in principle, virtually any individual feature of claim 1 can be omitted or replaced by at least one individual feature disclosed elsewhere in the application. Reference symbol list 1 swivel caster 2 Intake opening 3 roller housings 4 Through openings 5 wheel axle 6 wheel bearings 7 wheel 8 rim 9 Running surface 10 swivel devices 11 Brake pedal 12 core approaches 12a Injection opening 12b Nut 13 Mounting tab 14 brake shoes 14a Re-injection 15 Pedal axle 16. Locking mechanism on the roller housing E1 Vertical plane E2 Horizontal plane E3 Flat pedal axle E4 Flat brake shoe L Direction of travel M Center QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 39 13 722 A1

[0004] ES 1 047 165 U

[0005] Cited non-patent literature

[0000] DIN ISO 48-4:2021-02

[0039]

Claims

A brakeable swivel caster (1) for suitcases, comprising a caster housing (3) pivotable in a direction of travel (L) via pivot means (10) and two wheels (7) rotatably mounted on the caster housing (3) on a horizontal wheel axle (5), wherein the pivot means are arranged in front of the wheel axle (5) when viewed against the direction of travel (L), and comprising a brake device which is adjustable between a brake position in which the brake device exerts a braking force on at least one wheel (7) and a freewheel position in which the brake device releases the wheels (7), characterized in that a brake pedal (11) for generating the braking force is pivotably mounted on the caster housing (3) via a parallel to the wheel axle (5),The pedal axle (15) is mounted between the wheels (7) and is positively locked to the roller housing (3) in the freewheel position and in the braking position via locking means (16), and at least one brake shoe (14) arranged on the brake pedal (11) exerts a braking force parallel to the wheel axle (5) directly on one side of at least one wheel (7) in the braking position. Brakeable swivel caster according to claim 1, characterized in that the pedal axle (15) is arranged behind a vertical plane (E1) passing through the wheel axle (5) when viewed against the direction of travel (L). Brakeable swivel caster according to claim 1 or 2, characterized in that the pedal axle (15) is arranged above a horizontal plane (E2) passing through the wheel axle (5). Brakeable swivel caster according to one of the preceding claims, characterized in that the pedal axle (15) is arranged circumferentially to the running wheels (7) such that it lies in a plane (E3) with the wheel axle (5) which forms an angle (α) of at most - 45° with a horizontal plane (E2) passing through the wheel axle (5). Brakeable swivel caster according to one of the preceding claims, characterized in that the brake shoes (14) are arranged such that their centers (M) seen in the circumferential direction of the wheel (7) are located behind a vertical plane (E1) passing through the wheel axis (5) when viewed against the direction of travel (L). A brakeable swivel caster according to one of the preceding claims, characterized in that the braking device in the braking position pushes the wheels (7) apart on the side opposite the direction of travel (L) and indirectly pushes them together on the side in the direction of travel (L), wherein the wheels (7) are positioned against each other in the direction of travel (L) at an angle of 1° to 4°, preferably 2° to 3°. A brakeable swivel caster according to one of the preceding claims, characterized in that the brake shoes (14) are positioned circumferentially to the wheels (7) in the freewheel position such that they lie in a plane (E4) with the wheel axle (5) which forms an angle (β) of maximum + 15° with a horizontal plane (E2) passing through the wheel axle (5). Brakeable swivel caster according to one of the preceding claims, characterized in that the brake shoes (14) are positioned between the running wheels (7) in the braking position such that their centers of mass (M) seen in the circumferential direction of the running wheels (7) are below a horizontal plane (E2) passing through the wheel axis (5) in the braking position. Brakeable swivel caster according to one of the preceding claims, characterized in that the brake shoes (14) are positioned between the running wheels (7) in the braking position such that they lie in a plane (E4) with the wheel axle (5) which forms an angle (β) of maximum + 45° with a horizontal plane (E2) passing through the wheel axle (5). A brakeable swivel caster according to one of the preceding claims, characterized in that the pedal axle (15) is arranged centrally on the brake pedal (11) such that actuation of the brake pedal (11) at the end pointing towards the pivot means (10) moves the brake pedal (11) into the freewheel position and actuation of the brake pedal at the end away from the pivot means (10) moves the brake pedal (11) into the brake position. A brakeable swivel caster according to one of the preceding claims, characterized in that the brake pedal (11) is designed as a two-component injection molded part, wherein a first component forms a mounting tab (13) for attachment to the caster housing (3) and a second component forms the brake shoes (14). A brakeable swivel caster according to one of the preceding claims, characterized in that the brake shoes (14) are made of a plastic whose Shore A hardness is greater, in particular up to 10 greater, preferably 5 greater, than the Shore A hardness of a plastic of the wheels (7). A brakeable swivel caster according to one of the preceding claims, characterized in that the brake shoes (14) are each formed on opposing side surfaces of the brake pedal (11) facing the running wheels (7). Brakeable swivel caster according to one of the preceding claims, characterized in that the brake pedal (11) together with the brake shoes (14) have a thickness extending in a direction parallel to the wheel axle (5) which is greater than a lateral distance between the running wheels (7). Brakeable swivel caster according to one of the preceding claims, characterized in that the brake pedal (11) has a through-opening (4) in the area of ​​the brake shoes (14) and the brake shoes (14) are formed together as a one-piece injection-molded component with a material connection through the through-opening (4).

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