Caster brakes for swivel double casters for suitcases

Abstract

To provide a swivel caster with a brake that achieves an effective and long-lasting braking effect with low wear, allows for replacing a travel wheel as easily as possible, and being manufactured as simply as possible at a low cost.SOLUTION: Swivel means is arranged in front of a wheel shaft (5) when viewed opposite to a travel direction (L). A brake device is designed to be displaceable between: a braking position where the brake device applies brake force to at least one travel wheel; and a freewheel position where the brake device releases the travel wheel. A brake pedal (11) that generates the brake force is supported by a caster housing (3) pivotably via a pedal shaft (15) that extends parallel to the wheel shaft (5) and is arranged between the travel wheels, and at least one brake shoe (14) arranged on the brake pedal (11) applies the brake force parallel to the wheel shaft (5) directly to one side of the at least one travel wheel at the braking position.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a brakeable swivel caster. The swivel caster comprises a caster housing swivelable in the direction of travel via a swivel means, two running wheels rotatably supported on the caster housing on horizontal wheel axles, and a brake device. The swivel means is arranged in front of the wheel axles when viewed against the direction of travel. The brake device is designed to be displaceable between a brake position, in which the brake device applies a braking force to at least one running wheel, and a freewheel position, in which the brake device releases the running wheel. [Background technology]

[0002] Swivel casters have gained widespread market acceptance as the preferred type of caster for luggage such as suitcases. Steerable double casters are often used. In addition to the lowest possible cost, smooth running, and durability, suitcase casters also place special requirements on shock absorption and noise reduction. Furthermore, the design of the casters, especially the running wheels, is also important, especially for expensive suitcases. It would also be advantageous if worn running wheels could be replaced, thereby ensuring the continued full functionality of the luggage over a long period of use and preventing the negative effects that may be caused by running wheel wear (e.g., the generation of undesirable noise, limited running characteristics, or a poor feel when using the luggage). In particular, the extremely smooth running characteristics of high-quality suitcase casters today pose a problem of luggage undesirably rolling away, for example, on inclined surfaces while waiting in line, which is becoming common due to barrier-free and disability-friendly improvements at airports and train stations, or on public transportation when buses or trains depart or stop.

[0003] Even with commercially available suitcase casters that are equipped with brakes and are fully lockable, depending on the weight of the luggage on the suitcase and the nature of the ground, the suitcase may roll if the grip of the caster is insufficient, depending on the coefficient of friction between the caster and the floor material. On the other hand, if the grip or braking force is too great and the suitcase falls over when a certain amount of momentum is applied, it may be disadvantageous.

[0004] A brakeable swivel caster is described, for example, in German Patent Application No. DE 3913722. The brake device is designed for a caster housing that laterally surrounds two running wheels in a fork-like manner with two legs. The brake device for the swivel caster described there has a relatively complex design, in which the caster is not only braked by frictional forces, but also its rotational movement can be prevented. The braking force is generated by a braking force directed radially from above toward the caster.

[0005] Another brakeable swivel caster is known from Spanish Utility Model No. 1047165. This brake device is also designed for a caster housing with two legs that laterally surround two running wheels in a fork-like configuration. The brake device includes a brake pedal with a vertical partition wall in the shape of a slightly inverted truncated cone, located between the running wheels. The brake pedal is pressed into a hole formed in the legs of the caster housing by means of two molded cams. The partition wall has a slight thickening that limits its downward movement when it rests on the running wheels. In this swivel caster, the partition wall penetrates between the two running wheels, pressing them against the legs of the caster housing, thereby braking the running wheels, thereby achieving the braking effect. In such a design, the fork-shaped caster housing and the brake pedal itself are usually pushed apart when the brake pedal is operated, which can lead to relatively early fatigue phenomena in the brake pedal's mounting and bearing in the caster housing. Furthermore, in this embodiment, the braking device acts mainly on the upper part of the running wheels, which causes the running wheels to spread apart at the top and, consequently, press against each other at the bottom. This results in a positive camber that reduces the running wheel contact area and, therefore, grip. Furthermore, due to the forked caster housing and the forked brake pedal, changing the running wheels is difficult.

[0006] In both prior art casters, the caster housing surrounds the running wheels in a fork-like fashion, undesirably obscuring the running wheel design in this respect. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] DE 3913722 A1 [Patent Document 2] Spanish Utility Model No. 1047165 Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention is based on the object of providing an embodiment of a braked swivel caster that can be manufactured as simply and inexpensively as possible, which achieves an effective and at the same time low-wear, long-lasting braking action, and in addition allows the running wheels to be replaced as easily as possible. [Means for solving the problem]

[0009] The above-mentioned problem is solved by the present invention by the features of claim 1. The brake device has a brake pedal for generating a braking force. The brake pedal is pivotally supported on the caster housing via a pedal axle extending parallel to the wheel axis and positioned between the running wheels. In the freewheel position and the braking position, the brake pedal is engaged with the caster housing via a locking means. At least one brake shoe arranged on the brake pedal applies a braking force parallel to the wheel axis directly to one side of at least one running wheel in the braking position. This allows for a brake device that is very easy to manufacture and at the same time stable and durable. Furthermore, the running wheels can be easily replaced without loosening or removing the brake device. In addition, the running wheels are not obscured by the caster housing or the brake device, which allows for attractive design options for the running wheels (especially the wheel front, wheel hub / cap). Furthermore, this allows for braking without completely locking the casters. Depending on the weight of the suitcase and the forces acting on it, if the downhill force of the suitcase is greater than the restraining force of the brake, this will only allow the suitcase to roll slowly while at the same time preventing it from tipping over.

[0010] In an advantageous embodiment of the invention, the pedal axle is arranged behind a vertical plane extending through the wheel axle, viewed against the direction of travel. In particular, the brake shoes are arranged so that their center points, viewed in the circumferential direction of the running wheel, lie behind a vertical plane extending through the wheel axle, viewed against the direction of travel L. This particular arrangement of the axles and the brake shoes relative to one another makes it difficult or even impossible for the brake pedal to automatically release when the running wheel rotates in the direction of travel.

[0011] Furthermore, in the braking position, the braking device can push the running wheels apart on the sides pointing away from the direction of travel and indirectly press them against each other on the sides pointing in the direction of travel. This allows for an additional braking effect, since the running wheels are arranged opposite each other in the direction of travel. A braking effect similar to the flying position on snow when skiing is created. Furthermore, such positioning of the brake shoes reduces or prevents the positive or negative camber of the running wheels in the braking position, which also allows for the running wheels to have as straight and full a contact area with the ground as possible, and therefore the highest possible traction, and evenly distributed contact pressure across the entire possible contact area / wheel width. The full contact area (even in the braking position) ensures that the weight of the suitcase is distributed across the entire possible contact surface of the running wheels.

[0012] In a preferred embodiment, the caster housing and the brake pedal have cooperating locking means for engaging and positioning the brake pedal with a predetermined retention force in the braking and freewheeling positions, respectively, and the locking means in particular for generating tactile and / or acoustic feedback regarding operation of the brake pedal.

[0013] Particularly preferably, the brake pedal is designed as a two-component injection-molded part, with a first component forming a mounting tab for attaching the brake pedal to the caster housing and a second molded component forming the brake shoes. This reduces the number of parts, allowing for easier production and assembly of the assembly. Particularly preferably, the brake pedal has through-holes in the area of ​​the brake shoes, which are formed together as a single injection-molded component by material bonding via the through-holes. This allows for easier production of the brake shoes and a particularly stable design. It is particularly advantageous if the brake shoes are made of a plastic with a Shore hardness greater than the Shore hardness of the plastic of the running wheel, in particular, at most 10 Shore hardness greater, preferably 5 Shore hardness greater. This ensures that wear caused by the frictional forces of the brake shoes occurs primarily on the side surfaces of the running wheel, which have an effective area significantly greater than the effective area of ​​the brake shoes.

[0014] Further advantageous embodiments of the invention become apparent from the following description of the figures and the dependent claims. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a three-dimensional view of an embodiment of a brakeable swivel caster according to the present invention; FIG. [Figure 2] 2 is an exploded view of the brakeable swivel caster according to the present invention of FIG. 1; [Figure 3] 2 is a rear view of the brakeable swivel caster of FIG. 1 in the direction of travel according to the present invention; FIG. [Figure 4] 1 is a three-dimensional view of an embodiment of a brake pedal according to the invention and an embodiment of a brake shoe according to the invention; [Figure 5] 2 shows a side internal view of the brakeable swivel caster according to the invention of FIG. 1 in freewheel position with the running wheels removed; [Figure 6] 2 is a side internal view of the brakeable swivel caster according to the invention of FIG. 1 in a braking position with the running wheels removed; FIG. [Figure 7] 1 is a schematic plan view from above of a brakeable swivel caster according to the present invention in a braking position; FIG. DETAILED DESCRIPTION OF THE INVENTION

[0016] In the different figures of the drawings, the same parts are always provided with the same reference numbers.

[0017] In the following description, it should be understood that the present invention is not limited to the exemplary embodiments and, in so doing, not limited to all or some of the features of the described feature combinations, but rather that individual partial features of an exemplary embodiment / each exemplary embodiment are important to the subject matter of the present invention both alone, separately from all other partial features described in connection therewith, and also in combination with any features of other exemplary embodiments.

[0018] Figure 1 shows a three-dimensional view of an exemplary embodiment of a brakeable swivel caster 1 according to the invention. Figure 2 shows an exploded view of this embodiment, in which the individual parts of the brakeable swivel caster 1 according to the invention are visible. Figure 3 shows a rear view in the direction of travel L thereof.

[0019] The swivel caster 1 has a caster housing 3. The caster housing 3 includes, in particular, an accommodation opening 2 for accommodating at least one wheel bearing 6. A horizontally extending wheel axle 5 is rotatably supported in the caster housing 3 by the wheel bearing 6. Running wheels 7 are respectively attached to two outer surfaces of the caster housing 3 via the wheel axles 5. The running wheels 7 can be attached to the wheel axles 5 in particular via a riveted, screwed or locking connection.

[0020] The running wheel 7 has in particular a rim 8 and a tread 9 provided on the rim 8. The tread 9 is preferably made from a TPU material. Advantageously, the running wheel 7 has a wheel cap attached to the side of the rim 8.

[0021] The caster housing 3 has a swivel means 10 arranged offset from the wheel axle 5 so that the swivel caster 1 automatically faces the traveling direction L when moving. The swivel means 10 is arranged in front of the wheel axle 5 when viewed opposite the traveling direction L. Preferably, the swivel means 10 includes a vertical receiving hole in the caster housing 3, and a swivel shaft (not shown) is rotatably supported in this vertical receiving hole, and the caster housing 3 can be attached to the suitcase via this vertical receiving hole.

[0022] Furthermore, the caster housing 3 preferably has a horizontally extending through-opening 4 for mounting a braking device. The braking device is designed to be displaceable between a braking position in which the braking device applies a braking force to at least one running wheel 7 and a freewheel position in which the braking device releases the running wheel 7.

[0023] According to the invention, it is provided that the brake pedal 11, which generates the braking force, is pivotably supported on the caster housing 3 via a pedal axle 15 that extends parallel to the wheel axle 5 and is arranged between the running wheels 7. For this purpose, the brake pedal 11 has, in particular, a fork-shaped mounting tab 13, which laterally grips the caster housing 3 with its two legs between the running wheels 7. In this case, the legs of the mounting tab 13 each have a horizontal through-hole that is designed to be aligned with the through-opening 4 of the caster housing 3, and through which the pedal axle 15 for attaching the brake pedal 11 to the caster housing 3 is inserted. The pedal axle 15 can, in particular, be designed as a riveted connection part.

[0024] Furthermore, the brake pedal 11 has a preferably undulating operating surface, particularly in the radially outer region of the swivel caster 1, via which the brake pedal 11 can be displaced from the freewheel position to the braking position with the toe of the foot.

[0025] Advantageously, the brake pedal 11 is ergonomically shaped so that the brake pedal 11 can be retracted into the swivel caster 1 by applying force to a first lower step area, and can be extended out from the swivel caster 1 by applying force to a second upper step area.

[0026] Advantageously, the pedal shaft 15 is arranged in the center of the brake pedal 11, in particular in the center of the operating surface, so that operation of the brake pedal 11 at the end of the caster housing 3 facing towards the swivel means 10 moves the brake pedal 11 to a freewheel position, and operation of the brake pedal 11 at the end of the caster housing 3 facing away from the swivel means 10 moves the brake pedal 11 to a braking position.

[0027] The brake pedal 11 has a brake shoe 14 on each side facing the running wheels 7, which, in the braking position, exerts a braking force parallel to the wheel axle 5 directly on one side of the adjacent running wheel 7.

[0028] The brake shoes 14 are formed on the opposing side surfaces of the brake pedal 11 that face the running wheels 7 .

[0029] The brake pedal 11 is advantageously designed as a two-component injection-molded part, the first component forming a base having an operating surface and mounting tabs 13 for attachment to the caster housing 3, and the second component forming the brake shoe 14.

[0030] In that case, the base body of the brake pedal 11 advantageously forms a core attachment 12, in particular made from PA material, which is preferably overmolded with TPU material for the brake shoe 14.

[0031] FIG. 4 shows a three-dimensional view of a brake pedal 11 and a preferred embodiment of a brake shoe 14 formed as an injection-molded cover 14a of the brake pedal 11. For clarity, the injection-molded cover 14a is shown separately. The brake pedal 11 has a core attachment 12 on each of its two lateral sides. The core attachment 12 preferably has an injection-molded through-hole 12a arranged therein, extending through the brake pedal 11 from one end face of the core attachment 12 to the other end face of the core attachment 12. Preferably, grooves 12b are formed around the core attachment 12 on each lateral side of the brake pedal 11. The core attachment 12 is overmolded with the injection-molded cover 14a, which forms the brake shoe 14. Preferably, the injection-molded cover 14a extends through the injection-molded through-hole 12a, thereby connecting the two brake shoes 14. Particularly advantageously, the injection-molded covering 14a engages in the groove 12b. Such a configuration allows for a very stable and durable construction of the brake shoe 14.

[0032] Figure 5 shows a side internal view of a brakeable swivel caster 1 according to the invention with the brake pedal 11 in the freewheel position. Figure 6 shows the same internal view of the swivel caster 1 with the brake pedal 11 in the braking position. In order to be able to better appreciate the position of the brake pedal 11, the running wheel 7 nearest to the viewer has been removed from the figure.

[0033] The pedal axle 15 is preferably arranged behind a vertical plane E1 extending through the wheel axle 5, 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 relative to the running wheel 7 so that it lies in a plane E3 of 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 embodiment shown, the angle α=20°.

[0034] Preferably, the brake shoe 14 is arranged so that a center point M of the brake shoe 14, as seen in the circumferential direction of the running wheel 7, is located behind a vertical plane E1 extending through the wheel axle 5, as seen against the running direction L. In particular, the center point M of the brake shoe 14 is located behind the pedal axle 15, as seen in the running direction L.

[0035] In the freewheel position according to Fig. 5, the brake shoe 14 of the brake pedal 11 is positioned radially outside the running wheel 7. In particular, the brake shoe 14 is positioned circumferentially relative to the running wheel 7 so that in the freewheel position it lies in a plane E4 of the wheel axle 5 which forms an angle β of at most +15° with a horizontal plane E2 extending through the wheel axle 5. In the embodiment shown, the angle β = 4°.

[0036] In the braking position according to Figure 6, the brake shoes 14 of the brake pedal 11 are clamped axially between the two running wheels 7. For this purpose, the brake pedal 11 together with the brake shoes 14 has a thickness extending parallel to the wheel axis 5 which is greater than the lateral distance between the running wheels 7 (see also Figure 3).

[0037] In particular, the brake shoes 14 are positioned between the running wheels 7 in such a way that, in the braking position, the center points M of the brake shoes 14, as seen in the circumferential direction of the running wheels 7, lie below a horizontal plane E2 extending through the wheel axles 5. Preferably, the brake shoes 14 are positioned between the running wheels 7 in such a way that, in the braking position, they lie in a plane E4 of the wheel axles 5 which forms an angle γ of at most +45° with the horizontal plane E2 extending through the wheel axles 5. In the embodiment shown, the angle γ = 23°.

[0038] 7 shows a schematic plan view from above of an embodiment of a brakeable swivel caster according to the invention in the braking position. In the braking position, the brake shoes 14 push the running wheels 7 apart on the sides pointing away from the direction of travel L and indirectly press them against each other on the sides pointing in the direction of travel L, so that the running wheels 7 face each other at an angle Ω of 1° to 4°, preferably 2° to 3°, in the direction of travel L. In particular, this inclination relative to the direction of travel L is determined by the tolerances of the individual components of the swivel caster 1, preferably by the tolerances of the diameters of the wheel axles 5 and wheel bearings 6 of the running wheels 7 and / or by the tolerances of the form of the riveted connections of the wheel axles 5 and / or by the tolerances of the overdimensions of the brake shoes 14.

[0039] As can be seen in Figures 5 and 6, the brake pedal 11 is preferably held in a mating engagement with the caster housing 3 via a locking means in the freewheel position. In particular, the caster housing 3 has at least one molded locking projection 16 for this purpose. The locking projection 16 is arranged on at least one side of the caster housing 3 facing the running wheel 7 and is preferably molded integrally therewith. Advantageously, the caster housing 3 includes a locking projection 16 on each side. The locking projection 16 is particularly arcuately shaped so that it fits and locks with the end face of the leg of the brake pedal 11 in the freewheel position. Preferably, the locking projection 16 is curved in the direction of the leg of the brake pedal 11.

[0040] Particularly advantageously, the brake shoe 14 is made of plastic, in particular TPU, whose Shore A hardness is greater than the Shore A hardness of the plastic, in particular TPU, of the running wheel 7, in particular by at most 10, preferably 5. The Shore A hardness is determined in accordance with DIN ISO 48-4:2021-02.

[0041] In this respect, preferably, in the braking position, clamping occurs between the brake pedal 11 made of TPU and the wheel tire of the running wheel 7 made of TPU. Advantageously, the brake shoe 14 is smooth, i.e., formed without contours that would generate high contact pressure. At the same time, tilting of the brake shoe 14 is prevented by the material of the wheel tire. Ideally, the TPU material is selected with respect to its friction value so that the wheel can rotate from a certain limit value of the kinetic force acting on the load without the brake pedal 11 moving out of the braking position. This prevents the load from tipping over in the event of high kinetic forces, especially with a slope of more than 38°.

[0042] Advantageously, the core attachment 12 of the brake shoe 14 in particular is made of a PA solid material that is harder than the brake shoe 14, so that the spring effect and the resulting possible fatigue phenomenon of the material of the brake shoe 14 are reduced or even avoided.

[0043] The present invention is not limited to the exemplary embodiments shown and described, but includes all embodiments having the same effect within the spirit of the present invention. It is clearly emphasized that the exemplary embodiments are not limited to all combinations of features, but rather that individual partial features may have inventive significance alone, separate from all other partial features. Furthermore, the present invention is not yet limited to the combination of features defined in claim 1, but can also be defined by any other combination of all specific features of the individual features disclosed as a whole. This basically means that the individual features of claim 1 can actually be omitted or replaced by at least one individual feature disclosed elsewhere in this application. [Explanation of symbols]

[0044] 1 Swivel Caster 2. Storage opening 3 Caster housing 4 Through-hole 5 Wheel axle 6 Wheel bearings 7 Running wheels 8 rims 9 Tread 10. Rotation means 11. Brake pedal 12 Core appendage 12a Injection molding through opening 12b Groove 13 Mounting tab 14 Brake shoes 14a Injection molded cladding 15 Pedal shaft 16 Additional locking portion in caster housing E1 vertical plane E2 horizontal plane E3 Pedal Axle Flat E4 Brake shoe flat L Running direction M center point

Claims

1. A brakeable swivel caster (1) for a suitcase, said swivel caster (1) comprising a caster housing (3) swivelable in a running direction (L) via a swivel means (10), two running wheels (7) rotatably supported on said caster housing (3) on horizontal wheel axles (5), and a brake device; The turning means (10) is arranged in front of the wheel axle (5) when viewed against the running direction (L), the braking device is designed to be displaceable between a braking position in which the braking device applies a braking force to at least one of the running wheels (7) and a freewheel position in which the braking device releases the running wheel (7); A brake pedal (11) that generates the braking force is supported on the caster housing (3) so as to be rotatable via a pedal shaft (15) that extends parallel to the wheel shaft (5) and is disposed between the running wheels (7), and is fitted and held in the caster housing (3) via a locking means (16) in the freewheel position and the brake position; and At least one brake shoe (14) arranged on the brake pedal (11) exerts the braking force parallel to the wheel axis (5) directly on one side of at least one of the running wheels (7) in the braking position; the pedal shaft (15) is arranged behind a vertical plane (E1) extending through the wheel shaft (5) when viewed against the direction of travel (L); A brakeable swivel caster characterized in that the brake shoes (14) are formed on opposing side surfaces of the brake pedal (11) facing the running wheels (7).

2. The pedal shaft (15) is disposed above a horizontal plane (E2) extending through the wheel shaft (5). characterized in that The brakeable swivel caster according to claim 1.

3. The pedal shaft (15) is arranged in the circumferential direction with respect to the running wheel (7) so as to be located on a plane (E3) of the wheel shaft (5) that forms an angle (α) of up to −45° with a horizontal plane (E2) extending through the wheel shaft (5). characterized in that The brakeable swivel caster according to claim 1.

4. The brake shoe (14) is arranged so that the center point (M) of the brake shoe as viewed in the circumferential direction of the running wheel (7) is located behind a vertical plane (E1) extending through the wheel axle (5) as viewed opposite to the running direction (L). characterized in that The brakeable swivel caster according to claim 1.

5. In the braking position, the brake device pushes the running wheels (7) apart on the sides pointing opposite to the running direction (L) and indirectly presses them against each other on the sides pointing in the running direction (L), and the running wheels (7) face each other at an angle of 1° to 4°, preferably 2° to 3° in the running direction (L). characterized in that The brakeable swivel caster according to claim 1.

6. The brake shoe (14) is positioned circumferentially relative to the running wheel (7) so that, in the freewheel position, it is located in a plane (E4) of the wheel axle (5) that forms an angle (β) of up to +15° with a horizontal plane (E2) extending through the wheel axle (5). characterized in that The brakeable swivel caster according to claim 1.

7. The brake shoe (14) is positioned between the running wheels (7) so that, in the braking position, the center point (M) of the brake shoe (14) as viewed in the circumferential direction of the running wheels (7) is located below a horizontal plane (E2) extending through the wheel axle (5). characterized in that The brakeable swivel caster according to claim 1.

8. The brake shoes (14) are positioned between the running wheels (7) so that, in the braking position, they lie in a plane (E4) of the wheel axle (5) that forms an angle (γ) of up to +45° with a horizontal plane (E2) extending through the wheel axle (5). characterized in that The brakeable swivel caster according to claim 1.

9. The pedal shaft (15) is arranged in the center of the brake pedal (11) so that operation of the brake pedal (11) at the end facing towards the pivoting means (10) moves the brake pedal (11) to the freewheel position, and operation of the brake pedal (11) at the end facing away from the pivoting means (10) moves the brake pedal (11) to the braking position. characterized in that The brakeable swivel caster according to claim 1.

10. The brake pedal (11) is designed as a two-component injection molded part, the first component forming the mounting tabs (13) for attachment to the caster housing (3) and the second component forming the brake shoes (14). characterized in that The brakeable swivel caster according to claim 1.

11. The brake shoe (14) is made of a plastic having a Shore A hardness greater than that of the plastic of the running wheel (7), in particular a maximum of 10 Shore A hardness greater, preferably 5 Shore A hardness greater. characterized in that The brakeable swivel caster according to claim 1.

12. The brake pedal (11) together with the brake shoe (14) has a thickness extending in a direction parallel to the wheel axis (5), the thickness being greater than the lateral distance between the running wheels (7). characterized in that The brakeable swivel caster according to claim 1.

13. The brake pedal (11) has a through-opening (4) in the region of the brake shoe (14), which is formed together as a one-piece injection-molded component by material bonding via the through-opening (4). characterized in that The brakeable swivel caster according to claim 1.

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