Swivel caster device

Abstract

A swivel caster device comprising a container with a downward-facing opening and a top plate, and a mounting bracket that can slide vertically inside the container. One or more swivel casters are attached to one side of the mounting bracket and make contact with the ground. On the opposite side of the mounting bracket is at least one elastic element that is pressed against the underside of the container's top plate. When a certain weight is applied to the object supported by the container of the swivel caster device, the elastic element is compressed, causing the bottom edge of the container to contact the ground. This increases the friction between the swivel caster device and the ground, making the device difficult to move.

Description

TECHNICAL FIELD

[0001] The present invention relates to a caster wheel device, in particular to a caster wheel device that provides improved stability when a certain weight is applied to the object it supports. BACKGROUND OF THE INVENTION

[0002] Caster wheels are widely used in various applications, such as office chairs, shopping carts, and mobile devices, to facilitate the easy movement of the objects they support. Traditionally, caster wheels typically consist of a roller mounted on a bracket, which is then installed and secured to the bottom of the object. While these conventional casters allow for easy movement, if the user places weight on the object being supported, such as when sitting on an office chair, the roller can also cause unintended movement or instability.

[0003] To solve this problem, some caster designs incorporate locking mechanisms that must be manually activated to lock the casters. However, these locking mechanisms can be inconvenient, requiring the user to manually activate or unlock them each time they move or stabilize the object.

[0004] Another method to increase the stability of a caster system is to use larger or wider casters, which provide a larger contact area with the floor and can therefore generate more friction. However, larger or wider casters are not suitable for all applications, as they can increase the overall size and weight of the caster system, making it impractical for certain objects or environments.

[0005] Therefore, an improved caster assembly is needed that provides better stability when a certain weight is applied to the object it supports, without requiring manual activation or release, and without requiring the use of larger or wider casters. Therefore, the question of how to design such a caster assembly is one worth considering for the skilled person. SUMMARY OF THE INVENTION

[0006] The object of the present invention is to provide a caster device that can offer improved stability when a certain weight is applied to the carried object.

[0007] To achieve the above and other objects, the present invention provides a rolling device comprising a container with a downward opening and a top plate, as well as a mounting bracket that can slide vertically within the container. Furthermore, one or more casters that come into contact with the ground are attached to one side of the mounting bracket. On the other side of the mounting bracket, there is at least one elastic member that is pressed against the underside of the top plate of the container. When a certain weight is applied to the object carried by the container of the caster, the elastic member is compressed so that the bottom edge of the container touches the ground. This increases the friction between the caster and the ground and reduces the likelihood of the caster moving. The elastic member can be, for example, a spring.

[0008] In the aforementioned caster device, the container consists of an upper half container and a lower half container. The side walls of the lower half container and the upper half container each have a locking structure that serves to assemble the lower half container and the upper half container. After assembly, the side walls of the upper half container enclose the side walls of the lower half container.

[0009] The aforementioned swivel caster assembly also includes at least one rotary damper. This rotary damper is located between the side walls of the lower half-container and the upper half-container. The rotary damper contains a gear that is guided through a through hole in the side wall of the lower half-container and interacts with the rack on the mounting bracket.

[0010] In the aforementioned caster device, slide rails are attached to the sides of the mounting bracket, which correspond to several guide slots inside the container.

[0011] The aforementioned caster device also includes a fixing screw that is placed on the container and serves to fix the container to the bottom of the object.

[0012] The aforementioned castor device also includes at least one buffer mechanism, wherein the buffer mechanism may be the aforementioned rotary damper.

[0013] The aforementioned swivel castor is a two-wheeled, rotating swivel castor.

[0014] In the aforementioned swivel castor device, the roller comprises a tread made of thermoplastic rubber or polyurethane.

[0015] The foregoing and other objects, features and advantages of the invention will become more apparent from the following detailed description made with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The objects, scope, and advantages of the preferred embodiments of the present disclosure will be readily understood from the accompanying drawings and detailed descriptions, in which: Fig. 1A and Fig. 1B show the 3D views of the caster assembly at different angles. Fig. 2 shows the internal structure of the castor device. Fig. Figure 3 shows the changes in the castor assembly before and after the application of a force. Fig. Figure 4A shows a 3D view of the upper half-container in the upward direction. Fig. Figure 4B shows a 3D view of the lower half-container. Fig. 5 illustrates an embodiment of the rotary damper of the present invention. Fig. 6 shows an embodiment of the two-wheeled rotating roller according to the invention. Fig. 7 shows a further application of the castor device according to the invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] With simultaneous reference to the Fig. 1A, Fig. 1B, Fig. 2 and Fig. 3, these represent an embodiment of a castor device used for carrying an object and suitable for placement on the floor. Fig. 1A and Fig. 1B show the castor device from different angles, Fig. 2 shows the internal structure of the castor device, and Fig. Figure 3 shows the changes in the caster wheel device before and after it is subjected to a force. In this embodiment, the caster wheel device 100 includes a container 110 having a downward opening 114a and a top plate 112a. Furthermore, the caster wheel device 100 also includes a fastening screw 116 for attaching the container 110 to the underside of an object. In this embodiment, the object may be an office chair, a desk, or a living room sofa. By attaching multiple caster wheel devices 100 to the object, the object can be easily moved.

[0018] It is on Fig. 2. The caster wheel device 100 also includes a mounting bracket 120 and at least one caster wheel 130 (two in this embodiment), the mounting bracket 120 being inserted into the container 110 and capable of sliding vertically within the container 110. Furthermore, the caster wheel 130 is mounted on one side of the mounting bracket 120 and is in contact with the floor 10. Furthermore, in this embodiment, the elastic member 140 is located on the other side of the mounting bracket 120 compared to the caster wheel 130, and there are two of them. The upper part of the elastic member 140 is pressed against the underside of the top plate 112a of the container. Furthermore, the mounting bracket 120 includes two spring slots 126 for inserting springs (i.e., elastic members 140).

[0019] In this embodiment, the elastic element 140 is a spring, but one skilled in the art may also choose other elastic elements. The elastic element may, for example, be an elastic block or a pad made of an elastic material such as rubber, silicone, or polyurethane, which provides elastic support due to its properties. Furthermore, the elastic element may be a gel pad made of deformable gel material, which provides soft and elastic support and helps reduce vibrations and shocks. The elastic element may also be a stack of flat, curved metal strips clamped together to form a leaf spring, creating a soft yet stable support structure. Alternatively, the elastic element may be a torsion bar, i.e., a long, cylindrical metal rod that twists under the application of force and provides elastic support due to the torsion bar's resistance to twisting.The choice of elastic element depends on the requirements of a specific application, such as load capacity, shock absorption properties and environmental conditions.

[0020] It is Fig. 3 and simultaneously on Fig. 2. When a certain weight acts on the object carried by the container 110, e.g., when a user sits down on a chair, the force acting on the elastic element 140 causes it to compress. When the elastic element 140 is compressed, the container 110 is pushed downward, resulting in a vertical displacement of the container 110 relative to the roller 130, since the roller 130 leans against the floor 10 and does not perform any vertical movement. This vertical displacement causes the lower edge 114d of the container 110 to approach the floor 10. As the weight of the carried object increases, the compression of the elastic element 140 continues until the lower edge 114d of the container 110 finally directly touches the floor 10. In this case, the contact between the lower edge 114d and the floor 10 increases the friction between the caster device 100 and the floor 10.This increased friction makes the caster assembly 100 less likely to move or slip, allowing for stable and secure support of the supported object.

[0021] Next, at the same time, Fig. 2, Fig. 4A and Fig. 4B. Fig. Figure 4A shows a perspective view of the upper half of the container from the top view direction, while Fig. 4B shows a perspective view of the lower half of the container. In this embodiment, the container 110 includes an upper half-container 112 and a lower half-container 114. The side walls 114b of the lower half-container 114 and the side walls 112b of the upper half-container 112 each have a locking structure, referred to herein as a second locking structure 114c and a first locking structure 112c, respectively. The first locking structure 112c and the second locking structure 114c enable the assembly of the upper half-container 112 and the lower half-container 114. After assembly, a portion of the side wall 112b of the upper half-container 112 wraps around a portion of the side wall 114b of the lower half-container 114.

[0022] In this embodiment, the mounting bracket 120 is provided on both sides with a plurality of slide rails 124 (four in this embodiment), which are paired with a plurality of corresponding grooves 114e inside the container 110. This pairing ensures smooth vertical sliding movement of the mounting bracket within the container. The slide rails 124 and the grooves 114e provide increased stability and prevent unnecessary lateral movement or rotation when the elastic element 140 is compressed and rebounds. In addition to the slide rails 124 and the grooves 114e, various mechanisms are available to increase stability and prevent unnecessary movement or rotation of the elastic element 140 during compression and rebound, such as ball-bearing rails, telescopic rails, or linear rails and linear guides.Ball-bearing rails utilize a set of ball bearings to enable smooth vertical movement between the mounting bracket 120 and the container 110. Telescopic or linear rails feature extendable and retractable locking segments to ensure stability. Linear guides are precisely engineered systems with guides and rolling elements for stable movement along a single axis. In short, the skilled artisan can select a suitable mechanism for vertical movement based on factors such as manufacturing costs, space constraints, and desired performance.

[0023] Next, at the same time, Fig. 2, Fig. 4A, Fig. 4B and Fig. 5. Fig. Figure 5 shows an embodiment of the rotary damper of the present invention. In this embodiment, the caster wheel device 100 further includes at least one rotary damper 150 (two in this embodiment) disposed primarily between the side wall 114b of the lower half-container 114 and the side wall 112b of the upper half-container 112. As shown in Fig. 2, the mounting bracket 120 is also equipped with at least one rack 122 (two in this embodiment). As shown in Fig. 5, the rotary damper 150 also includes a gear 152. This gear 152 engages through the through hole 114g located on the side wall 114b of the lower half container 114 (as shown in Fig. 4B), into the rack 122 on the mounting bracket 120.

[0024] In this embodiment, the main function of the rotary damper 150 is to provide buffering and damping effects. For example, it helps prevent the chair from suddenly sinking when people sit down and from abruptly rebounding when people leave the seat. This buffering and damping effect is achieved by the coordination between the rotary damper 150 and the rack 122 on the mounting bracket. In this embodiment, the rotary damper 150 includes a main body 154, an input shaft 156 equipped with a gear 152, an output shaft (not shown), and a viscous fluid (not shown), with the output shaft and the viscous fluid located within the main body 154. When a force is applied to an object carried by the container 110 (e.g.,When a person sits on the chair, the input shaft 156 of the rotary damper 150 rotates, causing the output shaft to rotate, and the viscous fluid creates resistance to the output shaft. This resistance creates a damping and cushioning effect that helps control the movement of the object and prevent sudden falls or recoils.

[0025] In this embodiment, the rotary damper 150 is arranged in a groove 114f in the lower half-container 114, and the shape of the groove 114f corresponds to the shape of the main body 154 of the rotary damper 150. After inserting the rotary damper 150 into the groove 114f and assembling the upper container 112 with the lower half-container 114, the rotary damper 150 can be fixed between the side wall 114b of the lower half-container 114 and the side wall 112b of the upper container 112 without the need for additional screws or other fastenings. This effectively reduces the number of required parts and improves the appearance.

[0026] In addition to the rotary damper 150 described above, other types of damping mechanisms can also be used to achieve similar effects. For example, gas springs or pneumatic struts can be used as damping mechanisms. Gas springs use compressed gas (usually nitrogen) in a closed cylinder and a piston that moves according to the applied force. They provide controlled damping, allowing smooth movement and preventing sudden lowering or rebound of the caster 100. Another possible damping mechanism is the use of a friction damper, which relies on the frictional force between two surfaces (in this embodiment, the sidewall 114b of the lower half container 114 and the sidewall of the mounting bracket 120) to create a damping effect.Friction dampers typically consist of friction discs or plates in contact with a stationary surface. As the mounting bracket 120 moves, energy is dissipated by the friction between the surfaces, creating a smooth, controlled motion. Each of these damping mechanisms can be customized and integrated into the caster assembly 100 of this case to achieve the desired levels of control and stability, ensuring smooth and safe operation while preventing sudden movements.

[0027] In this embodiment, a two-wheeled castor is used as an example for the castor 130. Fig. 6, which shows an embodiment of the double-wheel castor of this invention. The double-wheel castor comprises two wheels 132 mounted on a common transverse axle (in Fig. 6 not shown), which in turn is attached to a bracket 134. The bracket 134 is attached to the underside of the mounting bracket 120 via a mounting shaft 136. Compared to single-wheel casters, two-wheel casters offer better stability and load distribution. The two-wheel caster is mounted below the mounting bracket 120 so that the wheels 132 can rotate freely about a vertical axis, allowing smooth and easy movement in any direction. The two-wheel caster design has several advantages, including increasing the contact area, improving stability, and reducing the risk of the caster 130 tipping over. In addition, the two-wheel design improves load distribution by reducing the pressure on each wheel 132 and the ground, thus reducing wear on both the wheels 132 and the ground surface.This design also allows the roller 130 to better overcome uneven surfaces or minor obstacles such as cracks or bumps in the floor, ensuring smooth and uninterrupted movement.

[0028] In addition, the tread of the wheel 132 in this embodiment is also made of materials such as thermoplastic rubber or polyurethane. These materials have several advantages that can improve the overall performance of the wheel 132. First, the use of thermoplastic rubber or polyurethane for the wheel ensures that the wheel 132 produces very little noise while rolling. This property is especially important in environments where quiet operation is required, such as offices, hospitals, or libraries. The noise reduction improves the usability of the rolling device 100 and minimizes disturbance to other people. In addition, the thermoplastic rubber and polyurethane wheels 132 provide better traction on various surfaces, such as hardwood, tile, and carpet.This improved traction ensures that the rolling device 100 remains stable and controlled during movement, reducing the likelihood of slipping. Furthermore, the use of a thermoplastic rubber or polyurethane tread can increase durability and wear resistance, as these materials are known for their elasticity and will not degrade or lose their performance characteristics even after prolonged use or under heavy loads.

[0029] In addition, the Fig. 1A, Fig. 2 and Fig. 7. Fig.Figure 7 shows another application of the caster device according to the invention. A person skilled in the art can attach the caster device 100 to the four corners of a table 20 using fastening screws 116, allowing the table 20 to adapt to uneven floors. This is because, when the weight of the table 20 is concentrated on a caster 100 due to uneven floors, the elastic element 140 in this caster 100 is compressed, allowing the device to adapt to the uneven floors. For example, if the floor 10 is uneven, the elastic element 140 can be compressed to keep the surface of the table 20 level. Of course, the caster device 100 can be installed not only on a table, but also on other objects (e.g., chairs, mobile bookshelves) to achieve this automatic balancing effect.

[0030] In summary, the present invention provides an innovative caster wheel device comprising two half-containers equipped with an elastic member and a mounting bracket. With this configuration, when a certain weight is applied to the supported object, better stability can be ensured without the need for manual activation or release, and without the need to use larger or wider casters. Furthermore, the combination of the slide rail and guide slot, together with the use of the rotary damper, improves the stability of the caster wheel device and the control during the compression and rebound process of the elastic member. Furthermore, other embodiments of this invention can also use various buffer mechanisms to achieve the same effect as the rotary damper.

[0031] In the aforementioned embodiments, the design of the swivel caster allows for screwless installation (although the invention does not restrict the use of screws or additional fasteners), facilitating easy assembly and disassembly. The choice of the caster's tread material, e.g., thermoplastic rubber or polyurethane, ensures that the caster produces as little noise as possible when rolling on the floor. This is especially important for environments requiring quiet operation, such as offices, hospitals, or libraries.

[0032] It should be noted that the invention represents an innovative and multifunctional caster device suitable for various applications, such as office tables and chairs, medical equipment, etc. It increases user comfort and satisfaction while ensuring optimal performance and reliability.

[0033] Although the invention has been disclosed and explained with reference to specific embodiments, the principles involved may be utilized in numerous other embodiments that will be apparent to those skilled in the art. The invention is therefore limited only by the scope of the appended claims.

Claims

[1] Castor device for carrying an object and suitable for placement on a floor surface, the castor device comprising: a container with a downward opening and a top plate; a mounting bracket inserted into the container and capable of sliding vertically within the container; at least one castor wheel attached to one side of the mounting bracket and in contact with the floor surface; at least one elastic element located on the other side of the mounting bracket and pressed against a lower surface of the top plate of the container; wherein, when a certain weight is applied to the object carried by the container, the elastic member is compressed, the lower edge of the container contacts the ground surface, thereby increasing the friction between the caster device and the ground surface, making the caster device difficult to move. [2] A caster wheel device according to claim 1, wherein the elastic member is a spring. [3] The caster wheel device according to claim 1, wherein the container comprises an upper half container and a lower half container, a side wall of the lower half container and a side wall of the upper half container each have a locking structure, and the lower half container and the upper half container are joined together by the locking structure. [4] A caster wheel device according to claim 3, further comprising at least one rotary damper disposed between the side wall of the lower half-container and the side wall of the upper half-container, the rotary damper comprising a gear, the gear passing through a through-hole in the side wall of the lower half-container and cooperating with a rack on the mounting bracket. [5] Caster device according to claim 1, wherein the side wall of the mounting bracket has a plurality of slide rails and cooperates with corresponding multiple grooves in the container. [6] The caster device of claim 1, further comprising a fixing screw, the fixing screw being attached to the container and serving to fix the container to the bottom of the article. [7] Caster wheel device according to claim 1, further comprising at least one buffer mechanism. [8] Caster device according to claim 7, wherein the buffer mechanism is a rotary damper. [9] Caster device according to claim 1, wherein the caster is a double-wheel swivel caster. [10] Caster device according to claim 9, wherein the caster has a tread made of thermoplastic rubber or polyurethane. [11] Caster device according to claim 1, wherein the caster has a tread made of thermoplastic rubber or polyurethane.

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