Casters with shock-absorbing function

Abstract

To provide a caster having a buffer function and capable of automatically correcting the position of a roller. [Solution] The caster includes a bracket assembly and a roller. The bracket assembly includes a bracket body 2, a roller holder 3, and a buffer spring. The roller holder is mounted in a positioning cavity 21 so as to be slidable up and down. The bracket body has elongated holes 22 on both lateral sides of the positioning cavity, and the shaft of the roller holder engages with the elongated holes. The buffer spring is mounted in the positioning cavity, with one end supported by the roller holder and the other end supported by the top wall of the positioning cavity. The roller holder is driven by the buffer spring to reach a lower extreme position, and can reach an upper extreme position by moving upwards against the elastic force. The positioning cavity has a cavity bottom wall 211, and the roller holder is supported on the cavity bottom wall when in the lower extreme position.

Description

[Technical Field]

[0001] This invention relates to casters and can be applied to suitcases, strollers, pushcarts, etc. [Background technology]

[0002] Casters are used in many applications, including suitcases, strollers, and carts. In the case of suitcase casters, the casters are attached to the case itself and act as the running parts that support the movement of the suitcase. As suitcases have become more widespread, interest in the operational stability and reliability of suitcase casters has grown, and related technologies have made significant advances.

[0003] Suitcase casters typically include a bracket and rollers attached to the bracket via axles. To improve the caster's performance, such as its adaptability to uneven terrain and vibration, the bracket is typically designed with shock-absorbing and vibration-absorbing features. For example, in the "Travel Luggage Roller Assembly" disclosed in Chinese Patent No. CN202520006276.4, the roller assembly includes a bracket body (corresponding to roller bracket 1 in the prior art), rollers installed on both sides of the bracket body, and roller holders (corresponding to vibration-absorbing block 3 in the prior art). A tray is attached to the top of the bracket body, which is used to attach the bracket assembly to the suitcase body. The roller holders are restricted to slide within the positioning cavity of the bracket body (corresponding to vibration-absorbing cavity 11 in the prior art). A shock-absorbing spring (corresponding to vibration-absorbing spring 4 in the prior art) is installed between the top of the roller holder and the inner wall of the positioning cavity. Slots are provided on both lateral sides of the positioning cavity of the bracket body, and the roller holder shafts fit into the slots. A roller is provided on each side of the bracket body, and the rollers are attached to the shaft of the roller holder. The sliding of the roller holder and the elastic buffering of the buffer spring provide a buffering effect for the caster, allowing the caster to move more smoothly.

[0004] However, in actual use, these suitcase casters still suffer from operational stability and reliability issues. For example, when assembling suitcase casters to the suitcase body, factors such as machining accuracy and assembly process make it impossible to ensure that each caster is level after being attached to the suitcase body during the suitcase assembly process (commonly known as "poor caster installation"). This results in the rollers on both sides not making good contact with the ground. In current casters with shock-absorbing functions, the bottom of the positioning cavity is an opening, and the roller holder is inserted into the positioning cavity through this opening. The shaft attached to the shaft is supported by the bottom end of the elongated hole, which defines the limit position for the roller holder's downward movement within the positioning cavity. This structural design makes it difficult for the rollers on both sides to automatically position themselves correctly, and improper installation can easily result in poor roller contact with the ground. Summary of the Invention [Problem to be solved by the invention]

[0005] SUMMARY OF THE INVENTION The present invention aims to overcome the drawbacks of the prior art and provide a caster with shock-absorbing function and capable of automatically adjusting the roller to the correct position. [Means for solving the problem]

[0006] To achieve the above objectives, the present invention provides the following technical solutions: a shock-absorbing caster comprising a bracket assembly and a pair of rollers symmetrically disposed on both lateral sides of the bracket assembly, the bracket assembly comprising a bracket body, a roller holder, and a shock-absorbing spring, the bracket body being provided with a positioning cavity, the roller holder being provided in the positioning cavity so as to be slidable up and down, the roller holder having a shaft for attaching a roller, the bracket body being provided with elongated holes on both lateral side walls of the positioning cavity, the shafts of the roller holder correspondingly engaging with the elongated holes, the shock-absorbing spring being attached in the positioning cavity, one end of the shock-absorbing spring being supported by the roller holder and the other end being supported by a top wall of the positioning cavity, the roller holder being driven by the shock-absorbing spring to a lower limit position, and being able to move upward by overcoming an elastic force to reach an upper limit position; The positioning cavity has a cavity bottom wall, the roller holder is supported on the cavity bottom wall when in the lowermost position, the roller holder is provided with an arcuate engagement surface which is configured to allow lateral pivotal rocking movement when the roller holder is supported on the cavity bottom wall, and the long hole is configured to be able to accommodate vertical displacement that occurs in the shaft portion when the roller holder swings.

[0007] Preferably, a limit post protrudes from the top of the roller holder, the buffer spring is attached to the limit post, and when the roller holder swings laterally, the limit post presses the buffer spring to abut against the lateral side wall of the positioning cavity, thereby forming a stopper that determines the maximum lateral swing angle of the roller holder, and the tip of the limit post engages with the upper part of the positioning cavity to form the stopper and determine the upper limit position of the roller holder.

[0008] Preferably, the head of the limit pillar is frusto-conical.

[0009] Preferably, the roller holder is provided with a pair of flat end surfaces arranged opposite to each other, the orientation of the pair of flat end surfaces being perpendicular to the axial direction of the shaft portion, and the flat end surfaces engage with the vertical side walls of the positioning cavity, thereby providing positioning guidance for the roller holder.

[0010] Preferably, a mounting opening extending to the positioning cavity is provided on one lateral side of the bracket body, the roller holder and the buffer spring are accommodated in the positioning cavity through the mounting opening, a cover plate is connected to the bracket body to seal the mounting opening, the cover plate forms one lateral side wall of the positioning cavity, and the cover plate is provided with the long hole.

[0011] Preferably, the shaft portion comprises two cylindrical shaft heads integrally molded with the roller holder and a shaft body, the two cylindrical shaft heads protruding from both lateral sides of the roller holder and arranged coaxially opposite each other, the two cylindrical shaft heads extending correspondingly from the elongated holes, connecting holes opened in the centers of the cylindrical shaft heads, the shaft body passing through the connecting holes of the two cylindrical shaft heads, and rollers 1 attached to both ends of the shaft body. [Effects of the Invention]

[0012] By adopting the above technical solution, the roller holder is supported on the bottom wall of the positioning cavity by the drive of a buffer spring. If imbalance occurs after the rollers on both sides contact the ground, they can pivot laterally around the arc-shaped engagement surface, automatically adjusting the position of the rollers on both sides and ensuring reliable contact between the rollers and the ground. The roller holder also maintains its buffering function through the action of the buffer spring. This achieves a multi-functional integrated design, with a simple and compact overall structure. Furthermore, the roller holder's lowest extreme position is achieved by the engagement between the roller holder and the bottom wall of the cavity, which shields and protects the roller holder, improving the stability and service life of the caster. [Brief explanation of the drawings]

[0013] The present invention will be described in more detail below with reference to the drawings.

[0014] [Figure 1] FIG. 1 is a schematic structural diagram of a first specific embodiment of the present invention. [Figure 2] FIG. 2 is a top view of a bracket assembly according to a first specific embodiment of the present invention (the shaft body is omitted). [Figure 3] FIG. 3 is a cross-sectional view taken along line AA in FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along line BB in FIG. [Figure 5] FIG. 5 is an exploded view of a bracket assembly according to a first specific embodiment of the present invention. [Figure 6] FIG. 6 is an exploded view of a second specific embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0015] In describing the present invention, the orientations or positional relationships indicated by terms such as "upper / lower direction," "longitudinal direction," and "horizontal direction" are based on the orientations or positional relationships shown in the drawings, and are intended only to facilitate and simplify the description of the present invention. They do not indicate or imply that a given device or element must have a specific orientation or be configured and operated in a specific orientation, and should not be construed as a limitation on the present invention. Referring to FIG. 1, the caster with shock-absorbing function disclosed in the present invention includes a bracket assembly and a pair of rollers 1 symmetrically arranged on both lateral sides of the bracket assembly. The bracket assembly includes a bracket body 2, a roller holder 3, and a shock-absorbing spring 4. The bracket body 2 is provided with a positioning cavity 21. The roller holder 3 is provided within the positioning cavity 21 so as to be slidable in the vertical direction (the vertical direction is referred to as the Z-axis direction in the drawing). The roller holder 3 includes a shaft 31 for attaching the roller 1. The bracket body 2 is provided with elongated holes 22 on both lateral side walls of the positioning cavity 21 (the horizontal direction is referred to as the X-axis direction in the drawing). The shaft 31 of the roller holder 3 is engaged with the elongated holes 22. The elongated holes 22 allow the roller holder 3 to retract relative to the shaft 31 when sliding in the vertical direction. In one embodiment, the shaft 31 may be a connecting hole formed in the roller holder 3. A shaft body is inserted into the connecting hole, passes through the elongated holes 22, and rollers 1 are attached to both axial ends of the shaft body. 1, 2, 4, and 5, the shaft 31 includes two cylindrical shaft heads 311 and a shaft body 312 integrally molded with the roller holder 3. The two cylindrical shaft heads 311 protrude from both lateral sides of the roller holder 3 and are arranged coaxially opposite each other. The two cylindrical shaft heads 311 extend correspondingly from the elongated hole 22, a connecting hole is opened in the center of the cylindrical shaft heads 311, the shaft body 312 is inserted through the connecting holes of the two cylindrical shaft heads 311, and the rollers 1 are attached to both ends of the shaft body 312. The buffer spring 4 is installed in the positioning cavity 21, one end of the buffer spring 4 is supported by the roller holder 3 and the other end is supported by the top wall of the positioning cavity 21. The roller holder 3 is driven by the buffer spring 4 to reach its lower limit position, and then overcomes its elastic force to move upward to reach its upper limit position.The positioning cavity 21 has a cavity bottom wall 211, and the roller holder 3 is supported on the cavity bottom wall 211 when in the lowermost position, and the roller holder 3 is provided with an arc-shaped engagement surface 32, which is configured to cause the roller holder 3 to pivot laterally when supported on the cavity bottom wall 3, thereby automatically positioning the rollers 1 on both sides. The dimensions of the elongated hole 22 are designed so that it can accommodate vertical displacement that occurs in the shaft portion 31 of the roller holder 3 when it swings.

[0016] As shown in FIG. 6 , in one embodiment of the present invention, a positioning boss protrudes from the top of the roller holder 3 to position and attach the buffer spring 4. However, this structure only serves the function of positioning the buffer spring 4 on the roller holder. As shown in FIGS. 3 to 5 , in another embodiment of the present invention, a limiting post 33 protrudes from the top of the roller holder 3, and the buffer spring 4 is attached to the limiting post 33. The limiting post 33 forms a stop with the lateral sidewalls 212 of the positioning cavity 21 via the buffer spring 4, thereby determining the maximum lateral swing angle of the roller holder 3. When the roller holder 3 swings laterally, the limiting post 33 presses the buffer spring 4, and the buffer spring 4 is restricted by the lateral sidewalls 212 of the positioning cavity 21, so the limiting post 33 abuts against the buffer spring 4, thereby determining the maximum lateral swing angle of the roller holder 3. This design controls the swing angle to prevent excessively large roller 1 positioning angles and friction between the roller 1 and the bracket body 2. The tip of the limit post 33 engages with the upper part 213 of the positioning cavity 21 to form a stopper, which defines the upper limit position of the roller holder 3. The head 331 of the limit post 33 is frustoconical, which ensures reliable positioning of the base and the buffer spring when the limit post has a large diameter base design. The frustoconical head can also accommodate the swinging motion of the roller holder.

[0017] To ensure stable and reliable operation of the roller holder, the roller holder 3 is provided with a pair of oppositely arranged flat end surfaces 34, the orientation of which is perpendicular to the axial direction of the shaft portion 31 (the axial direction of the shaft portion 31 corresponds to the horizontal direction, see the X-axis direction in the drawings), and the flat end surfaces 34 engage with the vertical side walls 214 of the positioning cavity 21, thereby providing positioning guidance for the roller holder 3 (the vertical direction is see the Y-axis direction in the drawings). The engagement between the flat end surfaces 34 of the roller holder 3 and the vertical side walls 214 of the positioning cavity 21, on the one hand, guides the vertical sliding movement of the roller holder 3, and on the other hand, limits the vertical displacement of the roller holder 3, thereby ensuring stable and reliable horizontal pivoting movement of the roller holder 3.

[0018] In this embodiment, one lateral side of the bracket body 2 is provided with an installation opening 215 that penetrates to the positioning cavity 21, the roller holder 3 and buffer spring 4 are accommodated in the positioning cavity 21 through the installation opening 215, a cover plate 2-1 for sealing the installation opening 215 is connected to the bracket body 2, the cover plate 2-1 forms one lateral side wall 212 of the positioning cavity 21, and the cover plate 2-1 is provided with the elongated hole 22. This makes it easy to assemble the roller holder and buffer spring, and the assembly is stable and reliable.

[0019] The casters shown in the specific embodiments of this invention are attached to suitcases, but they can also be used on strollers, carts, and other devices. The novel caster of this invention has at least the following advantages: 1. The roller holder can slide vertically, achieving a cushioning effect under the action of the buffer spring. 2. The roller holder is supported by the bottom wall of the positioning cavity, achieving its lowest limit position, resulting in reliable positioning. 3. If imbalance occurs after the rollers on both sides contact the ground, the roller holder swings to automatically adjust the roller position, ensuring reliable contact between the rollers and the ground. This eliminates the imbalance problem of rollers on both sides due to caster installation errors. 4. By installing the roller holder and buffer spring along one side in the horizontal direction, the roller holder and buffer spring are reliably confined within the positioning cavity, resulting in convenient assembly, a compact structure, and high reliability.

Claims

1. a bracket assembly and a pair of rollers symmetrically arranged on both lateral sides of the bracket assembly, the bracket assembly including a bracket body, a roller holder, and a buffer spring, the bracket body having a positioning cavity, the roller holder being slidably mounted in the positioning cavity in an up-down direction, the roller holder having a shaft for mounting a roller, the bracket body having oblong holes on both lateral side walls of the positioning cavity, the shafts of the roller holder correspondingly engaging with the oblong holes, the buffer spring being mounted in the positioning cavity, one end of the buffer spring being supported by the roller holder and the other end being supported by a top wall of the positioning cavity, the roller holder being driven by the buffer spring to a lower limit position, and being able to move upward by overcoming an elastic force to reach an upper limit position; a roller holder supported on the cavity bottom wall when in the lowermost position; an arc-shaped engagement surface provided on the roller holder, the arc-shaped engagement surface configured to allow lateral pivotal rocking movement when the roller holder is supported on the cavity bottom wall; and an elongated hole configured to accommodate vertical displacement occurring in the shaft portion when the roller holder rocks.

2. 2. The caster with shock-absorbing function according to claim 1, wherein a limit post protrudes from an upper portion of the roller holder, the buffer spring is attached to the limit post, and when the roller holder swings laterally, the limit post presses the buffer spring to abut against a lateral side wall of the positioning cavity, thereby forming a stopper that determines the maximum lateral swing angle of the roller holder, and the tip of the limit post engages with an upper portion of the positioning cavity to form the stopper, which determines the upper limit position of the roller holder.

3. 3. The caster with shock-absorbing function according to claim 2, wherein the head of the limiting post is frusto-conical.

4. 2. The caster with shock-absorbing function according to claim 1, wherein the roller holder has a pair of flat end surfaces arranged opposite each other, the orientation of the pair of flat end surfaces being perpendicular to the axial direction of the shaft portion, and the flat end surfaces engage with the vertical side walls of the positioning cavity to provide positioning guidance for the roller holder.

5. 2. The caster with shock-absorbing function according to claim 1, wherein an installation opening is provided on one lateral side of the bracket body, the installation opening extending to the positioning cavity, the roller holder and the buffer spring are accommodated in the positioning cavity through the installation opening, a cover plate is connected to the bracket body to seal the installation opening, the cover plate forms one lateral side wall of the positioning cavity, and the cover plate is provided with the long hole.

6. 2. The caster with shock-absorbing function according to claim 1, wherein the axle portion comprises two cylindrical axle heads integrally molded with the roller holder and an axle body, the two cylindrical axle heads protruding from both lateral sides of the roller holder and arranged coaxially opposite each other, the two cylindrical axle heads extending correspondingly from the elongated holes, connecting holes opened in the centers of the cylindrical axle heads, the axle body passing through the connecting holes of the two cylindrical axle heads, and rollers 1 attached to both ends of the axle body.

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