Lightweight transposition lifting universal trundle

Abstract

The invention belongs to the technical field of casters, and relates to a lightweight transposition lifting universal caster which comprises a connecting shell, a connecting column, an eccentric caster, a limiting cover, a ball, a driving shaft, a convex cap and a first compression spring. According to the lifting universal trundle, the support is pulled upwards, the ball groove can rise to the position of the ball, the ball is clamped into the ball groove, the first compression spring can promote the driving shaft to automatically move upwards, and therefore the conical face is used for preventing the ball from retracting inwards, and then the walking state of the trolley is kept; when the driving section is pressed downwards, the balls can retract inwards so that the connecting columns can move relative to the connecting shells, the connecting columns can ascend relative to the connecting shells due to supporting force of the ground to the eccentric trundles, the support can fall on the ground, and therefore the parking state of the trolley is maintained. As the surfaces of the balls are smooth, adjustment is smoother in the state switching process, the transposition failure risk is small, and the abrasion problem is small. And parts are simple in structure and convenient to process.

Description

Technical Field

[0001] The invention relates to the technical field of casters, and in particular to a lightweight transposition lifting universal caster. Background Art

[0002] Universal casters are generally used as walking parts to move hand-held transport vehicles. Because universal casters have a rotatable connecting shaft, they can rotate at any angle. Universal casters are used on mobile brackets. Because the bracket may not be parked on flat ground, but the hand-held transport vehicle needs to stay in place without slipping when loading and unloading goods, parking is generally achieved through a brake mechanism or retractable universal casters.

[0003] Our company has applied for Chinese patent CN216761354U, which discloses a lightweight push-type lifting universal caster that can switch the stop and go state of the trolley by pressing. The trolley includes a carbon fiber bracket and a plurality of lightweight push-type lifting universal casters. The principle is to use the cooperation of the upper and lower fixing pins and the upper and lower ratchet grooves to make the connecting rod rotate around the vertical axis. When the eccentric caster is lowered relative to the bracket, the eccentric caster contacts the ground and the trolley can move. On the contrary, the carbon fiber bracket contacts the ground, and the eccentric caster is off the ground, and the trolley stops.

[0004] However, this switching method has the following hidden dangers in actual use:

[0005] 1) You must press it every time you switch states, and you need to press it twice to switch back to the previous state;

[0006] 2) The connecting rod must be rotated. During this process, the bracket needs to be lifted so that the upper and lower fixing pins can collide with the upper and lower ratchet grooves. However, if the cooperation is not good, it will lead to failure to switch;

[0007] 3) During the state switching process, the upper and lower ratchet grooves will generate tangential pressure with the upper and lower fixing pins. Under load, smaller parts have a greater risk of wear and breakage.

[0008] Chinese patent CN213861716U discloses a carbon fiber bracket caster mechanism, which has the following defects:

[0009] 1) The structure is complex, the control axis and the caster connecting axis are not on the same axis, and the two axes have a larger lateral volume;

[0010] 2) Poor anti-destruction ability, most of the control shafts are stepped on by feet, and the control shafts are limited only by the top screw;

[0011] 3) The clamping part relies on the torsion spring, which will be deformed after long-term use. If used for too long, it may not be able to return to the theoretical position, and the durability is poor;

[0012] 4) The clamping part, the shaft and the limit groove are in hard friction with each other. Even if lubricating medium is added, wear cannot be avoided, resulting in damage to the surface of the metal material;

[0013] 5) The shaft and housing require more limit grooves, all of which require turning and milling composite processing, which is costly and complex.

[0014] Therefore, it is necessary to provide a new universal caster structure to solve the above problems. Summary of the invention

[0015] The main purpose of the present invention is to provide a lightweight transposable lifting universal caster, which can switch the bracket caster between the rising and falling states by pressing, and the eccentric caster can be docked at any angle, with smooth movement and simple structure.

[0016] The present invention achieves the above-mentioned purpose through the following technical scheme: a lightweight transposition lifting universal caster, comprising:

[0017] The connecting shell has a through hole extending vertically therethrough, and a ball groove is provided on the inner wall of the through hole along the circumferential direction;

[0018] A connecting column vertically passes through the through hole, an upper portion of the connecting column is provided with a driving cavity along the axial direction, a side wall of the driving cavity is provided with a plurality of ball receiving through holes along the radial direction, a ball is provided in each ball receiving through hole, and a wall thickness of the driving cavity is smaller than a diameter of the ball;

[0019] An eccentric caster wheel is rotatably connected to the lower end of the connecting column around a vertical axis;

[0020] The limiting cover is in a hollow cylindrical shape and is fixed on the top of the connecting shell, with an axial hole on the upper part and a lower cavity on the lower part, and the axial hole is connected with the lower cavity;

[0021] A driving shaft passes through the shaft hole and the driving cavity from top to bottom, and includes a driving section, a thick column section, a thin column section and a tapered section connected in sequence from top to bottom. A convex cap is provided on the top of the driving section, and a first compression spring is clamped between the edge of the convex cap and the upper surface of the limit cover. The first compression spring surrounds the driving section. The outer diameter of the thick column section is larger than the outer diameter of the thin column section and smaller than the inner diameter of the lower cavity. The difference between the inner diameter of the driving cavity and the outer diameter of the thin column section is not less than the difference between the diameter of the ball and the wall thickness of the driving cavity. The tapered section is thin at the top and thick at the bottom, and the diameter variation range is between the outer diameter of the thin column section and the outer diameter of the thick column section. The outer conical surface of the tapered section is used to push the ball into the ball groove.

[0022] Specifically, the connecting shell includes a spherical portion and a cylindrical portion which are connected as a whole, the through hole is arranged on the spherical portion, and the cylindrical portion is arranged on one side of the spherical portion in a downwardly inclined manner.

[0023] Specifically, the inner diameter of the shaft hole is smaller than the inner diameter of the drive cavity, the outer diameter of the drive section is smaller than the outer diameter of the thick column section and matches the inner diameter of the shaft hole, and the outer diameter of the thick column section matches the inner diameter of the drive cavity.

[0024] Specifically, a plurality of anti-rotation protrusions are provided on the upper side wall of the connecting column, and an anti-rotation groove is provided on the side of the lower cavity along the busbar direction, and the anti-rotation protrusion rises and falls within the range of the anti-rotation groove.

[0025] Furthermore, the connecting column is evenly distributed with three anti-rotation protrusions along the circumferential direction, and the limiting cover is correspondingly provided with three anti-rotation grooves. A second compression spring is clamped between the upper surface of the anti-rotation protrusion and the bottom surface of the lower cavity, and the second compression spring surrounds the driving shaft.

[0026] Furthermore, an upper marking band used to indicate that the anti-rotation protrusion is in a high position and a lower marking band used to indicate that the anti-rotation protrusion is in a low position are provided on the outer wall of the limit cover.

[0027] The beneficial effects of the technical solution of the present invention are:

[0028] The lifting universal caster can be lifted by pulling up the bracket, and the ball groove will rise to the ball. The ball will be stuck in the ball groove, and the first compression spring will cause the drive shaft to move upward by itself, thereby preventing the ball from shrinking with the conical surface, and then keep the trolley in the moving state; press down the drive section, the ball can shrink inward and the connecting column can move relative to the connecting shell. The support force of the ground on the eccentric caster will make the connecting column rise relative to the connecting shell, and the bracket can fall to the ground, thereby maintaining the trolley in the parked state. Because the surface of the ball is smooth, the adjustment is smoother during the state switching process, the risk of transposition failure is small, and the wear problem is small. In addition, the parts have a simple structure, and the drive shaft can be processed on a lathe, which is convenient to process. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a three-dimensional diagram of the lifting universal caster in the embodiment in the walking state;

[0030] Figure 2 It is a cross-sectional view of the lifting universal caster in the embodiment in the walking state;

[0031] Figure 3 This is a three-dimensional diagram of the lifting universal caster in the embodiment in the docked state;

[0032] Figure 4 It is a cross-sectional view of the lifting universal caster in the embodiment in the parked state;

[0033] Figure 5 is a three-dimensional diagram of the connection shell;

[0034] Figure 6A three-dimensional diagram of a connecting column;

[0035] Figure 7 A three-dimensional diagram of a limit cover;

[0036] Figure 8 A perspective view of the drive shaft.

[0037] The numbers in the figure represent:

[0038] 1-connecting shell, 11-spherical part, 111-through hole, 112-ball groove, 12-column part;

[0039] 2-connecting column, 21-driving cavity, 22-ball receiving through hole, 23-anti-rotation protrusion;

[0040] 3-Eccentric casters;

[0041] 4-Ball;

[0042] 5-limiting cover, 51-shaft hole, 52-lower cavity, 53-stop groove, 54-upper identification belt, 55-lower identification belt;

[0043] 6-driving shaft, 61-driving section, 62-thick column section, 63-thin column section, 64-conical section;

[0044] 7-convex cap;

[0045] 8- first compression spring;

[0046] 9- Second compression spring. DETAILED DESCRIPTION

[0047] The present invention is further described in detail below with reference to specific embodiments.

[0048] Example:

[0049] like Figure 1 and Figure 3 As shown, a lightweight transposing lifting universal caster of the present invention includes a connecting shell 1, a connecting column 2, an eccentric caster 3, a ball 4, a limit cover 5, a driving shaft 6, a convex cap 7, a first compression spring 8 and a second compression spring 9.

[0050] like Figure 2 As shown, the connecting shell 1 includes a spherical portion 11 and a cylindrical portion 12 connected as one body, and the connecting shell 1 has a through hole 111 which passes through from top to bottom, and a ball groove 112 is circumferentially arranged on the inner wall of the through hole 111, the through hole 111 is arranged on the spherical portion 11, and the cylindrical portion 12 is arranged downwardly inclined on one side of the spherical portion 11.

[0051] The cylindrical part 12 is used to fix the bracket, so as to form a mobile trolley. The spherical part 11 and the bracket will maintain relative positions, and the eccentric caster 3 can change the parking state of the trolley by lifting.

[0052] like Figure 1 As shown, the connecting column 2 vertically passes through the through hole 111, and the eccentric caster 3 is connected to the lower end of the connecting column 2 by rotating around the vertical axis. The upper part of the connecting column 2 is axially provided with a driving cavity 21, and the side wall of the driving cavity 21 is radially provided with a plurality of ball receiving through holes 22, and a ball 4 is arranged in each ball receiving through hole 22, and the wall thickness of the driving cavity 21 is smaller than the diameter of the ball 4.

[0053] The outer wall of the connecting column 2 fits tightly with the inner wall of the through hole 111, so the connecting column 2 can be raised and lowered in the vertical direction relative to the connecting shell 1. The relative height between the eccentric caster 3 and the connecting column 2 is fixed, so when the connecting column 2 is raised and lowered relative to the connecting shell 1, the eccentric caster 3 will also be raised and lowered relative to the bracket. The steering of the trolley is achieved by the rotation of the eccentric caster 3, and the steering of the eccentric caster 3 will not affect the direction of the connecting column 2. Because the wall thickness of the driving cavity 21 is smaller than the diameter of the ball 4, the ball 4 will not be completely hidden in the ball receiving through hole 22, and there will inevitably be a small part protruding from the inner wall of the driving cavity 21 or the outer wall of the connecting column 2.

[0054] like Figure 7 As shown, the limit cover 5 is hollow cylindrical and fixed on the top of the connecting shell 1. The upper part of the limit cover 5 is provided with an axial hole 51, and the lower part is provided with a lower cavity 52. ​​The axial hole 51 is connected with the lower cavity 52. ​​The driving shaft 6 passes through the axial hole 51 and the driving cavity 21 from top to bottom. The driving shaft 6 includes a driving section 61, a thick column section 62, a thin column section 63 and a tapered section 64 which are connected in sequence from top to bottom. A convex cap 7 is provided on the top of the driving section 61. A first compression spring 8 is clamped between the edge of the convex cap 7 and the upper surface of the limiting cover 5. The first compression spring 8 surrounds the driving section 61. The outer diameter of the thick column section 62 is larger than the outer diameter of the thin column section 63 and smaller than the inner diameter of the lower cavity 52. ​​The difference between the inner diameter of the driving cavity 21 and the outer diameter of the thin column section 63 is not less than the difference between the diameter of the ball 4 and the wall thickness of the driving cavity 21. The tapered section 64 is thin at the top and thick at the bottom, and the diameter variation range is between the outer diameter of the thin column section 63 and the outer diameter of the thick column section 62. The outer conical surface of the tapered section 64 is used to push the ball 4 into the ball groove 112.

[0055] The limit cover 5 guides the lifting and lowering of the drive shaft 6. The ball 4 has two stable positions: the first stable position is that the conical section 64 pushes the ball 4 radially outward and then snaps into the ball groove 112. In this state, the eccentric caster 3 is at the lowest relative to the connecting shell 1, corresponding to the walking state of the trolley; the second stable position is that the ball 4 is separated from the ball groove 112 and the inner side enters the outer periphery of the thin column section 63. In this state, the eccentric caster 3 is at the highest relative to the connecting shell 1, corresponding to the parking state of the trolley.

[0056] like Figure 3As shown, the inner diameter of the shaft hole 51 is smaller than the inner diameter of the drive cavity 21 , the outer diameter of the drive section 61 is smaller than the outer diameter of the thick column section 62 and matches the inner diameter of the shaft hole 51 , and the outer diameter of the thick column section 62 matches the inner diameter of the drive cavity 21 .

[0057] Because the outer diameter of the thick column section 62 is larger than the inner diameter of the shaft hole 51 , the thick column section 62 will not pass through the shaft hole 51 , so the driving shaft 6 cannot be separated from the limiting cover 5 .

[0058] like Figure 2 , Figure 6 and Figure 7 As shown, the connecting column 2 has three anti-rotation protrusions 23 evenly distributed along the circumferential direction, and three anti-rotation grooves 53 are correspondingly provided on the limit cover 5. A second compression spring 9 is clamped between the upper surface of the anti-rotation protrusion 23 and the bottom surface of the lower cavity 52, and the second compression spring 9 surrounds the drive shaft 6.

[0059] The three anti-rotation protrusions 23 can each move along their own anti-rotation grooves 53, and provide three support points for the same end of the second compression spring 9. The second compression spring 9 can exert downward pressure on the connecting column 2, thereby buffering the vibration of the connecting column 2 when it is lifted. The number of the anti-rotation protrusions 23 here is not limited to three.

[0060] like Figure 3 and Figure 7 As shown, an upper marking band 54 for indicating that the anti-rotation protrusion 23 is in a high position and a lower marking band 55 for indicating that the anti-rotation protrusion 23 is in a low position are provided on the outer wall of the limit cover 5.

[0061] When the lifting universal caster is in different states, the position of the anti-rotation protrusion 23 relative to the anti-rotation groove 53 is different, which is reflected in that the anti-rotation protrusion 23 is aligned with the upper identification tape 54 or the lower identification tape 55. Therefore, the upper identification tape 54 and the lower identification tape 55 can more intuitively distinguish the state of the lifting universal caster. The upper identification tape 54 and the lower identification tape 55 can use different colors for work identification, which is clear and eye-catching.

[0062] like Figures 1 to 4 As shown, the method of using this lifting universal caster is:

[0063] 1. Pull up the bracket, and the ball groove 112 will rise to the ball 4, and the ball 4 will be stuck in the ball groove 112. The first compression spring 8 will prompt the drive shaft 6 to move upward by itself, so that the conical surface will prevent the ball 4 from shrinking, and then keep the trolley in the moving state;

[0064] 2. Press down the driving section 61, the ball 4 can retract and allow the connecting column 2 to move relative to the connecting shell 1. The supporting force of the ground on the eccentric caster 3 will make the connecting column 2 rise relative to the connecting shell 1, and the bracket can fall to the ground, thereby maintaining the parking state of the trolley.

[0065] Since the surface of the ball 4 is smooth, the adjustment is smoother during the state switching process, the risk of transposition failure is small, and the wear problem is small. In addition, the parts have a simple structure, and the drive shaft can be processed by a lathe, which is convenient for processing.

[0066] The above are only some embodiments of the present invention. For those skilled in the art, several modifications and improvements can be made without departing from the creative concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A lightweight transposition lifting universal caster, characterized in that include: The connecting shell has a through hole extending vertically therethrough, and a ball groove is provided on the inner wall of the through hole along the circumferential direction; A connecting column vertically passes through the through hole, an upper portion of the connecting column is provided with a driving cavity along the axial direction, a side wall of the driving cavity is provided with a plurality of ball receiving through holes along the radial direction, a ball is provided in each ball receiving through hole, and a wall thickness of the driving cavity is smaller than a diameter of the ball; An eccentric caster wheel is rotatably connected to the lower end of the connecting column around a vertical axis; The limiting cover is in a hollow cylindrical shape and is fixed above the connecting shell, and includes an axial hole at the upper part and a lower cavity at the lower part, wherein the axial hole is communicated with the lower cavity; A driving shaft passes through the shaft hole and the driving cavity from top to bottom, and includes a driving section, a thick column section, a thin column section and a tapered section connected in sequence from top to bottom. A convex cap is provided on the top of the driving section, and a first compression spring is clamped between the edge of the convex cap and the upper surface of the limit cover. The first compression spring surrounds the driving section. The outer diameter of the thick column section is larger than the outer diameter of the thin column section and smaller than the inner diameter of the lower cavity. The difference between the inner diameter of the driving cavity and the outer diameter of the thin column section is not less than the difference between the diameter of the ball and the wall thickness of the driving cavity. The tapered section is thin at the top and thick at the bottom, and the diameter variation range is between the outer diameter of the thin column section and the outer diameter of the thick column section. The outer conical surface of the tapered section is used to push the ball into the ball groove.

2. The lightweight transposition lifting universal caster according to claim 1 is characterized in that: The connecting shell comprises a spherical part and a cylindrical part which are connected as one body, the through hole is arranged on the spherical part, and the cylindrical part is arranged on one side of the spherical part in a downward tilted manner.

3. The lightweight transposition lifting universal caster according to claim 1 is characterized in that: The inner diameter of the shaft hole is smaller than the inner diameter of the drive cavity, the outer diameter of the drive section is smaller than the outer diameter of the thick column section and matches the inner diameter of the shaft hole, and the outer diameter of the thick column section matches the inner diameter of the drive cavity.

4. The lightweight transposition lifting universal caster according to claim 1 is characterized in that: A plurality of anti-rotation protrusions are arranged on the upper side wall of the connecting column, and an anti-rotation groove is arranged on the side of the lower cavity along the busbar direction, and the anti-rotation protrusion rises and falls within the range of the anti-rotation groove.

5. The lightweight transposition lifting universal caster according to claim 4 is characterized in that: The connecting column is evenly distributed with three anti-rotation protrusions along the circumferential direction, and the limiting cover is correspondingly provided with three anti-rotation grooves. A second compression spring is clamped between the upper surface of the anti-rotation protrusion and the bottom surface of the lower cavity, and the second compression spring surrounds the driving shaft.

6. The lightweight transposition lifting universal caster according to claim 4 is characterized in that: An upper marking belt for indicating that the anti-rotation protrusion is in a high position and a lower marking belt for indicating that the anti-rotation protrusion is in a low position are arranged on the outer wall of the limit cover.

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