Trundle mechanism of ladder and ladder using trundle mechanism
By designing a platform ladder caster mechanism including a rotating arm and a rotatable mounting bracket, the problem of the caster mechanism occupying a large space when it is closed in the prior art is solved, and more efficient space savings are achieved.
Patent Information
- Application Number
- CN202510008748.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-03
- Publication Date
- 2025-03-11
AI Technical Summary
The caster mechanism of the existing platform ladder occupies a large space when it is closed, especially the larger caster is limited by the main body of the platform ladder, resulting in limited closing degree.
A caster mechanism including a connecting bracket, a rotary arm, a mounting bracket, a caster, a connecting shaft, a positioning shaft and an elastic member is designed. Through the cooperation of the rotary arm and the mounting bracket, the casters can switch between the working state and the closure state to achieve more efficient closure.
Through the single retraction of the rotating arm and the secondary retraction of the casters, the space occupied by the casters mechanism is significantly reduced, so that the thickness direction size of the platform ladder is smaller when it is retracted.
Smart Images
Figure CN119593684A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of ladders, and in particular to a caster mechanism of a ladder and a ladder using the caster mechanism. Background Art
[0002] As a common tool for climbing work, ladders are widely used in equipment installation, maintenance, cleaning and other fields. In order to improve the portability and mobility of platform ladders, many designs have introduced caster mechanisms, allowing operators to easily carry platform ladders between different work locations, significantly improving work efficiency and reducing physical burden.
[0003] When the platform ladder is not in use, it needs to be folded and stored to reduce the storage space occupied. Traditional caster mechanisms are often directly fixed on the bottom or side of the platform ladder, and because the casters themselves have a certain volume and protrusion, even after the platform ladder is folded and folded, the casters will still occupy a large space. Even if the caster mechanism can rotate along a certain axis relative to the platform ladder body, when the caster in the caster mechanism is large, the larger caster is restricted by the platform ladder body, resulting in a limited degree of folding of the caster mechanism.
[0004] Therefore, how to solve the problem of the caster mechanism in the prior art causing the platform ladder to occupy more storage space has become a problem to be studied and solved by the present invention. Summary of the invention
[0005] The object of the present invention is to provide a caster mechanism for a ladder and a ladder using the caster mechanism.
[0006] In order to achieve the above object, the technical solution adopted by the present invention is: A caster mechanism for a ladder, the ladder comprising a ladder frame consisting of two pillars and steps, the caster mechanism being arranged on the side of the bottom end of the ladder frame, the caster mechanism comprising a connecting bracket, a swivel arm, a mounting bracket, a caster, a connecting shaft, a positioning shaft and an elastic member; The connecting bracket, the swivel arm, the mounting bracket and the caster are sequentially arranged in a straight line on the side of the bottom end of the ladder frame; The connecting bracket is fixedly connected to the ladder frame; The swivel arm is hinged to the connecting bracket by the connecting shaft so that the swivel arm can rotate around the axis of the connecting shaft, so that the swivel arm has a supporting working position and a folding working position; a locking mechanism is provided between the swivel arm and the connecting bracket to position the swivel arm at the supporting working position or the folding working position; The positioning shaft is passed through the swivel arm toward the mounting bracket, so that the mounting bracket can rotate around the positioning shaft and can move along the length direction of the positioning shaft; a concave-convex structure is provided on the opposite surfaces of the swivel arm and the mounting bracket; the elastic member acts between the swivel arm and the mounting bracket, forcing the opposite surfaces of the two to approach each other, and the two are locked in the rotation direction through the concave-convex structure; and under the action of external force, the elastic force of the elastic member is overcome to disengage and unlock the opposite surfaces of the swivel arm and the mounting bracket; The caster is mounted and supported on the mounting bracket, and rotates around the positioning shaft through the mounting bracket, so that the caster has a working state and a retracted state; in the working state, the axis of the caster is parallel to the axis of the connecting shaft in space; in the retracted state, the axis of the caster is perpendicular to the axis of the connecting shaft in space; During use, when the swivel arm is in the supporting working position, it forms a certain angle with the height direction of the ladder frame, and the caster can be in a working state to support the work; when the swivel arm is in the folding working position, it is close to the side of the ladder frame, and the caster can be switched to a folded state to reduce the volume.
[0007] In the above scheme, the working state is switched to the retracted state for explanation, as follows: Here, the connecting bracket is installed on the platform ladder and is stationary relative to the platform ladder for explanation, and the caster is set to be smaller; first, the locking of the swivel arm by the locking member is released so that the swivel arm can rotate relative to the connecting bracket around the axis of the connecting shaft; then the swivel arm is moved from the supporting working position to the folding working position to achieve the retraction of the swivel arm and the initial retraction of the caster, thereby reducing the size of the space occupied by the caster mechanism; then the mounting bracket is moved along the length extension direction of the positioning shaft so that the protrusion is separated from the limiting groove; then the mounting bracket is caused to rotate around the axis of the positioning shaft to achieve the secondary retraction of the caster. Through the above arrangement, the swivel arm is retracted once, and the caster is retracted twice, which can greatly reduce the size of the space occupied by the caster mechanism; taking the caster mechanism being arranged on the platform ladder as an example, when the platform ladder is retracted, the caster mechanism is also retracted, and the combined structure of the caster mechanism and the platform ladder has a smaller size in the thickness direction of the platform ladder after retraction.
[0008] It should be emphasized that in order to transport the platform ladder, the orientation of the casters in the working state must be the same as in Figures 2 and 3; when the casters are larger, if the casters can only rotate around the axis of the connecting shaft, the casters will collide with the platform ladder body after rotating a small amount and will not be able to continue rotating; through the settings in this embodiment, for larger casters, the casters can first be rotated around the axis of the positioning shaft to ensure the degree of retraction of the caster mechanism.
[0009] By setting the locking piece, the swivel arm in the working state or the retracted state can be locked, which facilitates the stable operation of the caster and prevents the various structures in the caster mechanism from being scattered after being retracted.
[0010] By setting the positioning shaft, the moving direction of the mounting bracket is restricted and the activity range of the mounting bracket is limited; when the mounting bracket is moved along the length extension direction of the positioning shaft, the positioning shaft and the mounting bracket move synchronously, and the mounting bracket can be regarded as being sleeved on the outside of the positioning shaft.
[0011] Through the arrangement of the protrusion and the limiting groove, when the protrusion is placed in the limiting groove, the limiting groove limits the protrusion and the mounting bracket from rotating around the axis of the positioning shaft, and only when the two are separated can the mounting bracket be prompted to rotate around the axis of the positioning shaft. The protrusion and the limiting groove can have a variety of arrangements (such as arrangements in terms of shape), which are not specifically limited here, and one of the arrangements can be seen in the figure.
[0012] By setting the elastic member, the positioning shaft and the mounting bracket can be automatically reset in the length extension direction of the positioning shaft.
[0013] According to a further technical solution, the locking mechanism includes a locking piece, a first locking groove and a second locking groove; the locking piece is provided on one of the connecting bracket and the rotating arm, and the first locking groove and the second locking groove are provided on the other corresponding to the locking piece; when the rotating arm is in the supporting working position, the locking piece is engaged with the first locking groove to complete the positioning, and when the rotating arm is in the folding working position, the locking piece is engaged with the second locking groove to complete the positioning.
[0014] This section supplements the specific locking methods as a reference to achieve quick locking.
[0015] According to a further technical solution, the locking member is a locking shaft, which is perpendicular to and positioned with the positioning shaft, and both ends of the locking shaft are passed through long holes arranged on the connecting bracket or the rotating arm, so that the locking shaft can be displaced in the axial direction of the positioning shaft; a convex portion is provided on the positioning shaft to engage with the mounting bracket, so that when the mounting bracket moves in a direction away from the rotating arm, it can drive the positioning shaft to move together; thereby, when the elastic force of the elastic member is overcome under the action of an external force to disengage and unlock the relative surfaces of the rotating arm and the mounting bracket, the locking shaft is driven to move via the positioning shaft, so that the locking shaft and the first locking groove or the second locking groove are also disengaged and unlocked at the same time.
[0016] When the locking piece can be moved along the length extension direction of the long hole, the lock can be unlocked without moving the locking piece out of the long hole, and the linkage setting is used to improve convenience.
[0017] According to a further technical solution, the elastic member is configured as a compression spring, and the compression spring is sleeved on the positioning shaft.
[0018] According to a further technical solution, the positioning shaft is a positioning pin, and the end of the positioning pin is provided with a large head that is blocked on the mounting bracket.
[0019] According to a further technical solution, the caster is connected to the mounting bracket via a second bolt.
[0020] According to a further technical solution, the mounting bracket comprises a detachable bracket portion and a handle portion, the concave-convex structure is disposed at the handle portion, and the caster is mounted at the bracket portion.
[0021] The handle is easy to grasp and provides convenience for lifting the casters.
[0022] A ladder is also provided herein, comprising the caster mechanism in any one of the above embodiments.
[0023] The terms “first”, “second”, etc. used in this document do not specifically refer to an order or sequence, nor are they used to limit the present case. They are only used to distinguish components or operations described with the same technical terms.
[0024] As used herein, “connected” or “positioned” may refer to two or more components or devices being in direct physical contact with each other, or being in indirect physical contact with each other, or may refer to two or more components or devices operating or moving with each other.
[0025] The terms “include,” “including,” “have,” etc. used in this document are open-ended terms, meaning including but not limited to.
[0026] The terms used in this document generally have the ordinary meaning of each term used in this field, in the context of the case and in the specific context, unless otherwise noted. Certain terms used to describe the present invention will be discussed below or elsewhere in this specification to provide additional guidance to those skilled in the art in describing the present invention.
[0027] The terms "front", "back", "up", "down", "left", "right", etc. used in this article are all directional terms. In this case, they are only used to illustrate the positional relationship between the various structures, and are not used to limit the protection plan of this case and the specific direction during actual implementation.
[0028] The working principle and advantages of the present invention are as follows: Here, the working state is switched to the retracted state for explanation, as follows: Here, the connecting bracket is installed on the platform ladder and is stationary relative to the platform ladder for explanation, and the caster is set to be smaller; first, the locking of the swivel arm by the locking member is released so that the swivel arm can rotate relative to the connecting bracket around the axis of the connecting shaft; then the swivel arm is moved from the supporting working position to the folding working position to achieve the retraction of the swivel arm and the initial retraction of the caster, thereby reducing the size of the space occupied by the caster mechanism; then the mounting bracket is moved along the length extension direction of the positioning shaft so that the protrusion is separated from the limiting groove; then the mounting bracket is caused to rotate around the axis of the positioning shaft to achieve the secondary retraction of the caster. Through the above-mentioned setting, the swivel arm is retracted once, and the caster is retracted twice, which can greatly reduce the size of the space occupied by the caster mechanism; taking the caster mechanism being arranged on the platform ladder as an example, when the platform ladder is retracted, the caster mechanism is also retracted, and the combined structure of the caster mechanism and the platform ladder has a smaller size in the thickness direction of the platform ladder after retraction. BRIEF DESCRIPTION OF THE DRAWINGS
[0029] Figure 1 It is a structural schematic diagram of a caster mechanism of an embodiment of the present invention, which is arranged on a platform ladder and is in a working state; Figure 2 It is a structural schematic diagram of a caster mechanism of an embodiment of the present invention, which is arranged on a platform ladder and is in a retracted state; Figure 3 for Figure 1 Enlarged view of point A in the middle; Figure 4 for Figure 2 Enlarged view of point B in the middle; Figure 5 An exploded view of a caster mechanism according to an embodiment of the present invention; Figure 6 It is a structural schematic diagram of a caster mechanism in a working state according to an embodiment of the present invention; Figure 7 It is a structural schematic diagram of the caster mechanism when the protrusion is separated from the limiting groove according to an embodiment of the present invention; Figure 8 It is a schematic structural diagram of the swivel arm, handle portion and protrusion according to an embodiment of the present invention.
[0030] In the above drawings: 1. connecting bracket; 11. first locking groove; 12. second locking groove; 2. swivel arm; 21. limit groove; 22. long hole; 3. connecting shaft; 31. first bolt; 4. locking member; 5. positioning shaft; 6. elastic member; 7. mounting bracket; 71. bracket part; 72. handle part; 8. caster; 9. protrusion; 10. first through hole; 13. R-type pin; 14. second bolt; 15. pillar; 16. step. DETAILED DESCRIPTION
[0031] The present invention will be further described below in conjunction with the accompanying drawings and embodiments: Embodiment: The present invention will be clearly described below with diagrams and detailed descriptions. After understanding the embodiments of the present invention, any person skilled in the art can make changes and modifications based on the techniques taught by the present invention without departing from the spirit and scope of the present invention.
[0032] The terms used herein are only for describing specific embodiments and are not intended to be limiting of the present invention. Singular forms such as "a", "this", "here", "this" and "the" as used herein also include plural forms.
[0033] See also Figure 1-Figure 8 , a caster mechanism of a ladder, the ladder comprising a ladder frame consisting of two pillars 15 and a step 16, the caster mechanism being arranged on the side of the bottom end of the ladder frame, the caster mechanism comprising a connecting bracket 1, a swivel arm 2, a mounting bracket 7, a caster 8, a connecting shaft 3, a positioning shaft 5 and an elastic member 6; The connecting bracket 1, the swivel arm 2, the mounting bracket 7 and the caster 8 are sequentially arranged in a straight line at the side of the bottom end of the ladder frame; The connecting bracket 1 is fixedly connected to the ladder frame; The swivel arm 2 is hinged to the connecting bracket 1 by the connecting shaft 3, so that the swivel arm 2 can rotate around the axis of the connecting shaft 3, so that the swivel arm 2 has a supporting working position and a folding working position; a locking mechanism is provided between the swivel arm 2 and the connecting bracket 1 to position the swivel arm 2 in the supporting working position or the folding working position; The positioning shaft 5 is passed through the swivel arm 2 toward the mounting bracket 7, so that the mounting bracket 7 can rotate around the positioning shaft 5 and can move along the length direction of the positioning shaft 5; the swivel arm 2 and the mounting bracket 7 are provided with a concave-convex structure on the opposite surface; the elastic member 6 acts between the swivel arm 2 and the mounting bracket 7, forcing the opposite surfaces of the two to approach each other, and the two are locked in the rotation direction through the concave-convex structure; and under the action of external force, the elastic force of the elastic member 6 is overcome to disengage and unlock the opposite surfaces of the swivel arm 2 and the mounting bracket 7; The caster 8 is mounted and supported on the mounting bracket 7, and rotates around the positioning shaft 5 through the mounting bracket 7, so that the caster 8 has a working state and a retracted state; in the working state, the axis of the caster 8 is parallel to the axis of the connecting shaft 3 in space; in the retracted state, the axis of the caster 8 is perpendicular to the axis of the connecting shaft 3 in space; During use, when the swivel arm 2 is in the supporting working position, it forms a certain angle with the height direction of the ladder frame, and the caster 8 can be in a working state to support the work; when the swivel arm 2 is in the folding working position, it is close to the side of the ladder frame, and the caster 8 can be switched to a folded state to reduce the volume.
[0034] In the working state, the swivel arm 2 is perpendicular to the connecting bracket 1, and the extension direction of the axis of the caster 8 is parallel to the extension direction of the axis of the connecting shaft 3 (see Figure 1 , Figure 3 ), at this time, the caster mechanism is unfolded. Taking the platform ladder as an example, the caster mechanism is installed on the platform ladder, and the unfolded caster mechanism provides convenience for carrying the platform ladder.
[0035] The concave-convex structure includes a protrusion 9 and a limiting groove 21 , which are respectively arranged on the rotating arm 2 and the mounting bracket 7 .
[0036] In the retracted state, the swivel arm 2 is parallel to the connecting bracket 1, and the extending direction of the axis of the caster 8 is perpendicular to the extending direction of the axis of the connecting shaft 3 and the extending direction of the axis of the positioning shaft 5 (see Figure 2 , Figure 4 ), at this time, the caster mechanism is retracted to reduce the occupied space area.
[0037] Here, the explanation is given by switching from the working state to the stowed state. The process of switching from the stowed state to the working state refers to the following explanation: Here, the explanation is given by assuming that the connecting bracket 1 is installed on the platform ladder and is stationary relative to the platform ladder, and the caster 8 is set to be small; first, the locking member 4 on the swivel arm 2 is released (for example, the locking member 4 is removed to separate it from the swivel arm 2), so that the swivel arm 2 can rotate around the axis of the connecting shaft 3 relative to the connecting bracket 1; then, the swivel arm 2 is moved from the supporting working position to the folded working position, so as to realize the stowage of the swivel arm 2 and the preliminary stowage of the caster 8 (see Figure 6 ), reducing the space occupied by the caster mechanism; then moving the mounting bracket 7 along the length extension direction of the positioning shaft 5 so that the protrusion 9 is separated from the limiting groove 21; then causing the mounting bracket 7 to rotate around the axis of the positioning shaft 5 to achieve the secondary retraction of the caster 8 (see Figure 4 ).
[0038] Through the above arrangement, the swivel arm 2 can be folded once, and the caster 8 can be folded twice, which can greatly reduce the space occupied by the caster mechanism. Taking the caster mechanism being arranged on the platform ladder as an example, when the platform ladder is folded, the caster mechanism is also folded, and the combined structure of the caster mechanism and the platform ladder has a smaller dimension in the thickness direction of the platform ladder after folding.
[0039] It should be emphasized that in order to transport the platform ladder, the orientation of the castor 8 in the working state must be consistent with Figure 1 , Figure 3 The same as in the embodiment; when the caster 8 is larger, if the caster 8 can only rotate around the axis of the connecting shaft 3, the caster 8 will collide with the platform ladder body after rotating a small amount and cannot continue to rotate; through the arrangement in this embodiment, for a larger caster 8, the caster 8 can be first rotated around the axis of the positioning shaft 5 to ensure the degree of retraction of the caster mechanism.
[0040] By setting the locking member 4, the swivel arm 2 in the working state or the retracted state can be locked, which facilitates the stable operation of the caster 8 and prevents the various structures in the caster mechanism from being scattered after being retracted.
[0041] By setting the positioning shaft 5, the moving direction of the mounting bracket 7 is restricted and the activity range of the mounting bracket 7 is limited; when the mounting bracket 7 is moved along the length extension direction of the positioning shaft 5, the positioning shaft 5 and the mounting bracket 7 move synchronously, and the mounting bracket 7 can be regarded as being sleeved on the outside of the positioning shaft 5.
[0042] Through the arrangement of the protrusion 9 and the limiting groove 21, when the protrusion 9 is placed in the limiting groove 21, the limiting groove 21 limits the protrusion 9 and the mounting bracket 7 from rotating around the axis of the positioning shaft 5. Only when the two are separated can the mounting bracket 7 be prompted to rotate around the axis of the positioning shaft 5. The protrusion 9 and the limiting groove 21 can have a variety of arrangements (such as arrangements in terms of shape), which are not specifically limited here. One of the arrangements can be referred to Figure 8 .
[0043] By disposing the elastic member 6 , the positioning shaft 5 and the mounting bracket 7 can be automatically reset in the length extension direction of the positioning shaft 5 .
[0044] See also Figure 5 , Figure 6 In this embodiment, the connecting bracket 1 and the rotating arm 2 are both provided with a first through hole 10 for the connecting shaft 3 to pass through; the connecting shaft (which can also be set as a connecting member) 3 includes a first bolt 31, a nut, and two washers for connecting the connecting bracket 1 and the rotating arm 2.
[0045] This embodiment provides a specific method for connecting the connecting bracket 1 and the swivel arm 2. In this method, the two washers are respectively located on both sides of the connecting bracket 1, the first bolt 31 passes through each first through hole 10, the nut and the two washers (see Figure 5 ).
[0046] By adopting the above-mentioned method, quick connection is achieved and the first through hole 10 does not need to be set as a threaded hole, thereby reducing the degree and difficulty of modification of the connecting bracket 1 and the swivel arm 2.
[0047] See also Figure 5In this embodiment, the locking mechanism includes a locking piece 4, a first locking groove 11 and a second locking groove 12; one of the connecting bracket 1 and the rotating arm 2 is provided with the locking piece 4, and the other is provided with the first locking groove 11 and the second locking groove 12 corresponding to the locking piece 4; when the rotating arm 2 is in the first position, the locking piece 4 is engaged with the first locking groove 11 to complete the positioning, and when the rotating arm 2 is in the second position, the locking piece 4 is engaged with the second locking groove 12 to complete the positioning.
[0048] When the swivel arm 2 is in the supporting working position, part of the locking member 4 is in the first locking groove 11 to lock the swivel arm 2 in the supporting working position.
[0049] When the swivel arm 2 is in the folded working position, part of the locking member 4 is in the second locking groove 12 to lock the swivel arm 2 in the folded working position.
[0050] The first locking groove 11 and the second locking groove 12 correspond to the supporting working position and the folding working position respectively.
[0051] Here, the swivel arm 2 is in the supporting working position as an example, as follows: In one case, when the swivel arm 2 is in the supporting working position, the locking member 4 is provided with the first locking groove 11 (see Figure 6 ).
[0052] This embodiment supplements the specific locking method as a reference to achieve quick locking.
[0053] See also Figure 6 , Figure 7 In the present embodiment, the locking member 4 is a locking shaft, which is perpendicular to and positioned with the positioning shaft 5, and both ends of the locking shaft are passed through long holes 22 arranged on the connecting bracket 1 or the rotating arm 2, so that the locking shaft can be displaced in the axial direction of the positioning shaft 5; a convex portion is provided on the positioning shaft 5 to engage with the mounting bracket 7, so that when the mounting bracket 7 moves in a direction away from the rotating arm 2, it can drive the positioning shaft 5 to move together; thus, when the elastic force of the elastic member 6 is overcome under the action of an external force to disengage and unlock the relative surfaces of the rotating arm 2 and the mounting bracket 7, the locking shaft is driven to move by the positioning shaft 5, so that the locking shaft and the first locking groove 11 or the second locking groove 12 are also disengaged and unlocked at the same time.
[0054] The cross-sectional dimension of the long hole 22 is larger than the cross-sectional dimension of the locking member 4 ; the locking member 4 can move along the length extension direction of the long hole 22 to separate from the first locking groove 11 or the second locking groove 12 .
[0055] When the locking member 4 can be moved along the length extension direction of the long hole 22, the unlocking can be performed without moving the locking member 4 out of the long hole 22, and the convenience is improved by the linkage setting.
[0056] When unlocking, the locking member 4 is directly moved along the length extension direction of the long hole 22 so that the locking member 4 is separated from the first locking groove 11 or the second locking groove 12 , which is more convenient and quick.
[0057] See also Figure 6 , Figure 7 In this embodiment, the long hole 22 is set as a waist-shaped hole; and / or the locking member 4 is set as a cylindrical pin.
[0058] This embodiment provides a specific arrangement of the long hole 22, that is, a waist-shaped hole (see Figure 6 ), for reference and easy understanding.
[0059] The cylindrical pin is an existing configuration and is well understood by those skilled in the art, and will not be described in detail here.
[0060] The cylindrical pin is detachably connected to the positioning shaft 5, and can be connected by inserting the positioning pin (see Figure 6 ).
[0061] See also Figure 5 In this embodiment, the elastic member 6 is configured as a compression spring; and / or the positioning shaft 5 is configured as a positioning pin, and the end of the positioning pin is provided with a large head that is blocked on the mounting bracket 7; and / or the elastic member 6 is connected to the positioning shaft 5 via an R-type pin 13.
[0062] Optionally, the compression spring is sleeved on the outside of the positioning shaft 5 .
[0063] The connection method using the R-shaped pin 13 is an existing arrangement and is understood by those skilled in the art, and will not be described in detail here.
[0064] See also Figure 5 , Figure 6 In this embodiment, the caster 8 is connected to the mounting bracket 7 via a second bolt 14 .
[0065] Optionally, the axis of the caster 8 coincides with the axis of the second bolt 14 .
[0066] See also Figure 5 , Figure 8 In this embodiment, the mounting bracket 7 includes a detachable bracket portion 71 and a handle portion 72 , the protrusion 9 is provided on the handle portion 72 , and the caster 8 is installed on the bracket portion 71 .
[0067] The handle portion 72 is convenient for a person to grasp and provides convenience for lifting the caster 8 .
[0068] Optionally, both the handle portion 72 and the bracket portion 71 are provided with a through hole for the positioning shaft 5 to pass through. The combination of the handle portion 72, the bracket portion 71 and the positioning shaft 5 can be seen in Figure 6 .
[0069] Optionally, the protrusion 9 is arranged on the surface of the handle portion 72 away from the bracket portion 71; the protrusion 9 includes two pairs of edges; the limiting groove 21 has two ribs, and the two ribs cooperate to limit the rotation of the two pairs of edges.
[0070] See also Figure 1 , Figure 2 , a ladder, comprising the caster mechanism in any of the above embodiments.
[0071] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.
Claims
1. A caster mechanism for a ladder, characterized in that: The ladder comprises a ladder frame consisting of two pillars (15) and steps (16); the caster mechanism is arranged on the side of the bottom end of the ladder frame; the caster mechanism comprises a connecting bracket (1), a swivel arm (2), a mounting bracket (7), a caster (8), a connecting shaft (3), a positioning shaft (5) and an elastic member (6); The connecting bracket (1), the swivel arm (2), the mounting bracket (7) and the caster (8) are arranged in sequence in a straight line on the side of the bottom end of the ladder frame; The connecting bracket (1) is fixedly connected to the ladder frame; The swivel arm (2) is hingedly connected to the connecting bracket (1) by the connecting shaft (3), so that the swivel arm (2) can rotate around the axis of the connecting shaft (3), so that the swivel arm (2) has a supporting working position and a folded working position; a locking mechanism is provided between the swivel arm (2) and the connecting bracket (1) to position the swivel arm (2) in the supporting working position or the folded working position; The positioning shaft (5) is passed through the swivel arm (2) toward the mounting bracket (7), so that the mounting bracket (7) can rotate around the positioning shaft (5) and can move along the length direction of the positioning shaft (5); the opposing surfaces of the swivel arm (2) and the mounting bracket (7) are provided with a concave-convex structure; the elastic member (6) acts between the swivel arm (2) and the mounting bracket (7), forcing the opposing surfaces of the two to come closer together, and the two are locked in the rotation direction through the concave-convex structure; and under the action of an external force, the elastic force of the elastic member (6) is overcome so that the opposing surfaces of the swivel arm (2) and the mounting bracket (7) can be disengaged and unlocked; The caster (8) is mounted and supported on the mounting bracket (7) and rotates around the positioning shaft (5) through the mounting bracket (7), so that the caster (8) has a working state and a retracted state; in the working state, the axis of the caster (8) is spatially parallel to the axis of the connecting shaft (3); in the retracted state, the axis of the caster (8) is spatially perpendicular to the axis of the connecting shaft (3); When in use, when the swivel arm (2) is in the supporting working position, it forms a certain angle with the height direction of the ladder frame, and the caster (8) can be in a working state to support the work; when the swivel arm (2) is in the folding working position, it is close to the side of the ladder frame, and the caster (8) can be switched to a folded state to reduce the volume.
2. The caster mechanism according to claim 1, characterized in that: The locking mechanism comprises a locking member (4), a first locking groove (11) and a second locking groove (12); one of the connecting bracket (1) and the swivel arm (2) is provided with the locking member (4), and the other is provided with the first locking groove (11) and the second locking groove (12) corresponding to the locking member (4); when the swivel arm (2) is in a supporting working position, the locking member (4) is engaged with the first locking groove (11) to complete positioning; when the swivel arm (2) is in a folding working position, the locking member (4) is engaged with the second locking groove (12) to complete positioning.
3. The caster mechanism according to claim 2, characterized in that: The locking member (4) is a locking shaft, which is perpendicular to and positioned with the positioning shaft (5), and the two ends of the locking shaft are passed through long holes (22) provided on the connecting bracket (1) or the rotating arm (2), so that the locking shaft can be displaced in the axial direction of the positioning shaft (5); a convex portion is provided on the positioning shaft (5) to engage with the mounting bracket (7), so that when the mounting bracket (7) moves in a direction away from the rotating arm (2), it can drive the positioning shaft (5) to move together; thus, when the elastic force of the elastic member (6) is overcome under the action of an external force to disengage and unlock the opposing surfaces of the rotating arm (2) and the mounting bracket (7), the locking shaft is driven to move via the positioning shaft (5), so that the locking shaft and the first locking groove (11) or the second locking groove (12) are also disengaged and unlocked at the same time.
4. The caster mechanism according to any one of claims 1 to 3, characterized in that: The elastic member (6) is configured as a compression spring, and the compression spring is sleeved on the positioning shaft (5).
5. The caster mechanism according to any one of claims 1 to 3, characterized in that: The positioning shaft (5) is a positioning pin, and the end of the positioning pin is provided with a large head that is blocked on the mounting bracket (7).
6. The caster mechanism according to any one of claims 1 to 3, characterized in that: The caster (8) is connected to the mounting bracket (7) via a second bolt (14).
7. The caster mechanism according to any one of claims 1 to 3, characterized in that: The mounting bracket (7) comprises a detachable bracket portion (71) and a handle portion (72), the concave-convex structure is provided on the handle portion (72), and the caster (8) is mounted on the bracket portion (71).
8. A ladder, characterized in that: The invention comprises the caster mechanism according to any one of claims 1 to 7.