Dolly
The cart design with trolley frames connected by first and second members addresses weight and cost issues, providing flexible width adjustment for efficient loading and transport.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- SHINWA PACKAGE KABUSHIKI KAISHA
- Filing Date
- 2024-11-21
- Publication Date
- 2026-06-02
AI Technical Summary
Existing carts with expandable loading surfaces face issues of increased weight and cost due to complex slide mechanisms, and limited ability to reduce width for navigating narrow passages.
A cart design featuring a pair of trolley frames connected by first and second connecting members, allowing for fan-shaped expansion and contraction, reducing weight and cost while enabling narrow width for passage through narrow spaces and stable loading of various sizes.
The design achieves reduced weight, cost, and width flexibility, enabling stable transport of both narrow and large loads without compromising structural integrity.
Smart Images
Figure 2026089780000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a cart whose loading surface can be expanded and contracted in a fan shape.
Background Art
[0002] In order to be able to transport pallets and containers of different sizes, carts with expandable and contractible loading surfaces have been conventionally known. For example, the cart of Patent Document 1 (Utility Model Registration No. 3204751) has a loading surface that can be expanded and contracted in the front-rear direction. Also, the cart of Patent Document 2 (Japanese Unexamined Patent Application Publication No. 8-244618) has a loading surface that can be expanded and contracted in the left-right direction.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Patent Document 2
Summary of the Invention
Problems to be Solved by the Invention
[0004] Since these carts can expand and contract the loading surface in the front-rear direction and the left-right direction by a slide mechanism, the number of members constituting the slide mechanism increases, and thus there is a problem that an increase in the weight and cost of the cart cannot be avoided. Also, in order to transport luggage through a narrow passage, it is necessary to make the cart width as narrow as possible, but there is a limit to reducing the cart width in a cart that can expand and contract in the left-right direction by a slide mechanism as in Patent Document 2.
[0005] Therefore, an object of the present invention is to reduce the weight and cost of the cart and reduce the cart width.
Means for Solving the Problems
[0006] To solve the aforementioned problems, the trolley according to the present invention is characterized by comprising: a pair of left and right trolley frames having a first connecting portion at one end in the longitudinal direction and a second connecting portion at the other end in the longitudinal direction; a first connecting member that connects the first connecting portions of the pair of trolley frames to each other; and a second connecting member that connects the second connecting portions of the pair of trolley frames to each other. [Effects of the Invention]
[0007] According to the present invention, it is possible to reduce the weight and cost of the trolley, as well as reduce the width of the trolley. [Brief explanation of the drawing]
[0008] [Figure 1A] These are reduced-size perspective views of a trolley according to an embodiment of the present invention: (a) an empty state and (b) a loaded state. [Figure 1B] These are extended perspective views of the trolley according to an embodiment of the present invention: (a) an empty state and (b) a loaded state. [Figure 2] These are perspective views of the trolley in (a) its reduced state, (b) its intermediate state, and (c) its extended state. [Figure 3] (a) Perspective view of the extended state of a pair of bogie frames, (b) Perspective view of the base end connecting part of the bogie frame, (c) Plan view of the connecting plate, (d) Perspective view of the rotation locking structure of the connecting plate, and (e) Perspective view of the lower end of the bogie handle. [Figure 4] This is a plan view showing the connected state of a pair of trolley frames in the absence of a rotation locking mechanism. [Figure 5] This is a plan view of a trolley according to a modified embodiment 1 of the present invention. [Figure 6] (a) a front view of the trolley handle, (b) a reduced-size plan view, and (c) an enlarged plan view of the trolley according to a modified embodiment 2 of the present invention. [Figure 7] (a) to (d) are plan views showing the stepped expansion states of the trolley according to the third modified embodiment of the present invention. [Figure 8]These are plan views of the trolley according to modified embodiment 4 of the present invention in (a) a reduced state, (b) a fan-shaped expanded state, and (c) a parallel expanded state. [Modes for carrying out the invention]
[0009] Hereinafter, the trolleys according to each embodiment of the present invention will be described with reference to the drawings. Throughout the drawings, the same or corresponding parts will be denoted by the same reference numerals, and redundant explanations will be omitted as appropriate.
[0010] As shown in Figure 1A(a), the trolley 100 (unloaded state) according to an embodiment of the present invention has a pair of left and right trolley frames 10. The trolley frames 10 have an elongated rectangular frame shape. A trolley handle 20 is detachably mounted on one end of the trolley frame 10.
[0011] Casters 50 are attached to the lower ends of both ends of the trolley frame 10 via mounting plates 10c. Since there are four casters 50 arranged in the front, rear, left, and right directions, stable movement of the trolley 100 is possible.
[0012] The pair of left and right trolley frames 10 can be expanded and contracted in a fan shape, as shown in Figure 1B(a) (when unloaded). When transporting goods through a narrow passage, the trolley width can be narrowed as shown in Figure 1A(a).
[0013] Even with the trolley width narrowed in this way, narrow containers 200 can be loaded in two rows vertically, as shown in Figure 1A(b). On the other hand, by expanding in a fan shape as shown in Figure 1B(a), even large pallets 300 can be loaded stably, as shown in Figure 1B(b).
[0014] Figure 2(a) shows the trolley 100 in a reduced state, (b) in an intermediate state, and (c) in an extended state. In the reduced state shown in Figure 2(a), the pair of left and right trolley frames 10 are almost parallel. In the extended state shown in Figure 2(c), the pair of left and right trolley frames 10 are extended in a fan shape.
[0015] The left and right pair of bogie frames 10 are connected at the handle side (base end side) ends by a connecting plate 30 as a second connecting member. Also, the ends on the tip side of the bogie frames 10 are connected by link plates 41 and 42 as a first connecting member (first link member).
[0016] In the reduced state of FIG. 2(a), the link plates 41 and 42 are folded so as to substantially overlap. Also, in the extended state of FIG. 2(c), the link plates 41 and 42 are in a straight line. This straight line state can be held by appropriate locking means. The stopper member 60 in FIG. 7 described later is one such locking means.
[0017] The central side ends of the link plates 41 and 42 are connected by an intermediate connecting pin 45 so as to be bendable in the horizontal direction. Also, the opposite ends of the link plates 41 and 42 are connected by connecting pins 43 and 44 to a bracket 10b as a first connecting portion disposed on the tip side of the bogie frame 10 so as to be bendable in the horizontal direction.
[0018] Specifically, as shown in FIGS. 3(b) and (c), the ends on the handle side (base end side) of the pair of bogie frames 10 are connected by a connecting plate 30 in which a pair of long holes 30a are formed. An L-shaped bracket 10a as a second connecting portion is disposed at the end on the handle side (base end side), and connecting pins 31 and 32 inserted into the holes of this bracket 10a are inserted into the long holes 30a of the connecting plate 30. Therefore, the pair of bogie frames 10 are rotatable (rockable) relative to each other in the horizontal direction.
[0019] As shown in FIG. 3(d), a lock pin 33 is fixed (welded) to the side surface of the bogie frame 10 adjacent to the bracket 10a. By this lock pin 33, the rotation of the connecting plate 30 in the arrow direction is locked.
[0020] In other words, when the connecting plate 30 attempts to rotate in the direction of the arrow, the end of the connecting plate 30 comes into contact with the lock pin 33, preventing the connecting plate 30 from rotating any further in the direction of the arrow. Without the lock pin 33, as shown in Figure 4, the connecting plate 30 would swing in the front-to-back direction (up and down direction in Figure 4), making the connection of the bogie frame 10 unstable.
[0021] As shown in Figure 3(e), a cylindrical handle receiver 10d is fixed (welded) to the handle side (base end) of the trolley frame 10. The lower end of the trolley handle 20 is detachably and rotatably inserted into this handle receiver 10d.
[0022] ●Deformed Embodiment 1 Figure 5 shows a modified embodiment 1 in which the handle side (base end side) of the trolley frame 10 is connected by link plates 35 and 36 as second connecting members (second link members), instead of the connecting plate 30 in Figure 3(b).
[0023] The central ends of the link plates 35 and 36 are connected by an intermediate connecting pin 37 so as to be bendable horizontally. The opposite ends of the link plates 35 and 36 are connected by connecting pins 31 and 32 so as to be bend horizontally to a bracket 10b located on the front end of the trolley frame 10.
[0024] In this modified embodiment 1, the handle-side (base end) of the trolley frame 10 can be slightly extended in the left-right direction. Therefore, a large pallet 300, as shown in Figure 1B(b), can be loaded more stably.
[0025] ●Deformed Embodiment 2 Figure 6 shows a modified embodiment 2 in which the handle-side (base end) end of the trolley frame 10 is connected by a connecting shaft 38 as a second connecting member, instead of the connecting plate 30 in Figure 3(b). This connecting shaft 38 is inserted into the holes in the overlapping state of the brackets 10a at the handle-side (base end).
[0026] In this modified embodiment 2, three hinge portions 23 are provided at different heights (upper, middle, and lower) in the middle of the width direction of the trolley handle 20, coaxial with the connecting shaft 38. The lower ends 21a and 22a of the trolley handle 20 are inserted into the handle receiver 10d of the trolley frame 10. By making the left half 21 and the right half 22 of the trolley handle 20 bendable horizontally around the hinge portion 23, the trolley frame 10 can be expanded and contracted in a fan shape without obstruction.
[0027] ● Modified Embodiment 3 Figure 7 shows a modified embodiment 3 in which the bending angles of the link plates 41 and 42 can be fixed in stages by the stopper member 60. The stopper member 60 is a U-shaped metal fitting, and the engaging portions 61 and 62 at both ends are configured to be insertable into the four engaging holes 41a-41d and 42a-42d of the link plates 41 and 42, respectively.
[0028] The four engagement holes 41a-41d and 42a-42d of the link plates 41 and 42 are formed at predetermined intervals in the longitudinal direction of the link plates 41 and 42. Therefore, as shown in Figure 7(a), when the engagement portions 61 and 62 of the stopper member 60 are inserted into the engagement holes 41d and 42d closest to the intermediate connecting pin 45, the pair of left and right trolley frames 10 can be held in a state where they are fanned out at their maximum angle.
[0029] In this state, link plates 41 and 42 are almost in a straight line. When loading a large pallet 300 as shown in Figure 1B(b), it is best to extend the trolley frame 10 to its maximum extent as shown in Figure 7(a).
[0030] Furthermore, as shown in Figure 7(d), by inserting the engaging portions 61 and 62 of the stopper member 60 into the engaging holes 41a and 42a furthest from the intermediate connecting pin 45, the pair of left and right trolley frames 10 can be held in a state where they are expanded to the minimum angle in a fan shape. When loading a narrow container 200 as shown in Figure 1A(b), it is preferable to expand the trolley frame 10 to the minimum extent as shown in Figure 7(d).
[0031] Of course, the pair of left and right trolley frames 10 can also be closed in a nearly parallel state as shown in Figure 6(b). When transporting goods through a narrow passage, they can be extended to the minimum extent as shown in Figure 7(d), or closed in a nearly parallel state as shown in Figure 6(b).
[0032] ● Modified Embodiment 4 Figure 8 shows a modified embodiment 4 in which a pair of left and right trolley frames 10 are connected in an expandable and retractable manner by link plates 41 and 42 as first connecting members (first link members) on the front end side (upper side in Figure 8) and link plates 135 and 136 as second connecting members (second link members) on the handle side (base end side, (lower side in Figure 8)). Figure 8(a) shows the contracted state, Figure 8(b) shows the fan-shaped expanded state, and Figure 8(c) shows the parallel expanded state.
[0033] The lengths of link plates 41 and 42 and link plates 135 and 136 can be the same. Link plates 135 and 136 are connected by an intermediate connecting pin 137 so as to be bendable horizontally.
[0034] Figure 8(b) shows the front-end link plates 41 and 42 extended to their maximum length (in a straight line), while the handle-end (base-end) link plates 135 and 136 are folded. However, it is also possible to reverse this, folding the front-end link plates 41 and 42 and extending the handle-end (base-end) link plates 135 and 136 to their maximum length (in a straight line). Since the handle receivers 10d are fixed (welded) to both longitudinal ends of the trolley frame 10, this method of reversing the extension and contraction is convenient when you want to reverse the front and back of the trolley 100.
[0035] ●Summary Although embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and can be modified in various ways. For example, the elongated rectangular frame shape of the trolley frame 10 described above is merely illustrative, and its width, length, etc., can of course be modified as appropriate. [Explanation of Symbols]
[0036] 10: Bogie frame 10a (second connecting section) 10b: Bracket (first connecting part) 10c: Mounting plate 20: Cart handle 21: Left half 21a: Lower end 22: Right half 22a: Lower end 23: Hinge 30: Connecting plate 30a: Slotted hole 31, 32: Connecting pins 33: Locking pins 35, 36: Link plate 37: Connecting pin 38: Connecting shaft (second connecting member) 41, 42: Link plate (first connecting member, first link member) 41a-41d: Engagement holes 43, 44: Connecting pins 45: Connecting pin 50: Caster 60: Stopper member 61, 62: Engaging part 100: Dolly 135, 136: Link plate (second connecting member, second link member) 137: Connecting pin 200: Container 300: Palette
Claims
1. A pair of left and right bogie frames, each having a first connecting portion at one end in the longitudinal direction and a second connecting portion at the other end in the longitudinal direction, A first connecting member that connects the first connecting portions of the pair of trolley frames to each other, A second connecting member that connects the second connecting portions of the pair of trolley frames to each other, A trolley characterized by having the following features.
2. The first connecting member has a first link member that connects the first connecting portion in a manner that allows it to expand and contract, The second connecting member has a connecting shaft that coaxially connects the second connecting portion. A trolley according to feature 1.
3. The first connecting member has a first link member that connects the first connecting portion in a manner that allows it to expand and contract, The second connecting member has a connecting plate that swingably connects the second connecting portion. A trolley according to feature 1.
4. The first connecting member has a first link member that connects the first connecting portion in a manner that allows it to expand and contract, The second connecting member has a second link member that connects the second connecting portion in a manner that allows it to expand and contract. A trolley according to feature 1.
5. The trolley according to claim 4, characterized in that the first link member is longer than the second link member.
6. The trolley according to claim 4, characterized in that the lengths of the first link member and the second link member are the same.
7. A trolley according to any one of claims 1 to 6, characterized in that a trolley handle is detachably erected at the other longitudinal end of the pair of trolley frames.
8. The trolley according to claim 7, characterized in that a cylindrical handle receiver is fixed to the other longitudinal end of the pair of trolley frames, and the lower end of the trolley handle is rotatably inserted into the handle receiver.
9. The trolley according to claim 2, characterized in that a trolley handle is detachably erected at the other longitudinal end of the pair of trolley frames, and the widthwise intermediate portion of the trolley handle is bendable by a hinge portion arranged coaxially with the connecting shaft.