Trolley

Abstract

To provide a dolly with casters which is made lightweight by using a foamed resin and has sufficient strength for practical use. [Solution] The trolley comprises a foam resin board, an insert nut embedded in the foam resin board and positioned so that the upper end of the head does not protrude beyond the upper surface of the foam resin board and the lower end of the leg does not protrude beyond the underside of the foam resin board, a caster having a mounting seat positioned on the underside of the foam resin board and a wheel rotatably supported via a wheel support portion attached to the mounting seat, and a male screw that screws into the insert nut and fixes the mounting seat to the underside of the foam resin board.

Description

[Technical field]

[0001] The present disclosure relates to a dolly for carrying luggage. [Background technology]

[0002] Conventionally, efforts have been made to achieve both weight reduction and strength for trucks that carry luggage, that is, to alleviate the weakening of the structure that accompanies weight reduction.

[0003] For example, in Patent Document 1, synthetic resin foam is injected into a hollow housing with a top plate surrounded on all sides by hard plate material, heated to foam, filling the hollow part of the housing with the synthetic resin, and then cooled and hardened. The housing filled with the foamed resin is used as a loading platform member, thereby reducing the weight of the trolley base and ensuring its strength. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 7-205994 Summary of the Invention [Problem to be solved by the invention]

[0005] However, Patent Document 1 does not disclose casters or screw holes or other engagement parts for attaching casters on the cabinet with a top plate itself. In order to make the loading platform member of Patent Document 1 function as a cart, it is necessary to set the cabinet with a top plate filled with foamed synthetic resin as a base for carrying luggage on a separately prepared carrier with casters. Such a cart is not easy to use, and the weight of the carrier with casters is a negative factor in reducing the weight.

[0006] Furthermore, the case with a top plate disclosed in Patent Document 1 is formed by injecting a foamable synthetic resin into the case, heating it to foam, filling the hollow part of the case with the foamable synthetic resin, and then cooling and hardening it. This process requires equipment for mixing the foamable synthetic resin, an apparatus for injecting the foamable synthetic resin, a relatively large heat treatment furnace capable of precise temperature control, and the like, which poses a problem in terms of manufacturing costs, requiring a relatively large capital investment.

[0007] In addition, in the above-mentioned process, when the foamed synthetic resin that is heated and foamed inside the housing and fills the housing at a relatively high temperature is cooled and hardened, the foamed synthetic resin shrinks, causing separation between the inner wall surface of the housing and the surface of the foamed synthetic resin, and it is inevitable that some degree of voids will be generated. This reduces the force with which the foamed synthetic resin supports the housing from the inside, and has a negative effect on the strength of the housing as a whole. There is also the problem that it is difficult to perform non-destructive testing to check for the presence and extent of such voids inside the housing and to remove low-quality products during product shipping inspection, etc.

[0008] In view of the above, an object of the present disclosure is to provide a cart with casters that is lightweight due to the use of foamed resin and has sufficient strength for practical use. [Means for solving the problem]

[0009] The trolley of the first embodiment comprises a foam resin board, an insert nut embedded in the foam resin board and positioned so that the upper end of its head does not protrude beyond the upper surface of the foam resin board and the lower end of its leg does not protrude beyond the underside of the foam resin board, a caster having a mounting seat arranged on the underside of the foam resin board and a wheel rotatably supported via a wheel support portion attached to the mounting seat, and a male screw that screws into the insert nut and fixes the mounting seat to the underside of the foam resin board. Effect of the Invention

[0010] According to the present disclosure, it is possible to provide a cart with casters that is lightweight and has sufficient strength for practical use. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1(A) is a front view illustrating a dolly according to a first embodiment, and FIG. 1(B) is a bottom view illustrating the dolly. [Diagram 2] FIG. 2 is a partial cross-sectional view taken along the line S2-S2 of FIG. [Diagram 3] FIG. 2 is an exploded cross-sectional view of an insert nut and a male screw that are applied to the bogie according to the first embodiment. [Figure 4] Fig. 4(A) is a plan view explaining that the dolly according to the first embodiment can move in the depth direction, Fig. 4(B) is a plan view showing a state in which the dolly is rotated 45° clockwise with respect to Fig. 4(A), and Fig. 4(C) is a plan view explaining that the dolly can move in the width direction with a further rotation of 45° clockwise with respect to Fig. 4(B). [Diagram 5] FIG. 2 is a side view illustrating a method for transporting a cart according to the first embodiment. [Figure 6] 10 is a partial cross-sectional view illustrating a bogie according to a second embodiment taken from a viewpoint corresponding to that of FIG. 2. [Figure 7] FIG. 11 is a side view illustrating the carriage according to the third embodiment. [Figure 8] FIG. 11 is a top perspective view showing a state in which the handle is detached from the dolly according to the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an example of an embodiment of the technology of the present disclosure will be described with reference to the drawings. In each drawing, the same components and parts are given the same reference numerals. In addition, the dimensional ratios of the drawings are exaggerated for the convenience of explanation and may differ from the actual ratios.

[0013] Arrow D in the figure indicates the length direction (depth direction) of the platform of the dolly, and arrow W indicates the width direction (width direction) of the platform of the dolly. Arrow H indicates the vertical direction, which is the up-down direction of the dolly in an orientation in which the depth and width directions are horizontal. The depth, width, and up-down directions are mutually perpendicular. In this specification, the above directions are used for explanation, but the orientation of the dolly is not limited to these directions.

[0014] <Configuration of the First Embodiment> 1(A) and (B), the dolly 10 according to this embodiment is a dolly with casters attached to a plate, a so-called flatbed hand truck. The dolly 10 can run on a floor surface GR with a load placed on the loading surface. The dolly 10 has a foam resin board 20, an insert nut 30, a caster 40, and a male screw 50.

[0015] (Foam resin board) The foamed resin board 20 is a rectangular board with both the length in the depth direction and the length in the width direction being L. The planar shape of the foamed resin board 20 is not limited to a rectangle with the same length in the depth direction and the width direction, and may be any shape with different lengths in the depth direction and the width direction, as long as it has a required luggage loading surface. The board thickness of the foamed resin board 20 is T. The foamed resin board 20 is formed of foamed resin and functions as a loading platform for the dolly 10. The foamed resin board 20 is, for example, polystyrene foam with an expansion ratio of about 60 times. The foamed resin board 20 includes a loading surface protection sheet 22, a back protection sheet 24, and an embedded portion 26. The loading surface protection sheet 22 and the back protection sheet 24 are examples of thin-film-like protection portions.

[0016] ((Protection Department)) 2, the loading surface protection sheet 22 and the back surface protection sheet 24 are attached to the loading surface side surface layer portion 20H and the back surface side surface layer portion 20T opposite the loading surface side surface layer portion 20H of the foamed resin board 20. In this embodiment, the loading surface protection sheet 22 and the back surface protection sheet 24 are both PVC sheets having a thickness T2 in order to impart water resistance, acid resistance, alkali resistance, or solvent resistance.

[0017] The loading surface protective sheet 22 and the back surface protective sheet 24 as the protective part are not limited to PVC sheets. For example, the foamed resin board 20 may be immersed in a coating liquid or sprayed with a coating liquid to form a coating film on the foamed resin board 20, and then dried to form the protective part. In addition, the loading surface side surface layer 20H or the back surface side surface layer 20T of the foamed resin board 20 may be heated and melted and then solidified to form a hard metamorphic layer as the protective part. Furthermore, the loading surface protective sheet 22 and the back surface protective sheet 24 as the protective part may be attached not only to the loading surface and its back surface, but also to the entire circumference of the foamed resin board 20 or to a part of it. In the present invention, it is desirable to provide a protective part, but is not essential. For example, when the foamed resin board 20 has a low expansion ratio and is made of a relatively robust material, when the dolly is used to transport relatively light luggage, and there is little risk of the surface being damaged by impact when loading and unloading the luggage, the protective part can be omitted.

[0018] ((embedded part)) 2, the embedded portion 26 is a stepped opening that penetrates from the loading surface side surface layer portion 20H to the back surface side surface layer portion 20T of the foamed resin board 20 in the up-down direction. A plurality of embedded portions 26 are provided in the foamed resin board 20. The embedded portion 26 has a stepped surface 26A facing upward on the loading surface side surface layer portion 20H side.

[0019] (insert nut) As shown in FIG. 2, the insert nut 30 is a stepped nut embedded in the embedding portion 26 of the foamed resin board 20 from the loading surface side surface layer 20H side toward the rear surface layer 20T on the opposite side. The insert nut 30 is formed slightly smaller in the width direction and depth direction than the embedding portion 26. In addition, the insert nut 30 is embedded in the embedding portion 26, and the gap GP between the insert nut 30 and the foamed resin board 20 is filled with adhesive B. That is, the insert nut 30 is bonded to the foamed resin board 20 with adhesive B. In the present invention, it is preferable to use adhesive B, but it is not essential.

[0020] A plurality of insert nuts 30 are provided corresponding to the embedded portions 26. Specifically, the insert nuts 30 are provided corresponding to the mounting positions of the casters 40 described later.

[0021] As shown in FIG. 3, the insert nut 30 includes a head portion 32, a leg portion 34, and a female thread portion 36.

[0022] ((head)) The head 32 is a cylindrical shape with a bottom that extends in the vertical direction and opens downward. The head 32 is located on the loading surface side surface layer portion 20H side and functions as the head of the insert nut 30 (see FIG. 2). The head 32 is a portion on the loading surface side surface layer portion 20H side of the step surface 26A of the embedding portion 26. The upper end 32A (see FIG. 2) of the head 32 is located so as not to protrude beyond the loading surface protective sheet 22 of the foamed resin board 20. More specifically, the upper end 32A is located so as not to protrude beyond the loading surface side surface layer portion 20H of the foamed resin board 20. In addition, the upper end 32A is flat.

[0023] The upper end 32A does not necessarily have to be flat, and may have any shape, such as a hemispherical (dome-like) shape. In this case, if there is a gap between the upper end 32A and the loading surface side surface layer portion 20H or the loading surface protection sheet 22 in the embedded portion 26, the gap may be filled with another member.

[0024] ((leg)) The leg 34 is cylindrical and extends in the vertical direction, and is formed integrally with the head 32 so that the head 32 is located above the leg 34. The leg 34 and the head 32 share a central axis along the vertical direction. The outer diameter of the leg 34 is smaller than the outer diameter of the head 32. That is, the boundary portion between the leg 34 and the head 32 (the peripheral portion of the step surface 26A of the embedding portion 26 in the foamed resin board 20) appears as a stepped shape of the insert nut 30, and the head 32 has a larger diameter than the leg 34. The lower end 34A (see FIG. 2) of the leg 34 is positioned so as not to protrude from the rear protective sheet 24 of the foamed resin board 20. More specifically, the lower end 34A is positioned so as not to protrude from the rear surface layer portion 20T of the foamed resin board 20. The lower end 34A is also flat.

[0025] It should be noted that the lower end 34A does not necessarily have to be flat, and for example, the outer periphery may be chamfered.

[0026] ((female thread part)) 3, the female thread portion 36 is a thread formed on the cylindrical inner peripheral surfaces of the head 32 and the leg portion 34 from the lower end 34A of the leg portion 34 toward the upper end 32A of the head 32. The female thread portion 36 shares a central axis along the up-down direction with the leg portion 34 and the head 32. The length of the female thread portion 36 in the up-down direction (the depth from the lower end 34A to the bottom surface 36A) is designated as DI.

[0027] (caster) 2, a plurality of casters 40 are arranged on the back (lower) side of the foam resin board 20, and have the function of enabling the movement of the foam resin board 20. In this embodiment, as shown in FIG 1(B), a total of five casters 40 are arranged, including a mixture of two types of casters 40: swivel casters 40A arranged at the four corners CN1 of the foam resin board 20, and fixed casters 40B arranged at the center CN2 of the foam resin board 20.

[0028] The number of casters 40 is not limited to five. For example, the number of casters 40 may be six or more in order to improve the load-bearing performance by shortening the distance between the casters 40. The number of casters 40 may be three or four as long as the casters can bear the load of the foamed resin board 20 and the luggage LD (see FIG. 5) and function as the dolly 10. The material of the casters 40 may be either metal or resin.

[0029] The caster 40 includes a mounting base 42 , a wheel support portion 44 , and a wheel 46 .

[0030] ((Mounting base)) As shown in FIG. 2, the mounting seat 42 is a flat plate-like member having a thickness T1 and a plurality of screw holes 42H extending vertically and penetrating therethrough. The mounting seat 42 is disposed so as to include the gap GP between the foamed resin board 20 and the insert nut 30 on the inside of the outer edge of the mounting seat 42. The mounting seat 42 is disposed above the caster 40 and on the rear (lower) side of the foamed resin board 20. In this embodiment, the mounting seat 42 is disposed on the lower surface of the rear protective sheet 24. The screw holes 42H are through holes through which male screws 50, which will be described later, are inserted, and are formed in the mounting seat 42 in accordance with the number and positions of the insert nuts 30. In this embodiment, four screw holes 42H are formed in each mounting seat 42.

[0031] ((wheel support part)) As shown in Fig. 2, the wheel support part 44 is attached to the mounting seat 42 and supports the wheels described below. In this embodiment, the wheel support part 44 corresponding to the swivel caster 40A has two rotation axes: a vertical rotation axis that determines the direction of travel of the cart 10 on the floor surface GR (a rotation axis that determines a rotation angle θ that indicates the orientation of the caster based on the depth direction in Fig. 1), and a horizontal rotation axis that allows the cart 10 to move forward and backward. The rotation angle θ can be in the range of 0° to 360°. The wheel support part 44 corresponding to the fixed caster 40B has one horizontal rotation axis that allows the cart 10 to move forward and backward along the horizontal direction perpendicular to the vertical direction.

[0032] ((wheel)) The wheel 46 is disk-shaped and rotatably supported via the wheel support portion 44 .

[0033] As a result, the casters 40 enable the selection of the direction in which the cart 10 travels and allows it to move forward and backward.

[0034] (Male thread) 3, the male screw 50 has a head length DB. The male screw 50 is inserted into the screw hole 42H of the mounting seat 42 and threadedly engages with the insert nut 30. The mounting seat 42 is fixed to the rear (lower) surface of the foamed resin board 20 in an upward position, thereby attaching the caster 40 to the foamed resin board 20.

[0035] 2, in a state in which the male screw 50 fixes the mounting seat 42, the male screw 50 is screwed into the insert nut 30 by a length DH. In other words, a gap DS is formed in the vertical direction between the tip 50A of the male screw 50 and the bottom surface 36A of the female screw portion 36 as a space to absorb dimensional errors in the vertical direction of each member.

[0036] The bogie 10 is constructed as described above.

[0037] <Effects of the First Embodiment> The effects of this embodiment will be described with reference to a comparative example.

[0038] (1) Although there have been proposals to utilize the light weight of foamed resin for the purpose of weight reduction, foamed resin has a relatively fragile nature compared to metal, wood, etc. When casters are directly attached to a foamed resin body using the conventional caster attachment method, the area around the attachment base is easily damaged by external forces such as impacts that are continuously transmitted from the casters during operation of the trolley. Therefore, as shown in Patent Document 1, for example, when viewed from the perspective of the entire trolley structure, the areas where foamed resin can be used are limited. Even when foamed resin is used in a trolley, the only proposals made so far have been to surround the periphery with a separate, hard, and relatively heavy member that is resistant to impacts, etc., to reinforce the structure.

[0039] The trolley 10 of this embodiment has a foam resin board 20, an insert nut 30 that is embedded in the foam resin board 20 and is positioned so that the upper end 32A of the head 32 does not protrude beyond the loading surface side surface layer 20H of the foam resin board 20 and the lower end 34A of the leg 34 does not protrude beyond the rear side surface layer 20T of the foam resin board 20, a mounting seat 42 that is positioned on the rear side surface layer 20T side of the foam resin board 20, a caster 40 that has a wheel 46 that is rotatably supported via a wheel support portion 44 attached to the mounting seat 42, and a male screw 50 that screws into the insert nut 30 and fixes the mounting seat 42 to the rear side surface layer 20T side of the foam resin board 20.

[0040] An insert nut 30 is embedded in the foamed resin board 20, and an upper end 32A of a head 32 is located on the loading surface side surface layer 20H of the foamed resin board 20, and a lower end 34A of a leg 34 is located on the back surface side surface layer 20T of the foamed resin board 20. Then, the load of the luggage LD placed on the foamed resin board 20 is transmitted through the insert nut 30 to the wheel support portion 44 of the caster 40 arranged on the back surface side surface layer 20T side of the foamed resin board 20, and further transmitted through the wheel 46 to the floor surface GR on which the dolly 10 moves. Therefore, the use of the foamed resin board 20 reduces the weight of the dolly 10, and even if the strength of the foamed resin board 20 is low, the strength of the dolly 10 can be increased by transmitting the load to the caster 40 through the insert nut 30.

[0041] (2) In the dolly 10 according to this embodiment, the head 32 of the insert nut 30 has a larger diameter than the leg 34. This makes it possible to prevent the insert nut 30 embedded in the foam resin board 20 from shifting in the vertical direction.

[0042] More specifically, in the dolly 10 according to this embodiment, the mounting seat 42 of the caster 40 is fixed by abutting against the back surface (lower surface) of the foam resin board 20. In order to fix the mounting seat 42 to the back surface (lower surface) of the foam resin board 20, a male screw 50 is inserted into the screw hole 42H of the mounting seat 42 and screwed into the female threaded portion 36 of the insert nut 30, and the mounting seat 42 is pressed by the bottom surface of the head of the male screw 50 until it abuts (seats) against the back surface (lower surface) of the foam resin board 20. Then, the male screw 50 is further screwed in, drawing the insert nut 30 toward the mounting seat 42, until the lower surface 32B of the head 32 of the insert nut 30 is pressed against the foam resin board 20. When the caster 40 abuts (seats) against the step surface 26A of the embedded portion 26, and a constant torque is applied in the direction of further screwing the male screw 50, a tensile force is applied that stretches the screw in the vertical direction, slightly stretching the screw, and this restoring force acts as a fastening force between the underside 32B of the head 32 of the insert nut 30 and the bottom surface of the head of the male screw 50, firmly fixing the foamed resin portion sandwiched between them and the mounting seat 42, thereby firmly fixing the caster 40 to the foamed resin board 20.

[0043] (3) In the dolly 10 according to this embodiment, the gap GP between the foamed resin board 20 and the insert nut 30 is filled with adhesive B, but in the present invention, as long as the insert nut 30 has a size and shape that allows it to be inserted into the embedding portion 26, neither the gap GB nor the adhesive B that fills it is essential. If the gap GP between the foamed resin board 20 and the insert nut 30 is not filled with adhesive B, the pressing force of the luggage LD acting on the foamed resin board 20 is not transmitted to the insert nut 30, but is directly received by the mounting seat 42 of the lower caster 40, and is transmitted to the floor surface GR on which the wheel 46 is grounded. For this reason, all of the pressing force of the luggage LD acts as a vertical compression force on the foamed resin board 20. In addition, an upward reaction force acts on the caster 40 side from the grounding point of the caster 40, but this reaction force is transmitted to the underside of the foamed resin board 20 via the mounting seat 42, and is finally transmitted to the bottom surface of the luggage LD to support the luggage. Furthermore, when the gap GP is not filled with adhesive B, the insert nut 30 is simply inserted into the embedding portion 26 and embedded. However, when the male screw 50 is attached, the step surface 26A of the embedding portion 26 abuts against the underside 32B of the head 32 of the insert nut 30, and the fastening force of the male screw 50 fixes the insert nut 30 to the foam resin board 20, thereby preventing the entire insert nut 30 from shifting upward.

[0044] On the other hand, when the gap GP between the foamed resin board 20 and the insert nut 30 is filled with adhesive B and firmly bonded, as in the trolley 10 of this embodiment, even if vertical vibrations are transmitted from the floor surface GR to the wheels 46 in addition to the reaction force of the pressing force from the luggage LD during movement of the trolley 10, the embedded position of the insert nut 30 is further prevented from shifting, and the compressive strength of the foamed resin board 20 is also improved.

[0045] More specifically, when the cargo LD is loaded on the dolly 10, the foam resin board 20 is pressed by the cargo LD. Since the entire opposing surfaces of the foam resin board 20 and the insert nut 30 are bonded and integrated with the adhesive B filled in the gap GP, the pressing force is shared by the foam resin board 20 and the insert nut 30, and the insert nut 30 is further prevented from shifting relative to the foam resin board 20. In addition, the pressing force by the cargo LD is shared by the insert nut, which has a relatively large compressive strength, and the vertical compressive force acting on the foam resin board 20 is reduced, so that the apparent compressive strength of the foam resin dolly 10 is improved compared to when the adhesive B is not used. Therefore, the above-mentioned effects are achieved.

[0046] (4) In the dolly 10 according to this embodiment, the casters 40 are disposed at the four corners CN1 and the center CN2 of the foamed resin board 20. By disposing the casters 40 at the center CN2 of the foamed resin board 20, the load acting on the foamed resin board 20 is shared by the casters 40 disposed at the center CN2, compared to a case in which the casters 40 are not disposed at the center CN2. This reduces the load on each caster 40, and halves the diagonal distance, which was the longest distance between the casters 40. This reduces the downward deflection of the foamed resin board 20 due to the load, improving the load resistance. In addition, by making the casters 40 disposed at the center CN2 fixed casters 40B and the casters 40 disposed at the four corners CN1 swivel casters 40A, the dolly 10 can be rotated around the fixed casters 40B as a rotation center to transport luggage in a desired direction even in a narrow space such as a truck bed.

[0047] More details will be described with reference to FIG. 4. FIG. 4(A) is a plan view explaining that the dolly 10 according to the first embodiment is movable in the depth direction, and FIG. 4(B) is a plan view showing a state in which the dolly 10 is rotated 45° clockwise with respect to FIG. 4(A). FIG. 4(C) is a plan view explaining that the dolly 10 is movable in the width direction with a further rotation of 45° clockwise with respect to FIG. 4(B). By making the center part CN2 a fixed caster 40B with a restricted rotation direction, it is possible to pivot (spin) at that position without moving the dolly 10 by taking advantage of the difficulty of the fixed caster 40B to move. When such pivot rotation is performed, sliding occurs in the rotational direction at the contact point of the wheel 46 of the fixed caster 40B. However, since the contact area at the contact point of the wheel is generally small, the sliding resistance is also relatively small, and in practice this sliding resistance does not hinder the operation of the trolley 10. Furthermore, in order to prevent the contact point of the wheel 46 from getting caught in unevenness in the floor surface when pivot rotation is performed, the rotation can be performed more smoothly by applying a slight back and forth movement to the trolley 10 while rotating.

[0048] In terms of supporting the load of the luggage LD, the dolly 10 supports the load by dividing it among the number of casters 40, with the ground contact point of the caster 40 in contact with the loading platform floor surface FL (see FIG. 5) as a fulcrum. The load supported by each caster 40 is divided in magnitude inversely proportional to the vertical distance between the center of gravity of the luggage LD and the ground contact point of the caster 40 (i.e., the caster 40 closer to the luggage supports more load), and if there are multiple luggage LD, each caster 40 supports a load that is the sum of the divided loads of each luggage LD.

[0049] (5) In the dolly 10 according to this embodiment, the foamed resin board 20 is provided with a loading surface protective sheet 22 and a rear surface protective sheet 24 at least on the loading surface side surface layer portion 20H and the rear surface side surface layer portion 20T. This makes the foamed resin board 20 less susceptible to damage caused by the baggage LD itself or by stones (chipping) from the floor surface GR.

[0050] (6) For example, it is conceivable that the caster 40 may repeatedly collide with and overcome the unevenness of the floor surface GR. In such a situation, the impact may cause a vibrational movement of the caster 40 that shakes the caster 40 in the horizontal and vertical directions, and a force that tries to peel the mounting base 42 off the foam resin board 20 or a force that tries to pull out the fixing screw may act.

[0051] When the mounting base 42 is directly screwed to the underside of the foam resin board 20, the force of shaking the screw horizontally or vertically will cause the screw to be screwed directly into the relatively fragile foam resin board 20, and since the sharp threads will be in contact with the foam resin board 20, the screw may relatively easily fall out and the caster 40 may become detached.

[0052] On the other hand, in the dolly 10 according to this embodiment, the male screw 50 is screwed into the insert nut 30 extending in the thickness T direction of the foamed resin board 20 to fix the mounting seat 42. As a result, even if a shaking force acts on the male screw 50 in the horizontal or vertical direction, the sharp thread of the male screw 50 does not directly contact the foamed resin board 20. In addition, since the insert nut 30 extends to a deep position of the foamed resin board 20 (a position close to the surface layer portion 20H on the loading surface side), the horizontal or vertical shaking force acting on the male screw 50 is received three-dimensionally by the entire relatively wide and smooth contact surface between the insert nut 30 and the foamed resin board 20, and the force transmitted to the foamed resin board 20 is dispersed and reduced, so that a caster mounting strength sufficient for practical use is obtained.

[0053] (7) Also, as shown in FIG. 5(A), when the dolly 10 according to this embodiment is carried with the baggage LD placed on the pallet PL and brought into the box-shaped loading platform SP of a vehicle (not shown), the dolly 10 is light-weighted and does not impose a large burden on the allowable load weight of the vehicle. Therefore, the baggage LD placed on the pallet PL can be transported by the vehicle without being unloaded from the dolly 10 onto the loading platform SP, which is helpful in improving work efficiency. Also, as shown in FIG. 5(B), even when the baggage LD placed on the pallet PL is loaded onto the loading platform floor surface FL of the loading platform SP, the lightweight dolly 10 can be carried relatively easily by the worker, and can be easily stored and carried in the gap between the wall surface SW of the loading platform SP and the baggage LD. By carrying it in this way, the dolly 10 brought with it can be used at the destination where there is no transportation means such as a dolly or a forklift, which is helpful in improving work efficiency. It is optional whether the dolly 10 is used in FIG. 5(A) or FIG. 5(B).

[0054] <Modification of the first embodiment> In the above-mentioned first embodiment, the loading surface side surface layer portion 20H, the rear side surface layer portion 20T, the loading surface protection sheet 22, and the rear protection sheet 24 of the foamed resin board 20 are flat surfaces, but are not limited thereto. For example, the loading surface side surface layer portion 20H, the rear side surface layer portion 20T, the loading surface protection sheet 22, and the rear protection sheet 24 may have small uneven portions (dimples) formed on the entire surface or in places of the surface that contacts the luggage LD. As a result, for example, when the luggage LD is packed in a manner that may cause it to slide on the dolly 10, an appropriate frictional force acts between the luggage LD and the luggage LD.

[0055] <Second embodiment> Next, a dolly 210 according to a second embodiment will be described with reference to Fig. 6. The dolly 210 according to the second embodiment is basically the same as the dolly 10 according to the first embodiment, and a description of the common configuration will be omitted. Specifically, the dolly 210 differs from the dolly 10 in the mounting structure of the casters 40 to the foam resin board 220.

[0056] The dolly 210 includes a foam resin board 220, a reinforcing plate 260, casters 40, and male screws 250. Note that a description of the casters 40 will be omitted.

[0057] (Foam resin board) The foamed resin board 220 is a board formed of foamed resin having a board thickness t. The foamed resin board 220 includes a loading surface protection sheet 222 and a back surface protection sheet 224.

[0058] (Reinforcing plate) The reinforcing plate 260 is a plate disposed between the foamed resin board 220 and the caster 40. Specifically, the reinforcing plate 260 is a hard resin plate attached to the lower surface of the rear protective sheet 224 of the foamed resin board 220, and has a female screw hole 262 at least on the lower surface side. In this embodiment, as shown in FIG. 6, the female screw hole 262 is provided in the reinforcing plate 260 as a through hole in the plate thickness direction, but the female screw is formed only on the lower side in the plate thickness direction, and the female screw is not formed on the upper side in the plate thickness direction, and the plate has a size and shape such that a gap remains in the upper part in the plate thickness direction when the male screw 250 is screwed. Note that in the present invention, the female screw hole provided in the reinforcing plate is not limited to this, and the female screw may be formed over the entire length of the female screw hole, and may be a long hole of a required depth having an opening on the lower side instead of a through hole. The reinforcing plate 260 is also bonded to the lower surface of the foamed resin board 220 with an adhesive not shown.

[0059] In this embodiment, the reinforcing plate 260 is adhered to the foam resin board 220, but the present invention is not limited to this. For example, the reinforcing plate 260 may be attached to the foam resin board 220 by welding, screwing, or other attachment methods.

[0060] Furthermore, the mounting seats 42 of the casters 40 are disposed on the lower surface of the reinforcing plate 260. In other words, the reinforcing plate 260 is sandwiched between the foam resin board 220 and the mounting seats 42.

[0061] The reinforcing plate 260 is disposed on the underside of the foam resin board 220 in accordance with the location where the caster 40 is attached.

[0062] (Male thread) The male screws 250 screw into the female screw holes 262 of the reinforcing plate 260 to fix the mounting seats 42 of the casters 40 to the underside of the reinforcing plate 260. The number of male screws 250 corresponds to the number of female screw holes 262. When the male screws 250 screw into the female screw holes 262, a gap is formed between the male screws 250 and the foamed resin board 220. As the male screws 250, well-known male screws may be used.

[0063] <Effects of the Second Embodiment> The cart 210 of this embodiment has a foamed resin board 220, a reinforcing plate 260 attached to the underside of the foamed resin board 220 and having a female screw hole 262 provided on at least the underside, a mounting seat 42 arranged on the underside of the foamed resin board 220, a caster 40 equipped with a wheel 46 rotatably supported via a wheel support portion 44 attached to the mounting seat 42, and a male screw 250 that screws into the female screw hole 262 and fixes the mounting seat 42 to the underside of the reinforcing plate 260.

[0064] As a result, the cart 210 can provide a cart with a simpler structure and lower manufacturing costs in addition to the effects of the cart 10 according to the first embodiment.

[0065] <Third embodiment> Next, a dolly 310 according to a third embodiment will be described with reference to Figs. 7 and 8. The dolly 310 according to the third embodiment is basically the same as the dolly 10 according to the first embodiment, and a description of the common configuration will be omitted. Specifically, the dolly 310 has a structure in which a handle 370 is attached to the dolly 10. Note that the handle 370 described in this embodiment can also be attached to the dolly 210 according to the second embodiment.

[0066] 7, the cart 310 is operated by an operator OP with a baggage LD placed on a foam resin board 320. The cart 310 is movable on a floor surface GR by casters 40. The cart 310 is a so-called one-arm hand truck.

[0067] (Foam resin board) 8, the cart 310 includes a foamed resin board 320. On a side surface 320S of the foamed resin board 320, oblong holes 322 each having a circular cross section are formed so as to be spaced apart from each other by a distance IN in the width direction.

[0068] Although the oblong hole 322 is formed on one side surface 320S in the depth direction, this is not limited thereto. For example, the oblong hole 322 may be formed on the other side surface or on all side surfaces. Also, although the oblong hole 322 has a circular cross-sectional shape, this is not limited thereto in the present invention, and the cross-sectional shape may be, for example, an ellipse, a rectangle, a polygon, or any other arbitrary shape.

[0069] (Cylindrical member) As shown in FIG. 8, the tubular member 360 is a hollow tube that is embedded along the long hole 322 from the side surface 320S of the foamed resin board 320 toward the inside. The tubular member 360 is embedded with its outer wall surface in close contact with the inner wall surface of the long hole 322. The tubular member 360 is positioned so that its outer end surface is flush with the side surface 320S when embedded in the long hole 322 of the foamed resin board 320. The outer periphery of the cross section of the tubular member 360 according to this embodiment is circular to match the cross-sectional shape of the long hole 322, but the present invention is not limited to this, and may be, for example, an elliptical, rectangular, polygonal, or other arbitrary cross-sectional shape depending on the cross-sectional shape of the long hole provided in the side surface of the foamed resin board. The inner periphery of the cross section of the tubular member 360 is also circular, but the present invention is not limited to this, and may be, for example, an elliptical, rectangular, polygonal, or other arbitrary cross-sectional shape.

[0070] (handle) As shown in Fig. 8, handle 370 has a torii gate shape when viewed from the depth direction, and is an operating part that is detachable from side surface 320S of foam resin board 320. In Fig. 8, handle 370 shown by dashed lines shows a state in which it is attached to foam resin board 320, and handle 370 shown by solid lines shows a state in which it has been detached from foam resin board 320. Handle 370 includes anchor portion 372 and grip portion 374.

[0071] The anchor portion 372 is a pair of cylinders extending in the depth direction, disposed at the lower portion of the handle 370, and spaced apart by a distance IN in the width direction. One end of the anchor portion 372 can be inserted into the inside of the tubular member 360. The anchor portion 372 transmits the operating force of the operator to the foamed resin board 320. Note that the outer periphery of the cross section of the anchor portion 372 according to the present embodiment is circular in accordance with the shape of the inner periphery of the cross section of the tubular member 360, but the present invention is not limited to this, and may be, for example, an elliptical, rectangular, polygonal, or any other cross-sectional shape according to the shape of the inner periphery of the cross section of the tubular member. Also, the anchor portion 372 is a hollow cylinder for weight reduction, but the present invention is not limited to this, and may be a solid rod-shaped member.

[0072] The gripping portion 374 is formed in a torii gate shape when viewed from the depth direction. Specifically, the gripping portion 374 includes a columnar portion 374A and a grip 374B. The columnar portion 374A is a columnar body along the up-down direction, and stands up from the front end portion of the pair of anchor portions 372 in the depth direction while being spaced apart from each other by a distance IN in the width direction. The grip 374B is a rod-shaped body located at the top of the gripping portion 374, and is a member that connects the upper ends of the pair of columnar portions 374A in the width direction, and is gripped by the operator OP.

[0073] The grip 374 according to this embodiment is formed in a torii-shape, but the present invention is not limited to this. For example, the grip of the grip may be formed in an arch shape, or the upper ends of the pair of columnar parts may not be connected in the width direction, but the upper ends of each columnar part may be bent toward the front in the depth direction, and the bent parts may be used as the grip. The grip 374B of the grip 374 is a rod-shaped body, but can be modified in various ways as long as it is easy for the operator OP to grasp. The anchor part 372 and the columnar part 374A of the grip 374 according to this embodiment are each formed as a pair, but the present invention is not limited to this. They may be one anchor part and one columnar part standing up from it.

[0074] <Effects of the Third Embodiment> The cart 310 according to this embodiment has a hollow tubular member 360 embedded in a long hole 322 extending inward from a side surface 320S of a foamed resin board 320, and a handle 370 having an anchor portion 372 at one end which can be inserted into the tubular member 360 and a gripping portion 374 which rises from the other end of the anchor portion 372 and can be gripped by an operator OP at the top.

[0075] As a result, in addition to the effects of the cart 10 according to the first embodiment, by providing the handle 370, it is possible to provide the cart 310 with good operability.

[0076] Further, the slot 322 may be formed on a plurality of side surfaces of the foamed resin board 320, for example, the slot 322 may be formed on the other side surface or on all the side surfaces. In this case, the traveling direction of the cart 310 can be changed without moving the cart 310 by simply removing the handle 370 and inserting it into the cylindrical member 360 on the other side surface 320S.

[0077] In addition, the present disclosure may be configured by partially combining the configurations illustrated in the attached drawings. As described above, the present disclosure includes various embodiments not described above, and the technical scope of the present disclosure is defined only by the invention-specifying matters in the claims that are appropriate from the above description. [Explanation of symbols]

[0078] 10 Carts 20. Foam resin board 20H Loading surface side surface 20T Rear surface layer 22 Loading surface protection sheet 24 Rear protection sheet 26 Embedded part 26A Step surface 30 Insert nut 32 Head 32A top end 32B Bottom surface 34 Legs 34A bottom end 36 Female thread 36A Bottom 40 Caster 40A Swivel Caster 40B Fixed caster 42 Mounting seat 42H screw hole 44 Wheel support part 46 wheels 50 Male thread 50A tip 210 Trolley 220 Foam resin board 222 Loading surface protection sheet 224 Rear protection sheet 250 Male thread 260 Reinforcement plate 262 Female thread hole 310 Trolley 320 Foam resin board 320S side 322 Slot 360 Cylinder Part 360 Slot 370 Handle 372 Anchor section 374 Gripping part 374A Column 374B Grip θ Rotation angle B. Adhesive CN1 Four corners CN2 central part DS Gap FL Cargo floor surface GP Gap GR floor surface IN Distance OP Operator PL Palette SP Cargo Bed SW Wall LD Baggage t Plate thickness

Claims

1. One foam board, An insert nut embedded in the foamed resin board, with the upper end of a bottomed cylindrical head portion located on the surface layer portion of the loading surface side of the foamed resin board, and the lower end of a cylindrical leg portion having an outer diameter smaller than that of the head portion located on the surface layer portion of the back surface side of the foamed resin board; A caster including a mounting seat arranged on a lower surface of the foamed resin board, to which a load is transmitted from a lower end of the leg of the insert nut, and a wheel rotatably supported via a wheel support portion attached to the mounting seat; A male screw that is screwed into the insert nut and fixes the mounting seat to the lower surface side of the foam resin board and the lower end of the leg portion; A trolley having the above structure.

2. The insert nut is embedded in the foam resin board and adhered with an adhesive. The dolly according to claim 1 .

3. The casters are arranged at the four corners and the center of the foam resin board. The dolly according to claim 1 .

4. The foamed resin board has a thin film protective portion on at least the upper and lower surfaces. The dolly according to claim 1 .

5. A hollow cylindrical member embedded in the foamed resin board from a side surface toward the inside of the board; a handle having an anchor portion, one end of which can be inserted into the cylindrical member, and a grip portion, which rises from the other end of the anchor portion and can be gripped by an operator; 2. The dolly of claim 1, comprising:

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