Casters and transport carts

Abstract

To provide a caster and a transport carriage capable of preventing deformation and breakage of the caster in the case of transporting by a forklift truck.SOLUTION: A caster 20 includes: a wheel 21; a support part 25 for rotatably supporting the wheel 21; and a brake pedal 35 supported swingably in a vertical direction relative to the support part 25, and directly or indirectly applying braking to the wheel 21. The brake pedal 35 has an operation piece 35b whose vertical swinging is operated by a user. The operation piece 35b is arranged in a position to be overlapped on the wheel 21 when viewed from the traveling direction of the wheel 21, and is inclined in an upper direction as the undersurface goes to the tip in a state that the break is released when viewed from a direction orthogonal to the traveling direction of the wheel 21.SELECTED DRAWING: Figure 11

Description

Technical Field

[0001] The present invention relates to a caster and a transport cart.

Background Art

[0002] Among casters used for transport carts and the like, there are casters with brakes. The caster with a brake used for the transport cart of Patent Document 1 has a yoke, a wheel, a brake shoe, and a brake pedal. The brake pedal of the caster with a brake extends beyond the outer shape of the wheel so that it is easy for the user to operate with the foot. When the user steps on the brake pedal with the foot, the brake pedal is pushed down, and the brake shoe presses the wheel to fix the wheel. On the other hand, when the user pushes up the brake pedal with the foot, the pressing of the wheel by the brake shoe is released, and the wheel rotates freely.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present invention To enable more effective braking aims to

Means for Solving the Problems

[0006] The caster of the present invention includes a wheel, a fork member that rotatably supports the wheel via an axle, a pedal holding member that is fixed to the fork member and has a pair of side walls and a connecting plate that connects the pair of side walls, and is swingably supported with respect to the pedal holding member, and is provided on the wheel betweenA caster comprising a brake pedal that applies the brakes indirectly and has a pair of side walls and a connecting plate connecting the pair of side walls, wherein, with the direction of travel of the wheel forward and the opposite direction backward, there is a first shaft member that passes through the first holes of the pair of side walls of the pedal holding member and the first holes of the pair of side walls of the brake pedal; a second shaft member located below the first shaft member and passing through the second holes of the pair of side walls of the pedal holding member and the second holes of the pair of side walls of the brake pedal; and a third shaft member located in front of the first and second shaft members and passing through the third holes of the pair of side walls of the pedal holding member and the shaft holes of the pair of side walls of the fork member. The brake pedal comprises a leaf spring supported by the third shaft member, wherein when the brake pedal is pressed downward, the brake pedal swings downward around the first shaft member, and the second shaft member pushes the upper surface of the end of the leaf spring toward the wheel, causing the lower surface of the end of the leaf spring to press against the outer surface of the wheel, thereby applying the brake. It is characterized by the following: [Brief explanation of the drawing]

[0008] [Figure 1] This is a bottom view of the transport cart according to the first embodiment. [Figure 2] This is a plan view of the transport cart according to the first embodiment. [Figure 3] This is a side view of the transport cart according to the first embodiment. [Figure 4] This is a disassembled perspective view of the caster. [Figure 5] This is a cross-sectional view of a caster wheel with the brake released. [Figure 6] This is a cross-sectional view of a caster wheel with the brakes applied. [Figure 7] This is an exploded perspective view of the connection structure between the caster and the mounting plate, seen from above. [Figure 8] This is an exploded perspective view of the connection structure between the caster and the mounting plate, seen from below. [Figure 9] This is a view from below showing the mounting plate with the reinforcing member superimposed on it. [Figure 10] This is a partial cross-sectional view showing the connection structure between the caster and the mounting plate. [Figure 11] This is a side view showing the state of transporting a cart using a forklift. [Figure 12]This is a side view showing the state of transporting a cart using a forklift. [Figure 13] This is a perspective view showing the configuration of the cover portion of the second embodiment. [Figure 14] This is a plan view of the transport cart according to the second embodiment. [Figure 15] This is a side view of the transport cart according to the second embodiment. [Modes for carrying out the invention]

[0009] The casters and transport trolley according to this embodiment will be described with reference to the drawings. (First Embodiment) Figure 1 is a bottom view of the transport cart 1. Figure 2 is a top view of the transport cart 1. Figure 3 is a side view of the transport cart 1. In each figure, the direction of travel of the transport cart 1 is defined as the front-rear direction, with the front side indicated by Fr, the rear side by Rr, the right side by R, and the left side by L. Therefore, the side view in Figure 3 is a view from a direction perpendicular to the direction of travel of the transport cart 1. Note that the transport cart 1 in this embodiment is not limited to the front, but can travel in any direction including front, back, left, and right.

[0010] The transport trolley 1 is equipped with a trolley body 10, casters 20, and the like. First, let me explain the trolley body 10. The trolley body 10 has a frame section 12 made of multiple rectangular frame members pipes 11 made of iron or aluminum alloy, and a base 13 attached to the upper part of the frame section 12 for placing the articles to be carried. The pipes 11 and base 13 are, for example, anodized, so that the entire surface is a metallic color such as silver. As shown in Fig. 1, the frame portion 12 is formed in a lattice shape by joining pipes 11 together in the front-rear, left-right directions. Here, by joining four pipes 11a that are long in the front-rear direction, pipes 11b that are slightly shorter in the left-right direction, and pipes 11c that are short in the left-right direction, a plurality of rectangular spaces 14 are formed in three rows in the front-rear direction and four rows in the left-right direction. At the four corners of the frame portion 12, the pipe 11a and the pipe 11b are joined by a corner member 15. The corner member 15 is made of an aluminum alloy formed by, for example, extrusion molding, and an insertion hole 15a into which a hand bar C is inserted in the vertical direction is formed.

[0011] Among the plurality of spaces 14, mounting plates 40 for attaching casters 20 are respectively attached to the lower parts of the spaces 14 on the front side and both left and right sides and the lower parts of the spaces 14 on the rear side and both left and right sides. Each mounting plate 40 has a shape with a corner cut out close to the corner member 15, and is fixed to the pipes 11a, 11b, and 11c via blind rivets 16 so as to close the space 14 from below. As shown in Fig. 2, the base 13 is joined to the frame portion 12 by blind rivets, screws, welding, etc. so as to close the entire space 14 to which the mounting plate 40 is not attached from above.

[0012] Next, the caster 20 will be described. The caster 20 travels on the running surface while supporting the load of the article placed on the base 13. Also, the caster 20 is rotatable with respect to the turning axis O. In the present embodiment, since the casters 20 are arranged at at least the four corners of the lower surface of the cart body 10, when the transport cart 1 is run, the cart body 10 can be run in a stable state without tilting.

[0013] The caster 20 of the present embodiment is a so-called caster with a brake that can apply a brake or release the brake according to the operation of the user. In the transport cart 1, all four casters 20 may be casters with brakes, or any one to three of them may be casters with brakes.

[0014] Here, the details of the brake caster will be described with reference to FIG. 4. FIG. 4 is an exploded perspective view of the caster 20. The caster 20 of the present embodiment has a wheel 21, a support portion 25, a brake pedal 35, and the like. The wheel 21 is set to a load capacity that allows the cart body 10 on which an article is placed to run smoothly. The wheel 21 has a wheel portion 22 with a bearing built therein and a tire portion 23 fitted on the outer periphery of the wheel portion 22.

[0015] The support portion 25 rotatably supports the wheel 21 via a shaft 24. The support portion 25 has a fork member 26 that supports the wheel 21 and is attached to the cart body 10 via a mounting plate 40, and a pedal holding member 31 that swingably supports the brake pedal 35. The fork member 26 is formed, for example, by press-forming a steel plate. The fork member 26 is, for example, nickel-plated and the entire surface is a metallic color such as silver. The fork member 26 is integrally formed by a pair of side walls 26a respectively positioned on both sides of the wheel 21 and a circular top plate 26b that connects the pair of side walls 26a above the wheel 21. Axle holes 26c through which the axle 24 is inserted and shaft holes 26d for supporting the pedal holding member 31 are formed in the pair of side walls 26a respectively. The top plate 26b is sandwiched between an upper plate member 27 and a lower plate member 28 via a bearing described later.

[0016] FIG. 5 is a cross-sectional view of the caster 20. As shown in FIG. 5, an insertion hole 26e is formed coaxially with the turning axis O of the caster 20 at the center of the top plate 26b, and an annular accommodation groove is formed around the turning axis O on the upper surface of the top plate 26b and on the lower surface thereof so that a plurality of bearings 29 and a plurality of bearings 30 can be stably arranged. The upper plate member 27 is formed, for example, by press forming a steel plate. The upper plate member 27 is formed in a circular shape that is slightly larger than the top plate 26b, and an insertion hole 27a is formed in the center coaxially with the pivot axis O. In addition, an annular housing groove 27b is formed on the lower surface of the upper plate member 27 to stably position the bearing 29. By forming the annular housing groove 27b in this way, a protruding portion 27c is formed on the upper surface of the upper plate member 27 in a circular arc shape in cross-sectional view, along the annular shape centered on the pivot axis O. Furthermore, the upper plate member 27 has a sloping portion 27d that slopes downward from the protruding portion 27c toward the insertion hole 27a. In addition, the outer peripheral edge portion 27e of the upper plate member 27 is formed in a circular arc shape in cross-sectional view and then hangs down.

[0017] The lower plate member 28 is formed, for example, by press forming a steel plate. The lower plate member 28 is formed in a smaller circular shape than the top plate 26b, and an insertion hole 28a is formed in the center coaxially with the pivot axis O. In addition, an annular housing groove 28b is formed on the upper surface of the lower plate member 28 to stably position the bearing 30. Here, the upper plate member 27 and the lower plate member 28 are integrally connected so that they do not rotate relative to each other near the insertion holes 27a and 28a. Therefore, the top plate 26b, i.e., the fork member 26, can pivot around the pivot axis O with respect to the upper plate member 27 and the lower plate member 28 via the bearings 29 and 30.

[0018] Returning to Figure 4, the pedal holding member 31 is formed, for example, by press-forming a steel plate. The pedal holding member 31 is, for example, nickel-plated, so that the entire surface is a metallic color such as silver. The pedal holding member 31 is integrally formed from a pair of side walls 31a located on both sides of the wheel 21 and a connecting plate 31b that connects the pair of side walls 31a at the top. The pair of side walls 31a are formed by bifurcated first support portion 31c and second support portion 31d extending in different directions from the connecting plate 31b. At the tip of the first support portion 31c, an axle hole 31e is formed that communicates with the axle hole 26c of the fork member 26 and through which the axle 24 is inserted. On the other hand, at the tip of the second support portion 31d, an axle hole 31f is formed that communicates with the axle hole 26d of the fork member 26 and through which the axle member 32 is inserted. Furthermore, a support hole 31g is formed in the upper part of the side wall 31a, in close proximity to the connecting plate 31b, for pivotably supporting the brake pedal 35. Below the support hole 31g in the side wall 31a, an elongated hole 31h, which is roughly long in the front-to-back direction, is formed. When the pedal holding member 31 is supported by the fork member 26 via the axle 24 and the shaft member 32, the connecting plate 31b inclins downward as it approaches the rear. In this embodiment, the inclination angle of the connecting plate 31b is approximately 45 degrees.

[0019] Furthermore, the pedal holding member 31 supports a leaf spring 33 as a biasing member via a shaft member 32 that passes through the shaft hole 31f. The leaf spring 33 is formed, for example, by press forming a stainless steel plate. The leaf spring 33 has a support hole 33a through which the shaft member 32 is inserted, and one end 33b and the other end 33c that extend from the support hole 33a in different directions. A projection 33d is formed along the width direction of the plate on the tip side of the other end 33c, with a portion of it projecting upward.

[0020] The brake pedal 35 is formed, for example, by press forming a steel plate. The brake pedal 35 is, for example, nickel-plated, so that the entire surface is a metallic color such as silver. The brake pedal 35 has a pedal body 35a and an operating piece 35b that extends integrally from the pedal body 35a as an operating part. The pedal body 35a is integrally formed from a pair of side walls 35c located on both sides of the wheel 21 and a connecting plate 35d that connects the pair of side walls 35c at the top. When the caster 20 is viewed in the direction of travel, the brake pedal 35 is positioned to overlap with the wheel 21. Also, the distance between the pair of side walls 35c is formed to be narrower than the distance between the pair of side walls 31a of the pedal holding member 31. Therefore, the brake pedal 35 can be positioned inside the pedal holding member 31 so that the connecting plate 35d overlaps with the connecting plate 31b of the pedal holding member 31. Furthermore, a swing hole 35e is formed at the front and upper part of the side wall 35c, communicating with the support hole 31g of the pedal holding member 31, through which the shaft member 36 is inserted. Therefore, the brake pedal 35 can swing up and down relative to the pedal holding member 31 around the shaft member 36. Also, below the swing hole 35e of the side wall 35c, a shaft hole 35f is formed, communicating with the elongated hole 31h of the pedal holding member 31, through which the shaft member 37 is inserted. When the brake pedal 35 swings up and down, the shaft member 37 also moves in conjunction with it within the elongated hole 31h of the pedal holding member 31. The shaft member 37 is always in contact with the upper surface of the other end 33c of the leaf spring 33.

[0021] The operating piece 35b is roughly plate-shaped and is used to operate the up-and-down swinging of the brake pedal 35 with the user's foot or the like. The operating piece 35b is formed extending diagonally from the rear of the connecting plate 35d of the pedal body 35a. The operating piece 35b is formed in a rectangular shape with a plate width that is approximately the same as the plate width of the connecting plate 35d. In this embodiment, the operating piece 35b is designed to prevent the caster 20 from deforming or being damaged even if the fork comes into contact with the operating piece 35b when the fork is inserted under or raised on the transport cart 1. The function of the operating piece 35b will be described later.

[0022] As shown in Figure 3, when the caster 20 is attached to the trolley body 10 via the mounting plate 40, the caster 20 rotates around the pivot axis O. In particular, since the pivot axis O is set at an eccentric position with respect to the axle 24 of the caster 20, it rotates so that the wheel 21 is on the rear side relative to the front side, which is the direction of travel. At this time, with respect to the trolley body 10, at least a portion of the operating piece 35b of the brake pedal 35 of the rear caster 20 is located outside (behind) the rear end of the trolley body 10, specifically beyond the rear pipe 11b. Therefore, the user can easily see and operate the operating piece 35b of the brake pedal 35 with their foot. Furthermore, if the direction of travel is reversed by 180 degrees, the vehicle will rotate so that the wheels 21 are facing forward. Therefore, the front caster 20 has at least a portion of the operating piece 35b of the brake pedal 35 positioned outside (forward) of the front pipe 11b.

[0023] Next, we will explain the operation of each component of the caster 20 configured as described above, from the state where the brake is released to the state where the brake is applied. Figure 5 is a cross-sectional view of the caster 20 showing the brake released. As shown in Figure 5, when the brake is released, the brake pedal 35 is in a raised position around the axle member 36. Here, one end 33b of the leaf spring 33 is in contact with the top plate 26b, and the other end 33c is in contact only with the axle member 37 due to the biasing force of the leaf spring 33 itself. In other words, the state in Figure 5 is a brake-released state in which the wheel 21 is not in contact with any of the members, and the wheel 21 can rotate freely. The brake pedal 35 is held in place by frictional forces between the members, etc., at a position where the pedal body 35a overlaps with the pedal holding member 31.

[0024] From the state shown in Figure 5, when the user operates the brake pedal 35 by pressing the operating piece 35b of the brake pedal 35 downward with their foot, the brake pedal 35 swings downward around the shaft member 36 against the biasing force of the leaf spring 33 and the frictional force between the components. At this time, as the brake pedal 35 moves, the shaft member 37 moves within the elongated hole 31h toward the protruding portion 33d of the leaf spring 33.

[0025] Figure 6 is a cross-sectional view of the caster 20 showing the brake applied. As shown in Figure 6, when the user presses the operating piece 35b to its lower limit, the axle member 37, which moves with the brake pedal 35, moves over the top of the protrusion 33d of the leaf spring 33. Therefore, the leaf spring 33 is pushed toward the wheel 21 by the axle member 37, and the lower surface of the leaf spring 33 firmly presses against the outer circumferential surface of the tire portion 23. In other words, the state in Figure 6 is a brake applied state in which the wheel 21 cannot rotate because the outer circumferential surface of the wheel 21 is pressed by the leaf spring 33. Furthermore, from the state shown in Figure 6, the user can return to the state shown in Figure 5 by pushing the operating piece 35b of the brake pedal 35 upwards with their foot or other means, thereby releasing the brake.

[0026] Next, the coupling structure for connecting the caster 20 to the mounting plate 40 will be described. The transport trolley 1 of this embodiment is configured to prevent deformation and damage to the caster 20 when force is applied to the caster 20, such as when the wheel 21 collides with an obstacle. Figure 7 is an exploded perspective view of the connection structure between the caster 20 and the mounting plate 40, viewed from above. Here, we describe the connection structure between one caster 20 and the mounting plate 40, but the connection structures at other locations are similar. The transport cart 1 includes casters 20, mounting plates 40, reinforcing members 50, washer members 42, bolts 44, nuts 46, etc. The casters 20 shown in Figure 7 are already assembled.

[0027] The mounting plate 40 is formed, for example, by press-forming a plate-shaped aluminum alloy. A through-hole 40a is formed approximately in the center of the mounting plate 40, through which a bolt 44 is inserted coaxially with the pivot axis O. The through-hole 40a is formed in a conical, stepped position from the upper surface 40b of the mounting plate 40 so that the head 44a of the bolt 44 does not protrude upward from the upper surface 40b when the bolt 44 is inserted. Figure 8 is an exploded perspective view of the connection structure of the mounting plate 40 and the reinforcing member 50, viewed from below. When viewed from below, the through-hole 40a is conversely formed in a conical, bulging position from the lower surface 40c of the mounting plate 40. Furthermore, as shown in Figure 8, an annular rib 40d is formed on the mounting plate 40, centered on the pivot axis O. The annular rib 40d bulges out from the lower surface 40c of the mounting plate 40. In addition, a plurality of rectangular ribs 40e are formed on the mounting plate 40 so as to surround the annular rib 40d. The rectangular ribs 40e are formed by recessing the lower surface 40c along the outer shape of the rectangle. That is, the area within the rectangular rib 40e is a flat surface at the same height as the lower surface 40c. The rectangular ribs 40e are formed at equally spaced positions along the circumferential direction centered on the pivot axis O, at a total of eight locations: front, back, left, right, and in the middle of each of the front, back, left, and right sides. Here, among the plurality of rectangular ribs 40e, protrusions 40f are formed as positioning parts within the left and right rectangular ribs 40e to position the reinforcing member 50 in a predetermined position. The rigidity of the mounting plate 40 can be improved by forming the annular rib 40d and the rectangular ribs 40e. Furthermore, multiple fixing holes 40g are formed around the mounting plate 40 for inserting blind rivets 16 to attach the mounting plate 40 to the bogie body 10.

[0028] The reinforcing member 50 is formed, for example, by press-forming a plate-shaped aluminum alloy. In this embodiment, the reinforcing member 50 is positioned between the caster 20 and the mounting plate 40 when the caster 20 is coupled to the mounting plate 40, and contacts both the upper surface of the caster 20, i.e., the upper surface of the upper plate member 27, and the lower surface 40c of the mounting plate 40.

[0029] Specifically, the reinforcing member 50 is formed in an annular shape with a circular opening 50a drilled around the pivot axis O. The inner diameter of the opening 50a is smaller than the outer diameter of the upper plate member 27 and larger than the diameter of the annular projection 27c of the upper plate member 27. Furthermore, the reinforcing member 50 has a lower protrusion 50b that contacts the upper surface of the upper plate member 27 and an upper protrusion 50c that contacts the lower surface 40c of the mounting plate 40. The lower protrusion 50b is rib-shaped and bulges downward, and is formed at eight equally spaced positions along the circumference centered on the pivot axis O. Similarly, the upper protrusion 50c is rib-shaped and bulges upward, and is formed at eight equally spaced positions along the circumference centered on the pivot axis O. Therefore, when the reinforcing member 50 is viewed in plan, the lower protrusion 50b and the upper protrusion 50c are formed alternately along an annular shape.

[0030] Each lower protrusion 50b has a bulge 50d in its center that bulges outwards the most. That is, the lower surface of the lower protrusion 50b slopes downward from the opening 50a toward the bulge 50d, and then slopes upward beyond the bulge 50d. Each upper protrusion 50c has a recess 50e formed in the center of it, following an annular shape (see Figure 7). The recess 50e is formed to avoid interference with the annular rib 40d, in order to bring the upper protrusion 50c of the reinforcing member 50 and the lower surface 40c of the mounting plate 40 into contact with each other on a plane. Furthermore, notches 50f are formed at the left and right ends of the reinforcing member 50, serving as positioning parts that engage with the projections 40f of the mounting plate 40.

[0031] Figure 9 is a view of the mounting plate 40 from the bottom surface 40c, showing the state in which the reinforcing member 50 is superimposed on the mounting plate 40. In Figure 9, the upper protrusion 50c of the reinforcing member 50 is colored with dots for ease of understanding. As shown in Figure 9, when the reinforcing member 50 is superimposed on the mounting plate 40, the eight upper protrusions 50c are located midway between the front and rear left and right sides, and between the front and rear left and right sides. Since the lower protrusions 50b and upper protrusions 50c are formed alternately, lower protrusions 50b are located on both sides adjacent to each upper protrusion 50c. The mounting plate 40 and the reinforcing member 50 are positioned by the engagement of the projections 40f of the mounting plate 40 and the notches 50f of the reinforcing member 50. At this time, the outer periphery of the upper surface of each upper protrusion 50c, beyond the recess 50e, abuts against the rectangular rib 40e of the mounting plate 40. Since the inside of the rectangular rib 40e of the mounting plate 40 is a flat surface, the reinforcing member 50 and the mounting plate 40 overlap without any wobbling.

[0032] Furthermore, the reinforcing member 50 is formed using a steel plate with a thinner thickness than the mounting plate 40 and the fork member 26, thereby setting its strength to be lower than that of the mounting plate 40 and the fork member 26.

[0033] Returning to Figure 7, the washer member 42 is formed, for example, by press-forming a plate-shaped aluminum alloy. The washer member 42 is positioned between the head 44a of the bolt 44 and the mounting plate 40, and holds the head 44a of the bolt 44 so that the bolt 44 stands upright in the vertical direction. The washer member 42 has an insertion hole 42a through which the bolt 44 is inserted coaxially with the pivot axis O. The insertion hole 42a is formed in a conical, stepped position so that the head 44a of the bolt 44 does not protrude upward from the upper surface 40b of the mounting plate 40 when the bolt 44 is inserted. Furthermore, since the outer diameter of the washer member 42 is set to be approximately the same as the inner diameter of the opening 50a of the reinforcing member 50, it can be manufactured using a circular material obtained by press forming to punch out the opening 50a of the reinforcing member 50. Therefore, by effectively utilizing the material, the washer member 42 and the reinforcing member 50 can be manufactured at low cost.

[0034] To connect the caster 20 to the mounting plate 40, the bolt 44 is inserted in the following order: through hole 42a of the washer member 42, through hole 40a of the mounting plate 40, opening 50a of the reinforcing member 50, through hole 27a of the upper plate member 27, through hole 26e of the top plate 26b, and through hole 28a of the lower plate member 28, and then secured by screwing the nut 46 into the fork member 26. Figure 10 is a partial cross-sectional view showing the connection structure between the caster 20 and the mounting plate 40. As shown in Figure 10, the reinforcing member 50 is positioned between the mounting plate 40 and the caster 20, and is arranged in contact with the lower surface 40c of the mounting plate 40 and the upper surface of the caster 20. Specifically, the upper surface of the upper protrusion 50c of the reinforcing member 50 is in contact with the lower surface 40c of the mounting plate 40. At this time, the recess 50e formed in the upper protrusion 50c prevents interference with the annular rib 40d of the mounting plate 40. On the other hand, at the lower protrusion 50b of the reinforcing member 50, the inclined portion of the lower surface of the lower protrusion 50b, extending from the opening 50a to the bulging portion 50d, is in contact with the outer circumference and outer edge portion 27e of the upper surface of the upper tray member 27. Note that the protrusion 27c and the vicinity of the insertion hole 27a on the upper surface of the upper tray member 27 are in direct contact with the lower surface 40c of the mounting plate 40 without the reinforcing member 50 being interposed. In other words, the reinforcing member 50 is positioned to fill the gap between the lower surface 40c of the mounting plate 40 and the upper surface of the upper plate member 27.

[0035] The operation of the caster 20 and transport cart 1, configured as described above, will now be explained. First, let's explain the function of the operating piece 35b of the brake pedal 35. As shown in Figure 3, when transporting the transport cart 1 with a forklift, the two forks 60 of the forklift are inserted between the front and rear casters 20 below the transport cart 1 and raised, thereby supporting the underside of the transport cart 1 during transport. In this case, if the position where the two forks 60 are inserted into the transport trolley 1 or the position where they are raised is close to the casters 20, the brake pedal 35 may be pushed up by the forks 60, which could cause deformation or damage to the brake pedal 35 or the fork members 26.

[0036] In this embodiment, even if the brake pedal 35 of the caster 20 is pushed up by the fork 60, the caster 20 is prevented from deforming or being damaged. Figure 11 is a side view showing the state when the rising fork 60 contacts the operating piece 35b of the brake pedal 35. Here, the lower surface of the operating piece 35b is inclined upward toward the tip. Therefore, the force that the fork 60 exerts to raise the brake pedal 35 is converted by the inclined operating piece 35b into a force that moves the transport cart 1 in the direction of travel of the wheels 21. The inclination angle α of the operating piece 35b is preferably set to, for example, 10 degrees or more and 50 degrees or less so that the upward force can be efficiently converted into a force in the direction of travel, and here it is set to approximately 30 degrees. Figure 12 is a side view showing the state when the forks 60 are raised further. The transport cart 1 moves in the direction of travel due to the force converted by the inclined operating piece 35b. Therefore, even when the forks 60 are raised further, the brake pedal 35 moves away from the position where it contacts the forks 60, thus preventing deformation or damage to the casters 20. In other words, the transport cart 1 can be transported by a forklift without damaging the casters 20.

[0037] Furthermore, when the fork 60 is raised, contact is not limited to the operating piece 35b, but may also occur with the pedal body 35a. Therefore, in this embodiment, the lower rear surfaces of a pair of side walls 35c of the pedal body 35a are continuous with the inclination of the operating piece 35b and are inclined at approximately the same angle as the inclination of the operating piece 35b. Consequently, even if the pedal body 35a is pushed up by the fork 60, the transport cart 1 moves in the direction of travel in the same way as when it contacts the operating piece 35b, thus preventing deformation or damage to the caster 20. Here, as shown in Figure 11, the front-to-back length L1 of the lower surface of the pedal body 35a exposed to the rear from the outer outline of the rear end of the wheel 21, which is inclined at approximately the same angle as the inclination angle of the operating piece 35b, is formed to be longer than the front-to-back length L2 of the lower surface inclined at a different angle than the inclination angle of the operating piece 35b. Therefore, the rising fork 60 can be easily brought into contact with the operating piece 35b or the lower surface of the pedal body 35a that is inclined at approximately the same angle as the inclination angle of the operating piece 35b.

[0038] Furthermore, in this embodiment, when the fork 60 is raised and contacts the pedal body 35a, the structure is such that the pedal body 35a and the pedal holding member 31 do not deform before the transport cart 1 moves in the direction of travel. Specifically, the brake pedal 35 is positioned within the pedal holding member 31 such that the connecting plate 35d overlaps the connecting plate 31b of the pedal holding member 31. Therefore, even if an upward force is applied to the brake pedal 35, the force is transmitted to the connecting plate 31b of the pedal holding member 31, which is formed over a relatively large area, thus preventing deformation of the brake pedal 35. In addition, the pedal holding member 31 is firmly fixed to the fork member 26 by a first support portion 31c, in which a pair of side walls 31a are supported at the axle position, and a second support portion 31d, which is supported at a position above the axle position. Therefore, even if an upward force is applied to the pedal holding member 31 via the brake pedal 35, the pedal holding member 31 itself, which is firmly fixed to the fork member 26, receives the force, thus preventing deformation of the pedal holding member 31. In other words, deformation of the pedal body 35a and the pedal holding member 31 can be prevented before the transport cart 1 moves in the direction of travel.

[0039] In this embodiment, as shown in Figure 6, when the brake is applied, the operating piece 35b is approximately horizontal and is slightly inclined upward from horizontal towards the tip. By making the operating piece 35b approximately horizontal in this way, when the fork 60 is raised, it is possible to make contact with the lower surface of the operating piece 35b and make it easier to raise the brake pedal 35. When the brake pedal 35 is raised and the brake is released, the lower surface of the operating piece 35b is inclined upward towards the tip, so as shown in Figures 11 to 12, the transport cart 1 can be moved in the direction of travel, and deformation or damage to the caster 20 is prevented.

[0040] Next, the function of the reinforcing member 50 of the transport trolley 1 will be explained. As shown in Figure 10, consider the case where the wheel 21 of the caster 20 collides with an obstacle B located in front of the direction of travel. When the wheel 21 collides with obstacle B, a moment is generated in the caster 20 that causes it to rotate in the direction of arrow A around the bolt 44. Here, if the reinforcing member 50 is not placed, there is a gap between the lower surface 40c of the mounting plate 40 and the upper surface of the caster 20, more specifically between the lower surface 40c of the mounting plate 40 and the portion of the upper surface of the upper plate member 27 that extends beyond the protruding portion 27c to the outer peripheral edge portion 27e. Therefore, because the caster 20 is allowed to rotate in the direction of arrow A around the bolt 44 by the amount of the gap, there is a risk that the fork member 26 may undergo plastic deformation.

[0041] On the other hand, as in this embodiment, by arranging the reinforcing member 50 to fill the gap between the lower surface 40c of the mounting plate 40 and the upper surface of the caster 20, the moment generated in the caster 20 around the bolt 44 can be received by the mounting plate 40 via the reinforcing member 50. That is, the moment generated in the caster 20 when it collides with the obstacle B is first transmitted from the portion of the upper surface of the upper plate member 27 that extends beyond the protruding portion 27c to the outer peripheral edge portion 27e, to the lower protrusion 50b of the reinforcing member 50. Here, since the collision occurs at the front of the wheel 21, the force is mainly transmitted to the two lower protrusions 50b formed at the rear of the reinforcing member 50. That is, since the lower protrusions 50b are arranged spaced apart to the left and right at the rear of the reinforcing member 50, the moment generated in the caster 20 can be reliably received by the lower protrusions 50b.

[0042] The force transmitted to the lower protrusion 50b propagates within the reinforcing member 50 and is transmitted to the lower surface 40c of the mounting plate 40, mainly via the upper protrusion 50c formed between the two lower protrusions 50b, and also via the two upper protrusions 50c formed on the left and right sides of the two lower protrusions 50b. In this way, the moment generated in the caster 20 by collision with the obstacle B is transmitted to the strong mounting plate 40 via the reinforcing member 50, thereby preventing plastic deformation of the fork member 26 and improving the strength of the caster 20 and the transport trolley 1. Furthermore, since the lower protrusion 50b and upper protrusion 50c of the reinforcing member 50 are formed alternately along the annular shape of the reinforcing member 50, plastic deformation of the fork member 26 can be prevented not only when the obstacle B collides with the front of the wheel 21, but also when a force is applied to the pivot axis O from any direction.

[0043] Next, consider the case where the caster 20 collides excessively with obstacle B or is subjected to excessive force. In this case, the reinforcing member 50, which is set to have lower strength than the mounting plate 40 and fork member 26, undergoes plastic deformation. Specifically, the lower protrusion 50b and upper protrusion 50c of the reinforcing member 50 undergo plastic deformation so as to collapse in the vertical direction, thereby avoiding plastic deformation of the mounting plate 40 and fork member 26. In this case, it is sufficient to remove the nut 46 from the bolt 44 and replace only the reinforcing member 50.

[0044] (Second embodiment) Next, a second embodiment will be described. Components that are the same or substantially the same as those in the first embodiment will be denoted by the same reference numerals, and their descriptions will be omitted as appropriate. In the second embodiment, at least a part of the operating piece 35b of the first embodiment is covered with a cover portion 70, and the cover portion 70 functions as an operating part. Figure 13 is a perspective view showing the configuration around the cover portion 70. As shown in Figure 13, the operating piece 35b is formed by extending integrally from the rear of the connecting plate 35d of the pedal body 35a. The operating piece 35b is formed in a rectangular shape with a width slightly narrower than the width of the connecting plate 35d. Multiple ribs (two in this case) are formed at the boundary between the operating piece 35b and the pedal body 35a, spaced apart in the width direction. The ribs 35g increase rigidity so that they can maintain a bent state between the pedal body 35a and the operating piece 35b.

[0045] The operating piece 35b is fitted with a cover portion 70. The cover portion 70 is made of synthetic resin and is colored so that the user can recognize it at a glance. Specifically, the cover portion 70 is colored differently from the brake pedal 35, that is, differently from the pedal body 35a and the operating piece 35b. Here, the cover portion 70 may be one of the three primary colors, such as red, green, or blue, or it may be orange, etc. Note that in Figure 13, the cover portion 70 is colored gray for ease of understanding.

[0046] The cover portion 70 is roughly plate-shaped and includes a first cover member 71 and a second cover member 75. The first cover member 71 mainly covers the top surface and both sides of the operating piece 35b. The first cover member 71 has a roughly U-shaped cross-section that opens in the front-rear direction and has a space inside into which a part of the second cover member 75 and the operating piece 35b are inserted. The first cover member 71 has a stepped locking portion 72 formed on its inner surface. The first cover member 71 also has a roughly flat top surface, on which multiple anti-slip protrusions 73 are formed along the width direction, and a rib cover portion 74 is formed at the front end to cover the rib 35g. The second cover member 75 mainly covers the lower surface of the operating piece 35b. The second cover member 75 is substantially plate-shaped, and claw-shaped locking portions 76 that engage with the locking portion 72 are formed on both sides of its front end. The locking portions 76 are flexible inward due to adjacently formed notches 77. The second cover member 75 also has a lid portion 78 at its rear end that closes the opening of the first cover member 71. Furthermore, the lower surface of the second cover member 75 is substantially flat, and multiple anti-slip protrusions 79 are formed on the flat surface along the width direction (see Figure 15).

[0047] When attaching the cover portion 70 to the operating piece 35b, the operating piece 35b is inserted into the space of the first cover member 71 until it abuts against the pedal body 35a. In this state, the top and sides of the operating piece 35b are covered by the first cover member 71, and the rib 35g is covered by the rib cover portion 74. Next, the second cover member 75 is inserted into the space of the first cover member 71 through the opening at the rear end of the first cover member 71. At this time, the locking portion 76 of the second cover member 75 is pressed by the inner surface of the first cover member 71 and is inserted while bending inward, and when it reaches the locking portion 72 the bending is released and it locks into the locking portion 72. In this state, the lower surface of the operating piece 35b is covered by the second cover member 75. In this embodiment, the entire area of ​​the operating piece 35b is covered by the first cover member 71 and the second cover member 75. When the cover portion 70 is attached to the operating piece 35b, it is positioned so as to overlap with the wheel 21 when viewing the caster 20 in the direction of travel. The cover portion 70 is prevented from coming off the operating piece 35b by friction between it and the operating piece 35b.

[0048] As shown in Figure 14, in a plan view, the rear caster 20 in the direction of travel has its brake pedal 35 cover portion 70 positioned outside the rear end of the trolley body 10, specifically the rear pipe 11b. Furthermore, the cover portion 70 is colored, which improves the visibility of the brake pedal 35. In particular, since the cover portion 70 is a different color from the pipe 11b of the trolley body 10, and / or the base 13, the visibility of the brake pedal 35 is further improved. Therefore, even if the transport trolley 1 starts to move due to its own weight, for example, the user can immediately recognize the brake pedal 35 and operate it quickly.

[0049] Furthermore, since the cover portion 70 is installed so as to cover at least a part of the operating piece 35b of the brake pedal 35, it is not necessary to paint the entire brake pedal 35 a different color from the pipe 11b; only the cover portion 70 needs to be painted a different color from the pipe 11b. Therefore, the cover portion 70 can be easily painted. In addition, the entire cover portion 70 does not need to be located outside the rear pipe 11b; if at least a part of it is located outside the rear pipe 11b, the visibility for the user can be improved. Furthermore, since the cover portion 70 is a component operated by the user, it may wear out or break. Even in such cases, because the cover portion 70 is separate from the brake pedal 35, the cover portion 70 can be easily replaced.

[0050] Furthermore, as shown in Figure 15, the lower surface of the cover portion 70 is inclined upward toward the tip, similar to the operating piece 35b in the first embodiment. Therefore, when the rising fork 60 contacts the cover portion 70 of the brake pedal 35, the force exerted by the fork 60 to raise the brake pedal 35 is converted by the inclined cover portion 70 into a force that moves the transport trolley 1 in the direction of travel of the wheels 21. The inclination angle α of the lower surface of the cover portion 70 is preferably set to, for example, 10 degrees or more and 50 degrees or less, so that the upward force can be efficiently converted into a force in the direction of travel, and here it is set to approximately 30 degrees. Furthermore, as shown in the enlarged view of Figure 15, the inclination angle β of the virtual surface F formed by connecting the vertices of the multiple protrusions 79 formed on the lower surface of the cover portion 70 is preferably set to, for example, 10 degrees or more and 50 degrees or less, similar to the inclination angle α, and here it is set to approximately 30 degrees. In this embodiment, the inclination angle α and the inclination angle β are the same angle.

[0051] Thus, according to this embodiment, as in the first embodiment, even if the rising fork 60 comes into contact with the cover portion 70 of the brake pedal 35, the force that the fork 60 exerts to raise the brake pedal 35 is converted by the inclined cover portion 70 into a force that moves the transport trolley 1 in the direction of travel of the wheels 21. Therefore, deformation or damage to the caster 20 can be prevented.

[0052] Although the present invention has been described above with reference to the embodiments described above, the present invention is not limited to the embodiments described above, and modifications can be made within the scope of the present invention. For example, the first embodiment and the second embodiment may be combined. The above-described embodiment explains the case where four casters 20 are arranged on the underside of the trolley body 10, but it is not limited to this case. The number of casters 20 can be freely changed depending on the intended use of the transport trolley 1. For example, one or more casters 20 may be added to at least one of the following positions: inside, outside, or along the boundary line of the area enclosed by the four casters 20 in a plan view. For example, two casters may be added inside the area, in the center in the left-right direction, spaced apart front to back. Alternatively, for example, one caster may be added between two front and rear casters 20 located on the right side, and another between two front and rear casters 20 located on the left side, for a total of two casters. In any example, it is preferable to place a reinforcing member 50 between the two additional casters and the mounting plate 40. On the other hand, it is preferable that the two additional casters are brakeless casters without a brake pedal 35 or pedal holding member 31.

[0053] In the embodiment described above, the case in which the support portion 25 is constructed as separate components of the fork member 26 and the pedal holding member 31 was explained. By constructing them as separate components in this way, the fork member 26 of the brakeless caster can be made common. However, this is not the only case, and the fork member 26 and the pedal holding member 31 may be integrated.

[0054] In the embodiment described above, the brake pedal 35 indirectly presses against the wheel 21 via the shaft member 37 and the leaf spring 33 to apply the brakes, but the invention is not limited to this case. For example, the shaft member 37 and the leaf spring 33 may be omitted, and the brake pedal 35 may directly press against the outer surface of the wheel 21 to apply the brakes. Alternatively, the brake pedal 35 may directly or indirectly interfere with a member that rotates integrally with the wheel 21 to apply the brakes.

[0055] In the embodiment described above, the case in which the mounting plate 40 to which the caster 20 is attached is attached to the trolley body 10 was explained, but it is not limited to this case. For example, the lower surface of the trolley body 10 can be made flat so that the caster 20 can be directly attached to the lower surface of the trolley body 10, and the mounting plate 40 can be omitted. In this case, the through holes 40a and annular ribs 40d formed in the mounting plate 40 can be directly formed on the trolley body 10 so that the reinforcing member 50 can be positioned in contact with both the lower surface of the trolley body 10 and the upper surface of the caster 20.

[0056] In the embodiment described above, the reinforcing member 50 was described as having an upper protrusion 50c and a lower protrusion 50b formed alternately along an annular shape, but it is not limited to this case. For example, the wheel 21 often collides with an obstacle B on the front side, and a moment is generated in the caster 20 that causes it to rotate backward around the bolt 44. Therefore, the reinforcing member 50 only needs to have an upper protrusion 50c at the rear and lower protrusions 50b on both sides of this upper protrusion 50c. In this case, the reinforcing member 50 does not need to be formed in an annular shape.

[0057] In the embodiments described above, the cover portion 70 was described as being composed of a first cover member 71 and a second cover member 75, but it is not limited to this case. That is, the cover portion 70 only needs to be able to cover at least a part of the operating piece 35b, and its configuration is not limited. However, it is preferable that the cover portion 70 covers the upper surface of the operating piece 35b in order to improve visibility. The cover portion 70 may also be made of rubber to provide a better anti-slip effect.

[0058] In the embodiment described above, the cover portion 70 was described as being composed of two members, a first cover member 71 and a second cover member 75, but it is not limited to this case. That is, the cover portion 70 may be composed of a single member. For example, the first cover member 71 and the second cover member 75 may be injection molded together with a part (connecting portion) connected to each other, and the cover portion 70 may be attached to the operating piece 35b by rotating the connecting portion as a hinge portion to cover the operating piece 35b from above and below. [Explanation of symbols]

[0059] 1: Transport cart 10: Cart body 20: Caster 21: Wheel 25: Support part 26: Fork member 27: Upper plate member 27e: Outer edge part 28: Lower plate member 31: Pedal holding member 33: Leaf spring 35: Brake pedal 35a: Pedal body 35b: Operating piece 40: Mounting plate 40c: Bottom surface 44: Bolt (fastening member) 46: Nut (fastening member) 50: Reinforcement member 50b: Lower protrusion 50c: Upper protrusion 50f: Notch 70: Cover part

Claims

1. Wheels and, A fork member that rotatably supports the wheel via an axle, A pedal holding member is fixed to the fork member and has a pair of side walls and a connecting plate connecting the pair of side walls, A caster comprising a brake pedal that is pivotably supported with respect to the pedal holding member, indirectly applies a brake to the wheel, and has a pair of side walls and a connecting plate connecting the pair of side walls, If we define the direction of travel of the aforementioned wheels as forward and the opposite direction as backward, A first shaft member that passes through the first holes in the pair of side walls of the pedal holding member and the first holes in the pair of side walls of the brake pedal, A second shaft member is located below the first shaft member and passes through the second holes in the pair of side walls of the pedal holding member and the second holes in the pair of side walls of the brake pedal, A third shaft member is located in front of the first shaft member and the second shaft member, and passes through the third holes in the pair of side walls of the pedal holding member and the shaft holes in the pair of side walls of the fork member, The device comprises a leaf spring supported by the third shaft member, A caster characterized in that when the brake pedal is pressed downward, the brake pedal swings downward around the first shaft member, and the second shaft member pushes the upper surface of the end of the leaf spring toward the wheel, causing the lower surface of the end of the leaf spring to press against the outer surface of the wheel, thereby applying the brake.

2. The end of the leaf spring has a projection that partially protrudes upward, The caster according to claim 1, characterized in that when the brake pedal is pressed downward, the brake pedal swings downward around the first shaft member, and the second shaft member passes over the apex of the protrusion of the leaf spring, causing the lower surface of the end of the leaf spring to press against the outer surface of the wheel, thereby applying the brake.

3. The caster according to claim 1 or 2, characterized in that the central axis of the third shaft member is located below the position of the central axis of the first shaft member and above the position of the central axis of the second shaft member.

4. The caster according to any one of claims 1 to 3, characterized in that the third shaft member is inserted through a support hole formed in the leaf spring.

5. The fork member has a top plate that connects the pair of side walls of the fork member above the wheel, The caster according to any one of claims 1 to 4, characterized in that the opposite end of the leaf spring is in contact with the top plate.

6. The brake pedal has an operating part that is operated by the user to swing up and down, The caster according to any one of claims 1 to 5, characterized in that when the brake is released, the lower surface of the operating part is inclined upward toward the rear end.

7. The caster according to any one of claims 1 to 6, characterized in that the brake pedal is located between the pair of side walls of the pedal holding member.

8. The trolley body on which the goods are placed, A transport trolley comprising a caster according to any one of claims 1 to 7, which is attached to the lower surface of the trolley body.

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