Caster and transport carriage

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 technology]

[0002] Among casters used in transport carts and the like, there are casters with brakes. The caster with brakes used in the transport cart of Patent Document 1 has a yoke, wheels, brake shoes, and a brake pedal. In the caster with brakes, the brake pedal extends beyond the outer shape of the wheel so that the user can easily operate it with his / her foot. When the user steps on the brake pedal with his / her foot, the brake pedal is pushed down, and the brake shoes press against the wheels, fixing the wheels. On the other hand, when the user pushes up the brake pedal with his / her foot, the pressure on the wheels by the brake shoes is released, and the wheels rotate freely. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-61988 A Summary of the Invention [Problem to be solved by the invention]

[0004] At work sites, the transport cart itself is transported by a forklift. In this case, the two forks of the forklift are usually inserted between the front and rear casters below the transport cart and raised to support the underside of the transport cart. Here, because the casters of the transport cart of Patent Document 1 can rotate freely, there is a situation where the brake pedal is located below the transport cart. In this state, when the forks are inserted below the transport cart or raised, the forks may come into contact with the brake pedal, causing the brake pedal to be pushed up excessively, which may cause deformation or damage.

[0005] The present invention has been made in consideration of the above-mentioned problems, and has an object to provide a caster and a transport cart that can prevent deformation and damage of the caster when transported by a forklift. [Means for solving the problem]

[0006] The caster of the present invention is a caster comprising a wheel, a support part which supports the wheel so as to be freely rotatable, and a brake pedal which is supported on the support part so as to be swingable in the vertical direction and which directly or indirectly brakes the wheel, wherein the brake pedal has an operating part which is operated by a user to swing up and down, and the operating part is arranged in a position which overlaps with the wheel when viewed from the direction of travel of the wheel, and when the brake is released, the underside is inclined upwardly as it approaches the tip when viewed from a direction perpendicular to the direction of travel of the wheel. Effect of the Invention

[0007] According to the present invention, deformation and damage of the casters can be prevented when transporting with a forklift. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a bottom view of the transport cart according to the first embodiment. [Diagram 2] FIG. 2 is a plan view of the transport cart according to the first embodiment. [Diagram 3] FIG. 2 is a side view of the transport cart according to the first embodiment. [Figure 4] FIG. [Diagram 5] FIG. 13 is a cross-sectional view of the caster with the brake released. [Figure 6] FIG. 1 is a cross-sectional view of a caster in a braked state. [Figure 7] 1 is an exploded perspective view of the joining structure between the casters and the mounting plate as viewed from above. FIG. [Figure 8]FIG. 4 is an exploded perspective view of the joint structure between the caster and the mounting plate as viewed from below. [Figure 9] 13 is a bottom view of the mounting plate and the reinforcing member superimposed thereon. FIG. [Figure 10] FIG. 4 is a partial cross-sectional view showing the joining structure between the caster and the mounting plate. [Figure 11] FIG. 11 is a side view showing a state before the transport cart is transported by a forklift. [Figure 12] FIG. 11 is a side view showing a state before the transport cart is transported by a forklift. [Figure 13] FIG. 11 is a perspective view showing a configuration of a cover portion of the second embodiment. [Figure 14] FIG. 11 is a plan view of the transport cart according to the second embodiment. [Figure 15] FIG. 11 is a side view of the transport cart according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The caster and the transport cart according to the present embodiment will be described with reference to the drawings. (First embodiment) FIG. 1 is a bottom view of the transport cart 1. FIG. 2 is a plan view of the transport cart 1. FIG. 3 is a side view of the transport cart 1. In each drawing, the direction of travel of the transport cart 1 is the front-rear direction, with the front side indicated as Fr, the rear side as Rr, the right side as R, and the left side as L. Therefore, the side view of FIG. 3 is a view seen from a direction perpendicular to the direction of travel of the transport cart 1. Note that the transport cart 1 of this embodiment can travel in any direction, including front-rear, left-right, and front-rear, and is not limited to the front side.

[0010] The transport cart 1 includes a cart body 10, casters 20, etc. First, the carriage body 10 will be described. The cart body 10 has a frame section 12 constituted by pipes 11 as a plurality of angular frame members made of iron or aluminum alloy, and a base 13 for placing an article on the frame section 12. The pipes 11 and base 13 are, for example, anodized, and the entire surface is a metallic color such as silver. As shown in Fig. 1, the frame section 12 is formed in a lattice shape by joining pipes 11 together in the front-rear and left-right directions. Here, four pipes 11a that are long in the front-rear direction, pipes 11b that are slightly short in the left-right direction, and pipes 11c that are short in the left-right direction are joined together to form a plurality of rectangular spaces 14 in three rows in the front-rear direction and four rows in the left-right direction. At the four corners of the frame section 12, the pipes 11a and 11b are joined by corner members 15. The corner members 15 are made of an aluminum alloy formed by extrusion molding, for example, and have insertion holes 15a formed in the vertical direction into which the push rod C is inserted.

[0011] Of the multiple spaces 14, mounting plates 40 for mounting casters 20 are attached to the lower parts of the front spaces 14 on both the left and right sides and the lower parts of the rear spaces 14 on both the left and right sides. Each mounting plate 40 has a shape in which a corner adjacent to the corner member 15 is cut out, and is fixed to pipes 11a, 11b, and 11c via blind rivets 16 so as to close off 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, or the like so as to close from above the entire space 14 where the mounting plate 40 is not attached.

[0012] Next, a description will be given of the caster 20. The caster 20 runs on a running surface while supporting the load of an article placed on the base 13. The caster 20 is rotatable about a rotation axis O. In this embodiment, the casters 20 are arranged at least at the four corners of the underside of the cart body 10, so that the cart body 10 can travel in a stable state without tilting when the transport cart 1 is travelling.

[0013] The casters 20 in this embodiment are so-called braked casters that can be braked or released according to the user's operation. In addition, in the transport cart 1, all of the four casters 20 may be braked casters, or any one to three of the casters may be braked casters.

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

[0015] The support portion 25 rotatably supports the wheel 21 via the axle 24. The support portion 25 supports the wheel 21 and includes a fork member 26 that is attached to the carriage body 10 via a mounting plate 40, and a pedal holding member 31 that supports the brake pedal 35 so that it can swing freely. The fork member 26 is formed, for example, by press-molding 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 with a pair of side walls 26a located 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. The pair of side walls 26a are each formed with an axle hole 26c through which the axle 24 is inserted, and an axle hole 26d for supporting the pedal holding member 31. 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 caster 20. As shown in Fig. 5, an insertion hole 26e is formed in the center of top plate 26b coaxially with the pivot axis O of caster 20, and an annular housing groove is formed around the pivot axis O so that a plurality of bearings 29 can be stably arranged on the upper surface of top plate 26b, and a plurality of bearings 30 can be stably arranged on the lower surface. The upper plate member 27 is formed, for example, by press-molding a steel plate. The upper plate member 27 is formed in a circular shape slightly larger than the top plate 26b, and a through hole 27a is formed in the center coaxially with the pivot axis O. The upper plate member 27 also has an annular accommodation groove 27b formed on the lower surface to stably arrange the bearing 29. By forming the annular accommodation groove 27b in this way, an arc-shaped protrusion 27c is formed on the upper surface of the upper plate member 27 along a ring shape centered on the pivot axis O. The upper plate member 27 also has an inclined portion 27d that is inclined downward from the protrusion 27c toward the through hole 27a. The outer peripheral edge portion 27e of the upper plate member 27 is formed to be arc-shaped in cross section and then hangs down.

[0017] The lower plate member 28 is formed, for example, by press-molding a steel plate. The lower plate member 28 is formed in a circular shape smaller than the top plate 26b, and an insertion hole 28a is formed in the center coaxially with the pivot axis O. The lower plate member 28 also has an annular accommodation groove 28b formed on the upper surface thereof to stably dispose the bearing 30. Here, the upper plate member 27 and the lower plate member 28 are integrally joined 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 rotate about the pivot axis O relative to the upper plate member 27 and the lower plate member 28 via the bearings 29 and 30.

[0018] Returning to FIG. 4, the pedal holding member 31 is formed, for example, by press-molding a steel plate. The pedal holding member 31 is, for example, nickel-plated, and the entire surface is a metallic color such as silver. The pedal holding member 31 is integrally formed with a pair of side walls 31a located on both sides of the wheel 21, and a connecting plate 31b connecting the pair of side walls 31a at the upper side. The pair of side walls 31a are formed by extending a bifurcated first support portion 31c and a bifurcated second support portion 31d from the connecting plate 31b in different directions. An axle hole 31e is formed at the tip side of the first support portion 31c, which communicates with the axle hole 26c of the fork member 26 and through which the axle 24 is inserted. On the other hand, an axle hole 31f is formed at the tip side of the second support portion 31d, which communicates with the axle hole 26d of the fork member 26 and through which the shaft member 32 is inserted. Moreover, a support hole 31g for pivotably supporting the brake pedal 35 is formed in an upper portion of the side wall 31a and in a position close to the connecting plate 31b. Moreover, a long hole 31h that is long in the approximately front-rear direction is formed below the support hole 31g of the side wall 31a. 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 is inclined downward toward the rear. In this embodiment, the inclination angle of the connecting plate 31b is approximately 45 degrees.

[0019] The pedal holding member 31 also 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-molding a stainless steel plate. The leaf spring 33 is formed with a support hole 33a through which the shaft member 32 passes, and one end 33b and the other end 33c that extend in different directions from the support hole 33a. A protrusion 33d that partially protrudes upward is formed on the tip side of the other end 33c along the plate width direction.

[0020] The brake pedal 35 is formed, for example, by press-molding a steel plate. The brake pedal 35 is, for example, nickel-plated, and the entire surface is a metallic color such as silver. The brake pedal 35 has a pedal body 35a and an operation piece 35b as an operation part that extends integrally from the pedal body 35a. The pedal body 35a is integrally formed with 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 upper part. When the caster 20 is viewed in the traveling direction, the brake pedal 35 is disposed at a position overlapping the wheel 21. In addition, the distance between the pair of side walls 35c is formed 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 in the pedal holding member 31 so that the connecting plate 35d overlaps the connecting plate 31b of the pedal holding member 31. In addition, a swing hole 35e is formed in the front and upper part of the side wall 35c, which communicates with the support hole 31g of the pedal holding member 31 and 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. In addition, a shaft hole 35f is formed below the swing hole 35e of the side wall 35c, which communicates with the long hole 31h of the pedal holding member 31 and 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 the long 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 operation piece 35b is substantially plate-shaped, and is operated by the user's foot or the like to swing the brake pedal 35 up and down. The operation piece 35b is formed by extending obliquely from the rear part of the connecting plate 35d of the pedal body 35a. The operation piece 35b is formed in a rectangular shape with a plate width substantially the same as that of the connecting plate 35d. The operation piece 35b of this embodiment is designed to prevent the caster 20 from being deformed or damaged even if the fork comes into contact with the operation piece 35b when the fork is inserted below the transport cart 1 or raised. The function of the operation piece 35b will be described later.

[0022] As shown in FIG. 3, when the caster 20 is attached to the cart body 10 via the mounting plate 40, the caster 20 rotates around the rotation axis O. In particular, since the rotation axis O is set at a position eccentric to the axle 24 of the caster 20, the caster 20 rotates so that the wheel 21 is on the rear side relative to the front side, which is the traveling direction. At this time, at least a part of the operation piece 35b of the brake pedal 35 of the rear caster 20 is located on the outer side (rear side) of the rear end part of the cart body 10, specifically, the rear pipe 11b. Therefore, the user can easily see the operation piece 35b of the brake pedal 35 and can operate it with his foot. When the traveling direction is reversed by 180 degrees, the wheels 21 rotate so that they face forward. Therefore, the front caster 20 is positioned so that at least a part of the operation piece 35b of the brake pedal 35 is positioned outside (front of) the front pipe 11b.

[0023] Next, the operation of each member of the caster 20 configured as described above from a brake-released state to a brake-applied state will be described. FIG. 5 is a cross-sectional view of the caster 20 showing the brake released state. As shown in FIG. 5, in the brake released state, the brake pedal 35 is in a position raised around the shaft 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 shaft member 37 by the biasing force of the leaf spring 33 itself. In other words, the state of FIG. 5 shows a brake released state in which the wheel 21 is not in contact with any member and can rotate freely. The brake pedal 35 is held at a position where the pedal body 35a overlaps the pedal holding member 31 by frictional forces between the respective members.

[0024] 5, when the user operates the brake pedal 35 so as to depress the operating piece 35b of the brake pedal 35 downward with his / her foot, the brake pedal 35 swings downward about the shaft member 36 against the bias of the leaf spring 33 and the frictional forces between the respective members. 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] Fig. 6 is a cross-sectional view of the caster 20 showing the brake applied state. As shown in Fig. 6, when the user depresses the operating piece 35b to the lowest limit, the shaft member 37 moving with the brake pedal 35 climbs over the apex of the protruding portion 33d of the leaf spring 33. Therefore, the leaf spring 33 is pushed toward the wheel 21 by the shaft member 37, so that 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 Fig. 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. From the state shown in FIG. 6, the user can push the operating piece 35b of the brake pedal 35 upward with his / her foot or the like to return to the state shown in FIG. 5 again, thereby releasing the brake.

[0026] Next, a description will be given of a joining structure for joining the caster 20 to the mounting plate 40. The transport cart 1 of this embodiment is configured to prevent deformation and damage of the caster 20 when a force is applied to the caster 20, for example, when the wheel 21 collides with an obstacle. 7 is an exploded perspective view seen from above of the joint structure between the caster 20 and the mounting plate 40. Here, the joint structure between the caster 20 and the mounting plate 40 at one location will be described, but the joint 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 Fig. 7 are already assembled.

[0027] The mounting plate 40 is formed, for example, by pressing a plate-shaped aluminum alloy. An insertion hole 40a through which the bolt 44 is inserted is formed in the approximate center of the mounting plate 40, coaxially with the pivot axis O. The insertion hole 40a is formed at a position stepped down in a cone shape 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 (front surface) 40b of the mounting plate 40 when the bolt 44 is inserted. FIG. 8 is an exploded perspective view of the joint structure of the mounting plate 40 and the reinforcing member 50, as viewed from below. When the mounting plate 40 is viewed from below, the insertion hole 40a is formed at a position bulging out in a cone shape from the lower surface (rear surface) 40c of the mounting plate 40. As shown in FIG. 8, the mounting plate 40 is formed with an annular rib 40d centered on the pivot axis O. The annular rib 40d bulges from the lower surface 40c of the mounting plate 40. The mounting plate 40 is formed with a plurality of rectangular ribs 40e surrounding the annular rib 40d. The rectangular rib 40e is formed by recessing the lower surface 40c along the rectangular outer shape. That is, the area inside the rectangular rib 40e is a flat surface at the same height as the lower surface 40c. The rectangular ribs 40e are formed at equal intervals along the circumferential direction centered on the pivot axis O, at a total of eight locations in the front-rear, left-right, and front-rear, left-right, and middle positions. Here, among the plurality of rectangular ribs 40e, protrusions 40f are formed as positioning portions in the left and right rectangular ribs 40e in order to position the reinforcing member 50 at a predetermined position. The formation of the annular rib 40d and the rectangular ribs 40e can improve the rigidity of the mounting plate 40. A plurality of fixing holes 40g are formed around the periphery of the mounting plate 40 for inserting blind rivets 16 therein to mount the mounting plate 40 to the bogie body 10.

[0028] The reinforcing member 50 is formed, for example, by press-molding a plate-shaped aluminum alloy. When the caster 20 is joined to the mounting plate 40, the reinforcing member 50 of this embodiment is disposed between the caster 20 and the mounting plate 40, and contacts both the upper surface of the caster 20, i.e., the upper surface of the upper tray 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 formed therein, the circular opening 50a being centered on 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 protrusion 27c of the upper plate member 27. The reinforcing member 50 is formed with a lower convex portion 50b that contacts the upper surface of the upper dish member 27 and an upper convex portion 50c that contacts the lower surface 40c of the mounting plate 40. The lower convex portions 50b are rib-shaped that bulge downward, and are formed in a total of eight locations at equally spaced positions along the circumferential direction centered on the pivot axis O. The upper convex portions 50c are rib-shaped that bulge upward, and are formed in a total of eight locations at equally spaced positions along the circumferential direction centered on the pivot axis O. Therefore, when the reinforcing member 50 is viewed in a plan view, the lower convex portions 50b and the upper convex portions 50c are formed alternately along the annular shape.

[0030] Each lower protrusion 50b has a bulging portion 50d in the center that bulges most downward. That is, the lower surface of the lower protrusion 50b slopes downward from the opening 50a toward the bulging portion 50d, and slopes upward after passing the bulging portion 50d. Each upper protrusion 50c has a recess 50e formed along an annular shape in the center (see FIG. 7). The recess 50e is for preventing interference with the annular rib 40d so that the upper protrusion 50c of the reinforcing member 50 and the lower surface 40c of the mounting plate 40 are in contact with each other on their flat surfaces. Further, the reinforcing member 50 has, at its left and right ends, notches 50f formed as positioned portions for engaging with the projections 40f of the mounting plate 40. As shown in FIG.

[0031] Fig. 9 is a view of the mounting plate 40 as viewed from the underside 40c, and shows a state in which the reinforcing member 50 is superimposed on the mounting plate 40. In Fig. 9, the upper convex portion 50c of the reinforcing member 50 is colored with dots to facilitate understanding. As shown in FIG. 9, when the reinforcing member 50 is superimposed on the mounting plate 40, the eight upper convex portions 50c are located in the middle of the front-rear and left-right and the front-rear and left-right directions. The lower convex portions 50b and the upper convex portions 50c are alternately formed, so that the lower convex portions 50b are located on both sides adjacent to each upper convex portion 50c. The mounting plate 40 and the reinforcing member 50 are positioned by the engagement of the projections 40f of the mounting plate 40 with the notches 50f of the reinforcing member 50. At this time, the outer peripheral side of the recesses 50e on the upper surface of each upper convex portion 50c is abutted against the rectangular rib 40e of the mounting plate 40. Here, 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 are superimposed without rattling.

[0032] The reinforcing member 50 is formed using a steel plate having a thickness thinner than that of the mounting plate 40 and the fork member 26, and is therefore set to have a lower strength than the mounting plate 40 and the fork member 26.

[0033] Returning to Fig. 7, the washer member 42 is formed, for example, by press-molding a plate-shaped aluminum alloy. The washer member 42 is disposed 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 at a conically 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. In addition, since the outer diameter of the washer member 42 is set to be substantially the same dimension as the inner diameter of the opening 50a of the reinforcing member 50, it can be manufactured using a circular material punched by press molding to form the opening 50a of the reinforcing member 50. Therefore, by making effective use of the material, the washer member 42 and the reinforcing member 50 can be manufactured inexpensively.

[0034] To connect the caster 20 to the mounting plate 40, the bolt 44 is inserted through the insertion hole 42a of the washer member 42, the insertion hole 40a of the mounting plate 40, the opening 50a of the reinforcing member 50, the insertion hole 27a of the upper plate member 27, the insertion hole 26e of the top plate 26b, and the insertion hole 28a of the lower plate member 28 in that order, and fixed by screwing the nut 46 inside the fork member 26. FIG. 10 is a partial cross-sectional view showing the joint structure between the caster 20 and the mounting plate 40. As shown in FIG. 10, the reinforcing member 50 is located between the mounting plate 40 and the caster 20, and is arranged in a state of 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 convex portion 50c of the reinforcing member 50 contacts the lower surface 40c of the mounting plate 40. At this time, the recess 50e formed in the upper convex portion 50c can avoid interference with the annular rib 40d of the mounting plate 40. On the other hand, in the lower convex portion 50b of the reinforcing member 50, the inclined portion extending from the opening 50a to the bulging portion 50d of the lower surface of the lower convex portion 50b contacts the outer periphery side and the outer periphery edge portion 27e of the upper surface of the upper plate member 27. Note that the protrusion 27c and the vicinity of the insertion hole 27a of the upper surface of the upper plate member 27 directly contact the lower surface 40c of the mounting plate 40 without the reinforcing member 50 being interposed. That is, the reinforcing member 50 is disposed so as to fill the gap occurring between the lower surface 40c of the mounting plate 40 and the upper surface of the upper tray member 27.

[0035] The operation of the caster 20 and the transport cart 1 configured as above will now be described. First, the action of the operation piece 35b of the brake pedal 35 will be described. As shown in FIG. 3, when the transport cart 1 is transported by 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 while it is transported. At this time, if the position at which the two forks 60 are inserted into the transport cart 1 or the position at which they are raised is close to the casters 20, the brake pedal 35 will be pushed up by the forks 60, which may result in deformation or damage to the brake pedal 35, fork members 26, etc.

[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 being deformed or damaged. 11 is a side view showing a state when the ascending fork 60 comes into contact with the operation piece 35b of the brake pedal 35. Here, the lower surface of the operation piece 35b is inclined upward toward the tip. Therefore, the force of the fork 60 to raise the brake pedal 35 is converted into a force to move the transport cart 1 in the traveling direction of the wheels 21 by the inclined operation piece 35b. Note that the inclination angle α of the operation piece 35b is preferably set to, for example, 10 degrees or more and 50 degrees or less so that the ascending force can be efficiently converted into a force in the traveling direction, and is set to approximately 30 degrees here. 12 is a side view showing the state when the fork 60 is further raised. The transport cart 1 moves in the forward direction by the force converted by the tilting operation piece 35b. Therefore, even if the fork 60 is further raised, the brake pedal 35 has moved from the position where it contacts the fork 60, so deformation or damage of the caster 20 is prevented. In other words, the transport cart 1 can be transported by a forklift without damaging the caster 20.

[0037] Also, when the fork 60 is raised, it may come into contact with not only the operation piece 35b but also the pedal body 35a. Therefore, in this embodiment, the lower surface of the rear part of the pair of side walls 35c of the pedal body 35a is continuous with the inclination of the operation piece 35b and is inclined at approximately the same angle as the inclination angle of the operation piece 35b. Therefore, even if the pedal body 35a is pushed up by the fork 60, the transport cart 1 moves in the traveling direction in the same way as when it comes into contact with the operation piece 35b, so that the caster 20 is prevented from being deformed or damaged. 11, of the underside of the pedal body 35a exposed rearward from the outline of the rear end of the wheel 21, the front-rear length L1 of the underside inclined at substantially the same angle as the inclination angle of the operating piece 35b is formed longer than the front-rear length L2 of the underside inclined at an angle different from the inclination angle of the operating piece 35b. Therefore, it is possible to make it easier for the rising fork 60 to come into contact with the operating piece 35b or the underside of the pedal body 35a inclined at substantially the same angle as the inclination angle of the operating piece 35b.

[0038] In this embodiment, when the fork 60 is raised and contacts the pedal body 35a, the pedal body 35a and the pedal holding member 31 are not deformed before the transport cart 1 moves in the traveling direction. Specifically, the brake pedal 35 is positioned in 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 a force acts on the brake pedal 35 to push it up, the force is transmitted to the connecting plate 31b of the pedal holding member 31, which is formed to have a relatively large area, so that the brake pedal 35 is prevented from being deformed. In addition, the pedal holding member 31 is firmly fixed to the fork member 26 by the first support portion 31c, which supports the pair of side walls 31a at the axle position, and the second support portion 31d, which supports the pair of side walls 31a at a position above the axle position. Therefore, even if a force acts to push up the pedal holding member 31 via the brake pedal 35, the force is received by the pedal holding member 31 itself which is firmly fixed to the fork member 26, and therefore deformation of the pedal holding member 31 is prevented. In other words, before the transport cart 1 moves in the traveling direction, deformation of the pedal main body 35a and the pedal holding member 31 can be prevented.

[0039] In this embodiment, as shown in Fig. 6, when the brake is applied, the operation piece 35b is substantially horizontal and is slightly inclined upward from the horizontal toward the tip. By making the operation piece 35b substantially horizontal in this way, when the fork 60 is raised, it comes into contact with the lower surface of the operation piece 35b, making 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 operation piece 35b is inclined upward toward the tip, so that the transport cart 1 can move in the travel direction as shown in Figs. 11 and 12, and deformation or damage of the caster 20 is prevented.

[0040] Next, the function of the reinforcing member 50 of the transport cart 1 will be described. As shown in FIG. 10, it is assumed that the wheel 21 of the caster 20 collides with an obstacle B located in front of the caster 20 in the traveling direction. When the wheel 21 collides with the obstacle B, a moment is generated in the caster 20 that rotates in the direction of the arrow A about the bolt 44. Here, if the reinforcing member 50 is not arranged, a gap exists 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 a portion of the upper surface of the upper plate member 27 that extends beyond the protruding portion 27c and reaches the outer peripheral edge portion 27e. Therefore, the caster 20 is allowed to rotate in the direction of the arrow A about the bolt 44 by the amount of the gap, and therefore there is a risk that the fork member 26 will be plastically deformed.

[0041] On the other hand, as in this embodiment, by arranging the reinforcing member 50 so as 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 and centered on 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 by colliding 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 convex portion 50b of the reinforcing member 50. Here, since the collision occurs on the front side of the wheel 21, the force is mainly transmitted to the two lower convex portions 50b formed at the rear of the reinforcing member 50. That is, since the lower convex portions 50b are arranged at the rear of the reinforcing member 50 at a distance from each other on the left and right, the moment generated in the caster 20 can be reliably received by the lower convex portions 50b.

[0042] The force transmitted to the lower convex portion 50b propagates within the reinforcing member 50 and is transmitted to the lower surface 40c of the mounting plate 40 mainly via the upper convex portion 50c formed between the two lower convex portions 50b, as well as via the two upper convex portions 50c formed on the left and right of the two lower convex portions 50b. In this way, the moment generated in the caster 20 due to collision with the obstacle B is transmitted to the mounting plate 40, which has excellent strength, via the reinforcing member 50, so that plastic deformation of the fork member 26 can be prevented and the strength of the caster 20 and the transport cart 1 can be improved. Furthermore, since the lower convex portions 50b and upper convex portions 50c of the reinforcing member 50 are alternately formed along the annular shape of the reinforcing member 50, plastic deformation of the fork member 26 can be prevented not only when an obstacle B collides with the front side of the wheel 21, but also when a force is applied to the pivot axis O from any direction.

[0043] Next, assume that the caster 20 collides excessively with the obstacle B or an excessive force is applied thereto. In this case, the reinforcing member 50, which is set to have a lower strength than the mounting plate 40 and the fork member 26, undergoes plastic deformation. Specifically, the lower convex portion 50b and the upper convex portion 50c of the reinforcing member 50 undergo plastic deformation so as to be crushed in the vertical direction, thereby preventing plastic deformation of the mounting plate 40 and the 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. Note that the same or substantially the same configuration as the first embodiment will be given the same reference numerals, and the description thereof will be omitted as appropriate. In the second embodiment, at least a part of the operation piece 35b of the first embodiment is covered with a cover part 70, and the cover part 70 functions as an operation part. Fig. 13 is a perspective view showing the configuration around the cover portion 70. As shown in Fig. 13, the operation piece 35b is formed by extending integrally from the rear part of the connecting plate 35d of the pedal body 35a. The operation piece 35b is formed in a rectangular shape with a plate width slightly narrower than the plate width of the connecting plate 35d. At the boundary between the operation piece 35b and the pedal body 35a, a plurality of (here, two) ribs 35g are formed spaced apart in the width direction. The ribs 35g increase rigidity so that the bent state between the pedal body 35a and the operation piece 35b can be maintained.

[0045] A cover portion 70 is attached to the operation piece 35b. 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 a different color from the brake pedal 35, that is, a different color from the pedal body 35a and the operation piece 35b. Here, the cover portion 70 may be colored in one of the three primary colors, such as red, green, and blue, or may be colored orange. In FIG. 13, the cover portion 70 is colored gray to facilitate understanding.

[0046] The cover portion 70 is generally plate-shaped, and includes a first cover member 71 and a second cover member 75 . The first cover member 71 mainly covers the upper surface and both side surfaces of the operation piece 35b. The first cover member 71 has a generally 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 operation 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 generally flat upper surface, on which a plurality of anti-slip ridges 73 are formed along the width direction, and a rib covering portion 74 that covers the rib 35g is formed at the front end. The second cover member 75 mainly covers the underside of the operation piece 35b. The second cover member 75 is generally plate-shaped, and has claw-shaped locked portions 76 formed on both sides of the front end to be locked to the locking portions 72. The locked portions 76 are capable of bending inward due to cutout portions 77 formed adjacent thereto. 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 second cover member 75 has a generally flat underside, and a plurality of anti-slip ridges 79 are formed on the flat surface along the width direction (see FIG. 15).

[0047] When attaching the cover portion 70 to the operation piece 35b, the operation 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 side surfaces of the operation piece 35b are covered by the first cover member 71, and the rib 35g is covered by the rib covering portion 74. Next, the second cover member 75 is inserted into the space of the first cover member 71 from the opening at the rear end of the first cover member 71. At this time, the locked portion 76 of the second cover member 75 is pressed by the inner surface of the first cover member 71 and inserted while bending inward, and is released from bending when it reaches the locking portion 72 and is locked to the locking portion 72. In this state, the lower surface of the operation piece 35b is covered by the second cover member 75. The entire area of ​​the operation piece 35b of this embodiment is covered by the first cover member 71 and the second cover member 75. When the cover portion 70 is attached to the operation piece 35b, it is positioned so as to overlap the wheel 21 when the caster 20 is viewed in the traveling direction. The cover portion 70 is prevented from coming off the operation piece 35b due to friction between the cover portion 70 and the operation piece 35b.

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

[0049] In addition, since the cover portion 70 is attached so as to cover at least a part of the operation piece 35b of the brake pedal 35, it is not necessary to color the entire brake pedal 35 in a color different from that of the pipe 11b, and it is sufficient to color only the cover portion 70 in a color different from that of the pipe 11b. Therefore, it is easy to color the cover portion 70. Note that it is not necessary for the entire cover portion 70 to be positioned outside the rear pipe 11b, and as long as at least a part of the cover portion 70 is positioned outside the rear pipe 11b, visibility for the user can be improved. In addition, since the cover part 70 is a member that is operated by the user, it may become worn or damaged. Even in such a case, the cover part 70 can be easily replaced because the cover part 70 is separate from the brake pedal 35.

[0050] As shown in FIG. 15, the lower surface of the cover portion 70 is inclined upward toward the tip, similar to the operation piece 35b of the first embodiment. Therefore, when the rising fork 60 contacts the cover portion 70 of the brake pedal 35, the force of the fork 60 to raise the brake pedal 35 is converted into a force to move the transport cart 1 in the traveling direction of the wheels 21 by the inclined cover portion 70. 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 rising force can be efficiently converted into a force in the traveling direction, and is set to approximately 30 degrees here. As shown in the enlarged view of FIG. 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 is set to approximately 30 degrees here. 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 of the fork 60 lifting the brake pedal 35 is converted by the inclined cover portion 70 into a force that moves the transport cart 1 in the traveling direction of the wheels 21. Therefore, it is possible to prevent the caster 20 from being deformed or damaged.

[0052] Although the present invention has been described above with reference to the above-mentioned embodiment, the present invention is not limited to the above-mentioned embodiment, and modifications are possible within the scope of the present invention. For example, the first embodiment and the second embodiment may be combined. In the above embodiment, the case where four casters 20 are arranged on the underside of the dolly body 10 has been described, but this is not limited to this case. The number of casters 20 can be freely changed depending on the use of the transport dolly 1. For example, one or more casters 20 may be added at least in any position inside, outside, or on the area line surrounded by the four casters 20 in a plan view. For example, two casters may be added to the inside of the area, in the center in the left-right direction, spaced apart from each other in the front and rear. Also, for example, one caster may be added between the two front and rear casters 20 arranged on the right side, and one caster may be added between the two front and rear casters 20 arranged on the left side, for a total of two casters. In any example, it is preferable to arrange 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 that do not have a brake pedal 35 or a pedal holding member 31.

[0053] In the above embodiment, the support portion 25 is configured as separate members, the fork member 26 and the pedal holding member 31. By configuring them as separate members in this manner, the fork member 26 of the brakeless caster can be shared. However, this is not limited to this case, and the fork member 26 and the pedal holding member 31 may be integrated.

[0054] In the above embodiment, the brake pedal 35 applies the brakes by indirectly pressing the wheel 21 via the shaft member 37 and the leaf spring 33, but the present invention is not limited to this. For example, the shaft member 37 and the leaf spring 33 may be omitted, and the brake pedal 35 may apply the brakes by directly pressing the outer circumferential surface of the wheel 21. Also, the brake pedal 35 may apply the brakes by directly or indirectly interfering with a member that rotates integrally with the wheel 21.

[0055] In the above-described embodiment, the mounting plate 40 to which the caster 20 is coupled is attached to the cart body 10, but this is not limited to the above. For example, the underside of the cart body 10 may be made flat, so that the caster 20 is directly attached to the underside of the cart body 10, and the mounting plate 40 may be omitted. In this case, the insertion holes 40a and the annular rib 40d formed in the mounting plate 40 may be formed directly in the cart body 10, so that the reinforcing member 50 can be disposed in contact with both the underside of the cart body 10 and the upper surface of the caster 20.

[0056] In the above embodiment, the reinforcing member 50 is described as having the upper convex portions 50c and the lower convex portions 50b alternately formed along a ring, but this is not limited to this case. For example, there are many occasions when the wheel 21 collides with an obstacle B in front, and a moment that tends to rotate the caster 20 rearward about the bolt 44 is generated. Therefore, the reinforcing member 50 may be formed with at least the upper convex portion 50c at the rear and the lower convex portions 50b on both sides of the upper convex portion 50c. In this case, the reinforcing member 50 does not need to be formed in a ring shape.

[0057] In the above embodiment, the cover portion 70 is described as being composed of the first cover member 71 and the second cover member 75, but this is not limited to this. In other words, the cover portion 70 is not limited in its configuration as long as it can cover at least a part of the operation piece 35b. However, it is preferable that the cover portion 70 covers the upper surface of the operation piece 35b in order to improve visibility. The cover portion 70 may be made of rubber to provide a better anti-slip effect.

[0058] In the above-described embodiment, the cover unit 70 is described as being composed of two members, the first cover member 71 and the second cover member 75, but this is not limited to the above. That is, the cover unit 70 may be composed of one member. For example, the first cover member 71 and the second cover member 75 may be integrally injection molded in a state where they are connected at a portion (connecting portion), and the cover unit 70 may be attached to the operation piece 35b by covering the operation piece 35b from above and below by rotating the connecting portion as a hinge portion. [Explanation of symbols]

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

Claims

1. Wheels and A support portion that rotatably supports the wheel; A caster including a brake pedal that is supported so as to be swingable in the vertical direction relative to the support portion and that directly or indirectly brakes the wheel, The brake pedal has an operating portion that is operated by a user to swing up and down, The operation unit includes: The caster is arranged in a position overlapping the wheel when viewed from the direction of travel of the wheel, and when the brake is released, the lower surface is inclined upward toward the tip when viewed from a direction perpendicular to the direction of travel of the wheel.

2. The brake pedal has the operation portion and a pedal body, 2. The caster according to claim 1, wherein the lower surface of the pedal body is continuous with the inclination of the operating portion and is inclined at approximately the same angle as the inclination angle of the operating portion.

3. The brake pedal has the operation portion and a pedal body, The caster according to claim 1, characterized in that, when viewed from a direction perpendicular to the traveling direction of the wheel, the front-to-rear length of the underside of the pedal body exposed from the outline of the wheel, which is inclined at approximately the same angle as the inclination angle of the operating part, is longer than the front-to-rear length of the underside formed at an angle different from the inclination angle of the operating part.

4. The operation unit includes:

4. The caster according to claim 1, wherein, in a braked state, the caster is substantially horizontal when viewed from a direction perpendicular to the traveling direction of the wheel.

5. The brake pedal has a pedal body and an operation piece extending integrally from the pedal body, The caster according to any one of claims 1 to 4, wherein the operation portion covers at least a part of the operation piece and is colored.

6. The support portion is A fork member supporting the wheel; The caster according to any one of claims 1 to 5, further comprising a pedal holding member that is fixed to the fork member at an axle position of the wheel and at a position above the axle position, and that supports the brake pedal so that it can swing.

7. The support portion has a biasing member that presses an outer circumferential surface of the wheel, 7. The caster according to claim 1, wherein the brake pedal has a shaft member that is movable by vertical swing and comes into contact with the biasing member.

8. A cart body on which an object is placed; A transport cart comprising: a caster according to any one of claims 1 to 7 attached to an underside of the cart body.

Images