Electric dolly

Abstract

To provide an electric dolly enabling smooth movement even when a problem occurs in an electric system, and improved in convenience.SOLUTION: An electric dolly includes: a dolly body 1 having a loading surface L; a wheel portion 2 provided on the wheel body 1; and control means 3 configured to electrically control a rotation operation of the wheel portion 2. The wheel portion 2 includes: a plurality of first wheels 21 having a substantially circular shape; a second wheel 22 having a rotation shaft P in an anteroposterior direction; and a raising / lowering mechanism that positions the rotation shaft P in a vertical direction by raising / lowering the second wheel 22. The second wheel 22 includes: a shaft portion 22a extending in an anteroposterior direction; and a protruding portion 22b spirally provided on an outer peripheral surface of the shaft portion 22a and capable of being grounded on a predetermined traveling surface together with the first wheel 21. The raising / lowering mechanism S is configured to be capable of manually moving the shaft portion 21a in a vertical direction.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an electric trolley.

Background Art

[0002] Conventionally, trolleys have been used in various scenarios such as transporting goods in warehouses and factories, and moving house operations. In particular, in recent years, many electric trolleys have been developed and widely popularized in order to simplify the transportation work.

[0003] However, when simply using electric wheels, there is a problem that it is difficult to move up and down stairs, especially when carrying goods.

[0004] By the way, Patent Document 1 describes an invention related to an electric trolley that can safely move up and down stairs. This electric trolley is configured with a pair of spiral wheels having a rotation axis orthogonal to the traveling wheels during normal travel provided on the left and right. And when the user rotates and drives the spiral wheel with a controller provided on the handle of the trolley, the electric trolley can smoothly move up and down the stairs.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, even the electric trolley described in Patent Document 1 still has the following problems.

[0007] That is, in the electric trolley described in Patent Document 1, the lower ends of the traveling wheels and the lower ends of the spiral wheels are on substantially the same plane. Therefore, if a problem occurs in the electrical system, the user will have to push the electric trolley manually during normal driving. However, due to the friction force of the helical wheels against the ground surface, there is a problem that the movement operation by pushing requires a great deal of labor.

[0008] The present invention has been made in view of the above actual situation, and an object thereof is to provide an electric trolley that enables a smooth movement operation even when a problem occurs in the electrical system and improves convenience.

Means for Solving the Problem

[0009] The present invention for solving the above problems includes a base body having a loading surface, a wheel portion provided on the base body, and control means for electrically controlling the rotation operation of the wheel portion. The wheel portion includes a plurality of first wheels having a substantially circular shape, a second wheel having a rotation axis in the front-rear direction, and a lifting mechanism for positioning the rotation axis in the vertical direction by lifting and lowering the second wheel. The second wheel includes a shaft portion extending in the front-rear direction and a protrusion portion provided spirally on the outer peripheral surface of the shaft portion and capable of contacting a predetermined running surface together with the first wheels. The lifting mechanism is configured to be manually movable in the vertical direction with respect to the shaft portion.

[0010] According to the present invention, by moving the second wheel upward by the lifting mechanism so that only each first wheel contacts the running surface, the friction force of the second wheel against the ground surface is eliminated, and even when a problem occurs in the electrical system, a smooth movement operation by pushing is possible.

[0011] In a preferred form of the present invention, a pair of left and right second wheels are provided. The lifting mechanism has a hanging portion that extends in the vertical direction and suspends and pivotally supports each second wheel below the base body, and a swing mechanism that swings the hanging portion about its proximal end side. The swing mechanism includes a link portion having one end thereof connected to the lower suspension portion and extending in the left-right direction, a traction portion that pulls the other end side of the link portion upward, a support portion that supports the traction portion so as to be slidable in the vertical direction, and a stopper portion that fixes the swing angle of the lower suspension portion.

[0012] With such a configuration, the lifting and lowering operations of the pair of left and right second wheels can be performed all at once, improving the convenience of the present electric trolley.

[0013] In a preferred form of the present invention, the stopper portion is provided with fastening means for screw-fastening the link portion together with the traction portion and the support portion, and an adjustment lever for adjusting the fastening force by the fastening means.

[0014] With such a configuration, the position of the rotation axis can be determined with a simple configuration, improving the convenience of the present electric trolley.

[0015] In a preferred form of the present invention, the support portion is provided with biasing means for biasing the traction portion downward.

[0016] With such a configuration, when the fastening force by the fastening means is released, the biasing force of the biasing means can be used to press each second wheel toward the running surface. Thereby, for example, even on a running surface with some unevenness, it is possible to surely ground on the running surface together with each first wheel and run stably.

[0017] In a preferred form of the present invention, the first wheels are rotatably connected to the lower suspension portion.

[0018] With such a configuration, a configuration for separately supporting each first wheel is not required, and the configuration of the lower part of the trolley body can be simplified.

[0019] In a preferred form of the present invention, the lower suspension portion is provided at both ends of the second wheel. The traction part is a substantially rod-shaped body extending in the front-rear direction, The pair of support parts are provided at intervals in the front-rear direction to support both ends of the traction part.

[0020] With such a configuration, the lifting operation of each second wheel can be stabilized with a simple structure.

Effects of the Invention

[0021] According to the present invention, even when a problem occurs in the electrical system, a smooth moving operation can be enabled, and an electric trolley with improved convenience can be provided.

Brief Description of the Drawings

[0022]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Best Mode for Carrying Out the Invention

[0023] Hereinafter, with reference to FIGS. 1 to 10, an electric trolley according to an embodiment of the present invention will be described. It should be noted that the following embodiments are examples of the present invention, and the present invention is not limited to the following embodiments. Also, in these figures, reference numeral X indicates the electric trolley according to the present embodiment.

[0024] <Configuration> Hereinafter, with reference to FIGS. 1 to 8, the configuration of the electric trolley X will be described.

[0025] As shown in FIGS. 1 to 5, the electric trolley X according to the present embodiment includes a trolley body 1 having a loading surface L, a wheel portion 2 provided on the trolley body 1, and a control means 3 for electrically controlling the rotation operation of the wheel portion 2. For the sake of convenience of the following description, the x-axis direction shown in FIG. 1 is referred to as the front-rear direction, the y-axis direction as the left-right direction, and the z-axis direction as the up-down direction.

[0026] The trolley body 1 has a base portion 11 and a frame portion 12 provided around the base portion 11.

[0027] The base portion 11 is a substantially rectangular plate-like body that is long in the front-rear direction. In addition, substantially cylindrical brackets b through which a first frame portion 12a described later is inserted are provided at the front and rear end faces of the base portion 11.

[0028] The frame portion 12 includes a first frame portion 12a surrounding the four end faces of the base portion 11, a substantially inverted U-shaped second frame portion 12b erected from the first frame portion 12a at the rear, and a pair of substantially E-shaped third frame portions 12c erected from the left and right first frame portions 12a. It should be noted that the frame portion 12 is configured as a hollow pipe as a whole.

[0029] The wheel part 2 has a plurality of substantially circular first wheels 21 having a rotation axis in the left-right direction, a second wheel 22 having a rotation axis P in the front-rear direction, and a lifting mechanism S that positions the rotation axis P in the vertical direction by lifting the second wheel 22.

[0030] The first wheel 21 is composed of a pair of front wheels 21a provided in the front and a pair of rear wheels 21b provided in the rear.

[0031] Each of the front wheels 21a and each of the rear wheels 21b include a pair of main wheels w1 arranged adjacent to each other in the left-right direction, and a plurality of sub-wheels w2 provided at intervals along the outer circumference of each main wheel w1.

[0032] Each main wheel w1 is a substantially disk-shaped structure that rotates about the left-right direction as an axis. Each sub-wheel w2 is a caster provided on the outer circumference of each main wheel w1 at regular angles with respect to each main wheel w1 such that a plurality of tangential directions in the outer shape of each main wheel w1 serve as rotation axes.

[0033] A pair of second wheels 22 are provided on the left and right such that their respective rotation axes P are substantially parallel. In addition, each second wheel 22 includes a shaft portion 22a extending in the front-rear direction, and a protrusion portion 22b provided spirally on the outer peripheral surface of the shaft portion 22a and capable of contacting a predetermined running surface together with the first wheel 21.

[0034] Regarding the rotation of each second wheel 22 around the rotation axis P, the rotation operation can be transmitted at a right angle to each front wheel 21a by a gear or the like (not shown), and each front wheel 21a and each second wheel 22 can be rotated synchronously. In addition, each second wheel 22 is preferably formed of a synthetic resin, a highly lubricating and durable material, etc., to improve the slidability during rotation and prevent damage to convex portions such as stairs.

[0035] Each shaft portion 22a is a substantially columnar elongated rod-shaped body.

[0036] Each protruding portion 22b is twisted in opposite directions with respect to each other, and each is a plate-like member protruding in the radial direction of each shaft portion 22a, whereby a so-called screw groove is formed in each shaft portion 22a. In the present embodiment, the left protruding portion 22b is wound around each shaft portion 22a in a left-handed direction in the direction from the rear to the front, and the right protruding portion 22b is wound around each shaft portion 22a in a right-handed direction in the direction from the rear to the front.

[0037] Here, regarding the configuration of each second wheel 22, when described in detail with reference to FIG. 5, the shaft portion 22a includes a main shaft g1 to which a rotation motor 32 is connected and which extends from the front wheel 21a to the rear wheel 21b, a plurality of cylindrical bodies g2 externally fitted to the main shaft g1, and elastic packings g3 interposed between the respective cylindrical bodies g2.

[0038] The main shaft g1 is provided with a timing pulley p around which a timing belt n2 wound around the shaft (not shown) of the corresponding rotation motor 32 is wound at its rear end. Note that the front end of the main shaft g1 is supported by a bearing (not shown).

[0039] Each cylindrical body g2 is formed with engagement protrusions h having an uneven shape that engage with the respective end portions of the adjacent cylindrical body g2 and the main shaft g1 at both open ends thereof. In addition, a part of the protruding portion 22b is provided for one full turn on the outer peripheral surface of each cylindrical body g2.

[0040] Each elastic packing g3 is interposed between the respective engagement protrusions h so as to conform to the shape of each engagement protrusion h.

[0041] Thereby, by meshing the respective cylindrical bodies g2 via the respective elastic packings g3, a part of the protruding portion 22b provided on each cylindrical body g2 is connected at its ends, and the protruding portion 22b wound around for the number of cylindrical bodies g2 is formed. In addition, the rotation of the main shaft g1 is reliably transmitted to each cylindrical body g2 by each engagement protrusion h (and each elastic packing g3), and the entire protruding portion 22b can be rotated.

[0042] The configuration of the lifting mechanism S will be described later with reference to FIGS. 6 to 8.

[0043] The control means 3 includes a power unit 31 provided in the middle of the second frame portion 12b, a rotation motor 32 provided at the rear end of each second wheel 22, and a joystick J.

[0044] The power unit 31 has a battery and a control circuit built therein, and a joystick J for steering protrudes from the outside.

[0045] The rotation motor 32 drives each second wheel 22, that is, rotates it around the rotation axis P, in response to the operation of the joystick J.

[0046] The user can individually or simultaneously drive / stop each second wheel 22 and reverse the rotation direction by operating the joystick J.

[0047] Here, the electric trolley X can be easily lifted and lowered on the stairs with the above configuration including a pair of second wheels 22.

[0048] That is, when each second wheel 22 rotates in the opposite direction simultaneously, the protrusion 22b pushes the stepped portion fitted in the thread groove by the so-called feed screw effect, thereby applying a propulsive force in the ascending or descending direction to the electric trolley X. In addition to ascending and descending the stairs, the second wheels 22 also cooperate with the first wheels 21 to apply a high propulsive force in the front-rear direction to the electric trolley X on a rough running surface with unevenness. Furthermore, even when the rotation operation stops during the ascending and descending of the stairs, since the thread groove engages with the stepped portion, the slipping of the electric trolley X can be prevented and the safety can be improved.

[0049] As another configuration, the electric trolley X is provided with a foot stopper F. The foot stopper F has a release lever F1 and a wheel pressing portion F2, similar to a general trolley. Thus, when the user steps on the release lever F1 with their own foot, the wheel pressing part F2 rotates, and the curved portions provided on the left and right come into contact with the respective rear wheels 21b, suppressing the rotational movement of each rear wheel 21b.

[0050] Hereinafter, the configuration of the lifting mechanism S will be described later with reference to FIGS. 6 to 8. Note that FIG. 6 is an overall perspective view of the lifting mechanism S as viewed from above. Further, FIG. 7 is a front view of the lifting mechanism S as viewed from either the front or the rear, and FIG. 8 is a cross-sectional view taken along line QQ' in FIG. 7 (showing only the front side and the rear side). Also, in FIG. 8, each link part S21 is shown as an end view, and the illustration of the suspension part S1 and the second bracket k2 is omitted. FIGS. 7 and 8 schematically illustrate the configuration, respectively.

[0051] As shown in FIGS. 6 to 8, the lifting mechanism S includes a suspension part S1 that extends in the vertical direction and suspends and pivotally supports each second wheel 22 below the carriage body 1, and a swing mechanism S2 that swings the suspension part S1 about its proximal end side as an axis.

[0052] The suspension part S1 is provided at both ends of each second wheel 22, and its upper part (proximal end side) is pivotally supported by a second bracket k2 described later. In addition, each suspension part S1 is provided with a pivot support part n1 (see FIG. 4) that extends in the left or right direction, and each first wheel 21 is rotatably connected to each pivot support part n1.

[0053] The swing mechanism S2 includes a link part S21 whose one end side is connected to each suspension part S1 and extends in the left - right direction, a traction part S22 that pulls the other end side of the link part S21 upward, a support part S23 that slidably supports the traction part S22 in the vertical direction, and a stopper part S24 that fixes the swing angle of the suspension part S1.

[0054] The link part S21 is a plate - like member whose one end side is connected below the center of each suspension part S1, and a link part slit sl that extends in the length direction (left - right direction) of each link part S21 is provided at the other end side. Also, as shown in FIG. 9 and the like, a pair of left and right reinforcing members T of an elongated rod shape for stabilizing the swinging motion are provided and suspended on the respective front and rear link portions S21.

[0055] The traction portion S22 is a substantially rod-shaped body extending in the front-rear direction, and male threads are cut at both end portions thereof.

[0056] The support portions S23 are provided in a pair at intervals in the front-rear direction. Also, on each support portion S23, on the lower surface of the base portion 11, a first bracket k1 projecting downward from substantially the center in the left-right direction thereof, a pair of second brackets k2 arranged on the left and right of the first bracket k1, and biasing means k3 for biasing the traction portion S22 downward are provided.

[0057] Each first bracket k1 has a substantially U-shaped cross-section in a side view, and a traction portion slit sk extending along the vertical direction is provided. Here, each of the link portions S21 provided respectively in the front and rear directions is superimposed such that the respective link portion slits sl and the corresponding traction portion slit sk communicate with each other, and the traction portion S22 is inserted through the slits sl and sk.

[0058] Each second bracket k2 has a substantially inverted L-shaped cross-section in a side view (see FIG. 10), and pivotally supports the proximal end side of each hanging lower portion S1.

[0059] As particularly shown in FIG. 8, the biasing means k3 includes a piston rod k31, a head portion k32 provided at the tip of the piston rod k31, a support cylinder k33 in which the piston rod k31 is slidably externally fitted in the vertical direction, and a compression spring k34 provided on the outer periphery of the support cylinder k33 for biasing the head portion k32 downward.

[0060] The head portion k32 is provided with a female thread portion through which the traction portion S22 is screwed and penetrated, whereby the traction portion S22 is supported so as to extend along the front-rear direction.

[0061] Note that, as particularly shown in FIG. 6, a fixing bolt j is inserted and screwed into a hole (not shown) provided in the flange portion at the lower end of the piston rod k31 and a hole (not shown) which communicates with this hole and is a female screw portion provided in the head portion k32, and these members are connected to each other. Further, four fixing bolts j are provided along the circumferential direction of the flange portion at the lower end of the piston rod k31 for each one support portion S23.

[0062] The stopper portion S24 is provided with fastening means m1 for screwing together the link portion S21 and the first bracket k1, and an adjustment lever m2 for adjusting the fastening force by the fastening means m1. Note that, in the perspective view such as FIG. 1, the stopper portion S24 is provided only at the rear end portion of the traction portion S22 (a bolt head portion is provided at the front end portion), but as shown in FIG. 6 (and FIG. 8), a pair of stopper portions S24 may be provided at both end portions.

[0063] The fastening means m1 is a so-called pipe nut having a substantially cylindrical shape that is screwed to both end portions of the traction portion S22.

[0064] The adjustment lever m2 extends in the radial direction from the outer periphery of the fastening means m1, and a spherical body r that a user grips is provided at the tip thereof.

[0065] <Usage method> Hereinafter, with reference to FIGS. 7 and 8, the flow of positioning the rotation shaft P in the vertical direction by the elevating mechanism S will be described.

[0066] When a problem occurs in the electrical system of the electric trolley X and it is desired to move the trolley by hand using only each first wheel 21, the user changes the state from the state shown in FIG. 7(a) or FIG. 8(a) to the state shown in FIG. 7(b) or FIG. 8(b).

[0067] That is, first, the user grips the adjustment lever m2 and rotates the front fastening means m1 counterclockwise and the rear fastening means m1 clockwise, respectively. As a result, the force (fastening force) by which the fastening means m1 and each head portion k32 sandwich each link portion S21 (and each first bracket k1) is unloaded.

[0068] Next, the user, for example together with another user, grips each stopper portion S24 etc., and lifts the traction portion S22 upward against the biasing force of the biasing means k3 (compression spring k34). As a result, the other end side of each link portion S21 is pulled upward, and each hanging portion S1 inclines inward in a front view (see Fig. 7(b)). Due to the swinging operation of each hanging portion S1 described above, each shaft portion 22a moves obliquely upward, and each second wheel 22 is lifted upward.

[0069] Next, while maintaining the state where the traction portion S22 is lifted, the user grips the adjustment lever m2 and rotates the front fastening means m1 clockwise and the rear fastening means m1 counterclockwise, respectively. Then, by the above-described rotating operation, the user presses each fastening means m1 against each link portion S21 to generate an axial force in the front-rear direction. As a result, as shown in Fig. 7(b) or Fig. 8(b), each link portion S21 (and each first bracket k1) is clamped (fastened) by the fastening means m1 and each head portion k32, and the downward movement of the traction portion S22 by the biasing means k3 is suppressed, whereby the rotation axis P is positioned.

[0070] In addition, when it is desired to perform normal traveling using each first wheel 21 and each second wheel 22, the user may release the fastened state by the fastening means m1 etc. by rotating the fastening means m1 again. As a result, by gravity and the biasing force of the biasing means k3 (compression spring k34), the electric trolley X naturally returns from the state shown in Fig. 7(b) or Fig. 8(b) to the state shown in Fig. 7(a) or Fig. 8(a).

[0071] Also, when in the state shown in FIG. 7(a) or FIG. 8(a), by leaving the fastening state by the fastening means m1 etc. released, the biasing force that presses each second wheel 22 against the running surface by the biasing means k3 is constantly acting. Therefore, for a running surface with some unevenness, by setting it to the above state, the electric trolley X runs stably while surely bringing each first wheel 21 and each second wheel 22 into contact with the running surface.

[0072] On the other hand, when in the state shown in FIG. 7(a) or FIG. 8(a), by setting each link portion S21 to be fastened by the fastening means m1 etc., the position of each second wheel 22 (the position in the vertical direction of the rotation axis P) is fixed regardless of the biasing force. Therefore, for a flat running surface, by setting it to the above state, the electric trolley X runs stably while surely bringing each first wheel 21 and each second wheel 22 into contact with the running surface. Note that when in the state shown in FIG. 7(a) or FIG. 8(a), the lower end of each first wheel 21 and the lower end of each second wheel 22 (the protrusion 22b) are arranged on substantially the same plane.

[0073] FIGS. 9 and 10 are perspective views showing the configuration of the lower part of the trolley body 11 in a state where each second wheel 22 is moved upward. FIG. 9 is a perspective view seen from the front side, and FIG. 10 is a perspective view seen from the rear side.

[0074] Here, the electric trolley X can perform steering in the following manner in addition to switching the use and non - use of each second wheel 22 by positioning the above - mentioned rotation axis P.

[0075] That is, when the user tilts the joystick J to either the left or right, the rotation speed of the second wheel 22 on the tilted side increases. By this operation and the control of the rotation direction of each second wheel 22, a propulsive force in either the left or right direction is applied to the electric trolley X.

[0076] At this time, in each of the first wheels 21, while the main wheel w1 rotates under the influence of a forward or backward driving force, the sub-wheel w2 that sequentially contacts the running surface rotates as it goes. As a result, smooth steering of the electric cart X in an oblique direction is performed.

[0077] <Effect> According to the present embodiment, by the elevating mechanism S, the second wheels 22 are moved upward so that only each of the first wheels 21 contacts the running surface, thereby eliminating the frictional force on the grounding surface of the second wheels 22. Even when a problem occurs in the electrical system, a smooth moving operation by hand pushing becomes possible.

[0078] Further, due to the configuration of the hanging part S1 of the elevating mechanism S and the swing mechanism S2, the lifting and lowering operations of the pair of left and right second wheels 22 can be performed all at once, improving the convenience of the electric cart X.

[0079] In addition, since the stopper part S24 is provided with a fastening means m1 and an adjustment lever m2 for adjusting the fastening force by the fastening means m1, the position of the rotation shaft P can be determined with a simple configuration, improving the convenience of the electric cart X.

[0080] Also, by the biasing means k3, for example, even on a running surface with some unevenness, it can be surely grounded on the running surface together with each of the first wheels 21 and run stably.

[0081] In addition, since each of the first wheels 21 is rotatably connected to the hanging part S1, a configuration for separately supporting each of the first wheels 21 becomes unnecessary, and the configuration of the lower part of the cart body 11 can be simplified.

[0082] Moreover, since the support parts S23 are provided in a pair at intervals in the front-rear direction and support both ends of the traction part S22 which is a substantially rod-shaped body extending in the front-rear direction, the lifting and lowering operations of each of the second wheels 22 can be stabilized with a simple configuration.

[0083] Note that the "abbreviation" in the application documents means a concept that includes chamfering or rounding being applied to the subsequent shape, and also includes cases where the elements constituting the shape are deformed or their lengths are changed within a range that does not impede the purpose of the shape. Also, the various shapes, dimensions, etc. of each component member shown in the above-described embodiments are examples, and can be variously changed based on design requirements and the like.

[0084] For example, in order to improve driving force, drainage performance, etc., a plurality of grooves such as so-called treads may be provided on the protrusions 22b of each second wheel 22.

Explanation of Reference Numerals

[0085] X Electric Trolley 1 Trolley Body 2 Wheel Unit 21 First Wheel 22 Second Wheel S Lifting Mechanism S1 Suspended Portion S2 Swing Mechanism S21 Link Portion S22 Traction Portion S23 Support Portion k1 First Bracket k2 Second Bracket k3 Biasing Means k31 Piston Rod k32 Head Portion k33 Support Cylinder k34 Compression Spring S24 Stopper Portion 3 Control Means

Claims

1. A trolley body having a loading surface, a wheel portion provided on the trolley body, and control means for electrically controlling the rotation operation of the wheel portion, wherein the wheel portion includes a plurality of first wheels having a substantially circular shape, a second wheel having a rotation axis in the front-rear direction, and a lifting mechanism for positioning the rotation axis in the vertical direction by lifting and lowering the second wheel, the second wheel includes a shaft portion extending in the front-rear direction and a protrusion provided spirally on the outer peripheral surface of the shaft portion and capable of contacting a predetermined running surface together with the first wheel, and the lifting mechanism is configured such that the shaft portion can be manually moved in the vertical direction. An electric trolley.

2. A pair of the second wheels are provided on the left and right, the lifting mechanism includes a hanging portion extending in the vertical direction and pivotally supporting each second wheel below the trolley body, and a swing mechanism for swinging the hanging portion about its proximal end side, the swing mechanism includes a link portion having one end side connected to the hanging portion and extending in the left-right direction, a traction portion for pulling the other end side of the link portion upward, a support portion for slidably supporting the traction portion in the vertical direction, and a stopper portion for fixing the swing angle of the hanging portion. The electric trolley according to claim 1.

3. The stopper portion is provided with fastening means for screw-fastening the link portion together with the traction portion and the support portion, and an adjustment lever for adjusting the fastening force by the fastening means. The electric trolley according to claim 2.

4. The support portion is provided with biasing means for biasing the traction portion downward. The electric trolley according to claim 3.

5. The first wheel is rotatably connected to the hanging portion. The electric trolley according to claim 2.

6. The hanging portion is provided at both ends of the second wheel, the traction portion is a substantially rod-shaped body extending in the front-rear direction, and the support portion is provided in a pair with a space therebetween in the front-rear direction to support both ends of the traction portion. The electric trolley according to any one of claims 2 to 5.

Images