Abstract:
A conveyance cart having a drive source such as an engine or an electric motor has a complicated structure and is expensive. Using such a conveyance cart exclusively for carrying a generator is not economical. To solve the problem, a simple-structured, low-priced conveyance cart is provided. A walking conveyance cart has an electrically driven traveling part and a placement part for placing thereon a portable engine generator. The electric traveling part can be driven by the power outputted from the portable engine generator placed on the placement part.

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
       [0001]    This application is based upon and claims the benefit of priority from Japanese Patent Applications JP2014-160349 filed on Aug. 6, 2014, and JP2014-182207 filed on Sep. 8, 2014, the entire disclosure of which are incorporated herein by reference. 
       BACKGROUND 
       [0002]    The present invention relates to a conveyance cart provided with an electrically driven traveling part. 
         [0003]    Portable engine generators are in general use as simple power supplies which can be used outdoors where appropriate power supplies are not available. They are used in wide ranging applications, for example, at construction sites, on farm land, or for leisure activities. Portable engine generators are, however, relatively heavy. Hence, carrying a portable engine generator by human power to a site of use is a great burden on the persons to carry it. Particularly, in an area where such transportation means as vehicles cannot be used, it is not easy to carry a portable engine generator over a long distance. 
         [0004]    Hence, hand carts like the one described in Japanese Examined Utility Model Application Publication No. Sho-50 (1975)-14119 or self-driven conveyance carts are used to carry portable engine generators. However, carrying a portable engine generator using a non-powered hand cart through an outdoor route possibly including slopes is not always easy. Using a self-driven conveyance cart is, therefore, advantageous. The self-driven conveyance carts that have been publicly known include, for example: the one-wheeled hand conveyance cart provided with a motor disclosed in Japanese Examined Utility Model Application Publication No. Sho-51 (1976)-25250; the electric conveyance cart disclosed in Japanese Unexamined Patent Publication No. 2000-6815; the electric conveyance cart disclosed in Japanese Unexamined Patent Publication No. 2000-261912; and the cart mounted with a rechargeable battery disclosed in Japanese Examined Utility Model Application Publication No. Sho-50 (1975)-14119. 
         [0005]    The one-wheeled hand conveyance cart provided with a motor disclosed in Japanese Examined Utility Model Application Publication No. Sho-51 (1976)-25250 is provided with a fixing plate 15 (reference number used in the publication; the same applies to the following reference numbers concerning the same conveyance cart) rotatably supported thereon. The fixing plate 15 is for having a motor 25 fixed thereto. A drive roller 21 to be driven by the motor 25 is also attached to the fixing plate 15. The drive roller 21 drives a wheel 3 by being pressed against the wheel 3. 
         [0006]    The electric conveyance cart disclosed in Japanese Unexamined Patent Publication No. 2000-6815 includes an electric motor and batteries which are used to drive a front wheel axle mounted with two front wheels and which are provided downward of a cart frame, two rear wheels removably attached to a rear portion of the cart frame, and a one-wheel caster unit which can be attached to the cart instead of the two rear wheels. 
         [0007]    The electric conveyance cart disclosed in Japanese Unexamined Patent Publication No. 2000-261912 includes a forward travel operation member and a backward travel operation member. The forward travel operation member and the backward travel operation member are attached to an end portion of an operation handle extending rearwardly and upwardly from a cart frame which is provided with a wheel and a motor to drive the wheel. The forward travel operation member is used to make the motor generate auxiliary power for a forward travel. The backward travel operation member is used to make the motor generate power for a backward travel. 
       SUMMARY 
       [0008]    A conveyance cart having a drive source such as an engine or an electric motor has a complicated structure and is expensive. Using such a conveyance cart exclusively for carrying a generator is not economical. An object of the present invention is to provide a simple-structured, low-priced conveyance cart. 
         [0009]    In order to solve the above-described problem, the present invention provides a walking conveyance cart comprising an electrically driven traveling part, and the walking conveyance cart is characterized in that it includes a placement part for placing thereon a portable engine generator and the traveling part can be driven using power outputted from the portable engine generator placed on the placement part as a power source. 
         [0010]    Further, in one embodiment of the walking conveyance cart of the present invention, the placement part is provided on an open plane over the walking conveyance cart. 
         [0011]    Further, in another embodiment of the walking conveyance cart of the present invention, the placement part is provided on a cart frame included in the walking conveyance cart. 
         [0012]    Furthermore, in another embodiment of the walking conveyance cart of the present invention, the placement part for placing thereon a portable engine generator is configured to allow the portable engine generator to be fixed thereto and removed therefrom, and the traveling part is configured to be releasable from electric drive force to make the walking conveyance cart usable as a non-powered hand conveyance cart. 
         [0013]    In addition, in another embodiment of the walking conveyance cart of the present invention, it comprises an auxiliary basket provided adjacent to the placement part. 
         [0014]    The walking conveyance cart of the present invention has an electric traveling part which can be driven by the power outputted from a portable engine generator carried by the cart. This makes it unnecessary for the walking conveyance cart itself to be provided with a driving power source. Hence, the present invention can provide a simple-structured, low-priced conveyance cart. 
         [0015]    A placement part can be provided on an open plane over the walking conveyance cart, so that a portable engine generator can be easily placed on and removed from the placement part. 
         [0016]    The placement part can be provided on a cart frame included in the walking conveyance cart, so that a portable engine generator can be easily placed on and removed from the placement part. 
         [0017]    The electric traveling part can be released from electric drive force and, when the electric traveling part is released from electric drive force, the walking conveyance cart can be used as a non-powered hand conveyance cart. This makes it possible to use the walking conveyance cart in diversified ways. Thus, a highly convenient walking conveyance cart which can be used effectively can be provided. 
         [0018]    An auxiliary basket is provided adjacent to the placement part, so that objects other than a portable engine generator can also be carried by the walking conveyance cart. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]      FIG. 1  is a side view of a walking conveyance cart in a state with a portable engine generator placed thereon according to a first embodiment representing an example of the present invention. 
           [0020]      FIG. 2  is a plan view of the walking conveyance cart in a state with a portable engine generator placed thereon according to the first embodiment representing an example of the present invention. 
           [0021]      FIG. 3  is a sectional view taken along line A-A in  FIG. 1  of an electric traveling part according to the first embodiment representing an example of the present invention. 
           [0022]      FIG. 4  is a sectional view taken along line A-A in  FIG. 1  of the electric traveling part in a state released from electric drive force according to the first embodiment representing an example of the present invention. 
           [0023]      FIG. 5  is an electrical wiring diagram according to the first embodiment representing an example of the present invention. 
           [0024]      FIG. 6  is a perspective view of a walking conveyance cart in a state with a portable engine generator placed thereon according to a second embodiment representing an example of the present invention. 
           [0025]      FIG. 7  is a perspective view of the walking conveyance cart in a state with a portable engine generator and other materials placed thereon according to the second embodiment representing an example of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0026]    A walking conveyance cart  1  (hereinafter also referred to simply as the “cart  1 ”) according to a first embodiment of the present invention will be described below with reference to  FIGS. 1 to 5 .  FIG. 1  shows a side view of the cart  1  of the first embodiment. The following description is based on the assumption that the left side of the cart  1  is forward direction of traveling, but the right side of the cart  1  is backward direction of traveling as seen in  FIG. 1 . 
         [0027]    The cart  1  has tires  40 , i.e. drive wheels, positioned on each side of a forward portion of a cart frame  2  along the direction of travel of the cart  1 . The cart  1  also has caster wheels  22  positioned on each side of a rearward portion of the cart frame  2  with a horizontally swiveling shaft provided vertically and shifted from the wheel axis position of the cart  1 . The caster wheels  22  on both sides of the cart frame  2  may be replaced by a single caster wheel provided around the center in the rearward portion of the cart frame  2  or may be replaced by a downwardly projecting stand-like support frame. 
         [0028]    A placement part  20  shaped like an open box capable of carrying a portable engine generator  9  is provided over the cart frame  2  to be between the tires  40  positioned on both sides of the forward portion of the cart frame  2  and to be above the caster wheels  22 . An auxiliary basket  21  which can accommodate, for example, electric cords or a fuel container containing fuel for the portable engine generator  9  is provided forward of the placement part  20 . Positioning the placement part  20  such that its bottom part is upward of the tires  40  allows the placement part  20  to be made wider without causing interference between itself and the tires  40 . 
         [0029]    On the rear side of the cart frame  2 , a handle  3  is provided to extend upwardly and rearwardly from left and right rear end portions of the placement part  20  of the cart frame  2 , so that, as seen from above, the handle  3  is U-shaped with the open side of the U shape facing forward as shown in  FIG. 2 . The handle  3  is provided, in an upper central portion thereof, with a forward/backward changeover switch lever  31  and a travel switch lever  30  both for use by the user. When the forward/backward changeover switch lever  31  is pushed forward into a forward travel position, the cart  1  can travel forward. When the forward/backward changeover switch lever  31  is pulled backward into a backward travel position, the cart  1  can travel backward. When the travel switch lever  30  and the handle  3  are grasped together bringing the travel switch lever  30  closer to the handle  3 , the cart  1  starts traveling forward or backward. The base portions fixed to the cart frame  2  of the handle  3  are forwardly foldable, so that the cart  1  can be compactly stored when not in use. 
         [0030]    A power cord  8  for supplying power to an electric traveling part  4  extends from a lower portion of the cart frame  2 . The power cord  8  is, at an end portion thereof, provided with a power plug  80  which can be plugged into a power outlet of the portable engine generator  9  placed on the placement part  20 . 
         [0031]      FIGS. 3 and 4  are each a sectional view taken along line A-A in  FIG. 1  and each show a main portion of the electric traveling part  4 . An axle  42  is provided to extend horizontally in a direction perpendicular to the travel direction of the cart  1 . The axle  42  is rotatably supported, at left and right end portions of the cart frame  2 , by bearings  48 . The axle  42  is mounted, at left and right end portions thereof, with tires  40  to be drive wheels via tire bosses  41 , respectively. 
         [0032]    An electric motor  46  for driving the tires  40  is attached to a central portion of the underside of the cart frame  2 . The electric motor  46  has an output shaft which extends perpendicularly to the travel direction of the cart  1  and is fixedly provided with a motor sprocket  45 . A roller chain  44  is wound over the motor sprocket  45  and an axle sprocket  43  fixed to the axle  42 . In this configuration, when the electric motor  46  rotates, the axle  42  rotates to drive the tires  40 . 
         [0033]    Each tire  40  has a tire boss  41  over which the wheel portion of the tire is mounted and which is rotatably inserted over the axle  42 . For each tire  40 , a fixing hole formed through the tire boss  41  perpendicularly to the axial direction of the axle  42  and a tire fixing hole  420  formed through the axle  42  also perpendicularly to the axial direction of the axle  42  are aligned, and a lock pin  47  is inserted through both through-holes, thereby, fixing each tire  40  to the axle  42 . The axle  42  has two tire fixing holes  420  formed through an end portion thereof on each side. When, as shown in  FIG. 4 , a lock pin  47  is inserted through only the outer one of the two tire fixing holes  420  on each side of the axle  42  without inserting the lock pin  47  through the fixing hole formed through the tire boss  41 , the tire  40  is rotatably retained on the axle  42 . In this state, the drive force of the electric motor  46  is not conveyed to the tire  40 , that is, the electric traveling part  4  is released from the electric drive force, so that the cart  1  can be used as a non-powered hand conveyance cart. 
         [0034]      FIG. 5  is an electrical wiring diagram representing an example of the present invention. A relay  5  is connected by wiring with, in addition to a forward/backward changeover switch  7  which operates interlocked with the forward/backward changeover switch lever  31  attached to the handle  3 , a travel switch  6  which operates interlocked with the travel switch lever  30  attached to the handle  3  and the electric motor  46 . As the power source, the power plug  80  attached to the power cord  8  is plugged into the power outlet of the portable engine generator  9 , causing power to be supplied from the portable engine generator  9  to the relay  5 . 
         [0035]    When the forward/backward changeover switch lever  31  attached to the handle  3  is put in the forward or backward travel position, the forward/backward changeover switch  7  is switched to cause the circuit of the relay  5  to change the rotation direction of the electric motor  46  so as to allow the cart  1  to travel forward or backward. When, after the position of the forward/backward changeover switch lever  31  is changed, the travel switch lever  30  is grasped, the travel switch  6  interlocked with the travel switch lever  30  is switched on, thereby, causing the relay  5  to supply the power from the portable engine generator  9  to the electric motor  46 . As a result, the electric motor  46  rotates for a forward or backward travel. 
         [0036]    When the walking conveyance cart  1  of the present invention is used to carry a portable engine generator  9 , the portable engine generator  9  is placed on the placement part  20  of the cart frame  2  and is fixed there. Subsequently, the power plug  80  attached to the end of the power cord  8  extending from the electric traveling part  4  provided downward of the cart frame  2  is plugged into the outlet of the portable engine generator  9  and the portable engine generator  9  is started. 
         [0037]    When removing the portable engine generator  9  from the placement part  20 , the portable engine generator  9  is unfixed from the placement part  20 . Since the placement part  20  is easily accessibly positioned between the tires  40  on the left and right sides of a forward portion of the cart frame  2  and upward of the caster wheels  22 , the portable engine generator  9  can be smoothly placed on and removed from the placement part  20 . 
         [0038]    When the user grasping the handle  3  puts the forward/backward changeover switch lever  31  into the forward or backward travel position and grasps the travel switch lever  30 , the walking conveyance cart  1  travels forward or backward depending on the position of the forward/backward changeover switch lever  31 . In this case, the electric motor  46  for driving the tires  40  rotates using the power supplied from the portable engine generator  9 . The walking conveyance cart  1  itself does not require any power supply such as batteries, so that it can be provided as a simple-structured, low-priced conveyance cart. 
         [0039]    When, on each side of the cart  1 , a lock pin  47  is inserted through only the outer tire fixing hole  420  of the axle  42  without inserting the lock pin  47  through the fixing hole formed through the tire boss  41 , i.e. the fixing portion of the tire  40 , the tire  40  is rotatably retained on the axle  42 . In this state, the tire  40  is released from the electric drive force of the electric motor  46 , so that the cart  1  can be used as a non-powered hand conveyance cart. 
         [0040]    A second embodiment of the present invention will be described below with reference to  FIGS. 6 and 7 . In the second embodiment, the auxiliary basket  21  of the first embodiment is provided, on the handle  3  side of the cart  1 , as a placement part  20  where the portable engine generator  9  is placed. 
         [0041]    In the second embodiment, the part corresponding to the placement part  20  of the first embodiment is used as a flat pallet part  23  as shown in  FIG. 7 . The pallet part  23  is used to carry a load W other than the portable engine generator  9 , for example, a fuel container containing fuel for the portable engine generator  9  or various materials. 
         [0042]    The placement part  20  of the second embodiment is provided on an open plane over the cart  1 . 
         [0043]    With the placement part  20  easily accessibly positioned in the second embodiment, too, the portable engine generator  9  can be smoothly placed on and removed from the placement part  20 . 
         [0044]    The present invention can be applied to a walking conveyance cart provided with an electrically operated traveling part.