Patent Application
20160264166
This invention relates in general to hand trucks and, in particular, to a portable, collapsible, motorized hand truck.
There are many contexts in which modern persons desire to carry large or heavy items where it is not suitable to employ means such as a truck, fork lift and the like. Such contexts include public parks, beaches, campgrounds and similar places where there are restrictions on vehicular traffic. Hand trucks are a well known means of carrying heavy loads in places where vehicular traffic is not suitable. Typically, hand trucks have a ladder-like frame with a handle at a top end and a set of wheels at the bottom end thereof. A generally perpendicular platform or plate typically extends from the frame proximate the bottom end. The platform is typically used to support objects being transported by use of the hand truck. With a hand truck, the strength of a person is required to provide the motive force to move the load over a desired distance. Pushing or pulling a hand truck, particularly if heavily laden, can be inconvenient. To ease that physical burden, a motorized hand truck is desirable.
Examples of motorized hand trucks are known, but these motorized hand trucks lack the features of being collapsible, portable, and easily transported. For example, U.S. Pat. No. 3,527,314, and No. 5,577,568, disclose motorized hand trucks having a large, fixed frame with a second pair of wheels that are driven by a motor mounted on the fixed frame. While the second pair of wheels provides flexibility to operate the hand truck in either hand-driven or motor-driven modes, the second pair of wheels, along with the large, fixed frame make the hand truck not suitable for being conveniently transported to places like public parks and beaches. Such hand trucks are typically transported by means of a large truck or trailer to a single location (like a warehouse) where the hand truck is employed.
U.S. Pat. No. 2,740,484 and No. 7,137,464 disclose motorized hand trucks having a large, fixed frame with a second pair of wheels, both sets of wheels being driven by a motor that is mounted on the frame. These hand trucks have features that make them capable of climbing stairs by means of the motor driven wheels as the hand truck is held in position by a person. The second set of wheels along with the large, fixed frames of these hand trucks make them not suitable convenient transport in a conventional automobile. Such hand trucks are typically transported by means of a large truck or trailer along with other large items (e.g. a refrigerator) to locations where the operator uses the stair-climbing capability to transport the large item up stairs.
U.S. Pat. No. 7,017,691 discloses a collapsible, hand-operated cart having three wheels with a battery and a motor disposed directly on the base platform that connects the three wheels. Although the cart is disclosed as having an attachable basket, in such a configuration the cart cannot be collapsed for transportation or storage. Also, unlike a hand truck, the cart requires the third wheel for stability, and the basket must be attached to the cart in order to use the cart to transport items. Similarly, U. S. Pat. No. 8,596,389 discloses a motorized, hand-operated cart having a collapsible frame. The cart requires four or more wheels for stability and requires a platform for mounting a basket that is used for transporting items.
There is needed a motor-driven hand truck to provide motive force to move large and heavy items that is also compact and collapsible for ease of transportation and storage. There is additionally a need for such a hand truck to be stable, rugged, and adaptable to multiple transport situations such as the rough terrain of parks and the sandy terrain of beaches.
Accordingly, it is an aspect of the present invention to provide a motorized hand truck that is portable and collapsible into a configuration that makes it easily transported and stored.
The foregoing and other aspects of the present invention are achieved by providing a hand truck that has a collapsible frame, the frame being movable between collapsed, storage mode and an expanded, upright mode. The hand truck has at least one wheel disposed at a lower end of the frame, a folding support platform hingedly or rotatably connected to a lower end of the frame, and having a battery, a drive controller, and at least one motor. The motor is mechanically connected to at least one wheel or to an axle of the hand truck, and the motor is electrically connected to the battery and the drive controller. The motor and battery are positioned on a lower part of the frame of the hand truck, proximate the wheel or axle to provide a more compact area for collapsing the frame, as well as to provide a lower center of gravity for the hand truck, thereby making the hand truck more stable.
The foregoing and other aspects of the present invention are further achieved by providing a method of manufacturing a motorized hand truck including providing a collapsible frame, the frame being movable between collapsed, storage mode and an expanded, upright mode. The frame has a lower frame portion proximate the lower end of the frame and an upper frame portion proximate the upper end of the frame that is pivotally or slideably connected to the lower frame portion and a folding support platform hingedly or rotatably connected to the lower end of the frame. The method also includes providing at least one wheel that is connected to the lower frame portion of the frame. The method may include providing means for connecting two wheels to an axle that is connected to the lower end of the frame. The method also includes providing a battery, drive controller, and at least one motor mechanically connected to at least one wheel of the hand truck, with the motor being also connected electrically to the battery and drive controller. As an alternative to said motor being connected to at least on wheel, said motor may be connected to an axle that is connected to the lower frame portion of said frame with a pair of wheels mounted on said axle such that the wheels rotate around a single axis. The motor and battery are positioned on the lower frame portion of the frame of the hand truck, proximate the wheel or axle to provide a more compact area for collapsing the frame, as well as to provide a lower center of gravity for the hand truck, thereby making the hand truck more stable.
Other objects, features and objectives of the invention will be found throughout the following description, drawings and the claims.
For a more complete understanding of the features and advantages of the present invention, reference is now made to the detailed description of embodiments of the present invention, examples of which are illustrated in the accompanying drawings in which corresponding numerals in different figures refer to corresponding parts and in which:
Further, hand truck 10 includes a drive compartment 100 disposed on lower frame portion 23. Drive compartment 100 houses at least one battery 110, a drive controller 120, and at least one motor 130 electrically connected to battery 110 and drive controller 120. At least one motor 130 may be mechanically connected to at least one wheel 30 or mechanically connected to axle 31 in order to provide driving force for the motorized hand truck. A main power switch 121 and a charging port 122 are preferably disposed on the drive compartment 100 and electrically connected to drive controller 120. In an alternate embodiment, at least one battery 110, drive controller 120, and at least one motor 130 may be mounted directly to frame 20 without use of drive compartment 100.
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While various embodiments of the invention have been described, the description is intended to be exemplary, rather than limiting and it will be apparent to those of ordinary skill in the art that other embodiments and implementations are possible that are within the scope of the invention. Accordingly, the invention is not to be restricted except in light of the attached claims and their equivalents.
