HANDCART

Abstract

A handcart is provided that includes a frame, wheels, and a motor that drives the rotation of the wheels. The number of wheels is two. The handcart includes a platform coupled to the frame, including a base and a vertical structure. It allows providing a self-propelled handcart with the two wheels and a variable length chassis that is as simple, safe to use, and inexpensive.

Claims

1-15. (canceled)

16. A handcart, comprising: a frame, wheels, and a motor that drives rotation of said wheels, wherein the number of wheels is two.

17. The handcart according to claim 16, wherein said two wheels are connected to each other by means of a shaft.

18. The handcart according to claim 17, wherein said shaft comprises two bearings and a connecting element, which connects or disconnects said bearings from each other.

19. The handcart according to claim 16, wherein transmission from the motor to the wheels is carried out by means of first and second transmission elements.

20. The handcart according to claim 19, wherein the first transmission element is a pinion or a pulley.

21. The handcart according to claim 19, wherein the second transmission element is a ring gear or a belt.

22. The handcart according to claim 16, wherein the motor is an electric motor powered by a battery.

23. The handcart according to claim 16, wherein the wheels comprise a tire.

24. The handcart according to claim 16, wherein the wheels have a diameter between 40 and 50 cm.

25. The handcart according to claim 16, wherein said motor is connected to an electronic controller to regulate its power.

26. The handcart according to claim 16, wherein the frame is of variable length and comprises a pair of extensible beams located in the upper part of said frame.

27. The handcart according to claim 26, wherein said extensible beams are curved.

28. The handcart according to claim 16, comprising a platform coupled to the frame.

29. The handcart according to claim 28, wherein the platform comprises wheels that rotate freely.

30. The handcart according to claim 28, wherein the platform comprises a base and a vertical structure.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] For a better understanding of what has been stated, some drawings are attached in which, schematically and only as a non-limiting example, a practical case of embodiment is represented.

[0028] FIG. 1 is a schematic perspective view of the self-propelled handcart according to the present invention; and

[0029] FIG. 2 is a schematic perspective view of the self-propelled handcart according to the present invention, which includes a platform.

DESCRIPTION OF A PREFERRED EMBODIMENT

[0030] The self-propelled handcart according to the present invention comprises a frame 1, a transmission system and two wheels 2, which will be described below.

[0031] The self-propelled handcart comprises a variable-length frame that comprises two extendable beams 11, with which it is possible to lengthen the frame 11, achieving a greater lever force.

[0032] The two extendable beams 11, one on each side of the frame 1, unfold telescopically, so that the operator can adjust the lever distance to the extent that suits him/her best, allowing the total distance of frame 1 to be adjusted easily depending on the of the weight of the load to be handled.

[0033] In the handcart according to the present invention, it can be moved by a first transmission system of simplified design and another second transmission system that is more sophisticated.

[0034] The first transmission system comprises an electric motor 8 powered by a battery 7 that drives a first transmission element 6, such as a pinion or pulley, which is connected to a second transmission element 5, such as a ring gear or a belt.

[0035] This second transmission element 5 is integral, coupled inside one of the two wheels 2, in such a way that it can transmit the movement to the other wheel 2 through bearings of an shaft 4 that connects both wheels 2.

[0036] This way of driving the rotation of the two wheels 2 by means of a single motor 8 connected to one of the wheels 2 makes it possible to simplify the transmission system.

[0037] This shaft 4 preferably comprises two bearings that connect the two wheels 2 integrally by means of a connecting element 3 that connects both bearings, making them a single shaft 4 that causes the two wheels 2 to rotate jointly at the same speed of rotation.

[0038] However, and in order that the two wheels 2 can rotate according to the path they take when the truck has to turn to the right or to the left, the bearings can be manually disconnected by the operator using an actuator cable on the connection-disconnection element 3, or automatically by means of an electromagnet on the connection element 3 when it intends to rotate the direction of the truck.

[0039] In this way, by disconnecting the two bearings from each other so that one can rotate at a different speed from the other, it is achieved that each wheel 2 can rotate depending on the path and movement that it should make on the ground and in accordance with the arc and radius of rotation described by the truck.

[0040] Depending on whether the rotation is to the right or to the left, the motor 8 will go at a different speed so that the rotating speed is the same when rotating to the right or to the left. In this way, it is achieved that the rotating operation is the same, and also that the solution is achieved with a very low power motor while generating maximum torque, since this motor 8 is connected on the outside of the diameter wheel 2 where the least effort must be made to move both wheels.

[0041] In this way, a form of reduction is achieved without having to use a higher power motor or using a gear reduction, achieving a considerable reduction in the number of parts, which is another way to reduce cost, labor and maintenance costs.

[0042] As indicated, the first transmission element 6 can be a pulley and the second transmission element 5 can be a belt. In this way, an even greater reduction in cost and complexity is achieved since it is a lower cost part. In addition, this allows for a greasing-free system, minimizing the maintenance that must be performed periodically.

[0043] The second transmission system also comprises an electric motor 8 powered by a battery 7, it consists of a differential shaft system that comprises two bearings 4 that connect the two wheels 2 and at the same time the bearings are connected to a central differential gear 3. Likewise the central differential gear is connected to a ring gear (or a pulley) and this in turn is connected by a chain (or a belt) to the gear reduction or reducer that is connected to the electric motor.

[0044] In this way, when the truck moves in a straight line, the two traction wheels rotate at the same speed, and by virtue of the central differential gear, the wheels can rotate at different speeds when the truck should rotate or change direction.

[0045] With the second transmission system with central differential gear, the change of direction of the truck can be carried out with the force of the operator without having to disconnect the two shafts between them, unlike the first transmission system, simply by manually steering the truck clockwise to turn left, and vice versa, directing the truck to the left to turn right, as is done on the most commonly used manual trucks.

[0046] And with the second transmission system with central differential gear, when the truck has the platform that allows the operator to be mounted on the truck attached thereto, the operator changes direction by applying the brake to only one of the wheels by means of an independent brake system for each wheel. In this way, if the right wheel is stopped, the truck rotates to the right as the left wheel will continue to rotate, causing the truck to make a change in direction of its path and that it moves to the right, and the same if the left wheel is stopped, the path change will be to the left

[0047] In either of the two transmission systems, first or second, according to the represented embodiment, the transmission system comprises a regulator of the rotational speed of the electric motor (or two independent motors connected to each wheel) 8 by means of an electronic controller 10.

[0048] This electronic controller 10 allows the regulation of the power and the rotational speed depending on the difficulty of the load handling operation. For example, when a curb has to be overcome, the operator can regulate the torque and speed of the motor 8 in order to have an ability to overcome slopes far greater than what is required if only a flat surface is to be passed through.

[0049] For example, when traveling through tilled ground with great irregularities and a soft ground, the operator can also regulate reducing the turning speed and giving greater torque to the motor 8 so that the wheels 2 can overcome obstacles.

[0050] Said electronic controller 10 can incorporate an automatic regulation of power and speed depending on the effort exerted by the operator on the two handles of the truck holding beams, in this way the operator should not be aware of regulating the power and speed when a slope has to be overcome or getting into a soft ground that offers a lot of resistance to the push of the truck.

[0051] To protect the motor from mud or moisture from the ground or snow, the electric motor 8 is mounted at a high height, for example about 40 cm from the ground, as shown in the figure.

[0052] Additionally, it has been provided for the use of large diameter wheels 2, which offers advantages over small diameter wheels commonly used by handcarts. A large diameter wheel makes it easier to overcome an obstacle (curbs, stones, roots, etc.), it also offers greater adherence or traction to the ground, which allows the truck to be used on slippery surfaces with gravel, snow, ice, mud, etc.

[0053] In addition, it is provided for that the operator can easily regulate the pressure of the tires, which can reduce the air pressure, and thus, that the tire becomes low-pressure tires much more suitable for driving on slippery and fragile grounds such as grass.

[0054] A tire with larger diameter and greater width, as opposed to a narrow, small diameter one, does not sink as easily on soft ground, nor does it damage the ground as much, or leave as much mark on the ground, while those with a large diameter and greater width have a greater contact surface which distributes the pressure to the ground more evenly, minimizing the inconveniences of a tire with a reduced radius and width, which allows movement on fragile grounds such as grass or semi-set concrete that is not fully hardened.

[0055] The self-propelled two-wheeled handcart 2 according to the present invention has very diverse applications, usually in the construction, industry and agriculture and services sector, being intended, among other tasks, for the transport and handling of loads, as well as carrying out cleaning tasks on public roads.

[0056] Consequently, the present invention allows its application in various sectors such as construction, agriculture, gardening, industry, transport and home distribution/delivery of electrical appliances, furniture, heavy sacks or packages, facilitating and minimizing manual effort, which also have an effect on a reduction of working times with the consequent economic savings that this entails, and the minimization of injuries due to extreme physical efforts resulting in better health at work and a reduction in occupational accidents.

[0057] Furthermore, with the use of different tools or implements or semi-machines, which can be easily coupled, it is possible to convert the handcart into: a self-propelled snow-removing type handcart with the attachment of a blade; or a loader-type self-propelled handcart for the movement of bulk materials (earth, gravel, aggregates, concrete, raw materials, potatoes, compost, seeds, manure, farm/industry/agricultural waste, etc.); or a forklift-type self-propelled handcart for moving palletized loads for use in industry or agriculture (to handle wooden boxes or pallets when picking fruit).

[0058] FIG. 2 shows the handcart according to the present invention that includes a platform 12.

[0059] This platform 12 is coupled to the frame 1 of the handcart and comprises wheels 13 that rotate freely, that is to say, that are not driven. The platform 12 is formed by a base 14 and a vertical structure 15, being able to place a user and, if desired, loads on the base 14.

[0060] Although reference has been made to a specific embodiment of the invention, it is clear to a person skilled in the art that the described handcart is susceptible to numerous variations and modifications, and that all the mentioned details can be substituted by other being technically equivalent, without departing from the scope of protection defined by the appended claims.