FORM 2
THE PATENTS ACT-1970
(39 of 1970)
and
The Patent Rules, 2006
COMPLETE SPECIFICATION
(See Section 10 and Rule 13)
1. TITLE OF THE INVENTION IMPROVED HAND-CART (Haath Thela)
2. APPLICANT

a) Name DR. PRAKASH VERMA AND SHRI SANJAY SONI
b) Nationality Indian Nationals
c) Address 226, Ravindra Nagar, Adhartal, Jabalpur-482004 Madhya Pradesh India
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be performed.

FIELD OF THE INVENTION
The present invention relates generally to a cart. More particularly, it relates to a human-driven four-wheeled hand-cart used for carrying load. Still more particularly, it relates to a human-driven four-wheeled load-carrying hand-cart used for carrying load, which is capable of being steered like a motor vehicle.
BACKGROUND OF THE INVENTION
The name handcart is often used to refer to four-wheeled platform carts that are pushed or pulled by hand. In olden days, especially in India, it has been widely used in a variety of trades, such as delivering parcels, selling goods and hauling materials. In present times also, it is employed in some industries for material transport in the shop floor, for selling vegetables and other goods on the streets, and for hauling materials in both urban and rural areas. Hand-carts or hand-trucks which are also known as dollies are used in industries to facilitate transport of limited loads over limited distances and terrain. Some examples of such usage include movement and positioning of heavy articles of furniture and appliances to homes or offices, delivery of heavy paper goods (copier supplies, books etc.) inside offices, transport of cylinders of compressed gas in manufacturing or research units etc.
The presently used carts have a platform over four wheels, and are pulled or pushed by the person driving it, with the help of handles which are attached to the cart platform. This design however suffers from a major drawback of not being able to be turned around a bend. This happens because the wheels of the hand-cart are fixed on the front and rear axles, and can only be rotated about the fixed axle axis. As a result, the hand-cart can be turned around a bend only by physically lifting it by its rear wheels and turning the whole cart about the front wheels. Manually lifting the cart becomes extremely difficult for the person pushing it, especially if the cart is carrying heavy loads. The person moving the cart needs to provide energy for pushing the cart, as well as to lift the cart while turning while balancing the load on the front wheels. This becomes all the more challenging

when the cart needs to be moved over rough and uneven surfaces (in rural areas), or in hilly areas or any other inclined surfaces. Thus, operating the presently used hand-cart is a time-consuming and exhausting exercise for the person driving the cart. This not only increases the human effort required, but also limits the load carrying capacity of the cart to the weight lifting capacity of the person pushing the cart.
To overcome all the above mentioned problems, there was a need for a hand-cart which enables easy steering and maneuvering of the cart assembly on all kinds of roads, thereby reducing the physical human labour without incurring major costs. Several hand-carts in the prior art make use of a motor engine or electricity to drive them. The motorized carts cause pollution by emitting toxic gases while power-driven carts are expensive to maintain as they guzzle electricity. Examples of hand-carts using electricity include JP2012071817 and CN2923460, while examples of motorized hand carts are US4429758, US2008315541 and GB470589. The present invention runs on the natural resource of physical power of the human being driving it, which makes it inexpensive to manufacture and maintain, and free from polluting problems. This structurally simple and cost-effective invention is highly suitable for Indian rural areas.
The present invention proposes the incorporation of a steering mechanism in the existing hand-cart which is both structurally simple and economic to manufacture. The difficulty in turning is overcome by pivoting the front axle at the center and by connecting a long T-shaped liver bar to the front axle, in such a way that when the bar is moved to left or right, the axle turns left or right about the pivot. Using this mechanism, the cart is capable of turning around a bend like a motor vehicle. Moreover, this easy-to-operate steering mechanism is capable of being retrofitted to any existing cart (hand-carts/dollies/hand-trucks/other wheeled carriages).

OBJECTS OF THE INVENTION
The main object of the present invention is to provide a four-wheeled human-driven load-carrying cart assembly with an in-built steering mechanism.
Another object of the present invention is to provide a cart assembly which eliminates the need to be lifted from rear wheels while turning over a bend.
Yet another object of the present invention is to provide a cart assembly which enables transportation of heavy loads without causing fatigue or injuries to the person driving the cart while turning the cart over bends.
Still another object of the present invention is to provide a four-wheeled human-driven load-carrying cart assembly with good maneuverability and control on inclined surfaces and turns.
Further object of the present invention is to provide a steering sub-assembly of a pivot and T-bar, which can be retrofitted to other types of non-riding carts and carriages.
Still further object of the present invention is to provide a structurally simple and economic addition to the existing hand-cart, which enables it to be steered without extra physical efforts.
SUMMARY OF THE INVENTION
The present invention is directed to solve one or more of the problems encountered in the prior art. In the preferred and illustrative embodiment of the present invention, the four-wheeled human-driven load-carrying hand-cart with an in-built steering mechanism is described.
Briefly summarized, according to one aspect of the present invention, a four-wheeled human-driven load-carrying hand-cart comprises of a cart platform, a cart frame, two front wheels, two rear wheels, a steering sub-assembly attached to the front wheels, wherein the said steering sub-assembly further comprises of a pivot, a T-bar, a shaft welded to the front axle of the wheels.

In another aspect of the present invention, because of the presence of the steering mechanism, the need to lift the cart assembly from its rear wheels for turning around a bend is eliminated. To steer, the T-bar is rotated to the desired direction, which further causes the front wheels to rotate in the same direction, thereby steering the whole cart.
In yet another aspect of the present invention, the steering sub-assembly uses the pivot mechanism for turning, wherein the pivot is welded to the frame through two metal strips, and a short hollow metal pipe is fitted with two bearings at the ends. A shaft passes through the bearings, one end of which is welded to the front axle at its center. A T-shaped handle bar is also joined to the front axle at the point where the pivot shaft is welded to the front axle.
In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of the construction and arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of embodiments in addition to those described and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology herein as well as the abstract are for the purpose of description and should not be regarded as limiting.
The four-wheeled human-driven load-carrying hand-cart assembly will now be described with reference to the accompanying drawings. The description below does not limit the scope and ambit of the disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is described below in greater detail with reference to the drawings wherein:
Fig. 1 shows a perspective view of the human-driven four-wheeled hand-cart assembly equipped with a steering sub-assembly attached to its front wheels, according to the preferred embodiments of the present invention;

Fig. 2 shows a bottom view of the steering sub-assembly employed by the human-driven four-wheeled hand-cart assembly, according to the preferred embodiments ' of the present invention;
Fig. 3 shows a bottom view of the human-driven four-wheeled hand-cart assembly equipped with a steering sub-assembly attached to its front wheels, according to the preferred embodiments of the present invention.
DETAILED DESCRIPTION OF THE DRAWINGS
The present invention is primarily an addition or modification to existing handcarts, or similar non-riding ground engaging equipment like trucks and dollies. It is developed with the object of overcoming the problem of turning a hand-pushed cart over a bend by lifting it by its rear wheels and turning it about its front wheels. The steering mechanism employed in the present invention is adapted for use in such hand-carts through movement of a T-shaped handle bar (1) in such a way that when the bar is moved to the left or right, the cart moves in the opposite direction, making it possible to turn the cart around a bend like a motor vehicle. In the present invention, the steering sub-assembly is appended to the front wheels of the cart, which enables easy and effortless steering of the cart by the movement of the T-shaped handle-bar. Due to absence of such features in the currently used urban and rural human-driven push-carts, immense physical effort was required to lift them from the rear side and to rotate them about the front wheels. This limited the load carrying capacity of the cart to the weight lifting capacity of the person pushing the cart.
Referring to the Fig. 1, the four-wheeled human-driven load-carrying hand-cart with an in-built steering mechanism is shown. This cart assembly comprises of a metallic frame over which is placed the cart platform, preferably made of wood, two front wheels (4) and two rear wheels (5) along with their metallic axles (11) and (12), and a steering sub-assembly. The metallic frame supporting the cart

platform is narrow near the front wheels (4) and wide near the rear wheels (5). The Fig.l illustrates the narrow end of the frame (9) and the wide end of the frame (2). The metal strips (3) support the cart platform over the metallic frame. The cart is made capable of being steered, by pivoting the axle of the front wheels (12) at the centre.
With reference to Fig. 2, the perspective view of the pivot (7) and the steering sub-assembly is shown. The pivot (7) in the centre is welded to the metallic frame through two metal strips (10), wherein the pivot (7) is a short hollow metal pipe, preferably made up of commonly used mild steel. The pivot (7) is fitted with two bearings (6) at its ends. A shaft (8) passes through the bearings, wherein one end of the shaft (8) is welded to the axle of the front wheel (12) at its centre. The T-shaped handle bar (1) is also joined to the axle of the front wheels (12) at the point where the shaft (8) is welded to the front axle. When the T-shaped handle bar (1) is rotated to left or right side, the force is transmitted to the shaft (8) in the pivot (7), which further transmits it to the axle of the front wheel (12), which turns the front wheels (4) in the desired direction. The steering sub-assembly in the present invention is configured in such a way that the movement of the T-shaped handle bar (1) is translated in the turning of the front wheels (4).
Referring to Fig. 3, the bottom view of the entire cart assembly is shown. The figure clearly illustrates that the cart assembly is comprised of two front wheels (4), two rear wheels (5), front and rear axles ((11) and (12)), metallic frame ((2) and (9)) along with metallic strips (3) to hold the cart platform, and the steering sub-assembly which is made up of the T-shaped handle bar (1) which provides easy steering control to the person driving the cart and a pivot (7) along with bearings (6) and a shaft (8) passing through it. The shaft (8) in the pivot (7) is welded to the axle of the front wheels (12). The pivot (7) is welded to the frame through two metal strips (10) and is instrumental in transferring the steering force applied by the driver, to the axle (12), thereby causing the front wheels (4) to turn in the opposite direction as the T-shaped handle bar (1). Thus, by pivoting the axle

of the front wheels (12), the front wheels (4) of the cart can be easily turned around a bend without actually needing to lift the rear wheels (5).
In one of the preferred embodiments of the present invention, the four-wheeled human-driven load-carrying hand-cart assembly with an in-built steering mechanism is also capable of braking without effort at driver's will. The brakes employed are preferably drum-brakes.
Advantages of the invention:
The present invention was conceptualized to overcome some of the drawbacks of the commonly used hand-carts. Some of the distinct advantages of the invention are given below -
1) The four-wheeled human-driven load-carrying hand-cart with in-built steering mechanism is capable of easily being turned around a bend without having to lift the cart by its rear wheels like commonly used present-day hand-carts.
2) The use of the steering sub-assembly in the hand-cart allows greater weights to be carried over the cart, which was not possible with the conventional commonly used hand-carts, as the weight-lifting capacity of the cart was limited by the weight-lifting capacity of the person pushing it. Now, without the need to lift the cart to steer it, more loads may be transported on the cart, with less human effort.
3) The four-wheeled human-driven load-carrying hand-cart is structurally simple, easy to manufacture and economic to maintain.
4) The steering sub-assembly employed in the present invention is easy can be retrofitted into any other existing cart, which may or may not be human-driven.
5) The four-wheeled human-driven load-carrying hand-cart is inexpensive and environment-friendly when compared with more complicated carts which are either motor driven, or powered by electricity. This cart assembly is thus appropriate for the Indian scenario.
6) The use of steering sub-assembly in the hand-cart ensures better
maneuverability and control on the inclines (especially going downhill) and while
taking a turn.

CLAIMS
We claim,
1) A four-wheeled human-driven load-carrying hand-cart with in-built steering
mechanism comprising:
a metallic frame supporting the cart platform which is narrow towards the front end (9) and wider towards the rear end (2);
a cart platform over the metallic frame for keeping the goods that need to be transported;
two front wheels (4) and two rear wheels (5);and
a steering sub-assembly pivoted to the axle of the front wheels (12), which enables the cart to be turned around a bend.
2) The four-wheeled human-driven load-carrying hand-cart with an in-built
steering mechanism as claimed in Claim 1 wherein said steering sub-assembly
comprises:
a T-shaped handle bar (1) for manually steering the cart to the left or to the right
a pivot (7) at the end of the T-shaped bar (1) which is welded to the metallic frame of the cart through two metal strips (10), and consists of a short hollow pipe with two bearings (6) at its ends; and
a shaft (8) passing through the bearings (6), one end of which is welded to the centre of the axle of the front wheels (12).
3) The four-wheeled human-driven load-carrying hand-cart with an in-built
steering mechanism as claimed in Claim 1 wherein the T-shaped handle bar (1)
functions as a hand liver through which movement towards left or right is directly
transferred to the axle of the front wheels (12) thereby rotating the front wheels
and steering the cart.

4) The four-wheeled human-driven load-carrying hand-cart with an in-built steering mechanism as claimed in Claim 1 wherein the T-shaped handle bar (1), the pivot (7) and the shaft (8) are constructed using hollow mild steel pipes.
5) The four-wheeled human-driven load-carrying hand-cart with an in-built steering mechanism as claimed in Claim 1 wherein the said hand-cart is structurally uncomplicated and capable of being dismantled and re-assembled.
6) The four-wheeled human-driven load-carrying hand-cart with an in-built steering mechanism as claimed in Claim 1 wherein the said steering sub-assembly is capable of being retrofitted to any other non-riding ground engaging equipment like carts, hand-trucks or trolleys.