DESC:FIELD OF INVENTION
The present invention relates to a landing gear to support an unmanned aerial vehicle (UAV) during both takeoff and landing. More particularly, the present invention relates to a light weight flexible landing gear in the UAV, which can bear payload during takeoff and landing. Further, the present invention relates to a flexible landing gear, which absorbs shocks and reduces transmissibility of vibration to structures attached to it during incorrect or crashing landing of the UAV.

BACKGROUND OF INVENTION
Generally, unmanned aerial vehicle (UAV) commonly known as a drone is an aircraft without a human pilot aboard. The flight of the UAVs may operate with various degrees of autonomy either under remote control by a human operator, or fully or intermittently autonomously by onboard computers. Landing gear is undercarriage of an UAV used in both takeoff and landing. The landing gear is a critical part of the UAV built to handle three major functions such as: load bearing and provide support to frames and arms of the aircraft, provide enough space between ground and payload for easy mounting of payloads and absorb shock and reduce transmissibility of vibration to structures attached to it primarily during incorrect or crash landing. The entire weight of the quad rotor excluding the weight of the landing gear for an UAV with all up weight less than 2kg cannot be more than 2kg or 20 Newton.

The material for landing gear is chosen taking into consideration weight of the landing gear, manufacturability of the leg, cost of raw material and manufacturing, ease of procurement and repeatability. Existing literature and currently available products used polypropylene or carbon fiber as materials for landing gears.

The drawbacks with respect to use of landing gears made of polypropylene are as follows:
The structure was thinner and had a longer stem. Hence load withstanding capability with the material posed a greater risk.
The base of the landing gear does not offer larger surface area for easy balance on the ground.
Design at the base of the leg is complicated and hence complex involved in manufacturing.
Cost of manufacturing is high since a die has to be manufactured to mold these components.

The drawbacks with respect to use of landing gears made of carbon fiber are as follows:
Material cost is very high.
Involves complex and expensive methods of manufacturing.
Local stresses are high at both sharp corners.
Material procurement is difficult due to larger cost of manufacturing of raw material.

Known in prior art is a UAV landing gear shock absorber for reducing vibration during landing; a first shock mount and the second shock mount; the first shock mount comprising: a first end of the rod, a first spring strut and a first auxiliary strut. However, the UAV landing gear shock absorber fails to disclose about accommodating rotor base frame along with payload without causing damage to the landing gear and payload.
US20130105635 discloses a system and method are provided to control stability of quad tilt rotors in a vertical takeoff and landing (VTOL) unmanned aerial vehicle (UAV) by controlling the rotational speed of propellers at each rotor while simultaneously tilting the rotors aligned in a 45 degree configuration related to a central axis for directional flight control. However, the UAV does not provide safe takeoff or landing using gears or struts.

US20160272308 describes a configuration of an unmanned aerial vehicle (UAV) landing gear assembly that includes adjustable landing gear extension that may be extended or contracted so that the body of the UAV is contained in a horizontal plane when the UAV is landed, even on sloping surfaces. For example, when a UAV is landing, the slope of the surface may be determined and the landing gear extensions adjusted based on the slope so that the body of the UAV remains approximately horizontal when the UAV lands and is supported by the landing gear extensions. Also, known in the prior art are GB2483881 and CN205273842 that discloses about the landing gears of UAV. However, the landing gear is not a single component and also does not constitute proficient shape and material for the landing gears to dampen the shocks that transpire during landing.
20130105635A1
US20130105635A1
Accordingly, there exists a need for a light weight flexible landing gear, which can bear payload during takeoff and landing. Further, there exists a need for a landing gear, which absorbs shocks and reduces transmissibility of vibration to structures attached to it during incorrect or crashing landing of the UAV.

OBJECTS OF INVENTION
It is the primary object of the present invention to provide a light weight flexible landing gear to support an unmanned aerial vehicle (UAV), which can bear payload during takeoff and landing.

It is another object of the present invention to provide a light weight flexible landing gear which absorbs shocks and reduces transmissibility of vibration to structures attached to it during incorrect or crash landing of the UAV.

It is another object of the present invention to provide a landing gear, which enables trouble-free loading and unloading of payloads.

It is another object of the present invention to provide a landing gear, which enables equal distribution of stress with a payload.

It is another object of the present invention to bear the load and provide support to the rotor base frame and legs of the UAV.

It is another object of the present invention to provide greater flexibility to legs during shock loads.

It is another object of the present invention to manufacture landing gear which is cost effective.

It is another object of the present invention to larger stiffness for a given cross section and moderate strength to weight ratio which enables better shock absorbing capacity.

SUMMARY OF THE INVENTION
One or more of the problems of the conventional prior art may be overcome by various embodiments of the present invention.

It is the primary aspect of the present invention, wherein light weight flexible landing gear for unmanned aerial vehicle comprising of:
rotor base frame;
one or more arms; and
one or more legs,
wherein the rotor base frame includes base plate and the arms, and
wherein the legs are connected to the rotor base frame extending towards the ground through curvilinear structure.

It is another aspect of the present invention, wherein the leg comprises:
flat portion;
curved portion; and
at least two equally spaced slots,
wherein the flat portion is provided with the said slots to connect with the rotor base frame, and
wherein the curved portion is designed from lower most point of the flat portion of the each leg to the distal end of the leg to support the landing gear during takeoff and landing.

It is another aspect of the present invention, wherein the leg is preferably made of nylon material.
It is another aspect of the present invention, wherein the said flat portion is provided with the said slots to connect with the rotor base frame.

It is another aspect of the present invention, wherein the said slots are used to provide rigidity and load distribution.

It is another aspect of the present invention, wherein the rotor base frame along with payload is accommodated between the flat portion of the leg and the ground.

It is another aspect of the present invention, wherein the space is provided between lower most point of the curved portion of the leg and ground.

It is another aspect of the present invention, wherein the curved portions of the legs in the landing gear acts as shock absorbers.

BRIEF DESCRIPTION OF DRAWINGS:
So that the manner in which the features, advantages and objects of the invention, as well as others which will become apparent, may be understood in more detail, more particular description of the invention briefly summarized above may be had by reference to the embodiment thereof which is illustrated in the appended drawings, which form a part of this specification. It is to be noted, however, that the drawings illustrate only a preferred embodiment of the invention and is therefore not to be considered limiting of the invention's scope as it may admit to other equally effective embodiments.
Figure 1: illustrates landing gear for supporting an UAV according to the present invention.
Figure 2: illustrates enlarged view of the leg in the landing gear according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION ACCOMPANYING FIGURES
The present invention as herein described relates to a landing gear to support an unmanned aerial vehicle (UAV) during both takeoff and landing. Further, the present invention relates to a flexible landing gear, which absorbs shocks and dampen vibrations during takeoff and landing that consists both customary and unplanned landing of the UAV.

Referring to figures 1 and 2, an unmanned aerial vehicle comprising a rotor base frame [1], one or more arms [2], and one or more legs [3] building a landing gear. The rotor base frame of UAV carries a payload based on which the UAV meet the targets. The rotor base frame [1] includes base plate [4] and one or more arms [2] and one or more legs [3]. Each arm [2] has a propeller fastened to it in order to drive the UAV. The legs [3] are connected to the rotor base frame [1] extending downwards through a curvilinear structure.

The legs [3] of the unmanned aerial vehicle as shown in figure 2 comprise a flat portion [3a] and curved portion [6] and at least two equally spaced slots. The flat portion [3a] of the leg [3] is connected with the rotor base frame [1] by securing the two equally spaced slots in a flat portion [3a]. The slots [4] provide rigidity and distribute the load equally to each leg, thereby enabling load balancing and firmness. The curved portion [3b] in the leg extends from lower most point of flat portion [3a] to the distal end of the leg for supporting the landing gear while take off and also during landing. The structure of the landing gear is intended to be in curvilinear to withstand heavier loads and endow with safe landing. The shape of the landing gear provides flexibility to the legs, adjusts during incorrect or crash landings. The curved portion [3b] of the legs [3] in the landing gear absorbs shock and reduces transmissibility of vibration to structures attached to it during landing of the unmanned aerial vehicle. The legs [3] are made of nylon material to provide light weight and enhance strength to weight ratio enabling better shock absorbing capacity for landing gear of a quad rotor or UAV.

The landing gear accommodates a CMOS sensor payload along with a support fixture called gimbal. The gimbal in its extended position along with the payload is housed suitably to avoid damage to the payload and its support fixture and enables trouble-free loading and unloading of payloads. The rotor base frame [1] along with payload accommodates between the flat portion [3a] of the leg [3] and the ground. The curvature of the leg made of nylon material which is favorably light weight, also allows bending without causing structural weakness due to the greater flexibility at shock loads and larger stiffness of the nylon material. The light weight landing gear is a cost-effective UAV sustains efficient functionality and significantly protects the gimbal and payload of UAV during takeoff and landing.

Although the invention has been described with reference to specific embodiments, these descriptions are not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternative embodiments of the invention will become apparent to persons skilled in the art upon reference to the description of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. It is therefore, contemplated that the claims will cover any such modifications or embodiments that fall within the true scope of the invention.
,CLAIMS:WE CLAIM:
1. A light weight flexible landing gear for unmanned aerial vehicle comprising of:
rotor base frame [1];
one or more arms [2]; and
one or more legs [3],
wherein the rotor base frame [1] includes base plate and the arms [2], and
wherein the legs [3] are connected to the rotor base frame [1] extending towards the ground through curvilinear structure.

2. The landing gear for unmanned aerial vehicle as claimed in claim 1, wherein the leg [3] comprises:
flat portion [3a];
curved portion [3b]; and
at least two equally spaced slots [4],
wherein the flat portion [3a] is provided with the said slots [4] to connect with the rotor base frame [1], and
wherein the curved portion [3b] is designed from lower most point of the flat portion of the each leg [3] to the distal end of the leg [3] to support the landing gear during takeoff and landing.

3. The landing gear for unmanned aerial vehicle as claimed in claim 1, wherein the leg [3] is preferably made of nylon material.

4. The landing gear for unmanned aerial vehicle as claimed in claim 2, wherein the said flat portion [3a] is provided with the said slots [4] to connect with the rotor base frame [1].

5. The landing gear for unmanned aerial vehicle as claimed in claim 4, wherein the said slots [4] are used to provide rigidity and load distribution.

6. The landing gear for unmanned aerial vehicle as claimed in claim 1, wherein the rotor base frame [1] along with payload is accommodated between the flat portion [3a] of the leg [3] and the ground.

7. The landing gear for unmanned aerial vehicle as claimed in claim 2, wherein the space is provided between lower most point of the curved portion [3b] of the leg [3] and ground.

8. The landing gear for unmanned aerial vehicle as claimed in claim 2, wherein the curved portions [3b] of the legs [3] in the landing gear acts as shock absorbers.