FORM 2
THE PATENTS ACT, 1970 (39 of 1970)
&
THE PATENTS RULES, 2003
[See section 10, Rule 13]
RETROFITTING FOR STEEL TOWER STRUCTURE:
RELIANCE COMMUNICATIONS LIMITED WHOSE ADDRESS IS H-BLOCK, LEGAL DEPARTMENT 1ST FLOOR, WING-2, THANE - BELAPUR ROAD KOPAR-KHAIRNE, NAVI MUMBAI - 400 710 MAHARASHTRA, INDIA.
THE FOLLOWING SPECIFICATION
PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.

TECHNICAL FIELD:
The present invention relates generally to a retrofitting device and more particularly, to a retrofitting device for a steel tower, such as a telecom tower.
BACKGROUND OF THE INVENTION:
Generally, in telecommunication, connectivity is attained by means of either underground Optical Fibre Cables or by means of transmitting signals using microwave antennas. These antennas are mounted on supporting structures called Towers such as Ground base tower [ herein after referred as GBT] or Roof top tower [herein after referred as RTTI) or Poles. The above-mentioned GBT & RTT towers along with its foundation, is safe against specified existing antenna loadings and serving safely for years. However, with advent in technology there is an increase in number of subscribers for telecommunication connectivity. To serve this need more GBT & RTT towers need to be set up, but due to limitation of area, space and expense involved in building these towers, existing GBT & RTT towers are being over-loaded with antennas. Due to increase in numbers of antennas, the effect of wind force on the tower members increases and demands an increase in strength of the tower structure. Further, due to asymmetric placement of antennas, there may be demand for increase of torsional strength of the tower structure. Due to probable increase in number of antennas, either the available Factor of Safety is getting reduced or tendency for few members of the existing tower becoming unsafe against incremental forces increases. Further, there are cases of failure of R.C.C. foundation & pedestals due to increase in number of antennas.
However, to overcome these problems, retrofitting devices have been adapted to towers to increase the strength of the towers. But these retrofitting devices require structural changes in the tower before being installed on the towers. Since, retrofitting devices are usually installed on existing/in-use towers, making structural changes to the towers becomes complex and tedious.

Due to the complexity involved for incorporating structural changes to existing arrangements, improvements in support structures and/or devices for increasing strength of the tower is desired.
SUMMARY OF THE INVENTION:
The present invention describes a retrofitting device to be adapted along an existing (eg member of a tower, the device comprises of: elements defined by an external member devised in accordance with the existing leg member; a pair of angle cleats which has a L-shape with two arms and a means to receive a bolt on one of the arms; a angle bracket which has L-shape with two arms and a means to receive bolts on both the arms, a plurality of friction plates with a means to receive a bolt; a plurality of bolts and fasteners, wherein the elements of the device are coupled and gripped together in an arrangement to increase lateral and torsional strength and provide elasticity between the coupled elements such that a force acting on the elements due to incident wind energy is counter-balanced over the device to provide structural integrity and load balance to the tower.
In an exemplary embodiment, the present invention provides a method for assembling the retrofitting device, the method comprises steps of coupling an external member to an existing leg member; coupling an angle bracket and a pair of angle cleats to the external member and the existing leg member; mounting and coupling friction plates to the angle cleats and bracket, and coupling the elements using high strength friction grip bolts and fasteners.
BRIEF DESCRIPTION OF THE DRAWINGS:
Reference will be made to embodiments of the invention, examples of which may be illustrated in the accompanying figures. These figures are intended to be illustrative, not limiting. Although the invention is generally described in the context of these embodiments, it

should be understood that it is not intended to limit the scope of the invention to these particular embodiments.
The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a view showing a conventional steel tower,
FIG. 2 is a view showing deflection due to wind load.
FIG. 3 is a view showing the steel tower of FIG. 1 and the members which are to be strengthened in bold THICK.
FIG.4 is a view showing the retrofitting device - single bolt.
FIG.5 is a view showing the retrofitting device - double bolt.
FIG. 6 is a detailed view showing part of a post of the steel tower, and strengthening arrangement,
DETAILED DESCRIPTION OF THE INVENTION:
The embodiments herein provide a device and method for assembling the device to increase the lateral stiffness as well as the torsional stiffness of a tower. Further the embodiments may be easily implemented in various towers such as Ground base tower [herein after referred as GBT] or Roof top tower [herein after referred as RTT]) or Poles. The method of the invention may also be implemented as FRICTION — GRIP — CLAMP ARRANGEMENT with needed modifications.
The invention described herein is explained using specific exemplary details for better understanding. However, the invention disclosed can be worked on by a person skilled in the art without the use of these specific details.
References in the specification to "one embodiment" or "an embodiment" means that a particular feature, structure, characteristic, or function described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the

phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment.
Hereinafter, the preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Reference now should be made to the drawings, in which the same reference numerals are used throughout the different drawings to designate the same or similar components. For clear description of the present invention, known constructions and functions will be omitted.
The present invention describes a retrofitting device to be adapted along an existing leg member(114) of a tower, the device comprises of: elements defined by, an external member(102) devised in accordance with the existing leg member(114); a pair of angle cleats(106) having two arms and a means to receive a bolt on one of the arms; an angle bracket(104) having two arms and a means to receive bolts on both the arms, a plurality of friction plates having means to receive a bolt; a plurality of bolts(110) and fasteners(112), wherein the elements of the device are coupled and gripped together in an arrangement to increase lateral and torsional strength and provide elasticity between the coupled elements such that a force acting on the elements due to incident wind energy is counter-balanced over the device to provide structural integrity and load balance to the tower.
As per one exemplary embodiment the present invention provides a method for assembling the retrofitting device, the method comprises steps of: coupling an externa! member to an existing leg member; coupling an angle bracket and a pair of angle cleats to the external member and the existing leg member; mounting and coupling friction plates to the angle cleats and bracket, and coupling the elements using high strength friction grip bolts and fasteners.
As shown in FIG.1 a general steel telecom tower, includes main legs set up vertically, horizontally and cross diagonally having telecom antennas loaded at the top portion or at required height / elevation. Due to increase in loading, the members become susceptible to

cramping and failure in bearing the load as shown in the FIG.2 and hence this portion of the tower requires tower strengthening.
Fig.3 shows the area of the tower that needs a new member to strengthen the tower. The tower may adapt a plurality of retrofitting elements of the present invention ahng the legs of the tower to strengthen the tower.
Fig. 4 shows a retrofitting device - single bolt (100) as one embodiment of the present invention which is adapted to an existing tower without making any structural changes to the tower.
The retrofitting device comprises of an external member (102); a pair of angle cleats (106); an angle bracket (104); a plurality of friction plates (108); a plurality of bolts (110) and fasteners (112), wherein the element is coupled and gripped together using a single bolt arrangement,
The external member (102) has an elongated v-shape and is coupled along the vertex of the existing leg member of the tower.
The angle cleat (106) preferably has an L-shape with two extending arms. One of the arms of the L-angle cleat has means to receive a bolt for allowing the angle cleat to be coupled to the angle bracket.
The angle bracket (104) preferably has an L-shape with two extending arms. Both the arms have means to receive bolts to allow the bracket to couple the angle cleats (106) on both sides. Preferably the angle bracket is coupled to the inner side of the existing member (114) and further to the angle cleats (106) on both the arms.
The friction plates (108) are mounted on the angle cleats (106) and the bracket (104) and coupled using bolts (110) and fasteners (112). Preferably the bolts (110) used are high strength friction grip bolts. The high strength friction grip bolts facilitates load transfer across

the joints due to friction between the coupled elements. These high strength friction grip bolts also avoid loosening of the bolts at a slower rate and also has an ability to withstand alternating forces compared to other existing bolts.
Fig. 5 shows a retrofitting device - double bolt (200) as one another embodiment of the present invention which can be adapted to an existing tower without making any structural changes to the tower.
The retrofitting device comprises of an external member (102); a pair of angle cleats (206); an angle bracket (204); a plurality of friction plates (208); a plurality of bolts (110) and fasteners (112), wherein the element is coupled and gripped together using a double bolt arrangement.
The retrofitting device of Fig.5 couples to a tower in a similar manner as the device illustrated in Fig.4 but have different constructional features by way of bolt arrangement.
One skilled in the art will appreciate that the friction grip clamp arrangement - single or double arrangement, may be adapted to the telecom tower as per requirement, and the scope of the invention may not be limited to a single or a double bolt arrangement.
In an exemplary embodiment, the pair of angle cleats are coupled to an external member and to the outer-side of existing member of the tower. Further an angle bracket is coupled to the inner side of the existing member and coupled to the angle cleats. These elements are further mounted with friction plates and coupled to the tower using bolts and fasteners. In a preferable arrangement, the two angle cleats are coupled on outer-surface of the existing member and the angle bracket coupled on inner-surface of the existing member. The arrangement provides a counter balance against the wind force that may act possibly from all directions.

Fig.6 is a detailed view showing part of a tower and strengthening arrangement, wherein the retrofitting devices illustrated in Fig.4 and Fig.5 are adapted on an existing leg member of a tower. The tower as illustrated in Fig. 6 when subjected to wind energy will prevent the failure of tower members. When wind energy is incident on this tower, the incident wind energy is counter-balanced over the device as the arrangement provides elasticity between the coupled elements which increases lateral and torsional strength to provide structural integrity and load balance to the tower.
Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. The present embodiments are therefore illustrative and not restrictive.
As described above, the present invention provides a retrofitting device for steel tower structures, in which coupling parts are appropriately provided on posts of a steel tower, thus preventing the posts from buckling, and friction plates are provided on the coupling parts, thus attenuating vibrations generated by wind force, therefore increasing the durability of the steel tower.
The foregoing description of the invention has been described for purposes of clarity and understanding. It is not intended to limit the invention to the precise form disclosed.

We Claim:
1. A retrofitting device to be adapted along an existing leg member of a tower, the device
comprises of:
elements defined by
(a) an external member devised in accordance with the existing leg member;
(b) a pair of angle cleats preferably having two arms and means to receive a bolt on one of the arms;

(c) an angle bracket preferably having two arms and means to receive bolts on both the arms;
(d) a plurality of friction plates having means to receive a bolt;
(e) a plurality of bolts and fasteners,
wherein the elements of the device are coupled and gripped together in an arrangement to increase lateral and torsional strength and provide elasticity between the coupled elements such that a force acting on the elements due to incident wind energy is counter-balanced over the device to provide structural integrity and load balance to the tower.
2. A retrofitting device as claimed in claim 1, wherein the device in a single bolt arrangement is preferably adapted near and adjacent to the intersection point of a cross diagonal member and existing leg member of the tower.
3. A retrofitting device as claimed in claim 1, wherein the device in a double bolt arrangement is preferably adapted at the centre of two intersection points of a cross diagonal member and existing leg member of the tower.
4. A retrofitting device as claimed in claim 1, wherein the external member is coupled to the existing member of the tower.
5. A retrofitting device as claimed in claim 1, wherein the angle cleat is preferably L-shaped.

6. A retrofitting device as claimed in claim 1, wherein the pair of angle cleats are coupled to the external member and to the outer-side of the existing member of the tower.
7. A retrofitting device as claimed in claim 1, wherein the angle bracket is preferably L-shaped.
8. A retrofitting device as claimed in claim 1, wherein the angle bracket is coupled to the inner side of the existing member and further coupled to the L-angle cleats.
9. A retrofitting device as claimed in claim 1, wherein the friction plates are mounted and coupled to the L-angle cleats and the bracket with bolts and fasteners.
10. A retrofitting device as claimed in claim 1, wherein the bolts are high strength friction grip bolts.
11. A method for assembling the retrofitting device as claimed in claim 1, comprises the steps of:
coupling an external member to an existing leg member;
coupling an angle bracket and a pair of angle cleats to the external member and the existing leg member;
mounting and coupling friction plates to the angle cleats and bracket, and coupling the elements using high strength friction grip bolts and fasteners.
12. A method for assembling the retrofitting device as claimed in claim 11, wherein the external member is coupled by welding to the existing leg member at its vertex for increase in lateral and torosional strength.
13. A method for assembling the retrofitting device as claimed in claim 11, wherein the pair of angle cleats is coupled to the external member and the outer side of the existing member of the tower.

14. A method for assembling the retrofitting device as claimed in claim 11, wherein the angle bracket is coupled to the inner side of the existing member and further coupled to the L-angle
cleats.