FORM 2
THE PATENTS ACT. 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
A DEVICE AND A METHOD FOR JOINING PIPES AND/OR CHANNELS;
LARSEN & TOUBRO LIMITED, A COMPANY INCORPORATED UNDER THE COMPANIES ACT, 1956, WHOSE ADDRESS IS L&T HOUSE, BALLARD ESTATE, MUMBAI - 400 001, MAHARASHTRA, INDIA
THE FOLLOWING SPECIFICATION
PARTICULARLY DESCRIBES THE
INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.
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FIELD OF THE INVENTION:
This invention relates to a device and a method for joining two or more pipes and/or channels of different sizes.
BACKGROUND OF THE INVENTION:
Different pipes/channels of different sizes and/or shapes are joined together to form a pipe assembly. Multiple pipe assemblies may be used in various constructions. For instance, various pipe assemblies may construct a panel frame that can be used in a switchboard assembly. A pipe assembly with several joints being used in a panel-frame should be rigid enough to prevent twisting of the whole structure and any occurrence of failure upon loading.
Generally different pipes/channels are joined together using fasteners such as nuts & bolts or rivets. In case of nut & bolt fasteners, there may be a possibility of loosening of nuts over a period of time. This reduces the rigidity of the panel-frames. Further, constructing pipe assemblies by nut & bolt fasteners is quite time consuming. Therefore, rivets may be used that can improve rigidity and reduce the assembling time. However, pneumatic guns are required to fix a rivet. These pneumatic guns need pressurized air, which is a costly affair. Further, if any nail inside the rivet falls during shifting, the riveted joint would fail under loading.
As the above-mentioned joints are time consuming and also require some special arrangements, such as pressurized air as in case of riveted joints, panel-frames are usually not assembled at the customers end. They are assembled and then transported in assembled condition to the customer. However, the size and the weight of various constructions like switchboard result in a difficulty of transporting the whole assembled structure from one place to another. Further, there is also a possibility of damage to the aesthetics and the inner subassemblies.
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Therefore there is a need for a device and a method for providing a rigid yet simple assembly of the whole structure at customer's end within least possible time thereby avoiding the damages during transportation.
SUMMARY OF THE INVENTION:
The object of the present invention is to provide a device and method for joining two channels / pipes that form a part of an assembly of a panel frame. It is another object of the invention to provide the assembly of a panel frame at customers end in order to avoid the damages .during transportation of the whole panel frame.
According to the present invention, the device for joining an inner pipe and an outer pipe comprises a lever, a punch, a means to transfer mechanical force from the lever to said punch, multiple compression springs adapted between said means. The punch maintains a perpetual contact with said means. The lever is operated to exert force on the pipes through the punch via said means to join and lock the pipes in each other
The surface of the outer pipe is provided with a plurality of projections, whereas the surface of the inner pipe is provided with a plurality of cavities to accommodate the projections of said outer pipe. Said projections are bent into cavities to lock the pipes into each other.
The portable device further comprises plurality of legs for supporting the device, a support plate attached to these legs, a middle plate adapted between said legs and support plate for guiding the bending punch and multiple clamps. Each clamp is attached to its corresponding legs for holding the pipes centrally with respect to the device.
A screw and nut is provided in the device which act as the means to transfer the mechanical force from the lever to said punch. The screw is mounted on the punch and the nut is attached to the lever.
The present invention also provides a method for joining an inner pipe and an outer pipe. Said method comprises the steps of exerting pressure on a lever for
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transferring force to a punch through a screw and nut, applying a gradually increasing load on the punch, allowing the punch to enter into the cavities of the inner pipe for bending the projections of the outer pipe into said cavities such that the cavities accommodate the projections and the pipes get locked firmly into each other. The bending is accomplished without using any separate die. The cavity of the inner pipe is used as a die for bending.
Other objects, features and advantages of the invention will be apparent from the drawings, and from the detailed description that follows below.
BRIEF DESCRIPTION OF THE DRAWINGS:
Figure 1 illustrates the schematic view of the device of the present invention.
Figure 2 illustrates the schematic view of the device of the present invention.
Figure 3 illustrates the schematic view of the pipes and sequence of their joint
Figure 4 illustrates the schematic view of housing.
Figure 5 illustrates the schematic view of the nut.
Figure 6 illustrates the schematic view of the punch.
Figure 7 illustrates the schematic view of the screw.
Figure 8 illustrates the schematic view of actual assembly of the pipes
DETAILD DESCRIPTION OF THE PREFERRED EMBODIMENTS:
A device and a method for joining channels / pipes that forms a part of an assembly of a panel frame is described below. It should be understood that the present invention is not limited thereto. Those skilled in the art will recognize additional modifications, application and embodiments within the scope thereof and additional fields in which the invention would be of significant utility.
The present invention relates to a device, for joining the channel / pipes in less cost and time. The two pipes / channels to be joined are rectangular in shape but different in cross-sectional sizes. The dimensional difference between cross-sections of small section pipe / channel & large section pipe / channel is such
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that the former can easily slide into the latter. The difference in the two is such that inner pipe cannot rotate once put inside the larger one. To assemble the pipes, projected limbs are provided on outer pipe and corresponding slots are provided on the inner pipe. These projected limbs are bent in the respective slots to lock the two pipes together.
To form the above-mentioned joint a compact device is developed that can be placed on the cross sectional area of two pipes to be joined such that the smaller pipe is placed inside the larger. Then the whole device is kept on the two pipes. Figure 1 and Figure 2 show the diagrams of the device as per the present invention. The device comprises a housing (3), a base plate (1) and a plate (2). The pipes (14 and 15) that are placed beneath the device, get self-located at the centre of the punch (4) and space between the plate (2) and the housing (3). Two support legs are provided in the device and two L'shaped clamps are attached to the support legs with help of pivot pins. The L'shaped clamps are free to rotate on these pivot pins. After placing the device on the base plate (1), these L'shaped clamps are released. These clamps get locked in the respective slots (13), provided in base plate (1) by means of gravity. The plate (2) is clamped to housing (3) with help of alien screw (10). Screw (5) and nut (7) is provided to apply force on the punch (4). Punch (4) is directly connected to screw (5). The punch (4) is guided in the housing (3). The lever (6) is a loose piece and can be attached to the nut (7) with the holes provided on the periphery of the nut (7) and allow it to rotate. Nut (7) fits in the slot made in the housing (3).
Quick locking arrangement helps to reduce the operation time. Two clamps are designed in such a way that on lifting them tool gets released from base plate (1) and after releasing; it goes back to its position by means of gravity. After that an operator exerts force on lever (6) manually. This force gets transferred to the punch (4) with the help of screw (5) and nut (7) mechanism. Punch (4) is guided in the housing (3) and the plate (2).
When an operator rotates the lever (6), the nut (7) also rotates and the screw (5) moves up and down accordingly. Screw (5) makes the punch (4) to move
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downward as it is connected to punch directly. The force exerted by screw (5) and nut (7) mechanism on the punch (4) gradually increases and the punch (5) slowly starts to bend the projections (9) of outer pipe (14) into the respective slot in the inner pipe (15). The bending takes place against the sheet metal edge of inner pipe (15). Both the pipes (14 and 15) get assembled and locked by each other.
When the operator rotates the lever (6) in reverse direction, punch (5) comes out from the pipes (14 and 15). Thereafter the tool is released by lifting the 'L' shaped clamps and moved to another position on another bending.
Figure 3(a) to 3(c) illustrates the stage-wise assembly / formation of the joint. Small pipe (15) is provided with cavities (17) and large pipe (14) is provided with respective limbs or projections (16). The small pipe (15) slides into the large pipe (14) as shown in figure 3(b), in such a way that the projections and cavities perfectly match with each other. Figure 3(c) shows final assembly of the two pipes after bending.
Figure 4 illustrates the schematic view of the housing (3). Figure 5 illustrates the schematic and three-dimensional view of the nut (7). Figure 6 illustrates the schematic and three-dimensional view of punch (4). Figure 7 illustrates the schematic and three-dimensional view of the screw (5). The actual assembly of the pipes is shown in Figure 8.
The advantage of this device that it can be operated manually with very less effort and without any help of external source of power e.g. electric power supply, pressurized air. The device is compact in size and light in weight. Hence, it is easy to carry it to any place.
The present invention also discloses a method for assembling the pipes of rectangular section by means of bending. The bending is done manually by applying force through mechanical linkages without help of any power press or fly press.
The method for joining the pipes comprises the steps of placing two pipes to be joined on a base plate in such a way that the pipe having smaller cross sectional
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area is inside the pipe having larger cross sectional area; placing the device as per the present invention, on said pipes for allowing them to get self-located at the centre of the punch and space between the plate and the housing; releasing two 'L' shaped clamps; allowing the 'L' shaped clamps to enter the respective slots provided in the base plate by means of gravity for locking the pipes.
The method for joining the pipes further comprises the steps of exerting manual force on lever for transferring said force to the bending punch; applying a gradually increasing load on the punch; allowing the punch to enter into the cavity of pipe having smaller cross sectional area such that said cavity accommodates the projection provided in the pipe having larger cross sectional area; releasing the two pipes with each other by means of the tension spring; releasing the load on the lever for bringing the lever to its original position; lifting the clamps for releasing the device; and moving the device to another position for another bending.
The above-mentioned method is accomplished by rotating the lever of the device as per the present invention. As the lever rotates, the nut also rotates and the screw moves up and down accordingly. The force exerted by screw and nut mechanism on the punch gradually increases and the punch slowly starts to bend the particular section of outer pipe into the respective slot in the inner pipe. The bending takes place against the sheet metal edge of inner pipe. Both the pipes get assembled and locked by each other.
In the present invention, the bending process is made without using any separate die. The device as per the present invention is designed such that smaller section rectangular pipe is used as a die for bending. The larger pipe is provided with projections and the smaller section pipe has slots / cavities corresponding to the projections. Edges of these slots act as die edge for bending and take the whole bending load. Hence, the device provides an advantage of accomplishing bending process without using any separate die.
The foregoing description of the invention has been described for purposes of clarity and understanding and not to limit the invention to the precise form as
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disclosed. Various other modifications may be possible within the scope and equivalence of the appended claims.

WE CLAIM
1. A portable device for joining an inner pipe and an outer pipe
comprising:
a lever;
a punch;
a means to transfer mechanical force from the lever to said punch;
multiple compression springs adapted between said means and the punch for maintaining a perpetual contact between said means and said punch;
whereby the lever is operated to exert force on the pipes through the punch via said means to join and lock the pipes in each other.
2. The portable device for joining inner pipe and an outer pipe as claimed in claim 1 wherein the surface of the outer pipe is provided with a plurality of projections.
3. The portable device for joining inner pipe and an outer pipe as claimed in claim 1 and claim 2 wherein the surface of the inner pipe is provided with a plurality of cavities to accommodate the projections of said outer pipe.
4. The portable device for joining inner pipe and an outer pipe as claimed in claim 1, wherein the device comprises:
plurality of legs for supporting the device;
a support plate attached to said legs;
a middle plate adapted between said legs and support plate for guiding the bending punch; and
multiple clamps; each being attached to corresponding legs for holding the pipes centrally with respect to the device.
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5. The portable device for joining inner pipe and an outer pipe as claimed in claim 1, wherein the means to transfer mechanical force from the lever to said punch is a screw and nut; the screw being mounted on the punch and the nut being attached to the lever.
6. The portable device for joining inner pipe and an outer pipe as claimed in claims 1-3, wherein said projections are bent into cavities to lock the pipes into each other.
7. The portable device for inner pipe and an outer pipe as claimed in claim 1 wherein the pipes can be joined at customer's end.
8. A method for joining inner pipe and an outer pipe comprising the steps of:
exerting pressure on a lever for transferring force to a punch through a screw and nut;
applying a gradually increasing load on the punch;
allowing the punch to enter into cavities of the inner pipe for bending the projections of the outer pipe into said cavities such that the cavities accommodate the projections and the pipes get locked firmly into each other.
9. The method for joining inner pipe and an outer pipe as claimed in claim 8 wherein the bending is accomplished without using any separate die.
10. The method for joining inner pipe and an outer pipe as claimed in claim 8 wherein the cavities of the inner pipe are used as die for bending.
Dated this : 31st day of October, 2005
FOR LARSEN & TOUBRO LIMITED
By their Agents
(GIRISH VIJAYANAND SHETH) KRISHNA & SAURASTRI
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ABSTRACT
This invention relates to a device and a method for joining two or more pipes and/or channels of different sizes. A portable device for joining an inner pipe and an outer pipe comprising: a lever; a punch; a means to transfer mechanical force from the lever to said punch; multiple compression springs adapted between said means and the punch for maintaining a perpetual contact between said means and said punch; whereby the lever is operated to exert force on the pipes through the punch via said means to join and lock the pipes in each other. The advantage of this device that it can be operated manually with very less effort and without any help of external source of power e.g. electric power supply, pressurized air. The device is compact in size and light in weight. Hence, it is easy to carry it to any place.
Ref. Fig 1
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