FORM 2
The Patents Act 1970
(39 of 1970)
&
The Patent Rules 2003 COMPLETE SPECIFICATION
(See Section 10 and rule 13)
TITLE OF THE INVENTION:
TAF OFF BOX FOR BUS BAR TRUNKING SYSTEM


APPLICANT:

LARSEN & TOUBRO LIMITED
L&T House, Ballard Estate, P.O. Box No. 278,
Mumbai, 400 001, Maharashtra . INDIA.

PREAMBLE OF THE DESCRIPTION:
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT Is TO BE PERFORMED



A) TECHNICAL FIELD
[0001] The present invention generally relates to the circuit breakers and particularly relates to a bus bar trunking system of circuit breakers. The present invention more particularly relates to a tap off box for bus bar trunking system with circuit breakers like Miniature Circuit Breakers (MCB), Molded Case Circuit Breaker (MCCB), Switch Disconnector fuse (SDF) etc.
B) BACKGROUND OF THE INVENTION
[0002] The Bus Bar Trunking system (BBT) is the most efficient, safe and ideal system for supplying electricity to the industrial installations and high rise structures. The bus bar trunking system performs the function of a cable by transporting the current from one system to another. The system has been designed specifically for the installations and the projects where there is a need for a rapid and quick availability of the power supply. It is used generally in commercial, industrial and agricultural buildings where the need to have many control switches is limited. The BBT is a simple product solely made up from the enclosures, conductors and insulation. In the bus bar trunking system, the conductors are fitted inside the trunking. The BBT are the enclosed systems for supplying the electric power to the loads safely and reliably. The system also eliminates the need for the distribution and panel boards.
[0003] The bus bar trunking systems are provided with tap-off provisions at regular intervals. The trunking systems are supplied with tap-off boxes and are fitted with
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components such as Miniature Circuit Breakers (MCB), or Moulded Case Circuit Breakers (MCCB) for the protection and control of the loads.
[0004] The Tap-off box is a protection device for branch circuits, in which the MCCB/MCB will shut off electricity, when overloading or short circuit occurs. Where ever required, a tap-off box is installed and mounted with the required switchgear that is fed from the bus bars. The plug-in type tap-off boxes with protective devices can be relocated even when system is live. The Key advantages of using the tap-off box are, it is simple, quick to install using only a few tools and flexible for modifications and expansions.
[0005] The tap off box (TOB) is a unit which houses either a MCCB or SDF in an enclosure that is provided with all safety interlocks from the point of view of user. The TOB is used in BBT. The rating of TOB is generally as per the usage of the MCCB.
[0006] At present all the manufacturers of BBT use their own TOB. Thus the TOB is used only with the unique or only one type of MCCB. This feature restricts the user of TOB from using different types in one TOB or a desired MCCB in case of failure. Thus the currently available tap off box for bus bar trunking systems is costlier, difficult to operate, and is not easily adaptable for equivalent circuit breakers. The replacement of the MCCB in the currently available BBT is very difficult and more over it is not universal to accommodate all sizes of MCCBs in same TOB. Hence there is a need to develop a Tap-off Box (TOB) for bus-bar trunking system to accommodate the equivalent circuit breakers of different sizes.
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[0007] The currently available TOBs are provided with 3 interlocks. The TOB enclosure should be interlocked with the BBT. when the MCCB is on. The door of the TOB enclosure should be restricted to open, when MCCB is switched on. During the ON condition of the MCCB, the operating handle of the TOB should be pad lockable. Most of the manufacturers of TOB provide all the abovementioned interlocks. Moreover the currently available TOB is not economical and not appealing aesthetically. Also the interlock provided to fix the enclosure to BBT is susceptible to damage during the transhipment from the site of manufacturer to that of the user. The mechanism for operating the MCCB is not friendly when there is a need to replace the existing MCCB.
C) OBJECTS OF THE INVENTION
[0008] The primary object of the present invention is to develop a universal tap-off box for a Bus Bar Trunking System to accommodate different types or brands of MCB/MCCB/SDFs.
[0009] Yet another Object of the present invention is to develop a universal and flexible tap-off box for BBT to accommodate the circuit breakers of different size easily and efficiently.
[0010] Yet another Object of the present invention is to develop a tap-off box which is economical.
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[0011] Yet another Object of the present invention is to develop a tap-off box which has a compact design.
[0012] Yet another Object of the present invention is to develop a tap-off box which is easy to operate and adaptable to accommodate equivalent circuit breakers.
[0013] Yet another Object of the present invention is to develop a tap-off box provided with positive ON/OFF indicator that is visible from all the three sides of the enclosure.
[0014] Yet another Object of the present invention is to develop a tap-off box in which the MCCB is replaced easily.
[0015] Yet another Object of the present invention is to develop a tap-off box provided with reliable safety interlocks.
[0016] Yet another Object of the present invention is to develop a tap-off box provided with an insulated handle grip to ensure the safety of operator.
[0017] Yet another Object of the present invention is to develop a tap-off box which is not susceptible to damage during the transit from the manufacturing site to the installation site.
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[0018] Yet another Object of the present invention is to develop a tap-off box which enables the user to use desired or different types of MCCBs in the same TOB easily and efficiently without any trouble.
[0019] Yet another Object of the present invention is to develop a tap-off box to enable the user to replace the MCCB easily.
[0020] These and other objects and advantages of the present invention will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings.
D) SUMMARY OF THE INVENTION
[0021 ] The above mentioned shortcomings, disadvantages and problems are addressed herein and which will be understood by reading and studying the following specification.
[0022] The various embodiments of the present invention provide a universal Tap-off Box (TOB) for Bus Bar Trunking system to accommodate different types of MCBs/MCCBs/SDFs easily and efficiently. The Tap-off Box for bus bar Trunking system is designed to accommodate the circuit breakers of different manufacturers for equivalent or same current rating easily.
[0023] According to one embodiment of the present invention, the universal tap off box has a housing to enclose a circuit breaker mounted on a bus bar in a bus bar
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trunking system. A support assembly is arranged inside the housing for mounting a circuit breaker on the bus bar trunking system. The support assembly has a lower support frame and an upper support frame. The lower support frame is mounted on a bus bar. An upper support frame is movably fixed to the lower support frame to hold the circuit breaker inside the tap off box. The lower support frame and the upper support frame are provided with vertical slots so that the height of the upper slot is adjusted to accommodate the circuit breakers of different sizes. The upper support frame has a balancing link to ensure the planarity of the support. The lower support frame has mounting holes for installing the lower support on the bus bar.
[0024] The tap off box has a link assembly is fitted on the circuit breaker mounted on the support assembly to provide flexibility in the horizontal plane, when the circuit breaker is switched on. The link assembly has a horizontal link plate fixed to two vertical links provided each with an operating lever. The horizontal link has a rectangular slot to receive the dolly/knob of the circuit breaker. The vertical link has a slot to receive a bearing bush to enable the proper mounting of the link assembly with the circuit breaker to enable the smooth operation of the circuit breaker. The link plate and the vertical link are provided with horizontal slots. The link plate and the horizontal plates are moved horizontally and the slots in both the plates are aligned to provide horizontal clearance to accommodate the circuit breaker of different sizes. When the circuit breaker is switched on, the operating lever is moved to press the plunger in a plunger assembly down to get engaged with an interlocking assembly to prevent the removal of tap off box from the bus bar trunking system, when the circuit breaker is switched on and the bus bar trunking is in ON condition.
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[0025] The housing of the tap off box is closed with a top cover. The top cover is hingedly connected to the housing. The top cover/door of the tap of box is interlocked when the circuit breaker is switched on. A padlock arrangement is provided so that the pad lock may be released/ opened only by the authorized individuals. An operating handle is coupled to the link assembly to move the circuit breaker to ON/ OFF OR TRIP positions. A handle grip is provided on the operating handle to provide the safety of the operator. The entire assembly of the tap-off box is placed above the Bus Bar Trunking system with an interlock to hold the assembly when the circuit breaker is in ON condition. The circuit breaker may be a miniature circuit breaker, molded case circuit breaker, etc.
[0026] Thus the various embodiments of the present invention provide a universal tap off box arranged with a horizontal link assembly and a vertical support to accommodate the circuit breakers of multiple sizes, multiple brands and multiple ratings. The link assembly acts as a driving mechanism. [0027] The tap off box has indicator on all the three sides to indicate the ON/ OFF/ TRIP conditions of a circuit breaker easily. The box has reliable safety interlocks and insulating handle grip for the operating handle to improve the safety of an operator. The existing circuit breaker may be easily replaced with a desired circuit breaker.
[0028] These and other objects and advantages of the present invention will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings.
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E) BRIEF DESCRIPTION OF THE DRAWINGS
[0029] The other objects, features and advantages will occur to those skilled in the art from the following description of the preferred embodiment and the accompanying drawings in which:
[0030] FIGURE. 1 illustrates a top perspective view of a tap-off box mounted on the bus bar trunking system according to one embodiment of the present invention.
[0031] FIGURE.2 illustrates a top view of a tap off box according to one embodiment, with the cover in open condition.
[0032] FIGURE.3 illustrates a perspective view of a circuit breaker mounted on a bus bar trunking system according to one embodiment of the present invention.
[0033] FIGURE. 4 illustrates a perspective view of a circuit breaker mounted on a support in a tap off box according to one embodiment of the present invention.
[0034] FIGURE. 5 illustrates a perspective view of a circuit breaker mounted on a support in a tap off box according to one embodiment of the present invention, with a vertical offset by the support.
[0035] FIGURE. 6 illustrates a perspective view of a link assembly in a tap off box according to one embodiment of the present invention.
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[0036] FIGURE. 7 illustrates a perspective view of a link assembly in a tap off box according to one embodiment of the present invention, with the horizontal offset by the link assembly.
[0037] FIGURE.8 illustrates a perspective view of a circuit breaker mounted with horizontal link assembly inside a tap off box according to one embodiment of the present invention.
[0038] Although specific features of the present invention are shown in some drawings and not in others. This is done for convenience only as each feature may be combined with any or all of the other features in accordance with the present invention.
F) DETAILED DESCRIPTION OF INVENTION
[0039] In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which the specific embodiments that may be practiced is shown by way of illustration. These embodiments are described in sufficient detail to enable those skilled in the art to practice the embodiments and it is to be understood that the logical, mechanical and other changes may be made without departing from the scope of the embodiments. The following detailed description is therefore not to be taken in a limiting sense.
[0040] The various embodiments of the present invention provide a universal tap off box to accommodate circuit breakers of different sizes and brands easily and
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efficiently. The tap off box is a unit to house either a miniature circuit breaker (MCB) or molded case circuit breaker (MCCB) or Switch Disconnector fuse (SDF). According to one embodiment of the present invention the tap off box has a housing to enclose the circuit breaker mounted on a support assembly. The support assembly is mounted on a bus bar of the bus bar trunking system to provide vertical off set in Z direction so that the circuit breakers of multiple sizes, ratings and brands are mounted easily within the same tap off box. The support assembly has a lower support frame and an upper support frame. The lower support frame is mounted on a bus bar. An upper support frame is movably fixed to the lower support frame to hold the circuit breaker inside the tap off box. The lower support frame has mounting slots for fixing the whole assembly on the surface of the tap off box. The lower support frame has multiple mounting holes so that the mounting base of the circuit breakers of different manufacturers may easily be mounted on the same support assembly. The lower •support frame and the upper support frame are provided with vertical rectangular slots so that the height of the upper support frame is adjusted to accommodate the circuit breakers of different sizes. The upper support frame has a balancing link to ensure the planarity of the support.
[0041] A link assembly is fitted on the circuit breaker mounted on the support to provide flexibility in the horizontal plane, when the circuit breaker is switched on. The link assembly has a horizontal link plate fixed to two vertical links. Each vertical link has an operating lever and a slot. The horizontal link has a slot to receive the dolly/operating knob of the circuit breaker. The vertical link has a slot to receive a bush bearing to enable the proper mounting of the link assembly with the circuit breaker to enable the smooth operation of the circuit breaker. The link plate and the
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vertical link are provided with horizontal slots. The link plate and the horizontal plates are moved horizontally and the slots in both the plates are aligned to provide horizontal clearance to accommodate the circuit breakers of different sizes. The same link assembly may be used with the circuit breakers of different sizes, ratings and brands by varying the horizontal position of the link plate. The link plate has a rectangular slot to hold the knob of the circuit breaker. When the link assembly is moved circularly, then the circuit breaker is made to switch itself to OFF/ ON condition. When the circuit breaker is switched on, the operating lever is moved to press the plunger in a plunger assembly down to get engaged with an interlocking assembly to prevent the removal of tap off box when the circuit breaker is switched on and the bus bar trunking is in ON condition. The door of the tap of box is interlocked when the circuit breaker is switched on. A padlock arrangement is provided so that the pad lock may be released/ opened only by the authorized individuals.
[0042] The housing of the tap off box is closed with a top cover. The top cover is hingedly connected to the housing. An operating handle provided with a safety handle grip is coupled to the circuit breaker to switch on/off the circuit breaker mounted inside the housing. The operating handle is moved among three positions namely the on position, off position and trip position. The operating handle is displaced to move a link assembly based on the operating condition of the circuit breaker. A cam lock fitted on the top cover is rotated to ensure the locking of the top cover thereby preventing the inadvertent opening of the cover during the ON condition of circuit breaker.
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[0043] The operation of the tap off box is explained as follows. The slot in the horizontal link is made to engage the dolly/knob of the circuit breaker. Once the knob is engaged with the link, the circuit breaker is fastened with the two vertical levers. When the operating handle is rotated clock wise, the circuit breaker is turned on. Then the vertical lever presses a plunger down thereby preventing the enclosure being plugged out from the bus bar trunking system during the switched on condition of the circuit breaker. The slots in the horizontal link and vertical levers provide flexibility in horizontal and vertical directions respectively.
[0044] FIG.l illustrates a Tap off Box (TOB) with top cover in closed condition and mounted on a bus bar trunking system, according to one embodiment of the invention. With respect to FIG.l, the tap off box 100 is mounted on a bus bar 16 in a bus bar trunking system. Tap off box 100 encloses a circuit breaker. Tap-off box 100 includes a cover 2 coupled to the housing 1 encasing the circuit breaker through the hinges 4 that are provided at one end. A cam lock 3 is provided on the cover 2 to lock the cover 2 of the Tap-off Box 100. The cam lock 3 is moved to keep the cover 2 of the box in locked condition, when the cover 2 is in closed condition to prevent the opening of the box 100, when the circuit breaker is switched on. The box 100 includes an operating handle 5, which is rotated to indicate ON, TRIP and OFF position of the circuit breaker. The operating handle 5 is provided with an insulated handle grip 6 to ensure the safety of the operator. When the operating handle 5 is operated, the operating handle 5 moves a link assembly to operate the Molded Case Circuit Breaker (MCCB) in "ON' or "OFF" condition depending upon the status. When the operating handle 5 is rotated clockwise the MCCB is turned ON. When the operating handle 5 is operated, a link assembly mounted on the circuit breaker housed inside the housing 1
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in the tap off box 100 is operated to move a plunger down to interlock the plunger with an interlocking assembly 21 provided in the bus bar trunking system to prevent the removal of the tap off box 100 from the bus bar trunking system. A handle locking cap 20 is provided on the tap-off box 100 to lock the operating handle 5 once it is set, so that the handle 5 is not be operated by unauthorized personnel. The cover 2 cannot be opened in interlocked state. A padlock arrangement is provided so that the padlock can be opened only by an authorized personnel in case of emergency. Similarly the TOB 100 can not be removed from bus bar trunking arrangement when MCCB is ON condition.
[0045] FIG.2 illustrates a Tap-off Box (TOB) 100 with the cover opened condition. With respect to FIG.2, a moulded case circuit breaker (MCCB) 17 is mounted on a bus bar 16 in the bus bar trunking system and accommodated inside the housing 1 of the tap off box 100. The housing 1 is provided with hinges 4 at one end to couple the housing 1 with a top cover. An operating handle 5 coupled to the MCCB 17 is moved to ON, OFF OR TRIP position. A handle grip 6 is provided on the handle 5 to ensure the safety of the operator. A link assembly 7 including a horizontal link plate and vertical lever assembly is mounted on the MCCB 17 to engage with the dolly/operating knob of the MCCB 17. When the operating handle 5 is operated, the operating handle 5 moves the link assembly 7 to operate the MCCB 17 in "ON' or "OFF" condition depending upon the status. When the operating handle 5 is rotated clockwise the MCCB 17 is turned ON. When the operating handle 5 is moved, a link assembly 7 mounted on the MCCB 17 stored inside the housing 1 in the tap off box 100 is operated to move a plunger down to interlock the plunger with an interlocking assembly 21 provided at the bus bar trunking system to prevent the removal of the tap
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off box 100 from the bus bar trunking system. A handfe locking cap 20 is provided on the tap-off box 100 to lock the operating handle 5 once it is set, so that the operating handle 5 can not be operated by unauthorized personnel. A shroud terminal 23 is provided inside the housing 1 to connect the wire harnesses to the MCCB 17.
[0046] FIG.3 illustrates a perspective view of a circuit breaker such as MCCB that is accommodated inside a tap off box and mounted on a bus bar trunking system according to one embodiment of the present invention. With respect to FIG. 3, the MCCB 17 is mounted on a support assembly 18 installed on the bus bar 16 of a bus bar trunking system. The MCCB 17 is provided with an operating knob which is moved between a. switch ON position 34 and a. switch OFF position 33.
[0047] FIG. 4 illustrates a perspective view of a circuit breaker such as MCCB 17 mounted on a support in a tap off box according to one embodiment of the present invention. With respect to FIG.4, the MCCB 17 is mounted on a support assembly. The circuit breaker 17 has an operating knob which is rnoved between switched ON condition 34 and switched OFF condition 33. The support assembly is mounted on the bottom surface of the tap off box to provide vertical off set in Z direction so that the circuit breakers of multiple sizes, ratings and brands are mounted easily with in the same tap off box. The support assembly has a lower support frame 37 and an upper support frame 36. The lower support frame 37 is mounted on the bottom surface of the tap off box. The upper support frame 36 is movably fixed to the lower support frame 37 to hold the circuit breaker 17 inside the tap off box. The lower support frame 37 has mounting slots 38 for fixing the whole assembly on the surface of the tap off box. The lower support frame 36 has multiple mounting holes 38 so that the mounting
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base of the circuit breakers of different manufacturers rnay easily be mounted on the same support assembly. The lower support frame 37 and the upper support frame 36 are provided with vertical rectangular slots 40 so that the height of the upper support frame 36 is adjusted to accommodate the circuit breakers of different sizes. The upper support frame 36 has a balancing link 39 to ensure the planarity of the support.
[0048] FIG. 5 illustrates a perspective view of a circuit breaker mounted on a support in a tap off box according to one embodiment of the present invention, with a vertical offset by the support. With respect to FIG.5, the MCCB 17 is mounted on a support assembly. The circuit breaker 17 has an operating knob which is moved between switched ON condition 34 and switched OFF condition 33. The support assembly is mounted on the bottom surface of the tap off box to provide vertical off set in Z direction so that the circuit breakers of multiple sizes, ratings and brands are mounted easily with in the same tap off box. The support assembly has a lower support frame 37 and an upper support frame 36. The lower support frame 37 is mounted on the bottom surface of the tap off box. The upper support frame 36 is movably fixed to the lower support frame 37 to hold the circuit breaker 17 inside the tap off box. The lower support frame 37 has mounting slots 38 for fixing the whole assembly on the surface of the tap off box. The lower support frame 36 has multiple mounting holes 38 so that the mounting base of the circuit breakers of different manufacturers may easily be mounted on the same support assembly. The lower support frame 37 and the upper support frame 36 are provided with vertical rectangular slots 40 so that the height of the upper support frame 36 is adjusted to accommodate the circuit breakers of different sizes. The upper support frame 36 has a balancing link 39 to ensure the planarity of the support.
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[0049] FIG. 6 illustrates a perspective view of a link assembly in a tap off box according to one embodiment of the present invention. The link assembly is mounted on the circuit breaker to provide off set in horizontal and vertical directions to accommodate the circuit breakers of different sizes, ratings and manufacturers easily and efficiently in the same tap off box. With respect to FIG.6, the link assembly has a horizontal link plate 30 fixed to two vertical links 24, 25. Each vertical link 24, 25 has an operating lever 28 and a slot 29. The horizontal link plate 30 has a rectangular slot 26 to receive the dolly/operating knob of the circuit breaker. The vertical link 24, 25 has a slot 29 to receive a bush bearing to enable the proper mounting of the link assembly with the circuit breaker to enable the smooth operation of the circuit breaker. The link plate 30 and the vertical link 24, 25 are provided with horizontal slots 27. The link plate 30 and the horizontal plates 24, 25 are moved horizontally and the slots 27 in both the plates are aligned to provide horizontal clearance to accommodate the circuit breaker of different sizes. The same link assembly may be used with the circuit breakers of different sizes, ratings and brands by varying the horizontal position of the link plate. The link plate 30 has a rectangular slot 26 to hold the knob of the circuit breaker. When the link assembly is moved circularly, then the circuit breaker is made to switch itself to OFF/ ON condition. When the circuit breaker is switched on, the operating lever 28 is moved to press the plunger in a plunger assembly down to get engaged with an interlocking assembly to prevent the removal of tap off box when the circuit breaker is switched on and the bus bar trunking is in ON condition.
[0050] FIG. 7 illustrates a perspective view of a link assembly in a tap off box according to one embodiment of the present invention, with the horizontal offset by
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the link assembly. With respect to FIG.7, the link assembly has a horizontal link plate 30 fixed to two vertical links 24, 25. Each vertical link 24, 25 has an operating lever 28 and a slot 29. The horizontal link plate 30 has a rectangular slot 26 to receive the dolly/operating knob of the circuit breaker. The vertical link 24, 25 has a slot 29 to receive a bush bearing to enable the proper mounting of the link assembly with the circuit breaker to enable the smooth operation of the circuit breaker. The link plate 30 and the vertical link 24, 25 are provided with horizontal slots 27. The link plate 30 and the horizontal plates 24, 25 are moved horizontally and the slots 27 in both the plates are aligned to provide horizontal clearance to accommodate the circuit breaker of different sizes. The same link assembly may be used with the circuit breakers of different sizes, ratings and brands by varying the horizontal position of the link plate. The link plate 30 has a rectangular slot 26 to hold the knob of the circuit breaker. When the link assembly is moved circularly, then the circuit breaker is made to switch itself to OFF/ ON condition. When the circuit breaker is switched on, the operating lever 28 is moved to press the plunger in a plunger assembly down to get engaged with an interlocking assembly to prevent the removal of tap off box when the circuit breaker is switched on and the bus bar trunking is in ON condition.
[0051] FIG. 8 illustrates a perspective view of a circuit breaker mounted with horizontal link assembly inside a tap off box according to one embodiment of the present invention. With respect to FIG.8, A circuit breaker such as MCCB 17 is mounted inside the tap-off box and installed on a bus bar 16 of a bus bar trunking system. The link assembly 7 with the horizontal link and the lever assembly is mounted on the circuit breaker 17. The hole on the horizontal link engages with the knob of the circuit breaker. An operating handle 5 is coupled to the link assembly so
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that the operating handle is operated to move the link assembly mounted on the circuit breaker. A handle grip 6 is provided on the operating handle to provide safety to the operator. The entire assembly of the tap-off box is placed above the Bus Bar Trunking system with an interlock assembly 21. When the operating handle 5 is operated, the operating handle 5 moves the link assembly 7 to operate the MCCB 17 in "ON' or "OFF" condition depending upon the status. When the operating handle 5 is rotated clockwise the MCCB 17 is turned ON. When the operating handle 5 is moved, a link assembly 7 mounted on the MCCB 17 is operated to move a plunger down to interlock the plunger with an interlocking assembly 21 provided at the bus bar trunking system to prevent the removal of the tap off box 100 from the bus bar trunking system. A handle locking cap 20 is provided to lock the operating handle 5 once it is set, so that the operating handle 5 can not be operated by unauthorized personnel. The circuit breaker 17 has copper links mounted on the mold 32.
[0052] Thus the various embodiments of the present invention provide a universal tap off box arranged with a horizontal link assembly and a vertical support to accommodate the circuit breakers of multiple sizes, multiple brands and multiple ratings. The link assembly acts as a driving mechanism. The tap off box has indicator on all the three sides to indicate the ON/ OFF/ TRIP conditions of a circuit breaker easily. The box has reliable safety interlocks and insulating handle grip for the operating handle to improve the safety of an operator. The existing circuit breaker may be easily replaced with a desired circuit breaker.
G) ADVANTAGES OF THE INVENTION
[0053] Thus the various embodiments of the present invention provide a universal tap off box arranged with a horizontal link assembly and a vertical support to
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accommodate the circuit breakers of multiple sizes, multiple brands and multiple ratings. The link assembly acts as a driving mechanism. The tap off box is pushed/plugged in a sandwiched bus bar of a bus bar trunking system. The tap off box is used along with MCB, MCCB AND SDF. The tap off box is economical and operated easily. The TOB has a compact design and may be used with circuit breakers of different manufacturers easily. The TOB may accommodate two different types of circuit breakers easily and efficiently. The tap off box has positive indicator on all the three sides to indicate the ON/ OFF/ TRIP conditions of a circuit breaker easily. The box has reliable safety interlocks and insulating handle grip for the operating handle to improve the safety of an operator. The existing circuit breaker may be easily replaced with a desired circuit breaker.
[0054] Although the invention is described with various specific embodiments, it will be obvious for a person skilled in the art to practice the invention with modifications. However, all such modifications are deemed to be within the scope of the claims.
[0055] It is also to be understood that the following claims are intended to cover all of the generic and specific features of the present invention described herein and all the statements of the scope of the invention which as a matter of language might be said to fall there between.
Date: August 28, 2008. RAKESH PRABHU
Place: Bangalore. Patent Attorney
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CLAIMS
WHAT IS CLAIMED IS:
1. A tap off box unit for bus bar trunking system, the unit comprising:
A housing to enclose a circuit breaker mounted on a bus bar;
A support assembly arranged inside the housing to mount the circuit breaker
on the bus bar;
A link assembly mounted on circuit breaker;
An operating handle connected to the link assembly; and
A top cover connected to the housing;
Wherein the support assembly is provided with vertical offset to accommodate
circuit breakers of different sizes and link assembly is provided with
horizontal and vertical offsets to accommodate circuit breakers of different
sizes.
2. The unit according to claim 1, wherein the support assembly has an upper support frame and a lower support frame.
3. The unit according to claim 2, wherein the upper support frame and the lower support frame has vertical slots to provide vertical off set.
4. The unit according to claim 2, wherein the lower support frame is mounted on the bus bar.
5. The unit according to claim 2, wherein the upper support frame is movably mounted on the lower support frame to hold the circuit breaker.
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6. The unit according to claim 2, wherein the upper support frame and the lower support frame are moved with respect to each other to accommodate the circuit breakers of different sizes.
7. The unit according to claim 1, the support assembly further comprises a balancing link to ensure the planarity of the circuit breaker.
8. The unit according to claim 1, wherein the link assembly includes a horizontal link plate and two vertical links.
9. The unit according to claim 8, wherein the two vertical links are connected to the two ends of the horizontal link plate.
10. The unit according to claim 8, wherein the horizontal link plate has a rectangular slot to receive the operating knob of the circuit breaker.
11. The unit according to claim 8, wherein each vertical link has a circular slot to receive a bush bearing to support the link assembly on the circuit breaker in a balanced manner.
12. The unit according to claim 8, wherein each vertical link has an operating lever.
13. The unit according to claim 8, the horizontal link plate and the vertical links are provided with horizontal slots to provide horizontal offset.
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14. The unit according to claim 8, wherein the horizontal link plate is moved in a horizontal plane by varying the position of the link plate by moving the horizontal link plate with respect to the vertical link along the horizontal slots to provide horizontal offset to accommodate the circuit breakers of different sizes.
15. The unit according to claim 1, wherein the operating handle is operated to move the circuit breaker among ON, OFF and TRIP positions.
16. The unit according to claim 1, further comprises a plunger assembly.
17. The unit according to claim 1, further comprises an interlocking assembly mounted on the bus bar.
18. The unit according to claim 8, wherein the horizontal link plate is moved to displace the operating levers in the vertical links to press a plunger in the plunger assembly to interlock the plunger with an interlocking assembly to prevent the removal of the tap off box from the bus bar trunking system, when the circuit breaker is switched on.
19. The unit according to claim 1, wherein the operating handle is provided with a handle grip to improve the safety of the operator.
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To,
The Controller of Patents,
The Patent office,
At Chennai
24
20. The unit according to claim 1, wherein the top cover is hingedly connected to the housing.
21. The unit according to claim 1, wherein the circuit breaker is a miniature circuit breaker.
22. The unit according to claim 1, wherein the circuit breaker is a molded case circuit breaker.