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:
COMMON TERMINATION ARRANGEMENT FOR BARE CABLE AND LUG IN CHANGEOVER SWITCH

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
[OOOl] The present invention generally relates to low voltage, low rating electrical switchboxes and particularly to box cage and clamping arrangement connection of bare cable and lug in the changeover switches. The present invention more particularly relates to a common termination arrangement for the bare cable and lug in the changeover switches.
B) BACKGROUND OF THE INVENTION
[0002J An electrical switchbox is commonly used for the distribution of electrical power to its connected peripheral devices. The electrical switchbox includes at least one connector for receiving the source electrical power and plurality of termination windows through which the electrical power is distributed to the connected peripherals.
[0003] The termination window in the electrical switchbox includes a nut and a clamp to retain the cable in the slot. The peripheral connecting cable can either be directly connected to the termination window (bare cable) or the cable can be fixed to a lug which is in-turn connected to the termination window. At the termination window, the peripheral connecting cable is placed between the electrical contact pin and the clamp. Further the screw is tightened to move the clamp down to hold the peripheral connecting cable firmly in the termination window.
[0004] In this arrangement, when the screw in the termination window gets loosened due to wear and tear, then there is a possibility that the lug or the bare cable might get disconnected from the electrical switchbox and might get in contact with other terminal window contact pins. Moreover this can be the cause for the damage of electrical switchbox.
[0005] Hence there is a need to provide a common termination arrangement for clamping both the bare cable and lug in the electrical switchbox. Also there is a need to provide a common bare cable and lug clamping arrangement with the electrical
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switchbox such that the bare cable or the lug shall not come out of termination window when the screw at the termination window gets loosened.
[0006] The abovementioned shortcomings, disadvantages and problems are addressed herein and which will be understood by reading and studying the following specification.
C) OBJECTS OF THE INVENTION
[0007] The primary object of the present invention is to develop a changeover switch with a common termination arrangement that is used to clamp both the bare cable and lug in terminations.
[0008] Another object of the present invention is to provide a changeover switch with a common termination arrangement that is used to clamp both the bare cable and lug in terminations and that does not allow the disconnection of a lug from the contact surface, even when the screw gets slightly loosened due to wear and tear.
[0009] 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
[0010] The various embodiments of the present invention provide a changeover switch with a common termination arrangement that is used to clamp both the bare cable and lug in terminations. A common termination arrangement for a bare cable and a lug in a change over switch has housing for the change over switch. A termination window is formed in the housing. A terminal is provided in the termination window and connected to the switch. A hole is formed in the terminal to receive a pin loaded with a spring. A box clamp screw is mounted above the terminal in the housing. A nut plate is arranged below the box clamp screw and above the terminal. A clamp is movably arranged above the terminal. The spring loaded pin and
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the clamp are used to hold a lug or a bare cable conductor with the terminal in the termination window.
[0011] The lug is inserted into the termination window and held firmly with the terminal using the pin and the clamp. The lug inserted in the termination window is firmly held with the terminal by tightening the screw and moving down the clamp so that the hole provided in the lug forms a hinge with the pin and the lug is not pulled out due to the hindrance of the pin, even when the screw is loosened.
[0012] The bare cable conductor is inserted into the termination window and held firmly with the terminal using the pin, the clamp and the screw. The bare cable conductor inserted in the termination window is firmly held with the terminal by tightening the screw and moving down the clamp so that the clamp applies a force on the bare cable and on the pin to press the pin to enable the bare cable form a proper contact with the terminal.
[0013] The pin is a spring loaded pin and forms a hinge point with the inserted lug. The pin is inserted into the hole of the terminal and projected out of the terminal to form a hinge point with the lug. The spring applies an axial force on the terminal. The nut plate acts as a nut and sandwiched between the box clamp screw and the terminal.
[0014] According to one embodiment, a changeover switch has a termination module in at least one side. The termination module includes a plurality of top and bottom switches in which bare cables and lugs are fitted to the changeover switch. The bare cables and lugs are used to receive and/or provide the electrical power to the changeover switch. Each of the top and bottom switch in the termination module of the changeover switch includes a termination window. Each termination window is used to receive either the bare cable or the lug when connection is made with the changeover switch. The termination window includes a terminal plate. The terminal plate is a plate of metal component such as copper, which provides a fixed contact of the changeover switch. The terminal plate is rigidly mounted inside the bottom of the termination window in a horizontal position. The terminal plate is used to carry the electrical power from the bare cable and lug to the changeover switch as well as to
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carry the electrical power from the changeover switch to the bare cable and lug. Each terminal plate includes a hole at the surface. A pin of mild steel component is vertically inserted through the hole of the terminal plate and protruded above the surface of the terminal plate. The bottom of the pin is mounted on a spring which enables the pin to move in vertical direction. The pin loaded with the spring is used to provide a hinge point when a lug is inserted into the termination window.
[0015] Above the terminal plate, a nut plate of mild steel component is rigidly fitted in between the housings of the termination window, in a horizontal position. The nut plate includes a nut at the surface. A box clamp screw which is a mild steel component is vertically screwed through the nut in the nut plate. The bottom of the box clamp screw is attached to the surface of a clamp which is vertically movable along with the box clamp screw. The clamp which is a mild steel component is used to apply forces on the terminal plate when the box clamp screw is screwed down.
[0016] When a lug is inserted to the termination window in the termination module of the changeover switch, the pin and the hole of the lug form a hinge point with the lug. The box clamp screw with the clamp is screwed down till the clamp presses the lug and hence the pin tightly to the terminal plate. Hence the lug is clamped in between the clamp and the terminal plate of the changeover switch to make connection between the lug and the terminal plate. Though the box clamp screw becomes slightly loosen due to wear and tear, the lug does not be disconnected from the terminal plate of the changeover switch since the pin with the spring makes a hindrance to the lug.
[0017] When a bare cable is inserted to the termination window in the termination module of the changeover switch, the bare cable is initially placed on the pin. The box clamp screw with the clamp is screwed down to force the bare cable on the pin. Due to the force of the clamp, the pin is restrained down and the bare cable is firmly tightened to the terminal plate. Hence the bare cable is clamped in between the clamp and the terminal plate of the changeover switch to form proper contact surface with the terminal plate. Even though the box clamp screw becomes slightly loosen due to wear and tear, the bare cable does not come out from the terminal plate of the
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changeover switch since the pin with the spring provides a force on the bare cable in upwards.
[0018] The changeover switch includes a cover at the top of the termination module which covers the box clamp screws. The box clamp screws are available to screw down or up only when the cover is opened or removed from the changeover switch.
E) BRIEF DESCRIPTION OF THE DRAWINGS:
[0019] 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:
[0020] FIG. 1 illustrates a top side perspective view of a changeover switch with a common termination arrangement according to one embodiment of the present invention.
[0021] FIG. 2 illustrates an enlarged front perspective view of a common termination arrangement in a changeover switch according to one embodiment of the present invention.
[0022] FIG. 3 illustrates an enlarged front view of a lug termination arrangement in a common termination arrangement in a changeover switch according to one embodiment of the present invention.
[0023] FIG. 4 illustrates a partially enlarged front view of a common termination arrangement in a changeover switch with insertion of a lug into the termination window according to one embodiment of the present invention.
[0024] FIG. 5 illustrates a partially enlarged front view of a common termination arrangement in a change over switch with insertion of a lug into the termination window according to one embodiment of the present invention, when the clamp is moved partially downward.
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[0025] FIG. 6 illustrates a partially enlarged front view of a common termination arrangement in a change over switch with insertion of a lug into the terminal at the termination window according to one embodiment of the present invention.
[0026] FIG. 7 illustrates a partially enlarged front view of a common termination arrangement in a change over switch with the insertion of a bare cable according to one embodiment of the present invention.
[0027] FIG. 8 illustrates a partially enlarged front view of a common termination arrangement in a change over switch with the partial clamping of the inserted bare cable according to one embodiment of the present invention.
[0028] FIG. 9 illustrates a partially enlarged front view of a common termination arrangement in a change over switch with the insertion of a bare cable according to one embodiment of the present invention.
[0029] FIG. 10 illustrates a partially enlarged front view of a common termination arrangement in a change over switch with the insertion of a bare cable according to one embodiment of the present invention.
[0030] Although the 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 THE INVENTION
[0031] In the following detailed description, a 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.
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[0032] The various embodiments of the present invention provide a changeover switch with a common termination arrangement that is used to clamp both the bare cable and lug in terminations. A common termination arrangement for bare cable and lug in a change over switch has a housing for the change over switch. A termination window is formed in the housing. A terminal is provided in the termination window and connected to the switch. A hole is formed in the terminal to receive a pin loaded with a spring. A box clamp screw is mounted above the terminal in the housing. A nut plate is arranged below the box clamp screw and above the terminal. A clamp is movably arranged above the terminal. The spring loaded pin and the clamp are used to hold a lug or a bare cable conductor with the terminal in the termination window.
[0033J The lug is inserted into the termination window and held firmly with the terminal using the pin and the clamp. The lug inserted in the termination window is firmly held with the terminal by tightening the screw and moving down the clamp so that the hole provided in the lug forms a hinge with the pin and the lug is not pulled out due to the hindrance of the pin, even when the screw is loosened.
[0034] The bare cable conductor is inserted into the termination window and held firmly with the terminal using the pin, the clamp and the screw. The bare cable conductor inserted in the termination window is firmly held with the terminal by tightening the screw and moving down the clamp so that the clamp applies a force on the bare cable and on the pin to press the pin to enable the bare cable form a proper contact with the terminal.
[0035] The pin is a spring loaded pin and forms a hinge point with the inserted lug. The pin is inserted into the hole of the terminal and projected out of the terminal to form a hinge point with the lug. The spring applies an axial force on the terminal. The nut plate acts as a nut and sandwiched between the box clamp screw and the terminal.
[0036] According to one embodiment, a changeover switch has a termination module in at least one side. The termination module includes a plurality of top and
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bottom switches in which the bare cables and lugs are fitted to the changeover switch. The bare cables-and lugs are used to receive and/or provide the electrical power to the changeover switch. Each of the top and bottom switch in the termination module of the changeover switch includes a termination window. Each termination window is used to receive either the bare cable or the lug when connection is made with the changeover switch. The termination window includes a terminal plate. The terminal plate is a plate of metal component such as copper, which provides a fixed contact of the changeover switch. The terminal plate is rigidly mounted inside the bottom of the termination window in a horizontal position. The terminal plate is used to carry the electrical power from the bare cable and lug to the changeover switch as well as to carry the electrical power from the changeover switch to the bare cable and lug. Each terminal plate includes a hole at the surface. A pin of mild steel component is vertically inserted through the hole of the terminal plate and protruded above the surface of the terminal plate. The bottom of the pin is mounted on a spring which enables the pin to move in vertical direction. The pin loaded with the spring is used to provide a hinge point when a lug is inserted into the termination window.
[0037] Above the terminal plate, a nut plate of mild steel component is rigidly fitted in between the housings of the termination window, in a horizontal position. The nut plate includes a nut at the surface. A box clamp screw which is a mild steel component is vertically screwed through the nut in the nut plate. The nut plate also provides support to the box clamp screw. The bottom of the box clamp screw is attached to the surface of a clamp which is vertically movable along with the box clamp screw. The clamp which is a mild steel component is used to apply forces on the terminal plate when the box clamp screw is screwed down.
[0038] When a lug is inserted to the termination window in the termination module of the changeover switch, the pin and the hole of the lug form a hinge point with the lug. The box clamp screw with the clamp is screwed down till the clamp presses the lug and hence the pin tightly to the terminal plate. Hence the lug is clamped in between the clamp and the terminal plate of the changeover switch to make connection between the lug and the terminal plate. Though the box clamp screw becomes slightly loosen due to wear and tear, the lug does not be disconnected from
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the terminal plate of the changeover switch since the pin with the spring makes a hindrance to the lug.
[0039] When a bare cable is inserted to the termination window in the termination module of the changeover switch, the bare cable is initially placed on the pin. The box clamp screw with the clamp is screwed down to force the bare cable on the pin. Due to the force of the clamp, the pin is restrained down and the bare cable is firmly tightened to the terminal plate. Hence the bare cable is clamped in between the clamp and the terminal plate of the changeover switch to form proper contact surface with the terminal plate. Even though the box clamp screw becomes slightly loosen due to wear and tear, the bare cable does not come out from the terminal plate of the changeover switch since the pin with the spring provides a force on the bare cable in upwards.
[0040] The changeover switch includes a cover at the top of the termination module which covers the box clamp screws. The box clamp screws are available to screw down or up only when the cover is opened or removed from the changeover switch.
[0041] FIG. 1 illustrates a top side perspective view of a changeover switch with a common termination arrangement according to one embodiment of the present invention. With respect to FIG. 1, a changeover switch 100 has a termination module 102 in at least one side. The termination module 102 includes a plurality of top switches 1041 and a plurality of bottom switches 1042 in which bare cables and lugs are fitted to the changeover switch 100. Each of the top and bottom switches 1041 and 1042 in the termination module 102 includes a termination window 106. Each termination window 106 is used to receive either the bare cable or the lug when connection is made with the changeover switch 100. The changeover switch 100 further includes a cover 108 at the top of the termination module 102 to cover box clamp screws of the changeover switch 100. The box clamp screws are available to screw down or up only when the cover 108 is opened or removed from the changeover switch 100.
[0042] FIG. 2 illustrates an enlarged front perspective view of a termination arrangement in a changeover switch according to one embodiment of the present
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invention. With respect to FIG. 2, the termination window 106 includes a terminal plate 202. The terminal plate 202 is a plate of metal component such as copper, which provides a fixed contact of the changeover switch. The terminal plate 202 is rigidly mounted inside the bottom of the termination window 106 in a horizontal position. The terminal plate 202 is used to carry the electrical power from the bare cable and lug to the changeover switch as well as to carry the electrical power from the changeover switch to the bare cable and lug. Each terminal plate 202 includes a hole at the surface. A pin 204 of mild steel component is vertically inserted through the hole of the terminal plate 202 and protruded above the surface of the terminal plate 202.
[0043] FIG. 3 illustrates an enlarged front view of a lug termination arrangement in a common termination arrangement in a changeover switch according to one embodiment of the present invention. FIG. 3 illustrates an enlarged perspective view of a construction of termination module of a changeover switch according to one embodiment of the present invention. With respect to FIG. 3, the bottom of the pin 204 is mounted on a spring 302 which enables the pin 204 to move in vertical direction. The pin 204 loaded with the spring 302 is used to provide a hinge point when a lug is inserted into the termination window. Above the terminal plate 202, a nut plate 304 of mild steel component is rigidly fitted in between the housings of the termination window, in a horizontal position. The nut plate 304 includes a nut at the surface. A box clamp screw 306 which is a mild steel component is vertically screwed through the nut in the nut plate 304. The bottom of the box clamp screw 306 is attached to the surface of a clamp 308 which is vertically movable along with the box clamp screw 306. The clamp 308 which is a mild steel component is used to apply forces on the terminal plate 202 when the box clamp screw 306 is screwed down.
[0044] FIG. 4 illustrates a partially enlarged front view of a common termination arrangement in a changeover switch with insertion of a lug into the termination window according to one embodiment of the present invention. With respect to FIG. 4, a lug 402 is inserted to the termination window in the termination module of the changeover switch. The pin and the hole of the lug 402 form a hinge point with the lug 402.
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[0045] FIG, 5 illustrates a partially enlarged front view of a common termination arrangement in a changeover switch with insertion of a lug into the termination window according to one embodiment of the present invention, when the clamp is moved partially downward. With respect to FIG. 5, the transparent view of the lug 402 illustrates that the pin 204 and the hole of the lug 402 form a hinge point with the lug 402, when the lug 402 is inserted to the termination window in the termination module of the changeover switch.
[0046] FIG. 6 illustrates a partially enlarged front view of a common termination arrangement in a changeover switch with insertion of a lug into the terminal at the termination window according to one embodiment of the present invention. With respect to FIG. 6, the box clamp screw 306 with the clamp 308 is screwed down till the clamp 308 presses the lug 402 and hence the pin 204 tightly to the terminal plate 202. Hence the lug 402 is clamped in between the clamp 308 and the terminal plate 202 of the changeover switch to make connection between the lug 402 and the terminal plate 202. The transparent view of the lug 402 illustrates that even the box clamp screw 306 becomes slightly loosen due to wear and tear, the lug 402 does not be disconnected from the terminal plate 202 of the changeover switch since the pin 204 with the spring 206 makes a hindrance to the lug 402.
[0047] FIG. 7 illustrates a partially enlarged front view of a common termination arrangement in a changeover switch with the insertion of a bare cable according to one embodiment of the present invention. With respect to FIG. 7, a bare cable 702 is inserted to the termination window 106 in the termination module 102 of the changeover switch.
[0048] FIG. 8 illustrates a partially enlarged front view of a common termination arrangement in a changeover switch with the partial clamping of the inserted bare cable according to one embodiment of the present invention. With respect to FIG. 8, when the bare cable 702 is inserted to the termination window 106 in the termination module 102, the bare cable is placed in between the pin and the clamp of the changeover switch.
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[0049] FIG. 9 illustrates a partially enlarged front view of a common termination arrangement in a changeover switch with the insertion of a bare cable according to one embodiment of the present invention. With respect to FIG. 9, the transparent view of the bare cable 702 illustrates that the bare cable 702 is placed in between the pin 204 and the clamp 308 of the changeover switch.
[0050] FIG. 10 illustrates a partially enlarged front view of a common termination arrangement in a changeover switch with the insertion of a bare cable according to one embodiment of the present invention. With respect to FIG. 10, after the insertion of the bare cable 702, the box clamp screw 306 with the clamp 308 is screwed down to force the bare cable 702 on the pin 204. Due to the force of the clamp 308, the pin 204 is restrained down and the bare cable 702 is firmly tightened to the terminal plate 202. Hence the bare cable 702 is clamped in between the clamp 308 and the terminal plate 202 of the changeover switch to form proper contact surface with the terminal plate 202. The transparent view of the bare cable 702 illustrates that even though the box clamp screw 306 becomes slightly loosened due to wear and tear, the bare cable 702 does not come out from the terminal plate 202 of the changeover switch since the pin 204 with the spring 302 provides a force on the bare cable 702 in upwards.
G) ADVANTAGES OF THE INVENTION
[0051] The various embodiments of the present invention provide a common termination arrangement that is used to clamp both the bare cable and lug to the changeover switches. The changeover switch in the present invention is provided with a common termination arrangement having a screw with a clamp and a pin loaded with a spring, which does not allow a lug to disconnect from the contact surface once contact is made even when the screw becomes slightly loosen due to wear and tear. Further the changeover switch with the common termination arrangement does not
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allow a bare cable to come out from the contact of terminal plate once the contact is made between the changeover switch and the bare cable even when the screw becomes slightly loosen due to wear and tear.
[0052] 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.
[0053] 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: September 10,2009 RAKESH PRABHU
Place: Bangalore. Patent Agent
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CLAIMS
What is claimed is:
1. A common termination arrangement for bare cable and lug in a change over switch comprising: a housing for the change over switch; a termination window formed in the housing;
a terminal provided in the termination window in the housing and connected to the switch;
a hole formed in the terminal; a pin inserted into the hole of the terminal, a spring connected to the pin;
a box clamp screw mounted above the terminal in the housing; a nut plate arranged below the box clamp screw and above the terminal; and a clamp arranged movably above the terminal;
Wherein the spring loaded pin and the clamp are used to hold a lug or a bare cable conductor with the terminal in the termination window.
2. The arrangement according to claim 1, wherein the lug is inserted into the
termination window and held firmly with the terminal using the pin and the
clamp.
3. The arrangement according to claim 1, wherein the bare cable conductor is inserted into the termination window and held firmly with the terminal using the pin, the clamp and the screw.
4. The arrangement according to claim 1, wherein the lug inserted in the termination window is firmly held with the terminal by tightening the screw and moving down the clamp so that the hole provided in the lug forms a hinge with the pin and the lug is not pulled out due to the hindrance of the pin, even when the screw is loosened.
5. The arrangement according to claim 1, wherein the bare cable conductor inserted in the termination window is firmly held with the terminal by tightening the screw and moving down the clamp so that the clamp applies a

force on the bare cable and on the pin to press the pin to enable the bare cable form a proper contact with the terminal.
6. The arrangement according to claim 1, wherein the pin is a spring loaded pin
and forms a hinge point with the inserted lug.
7. The arrangement according to claim 1, wherein the pin is inserted into the hole
of the terminal and projected out of the terminal to form a hinge point with the
lug.
8. The arrangement according to claim 1, wherein the spring applies an axial
force on the terminal.
9. The arrangement according to claim 1, wherein the nut plate acts as a nut and
sandwiched between the box clamp screw and the terminal.
Dated this the day of September, 2009
Rakesh Prabhu,
Patent Agent, ALMT Legal,
No.2, Lavelle Road, Bangalore-560 001, INDIA
To,
The Controller of Patents, The Patent office, At'" MUMBAI
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