FORM 2
THE PATENT ACT 1970
&
The Patents Rules, 2003
COMPLETESPECIFICATION
(See section 10 and rule 13)
1. TITLE OF THE INVENTION:
"A Sliding Arrangement for a Terminal Shroud"
2. APPLICANT:
(a) NAME: Larsen & Toubro Limited
(b) NATIONALITY: Indian Company registered under the
provisions of the Companies Act-1956.
(c) ADDRESS: Larsen & Toubro Limited
Electrical & Automation North Wing, Gate 7, Level 0, Powai Campus, Saki Vihar Road, Mumbai 400 072, INDIA
3. PREAMBLE TO THE DESCRIPTION:
COMPLETE
The following specification particularly describes the invention and the manner in which it is to be performed.

A Sliding Arrangement for a Terminal Shroud
Field of invention
The present invention relates to shrouding of terminals in electrical switches. More particularly, the present invention relates sliding terminal shroud arrangement in electrical switches.
Background of the Invention
In low voltage switchgear, switches are connected to supply through cables and bus-bar. The end of the cable is terminated on the current carrying terminal by means of lug of appropriate size. Though cable is insulated by means of insulation, however the lug is not insulated. Bare lug is still a live connection which may cause the accidental electric shock to operator while operating the switch. In case of bus-bar connection, the bus-bars are provided with the insulating sleeve. However the sleeves are not up to the point where the bolts are terminated with switch terminals. Hence some parts of the bus-bar are also exposed and prone to cause the accidental shock injury to operator. There is a need to isolate the operator from these live parts when the switch is in normal operating conditions.
US 2007/0267428 A1 teaches that a casing includes a base, a flip cover pivotally attached to the base, a first member fixed to the flip cover, and a second member fixed to the base. The flip cover is rotatable around an axis of rotation with respect to the base. The first member forms a tip toward the base along a direction perpendicular to the axis of rotation. The second member extends an elongated arm, the elongated arm being crushed by the tip of the first member in an opening process of the flip cover with respect to the base so as to block the flip cover from opening with a rush.

US 7,227,740 document teaches that a non-conductive bus shroud for a dual circuit breaker system that has a plurality of vertical walls extending generally perpendicular from the top side and including at least one bus member support vertical wall. The dual circuit breaker system includes a housing assembly having a back wall, a first circuit breaker having at least one protruding line terminal, a second circuit breaker having at least one protruding line terminal and at least one bus member extending between the at least one first circuit breaker line terminal and the at least one second circuit breaker line terminal. The bus shroud has a planar member with a top side, a bottom side, a front edge, a back edge, at least one first circuit breaker terminal opening, and a second circuit breaker terminal opening. When the shroud is installed over the circuit breakers, the vertical walls protect and support the bus member.
CN 2485780 (Y) document teaches that a safety installation device for heat overload relay. Terminals of power source and the terminal of electric load are exposed and arranged on foreside and rear of the relay. The device comprises: a base which consists of a hole and a slot used for fixing, a hook-shaped component which is used for being connected with main body of the relay, a support wall which is horizontally stretched and installed out of the base and a safe lid used for covering the terminal of electricity connection and the terminal of electric load connection. Thereby, the safe installation device for the heat overload relay can be easily installed and the accidents of electric stroke can be prevented.
US 1,564,321 recites about a cover or cap made out of a suitable insulating material and adapted to fit over the switch terminals when they are not in use.
US 3,165,574 recites talks about an insulating or dust cover formed of an insulating material and having a pair of claws or flanges that releasably engage corresponding projecting ends of terminal lugs that are mounted on the switch case. The cover is connected to the switch case by means of a simple snap action.

The cover is also capable of being removed from terminal lug by the flexure of its flanges, the cover also has a slot for the accommodation of lead wires.
The terminal shroud is intended to protect the operator from the live parts of the switch even when the switch may be in operation. The terminal shroud should provide protection to the user without, in any way, interfering with the functioning of the switch. Sometimes the operator may be required to terminate the switch using cable lugs or bus-bars. He may remove the shroud and forget to place it back. Therefore, inventors have developed terminal shroud arrangement in such a way that the terminal shroud need not be removed for termination. Instead it just has to be slid back and forth.
The requirements of a well designed terminal shroud are:
1. It should easily be fixable at site.
2. Termination should be possible without removal of the shroud.
3. The shroud should be capable of locking in two distinct positions namely, one for termination (T) and the other for operation (O) of the switch.
4. Selective termination. The operator should be allowed to only terminate the pole of his choice without having to compromise on safety by removing the protection on other poles.
Objects of the inventions
Object of the present invention is to provide a shroud, which can be assembled at site.
Another object of the present invention is to provide a shroud, which allows the switch to be terminated while the shroud remains assembled.

Yet another object of the present invention is to provide a shroud, which is capable of locking in two distinct positions namely, one for termination (T) and the other for operation (O) of the switch.
One more object of the present invention is to provide a shroud, operator should be allowed to only terminate the pole of his choice without having to compromise on safety by removing the protection on other poles.
Summary of the invention
According to the present invention there is provided a terminal shroud for quick assembly of switches, the terminal shroud comprising;
grooves configured on a top side portion of a housing of a switch;
projects configure on the terminal shroud;
a sliding projection configured on each of the projection of the terminal shroud, wherein the sliding projections engages with the groove in the housing and slides therein thereby enables press fit arrangement; and
at least one locking means configured on each of the groove for locking the terminal shroud in either slide in or slide out position.
Brief description of the invention
Figure 1 shows poles with a terminal shrouds in 'O' position in accordance with the present invention;
Figure 2 shows the pole with the terminal shrouds in the 'T position of figure 2;
Figure 3 shows an exploded view of the terminal shroud arrangement of figure 1;
Figure 4 demonstrates the fitment of the terminal shroud onto the pole cassette;

Figure 5 shows a unique click-cum-locking feature of the terminal shroud;
Figure 6 shows the locking feature of the pole housing; and
Figure 7 shows the concept of selective termination.
Detail description of the invention
Various embodiment of the present invention provide an actuation mechanism for coupling a plurality of electrical devices, the mechanism comprising a shaft for each electrical device, the shaft having a variable cross-section, the shaft adapted to reversibly engage with an internal operating system of the electrical devices; and a seat on a casing of each electrical device, the seat providing an access to the internal operating system of the electrical devices.
Referring now to figure 1, poles of the terminal shroud (1) in "O" position in accordance with the present invention is illustrated. The terminal shroud (1) slides in a slot provided in the housing (3) of the contact pole cassette of a switch intended to isolate the operator from the live terminal (2) of the pole. In the figure 1 the terminals shrouds are in the "O" position or operating position. This position does not permit access to the terminals for an operator.
Figure 2 shows the terminal shroud in the T' position or termination position, wherein the operator has access to the terminals of the pole as can be seen in the figure. The 'T' position can be achieved by sliding the terminal shroud from the O position. The housing includes groove (10) having at least one locking means (C) refer figure 6.
Figure 3 shows the exploded view of the assembly. The terminal shroud (1) can easily be click-fitted onto the pole housing.

Figure 4 shows the fitting of the terminal shroud onto the housing. The click-fit features of the terminal shroud engage with the groove provided in the housing. As a result the terminal shroud gets locked in the groove although it is capable of sliding in it. The terminal shroud can also be easily removed.
Figure 5 shows the detailed view of the terminal shroud along with its click-fit feature (projection (A)) and a locking/ sliding projection (B). The locking feature has a chamfer that allows smooth transition from one locking position to the other. The locking feature of the terminal shroud corresponds to at least one locking means provided on the pole housing (refer Figure 6). The locking means include angular slant (C) and desperation (D) for looking. The grooves (10) are provided in the housing (3) for the purpose of sliding of each terminal shroud. Each groove, is split into two levels. The higher level is centrally located while the desperations (D) are on either side of the higher level. The terminal shroud locks into the positions T and O at these lower levels while the sliding occurs at the higher level. The locking features prevent the terminal shroud from sliding from one locking position to another unless a force significantly higher than that of gravity is applied to the terminal shroud. ,
The novel feature of this invention is the sliding arrangement which is not used by any other existing switch manufacturer. Most manufacturers use a flip arrangement or a click-fit arrangement.
Another novel feature of this invention is that each terminal shroud is specific for a contact pole. This allows the user to terminate the pole of his choice without removing the protection of the other poles (refer figure 12). This feature may be termed as selective termination.
The following advantages are achieved with this invention:
1. The terminal shroud does not increase the dimensions of the switch in any position.

2. It is easily fixable at site.
3. Termination is possible without removal of the shroud.
4. The shroud locks itself in two distinct positions namely, T and O.
5. Termination of one pole is possible in T position while terminal shrouds of other poles may be maintained in O position (selective termination).

6. Common shroud for unit with single pole /2 pole / multiple poles; this reduces inventory and manufacturing efforts.
7. While switch is in operation, inspection of'terminal joint' of one pole is possible in T position while terminal shrouds of other poles will be maintained in O position (Safety during inspection).

We Claim:
1. A terminal shroud for quick assembly of switches, the terminal shroud comprising;
grooves configured on a top side portion of a housing of a switch;
projects configure on the terminal shroud;
a sliding projection configured on each of the projection of the terminal shroud, wherein the sliding projections engages with the grove in the housing and slides therein thereby enables press fit arrangement; and
at least one locking means configured on each of the groove for locking the terminal shroud in either slide in or slide out position and also enables selective termination of a pole.