FORM 2
THE PATENT ACT 1970
&
The Patents Rules, 2003
COMPLETE SPECIFICATION (See section 10 and rule 13)
1. TITLE OF THE INVENTION:
"Modular Electric Device Having Screw-Less Termination and Actuation"'
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.

Modular Electric Device Having Screw-Less Termination and Actuation
Field of the invention
The present invention relates to an electrical device, such as circuit breaker, residual current circuit breaker, residual devices, accessories and contactors, and more specifically, to miniature circuit breakers (MCB) which is modular and din rail mountable installations.
Background of the invention
The growing use of modular devices in electrical installation has made distribution systems large with high quantities of these devices to be mounted. With conventional screw tightening termination, the time and efforts required for the installations are increasing.
The regular devices used in general are the screw types of clamping system to make a firm electrical connection between terminal and wire/cable. The required contact pressure is generated by tightening of the screw beyond electrical contact. The installation operation involves loosening the screw to make a cavity for wire or cable, inserting the cable and then tightening the cable. This consumes a lot of time. Also, there is a chance of insufficient tightening and loosening over period oftime.
There already exist some solutions to this effect (inventions owned by ABB, Hager, GE etc. as mentioned below) but they have some drawbacks as mentioned below.
Prior Art
US patents US2713668 and US2720634 claim designs which are generally used for the spring clamp. Other prior arts in the same area have been disclosed in

patent number US7510448 which shows another clamping connection that has completely different structure as compared to proposed design.
US20110209972A1 - Patent Application - Owned by ABB AG, Mannheim (DE) addresses a problem of fast installation. A clamp spring rests against connecting conductor and is actuated by a terminal cover part which is pivoted on side of the device. This arrangement provides leverage when user applies an actuating force on Pressure Surface . Also a part acts to partially cover terminal area and also provides suitable opening for wire insertion from front side.
Though the device allows leverage for actuation, this leverage is limited by dimensions of product and no external leverage can be applied. Also this actuation arrangement is not suitable for use of tool for actuation of the part.
Also, this arrangement is very different from regular miniature circuit breaker. The external housing and cover are different than the regular screw tightened product of the same assignee. These are the parts requiring high investments for manufacturing.
Further, these patents do not describe means of achieving the dual state actuation. User has to keep on applying the force on the part and do the wire insertion or removal activity using other hand. There is no stable state in actuated condition.
Patent US7491098B1 of General Electric Company, Schenectady describes screw less terminal connection for the concerned devices. Here an actuator is required to be pushed by user (using a tool). It acts against a spring directly. The spring is mounted inside terminal compartment, which in turn is connected to a current bar . The patent '098 claims allows direct insertion of rigid wire through cavity . To insert flexible wire actuation of a part is required. For removal of both types of wires actuation of the part is required.

Here it may be possible to use the housing and cover of the same device which uses the screw tightened terminals. But there is little or no mechanical advantage for user while applying load on actuator as it acts directly on the spring . Hence user will experience a high operating force causing fatigue. Also it is difficult to develop an external leverage using product geometry by considering the given description. Also this solution does not mention any way of achieving the dual state actuation. User has to keep on applying the force on part 2 and do the wire insertion or removal activity using other hand. There is no stable state in actuated condition.
Summary of prior art inventions

Sr Reference Number Assignee Housing / Internal External Dual Provision
No Cover as Mechanical mechanical State of test
compared to regular screw tightened products advantage or leverage advantage / leverage using external geometry Operation tab
1 US20110209972A1 (Explained in point 2 above) ABB AG No/ difficult to obtained Yes No No No
2 US7491098B1 (explained in point 3 above) General Electric Company, Schenectady NY USA Yes/ possible to obtain No No No No
3 US7625253 ABB Patent No/ Very less No No No

Gmbh Difficult to obtain
Objects of the invention
Object of the invention is to provide a modular electric device having screw-less termination and actuation, which is configured with minimal modifications in the existing screw tightened product thereby reducing manufacturing cost.
Another object of the invention is to provide a modular electric device having screw-less termination and actuation, which reduces force required to actuate to very low value.
Yet another object of the invention is to provide a modular electric device having screw-less termination and actuation, which provides dual state operation thereby enabling an user to use both hands for wire insertion rather than continuously applying force by one hand on actuator to the clamp open.
One more object of the invention is to provide a modular electric device having screw-less termination and actuation, which is modularized into sub assemblies for ease of assembly.
Further object of the invention is to provide a modular electric device having screw-less termination and actuation, which houses the calibration terminal to make a pressure contact with a main terminal.
Summary of the invention
Accordingly, the present invention provides a electrical protection device (100) for termination and actuation of electric circuit, the device comprising:

an enclosure (30) configured by mating a housing (1) and a first cover (2), a termination cavity (3), a fork cavity (4), a calibration cavity (8) arid a clamping cavity (6) configured on a side (30a) of the enclosure (30), a screw cavity (5), configured on a side (30b) of the enclosure for tightening a screw therethrough; characterized in that the device comprises,
at least one clamp spring (17) disposed below the termination cavity for clamping the wire;
at least one actuator (11) disposed in the device (100) through respective the fork cavity (4);
at least lever (18) entangled with the actuator (11) and adapted to operate the clamp spring, the lever provided with lever pin for restoring position;
a base (23) disposed adjacent to the lever, wherein the base (23) having guide for sliding the actuator up and down for clamping and releasing the wire; and
a second cover (24) disposed opposite to the base and adjacent to the clamp spring, wherein an actuator tool is inserted in a cavity of the actuator (11), placed on a pivot and pressed down to lift the actuator (11) up thereby operating the lever and releasing/clamping the wire in the clamp spring (17).
Brief description of the drawings
The objectives and features of the present invention will be more clearly understood from the following description of the invention taken in conjunction with the accompanying drawings, wherein,
Figures 1 and 2 shows a perspective view of screw tightened Miniature Circuit Breaker (MCB) termination of the prior art;
Figure 3 shows a perspective view of a modular electric device in accordance with the present invention;

Figure 4 shows a side view of the modular electric device of figure 3 with a tool in idle state;
Figure 5 shows a side view of the modular electric device of figure 3 with a tool in actuated state;
Figure 6 shows an internal architecture of the modular electric device of figure 3 in idle state;
Figure 7 shows an internal architecture of the modular electric device of figure 3 in actuated state;
Figure 8 shows an exploded view a subassembly of the modular electric device in accordance with the present invention;
Figure 9 shows a bottom assembled perspective view of the subassembly of figure 8;
Figure 10 shows a top perspective view of the subassembly of figure 9;
Figure 11 shows a top view of the subassembly of figure 9;
Figure 12 shows working of bi-stable state operation; and
Figure 13 shows operated bi-stable state with an actuator locked also showing direction of release force in accordance with an embodiment of the present invention.

Detail description of the invention
The foregoing objects of the present invention are accomplished and the problems and shortcomings associated with the prior art, techniques and approaches are overcome by the present invention as described below in the preferred embodiments.
The present invention provides a modular electric device having screw-less termination and actuation. Further, the modular electric device is configured with minimal modifications in the existing screw tightened product thereby reducing manufacturing cost. Furthermore, the modular electric device provides dual state operation which enables a user to use both hands for wire insertion rather than continuously applying force by one hand on actuator to the clamp open. Also, the modular electric device is modularized into sub assemblies for ease of assembly and houses the calibration terminal to make a pressure contact with a main terminal.
For the better understanding of this invention, reference would now be made to the embodiment illustrated in greater depth in the accompanying figures and description herein below, further, in the following figures, the same reference numerals are used to identify the same components in various views/figures.
Referring now to figure 1 and 2, a perspective view of an electrical protection device/Miniature Circuit Breaker (herein after referred as "MCB (100)) of the prior art is illustrated. The MCB (100) includes a housing (1), a first cover (2), a termination cavity (3), a fork cavity (4), a screw cavity (5), a clamping cavity (6), a screw (7) and a calibration cavity (8). The housing (1) and the first cover (2) are joined together to provide an enclosure for various elements. The housing (1) and the first cover (2) are configured to provide the termination cavity (3), the fork cavity (4), the screw cavity (5), the clamping cavity (6) and a calibration cavity (8) on the mating portion thereof. The clamping cavity (6) enables insertion of wires.

The screw cavity (5) provides space to insert a tightening tool for tightening the screw (7) therethrough.
Referring now to figure 3, 6, 7, 8, 9 and 10, improvement in the MCB (100) includes at least one actuator (11) (one actuator is shown for explanation), a pivot (10), a base (23), a second cover (24), a calibration terminal (25), a test terminal (20), a shroud (21) and a lever spring (26). The actuator (11) is disposed through the fork cavity (4). The actuator (11) includes an actuator tool cavity (11a), a cavity for insertion visibility (lib), a lever-arm slot (1 lc), a projection (lid) and a slide slots (lie). In an embodiment, the actuator (11) is 'T' shaped. The actuator tool cavity (1 la) is configured on a top portion of the actuator (11), which always projects out of the MCB (100). The cavity for insertion visibility (1 lb) allows the users to see through it a termination area during wire insertion when actuator is pulled out completely. The lever-arm slot (lie) and the slide slot (lie) are designed symmetrical so that actuator can be used in a state flipped by 180 degrees along an axis parallel to its motion for foolproof assembly. The lever-arm slot (lie) enables to secure one end of the lever (18) for operating therethrough.
The MCB (100) includes a termination cover (14) disposed inside the enclosure formed by the housing (1) and the first cover (2). The termination cover (14) partially covers the termination cavity (3) (Refer figure 6). The MCB (100) also includes at least one clamping spring (17) along with and a spring locking arm (17a) for clamping the wire (22) through a wire guide (15) in the terminal (16). The number of the clamping spring (17) along with and respectively the spring locking arm (17a) may vary depending upon number of wires for clamping. Further, the MCB (100) includes at least one lever (18) (two levers are shown for explanation) disposed adjacent to the clamping spring (17) for operating the spring locking arm (17a). In an embodiment, the lever (18) rotates around a lever pin (19).

Further, the projection (lid) enables to hold the actuator (11) when pulled up for inserting wires thereby enabling the user to use both hands for operation. The lever (18) has an actuator side arm (18a), a spring side arm (18b), a locking pin (18c), a locking hole (18d) and a lever pivot hole (18e). The actuator side arm (18a) engages with the lever-arm slot (lie). Therefore, upon operating the actuator (11) the lever (18) is operated thereby operating the clamp spring (17) for clamping the wire (22). In an embodiment, the lever pin (19) is passed through pivot hole (18e) and secured rigidly in mechanism base (23) such that lever (18) rotates freely around pin (19). However, a person skilled in the art may use various means for pivoting the lever (18).
Referring again to figures 6, 7 and 8, the MCB (100) includes a test terminal (20), shroud (21) having a seat for test terminal (21a), a protrusion for bi-stable operation (21b) and an access cavity for test tab (21c). The seat for test terminal (21a) prevents deformation when user inserts an electrode or metallic tool to check system after installation or during maintenance. The projection (1 Id) comes in contact with a protrusion (21b) of the shroud (21). To remove the actuator (11) from its locked state and complete the clamping of the wire (22), the user have to apply force as shown in figure 13 in the direction (27). The force is equivalent to force required to deflect the shroud protrusion (21b) and clear the actuator bottom portion from bi-state projections (or cuts) (23b) of the mechanism base (23). Once the actuator (11) is again fully guided by a guide spline (23a), the actuator (11) moves inwards on account of clamp spring load and thus clamping the wire (22). Further, a tool (9) is provided to lift the actuator (11) for inserting the wire (22). However, it may be evident to those skilled in the art that the tool (9) can be a screw driver, a rod or the like similar means.
Referring to figures 7 to 10, the arrangement has terminal (16) connected to the internal live part of the MCB (100). The clamp spring (17) is assembled on the terminal with an initial loading so as to have a residual contact pressure to be applied by the spring locking arm (17a) on the terminal (16). The number of

spring is equal to number of wires to be terminated. The wire guide (14) is 'E' shaped component (not shown in detail), which guides the wires for a dual termination device and supports them. The angled design of the spring locking arm (17a) allows the insertion of rigid wire without the need of actuation.
The right side of the clamp spring (17) in contact with the lever (18) is pivoted around the lever pin (19) which in turn is tightly fitted in the hole (23d) of the mechanism base (23) and the second cover (24). However, a person skilled in the art may use various other means for pivoting the lever (18). The lever pivot (18e) lies in between the clamp spring (17) and the actuator (11). The arm lengths of the lever (arms 18a and 18b) are designed such that apart from getting required spring deflection, there is leverage or mechanical advantage so that force applied along actuator motion is less than corresponding spring force. The actuator side arm (18b) of the lever (18) is inserted in the lever arm slot (1 lc) of the actuator (11).
The actuator has slide slot (1 le) along its length engages with guide spline (23a) of mechanism base (23) thus constructing the motion in direction 13. Similar engagement is along with guide spline (not shown) of the mechanism cover (24). The actuator has a tool cavity (1 la) for inserting the tool (9). The slide slots (lie) and the lever arms slots (1 lc) are designed symmetrical so that actuator can be used in a state flipped by 180 degrees along an axis parallel to its motion for foolproof assembly.
The mechanism forms a standalone sub assembly as shown in figure 8. The mechanism base (23) receives a calibration terminal (25) such that the side (25a) of the terminal comes in a cavity formed between mechanism base (23) and cover (24) and it becomes accessible from outside at the calibration cavity (8) of the device. The other arm (25b) of the calibration component is angled such a way that after assembly of mechanism in the device it forms a pressure contact with the terminal (16) thus making arm (25b) of the component live and available for calibration from outside of the device through arm (25a).

Here two levers (18) are locked together by providing the locking pin (18c), which engages with locking hole on other side of the second lever (not shown). Both the levers (18), with the lever spring (26) in between, lock together easing the assembly process with the actuator (ll).The lever (18) house lever spring (26) between the two components. The lever spring (19) has a first arm (26a) loading one of the lever while a second arm (26b) resting on stopper (23f) on the mechanism base (23) such that it always exerts a clockwise torque on the lever (18) (torque direction with reference to figure 6 and figure 7). The lever spring (26) is used to bring the actuator (11) back inside once the wire (22) is clamped and the clamp spring (17) no longer brings the actuator (11) to its initial position. The arrangement can also be made by using a single lever actuating both the clamp spring (17) together as shown in figure 8 The mechanism cover fits with mechanism base at two snap fits (23c) and a snap cavities (24a) and also a guide projection (23g) on base (23) fits in corresponding hole (not shown) on the mechanism cover (24). The lever pin (19) has a tight fit in pin pivot (23d) and same feature in mechanism cover (not shown) thus forming a standalone mechanism sub assembly.
The actuator (11) is pulled out by use of the actuator tool (9) and rotating the levers (18) because of engagement at the lever arm slots (lie). The rotation of lever deflects the spring and it takes the form (17') as shown in the figure 7. The movement of the spring locking arm (17a) with respect to the terminal (16) creates a cavity in which the wire (22) can be inserted. Because of angled design of spring locking arm (17a) and projections on terminal wire gets locked. The outer motion of actuator in direction (13) stopped by a lever stopper (23e), while stopper for inside position for mechanism is the lever spring stopper (23f) (Refer figure 11).
In figure 7, the test terminal (20) is secured to have an electric contact with terminal (16). In an embodiment, the test terminal (20) is secured to have an electric contact with terminal (16) by welding. On other side, the test terminal (20)

rests on the seat (21a) provided with the shroud (21). The seat (21a) in the shroud (21) prevents deformation when user inserts an electrode or metallic tool to check system after installation or during maintenance.
Referring now to figure 11, more features of the mechanism assembly base (23) which were not visible in previous figures are depicted. It also shows another possible embodiment of the same part to achieve a dual state operation. The guide spline (23a) is modified to accommodate the guide for bistable operation (23b). It is nothing but cuts/ projections to lock the actuator (11) when it is fully extended out.
Referring to figure 12 and 13, working of arrangement for dual state operation is illustrated. Actuator (11) has "projections for bi-stable operation" (lid). When user moves the actuator upwards (Refer figure 12), the projection (lid) comes in contact with a protrusion (21b) on the shroud (21). The further motion of the actuator (11) deflects the protrusion (21b) in the right direction (Refer figure 12). This in turn exerts a force on the actuator (11) in left side direction. The actuator (11) moves straight till the actuator (11) is guided by the guide spline (23a). As soon as bottom side of actuator (11) comes in cuts for a bi-stable operation of guide (23b), the actuator (11) rotates clockwise (Refer figure 13) and takes position. In this position, the actuator (11) experiences a downward force exerted by the clamp spring (17) and the lever spring (26), which is transferred by the lever (18). The actuator (11) gets locked because of the bi-stable operation of the guide (23b). Thus dual state operation is achieved. User is then free to use its both hands for wire insertion / removal or other installation activities.
To remove actuator (11) from its locked state and complete the clamping, user will have to apply force as shown in figure 13 by direction (27). This force is equivalent to force required to deflect the shroud protrusion (21b) and clear bottom portion of the actuator (11) from bi-state projections (or cuts) (23b) of the mechanism base (23). Once actuator (11) is again fully guided by guide spline

(23a), the actuator (11) moves inwards on account of clamp spring load and thus clamping the wire.
The foregoing objects of the invention are accomplished and the problems and shortcomings associated with prior art techniques and approaches are overcome by the present invention described in the present embodiment. Detailed descriptions of the preferred embodiment are provided herein; however, it is to be understood that the present invention may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention in virtually any appropriately detailed system, structure, or matter.
The embodiments of the invention as described above and the methods disclosed herein will suggest further modification and alterations to those skilled in the art. Such further modifications and alterations may be made without departing from the spirit and scope of the invention.

We Claim:
1. A electrical protection device (100) for termination and actuation of
electric circuit, the device comprising:
an enclosure (30) configured by mating a housing (1) and a first cover (2), a termination cavity (3), a fork cavity (4), a calibration cavity (8) and a clamping cavity (6) configured on a side (30a) of the enclosure (30), a screw cavity (5), configured on a side (30b) of the enclosure for tightening a screw therethrough; characterized in that the device comprises,
at least one clamp spring (17) disposed below the termination cavity for clamping the wire;
at least one actuator (11) disposed in the device (100) through respective the fork cavity (4);
at least one lever (18) entangled with the actuator (11) and adapted to operate the clamp spring; and
a base (23) disposed adjacent to the lever; and
a second cover (24) disposed opposite to the base and adjacent to the clamp spring, wherein an actuator tool is inserted in an actuator tool cavity (11a) of the actuator (11), placed on a pivot and pressed down to lift the actuator (11) up thereby operating the lever and releasing/clamping the wire in the clamp spring (17).
2. The modular electric device as claimed in claim 1, wherein the screw cavity (5) covered by a shroud (21).
3. The modular electric device as claimed in claim 1, wherein the shroud (21) having an access cavity (21c), a terminal seat (21a) and projection (2 lb), wherein a test terminal configured (3) configured between the terminal seat (21a) and an access cavity (21c) of shroud (21).

4. The electrical protection device (100) as claimed in claim 1, wherein the
actuator comprises,
an actuator tool cavity (11a) configured on upper portion of the actuator for inserting the actuator tool therein for operating thereof;
a cavity for insertion visibility (1 lb) configured on central portion of the actuator for visibility;
a lever-arm slot (lie) configured on lower portion of the actuator for entangling with the lever;
slide slots (He) configured on side portion of the actuator for sliding the actuator (11) up and down in the guide of the base (23), and
a projection (lid) configured on the lower most portion for retaining the actuator up while inserting and removing the wire.
5. The modular electric device as claimed in claims 1 , wherein the base (23)
comprises,
a guide spines (23a) for guiding the actuator (11) for reciprocation;
a guide (23b) for bi-stable operation for holding the actuator (11) in raised position for inserting the wire;
a snap-fit arm (23c);
a pin pivot (23d) for inserting and securing the lever;
a lever spring (26) stopper for stopping the movement of the clamp spring, and
a guide projection (23g) for securing with the first cover (2) thereof.