FORM 2
THE PATENT ACT 1970
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)
1. TITLE OF THE INVENTION:
Padlocking Device for Circuit breaker
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,
L&T House, Ballard Estate, P. 0. Box: 278, Mumbai 400 001, India
3. PREAMBLE TO THE DESCRIPTION:
COMPLETE
The following specification particularly describes the invention and the manner in which it is to be performed.


Padlocking Device for Circuit breaker
Field of the invention
The present invention relates generally to padlocking devices, and more particularly, to padlocking devices used for modular devices such as low voltage circuit breakers.
Background of the invention
Modular devices such as circuit breakers (miniature circuit breakers, residual current circuit breakers, isolators, changeovers) are used for switching and/or protection in electrical distribution network. Padlocking devices are required to have controlled access for preventing unauthorized or accidental operation of the circuit breakers. Further, padlocking of the circuit breakers, is also required to avoid danger or health hazard to a person operating on network or process industries where undesired switching (on or off) can cause damage and loss of production. In such cases, the padlocking device (with padlock] or sealing wires are mounted on the circuit breakers.
The padlocking device and padlock of the prior art, when mounted on the circuit breaker, may hide important data (rating of device) or indications such as position indication, fault indication etc. behind the padlock. Use of padlocking device can therefore also affect designing of layout and printing of data on the circuit breaker and become a limitation.
One such padlocking device is currently available in the market as shown in figure 1. For mounting the padlocking device on the circuit breaker, a first portion (1) of padlock device (2) is to be brought down. Then wires are pressed as shown in figure 1. Ends of wires are inserted in holes of the circuit breaker 3 and again the first portion (1) is brought up for putting up the padlock.

However, after putting the padlocking device on the circuit breaker, a contact position indicator (4) is hidden behind the padlocking device (2] and cannot be read. Accordingly, an indication feature of circuit breaker remains of no use after putting the padlocking device, as shown in figure 2.
Another padlocking device as shown in figure 3 is also available currently. For mounting the padlocking device on the circuit breaker, a flap (5} of padlocking device [6] is to be rotated first. Then side portion is pressed so that wires are moved inside the padlocking device. Then the padlocking device is mounted on the circuit breaker such that wires are inserted in holes of the circuit breaker. The flap (5) of the padlocking device is then rotated back and the padlock can be put for locking.
However, the construction of abovementioned padlocking device is complicated and number of parts required are more. Also plastic riveting/hot pressing is required for making the padlocking assembly. This increases the cost of device as well as time required for assembly of the padlocking device on the circuit breaker. Also, the aforesaid padlocking device is suitable when all data is printed above knob of the padlocking device.
Accordingly, there exists a need to provide a padlocking device for circuit breaker which overcomes abovementioned drawbacks.
Objects of the invention
An object of the present invention is to provide visibility to information and indicators printed on circuit breaker, even when padlock is mounted thereon.
Another object of the present invention is to provide a padlocking device for the circuit breaker with simple and easy construction.

Summary of the invention
Accordingly, the present invention provides padlocking device for circuit breakers. The padlocking device includes a base member, a torsion spring and a cover member. The base member includes a fixed member having a first protrusion and a second protrusion configured on front surface thereof and a third protrusion with a provision for padlock insertion configured on rear surface thereof. The base member further includes a flexible member hinged to the fixed member. The flexible member includes at least two cut-outs adapted thereon and a slit for receiving the third protrusion therethrough when the flexible member is in proximity to the fixed member.
The torsion spring includes a base portion and two limbs extending from the base portion. The base portion is capable of being secured around the first protrusion of the base member. A first limb out of the two limbs of the torsion spring gets support by the second protrusion thereby allowing movement thereof in one direction when torsion spring is configured within the base member.
The cover member is capable of being secured to the front surface of the fixed member of the base member by click fit mechanism. The cover member includes a stopper member configured on inner surface thereon for supporting a second limb out of the two limbs of the torsion spring when the cover member is assembled to the base member with the torsion spring therebetween.
Upon rotating/moving the flexible member about the hinge, and compressing two limbs of the torsion spring against load thereof for inserting into openings provided above knob of the circuit breaker, and thereafter again rotating moving the flexible member back to the original position, the third protrusion of the fixed member protrudes out through the slit of the flexible member to which a padlock is capable of being mounted thereby restricting rotation of flexible member and padlocking the circuit breaker which allows view of indicators of the circuit breaker from the cut outs of the flexible member.

Brief description of the drawings
Figures 1, 2 and 3 show padlocking devices, of the prior art;
Figure 4 shows an exploded view of a padlocking device, in accordance with the present invention;
Figure 5 shows a perspective view of a base of the padlocking device of figure 4;
Figure 6 shows another perspective view of the base of figure 5;
Figure 7 shows a perspective view of a torsion spring of the padlocking device of figure 4;
Figure 8 shows another perspective view of the torsion spring of figure 7;
Figure9 shows a perspective view of a cover of the padlocking device of figure 4;
Figure lOshows a side view of the padlocking device of figure 4;
Figure llshows a rear view of the padlocking device of figure 4;
Figure 12 shows mounting of the padlocking device on a circuit breaker, in accordance with the present invention;
Figure 13 shows a perspective view of the padlocking device mounted on the circuit breaker along with a padlock; and
Figure 14 shows a front view of the padlocking device mounted on the circuit breaker along with the padlock.

Detailed 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 padlocking device for a circuit breaker. The padlocking device of present invention allows all data on the circuit breaker to be visible while serving all required functions of the padlocking. The padlocking device of the present invention is prominent when construction of modular device such as the circuit breaker is such that its indicators as well as important data of are located below knob of circuit breaker,
Referring now to figure 4 to 14, there is shown a padlocking device and various components thereof in accordance with the present invention. Specifically, figure 4 shows an exploded view of the padlocking device (100) for modular device such as circuit breaker, in accordance with the present invention. The padlocking device (100) includes a base member (10), a torsion spring (20), and a cover member (30).
The base member (10), as shown in figure 5 and 6, includes a fixed member (12) and a flexible member (14). The fixed member (12X is hinged to the flexible member (14). In an embodiment, the fixed member (12) and the flexible member (14) are hinged together to form single moulded component joined together with flexible portion (16). The flexible member (16] exhibits plastic hinge property therebetween.
The fixed member (12) includes a first protrusion (12a) and a second protrusion (12b) configured on front surface thereof and a third protrusion (12c) with a provision for padlock insertion configured on rear surface thereof. In an embodiment the first protrusion (12a) is circular protrusion, the second

protrusion (12c) is an elongated protrusion and the third protrusion [12c] is semicircular elongated protrusion having an opening adapted centrally thereon.
The flexible member (14) includes at least two cut-outs [14a, 14b) adapted thereon and a slit (not shown) for receiving the third protrusion (12c) therethrough when the flexible member (14) is in proximity to the fixed member (12).
In an embodiment, the base member (10) is made of plastic material such as unfilled nylon 66 which exhibits good flexibility. The padlocking device (100) includes the torsion spring (20) which is capable of being configured within the fixed member (12) of the base member (10). In an embodiment, the torsion spring is made with a suitable metal known in the art.
The torsion spring (20) includes a base portion (22) and two limbs (24a, 24b) extending from the base portion (22) as shown in figure 7 and 8. The base portion (22) is capable of being secured around the first protrusion (12a) of the flexible member (12) of the base member (10). In an embodiment, the base portion (22) is a circular in shape which gets inserted around the circular first protrusion (12a) of the fixed member (12). Further, a first limb (24a) out of the two limbs of the torsion spring (20) gets support by the second protrusion (12b) which allows movement of the limb (24a) in one direction, when the torsion spring (20) is configured within the fixed member (10).The shape of the two limbs (24a, 24b) is such that ends the two limbs (24a, 24b) can be brought closer without interference in the limbs. Further, there is sufficient length of straight portion of the two limbs (24a, 24b) which comes one over another. The second limb (24b) of the two limbs (24a, 24b) gets support from the cover member (30).
The cover member (30) as shown in figure 9 is capable of being secured to the front surface of the fixed member (12) of the base member (10) by click fit mechanism. In an embodiment, the cover member (30) includes flexible hooks (32a, 32b) configured thereon for click fitting the cover member (30) to the base member (10). The cover member (30) further includes a stopper member (34)

configured on inner surface thereof for supporting a second limb (24b) out of the two limbs of the torsion spring (20) when the cover member (30) is assembled to the base member (10) with the torsion spring (20) therebetween. In an embodiment, the stopper member (34) is an elongated protrusion. In another embodiment, the cover member (30) is made of suitable plastic material known in the art.
Now, assembly of the padlocking device (100) is described in conjunction with the figure 4. The torsion spring (20) is inserted in base member (10). Specifically, the base portion (22) of the torsion spring (20) is inserted around the first protrusion (12a) of the base member (10), wherein the first limb (24a) of the torsion spring (20) is supported by the second protrusion (12b) such that the first limb (24a) is allowed to move only on one direction. Thereafter, the cover member (30) is inserted and click fitted on the base member (10), wherein the second limb (24b) of the torsion spring (20) is supported by stopper member (34) of the cover member (30). Figure 10 shows a side view of the padlocking device (100) and figure 11 shows a rear view of the padlocking device (100) when assembled. As shown in figure 11, the cut-outs (14a, 14b) made in the flexible member (14) of the base member (10) are seen and construction of the torsion spring (20) is such that, after assembly of the padlocking device (100) to the circuit breaker, various indicators of the circuit breaker can be seen through cut out (14a) and (14b).
Referring to figure 12, assembly of the padlocking device (100) to the circuit breaker (200) is shown. During the assembly, the flexible member (14) is rotated /moved about the hinge. Thereafter, the two limbs(24a, 24b) of the torsion spring (20) are compressed manually against load of the torsion spring (20) and ends of the two limbs(24a, 24b) are inserted in corresponding holes (A,B) located above knob (40) of the circuit breaker (200). Thereafter, the flexible member (14) is rotated/moved back to its original position as shown in figure 13. Closing of the flexible member (14) towards the fixed member (12) with the torsion spring (20) therebetween does not allow the two limbs (24a, 24b) to collapse inside. Then a padlock (50) is mounted to the third protrusion (12c) of the fixed member (12) protruding out through the slit of the flexible member (14) so that the padlock

(50) does not allow rotation of flexible member (14) and thus locks the circuit breaker (200).
Specifically, when ends of two limbs (24a, 24b) are inserted in holes (A, B) of the circuit breaker (200), the two limbs (24a, 24b) restrict movement of the knob (40). More specifically, when the padlock (50) is mounted, it is not possible to operate knob (50) of the circuit breaker (200). The padlocking device (100) can be used when it is required to restrict operation of knob (50) from OFF to ON or ON to OFF position.
For un-mounting the padlocking device (100) and to operate the circuit breaker (200), the padlock (50) has to be removed first, and the flexible member (14) has to be rotated/moved about the hinge. Thereafter, the two limbs (24a, 24b) of the torsion spring are pressed for retrieving from the holes (A, B) to take out the padlocking device (100) from the circuit breaker (200).
Figure 14 shows a front view of the padlocking device (100) mounted on the circuit breaker (200). The figure 14 shows that, even when the padlocking device (100) is mounted on the circuit breaker (200), indicators (C, D) are clearly visible from front. The padlocking device (100) as well as the padlock (40) does not obstruct the view of the indicators of the circuit breaker (200).
Advantages of the invention
1. The padlocking device (100) does not obstruct the indicators on the circuit
breaker even when the indicators are below the knob. .
2. Using, the padlocking device (100), indicators on the circuit breaker are visible
through cut-out provided on the base member even when the padlocking device is
mounted on the circuit breaker.
2. The padlocking device (100) is easy in construction because only three parts are required to form the padlocking device which also has ease of assembly.

The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, to thereby enable others skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omission and substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but such are intended to cover the application or implementation without departing from the spirit or scope of the present invention.

We Claim:
1. A padlocking device (100] for circuit breakers (200), the padlocking device (100) comprising:
a base member (10) having:
a fixed member(12) having a first protrusion (12a) and a second protrusion (12b) configured on front surface thereof and a third protrusion (12c) with a provision for padlock insertion configured on rear surface thereof, and
a flexible member(14) hinged to the fixed member (12), the flexible member having at least two cut-outs (14a, 14b) adapted thereon and a slit for receiving the third protrusion (12c) therethrough when the flexible member (14) is in proximity to the fixed member (12);
a torsion spring (20) having a base portion (22) and two limbs (24a, 24b) extending from the base portion (22), the base portion (22) is capable of being secured around the first protrusion (12a) of the base member (10), wherein first limb (24a) out of the two limbs (24a, 24b) gets support by the second protrusion (12b) thereby allowing movement thereof in one direction when torsion spring (20) is configured within the base member (10) and in assembled condition two limbs (24a, 24b) of the torsion spring (20) come over one another; and
a cover member (30) capable of being secured to the front surface of the fixed member (12) of the base member (10) by click fit mechanism, the cover member (30) having a stopper member (34) configured on inner surface thereon for supporting a second limb (24b) out of the two limbs (24a, 24b) of the torsion spring (20) when the cover member (30) is assembled to the base member (10) with the torsion spring (20) therebetween,
wherein upon rotating/moving the flexible member (14) about the hinge, and compressing the two limbs (24a, 24b) of the torsion spring (20) against load thereof for inserting into openings ( A,B) provided above knob (40) of the circuit breaker (200), and thereafter again rotating/moving the flexible member (14) back to the original position, the third protrusion (12c) of the fixed member (12) protrudes out through the slit of the flexible member (14) to which a padlock

(50) is capable of being mounted, thereby restricting rotation of the flexible member (14) and padlocking the circuit breaker without obstructing view of indicators of the circuit breaker(20) from the cut outs (14a, 14b) of the flexible member (14).
2. The padlocking device (100) as claimed intlaim 1, wherein the fixed member (12] and the flexible member (14} are hinged together to form single moulded component.
3. The padlocking device (100) as claimed in claim 1, wherein the cover member (30) includes flexible hooks (32a, 32b) configured thereon for click fitting the cover member (30) to the base member (10).