Claims:WE CLAIM:

1. A safety latch lock assembly comprising:
a fixed housing (1), said housing having a plurality of substantially contoured projections (11), and a wedge shaped projection (12);
a leaf spring (2) operably coupled to the fixed housing (1), said leaf spring (2) having a plurality of substantially contoured edges (21) with substantially circular groves designed so as to co-operatively receive said contoured projections (11) of said fixed housing (1); and
a removable frame (3) having at least one projection (32) designed so as to co-operatively engage with at least one slotted member (22) of said leaf spring (2).

2. The lock assembly as claimed in claim 1, wherein the projection (32) of the removable frame (3) is aligned with an edge of the slotted member (22) of the leaf spring (2) so as to facilitate the engaging of the removable frame (3).

Dated this 29th day of March 2019

Abhishek Sen
Of S. Majumdar & Co.
(Applicant’s Agent)
Registration No. 980
, Description:FIELD OF INVENTION
The present invention relates to a connector which has a snap latching structure and particularly to a connector that has a snap latching structure for preventing the connector from disengaging.

BACKGROUND

A relay is an electrical switch with electromagnet or solid state devices along with required logic inbuilt to operate the main switch for an intended function. In protective relay, relay device designed to trip a circuit breaker when it detects of abnormal operating conditions such as over-current, over-voltage, reverse power flow, over-frequency, and under-frequency fault is detected. The feeder protection relays are widely used at the feeder levels in electrical circuit for monitoring the effective functioning of feeder.
For making feeder protection relay maintenance supportive, draw-out type is made. The draw-out type relay has fixed frame and removable relay. In the existing relay being fixed type relay, the door is locked using screw and bracket arrangement by screwing bracket against the door inner surface. This screw-bracket arrangement occupies more space and laborious to work. Since relay is fixed, any maintenance to be done, the whole circuit to be shut down for maintenance. To overcome the aforementioned problems, the present invention avoids unintentional removal by providing self-locking feature. The self-locking feature is necessary to ensure the contact of the relay to remain engaged to the required level, so that at particular position the relay self-lock, indicating the required position has been achieved in insertion by locking the position.
Reference has been made to US6346002B1, disclosing connector equipped with snap latching structure includes a body, a latch member, a sleeve member and a socket. The body has a coupling section for engagement with the socket. The latch member is disposed in a recessed section of the coupling section of the body. The sleeve is disposed in the recessed section of the body to cover the latch member. The latch member has a pair of hook arms engage able with the wedge slots formed at the coupling section of the body. When the coupling section of the body engages with the socket, the hook arms latch with the side stubs located at two sides of the socket for preventing the connector from disengaging from the socket.
Reference has been made to US5295602A, which teaches an engine air cleaner housing has a snap latch closure that secures the housing cover on the housing base. To form the snap latch closure, the base has a depending retaining wall, a pair of lateral projections at opposite ends of the retaining wall, and a cross bar interconnecting the lateral projections. The retaining wall, lateral projections and cross bar define a rectangular opening which receives a U-shaped tongue extending from the cover. The tongue includes a firm leg depending adjacent the retaining wall, a flexing leg adjacent the cross bar, a cam surface formed on the flexing leg and engaging the cross bar to deflect the flexing leg as the tongue is received in the opening, and a barb that snaps into engagement with the cross bar after the tongue is fully received in the opening. Engagement of the barb with the cross bar serves to retain the tongue in the opening. Engagement between the depending wall and the firm leg prevents pivotal motion of the tongue within the opening that might otherwise reduce air filter seal compression or release the barb from the cross bar.
Reference has been further made to US4435031A, teaching a snap latch for securing a connector block on a circuit board or like support includes a central portion and prongs extending to either side of central portion. The prongs on one side of the central portion extend through a bore in a circuit board mounting portion to secure the snap latch to the block. The prongs on the other side of the central portion extend through a circuit board hole and secure the snap latch and block to the circuit board. The latch may be heat-shrunk to clamp the block to the board.
Yet another reference has been made to US5664811A disclosing a release mechanism for use with fuel filler door latch systems that provides superior control of door movement during the entire service life of the motor vehicle.
Thus there is a need for a safety latch lock adapted to snap lock a moving front relay unit with the parent housing to avoid the unintended disengagement from the relay housing which avoids the relay failure. This invention is developed for using in draw-out type feeder protection relay but its use does not limit to relay products only.
SUMMARY OF THE INVENTION
The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the present invention. It is not intended to identify the key/critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concept of the invention in a simplified form as a prelude to a more detailed description of the invention presented later.
An object of the present invention is to provide a safety latch lock assembly.
An object of the present invention is to provide an automatic lock provision, which enables withdrawable relay to self-lock in its required positions.
In accordance with an aspect of the present disclosure, is to provide a safety latch lock assembly comprising a fixed housing, said housing having a plurality of substantially contoured projections, and a wedge shaped projection; a leaf spring operably coupled to the fixed housing , said leaf spring having a plurality of substantially contoured edges with substantially circular groves designed so as to co-operatively receive said contoured projections of said fixed housing; and a removable frame having at least one projection designed so as to co-operatively engage with at least one slotted member of said leaf spring.

Other aspects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The above and other aspects, features and advantages of the embodiments of the present disclosure will be more apparent in the following description taken in conjunction with the accompanying drawings, in which:
Figure 1 illustrates an isometric view of the entire self-locking feature in a protection relay in accordance to the invention.
Figure 2 illustrates an exploded view of the self-locking feature in a protection relay in accordance to the invention.
Figure 3 illustrates a fixed part housing, which acts as integration between fixed and removable relay parts in accordance to the invention.
Figure 4 illustrates a spring part having a wedge shaped profile to facilitate the self-locking feature in a protection relay in accordance to the invention.
Figure 5 illustrates a front part of a removable frame, which form the integral frame to house components within, in accordance to the invention.
Figures 6 (a)-(c) illustrate a fixed part housing along with the spring part to facilitate the self-locking feature in a protection relay in accordance to the invention.
Figure 7 illustrates an exploded view of a fixed part housing along with the spring part to facilitate the self-locking feature with a removable frame in a protection relay in an open condition in accordance to the invention.
Figure 8 illustrates an exploded view of a fixed part housing along with the spring part to facilitate the self-locking feature with a removable frame in a protection relay in a locked condition in accordance to the invention.
Persons skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and may have not been drawn to scale. For example, the dimensions of some of the elements in the figure may be exaggerated relative to other elements to help to improve understanding of various exemplary embodiments of the present disclosure. Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures.

DETAILED DESCRIPTION
The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of various embodiments of the present disclosure as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the various embodiments described herein can be made without departing from the scope and spirit of the present disclosure. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness.
The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the present disclosure. Accordingly, it should be apparent to those skilled in the art that the following description of various embodiments of the present disclosure is provided for illustration purpose only and not for the purpose of limiting the present disclosure as defined by the appended claims and their equivalents.
It is to be understood that the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a component surface" includes reference to one or more of such surfaces.
All terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which various embodiments belong. Further, the meaning of terms or words used in the specification and the claims should not be limited to the literal or commonly employed sense, but should be construed in accordance with the spirit of the disclosure to most properly describe the present disclosure.
The terminology used herein is for the purpose of describing particular various embodiments only and is not intended to be limiting of various embodiments. As used herein, the singular forms "a," "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising" used herein specify the presence of stated features, integers, steps, operations, members, components, and/or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, members, components, and/or groups thereof. Also, Expressions such as "at least one of," when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list.
The present disclosure will now be described more fully with reference to the accompanying drawings, in which various embodiments of the present disclosure are shown. The present disclosure may, however, be embodied in many different forms and should not be construed as being limited to the various embodiments set forth herein, rather, these various embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the present disclosure. Furthermore, a detailed description of other parts will not be provided not to make the present disclosure unclear. Like reference numerals in the drawings refer to like elements throughout.
The subject invention lies in providing a safety latch lock assembly comprising a fixed housing (1), said housing having a plurality of substantially contoured projections (11), and a wedge shaped projection (12), a leaf spring (2) operably coupled to the fixed housing (1), said leaf spring (2) having a plurality of substantially contoured edges (21) with substantially circular groves designed so as to co-operatively receive said contoured projections (11) of said fixed housing (1) and a removable frame (3) having at least one projection (32) designed so as to co-operatively engage with at least one slotted member (22) of said leaf spring (2).
The construction described herein can be modified accordingly to suit a variety of applications and the construction shown below does not limit its application to the above system alone.
According to an exemplary embodiment of the present invention, a latch lock assembly for a relay is a supported leaf spring with inbuilt wedge shaped lock provision in it. The fixed external relay housing with spring mounting provisions, spring are mounted on housing. The removable relay part will have the female part of the locking provision, when it is inserted, the provision female part will engage with male part in the fixed part to get locked. This lock provision consists of a fixed housing part (1), a leaf spring (2), a removable frame (3) and a cover (4) for the leaf spring.
The withdrawable relay consists of a fixed outer frame and removable relay. This removable relay contains the logical devices for operation. These logical devices are sequenced for the required output for the main breaker which performs its make and break function on discrete signal from this removable relay.
This removable relay is compromises of a motherboard with these logical devices and contact system which facilitates push in and pull out removable relay. The motherboard and contact system are housed in the rigid frame with a display in the front to help the operators to directly read out the required details from the display.
The whole removable unit with rigid frame with motherboard, contact system is inserted in to the fixed relay part to complete the assembly. This fixed part can be separately fitted in the board, and later the removable relay part could be inserted into it.
When the removable part is inserted into the fixed frame, it need to be held in particular position to make the contact energized and perform its function. From this, lock is to be provided in the assembly which will have relative position between the fixed and removable relay to combine to complete it functional assembly.
The construction described herein can be modified accordingly to suit a variety of applications and the construction shown below does not limit its application to the above system alone.
Some of the non-limiting advantages of the present invention are:
a) Self-locking feature achieved with single leaf spring.
b) Can be handled by single hand.
c) Operator gets the feedback of lock by lock sound.

Although a safety latch lock assembly has been described in language specific to structural features, it is to be understood that the embodiments disclosed in the above section are not necessarily limited to the specific methods or devices described herein. Rather, the specific features are disclosed as examples of implementations of a safety latch lock assembly.