Abstract
A door close interlock mechanism, said mechanism comprises: roller adapted to roll about a bar pin inserted through the arms of a U-bracket, said roller adapted to co-operate with an external cam such that the rack-in and rack-out motion of VCB truck assembly operates said roller and said mechanism, said cam being mounted on VCB Truck assembly; co-axial spring-loaded plunger shaft extending operatively downwards from said U-bracket, said spring encircling said plunger shaft to provide resilience to said plunger shaft movement, thus making it retractable, said spring being located between a base of a U-bracket and an operative top of a lower housing, wherein, said lower housing includes a slot to allow passage of said plunger shaft through it, so that said plunger shaft engage with other elements of said mechanism; hollow open cylindrical housing adapted to receive said spring loaded plunger shaft, said plunger shaft adapted to enter said cylindrical housing once said roller is engaged to push said plunger shaft operatively downwards; inverted spoon shaped bracket with its handle fitted below said cylindrical housing in a manner such that said plunger shaft hits said bracket in order to angularly displace a far end of said bracket about a split pin provided to facilitate angular displacement, thereby facilitating an open position of said lock mechanism.
Specification
FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
As amended by the Patents (Amendment) Act, 2005
AND
The Patents Rules, 2003 As amended by the Patents (Amendment) Rules, 2005
COMPLETE SPECIFICATION (See section 10 and rule 13)
TITLE OF THE INVENTION
A door close interlock mechanism.
APPLICANTS :
Crompton Greaves Limited, CG House, Dr Annie Besant Road, Worli, Mumbai 400 030, Maharashtra, India, an Indian Company
INVENTOR (S):
Chavan Narendrakumar Bhaskar and Thakare R D of Crompton Greaves Ltd, MV
R&D/ S2, A3, MIDC Ambad, Nashik Maharashtra, India; an Indian National.
PREAMBLE TO THE DESCRIPTION:
The following specification particularly describes the nature of this invention and the manner in which it is to be performed:
Field of the Invention:
This invention relates to the field of mechanical assemblies and equipment. Particularly, this invention relates to a door close interlock mechanism.
Background of the Invention:
The term switchgear, used in association with the electric power system, or grid, refers to the combination of electrical disconnects, fuses and/or circuit breakers used to isolate electrical equipment. Switchgear is used both to de-energize equipment to allow work to be done and to clear faults downstream. This type of equipment is important because it is directly linked to the reliability of the electricity supply.
The circuit breaker truck is of withdraw-able type provided with operating mechanism of circuit breaker. Withdrawal or insertion of racks in and out of the truck is done during testing and servicing.
There was no interlock available for any vacuum circuit breaker panel and door before this. There is a need to develop a door interlock for the safety of operator.
Objects of the Invention:
An object of the invention is to provide a lock which is VCB truck dependent. Another object of the invention is to provide an automatically operable lock which is dependent on movement of VCB truck in panel.
Yet another object of the invention is to provide a lock such that the door should be automatically closed if there is no VCB truck present in the panel.
Another object of the invention is to provide a lock which is relatively compact.
Yet another object of the invention is to provide a lock which is suitable for any VCB Truck which gets racks in and out of the panel.
Still another object of the invention is to provide a lock which is easy to assemble and manufacture; whose components do not require special machining.
An additional object of the invention is to provide a relatively inexpensive lock.
Summary of the Invention:
According to this invention, there is provided a door close interlock mechanism, said mechanism comprises:
a. roller adapted to roll about a bar pin inserted through the arms of a U-bracket,
said roller adapted to co-operate with an external cam such that the rack-in
and rack-out motion of VCB truck assembly operates said roller and said
mechanism, said cam being mounted on VCB Truck assembly;
b. co-axial spring-loaded plunger shaft extending operatively downwards from
said U-bracket, said spring encircling said plunger shaft to provide resilience
to said plunger shaft movement, thus making it retractable, said spring being
located between a base of a U-bracket and an operative top of a lower
housing, wherein, said lower housing includes a slot to allow passage of said
plunger shaft through it, so that said plunger shaft engage with other elements
of said mechanism;
c. hollow open cylindrical housing adapted to receive said spring loaded plunger
shaft, said plunger shaft adapted to enter said cylindrical housing once said
roller is engaged to push said plunger shaft operatively downwards; and
d. inverted spoon shaped bracket with its handle fitted below said cylindrical housing in a manner such that said plunger shaft hits said bracket in order to angularly displace a far end of said bracket about a split pin provided to facilitate angular displacement, thereby facilitating an open position of said lock mechanism.
According to another embodiment of the invention, there is provided a door close interlock mechanism, said mechanism comprising:
a. roller adapted to roll about a bar pin inserted through the arms of a U-bracket,
said roller adapted to co-operate with an external cam such that, said cam
actuates roller motion;
b. co-axial spring-loaded plunger shaft extending operatively downwards from
said U-bracket, said spring encircling said plunger shaft to provide resilience
to said plunger shaft movement, thus making it retractable, said spring being
located between a base of a U-bracket and an operative top of a lower
housing, wherein, said lower housing includes a slot to allow passage of said
plunger shaft through it, so that said plunger shaft engage with other elements
of said mechanism;
c. hollow open cylindrical housing adapted to receive said spring loaded plunger
shaft, said plunger shaft adapted to enter said cylindrical housing once said
roller is engaged to push said plunger shaft operatively downwards; and
d. inverted spoon shaped bracket with its handle fitted below said cylindrical
housing in a manner such that said plunger shaft hits said bracket in order to
angularly displace a far end of said bracket about a split pin provided to
facilitate angular displacement, thereby facilitating an open position of said
lock mechanism.
Typically, said bar pin includes a plain washer on one side and a circlip on the other; both being placed exterior to said arms of said U-bracket in order to facilitate its angular displacement.
Brief Description of the Accompanying Drawings:
The invention will now be described in relation to the accompanying drawings, in which:
Figure 1 illustrates a front isometric view of the door close interlock mechanism;
Figure 2 illustrates a front view of the door close interlock mechanism;
Figure 3 illustrates a side of the door close interlock mechanism; and
Figure 4 illustrates a top view of the door close interlock mechanism.
Detailed Description of the Accompanying Drawings:
According to this invention, there is provided a door close interlock mechanism (100).
Figure 1 illustrates a front isometric view of the door close interlock mechanism. Figure 2 illustrates a front view of the door close interlock mechanism. Figure 3 illustrates a side of the door close interlock mechanism. Figure 4 illustrates a top view of the door close interlock mechanism.
In accordance with an embodiment of this invention, there is provided a roller (12) adapted to roll about a bar pin (14) inserted through the arms (16, 18) of a U-bracket (20). The bar pin includes a plain washer (22) on one side and a circlip (24)
on the other; both being placed exterior to the arms of the U-bracket, and facilitates its angular displacement.
An external cam co-operates with the roller such that the rack-in and rack-out motion of VCB truck assembly operates the roller and the entire mechanism, thereby, in an automatic fashion (without human or manual intervention). The cam is mounted on VCB Truck assembly.
In accordance with another embodiment of this invention, there is provided a coaxial spring-loaded plunger shaft (26) extending operatively downwards from said U-bracket. The spring (28) encircles the plunger shaft and provided resilience to the plunger shaft upward and downwards movement, thus making it retractable. The spring is located between the base (30) of the U-bracket and an operative top of a lower housing (32). The lower housing includes a slot to allow passage of plunger shaft through it, so that the plunger shaft may engage with other elements of this invention.
In accordance with yet another embodiment of this invention, there is provided a hollow open cylindrical housing (34) adapted to receive said spring loaded plunger shaft. The plunger shaft enters this cylindrical housing once the roller is engaged to push the plunger shaft operatively downwards.
In accordance with still another embodiment of this invention, there is provided an inverted spoon shaped bracket (36) with its handle fitted below the cylindrical housing in a manner such that the plunger shaft hits the bracket. The spoon shaped bracket is a lever of sorts wherein the handle of the spoon acts as the load arm, the
cup of the spoon acts as the effort arm, and the cusp of their juncture acts as fulcrum. At this fulcrum point, a split pin (38) is provided to facilitate angular displacement of the effort arm in one direction when the plunger shaft acts as a load on the load arm. This mechanism of lifting the bracket acts as the unlocking of the lock. Conversely, the mechanism of lifting of the plunger shaft (load) from the bracket load arm results in effecting the angular displacement of the bracket effort arm in an opposite direction, thereby actuating a locking position.
Thus, there is provided a door close interlock, which consist of an Interlock Assembly mounted on housing (Panel) and automatically gets operated by rack in rack out of VCB Truck Assembly. This interlock assembly consists of spring operated latch and driving cam. This is a compact solution which is very cost effective and which satisfies the requirement of VCB Panel as per IEC62271-200.
The door will not get close if there is no VCB truck available in panel. As soon as VCB truck gets in the panel the interlock mechanism gives access to lock the door. As the VCB Truck gets rack in while door close, the interlock get operated and locks the door. When VCB truck gets back from service to test position again, the latch will get opened to permit opening of door.
While this detailed description has disclosed certain specific embodiments of the present invention for illustrative purposes, various modifications will be apparent to those skilled in the art which do not constitute departures from the spirit and scope of the invention as defined in the following claims, and it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.
We claim,
1. A door close interlock mechanism, said mechanism comprising:
a. roller adapted to roll about a bar pin inserted through the arms of a U-
bracket, said roller adapted to co-operate with an external cam such that the
rack-in and rack-out motion of VCB truck assembly operates said roller and
said mechanism, said cam being mounted on VCB Truck assembly;
b. co-axial spring-loaded plunger shaft extending operatively downwards from
said U-bracket, said spring encircling said plunger shaft to provide resilience
to said plunger shaft movement, thus making it retractable, said spring being
located between a base of a U-bracket and an operative top of a lower
housing, wherein, said lower housing includes a slot to allow passage of said
plunger shaft through it, so that said plunger shaft engage with other
elements of said mechanism;
c. hollow open cylindrical housing adapted to receive said spring loaded
plunger shaft, said plunger shaft adapted to enter said cylindrical housing
once said roller is engaged to push said plunger shaft operatively
downwards; and
d. inverted spoon shaped bracket with its handle fitted below said cylindrical
housing in a manner such that said plunger shaft hits said bracket in order to
angularly displace a far end of said bracket about a split pin provided to
facilitate angular displacement, thereby facilitating an open position of said
lock mechanism.
2. A mechanism as claimed in claim 1 wherein, said bar pin includes a plain washer on one side and a circlip on the other; both being placed exterior to said arms of said U-bracket in order to facilitate its angular displacement.
3. A door close interlock mechanism, said mechanism comprising:
a. roller adapted to roll about a bar pin inserted through the arms of a U-
bracket, said roller adapted to co-operate with an external cam such that,
said cam actuates roller motion;
b. co-axial spring-loaded plunger shaft extending operatively downwards from
said U-bracket, said spring encircling said plunger shaft to provide resilience
to said plunger shaft movement, thus making it retractable, said spring being
located between a base of a U-bracket and an operative top of a lower
housing, wherein, said lower housing includes a slot to allow passage of said
plunger shaft through it, so that said plunger shaft engage with other
elements of said mechanism;
c. hollow open cylindrical housing adapted to receive said spring loaded
plunger shaft, said plunger shaft adapted to enter said cylindrical housing
once said roller is engaged to push said plunger shaft operatively
downwards; and
d. inverted spoon shaped bracket with its handle fitted below said cylindrical
housing in a manner such that said plunger shaft hits said bracket in order to
angularly displace a far end of said bracket about a split pin provided to
facilitate angular displacement, thereby facilitating an open position of said
lock mechanism.
4. A mechanism as claimed in claim 1 wherein, said bar pin includes a plain washer on one side and a circlip on the other; both being placed exterior to said arms of said U-bracket in order to facilitate its angular displacement.
