Specification
FORM 2
The Patents Act 1970 (39 of 1970)
&
The Patent Rules 2003 COMPLETE SPECIFICATION
(See Section 10 and rule 13)
TITLE OF THE INVENTION:
MECHANICAL SAFETY INTERLOCKING DEVICE FOR
CABINETS
APPLICANT:
LARSEN & TOUBRO LIMITED
L&T House, Ballard Estate, P.O. Box No. 278,
Mumbai, 400 001, Maharashtra . INDIA.
PREAMBLE OF THE DESCRIPTION:
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE
INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED
A) TECHNICAL FIELD
[0001] The present invention generally relates to cabinets in switch boards and particularly relates to an interlocking device. The present invention more particularly relates to a mechanical interlocking device for cabinets.
B) BACKGROUND OF THE INVENTION
[0002] An interlocking device is the one which prevents a machine from operating whenever any of interlocking conditions are not satisfied. To ensure that various types of machinery are operated safely, machinery is typically provided with a safety interlocking device so that the machine cannot be operated if one or more of the safety mechanical guards, gates, covers, etc are not properly in position. Mechanical safety interlocking devices couple a moveable guard door with the power source of the hazard. When the guard door is opened, the power is isolated, ensuring that the machine does not pose a hazard while an operator requires access to the machine during maintenance.
[0003] A mechanical interlocking device involves the use of a key and several locking mechanisms. A mechanical interlocking device includes three mechanisms. Two mechanisms may be mounted in the vicinity of the equipment, such as mounted on movable guards or located on a specific component of the equipment such as a cover. A third mechanism may be located adjacent to the electrical power source in a
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position such that in a de-actuated position the power is not available. The key can be used to separate the two halves of the locking mechanism, located in the vicinity of the equipment.
[0004] Theoretically, power is available to equipment only when all the conditions required by the mechanical interlocking device are satisfied. The mechanical interlocking device is designed such that the equipment is in a safe operating position.
[0005] Currently available mechanical interlocking devices may cause improper insertion of the module into feeder cabinets. There can be unsafe withdrawing of cabinets. In light of foregoing discussion, there exists a need for safety mechanical interlocking device.
[0006] The above mentioned shortcomings, disadvantages and problems are addressed herein and which will be understood by reading and studying the following specification.
C) OBJECT OF THE INVENTION
[0007] The primary objective of the present invention is to provide a mechanical safety interlocking device to avoid the improper insertion of module in feeder cabinets, thereby eliminating the possibilities of fault due to improper contact between module contacts and electrical system.
[0008] The secondary object of the present invention is to provide a safety interlocking device that requires predetermined conditions to be satisfied prior to permitting electrical power to be supplied to the equipment.
[0009] Another objective of the invention is to provide a safety interlocking device which prevents unsafe withdrawing of cabinets which may cause injury to personnel.
[0010] These and other objects and advantages of the present invention will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings.
D) SUMMARY OF THE INVENTION
[0011] The various embodiments of the present invention provide a mechanical safety interlocking device to avoid the improper insertion of module in feeder cabinets, thereby eliminating the possibilities of fault due to improper contact between module contacts and electrical system. According to one embodiment of the present invention, a mechanical safety interlocking device for switch board cabinets has a module interlock arranged inside a housing. A module interlock pin is connected to the module interlock. A module interlock spring is arranged around the module interlock pin. A module interlock knob is connected to the module interlock. The module interlock is freely moved up and down with the help of spring. The module interlock pin ensures the movement of the module interlock in vertical direction only. The module interlock knob is pressed up during the insertion and the withdrawal of
the module into a cabinet. The withdrawal of the inserted module is not possible without defeating the module interlock.
D) BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The other objects, features and advantages will occur to those skilled in the art from the following description of the preferred embodiment and the accompanying drawings in which:
[0013] FIG. 1 illustrates a perspective view of an interlocking device according to one embodiment of the present invention.
[0014] FIG. 2 illustrates a side perspective view of an interlocking device assembled into a module according to one embodiment of the present invention.
[0015] Although specific features of the present invention are shown in some drawings and not in others. This is done for convenience only as each feature may be combined with any or all of the other features in accordance with the present invention.
F) DETAILED DESCRIPTION OF THE INVENTION
[0016] In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which the specific embodiments that may be
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practiced is shown by way of illustration. These embodiments are described in sufficient detail to enable those skilled in the art to practice the embodiments and it is to be understood that the logical, mechanical and other changes may be made without departing from the scope of the embodiments. The following detailed description is therefore not to be taken in a limiting sense.
[0017] The various embodiments of the present invention provide a mechanical safety interlocking device to avoid the improper insertion of module in feeder cabinets, thereby eliminating the possibilities of fault due to improper contact between module contacts and electrical system. According to one embodiment of the present inveiifibiT, a- ffleehsrnsst safety- arterioekffig atevire fer swi'Ccft board cacVnefs has a module interlock arranged inside a housing. A module interlock pin is connected to the module interlock. A module interlock spring is arranged around the module interlock pin. A module interlock knob is connected to the module interlock. The module interlock is freely moved up and down with the help of spring. The module interlock pin ensures the movement of the module interlotk in vertical direction only. The module interlock knob is pressed up during the insertion and the withdrawal of the module into a cabinet. The withdrawal of the inserted module is not possible without defeating the module interlock.
[0018] Thus the various embodiments of the present invention provide a mechanical safety interlocking device that avoids the improper insertion of module in feeder cabinets, thereby eliminating the possibilities of fault due to improper contact between module contacts and electrical system. Power is made available to an
equipment only when all the conditions required by the mechanical interlocking device are satisfied. The mechanical interlocking device is designed such that the equipment is in a safe operating position.
[0019] Usually in a Switchboard, Control panel or Electrical enclosure applications, draw out modules are being used for controlling Motors or Outgoing feeders. When the module is inserted into the switchboard feeder cabinet and attains service condition and is switched ON, it should not be withdrawn unless it is switched OFF and taken into isolated position.
[0020] The preferred embodiment of the invention facilitates locking of the module while the module is in service state and ON condition. Once the module is inserted and placed in its final position, the module gets locked with respect to fixed part of switchboard. Hence, the preferred embodiment ensures that current position of the module in service is sustained and the module cannot be withdrawn without unlocking the interlocking device in case of intended action.
[0021] FIG. 1 illustrates a perspective view of an interlocking device according to one embodiment of the present invention. With respect to FIG. 1, the interlocking device includes three parts a module interlock 1, a module interlock pin 2 and a module interlock spring 3. With the help of the module interlock spring 3 the module interlock is free to move up and down. The module interlock pin 2 ensures the module interlock 1 movement in vertical direction only. The three parts of the interlocking device are assembled on the basic module is explained in conjunction with FIG 2.
[0022] FIG. 2 illustrates a side perspective view of an interlocking device assembled into a module according to one embodiment of the present invention. With respect to FIG.2, the interlocking device facilitates the locking of the module 4 while the module 4 is in service and ON condition. Once the module 4 is inserted and placed in its final position, the module 4 gets locked with respect to fixed part of switchboard 5.
[0023] When the module 4 is required to be withdrawn, the Module interlock knob 6 is lifted up to unlock the module 4 with respect to fixed part of switchboard 5 and then module 4 is pulled out.
[0024] When the module 4 is inserted in feeder cabinet; Module interlock knob 6 is lifted up and module 4 is racked inside the compartment. Once the module 4 reaches its final position, the slots provided on module 4 base and fixed part of panel get aligned. Further, the module interlock knob 6 is released to lock the module 4 with compartment tray.
G) ADVANTAGES OF THE INVENTION
[0025] Thus the various embodiments of the present invention provide a mechanical safety interlocking device. The mechanical safety interlocking device ensures that current position of the module in service is sustained and the module cannot be withdrawn without unlocking the interlocking device in case of intended action. The invention can be widely extended to draw out apparatus such as kitchen drawers,
Industrial cabinets, safety junction boxes etc. The invention provides a simple safety interlocking device facilitating rapid installation into the module saving time and labour of the personnel.
[0026] Although the invention is described with various specific embodiments, it will be obvious for a person skilled in the art to practice the invention with modifications. However, all such modifications are deemed to be within the scope of the claims.
[0027] It is also to be understood that the following claims are intended to cover all of the generic and specific features of the present invention described herein and all the statements of the scope of the invention which as a matter of language might be said to fall there between.
Date: March 30, 2008. Place: Bangalore.
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CLAIMS
What is claimed is:
1. A mechanical safety interlocking device for switch board cabinets
comprising:
a housing;
a module interlock arranged inside the housing;
a module interlock pin connected to the module interlock;
a module interlock spring arranged around the module interlock pin; and
a module interlock knob connected to the module interlock;
wherein the module interlock is freely moved up and down with the help of
spring.
2. The device according to claim 1, wherein the module interlock pin ensures the movement of the module interlock in vertical direction only.
3. The device according to claim I, wherein the module interlock knob is pressed up during the insertion and the withdrawal of the module into a cabinet.
4. The device according to claim 1, wherein the withdrawal of the inserted module is not possible without defeating the module interlock
Date: March 30, 2008. RAKESH PRABHU
Place: Bangalore. Patent Agent
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