FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
As amended by the Patents (Amendment) Act, 2005
& The Patents Rules, 2003 As amended by the Patents (Amendment) Rules, 2006
PROVISIONAL SPECIFICATION
(See section 10 and rule 13)
TITLE OF THE INVENTION
A shock absorbing means
APPLICANTS
Crompton Greaves Limited, CG House, Dr Annie Besant Road, Worli, Mumbai 400 030, Maharashtra, India, an Indian Company
INVENTORS
Bagade Vishal Vijay and Khedkar Parag Prabhakar, both of Crompton Greaves Limited, Technology Cell (S3), A-3 MIDC, Ambad, Nasik, Maharashtra, India, both are Indian Nationals
PREAMBLE TO THE DESCRIPTION
The following specification describes the invention

This invention relates to Seismic proof Damper for Circuit Breaker.
Dampers or Shock absorbers as they are popularly known are commonly used in automobiles, railways, machine, circuit breaker etc. These means absorb the vibrating energy to provide comfort, safety etc to the vehicles, machines. There are various types of shock absorbers which uses oil, air, electromagnetic, friction etc., as the medium to absorb energy. Rubber is also one of the commonly known medium which is used for absorbing the shock, vibrations etc. The oil type and air type dampers are more costly, the construction is complicated and are prone to leakage etc. Electromagnetic and friction type have capacity limitations.
GB Patent No. 910273 discloses an invention having a spring closing mechanism for switchgear of the kind in which such mechanism and the associated linkage in contained in a fixed framework or compartment external to the main circuit-breaker compartment, shock absorbing means for absorbing the shock otherwise imparted to the framework and closing mechanism by the release of the closing spring comprises a stack of disc-like shock absorber elements housed coaxially within a movable cylindrical shock absorber casing which is connected to a member which moves the casing in one direction for charging the closing spring and is driven by the spring in the return direction when the spring is released to impart the closing effort to the mechanism. However, the independence in modification of the shape of dampers depending upon the capacity of the circuit breaker is missing in the invention disclosed herein.
3 1 MAR 2009
2

US Patent No. 4891617 discloses an invention having a molded case circuit breaker is provided with rubber stop assemblies disposed between the contact assemblies adjacent the outside poles and the cover portion of the housing. The rubber stop assemblies are disposed such that they prevent the contact assemblies from damaging the cover. The stop assemblies include a dual purpose U-shaped bracket having two parallel sets of arms. The shock absorber assembly is mounted adjacent outside poles above the contact carrier but spaced away from the inside of the cover of the circuit breaker. Thus, when the contact arm is opened, it will stop against the shock absorber and not damage the circuit breaker cover. However, the constructions features of the assembly are designed to prevent the assembly from any damage but the patent does not highlight the strength of the assembly as well the overall life of the rubber stop, which again is a crucial parameter.
Hence to overcome all the disadvantages mentioned herein a shock absorbing means for circuit breakers is disclosed herein.
An objective of the invention is to provide a shock absorbing means to protect Circuit Breaker from Seismic Vibrations.
Another objective of the invention is to provide a shock absorbing means to protect circuit breaker from operational vibrations
Another objective of the invention is to provide a shock absorbing means, which can be simple in construction and cost effective arrangement for serving above purpose without change in actual circuit breaker.
3 1 MAR Z009
3

In accordance with the invention a shock absorbing means comprising of damper plates and damper blocks as damping elements. Damper plate provides damping in axial direction and the damping blocks provide rotational damping in vertical plane. Due to this arrangement the seismic vibrations in any direction will get absorbed in damping element. This is how a single damping element can be used to absorb earth excitations in all directions.
Upper and lower support brackets are joined by a pin in a pivot-able joint. Due to this the upper support bracket can tilt in the plane perpendicular to the pin, by 10-15 degrees in both directions. The upper support bracket has a mate "V" shape, which engages the female "V" cavity of the rubber block. Due to vibration the upper support bracket will tilt, while tilting the "V" shaped bracket will press against the "V" shaped rubber block and provide rotational damping in vertical plane.
In accordance with the invention the second embodiment comprising a rubber block with bulging shape in center with a center hole in direction perpendicular to direction of application of load. The shape facilitates damping absorption in vertical and angular direction both. Center hole provides flexibility in damping element.
In accordance with the invention, the construction of shock absorber is in such a way that it enables rotational damping in such a way that damper block always remain in compression. The life of shock absorbing material like rubber will be more in compression than in tension.
4

3 1 MAR 2009
5
In accordance with the invention, the shock absorbing means can be sued in both directions. A damper plate provides damping in axial direction and the damping blocks provide rotational damping in vertical plane. The "V" shape of damper block and upper support bracket provides rotational damping. The bulging shape of damper facilitates damping absorption in vertical and angular direction both. The center hole in damping element provides flexibility and enables angular damping.