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
COMPLETE SPECIFICATION
(See section 10 and rule 13)
TITLE OF INVENTION
Interchangeable Multi Layer Blade-cutter assembly for Mixer Grinder
APPLICANTS
Crompton Greaves Limited, CG House, Dr Annie Besant Road, Worli, Mumbai 400 030, Maharashtra, India, an Indian Company
INVENTOR
Nadkarni Mayur Prakash, Fans & Appliances Division, Crompton Greaves Limited, Plot No 1, Bethora Industrial Estate, Bethora, Ponda, Goa 403401, India, an Indian National
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the nature of this invention :

FIELD OF THE INVENTION
This invention relates to mixer grinder having interchangeable multi layer blade-cutter assembly to enhance the performance for Wet Grinding, Blending, Dry Grinding, and Chutney Grinding.
BACKGROUND ART
Food mixer grinder generally consists of main unit or motor unit and utility jars. The jars provided could be Blender, Wet Grinding jar, Dry Grinding jar or Chutney Grinding jar. The main unit houses the electric motor mostly of universal type motor placed vertical, speed control knob and acts as the support for the structure. At the top of the motor shaft, motor coupler is press fitted or screwed to transfer the rotational motion of the motor to the jars. The food ingredients to be ground are poured in the jar and the jar is mounted on the main unit. Two grooves are cut on main unit top portion for mounting the jar. The lower portion of jar has two lugs which help in mounting the jar on main unit. The jar is placed on the main unit and lugs of jar base are aligned with the grooves on the main unit. The jar is slid vertically along the grooves and then rotated to lock at place. The purpose is to restrict the rotational movement and vertical movement of the jar while the mixer grinder is operated. When the jar is placed on to the main body, it also ensures the positive coupling of motor coupler and jar coupler. Motor coupler is mounted on to the shaft of the motor whereas jar coupler is mounted on the shaft, the other end of which carries the blade mounted on to it.


The blade assembly consists of main shaft, plastic head with brass insert, nut cap, blade and washers. Nut cap is press fitted on to the shaft. The shaft has a rectangular slot along with the threaded part on which the head with brass insert needs to be tightened. The Blade is first mounted on top of the rectangular slot and plastic head is then threaded on to the shaft whereas the other end, threading is provided to mount the jar coupler. By holding one end, i.e. the coupler side, the blades can be removed from the assembly by rotating the blade on clockwise direction. The blade can have 2/ 3/ 4 arms as per the requirement of grinding. In the present scenario only one blade can be mounted on to the shaft of the jar assembly which grinds the ingredients in particular time period.
OBJECTS OF THE INVENTION
An object of the invention is to provide an arrangement for mounting multi layer a series of blades interlockably, held on to the shaft through simple threading and locking mechanism in the jar.
Another object of the invention is to improve the grinding efficiency of the ingredients such as turmeric.
Another object of the invention is to decrease the grinding time with this blade assembly.
Another object of the invention is to provide add on blade system in which the customer has the option of using single or double or multi level of series of blades on top of one another.


Another object of the invention is to facilitate the cleaning operation of the jar and blade assembly by independently removable blade sets of assembly from the jar and cleaning them separately.
Another object of invention is to reduce the power required to grind the ingredients as multi layers blades will cut the ingredients to finer pieces as it moves down and will require less power subsequently during the operation.
DETAILED DESCRIPTION
According to the invention, there is provided an arrangement on to the blade assembly wherein a series of cutting blades are interlockably screwed one over the other to form an assembly of multi layer blades, as an add on blades.
In accordance to the present invention, there is provided a double or multi layer of blades combination, preferably to maximum three sets; each blade set preferably has two cutting arms, and the shaft of the blade set having own thread locking arrangement at bottom with internal threading and top provided with external threading, so as to screwably lock one over the other and to the hub of the jar, the topmost blade set with a plastic head; and all these three blades are locked at 120 Degree apart for 3 layer blade combinations or 180 degree apart for 2 layer blade combination.
In accordance to the present invention, there is provided sufficient difference in height between each blade set to facilitate the free movement of ingredients; the diameter of the blade at the lower most position is the minimum followed by middle blade and


third level of blade; to facilitate equal amount of gap to be maintained between the maximum diameter of blade and the jar inner diameter.
In accordance to the present in invention, the direction of the threading of both internal and external threads of each blade set is opposite to the rotation of cutting blade direction.