FORM2
THE PATENTS ACT, 1970
(39 of 1970)
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See section 10; rule 13)

1. Title of the invention. -

AN IMPROVED ARRANGEMENT FOR PROVIDING DAMAGE FREE MATTE FINISH COMPONENTS FROM INJECTION MOLD

2. Applicant(s)
(a) NAME :
(b) NATIONALITY:
(c) ADDRESS :

LARSEN & TOUBRO LIMITED
An Indian Company.
L & T House, Ballard Estate, Mumbai 400 001, State of Maharashtra, India

3. PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be performed:


TECHNICAL FIELD OF INVENTION
The present invention relates to an improved arrangement for providing damage free matte finish components in injection mold. More particularly, the invention relates to an arrangement comprising unique construction and mechanism so as to avoid rubbing and therefore, ameliorating damaging of matte finish components in an injection-mold. In this way it is possible to release the under cut in the component without damaging the matte finish.
BACKGROUND OF THE INVENTION
Injection molding is generally used to produce plastic moulds in the industries. Injection mould is a tool to produce plastic molded component in large quantities on injection molding machines, available in different tonnage and sizes to make variety of components. Mould design is made to suit the molding machines and plastic material processing condition. Generally mould construction includes two halves - Fix Half (cavity side) and moving half {core side) . Fix half is clamp on the stationary platen of the machine or in other words on the injection unit side of the machine. Moving half is clamped on the moving half of the machine or ejection side of the side. It also includes an ejection assembly to eject the component after molding and cooling line to set the material in core and cavity.


In general practice to make different features of the product design different mechanism in mould design is used and it has been noticed that in some product design component feature is designed in such a manner that it is not in the direction of the mould opening called as under cuts. In most cases different mechanisms are used to remove the under cuts normal to the mould opening direction. Few mechanisms which are known are :
1} Dog leg cam mechanism
2} Hydraulic cylinder
3) Sprung Core
4) Angular Core
It has been found that in the above mechanisms some portion of the side core which is of steel during molding operation rubs against the component which leaves some rubbing mark on the component. This causes damage to the exterior portions of the moulds and affects the aesthetics of the mould.
In standard practice to release the under cut side cores move perpendicular to the under cut and therefore causes damage to the component and its matte finish.
Thus there is a need to provide for an improved mechanism which would enable to release the under cut in such a way that no damage would be caused to the components and therefore the appropriate shape, dimension, technicalities and aesthetic look of the component can be maintained.


The present inventors have found that by incorporating a uniquely designed element and interengaging it with the other components in an injection mold one could achieve component without damaged matte finish. The element further adds to a simplicity in the construction and function of the mold. Further the inventors have found that desired movement of side core and appropriate releasing of the under cut can be achieved by required length of the element thus, protecting the component from any damage.
OBJECTS OF THE INVENTION
Accordingly one object of the present invention is to overcome the drawbacks / disadvantages of the prior art.
Another object of the present invention is to provide an arrangement for protecting component from damage in injection molding.
SUMMARY OF THE INVENTION
According to one aspect of the present invention there is provided an improved arrangement for producing damage free matte finish component in injection molding, said arrangement comprising :
plurality of halves which include a fixed half and movable halve, said fixed half acting as a base to support component which is to be molded;

said movable half comprising guiding means which accept plurality of holder means and plurality of side core, both holder means and side core being movably located on said guiding means;
wherein said fixed half comprises plural pin elements being located in substantial vertical plane and being angular to the vertical axis of said fixed half in a manner that movement of the said movable half will produce an angular movement of said side cores in forward and backward directions such that in the backward direction angular movement of said side cores provides release of under cuts in the manner that the components have damage free matte finish.
The other objects and advantages of the present invention will be apparent from the description provided hereinbelow with reference to the accompanying figures and detailed description provided herein below.
BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS
Figure 1 illustrates the partial assembly of the mould fixed half and moving half of the arrangement of the present invention in close condition.
Figure 2 illustrates the mould assembly in open condition and also side core moved back at an angle.


Figure 3 illustrates the open mould condition with ejector assembly moving forward ejecting the component.
DETAILED DESCRIPTION OF THE INVENTION
Accordingly, the present invention relates to an arrangement for providing damage free matte finish components in injection mold. Further, the invention relates to an arrangement comprising unique construction and mechanism so as to avoid rubbing and therefore, ameliorating damaging of matte finish components in an injection-mold.
Moreover, by incorporation of a uniquely designed element and inter-engaging it with the other components in an injection molding machine, component without damaged matte finish is achieved. The element further adds to simplicity in the construction and function of the machine. Further the desired movement of side core and appropriate releasing of the under cut is achieved by required length of the element thus, protecting the component from any damage.
The present invention relates to an arrangement (as shown in Figure 1) comprises plurality of halves which include a fixed half (14) and movable halve (15). The fixed half (14) acts as a base to support component which is to be molded and movable half (15) comprises guiding means such as guide plates (11, 12) which accept plurality of side core holder (5, 6) and plurality of side core (3, 4).
3 1 MAR 2009

Both the side core holders (5, 6) and side core (3, 4) are movably located on the guide plates (11, 12) . The fixed half (14) comprises plural pin elements(1, 2) located in substantial vertical plane and are angular to the vertical axis of said fixed half (14) in a manner such that movement of the movable half (15) will produce an angular movement of the side cores (3, 4) in forward and backward directions such that in the backward direction angular movement of the side cores (3, 4) provides release of under cuts in the manner that the components have damage free matte finish.
According to the present invention the angular pin elements (1, 2) are such that during closing of the mould, the pin element (1, 2) engages with the side core (3, 4) moving it in a pre-determined forward position.
Further, the arrangement of the present invention
comprises stopper means (9, 10) adapted to stop .the side
core in a fixed position and further ensures re-entry of
angle pin (1, 2) during mould closing.
3 1 MAR 2009

WE CLAIM
1. An improved arrangement for producing damage free matte finish component in injection molding, said arrangement comprising :
plurality of halves which include a fixed half and movable halve, said fixed half acting as a base to support component which is to be molded;
said movable half comprising guiding means which accept plurality of holder means and plurality of side core, both holder means and side core being movably located on said guiding means;
wherein said fixed half comprises plural pin elements being located in substantial vertical plane and being angular to the vertical axis of said fixed half in a manner that movement of the said movable half will produce an angular movement of said side cores in forward and backward directions such that in the backward direction angular movement of said side cores provides release of under cuts in the manner that the components have damage free matte finish.
2. An arrangement as claimed in claim 1, wherein pin elements are angle pins.
3 1 MAR 2009

3. An arrangement as claimed in claims 1 and 2, wherein said pin elements are such that during closing of the mould said pin element engages with said side core moving it in a pre-determined forward position.
4. An arrangement as claimed in claim 1, wherein said guiding means comprises guide plates.
5. An arrangement as claimed in claim 1, wherein said holder means is side core holder.
6. An arrangement as claimed in any of the preceding claims further comprises stopper means adapted to stop said side core in a fixed position.
7. An arrangement as claimed in claim 6, wherein said stopper means further ensures re-entry of angle pin during mould closing.
8. An improved arrangement for producing damage free matte finish component in injection molding substantially as herein described and illustrated with reference to the accompanying figures.
Dated this 31st day of March 2009

Saloni Rastogi Of S. Majumdar & Co. Applicant's Agent
3 1 MAR 2009