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: LEAK PREVENTION ARRANGEMENT FOR INJECTION
MOULDING MACHINES
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 injection moulding process which is used for converting plastic materials into different shapes. The present invention more particularly relates to an arrangement in the injection molding machine which avoids material leakage from the mould during injection moulding.
B) BACKGROUND OF THE INVENTION
[0002] Injection moulding is a manufacturing process for producing parts from both thermoplastic and thermosetting plastic materials. The plastic material is fed into a heated barrel, mixed, and forced into a mould cavity where it cools and hardens to the configuration of the mould cavity. After a product is designed, the moulds are made by a mould maker from a metal and precision-machined to form the features of the desired part. Injection moulding is widely used for manufacturing a variety of parts, from the smallest component to entire body panels of cars.
[0003] Mould or die are the common terms used to describe the tooling used to produce plastic parts in moulding. Conventionally two separate plates of manifolds are directly clamped with Allen bolts and the material in liquid form is forced into cold manifolds to form a shape. After few shots due to presence of glass percentage it starts wearing threads of Allen bolts and makes path to move out from manifolds. Also, the material becomes hard and closes path of further injected material, thus forcing the material to rush out from Allen blots, cooling nipples and plates.
[0004] The thermoset material is very fluid in hot condition. The hot fluid material leaks through the clearance space between the screw mating threads as

well as clear holes of clamping screws under injection pressure. The leaked material would in turn exert pressure on the interface of two manifolds and deflect them to cause a gap between the two plates. Once a gap is produced between the two manifold plates, the material spreads all over the manifold plates, gets cured and blocks further passage of material. This would require unloading the mould, allowing it to cool, dismantle and clean the blocked material. The entire process is time consuming and affects productivity.
[0005] Thus there exists a need to provide an arrangement to avoid liquid material leakage from mould with cold manifold of dough moulding compound injection or thermoset injection molding.
[0006] The abovementioned shortcomings, disadvantages and problems are addressed herein and which will be understood by reading and studying the following specification.
C) OBJECTS OF THE INVENTION
[0007] The primary object of the present invention is to develop an arrangement in an injection moulding machine which avoids liquid fluid material leakage from the mould with cold manifold of thermoset injection moulding.
[0008] Another object of the present invention is to develop an arrangement which avoids fluid material leak through the clearance space between the screw mating threads.
[0009] Another object of the present invention is to develop an arrangement which avoids fluid material leak through the holes of clamping screws under injection pressure.

[0010] Yet another object of the present invention is to develop a sleeve arrangement in the injection moulding machine which has close tolerance to restrict leakage of the fluid material.
[0011] 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
[0012] The various embodiments of the present invention provide an arrangement for injection moulding machine where plastic fluid material leakage from the mould in the cold manifold of thermoset injection moulding is avoided. An injection moulding machine assembly comprising two halves of cold manifolds and a sleeve. The sleeves are manufactured with preset tolerance to interlock two halves of manifold. Further the two halves of cold manifold are clamped to each other using Allen bolts. Here the sleeves are manufactured using hardened steel.
E) BRIEF DESCRIPTION OF THE DRAWINGS:
[0013] 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:
[0014] FIG. 1 illustrates a sectional view of the injection moulding machine arrangement with interlocking two halves of manifolds according to one embodiment of the present invention.

[0015] FIG. 2 illustrates an enlarged sectional view of the injection moulding machine showing the sleeve with fitting tolerance according to one embodiment of the present invention.
[0016] 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
[0017] 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 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.
[0018] The various embodiments of the present invention provide an arrangement for injection moulding machine where plastic fluid material leakage from the mould in the cold manifold of thermoset injection moulding is avoided. According to one embodiment of the present invention, the injection moulding machine includes sleeve of through hardened steel manufactured with close tolerance interlocking the two halves of cold manifolds with the sleeves and Allen bolts.

[0019] The sleeves are of through hardened steel or hot work tool steels that are manufactured with close tolerance. The two halves of the cold manifolds are interlocked with each other with the help of the sleeves and clamped by Allen (socket head) bolts. The sleeve has a tight fit with respect to positional matching blind holes in manifold plates. The screw is made to pass through the sleeve. The tight fit between the sleeves and manifold plates acts as a barrier to the material from entering into the thread clearances or the clear hole for clamping bolt.
[0020] FIG. 1 illustrates a sectional view of the injection moulding machine arrangement area with interlocking two halves of manifolds according to one embodiment of the present invention. With respect to FIG. 1, the injection moulding machine constitutes of a two halves of cold manifolds plates 102 interlocked with each other with the help of sleeves 101 and clamped by Allen (socket head) bolts 103. The sleeve 101 has a tight fit with respect to positional matching blind holes in manifold plates. The screw 103 is made to pass through the sleeve 101 and the tight fit between the sleeves 101 and manifold plates 102 acts as a barrier to the material from entering into the thread clearances or the clear hole for clamping bolt.
[0021] FIG. 2 illustrates an enlarged sectional view of the injection moulding machine showing the sleeve 101 with fitting tolerance according to one embodiment of the present invention. With respect to FIG. 2, the assembly consists of manifold plates 102 interlocked each other. The manifolds are interlocked with the help of sleeve 101 and clamped by Allen bolts 103.
G) ADVANTAGES OF THE INVENTION
[0022] The various embodiments of the present invention provide an arrangement for injection moulding machine where plastic fluid material leakage from the mould in the cold manifold of thermoset injection moulding is avoided.

The present invention provides a sleeve which clamps two halves of cold manifolds plates by Allen (socket head) bolts.
[0023] The present invention provides an arrangement where interlocking
two halves of manifold plates is done with sleeves which have close tolerance and manufactured using hot die steel material restrict hot fluid liquid material to ejecting out.
[0024] 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.
[0025] 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.

CLAIMS
What is claimed is:
1. A leak prevention arrangement for injection moulding machines comprising; Two halves of cold manifolds plates; and at least one sleeve; Wherein the sleeves are manufactured with preset tolerance to interlock two halves of manifold plates such that a leakage of a mould material is prevented
2. The arrangement according to claim 1, wherein the two halves of the cold manifold plates are manufactured using Hot Die Steel (HDS).
3. The arrangement according to claim 1, wherein the two halves of cold manifold are clamped to each other using Allen bolts.
4. The arrangement according to claim 1, wherein the sleeves are manufactured using hardened steel.
5. The arrangement according to claim 1, wherein the sleeve provides a tight fit with blind holes in the manifold plates.