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:
INSERT RETAINER ASSEMBLY IN THE MOULDING
TOOL ASSEMBLY
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
The present invention generally relates to a moulding tool assembly and particularly to an insert retainer assembly in the moulding tool assembly. The present invention more particularly relates to an insert carrier assembly using a ball plunger.
B) BACKGROUND OF THE INVENTION
Molding is the process of manufacturing by shaping pliable raw
material or plastic using a rigid frame or model called a mold. The plastic raw material is heated until it melts and then forced under pressure with the help of moulding machines into a mould where it solidifies. The mould is then opened and the product is ejected out. The plastic molds may be any one of the following types such as compression moulds, injection moulds and transfer moulds.
Any of these moulding processes are selected based on the type of material to be molded. A typical mold consists of a fixed half and a moving half. They arc either mounted horizontally or vertically on the moulding machines based on the machine construction. The components after moulding are ejected by means of ejector pins that are provided on the half where the component adheres after solidification.
A compression mould is used to process the thermoset plastic to
produce intricate and accurate parts at relatively low cost. This is one of the oldest methods of mass production of components made of thermoset plastics. The process consists of placing a suitable amount of moulding material in powder or tablet form into a heated steel mould and applying pressure. The resin in the thermoset plastic material fluxes with the heat and

the whole mass is pressed into the shape of the mould. Further the polymerization process proceeds and after a suitable interval, the mould is opened and the moulding is removed in hot, set and infusible conditions in the cured stage. These moulds are normally vertical mounted and ejector pins are provided on both the fixed half and the moving half.
Injection moulding is one of the most popular processing
techniques for converting thermoplastic and thermoset materials into different shapes. In this process, the plastic raw material is heated until it melts and then forced under pressure with the help of injection moulding machines into a cold mould where it cools and solidifies. The mould is then opened and the product is ejected out by means of ejector pins provided on the moving half of the mould.
A transfer mould is used to process thermoset plastics to produce components which have a geometry leading to the use of delicate parts in moulds like pins, inserts, side cores to form undercuts in components. The mould acts like a receiver for the entry of heated, plasticized material, which Hows in and fills the cavity without a direct pressure being applied to the delicate parts. The procedure is known as transfer moulding as it involves the flow or movement of material from the heated pot or container, through an orifice or feed channel in the die into the cavity between the heated plates (mould). The process consists of placing a suitable amount of moulding material in powder or tablet form into the transfer chamber in the heated mould. The mould is immediately closed and pressure is applied to it by means of transfer piston. The resin in the thermoset plastic material fluxes with the heat and the whole mass is pressed into the mould to take the shape of the mould cavity. Further the polymerization process is proceeded and after a suitable interval the mould is opened and the moulding is removed in hot, set and infusible conditions, i.e.

in the cured stage. These moulds are normally vertical mounted and ejector pins are provided on both the fix half and the moving half.
There are many plastic components which require metallic
inserts to be molded with the component during molding. Inserts are typically metallic parts made from hexagonal bar to prevent rotational movement and may be grooved in one or more places of the plastic mould to prevent axial movement. These inserts are used in all kinds of plastic components where the threaded screws are commonly used for fixing other components to molding with nut. Molding inserts lead to increase in cycle time of the mould during production.
The current methods being used for molding inserts have certain inherent difficulties. Conventionally, the inserts need to be molded on the top half of the mold in areas which is difficult to access by the operator of the molding machine. This causes inconvenience to the operator thereby increasing the time to produce a component and hence increasing the part cost. Manufacturing three different inserts and maintaining concentricity of insert with respect to ejector pin on assembly is tedious. Moreover the spring holding the insert carrier in place malfunctions frequently.
Hence there exists a need to provide a retainer assembly to hold
the inserts on the molds in inaccessible areas during a moulding process.
There also exists a need to provide a retainer assembly which is compact and
makes the loading of the insert easier and cost-effective.
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

The primary object of the present invention is to provide a
system and method for holding the inserts to be molded in an ejector pin or part forming insert.
Another object of the present invention is to provide a system
and method where loading and unloading of inserts is simple and easy.
Yet another object of the present invention is to provide a system and method where the insert is held directly in the punch or part forming the insert without requiring the ejection of the inserts from the top of the moulding tool assembly.
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
The various embodiments of the present invention provide an
insert retainer assembly in a moulding tool assembly. The assembly comprises an ejector pin placed vertically on the moulding tool assembly, an insert carrier adapted to fit in the ejector pin and a spring loaded ball plunger press fitted inside the insert carrier. The insert carrier is adapted to hold an insert to be molded using the spring loaded ball plunger which is press fitted inside the insert carrier.
According to an embodiment of the present invention, the
ejector pin includes at least one groove adapted to receive a ball of the spring loaded ball plunger, at least one groove as a guiding hole for the insert

carrier, at least one groove as a clear hole adapted to accommodate the insert carrier and at least one groove as a passage for venting of air.
According to an embodiment of the present invention the
weight of the insert carrier along with the insert to be molded is less than the force with which the ball plunger is ejected from the groove in the ejector pin. Here the frictional force to hold the insert in a molded component is greater than the force required to eject the ball plunger from the groove in the ejector pin.
These and other aspects of the embodiments of the present
invention will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments of the present invention without departing from the spirit thereof, and the embodiments herein include ail such modifications.
E) BRIEF DESCRIPTION OF THE DRAWINGS
The other objects, features and advantages will occur to {hose
skilled in the art from the following description of the preferred embodiment and the accompanying drawings in which:
FIG.l illustrates a front perspective view of the insert retainer
assembly, according to one embodiment of the present invention.

FIG.2 illustrates a cross-sectional view of the ejector pin. according to one embodiment of the present invention.
[0022] FIG.3 illustrates a cross-sectional view of the insert retainer
assembly, according to one embodiment of the present invention.
FIG.4 illustrates a side perspective view of a spring loaded ball
plunger in the insert retainer assembly, according to one embodiment of the present invention.
FIG.5 illustrates a side perspective view of the mould assembly in which the ejector plate is lowered to facilitate insert loading during a molding process, according to one embodiment of the present invention.
FIG.6 illustrates a side perspective view of the mould assembly in which the ejector plate is moved towards the upper direction after loading the insert during a molding process, according to one embodiment of the present invention.
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.
E) DETAILED DESCRIPTION OF THE INVENTION
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.
The various embodiments of the present invention provide an
insert retainer assembly design to hold the inserts on the molds in inaccessible areas during production. An insert carrier is directly held in an ejector pin by means of a spring loaded ball plunger. According to an embodiment, an insert carrier is designed to directly fit in an ejector pin while also holding the insert to be molded. The insert carrier can also be held directly in the part forming an insert. The spring loaded ball plunger is press fit in the insert carrier which is held in the ejector pin. The spring loaded ball of the ball plunger fits into the groove made into the ejector pin.
The total weight of the insert carrier along with the insert to be
molded is less than the force with which the ball plunger gets ejected from the groove in the ejector pin. Hence the assembly does not fall down when held vertically. This satisfies the first requirement that the insert carrier assembly does not fall when held vertically. The frictionai force which holds the insert in the molded component is greater than the force required to eject the ball plunger from the groove. Thus when the component is ejected the insert carrier assembly is ejected along with the component. This satisfies the second requirement that insert carrier assembly gets ejected along with the component.
FIG.l illustrates a front perspective view of the insert retainer
assembly, according to one embodiment of the present invention. The assembly comprises of an insert 104. insert carrier 102. spring loaded ball plunger 103 and ejector pin 101. The insert carrier 102 holds the insert 104 to be molded and is designed to directly fit in the ejector pin 101. The insert

carrier 102 can also be held directly in the part forming insert. The spring loaded ball plunger 103 is press fit in the insert carrier 102 which is held in the ejector pin 101. The spring loaded ball of the ball plunger 103 fits into the groove made into the ejector pin 101. The total weight of the insert carrier 102 along with the insert 104 to be molded is less than the force with which the ball plunger 103 is ejected from the groove in the ejector pin 101. This provides stability for the insert retainer assembly when held vertical.
The factional force which holds the insert 104 in the molded
component is greater than the force required to eject the bail plunger 103 from the groove. Thus when the molded component is ejected, the insert carrier 102 assembly is also ejected along with the molded component.
The concentricity of the insert retainer assembly is achieved by
machining the ejector pin 101 with the reference of the outer diameter in one setting. This provides for concentricity of the inner diameter with respect to the outer diameter. The guiding diameter and threading of the insert carrier 102 is maintained on the lathe in one setting itself. Thus the concentricity of the two diameters is achieved. As the guiding diameters of the ejector pin
101 and insert carrier 102 are concentric to their respective features
concentricity of the assembly is achieved. Besides, as concentricity of each
part is independent of its mating part, interchangeability of insert carriers
102 is achieved without any additional effort.
FIG.2 illustrates a front cross-sectional view of the ejector pin
101. according to one embodiment of the present invention. The ejector pin includes at least 3 holes are machined on it. The first hole is a guiding hole 202 for the insert carrier 102. the second is a clear hole 201 to accommodate the insert carrier 102 and the third hole is the air venting hole 203. The groove is made in the clear diameter section. The groove is made in such a way as to accommodate the spring loaded ball of the ball plunger 103.

FIG.3 illustrates a side perspective view of the insert retainer
assembly, according to one embodiment of the present invention. The ejector pin 101 comprises of three diameters, the first diameter is the mating diameter 303 with the ejector pin 101, the ejector pin 101 moves freely in the second diameter further a flat hole is milled on the diameter of the cross hole 302 is to accommodate the ball plunger 103.
FIG.4 illustrates a side perspective view of the spring loaded
ball plunger, according to one embodiment of the present invention. The ball plunger 103 is a standard component available with molding accessory suppliers. The spring loaded ball plunger is adapted to hold the insert carrier 103 directly in the ejector pin 101.
FJG.5 illustrates a side perspective view of the mould assembly
during the mold condition wherein the ejector plate 501 is lowered to facilitate insert 104 loading, according to one embodiment of the present invention. The insert 104 is screwed on to the insert carrier 102 and the insert carrier 102 is then inserted in the ejector pin 101 till the spring loaded ball plunger 103 engages in the groove made in the ejector pin 101.
FIG.6 illustrates a side perspective view of the mould assembly
during mold condition wherein the ejector plate 501 is moved towards the upper direction after loading the insert carrier 102, according to one embodiment of the present invention.
G) ADVANTAGES OF THE INVENTION
The various embodiments of the present invention provide an
insert retainer assembly to hold the inserts on molds in inaccessible areas

during production wherein an insert carrier is directly held in an ejector pin by means of a spring loaded ball plunger.
The present invention provides concentricity in the design and the manufacturing processes. The compact design of the insert retainer assembly makes the loading and unloading of inserts easier thereby reducing the production time and the cost involved. The insert retainer assembly according to the embodiment herein is standardized for different type of inserts. Further it is easily replaceable, and is held directly in the punch or part forming insert without requiring top ejection.
The foregoing description of the specific embodiments will so
fully reveal the general nature of the embodiments herein that others can. by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the appended claims.
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.

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. An insert retainer assembly in a moulding tool assembly, the mechanism
comprising:
an ejector pin ;
an insert carrier adapted to fit in the ejector pin; and
a spring loaded ball plunger press fitted inside the insert carrier;
Wherein the insert carrier is adapted to hold an insert to be molded using
the spring loaded ball plunger which is press fitted inside the insert
carrier.
2. The assembly according to claim 1, wherein the ejector pin includes at least one groove adapted to receive a ball of the spring loaded ball plunger.
3. The assembly according to claim 1, wherein the at least one groove is a guiding hole for the insert carrier.
4. The assembly according to claim 1, wherein the at least one groove is adapted to accommodate the insert carrier.
5. The assembly according to claim 1, wherein the at least one groove is a passage for venting of air.
6. The assembly according to claim 1, wherein weight of the insert carrier along with the insert to be molded is less than the force with which the ball plunger is ejected from the groove in the ejector pin.
7. The assembly according to claim 1. wherein frictional force to hold the insert in a molded component is greater than the force required to eject the ball plunger from the groove in the ejector pin.

8. The assembly according to claim 1, wherein the first diameter of the insert carrier is a mating diameter with the ejector pin.
9. The assembly according to claim 1. wherein the insert is screwed on to the insert carrier and the insert carrier is then inserted in the ejector pin until the spring load engages with the at least one groove in the ejector pin.