Title of Invention

METHOD FOR FABRICATION OF DIES PREFERABLY LESS THAN ONE CUBIC FEET VOLUMETRIC IN DIMENSION WITH SAND CASTING

Abstract The present invention relates to development of a method for manufacturing of small sized preferably less than one cubic feet volumetric in dimension cast iron dies like, cast iron, mild steel or equivalent metal alloys, wherein the cast iron dies which could be used for producing the parts from materials such as wax, plastic or low melting point alloys, like aluminium, brass or copper. The method comprises : creation of three dimensional drawing of a part with it's digital description using CAD (computer aided design) and it's layered description in stl file in digital form, fabrication of plastic patterns using stl file with fused deposition modeling rapid prototyping process, preparation of sand molds using plastic patterns using sand molding process, pouring of molten metal in sand molds and forming rough parts after solidification of molten metal, and finishing the rough surfaces of parts with machining processes like turning, milling, grinding followed by surface treatments required for metal coating of the surfaces of finished part finally outcome as the cast iron dies. Following invention is described in the detail with the help of the block diagram showing various stages in the manufacturing of small dies with sand casting process is shown in Figure 1.
Full Text FORM 2
THE PATENT ACT 1970
(39 of 1970)
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(see section 10 and rule 13)
1. Title of the invention
"Method for fabrication of dies preferably less than one cubic feet volumetric in dimension with sand casting"
2. Applicant(s)
1. Dilip Sahebrao Ingole
57, Rathi Nagar, Amravati - 444 603 (M.S.), India -Indian National
2. Abhaykumar Madhusudan Kuthe
Trimurti Nagar, Nagpur (M.S.), India
- Indian National
3. PREAMBLE TO THE DESCRIPTION
COMPLETE
The following complete specification particularly describes the invention and the manner in which it is to be performed

FIELD OF INVENTION
This invention relates to a method for rapid manufacturing of small sized dies suitable for producing wax, plastic or low melting point alloy components.
BACKGROUND OF THE INVENTION
Casting is the process of producing parts by pouring molten metal in to a cavity called a mold, which is the negative of the object. It is the cheapest and most suitable method for producing large metal parts, typically iron, but also bronze, brass and aluminum. These metal parts sometimes can further be used as permanent molds or dies. The sand casting practices are not suitable for manufacturing of small and intricate components due to many reasons and it's following major disadvantages :
1) Preparation of small sized sand molds is difficult with conventional patterns
2) Perfection in producing contoured patterns is always the problem
3) Conventionally, process uses wooden or metal patterns to prepare sand moulds. The wooden patterns are dimensionally unstable and metal patterns incur more finishing time and cost
4) Accuracy is the major problem for parts produced with sand casting
5) The parts produced with conventional patterns require further finishing
6) The cores and core prints are required to be separately prepared and assembled, in existing practices
7) The lead time of producing conventional patterns is considerably large
8) The conventional patterns are difficult for handling. The metal patterns are heavy and require to be handled carefully and wooden patterns are delicate
9) The conventional patterns cannot be reused once distorted
10) The conventional dies in the industry tend to be expensive as they are made from hardened steel. Also the cycle time for building these dies tend to be long.

Because the established tooling technologies require a great deal of time and expense, a series of Rapid prototyping (RP) technologies have been emerged for quickly creating three dimensional (3D) products directly from Computer Aided Design (CAD) models. RP techniques involve no tooling or fixtures, resulting in simpler set-up, lower overhead cost and shorter production lead times compared to other fabrication methods. The parts those were previously impossible or extremely costly and time consuming to fabricate can be built with an ease with RP. RP techniques are limited neither by the geometry nor by complexity of the parts to be fabricated. To substantially shorten the time for developing patterns, moulds, and prototypes, RP is an ideal method for complex pattern making and component prototyping. RP processes can be used for directly producing the casting patterns, referred to as direct Rapid Tooling (RT). The bottlenecking in pattern development by conventional methods can be overcome by using RP technology. To stay ahead in competition, the updated technology demands development of fast and accurate castings of high standards from foundries. The sand cast components manufactured using RP patterns shown better results for dimensions and surface finish as compared to the conventional method. These facts highlight the importance of developing a method for the rapid manufacturing of intricate dies. The present invention intends to substantially shallow the lead time and cost in manufacturing of the small sized dies. The suggested method ensures application of sand casting for manufacture of small and intricate dies in record time and with lower costs.
The present invention provides improved method for manufacturing of small and intricate dies with conventional sand casting method. Following are the major advantages of invented method :
1) The suggested method is faster, since the time of producing patterns is drastically reduced
2) The suggested method produces accurate cast iron dies, since it uses accurately produced plastic patterns
3) The suggested method is economical, since the patterns are directly fabricated from CAD model. The manufacturing of patterns do not require special tooling or process planning

4) Intricate cast iron dies can be easily produced, since there is no limitation for shape of the required pattern
5) The dies produced with suggested method are suitable for investment casting, injection molding and blow molding
6) The dies manufactured with invented method are suitable for materials like wax, plastics and low melting point alloy parts.
The present invention suggests the method for rapid fabrication of cast iron dies of small sizes, preferably less than one cubic feet volumetric in dimension, in considerably less time compared to the conventional die manufacturing techniques. The invented method involves both modern and conventional technologies. The blending of two technologies result in time and cost effective output. The patents registered earlier in this field relates with either improvement in dies and molds manufacturing processes or rapid prototyping processes. This is the first attempt in its kind where patterns manufactured with rapid prototyping process are utilized in sand casting process to produce cast iron dies.
For example, U.S. Pat. No. WO0023217 describes a method for rapidly manufacturing metal tooling utilizing injection molding techniques. The method includes the steps of providing a mold of a desired shape tool and the design of fixture for injection molding machine. This invention further contemplates the manufacture of finished parts in an injection molding machine using a tool insert made by the rapid manufacturing process according to the present invention.
Pat. No. WO0196049 relates to a method for the production of dies and molds and more particularly to a spray forming process for the deposition and rapid solidification of atomized molten droplets onto a pattern for manufacturing dies, molds and related tooling.
Pat. No. EP0764487 relates to methods of free form fabrication and, in particular, to a method of free form fabrication of metallic components using selective laser binding and transient liquid sintering of blended powders.

U.S. Pat. No. 5189781 is related to rapid tool manufacturing. More specifically, the present invention is related to rapid tool manufacturing using solid freeform fabrication, such as stereolithography, and thermal spray deposition.
THE OBJECTS OF THE INVENTION
The objects of the present invention are :
1) To develop a faster and cheaper method of die making
2) To transfer the technology from conventional to modern, so as to take time and cost effective advantages from their blend
3) To provide a method for development of rapid tooling for investment casting, injection molding and blow molding processes
4) To produce metal dies from materials such as cast iron or mild steel for producing wax, plastic or low melting point material parts
SUMMARY OF THE INVENTION
The present invention relates to development of a method for manufacturing of small sized preferably less than one cubic feet volumetric in dimension cast iron dies like, cast iron, mild steel or equivalent metal alloys, wherein the cast iron die which could be used for producing the parts from materials such as wax, plastic or low melting point alloys, like aluminium, brass or copper comprising mainly the stages of: creation of three dimensional drawing of a part with it's digital description using CAD (computer aided design) and it's layered description in stl file in digital form, fabrication of plastic patterns using stl digital file with fused deposition modeling rapid prototyping process, preparation of sand molds using plastic patterns by sand molding process, pouring of molten metal in sand molds and forming rough parts after solidification of molten metal, finishing the rough surfaces of parts with machining processes like turning, milling, grinding followed by surface treatments required for metal coating like electroplating of the surfaces of finished part finally outcome as the cast iron dies.

BRIEF DESCRIPTION OF THE DRAWING
The invention is described further with reference to the accompanying drawing. Figure 1 illustrates a block diagram of a method, comprising various steps, involved in the manufacturing of small dies. For the purpose of illustrating invention, the drawing shows an embodiment that is presently preferred. The invention is, however, not limited to the steps disclosed in the drawing. The entire process comprises, CAD unit for obtaining 3D model of part and it's layered description in digital form, fabrication of pattern on RP machine with fused deposition modeling rapid prototyping process, sand mold preparation from plastic pattern, pouring of molten metal in sand mold to obtain rough casting of die, finishing of die, like machining, grinding and surface treatment and metal coating of the die.
DETAILED DESCRIPTION OF THE INVENTION
The existing sand casting practice discourage the production of small intricate parts due to it's limitations. Conventional casting process uses wooden or metal patterns to prepare sand molds. Pattern development is the main bottleneck in terms of time and cost for manufacturing intricate castings in foundries. Pattern making is the very tedious job especially when parts are complex. This incurs long time thereby increasing the lead time.
The present invention uses RP process for manufacturing patterns directly from CAD data in order to shorten product design and development time. RP involve no tooling or fixtures, resulting in simpler set-up, lower overhead cost and shorter production lead times compare to other fabrication methods. The RP techniques are neither limited by geometry nor by complexity of the parts. The basic invention uses both the conventional and recent technologies. The blending of two technologies produce synergistic effect and evolved rapid tooling application for investment casting and plastic industries. This is the pioneer attempt toward technology transfer. The invented method ensures application of sand casting for manufacture of small intricate dies in faster, accurate and economic way.

The invented method for manufacturing casting dies is described in Figure 1, which identifies steps for the rapid fabrication of cast iron dies. The invention begins with development of digital CAD database of component drawings. The component geometry description is produced in digital form by using solid modeling software. The stage 1 also forms electronic database file of the part geometry, called stl file that embodies digital information of planer coordinates. Stage 2 represents the fabrication of part using rapid prototyping process. The parts produced by RP which are used as patterns in sand casting have many advantages over the conventional. The sand mold/cavity is prepared by using these patterns as represented in Stage 3. All of the established conventional methods start from this same point. The stage 4 represents pouring of molten metal in sand mold at the specified temperature, which produces cast product after cooling. At stage 5, the finishing operations like, turning, milling, grinding are performed as per the requirement. Stage 6 represents the surface treatment process comprising finishing for irregularities in cast part and surface coating like electroplating of the finished surfaces.

CLAIMS:
We claim :
1. A method for manufacturing of small sized preferably less than one cubic feet volumetric in dimension cast iron dies like, cast iron mild steel or equivalent metal alloys, wherein the cast iron die Which could be specifically used for producing the small sized, parts from materials such as wax, plastic or low melting point alloys, like aluminium, brass or copper comprising the steps of:
(0 cheating three dimensional part with it's digital description
using CAD (computer aided design) and it's layered
description in stl digital form; (ii) fabrication of plastic patterns using stl file with fused
deposition modeling rapid prototyping process; (iv) Preparation of sand molds using plastic patterns by sand
molding process; (iv) thereafter, pouring molten metal in sand molds and forming
rough parts after solidification of molten metal; (v) thereafter, finishing the rough surfaces of parts with
machining processes like turning, milling, grinding (vi) followed by surface treatments required for metal coating
like electroplating of the surfaces of finished part finally
outcome as the cast iron dies.

Documents:

1127-MUM-2007-ABSTRACT(10-7-2012).pdf

1127-mum-2007-abstract(15-6-2007).pdf

1127-MUM-2007-ABSTRACT(27-11-2009).pdf

1127-mum-2007-abstract.doc

1127-mum-2007-abstract.pdf

1127-MUM-2007-CANCELLED PAGE(27-11-2009).pdf

1127-mum-2007-cancelled pages(20-7-2009).pdf

1127-mum-2007-claims(15-6-2007).pdf

1127-MUM-2007-CLAIMS(AMENDED)-(10-7-2012).pdf

1127-MUM-2007-CLAIMS(AMENDED)-(27-11-2009).pdf

1127-mum-2007-claims.doc

1127-mum-2007-claims.pdf

1127-MUM-2007-CORRESPONDENCE(10-7-2012).pdf

1127-MUM-2007-CORRESPONDENCE(16-3-2012).pdf

1127-mum-2007-correspondence(27-11-2009).pdf

1127-mum-2007-correspondence(ipo)-(15-1-2009).pdf

1127-mum-2007-correspondence-received.pdf

1127-mum-2007-descripiton (complete).pdf

1127-mum-2007-description(complete)-(15-6-2007).pdf

1127-MUM-2007-DRAWING(10-7-2012).pdf

1127-mum-2007-drawing(15-6-2007).pdf

1127-MUM-2007-DRAWING(27-11-2009).pdf

1127-mum-2007-drawings.pdf

1127-MUM-2007-FORM 1(27-11-2009).pdf

1127-MUM-2007-FORM 13(10-7-2012).pdf

1127-mum-2007-form 18(15-6-2007).pdf

1127-mum-2007-form 2(15-6-2007).pdf

1127-MUM-2007-FORM 2(TITLE PAGE)-(10-7-2012).pdf

1127-mum-2007-form 2(title page)-(15-6-2007).pdf

1127-MUM-2007-FORM 3(27-11-2009).pdf

1127-mum-2007-form 9(15-6-2007).pdf

1127-mum-2007-form 9(4-2-2008).pdf

1127-mum-2007-form-1.pdf

1127-mum-2007-form-2.doc

1127-mum-2007-form-2.pdf

1127-mum-2007-form-3.pdf

1127-mum-2007-form-9.pdf

1127-MUM-2007-REPLY TO EXAMINATION REPORT(27-11-2009).pdf

1127-MUM-2007-SPECIFICATION(AMENDED)-(10-7-2012).pdf

1127-MUM-2007-SPECIFICATION(AMENDED)-(27-11-2009).pdf

abstract1.jpg


Patent Number 253363
Indian Patent Application Number 1127/MUM/2007
PG Journal Number 29/2012
Publication Date 20-Jul-2012
Grant Date 16-Jul-2012
Date of Filing 15-Jun-2007
Name of Patentee DILIP SAHEBRAO INGOLE
Applicant Address 57 RATHI NAGAR, AMRAVATI-444603,
Inventors:
# Inventor's Name Inventor's Address
1 DILIP SAHEBRAO INGOLE 57 RATHI NAGAR, AMRAVATI-444603.
2 ABHAYKUMAR MADHUSUDAN KUTHE TRIMURTI NAGAR, NAGPUR
PCT International Classification Number B22C9/28
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA