Title of Invention	A METHOD OF MANUFACTURE OF ASBESTOS FREE LOW HEAT, LOW WEAR COMPOSITE BRAKE BLOCKS FOR RAILWAY COACHES & LOCOMOTIVES BY HOT COMPRESSION MOULDING PROCESS"
Abstract	The method of manufacture of asbestos free low heat, low wear composite brake blocks for Railway coaches & Locomotives, comprising of, selecting the specific ingredients by weight namely Antimony powder 22.95 %, Fire clay powder 16.86%, Phenol Formaldehyde moulding powder 15.93%, Cashew nut shell liquid 14.05%, Cashew Friction dust 6.74 %, Ferro silicon powder 6.74%, Rubber powder (30 mesh) 5.90%, Plaster of paris (gypsum) 4.68%, Fibre Glass strands 2.52%, Hexamine 1.68%, Linseed oil 0.84%, Carbon Black Powder (Hot Finishing Grade) 0.46%, Phenol Formal dehyde resin liquid 0.14%, Incence powder 0.015% mixing the ingredients in selected proportion, placing the cleaned and adhesive coated back plate assembly in the mould, filling the correct quantity of composite material mixture in the preheated metallic mould, closing the mould hydraulically, soaking the entire mould under the prescribed heat of 120-135 C and suitable pressure of 40 T for a specified time of 50 Minutes , opening the mould hydraulically , removing the set brake block from the mould , dressing the brake block all round and curing under controlled temperature of 120 C in an oven for a specified time of 24 hrs in order to give asbestos free, low heat, low wear and uniform co-efficient of friction while brake application for retarding the motion of the Railway coaches and Locomotives.

Title of Invention

A METHOD OF MANUFACTURE OF ASBESTOS FREE LOW HEAT, LOW WEAR COMPOSITE BRAKE BLOCKS FOR RAILWAY COACHES & LOCOMOTIVES BY HOT COMPRESSION MOULDING PROCESS"

Abstract

The method of manufacture of asbestos free low heat, low wear composite brake blocks for Railway coaches & Locomotives, comprising of, selecting the specific ingredients by weight namely Antimony powder 22.95 %, Fire clay powder 16.86%, Phenol Formaldehyde moulding powder 15.93%, Cashew nut shell liquid 14.05%, Cashew Friction dust 6.74 %, Ferro silicon powder 6.74%, Rubber powder (30 mesh) 5.90%, Plaster of paris (gypsum) 4.68%, Fibre Glass strands 2.52%, Hexamine 1.68%, Linseed oil 0.84%, Carbon Black Powder (Hot Finishing Grade) 0.46%, Phenol Formal dehyde resin liquid 0.14%, Incence powder 0.015% mixing the ingredients in selected proportion, placing the cleaned and adhesive coated back plate assembly in the mould, filling the correct quantity of composite material mixture in the preheated metallic mould, closing the mould hydraulically, soaking the entire mould under the prescribed heat of 120-135 C and suitable pressure of 40 T for a specified time of 50 Minutes , opening the mould hydraulically , removing the set brake block from the mould , dressing the brake block all round and curing under controlled temperature of 120 C in an oven for a specified time of 24 hrs in order to give asbestos free, low heat, low wear and uniform co-efficient of friction while brake application for retarding the motion of the Railway coaches and Locomotives.

Full Text	This invention relates to a method of manufacture of Asbestos free low heat, low wear composite brake blocks for Railway Coaches & Locomotives by hot compression moulding process- "Previously, these brake blocks were made of Grey Cast Iron to grade Fg220, having the hardness in the range of 180 to 220 BHN. Since, during brake application, metal to metal contact was in force, the tread of the wheel used to wear more rapidly along with the wear of the cast iron brake blocks. Thus, brake blocks and wheel life was reduced necessitating the frequent renewal of both brake blocks and the wheel in the Railway coaches and Locomotives. The asbestos free low heat low wear composite brake blocks are attached to the brake gear system of coaches & Locomotives for application of braking force to retard/ stop the movement of the rolling stock. There are two types of brake blocks, ( L & K type) which depends upon type of back plate which fits with the brake head for coaching stock , one type each for WDM2 type locos and WDG4,WDP4 type locos This shall have the following main characteristics: 1. The ingredients of the brake block to be environment friendly. 2. Low heat generation while braking. 3. Wear rate should be minimum. 4. It should not damage the wheel tread. 5. Cost effective. 6. Operation & ingredients should be similar to both the type of brake blocks. The ingredients of the composite mixture shall have the following characteristics: 1. User friendly while manufacturing. 2. Should develop wear resistance properties to the brake block. 3. Should impart adequate density to the brake block 4. Possesses the required work hardening properties to the brake block. 5. Possesses heat dissipating properties 6. Should not have adverse effect on the wheels. 7. Adequate control, in fixing the hardness of the brake block, during manufacturing process. 8. Should have the tendency of becoming a solid block of required shape, at a particular temperature & pressure while manufacturing. 9. Environmental friendly and susceptible for re-cycling. The asbestos free low heat, low wear composite brake blocks has a holder ( Clip) attached to the steel plate called back plate which in turn is moulded with the ingredients of asbestos free composite material. This brake block unit is fixed on the brake head through a brake head key and hangs vertically on the wheel thread. Whenever the brake force is applied on the brake head, the brake block unit moves horizontally towards the circumference of the Rail wheel and retards the movement of the rolling vehicle through frictional force. The method herein has the following advantages :- That the various ingredients of the composite brake blocks are so selected that the final product has the capability of withstanding the braking force without disintegrating itself, and dissipating the heat generated during the course of brake application quickly and without adversely affecting the wheel tread. The method herein is also streamlined to render it simple, convenient and feasible for mass production. The final product is also absolutely environmental friendly, as it does not cause any kind of pollution during production, storage or application. The various other feature of this invention will be apparent from the following further description given hereunder in respect thereof The method of manufacture of asbestos free low heat, low wear composite brake blocks for Railway coaches & Locomotives, according to this invention, comprises of mixing the ingredients in selected proportion as in page 6, placing the cleaned and adhesive coated back plate assembly in the mould, filling the correct quantity of composite material mixture in the preheated metallic mould, closing the mould hydraulically, soaking the entire mould under the temperature between 120-135° C and suitable pressure of 40 T for a specified time of 50 Minutes, opening the mould hydraulically , removing the set brake block from the mould , dressing the brake block all round and curing under controlled temperature of 120 C in an oven for a specified time of 24 hrs. This invention will now be described in further detail by referring to the accompanying Figures which illustrate by way of example various views of one of possible embodiments of the asbestos free low heat low wear composite brake block proposed herein and wherein. Figurel Illustrates the back plate and holder assembly in perspective view from the top. Figure2 Figures illustrates the back plate and holder assembly in perspective view from the bottom illustrates the back plate and holder assembly in perspective view from the side. Figure4 illustrates the "K" type brake block for air brake coaches in perspective view from the side. Figures illustrates the "K" type brake block for air brake coaches in perspective view from the top. Figures Figure/ illustrates the "K" type brake block for air brake coaches in perspective view from the bottom illustrates the "L" type brake block for air brake coaches in perspective view from the side. Figure 8 illustrates the" L" type brake block assembly for air brake coaches in perspective view from the top. Figure 9 illustrates the embodiment in its assembled form with brake head in perspective view from the side. Figurel 0 illustrates the embodiment in its assembled form with brake head in perspective view from the top Figure11 Illustrates the basic brake block mould construction for air brake coaches - bottom female and male die in perspective view from the side. Figurel 2 Figurel 3 Illustrates the basic brake block mould construction for air brake coaches - bottom female die in perspective view from the top. Illustrates the basic brake block mould construction for air brake coaches - top die in perspective view from the bottom. Figure14 Figure15 Figure16 Figure17 Figure18 Figure19 Figure20 Illustrates the basic brake block mould in assembled form in hydraulic press. Illustrates the basic brake block mould construction for Locomotives - bottom female and male die in perspective view from the side. Illustrates the basic brake block mould construction for Locomotives - top die in perspective view from the bottom. Illustrates the perspectivetop view of back plate of Diesel Locomotives (WDG4,WDP4) Illustrates the perspective top view of brake block of Diesel Locomotives (WDG4 , WDP 4 ) Illustrates the perspective top view of back plate of Diesel Locomotives (WDM2 ) Illustrates the perspective top view of brake block of Diesel Locomotives (WDM2 ) The back plate is designed with stiffeners on either side as shown in fig 2 to give extra strength and to eliminate breakage in service. The back plate and holder (Clip) are prepared separately and assembled together making it an integral part permanently. This is then grit blasted, cleaned further and adhesive solution is applied over the surfaces 'A" as shown in Figure2. The back plate assembly is air dried and kept ready for moulding. The entire mould is preheated to the required temperature. The mould release solution is applied to the female mould cavity and male mould as shown in Figure 11 to 13. The ready back plate assembly is placed inside the female mould cavity to rest over the bottom male die and properly aligned. The specified quantity of asbestos free composite material mixture is properly filled in the female mould cavity and covered with the male die at the top. The mould is closed hydraulically and the specified pressure is applied through the top die over the entire mould assembly. The heating and pressure application over the mould is continued for a specified time, allowing the complete setting of the composite mixture in the cavity for getting a homogeneous product of brake block unit. The mould is opened hydraulically and the brake block is ejected out and further dressed to remove the burrs. The dressed brake blocks are cured in the hot air oven under controlled temperature for a specified period to acquire the required hardness. The brake blocks with the specified hardness are marked with the wear limit line as shown in Figure9. The mould consists of three parts namely the bottom die, middle female mould cavity and the top male die. The bottom and top male die parts are freely sliding in the female die cavity. The inner surface of the top male die is suitably designed to accommodate the centre line contact with the wheel tread during brake application. The method comprises of selecting the specific ingredients in the following proportions SI no Description % additions 1 ANTIMONY POWDER 22.95 2 FIRE CLAY POWDER 16.86 3 PHENOLE FORMAL DEHYDE MOULDING POWDER 15.93 4 CASHEW NUT SHELL LIQUID 14.05 5 CASHEW FRICTION DUST 6.74 6 FERRO SILICON POWDER 6.74 7 RUBBER POWDER (30 MESH) 5.90 8 PLASTER OF PARIS (GYPSUM) 4.68 9 FIBRE GLASS STRANDS 2.52 10 HEXAMINE 1.68 11 LINSEED OIL 0.84 12 CARBON BLACK POWDER- HOT FINISHING GRADE 0.46 13 GRAPHITE BLACK POWDER 0.46 14 PHENOL FORMAL DEHYDE RESIN LIQUID (for Back plate and clip) 0.14 15 INCENSE POWDER 0.015 We claim 1) A method of manufacture of asbestos free low heat, low wear composite brake blocks for Railway coaches & Locomotives by hot compression moulding process comprising the steps of preparing the back plate assembly, selection of the specific ingredients by weight namely Antimony powder 22.95 %, Fire clay powder 16.86%, Phenol Formaldehyde moulding powder 15.93%, Cashew nut shell liquid 14.05%, Cashew Friction dust 6.74 %, Ferro silicon powder 6.74%, Rubber powder (30 mesh) 5.90%, Plaster of paris (gypsum) 4.68%, Fibre Glass strands 2.52%. Hexamine 1.68%, Linseed oil 0.84%, Carbon Black Powder (Hot Finishing Grade) 0.46%, Phenol Formal dehyde resin liquid 0.14%, Incence powder 0.015% to generate low wear, and uniform co-efficient of friction during service. 2) A method as claimed , in claim 1 wherein the moulds assembly is heated to 120 to 135 degree centigrade and applying a pressure load of 40 tons to compress the ingredients in the mould for a period of 50 minutes to form a composite structure of the asbestos free composite brake block and curing the brake block after removal from the mould assembly for a period of 24 hours at a temperature of 120 degree centigrade, to give characteristics such as low heat generation during application, low rate of wear ie below 0.3 mm per 1000 kms or 5 cubic centimetres per KWH , and uniform co-efficient of friction ie between 0.2 and 0.45 U, 3) A method of manufacture of asbestos free composite brake block for Railway coaches & Locomotives substantially as herein describedwith reference to, and as illustrated by the accompanied Figures.

Full Text

This invention relates to a method of manufacture of Asbestos free low heat, low wear composite brake blocks for Railway Coaches & Locomotives by hot compression moulding process- "Previously, these brake blocks were made of Grey Cast Iron to grade Fg220, having the hardness in the range of 180 to 220 BHN. Since, during brake application, metal to metal contact was in force, the tread of the wheel used to wear more rapidly along with the wear of the cast iron brake blocks. Thus, brake blocks and wheel life was reduced necessitating the frequent renewal of both brake blocks and the wheel in the Railway coaches and Locomotives.
The asbestos free low heat low wear composite brake blocks are attached to the brake gear system of coaches & Locomotives for application of braking force to retard/ stop the movement of the rolling stock. There are two types of brake blocks, ( L & K type) which depends upon type of back plate which fits with the brake head for coaching stock , one type each for WDM2 type locos and WDG4,WDP4 type locos This shall have the following main characteristics:
1. The ingredients of the brake block to be environment friendly.
2. Low heat generation while braking.
3. Wear rate should be minimum.
4. It should not damage the wheel tread.
5. Cost effective.
6. Operation & ingredients should be similar to both the type of brake blocks.
The ingredients of the composite mixture shall have the following characteristics:
1. User friendly while manufacturing.
2. Should develop wear resistance properties to the brake block.
3. Should impart adequate density to the brake block
4. Possesses the required work hardening properties to the brake block.
5. Possesses heat dissipating properties
6. Should not have adverse effect on the wheels.
7. Adequate control, in fixing the hardness of the brake block, during manufacturing process.

8. Should have the tendency of becoming a solid block of required shape, at a particular temperature & pressure while manufacturing.
9. Environmental friendly and susceptible for re-cycling.
The asbestos free low heat, low wear composite brake blocks has a holder ( Clip) attached to the steel plate called back plate which in turn is moulded with the ingredients of asbestos free composite material.
This brake block unit is fixed on the brake head through a brake head key and hangs vertically on the wheel thread. Whenever the brake force is applied on the brake head, the brake block unit moves horizontally towards the circumference of the Rail wheel and retards the movement of the rolling vehicle through frictional force.
The method herein has the following advantages :-
That the various ingredients of the composite brake blocks are so selected that the final product has the capability of withstanding the braking force without disintegrating itself, and dissipating the heat generated during the course of brake application quickly and without adversely affecting the wheel tread. The method herein is also streamlined to render it simple, convenient and feasible for mass production. The final product is also absolutely environmental friendly, as it does not cause any kind of pollution during production, storage or application.
The various other feature of this invention will be apparent from the following further description given hereunder in respect thereof
The method of manufacture of asbestos free low heat, low wear composite brake blocks for Railway coaches & Locomotives, according to this invention, comprises of mixing the ingredients in selected proportion as in page 6, placing the cleaned and adhesive coated back plate assembly in the mould, filling the correct quantity of composite material mixture in the preheated metallic mould, closing the mould hydraulically, soaking the entire mould under the temperature between 120-135° C and suitable pressure of 40 T for a specified time of 50 Minutes, opening the mould hydraulically , removing the set brake block from the mould , dressing the brake block all round and curing under controlled temperature of 120 C in an oven for a specified time of 24 hrs.

This invention will now be described in further detail by referring to the accompanying Figures which illustrate by way of example various views of one of possible embodiments of the asbestos free low heat low wear composite brake block proposed herein and wherein.
Figurel
Illustrates the back plate and holder assembly in perspective view from the top.
Figure2
Figures
illustrates the back plate and holder assembly in perspective view from the bottom
illustrates the back plate and holder assembly in perspective view from the side.
Figure4
illustrates the "K" type brake block for air brake coaches in perspective view from the side.
Figures
illustrates the "K" type brake block for air brake coaches in perspective view from the top.
Figures
Figure/
illustrates the "K" type brake block for air brake coaches in perspective view from the bottom
illustrates the "L" type brake block for air brake coaches in perspective view from the side.
Figure 8
illustrates the" L" type brake block assembly for air brake coaches in perspective view from the top.
Figure 9
illustrates the embodiment in its assembled form with brake head in perspective view from the side.
Figurel 0
illustrates the embodiment in its assembled form with brake head in perspective view from the top
Figure11
Illustrates the basic brake block mould construction for air brake coaches - bottom female and male die in perspective view from the side.
Figurel 2
Figurel 3
Illustrates the basic brake block mould construction for air brake coaches - bottom female die in perspective view from the top. Illustrates the basic brake block mould construction for air brake coaches - top die in perspective view from the bottom.

Figure14
Figure15
Figure16
Figure17
Figure18
Figure19
Figure20

Illustrates the basic brake block mould in assembled form in hydraulic
press.
Illustrates the basic brake block mould construction for Locomotives
- bottom female and male die in perspective view from the side.
Illustrates the basic brake block mould construction for Locomotives
- top die in perspective view from the bottom.
Illustrates the perspectivetop view of back plate of Diesel
Locomotives (WDG4,WDP4)
Illustrates the perspective top view of brake block of Diesel
Locomotives (WDG4 , WDP 4 )
Illustrates the perspective top view of back plate of Diesel
Locomotives (WDM2 )
Illustrates the perspective top view of brake block of Diesel
Locomotives (WDM2 )

The back plate is designed with stiffeners on either side as shown in fig 2 to give extra strength and to eliminate breakage in service.
The back plate and holder (Clip) are prepared separately and assembled together making it an integral part permanently. This is then grit blasted, cleaned further and adhesive solution is applied over the surfaces 'A" as shown in Figure2. The back plate assembly is air dried and kept ready for moulding.
The entire mould is preheated to the required temperature. The mould release solution is applied to the female mould cavity and male mould as shown in Figure 11 to 13.

The ready back plate assembly is placed inside the female mould cavity to rest over the bottom male die and properly aligned. The specified quantity of asbestos free composite material mixture is properly filled in the female mould cavity and covered with the male die at the top. The mould is closed hydraulically and the specified pressure is applied through the top die over the entire mould assembly.
The heating and pressure application over the mould is continued for a specified time, allowing the complete setting of the composite mixture in the cavity for getting a homogeneous product of brake block unit. The mould is opened hydraulically and the brake block is ejected out and further dressed to remove the burrs.
The dressed brake blocks are cured in the hot air oven under controlled temperature for a specified period to acquire the required hardness. The brake blocks with the specified hardness are marked with the wear limit line as shown in Figure9.
The mould consists of three parts namely the bottom die, middle female mould cavity and the top male die. The bottom and top male die parts are freely sliding in the female die cavity.
The inner surface of the top male die is suitably designed to accommodate the centre line contact with the wheel tread during brake application.

The method comprises of selecting the specific ingredients in the following proportions

SI no Description % additions
1 ANTIMONY POWDER 22.95
2 FIRE CLAY POWDER 16.86
3 PHENOLE FORMAL DEHYDE MOULDING POWDER 15.93
4 CASHEW NUT SHELL LIQUID 14.05
5 CASHEW FRICTION DUST 6.74
6 FERRO SILICON POWDER 6.74
7 RUBBER POWDER (30 MESH) 5.90
8 PLASTER OF PARIS (GYPSUM) 4.68
9 FIBRE GLASS STRANDS 2.52
10 HEXAMINE 1.68
11 LINSEED OIL 0.84
12 CARBON BLACK POWDER- HOT FINISHING GRADE 0.46
13 GRAPHITE BLACK POWDER 0.46
14 PHENOL FORMAL DEHYDE RESIN LIQUID (for Back plate and clip) 0.14
15 INCENSE POWDER 0.015

We claim
1) A method of manufacture of asbestos free low heat, low wear composite brake
blocks for Railway coaches & Locomotives by hot compression moulding
process comprising the steps of preparing the back plate assembly, selection
of the specific ingredients by weight namely Antimony powder 22.95 %,
Fire clay powder 16.86%, Phenol Formaldehyde moulding powder 15.93%, Cashew nut shell liquid 14.05%, Cashew Friction dust 6.74 %, Ferro silicon powder 6.74%, Rubber powder (30 mesh) 5.90%, Plaster of paris (gypsum) 4.68%, Fibre Glass strands 2.52%. Hexamine 1.68%, Linseed oil 0.84%, Carbon Black Powder (Hot Finishing Grade) 0.46%, Phenol Formal dehyde resin liquid 0.14%, Incence powder 0.015% to generate low wear, and uniform co-efficient of friction during service.
2) A method as claimed , in claim 1 wherein the moulds assembly is heated to
120 to 135 degree centigrade and applying a pressure load of 40 tons to
compress the ingredients in the mould for a period of 50 minutes to form a
composite structure of the asbestos free composite brake block and curing
the brake block after removal from the mould assembly for a period of 24
hours at a temperature of 120 degree centigrade, to give characteristics such
as low heat generation during application, low rate of wear ie below 0.3 mm
per 1000 kms or 5 cubic centimetres per KWH , and uniform co-efficient of
friction ie between 0.2 and 0.45 U,
3) A method of manufacture of asbestos free composite brake block for Railway
coaches & Locomotives substantially as herein describedwith reference to, and as
illustrated by the accompanied Figures.

Documents:

958-che-2003-abstract.pdf

958-che-2003-claims duplicate.pdf

958-che-2003-claims original.pdf

958-che-2003-correspondence others.pdf

958-che-2003-correspondence po.pdf

958-che-2003-description complete duplicate.pdf

958-che-2003-description complete original.pdf

958-che-2003-drawings.pdf

958-che-2003-form 1.pdf

958-che-2003-form 6.pdf

« Previous Patent

Next Patent »

Patent Number

200747

Indian Patent Application Number

958/CHE/2003

PG Journal Number

8/2007

Publication Date

23-Feb-2007

Grant Date

01-Jun-2006

Date of Filing

24-Nov-2003

Name of Patentee

CENTRAL WORKSHOP

Applicant Address

SOUTH WESTERN RAILWAY, ASHOKAPURAM, MYSORE 570 008, KARNATAKA, INDIA.

Inventors:

#	Inventor's Name	Inventor's Address
1	K. UMASHANKAR	"CENTRAL WORKSHOPS, SOUTH WESTERN RAILWAY, ASHOKAPURAM, MYSORE-570 008, KARNATAKA, INDIA.

PCT International Classification Number

B61H7/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA