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FORM 2
The Patent Act 1970
(39 of 1970)
&
The Patent Rules  2005
COMPLETE SPECIFICATION
(SEE SECTION 10 AND RULE 13)
TITLE OF THE INVENTION
METHOD OF MANUFACTURING HONING SLEEVE
APPLICANTS:
Name Nationality Address
Wendt India
Ltd
Indian 69/70 Sipcot Hosur 635 126 Tamil Nadu
India
The following specification particularly describes and ascertains the nature of this
invention and the manner in which it is to be performed:-
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TECHNICAL FIELD
[001] The embodiments of this invention relate to an abrasive tool and  more
particularly but not exclusively the embodiments of this invention 5 relate to a method
of manufacturing the honing sleeve that may be used as an abrasive tool.
BACKGROUND
[002] Abrasive tools have been used in numerous applications  including
10 honing  cutting  drilling  sawing  grinding  lapping and polishing of materials.
Further  when the super abrasives such as cubic boron nitride (CBN) and diamond
were adapted in to the abrasive tools  the process of using abrasive tools leaped from
being a relatively fussy  labor-intensive finishing operation to a long-running 
automated production process that could correct cylinder geometry and cut quickly
15 enough to replace some intermediate boring and grinding operations.
[003] Honing is an abrasive machining process that uses a honing tool in
numerous applications  including finishing of cylinders for internal combustion
engines  connecting rod and gears. Further  the honing tool typically employs three or
more bonded abrasive sleeves mounted in holders and expanded outwardly with
20 respect to a rotational axis  to work on the material surface being finished. The honing
tool is rotated and reciprocated along the material surface  and as the operation
proceeds the honing sleeves are forced out radially from the center of the tool.
[004] Honing tool and honing sleeves have a huge demand in the market for
their accuracy  surface finish and productivity. Increase in demand for honing sleeve
25 requires the manufacturing industries to optimize the process of manufacturing honing
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sleeve to produce more sleeves in minimum duration of time thereby meeting the
demand in the market.
[005] Generally  the honing sleeves are manufactured by preparing the
mixture of abrasive particles  a Metal bond and a basic layer wherein the basic layer
may include bronze powder. The mixture is then sintered using 5 a vertical mould.
Further  the sintered particle is removed from the mould and machined to the
dimensions of the sleeve.
[006] The conventional method of manufacturing honing sleeve does not meet
the increasing demand for the honing sleeves as the conventional methods have
10 various constraints such as frequent breakage of the graphite mould during the
manufacturing process  improper sintering which may affect the quality of the honing
sleeves and the high production time thereby making the whole process partially
inefficient.
[007] The graphite mould that is used in the conventional method of
15 manufacturing is placed vertically and therefore during the pressing operations there
is a possibility of frequent breakage of the graphite mould. Further  during the
sintering process in conventional method of manufacturing the honing sleeves  area of
contact between the press and the mould is less which results in improper sintering of
the mixture of abrasive particles  metal bond and a basic layer. Furthermore  the final
20 machining process includes the process of face grinding  drilling the inner surface of
the sleeve  rough grinding to provide rough outer diameter of the sleeve  wire cutting
for providing taper in the inner surface of the sleeve  groove sparking and final
grinding for the outer diameter of the sleeve.
[008] Therefore  there is a need for an efficient process in the manufacturing
25 of honing sleeve which can be used to overcome the above mentioned drawbacks.
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OBJECT OF INVENTION
[009] The principal object of the invention is to provide an efficient method of
manufacturing 5 sleeve.
[0010] Another object of the invention is to provide a mould that is capable of
withstanding high load during the sintering process without breakage.
[0011] Another object of the invention is to provide an improved method of
sintering to manufacture the sleeve.
10 [0012] Yet another object of the invention is to provide an improved method
of filling the abrasive particles to manufacture the sleeve.
BRIEF DESCRIPTION OF THE FIGURES
[0013] The embodiments herein will be better understood from the following
15 detailed description with reference to the drawings  in which:
[0014] FIG. 1a depicts a front view of a sleeve member according to the
embodiments of the present invention.
[0015] FIG. 1b depicts a side view of a sleeve member according to the
embodiments of the present invention.
20 [0016] FIG. 2 depicts a sectional view of a mould with the arresting element
according to the embodiments of the present invention.
[0017] FIG. 3 depicts a sectional view of a mould with the basic layer
according to the embodiments of the present invention.
[0018] FIG. 4 depicts a sectional view of both the moulds according to the
25 embodiments of the present invention.
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[0019] FIG. 5 depicts a flow chart that describes the method of manufacturing
the sleeve according to the embodiments of the present invention.
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DETAILED DESCRIPTION OF EMBODIMENTS
[0020] The embodiments herein and the various features and advantageous
details thereof are explained more fully with reference to the non-limiting
embodiments that are illustrated in the accompanying drawings and detailed in the
following description. Descriptions of well-known components 5 and processing
techniques are omitted so as to not unnecessarily obscure the embodiments herein.
The examples used herein are intended merely to facilitate an understanding of ways
in which the embodiments herein may be practiced and to further enable those of skill
in the art to practice the embodiments herein. Accordingly  the examples should not
10 be construed as limiting the scope of the embodiments herein.
[0021] The embodiments herein disclose a system and method of
manufacturing a honing sleeve that can be used in honing tool. Referring now to the
drawings and more particularly to Figs 1a and 1b where similar reference characters
denote corresponding features consistently throughout the figures there are shown
15 preferred embodiments.
[0022] Figs 1a and 1b depict a front view and a side view of a sleeve member
according to the embodiments of the present invention. The sleeve member may be
used in a honing operation. The sleeve member 10 has an inner portion 12 and an
outer surface 16. The inner portion 12 defines a hollow passageway 14 that is tapered
20 and extending from end to end along the entire length of the sleeve member 10. The
outer surface 16 includes a plurality of circumferentially spaced longitudinal channels
18. Further  each channel 18 is defined by a face 20 which is recessed between
opposing parallel side walls 22 and a projection 24 that separate the plurality of
channels 18 from each other. The outer surface 16 also includes a slot 26 located
25 through the face 20 of one of the channel 18. The slot 26 extends a full length of one
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side of the sleeve member 10 to permit uniform expansion and contraction when the
portion of the honing tool (not shown) is axially moved within the passageway 14.
[0023] Figs 2  3a  3b and 4 depict a sectional front view of a mould 100 and
arresting elements 110 which are is used to manufacture the sleeve member 10
according to the embodiments of the present invention. In one 5 embodiment  the
mould 100 may be made of graphite. Further  the graphite may be of grade
G535/G347.
[0024] In another embodiment  the mould may be made of steel. However  it
is also within the scope of the invention that the mould may be of a different material
10 without otherwise deterring the intended function of the mould 100 as can be deduced
from this description. The mould 100 has a base surface 102 where the base surface
has at least a pair of wall 104 extending from the opposite edges of the base surface
102 thereby resembling a rectangular cuboidal cross section. However  it is also
within the scope of the invention that the mould may resemble a different cross
15 section without otherwise deterring the intended function of the mould 100 as can be
deduced from this description. The base surface 102 includes an inner surface 108
that extends to the length of the sleeve member 100. The inner surface 108 has an
equally spaced projection (not shown)  where the projections have the cross section
(radius and the width) same as that of the channel 18 of the sleeve member 10 and
20 extends linearly along the entire length of the inner surface 108. Further  in an
embodiment  the inner surface 108 of the mould 100 has a concave or convex shape.
The shape of the inner surface 108 of the mould 100 may resemble the shape of the
outer surface 16 of the sleeve member 10.
[0025]
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[0026] The arresting element 110 is placed on the opposite sides of the inner
surface 102 of the mould 100 and it defines the area in the outer surface 16 of the
sleeve 10 that is free from the abrasive materials. The arresting element 110 is made
of a material that is capable of arresting the area of the inner surface that it covers
from the foreign material. In one embodiment  the arresting 5 element 110 may be
made of steel. However  it is also within the scope of the invention that the arresting
element 110 may be made of different material without otherwise deterring the
intended function of the arresting element 110 as can be deduced from this
description.
10 [0027] Fig. 5 depicts a flowchart that describes the method 201 of
manufacturing the sleeve member 10. The mould 100 with the arresting element 110
on both sides of the inner surface 108 is prepared (step 202). The mixture of the
abrasive particle and the bond 114 is prepared (step 204) wherein the bond may
include the compound of metals and active fillers. The active filler material may be
15 sodium aluminium fluoride  iron sulphide and Boron Carbide. Further  in one
embodiment  the active filler material constitutes 40-80% by volume of the bond.
The mixture of the abrasive particle and the bond is poured in the inner surface 102 of
the mould 100 in the area provided between the arresting element 110 (step 206) 
wherein the inner surface 102 of the mould 100 is provided with an equally spaced
20 projections (not shown)  where the projections have the cross section (radius and the
width) same as that of the channel 18 of the sleeve member 10 and extends linearly to
the entire length of the inner surface 108.
[0028] Further  the mixture of abrasive particle and the bond is cold pressed
under the predetermined pressure using a press thereby compact the mixture of
25 abrasive particles and the bond (step 208). In an embodiment  the abrasive particles
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and the bond is cold pressed by using a cold compacting element 111  wherein the
outer surface 113 of the cold compacting element 111 may have a shape that
resembles the shape of the outer surface 16 of the sleeve member 10. Once the
mixture is compacted the arresting element 110 is removed from the mould 100.
Further  the mould is filled with a basic layer 112  which might be 5 of a bronze powder
(step 210). Further  the cold compacted mixture and the basic layer is sintered using a
hot press with a calculated load at approximately 600 degrees Centigrade using a
suitable programmed cycle (step 212). During the sintering process the mould 100 is
placed horizontally so that the area of contact of the press to the mixture and the basic
10 layer can be increased. However  it is also within the scope of the invention that the
mould may be kept in different orientation without otherwise deterring the intended
function of the mould 100 as can be deduced from this description.
[0029] Similarly  the mirror image of mould 100 with arresting element is
prepared as mould 200 (step 214). The mixture of the abrasive particle and the bond
15 114 is prepared (step 216) wherein the bond may include the compound of metals and
active fillers. The active filler material may be sodium aluminium fluoride  iron
sulphide and Boron Carbide. Further  the active filler material constitutes 40-80% by
volume of the bond. The mixture of the abrasive particle and the bond is poured in
the inner surface 102 of the mould 200 in the area provided between the arresting
20 element 110 (step 218)  wherein the inner surface 102 of the mould 200 is provided
with the equally spaced projections (not shown)  where the projections have the cross
section (radius and the width) same as that of the channel 18 of the sleeve member 10
and extends linearly to the entire length of the inner surface 108.
[0030] Further  the mixture of abrasive particles and the bond is cold pressed
25 under the predetermined pressure that is used to compact the mixture of abrasive
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particles and the bond (step 220). In an embodiment  the abrasive particles and the
bond is cold pressed by using a cold compacting element 111  wherein the outer
surface 113 of the cold compacting element 111 may have a shape that resembles the
shape of the outer surface 16 of the sleeve member 10. Once the mixture is
compacted the arresting element 110 is replaced by a basic layer 112  5 which might be
of a bronze powder (step 222). Further  the cold compacted mixture of abrasive
particle  bond and the basic layer is sintered using a hot press with a calculated load at
approximately 600 degrees Centigrade using a suitable programmed cycle (step 224).
During the sintering process the mould 100 is placed horizontally so that the area of
10 contact of the press to the mixture and the basic layer can be increased. However  it is
also within the scope of the invention that the mould may be kept in different
orientation without otherwise deterring the intended function of the mould 100 as can
be deduced from this description.
[0031] The final sintering is done using a hot press with a calculated load at
15 approximately 600 degrees Centigrade by providing the mould 100 and the mould 200
opposite to each other  such that the wall 104 of the moulds is in contact with the wall
104 of the mould 200 (step 226). After final sintering the sintered part that includes
the mixture of the abrasive particles and bond and the basic layer is removed from the
mould 100 and the mould 200. (step 228)
20 [0032] In one embodiment  the inner surface 102 and the wall 104 of the
mould are provided as separate parts and are connected together by suitable means 
for example glue  clamp etc.  so that after final sintering the mould can be easily
removed from the sintered part.
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[0033] In another embodiment  the inner surface 102 and the wall 104 of the
mould are provided as an integral part  which can be machined after final sintering
thereby removing the mould from the sintered part.
[0034] The sintered part is then machined for the hollow passageway 14 that is
tapered and extending from end to end along the entire length of 5 the sleeve member
10 (step 230). The machining can be performed by any of the well known technique 
say for example drilling  wire cutting. In one embodiment  the final grinding is done
thereby providing more accurate finish in the sleeve member 10.
[0035] The various actions in method 200 may be performed in the order
10 presented  in a different order or simultaneously. Further  in some embodiments  some
actions listed in FIG. 5 may be omitted.
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
15 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
20 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
embodiments as described herein.
25
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We claim:
1. A method of manufacturing a sleeve member  the method comprising:
providing a first mould and a second mould  each of said first mould
and second mould having a base and a plurality of walls extending
away from said base  said base and said plurality of walls together
defining a cavity;
providing at least a first arresting element and a second arresting
element inside each of said moulds  said first and second arresting
element defining a gap there between;
filling abrasive particles along with bonding material in said gap;
cold compacting said abrasive particles and said bonding material;
removing said first and said second arresting elements from the mould;
filling each of the said mould with a basic layer;
hot pressing said abrasive particles along with basic layers; and
engaging said first and second moulds containing hot pressed abrasive
particles and basic layers.
2. The method as claimed in claim 1  wherein said method further comprises hot
pressing the first and second moulds after said engaging step is performed.
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3. The method as claimed in claim 2  wherein said method comprises separating
said hot pressed first and second mould from said abrasive particles and basic
layers.
4. The method as claimed in claim 3  wherein said method comprises machining
said abrasive particles and basic layer after separating the hot pressed first and
second mould.
5. The method as claimed in claim 1  wherein said bond includes at least a metal
bond.
6. The method as claimed in claim 1  wherein said hot pressing said abrasive
particles along with said first and second basic layers is performed at a
temperature of about 600 degree centigrade.
7. The method as claimed in claim 1  wherein said mould is made from one of
graphite and steel.
8. The method as claimed in claim 7  wherein each of said first and second
arresting elements is made from at least one of aluminum and steel.
9. The method as claimed in claim 1  wherein said basic layer is a bronze layer.
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10. A mould for manufacturing a honing sleeve  said mould comprising:
A base;
A plurality of walls extending away from said base  said base and said
plurality of walls together defining a cavity  wherein said base defines
a plurality of projections spaced at regular interval.
11. The mould as claimed in claim 10  wherein said projections has dimensions
Corresponding to a cavity defined by the sleeve member.
12. The mould as claimed in claim 10  wherein said base defines a shape
corresponding to an outer surface of the sleeve member.
Dated this 13th September 2011
Dr. Kalyan Chakravarthy
Patent Agent
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ABSTRACT
A method of manufacturing honing sleeve includes  providing a first mould and a
second mould horizontally  filling abrasive particles along with a basic layer in the
first and second mould respectively  hot pressing the abrasive particles along with the
basic layer and engaging the first and second mould. The inner surface 5 of the first
and second mould corresponds to the outer surface of the honing sleeve.
Reference Figure: Fig. 5