FIELD OF INVENTION
This invention relates to a balanced draft gear for railways.
PRIOR ART
Currently available draft gears are used for heavy railway application. The
same is discussed herein below:-
1. Single Pack Draft Gear
The elastomeric spring column (consisting of various spring) are housed
inside housing and held together with a central longitudinal Bolt (which
is not load bearing). This housing is then placed inside the pocket in the
under frame of the Railway vehicles and held in place by using support
plates. While functioning all the spring elements of the spring column are
Compressed during both buff and draw mode.
2. Twin Pack Draft Gear/Floating Plate
The elastomeric spring column is housed m a housing consisting of a
middle plate (part of housing). This housing is then placed inside the
pocket in the under frame of the Railway Vehicle and held in place by
using support plate. The spring elements are placed on either side of the
middle plate. While functioning, all the spring elements of the spring
column are compressed during Buff Mode. Further, the spring behind
the middle plate expands during Buff Mode.
Both the above types of draft gears have the problem of same preload on
the spring Column assembly. This creates )erks' due to unsmooth
transitions of load during the start of buff or draw cycle and during
reversal of strokes. This drawback makes them unsuitable for passenger
service application.
-3-
To obviate this, the balancing of spring forces is required. This can be achieved
by having a fixed middle plate and spring column for both buff and draw
application, positioned before and after it. The spring column assembly is held
together by means of a longitudinal bolt, which also is supposed to take the
buffing and traction load.
The known art has the articulation required to negotiate curves placed inside
the middle place. This causes the longitudinal bolt stressed in bending during
the negotiation of curves, which makes it unsuitable for use on locomotive
hauled trailer train. This concept is widely used in EMU"s and where the
middle Bogie j Coaches of the train being powered.
3. Draft
To overcome the above mentioned drawbacks, a draft gear housing with
balanced placement of springs on both side of the middle plate is used.
The middle plate is part of the housing which is fixed in the pocket of the
Underframe with the help of the single sided wedge arrangement.
However, the disadvantage with this concept is that the single sided
wedge is not able to accomplish its function of fixing the housing inside
the underframe pocket, as due to the reactive load the wedge assembly
slipped out of the pocket of the under frame. There is also the chance of
this causing accident during the service as this could have resulted in
draft gear generating excess slack which would stress the coupler parts
and lead to breakage.
-4-
Another problem faced with this design IS that there is a change of the buff
spring pads decompressing to free state during draw mode(extension) and
draw pads decompressing to free condition in buff mode(comprcssion). This
necissaites the use of slit sleeve in the separating plate. So that separating
plate do not slip off , as the TPE spring pads used for this purpose do not
have lugs to support the separating plate. During the compression of the
Elastomeric pads the slit sleeve compresses and grabs the end of this
longitudinal bolt which causes substantial increase in friction forces and stick
slip operation.
OBJECTS OF THE INVENTION
The primary object of the present invention is to provide a balanced draft gear
for railways which overcomes disadvantages associated with the prior art.
Another object of the present invention is to provide a balanced draft gear for
railways which is simple in construction.
-
Further object of the present invention is to provide a balanced draft gear for
railways which is efficient.
SUMMARY OF THE INVENTION
According to this invention, there is provided a balanced draft gear for railways
comprising of a housing with a middle plate accommodating a pad assembly
around a guiding rod and on both sides of said middle plate wherein said pad
assembly is disposed between wedge at top and bottom and a novel bushing is
provided around the guiding rod.
-5-
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Further objects and advantages of this invention will be more apparent from
the ensuing description when read in conjunction with the accompanying
drawings and wherein:
Fig. 1 shows: balanced draft gear.
Fig. 2 shows: separating plate, bush and spacer assembly.
Fig. 3 shows: separating plate and cylindrical sleeve assembly.
Fig. 4 shows: load vs. displacement in reverse cyclic loading.
Fig. 5 shows: load vs. strain in compressive proof load test maximum load
2000 KN.
Fig. 6 shows: load vs. strain behaviour proof load test under tension maximum
load 1 000 KN.
Fig. 7 shows: Tup hammer test in hoff mode.
Fig. 8 shows: Tup hammer test in draw mode.
DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE -----
ACCOMPANYING DRAWINGS
The present invention discloses a balanced draft. gear for railways. Now, reference
may be made to fig. 1 and 2, wherein said draft gear comprising of a housing
(1) with a middle plate (2). Said housing accommodates a pad assembly (3 and
4) around a guiding rod (6) and on both sides of said middle plate. The guiding
rod (6) guides the pad assembly. Said pad assembly is disposed between wedge
(5) at top and bottom. Said pad assembly comprising of a plurality of buff
spring pads (3) on one side and draw spring pads (4) on other side of middle
plate. The pads are separated by separating plate. Said wedge (5) is connected
to a bolt (7) for its actuation. So that, the wedges can move in or out to
accommodate fitment of draft gear assembly in the draft gear pocket of coach.
-6-
During compression while applying brake, the pads get compressed as a result
the bushing ( 1 B) at the center of the separating plate ( 1A) around the rod grips
the rod (6). As it is made of engineering plastic therefore due to high
temperature during movement of the train the plastic bushing (1B) sticks to
the rod. Hence, it does not allow to expand comfortably after compression.
Therefore, the functioning is adversely affected i.e. as a result jerk is felt.
Hence, a spacer (1C) is provided between the ends of said bushing (1B),
constituting split bushing. So that, the separating plate ( 1A) also won't get
displaced from its position.
Thus, the present invention comprising of double wedge arrangement as two
separate wedges (5) opening in opposite direction on actuation of the bolt (7)
with left hand and right hand threading in which the geometry of the wedge is
suitable for the application as the wedge assembly once inserted inside the
pocket of the under frame is accommodated within the housing (1). The slit
sleeve (1B) after assembly on the separating plate (1A) is assembled with the
spacer sleeve ( 1 C), which does not allow the sleeve ( 1 B) to squeeze and grab
the longitudinal rod (6), thus allowing the draft gear to function smoothly with
very low friction.
Instead of split bushing as discussed hereinabove, a cylindrical bushing (as
shown in fig. 3) can also be provided. The cylindrical bushing comprising of a
cylindrical sleeve (1B') assembled on a separating plate (1A). So that, it
prevents stick slip behaviour, arrests the movement of separating plate and
acts as a mechanical stop.
Therefore, the pads don't get compressed beyond the designed limit
The invention meets International Standards such as AAR, UIC and RDSO
standards.
BURN STANDARD CO. LTD
HOWRAH WORKS
TUP HAMMER TEST REPORT
(27,000 POUND/12.5 TON)
SPECIFICATION NO.: AAR-M 901 E DATE: 11/10/12
DRAFT GEAR TYPE : BALANCED DRAFT GEAR
MAKE: WSF / SANROK
ENDURANCE TEST IN BUFF MODE
CALIBRATION AFTER 5 MilLION FT.lBS CAPACITY
FIRST OFFICIAL CALIBRATION
Time
From 8:35
Free
Fall
Travel
in Inch in Inch
Reaction
force TON
Reaction
force lbs
S.NO OF DRAFT GEAR: SRPD-1001
TYPE OF PAD : DUREL DC-45/80-B
Capacity
in ft-lb
1350.00
!
AMupto r---~~-----+----------+------~---------------------~
4:45PM
with an
interval of r------.r---+----------+------+-------------------l
10to 15
Mins
between
Remarks
each drop *Official
r---~r----+--------+----4---------~---------l
·12.0 2.7
TOTAL ENERGY INPUT IN THIS SHEET
PREVIOUS
CUMULATIVE ENERGY INPUT
129.6 285120
360450
5102550
5463000
Rating
Travel
69.8 mm
45.1 KJ
44.8 KJ
i
. 1i .
-~-
BURN STANDARD CO. LTD
HOWRAH WORKS
TUP HAMMER TEST REPORT
(27,000 POUND/12.5 TON}
SPECIFICATION NO.: AAR-M 901 E DATE: 25/10/12
DRAFT GEAR TYPE : BALANCED DRAFT GEAR
MAKE : WSF / SANROK
ENDURANCE TEST IN BUFF MODE
S.NO OF DRAFT GEAR: SRPD-1001
TYPE OF PAD : DUREL DC-45/80-B
CALIBRATION AFTER 15 MILLION FT. LB CAPACITY
SECOND OFFICIAL CALIBRATION
Free
Travel Reaction Reaction Capacity
Time Fall
in Inch in Inch force TON force lbs in ft-lb
From 8:35 0.5 0.1 42.2 92840 1350.00
AM upto 1.0 0.2 47.7 104940 2700.00
4:45PM 1.5 0.4 52.3 115060 4275.00
with an 2.0 0.6 55.2 121440 5850.00
interval of
2.5 0.7 57.2 125840 72QO.OO
lOto 15
Mins 3.0 0.8 60.2 132440 8550.00
between 3.5 0.8 63.7 140140 9()'15.00
each drop 4.0 0.9 64.9 142780
4.5 1.0 58.4 128480
5.0 1.2 68.6 150920
5.5 1.1 74.3 163460
6.0 1.3 78.2 172040
6.5 1.2 86.2 189640
7.0 1.3 85.3 187660
7.5 1.4 92.5 203500
8.0 1.4 96.2 211640
8.5 1.3 98.6 216920
9.0 1.5 103.2 227040
9.5 1.4 104.2 229240
10.5 1.6 108.9 239580
11.5 1.7 115.3 253660
12.5 2.0 124.3 273460
13.5 2.1 129.2 284240
13.5 2.3 128.1 281820
TOTAL ENERGY INPUT IN THIS SHEET 415800
PREVIOUS 15351463
CUMULATIVE ENERGY INPUT ...L .. ,. ....
Remarks
*Official
Rating
Travel
55.8 mm
47.6 KJ
48.2 KJ
-'\-
BURN STANDARD CO. LTD
HOWRAH WORKS
TUP HAMMER TEST REPORT
(27,000 POUND/12.5 TON)
SPECIFICATION NO.: AAR-M 901 E DATE: 06/11/12
DRAFT GEAR TYPE : BALANCED DRAFT GEAR S.NO OF DRAFT GEAR: SRPD-1001
MAKE : WSF / SANROK TYPE OF PAD : DUREL DC-45/80-B
ENDURANCE TEST IN BUFF MODE
CALIBRATION AFTER 25 MILLION FT. LB CAPACITY
FINAl CALIBRATION OF DRAFT GEAR
Free
Travel Reaction Reaction Capacity
Time Fall
in Inch in Inch force TON force Lbs in ft-lb
From 8:35 0.5 0.2 42.1 92620 1575.00
AM upto 1.0 0.3 47.6 104720 2925.00
4:45PM 1.5 0.4 51.3 112860 4275.00
with an 2.0 0.4 55.3 121660 5400;00
interval of
2.5 0.5 58.2 128040 6750.00
10to 15
Mins 3.0 0.7 60.4 132880 8325.00
between 3.5 0.8 63.2 139040 ~~s.oo
each drop 4.0 1.1 65.9 144980
4.5 1.1 67.0 147400
5.0 1.2 68.8 151360
5.5 1.2 73.6 161920
6.0 1.1 77.1 169620
6.5 1.3 81.5 179300
7.0 1.2 86.6 190520
7.5 1.4 90.7 199540
8.0 1.5 94.3 207460
8.5 1.7 98.6 216920
9.5 1.9 103.2 227040
10.5 2.1 112.3 247060
11.5 2.4 120.6 265320
11.5 2.5 126.9 279180
TOTAL ENERGY INPUT IN THIS SHEET 325125
PREVIOUS 25102476
CUMULATIVE ENERGY INPUT 25427601
Total Energy delivered to Balanced Draft Gear during En nee
Remarks ;
*Official
Rating
Travel
62.2mm
42.4KJ
42.7 KJ
-loc~
PACITY DEVELOP DURING ENDURANCE TEST IS ABOVE 80% OF OFFICIAL CAPACITY
BURN STANDARD CO. LTD
HOWRAH WORKS
TUP HAMMER TEST REPORT
(27,000 POUND/12.5 TON)
SPECIFICATION NO.: AAR-M 901 E DATE: 08/11/12
DRAFT GEAR TYPE : BALANCED DRAFT GEAR
MAKE : WSF / SANROK
S.NO OF DRAFT GEAR: SRPD-1001
TYPE OF PAD : DUREL DC-45/80-B
STURDINESS TEST REPORT
Time
Free
Fall
Travel Reaction Reaction
in Inch in Inch
force
TON
From 8:35AM
upto 4:45PM
with an interval
Capacity
in ft-lb
of 10 to 15 1---==--l-..:..:..=~-t-~~-l-~~~1--_.;.__::.~=:_-------l
Mins between
each drop
Remarks
..----
_,,_
BURN STANDARD CO. LTD
HOWRAH WORKS
DROP HAMMER TEST REPORT
(27,000 POUND/12.5 TON)
SPECIFICATION NO.: AAR-M 901 E DATE: 09.11.2012
DRAFT GEAR TYPE : BALANCED DRAFT GEAR
MAKE : WSF / SANROK
OFFICIAL CALIBRATION
AFTER STURDINESS
Time
Free
Fall
Travel Reaction Reaction
in Inch in Inch
From 8:35
AMupto
4:45PM
with an
interval of
10 to 15
Mins
between
each drop
S.NO OF DRAFT GEAR: SRPD-1001
TYPE OF PAD: DUREL DC-45/80-B
Capacity
in ft-lb
i
Remarks I
*Official
Rating
Travel
59.7mm
SPECIFICATION NO.: AAR-M 901 E
_, t.-
BURN STANDARD CO. LTD
HOWRAH WORKS
DROP HAMMER TEST REPORT
(27,000 POUND/12.5 TON)
DATE: 10.11.2012
DRAFT GEAR TYPE : BALANCED DRAFT GEAR
MAKE: WSF / SANROK
S.NO OF DRAFT GEAR: SRPD-1001
TYPE OF PAD: DUREl DC-45/80-B
STURDINESS TEST REPORT
Time
From 8:35
AM upto
4:45PM
with an
Free
Fall
Travel Reaction Reaction · capacity
in ft-lb
interval of i----l----1----+------+-----------;
lOto 15
Mlns
between
each drop
-.. ,. .~......
Remarks
..
-'~-
BURN STANDARD CO. LTD
HOWRAH WORKS
TUP HAMMER TEST REPORT
(27,000 POUND/12.5 TON)
SPECIFICATION NO.: AAR-M 901 E DATE: 15/11/12
DRAFT GEAR TYPE : BALANCED DRAFT GEAR
MAKE : WSF / SANROK
S.NO OF DRAFT GEAR: SRPD-1001
TYPE OF PAD: DUREL DC-45/80-B
OFFICIAL CALIBRATION
AFTER STURDINESS
Time
Free
Fall
Travel Reaction Reaction
in Inch in Inch
force
Lbs
From 8:35AM
upto 4:45PM
Capacity
in ft-lb
with an interval 1-----+---+----+---1------------·-·············-··------i
of10to 15
Mins between
each drop
Remarks
*Official
Rating
Travel
(--=:~i-~:__.+--..!...:~-1-..:::_~~(_--3.:~~--__:~ 60.9 mm
CAPACITY DEVELOP DURING ENDURANCE TEST IS ABOVE 70%
VISIUAL OBSERVATION:NO
PHYSICAL DAMAGE IS OBSERVED TO ANY PART DRAFT GEAR
. ''
•
SPECIFICATION NO.: AAR-M 901 E
.,.,~-
BURN STANDARD CO. LTD
HOWRAH WORKS
TUP HAMMER TEST REPORT
(27,000 POUND/12.5 TON)
DATE: 20/11/12
DRAFT GEAR TYPE : BALANCED DRAFT GEAR S.NO OF DRAFT GEAR: SRPD-1001
MAKE : WSF / SANROK
ENDURANCE TEST IN DRAW MODE
CALIBRATION AFTER 5 MILLION FT.LB CAPACITY
FIRST OFFICIAL CALIBRATION
Free
Travel Reaction Reaction Capacity Remarks
Time Fall
in Inch in Inch force TON force lbs in ft-lb --
From 8:35 0.5 0.1 30.5 67100 1350.00
AM upto 1.0 0.2 35.4 77880 2700.00 *Official
4:45PM 1.5 0.3 39.6 87120 4050.00 Rating
with an 2.0 0.3 44.5 97900 5175.00 Travel
interval of 26.67
10to 15 2.5 0.4 48.9 107580 6525.00 mm
Mihs 3.0 0.5 53.6 117920 7875.00
between 3.5 0.6 59.5 130900 9225.00
each drop
4.0 0.7 63.5 139700 10575.00
4.5 0.8 68.1 149820 11925.00
5.0 1.0 72.3 159060 13500.00 18.3 KJ
5.0 1.1 76.1 167420 13725.00
i- i
18.6 KJ .J
~&S~,.oo
TOTAL ENERGY INPUT IN THIS SHEET 86625
PREVIOUS 5298423
CUMULATIVE ENERGY INPUT 5385048
SPECIFICATION NO.: AAR-M 901 E
-IS"-
BURN STANDARD CO. LTD
HOWRAH WORKS
TUP HAMMER TEST REPORT
(27,000 POUND/12.5 TON}
DATE: 27/11/12
DRAFT GEAR TYPE : BALANCED DRAFT GEAR S.NO OF DRAFT GEAR: SRPD-1001
MAKE : WSF / SANROK
ENDURANCE TEST IN DRAW MODE
CALIBRATION AFTER 15 MILLION FT.lB CAPACITY
FINAL OFFICIAl CALIBRATION
Free
Travel Reaction
Time Fall
in Inch in Inch force TON
From 8:35 0.5 0.1 31.6
AM upto 1.0 0.1 36.5
4:45PM
1.5 0.2 38.9
with an
interval of 2.0 0.4 42.1
10to 15 2.5 0.3 46.3
Mins 3.0 0.6 49.5
between 3.5 0.5 53.6
each drop 4.0 0.8 58.4
4.5 0.8 63.4
5.0 0.9 69.5
5.5 1.2 73.7
5.5 1.1 79.6
TOTAL ENERGY INPUT IN THIS SHEET
PREVIOUS
CUMULATIVE ENERGY INPUT
Reaction
force Lbs
69520
80300
85580
92620
101860
108900
117920
128480
139480
152900
162140
175120
102375
15221462
15323837
ft lb
SPECIFICATION NO.: AAR-M 901 E
-I(,-
BURN STANDARD CO. LTD
HOWRAH WORKS
TUP HAMMER TEST REPORT
(27,000 POUND/12.5 TON)
DATE: 29/11/12
DRAFT GEAR lYPE : BALANCED DRAFT GEAR
MAKE : WSF / SANROK
S.NO OF DRAFT GEAR: SRPD-1001
lYPE OF PAD : DUREL DC-45/80-B
STURDINESS TEST REPORT
Time
From 8:35 AM upto
Free
Fall
Travel
in Inch in Inch
Reaction Reaction
force TON
force
Lbs
Capacity
in ft-lb
4:45PM with an 1-----t------t------+-----r-------------:
interval of 10 to 15
Mins between each (-~_.f--___:~--1--~::__,.----~~~~---~~~-----~
drop
Remarks
-J~-
BURN STANDARD CO. lTD
HOWRAH WORKS
DROP HAMMER TEST REPORT
(27000 POUND/12.5 TON}
SPECIFICATION NO.: AAR-M 901 E DATE: 30.11.2012
DRAFT GEAR TYPE : BALANCED DRAFT GEAR
MAKE : WSF / SANROK
OFFICIAL CALIBRATION
AFTER STURDINESS
Time
Free
Fall
Travel Reaction Reaction
From 8:35
AM i.Jpto
4:45PM
with an
force
lbs
S.NO OF DRAFT GEAR: SRPD-1001
TYPE OF PAD: DUREL DC-45/80-B
Capacity
in ft-lb
interval of t------+---+----1-----+-----------l
Remarks
10 to 15 *Official
Mins
Rating
between Travel
each drop 1---+---+---+----+------:-::--:--------i 25.4 mm
.. . . , ....
. '
l
BURN STANDARD CO. LTD
HOWRAH WORKS
DROP HAMMER TEST REPORT
{27000 POUND/12.5 TON)
SPECIFICATION NO.: AAR-M 901 E DATE: 01.12.2012
DRAFT GEAR TYPE : BALANCED DRAFT GEAR
MAKE : WSF / SANROK
STURDINESS TEST REPORT
Time
Free
Travel Reaction Reaction
Fall
in in force force
Inch Inch TON lbs
From 8:35 7 1.8 92.6 203720
S.NO OF DRAFT GEAR: SRPD-1001
TYPE OF PAD : DUREL DC-45/80-B
Capacity
in ft-lb
AM upto f---t---+---+----t-----------l
4:45 PM
with an
interval of f-----+--=--+---+----+-----------J
10to 15
Mins
between
each drop
Remarks
SPECIFICATION NO.: AAR-M 901 E
-I'\-
BURN STANDARD CO. LTD
HOWRAH WORKS
TUP HAMMER TEST REPORT
(27000 POUND/12.5 TON)
DATE: 03/12/12
DRAFT GEAR TYPE : BALANCED DRAFT GEAR
MAKE : WSF / SANROK
S.NO OF DRAFT GEAR: SRPD-1001
TYPE OF PAD: DUREL DC-45/80-B
OFFICIAL CALIBRATION
AFTER STURDINESS
Time
Free
Fall
in Inch
Travel
in Inch
Reaction Capacity Remarks 1
force
in ft-lb
Reaction
force TON
lbs ---·----.-----~
From 8:35AM 0.5 0.2 32.3 71060 1575.00 *Official I
upto 4
=
45 PM 1.0 0.3 36.2 79640 2925.00 i Rating
with an interval 1---~1------11------11----+----------~--· ·····-------l 1
of 1b to 15 1.5 0.4 39.5 86900 4275.00 i Travel 1
I---2-0-I---0-4---11---43-1--t--9-48_2_0-+----5-400_0_0 ___ __,. 34·3 mm I Mins between · · · ·
each drop 2.5 0.6 47.5 104500 6975.00 1
3.0 0.5 49.3 108460 7875.00
3.5 0.7 51.8 113960 945t:WO
4.o o.9 54.2 119240 t •• m
4.5 1.3 59.8 131560
4.5 1.4 63.2 139040
CAPACITY DEVELOP DURING ENDURANCE TEST IS ABOVE 70%
VISIUAL OBSERVATION:-
AFTER THE WHOLE TEST, NO SIGNIFICANT PHYSICAL DAMAGE IS
GEAR.
17.7 KJ
·----1-
17.9 KJ
~-
NAME: NAME: ..}.\1r. Goutam Dhar
Desg: Desg: . Dy~M/QAIBSCL(HW)
GOUTAM DHAR
OY. MANAGER (QUAliTY ASSURANCE)
BURN STANDARD CO. LTD.
HOWRAH V;ORKS, HOWRftii-'1'!'01
2.0 Conclusions
Test Test
No
1.1
1.2
: 1.3
1.4
Static cyclic load with
complete reversal of load
Proof load in Compression
Proof Load in Tension
permanent
deformation load
Signature and Stamp
-;l_.,-
Conclusions
The m End load during compression
was measured to be 1 059 kN
The Preload observed was 20 kN
The energy absorption was 29 kJ
The energy dissipated was 9.2 kJ
The energy stored=19.8 kJ
The Dam Factor in Static Mode was 68 o;.:,
At the proof load 2000 , all the strain
gauges were observed to be well within the
elastic range of the material (1600 !Jm/m).
The strains at the peak load and the residual
strain on unloading were found to be less than
0.2%(2000 J.Jm/m) in all the strain gauges.
At the proof load of 1000 kN, all the strain
gauges were observed to be well within the
elastic range of the material (1600 !Jmlm).
The strains at the peak load and the residual
strain on unloading were found to be less than
0.2%(2000 J.Jm/m) in al1 the strain gauges.
there was
l,/distclrticm· observed
liiiC'AM-.I-I-I ·.I-&·. s--a M--Jt·lvt at CMRE
..
" .
[
f i,
-~H..;
BURN STANDARD CO. LTD.
HOWRAH WORKS
TUP HAMMER TEST REPORT
Type of Draft Gear Balanced Draft Gear
Serial/Sample No. SRPD-1001
Make WSF/SANROK
Type of Pad : DUREL DC 45/80-B
Date Time Free Fall
in Inch
28.07.12 12:30:00PM 2
4
6
8
to 10
12
12.5
15.20:00PM 12.5
Total Energy input:
Asit Kr. Naskar
Inspector /BSCL-HW
Travel
in Inch
Name
Desg .
0.6
0.9
1
1.2
1.4
1.6
2.4
2.3
Purchaser:
TypeofTest:
Date of Testing:
Reaction Reaction
force TON force lbs
0
65.2 143739.9
69.7 153660.6
&7.4 1926&2
98.4 216932.6
110.4 243387.8
127.1 280204.7
147.7 325619.4
151.2 333335.5
0
0
0
0
0
lila me
Desg.
Org. ................. --r Or'irf. MAI'fjlGER
Dynamic in Buff Mode
28/07/2012
Capacity Remarks
in ft-lb
0
5850
11025
15750
20700
25650
30600
33525 45.5 KJ
33300 45.2 KJ
0
0
0
0
0
.. 176400
3{b
I
BURN STANDARD CO. l TO.
HOWRAH WORKS
TUP HAMMER TEST REPORT
Type of Draft Gear Balanced Draft Gear Purchaser:
Serial/Sample No. SRPD-1001 Type ofT est :
Make WSF/SANROK
Type of Pad : DUREL DC 45/80-B
Date ofT esting:
Date Time Free Fall Travel Reaction Reaction
in Inch in Inch force TON force lbs
0
30.07.12 10:30:00AM 2 0.3 49.2 108466.3
4 0.8 68 149912.8
6 1.3 86.1 189816.1
6 L4 87 191800.2
to
11.45:00AM
0
0
Dynamic in Draw Mode
30/07/2012
Capacity Remarks
in ft-lb
0
5175
10800
16425 22.28 kJ
16650 22.59 KJ
0
o::;;~:
0
0
0
0
0
Total Energy input:
Asit Kr. Naskar
.,A.IJn..slp'l.e'1ct'.o Gr/ .BOS.C.nL'.-MHW t @Y/
Name Mr.G. Ohar
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1 The Dynamic
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3 TheDraft
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Name Asit Kr Naskar
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It is to be noted that the present invention is susceptible to modifications,
adaptations and changes by those skilled in the art. Such variant embodiments
employing the concepts and features of this invention are intended to be within
the scope of the present invention, which is further set forth under the
following claims:

WE CLAIM:
1. A balanced draft gear for railways comprising of a housing with a middle
plate accommodating a pad assembly around a guiding rod and on both
sides of said middle plate wherein said pad assembly is disposed between
wedge at top and bottom and a novel bushing is provided around the
guiding rod.
2. A balanced draft gear as claimed in claim 1, wherein said pad assembly
comprising of a plurality of buff spring pads on one side and draw spring
pads on other side of the middle plate between the wedge connected to
bolt for its actuation, in which the pads are separated by the separating
plate.
3. A balanced draft gear as claimed in claim 1 or 2, wherein said bushing is
split bushing comprising of a spacer between the ends of slit sleeve
assembled on a separating plate, which does not allow the slit sleeve to
squeeze and grab the rod, thereby allowing the draft gear to function
smoothly with very low friction.
4. A balanced draft gear as claimed in any of the preceding claims, wherein
the novel bushing comprising of a cylindrical bushing, which prevents
stick slip behaviour, arrests the movement of separating plate and acts
as a mechanical stop that the pads do not get compressed beyond the
desired limit.
5. A balanced draft gear as claimed in any of the preceding claims, meets
International Standards such as AAR, UIC and RDSO standards.
6. A balanced draft gear for railways substantially as herein descri~ed with
reference to the accompanying drawings.