FIELD OF INVENTION
The present invention relates to a coupling device adaptable to a divide shearing
machine.
BACKGROUND OF THE INVENTION
The divide shearing machine installed in Tata Steel Plant to produce 8,10,12,16
mm straight rebars from 130 square mm billet. The main function of this
equipment is to cut bat at every 72 m length. Per day on an average it cuts
10,000 nos. This divide share takes feedback from the encoder which is attached
to the main shaft. The main shaft of the encoder was connected with one side of
a metallic coupling (membrane coupling fig-2,2A,2B) flange and the other end of
the metallic coupling flange is connected with a flange which is in turn connected
to main shaft of divide shearing machine and the whole arrangement is mounted
in a bell housing fig-1 & 2. The machine works smoothly for cutting operation of
8,10,12 mm dia rod. The problem arises for cutting operation of 16mm dia rod
and the machine starts malfunctioning due to various failure. The phenomena
observed for failure due to one of the 3 reasons:
(a) Rupture of membrane coupling (metallic coupling)
(b) Encoder malfunctioning due to impact during bar cutting
(c) Encoder shaft breaking due to generation of high vibration in the shearing
machine during the cutting time of 10mm or above rod.
In the existing state of art as shown in fig-1 & 2, encoder bell housing was
directly mounted on gear box housing. In the existing art
(a) There was hardly any scope for alignment between encoder shaft and
main shaft

(b) Change of vibration transfer (from gearbox housing to encoder bracket)
was there
In the existing state of art once the divide shearing machine is breakdown entire
mill will go down since NBM is a continuous mill and the opportunity cost of NBM
is approx Rs lOL/hour.
In order to overcome such problem in shop floor a tremendous brain storming
started and a new idea evolved to develop a new coupling device and the
existing problem was abolished forever.
OBJECTS OF THE INVENTION
It is therefore an object of the present invention to propose a coupling device
adaptable to a divide shearing machine which eliminates the disadvantages of
prior art.
Another object of the present invention is to propose a coupling device adaptable
to a divide shearing machine which enhance reliability and availability of divide
shear machine.
A still another object of the present invention is to propose a coupling device
adaptable to shearing machine which reduce break-down hours.
A further object of the present invention is to propose a coupling device
adaptable to a divide shearing machine which enhance better length accuracy of
cut bars.

A still further object of the present invention is to propose a coupling device
adaptable to a divide shearing machine which enhance the maintainability of the
equipment.
An yet further object of the present invention is to propose a coupling device
adaptable to a divide shearing machine which expenses less cost for
manufacturing.
SUMMARY OF THE INVENTION
The coupling device as shown in Fig 3B & 3C is made of rubber. A cylindrical
shaped rubber roller is machined properly to form a 'H' shaped part. A central
hollow boring is made by horizontal boring. Both the flanges have 4 nos. drilled
holes having their centres at 90°C apart. A pair of matching flanges are made of
steel material for mounting with the rubber coupling. The encoder base is
separated from bell housing to avoid multiple vibrations coming from gearbox
housing through housing and this rubber coupling installed in between the
encoder and main shaft of gear box exerts better flexibility. A modified shaft with
gradual diminishing in diameter is installed to avoid stress concentration.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Fig-1 shows a schematic diagram of general arrangement of divide shear
machine in prior art
Fig-2 shows a pictorial view of membrane coupling mounted inside a bell
housing in prior art

Fig-2A & 2B isometric view and plan of a membrane coupling in prior art
Fig-3A shows a pictorial view of separate mounted base for Encoder
assembled with now coupling device as per the invention
Fig-3B shows a pictorial view of Rubber coupling mounted with
metallic flange by 4 nos. of bolts and nuts
Fig-3C shows a plan of rubber coupling and plan of metallic flanges
at both side
Fig-3D shows a schematic view of elevation and end view of metallic
Flange
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE
INVENTION
As shown in Fig 3B & 3C, a 'H' shaped coupling device is made of rubber
developed in house from a cylindrical shaped rubber material by machining in the
central part (1), inside (2) and outside (3) of the round flange. The coupling
device have a central hollow bore (4) which is machined in horizontal boring
machine/ or drilling. Each flange of the rubber coupling device contains 4 nos. of
drill holes (5) which is machined by drilling. Two identical metallic inverted T'
shaped coupling holder (Fig-3D) are prepared by machining. The flange of the
holder also contains 4 nos. of holes (6) to match with the holes (5) of coupling
device for fastening and fix the two holes (5,6) by means of a fastener. One

coupling holder is attached to the shaft of encoder and the other coupling holder
is attached with a taper shaft connect to gear box. The encoder mounted base is
separated to avoid the vibration getting transmitted from gear box housing on to
the encoder. The rubber coupling thus made and fixed in place of membrane
coupling. The flexibility in rubber absorbs the vibrations which gets transmitted
on encoder.

WE CLAIM
1. A new coupling device adaptable to divide shearing machine
comprises:-
- 'H' shaped rubber parts having a central hollow bore (4) and having
4 nos. of holes (5) at both side of round flanges manufactured by
machining from a cylindrical rubber part;
- two identical inverted metallic T shaped coupling holder having 4
nos. of holes (6) at round flange and having a centrally inside
thread part at back side;
- the 4 nos. holes of flange (5) of rubber coupling matches with 4
nos. holes (6) of flange of coupling holder are fixed with a
fastening means;
- one coupling holder is attached to encoder end and other coupling
holder is attached to gear box side.

2. The coupling device as claimed in claim 1, wherein coupling device
is made of neoprene rubber or ordinary rubber.
3. The coupling device as claimed in claim 1, wherein the 4 hole in the
flange are made at 90°C apart.

4. The coupling device as claimed in claim 1, wherein the metallic
coupling holder is made of steel material and the configure made
by machining.
5. The coupling device as claimed in claim 1, wherein the rubber
coupling and coupling holder are mounted by means of nuts and
bolts.
Dated this 21st day of October 2008.

The coupling device as shown in Fig 3B & 3C is made of rubber. A cylindrical shaped rubber roller is machined properly to form a 'H' shaped part. A central hollow boring is made by horizontal boring. Both the flanges have 4 nos. drilled holes having their centres at 90°C apart. A pair of matching flanges are made of
steel material for mounting with the rubber coupling. The encoder base is separated from bell housing to avoid multiple vibrations coming from gearbox housing through housing and this rubber coupling installed in between the
encoder and main shaft of gear box exerts better flexibility. A modified shaft with gradual diminishing in diameter is installed to avoid stress concentration.