FIELD OF THE INVENTION
[001]The present invention relates to cooling bed rotary arm transfer (RAT)
system in a seamless steel manufacturing plant. Moreover, the present
5 invention in particular relates to a method to detect tube occupancy and
interlock for RAT, when to operate if tubes are occupied. Further, the
invention relates to a method of safeguarding RAT bucket. BACKGROUND OF THE INVENTION
10 [002] Background description includes information that may be useful in
understanding the present subject matter. It is not an admission that any
of the information provided herein is prior art or relevant to the presently
claimed subject matter, or that any publication specifically or implicitly
referenced is prior art.
15 [003] In the process of seamless steel tube manufacturing, the final hot
finished tubes come from Stretch Reducing Mill (SRM). These tubes
transferred to walking beam type Cooling Bed to allow natural cooling. By
the time hot finished tubes reaches the end of Cooling Bed, temperature
drops down to approximately 70°C. Then layer of tubes of maximum width
20 800 mm transferred to Cold Saw (CS) Roller Conveyor (RC) line with the
help of RAT bucket system.
[004] During this process, if any pre-occupied tubes present in anywhere
(span of 65 meters) of RC line, RAT system shall operate and foul with
25 tube(s). In this case, it is not possible to identified the damaged tube and
also not able to trace the tube.
[005] Figure 1 illustrates the existing RAT bucket system and figure 3
illustrates CS RC line and no sensor installed to detect tube occupancy.
3
Figure 1 illustrates RAT system operation without tube occupancy interlock.
Moreover, fig1 shows the single line diagram system before implementing
5 the sensors interlock. Figure 1a shows the control circuit and figure 1b
shows the power circuit having switchgear and electric motor. The terms K
means control contactor coil, PC means power contactor coil, MCCB means
moulded case circuit breaker for the protection of Motor, OLR means over
load relay and M is the three phase squirrel cage induction motor which
10 drives the Rotary arm transfer bucket system. Figure 3 illustrates an existing
CS RC line system with few tubes occupied on the roller conveyor bed (1). During normal operation, RAT system doesn’t know whether anywhere on
RC bed (2) tubes are occupied or not. Further in Figure 3, the reference
numeral 2 indicates that the roller is driven by electrical motor (7) and by
15 using gearbox mechanism (6). If one cycle operation push button pressed
from operator desk, RAT start moving and it will foul with pre occupied
tubes (1). Thus, the RAT buckets may bend or fail.
[006] Hence, there is no mechanism to detect tube occupancy on RC line.
20 This resulting frequent RAT bucket failure. Therefore, there is a need for a
method and a system to overcome above problems.
OBJECTS OF THE INVENTION
[007] In view of the foregoing limitations inherent in the state of the art, some
25 of the objects of the present disclosure, which at least one embodiment herein
satisfy, are listed herein below.
[008]The primary object of the present invention is to propose a method of
safe guarding Cooling Bed RAT buckets from failure of gear mechanism
during fouling with tube (s) on Cold Saw RC line in a process of tube
30 manufacturing.
4
[009]Another object of the present invention is to propose a method of safe
guarding Cooling Bed RAT buckets from failure of gear mechanism, in which
5 a system to detect tube occupancy on Cold Saw RC line and interlock for
RAT bucket system not to operate if tubes are occupied.
[010] These and other objects and advantages of the present invention
will be apparent to those skilled in the art after a consideration of the
10 following detailed description taken in conjunction with the accompanying
drawings in which a preferred form of the present invention is illustrated.
SUMMARY OF THE INVENTION
[011] One or more drawbacks of conventional system/method for
15 finding/detecting out the tubes which are occupied in COLD SAW RC line
and other problems are overcome, and additional advantages are provided
through the system in the present disclosure. Additional features and
advantages are realized through the technicalities of the present disclosure.
Other embodiments and aspects of the disclosure are described in detail
20 herein and are considered to be part of the claimed disclosure.
[012] The present invention is directed to a method of safe guarding a RAT
(Rotary Arm Transfer) bucket system, while transferring layer of tubes from
walking beam type cooling bed (CB) to Cold Saw (CS) RC line, in tube
manufacturing process, the method comprising the steps of: acquiring real
25 time feedback of RC (Roller Conveyor) bed line of tube occupancy by using
LB sensors (LB1, LB2, LB3, LB4, LB5, LB6, LB7) fitted on the roller bed;
enabling or disabling the power to RAT (Rotary Arm Transfer) bucket
system based on LB (light barrier) sensor feedback; indicating the tube
occupancy details by using GREEN signal and RED signal from the reflector,
5
wherein green signal refers there is no tubes occupied in the system and
RED signal refers tubes are occupied and RAT bucket system shall not
5 operate due to non-supply of power to said system; and displaying the
details of tube which is/ are occupied by using display unit connected with
the system.
[013] In the embodiment of the present invention, there is provided a
10 method of safe guarding Cooling Bed (CB) RAT buckets from failure of gear
mechanism during fouling with tube (s) on Cold Saw (CS) RC line in a
process of tube manufacturing. Total 7 numbers Light Barrier (LB) sensors
installed on Cold Saw RC bed line at regular intervals which covers entire
cooling bed with accommodating minimum tube length of 10 mtrs. Based
15 on seven sensors feedback ready for operation interlock flag made using
Programmable Logic Controller in ladder language.
[014] In the embodiment of the present invention, the method is used to
detects that tube (s) occupied anywhere within 65 mtrs length, ready for
20 operation flag is disable and RAT bucket system shall not operate.
[015] In the embodiment of the present invention, the method is used to
detects that tube (s) are not occupied anywhere within 65 mtrs length,
ready for operation flag is enable and RAT bucket system shall operate.
25
[016] The preferred embodiment of the present invention is having other
features and advantages which are disclosed in the appended dependent
claims.
[017] Other objects, features, and advantages of the present disclosure will
30 become apparent from the following detailed description. It should be
6
understood, however, that the detailed description and the specific
examples, while indicating specific embodiments of the invention, are given
by way of illustration only, since various changes and modifications within
5 the spirit and scope of the invention will become apparent to those skilled
in the art from this detailed description.
[018] Various objects, features, aspects and advantages of the inventive
subject matter will become more apparent from the following detailed
description of preferred embodiments, along with the accompanying
10 drawing figures in which like numerals represent like components.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[019] The illustrated embodiments of the subject matter will be best
understood by reference to the drawings, wherein like parts are designated
15 by like numerals throughout. The following description is intended only by
way of example, and simply illustrates certain selected embodiments of
apparatus that are consistent with the subject matter as claimed herein,
wherein:
[020] Figure 1a and 1b: illustrates an existing RAT bucket system operation. 20 Figure 1a shows the control circuit and figure 1b shows the power circuit
having switchgear (6) and electric motor(7).
[021] Figure 2a and 2b: illustrates the improvised RAT bucket system
operation according to the present invention. Moreover, figure 2a shows
25 the illustration of control circuit incorporates with seven LB sensors (LB1,
LB2, LB3, LB4, LB5, LB6, and LB7) for detecting tube occupancy on the
roller bed. Figure 2b represents power circuit with switchgear. The terms in
the figure 2a and 2b represents that K1 means RAT ready to ON command
7
coil, K2 means control contractor coil get de-energise if any one of the
sensors detected with tubes, PC means power contactor coil, MCCB means
5 moulded case circuit breaker for the protection of Motor, OLR means over
load relay and M is the three phase squirrel cage induction motor which
drives the Rotary arm transfer bucket system.
[022] Figure 3 illustrates the CS RC line and no sensor installed to detect
10 tube occupancy. Further the reference numeral 1 indicates layer of tubes
on the roller conveyor bed, reference numeral 2 indicates that the roller is
driven by electrical motor (7) and by using gearbox mechanism (6).
[023] Figure 4 illustrates the LB sensor, CS RC line and few tubes occupied
15 on RC bed. Further the reference numeral 1 indicates layer of tubes on the
roller conveyor bed, reference numeral 2 indicates that the roller is driven
by electrical motor (7) and by using gearbox mechanism (6), reference
numeral 3 means Light barrier with no detection of tubes by indicating
GREEN signal, and reference numeral 4 means Light barrier with detection
20 of tubes by indicating RED signal.
[024] Figure 5 illustrates sensors unit comprising reflector and light barrier
(LB) sensor.
25 [025] The figures depict embodiments of the disclosure for purposes of
illustration only. One skilled in the art will readily recognize from the
following description that alternative embodiments of the structures and
methods illustrated herein may be employed without departing from the
principles of the disclosure described herein.
30
8
DETAILED DESCRIPTION OF THE INVENTION
[026] The detailed description of various exemplary embodiments of the
5 disclosure is described herein with reference to the accompanying drawings.
It should be noted that the embodiments are described herein in such details
as to clearly communicate the disclosure. However, the amount of details
provided herein is not intended to limit the anticipated variations of
embodiments; on the contrary, the intention is to cover all modifications,
10 equivalents, and alternatives falling within the spirit and scope of the present
disclosure as defined by the appended claims.
[027] It is also to be understood that various arrangements may be devised
that, although not explicitly described or shown herein, embody the
15 principles of the present disclosure. Moreover, all statements herein reciting
principles, aspects, and embodiments of the present disclosure, as well as
specific examples, are intended to encompass equivalents thereof.
[028] The terminology used herein is for the purpose of describing particular
embodiments only and is not intended to be limiting of example
20 embodiments. As used herein, the singular forms “a”, “an”, and “the” are
intended to include the plural forms as well, unless the context clearly
indicates otherwise. It will be further understood that the terms “comprises”,
“comprising”, “includes”, “consisting” and/or “including” when used herein,
specify the presence of stated features, integers, steps, operations, elements
25 and/or components, but do not preclude the presence or addition of one or
more other features, integers, steps, operations, elements, components
and/or groups thereof.
[029] It should also be noted that in some alternative implementations, the
functions/acts noted may occur out of the order noted in the figures. For
9
example, two figures shown in succession may, in fact, be executed
concurrently or may sometimes be executed in the reverse order, depending
5 upon the functionality/acts involved.
[030] Unless otherwise defined, all terms (including technical and scientific
terms) used herein have the same meaning as commonly understood by one
of ordinary skill in the art to which example embodiments belong. It will be
further understood that terms, e.g., those defined in commonly used
10 dictionaries, should be interpreted as having a meaning that is consistent
with their meaning in the context of the relevant art and will not be
interpreted in an idealized or overly formal sense unless expressly so defined
herein.
[031] The present invention is directed to a method of safe guarding a RAT
15 (Rotary Arm Transfer) bucket system, while transferring layer of tubes from
walking beam type cooling bed (CB) to Cold Saw (CS) RC line, in tube
manufacturing process, the method comprising the steps of: acquiring real
time feedback of RC (Roller Conveyor) bed line of tube occupancy (1) by
using LB sensors (LB1, LB2, LB3, LB4, LB5, LB6, LB7) fitted on the roller
20 bed; enabling or disabling the power to RAT (Rotary Arm Transfer) bucket
system based on LB (light barrier) sensor feedback; indicating the tube
occupancy details by using GREEN signal (3) and RED signal (4) from the
reflector, wherein green signal (3) refers there is no tubes occupied in the
system and RED signal (4) refers tubes are occupied and RAT bucket system
25 shall not operate due to non-supply of power to said system; and displaying
the details of tubes which are occupied by using display unit connected with
the system.
10
[032] The present invention relates to a method of safeguarding Cooling
Bed (CB) RAT buckets from failure of gear mechanism during fouling with
5 tube (s) on Cold Saw RC line in a process of tube manufacturing,
implemented in a Walking Beam type Cooling Bed system
comprising/having a RAT bucket system to transfer layer of tubes from CB
to CS RC bed, seven numbers of light barrier sensors; seven numbers of
reflector plates; Siemens S7 300 Digital Input Card; PLC Ladder logic; the
10 method comprising the steps of getting real time feedback of RC bed line
tube occupancy using LB sensors; enabling or disabling the power to RAT
bucket system based on LB sensor feedback, leading the RAT bucket system
to operate safely.
15 [033] There are three modes of operation performed in the RAT system as
discussed: Manual (inching), One cycle and Automatic mode of operation. During Manual (inching) operation mode, operator has to press
continuously the Cycle run Push button to enable the Rotary Transfer bucket
system to operate. If cycle run push button is released, then immediately
20 stop command goes to RAT. This operation mainly used for tool change, home position setting etc.
[034] During One Cycle mode of operation, Operator has to press once the
cycle run push button to enable the Rotary Transfer bucket system to
25 operate. RAT system starts from home position and makes a full revolution
before it stops. To start next cycle operator needs to press the cycle run
push button again. This mode is intended to enable cycle start even though
transfer bed is not full.
30 [035] During Auto Cycle mode of operation, Operator interference is NILL.
Whenever Cooling Bed transfer bed is full, RAT starts operating and
11
transfers the layer of tubes to RC bed and wait until Cooling Bed transfer
bed is filled again. In all the above operations the method is applicable in
5 the system occupied with sensor interlock to safeguard the RAT bucket
system.
[036] In the embodiment of the present invention, there is provided a
method of safe guarding Cooling Bed RAT buckets from failure of gear
10 mechanism during fouling with tube (s) on Cold Saw RC line in a process of
tube manufacturing. Total seven numbers Light Barrier (LB) sensors
installed on Cold Saw RC bed line at regular intervals which covers entire
cooling bed with accommodating minimum tube length of 10 mtrs. Based
on seven sensors feedback ready for operation interlock flag made using
15 Programmable Logic Controller in ladder language as shown in the figure 2. Figure 2 further illustrates the single line diagram system after introduction
of sensors interlock. Moreover, figure 2a shows the illustration of control
circuit incorporates with seven LB sensors (LB1, LB2, LB3, LB4, LB5, LB6,
and LB7) for detecting tube occupancy on the roller bed. Figure 2b
20 represents power circuit with switchgear. The terms in the figure 2
represents that K1 means RAT ready to ON command coil, K2 means control
contractor coil get de-energise if any one of the sensors detected with
tubes, PC means power contactor coil, MCCB means moulded case circuit
breaker for the protection of Motor, OLR means over load relay and M is
25 the three phase squirrel cage induction motor which drives the Rotary arm
transfer bucket system.
[037] The sensors unit is configured with two portion: one is Light barrier
and other one is reflector as shown in figure-5. Each sensors are placed on
30 RC bed line of roller bed in an interval of 10 mtrs.
12
[038] In the embodiment of the present invention, figure 4 illustrates CS
RC line and LB sensor installed to detect tube occupancy. Moreover, figure
5 4 illustrates the system with LB sensors (LB1, LB2, LB3, LB4, LB5, LB6, and
LB7), CS RC line (6 (gear box transmission) & 7 (electric motor)) with few
pre-occupied tubes on RC bed. During operation, RAT system aware that
whether anywhere on RC bed tubes are available or not by using claimed
method. The method is used for safeguarding Cooling Bed RAT buckets
10 from failure of gear mechanism during fouling with tube (s) on Cold Saw
RC line in a process of tube manufacturing, while transferring layer of tubes
from Walking Beam type Cooling Bed (CB) to Cold Saw RC line. If one cycle
operation push button pressed from operator desk, RAT will check the
feedback of all 7 LB sensor feedback and then main power contactor will
15 energize. LB GREEN (3) status is meant that there are no tubes occupied
and LB RED (4) means tubes are occupied and it shall not let RAT bucket
system to operate.
TECHNICAL ADVANTAGE
20 [039] One of the advantages of the present invention is that, the draw
backs of the prior art are eliminated and there is a substantial savings time
and increases machine availability.
[040] Another advantages of the present invention is that all the sensors
25 are glowing Green i.e. tubes are not occupied on the entire length of RC
bed and RAT bucket system shall operate by getting the power.
[041] Another advantages of the present invention is that all the sensors
or out of seven any one LB sensor are glowing RED i.e. tube or tubes is/are
30
13
occupied on the entire length of RC bed. RAT bucket system shall not
operate.
5
[042] Another advantages of the present invention is that the performance
of the system is improved.
[043] Thus, the present invention is having above advantages which are
10 reduced time taken for detecting tube occupancy in the system. [044] Furthermore, each of the appended claims defines a separate
invention, which for infringement purposes is recognized as including
equivalents to the various elements or limitations specified in the claims.
Depending on the context, all references below to the “invention” may in
15 some cases refer to certain specific embodiments only. In other cases, it
will be recognized that references to the “invention” will refer to subject
matter recited in one or more, but not necessarily all, of the claims.
[045] Groupings of alternative elements or embodiments of the invention
disclosed herein are not to be construed as limitations. Each group member
20 can be referred to and claimed individually or in any combination with other
members of the group or other elements found herein. One or more
members of a group can be included in, or deleted from, a group for reasons
of convenience and/or patentability. When any such inclusion or deletion
occurs, the specification is herein deemed to contain the group as modified
25 thus fulfilling the written description of all groups used in the appended
claims.
[046] Furthermore, those skilled in the art can appreciate that the
terminology used herein is for the purpose of describing particular
14
embodiments only and is not intended to be limiting of the present
disclosure. It will be appreciated that several of the above-disclosed and
other features and functions, or alternatives thereof, may be combined into
5 other systems or applications. Various presently unforeseen or
unanticipated alternatives, modifications, variations, or improvements
therein may subsequently be made by those skilled in the art without
departing from the scope of the present disclosure as encompassed by the
following claims.
10 [047] The claims, as originally presented and as they may be amended,
encompass variations, alternatives, modifications, improvements,
equivalents, and substantial equivalents of the embodiments and teachings
disclosed herein, including those that are presently unforeseen or
unappreciated, and that, for example, may arise from applicants/patentees
15 and others.
[048] While the foregoing describes various embodiments of the present
disclosure, other and further embodiments of the present disclosure may
be devised without departing from the basic scope thereof. The scope of
the present disclosure is determined by the claims that follow. The present
20 disclosure is not limited to the described embodiments, versions or
examples, which are included to enable a person having ordinary skill in the
art to make and use the invention when combined with information and
knowledge available to the person having ordinary skill in the art.

WE CLAIM:

1. A method of safe guarding a RAT (Rotary Arm Transfer) bucket
system, while transferring layer of tubes from walking beam type
cooling bed (CB)(1) to Cold Saw (CS) RC line, in tube manufacturing
process, the method comprising the steps of: - acquiring real time feedback of RC (Roller Conveyor) bed line of tube
occupancy (1) by using LB sensors (LB1, LB2, LB3, LB4, LB5, LB6,
LB7) fitted on the roller bed;
- enabling or disabling the power to RAT (Rotary Arm Transfer) bucket
system based on LB (light barrier) sensor feedback;
- indicating the tube occupancy details by using GREEN signal(3) and
RED signal(4) from the reflector, wherein green signal refers there is
no tubes occupied in the system and RED signal refers tubes are
occupied and RAT bucket system shall not operate due to non-supply
of power to said system; and
- displaying the details of tube which is/ are occupied by using display
unit connected with the system.
2. The method as claimed in claim 1, wherein if the sensor detects that
tubes are occupied on the roller bed indicating by blinking RED signal
(4), and there is no power supplied to the RAT bucket system until
the RC line vacant.

3. The method as claimed in claim 1, wherein if the sensor detects that
tubes are no occupied on the roller bed indicating by blinking GREEN
signal (3) and this condition enables power supply to the RAT bucket
system.
4. The method as claimed in claim 1, wherein there are seven LB
sensors (LB1, LB2, LB3, LB4, LB5, LB6, LB7) are
placed/fitted/configured on the roller bed to provide the occupancy
details of tube (1) during transferring layer of tubes from walking
beam type cooling bed to cold saw RC line.
5. The method as claimed in claim 1, wherein each of the LB sensor
unit fitted in the system, in the interval of a predetermined distance
(example 10 mtrs), consists of two portion as light barrier for
detecting the tube occupancy details and reflector for indicating of
tube occupancy details by using GREEN (3) or RED (4) signal.