FORM 2THE PATENT ACT 1970(39 OF 1970)&The Patent Rules, 2003COMPLETE SPECIFICATION(See Section 10 and Rule 13)1 TITLE OF THE INVENTION :COLLISION AVOIDANCE DEVICE FOR INGOT BUGGY.2 APPLICANT (S)Name : STEEL AUTHORITY OF INDIA LIMITED.Nationality : A Govt, of India Enterprise; Bhilai Steel Plant, Bhilai, State of Chattisgarh,India.3 PREAMBLE TO THE DESCRIPTIONCOMPLETE The following specification particularly descibes the invention and the manner in which it is to be performed.

FIELD OF THE INVENTION
The present invention relates to a device to control of speed of buggy carrying bloom or billet, used to transport hot blooms from soaking pit and deliver to the receiving roll tables in order to avoid damage due to collision. The present invention can sense the over speed, trip and stop the buggy prior to reaching to the roll table, operatively through said collision avoidance device comprising a hardware based relay logic circuit. The device of the invention is directed to providing two stages of braking for precise stoppage of the buggy at receiving roll table, without which either the buggy or the receiving table is subjected to severe damage due to over travel with huge momentum of the buggy moving at high speeds loaded with tons of blooms. The device according to the invention can be effectively used where no speed check circuit is available; alternatively the same device can be used as a second line of protection where speed check circuit is present. The collision avoidance device of the invention is a hardware based relay logic circuit that comprises current relays, timers, and auxiliary relays operatively controlling speed/apply brake based on sensing time taken to travel through fixed distance and by tripping of a line contactor is initiated to precisely and instantaneously stopping the buggy at right spot without damaging any equipment. The invention thus provide for a fail safe device to totally eliminate crashing of Bloom buggy against the receiving roll table thereby saving financially from the damages otherwise would have been suffered; and also enhances mill operating/availability time boosting up the productivity and is thus capable of wide industrial applications in similar large integrated steel plants.
BACKGROUND ART
It is well known in the field of large steel making, casting and rolling plants, that the ingot buggies are used to transport the blooms and billets after being cast, from the soaking pit to the respective receiving roll tables for subsequent rolling operation to obtain different section sizes. It is a common experience in such in-house transportation of buggy carrying blooms/billets that serious repetitive breakdowns takes place because of over travel of the high travel speed of buggy without means for precise braking/stopping at desired position. This caused huge damage not only of the receiving roll tables but also the buggy. The usual speed of the ingot buggy travel is 5 meters/sec. Normally, for horizontal movement no provision was available for sensing the over speed, controlling and stopping the buggy prior to reaching to the roll receiving table without

causing damage, eliminating the possibility of any damage due to the over travel of buggy dashing against the roll table.
There has been therefore a need for a fail safe device that would sense the speed of the travel of buggy carrying blooms and precisely control the speed limit and initiate application of brake such that the buggy is stopped in right position without causing any damage either to roll table or to the buggy itself, due to over travel and thereby save loss of production and ensure safe operation in sections of large steel plants.
OBJECTS OF THE INVENTION
It is thus the basic object of the present invention to provide a collision avoidance device for the high speed traveling bloom buggy by controlling and precisely stopping the buggy at a desired location near the receiving roll table without crashing against it due to over travel and thereby saving huge damages and downtime costs.
A further object of the present invention is directed to providing a system/device, which can sense over speed, trip and stop the buggy prior to reaching to the roll table.
A still further object of the present invention directed to said collision avoidance device to work on the principle that is effectively applicable where no speed check circuit is available for motion control or can be used as a second line of protection where speed check circuit is available.
A still further object of the collision avoidance device of the present invention is directed to sense the speed of travel by measuring the time taken to travel through a fixed predetermined distance such that the speed is controlled based on the actual time taken is more or less than the normal predetermined value.
A still further object of the collision avoidance system whereby the time taken for traveling through predefined distance is sensed such that it indicate more than desired speed indicative of not stopping the buggy at right place or there is possibility of an imminent collision, tripping of line contactor is initiated such that stopping the buggy at the proper place avoiding collision is ensured.

A still further object of the collision avoidance system of the present invention is directed to speed control and stopping of ingot buggy for blooming mill at the right place before the roll receiving table, based on a hardware based relay logic circuit that works reliably irrespective of the track condition or current collector assembly or the electrical/mechanical condition of the buggy in operation.
SUMMARY OF THE INVENTION
Thus according to the basic aspect of the invention there is provided a collision avoidance device for ingot buggy delivering blooms to receiving roll table in blooming mill, comprising
a hardware based relay logic circuit comprising the current relays, time delay relay and auxiliary relays operatively sensing and controlling the speed of the buggy;
the speed of buggy is sensed by sensing the time taken to travel a fixed distance at the first stage of control;
said time sensed if is less than a preset value that is constant for a given speed of buggy, it is indicative of higher than desired speed of travel such that the circuit operatively initiates tripping of the line contactor causing the buggy to come to a halt before reaching to or dashing against the receiving roll table.
A further aspect of the present invention directed to said collision avoidance device for ingot buggy delivering blooms to receiving roll table in blooming mill, wherein the device is adapted to operate effectively where no speed check circuit is available for motion control or can be used as a second line of protection when speed check circuit is available.
According to another important aspect of the present invention directed to a method for collision avoidance for ingot buggy delivering blooms to receiving roll table in blooming mill by the use of the device, wherein

the speed control achieved in two stages of braking of the buggy;
for precise stoppage of the high speed buggy, the time taken to travel across fixed distance between two columns selectively spaced apart is sensed, in the region of the first stage;
said sensing of time taken to travel is operatively performed by the current relays and the time delay relays in the logic circuit of the device;
the relative magnitude of the time sensed helps deciding the corrective action to initiate in the next stage including tripping of the line contactor to control over travel/stoppage of the ingot buggy.
A still further aspect of the collision avoidance device of the present invention directed to speed control of the ingot buggy delivering blooms to receiving roll table in blooming mill, wherein the relay logic circuit of the device is adapted to precisely sense the speed of the ingot buggy irrespective of the conditions of non-alignment of trolley line/track maintenance, current controller assembly, failure of mechanical or electrical component failure of the buggy.
According to yet another aspect of the present invention directed to a collision avoidance device for ingot buggy delivering blooms to receiving roll table in blooming mill, wherein the configuration of the speed sensing device brings the movement of the ingot buggy in to a time frame such as to favor achieving said speed control and collision avoidance by monitoring/ initiating positive action, irrespective of condition of track/buggy.
According to a further aspect of the present invention directed to a collision avoidance device for ingot buggy delivering blooms to the receiving roll table, said device operatively ensure saving damages to either the buggy or the roll table, increased mill availability, reducing cost of repair maintenance and thereby improve overall productivity;
The present invention its advantages and objects are described in greater details with reference to the accompanying non-limiting illustrative diagram.

BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURES
Figure 1: is the illustration of the circuit diagram of the hardware based relay logic circuit comprising various components, and its operative connection to the line contactor.
DETAILED DESCRIPTION WITH REFERENCE TO THE ACCOMPANYING FIGURES
The present invention is directed to providing a collision avoidance system/device for speed control and stopping of the ingot buggy for the blooming and billet mills, which are normally used for transporting hot blooms from soaking pit and delivers to the receiving roll tables. The usual speed of the ingot buggy is preferably maintained at 5 meters /sec. The precise stoppage of the ingot buggy is achieved in two stages at receiving roll table. The device according to the present invention is capable to check the speed and take corrective action as necessary to avoid damage due to high-speed travel of the buggy, crashing against the receiving roll table due to over travel failing to stop at right place. Moreover, the invention is directed to advantageously avoiding such damages caused due to the buggy dashing at high momentum with receiving roll table, by sensing the over speed based on measuring time taken to travel across two fixed columns, which when compared against a predetermined speed, detects the quantum of over speed and accordingly it trips the circuit and stops the buggy prior to reaching the roll table. More advantageously, the device according to the present invention stops the buggy over travel by sensing its traveling speed/time of travel for a prefixed distance such as to control the speed or tripping the contactor to bring it to halt immediately.
The collision avoidance system device of the present invention is hardware based relay logic circuit that comprises of current relays, timers and auxiliary relays. At any particular speed, the travel time between two fixed points is constant. The device sense the travel speed between two predetermined fixed columns, along the track on which the buggy travels at selective location such that if the time recorded is more, it indicates that the speed is less and vice versa. The device is used to sense the over travel and take corrective action immediately. In the region of the first stage of braking, the time taken to travel of the buggy across two predetermined columns at a fixed distance and at selective location along side the track on which the buggy runs, is sensed through two current relays and time delay relays. If the time of travel by the buggy over the said

prefixed distance is less then it is concluded that the braking is not proper and speed is on higher than desired level and a tripping of the line contactor is initiated.
Reference is now invited to the accompanying Figure 1, wherein the circuit diagram for the hardware based relay logic circuit according to the invented collision avoidance device of the present invention has been illustrated. A 220v DC supply is supplied across the groups of current relays, time delay relay, auxiliary relay etc. Here, in the circuit the current relay (IP 0) or P 31 are in series connection with the time delay Relay (TDR-1) and an auxiliary relay R-l across the time delay relay in parallel through a push button switch has been arranged. Here, the time taken to travel a fixed distance at the first stage between two columns at predefined locations is sensed. In the region of the first stage of braking, two columns with selective spacing has been chosen and the time taken to travel the distance is sensed through two current relays and time delay relay. If the time taken is less or the speed of buggy is more a tripping of line contactor is initiated such that the buggy is stopped before it reaches or crash against the receiving roll table and thereby the damage due to over travel and crashing caused either to the ingot buggy or the receiving roll table is avoided. The hardware based relay logic circuit is thus fail safe and enable working of the collision device with reliability even when the track or buggy conditions are not in perfect order i.e. the device is capable to function irrespective of the track/trolley line condition or misalignment, current collector assembly or the electrical or mechanical condition of the ingot buggy and the buggy speed is correctly monitored and positive action initiated.
It is thus possible by way of the device of this invention to sense the travel speed of the ingot buggy transporting the hot blooms from the soaking pit to deliver to the receiving roll table and avoid damage due to collision of the buggy against the roll table by sensing the speed of buggy in terms of the time of travel across a predefined fixed distance, and thereby ensuring saving loss of production, higher mill availability, less repair/maintenance cost and reliable and safe operation in material transfer in large steel plants, irrespective of the operating condition of the track or the buggy.

We Claim:
1. A collision avoidance device for ingot buggy delivering blooms to receiving roll
table in blooming mill, comprising
a hardware based relay logic circuit comprising the current relays, time delay relay and auxiliary relays operatively sensing and controlling the speed of the buggy;
the speed of buggy is sensed by sensing the time taken to travel a fixed distance at the first stage of control;
said time sensed if is less than a preset value that is constant for a given speed of buggy, it is indicative of higher than desired speed of travel such that the circuit operatively initiates tripping of the line contactor causing the buggy to come to a halt before reaching to or dashing against the receiving roll table.
2. A collision avoidance device for ingot buggy delivering blooms to receiving roll table in blooming mill, as claimed in claim 1, adapted to operate effectively where no speed check circuit is available for motion control or as a second line of protection when speed check circuit is available.
3. A method for collision avoidance for ingot buggy delivering blooms to receiving roll table in blooming mill by the use of the device, as claimed in claims 1 and 2, wherein
the speed control achieved is in two stages of braking of the buggy;
for precise stoppage of the high speed buggy, the time taken to travel across fixed distance between two columns selectively spaced apart is sensed, in the region of the first stage;
said sensing of time taken to travel is operatively performed by the current relays and the time delay relays in the logic circuit of the device;

the relative magnitude of the time sensed provides for the corrective action in the next stage including tripping of the line contactor to control over travel/stoppage of the ingot buggy.
4. A collision avoidance device for ingot buggy delivering blooms to receiving roll table in blooming mill, as claimed in anyone of claims 1 to 3, wherein the relay logic circuit of the device is adapted to precisely sense the speed of the ingot buggy irrespective of the conditions of non-alignment of trolley line/track maintenance, current controller assembly, failure of mechanical or electrical component failure of the buggy.
5. A collision avoidance device for ingot buggy delivering blooms to receiving roll table in blooming mill, as claimed in anyone of claims 1 to 4, wherein the configuration of the speed sensing device is adapted to bring the movement of the ingot buggy in to a time frame such as to favor achieving said speed control and collision avoidance by monitoring/ initiating positive action, irrespective of condition of track/buggy.
6. A collision avoidance device for ingot buggy delivering blooms to the receiving roll table in blooming mills, as claimed in anyone of claims 1 to 5, where in said device operatively ensures saving damages to either the buggy or the roll table caused due to over travel, increased mill availability, reducing cost of repair maintenance and thereby improve overall productivity.
7. A collision avoidance device for ingot buggy delivering blooms to receiving roll table in blooming mill and a method for time dependent speed control of buggy reliably enabling precise stoppage of the ingot buggy avoiding damage due to crashing against the roll table substantially as herein described with reference to the accompanying non-limiting illustrative diagram.

ABSTRACT
Title : COLLISION AVOIDANCE DEVICE FOR INGOT BUGGY .
The present invention relates to a device to control the speed of ingot buggy carrying hot blooms from soaking pit to receiving roll tables, to avoid damage due to collision. The device senses the over speed, trips and stops the buggy prior to reaching to the roll table, through a hardware based relay logic circuit, providing two stages of braking comprising current relays, timers, and auxiliary relays in said circuit, operatively controlling speed sensing time taken to travel through a fixed distance in the first stage and by tripping of a line contactor initiated in the second stage to precisely stopping the buggy without damaging any equipment. Said device can be effectively used where no speed check circuit is available or as a second line of protection where speed check circuit is present. A fail safe method to curb collision of ingot buggy against the receiving roll table so obtained, save financial loss due to damages, enhances mill availability at reduced maintenance cost and improves productivity making the device worthy of wide industrial applications.
Figure 1.