Title of Invention

" AN IMPROVED ENTRY GUIDE FOR FEEDING STEEL BARS INTO ROLL-PASSES OF STRUCTURAL ROLLING MILLS"

Abstract The invention provides an improved entry guide for feeding steel bars into roll-passes of structural rolling mills, the said guide, being suitable for allowing uninterrupted and smooth entry of steel bars to be deformed in the roll passes with resultant reduction in generation of cobbles, increase in rolling rate and productivity of rolled sections and joists in the mills. The entry guide comprises; (i) a guide box of U-shaped cross section; (li) wedge headed bolt system for fixing the bottom of the guide box rigidly on a cramp bar, (iii) a downwardly sloppy portion of the said bottom at entry side of the guide box to support L-shaped guides, (iv) two guide plates of L-shaped cross section fitted inside the guide box with the vertical side of one guide plate placed adjacent to one vertical side of the guide box and the vertical side of the other guide plate placed adjacent to the opposite vertical side of the guide box and the horizontal sides of both guide plates resting on the bottom of the guide box, the gap between the vertical sides of the two guide plates bang made divergent at the entry end and convergent in the remaining part thereof and the inner surface of the part of vertical sides of the guide plates projected beyond exit end of the guide box up to roll pass being flat and smooth to facilitate proper alignment of bar with roll pass; and the part of the horizontal sides of both the guide plates lying at the entry end of the guide box bang made sloppy downwardly for smooth entry of bar, (v) packing plates of required thickness inserted between adjacent vertical sides of the guide box and guide plates to adjust the gap between the two guide plates; and (vi) means for fixing rigidly the vertical side of each guide plate to the bottom of the guide box and also to the adjacent vertical sides of the guide box along witth the packing plates inserted between them.
Full Text The present invention relates to an improved entry
guide for feeding steel bars into roll-passes of structural rolling mills.
An existing entry guide comprises essentially two separate metallic plates mounted side by side on a guide bar of rectangular cross section with their vertical planes parallel to each other and with a gap between them, which is substantially equal to and aligned with the corresponding roll-pass width.
The main drawback of the existing entry guide is that mounting of the two plates of the guide on the guide bar of rectangular cross section cannot be done with adequate tightness to prevent their displacement during the course of the 3nolling operations on the steel bars in rolling mills, causing misalignment of the guide with the roll-pass to cause interruption in the rolling operations and hence loss in production in rolling mills.
The object of the present invention is to provide an entry-guide of improved design and constructions, which can be mounted on the guide bar of modified cross section with adequate tightness so as to prevent any displacement of the guide plates during the course of the rolling operations in rolling mills.
Another object is to provide an entry guide which can be shifted easily from one roll-pass to another without disturbing the gap between the guide plates,
Yet another object is to provide an entry guide which provides gravitational support to the steel bars to be rolled and allows smooth entry and movement of the bars through it to the roll-pass without encountering any obstruction.
The invented entry guide comprises essentially a guide box of U-shaped cross section, having a bottom surface which is sloppy downwardly at the entry side for easy entry of steel bars into the guide. An improved means is provided for mounting the guide box on the guide bar of modified cross section, using devices for preventing any dislocation of the guide box during the course of the rolling operations in rolling mills. Two guide plates of L-shaped cross section are, fitted inside the guide box, the outer surface of the vertical side of one guide plate being disposed adoacent to the inner surface of one vertical side of the box and the outer surface of the vertical side of the other guide plate being disposed adjacent to the inner surface of the other vertical side of the box. The adjacent vertical sides of the guide plate and box are fixed to each other by means of nuts and bolts. The gap between the vertical sides of the two guide plates can be adjusted by inserting packing plates of required thickness between the adjacent vertical sides of the guide box and the guide plate. The vertical side of each guide plate is rigidly fixed to the bottom side of the box by means of nuts and bolts. The horizontal side of each guide plate is disposed inwardly to lie on the bottom
surface of the box and provides gravitational support to the bars moving through the gap between the vertical sides of the two guide plates towards the roll-pass during the rolling operations in rolling mills. At the entry side of steel bars the vertical sides of the two guide plates diverge from each other to provide a bell-shaped mouth to allow unobstructed entry of steel bars into the gap between the vertical sides of the two guide plates. At the exit side of steel bars, the curvature at the end of the vertical side of each guide plate is shaped to match with the outer curvature the roll forming the two lateral sides of a roll-pass with a view to guiding the steel bars to be rolled close to the roll-pass. The inner vertical surface of the two guide plates are machined flat and smooth to act as the bearing surface for the steel bars.
The invention is now described fully and particularly, without restricting the scope of the invention in any manner, with reference to the accompanying drawings in which -
Figure 1 is a view of the existing entry guide in the
vertical plane: Figure 2 is the view of the invented entry guide in the
horizontal plane; and Figure 3 is the view of section A-A in Figure 2,
Referring to Fig, 1, the existing entry guide comprises two vertical plates (2,3)ยป each being mounted on guide bars(12) of rectangular cross section and fixed to the guide bars by means
of nuts and bolts(8) and clamps(13). The guide bars are fitted on stand posts (not shown). At the exit end (19), the curvature at (16) in the vertical plane of the portions (17) of the guide plates is shaped to match with the curvature of rolls (14) for guiding the steel bars to be rolled close to the roll-pass (15). The two guide plates (2,3) remain straight and parallel to each other along their entire length from the exit end (17) to the entry end (18).
Referring to Figs. 2 and 3, the invented entry guide comprises a guide box (1) having cross section of U-shape and a downwardly sloppy tail (1A) at the entry end (18). Instead of using a guide bar (12) of reactangular cross section as in the existing entry guide (Fig. 1), a cramp bar (12A)of cross section tapering downwardly i.e. containing two tapered lateral sides is used for fixing the bottom (1B) of the guide box thereon. For this purpose a groove is provided at the bottom of the guide box, having a vertical edge (10) towards the entry end (18) and a slanting edge (9), with a taper matching with the adjacent tapered lateral side of the cramp bar (12) towards the exit end (17) of the guide box. After mounting the groove of the bottom of the guide box on the cramp bar with the slanting edge (9) of the said groove lying close to the adjacent tapered side of the cramp bar, two wedge heads (6) are pushed into the gap remaining between the vertical edge (10) of the said groove and the other tapered lateral side of the cramp bar, and fitted rigidly therein by means of nuts and bolts (7) passing through
each wedge and vertical side of the guide box. Two guide plates (2,3) of L-shaped crosssection, having vertical sides (2A,3A) and horizental sides (2B,3B), are fitted inside the guide box with the outer surface of their vertical sides lying close to the inner surface of the ad;3acent vertical side of the guide box. The vertical side of each guide plate is fixed to the bottom (1B) of the guide box rigidly by means of a pair of nuts and bolts (8). The gap between each vertical side of the guide box and that of the adjacent guide plate can be adjusted by inserting packing plate (4) of required thickness between them. The vertical side of each guide plate and the packing plate are fixed rigidly to the adjacent vertici side of the guide box by means of a pair of nuts and bolts (5).
The horizontal sides (2B,3B) of the two guide plates (2,3) are disposed inwardly to lie on the upper surface of bottom (1B) of the guide box and provide gravitational support to the bars to be rolled during their passage through the entry guide.
The horizontal sides (2B,3B) of the two guide plates are made sloppy downwardly to lie on the sloppy portion (1A) of the bottom of the guide box at the entry end thereof.
The vertical sides (2A,3A) of the two guide plates are made to deviate outwardly from each other at the entry end of the guide box. The gap between the vertical sides of the two guide plate is made to converge from the entry end to the exit end of the guide box and the inner surface of the portions (17) of the
vertical sides of the two guide plates are machined, flat and smooth, to act as the bearing for the bars to be rolled in the roll pass (15). The curvature (16) in the vertical plane of the portions (17) of the vertical sides of the two guide plates at the exit end of the guide box is made to coincide with the curvature of the rolls (16),
The location of the guide box on the cramp bar can be
changed easily without altering the gap between the vertical sides of
the two guide plates by loosening the fixing thereof by means of nuts and bolts (7). When a roll-pass gets worn out, the entry guide is shifted on cramp bar to be aligned with another roll-pass. The fastening arrangement of the guide box on the cramp bar prevents any misalignment of the entry guide with respect to the roll-pass and thereby ensures uninterrupted rolling operations in the rolling mills.
The invented entry guide is installed at the finishing, prefinishing and preleader passes for rolling of steel bars into channels and joists in a steel plant and extensive trials have been conducted under industrial production conditions. It has been found that
a) the generation of cobbles has reduced from the normal
3.5% to 2,5%.
b) The average rolling rate of the mill has increased from
the normal 36 T/hr to 39 T/hr.
c) The production in the mill has increased by more than
d) The overall performance of the mill has been highly
Satisfactory because of non-interruption of the rolling operations
by
causedi by.misalignment of the entry guide with respect to the roll-pass.





We claim:
1. An improved enty guide for feeding steel bars into roll-passes of structural rolling mills, the said guide, being suitable for allowing uninterrupted and smooth entry of steel bars to be deformed in the roll passes with resultant reduction in generation of cobbles, increase in rolling rate and productivity of rolled sections and joists in the mills, is characterized in that it comprises; (i) a guide box (1) of U-shaped cross section; (ii) wedge headed bolt system for fixing the bottom (1B) of the guide box rigidly on a cramp bar (12A), (iii) a downwardly sloppy portion (1A) of the said bottom at entry side (18) of the guide box to support L-shaped guides, (iv) two guide plates (2.3) of L-shaped cross section fitted inside the guide box with the vertical side (2A) of one guide plate placed adjacent to one vertical side of the guide box and the vertical side (3A) of the other guide plate placed adjacent to the opposite vertical side of the guide box and the horizontal sides (2B, 38) of both guide plates resting on the bottom (1B) of the guide box, the gap between the vertical sides of the two guide plates being made divergent at the entry end (18) and convergent in the remaining part thereof and the inner surface of the part of vertical sides of the guide plates projected beyond exit end (19) of the guide box up to roll pass (15) being flat and smooth to facilitate proper alignment of bar with roll pass; and the part of the horizontal sides of both the guide plates lying at the entry end of the guide box being made sloppy downwardly for smooth entry of bar, (v) packing plates (4) of required thickness inserted between adjacent vertical sides of the guide box and guide plates to adjust the gap between the two guide plates; and (vi) means, such as herein described, for fixing rigidly the vertical side of each guide plate to the bottom of the guide box and also to the adjacent vertical sides of the guide box along with the packing plates inserted between them.
2. The entry guide as claimed in claim 1, wherein the means for fixing the bottom of the guide box rigidly to the cramp bar of mill housing comprises a groove at the bottom of the guide box, having vertical edge (10) towards the said entry end with a slanting surface (9) towards the said entry end of the guide box, two tapered lateral sides of cramp bar (12), two wedge heads (6) with central hole inserted into the gap between the said vertical edge of the groove and adjacent tapered lateral side of the cramp bar, and nuts and bolts (7) passing through each said wedge heads hole an vertical side of the guide box.
3. the entry guide as claimed in claim 1 or 2, wherein the means for fixing rigidly the vertical side of each guide plate to the bottom of the guide box comprises a pair of nuts and bolts (8) and that for fixing rigidly the vertical side of each guide plate along with the packing plates to the adjacent vertical side of the guide box comprises a pair of nuts and bolts (5).

Documents:

147-del-1997-abstract.pdf

147-del-1997-claims.pdf

147-del-1997-complete specification (granted).pdf

147-del-1997-correspondence-others.pdf

147-del-1997-correspondence-po.pdf

147-del-1997-description (complete).pdf

147-del-1997-drawings.pdf

147-del-1997-form-1.pdf

147-del-1997-form-19.pdf

147-del-1997-form-2.pdf

147-del-1997-form-3.pdf

147-del-1997-gpa.pdf

abstract.jpg


Patent Number 256825
Indian Patent Application Number 147/DEL/1997
PG Journal Number 31/2013
Publication Date 02-Aug-2013
Grant Date 31-Jul-2013
Date of Filing 20-Jan-1997
Name of Patentee STEEL AUTHORITY OF INDIA LTD.,RESEARCH & DEVELOPMENT CENTRE
Applicant Address IRON & STEEL ENTERPRISE, ISPAT BHAWAN,LODI ROAD, NEW DELHI-110003,INDIA.
Inventors:
# Inventor's Name Inventor's Address
1 DAYA SHANKAR GUPTA RDCIS,SAIL,DORANDA,RANCHI-834 002, INDIA.
2 RABINDRA SHUKLA RDCIS,SAIL,DORANDA,RANCHI-834 002, INDIA.
3 BIMALENDRA ROY RDCIS,SAIL,DORANDA,RANCHI-834 002, INDIA.
4 BASUDEO ROY RDCIS,SAIL,DORANDA,RANCHI-834 002, INDIA.
PCT International Classification Number B22D 11/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA