FORM 2 THE PATENTS ACT 1970 [39 OF 1970] & THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See Section 10; rule 13] "A SHEAR FOR SUBDIVIDING AN ELONGATED PRODUCT
MORGAN CONSTRUCITON COMPANY, a Massachusetts corporation of 15 Belmont Street, Worcester, Massachusetts 01605, USA,
GRANTED
The following specification particularly describes the invention and the manner in which it is to be performed:
4-10-2005
-4 OCT 2005
ORIGINAL

The present invention relates to a shear for subdividing an elongated product.
Field of the Invention
This invention relates to flying shears for cropping the frond and tail ends of hot rolled steel rods and other like products being delivered from a continuous high speed rolling mill.
Description of the Prior Art
Rods, bars and other like long products produced by a continuous hot rolling process inevitably have off gauge front and tail ends that must be "cropped", i.e., severed and discarded. This can be accomplished by manual trimming after the products have left the rolling line. However, manual trimming requires the constant attention of mill personnel, and is both inefficient and expensive.
Preferably, therefore, cropping is effected by so-called "flying shears" designed to operate automatically on line at mill delivery speeds. Although flying shears have operated successfully in the past, improvements in their design have failed to keep pace with ever increasing mill delivery speeds, which in modern day high speed rod mills are now reaching 100-120 m/sec.
The objective of the present invention is the provision of an improved flying shear which is fully capable of operating reliably at all mill delivery speeds, including the highest delivery speeds of modern day rod mills.

Accordingly, there is provided a shear for subdividing an elongated product (R) moving longitudinally in a plane (PH), said shear having
leader and follower blades mounted of rotation about parallel axes located on opposite sides of said plane, said blades being arranged to coact in a radially overlapping relationship at a cutting zone (Z1) located between said axes and spaced vertically from said plane, the radius of rotation (RL) of said leader blade being longer than the radious of rotation (RF) of said follower blade;
means for continuously rotating said blades at equal angular velocities, with said leader blade preceding said follower blade in said cutting zone; and
switch means located upstream of said cutting zone, said switch means being operable in a first mode to direct said product along a path bypassing said cutting alone, and being operable in a second mode to divert said product from said path into said cutting zone for cutting by said blades into leading and trailing segments, characterized by said blades being configured and arranged to deflect the tail end of said leading segment away form said plane while directing the front end of said trailing segment toward said plane.
SUMMARY OF THE INVENTION
A shear in accordance with one aspect of the present invention has leader and follower blades contrarotating continuously at equal angular velocities. The blades coact in a radially overlapping relationship at a cutting zone spaced vertically form the plane of product movement, with the leader blade preceding the follower blade, and 2ith the radius of rotation of the leader blade being longer than that of the follower blade. A switch upstream of the cutting zone operates in one mode to direct a product along a path bypassing the cutting zone, and in a second mode

direct the product through the cutting zone for cutting by the contrarotating blades into leading and trailing segments. The blades are configured to deflect the tail end of the leading segment away from the lane of product movement.
In accordance with another aspect of the present invention, the shear is preferably provided with tow sets of the aforesaid blades arranged in a side-by-side arrangement, one set being operable to crop a product front end, and the other set being operable to crop the product tail end. In accordance, with still another aspect of the present invention, the cropped ends and intermediate acceptable product lengths are received in the separate guide passageways of a stationary trough located downstream of the cutting zone. Chopping shears operate to subdivide the cropped ends into shorter scrap pieces.
These and other features and objectives of the preset invention will now be described in great detail with reference to the accompanying drawings, wherein:

BRIEF DESCRIPTION OF THE DRAWINGS:
Figure 1 is a view in side elevation of a shear in accordance with the present invention;
Figure 2 is a top plan view of the shear;
Figure 3 is a sectional view taken along line 3-3 of Figure 1;
Figure 4 is a diagrammatic illustration of the speed relationship between the leader and follower blades;
Figure 5 is an enlarged plan view of the switch assembly;
Figure 6A is a view taken along line 6A-6A of Figure 5;
Figure 6B is a sectional view taken along line 6B-6B of Figure 5;
Figure 7 is a sectional view on an enlarged scale taken along line 7-7 of Figure 1;
Figure 8 is a view of the cropping discs and blades taken along lie 8-8 of Figure 1;
Figure 9 is a partial view of the cropping discs and blades with the stationary trough shown in the background;
Figures 10A-10D are schematic illustrations showing a typical cropping cycle; and
Figure 11 is a schematic view showing the path of travel of the product as it is directed across the two cutting zones of the cropping shear.
Referring initially to Figures 1-3, a shear in accordance with the present invention is depicted generally at 10. The shear includes a stationary housing 12 rotatably supporting a parallel pair of upper and lower shafts 14, 16. The shafts are mechanically coupled by intermeshed gears 18, with the lower shaft 16 being driven continuously by a motor 20. An upper rotor 21 is mounted in cantilever fashion on me upper shaft 14. As can best be seen by

additional reference to Figures 8 and 9, rotor 21 has axially spaced rims 22 each carrying an upper "follower" blade 24. A lower rotor 25 is similarly mounted in cantilever fashion on the lower shaft 16. Rotor 25 has axially spaced rims 26 each carrying a lower "leader" blade 28. As can best be seen when viewed from left to right in Figures 8, 9 and 11, the rims 26 are each laterally preceded by ramps 29 having gradually increasing diameters.
The shafts 14, 16 and their respective rotors 21, 25 and blades 24, 28 are contrarotated continuously by die motor 20 at equal angular velocities as shown by the arrows identified at Va in Figure 1. The leader blades 28 precede the follower blades 24 in a radially overlapping relationship as they rotate through laterally spaced cutting zones Z1, Z2.
With reference to the diagrammatic depiction in Figure 4, it will be understood mat the
radius of rotation RL of me leader blades 28 (measured from the axis of rotation of shaft 16 to the outermost tip of die blade) is longer man the radius of rotation RF of die follower blades 24. It follows, therefore, mat for any given angular blade velocity Va, the tangential tip velocity Vn of the leader blades 28 will exceed the tangential tip velocity VTF of me follower
blades 24. Thus, as shown by the overlapping tangential velocity profiles PL, PF of the leader and follower blades 28, 24, at each point in the area of radial blade overlap in me cutting zones, the tangential speed of the leader blades will exceed that of the follower blades. This speed differential allows for maximum blade overlap without attendant damaging interference between me coacting blades.
With reference additionally to Figures 6A and 6B, it will be seen mat a switch 30 is
located upstream of the cutting zones Z1, Z2. The switch includes a guide pipe 32 mounted as at 34 for pivotal movement in a horizontal plane PH in which me product to be cropped, e.g., hot rolled steel rod R, exits from the mill.

The pipe 32 may be pivoted by any appropriate mechanism, such as a servo motor 36 acting through a gear head 38 to rotate a drive gear 40. Gear 40 meshes with a rack 42 on an arm pivotally connected to and extending laterally from the pipe 32. As shown in Figure 5, the pipe 32 is pivotally shiftable between positions indicated at "a", "b" and "c".
A stationary guide trough 44 is arranged downstream of the cutting zones Z,, Z2. As can be best seen by additional reference to Figure 7, the guide trough is internally divided by walls 46 into three passageways 48a, 48b, and 48c. The walls 46 each have a horizontal
segment defining a ledge 46 positioned slightly above the horizontal plane PH.
The housing 12 also rotatably supports additional upper and lower parallel shafts 48, 50 downstream of the stationary trough 44. The shafts 48, 50 are mechanically coupled by gears similar to those shown at 18 in Figure 3, and carry side-by-side cantilevered discs 52, 54. These discs carry multiple chopping blades 56 designed to coact at cutting zones aligned with the passageways 48a, 48c of the upstream trough 44. The chopping blades are contrarotated continuously by a drive motor 58 connected to the lower shaft 50.
Referring now to Figures 2, 9 and 10A-10D, the shear operates in the following manner:
Front End Crop
At the beginning of a front end cropping sequence, the guide pipe 32 of switch 30 is shifted to the position indicated at "a". This causes the off gauge front end of the product to bypass cutting zone Z1 and to pass through guide passageway 48a of trough 44 for subdivision by the chopping blades 56 on disc 52.

At the appropriate time, the switch pipe 32 is traversed from position "a" to position
"b" thus directing the product across cutting zone Z, where it is subdivided into a leading
segment which continues through guide passageways 48a, and a trailing section (in this case,
the acceptable intermediate product length), which continues between the cutting zones Z,, Z: and through guide passageway 48b between the cropping shear discs 52, 54 to other material handling equipment, typically a pinch roll unit preceding a laying head (not shown).
The cutting sequence is sequentially depicted diagrammatically in Figures 10A to 10D. Figure 10A shows the blades 24, 28 approaching the cutting zone Z,. The product front end passing through trough passageway 48a begins to traverse across the cutting zone Z, and while being lifted above plane PH as it rides up shoulder 29.
Figure 10B shows the product severed into leading and trailing segments by the blades
24, 28. The leader blade 28 has preceded the follower blade 24 into the cutting zone and has begun to lift the tail end of the leading segment away from the front end of the trailing
segment.
Figure 10C shows the blades 24, 28 in their condition of maximum radial overlap in the
cutting zone Z,. The leader blade 28 continued to lift the tail end of the leading segment away from the plane PH. The follower blade 24 now serves to redirect the front end of the trailing segment back to plane PH while it contacts and begins to exert a lifting action on the tail end of the leading segment.
In Figure 10D, the blades 24, 28 are moving out of the cutting zone. The trailing blade 24 continues to lift the tail end of the leading segment away from the front end of the trailing segment. The leader blade 28 is now out of contact with the product, and the front end of the

trailing segment has passed beneath the ledge 46' of the trough wall 46 into the central guide passageway 48b.

Tail End Crop
As the product tail end approaches the shear, the guide pipe 32 of switch 30 will be shifted from position "b" to position "c". The product will be severed in cutting zone Z2 in the manner described above, with the leading segment continuing on through guide passageway 48b, and with the trailing segment being directed into trough passageway 48c for subdivision by the chopping blades 56 on disc 54.
The path of the product as it is directed dirough the successive cutting zones Z,, Z2 is diagrammatically shown in Figure 11. Positions "a", "b" and "c" coincide with the same settings of the guide pipe 32. During the interval between billet lengths of product being rolled, the switch pipe 32 is returned to position "a" in readiness for the next front and tail end cropping sequence.
It will now be appreciated by those skilled in the art that the present invention provides a number of significant advantages not available with conventional prior art shears, To begin with, by rotating the leader blades 28 on a radius RL which is longer than the radius of rotation RF of the follower blades, for any given angular blade velocity Va, the tangential speed VTL of the leader blades at any point of blade overlap will equal or preferably slightly exceed the tangential speed VTF of the follower blades. Thus, the extent of blade overlap in the cutting zone can be maximized without experiencing damaging contact between the blades. Maximizing blade overlap is important to effecting a clean cut of the product into leading and trailing segments.

The difference in rotational radii RE, RL of the blades 24, 28 and the resulting
maximum blade overlap is further beneficial in that during a cropping sequence, the tail end of
the leading segment is lifted away from the front end of the trading segment, while allowing
the front end of the trailing segment to continued in the horizontal plane PH beneath the
downstream ledge 46' of the trough dividing wall. By lifting the tail end of the leading
segment out of the path of the advancing front end of the trailing segment, troublesome contact between to two is avoided. This is accomplished with minimal deflection of the front end of the trailing segment, which is important to the avoidance of cobbles, particularly when cropping products moving at speeds on the order of 100/120 m/sec. and higher.
A further advantage stems from employing two sets of cutting blades in a side-by-side
relationship to provide two cutting zones Z1, Z2, one for cropping front ends and the other for cropping tail ends. Since only one set of blades operates in each cutting zone, more time is available for effecting product traverse across each cutting zone.
Those skilled in the art will appreciate that, various changes and modifications may be
made to the above described shear without departing from applicant's inventive concepts. For example, other mechanically equivalent mechanisms may be employed to adjust the switch pipe to its different settings. The orientation of the follower and leader blades 24, 28 and the

associated guide trough 44 can be turned 180 . Different blade designs may be employed. It
is my intention to include these and all other equivalent changes and modifications within the scope of the appended claims,

WE CLAIM:
1. A shear (10) for subdividing an elongated product (R) moving
longitudinally in a plane (PH), said shear comprising:
leader and follower blades (28, 24) mounted for rotation about parallel axes located on opposite sides of said plane, said blades being arranged to coact in a radially overlapping relationship at a cutting zone (Zi) located between said axes and spaced vertically from said plane, the radius of rotation (RL) of said leader blade being longer than the radius of rotation (RF) of said follower blade;
means for continuously rotating said blades at equal angular velocities, with said leader blade preceding said follower blade in said cutting zone; and
switch means (30) located upstream of said cutting zone, said switch means being operable in a first mode to direct said product along a path bypassing said cutting alone, and being operable in a second mode to divert said product from said path into said cutting zone for cutting by said blades into leading and trailing segments, characterized by said blades being configured and arranged to deflect the tail end of said leading segment away form said plane while directing the front end of said trailing segment toward said plane.
2. The shear as claimed in claim 1, wherein said plane is horizontal, and the rotational axes of said leader and follower blades are respectively located below and above said plane.
3. The shear as claimed in claim 2, comprising a stationary receiving trough (44) having first and second channels (48a, 48b) separated by an intermediate wall (46), said channels being positioned respectively to receive said leading and trailing segments.

4. The shear as claimed in claim 3, wherein said intermediate wall includes a horizontal ledge (46) located above said horizontal plane.
5. The shear as claimed in claim 1, wherein first and second sets of
said upper and lower continuously rotating blades (28,24) respectively
coact in radially overlapping relationships at first and second laterally
disposed cutting zones (Z1, Z2) located above said plane; and wherein
said switch means (30) operates sequentially:
(i) to direct said product along a first path by passing said cutting zones;
(ii) to divert said product form said first path into said first cutting zone for cutting the blades of said first set into a leading segment continuing along said first path and intermediate segment continuing along a second path; and
(iii) to divert said product form said second path into said second
cutting zone for cutting the blades of said second set to
separate said intermediate segment continuing along said
second path form a trailing segment continuing along a third
path.
6. The shear as claimed in claim 5, comprising a stationary receiving
trough (44) located downstream of said cutting zones, said receiving
trough being subdivided into first, second and third channels (48a, 48b,
48c) by intermediate walls (46), said first and third channels being
positioned respectively to receive said leading and trailing segments, and
said second channel being positioned to receive said intermediate
segment.
7. The shear as claimed in claim 6, wherein said intermediate walls
include horizontal ledges (46) located above said horizontal plane.

The shear as clamed in claim 1, wherein said leader and follower blades are mounted respectively on rotors (25, 21), and wherein said switch means operates in said second mode in concert with said rotor (25).
9. A shear substantially as hereinbefore described with" reference to and the accompanying drawings.
Dated this 3rd day of April, 2000.
[ JAYANTA PAL]
Of REMFRY & SAGAR
ATTORNEY FOR THE APPLICANTS