CROSS REFERENCE TO RELATED APPLICATIONS
BACKGROUND
1. Field
[0002] Aspects of the present invention relate to high speed rod rolling mills, and more
particularly to improvements to the laying heads employed in such mills to form the
hot rolled product into a helical series of rings.
2. Description of Related Art
[0003] With reference to Fig. 1, a conventional laying head 10 includes a housing containing
a rotatably driven hollow quill 12. The quill is subdivided into a tubular body 12a
journalled for rotation between axially spaced bearings 14, 16, and a nose 18 detachably
secured by means of a mounting flange 20 to the tubular body 12a. The nose projects
axially and forwardly in cantilever fashion from the tubular body.
[0004] The quill 12 carries a product guide, typically in the form of a three dimensionally
curved laying pipe 22. The laying pipe has an entry end 22a aligned with the rotational
axis "X" of the quill 12, and a curved intermediate section 12b leading to a delivery
end 12c spaced radially from axis X.
[0005] Hot rolled steel rod is directed into the entry end 22a of the laying pipe 22 along
axis X, and exits from the delivery end 22c as a helical formation of rings (not shown).
Upon exiting from the delivery end 22c of the laying pipe 22, the rings are additionally
confined and moved forward by a helical guide trough 24 surrounded by a cylindrical
shroud 26. The guide trough 24 is configured and dimensioned to coact with the shroud
26 in providing an axially and radially confined helical extension of the guide path
defined by the laying pipe 22.
[0006] Although this extended confinement has proven to be highly beneficial in resisting
distortion and kinking of the tail ends of products as they exit from the laying head
10, the manner of supporting the guide trough 24, as well as its design, have given
rise to difficulties that have been found to compromise high speed operation of the
laying head.
[0007] For example, the curved intermediate portion 22b of the laying pipe 22 is supported
on the nose 18 by radially projecting struts 28, whereas the guide trough 24 is carried
on a separate disc-shaped trough support 30 detachably mounted on the end of the cantilevered
nose 18.
[0008] With further reference to Figs. 2 and 3, the disc-shaped trough support 30 may be
seen as including a hub 32 at the center of a helical plate 34 on the outer rim of
which are attached channel-shaped trough segments typically indicated at 24'.
[0009] The helical plate 34 is typically welded to the hub 32, with the resulting structure
of the trough support 30 being robust and consequently heavy in order to withstand
the stresses resulting from high speed operation of the laying head. Moreover, difficulties
are encountered in accurately aligning the trough support 30 with the rotational axis
X of the laying head, with even slight misalignments causing disruptive vibrations
at high speeds.
[0010] An additional drawback relates to the conventional trough segments 24', which typically
comprise unitary expensive investment castings. The traditional casting materials
have been found to lack adequate resistance to wear occasioned by factional contact
with the hot rolled product. Attempts at dealing with this problem have included increasing
the thicknesses of the trough segment side walls, but the resulting increased weight
has been found to further contribute to instability of the laying head.
[0011] WO 03/051553 A1 shows a laying head for forming an axially moving hot rolled product into a helical
series of rings, said laying head comprising a quill rotatable about an axis, said
quill having a tubular body journalled for rotation between axially spaced bearings,
and having a nose projecting axially and forwardly from said body; a product guide
carried by said quill, said product guide having an entry and aligned with said axis
and arranged to receive said product; a guide trough providing a helical extension
of said product guide.
SUMMARY
[0012] Broadly stated, aspects of the present invention include supporting both the product
guide, which may comprise a laying pipe, and the guide trough, on a continuous helical
support formed as an integral component of the nose projecting axially and forwardly
from the tubular body of the quill.
[0013] In accordance with other aspects of the present invention, the guide trough segments
are subdivided into a continuous bottom comprising the outer rim of the helical support,
with the side walls being segmented, detachably secured to the trough bottom, and
readily replaceable when worn.
[0014] These and other objects, features and advantages of the present invention will become
more apparent upon reading the following detailed description in conjunction with
the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015]
Fig. 1 is a side view, with portions in section, of a conventional laying head;
Fig. 2 is a perspective front view of the nose and guide trough assembly of the conventional
laying head shown in Fig. 1;
Fig. 3 is a partially exploded perspective view of the conventional guide trough assembly
shown in Figs. 1 and 2;
Fig. 4 is a rear perspective view of the nose of a laying head quill in accordance
with an exemplary embodiment of the present invention, with the laying pipe and guide
trough carried on a continuous helical support comprising an integral component of
the nose;
Fig. 5 is a front perspective of the nose depicted in Fig. 4;
Fig. 6 is a view showing one side of the nose depicted in Fig. 5;
Fig. 7 is a view showing the opposite side of the nose depicted in Fig. 5;
Fig. 8 is a sectional view on an enlarged scale taken along line 8-8 of Fig. 4 and
showing details of trough segments in accordance with an exemplary embodiment of the
present invention; and
Figs. 9A and 9B are respectively perspective and side views of a guide trough side
wall segment in accordance with an exemplary embodiment of the present invention.
DETAILED DESCRIPTION
[0016] In accordance with the present invention, the conventional assembly of the nose 18
and separate disc-shaped trough support 30 depicted in Fig. 1 is replaced by a unitary
nose 36, an exemplary embodiment of which is depicted in Fig. 4. The unitary nose
36 has a central tubular body 38 provided at one end with a mounting flange 40 adapted
to be connected to the tubular body 12a of the conventional laying head quill 12 shown
in Figs. 1-3. A helical support, which may comprise a continuous auger plate 42 configured
as an unwinding spiral scroll, is permanently joined to the central body 38.
[0017] As can best be seen by additional reference to Figs. 5-7, the auger plate 42 extends
continuously from the mounting flange 40 to the distal end of the central body 38.
A segment of the plate 42 carries brackets 44 on its rim. As can best be seen in Fig.
4, the brackets 44 coact with clamps 46 to secure the laying pipe 22 in its operative
position. The remaining rim of the auger plate 42 is defined by a continuous collar
serving as the bottom 48 of a channel-shaped guide trough 50.
[0018] By supporting both the laying pipe 22 and the guide trough 50 on a continuous auger
plate 52 formed as an integral component of the cantilevered nose 36, stress concentrations
are significantly reduced. This in turn makes it possible to reduce the weight of
the nose 36, with the result that the center of gravity of the laying head's rotating
assembly is advantageously shifted rearwardly and closer to the bearings 14, 16. Overall
rigidity and resistance to vibration is thus beneficially enhanced.
[0019] With reference to Figs. 8, 9A and 9B, the sides 52 of the guide trough 50 are segmented
and detachable secured to the bottom 48 by conventional fasteners which may comprise
bolts 54 and nuts 56. An exemplary embodiment of a trough side wall segment 52 is
depicted in Figs. 9A and 9B.
[0020] When individual side wall segments 52 experience accelerated wear, they may be readily
replaced without replacing others that experience lesser wear.
[0021] Preferably, the side wall segments 52 are identical. The side wall segments may be
cast or fabricated from light weight wear resistant materials, illustrative examples
including aluminum, aluminum alloys, carbon fibers, thermoplastics, etc. Additionally,
or alternatively, the interior surfaces 52' of the side wall segments 52 may comprise
or be coated with a wear resistant material, for example, a nano metal.
[0022] The foregoing description and drawings are merely illustrative of the principles
of the present invention and are not to be construed in a limiting sense. Various
changes are modifications will become apparent to those of ordinary skill in the art.
All such changes and modifications are seen to fall within the scope of the invention
as defined by the appended claims.
1. A tubular nose (36) adapted to project axially in cantilever fashion from the rotatable
quill of a rolling mill laying head, said quill carrying a product guide having an
entry end aligned with a rotational axis of the quill, and having an intermediate
curved portion leading from said entry end to a delivery end communicating with a
guide trough (50) providing a helical extension of said product guide, said nose (36)
having an auger plate (42) configured and arranged to provide continuous support for
said guide trough (50) and for the intermediate curved portion and delivery end of
said product guide, said nose (36) further having a mounting flange (40) and a central
body (38), wherein the auger plate (42) extends continuously from the mounting flange
(40) to a distal end of the central body (38),
wherein said auger plate (42) is fabricated as an integral component of said nose
(36).
2. Tubular nose according to claim 1 wherein an outer rim of said auger plate (42) comprises
a bottom (48) of said guide trough (50).
3. Tubular nose according to claim 1 or 2 wherein said continuous auger plate (42) is
configured as an unwinding spiral scroll permanently joined to the central body (38).
4. Tubular nose according to claim 1 wherein the tubular nose (36) has one end thereof
configured and arranged to be detachably secured to said quill.
5. Tubular nose according to claim 1 wherein the intermediate curved portion and delivery
end of said product guide are secured by brackets on a rim of said auger plate (42).