US3677394A

US3677394A - Conveyor roll

Info

Publication number: US3677394A
Application number: US29918A
Authority: US
Inventors: William M Bloom
Original assignee: Allegheny Ludlum Industries Inc
Current assignee: Sunbeam Oster Co Inc
Priority date: 1970-04-20
Filing date: 1970-04-20
Publication date: 1972-07-18
Anticipated expiration: 1989-07-18
Also published as: SE360628B; JPS5229076B1; DE2118600A1; FR2086191B1; FR2086191A1; GB1336886A; CA931517A

Abstract

Improved conveyor roll structure for retaining thereon advancing elongated work pieces such as steel rods, bars, or the like wherein the roll exhibits a first retaining surface of revolution inclined at an angle less than 45* to the axis of the roll and a second inclined retaining surface of revolution meeting the first at an angle greater than 90* and inclined from the roll axis at an angle of less than 45*, the second surface of revolution having a depression therein whereby the cross section of said second surface presents a generally concave aspect and the second surface extends outwardly from the juncture of the first and second surfaces a predetermined distance such that the longitudinal centroid of the conveyed work piece may be contained within the vertical extent of the first and second retaining surfaces while being advanced across a plurality of rolls comprising the conveyor.

Description

United States Patent [151 3,677,394 51 July 18, 1972 Bloom 1 1 CONVEYOR ROLL [72] inventor: William M. Bloom, Pittsburgh, Pa. [73] Assignee: Allegheny Ludlnln [M lnc., Pittsburgh, Pa.

[22] Filed: April 20, 1970 [21] Appl.No.: 29,918

[52] U.S. Cl. ..198/127, 29/121 R [51] lnLCl...... 15/110,B21b31l08,B6$g 13/02 [58] Fleldolsearch ..29/l10,124,12$, 127-130, 29/122, 121; 198/127, 33, 192, 29, 103, 104

[$6] Relerencea Cited UNITED STATES PATENTS 2,335,594 11/1943 Kerr ..29/l2lA Primary Examiner-Richard E. Aegcrter AnomeyRichard A. Speer, Vincent G. Gioia and Howard R. Berkenstock. Jr.

[57} ABSTRACT Improved conveyor roll structure for retaining thereon advancing elongated work pieces such as steel rods, bars, or the like wherein the roll exhibits a first retaining surface of revolution inclined at an angle less than 45 to the axis of the roll and a second inclined retaining surface of revolution meeting the first at an angle greater than 90 and inclined from the roll axis at an angle of lea than 45', the second surface of revolution having a depresion therein whereby the cross section of said second surface presents a generally concave aspect and the second surface extends outwardly from the juncture of the first and second surfaces a predetermined distance such that the longitudinal centroid of the conveyed work piece may be contained within the vertical extent of the first and second retaining surfaces while being advanced across a plurality of rolls comprising the conveyor.

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Patented July 18, 1972 3,677,394

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BACKGROUND OF THE INVENTION This invention relates generally to rolls utilized in conveyor lines and particularly to rolls installed in the line where their centerlines are skewed from the perpendicular of the conveyor line. Such a line may be installed through an annealing furnace in which rods and bars of round, square, and rectangular shapes are heat treated. Conventionally, annealed bars of round, square, and hexagonal cross sections varying from five-eighths of an inch to 4 inches in diameter and from oneeighth of an inch to 4 inches thick and up to 4 inches wide for rectangular cross sections may be treated in such a furnace by being heated to approximately 2,200 F. while being conveyed through the furnace. Immediately thereafter the workpieces are conventionally fast quenched as they exit the annealing furnace. Usually the quenching is accomplished with the annealed pieces traveling through a round quench ring from which the workpiece is sprayed from all aspects by the quenching liquid exiting the ring. Those familiar with the art will recognize that pieces exiting an annealing furnace going through such stationary quench rings must be relatively straight and aligned with the center of the ring in order to be quenched throughout at an even rate thereby minimin'ng distortion that would otherwise result. Some prior conveyor systems having aligned rolls have employed general V-shaped grooves on the roll surfaces to assure the alignment of material passing therethrough and a few of these conveyors have utilized slightly skewed rolls but only for the conveying of bars of a round cross section. There exists a need in the conveyor art for a roll shape capable of conveying workpieces of a variety of cross sections such as squares, rounds, rectangles, etc. without particular adaptation for each. There is a further need for a roll shape which will preserve the initial straightness of the bar entering the furnace as well as providing a straightening function to those non-straight bars which are charged into the annealing furnace. The roll structure of my invention meets the foregoing existing needs and is hereinafter described.

SUMMARY OF THE INVENTION An improvement in roll design for a conveyor having a plurality of such rolls for advancing elongated workpieces such as steel rods, bars or the like through a chamber such as a furnace for heat treating of the workpieces, said roll structure having retaining means for guiding the workpiece through the chamber wherein the improvement includes a first retaining surface of revolution inclined at an angle of less than 45 to the axis of the roll, a second retaining surface of revolution meeting the first retaining surface at an angle of greater than 90" and inclined at an angle of less than 45 to the axis of the roll. Said second surface of revolution has a depression therein whereby the cross section thereof presents a generally concave aspect, the second surface of revolution being adapted to extend outwardly from the juncture of the first and second retaining surfaces a predetermined distance whereby the longitudinal centroid of the workpieces may be contained within the extent of the first and second retaining surfaces while being advanced across a plurality of rolls comprising the conveyor.

DESCRIPTION OF THE DRAWINGS FIG. I is a side elevation of an improved conveyor roll of my invention, appearing in section.

FIG. 2 is a partial view of the invention illustrated in FIG. 1.

FIG. 3 is a front elevational view of an alternative embodiment of my invention.

FIG. 3a is a side elevational view of the embodiment of FIG. 3.

FIG. 4 is a schematic illustration of a conveyor using the rolls of the invention, showing the manner in which they are skewed.

2 DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings and FIG. I, in particular, reference numeral 2 indicates a roll body adapted at either end to be conventionally mounted in a conveyor line (not shown). In the usual conveyor installation a plurality of rolls would be mounted over the full extent of the conveyor. The preferred embodiment of the roll described herein is included in a conveyor line extending through an annealing furnace. Rolls 2 are mounted on center lines approximately 2 feet apart and throughout the distance of the furnace as well as in the areas of entrance and exit thereto. Roll 2 may be adapted with motor means (not shown) to advance a workpiece progressively along the conveyor line.

The improved roll structure of my invention, illustrated in the figures includes a first retaining surface 6 being a surface of revolution inclined at an angle A less than 45 to roll axis 8. In the embodiment illustrated herein, the retaining surface 6 is contained on a sleeve 10 which closely fits over roll body 2 and is secured thereto by conventional means such as keys 12. Further contained on roll body 2 is second retaining surface 14, also a surface of revolution and centered about roll axis 8. Second retaining surface 14 may also be contained on sleeve 16 as illustrated in the described embodiment, and secured conventionally to roll body 2. In the invention retaining surface 14 exhibits a varying slope to roll axis 8. In the illustrated embodiment the surface 14 is broken into two surfaces 17 and I8. The initial slope of surface [4 lies in surface I7 forming an initial slope at angle B. Surface 14 exhibits a second slope at angle C and lies in surface 18. The slope of surface [8 measured by angle C is greater than the slope of surface I7 measured at angle B, however, both are inclined to roll axis 8 at angles of less than 45. In the embodiment disclosed, surface 14 is a surface of revolution of a compound line extending from the juncture 20, of surfaces 6 and I4 to point 22, a predetermined distance from juncture 20 and further to point 24, a predetermined distance fromjuncture 20.

In the illustrated embodiment adapted to convey steel rods and bars of A.I.S.I. 300 series alloy through an annealing furnace heated to a temperature of approximately 2,200 E, angle A is approximately 38, angle B, approximately 40, and angle C, approximately 43. Surface 6 extends a length of 2% inches from juncture 20. Surface 17, reaching from juncture 20 to point 22 extends a distance of 2% inches and surface 18, reaches from point 22 to point 24 extending a distance of 2% inches. The surfaces 6, I7, and 18 are adapted for rods generally five-eighths inches in diameter up to 4 inches in diameter and bars rectangular in cross section from oneeighth inch in thickness up to 4 inches in thickness and up to 4 inches in width.

In the preferred embodiment of the roll structure illustrated in the figures, an additional retaining surface 26 may be included being a surface of revolution from an are extending from point 24 to a vertical to roll axis 8.

As viewed in cross section in FIGS. l and 30, it may be seen that the roll structure of my invention appears generally as a V built onto the roll body 2. In the preferred embodiments each V groove consists basically of two surfaces (6 and 14) inclined with respect to each other and the axis of the roll 8 upon which they are carried. The V shape is adapted for rolls which are mounted in a manner skewed from a line extending perpendicular to the furnace longitudinal center line or pass line of the conveyed material up to approximately 8". (See FIG. 4.) The roll body 2 is skewed to cause the workpiece W to ride in the V and the retaining surfaces 6 and 14 preferably against side 14 tending to ride up the advance surface 14, which in the invention is so adapted with the increasing slope to contain the work piece W within the V area.

As previously described, surface 14in cross section is composed of two retaining surfaces of revolution, the first (6) being inclined at an angle of approximately 38 to roll axis 8 and the second (l4) generally being inclined at an angle of greater than its initial slope as at surface 17. The total length of surface 14 is sufficiently long to contain the maximum expected deviation from longitudinal straightness of the bar to be processed. in the preferred embodiment the end of the inclined surface 18 terminates in a third retaining surface 26 being an upward concave curve to further deepen the slope of the overall surface 14 to increase the maximum amount of deviation from straightness of workpiece W which may be conveyed by the roll 2. While in the preferred embodiment the overall surface 14 in cross section appears as two flat lines 17 and 18 of different slope and a third surface 26 being a concave curve attached thereto, the cross section of surface 14 may exist as a long radius curve or a compound curve meeting the foregoing slope requirements.

In the charging of a non-straight workpiece W into the furnace on the skewed rolls 2 retained by surfaces 6 and 14, the bar proceeds through the furnace resting generally upon surface I as it is conveyed by subsequent rolls 2. As previously discussed, the skewed relationship of the rolls and the nonstraight characteristics of the bar W cause it to climb up slope l4, advancing from surface 17 to surface 18 and occasionally to surface 26. The slope of surfaces l7, l8, and 26 is such that the center of gravity of the advancing bar is contained within the top edge of the surface 14 so that the bar preferably slides back down surface 14 toward juncture 20 of surfaces 14 and 6 or flips over and rests on surface 6 primarily rather than surface 14. As the workpiece W rides up surface 14 and to the extent that its frictional force with surface 14 becomes insufficient to hold the bar on the slope, it slides down surface 14 arriving at surface 6 with an impact which contributes to the straightening of the bar W. The slightly concave aspect of surface 14 defined by the increasing slopes of surfaces l7, l8, and 26 further contribute to this tendency of a workpiece W to first climb up the surface 14 and then slide down to the juncture 20 with an impact. This is accomplished by causing the workpiece to ride on surface 14 as illustrated in FIG. 2 at points Pl and P2 by virtue of the depression in surface 14. It will be recognized that the frictional force between workpiece W and surface 14 is continually reduced as the workpiece W rides upwardly on surface 14 to a position approaching that indicated by the dotted lines in FIG. 2. l have found that for a hot roll surface of an alloy such as Supertherm, available from Abex Corporation, Elyria, Ohio, which is utilized in the preferred embodiment that a slope of 38 to 40 is sufficient to generally prevent a bar climbing upwardly on a slope V if the bar is straight. The greater the degree of curvature, or nonstraightness of a bar, the greater is its tendency or ability to climb its supporting surface 14. it will be noticed that for larger size material, (e.g., that having a width of over 2% inches in the illustrated embodiment) will span both surfaces 17 and 18 when straight.

It is important to keep the difference in slope between the two surfaces l7 and 18 small to provide sufficient support for the workpiece W should the workpiece be a relatively thin bar. Such minimum difference in slope between the two surfaces limits the tendency for deformation of the thin bar material.

Referring now to FIGS. 3 and 30, an alternative embodiment of my invention is illustrated. if there are space limitations restricting the installation of a roll having a sleeve 16 with the compound retaining surfaces previously described, the sleeve may be made elliptical in shape as at 16'. This may also be advantageous in situations wherein weight restrictions on the roll body 2 are important. It may be further appreciated that the multiple ellipsoid sleeves may be oriented on different axes to provide a balancing of the weight about roll body 2 having a plurality of such retaining surfaces.

lclaim:

I. In a conveyor, a plurality of rolls for conveying an elongated workpiece such as steel rods, bars, or the like through a chamber such as a furnace for heat treating said workpieces, each of said rolls having retaining means for guiding said workpiece through said chamber and corn risin a first retainmg surface of revolution inclined at an angle of ess than 45 to the axis of said roll; a second retaining surface of revolution meeting said first surface at an angle of greater than and inclined at an angle of less than 45 to the roll axis, said second surface of revolution having a depression therein, the cross section thereof presenting a generally concave aspect, said second surface of revolution being adapted to extend outwardly from the juncture of the first and second surfaces a predetermined distance so that the longitudinal centroid of said workpiece is contained within the extent of said first and second retaining surfaces while being advanced along said conveyor; the rolls being mounted for rotation about axes which are all skewed in the same direction with respect to the longitudinal center line of a workpiece conveyed thereon.

2. A roll according to claim 1 wherein the depression in said second surface of revolution is defined by the revolution of a long radius curved line which meets said first surface of revolution and extends such that the chord to said curve from the juncture with said first surface to the termination of said curve forms an angle of greater than 90 with said first surface and is inclined to said roll axis at an angle of less than 45.

3. A roll according to claim 2 wherein said second surface of revolution is defined by the revolution of a series of long radius curved lines.

4. In a conveyor having a plurality of rolls for conveying an elongated workpiece such as steel rods, bars, or the like through a chamber such as a furnace for heat treating said workpieces, an improved roll having retaining means for guiding said workpiece through said chamber, comprising: a first retaining surface of revolution inclined at an angle of less than 45 to the axis of said roll; a second retaining surface of revolution meeting said first surface at an angle of greater than 90 and inclined at an angle of less than 45 to the roll axis, said second surface of revolution having a depression therein defined by the revolution of a line composed of two connected straight lines, said first straight line meeting said first surface of revolution and inclined at an angle of less than 45 to said roll axis, said second straight line having a slope greater than said first straight line and inclined at an angle of less than 45 to said roll axis, the cross section of said roll in the area of said retaining surfaces presenting a generally concave aspect, and said second surface of revolution being adapted to extend outwardly from the juncture of the first and second surfaces a predetermined distance so that the longitudinal centroid of said workpiece is contained within the extent of said first and second retaining surfaces while being advanced along said conveyor.

5. A conveyor roll according to claim 4, wherein said second retaining surface includes a lip defined by the revolution of said line extended such that said second straight line terminates in a line curving to a vertical to said roll axis, the slope of said second retaining surface being defined by the chord from said lip to the juncture of said second surface and said first surface.

t i i I! i

Claims

1. In a conveyor, a plurality of rolls for conveying an elongated workpiece such as steel rods, bars, or the like through a chamber such as a furnace for heat treating said workpieces, each of said rolls having retaining means for guiding said workpiece through said chamber and comprising a first retaining surface of revolution inclined at an angle of less than 45* to the axis of said roll; a second retaining surface of revolution meeting said first surface at an angle of greater than 90* and inclined at an angle of less than 45* to the roll axis, said second surface of revolution having a depression therein, the cross section thereof presenting a generally concave aspect, said second surface of revolution being adapted to extend outwardly from the juncture of the first and second surfaces a predetermined distance so that the longitudinal centroid of said workpiece is contained within the extent of said first and second retaining surfaces while being advanced along said conveyor; the rolls being mounted for rotation about axes which are all skewed in the same direction with respect to the longitudinal center line of a workpiece conveyed thereon.

2. A roll according to claim 1 wherein the depression in said second surface of revolution is defined by the revolution of a long radius curved line which meets said first surface of revolution and extends such that the chord to said curve from the juncture with said first surface to the termination of said curve forms an angle of greater than 90* with said first surface and is inclined to said roll axis at an angle of less than 45*.

4. In a conveyor having a plurality of rolls for conveying an elongated workpiece such as steel rods, bars, or the like through a chamber such as a furnace for heat treating said workpieces, an improved roll having retaining means for guiding said workpiece through said chamber, comprising: a first retaining surface of revolution inclined at an angle of less than 45* to the axis of said roll; a second retaining surface of revolution meeting said first surface at aN angle of greater than 90* and inclined at an angle of less than 45* to the roll axis, said second surface of revolution having a depression therein defined by the revolution of a line composed of two connected straight lines, said first straight line meeting said first surface of revolution and inclined at an angle of less than 45* to said roll axis, said second straight line having a slope greater than said first straight line and inclined at an angle of less than 45* to said roll axis, the cross section of said roll in the area of said retaining surfaces presenting a generally concave aspect, and said second surface of revolution being adapted to extend outwardly from the juncture of the first and second surfaces a predetermined distance so that the longitudinal centroid of said workpiece is contained within the extent of said first and second retaining surfaces while being advanced along said conveyor.