Triple roller entry guide

Abstract: An entry guide device (10) comprising a funnel shaped inlet (32) member in close proximity to three adjustable rollers (24,26,28) mounted at 120° around the axis of work (30) moving through the entry guide device (10). The adjustable rollers (24,26,28) are actuated to move in concert so as to be able to accommodate a work product (30) of difference diameters, whilst preserving the concentricity of the three rollers (24,26,28). The funnel shaped inlet (32) member is replaceable to accommodate for wear and provision is made to calibrate the position of the three movable rollers (24,26,28) with a calibration device which may be conveniently inserted into the device to check and calibrate the three rollers for concentricity. This entry guide device (10) is ideally suited for guiding a work product (30) having circular, triangular or hexagonal cross-sections.

Description: BACKGROUND OF THE INVENTION Roller entry guides are used in rod mills to guide a work product accurately into a set of work rolls where the work is to be altered in cross-sectional shape. Usually, a guide employing two opposed rollers is used to guide the work product into the work rollers but with the present trend to faster throughput in a modern mill and increased emphasis on quality, it may be found that roller guides having only two opposed rollers are not capable of providing the required accuracy in guiding a work product to the work rolls. Additionally when rolling materials which are of triangular or hexagonal cross-section, it may be found that entry guides having two opposed rollers may not provide the proper guiding function to achieve a quality finished product DESCRIPTION OF THE PRIOR ART U.S. Patent 4,680,953 to Fabris shows a dual roller entry guide having shaped rollers which are adjustably mounted in the housing so as to be movable during passage of a work product therethrough. U.S. Patent 4,373,367 to Fabris shows a double roller entry guide having a funnel shaped entrance. U.S. Patent 4,295,356 to Fabris shows a double roller entry guide having a funnel shaped entrance. Roller entry guides are used in rod and bar mills to guide the rod to the next stand of the mill. The Inlet to the entry guide is usually funnel shaped in order to guide the work product into the bite between the opposed rollers. The rollers provide accurate placement and orientation of the rod to the work rolls. The initial setting of the rollers in the entry guide is usually made to a setting which corresponds to the nominal diameter of the rod that will be passing between them. It is usual for the diameter of the rod passing between the rolls to have substantial variations in shape and size to cause premature wear on the rolls. This can lead to frequent stoppage of the complete mill (which may contain several rolling stages) for adjustment and maintenance. Adjustment of the spacing between the rollers has always been provided and with modern dual roller guides some provision is usually made to allow for adjustment of the roller spacing while the work is passing therethrough (see U.S. Patent 4,680,953). German Patent DE-B-1 025 369 describes a four roller entry guide having a funnel shaped entrance and set screws mounted on the body of the guide for individually adjusting the positions of the four roller assemblles. Certain types of rolling mills require a triple roller entry guide for proper functioning of the mill. The guide of this invention will fulfil the needs of these special types of rolling mills. SUMMARY OF THE INVENTION According to the present invention, there is provided a roller entry guide having the features of claim 1. The present invention thereby enables the provision of a triple roller entry guide in which the spacing of the three rollers in the guide may be simultaneously adjusted in such a manner that the concentricity of the roller bite is preserved during any adjustment of the position of the three rollers. The guide has a body in which three lever arms are pivotally mounted at 120° intervals on the body. Each lever arm is spring loaded to urge the lever against an adjustment cone which moves along the axis of the guide to cause the three rollers to simultaneously move in and outfrom the axis along which the work material travels. The guide has a locking ring to lock the movable cone in a locked position. Each lever arm is provided with a set screw type adjusting device which permits individual adjustment of each lever arm with respect to the mating surface of the cone. The guide also features a replaceable tapered inlet chute which is easily removed from the guide when the chute is wom or damaged. At the same time, a calIbration standard may be inserted into the guide in the place of the tapered chute to allow the position of the individual rollers to be set to assure concentricity in the final roller adjustment. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of a triple roller entry guide embodying this invention; Figure 2 is an axial view of the guide looking at the exit end of the guide; Figure 3 is an illustration of the positioning of the rollers of the guide shown in Figure 2; Figure 4 is an illustration of the guide showing the position of two of the lever-roller assemblies; Figure 5 is an illustration of the adjustable feature of the rollers of the guide; Figure 6 is a partial sectional view showing the use of a calibration standard; Figure 7 is a partial sectional view of a lever-roller assembly of the guide. DESCRIPTION OF THE PREFERRED EMBODIMENT Figure 1 shows a triple roller entry guide 10 having a body 12 which is mounted on a rolling stand of a rod mill. Three lever arms 14, 16 and 18 arc shown on pivots of which 20 and 22 are shown. Lever arms 14,16 and 18 which arc more fully shown in Figure 7 have rollers 24, 26 and 28 mounted at the ends thereof to engage a work product passing through the interior of body 12. An adjusting ring 29 is shown for locating lever arms 14, 16 and 18 at the desired working position. Figures 2 and 3 show the alignment of rollers 24, 26 and 28 looking toward the exit end of the guide. The rollers are confined to movement in a radial direction only because of the pivot placement in body 12. Referring to Figure 4 where a rod 30 is shown passing through the entry guide, it will be seen that body 12 houses an insert 32 which fits into body 12 in a sliding fit Insert 32 is a tapered inlet chute. Surfaces 34 and 36 of body 12 mate with surfaces 38 and 40 of insert 32. Ring 29 is integrally attached to cone 42 which is in engagement with set screws 44 and 46 of lever arms 16 and 14 respectively. Springs 48 and 50 serve to ensure that the lever arms are biased in such a manner as to keep set screws 44 and 46 in contact with cone 42. Cone 42 has a threaded bore 56 and is adjusted by twisting ring 29 so that the position of the cone may be moved laterally back and forth on the mating threads 58 of body 10 to open and close the roller gaps. Locking ring 54 serves to lock cone ring in its final position. Referring to Figure 6, a calibration device 60 is shown in body 12 in place of tapered inlet chute insert 32. Insert 32 is removed from body 12 and calibration standard 60 is inserted therefor. Standard 60 has mating surfaces 62 and 64 which mate with surfaces 34 and 36 so as to accurately position the cylindrical nose 66 concentric with the central axis of the entry guide 10. To calibrate the roller positions cone 42 is advanced toward the lever arms 14, 16 and 18 until one of the rollers 24, 26 and 28 contacts nose 66 of standard 60. The set screw such as 44 is relaxed until another one of the rollers touches the nose 66. At this time, it is possible to continue relaxing the set screws in the two arms whose rollers have previously engaged nose 66, or alternatively the set screw in the lever arm of the roller which has not engaged the nose 66 may be advanced until its corresponding roller engages nose 66. At this time, the three lever arm set screws are locked to preserve the concentricity of the surfaces of rollers 24, 26 and 28. Cone 42 is now adjusted to provide the final position of arms 14, 16 and 18 and when the desired position is reached, locking ring 54 locks cone 42 in place. Figure 7 shows a detail drawing of lever arm 16. Wheel 26 is mounted on a pair of bearings 72 and 74. Members 70 and 76 form a pivot for the bearings 72 and 74. The bearings 72 and 74 are standard bearings and roller wheels are standard guide rollers well known by those skilled in the art. The advantages of the three roller entry guide are as follows: The presence of the third roller assists in accurate placement of the work rod as it passes through the guide. Reduced wear on the rollers may result because the profile of the rollers may be modified somewhat when compared to the profile of the rollers on a two roller guide. Attimes it is necessary to guide hexagonal and triangular shaped rods through a mill and this entry guide device provides the precision required for accurate rolling of these products. Of course, this entry guide provides superior performance when used with round work products. The position of the guide rollers may be adjusted while a product is passing through the entry guide to accommodate stock having variations in size. The ability to adjust roller position whilst a rolling operation is being carried out improves mill efficiency and avoids needless down time.

Claims: A roller entry guide (10) to guide material (30) along a longitudinal axis, said guide comprising: a hollow housing (12) having multiple pivots incorporated therein and for pivotally mounting thereon three roller assemblies (14, 24; 16, 26; 18, 28) at equally spaced angles about said longitudinal axis, said pivots (20, 22) being located in a common plane transverse to said longitudinal axis, a funnel shaped guide insert (32) concentric with said longitudinal axis being fitted into said hollow housing (12), said funnel shaped guide insert (32) defining an entrance aperture and a substantially smaller exit aperture, said housing (12) having a threaded boss (58) surrounding the entrance aperture; each roller assembly (4, 24; 16, 26; 18, 28) comprising a lever (14, 16, 18) and a roller (24, 26, 28) mounted on a first end of the lever (14, 16, 18), each lever (14, 16, 18) being mounted on one of the pivots (20, 22) at a point intermediate the first end and the second end of the lever (14, 16, 18), the rollers (24, 26, 28) having a common confluence at a point adjacent to and slightly spaced from said exit aperture; and adjustment means for pivoting the roller assemblies (4, 24; 16, 26; 18, 28) to adjust the rollers (24, 26, 28) relative to said longitudinal axis; characterised in that the adjustment means comprises a cone (29, 42) which is threaded on said threaded boss (58) and rotatable on said threaded boss (58) for movement along said longitudinal axis to cause the roller assemblies (4, 24; 16, 26; 18, 28) to pivot simultaneously in a radial direction to move the rollers (24, 26, 28) in concert inwardly toward the longitudinal axis. A roller entry guide as claimed in Claim 1, wherein each lever (14, 16, 18) is provided with a bias means (48, 50) which urges the lever in a direction to move the respective roller (24, 26, 28) away from said longitudinal axis. A roller entry guide as claimed in Claim 1 or 2, wherein said adjustment means comprises setting means (44, 46) for moving individual levers (14, 16, 18) independently of the remaining levers (14, 16, 18). A roller guide as claimed in Claim 3, wherein the setting means comprises a respective set screw (44, 46) mounted on each lever (14, 16, 18). A roller entry guide as claimed in Claim 1, wherein a locking means (54) is provided to lock said cone (29, 42) in a predetermined location. A roller entry guide as claimed in any preceding claim, wherein a calibration device is fitted into said housing (12) to provide a cylindraceous calibration surface adjacent to said rollers (24, 26, 28), said cylindraceous surface being concentric with said longitudinal axis.

Inventors: FABRIS MARIO, FABRIS, MARIO
Applicants: FABRIS MARIO, FABRIS, MARIO
Application year: 1999
Main classification: B21B39
IPC codes: B21B38, B21B39