US2958244A - Piercer inlet table - Google Patents

Description

Nov. 1,1960

w. RODDER PIERCER INLET TABLE 4 Sheets-Sheet 1 Filed Aug. 17, 1956 INVENTOR. WILL/AN EODDEE 6M, M,

Nov. 1, 1960 w. RODDER PIERCER INLET TABLE 2 t u h S .u. t e e h S 4 ill! q N 3 I- Filed Aug. 17, 1956 ma 0 A N w W J Al N M wv m A W \Lv Av u M g 5 m m w Q N 0 [=1 QJIJ m \\\N 0% iww .WQ MW ||l ll .1 l llliL o. 6 \l.\\ w L d IILW 6 ATTORNEYS Nov. 1, 1960 w. RODDER 2,958,244

I PIERCER INLET TABLE Filed Aug. 17, 1956 4 Sheets-Sheet 4 d hl IN V EN TOR.

ATTORNEYS 2,958,244 Patented Nov. 1, 1960 PIERCER INLET TABLE William Rodder, Poland, (BlfiO, assignor, by mesne assignments, to Blew-Knox Company, Pittsburgh, Pa., a corporation of Delaware Filed Aug. '17, 1956, Ser. No. 604,801

4 Claims. (Cl. Sit-13) This invention relates to piercing mills for the manufacture of seamless tubing and more particularly to an improved inlet table for feeding heated billets to the rolls of a piercing mill in which the billets are forced over a piercing mandrel by the action of inclined rolls.

In mills of this type, it is the practice to provide an inlet table which receives heated billets from a furnace; the billets are supported in a groove or trough along which they are pushed by a'hydraulically actuated pusher to the mill rolls. The inlet table is mounted on a base or frame work separate from the support for the mill itself; the mill includes appropriate bearings for supporting the mill rolls and supports for the guide shoes which engage the billet as it is being acted upon by the rolls. Heretofore, in such mills it has been customary to employ a device known as an inlet cannon which is mounted on the supporting frame of the mill and consists of a heavy cylinder which guides the billet to a point immediately adjacent the guide shoes. The inlet cannonis subject to severe wear and when worn, does not guide the billet accurately with respect to the mill pass. Accordingly, inlet cannons must be replaced rather frequently on account of wear and furthermore, a different size of inlet cannon must be employed for every different size of tube that is produced by the mill. Changing the inlet cannon is a time-consuming job which results in an important loss of production time. Heretofore, an inlet cannon has been required to guide the billet into the guide shoes because the conventional inlet table was incapable of supporting the billet in proper relationship to the mill guides.

According to the present invention, the necessity for using an inlet cannon in a piercing mill is eliminated, and improved results are obtained by providing an extension on the inlet table that projects into close proximity'to the guide shoes of the mill and supports the billets in a. zone closely adjacent the guide shoes, and by providing" power operated adjustment means so that the height of the inlet table and the extension can be adjusted accurately and quickly. Thus, the inlet table and its extension-can be adjusted precisely to the desired level.

A preferred form of the invention is shown in the drawings, in which Figure 1 is a side elevational view of an-inlet table and mill embodying my invention, the mill rolls and drive shafts being shown in broken lines.

Figure 2 is a plan view of the apparatus shown in Figure 1, the mill frame being shown in outline only for convenience of illustration.

Figure 3 is a transverse section through the inlet table showing the adjusting mechanism, the section being taken along the lines 3-3 of Figure 1.

Figure 4 is a side elevational view showing the mechanism for holding the inlet table down on its supporting base, the view being taken along the line 44 of Figure 3.

Figure 5 is a longitudinal sectional View on an enlarged scale showing the manner in which the inlet table extension projects into close proximity to the working zone of the mill to support the billet.

Figure 6 is a section as indicated by line 66 of Figure 5.

Figure 7 is a section as indicated by 7-7 of Figure 5 and illustrating a billet retaining ring, and

Figure 8 illustrates a support that may be used in place of the retaining ring of Figure 7.

Referring to Figures 1 and 2, the rolls of the piercing mill are indicated at 1 and 2. These are driven by shafts 3 and 4 through appropriate universal joints 5 and 6. For

convenience of illustration, these parts are shown in phan-- tom lines, and only the outline of the mill structure 8 is shown in Figures 1 and 2. The inclined rolls 3 and 4 are adapted to force a heated billet over a piercing point or mandrel 10 in a well-known manner, this being the initial operation in the formation of a seamless tube. While the mill rolls 1 and 2 may be adjusted toward and away from each other in a horizontal plane to accommodate different sizes of billets and to produce tubes of varying diameters, the pass line of the mill, which is indicated at 12 in Figures 1, 2 and 5, remains fixed and at the same elevation above the floor line. The billet is guided at this elevation by means of guide shoes 14 (see Figure 5) which are suitably supported from the mill structure 8 and which are arranged to be removed and replaced to compensate for wear and to accommodate different sizes of billets. The mechanism for holding the guide shoes in place is illustrated in Figure 5; but inasmuch as this mechanism forms no part ofthe present invention, it is not described herein.

Inasmuch as the pass line of the mill remains fixed for various sizes of billets, it is necessary to provide an adjustable support for the billets as they are fed to the mill in order to adapt the mill to the production of various sizes of tubing; This support is provided by means of the inlet table of the present invention which is arranged to feed the billets directly to the mill without requiring the intervention of the conventional inlet cannon. As shown in Figures 2 to 4, the inlet table, which is indicated in general at 15, comprises an elongated box girder section made up of vertically extending side plates 16, a top plate 17, and a bottom plate 18; This section supports a massive trough or guide 19, preferably made up of a series of sections as shown, upon which the billet B rests, it being understood that in some instances two or more billets may be suported by the trough 19 in end to end relation. The billets are pushed into the mill in a conventional manner by means ofa pusher'mechanism not shown.

The main portion of the inlet table 15 is supported by a pair of elevator units 20 and 21 at either end thereof. Inasmuch as these units are substantially identical, only the unit 20 is described in detail herein. As shown in Figures 1 and 3, the side plates 16 are cut away as at 22 to receive the inverted V-shaped elevator mechanism which is made up of vertical'plaxtes 23 and a top plate which is welded to the plates 23 and comprises inclined portion 24 and a horizontal portion 25. The horizontal portion 25' is welded to the girder side plates 16 and constitutes the bottom plate of the girder where the side plates are cut away. A flat, horizontal plate 27 extending transversely of the inlet table is welded to the vertical plates 23 and this, in turn, is supported by a pair of oppositely sloping inclined slideways 29. The slideways are supported by Wedge members 31 which have inclined faces 32 corresponding to the slope ofthe slideways. The wedge members are slidably supported on horizontal tracks 34 carried by the base structure 35 of the elevator mechanism. Preferably, the slideways 29 and faces 32 of the wedge members and'the tracks 34 and bottom surfaces 36 of the wedge members are provided with interfitting' surfaces as shown to prevent longitudinal movement of the table.

In order to move the wedge members toward and awayfrom each other and thereby to raise and lower the inlet table, each of the wedges is recessed as at 36 to receive an adjusting nut 37. Nuts 37 have internal threads of opposite hand and are engaged by threads 39 of shafts 40 and 41. Shaft 4th is supported at its outer end by thrust bearing 42 which engages a collar 43 secured to the'end of the shaft. The outer end of shaft 41 is supported by bearing 44, and the shafts are coupled together at their inner ends by a coupling 45. Shaft 41 is arranged to be driven through a gear drive 47 connected to the coupling 46. It will be evident that rotation of shaft 41 in one direction moves the wedges 31 toward each other and raises the elevator mechanisms, while rotation in the opposite direction moves the wedges apart and lowers the elevator mechanism. Gear drives 47 for the identical elevator mechanisms 20 and 21 are driven in synchronism by shafts 48 from gear box 49, which may be connected to a suitable electric motor (not shown). Therefore, the elevator mechanisms operate simultaneously and the inlet table 14 is maintained in the desired substantially horizontal plane at all times. Conventional push button controls (not shown) may be provided for the drive motor for the elevator mechanisms.

In order to lock the inlet table to the elevator mechanisms 20 and 21 upon which it is supported and thus to prevent undesirable vibration or movement of the table during operation of the mill, hold-down mechanisms indicated in general at 50 and shown particularly in Figures 3 and 4 are provided at each end of both elevator mechanism 20 and 21. The hold-down mechanisms each cornprise a pair of vertically extending links 51 pivotally secured to the base structure 35 of the elevator mechanisms by brackets 53 and carrying at their upper ends a rigid cross member 54. In each mechanism, cross member 54 is engaged by the end of the piston rod 55 of a hydraulic piston and cylinder mechanism 56 which is secured to the adjacent vertical plate 57 of the frame structure of the elevator mechanism as by welding thereto. A horizontally extending bar 58 is also secured to each cylinder, and the ends of the bar 58 overlie the links 51 and maintain them in vertical position. With this arrangement, fluid pressure in the four cylinders 56 of the hold-down mechanisms urges their pistons upwardly, and the engagement of the piston rods 55 with the cross members 54 results in a downward reaction which is transmitted to the inlet table through the cylinders 56 and the vertical plates 57. Thus the table may be urged downwardly against its supports in any of its positions of adjustment and is thereby held securely against vibration during the operation of the mill. In practice, the pressure in the cylinders 56 preferably is released when the height of the table is'to be adjusted, and applied again after the adjustment has been completed.

In order to hold the billets in the trough 19, a pivoted top guide 60 may be provided as shown in Figures 1 and 2. Guide '60 may be of known construction and is mounted on bearings 61 disposed at one side of the trough so that the guide can be raised and lowered by hydraulic cylinder 62 acting through piston rod 64 which is pivotally connected at 65 to a lever arm 66 formed integrally with the guide. The top guide moves up and down with the table when the height of the table is adjusted and is arranged to engage the upper surfaces of the billets as they are being actedlupon by the mill in order to retain the billets in trough 19.

As noted above, according to the present invention, billets to be pierced are guided into the working zone of the mill and supported at the proper level by means of an inlet table extension which projects into close proximity to the mill rolls 1 and 2 and the guide shoes 14. The extension is indicated in general at 70 and is shown particularly in Figures 1, 2 and 5. The table extension comprises a pair of side plates 71 which are welded to a vertical end plate 72 that is bolted as indicated at 73, or otherwise suitably secured, to the delivery end of the main portion of the inlet table 15. A V-shaped trough member 75 is welded to the top surfaces of the side plates 71; wear plates 76 (see Figure 6) are secured to trough member 75 and provide a trough that constitutes a continuation of the trough 19 of the main portion of the inlet table. It will be noted that the bottom edges of the side plates 71 are reduced in vertical depth as the extension approaches the mill to provide a projecting nose portion 77 on the inlet table extension which overlies the portion 78 of the frame structure 8 of the mill. This construction enables the supporting trough 75 to extend almost into contact with the guide shoes 14 and provides for support of the billet in a zone closely adjacent to working zone of the mill.

In order to guide the inlet table extension and particularly the nose portion 77 thereof, a guide member 79 is secured as by welding to the portion 78 of the mill frame. Guide member 7 has a head portion 80a which engages the inner surfaces of a recess 80 (see Figures 5 and 6) formed in the nose portion 77 of the extension by the side plates 71 and transverse plates 81 and 82.

For some operations, particularly Where short billets are being pierced, it may be desirable to provide a billet retaining ring 85, as shown particularly in Figures 5 and 7, to hold the billets in the trough 75 of the projection 76 after the billets have become disengaged from the top guide 60. The retaining ring 85 is mounted on a stem 86 which extends through an opening 87 in the trough 75, the wear plates 76 being cut away to receive the lower V-shaped portion 88 of the retaining ring. The ring is held in position by means of a wedge 90 that extends through a suitable slot in the lower portion of the stem 86, the upper surface of the wedge engaging the bottom end surface of a collar 91 that is welded in place between the side plates 71 of the table extension. When it is not necessary to use a billet retaining ring, the ring is removed by releasing the wedge member; and the supporting member 94 shown in Figure 8 is substituted for the retaining ring. Member 94 has a V-shaped supporting portion 95 which fills the gaps in the wear plates 76 and has a stem portion 96 identical with the stem 86 of the billet retaining member and which is arranged to be locked in position by means of the wedge 90.

In operation, the inlet table is positioned at approximately the correct level to feed the billets properly to the mill, and heated billets are deposited in the trough 19 and advanced to the mill by the pusher mechanism. The billets are supported by the inlet table extension as they are pushed into the guide shoes and are held on the trough by means of the top guide 60. If short billets are being pierced, the billet retaining ring 85 is employed. Otherwise, the guide member 94 is substituted for the retaining ring. As the first billet is pushed into engagement with the mill rolls and advanced by the rolls over the mandrel, the operator observes the operation of the mill and makes whatever small adjustments may be necessary to bring the inlet table to the precise level necessary for best operation of the mill. This is accomplished through the power-operated elevating mechanism 20 and 21 which simultaneously elevate the main portion of the inlet table and the inlet table extension 70. The holddown mechanisms 55 hold the inlet table solidly on its supports during operation of the mill.

When it is desired to pierce billets of a different diameter, the guide shoes 14 are changed in conventional manner and the horizontal spacing of the rolls 1 and 2 is changed. The inlet table is raised or lowered as the case may be in order to bring it to the proper level for the new size of billet, and the final adjustment is made as before by the operator upon observing the operation of the mill. As wear takes place in the supporting trough of the inlet table and the projecting portion of the mill, appropriate compensation can be made simply by elevating the inlet table a slight amount. The

V-shaped trough supports the tube more accurately than the conventional inlet cannon.

Thus, by the elimination of the inlet cannon, not only are the expense of providing cannons for each different size of billet and the time consumed in changing the cannons eliminated, but, in addition, the ability of the operator to adjust the level at which the billets are fed to the mill so that the billets are fed at the optimum level makes possible more accurate piercing of the billets, particularly at the entering ends, and the production of tubing with walls of more uniform thickness. Thus, the invention provides an apparatus which is capable of producing greater tonnages of higher quality tubing at lower cost than previous types of piercing mills.

Those skilled in the art will appreciate that various changes and modifications can be made in my invention without departing from the spirit and scope thereof. The essential characteristics of the invention are defined in the appended claims.

I claim:

1. An inlet table for feeding billets to a piercing mill and supporting them as they are being rolled, said inlet table comprising a main portion of substantial depth having a feed trough extending along the top thereof and adapted to receive and support billets to be pierced, power operated elevating mechanisms for supporting said main portion and for adjusting the elevation thereof, hydraulic means for holding said main portion down on said elevating mechanisms, said main portion having an extension projecting from the delivery end thereof, rigidly secured thereto and supported solely thereby, said extension having a nose portion of reduced depth as compared to said main portion adapted to overlie a portion of the frame structure of the mill, said extension having a trough in alignment with said feed trough on said main portion, said trough on said extension being adapted to extend into close proximity to the working zone of said mill and to support a billet between the main portion of said inlet table and said mill.

2. In combination with a piercing mill having a frame structure, inclined rolls having their axes disposed in planes substantially parallel to the pass line of the mill for rolling a solid billet over a mandrel and guides for guiding the billet in the zone in which it is acted on by the rolls, an inlet table disposed on the opposite side of the mill rolls from the mandrel for feeding billets to said mill and supporting them as they are being rolled, said frame structure of said mill having a portion extending toward said inlet table from the zone in which the billet is acted upon by the rolls, said inlet table extending parallel to the pass line of the mill and comprising a main portion, a feed trough carried by said main portion and adapted to receive and support billets to be pierced, power means for adjusting the elevation of said main portion, said inlet table having an extension projecting toward said mill from said main portion and rigidly secured thereto and supported solely thereby, said extension having a feed trough in alignment with said trough on said main portion, said trough on said extension extending into a position immediately adjacent said guides and constituting the sole support for a billet between the main portion of said inlet table and said mill, said extension having a nose portion of reduced depth as compared to said main portion adapted to overlie said extending frame portion of said mill, said projecting frame portion of said mill and said extension having inter-engaging portions for aligning said extension with respect to said mill.

3. In combination with a piercing mill having a supporting frame structure, inclined rolls having their axes disposed in planes substantially parallel to the pass line of the mill for rolling a solid billet over a mandrel and guides for guiding the billet in the zone in which it is acted on by the rolls, an inlet table disposed on the opposite side of the mill rolls from the mandrel for feeding billets to said rolls and supporting them as they are being rolled, said frame structure of said mill having a portion extending toward said inlet table below the pass line of the mill from the zone in which the billet is acted upon by the rolls, said inlet table extending parallel to the pass line of the mill and comprising a main portion, a feed trough carried by said main portion and adapted to receive and support billets to be pierced, power operated elevating mechanisms for supporting said main portion and for adjusting the elevation of said main portion with respect to said mill, hydraulic means for holding said main portion of said inlet table down on said elevating mechanisms, said inlet table having an extension projecting toward said mill from said main portion and rigidly secured thereto and supported solely thereby, said extension having a trough in alignment with said trough on said main portion, said trough on said extension extending into close proximity to said guides and constituting the sole support for a billet between the main portion of said inlet table and said guides, said extension having a portion overlying a portion of the frame structure of said mill, and said mill and said extension having interengaging portions for aligning said extension with respect to said mill.

4. In combination with a piercing mill having a supporting frame structure, inclined rolls having their axes disposed in planes substantially parallel to the pass line of the mill for rolling a solid billet over a mandrel and guides for guiding the billet in the zone in which it is acted on by the rolls, an inlet table disposed on the opposite side of the mill rolls from the mandrel for feeding billets to said rolls and supporting them as they are being rolled, said frame structure of said mill having a portion extending toward said inlet table below the pass line of the mill from the zone in which the billet is acted upon by the rolls, said inlet table extending parallel to the pass line of the mill and comprising a main portion, a feed trough carried by said main portion and adapted to receive and support billets to be pierced, power operated elevating mechanisms for supporting said main portion and for adjusting the elevation of said main portion with respect to said mill, hydraulic means for holding said main portion of said inlet table down on said elevating mechanisms, said inlet table having an extension projecting toward said mill from said main portion and rigidly secured thereto, said extension having a trough in alignment with said trough on said main portion, said extension extending into close proximity to said guides and constituting the sole support for a billet between the main portion of said inlet table and said guides, a retaining ring carried by said extension and having a portion adapted to extend over a billet disposed in said trough on said extension to retain the billet against lateral displacement from said trough during operation of said mill, said extension having a portion overlying a portion of the frame structure of said mill, and said mill and said extension having interengaging portions for aligning said extension with respect to said mill.

References Cited in the file of this patent UNITED STATES PATENTS 778,816 Wikstrom et a1 Dec. 27, 1904 971,512 Adams Oct. 4, 1910 1,040,134 Brock Oct. 1, 1912 1,329,550 Scholl Feb. 3, 1920 1,794,798 Sarr Mar. 3, 1931 1,964,507 Diescher June 26, 1934 2,156,218 Assel Apr. 25, 1939 2,333,344 Smith et a1. Nov. 2, 1943 2,569,104 Jaenchen Sept. 25, 1951 2,599,847 Kritscher June 10, 1952 2,753,234 Haag July 3, 1956 FOREIGN PATENTS 601,468 Great Britain May 6, 1948

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