US2837945A

US2837945A - Bar steadier for seamless tubing mills

Info

Publication number: US2837945A
Application number: US368449A
Authority: US
Inventors: George R Griffiths
Original assignee: United States Steel Corp
Current assignee: United States Steel Corp
Priority date: 1953-07-16
Filing date: 1953-07-16
Publication date: 1958-06-10
Anticipated expiration: 1975-06-10

Description

June 10, 1958 a. R. GRIFFITHS- 2,337,945

BAR STEADIER FOR SEAMLESS TUBING MILLS 2 Sheets-Sheet 1 Filed July 16. 1953 INVENTOR. GEORGE R. GRIFFITHS XMQZM? 434% ATTORNEY June 10, .1958 G. R. GRIFFITHS BAR STEADIER FOR SEAMLESS TUBING MILLS 2 Sheets-Sheet 2 Filed July 16, 1953 FIG.

F'IG.3

INVENTOR. GEORGE R. GRIFFITHS i OMZJ/.

BAR STEADIER FOR SEAMLESS TUBING MILLS George R. Grifiiths, Gary, Ind., assignor to United States This invention relates to an improved barsteadier for seamless tubing mills and the like.

Seamless tubing mills, such as piercing or rotary expanding mills, conventionally include a mandrel which is supported in the roll pass at the free end of a rotatable elongated bar. The mandrel is used to work the inside surface of the tubing :shell; consequently the bar must be of a length somewhat greater than the maximum shell length. To prevent vibration and sagging of the bar it is customary to support it with steadiers located intermediate its length. Each steadier includes a cluster of rolls which normally engage the bar, but which retract to allow the shell to pass. For a more complete disclosure of such steadiers and their relation to a mill reference can be made to Olson Patent No. 1,950,- 929, dated March 13, 1934, or Mohan Patent No. 2,306,- 827, dated December 29, 1942.

In some instances it is preferred to employ four-roll steadiers since they furnish a more positive grip on a bar than a three-roll steadier. However, previous four-roll steadiers with which I am familiar have not been suitable for bars of smaller sizes since the rolls cannot move sufiiciently close together to grip the bar. The minimum diameter bar they can grip is about 2 /2 inches.

An object of the present invention is to provide fourroll :steadiers which have improved rolls capable of gripping bars of a wider size range, that is, capable of gripping bars of small diameter without impairing their ability to grip larger bars. 1

A more specific object is to provide four-roll steadiers whose rolls have mating lands and grooves that enable the rolls to overlap for gripping small diameter bars.

In accomplishin-gthese and other objects of the invention, 1 have provided improved details of structure, a preferred form of which is shown in the accompanying drawings, in which:

Figure 1 is a vertical sectional view of a steadier which has rolls constructed in accordance with my invention, the rolls being retracted from the bar;

Figure 2 is a fragmentary vertical section-a1 view showing the rolls engaging a small diameter bar;

Figure 3 is a top plan view on a larger scale of a pair of mating rolls constructed in accordance with my invention; and

Figure 4 is a top plan view of a pair of rolls constructed in accordance with a modification of my invention.

Figure 1 shows a pair of supporting beams and a small diameter bar 12 of a seamless tubing mill. The mill is not otherwise shown since it can be of any standard or desired construction, for example, as shown in the aforementioned Olson or Mohan patents. The'beams 10 carry a bar steadier, which is illustrated as comprising a shaft 13 fixed to the top of the beams, 21 pair of opposed triangularly shaped

arms

14 and 15 pivotally mounted on said shaft, and double-acting

operating cylinders

16 and 17 for opening and closing said arms scissors fashion. The two arms are connected by an equalizer 18. The arm 14 carries upper and

lowerrolls

19 and 19a, and the arm 15 carries upper and lower rolls 21) and 29:2, all con- Patented June 10, 1958 structed in accordance with my invention and hereinafter fully described. The operating mechanism illustrated is merely typical of those used in this type of steadier, and hence is not described in detail and is not to be construed as limiting the invention.

In accordance with the embodiment of my invention shown in Figure 3, the periphery of the upper roll 19 on the arm 14 has a central land 21 and a pair of

grooves

22 and 23 at each end of said land. The periphery of the upper roll 20 on the arm 15 has a central groove 24 and a pair of

lands

25 and 26 at each end of said groove. The land and grooves on the roll 19 are adapted to interfit with the groove and lands on the roll 29. Thus when the

arms

14 and 15 are closed to grip the bar 12, as shown in Figure 2, the rolls overlap and can grip a bar of small diameter. The

lower rolls

19a and 20a are shown as of uniform diameter, but it is apparent the lower rolls can have lands and grooves the same as the upper rolls if desired.

In the modification shown in Figure 4 the two upper rolls, designated 30 and 31, each have a somewhat larger number of interfitting lands 32 and corresponding grooves 33. The roll 30' is shown as having four lands 32 and five grooves 33, while the roll 31 has five lands and four grooves, but obviously the number can vary.

it is seen that with either embodiment of my invention the

arms

14 and 15 can close considerably farther than is possible with the usual rolls of uniform outside diameter. I have found in actual practice that bar steadiers which are equipped with my improved rolls can successfully grip bars of an outside diameter of 1% inches or smaller. At the same time there is no loss in the effective maximum diameter of the rolls, and consequently they can be used just as successfully to grip larger bars. They furnish the same support to a larger bar as rolls of uniform diameter equal to that of the lands.

While two embodiments of my invention have been shown and described, it will be apparent that other adaptations and modifications may be made without departing from the scope of the following claim.

I claim:

In a bar steadier which comprises a cluster of four opposed rolls and means journalling said rolls on parallel axes and supporting at least two of the rolls for relative movement toward and away from the other two, said four rolls when brought together defining a space for receiving a bar, which space is bounded by a portion of the circumference of each roll so that the four rolls cooperate to grip the bar, the improvement comprising high cylindrical sections and mating low sections formed on at least two of said rolls, which two rolls are relatively movable toward and away from each other, said high and low sections interfitting when the rolls are brought together enabling the circumferences of the high sections of two rolls and the circumferences of the other two rolls to contact a bar of diameter smallerthan the distance across a space defined by four rolls of uniform diameter equivalent to that of said high sections, the circumferences of said high sections also being adapted to contact a bar of larger diameter without the sections interfitting.

References Cited in the file of this patent UNITED STATES PATENTS 272,995 Whitney Feb. 27, 1883 1,375,896 Carson Apr. 26, 1921 1,401,131 Blackburn Dec. 27, 1921 2,263,744 Smith Nov. 25, 1941 2,306,827 Mohan Dec. 29, 1942 2,458,110 Sleeman Ian. 4, 1949 2,686,444 Reichl Aug. 17, 1954