US2140434A

US2140434A - Manufacture of metal tubes and tubular articles

Info

Publication number: US2140434A
Application number: US126498A
Authority: US
Inventors: Smith Sydney
Original assignee: WELLMAN SEAVER ROLLING MILL CO
Current assignee: WELLMAN SEAVER ROLLING MILL CO; WELLMAN SEAVER ROLLING MILL Co Ltd
Priority date: 1936-03-11
Filing date: 1937-02-18
Publication date: 1938-12-13
Anticipated expiration: 1955-12-13

Description

Dec. 13,.l938. 5. SMITH 2,140,434

MANUFACTURE OF METAL TUBES AND 'IUBULAR'ARTICLES Filed Feb. 18, 1937 UNITED STATES PATENT OFFICE MANUFACTURE OF METAL TUBES AND TUBULAR ARTICLES Sydney Smith, London, England, assignor to Wellman Seaver Rolling Mill Company Limited, London, England, a British company Application February 18, 1937, Serial No. 126,498

In Great Britain March 11, 1936 10 Claims.

This invention relates to the manufacture of metal tubes and tubular articles by a method in which a square or other sectioned billet is heated and then transferred to a container where a punch is forced into it from one end so that the metal displaced by the punch causes the billet to fill the container.

In the manufacture of metal tubes and tubular v articles by the push bench method the punch is forced into the billet to within a short distance of the other end and the billet or hollow, now usually termed a bottle, is placed on a mandrel and treated in push bench apparatus in which it is carried through a series of dies or through passes between rolls by which is is drawn out to a tube which is subsequently stripped from the mandrel.

In other methods of manufacture of metal tubes and tubular articles, as for example in which a pilger or automatic mill is employed,

the punch is forced right through the billet so as to produce a tubular hollow open at both ends which is subsequently treated for the production of the metal tube or tubular article in the pilger or automatic mill or other apparatus.

The container usually has a replaceable internal sleeve which is slightly tapered from top to bottom and which is changed according to the dimensions of the billet to be received. For example,.when a cast steel ingot is cut into lengths andv the separate lengths are employed to produce tubes a different liner may have to be used when dealing with the length from the small end of the ingot from that required when dealing with the length from the large end of the ingot.

' When using rolled billets they are found often to be over-size, this sometimes causing difliculty in introducing them into the container.

In other words, the billet is seldom of the correct size for the container whereby not only may the liner have to be changed, thus involving loss of time in the operation of the plant, but the billet'may be small and slackin the container f 'so that it may fall to one side whereby the piercing is not correctly central and an imperfect bottle is obtained. p

The present invention has for object improvements in the manufacture of metal tubes and like tubular articles and in the apparatus employed whereby cheaper material may be employed, for example, cast billets and more accurately punched hollows produced with consequent greater accuracy in the gauge of the finished tube and also a cheaper tube.

The present invention comprises a method of producing a metal tube or tubular article consisting in pressing a heated square or other sectioned billet to reduce its cross-sectional area and form to that required to be received into the container of a punching or piercing apparatus, introducing it into the container of said punching or piercing apparatus, forcing in a punch from one end, removing the tubular hollow thus produced from the container and treating it in an apparatus to convert it into a tube or tubular article, for example, in a push bench apparatus.

The invention also comprises means for treating the billet consisting of a press having two parts with depressions in their adjacent faces, a power cylinder formed on or connected to .one part and a piston in said cylinder connected to the other part so that relative movement of the piston and cylinder in one direction causes the press parts to .close together and in the other direction to open.

One form of press for use in carrying out the present invention will now be described by way of example and with reference to the accompanying drawing wherein:

Figure l is an elevation partly in section of a press,

Figure 2 a plan, and

Figure 3 shows a modification which may be used in the apparatus of Figures 1 and 2.

Referring to Figures 1 and 2 the press consists of two parts I, 2 positioned face to face with semicircular depressions in their adjacent faces. The part i is formed'at its end remote from the semicircular depression with a cylindrical cavity 3 constituting a cylinder in which is a piston 4. 5 is a gland cover. The ports for the admission of operating fluid, such as pressure wa'teror oil, are not shown. f

The piston carries or is attached to acrosshead 6 which is connected to the part 2 of the press by links I, 8 through the intermediary of pins 9, l0 extending from ears ll, l2 respectively which are extensions from the part 2. The earsll, I2 ,slide in depressions in the sides of the part I and their forward faces, when the part 2 is drawn up to the part I, engage wedges l3, l4 disposed at the bottoms of said depressions. The wedges are carried on threaded rods [5, I6 and ar adjustable by means of nuts, e. g. Ill. The wedges govern the amount by which the parts of the press may be drawn up together and constitute means for taking up wear. I 9, 20 are bolts carried on the part I, extending through the I and placed in the press. Presure fluid is admitted 'to the cylinder 3 whereby the two parts I; 2 of the press are drawn up and. the billet is brought to a cross-sectional area and form required for treatment in the punching or piercing apparatus. The fluid pressure in the cylinder 3 is then released and the partsof the press are separated by the action of the springs 2!, 22. In this operation the flat plate's hold the billet in correct position and the press acts on it across the corners true with the fiat faces of the billet. The sized and shaped billet is thus released so that it can be conveyed to a punching or piercing apparatus to be prepared for treatment in a further apparatus such as a push bench apparatus of the kind described in the Patent No. 1,979,579 or in a pilger or automatic mill or other apparatus. The plates may be removable and arranged to be stationary when the parts of the press are separated or one or more of them may move with a part or parts of the press. Instead of plates other means may be employed to engage the faces of the billet to maintain its axis central in the press while the press operates across the corners of the billet. In Fig. 3 a liner 23 is shown which is so shaped as to produce a slightly rounded edge at one end of the billet.

The press produces as accurately as possible the required size across the corners of the billet. By treating the billet to bring its cross-sectional area and form to that required to fit the container of the punching or piercing apparatus, in accord- 'ance with the present invention, it is possible to 45 'use the same liner in the container of the punching or piercing apparatus for treating portions of a billet from any part oi: the same cast billet.

What Iclaim is:

l. A method of producing a metal tubular article consisting in pressing a heated billet between jaws to reduce its cross-section throughout its length to the areaand form required to be received into the container of a punching apparatus, introducing it after such pressing into the container of said punching apparatus, forcing in a punch from one end, removing the tubular hollow thus produced from the container and treating it in a reducing apparatus to convert it into a tubular article.

2. A method of producing a metal tubular article according to claim 1, wherein the billet is polygonal and is pressed across its corners while its axis is maintained-central.

3. A press for reduclngthe cross-section of a billet in the production of a tubular article constituted of two parts with depressions in their adjacent faces for engaging the billet, means disposed in the said depressions for maintaining the axis of the billet central in the press during pressing. a power cylinder connected to one part and a piston in said cylinder connected to the other part so that relative movement of the piston and cylinder in one direction causes the press parts to close together and in the other direction to open.

4. A press according to claim 3 wherein the depressions are shaped at one end to produce a rounded edge at one end of the billet.

5. A press according to claim 3 having. a removable liner in two parts arranged in the depressions and having the billet-centralizing means arranged in the said liner.

6. A press according to claim 3 having plates in the depressions to engage flat faces of the billet for the purpose of maintaining the axis of the billet central in the press while the press operates across the corners of the billet.

7. A method of producing a metal-tubular article, comprising the steps of pressing a hot polygonal billet transversely of its axis to reduce its cross-section throughout its length to the area and form required for it to be received into the container of a piercing apparatus, introducing the billet after such pressing into the said container, forcing the punch of the piercing apparatus into the billet from one end, removing the tubular hollow thus produced from the container, and reducing and elongating the said hollow to the form of the tubular article in push-bench apparatus.

8. A method according to claim 7, wherein the billet is pressed across-its corner edges only and without being subjected at the same time to any axial pressure.

9. A press for reducing the cross-section of a polygonal billet from which a tubular article-is to be produced, comprising two co-acting pressparts with depressions in their adjacent faces to form a cavity for receiving the billet and engaging it across its corners, means in the depression to engage flat faces of the billet for maintaining its axis central in the-press whilst pressure is exerted across the corners, a power cylinder connected to one press-part and a piston in said cylinder connected to the other press -part.

10. A method of producing a metal tubular article, comprising the steps of treating a hot polygonal billet to reduce its cross-section throughout its length to the area and tapered form required for it to be received into the tapered container of a piercing apparatus, introducing the billet after such pressing into the said container, forcing the punch of the piercing apparatus into the billet from one end, removing the tubular hollow thus produced from the container, and reducing and elongating the said hollow to the form of the tubular article in push-bench apparatus.

.- SYDNEY SMITH.