US1903676A

US1903676A - Rolling mill for widening out tubes

Info

Publication number: US1903676A
Application number: US540428A
Authority: US
Inventors: Heetkamp Heinrich
Original assignee: Demag AG
Current assignee: Mannesmann Demag AG
Priority date: 1930-06-11
Filing date: 1931-05-27
Publication date: 1933-04-11
Anticipated expiration: 1950-04-11

Description

April 11,1933.

`H. HEETKAMP ROLLING MILL FOR WIDENING OUT TUBES Filed May 27, 1951 ml] A'M wy/lm Wwf/M5 Attorney.

Patented Apr. 11, 1933 UNITED STATES PATENT 'or-*Fica HEINRICH HEETKAMROF DUISBURG, GERMANY, ASSIGNOB TU DEHAG AKTIENGESELL- SCHAFT, 0F DUISBURG, GERMANY I ROLLING MILL FOR WIDENING OUT TUBES I Application led Hay 27, 1981, Serial No. 540,428, and in Germany June 11., 1980.

It is known in connection with themanufacture of seamless tubes to pass the partly made tube, immediately after it leaves the tube rolling mill, through a -smoothing rolling mill, whereby the tube is not only smoothed but is restored to its circular shape.

According t0 the present invention, a tube widening rolling mill. in which the partially prepared tube is forced over a conical mandrel head with a rotary movement by means of inclined externally provided rollers and widened, is directly followed by a smoothing rolling mill comprising rods or plugs and externally provided operating rollers, this mill being in turn followed by a former lbush for bringing the tube back toits circular shape, the former bush being providedto rotate more rapidly than the tube. The smoothing rolling mill is employed solely for smoothing the partially formed tube because the tubes, as they leave the widening rolling mill, are scratched by the edges of the widening rollers and the scratches must be removed. The tubes that have been smoothed by this method are continuously guided in a heatedcondition through the former bush, so that tubes ready for use are produced by the use, in co-operation, of the three apparatus here- `inbefore described.

4 Figure 1 shows the apparatus in longitudinal section,

Figure 2 is a section of the apparatus taken on the line 2-2`of Figure 1,

Figure 3 is a section on the line 3-3 of Figure 1, and

Figures 4 and 5 are sections of the appa- 'ratus corresponding to Figure 2, to illustrate modifications of construction.

In the drawing, 1 is a mandrel, provided with the conical mandrel head2. Within the head 2 are mounted conical rollersV 3, which loperate in conjunction with externally yprovided inclined mechanically driven rollers 4. The front head 5, whichis connected to the head2, serves to guide in the partially prepared tube 6. Beyond the rollers 3 and 4 a smoothing rolling mill is provided, disposed in'the direction indicated by the arrow w; th1s smoothin rolling mill comprises externally provide driven rollers 7 and a corre- .l spondmg number of ribs 8 upon the mandrel 1. After the smoothing rolling mill a device 1s provlded consisting of a rotatable funnelshaped former ring 9; this is provided at the end of a bush 10 mounted so as to be rotated by means of the chain wheel 11.

The plant operates as follows:

The partially formed tube which is inserted between the rollers 4 and 5, is flared out p at the end by the rollers until it becomes funnel shaped, and after the tube leaves theseV rollers it is in its flared out form forced over the ribs 8 with a rotary movement, where it is operated upon internally and externally by means of the externally provided smoothing rollers 7. This treatmentcauses the tube to lose its exact circular sha e, and thus the tube, immediately after leavlng the smoothing' apparatus, is passed into the funnelshaped rotating bush 10 and is restored to its circular shape. The forming action of the ring 9 upon the tube is considerably assisted,

yif the ring is rotated at a speed that exceeds the rotational speed of the tube as it moves past.

The apparatus is not limited to the construction illustrated. Thus the ribs or parts 8 may be replaced by rollers 11, as represented in Figure 4. Furthermore a rib 12 (Figure 5) in the form of a helix may be internally provided in such manner that the pitch ofthe rib' changes continuously. The effect of providing this helical rib is to cause the tube to move forward, this being particularly necessary after the tube has left the flaringout rollers 3 and 4. The alteration in the pitch of the thread formed by the rib prevents helical scratches in the tube from bein .exposed. The finished tubeleaves the widening-out rolling mill at the end of the bush.

I claim:

1. A tube widening mill provided with a mandrel with conical head, externally disposed inclined rollers co-operating with said rolls, and s, former bush following the smoothing rolls, which bush is rotated around the tube with a relative speed.

2. A tube widening mill according to claim 5 1, in which said means is provided with ribs disposed within the tubo to co-operate with the smoothing rolls.

3. A tube widening mill according to claim 1, in which said means is provided with a helical rib Within the tube to co-operate with the sinoothing rolls.

HEINRICH HEETKAMP.