US1808631A - Tube expander - Google Patents

Description

June 2, 1931. l R. BUNGEROTH 1,808,531

` TUBE EXPANDER Original Filed VJuly 23. 1927l Patented June 2, 19,31

UNITED STATES vRIUDOIE' BUNGEBOTH, 0F DUSSLDORF, GERMANY v' TUBE EXPANDER Original application led July 23, 1927, Serial Io. 208,013, and in Germany .December 29, 1925. Divided .and this application led December 17, 1927. Serial No. 210,884.

The invention relates to apparatus for expanding metal tubes with regular or varying thickness of wall, and is a division of my copending application Serial No. 208,013, filed July 23rd, 1927, now Patent 1,682,724.

l The expanding of tubes by inclined roller devices by the use of a mandrel has been sev- ,eral times attempted. The arrangements hitherto preferably) used, in which the' mandrelLshafts are su j ected to pressure, have given rise to considerable diiliculty since the mandrel, subjected to pressure, yields more or less in accordance with the degree of the rolling pressure and accordingly alters its positicn relative to the rollers.

The result is an irregular and uncommercial manufacture.

It has also been proposed to secure the mandrel to a shaft of the machine where y pressure on the mandrel or the-mandrel shaft is avoided.

However, in these machines also it is not possible to realize the main condition for the production of a uniform product, .which conb sists in maintaining the mandrel during the working period exactly in its position between the rollers.

'lhese defects of the known arrangemen have been particularly noticeable in the manufacture of tubes of considerable length, as

they are now generally required. "E

The present invention relates to machines in which the expanding is effected by means of a mandrel which is secured to a mandrel shaft placed on the inlet side of the machine v and it is differentiated from the known apparatus in that the mandrel shaft is adjustably arranged.

In this manner, it is possible to maintain the mandrel always in a definite position between the rollers during the working period, and consequently to compensate for 4any al teration of the mandrel shaft'. l

The adjusting means may bev of` any suitable kind. l

' A coarse or fine adjustment of the mandrel may be provided. In the improved machine, the expanding of tubes of considerable length j 0 'and constant dimensions presents no diilicul-` question of moving the mandrel and tube corlaced at the inlet sideties as the mandrel always maintains its defimte position between the rollers.

The invention is illustrated by the accompanying drawings in which- Fi re 1 is a longitudinal section showing one orm of the invention;

Fig. 2 is a longitudinal section showing another forml of the invention.

It has already been proposed to effect movement of a mandrel by means of an hydraulic piston in rolling operations in which the mandrel and article Whichis being rolled are moved to correspond with the rolling operation. In the present case it is not a responding to the rolling operation, but rather one of giving' an absolutely definite position to the mandrel relative to the rollers and retaining the mandrel in this position during the working period.

Two constructionsv embodying the inven tion are illustrated in the drawings. Figure 1 shows a disc apparatus in plan view in which roller discs a, which are relatively disposed in known manner, act in conjunction with the mandrel b to effect the expansion of the tube. r The mandrel shaft c 1s in thisv case arranged on the entry side of the ap aratus. To one end' of the mandrel shaft 1s secured the mandrel b, the other end being connected to an adjusting devicel which consists of a piston rod 3, piston 4 andcylinder 5.l With this construction the mandrel shaft is not subjected to a bending, but to a tensile stress. 'In this manner even in the case of considerable lengths, which exceed that of the tube to be produced by from about one `to two meters, a considerable lreduction in the cross sectional area of the mandrel shaft is effected, in contrast to the mandrel shafts heretofore-used which have been subjected to pressure, and, therefore, made very heavy with resulting inconvenience in handling. The mandrel shaft which is subjected to tension, does not alter its length '1n proportion to the roller pressure, and, therefore, retains dthe mandrel. in the ad-v usted V'tion un er varying rassure.

l* In thldodlonstruetion illustrate in Figure 1 vthe mandrel shaft c isoonneeted to one end 109 so I of the piston rod 3. The other end of the piston ro moves' in the cylinder 5' in known manner.

Pipes 6 and'7 are rovided at the ends of the cylinder 5 throug which pressure may be transmitted to the cylinder by means of a fluid, which may he hquid or gaseous. Suitable known controls may be provided wherepiston may be accurately regulated and an absolutely definite position thereby given the mandrel.' It is evident that the mandrel osition may be maintained by the means just described or that if the mandrel shaft should have altered its length because of heat during the rolling, the position of the mandrel may be readjusted during the rolling.

If a 1particularly ine adjustment'of the mandre is required a supplementary ne adjustment means may'be provided.

Fig. 2 illustrates iuidV actuated means for giving the mandrel coarse adjustment, to which is added other means for giving fine adjustment. In this case a screw spindle, worm wheel, worm, and hand-wheel are illustrated as giving the iine adjustment.

arrangement is here shown which is somewhat similar to that illustrated in Fig.- ure 1. A mandrel b is fastenedto one end of a mandrel shaft lc which is arranged on the entry side of the apparatus. The other end of the mandrel shaft, as in Figure 1', is connected to an adjusting device which consists primarily of a piston'rod 31, piston 4 and cylinder 5.

Instead of attaching the mandrel shaft directl to the ,-piston rod as is the case in the examp e illustrated in Figure 1, in the present case the mandrel shaft is connected to one end of a stem 8 whose other end 9 is expanded and threaded. The threaded end 9 of the' stem 8 turns within a flanged nut 10, with whose internal threads it engages. The piston rod 31 is extended beyond thev piston4 away from the mandrel and Ycontains a bore into which lthe nut 10 extends and in which the nut is free to rotate. lThe nut 10 has a flange 11 which bears on one side against 'a shoulder 12 formed on the piston rod 31,

and on the other side against a plate 13 spaced `from the shoulder 12.' Thus, while the nut is free'to rotate in the bore of the piston lrod 1t is constrained against axial movement with to the piston rod.

to the flanged nut 10 and serves torotate it. A worm 15, upon whose shaft 16 is ahandwheel 17, provides means for operating the worm wheel and with itthe nut 10.Y Ihus the 3 is connected with the piston 4, which the fluid pressure on both sides of the eglitere shown, a worm wheel 14 is attached Bymeans of the present invention it is therefore possible to maintain the mandrel always in a definite position between the roll'- adjust the` mandrels 'position during the working period to compensate for any alteration in the length ofthe mandrelshaft.

I claim:

1. In apparatus for expanding metal tubes, a mandrel shaft located at the inlet side of the apparatus, anda mandrel carried by said shaft, in combination with iuid actuated means forgiving rough adjustment to said mandrel during rolling, and other means axially movable with said luidactuated means and mandrel shaft for giving fine adjustment t0 said mandrel.

2. In apparatus for expanding metal tubes, a mandrel shaft located at the inlet side of the apparatus, and a mandrel carried by said shaft, in combination with fluid actuated means for giving rough adjustment to said mandrel during rolling, and screw means' axially movable with said fluid actuated means and mandrel shaft for giving fine adjustment to said mandrel.

3. In apparatus for expanding metal tubes, a fluid cylinder mounted at the inlet side of the apparatus, a piston reciprocable therein, a mandrel shaft, a mandrel carried lers during the working period, and also t0 by the mandrel shaft, means connecting said v piston and mandrel shaft, and means for re ulating fluid pressure in the cylinder on bot Sides of the piston to position the mandrel and to maintain the mandrel in adjusted positions during expansion of the tube.

4. In apparatus for expanding metal tubes, a fluid cylinder .mounted at the inlet side of the apparatus, a Liston reciprocable therein, a mandrel shaft, a mandrel carried by the mandrel shaft, means connecting said piston and mandrel shaft, and means for regulating fluid pressure inthe cylinder on both sides ofthe piston for giving rough adjustment to said mandrel, and other means associated with .the piston and mandrel shaft forgiving fine adjustment to the mandrel.

In testimony whereof I vhave signed my 60 threaded end 9 of the stem 8 is moved longitudinally of the piston rod and piston, and

the mandrel is given fine adjustment.

Thecylinder may be varranged pivotally to facilitate connectin and disconnecting the plston rod and man rel shaft.

Images