US1744731A - Pilgering mill - Google Patents

Description

Jan. 28,' 1930. BAMBERGER 1,744,731

PILGERING MILL Filed March 25, 1926 Fig.2.

V by

L s. W Attorney.

Patented Jan. 28, 1930 UNITED STATES PATENT OFFICE OTTO BAMBERGER, 0F DUISB'URG, GERMANY, ASSIGNOR TO IlJEUTSCHE MASOHINEN- FABRIK AKTIENGESELLSCHAFT, 0F DUISBURG, GERMANY PILGERING MILL Application filed March 25, 1926, Serial No. 97,329, and in Germany February 6, 1926.

The present invention relates to driving gear for the feeding mechanism of pilgering mills.

Hitherto the various movements of the feeding mechanism were effected by hydraulic means.

The method of operating thefeeding mechanism renders necessary varying powers and speeds; On the oneehand the blank, which is placed upon the mandrel, is very quickly rolled, while on the other hand the actual pilgering proceeds slowly in exactly uniform finely graduated forward movements of the blank. After the tube has been rolled, the feeding mechanism is used for withdrawing the mandrel from the completed tube, for which operation very considerable power must be employed. The feeding mechanism must then be rapidly retracted whereby the consequent placing of a new hollow block upon the mandrel requires the expenditure of considerable power.

Provision for the changing requirements in connection with the hydraulic feeding mechanism hitherto employed could be niade only by employing complicated controlling devices, and attention to them was troublesome, with the consequence that the apparatus was frequentlyput out of order. Furthermore, the solution of the problems involved in working by hydraulic m'eans necessitates apparatus that is expensive, indeed it was usually necessary to install a special source of power for the feeding mechanism. The present invention solves the practical difficulties in a simple and effective way.

According to the invention the carriage for the blank isdriven by one or more electric motors in the use of gearing, in such manner that by graduating or dividing the drive the appropriate power and speed are exerted on the carriage.

It is particularly advantageous to use two electric motors for the drive, one of which runs at a high speed and does considerable work by advancing the blank to and withdrawing it from the mill, and also removing the blank from and replacing it on the mandrel, while the other motor, working at a considerably lower speed and doing far less work, advances the blank during the rolling operation.

It is furthermore advantageous to arrange the motors in such manner that they can be put into and out of operation by an electrical switch or by coupling or uncoupling as desimplicity of the whole arrangement the possible sources of error are reduced to a minimum.

The invention is illustrated diagrammatically in the accompanying drawings by way of example:

Figure 1 is a plan of the mechanism,

Figure 2 is an elevation,

Figure 3 is a partial side elevation, and

Figure 4 is a longitudinal sectional elevation, to an enlarged scale, showing the rear portion of the mechanism to which the invention relates.

The pilgering rolls are indicated by a. The blank or hollow block b is mounted upon a mandrel b, which is loosely mbunted on the carriage d with an automatic retracting device interposed. The carriaged comprises a cylinder having a piston the rod of which forms or is connected to the rifled spindle to which the mandrel b is secured. The iston is subjected to air pressure by means 0 compressed air supplied from a suitable reservoir or container. Thus when the blank is worked by the rolls a, it is forced backwards against the air pressure and when released by the rolls is thrown forward by the air pressure acting upon the piston. The carriage d is moved upon guide rails by the means of spindles 0.

- power is applie The spindles c are moved by toothed wheels e-mounte-d upon them, with which toothed wheels engage a pinion mounted upon the shaft of the motor f. h is the second driving motor connected through the clutch g to the motor f by means of a worm wheel drive is, the shaft of the motor f carrying the worm is, while the worm wheel 7.: is, for example, mounted on a short shaft in alignment with the shaft of the motor f and adapted to be coupled thereto by the clutch g, or upon a sleeve carried by an extension of the shaft of the motor 7, the sleeve being engaged therewith by the clutch g.

The mechanism is operated as follows:

The hollow block is first placed upon the mandrel. As for this purpose a great consumption of power is necessary, the operator switches in the more powerful motor 7, and throws out the clutch g. After the hollow block has been placed in position, the same source of power feeds the blank at a considerable speed 11 to a position in front of the pilgering rol s. Here the current is passed through the motor I) and the clutch g is engaged. Thereupon the the motor 71-, which is now energized, drives the worm gearing k, k and, through the clutch g, the shaft of the motor f with the armature and thus, through the toothed wheels 6 of the spindle 0, moves the blank slowly forward through the pilgering rolls. If there are any interruptions during pilgering, that is to say, if the block should am by reason of flaws in the metal, the blank may at all times be assisted over the diflicult part by the motor f, or the blank may be quickl drawn back.

When the pi gering operation is completed the motor his cut out and the more owerful motor f comes into operation and withdraws the mandrel b from the finished tube, retracts the feeding mechanism at a high speed and places a new hollow block upon the mandrel.

I claim:

1. Feeding mechanism for pilgerin mills consisting in combination, a mandre upon which the blank is applied, means com ri 'n an electric motor ada ted to cause 51c ed vancement of the sai mandrel and its retraction from the pilgering rolls, a separate smaller electric motor adapted to advance the blank durin the pilgermgoperation, and means where y either motor may be set into blank from and applying a new blank on the said mandrel, a second smaller electric motor adapted to advance the blank during the pilgering operation, and means whereby either motor may be set into operation to move the blank and the mandrel, substantially as hereinbefore described.

3. Feeding mechanism for pilgerin mills consisting in combination of a mandre upon which the blank is applied, a carriage upon which the mandrel is supported and by which the mandrel is advanced to and retracted from the pilgering rolls, gear through which power is applied to the said carria e, an electric motor adapted for the operation of the said gear in advancing the mandrel and retracting it and in removing the finished blank from and replacing a new blank on the said mandrel, a second smaller electric motor adapted to advance the blank during the pilgermg operation, and means comprising a clutch'through which the drive may be 1mparted to the said gear from the second smaller electric motor, substantially as hereinbefore described.

' OTTO BAMBERGER.

operation to move the blank and themhndrel" substantially as hereinbefore described.

2. Feeding mechanism for pilgerin mills consisting in combination a mandre upon which the blank is applied, a carriage upon which the mandrel is supported and by which the mandrel is advanced to and retracted from the pilgerin rolls, gear through which to the said carria an electric motor ada ted for the operation of the said gear in a. vaneing the mandrel and retracting'it and in removing the finished

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