US2024305A - Rolling of electrical conductors of noncircular cross section - Google Patents

Description

A. ROHS 'necfn, 1935'.

ROLLING OF ELECTRICAL CONDUGTOBVS OF NONCIRCULARCRO SS SECTiON Filed Dec; 15, 1932 Patented Dec. 17, 1935 UNITED STATES PATENT OFFICE ROLLING OF ELECTRICAL CONDUCTORS OF NONCIRCULAR CROSS SECTION Application December 15, 1932, Serial No. 647,486 In Czechoslovakia December 15, 1931 4 Claims.

The diameter of electrical conductors depends inter alia upon the solid part of the cross-section of the copper conductor hereinafter referred to as the filling factor. In the case of solid conductors, the filling factor is whereas in the case of stranded conductors the filling factor drops down to 70% of the surface enclosed by the profile oi the conductor. In order to increase the filling factor in the case of stranded conductors, it is known more especially in the case of sector-shaped conductors of electric cables the edges of which run parallel to the longitudinal axis of the conductor, to pass the conductors after they have been stranded, once more through suitable sized rolls, wherein they are reduced, viz.

rolled into a form having the desired higher filling factor.

The invention relates to an apparatus for rolling electrical conductors of non-circular crosssection. The object of the invention is to proer. According to the invention the apparatus for the rolling of electrical conductors of non-circular cross-section consists of a casing rotatable around the axis of the conductor and containing the rolls, whereby the drive of the rolls is effected independently of the drive of the casing containing the rolls. The roll casing is driven only when it is intended to press electrical conductors of non-circular cross-section having a helical twist.

According to the invention the rolls rotating around the axis of the conductor may be driven by an electromotor through the intermediary of a slip coupling, which motor rotates together with the roller casing around the longitudinal axis of the conductor to be rolled, the electric current being supplied thereto through slip rings and sliding contacts. The rotating roll casing must be exactly balanced in this form of construction. The object of the slip coupling is to ensure that approximately the same torque should be transmitted to the rolls.

The electric-motor which is to be incorporated in the rolling apparatus causes the latter to become comparatively long, which in many cases, especially if it is to be incorporated in existing stranding machines, constitutes an obstacle. The length of the apparatus may be reduced according to the invention by effecting the drive of thethe planet wheels more slowly or more rapidly.

The accompanying drawing illustrates the various devices which are required for carrying the method according to the .present invention into effect. 5

Figs. 1, 2, 3, and 4 illustrate the construction of a rolling apparatus, the rolls of which are driven by an electric motor arranged in the roll casing and which is incorporated in a stranding machine, Fig. 1 being a side elevation, Fig. 2 a 10 plan view, Fig. 3 a front view of the apparatus and Fig. 4 a section along the line 44 in Fig. 1.

Referring to the construction illustrated in Figs. 1 to 4, theactual rolling apparatus is mountv ed in two bearings, 2a., 21) provided on the table l. 15 The rolling apparatus consists of a rotatably mounted casing 3 having two hollow journals for the'reception of the two rolls 4.

The two rolls are interconnected by means of toothed wheels 5, it being, however, sufficient to 0 drive one roll only. The rolls are mounted in the slotted guides of the roll casing 3, which allows the rolls to be easily replaced. The rolls are pressed against one another and kept in their position by means of clamping screw 1 acting 25 on the bearings 6 of the roll shafts. The driving of the roll casing which has to rotate around the longitudinal axis of the helically wound conductor when the latter passes through is effected by means of chain or toothed wheel transmission, 39 the driving wheel 8 being secured so as to rotate with the roll casing 3.

The chain or toothed wheel transmission is such that the speed of the roll casing 3 corresponds exactly to the pitch of the helical line, 35 which the conductor to be rolled must have in the completed cable, that is to say it must correspond exactly to the speed of that part of the stranding machine which strands the core of the conductor into the helical form thereby im- 40 parting the above-mentioned helical form to the stranded conductor of non-circular cross-section. The hollow journal M of the casing is constituted as a holder for the stranding die l5, which rotates with the casing, in which die the wires of 45 the core coming from the rear part of the machine are stranded in to the helical form and the covering wires are helically laid or stranded on the said helical core. The stranding die I5 is adjustable in its holder in order to enable it to be 50 adapted to the helical line of the conductor with respect to the rolls. The driving of the rolls is effected by means of an electric-motor l6 which is provided on the roll casing and rotated therewith, The current is supplied to the motor by 55 means of sliding contacts and slip rings I! (see Fig. 1). The latter are shown by way of example mounted on the hollow journals l8 of the casing, the required speed of the rolls 4 can easily be obtained by suitable transmission ratios between the motor and one or the other roll shaft, for instance by means of toothed wheels, worms and worm wheels or like combinations.

In Figs. 1-4 the transmission consists of worms and worm wheels. The slip coupling 19 is provided in the transmission between the motor and the rolls in order to obtain a balance by a suitable adjustment thereof if the speed of the rolls is greater than the speed on which the conductor runs to the machine and which latter speed is dependent upon the peripheral speed of the discharge disc 20. Moreover, the speed of the motor may be regulated by regulating the current. The rotating roll casing is correspondingly balanced. The operation is as followsz-The wires coming from the stranding machine which serves for the manufacture of conductors of non-circular crosssection which are preliminarily twisted into a helical form, are stranded in the stranding die l5 and are subsequently rolled by means of rolls 4, the roll casing, together with the stranding die I5 and rolls 4 rotating around the longitudinal axis of the conductor at the same speed as the stranding machine which, together with the die l5 imparts to the conductor of non-circular cross-section the above-mentioned correct helical form.

It is to be understood that any kind of speed regulation may be employed for regulating the speed of the rolls and that the invention is not limited to the use of change wheels; further, that instead of chains, use may be made of any other means of transmission.

What I claim is:

1. An apparatus for rolling electrical conductors of non-circular cross section comprising rolls, a casing containing said rolls and rotatable around the axis of the conductor, a drive for said casing, and a drive for the rolls independent of said drive for said casing.

2. An apparatus for rolling electrical conductors of non-circular cross section comprising rolls, a casing containing said rolls and rotatable around the axis of the conductor, a drive for said casing, and a drive for said rolls independent of 1.5

drive for said rolls, and a motor drive for the casing independent of the planet gear drive of the machine in which the rolling apparatus is built.

ADOLF ROHS.

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