US2356639A

US2356639A - Apparatus for producing matrices in galvanic baths

Info

Publication number: US2356639A
Application number: US395318A
Authority: US
Inventors: Woitscheck Arno
Original assignee: Individual
Current assignee: Individual
Priority date: 1940-05-17
Filing date: 1941-05-26
Publication date: 1944-08-22
Anticipated expiration: 1961-08-22

Description

"Aug.22, 1944. A. WQITSCHECK 2,355,639

APPARATUS FOR PRODUCING MATRICES IN GALVANIC BATHS Filed May 26, 1941 2 Sheets-Sheet 2 I 16 1 jfz'gr. 1s

15 V52 1 a g 19 1.3 20 15 //7/ en for.-

Patented Aug. 22, 1944 1 APPARATUS FOR PRODUCING'MATRICES" 7 N GALVANIC BATHS Arno Woitscheck, l?orz, near-Cologne, Germany; vested in the Alien Property Custodian I 5 Application May 26,1941, Serial No. 395,318 7 r In Germany May l7, 1940 Claims. (0-1. ant-2 86) The object of the invention is to provide, in place of the known method of producing mechanically recorded sound-bands in a galvanic bath, a method of and a device for the production perfect sound band matrices in the most sim ple manner and within the shortest possible time. It relates especially to the production of matrices from long and comparatively wide sound bands, in whose sound record layer are cut a. number of sound grooves running parallel or nearly parallel to'the edge of the band, though the invention may likewise be applied to short and narrow sound bands.

"The original sound bands, afterhaving been recorded in known manner, are provided with an electrically conductive coating, for example a graphite coating, and are then placed in a galvanic-bath, in which a galvanic deposit-of the desired thickness of the sound bandmatrix is produced on the surface of the band that has been renderedconductive. In this operation, not only the handling of the original sound band, which is provided with an extremely delicate layer, for example a wax layer, but particularly the electric connection of the conductive surface of the band, cause considerable difliculties. Since the conductive coating. on the recorded side of the: band has to be extremely thin, because otherwisethe reproduction of the sound record by the matrix would be imperfect, care must be taken that the coating produced in the galvanic bath grows as quickly and uniformly as possible, and at the same time that the band-shaped matrix has in all parts the same thickness,

In order to achieve these objects, the invention provides a current connection at the conductive recorded surface of the original sound band for the entire length of this band, ensuring an uninterrupted contact along the edge of the conductive surface strip, preferably along both edges of this strip. For this purpose, the original sound band is clamped at its longitudinal edges on to a current carrying rail by means of conducting angular strips, the one leg of which rests on said rail, whereas the other leg lies on the edge of the conductive surface of the sound band. The free surfaces of said rail and of the conducting strip, serving to clamp fast the sound band, are provided with an insulating layer or cover, and then the band is brought into the galvanic bath.

In order to save room and to be able to more easily handle the sound band, it is known to wind the sound band in a helical line upon a drum when it is immersed in the galvanic bath. As a carrier for the sound band, the invention proiii vides, instead of the drum, a helical current-com ducting rail with clamping devices for the sound ban'darranged along the edges of the rail. This helical rail is advantageously mounted to rotate and is connected by means of a slip current conductor.

According to the invention, the clamping devices for the sound band comprise segmental sections of angularly bent metal strips which, on the one hand, bear by means of angular segments of insulating material against the current conducting rail and, on the other hand, against the conductive surface of the sound band.

A constructional example of the device for car-' rying out the method-according to the invention devices for the original sound band, on an en-' larged scale and a I a Fig. 5 is a top view of the current conducting mil with the clamping devices attached thereto,

also on an enlarged scale.

The current conducting rail 1, consisting for example of copper, has, as will be seen from the drawing, a helical shape and forms at-its outer circumference a smooth resting surface 2 for the original sound band of which a matrix is to be made. The current conducting rail is carried by a cage consisting of an upper ring 3, preferably of copper, a lower ring 4, and rods 5 running between these two rings. The rods 5 pass through the convolutions of the current conducting rail and serve to carry this rail and to ensure a uniform spacing of the individual convolutions of the rail; they are conductively connected to the rail l and the rings 3 and 4.

The ring 3 is connected by means of spokes 6, preferably consisting of copper, with a hub 1 of insulating material rigidly attached to a vertical shaft -8 rotatable about its axis. a slip ring 9 being provided at the circumference of the hub and being conductively connected to the spokes 6. The current conduction to the slip ring 9 is effected by the diagrammatically indicated brush it.

The ring 4 has spokes II supported by a hub 12 of insulating material, which is carried by the shaft 8 at its lower end.

To the rail I are attached, at the side at certain distances, bolts l3 of insulating material serving to attach the clamping devices for the ring to the sound band of which a matrix is to be made. The bolts I3 carry nuts I4, also consisting of insulating material. The clamping devices for the sound band consist of segmental sections of angularly bent copper strips l5 and of angular segments I6 of insulating material. The copper strips I5 have longitudinal slots I1, and the segments I6 have longitudinal slots I8 in which, in the operating position of these clamping means, the bolts I3 are disposed.

The sound band, of which a matrix is to be made, for example, consists of a carrier layer I9 and a sound record layer 20 of wax, into which the sound grooves 2| are cut. After the recorded surface has been made conducting, for example by coating it with graphite or in some otherway, the band is found upon the outer surface 2 of the'helical rail I so that the carrier layer rests on the rail. As this winding proceeds, first the copper strips I5 and then the insulating segments I6 are slipped with their slots I1 and I8 on to: e bolts I3 of the rail I, whereupon the nuts I are tightened. In this way, the leg I5a of the copper strip I5 is pressed against the lateral face of the rail I, whereas the leg I5b projects over the edge of the original sound band and bears against the conductive surface of this band. As wil1 be seen from the drawing, one copper strip I5 follows the other copper strip I5 so that the current connection at the conductive recorded surface of the original sound band is ensured over the entire length of this band by uninterrupted contacts along the edge of the conductive surface strip, at both edges of this strip. Consequently, when the sound band is brought into the galvanic bath, the material forming the matrix, for example copper, very rapidly accumulates on the surface of the band of which the matrix is to be made.

When the sound band is completely attached to the current conducting rail, the remaining free surfaces of the rail and of the conducting strip serving to clamp the sound band on to the rail are provided with an insulating layer or cover. This may be done, for example, by applying an insulating varnish. The same refers to all other condifcting surfaces of th ring 4, the rods 5, the spokes II, and the shaft 8. Of course, all these parts may just as well be varnished before winding the sound band upon the rail.

The device described above, carrying the sound band, is immersed in the galvanic'bath 22, into which the anodes 23 dip, in a manner known per se, said anodes being suspended on a conductive ring 24 connected at 25 to the source of current. While the matrix is being formed, the rail I is rotated by the shaft 8 with respect to the anodes 23.

When the matrix has been formed, the rail I is drawn out of the bath, the clamping devices I5, I6 are removed, and the matrix band formed is detached from the original sound band while the latter is still wound on the rail.

What is claimed, is:

1. An apparatus for producing matrices in a galvanic bath from mechanically recorded flexible sound bands having a prepared conductive surface at the recorded portion thereof, comprising a supporting cathode for receiving the band with its recorded and prepared surface exposed, said cathode having a helical rail comprised of spaced convolutions of channel-shaped cross-section, angular conductive segments extending around the edges of said helical rail and adapted to overlie the margins of the band in coextensive conductive relation with said conductive surface thereof, angular insulating segments extending over the outer surfaces of said conductive segments, and clamping means for securing the segments in position.

2. An apparatus for producing matrices in a galvanic bath from mechanically recorded flexible sound bands having a prepared conductive surface at the recorded portion thereof, comprising a supporting cathode for receiving the band with its recorded and prepared surface exposed, said cathode having a helical rail comprised of spaced convolutions of channel-shaped cross-section, angular conductive segments extending around the edges of said helical rail and adapted to overlie the margins of the band in coextensive conductive relation with said conductive surface thereof, angular insulating segments extending over the outer surfaces of said conductive segments, and clamping bolts extending through the channel members for securing the segments in position, the segments having slots for receiving the stems of the bolts and with open ends directed toward the axis of the helix for facilitating the placing and removal of the segments on the bolts.

ARNO WOITSCHECK.

CERTIFICATE OF CORRECTION. Patent No. 2,556,659. August 22, 19th.

ARNO woITsCEECK.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, first column, line 17, for the word "found" read -wound-; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 28th day of November, A. D. 191411..

Leslie Frazer (Seal) Acting Commissioner of Patents.