US1282261A - Galvanoplastic method and apparatus. - Google Patents

Description

M. M. MERRITT.

GALVANOPLAS'HC METHOD AND APPARATUS.

APPLICATION FILED MAR. 29. I917.

Patented Oct. 22, 1918.

days.

Ewen/Ear.- mifiwew M. Merzefi.

HE sex a i MATTHEW M. MEBRITT, OF DANVERS, MASSACHUSETTS, ASSIGNOR- TO COPPER PROD- UCTS COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORATION OF MAINE.

To all whom it may concern:

Be it known that I, MATTHEW M. MER-- RITT, a citizen of the United States, and a resident of Danvers, co unty of Essex, Com- .posited.

the deposited metal.

sirable that the deposit of metal be as unimonwealth of Massachusetts, (whose postofiice address is Danvers, Massachusetts,) have invented an Improvement in Galvanoplastic Methods and Apparatus, of which the following descriptlon, in connection with the accompanying drawings, is a specification, like characters on the drawings representing like parts.

This invention pertains to improvements in .galvanoplastic methods and apparatus,

and more particularly, though not exclusively, to improvements in methods and apparatus for manufacturing copper tubing and sheets by galvanoplastic deposit.

Among the objects of the invention are to provide more perfect galvanoplastic deposits, and to accelerate and otherwise cheapen the manufacture of such deposits.

In the drawings:

Figure 1 is a section .through a tank containing an electrolytic bath, an anode and a cathode, the latter being a mandrel adapted for use in manufacturing copper tubes.

' Fig. 2 is a' cross section on an enlargedscale, of the mandrel with the galvanoplastic deposit thereon.

Fig. 3 is a perspective of a larger mandrel on which a sheet of copper has been de Fig. 4 is a perspective showing the sheet 3f popper partially stripped from the man- It is essential to the manufacture ofarticles by galvanoplastic processes that the mandrel or mold be readily separable from It is also highly deform in thickness as possible, that the process be accelerated and that the mold or mandrel be preserved from deleterious chemical action and be of permanent character'so that it can be used many times and' this without repeated and expensive treatment.

Copper tubes have heretofore been'electrolytically .deposited on fusible mandrels or on metallic mandrels from which they have been separated by burnishing orirolling to enlarge the tube. In some instances metallic mandrels for this purpose have been coated with tin or zinc, either elec- Specification of Letters Patent.

Patented Oct. 22, 11918.

Application filed March 29, 1917. Serial No. 158,428.

trolytically or by dipping, prior to the galvanoplastic deposit. In such cases the separation of the deposit from the mandrel is more difiicult than by my process hereinafter described, and usually necessitates the recoating of the mandrel after use thereof.

,Also the deposit is considerably thicker at and near the electric connection to the mandrel and at the portion of the mandrel nearest the anode. In some instances several electric connections have been provided, but this merely results in increasing the number of'irregularities in the deposit.

I have found thatby using a permanent metallic mandrel which has been covered with .a mercury deposit by amalgamation or otherwise, I can very readily remove the galvanoplastic deposit'with little if any expansion of the deposit by burnishing or otherwise. I I have also found that the electro deposit is very even on all parts of the mandrel because of the superior conductivity of the surface of the mandrel when coated with mercury. The mandrel. should be very smooth but the mercury coating fills the pores or other roughnesses of the core of the mandrel, and in one sense lubricates the I The core of the mandrel may be of brass,

steel, or other metal, but I prefer the former.

1 Where the latter is used the mercury protects the steel. from the chemicals in the bath. The mercury coating is durable and -a mandrel may be used many times without the application of a fresh-coating of mer- 'cury, especially where, as when a brass mandrel is coated, there is a considerable chemical union of the surface of the brass and the mercury.

In the manufacture of sheets the same ad-- convenient to remove the deposit from the mandrel by splitting the deposit lengthwise of the mandrel.

While I have described andv illustrated cylindrical mandrels, it will be understood that the mandrels may be of any form without departing from the broader aspects of -my invention. It will also befunderstood that, within the scope of the appended claims, considerable changes may be made in materials and methods, of utilizing the same. My invention and What I desire by Letters Patent to secure, is best defined by the following claims.

Claims: v 1. The method of preparing a metallic mandrel for galvanoplasticdeposit, which comprises coating said mandrel with mercury amalgam.

2. The method of preparing a permanent mandrel for cury amalgam entering into chemical union with the surface of the mandrel.

3. The method of manufacturing articles by galvanoplastic deposit which comprises electrolytically depositing metalon a permanent metallic mandrel coated with a conductor fluid at ordinary temperatures and providing per s e no substantial resistance I galvanoplastic deposit which 1 comprises coating said mandrel with a mername to this specification.

to removal of said deposit from said mandrel.

4. The method of manufacturing copper tubes which comprises galvanoplastically depositing copper on the mercury coated surface of a cylindrical mandrel, slightly en- I larging said tube by bulfing, and withdrawing said tube from said mandrel.

5. The method of manufacturing copper sheets which comprises galianoplastically depositing copper on a mercury coated surface of a matrix, and subsequently stripping body portion having its surface amalgamated with mercury.

In testimony whereof I have signed my MATTHEW M. MERRITT.

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