US2063721A - Galvanizing apparatus - Google Patents

Description

Dec. 8, 1936.l A, F, BRADLEY y2,063,721

GALVANIZING APPARATUS Filed Oct. 8, 1934 Patented Dec. 8, 1936 UNITED STATES.

'l 2,063,721 lciALvAiiuzlNc. APPARATUS Albert r.1 Bradley, sterling, m., assigner to Northwestern Barb Wire Company, Sterling, lll., a corporation of Illinois Application October 8, 1934, Serial No. 747,415 3 Claims. (Cl. ill-12.5)

The present invention relates to galvanizing apparatus, and more particularly tofv apparatus for applying superposed coatings of zinc to ferrous material, such as wire, sheets or other ilex- 5 ible material.

to apply the successive coatings while continuously moving the material through the apparatus. 15, Another object of the present invention is to provide galvanizing apparatus adapted to apply successive coatings of zinc to material and cooling the material in the presence of a non-oxidizing atmosphere, between successive coatings, so that the finished product may be bent or flexed without causing the coating to crack, peel oif or loosen, thereby fully protecting the material from deterioration in use. f A further object of the present invention is to .provide galvanizing apparatus adapted to apply thin and flexible 4'coatings of zinc to flexible ferrous material, such as wire, sheets and the like, so that the' ilnished product may be bent or iiexed without impairing the coating. A still further object of the invention' is to improve galvanizingfapparatus, whereby wire,

sheets and the like of ferrous material may be to be coated is passed.

coated to prevent deterioration in use.

A yet further objeci'fof the invention is to provide. galvanizing apparatus for successively applying two thin layers or coatings of zinc to exible or bendable material, such as wire, sheets and the like. z n Coatings of zinc on iron or steel, produced by 40 exposing the surface of the iron or steel to the action of molten zinc, adhere firmly to the iron or steel by reason of a thin layer of zinc-iron I alloy, or a mutual solution of the two metals, occurring at the surface of contact.A This alloy, however, has the disadvantage of'. being very brittle, so that when a wire or other flexible material is galvanized, there is a tendency for the alloy to break when thewire is bent, thus ,causing the coating to crack and loosen or peel oir the material. v

The present invention overcomes this difficulty by providing an apparatus wherein the application o! zinc to the iron or steel is made under 55 conditions which favor the formation of a thin and, therefore, flexible coating of Vzinc-iron alloy,

with a superposed coating of zinc.

The above, other and further objects of the invention will be apparent from the following,

description, accompanying drawing and ap- 5 pended claims. r

The accompanying drawing, schematically, represents an apparatus embodying principles of' the present invention and the views thereof are as follows: 10

Figure l is a view, partiallyin plan and partially in section, of the tank illustrated uin Figure 2, the section being through the cooling chamber, with certain parts in elevation.

Figure 2 is a side elevational view of an ap- 15 paratus of the present invention,wlth certain parts in plan, certain parts in section and-other parts broken away, all to show details of construction.

The coating of iron-zinc alloy forms during 20 the passage of the material, such as wire, through the molten zinc, and its thickness is dependent, i to'scme extent, on the time during which the wire remains in the zinc bath. 'I'he longer time the wire is immersed in the bath, lthe greater the 25 zinc deposit thereon and the thicker will be thelcoat of alloy formed. When a short passage orf l time is employed, a comparatively Cthin, weak coating will be formed.

' The apparatus of the present invention includes a tank I for containing a bath `2 of molten zinc or spelter through which the material The bath is advantageously maintained at a "temperature of sbstannauy 875. F. during the 35 coating operation. Material to be coated, such as a wire 3 is drawn through the apparatus byv vany suitable means, not shown. The wire is inserted through the machine and as it is drawn through, it passes iist underneath a submerged 40 roller or equivalent means 4 supported in the tank I by means of yokes 5 suspended from brackets 6 suitably secured to the side walls of the tank. After passing underneath the submerged roller 1 the material is removed from the bath and passes over a roller I9, thence downwardly and is again immersed in the.v bath, passing under-v neath another submerged roller v'|, thence outwardly of the bath througha wiper 8 to a. point of disposal. 50

The roller l! is journalled in sliding blocks l which are supported on upright brackets 8 suitably secured to the side walls of the tank; At the upper end of each of the brackets 8 is a plate or similar means 9 having a vertically disposed l threaded screw I0. The heads of the screws are secured to the blocks 1 by means of connections II. The vertical adjustment of the screws I is effected by means of nuts I2 surrounding the screws and engageable with the plates 9. By the means just described, the angle at which the wire or other material being coated leaves the bath after the first immersion and enters the bath for the second immersion may be regulated. In this way the times of immersion and of exposure to the non-oxidizing atmosphere may be increased or decreased without changing the speed of travel of the material through the bath.

A housing I3 is suitably attached to the tank I and includes the adjusting roller I9. 'I'he end walls of the housing I3 project downwardly a slight distance into the bath 2. The interior of the housing I3 forms a cooling chamber and the atmosphere in this chamber is maintained as a reducing or non-oxidizing atmosphere by admission, through a supply pipeI4 from a suitable source, of suitable non-oxidizing agents, such, for instance, as carbon dioxide, nitrogen, hydrogen, producer gas, illuminating gas, mixtures of these gases or other suitable gases. It is preferable, however, that the gases be non-inammable.

It will be observed that the material, such as the'wire, is given-successive immersions in the coating bath and `between these immersions is cooled in a reducing or non-oxidizing atmosphere. The result of such action is to form on the wire by the rst immersion an initial coating of zinc-iron alloy. This initial coating is cooled within the housing or chamber I 3, and the second immersion applies a superposed coating of zinc to the initial coating of zinc-iron alloy.

The product resulting from the use of the present apparatus produces a coated wire or similar material with superposed coating. The initial or rst coating is a relatively thin one of an alloy of zinc and iron, while the major portion of the superposed or second ,coating is of practically pure zinc. The resulting product is one which may be bent or twisted without impairing the galvanized coating in any respect whatsoever, thereby preventing access of moisture through the pores of the metal of the wire.

While the accompanying drawing illustrates but a single wire 3 as passing through the apparatus; it is to be understood that a plurality of wires may be continuously passed through the apparatus, so that quantity production may be `lili slightly longer time during the first immersion readily accomplished.

As the apparatus appearsl in the illustration,`

the material being coatedA remains immersed a than during the second. However, the time-of immersion may be changed` as desired in accordance with the material being coated, and also in accordance with the nature of the coating applied.

The speed of movement of the wire through the apparatus may vary over a wide range. In general, larger'sizes of wire require more time, and consequently slower speeds, as more time is needed t o bring such larger wires to the temperature of the bath for receiving the initial coating. By Way of example, when it is desired to galvanize wires having diameters between .0348 and .192 inches, the most effective speed will vary from 210 to 46 feet per minute.

It is to be understood that the speeds specified.

are not critical but are illustrative only, as the speed of the wire depends to some extent on th'e length of the tank. The specied temperature of the zinc bath hereinbefore mentioned is not critical and may be varied somewhat, as desired.

It is to be understood that while this invention has been described as applied to the production of galvanized wire, sheet material may also be run through the apparatus and treated in the Same manner. treated in this apparatus, it is advantageous principally in the treatment of ilexible articles, as the apparatus is utilized for the coating of material which is exed or bent in use, such as wire, and to coat such material with a galvanized coating preventing any tendency for the coating to crack or double when the article is bent or iiexed.

The second submerged roller 1 is supported in the tank in the same manner as the first sub-4 merged roller 4, that is to say by means of hangers I5 supported on brackets I6 suitably secured to the side walls I'l of the tank I.

The wiper 8 may be of any well-known form and construction. Adjacent the leaving end of the apparatus is a drip pan I8, in which any matter wiped oi of the wire 3 by the wiper 8 may be collected.'

The wires from this galvanizing apparatus may be led to any suitablepoint for disposition, such, for instance, as winding on reels for the market.

This application is a continuation, as to all common subject matter, of my co-pending application Serial No. 724,305, led May 7, 1934.

I am aware that many changes may be made and numerous details of construction may be varied through a wide range without departing from the principles of this invention, and I, therefore, do not purpose limiting the patent granted hereon otherwise than necessitated by the prior art.

The invention is claimed as follows:

1. In a galvanizing apparatus, means for applying superposed coatings of zinc on exble material including means providing a bath of molten zinc, means for immersing the material inV said bath for the formation of an initial coating, means for removing the initially coated material from the bath and cooling it in a non-oxidizing atmosphere, and means for immersing the initially cooled material inthe same bath to acquire a coating of zinc about said initial coat.

2. A galvanizing apparatus including, in combination, a tank, a bath of molten zinc in said tank, means for passing a wirey along said tank and immersing portions of said wire at different points in the length of the tank, means intermediate said points of immersion for cooling the wire in a non-oxidizing atmosphere, and means for varying the angularity of the wire with respect to the surface of the bath as it leaves the bath after the first immersion and as it enters the bath for the second immersion,

3. A galvanizing apparatus comprising a tank for containing a bath of molten zinc, means for guiding flexible material along said tank and for immersing spaced lengths of said material in said bath, a housing forr enclosing the unimmersed portion of said material between the points of immersion, walls of said housing extending into said bath to form a seal therewith, and means for introducing a non-oxidizing atmosphere into the space enclosed by said housing.

ALBERT F. BRADLEY.

While rigid articles may also be.

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