Improvements in or relating to the Art or Process of Galvanizing Metal Tubes and Bars, and in Means or Appliances for Use therein or relating thereto.
Year: 1890

page_text: Date of Application, 3rd June, 1890
Complete Specification Left, 28th Oct., 1890-Accepted, 13th Dec., 1890
PROVISIONAL SPECIFICATION.
Improvements in or relating to the Art or Process of Galvanizing
Metal Tubes and Bars, and in Means or Appliances for Use
therein or relating thereto.
We, THOMAS LESTER THOMAS, of 88 Albert Street, Princes End near Tipton in the
County of Stafford, Washer and Axle Plate Manufacturer, and JOSEPH BEARD
HILLMAN, of 35 Victoria Street, Princes End, aforesaid, Galvanizing Works Manager,
do hereby declare the nature of this invention to be as follows:-
-
This invention has for its chief objects to facilitate the operation of galvanizing
metal tubes and bars, to give a uniform coating of zinc and thereby avoid the waste
thereof which results from an uneven coating as is produced in the ordinary method
of galvanizing such articles, and to give a greatly improved surface.
According to the ordinary process of galvanizing such articles they are first dipped
into the bath of molten zinc, and are then slowly drawn up slantwise through a
special flux, and are at the same time turned slowly, the object being to draw off the
superfluous zinc and leave a uniformly coated surface. They are then laid on fine
supporting edges and rolled or turned to-and-fro to maintain a uniform coating. When
the coating is set the articles are dipped in a water bath. This process is, however,
tedious and requires considerable skill in manipulation, and the coating of zinc is not
really uniform and considerable waste results. Moreover, the surface is not as smooth
and finished as is frequently desirable.
Now, according to this invention, the articles aforesaid are first dipped in the bath
of molten zinc, and are then withdrawn therefrom as quickly as may be convenient
regardless of the quantity or unevenness of the coating metal adhering thereto. They
are then drawn through a pair of asbestos dies to distribute the coating metal evenly
over their surface, and to wipe off all the surplus coating metal, and at the same time
produce a greatly improved surface of the coating metal.
After the wiping by means of the dies the articles are immediately dipped into a
water bath, the rolling ordinarily resorted to, previously to such dipping, being in
this case unnecessary. No special flux has to be maintained on the surface of the
molten zinc in the bath through which to draw out the articles therefrom.
The asbestos dies are fixed, respectively, to an upper and lower wood block the latter
of which is fixed to a frame or bracket which is itself fixed at or adjacent to one end
of the galvanizing bath, and the former of which is carried by a lever or vertical slide
by which it may be raised or lowered as desired. The dies are formed so as between
them to embrace the entire circumference of the tube or bar, and the one die
preferably overlaps the other to some extent at the face, when the dies are closed up, so
as to avoid a gap at the joint between them. Previously to entering a tube or bar
between the dies the upper die is raised up.
The tube or.
bar is laid with one end
within the lower die, but projecting beyond it sufficiently to be grasped by a pair of
tongs, and the upper die is then brought down upon the surface of such tube or bar,
and the tube or bar is then drawn through the dies. More than one pair of asbestos
dies may be carried by one apparatus.
The asbestos dies hereinabove referred to, being novel for the purpose for which
they are employed, constitute an important feature of the invention.
Dated this 2nd day of June 1890.

page_text: T
COMPLETE SPECIFICATION.
Improvements in or relating to the Art or Process of Galvanizing
Metal Tubes and Bars, and in Means or Appliances for Use
therein or relating thereto. .
We, THOMAS LESTER THOMAS, of SS Albert Street, Princes End near Tipton in the
County of Stafford, Washer and Axle Plate Manufacturer, and JOSEPH BEARD
HILLMAN, of 35 Victoria Street, Princes End, aforesaid, Galvanizing Works Manager,
do hereby declare the nature of this invention and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
Our invention relates to the galvanizing of metal tubes and bars, and has for its
object to facilitate the process thereof, to give a uniform coating of zinc and thereby
avoid the waste of such metal which results from the uneven coating which is pro-
duced in the ordinary method of galvanizing such articles, and to give a greatly
improved surface.
According to the ordinary process of galvanizing metal tubes and bars, they are
first dipped in the bath of molten spelter and are then slowly drawn up slantwise
through a special flux (formed by constantly adding new or fresh ammonia to the
surface of the molten metal at the drawing out end of the bath), being at the same time
turned slowly, with the object of drawing off the superfluous spelter and leaving a
uniformly coated surface. Such tubes and bars are then laid on fine supporting edges,
and rolled or turned to-and-fro to maintain a uniform coating. When the coating is
set, the articles are dipped in a water bath. This process is, however, tedious and
requires considerable skill in manipulation, and the coating of spelter (zinc) is not
really uniform and considerable waste results. Moreover, the surface is not as smooth
and finished as is frequently desired.
Now, according to this invention, the tubes and bars are first dipped in the
bath of molten spelter, and are then withdrawn therefrom as quickly as may be
convenient regardless of the quantity or unevenness of the coating metal adhering
thereto, and without turning them as in the ordinary process. As each tube or bar is
being drawn out slantwise from the bath, the upper end is entered between asbestos
dies, which are then closed around it, and the tube or bar is drawn through such
dies, whereby the coating metal is evenly distributed over the surface thereof and the
surplus metal is wiped off, the action of the dies producing also a greatly improved
surface of the coating metal.
The tubes or bars are dipped in a water bath immediately they have been drawn
through the dies, and the rolling above described, as practised in the ordinary process,
is, according to this invention, entirely dispensed with, the operation of the dies
rendering it quite unnecessary. The articles are withdrawn from the bath through the
ordinary flux, as it is not necessary to add new or fresh ammonia through which to
withdraw them, the even distribution of the coating metal, and the wiping the surplus
therefrom, being performed entirely by the dies. A considerable saving in flux is
thus effected.
This invention is illustrated by the accompanying drawings, of which
Figure 1 is a front elevation of the asbestos dies and mechanism by which they are
operated, and shews such mechanism to be mounted in position upon the bath the
upper portion of one end of which is shewn in section ;
Figure 2 is a plan of Figure 1;
Figure 3 is a longitudinal section taken on line ca of Figure 1;
Figure 4 is a detached front view of the bottom die hereinafter described;
Figure 5 is a-longitudinal section (drawn. to. a reduced scale and broken in length
for convenience of illustration) through the bath, dies and apparatus by which they
are operated, and through the inclined platform hereinafter described;
Figure 6 is a front elevation of a modified form of apparatus for carrying and
operating the asbestos dies; and
T

page_text: Referring, first, to the modification shewn by Figures 1 to 5 inclusive, an angle-
plate B, having a base plate a and vertical member b, is bolted through such base
plate to the top of the bath A which holds the molten galvanizing metal, and in such
position near the end of the bath, as shewn, that the dies hereinafter described are
over a portion of the interior of the bath into which therefore the molten metal can
run as it is wiped off by the operation of the dies. Near each end of the member b of
the angle plate is bolted a pair of guide standards c, one on each side of the member b,
a space being left between them above such member, as shewn clearly more especially
in sectional elevation Figure 3. Fillets d project, preferably, from the faces of the
member b across each edge of each standard c, to act as joggles for keeping the
standards in position edgeways or sideways. Between the one pair of standards c is
pivoted, by means of a pin t, a lever C. This lever passes between the other pair of
standards, and terminates in a handle e, and is extended beyond its fulcrum at the
other end, the extended portion carrying a counter-balance weight. The lower
asbestos die g is carried at the outer face of the member of the angle-plate B, by
being placed against such face and held thereto by a bar which is bolted, by means
of bolts i, to the member b. This die projects above the top of the member b, and
has a notch 7, of the width of the tubes or bars to be wiped, formed in its upper edge,
along which the tubes or bars are passed as they are drawn through the dies. The
notch is of a semicircular shape at bottom, as shewn, when for use for tubes or round
bars, but is carried up straight at the sides to give it a somewhat greater depth than
that of the semicircle. As the upper portion of this die is shewn by broken lines in
Figure 1, the detached view, Figure 4, is given thereof, so as to clearly shew the
shape of the notch. The top die j, having a notch in the lower edge thereof corre-
sponding to the notch, is of the same shape as the bottom die g. This die is carried
by the lever C, being placed against the forward face thereof and held by a bar k
bolted to the lever by means of bolts 1. There is thus, as will be clearly seen more
especially by reference to Figure 3, some space between the planes of those faces of
the dies which are toward one another. The counter-balance weight tilts up the
lever into the position indicated by broken lines Figure 1, when the same is not held
down by hand, or by the pin o hereinafter described; and the chain m, which is
attached at one end to the angle-plate B, and at the other to the lever, prevents
the lever from being tilted up, by the weight, beyond any desired point. The lower die
is stationary, and when a tube or bar is not being drawn through the dies the upper
die is in the position shewn by broken lines Figure 1, the lever being tilted up.
When a tube or bar n, Figure 5, is raised up slantwise from the bath A, its end which
is the nearer to the dies is grasped in a pair of tongs, passed through between the
open dies by an attendant who stands upon the incline platform D. The attendant
then pulls the tube forward so as to bring its end between the dies, and an attendant
immediately brings down, by means of the handle e, the upper die upon the top of
the tube or bar, whereupon the attendant upon the platform draws such tube or har
in an inclined position through the dies, himself walking up the platform D for this
purpose. The tube or bar is put direct into a bath of water immo fiately it has passed
from the dies. There is nothing unusual in the platform D. It is what is commonly
employed in the galvanizing of tubes and bars, in order to enable the attendant to
properly withdraw them from the bath. As the notches in the dies are somewhat
deeper than the half diameter of the tubes or bars, the edges of the dies overlap, as
shewn in Figures 1 and 3, when in operation. The drawing of the tubes through
the dies tends, of course, to wear the notches deeper, and it is necessary therefore,
even if the notches in the dies are originally formed only halt the diameter of the
tubes or bars in depth, that the dies should be the one forward of the other so that
as wear takes place the lower edge of the one die may be moved down below the
upper edge of the other; and when the notches are originally formed deeper than
the half diameter of the tubes or bars for which they are to be usel, as is preferred
for the purpose of more effectually wiping the entire surfaces thereof, the dies overlap
one another from the commencement of their operation. The asbestos is of a some-
what yielding nature, and the one die tends therefore to be bent somewhat towards

page_text: the other as the tubes or bars are drawn through them, and thus it is necessary to
place the dies with sufficient space between the planes of their faces which are
towards one another to prevent the upper die catching on the lower as it is brought
down after a tube or bar has been placed between the dies. The dies can be readily
adjusted in position, as wear takes place, by first slackening the bolts by which they
are held to the angle-plate and lever, respectively, then moving the dies into the
required position and re-tightening the bolts. A considerable adjustment in the
reative position of the dies may, however, be conveniently given by lowering
the lever fulcram; and the position of the dies in their holders need not be altered
till the lever fulcrum has been moved down as far as is convenient. A number of
holes are provided in the pair of standards e to which the lever is fulcrumed, to permit
of the position of its fulcrum being altered as required. A portion of the upper
inner edge of the member of the angle-plate B is chamfered off, as shewn, to allow
of the metal, wiped off the surface of the tubes or bars, readily flowing or falling back
into the bath.
For bars of other section than round the notches are, of course, altered in shape to
suit the difference in section.
For convenience in setting the dies, a peg o is pushed through one of a number of
holes formed in one of the pairs of standards c and immediately over the top of tho
lever, in order to keep the lever in the position into which it is intended to be moved
to bring the dies into operation.
Two or more pairs of dies for different sizes of tubes or bars may be carried by one
apparatus, or the same pair of dies may be provided with two or more pairs of different
sized notches; and in either case batches of different sizes of tubes or bars may be
operated upon without changing the dies.
Referring to the modification shewn by Figures 6 and 7, it will be seen that the
dies and are carried, respectively, in the upper and lower jaws of a pair of tongs E.
Each die is fixed by being placed against the inner face of the jaw and held by a
plate wat its opposite side, which is fixed by bolts to the jaw. The tongs are sus-
pended, by means of a D-link p, from a chain q. The end of a set-pin y, which is
screwed through one lever or handle of the tongs, acts as a stop against the other
lever and fixes the point to which the levers may be brought towards one another;
and thus the set-pin may be used to maintain the jaws in proper position (as the levers
are pressed towards one another) while the dies are set in place.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
:-
1. The improvement in, or relating to, the process of galvanizing metal tubes and
bars which consists in drawing them between asbestos dies, after they ave been
dipped in the galvanizing bath, substantially as described and shewn, for the purpose
set forth.
2. The improvements in, or relating to, the process of galvanizing metal tubes and
bars which consist in drawing them between asbestos dies, after they have been dipped
in the galvanizing bath, and putting them, as they leave the dies, direct into water
without first rolling them to-and-fro as in the ordinary process of galvanizing them,
substantially as described for the purpose set forth.
3. In combination with a galvanizing bath used in galvanizing metal tubes and bars,
a pair of notched asbestos dies, substantially as described for the purpose set forth.
4. In combination with a galvanizing hath used in galvanizing metal tubes and
bars, asbestos dies carried or mounted so that they may be opened to admit a tube or
bar between them and be closed to press therearound, substantially as described, for
the purpose set forth.
5. In combination with a- galvanizing-bath- used. in galvanizing metal tubes and
bars, a pair of asbestos dies one of which is carried by a lever by means of which it
may be moved towards or from the other, substantially as described and shewn, for
the purpose set forth.

page_text: 6. In combination with a galvanizing bath used in galvanizing metal tubes and
bars, a pair of notched asbestos dies mounted in the parts by which they are,
respectively, carried with a clearance between the planes of their faces which are
towards one another, substantially as described for the purpose set forth.
7. The improvements in means or appliances for use in or connected with
galvanizing nietal tuhes and bars, substantially as described and illustrated (according
to different modifications) by the drawings herewith, for the purpose set forth.
Tih da s
in 1000
STEPHEN WATKINS,
Wolverhampton, Agent for the Applicants.