Improvements in Preparing Metal Sheets for the Purpose of Galvanizing them or otherwise Coating them with Metal or Metallic Alloy.
Year: 1895

page_text: Date of Applicktion, 25th 6=pt., 1895
Complete Specification Left 24th June. 1896-Accepted. 15th Aug., 1896
Date of Application, 25th Sept., 1895
Complete Specification Left 24th June. 1296-Accepted. 15th Aug.. 1896
PROVISIONAL SPECIFICATION,
Improvements in Preparing Metal Sheets for the Purpose of
Galvanizing them or otherwise Coating them with Metal or
Metallic Alloy.
We, DAVIES BROTHERS AND COMPANY, LIMITED, of the Crown Works,
Wolverhampton, in the County of Stafford, Galvanizers, EDWARD ALBERT
DAVIES, Managing Director of the said Company, and STEPHEN THORPE
THOMAS, Works Manager to the said Company, do hereby declare the nature of
this invention to be as follows
This invention has for its object, the preparation of metal sheets, for the purpose
of galvanizing them or otherwise coating them with metal or metallic alloy, by a
process which is an improvement in or upon the process of preparing such sheets
described in Patent Specification No. 14,306 of 1894.
The method, according to this invention, of preparing the sheets for the purpose
of galvanizing them or otherwise coating them with metal or metallic alloy, consists
in raising the scale upon the surfaces of the sheets within a suitable furnace
(preferably such as that hereinafter described, and provided with means, as herein-
after described, for automatically carrying the sheets therethrough); then while the
sheets are hot from such furnace, brushing, scouring, or grinding, the surfaces of
the sheets by means of apparatus, such as that described in the aforesaid patent
specification, provided with a metallic brush or brushes of the character of the
grinder or grinders described in such specification, so as to thoroughly remove
the scale; and finally pickling the sheets. The furnace which it is preferred to
use in raising the scale upon the surfaces of the sheets, preparatory to galvanizing
them or otherwise coating them with metal or metallic alloy, is formed with a
heating chamber for the sheets which is of a width to suit the maximum width of
the sheets which are to be scaled therein, and of a length which is considerable
compared with its width, and such chamber is formed with an opening at each end
for the entrance and exit of the sheets into and from the furnace. Endless chains
are caused to pass through the chamber lengthways thereof, and the sheets are
carried automatically into and through the chamber upon such chains, and are
delivered thereby into the brushing, scouring or grinding apparatus. Suitable fire-
grates are arranged along one side of the furnace, and are divided off from the
heating chamber by a wall or bridge between the top of which and the underside
of an arched roof, which spans across the fire-grates and the heating chamber, is
left an opening for the passage of the products of combustion from the fire-grates
into the heating chamber. The products of combustion pass away through suitable
openings from the heating chamber to the chimney.
By the use of this invention, the advantage, resulting from the old method of
raising the scale and beating it from the sheets, of using a small quantity of acid
for pickling, compared with the modern method of pickling without scaling the
sheets, is obtained; and the removal of the scale from the surfaces of the sheets is
effected at a considerably less cost in labour than in the old method of scaling.
Dated this 24th day of September 1895.

page_text: Improvements in Preparing Metal Sheets for the Purpose of
Galvanizing them or otherwise Coating them with Metal or
Metallic Alloy.
We, DAVIES BROTHERS AND COMPANY, LIMITED, of the Crown Works,
Wolverhampton in the County of Stafford, Galvanizers, EDWARD ALBERT
DAVIES, Managing Director of the said Company, and STEPHEN THORPE
THOMAS, Works Manager to the said Company, 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:-
This invention has for its object, the preparation of metal sheets, for the purpose
of galvanizing them or otherwise coating them with metal or metallic alloy, by a
process which is an improvement in or upon the process of preparing such sheets
described in Patent Specification No. 14306 of 1894.
The method, according to this invention, of preparing metal sheets for the
purpose of galvanizing them or otherwise coating them with metal or metallic
alloy, consists in raising the scale upon the surfaces of the sheets within a suitable
furnace, such as that hereinafter described, provided with means, as hereinafter
described, for automatically carrying the sheets therethrough, then scouring the
surfaces of the sheets by means of apparatus, of the character of that described in
the aforesaid patent specification, that is to say apparatus provided with metallic
scouring brushes, so as to thoroughly remove the scale; and finally pickling the
sheets.
In order that the invention may be clearly understood, we will proceed to
describe the same with reference to the accompanying drawings, which illustrate
the furnace and other appliances used in carrying out the invention in the best
manner at present known to us.
Figure 1 is a longitudinal section through a furnace such as we employ for
scaling the sheets, and shews also the appliances by means of which the sheets are
carried automatically into, through, and out from the furnace.
Figure 2 is a sectional plan of the furnace, and shews also in plan view the
appliances for carrying the sheets into, through, and out from the furnace.
Figure 3 is a transverse section through the furnace, taken on line ax of Figure 1.
Figure 4 is a plan, to an enlarged scale, of apparatus by which the metallic
scale which has been raised in the furnace is removed from the surfaces of the
sbects, and by which such surfaces are thoroughly scoured and brushed, and
shews also a portion of the apparatus by which the sheets are carried through the
furnace.
Figure 5 is a vertical longitudinal section taken through the middle of the
apparatus shewn by Figure 4.
Figure 5A is a vertical section taken through a pair of rolls which may be used
in lieu of the first pair of scouring brushes. hereinafter described.
The remaining figures refer to details, and will be described later on.
Referring first to Figures 1, 2 and 3, the furnace illustrated by such views is
formed with a heating chamber A for the sheets. This chamber is of a width to
suit the maximum width of the sheets which are to be scaled therein, and is of a
length which is considerable compared with its width, being conveniently about
thirty to thirty-five feet in length between the doors. Each end of the chamber A
is normally closed by means of a door 13 capable of being raised in vertical guides,
in the usual manner of raising similar doors, so as to completely open the ends.
These doors, however, when closed do not completely close the ends of the

page_text: chamber A but leave a space at each end between the floor of the chamber A and
the lower edge of the corresponding door through which the sheets are carried.
The doors B do not appear in Figure 2, as the section of such view is taken at a
level immediately below the bottoms of the doors. Endless chains a pass around
wheels which are in position some distance from the feeding-in end of the furnace,
and around sprocket wheels c which are in position a short distance beyond the
delivering end of the furnace and these chains pass through the chamber A of the
furnace and run upon plates & upon the bottom of the chamber. The undersides
space C
of the chains run along metal channels e which pass also through a hollow
formed underneath the chamber A of the furnace. The spindle carrying the
sprocket wheels c is driven continuously from any suitable source of power, and the
links of the chains are caused to move constantly through the chamber A. in
the direction of the arrow f, Figure 1.
Figures 6 and 7 shew, to an enlarged scale, detached views of one of the sprocket
wheels cand a portion of one of the chains a. Figure 6 shews a section of the
plan
sprocket wheel and a side elevation of the portion of chain, and Figure 7 is a
upon which
of Figure 6. Each pair of side links are formed with projections a¹
the sheets are placed for being carried into and through the chamber A by the
movement of the endless chains. The portions of the endless chains a which are at
any time passing from the wheels towards the furnace are carried by rollers
which are capable of revolving in bearings supported by longitudinal bearers.
The chains may be tightened up from time to time, as the joints thereof wear, by
screw tightening devices which draw back along guides on their supporting bed
the bearings which support the spindle j carrying the wheels b.
Furnace grates D are arranged along one side of the heating chamber A and are
provided with suitable firing doors k. The products of combustion from the
furnace grates D pass over the top of a wall which divides them from the heating
chamber A, and thence into the heating chamber, and pass away from such chamber
through Blues m at the bottom of the wall on the opposite side of such chamber,
and thence into a flue E running along the side of the chamber, and from thence
through a flue F to the chimney.
The chains are caused to move preferably at the rate of about from nine to
eighteen feet per minute according to the thickness of the sheets under treatment,
the slower rate being suitable for sheets of 14 B.W.G. and thereabouts, and the
quicker rate for sheets of 26 B.W.G. and thereabouts. Thus every portion of a
sheet is exposed to the heat of the chamber for from about 3 minutes 20 seconds
to about 1 minute 40 seconds. The chamber is maintained at a temperature which
causes the sheets to be heated to a bright red heat, and the scale is thus raised on
the surfaces of the sheets in a manner which adapts it to be removed by a scouring
force.
The doors B are normally down while the sheets are being carried into, through,
and out from, the beating chamber A, and are required only for obtaining access
to the interior of the chamber for the purpose of repairs or in case of a sheet
getting out of place during its passage therethrough.
Referring now to Figures 4 and 5, c are the sprocket wheels shewn also by
Figures 1 and 2. nare a pair of rolls which receive the sheets as they pass from
the heating chamber A. The sheets are automatically fed to the rolls by the
operation of the endless chains, and are guided thereto between the upper and
lower guides o o¹. G. G' are upper and lower rotating scouring brushes having
0 metallic bristles, between which the sheets are passed as they are fed onwards by
the rolls n n, the sheets being guided thereto along the upper surfaces of curved
guides gl. As the forward ends of the sheets pass onwards from the brushes G G¹
they are caught between withdrawing rolls p_p, to which they are guided
between the guides q' and an upper guide g. The sheets are carried forward
, and between a second pair of
6 by the rolls p p between the curved guides
nietallic scouring brushes H H', and thence between withdrawing rolls & s
formed, preferably, with collars s which alone bear against the surfaces of the

page_text: sheets. The brushes are indicated by broken lines in Figure 4, for convenience
of illustration.
As the sheets pass from the rollsss they are deflected by curved guides t
and fall over a drum or barrel J down the inclined guides on to a truck by
means of which they are conveyed to the pickling tank. The sheets are then
pickled, and subsequently galvanized or otherwise coated with metal or metallic
alloy by immersion in the usual manner in a bath of the molten metal or metallic
alloy.
The sprocket wheels c and the rolls and brushes may be driven in any convenient
manner, hut so that the brushes H. H¹ revolve continuously in the directions,
respectively, indicated by the arrows 61, and so that the brush G¹ revolves con-
tinuously in the direction of the arrow c', and the brush G revolves in the direction
of the arrow while a sheet is passing between the brushes G G previously to its
forward end being caught between the rolls p, and so that the brush G revolves
.in the opposite direction after the forward end of the sheet has been caught between
the rolls p p and before the hinder end of the sheet has left the rolls nn and
.continues to revolve in such direction during the further operation of these brushes
upon the surfaces of the same sheet. It is preferred to reverse the direction of
revolution of the brush G as soon as possible after the forward end of a sheet has
been caught between the rolls pp as the scouring effect of the brush is better when
rubbing backwards on the surface of the sheet than when rubbing forwards.
Both pairs of scouring brushes should be driven at about 100 revolutions
per minute.
i'
A
The
According to a convenient method of driving the scouring and brushing
apparatus, a spindle d', carrying fast and loose pulleys eles to receive the driving
belt, is driven from a pulley on an overhead shaft. This spindle extends across
the width of the apparatus and has a hand-wheel f¹ fixed on the opposite end to
that, on which the pulleys e¹ are carried, in order that it may be turned by hand
to reverse a sheet which may be entered skew-wise or in a puckered condition.
A pinion g' on the spindle d' genrs into a wheel on a short spindle ¹, and a
pinion on the spindle d' gears into a wheel k¹ on the spindle of the top roll n.
pinion on the spindle gears into a wheel m' on the spindle which carries the
sprocket wheels c. The rolls n are geared together by equal spur pinions, one of
which only is shewn, fixed on their spindles. The rolls p are similarly geared
together, and are driven from the spindle of the top roll n by chain gear.
rolls s are also similarly geared together, and are driven by chain gear from the
spindle of the top roll p. The brush G is driven independently from an overhead
shaft through the medium of a straight and crossed belt and a pulley u fixed on its
spindle on each side of which is a loose pulley u¹; and the spindle of the brush G
carries fast and loose pulleys vv which are driven by a belt from an overheid
shaft. The brushes H H are geared together by a belt pl, and are driven by a
belt from an overhead shaft which may be engaged, alternatively, with a fixed
pulley won the spindle of the brush H or with a loose pulley w' on such spindle.
Suitable belt guides, all capable of being operated from the same side of the
apparatus, are provided for moving any belt from a fixed pulley on to an adjacent
loose pulley, and vice versa.
The drum or barrel J is not driven by mechanism for such purpose, but is free
to be revolved by the movement of the sheets as they pass over it.
It may be explained that the purpose in revolving the brush G in the direction
of the arrow until the forward end of a sheet has been caught by the rolls p
and subsequently in the opposite direction, is to prevent either end of a sheet
becoming puckered or bent while passing between the rolls n and the rolls p. The
reversal of the rotation of the brush is effected by the attendant moving the strap
guide of the belts which alternatively drive the fixed pulley u.
In order to facilitate the rapid reversal of the direction of revolution of the
brush G, a brake drum a² is fixed on the spindle of the brush, and a brake block
is pressed thereagainst immediately the belt which has just been driving the brush

page_text: is moved from off the fixed pulley u. A front elevation of this block, and the
means by which it may be operated, are shewn by Figure 8. The block is.
carried on the inner end of a lever d which is fulcrummed to a support f³. The
outer end of the lever d' is connected by a rod g' with a treadle lever h³, and thus.
as the treadle lever is depressed the block is pressed against the pulley a..
The lever may rest, when the block is clear of the pulley, upon an arm which
projects from the support f'.
Figures 9, 10 and 11 illustrate a convenient construction of the scouring brushes..
Of these views, Figure 9 is a longitudinal section through one of the brushes G G¹
to the same scale to which the brushes are drawn in Figure 5; and Figures 10-
and 11 are, respectively, a transverse section and front elevation of a portion of
one of such brushes drawn to an enlarged scale. In Figure 11 the curved surface
which bounds the outer ends of the wires or metallic bristles is shewn, for
convenience, as if spread out flat. The core of the brush consists of three plain.
pulleys K keyed on to the spindle . The sole or base to which the wires or
metallic bristles are fixed is made up of a number of segments each of which
consists of an outer plate and an inner plate m² with a thickness of wood n*
between. The wires are formed of steel, preferably of flat section of say 16th of
an inch wide by about 26 B.W.G. in thickness, and are bent flatways each with
a portion which passes in a circumferential direction along the back of the
wood n' and with portions which pass through holes formed in the wood and in
the outer plate and project beyond the outer face of such plate, as shewn. Four
of these bent wires are put through two holes formed the required distance apart
through the wood n³ and outer plate, and thus four metallic bristles project from
each of such holes. The sets of wires are placed in position in relation to one-
another in the manner indicated by Figure 11, the holes for one set of wires
running across the face of the brush being midway between the holes of the
adjacent sets on each side, and the metallic bristles are bent out from one another
in the manner indicated by such figure. The inner plate m³ is fixed to the wood n
and to the outer plate by means of bolts p², as shewn by Figure 9, after the wires
have been put through their respective licles, and the segments are then bolted to
the pulleys K by means of bolts q², as shewn by such figure. A portion of the rim
only of one of the pulleys K is shewn by Figure 10. The wood n³ may be soaked
in tungstate of soda as a protection against the heat of the sheets, or a layer of
asbestos may be interposed between the outer face of the wood and the outer
plate, but neither of these precautions is essential. The entire circumference.
of the sole which carries the metallic bristles of a brush may conveniently be
made up of six segments in the case of the brushes G G¹, and of five segments in
the case of the smaller brushes H H', as shewn in Figure 5; but any number of
segments may be used for a brush as may be found most convenient.
In lieu of the scouring brushes G G', a pair of rolls 3, Figure 54, may be
employed through which the sheets pass on their passage from the feeding-in
rolls n to the withdrawing rolls p. The upper roll is pressed down upon the
upper surface of a sheet by spiral springs, such as the spring, the tension of
which is adjusted by screws, such as t. These rolls are operated in the manner
of the brushes G G³, and by their rapid rotation compared with the speed of
rotation of the rolls n and p tend to thoroughly scour off the scale from the surfaces.
of the sheets.
By the use of this invention, the advantage resulting from the old method of
raising the scale and beating it from the sheets, of using a small quantity of acid
for pickling, compared with the modern method of pickling without previously
scaling the sheets, is obtained; and the removal of the scale from the surfaces of
the sheets is effected at a considerably less cost in labour than in the old method of
scaling.
While it is preferred to use the entire process substantially as above described,
it will be obvious that the sheets may be passed automatically through a scaling
furnace in the manner above described and the scale be subsequently mechanically

page_text: removed by beating in a manner heretofore practiced, and the advantage thus be
obtained which results from the novel method of scaling the sheets.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is :-
1. The improved process of preparing metal sheets for the purpose of galvanizing
them or otherwise coating them with metal or metallic alloy, which consists in
first passing the sheets automatically through a scaling furnace, and thus raising
the scale on their surfaces, then mechanically removing the scale from such
surfaces, and finally pickling the sheets, substantially as described.
2. The improved process of preparing metal sheets for the purpose of galvanizing
them or otherwise coating them with metal or metallic alloy, which consists in
first passing the sheets automatically, by a continuous movement, through a scaling
furnace, and thus raising the scale on their surfaces, then mechanically removing
the scale from such surfaces, and finally pickling the sheets, substantially as
described.
3. The improved process of preparing metal sheets for the purpose of galvanizing
them or otherwise coating them with metal or metallic alloy, which consists in
first passing the sheets automatically through a scaling furnace and thus raising
the scale on their surfaces, then scouring the surfaces of the sheets by means of
revolving metallic scouring brushes, or rolls, to remove the scale, and finally
pickling such sheets, substantially as described.
4. In the process of preparing metal sheets for the purpose of galvanizing them
or otherwise coating them with metal or metallic alloy, the employment of a
furnace having a long heating chamber within which the scale is raised upon the
surfaces of the sheets, such chamber having a permanent opening at each end
through which, respectively, the sheets are entered into and withdrawn from the
chamber, the sheets being carried automatically into, through, and out from, such
chamber by endless chains, substantially as described.
Dated this 23rd day of June 1896.
STEPHEN WATKINS,
Wolverhampton, Agent for the Applicants.