A Novel or improved Method of "Preparing Metal Sheets for the purpose of Galvanizing them, or otherwise Coating them with Metal or Metallic Alloy, and Apparatus:for Use therein.
Year: 1894

page_text: Date of Application, 25th July, 1994
Complete Specification.Left;: 27th May,, 1.895-Accepted, .25th Sept., 1895
Date of Applicatio, GULY
..Complete Specification".Left;: 27th May,, 1895-Accepted, .25th Sept., 1895
PROVISIONAL SPECIFICATION:
A Novel or improved Method of "Preparing Metal Sheets for the
purpose of Galvanizing them, or otherwise Coating them with
Metal or Metallic Alloy, and Apparatus:for Use therein.
We, DAVIES BROTHERS AND COMPANY, LIMITED, of the Crown Works,
Wolverhampton in the County of Stafford, Galvanizers, EDWARD ALBERT
DAVIES, of the same address Managing Director of the said company and
STEPHEN THORPE .THOMAS: also.of.the same address Works Manager to the
said company, do hereby declare the nature of this invention to be as follows:-
According to the ordinary method of preparing metal-sheets for the purpose of
galvanizing them, or otherwise coating them with a metal-or-metallic alloy, they
are pickled, to remove scale and other impurities, in a dilute: acid solution, the
acid employed beings usually either muriatic or sulphuric. Large quantities of
acid are required in the process; and therwaste pickle or liquor, being of a very
déleterious character, cannot be run off into the ordinary drainage system without
being first neutralised at a very heavy cost.
Now; the object of this invention is to dispense with the heed.for pickling the
sheets to prepare them for receiving the metallic coating, or at least to greatly
reduce the extent or degree of pickling necessary and consequently. the quantity
of acid required.
The above object is effected, according to this invention, by a novel er improved
proces which consists in grinding the surfaces of the sheets so as to remove all scale
and other impurities which would interfere with the proper adherence of the coating.
This might, of course, be effected by holding the sheets by hand against a revolving
grindstone or other revolving grinder, grinding first the one face and then the
other; but this would be a very tedious process,, and would entail considerable
expense in labour. We have, therefore, devised mechanism for effecting the
grinding automatically.
This mechanism comprises appair of feeding-inrolls, æfidirṛof withdrawing rolls,
and..a revolving grinder to grind one side of a sheet at a time. The sheet to be
grblind' is 'first entered between the feedingªió rolls and³this carried forward¾ into
contact with the grinder. "The grinder revolves a high-velocity compared with
the velocity of the rolls, in a direction tending to carry the sheet forwards; add thus
the sheet is prevented from butkling or pubkering as it would häv¿ª³à¸ ¤éïd¤òcyto
do if the grinder révolved in a direction' tending to carry the sheet backwards; and
when the sheet contes into contact therewith it continues to advance by the
continued rotation of the feeding-in rolls, the advance movement being assisted also
by the revolution of the grinder. Asthe front end of the sheet passés forwards
from the grinder. it enters between the withdrawing rolls and subsequently to..or
simultaneously with the sheet being gripped between auch rolls, and: previously to
the binder end of the sheet passing clear of the deeding-in rolls, the revolution of
the grinder is reversed so that it tends to hold back the sheet and thus prevents the
sheet being buckled: or: puckered up as it would be liable to be if the grinder
revolved in a direction tending to carry the sheet forwards towards the withdrawing
rolls. The sheet is of course supported by a backing-piece.
!
A simple form of machine, for grinding a sheet, consists: in an arrangement
such as described in the last preceding paragraph having a single grinder which
may be formed as a revolving brush having wire or metallic bristles, and a backing-
piece against which the sheet traverses as it passes between the rolls, the said

page_text: backing-piece having a curved recess across its face within which a portion of the
grinder enters and causes the sheet to follow the curve of the hollow, whereby a
considerable portion of the periphery of the grinder is in contact with the surface
of the sheet at a given time. The exposed portion of the grinder may be covered
with a suitable case.
A more complex form of machine, which avoids the necessity for reversing the
grinder, consists in its main features of a pair of feeding rolls, of a first revolving
grinder, of a second revolving grinder, and of a pair of withdrawing rolls. A sheet
to be ground is first entered between the pair of feeding rolls, which propel it
forwards into contact with the first revolving grinder as in the machine already
described. As the sheet continues to advance, the forward end passes the second
revolving grinder. This second grinder is, however, at the time in position to
prevent it from grinding the sheet. The forward end of the sheet is nipped, as it
continues to advance, between the withdrawing rolls. At this stage of the progress
of the sheet through the machine, or at any time after the sheet has become nipped
between the withdrawing rolls and before it ceases to be nipped by the feeding
rolls, the first grinder is moved into position to prevent the sheet being ground
thereby. The continued traverse of the sheet brings the forward end of the
unground portion thereof into position, in which it may be ground by the second
grinder. The second grinder is then caused to grind the unground surface of
the sheet. This grinder revolves oppositely to the first grinder, and thus tends to
draw back the sheet from the withdrawing rolls and thereby prevents it buckling
or puckering. The first and second grinders may be carried in the opposite ends
of centrally-pivoted arms, or in a pivoted or rocking frame operated by a suitable
lever, so that as one of the grinders thus carried is raised the other is depressed.
Dated this 24th day of July 1894:
STEPHEN WATKINS,
Wolverhampton, Agent for the Applicants.
COMPLETE SPECIFICATION.
A Novel or Improved Method of Preparing Metal Sheets for the
purpose of Galvanizing them, or otherwise Coating them with
Metal or Metallic Alloy, and Apparatus for Use therein.
We, DAVIES BROTHERS AND COMPANY, LIMITED, of the Crown Works,
Wolverhampton in the County of Stafford, Galvanizers, EDWARD ALBERT
DAVIES of the same address Managing Director of the said company, and
STEPHEN THORPE THOMAS, also of the same address, 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 :-
According to the ordinary method of preparing metal sheets for the purpose of
galvanizing them, or otherwise coating them with metal or metallic alloy, they are
pickled, to remove scale and other impurities, in a dilute acid solution, the acid
employed being usually either muriatic or sulphuric. Large quantities of acid are
required in the process, and the waste pickle or liquor, being of a very deleterious
character, cannot be run off into the ordinary drainage system without being first
neutralised at a very heavy cost.
Now, the object of this invention is to dispense with the need for pickling the
sheets to prepare them for receiving the metallic coating.
The above object is effected, according to this invention, by a novel or improved
process which consists in grinding the surfaces of the sheets in lieu of pickling
them. This might be effected by holding the sheets by hand against a revolving
grindstone or other revolving grinder, grinding first the one face and then the

page_text: other; but this would be a very tedious process, and would entail considerable
expense in labour.
We have, therefore, devised mechanism for effecting the
grinding, automatically.
:
The mechanism comprises, in its simplest form, a pair of feeding-in rolls, a pair
of withdrawing rolls, and a revolving grialer to grind one side of a sheet at a time.
The sheet to be ground is first entered between the feeding-in rolls and thus
carried forwards into contact with the grinder. The grinder revolves at a high
velocity, compared with the velocity of the rolls, in a direction tending to carry
the sheet forwards, and thus the sheet is prevented from buckling or puckering
as it would have a tendency to do if the grinder revolved in a direction tending to
carry the sheet backwards; and when the sheet comes into contact therewith it
continues to advance by the continued rotation of the feeding-in rolls, the advance
movement being assisted also by the revolution of the grinder. As the front end
of the sheet passes forwards from the grinder it enters hetween the withdrawing
rolls; and subsequently to or simultaneously with the sheet being gripped between
such rolls, and previously to the hinder end of the sheet passing clear of the
feeding-in rolls, the revolution of the grinder is reversed so that it tends to hold
back the sheet and thus prevents the sheet being buckled or puckered up as it
would be liable to be if the grinder revolved in a direction tending to carry the
sheet forwards towards the withdrawing rolls. The sheet is supported, against
the pressure of the grinder, by a backing-piece.
A convenient form of machine, for the purpose described, consists in an
arrangement such as described in the last preceding paragraph having a single
grinder which may be formed as a revolving brush having wire or metallic bristles,
and a backing-piece against which the sheet traverses as it passes between the
rolls, the said backing-piece having a curved recess across its face within which a
portion of the grinder enters and causes the sheet to follow the curve of the hollow,
hereby a considerable portion of the periphery of the grinder is in contact with
the surface of the sheet at a given time. The exposed portion of the grinder may
be covered with a suitable case.
11
A more complex form of machine, which avoids the necessity for reversing the
grinder, consists in its main features of a pair of feeding rolls, of a first
revolving grinder, of a second revolving grinder, and of a pair of withdrawing
rolls. A sheet to be ground is first entered between the pair of feeding
rolls, which propel it forwards into contact with the first revolving grinder
as in the machine already described. As the sheet continues to advance, the
forward end passes the second revolving grinder. This second grinder is, however,
at the time in position in relation to a backing-piece which supports the sheet to
prevent it from grinding the sheet. The forward end of the sheet is nipped, as it
continues to advance, between the withdrawing rolls. At this stage of the progress
of the sheet through the machine, or at any time after the sheet has become nipped
between the withdrawing rolls and before it ceases to be nipped by the feeding
rolls, the position of the first grinder in relation to the backing-piece which supports
the sheet is altered to prevent the sheet being ground thereby. The continued
traverse of the sheet brings the forward end of the unground portion thereof into
position in which it may be ground by the second grinder. The second grinder is
then caused to grind the unground surface of the sheet. This grinder revolves
oppositely to the first grinder and thus tends to draw back the sheet from the with-
drawing rolls and thereby prevents it buckling or puckering. The grinders may be
carried in the opposite ends of centrally-pivoted arms, or in a pivoted or rocking
frame operated by a suitable lever, so that as one of the grinders thus carried is
raised the other is depressed; or the backing-piece may be mounted on a transverse
axis so that the sheet may be pressed up against either grinder as required.
A simple form of apparatus constructed according to this invention, by means of
which the surface of a metal sheet is ground by a single revolving grinder, is
illustrated by Figures 1 and 2 of the drawings herewith, of which Figure 1 is a
section taken on line x x of Figure 2, and Figure 2 is a plan view of the apparatus.

page_text: The metal sheet to be treated is passed into the machine between the guides a a¹
until it is caught between the feeding-in rolls b. It is fed forward. by such rolls
beneath the grinder A, being deflected downwards, so that its forward.end. passes
properly under the grinder, by the downwardly inclined guides c. The sheet. is
supported against the pressure of the grinder A by the curved backing, plate. B.
along the surface. of which, it travels. The sheet. is guided by the. upwardly..
inclined guides d to the withdrawing rolls e by.means. of which it.is. drawu.oup
from under the grinder.and passed out from. the apparatus. During the whole time
which elapses between the forward end of the sheet being first acted upon by the
grinder, and such end of the sheet being nipped between the withdrawing rolls e,
the grinder revolves in the direction of the full-line arrow Figure 1, and its
tendency is thus to.draw the.sheet forwards from the feeding-in rolls b. If, during
such time; it revolved in the opposite direction, it would obviously have a tendency
to buckle the sheet. As soon, however, as the forward end of a sheet has been
nipped between the withdrawing rolls e, the grinder A may be caused to revolve in
the opposite direction, that is to say, in the direction of the broken line arrow
Figure 1, as the pull.of the rolls e.prevents the sheet. from buckling between the
part thereof against which the grinder operates and the feeding rolls b. The
grinder should be caused to revolve in the direction of the broken line
arrow Figure 1 before the sheet ceases to be gripped between the rolls b, as
otherwise the sheet. (especially if of light gauge) would have a tendency to
buckle between the part thereof which is being operated upon by the grinder
and the rolls e, because. the grinder would have a tendency to push the
sheet forward quicker than it is carried forward. by the rolls. The grinder is
covered by a sheet metal casing C, (which is omitted in. Figure 2) of which a
portion C is conveniently hinged at so that it may be lifted up, to expose the
grinder. Water (which should, preferably, be clean) is. supplied to the grinder.
through a perforated pipe.g. In the illustration, this pipe is shewn in position to
deliver its streams of water into a pocket or trough h formed along, the casing C,
and the water passes through the. bottom of such. trough into. the. interior of the
casing through perforations i in the bottom thereof. The revolving grinder A.may
be rotated by a pair of driving belts either of which may be moved by means of
strap guides, as shewn, on to a pulley D which is fixed upon: the spindle of the
grinder. Oue of the belts will drive the pulley in one direction of rotation. and
the other in the other direction of rotation. When the strap guides. are moved
into their mid-position, as shewn by Figure 2, both the belts are around loose
pulleys D¹ one on each side of the fixed pulley D., and the grinder is then
stationary. The feeding-in and withdrawing rolls may be driven in any convenient
manner. According to the methud.shewn, the rolls of each. pair are. geared
together by means of pinions ; fixed on the outer ends of their spindles, and the
pairs of rolls are geared together at their opposite ends by a chain passing around
sprocket wheels.k fixed. on the spindle of the corresponding roll of each pair.
A spur wheel is fixed on the spindle of the roll b on which the. sprocket wheel k
is fixed, and a pinion m which is fixed on a. spindle. or cross-shaft n gears into the
wheel. The spindle n is driven by a pulley o which turns loosely thereon, but
has clutch teeth formed. therewith into which: a clutch p may be moved into gear
to cause the pulley o to drive the shaft n and consequently drive the rolls. The
clutch p, slides along. a feather key fixed to the shaft n, and may be. moved into. and
out of gear with the pulley o by means of a handle lever which gears with a
slides which is guided within the bottom of a bracket t. The slides has a forked
part u which engages with a circumferential groove v formed around the clutch.
During the process of reversing the revolution of. the grinder A, the movement
of the rolls bande should be stopped to prevent the traverse of the sheet, as if the
sheet is allowed to traverse while the revolution of the grinder is being reversed a
short length of the sheet may be found to be not properly ground; but as soon as
the revolution of the grinder has been properly reversed the feeding forwards of
the sheet should recommence.

page_text: The exact height of the curved backing plate B in relation to the revolving
grinder A may be readily adjusted by means of set-screws, such as b¹, screwed up
through the bed of the machine and against the underside of feet, such as c', of
the plate. The plate is of considerable weight, and may simply rest upon the set
pins b
Figures 3 and 4 illustrate, respectively, in section and front elevation a portion
of a.grinder such as we find it convenient to use for the purpose of this invention.
These illustrations are drawn full size. In Figure 4 the curved surface from which'
the wires project is shewn for convenience as if spread out flat. The core d' of
the grinder is made up as a plain cylinder, by screwing longitudinal wooden
segments e' (Figure 1) on to dises fixed securely to the spindle f¹ The wires are
carried in outer segments g', a small portion of one of which is shewn by Figures 3"
and 4. Lengths of flat steel wire, of say rather more than one eighth of an inch
wide by about one thirty second of an inch in thickness, are bent flatways each
with a portion h¹ which passes in a circumferential direction along the back
of the segment gl, and with. portions which pass through holes formed in
the segment and project beyond the face thereof. The bent wires are put
in place two together, one wire being inside the other wire, as clearly shewn
by Figure 3. The bent wires which are adjacent in a circumferential direction to
any two wires put together in place have their ends which are the nearer to such
last mentioned wires passed through the same holes, respectively, through which
the ends of the said last-mentioned wires have been passed, and so on across the
curved width of the segment. The sets of wires are placed in parallel lines about
five-sixteenths of an inch distance apart from centre to centre; but the projecting
wires of a line are in position respectively, opposite the middles of the spaces
between the projecting wires of the lines on each side thereof. The segments,
with the wires placed in position therein as described, are screwed against the
cylindrical surface of the core of the grinder, and the wires are thus securely
kept in place. Each set of wires projecting through the holes.in the segments g¹
are opened out from one another sideways, as shewn by Figure 4, so as during the
revolution of the brush to cover the entire surface of a sheet which is being.
operated upon. The opening out of the wires has the advantage also of keeping
them securely in place when the segments are not fixed in position upon the core
of the grinder.
Each face of a sheet will usually require to be operated upon by the grinder
two or three times to prepare it for receiving the coating metal; but once grinding
will sometimes be found sufficient. The extent of grinding, which would otherwise
be necessary, may be reduced by previously raising the scale in a scaling furnace.
If the sheets are thoroughly ground in the manner above described, they may be
coated without being previously pickled; but the sheets may, of course, if preferred,
be only partially or lightly ground, and then be pickled to complete their
preparation for receiving the coating metal. In such latter case, however, the
extent of pickling, and consequently the quantity of acid used, will be considerably
less than if the sheets had not been previously ground.
A sheet which is being operated upon by the grinder may travel thereunder at
the rate of about from twelve to eighteen feet per minute; and the grinder may
revolve at the rate of from four hundred to eight hundred revolutions per minute,
according to the quality of steel wire used for the grinder; and the quality of
the sheets being ground.
The machine above described with reference to the drawings may be readily
duplicated, so as to grind the surface of a sheet twice as it passes once through the
machine, by adding a grinder, a pair of withdrawing rolls, and a backing plate,
thereto in position beyond the withdrawing rolls e. In such case, the rolls e act as
the withdrawing rolls from the first grinder and as the feeding rolls to the second
grinder. The machine may similarly be triplicated, if desired, or arranged with
any desired number of grinders.
A modification of the invention, by which the need for reversing a grinder is-

page_text: obviated, is shewn in longitudinal section by Figure 5. For the sake of simplicity,
only the essential or main features of the machine are shewn. Two revolving
grinders A¹ A are used revolving, respectively, in the direction of the arrows
adjacent thereto. A rocking table or backing-plate G is pivoted transversely at kl.
The sheet to be ground is fed in between the backing-plate G and the grinder A
by, the feeding rolls b, and the plate is tilted up at its leading end to cause the
sheet to press sufficiently against the wires of the grinder. The forward end of
the sheet passes along under guides, and as it approaches the withdrawing rolls e
it is guided to them by the guides m'. Previously to the hinder end of the sheet
ceasing to be gripped by the rolls b, the binder end of the plate & must be lowered
somewhat to prevent the sheet touching the wires of the grinder A'; and after the
sheet bas become gripped between the rolls e, and just as the hinder end of the
surface of the sheet which has been ground by the grinder A' is nearing the line
of the vertical axis of the grinder A³ (say when it is about an inch or so from
such line) the rear end of the plate G is tilted up to press the sheet against the
wires of the grinder A2, so that the remaining surface of the sheet may be ground
by the grinder A². The plate G may be readily tilted as required, and be held in
mid-position while the ground portion of the face of a sheet passes from under
the grinder A' to beneath the grinder A³, by means of a lever on the axis of the
plate. The portion of the surface of the plate G which is liable to come into
direct contact with the revolving grinder A² as the hinder end of a sheet passes
from between the plate and grinder, may be chilled to increase its durability; or a
piece of hard steel may be dovetailed for the purpose into the plate G, and may
thus be replaced, when worn, by a fresh piece.
The modified form of machine just described, in which two grinders A' A' are
employed, may be itself modified by using a fixed backing plate, and carrying the
grinders in a rocking frame. In such case, the grinders are moved instead of
the plate.
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 novel or improved method of preparing metal sheets for the purpose of
galvanizing them, or otherwise coating them with metal or metallic alloy, which
consists in grinding their surfaces in lieu of pickling them, substantially as
described.
2. The novel or improved method of preparing metal sheets for the purpose of
galvanizing them, or otherwise coating them with metal or metallic alloy, which
consists in partially or lightly grinding their surfaces and then pickling, substantially
as described.
3. Apparatus for use in preparing metal sheets for the purpose of galvanizing
them, or otherwise coating them with metal or metallic alloy, which comprises a
revolving grinder or revolving grinders which operates or operate on the surfaces
of the sheets, substantially as described.
a
4. Apparatus for use in preparing metal sheets for the purpose of galvanizing
them, or otherwise coating them with metal or metallic alloy, which comprises
revolving grinder or revolving grinders having wires the ends of which grind the
surfaces of the sheets, substantially as described.
5. Apparatus for use in preparing metal sheets for the purpose of galvanizing
them, or otherwise coating them with metal or metallic alloy, which comprises a
revolving grinder or revolving grinders and a backing piece or backing pieces,
the said grinder or grinders operating on the surfaces of the sheets while the
sheets are pressed up thereagainst by the backing piece or pieces, substantially as
described.
6. Apparatus for use in preparing metal sheets for the purpose of galvanizing
them, or otherwise coating them with metal or metallic alloy, which comprises a
revolving grinder or revolving grinders and a backing piece or backing pieces

page_text: formed or each formed with a concave curve into which the sheets are presse.
against the surface thereof by such grinder or grinders, substantially as described.
7. Apparatus for use in preparing metal sheets for the purpose of galvanizing
them, or otherwise coating them with metal or metallic alloy, which comprises a
revolving grinder or revolving grinders having wires the ends of which grind the
surfaces of the sheets, and a backing piece or backing pieces which presses or press.
the sheets against the wires, substantially as described.
8. Apparatus for use in preparing metal sheets for the purpose of galvanizing
them, or otherwise coating them with metal or metallic alloy, which comprises a
revolving grinder in combination with means by which it may be rotated at will
in opposite directions, a pair of feeding rolls, a pair of withdrawing rolls, and a
backing piece or support which supports the sheets under the operation of the
grinder, substantially as described.
9. Apparatus for use in preparing metal sheets for the purpose of galvanizing
them, or otherwise coating them with metal or metallic alloy, which comprises a
pair of grinders revolving in opposite directions, a pair of feeding rolls, a pair of
withdrawing rolls, and a backing piece for supporting the sheets under the
operation of the grinders, with means by which a sheet which is being operated
upon may be first pressed between the backing piece and one of the grinders, and
subsequently between the backing piece and the other grinder, substantially as
described.
10. Apparatus for use in preparing metal sheets for the purpose of galvanizing
them, or otherwise coating them with metal or metallic alloy, which comprises a
pair of grinders revolving in opposite directions, a pair of feeding rolls, a pair of
withdrawing rolls, and a backing piece for supporting the sheets under the operation
cf the grinders, with means by which a sheet which is being operated upon may be
first pressed between the backing piece and one of the grinders while a portion of
its surface commencing at the forward end is ground, and then be carried forwards.
clear of such grinder until the forward end of the unground portion of its surface
is beneath the other grinder, and then be pressed between such grinder and the
backing piece while the remainder of the partially ground surface is ground by the
last mentioned grinder, substantially as described.
11. Apparatus for use in preparing metal sheets for the purpose of galvanizing
them, or otherwise coating them with metal or metallic alloy, which comprises a
pair of grinders revolving in opposite directions, a pair of feeding rolls, a pair of
withdrawing rolls, and a backing piece for supporting the sheets under the operation
of the grinders, with means by which a sheet which is being operated upon may be
first pressed between the backing piece and one of the grinders while a portion of
its surface commencing at the forward end is ground, and then be carried forwards
clear of such grinder until the forward end of the unground portion of its surface
is beneath the other grinder, and then be pressed between such grinder and the
backing piece while the remainder of the partially ground surface is ground by the
last-mentioned grinder, the forward grinder operating upon the sheet only while
the sheet is gripped between the feeding rolls and in a direction tending to draw
the sheet forwards, and the rear grinder operating only while the sheet is gripped
between the withdrawing rolls and in a direction tending to pull the sheet
backwards, substantially as described.
12. Apparatus for use in preparing metal sheets for the purpose of galvanizing
them, or otherwise coating them with metal or metallic alloy, substantially as
described and shewn by the drawings herewith.
1002
STEPHEN WATKINS,
Wolverhampton, Agent for the Applicants.
STEPHEN WATKINS,
Wolverhampton, Agent for the Applicants.