CERTAIN IMPROVEMENTS IN SUCH DISH COVERS AS ARE MADE WITH IRON COVERED WITH TIN ;
Year: 1841

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
GRIFFITHS, of Birmingham, in the County of Warwick, Tin Plate Worker,
send greeting.
WHEREAS I did, by Petition, humbly represent to Her present most
Excellent Majesty Queen Victoria, that, after considerable application and
expense, I had invented "CERTAIN IMPROVEMENTS IN SUCH DISH COVERS AS ARE
MADE WITH IRON COVERED WITH TIN ;" and Her said Majesty, being willing to give
encouragement to all arts and inventions which may be for the public good,
was graciously pleased, by Her Royal Letters Patent under the Great Seal of
the United Kingdom of Great Britain and Ireland, bearing date at West-
minster, the Eighth day of February, One thousand eight hundred and
forty-one, in the fourth year of Her reign, for Herself, Her heirs and
successors, to give and grant unto me, the said Thomas Griffiths, my exors,
admiors, and assigns, Пer especial license, full power, sole privilege and
authority, that I or they, by myself or themselves, or by my or their deputies,
servants, or agents, or such others as I or they should agree with, and no
others, during the term of fourteen years from the date of the said Letters
Patent, should and lawfully might make, use, exercise, and vend my said
Invention, within that part of Her said Majesty's Dominions called England,
Her Dominion of Wales, and Town of Berwick-upon-Tweed, in such manner
as to me, my exors, adñiors, and assigns, should seem meet, and that I or
they should enjoy the whole profit and advantage arising by reason of the said
Invention during the said term of fourteen years: And whereas the said
Letters Patent contain a proviso obliging me, the said Thomas Griffiths;

page_text: particularly to describe and ascertain the nature of my said Invention, and in
what manner the same is to be performed, by an instrument in writing under
my hand and seal, and to cause the same to be inrolled in Her Majesty's High
Court of Chancery within six calendar months next and immediately after the
date of the said Letters Patent, as in and by the same (reference being
thereunto had) will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Thomas Griffiths, do hereby declare that my said Invention is described and
ascertained in manner following, and by the aid of the Two Sheets of Drawings
hereunto annexed, that is to say:-
My improvements "in such Dish Covers as are made with Iron covered with
Tin" consist in making such covers with one piece of rolled iron plate, which,
by the means herein-after described, is rendered so deepy concave as to serve
for the upright sides and the rim at the base of the dish cover as well as for
the mere top or dome thereof, the covering of tin being applied to the iron
after it has been brought to the said deeply concave form, but previous to the
final finishing thereof to the intended form of the dish cover. Figure 1,
Sheet I., represents a blank cut out of a flat piece of rolled sheet or plate of
charcoal iron, of the best quality of such metal, and of uniform thickness.
Figure 2 is an edge view of the blank, shewing that the same is flat and of a
uniform thickness of metal. From one such blank a dish cover (according
to my improvements) is to be formed by stamping the blank, at a succession
of stamping operations, to a deeply concave form (see Figures 3, 4, and 5),
and afterwards raising the same to a farther depth of concavity at a succession
of operations (some previous to the tin being applied, and others subsequent
thereto), those operations being performed by machinery containing suitable
rollers or revolving wheels, applied in pairs, between which the iron covered
with tin is ultimately wrought into the intended form of the dish cover
see Figures 12, 13, 14, 15. Figures 3 and 4 are longitudinal and transverse
vertical clevations of the same blank or piece of charcoal iron, after it has
been submitted to a succession of operations of stamping it into concave iron
dies in a stamping machine, with a series of convex forcers of lead, of different.
degrees of convexity, to be used one after another, the least convex first
and the more and more convex one after the other, in the ordinary manner
of stamping metal plate. Figure 5 is a horizontal plan of Figures 3
and 4. When the blank, Figure 1, by such progressive stamping, has been
raised to the form shewn at Figures 3 and 4 and 5, the surfaces of the iron
are pickled in a solution of sulphuric acid and water, in order to remove the
scale or oxyde of iron, and then three of the stamped and pickled blanks
;

page_text: in that form are placed one within the other, shewn in section at Figure 6
and in elevation at Figure 7, their surfaces being smeared with oil before
putting them together, and all three are confined together as one by means
of a fillet or strip of plate iron (a), which is folded or turned over the projecting
border elges of all three by hammering, so as by including those three edges
within the said fold to confine the three stamped blanks securely one upon
another, and in this state they are submitted, all three at once, to the operation
of the machine shewn in Figures 33 and 34, Sheet II.; and by a series of
succeeding operations in that machine (with suitable rollers or wheels) the
said three blanks are raised, as it is technically termed, by working upon
them between the rollers of such machine, until they are brought to the
height or depth required for the upper part or dome of the intended dish
cover. The oil that was smeared over the surfaces before they were fastened
together facilitates the operation of raising, by allowing the contiguous
surfaces of metal to slide over each other as they become expanded by the
operation of the rollers of the machine. The fillet (a) is next removed, and
the three partly formed covers are detached from each other, and then they are
each separately raised by the machine Figures 33 and 34, by working with
the circumferential or border parts between the rollers thereof, until those
parts are brought into the form of nearly upright sides, shewn at Figures
9, 10, and 11, Sheet I., the upper part or dome remaining of the same form
as was given to it by the previous stamping and working of three together.
All the previously described transformations are effected upon the blank,
Figures 1 and 2, whilst it is in the state of untinned iron; and in order to
enable the iron to endure the succession of operations of stamping and
machine raising as aforesaid, the blank is carefully annealed by heating and
slow cooling, at such times or stages during the said operations as the
workman finds requisite, in order to keep the iron soft and ductile, so as to be
succeptable of spreading easily without cracking. Annealing is a usual and
well-known process in the business of stamping or rolling metals, and is
resorted to as often as is requisite, in order to soften the metal whenever the
same has become too much hardened by the operations of rolling, stamping,
or raising, or hammering, for the heat to which the metal is submitted in
annealing, and followed by gradual slow cooling, restores to the metal the
ductility which had been impaired by the working in a cold state. For
annealing the blanks, or, partly formed covers, they are heated in an oven or
furnace to a red heat, and then left to cool slowly in the open air. Care is
required in the heating to avoid oxydizing the surface of the iron to such an
extent as to injure the quality of the iron, or so as to materially reduce its

page_text: thickness by raising a scale of oxyde on the surface. The annealing will
require to be performed many times before the blank can assume the form
shewn at Figures 9, 10, and 11, Sheet I. The number of times which the
blanks require to be so annealed depends on the quality of the iron, and no
precise directions can be given, but an experienced workman can have no
difficulty in deciding when the iron has become so much hardened by the
operations that it has gone through since the last annealing that another
annealing is become requisite, in order to enable him to proceed further in
the series of operations without risk of cracking the iron. When the form
shewn at Figures 9, 10, and 11, Sheet I., has been attained in manner
aforesaid, the partly formed cover is then ready for the tinning, to cover every
part of the surfaces of the iron with tin, after which it can no longer be
submitted to the annealing process, because of the tin upon its surfaces,
tinning being performed by immersing the iron into a bath of melted tin, in
a manner well understood, and commonly practised by sheet tinners, does not
require to be further described than to state at what period in the series of
operations aforesaid the tinning is to be performed. Figure 10, Sheet I., is a
plan of the partly formed cover, and Figures 9 and 11 are transverse and
longitudinal elevations of the same. It is obvious, that before the partly
formed cover is tinned, all the required concavity of form ought to have been
given it, or nearly all, for although the operation of working between the
rollers or wheels of the machinery, Sheet II., is to be resorted to again after
the tinning, that working is intended to consolidate and harden the tin,
so that it will acquire what is called a colour and a polish upon the tinned
surface, but in performing that operation there will also be some small effect
of raising or deepening the concavity of the cover. Raising is a technical
term used by workers in metal plate to express the act of converting a flat
plate of metal into a concave or dish-like form, so as to become concave on
one side or surface of such plate and convex on the opposite side or surface;
and the said term raising is used whether the operation is performed by
stamping in dies, or by hammering, or by compressure between suitable
rollers, which are adapted to produce concavity of form.
Two machines represented in Sheet II.-One of them, Figure 33, is what
is called the wheeling machine, which is in common use for the purposes of
raising plates of metal, and for planishing or consolidating the tin on the
surfaces of tinned plates, to give a colour thereto. (a) is a small roller, or
rather a segment of a roller, called a quadrant, fastened firmly upon the end
of the horizontal axis (c) so that the said quadrant a will be turned round
with the axis c when the same is turned, and (b) is another small roller

page_text: or complete wheel, which is mounted on pivots at the two ends of its short
axis, so as to be capable of turning freely round on those pivots which are
lodged in suitable bearings in a fork, at the upper end of an upright slider e,
which can be moved endway upwards by means of an upright screw applied
beneath the lower end of the slider e, so as to elevate or move up the roller
or wheel towards the roller or quadrant a, in order to give the required
intensity of pressure upon the metal plate, which is interposed between the
circumference of the quadrant and of the wheel (a) and (b). The article of
metal plate which is to be wheeled, as it is termed, (that is, submitted to the
said machine for the purpose of raising, planishing, or burnishing it,) is placed
above the wheel (6) and below the quadrant (a), and by force of the said
screw the lower wheel (b) is elevated until the circumferences of the wheel (b).
and of the quadrant (a) press the thin metal plate of the article that is to be
wheeled between them with sufficient force to produce the effect of raising,.
polishing, or planishing, when the quadrant and wheel (a) and (b) are turned
backwards and forwards alternately, which is done by giving a reciprocating
or rocking motion, by means of the lever handle (d), to the horizontal axis (c),.
and the quadrant (a) thereon. For that purpose the workman actuates
the handle (d) with one hand, and alternately pulls and pushes that handle
backwards and forwards to produce a vibrating motion of the lever of the
handle, whilst with the other hand he holds the article to be wheeled, and
guides it as it moves backwards and forwards between the quadrant (a) and
wheel (6), so as to produce the compressing or planishing effect upon such
parts of the surface as is required. The quadrant (a) and wheel bare
made of steel, and their circumferences or edges are hardened, and as highly
polished as possible, which polish is partly communicated to the tinned
surface, which is operated upon by. the two circumferences. The said
wheeling machine, Figure 33, is used by tin plate workers for raising
iron plate, and to produce compression of the tin surface, and consequently
a colour or polish upon the surfaces of articles of tinned plate, but in the
most common construction of the machine its use is very limited; and
in order to be able to employ such machine with full advantage, in
raising plates so much from a flat surface as is requisite to form the same
into a dish cover, the machine requires the modification in construction
which is represented by Figure 34, where the upper end of the upright
slider e appears with a cranked arm for carrying the wheel bin bearings of
the fork at the upper end of that arm. The slider c, Figure 34, with such
cranked arm, being substituted for the upright slider e, Figure 33, will enable
a very deeply concave dish cover to be wheeled over the entire surface
:

page_text: thereof, in order to raise it from the form, Figures 6, 7, 8, Sheet I., to
the form, Figures 9, 10, 11; and also, after the tinning, whilst in the form
of those Figures, to wheel the surface of the tin in order to obtain colour and
polish. The machine, Figure 33, when modified by the substitution of the
the cranked arm, Figure 31, requires the aforesaid quadrant a to be further
along the axis c, to enable the wheel b, when the same is carried by the
cranked arm, Figure 34, to be used in connection with the quadrant a,
Figure 33. The machine, so modified, is often employed to raise, burnish,
or planish the surfaces of tinned articles, but is not used for the purpose,
as herein-before described, of further raising of untinned stamped blanks
of plate iron, after the same have been raised to as great a convexity as is
practicable to be done by stamping only.
The improvements on the ordinary wheeling machine, which are more
particularly required for the purpose of making dish covers according to my
improvements, are shewn at Figures 19 to 24, Sheet II. The upper end of the
upright slider e is a cranked arm, with a fork which carries the pivots of the wheel
(b). In Figure 24 a dish cover is shewn, undergoing the operation of what is
called the swaging, by means of wheels for forming the moulding around the
lower part or base of the dish cover; Figure 24 being a vertical section of part
of the machine, which is shewn complete at Figures 19 to 24. The upper wheel
or roller c of that machine is a complete circle, instead of being only a segment
of a wheel or quadrant, as in the common wheeling machine, Figure 33. In the
Drawings, Figures 20, 21, 24, the wheels or rollers c and bare shewn with
their circumferences suitably formed to produce a moulding on the metal
plate, which is compressed between them, but plain wheels or rollers such as
a and b, Figure 33, are also to be used in the same machine for the purpose
of raising, planishing, or polishing the dish cover which has been stamped, as
well before as after the same bas been tinned. When the metal plate has
been brought to the form shewn at Figures 9, 10, and 11, by first stamping
at several operations, and afterwards raising at several operations in the
machine, Figures 33, 34, or else the machine, Figures 19 to 23, with plain
rollers therein, as already described, and then, after tiuning in the form
Figures 9, 10, and 11, and after the surface of the tin has been consolidated
and planished by further operation of the said plain rollers, then is the time
that the tinned cover in the state of Figures 9, 10, and 11, is ready to have
the moulding form around it, as is shewn at a, a, Figures 12, 14, and 15.
The operation of forming such moulding is termed swageing, because it has
been hitherto commonly performed by tools, Figure 35, called swagcs,
although now performed by wheeling in lieu of swageing with .swages. At

page_text: Figure 24, Sheet II., a dish cover is shown in the operation of having the
said moulding impressed upon it, by means of the two wheels c and b, which
are formed to suit the particular moulding required. The upper axis w,
Figures 19 to 23, which carries the wheel or roller c, has a spur wheel M,
fixed upon the other end of it, the teeth of which are engaged by a pinion m,
which is termed by a winch handle upon its axis, with either a continuous
rotary motion or else a reciprocating motion, backwards and forwards alter-
nately, which motion is transmitted in a slower degree, but with increased
force, to the wheel or roller c. The handle (=) can be turned by a boy.
The workman guides the dish cover, when it is applied as in Figure 24, so
as to be pressed between the upper roller or wheel c and the lower one b.
The cover circulates round and round, so as to bring every part of its
circumference in turn between the said rollers c, b, and the same is brought
repeatedly between them in consequence of the cover so revolving. The
compressure that they are to exert is brought on by degrees by turning the
upright screw y slowly round by means of its handle N. The upper wheel
or roller (c) need not be changed during the process of raising the moulding
a, a, a, around the lower part or base of the dish cover unless the moulding
be complicated; but the lower wheel or roller (b) must be changed from
time to time for other wheels (Figures 32 and 29) of such forms as will
best suit, one after another, for the progressive formation of the moulding,
so as to raise it by degrees, and the discretion of the workman must be
exercised to choose the forms of the rollers b, which he uses from time to time,
as well as the degree of pressure he causes by the screw y, so as to form the
moulding as effectually and as quick as he can without cracking the metal.
At the commencement of the operation of swageing or forming the moulding
around the lower part of the dish cover the workman places that cover with
the concavity thereof over the lower roller or wheel b, as shewn in Figure 24,
the lower edge or rim of the cover being in contact with the gage or fixed'
stop (d), which stop regulates the position or place that the moulding is to
occupy around the dish cover, either nearer to or further from the base or
lower edge thereof; and the gage or stop (d) is capable of adjustment to suit
the said place; and after being duly adjusted the stop (d) is fastened in its
position by means of the thumb screw (1). The boy turns the machine round by
turning the handle of the pinions; the wheels or rollers c, b, are thereby turned
and the dish cover circulates by the action of the wheels or rollers c, b.
The man guides the edge of the dish cover against the stop d, and brings on
the pressure gradually by the screw y; also from time to time, as the operation
progresses, he changes the lower wheel (b) for another, so as by means of them to

page_text: produce the effect which is techincally called swageing, and which is commonly
produced by driving the end (h) of the swage, Figure 35, into a hole in
the work bench wherein it fits; the upper half g of the swage rises and falls
about the joint pin r, and the upper half g fits to the lower half q. The
article to be swaged (suppose it be the intended moulding around the
lower part of the dish cover), the same is placed between the two swages q
and g, and the form of the faces of the swages becomes gradually imprinted
around the base of the dish cover by lifting up and striking down the upper
swage g with a series of smart blows given by the hand of the workman
applied at t, while with the other hand he holds and guides the dish cover
which is undergoing the swageing, as it is called, or, in other words, is in
progress of having a moulding worked around it; and the workman slowly
turns the dish cover round and round, in order to bring every part all
around it in succession under the swageing action. By means of the machine,
Figures 19 to 24, with the rollers or wheels b and c mounted therein and
turned round continously in one direction, the same effect is produced as by
the ordinary swages, Figure 35, aforesaid, but with greater economy and effect.
It is manifest that the form of the rollers or wheels c and 6 must be varied to
suit the particular moulding that is to be produced, and the number of rollers or
wheels to be employed in succession, for the progressive formation of the same
moulding will also depend upon the character of the moulding to be produced
around the dish cover. A continuous rotary motion is given to the upper roller
or wheel c, as before described, and by means of turning the screw y, Figures 19
to 24, the lower roller or wheel b is moved upwards towards the upper roller c,
so that the two will press the metal that is introduced between them with
sufficient force to produce the moulding; the pressure of the upper roller or
wheel c on the dish cover causes the same to circulate, as already mentioned,
and the motion of the dish cover causes the lower roller or wheel c to revolve.
Such revolving motion of the rollers or wheels and circulating motion of the
dish cover is continued until the moulding is produced with the required
sharpness, but during the progress of such operation the rollers or wheels c
and 6 are caused to compress the dish cover more and more between them by
means of the screw y until the moulding is compleated to its true intent and
After that is done, the lower edge of the dish cover is turned inwards,
so as to double it into a bead. Figure 16 shews the said lower edge before it
is begun to be turned inwards.
as far as a right angle (or
the formation of the bead.
form.
Figure 17, a, shews how the edges turned in
nearly so) from the state of Figure 16, in part of
This degree of turning in as far as Figure 17 is
effected at twice by beginning with the two rollers or wheels, Figures 25 for

page_text: the upper and 31. for the lower wheel, and then the turning in, is continued
further by changing the lower wheel 31, and putting the wheel, Figure 26,
into its place, whereby the turning in as far as Figure 17 is effected; and
then the final turning in of the bead is compleated by again changing the
lower wheel, Figure 26, and putting Figure 30 in its place, and by action of
the wheels 25 and 30 working together the bead is finally turned inwards into
the form shewn at the Figures 17 and 18, and also at b, Figure 15. The
metal of the dish cover is completely turned inwards by the aforesaid action of
the rollers or wheels when they are worked in the machine, Figures 19 to 24,
but the bead contains no wire as is usually inserted into the lower edges of
dish covers, which are made in the ordinary way. The external surface of the
dish cover is wheeled all over in order to planish or burnish and grain the
tin, that it may shew a good colour and bear a good polish. Figures 12, 13,
14, and 15, Sheet I., represent the dish cover when compleated by the
process above described. The dish cover has no seam upon its surface as
ordinary dish covers have, but the whole cover is formed out of one piece
of iron plate tinned by the several succeeding operations of stamping in dies,
raising by wheeling, swageing by wheeling, and beading or turning in by
wheeling, as herein-before described. The upper or dome part of the cover
may be formed out of one piece of iron plate, the same as usual in dish
covers, and the lower part or base with upright sides being raised out of
another piece of iron extending all round that base without any joint in the
circumferance thereof, those upper and lower parts being, afterwards joined
together at or about the line b, b,. Figure 14, by seaming the one part into the
other by action of properly formed rollers or wheels, such seam or joint being
horizontal or parallel with the lower edge of the dish cover, the same as is
usual in dish covers; but by forming the base or lower part in onc piece
extending all round, all other seams or joints, except the said joint in a
horizontal direction, are avoided, and that seam or joint is easily concealed by
a suitable moulding at the place of junction, but there are no vertical or up
and down joints, as is usual in dish covers, and which disfigure the external
surface of the cover, and such vertical joints would also prevent the operation
of wheeling being performed in the manner herein-before described, as well
when that operation is to be performed for the purpose of raising the iron to
give the required form and for planishing it, also for burnishing or graining the
tinned surface thereof, as also when the operation is performed for the purpose
of swagcing the moulding around the lower part or base of the cover by
wheeling instead of using the ordinary swageing tool, Figure 35, Sheet II., for

page_text: that purpose; for wherever a seam or joint is made there must of necessity be
an overlapping of more than one thickness of metal, and if the direction of
such seam or joint deviated from the horizontal direction it would oppose an
obstacle to the mode herein-before described of wheeling in lieu of swageing,
and beading or turning in by wheeling; and for making such base or lower part
in one piece all around its circumference, the same is to be raised out of a
blank of iron plate by stamping the same in the manner already explained, and
when it is thereby raised nearly to the form of Figures 3, 4, and 5, Sheet I.,
then the upper part of what has been so stamped being cut out and removed,
the form required for the base part will be easily raised from the lower
part of the stamped blank by wheeling, by the machine, Figures 19 to 24,
Sheet II., with the rollers or wheels thereof turning continually round in the
same direction instead of turning alternately backwards and forwards; and by so
wheeling tho said lower or base part it may be properly formed and then tinned,
and afterwards seamed to the upper or dome part which has been prepared in
the usual manner of the dome part of ordinary dish covers; the seaming of
the two parts together being performed in the usual manner; but after the
two parts aro so seamed together, then the final completion of the cover is to
be performed by wheeling for swagcing the moulding, and turning in the bead
by wheeling, in the same manner as herein-before described respecting a dish
cover which is made in one piece. And note, whereas ordinary dish covers, of
the kind commonly called hash or steak dish covers, requiring but a small
height, are commonly made in one piece, which is raised by stamping or by
hammering, no claim is made to the making of such hash or steak dish
covers in one piece of iron; but claim is only made to the making in one
piece, or in two pieces, in manner and by the means aforesaid, of dish covers
of such a height as that the same have been heretofore commonly made in two
heights, viz., the uppermost or dome and the lowermost or base part, the latter
being made in two picces to go round the circumference, and conscquently
having two up and down or vertical joints to unite the said two pieces together
to form such base part. Note.-A simple lever handle, similar to that
marked d, in Figure 33, Sheet II., may be applied to the upper horizontal
axis w of the machine, Figures 19 to 24, in lieu of the cog wheel M and
pinion m, which may be removed, and theu a reciprocating motion can be
communicated to that axis w, and the wheel or roller that is fixed thereon;
thereby the same machine can be used for the ordinary purpose of a raising
machine, such as Figures 33, 34; and as a planishing or polishing machine
for the purpose of consolidating the covering of tin, in order to give a colour

page_text: thereto, and also as a swaging or moulding machine of the kind herein-before
described, the machine being in each particular case furnished with properly
and suitably formed rollers or wheels. And though it has been stated that the
said rollers or wheels are to be changed as is requisite to suit each particular
stage of operation, it is evident that if a sufficient number of machines be
employed different machines may have the rollers or wheels for different
stages of the operation mounted in them without a necessity for changing
frequently. Figure 16 is a section of the lower part of the circumference or
upright side of the dish cover before the lower edge is turned inwards.
Figure 17 shews that lower edge partly turned inwards, and at Figure 18, the
edge is shewn turned completely inwards so as to form a bead around the
lower edge of the dish cover without requiring a wire to be included in such
bead. The requisite turning inwards of the said edge is performed by suitable
use of the wheels as before described, instead of by the ordinary process by
the hammer. The same letters of reference are used to denote the same parts
wherever they appear in different Figures on the Drawings. The Figures on
Sheet I. are all drawn one half the real size; but the Figures on Sheet II.
are drawn one fourth the real size, except the wheels or rollers Figures 25 to
32, which are drawn one half the real size, and the machine Figures 33 and
34, which is drawn one eighth the real size. Figures 25 to 32, Sheet II., are
the wheels or rollers to be employed in swaging or forming the moulding and
graining the surface of the tin, and beading or turning inwards the lower edge
of the dish cover, in the manner shewn at Figures 12, 13, 14, and 15, also
Figures 16, 17, 18, on Sheet I. The wheels or rollers, Figures 25 or 28, are
adapted to be fixed upon the end of the upper axis w of the machine,
Figures 19 to 24, which axis w, together with such wheel or roller as is so
fixed thereon, may be either turned continuously round, or may be turned
alternately backwards and forwards as may be required, and the circumferences
of those wheels or rollers are to act upon the exterior of the cover. The other
rollers or wheels, Figures 26, 27, 29, 30, 31, and 32, are adapted to be
mounted in the position shewn by b, Figures 19 to 24, Sheet II., so as to turn
round freely on their pivots. The circumferences of those wheels or rollers
apply to the inside of the cover. The form of the edges of the circumferences
of all the wheels must of course be varied to suit or produce the particular
moulding or swaging or beading required around the sides of the dish cover.
The blank of plate iron, Figures 1 and 2, Sheet I., is about one thirty-second
part of an inch in thickness.
Having now described my said improvements, and the manner in which the

page_text: same are to be performed, I, the said Thomas Griffiths, do hereby declare that
the new Invention, whereof the exclusive use is granted to me by the said
Letters Patent of the Eighth of February, One thousand eight hundred and
forty-one, consists in the following particulars, namely:-The improvement
hercin-before described in such dish covers as are made with iron covered with
tin, of forming the same out of one piece of sheet iron or iron plate without
seam or grooved joint, in the manner herein-before described, and as
represented by Figures 12 to 15, Sheet I. of the Drawings hereunto annexed.
Also in the improvement herein-before. described in such dish covers as are
made with iron covered with tin, of forming the same out of only two pieces of
sheet iron or iron plate, in the manner herein-before described, without any
vertical or up and down joints, that is to say, one of the said pieces being the
dome or upper part of the cover, as usual in common dish covers (and therefore
no claim is made to that piece), and the other piece being the lower part or base
of the cover, extending without joint all around the upright sides of the cover,
the only joint being that joint which extends horizontally all around the, cover,
and which unites the dome to the said lower part or base, as usual in ordinary
dish covers, but in which covers there are also vertical or up and down joints
to unite the pieces which extend around the base or lower part of the cover,
and which pieces form that lower part; but the said base or lower part
being (according to this part of my improvements) made in one piece, such
vertical or up and down joints therein are avoided. Likewise, in the im-
provement herein-before described, in producing the mouldings around the
lower part or base of such dish covers by means of revolving rollers or
wheels, which are turned round in the same direction, in the manner and.
by the machinery herein-before described and represented by Figures 19
to 24, insted of the rollers being turned partly round one way and then back
again; the said base in which the mouldings are so produced being in one
piece extending all round the lower part of the dish cover, whether it be also
in the same piece, with the dome or upper part of the cover, or whether it be
a distinct piece from that dome, so that it; be one piece all around without
vertical joint therein.
In witness whereof, I, the said Thomas Griffiths, have hereunto set: my
hand and seal, this Seventh day of August, One thousand eight
hundred and forty-one.
THOMAS (L.S.) GRIFFITHS.

page_text: AND BE IT REMEMBERED, that on the Seventh day of August, in the
year of our Lord 1841, the aforesaid Thomas Griffiths came before our said
Lady the Queen in Her Chancery, and acknowledged the Specification afore-
said, and all and every thing therein contained and specified, in form above
written. And also the Specification aforesaid was stamped according to the
tenor of the Statute made for that purpose..
Inrolled the Seventh day of August, in the year of our Lord One thousand
eight hundred and forty-one.