AN IMPROVED PROCESS AND MACHINERY FOR MAKING THE HEADS OF CHAIN SWIVELS
Year: 1875

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery
Lanc, in the County of Middlesex, Patent Agent, for the Invention
of AN IMPROVED PROCESS AND MACHINERY FOR MAKING THE HEADS OF
CHAIN SWIVELS." -A communication from abroad by William Edge,
of Newark, in the County of Essex, and State of New Jersey, United
States of America.
Scaled the 15th June 1875, and dated the 1st May 1875.
COMPLETE SPECIFICATION filed by the said Alexander Melville Clark
at the Office of the Commissioners of Patents, with his Petition
and Declaration, on the 1st May 1875, pursuant to the 9th
Section of the Patent Law Amendment Act, 1852..
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent, send greeting.
WHEREAS I am in possession of an Invention for "AN IMPROVED
PROCESS AND MACHINERY FOR MAKING THE HEADS OF CHAIN SWIVELS," and have
O petitioned Her Majesty to grant unto me, my executors, admini-
strators, and assigns, Her Royal Letters Patent for the same, and have

page_text: made solemn Declaration that it has been communicated to me from
abroad by William Edge, of Newark, in the County of Essex, and State.
of New Jersey, United States of America.
NOW KNOW YE, that I, the said Alexander Melville Clark, do
hereby declare that the following Complete Specification, under my
hand and seal, fully describes and ascertains the nature of tho said
Invention, and in what manner the same is to be performed, in
and by the following statement :—
This Invention has for its object to manufacture the heads of watch
chain swivels from sheet metal and to dispense with the casting, boring,
and turning of solid swivels, by which a perfect swivel head can be
formed from a small piece of sheet metal not. exceeding one-half inch in
diameter, said sheet being either entirely of gold or other precious metal,
or merely plated therewith on one face, in which latter case the plating
will under the present process be caused to embrace the entire finished
swivel.
The Invention consists principally in subjecting the sheet metal to a
series of punches and dies, whereby it is first caused to acquire a cup
form, then a more and more elongated cup form, and finally the pear
shape or other shape generally imparted to the heads of watch chain
swivels. This hollow sheet metal pear is lastly subjected to the action
of a pair of hollow moulds, within which it is turned to receive the
complete outline finish required.
During the upsetting process, and before receiving the pear form, a
square hole is punched through the end of the blank to allow the blank
to be held on the end of a square rod and turned within the recipro-
cating moulds while receiving the final outline finish.
The Invention also consists in the new mechanism for imparting the
pear form to the blank, said mechanism being composed of a fixed die,
reciprocating punch, guide ring, and spring ejector, all as herein-after
more fully described.
In the accompanying Drawing, Figures 1, 2, 3, 4, 5, 6, 7, and 8 repre-
ent side views partly in section of the tools which are successively
employed in forming the swivel head from a flat plate of sheet metal.
Figure 9 is a face view partly in section of the finishing moulds.
All the Figures are drawn on the natural scale or nearly so.

page_text: Similar letters of reference indicate corresponding parts in all the
Figures.
The letter a, Figure 1, represents a section of a sheet metal disc, which
is by a punch b cut from a suitable plate or sheet. This circular blank a
is next laid over the cavity of a die d², Figure 2, and subjected to the
action of a descending plunger 6³, which upsets the blank and drives it
through the die, from which it will drop in form of a short cup a². The
cup a² is next placed bottom downwards on a die d³, Figure 3, whose
cavity is somewhat smaller than that in d², and subjected to the action
of a descending plunger 63,which is smaller than 6, and which in driving
the blank through the die clongates it, producing a cup a³ somewhat
longer and smaller in diameter than a³. The cup a³ not yet having the
requisite length, thinness, and reduction of diameter is next put bottom
downwards over the cavity of a die d', and subjected to the action of a
still smaller punch 6, by which it will be driven through the die d³, and
formed into the still more elongated cup a', shown in Figure 4. It may
be presumed that the cup has now the requisite extent, but I wish it to
be understood that either a larger or a smaller number of punches and
dies may be used to upset the blank and gradually elongate the cup
formed therefrom. Over each of the dies d³, d³, and d', is placed a guide
ring e, as shown in Figures 2, 3, and 4, which ring serves to prevent the
spreading of the blank above the respective surfaces of the dies.
The next operation is to pierce a square hole through the end of the
blank, which is done by a suitable punch fand die g, as indicated in
Figure 5. The blank a' is now placed with its edges downwards in the
tape ring cavity of a die d³, and gradually forced into said cavity by a
plunger 6, which has its lower end made concave, as shown in Figure 6,
so that it will fit the rounded end of the blank. To ensure central
guidance the plunger 65 has by preference a projecting pin h, which
enters the afore-mentioned square hole in the end. A guide ring is
placed on the dic d³ to embrace the blank before it has been forced down,
and prevent the same from being spread. Within the cavity of the
dic is placed a pin resting on a suitable spring. When the blank
is by the plunger forced into the die d³ the lower part of the blank is
gradually contracted by entering the contracted part of the cavity of the
die, and assumes a shape approaching the form of a pear. In descending
the blank forces the pin i³ downwards and compresses the spring j³, the
effect of which will be that upon the elevation of the plunger the spring

page_text: in expanding will raise the pin ³, and thereby throw the blank out of
the dic.
Figure 6 shows the blank a³ in the position of being just raised out of
the die after having been shaped therein.
The blank as is next placed with its edges downwards in the tapering a
cavity of another die do, shown in Figure 7, which die, with. all its
appurtenances, is substantially like that represented in Figure 6,
excepting that the cavity of the die d is more tapered, so the blank will
have its open end still more contracted, as appears from the shape of
the blank a in Figure 7, that being the shape imparted to the blank in
the die d³.
Apparatus of the same style as that shown in Figures 6 and 7 may be
still further duplicated in accordance with the form to be imparted to
the blank, and in some cases the device shown in Figure 6 alone may
suffice without having even that shown in Figure 7.
As to the device shown in Figure 5 it should be remarked that the
same or its equivalent may be employed at any other stage of the opera-
tion. The square hole may even be punched through the flat blank a
or through the end of the pear shaped blank a³.
The blank a is now put on the squared end of a rod A, shown in
Figure 8, said rod being inserted through the square hole in the end of
the blank, and by means of said rod, which constitutes a handle for the
blank the latter is held between two metal moulds B and G. The shape
of the complete swivel head is formed as a cavity in the contiguous
surfaces of the moulds B, C, one half in each mould, as indicated in
Figure 8. The upper mould B receives reciprocating motion by suitable
mechanism, and whenever it is raised off the mould C the attendant
turns the blank slightly in the mould C, so that a new surface of the
blank will be exposed to the action of the reciprocating mould on each
descent. Thus by turning the blank beneath the reciprocating mould
the same finally receives the required shape, being in exact conformity
with the form of the recesses in the moulds B and C.
The swivel head a' as it comes from the moulds B, C, is in condition
for application to the other parts of a chain swivel. The reciprocating
mould B and stationary mould O may also be employed for shaping cast
swivel heads where a continuous row of such heads is cast in one-piece,

page_text: those projecting from the moulds serving in such a case as handles for
those subjected to the action of the moulds.
Having described the nature of the said Invention, and the manner
of performing the same, I declare that what I claim as new and desire
to secure by Letters Patent is,―
1st. The process herein described of forming swivel heads from sheet
metal blanks a by first forming each blank into a cup a³, then elongating
said cup, next forming it into a pear shape, and lastly finishing it by
turning it between a stationary mould C and reciprocating mould B, sub-
stantially as set forth.
2nd. The combination of the die d³, guide ring e, plunger 6, pin 2,
and spring, all arranged for the purpose of contracting the open end
of the cup shaped swivel head blank, substantially as set forth.
3rd. The reciprocating mould B, combined with the stationary
mould C and handle A, the opposite faces of the two moulds having
cavities for the reception of a swivel head blank a³, which is to be formed
into a swivel head a' by the operation of the moulds, substantially as
specified.
4thly. The process herein described of adapting a sheet metal swivel
head blank to the reception of a handle A, and to the operation of the
moulds B, C, by punching a square hole through the end of the blank
previous to the insertion within said moulds, substantially as set forth.
In witness whereof, I, the said Alexander Melville Clark, have
hereunto set my hand and seal, this First day of May, in
the year of our Lord One thousand eight hundred and seventy-
five.