Improvements in Apparatus for the Manufacture of Metal Caps.
Year: 1898

page_text: Date of Application, 17th Oct., 1898-Accepted, 3rd Dec., 1898
[Communicated from abroad by WILLIAM PAINTER, of 500, East Monument Street,
in the City of Baltimore, in the State of Maryland, United States of America,
Manufacturer.]
Improvements in Apparatus for the Manufacture of Metal Caps.
We, THE CROWN CORK COMPANY LIMITED, of 79 and 81, Paul Street, Finsbury, in
the County of London, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement :-
Our invention relates to improvements in apparatus for the manufacture of metal
caps or crowns having turned corrugated flanges; such as are referred to in the
Specification of British Letters Patent No. 2031 of February 2, 1892, and are for
use for sealing bottles.
In the production of these flanges, corrugated caps or crowns, we have hitherto
used a form of punching and drawing press well known in the arts, having
incorporated therein gangs of punches, dies, &c., as hereinafter shown and described.
As the mechanism of the press which actuates the device forming the subject
matter of this invention forms no part thereof, and is well known and in very wide
use for similar purposes, we have not shown or described the same herein. In the
operation of this well known apparatus a series of punches first cut the discs of
which these caps are made, from sheet metal, after which a corresponding series of
corrugated male formers force or draw the discs downward into corresponding
female dies or formers, the whole of which operations are old and well known in
the art of stamping or drawing of sheet metals.
In the formation of sheet metal objects of this character having corrugated
flanges, it has heretofore been thought necessary to employ not only corrugated
female formers, but also correspondingly corrugated male formers for use therewith.
In the formation of uncorrugated cup, or cap shaped articles from discs of sheet
metal by the stamping or drawing process, in order to avoid the formation of
irregular corrugations at the edges of the disc, which are not easily obliterated
thereafter, it is generally found necessary to employ a follower or drawing plate,
pressing upon and holding the outer edges of the disc in contact with the flat top
of the lower or female former, or die. In the similar formation of the caps or
crowns shown in the patent above referred to, although the flanges are purposely
corrugated, it is also necessary to prevent the formation of irregular corrugations
in the regularly corrugated edges thereof, as irregular corrugations would interfere
with the proper formation of the regular corrugations in the same manner as with
plain uncorrugated flanges; it is therefore also necessary to employ followers, or
holding plates, in the formation of regularly corrugated flanges.
In practice we have found that where the operations of forming a turned flange
upon a disc of sheet metal and the drawing of regularly spaced corrugations upon
said flange are simultaneously performed by means of a male and female die or
former, it is not necessary to conform the male former to the corrugations of the
lower or female former, so long as the metal disc is held against the top surface of
the female die-as required to prevent the formation of irregular corrugations as
+

page_text: above cited-but that the employment of a plain, smooth, uncorrugated male former
is equally efficient under the conditions described, in completely drawing the sheet
metal into the depressions or corrugations of the female former.
In the employment of corrugated male formers, as has heretofore been thought
necessary, the wear and tear upon the projections constituting the corrugations of
said male former is very great, and on account of their necessary fragility, these
projections are very liable to fracture; while the projections forming the
corrugations in the female die are from its interior structure necessarily much
stronger and more resistant and much less subject to wear.
It is the object of this invention to avoid the great expense incident to the wear
and tear of a corrugated or fluted male former, and the expense of its production
and renewal, and to effect this purpose I have found it expedient to use a plain,
smooth, uncorrugated or unfluted male former surrounded by a suitable follower or
holder, in conjunction with a corrugated female former or die, for the production of
the said cap having corrugated metal flanges.
In order that our said invention may be clearly understood and readily carried
into effect, we will now proceed to describe the same more fully with reference to
the accompanying drawings in which :-
Figure 1 is a perspective view of a corrugated male former of well known
construction, as heretofore used.
Figure 2 a similar view of the female die or former surrounded by its cutting
ring or die, and
Figure 3 a similar view of the follower, which in this case also serves as a
punch for severing the discs from the sheet of metal; also of well known
construction as heretofore used.
Figure 4 is a sectional view of Figures 1, 2 and 3 showing all parts in juxtaposition
with the completed cap or crown between them.
Figure 5 is a similar sectional view of the corresponding parts as made in
conformity with this invention.
In the figures B is the lower or female former or die with the depressions or
notches B¹ forming the corrugations shown therein in Figure 2. The former or
die B is surrounded by a cutting ring or die A. C is the follower whose lower end,
in conjunction with the cutting ring or die A, serves as punch and die for removing
the discs from the sheet of metal. D is the male former in each case and E the
completed cap in position in the dies or formers.
In Figure 3 there is shown in dotted lines, and in full lines where broken away,
grooves or corrugations formed in a part of the interior of the follower C required as
heretofore made as a guide for the corresponding corrugations on the male former D,
to guide them into proper juxtaposition with the corresponding_corrugations in
the female former B, the projecting members of the male former D sliding within
the grooves or re-entering spaces in the follower C.
The operation of the parts in both the old device and in this invention is as
follows: The sheet of metal, from which the caps or crowns are to be made are
fed over the cutting ring or die A, while the male former D and its follower C are
raised to allow of its passage. The follower C is then caused to descend, and
acting as a punch with the cutting ring or die A, severs the disc from the sheet,
leaving it lying flat upon the top surface of the female former or die B. The
follower C is then caused to further descend until it holds the disc by its outer
edges against the top surface of the female former or die, but not with sufficient
pressure to prevent the edge of the disc (which is to form the corrugated flange)
from sliding into the female former or die B as forced into it by the descent of the
male former D, which latter immediately succeeds the arrival of the follower Cat
its lower position. In this operation the plain male former D shown in Figure 5
serves, in conjunction with the follower C, to draw the metal of the flange into the
depressions or corrugations of the female former or die as effectually as does the
corrugated male former and follower shown in Figures 1, 2, 3 and 4, and the product
in each case is exactly similar.

page_text: This invention saves the very considerable cost generally incurred by forming
corrugations upon the exterior of the male former D and corresponding corrugations
on the interior of the follower C, and also the cost and loss of time involved in
keeping in order the fragile points of the projection forming the said corrugations
on the male former D, when using apparatus of ordinary construction.
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. Metal stamping or forming apparatus, in which a plain or smooth cylindrical
male former or die and an independent follower are employed in conjunction
with a corrugated or notched female former, for the purpose specified.
2. Metal stamping or forming apparatus constructed arranged and operating
substantially as herein before described with reference to Figure 5 of the
accompanying drawings, for the purpose specified.
Dated this 17th day of October 1898.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicants.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicants.