Work, and in the Manufacture and Treatment of the same.
Year: 1885

page_text: Work, and in the Manufacture and Treatment of the same.
I ALBERT HAMILTON EMERY of Stamford in the County of Fairfield and State
of Connecticut; United States of America, Civil Engineer, Vice President of the
Emery Scale Company do hereby declare the nature of the said invention for
IMPROVEMENTS IN WROUGHT METAL PLATES FOR USE IN THE CONSTRUCTION OF
BOILERS, SHIPS, AND OTHER BOLTED OR RIVETTED WORK; AND IN THE MANU-
FACTURE AND TREATMENT OF THE SAME, to be as follows:-
The object of this invention is to increase the strength of metallic plates used in
the manufacture of rivetted, bolted and like work, such as boilers, ships, bridges
buildings and the like, and also to increase the strength of structures made up
from such plates. To this end the marginal parts of the plates, through which the
bolt or rivet holes are to be made, are subjected to compression between rolls or
dies, while in a cold or moderately heated state, so that the limit of elasticity in
the reduced section of this part of the plate, after punching or drilling will be at
least as great as the whole section of the unpunched portions; and when practicable
of equal or greater ultimate strength.
Or if preferred, the invention may be carried into effect by compressing the
metal around the bolt or rivet holes or the places where they are to be made, to a
sufficient distance to extend beyond the heads of the bolts or rivets.
In the latter mode of carrying out the invention it is preferred to have the com-
pressed portions extend to a sufficient radial distance to overlap one another.
Another mode of carrying the invention into effect, which possesses some special
advantages, consists in compressing the metal around the bolt or rivet holes while
the punch is in the hole or after the insertion of the bolt or rivet. In this case the
metal under pressure of the dies, is forced closely against the surface of the punch
or against the bolt or rivet, as the case may be.
Under either mode of carrying the invention into effect the dies or rolls are
formed in such a manner as to exert a reduced pressure on the metal at points
adjacent to those at which the maximum condensing pressure is applied, which
reduced pressure, while insufficient to cause flowing of the metal, gives friction on

page_text: the pressing surfaces, sufficient to prevent flowing under the greater pressure
applied where the metal is to be condensed and which condensing pressure would
cause flowing of the metal if such flowing were not resisted by confining the
adjacent metal by pressure and consequent friction, by a surrounding area of less
pressure.
One or more plates prepared by condensing the metal at or near the margins
and punching or drilling as explained, are connected by rivetting or bolting as
usual, after which in the case of steam boilers and other similar structures the
boiler is subjected to internal hydraulic pressure, sufficient to stretch the metal
beyond its elastic limit imparting a permanent set, and resulting in a higher elastic
limit and increased rigidity and ultimate strength in the metal.
The strength of the structure is thus materially increased, not only by the
results last stated, but because by the stretching operation, all parts of the metal
acquire such a set that in the future use of the structure, the various. parts of the
plates and all the rivets or other fastenings will be equally strained so far as
practicable, instead of one being relieved at the expense of another, as is the case
where the plates are simply rivetted together in the usual way. It will be
apparent that a boiler or other structure, having been stretched in the manner
described so as to impart a sufficient permanent set to the metal, will be prepared
to endure its proper strains in use without distortion or the overloading of any of
its parts.
•
The invention is manifestly applicable to plates of various shapes according to
the various purposes for which the structures are designed. The said plates may
be in flat or bar form, or in the shape of angle irons or irregular in shape. It
often happens that some holes are so located by reason of the peculiar form of the
plate or structure or from other causes, that the compression of the metal around
such holes is impracticable or unnecessary. In all such cases the stretching of the
structure so as to impart a considerable permanent set, and bring all parts under
equable strain is highly beneficial.

page_text: Work, and in the Manufacture and Treatment of the same.
I ALBERT HAMILTON EMERY of Stamford in the County of Fairfield and State
of Connecticut; United States of America, Civil Engineer, Vice President of the
Emery Scale 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:-
The object of this invention is to increase the strength of metallic plates used in
the manufacture of rivetted, bolted and like work, such as boilers, ships, bridges,
buildings and the like, and also to increase the strength of structures made up from
such plates.
To this end the marginal parts of the plates, through which the bolt or rivet
holes are to be made, are subjected to compression between rolls or dies, while in
a cold or moderately heated state, so that the limit of elasticity in the reduced
section of this part of the plate, after punching or drilling, will be at least as great
as the whole section of the unpunched portions; and when practicable of equal or
greater ultimate strength. Or if preferred, the invention may be carried into
effect by compressing the metal around the bolt or rivet holes, or the places where
they are to be made, to a sufficient distance, to extend beyond the heads of the
bolts or rivets.
In the latter mode of carrying out the invention, it is preferred to have the
compressed portions extend to a sufficient radial distance to overlap one another.
Another mode of carrying the invention into effect, which possesses some special
advantages, consists in compressing the metal around the bolt or rivet holes while
the punch is in the hole, or after the insertion of the bolt or rivet. In this case the
metal under pressure of the dies, is forced closely against the surface of the punch
or against the bolt or rivet, as the case may be.
Under either mode of carrying the invention into effect, the dies or rolls are formed
in such a manner, as to exert a reduced pressure on the metal, at points adjacent to
those at which the maximum, condensing pressure is applied, which reduced
pressure, while insufficient to cause flowing of the metal, gives friction on the
pressing surfaces, sufficient to prevent flowing under the greater pressure applied,
where the metal is to be condensed and which condensing pressure would cause
flowing of the metal, if such flowing were not resisted by confining the adjacent
metal by pressure, and consequent friction, by a surrounding area of less pressure.
One or more plates prepared by condensing the metal at or near the margins, and
punching or drilling as explained, are connected by rivetting or bolting as usual,
after which, in the case of steam boilers and other similar structures, the structure

page_text: T
is subjected to internal hydraulic pressure, sufficient to stretch the metal beyond its
elastic limit, imparting a permanent set, and resulting in a higher elastic limit, and
increased rigidity and ultimate strength in the metal. The strength of the
structure is thus materially increased, not only by the results last stated, but
because by the stretching operation, all parts of the metal acquire such a set, that
in the future use of the structure, the various parts of the plates and all the rivets
or other fastenings will be equally strained so far as practicable, instead of one
being relieved at the expense of another, as is the case where the plates are simply
rivetted together in the usual way. It will be apparent that a boiler or other
structure, having been stretched in the manner described, so as to impart a
sufficient permanent set to the metal, will be prepared to endure its proper strains
in use, without distortion or the over loading of any of its parts.
The invention is manifestly applicable to plates of various shapes, according to
the various purposes for which the structures are designed. The said plates may
be in flat, or bar form, or in the shape of angle-irons, or irregular in shape. It
often happens that some holes are so located, by reason of the peculiar form of the
plate or structure, or from other causes, that the compression of the metal around
such holes is impracticable, or unnecessary. In all such cases the stretching of the
structure, so as to impart a considerable permanent set, and bring all the parts
under equable strain, is highly beneficial.
Various modes of carrying the invention into effect, are illustrated in the
accompanying drawings.
Figures 1 and 2 are sectional views of dies suitable for compressing the metal
during punching and rivetting respectively, showing also the plate or plates
between the dies.
Figure 3 is a plan of a punched plate, indicating by dotted circles the areas of
compressed metal around the rivet-holes.
1, represents the plate, and 2 the rivet holes therein. 3 are the areas of con-
densed metal surrounding the rivet-holes, and 4 the annular spaces surrounding
the condensed portions 3 and overlapping each other, where the metal is compressed
and held with sufficient force to prevent the flow of metal from the inclosed
portions 3 under the heavy pressure applied thereto to permanently condense the
metal.
Figure 1 is a sectional view illustrating the condensing and punching operations.
5 represents a bed die with an aperture 6, to discharge the punchings. 7 repre-
sents the upper compressing die, and 8, a punch working therein, which is to be
driven by a hydraulic ram or other adequate and usual means, so as to perforate
the plate 1.
The compression die 7 is also pressed down by a hydraulic ram or other adequate
means with sufficient force to condense the metal in that portion of the plate 1 on
which it acts, indicated at 3 in Figure 3 so as to impart a permanent set.
The face of the said die is formed with a precisely straight or level face from 7a
to 7a, so as to exert its maximum pressure over this area and permanently condense
the metal in the portion 3 of the plate, and with a very slightly receding surface
from 7 to the margin 7b, so as to apply over the annular surface 4 a reduced
pressure which, while insufficient to cause a flow of metal or produce any consider-
able condensation or permanent set therein, will suffice to prevent any outward
flow of metal from the inclosed portion 3 to which the maximum pressure is
applied to condense the metal. The compression and condensation of the metal
may take place either before or after punching. In the latter case (which is the
preferred mode) the punch remains in the hole during the compression of the
metal, and in the former case the pressure is maintained during the punching.
In practice the recession of the surface from 7a to 7b will be so slight as to be
scarcely perceptible to the eye, but it is exaggerated in the drawing for the purpose
of illustration. The compression die 7 may, if preferred be divided concentrically
as illustrated, the outer annular portion 7° being forced down first by a separate
fram, with sufficient pressure to effectually grip the metal and confine it against

page_text: flowing radially under the heavier pressure subsequently applied by the com-
pression die 7. Figure 2 is a sectional view illustrating a mode of compressing
and condensing the metal during or subsequently to the rivetting operation. In
this Figure, 6 represents the bed die; 1, 1, the two parts of the plate; 8 a rivet
connecting them, and 9 the rivetting tool. The face of the said tool is so formed
from 9 to 9a as to apply condensing pressure and permanent set to the parts 3 of
the plates and between 9a and the margin 9b to apply reduced pressure to the
surrounding parts 4 so as to prevent outward flow of metal from the central part,
where the maximum pressure is received, as before explained.
As before stated with reference to the compressing die 7, 70, Figure 1 the
compressing die or tool 9, 9° may be made in two parts worked by separate rams
so that after both have been brought down with sufficient pressure to confine the
metal, the main compressing die 9 may be forced down with increased pressure,
sufficient to condense the metal.
The expression "cold or moderately heated means that the metal must not be
so heated as to impart frée ductility to it or adapt it to flow easily under pressure
as in the customary operations of forging and swaging. A boiler plate cold rolled
equally all over is not the equivalent of this invention for the reason that a boiler
plate cold rolled throughout so as to be condensed equally all over will when
subjected to strain tear first in the punched portion owing to its reduced section.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:-
:-
1. A plate or plates of metal for bolted or rivetted work, having a greater
density strength or limit of elasticity in the metal in the parts through which bolts
or rivets are passed or to be passed, the said increased density strength and limit
of elasticity being produced by compressing the said parts of the plates while in a
cold or moderately heated state to a sufficient degree to impart a permanent set as
herein set forth.
2. A plate for the manufacture of boilers, ships or bridges or for other like
purposes, compressed while in a cold or moderately heated state around the bolt or
rivet holes, or the places, where such holes are to be made, to a sufficient distance
to extend beyond the heads of the bolts or rivets.
3. A plate for the manufacture of boilers, ships or bridges, or for other like
purposes, compressed while in a cold or moderately heated state, around the bolt
or rivet-holes to a sufficient radial distance to cause said compressed portions to
overlap each other, or nearly so.
4. A plate for the manufacture of boilers ships or bridges, or for other like
purposes, compressed while in a cold or moderately heated state, immediately
around the parts where the rivet holes are made or to be made and to a less
degree around such compressed portion so as to arrest or prevent the radial or
outward flow of metal in the act of compressing the parts immediately around the
holes.
5. A plate or plates for the manufacture of boilers ships or bridges, or for like
purposes having punched or drilled holes and with the metal compressed in a cold
or moderately heated state around the bolt or rivet holes to a sufficient extent to
produce radial pressure against a punch, drill, bolt or rivet therein contained
substantially as set forth.
6. A boiler plate or plates connected by bolting or rivetting and subsequently
stretched so as to impart a permanent set and greater rigidity and strength to the
body:
7. The process substantially as herein described of strengthening plates for
boilers or other bolted or rivetted work consisting in condensing the metal by cold
compression, in or around the parts where bolt or rivet holes are made or to be
made so that the metal shall be more condensed in the punched portion than in the
main body of the plate.

page_text: 8. The process herein described of treating plates for boilers or other bolted or.
rivetted work to increase their strength,, which consists in cold compressing the
metal so as to condense it directly around the parts where bolt or rivet holes are
made or to be made and to a reduced extent around the said areas of maximum
compression and condensation so as to confine the metal which is subjected to such
maximum compression.
9. In the manufacture and treatment of wrought metal plates in the employment
of a punching or rivetting apparatus having means for cold compressing and con-
densing the metal directly around the rivets or rivet holes and to a less degree
around such areas of maximum compression or condensation.