IMPROVEMENTS IN WROUGHT METAL COLUMNS, BEAMS, GIRDERS AND OTHER MEMBERS DESIGNED TO BEAR COMPRESSION OR TRANSVERSE LOADS IN BRIDGES BUILDINGS AND OTHER STRUCTURES; AND IN THE MANUFACTURE AND TREATMENT OF THE SAME TO INCREASE THEIR RIGIDITY AND STRENGTH
Year: 1885

page_text: 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 COLUMNS, BEAMS, GIRDERS AND OTHER MEMBERS
DESIGNED TO BEAR COMPRESSION OR TRANSVERSE LOADS IN BRIDGES BUILDINGS AND
OTHER STRUCTURES; AND IN THE MANUFACTURE AND TREATMENT OF THE SAME TO
INCREASE THEIR RIGIDITY AND STRENGTH, to be as follows:-
=
The object of this invention is to so construct such members of bridges,
buildings and other structures as are required to sustain compression or transverse
loads that their rigidity and ultimate strength to resist such loads, will each bé
increased; and by reason of the increased rigidity and strength of such member or
members in resisting the distortion of a truss or other structure, of which they
form a part, the strength of such structure will be greatly increased.
To this end the invention consists, in part, in subjecting plates or bars of metal
which are to be used in the manufacture of columns girders or the like, to
compression between dies or rolls while the metal is cold or nearly so, so as to
permanently condense it, especially in those parts which will be subjected to the
greatest strain in service.
And the invention further consists in setting the column, girder, beam' or like
structure, by pressure applied in the direction in which its load will be sustained in
service, to such a degree and for a sufficient time to impart a permanent set to
such column, girder or the like, the said column, girder or the like being originally
made of such dimensions or form that it may be reduced, by very heavy pressure
(applied in the direction in which its load will be sustained in service) to the size
and shape which it is required to have in making up the truss or other structure
of which it is to form a part, so that after having been reduced to such size lëngth
or shape by pressure it will have greater strength to resist strains in the same
direction, which may be received in service.
In carrying out the invention as applied to the construction and treatment of
columns, braces or other compression members for bridges, buildings or other
structures the iron or steel plates of which such column or other compression
member is to be made up are subjected to pressure between dies or rolls preferably
the former, while the metal is cold or practically or nearly cold and to a sufficient
degree and for a sufficient length of time to permanently compress and condense

page_text: the metal. The working faces or surfaces of the dies or rolls are formed on one
or both sides of the areas by which the maximum condensing pressure is applied
with graduated pressure areas, so that the condensation of the metal will not
terminate abruptly and thus leave a defined line of fracture. The graduated
pressure surfaces have the further advantage of confining the metal which is
subjected to maximum pressure so as to prevent it from flowing or squeezing out,
which if permitted, would in a measure impair the condensing effect desired.
The column, brace or other compression member having been constructed in any
usual or suitable manner from parts treated as above set forth and of a length
sufficiently in excess of what it is to have in use, is subjected to very heavy
longitudinal pressure (or in the direction in which its load will be sustained in
service) to a sufficient degree in excess of its elastic limit and for a sufficient period
to impart a permanent set with a length in such column or other compression
member reduced to adapt it for its place in the truss, building or other structure
of which it is to form a part.
If the column, brace or other compression member of a truss, building or other
structure, be made in one piece of metal it is in like manner, while cold or nearly
so, subjected to heavy longitudinal pressure, sufficient to compress and condense it,
and set it to the required reduced length as already explained, and in each case,
while the column or other member is undergoing longitudinal compression, it is so
supported laterally (whenever its structure or proportions render this necessary) as
to prevent its deflection or distortion under the strain.
By the means above described the elastic limit of the column or other structure
will be raised and its rigidity and ultimate strength in resisting a load of
compression, or a crushing strain materially increased.
The same principles are applied to the construction and treatment of girders,
beams and like members which are to sustain transverse loads.
As in the case of the column, the wrought or rolled iron or steel of which a
beam or girder is to be made up, or the entire beam or girder if made in one piece
is subjected to compression while in a cold or practically or nearly cold state, the
areas of maximum pressure being flanked or surrounded by areas of gradually
reduced pressure to confine the metal, prevent it from flowing out under the heavy
pressure and cause its effective condensation.
The beam or girder is rolled or made up, as the case may be, with an upwardly
arched or curved shape from which it is forced down, by heavy pressure while in
a cold or practically or nearly cold state, to the normal shape it is to have in use,
so as to impart a permanent set of tension to the lower flange or part of the beam
or girder and a permanent set of tension to the upper flange or part thereof.
These being the strains to which the structure will be subjected when loaded it
is apparent that the elastic limit and rigidity and the ultimate strength of the
structure will be materially increased by the treatment explained.
"In the case of any member of a bridge, truss, building, or other structure to
which this invention is applied or in which it is carried into effect such member or
each of its parts receives a permanent set by tension, compression or bending, as
the case may be, so as to produce an initial strain and set in the same direction in
which the strain will be sustained in service.
By thus reducing the liability of trusses and other structures of which these
columns, beams or other members form parts, to become distorted in use, the
durability and strength of such structures are materially increased.
1007

page_text: 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 so construct such members of bridges, buildings
and other structures as are required to sustain compression or transverse loads, that
their rigidity and ultimate strength to resist such loads will each be increased; and
by reason of the increased rigidity and strength of such member or members in
resisting the distortion of a truss or other structure, of which they form a part, the
strength of such structure will be greatly increased.
To this end the invention consists, in part in subjecting plates or bars of metal
which are to be used in the manufacture of columns, girders or the like, to
compression between dies or rolls while the metal is cold or nearly so, so as to
permanently condense it, especially in those parts which will be subjected to the
greatest strain in service.
And the invention further consists in setting the column, girder, beam or like
structure, by pressure applied in the direction in which its load will be sustained
in service, to such a degree and for a sufficient time to impart a permanent set to
such column, girder or the like, the said column girder or the like, being originally
made of such dimensions or form that it may be reduced, by very heavy pressure
(applied in the direction in which its load will be sustained in service) to the size
and shape which it is required to have in a bridge or building or in making up the
truss or other structure of which it is to form a part, so that after having been
reduced to such size, length or shape by pressure it will have greater strength to
resist strains in the same direction, which may be received in service.
In carrying out the invention as applied to the construction and treatment
of columns, braces or other compression members for bridges, buildings or other
structures, the iron or steel plates of which such column or other compression
member is to be made up, are subjected to pressure between dies or rolls, prefer-
ably the former, while the metal is cold or practically or nearly cold and to
a sufficient degree and for a sufficient length of time to permanently compress and
condense the metal. The working faces or surfaces of the dies or rolls are formed
on one or both sides of the areas by which the maximum condensing pressure
is applied with graduated pressure areas, so that the condensation of the metal will
not terminate abruptly and thus leave a defined line of fracture.

page_text: The graduated pressure surfaces have the further advantage of confining the
metal which is subjected to maximum pressure so as to prevent it from flowing or
squezing out, which if permitted would in a measure impair the condensing effect
desired.
The column brace or other compression member having been constructed in any
usual or suitable manner from parts treated as above set forth and of a length
sufficiently in excess of what it is to have in use, is subjected to very heavy
pressure longitudinally or in the direction in which its load will be sustained
in service to a sufficient degree in excess of its elastic limit and for a sufficient
period to impart a permanent set with the length, elevation or form of such column
or other compression member reduced or changed to adapt it for its place in the
truss, building or other structure of which it is to form a part.
If the column brace or other compression member of a truss, building or other
structure, be made in one piece of metal, it is in like manner, while cold or nearly
so, subjected to sufficiently heavy and sustained pressure longitudinally or in the
direction of its intended load, to compress and condense it, and set it to the
required reduced length or modified form, as already explained, and in each case,
while the column or other member is undergoing longitudinal compression it is so
supported laterally (whenever its structure or proportions render this necessary) as
to prevent its deflection or distortion under the strain.
By the means above described the elastic limit of the column, brace or other
structure will be raised and its rigidity and ultimate strength in resisting a load of
compression, or a crushing strain materially increased.
The same principles are applied to the construction and treatment of girders,
beams and like members which are to sustain transverse loads.
As in the case of the column, the wrought or rolled iron or steel of which a beam
or girder is to be made up, or the entire beam or girder if made in one piece,
is subjected to compression while in a cold or practically or nearly cold state, the
areas of maximum pressure being flanked or surrounded by areas of gradually
reduced pressure to confine the metal, prevent it from flowing out under the heavy
pressure and cause its effective condensation.
The beam or girder is rolled or made up, as the case may be, with an upwardly
arched or curved shape from which it is forced down, by heavy pressure while in a
cold or practically or nearly cold state, to the normal shape it is to have in use, so
as to impart a permanent set of tension to the lower flange or part of the beam or
girder and a permanent set of compression to the upper flange or part thereof.
These being the strains to which the structure will be subjected when loaded, it is
apparent that the elastic limit and rigidity and the ultimate strength of the
structure will be materially increased by the treatment explained.
In the case of any member of a bridge, truss, building or other structure to
which this invention is applied or in which it is carried into effect such member or
each of its parts receives a permanent set by tension, compression or bending, as
the case may be, so as to produce an initial strain and set in the same direction in
which the strain or load will be sustained in service. By thus reducing the
liability of trusses and other structures of which these columns, braces, beams or
other members form parts, to become distorted in use, the durability and strength
of such structures are materially increased.
"
By the expression "cold" or practically or nearly cold," describing the
condition of the metal while under treatment according to this invention, it
is meant that the metal must not be so hot as to impart to it free ductility
or adapt it to flow readily under pressure, as in the ordinary rolling, swaging and
forging operations.
It is evident that this condition of rigidity, adapting the metal to be what
is termed "cold compressed" so as to be condensed and receive a permanent set
with strains differing from those which the metal acquired in cooling, may exist
before the temperature of the metal is reduced to that of the atmosphere; but it

page_text: should be practically "cold" as this term is commonly used with reference to
metal working.
In the accompanying drawings Figure 1 is a transverse sectional elevation of a
pair of dies adapted for compressing one member of a compound hollow column,
such column-member being shown in section. Figure 2 is a transverse section of a
column made up of four such members. Figure 3 is a plan view, on a smaller
scale, illustrating the application of endwise pressure to the column to impart to it
a permanent set with some reduction in length. Figure 4 is a transverse section of
a pair of dies adapted for applying cold compression to a beam or girder, and
of such beam or girder under compression. Figure 5 is an end view of the curved
or arched beam or girder prior to setting it down to the normal and straight
or more nearly straight form it is to have in use. Figure 6 is a side view of the
same, illustrating in dotted lines the set to be imparted to the beam. Figure VII
is a side elevation of the beam set down to the normal and straight or nearly
straight form which it is to have in use. Figure VIII is an elevation illustrating
one mode of setting or bending down the beam. In Figure 1-1 represents a
bed-die formed to correspond exactly with the shape of one face of the column-
member 4 which is placed thereon, and 5 an upper die formed with a face to
correspond exactly with the upper surface of the column member 4 and forced
down to apply pressure thereto by any adequate means such, for example as
hydraulic presses or rams. The pressure on the column member is sufficient in
degree to permanently condense the metal, and is maintained for a sufficient period
of time to permit the particles of metal to accommodate themselves to each other
in their closer relations. The column members having been in this manner com-
pressed, so as to permanently condense the metal of which they are composed, may
be assembled and secured together in the usual way by rivetting or bolting through
their flanges or margins. The entire column 6 is then compressed longitudinally.
This may be effected by means of the press shown in Figure 3 having one or more
wedge shaped followers 9, or other adequate means for sustaining the column
against flexure, either one or both of the clamping jaws 8, 8, being made adjustable
as preferred. One end of the column is sustained by an abutment 10 and a
plunger 11 is pressed against the other end by means of a hydraulic ram 12 with
sufficient force to compress the metal endwise of the column beyond the limit of
elasticity, imparting a permanent set. This pressure is maintained for a consider-
able period to permit the particles of metal to become seated in their new relations.
If preferred, the separate sections of the column may receive the required
endwise set by compression applied to them severally before assembling.
The same principle is applied to either solid or hollow columns made in one piece.
instead of compound, as herein before described, by pressing the entire column
transversely in sections between dies formed to fit its surface. In the case of a
hollow column, a supporting mandrel is applied to the interior, either the whole
length of the column or made adjustable therein, but in all cases extending to
a greater length than the external condensing dies. After the metal of the column
has been thus condensed by lateral pressure, longitudinal pressure is applied to the
columo, sufficient to give it a permanent set as before explained.
In all parts of the operation the condensing and setting pressure is applied to
the metal while in a cold or moderately heated state.
The lateral and longitudinal compression of the metal each imparts to it a
higher limit of elasticity and greater ultimate strength, and the longitudinal
compression of the column previous to use (either with or without previous con-
densation) imparts a higher limit of elasticity and greater ultimate strength to the
column.
In Figure 4 which illustrates a set of dies suitable for cold compressing an I-beam
or girder, 1 represents a bed die formed to fit one side or face of the beam or
girder 4, which is placed thereon and 2 a pair of side dies adjustable to and from
each other on the bed-die 1 and formed on their faces to fit the faces of the.beain
or girder, against which they are forced and firmly held and supported by wedge

page_text: shaped followers 3 or bydraulic rams or other adequate means which may be made,
simply to confine the metal or to compress and condense it. 5 is an upper die
formed to fit the other side of the beam or girder 4, and forced down to apply
pressure thereto by any adequate means such, for example, as one or more hydraulic
rams acting on a suitable follower 5ª.
The working faces of the top and bottom dies are straight in the central and
principal part where the maximum pressure is applied and recede slightly toward
the ends, so that for some distance on each side of the part under the maximum
pressure, the metal 1, will be subject to a smaller pressure insufficient to cause a
flow or attenuation of the metal, but sufficient to confine the metal and prevent
the outward flow of that which is under maximum pressure.
This condensing pressure may be from forty thousand pounds to one hundred
thousand pounds to the square inch, (more or less) depending on the nature of the
metal. The side dies are correspondingly formed when necessary.
In Figure 8-7, represents a hydraulic ram pressing the curved beam or girder
in sections for the purpose of forcing it from the arched form shown in Figure 6 to
the straight or nearly straight form shown in Figure 7. This may if preferred be
effected by the use of rolls or the entire beam may be pressed down at one
operation, by interposing between the ram or rams and the curved beam, a pattern
beam adapted by its shape to bear first on the center or most prominent part and
cover a more extended surface as the movement progresses and to gradually press
the said curved beam downward to a sufficient extent beyond its required shape
that it will, in springing back, permanently assume the shape it is to have in use.
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. The mode or process of increasing the strength and rigidity of a common
brace, or other compression member, which consists in compressing it longitudinally
while in a cold or moderately heated state with sufficient force and for a sufficient
time to reduce its length and impart a considerable permanent set to the material.
2. The mode or process of increasing the strength and rigidity of a column,
brace, or other compression member of a bridge or other structure, which consists
in compressing it longitudinally in a cold or moderately heated state, while stayed
against flexure with sufficient force and for a sufficient time to reduce its length
and impart a considerable permanent set to the material.
3. The improved mode or process of increasing the strength and rigidity of
columns, braces or other compression members of bridges or other structures, which
consist in condensing the metal by pressure while it is in a cold or moderately
heated state, and subsequently compressing the column longitudinally with
sufficient force and for a sufficient period of time to impart a considerable perma-
ment set, reducing its length without flexure.
4. The improvement in the mode or process of manufacturing compound columns,
braces, or other compression members of bridges and other structures, which
consists in compressing the separate parts or members thereof while in a cold or
noderately heated state, so as to condense the metal, assembling and connecting
the parts in any customary or suitable manner, and subjecting the whole to a
longitudinal strain, permanently compressing the structure in the direction of its
length.
5. The improved mode or process for increasing the rigidity and strength of a
beam or girder designed to bear a transverse load, or a column, brace or other
compression member of a truss, building or other structure, which consists in com-
pressing the material between dies having receding faces, as described, while in a
cold or moderately heated state, so as to permanently condense the same.
6. The improved mode or process for increasing the rigidity and strength of a
beam or girder designed to bear a transverse load, which consists in bending it
downward while in a cold or moderately heated state to the shape it is to have in
$

page_text: use, and thereby putting a permanent set of tension, and a permanent set of
compression on the upper part, which will be subjected to compression when the
beam or girder is loaded.
7. The improved mode or process for increasing the strength and rigidity of a
beam or girder which is to bear a transverse load, the same consisting in
compressing the material while in a cold or moderately heated state, so as to
permanently condense the same, and bending the structure downward to the
shape it is to bear when loaded, so as to apply a permanent set of tension to the
lower part and a permanent set of compression to the upper part, as explained.
8. The improved mode or process for increasing the strength of a beam or girder
which is to bear a transverse load, which consists in forging or bending the same
while in a heated state, or constructing it, if compound, with a permanent upward
curvature, and subsequently, while cold or in a moderately heated state, bending
it downward, so as to apply a permanent set of tension to the lower part and a
permanent set of compression to the upper part substantially as and for the
purposes set forth.
9. The mode or process of increasing the rigidity and strength of a column, brace,
beam, girder or other member designed to sustain a strain of compression or a
transverse load in a truss, building or other structure or in which the intended
load in service will subject the metal or some part thereof to a strain of compression,
said process consisting in imparting a considerable permanent.set to the metal of
which said member is composed, by pressure applied to said member in the
direction of the load which it is intended to sustain in service.
10. The improvement herein described in the manufacture and treatment of
columns, braces, beams, girders, and other members of trusses, buildings or other
structures in which the metal or portions thereof will be subject to strains of
compression in service, which consists in condensing the metal by cold compression
and imparting a permanent set to it by pressure applied to the member in the
same direction as the intended load which it is to sustain in service.
11. A column, brace, beam, girder or similar member of a truss, building or
other structure, having a permanent set by pressure applied before placing it in
the structure of which it is to form a part and in the direction in which its load
will be sustained in service.