Method or Process of Electric Riveting.
Year: 1892

page_text: Date of Application, 5th Feb., 1892-Accepted, 5th Mar., 1892
COMPLETE SPECIFICATION.
Method or Process of Electric Riveting.
I, ELIAS ELKAN RIES, of 430 South Broadway, in the City of Baltimore
and State of Maryland, one of the United States of America, Electrician, 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:-
My invention has reference to a novel process of riveting in which the rivets are
ordinarily inserted into the holes in a cold state, and then heated to incandescence
by the passage of an electric current through the same, and are maintained in that
incandescent condition during the operation of heading, whereby the riveting
process is greatly facilitated and is accomplished with greater perfection than by
the processes heretofore employed for this purpose.
In the Specification forming part of my previous British Letters Patent,
No. 8,148 of 1891, I have shown and described certain improvements in methods
of and apparatus for electric riveting, as more particularly set forth in my United
States Patent No. 452,042 of similar date (May 12, 1891). My present Specifi-
cation however, relates to the broad art or process of electric riveting first invented
and put into practice by me, and is based upon my broad United States Patent
No. 465,089, granted to me by the Hon. Commissioner of Patents (upon my
application filed Sept. 15, 1888,) on December 15, 1891, after prolonged inter-
ference proceedings in which priority of invention was decided in my favor.
It is common to heat rivets to incandescence before inserting the same into the
hole of the plate or plates, more especially when these rivets are large, as in the
manufacture of steam-boilers and other like heavy structures; but by reason of
the contact of those heated rivets with the cold boiler or other plates they cool
down very rapidly, and the heading of the rivet is practically performed and more
especially finished after the latter has cooled down to very nearly the normal
temperature. This is due not only to the rapid cooling of the rivet when the same
is in place in the hole of the cold plate, but also to the cooling of the rivet during
the transfer from the furnace where it has been heated and during the insertion
into the hole. Such transfer and insertion occupies more or less time, according to
the distance of the furnace from the work and according to the position of the hole
in the article under process. It frequently happens that the rivet-bolt, after the
same has been heated to the desired degree of incandescence in the furnace, has to
be grasped between the cold jaws of blacksmith's tongs, has to be carried some
considerable distance to the work under process, passed from hand to hand unto
the interior of the boiler or other structure, and then by a series of awkward,
uncertain, and time-consuming manipulations it has to be inserted into the hole and
a cold anvil placed against the head. Thus it happens that the facility of heading
which is expected from the heating of the rivet becomes illusive, and, as before
stated, the heading is practically done when the rivet has almost attained its normal
temperature. By my improved process all this is avoided. The rivet is inserted
into the hole while in a cold state with deliberation and comfort. It is then heated
to any desired degree of incandescence and is maintained in that state of incan-
descence or at any other desired state of incandescence during the whole process
of heading so that the operation is performed upon the rivet while it is as soft as it
can be made by heating.
This process may be practised by means of a great variety of apparatus, and
while. I have shown one apparatus which is quite effective for the purpose of my
invention it will be evident to those skilled in the art that other apparatus entirely
different in form and construction may be employed. I am therefore not limited to

page_text: any particular means in the practice of my invention which is in the nature of an
electro-mechanical process, pure and simple.
In the accompanying drawings, which form a part of this Specification, I have
illustrated in Figure 1 an elevation of one form of apparatus by means of which my
improved process may be practised, in Fig. 2 a detail view, upon a large scale, of
the riveting-dies and the insulation of one of these dies, and in Fig. 3, a view of the
dies when used for heating alone.
Like numerals of reference indicate like parts in the two figures of the drawings.
The frame 1 of the riveting-machine has three parallel projecting brackets 2, 3, 4,
the lowest one 2 supporting the anvil 5, the middle bracket 3 serving as a guide
for the reciprocating die 6, and the upper bracket 4 having one of the links of a
toggle 7 pivoted to it. The other link of this toggle is pivoted to the reciprocating
die 6, and the toggle is actuated by a piston-rod 8 of a piston working in the
cylinder 11, to which steam or compressed air is supplied by the pipe 12. The
admission of steam to the cylinder is controlled and regulated by the valve 13,
actuated by the valve-rod 14, having a suitable handle 15 within convenient reach
of the operator.
The riveting-machine so far as described is of ordinary construction, and its
operation is well understood by those skilled in the art. The valve 13 is of a kind
commonly used in such machines, which when turned to one position admits steam
behind the piston, which then actuates the toggle to raise the die 6, and when
turned to another position admits steam in front of this piston, which then actuates
the toggle to depress the die 6.
For the purpose of my invention the anvil 5 is preferably, although not
necessarily, formed with a massive head, as shown in Fig. 2, and with a shank 16,
which passes through the bracket 2. This shank is screw-threaded at its lower end
and the anvil is clamped to the bracket by a nut formed in the binding-post 17,
which is screwed upon the projecting end of the shank 16. The whole anvil is
insulated from the frame of the machine by an insulating brush 18 of suitable
material, as shown in Fig. 2. The upper part of the anvil is preferably formed
into a truncated cone 19, and in the upper face is formed a cavity, as shown, for
the reception of one end of the rivet 20, which, when placed in position, may or
may not have a head formed at this end.
The construction of the anvil so far described is by no means essential, since the
same may be replaced by any ordinary anvil of any desired size, so long as it has
one or more rivet-receiving cavities formed on its upper face; but if such ordinary
anvil be used it will be understood that the same must be insulated-as, for instance,
by placing it upon a block of wood, like any other stationary anvil-and it will be
provided with suitable means for connection with an electrical conductor 23.
The die 6, as shown, is a cylindrical body with a frusto-conical lower end 21,
provided on its lower face with a cavity to receive the free end of the rivet. This
cavity is preferably conical, but may be of any other shape to correspond to the
desired form of rivet-head. The body of the die is formed into a binding-post
having the clamp-screw 22, and this binding-post receives a conductor 24, as shown.
The two conductors 23, 24 lead to the terminals of a suitable generator, which
furnishes a current of great quantity and low tension. It will now be understood
that the current coming from the generator will pass by the conductor 24 through
die and rivet, and then through the anvil back to the generator. The rivet offers
a resistance to the passage of the current, and becomes heated thereby, according
to the current employed, to any degree of incandescence, and this heating may be
continued so long as the heading die remains in contact with the rivet, so that the
latter may be maintained in a soft plastic condition until the riveting process is
completed and the heading-die removed; but before the heading die is removed
and when the heading of the rivet is nearly completed it will be found advisable to
turn the current off gradually, so that the riveting process is practically completed
when the rivet has lost all incandescence. This practice, however, may be changed,
according to the nature of the joint which it is intended to produce.

page_text: Any suitable source of electric current, including the direct low-tension current
of a dynamo or of a secondary battery, may be used; but by preference I use the
alternating currents of low tension and great quantity furnished by the thick-wire
secondary coil 25 of a transformer 26, the fine-wire primary coil 27 of which is
charged by alternating currents of high tension and small quantity by the
circuit 28, 28, derived from the main circuit 29, 29, which in turn is charged by an
alternating current dynamo 30.
The conductor 23 includes a switch-lever 31, which may be moved by hand to
make contact with any one of a series of contact-plates 32, connected, respectively,
to different points of the secondary coil, and it will now be understood that all or a
part of the secondary coil may be placed in circuit with the conductors 23, 24,
leading to the anvil and heading-die, and thus the current regulated or entirely cut
off, as desired. The switch device 31, 32, may be located in the primary coil 27
or in one of the branches 28 leading thereto, or in place of regulating the current
by the switch this may be done by moving the core 26' of the transformer within
the coils, or I may use any other means of controlling the current.
The whole process will now be readily understood. A rivet is placed with its
head (if there is a head) or with the head end upon the anvil in the cavity provided
for this purpose, and the plates 33, 34, to be joined to the rivet, are placed with
the rivet-holes over the shank of the rivet, one above the other. The operator
now manipulates the valve-rod 14 to open the valve 13 (more or less) to admit
steam to the cylinder in front of the piston to actuate the toggle and depress the
die until in contact with the rivet. The switch-lever is then operated to close the
circuit and is moved until sufficient current is obtained to bring the rivet to
the desired state of incandescence. More steam is then admitted to the cylinder
behind the piston, and the heading-die is forcibly moved downward upon the pro-
jecting end of the rivet-shank and the latter headed by a single stroke, or if it
should be found necessary this operation may be repeated a number of times upon
the same rivet. During all this time the operator can regulate the incandescence
of the rivet to a nicety by suitable manipulation of the switch-lever or of the
movable core of the transformer. According to the nature of the work the current
may be cut off suddenly after the rivet has been raised to the desired degree of
incandescence and the heading of the rivet then proceeded with and completed, or
the current may be cut off gradually while the heading is progressing, so that it is
completed after the rivet has lost all incandescence.
It is not at all necessary that my process be practised by means of the highly-
organized machine shown in Fig. 1, since quite simple devices in the nature of
hand-tools will be sufficient for this purpose.
Thus the element of construction
marked in Fig. 2 with the numeral 2 need not be a bracket forming part of the
frame of a riveting machine, but may be any suitable support for the anvil 5, or
the latter may be used without a specially constructed support. It may be held by
an assistant against the head of the rivet after the latter has been inserted into the
rivet-hole. Similarly the heading-die need not be actuated by a toggle which in
turn is actuated by steam or compressed air or other machine-power, for it may be
used like an ordinary blacksmith's heading-die, as a hand-tool, which is grasped by
one hand and placed with the die-cavity over the end of the rivet-shank while the
upper end of the die is struck with a hammer, as is well understood by those skilled
in the art. In this case, however, the conductors 23, 24, must be quite flexible, as
it will be readily understood; but owing to the very low tension of the currents
which are employed in this process neither the anvil nor the heading-die need to
be insulated with special care. The most primitive insulating means will be
sufficient.
In case of heavy work it is not absolutely necessary that the rivets should be
inserted when in a cold state; but it may first be heated in the ordinary manner
in the furnace, then inserted into the rivet hole, and the heat lost by radiation
or conduction may then be supplied electrically in the manner hereinbefore
described.

page_text: It will be apparent that my invention may also be used to advantage for the
purpose of electrically heating rivets or rivet-blanks preparatory to their insertion
into the holes in which they are to be headed. When this is done the rivet blank
is heated as already described between dies 5 and 6, Fig. 3, which in this case need
not form part of the heading or riveting apparatus proper, but constitute the
terminals of an electric heating circuit. For certain classes of work this process
possesses advantages in that no special insulation of working parts is required and
as the heat is entirely localized in the rivet it is found to be more economical and
more uniform, rapid and convenient than the old time methods of heating the rivet
blanks in a forge or furnace. As before stated, the heat lost by conduction may be
supplied to the rivet during the heading process, but as the original degree of
plasticity imparted to the rivet blank can be so perfectly controlled during the
electric heating operation, this will not ordinarily be required.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is
1. The method or process of riveting which consists in heating the rivet or rivet-
blank electrically by the passage of an electric heating current therethrough, and
then heading the rivet, substantially as described.
2. The method or process of riveting, which consists in subjecting the rivet or
rivet-blank to the heating effect of an electric current or currents, until it has
reached the desired degree of plasticity, and then heading the rivet by subjecting
it to end wise pressure, substantially as described.
3. The method or process of riveting, which consists in heating the rivet or rivet-
blank electrically while subjected to end wise pressure, and then heading either or
both ends of the same, substantially as described.
4. The method or process of riveting which consists in heating the rivet when
inserted in the rivet hole or holes by the passage of an electric current through the
same and then heading the rivet, substantially as described.
5. The method or process of riveting which consists in first inserting the rivet
into the rivet hole or holes, then heating the rivet by the passage through the
same of an electric current of comparatively great quantity and low tension, and
then heading the rivet, substantially as described.
6. The method or process of riveting which consists in heating the rivet when
inserted in the rivet hole or holes to the required degree of incandescence by the
passage through the same of an electric current of suitable quantity and tension,
then heading the rivet and maintaining the same in the desired state of incandescence
by suitably regulating the current during the heading operation, substantially as
described.
7. The method or process of riveting which consists in first inserting the rivet
into the rivet hole or holes, then passing an electric current of comparatively great
quantity and low tension through the rivet until the latter is heated to the desired
degree of incandescence, then heading the rivet and at the same time maintaining
the incandescence of the same by the continued flow of current, and finally
gradually reducing and cutting off the current while the heading is completed,
substantially as described.
8. The method or process of riveting metal structures together, which consists in
first inserting a rivet into the rivet-hole, then making electrical contact between
the ends of the rivet and an anvil and the heading-die, respectively, which constitute
the terminals of an electric circuit, then charging said circuit with an electric
current or currents, until the rivet is heated to the desired degree of incandescence,
and then forcing the heading-die upon the rivet until the heading operation is
completed, substantially as described.
9. The method or process of riveting which consists in heating the rivet
preparatory to subjecting the same to the action of suitable heading mechanism
and in maintaining the same in the desired state of incandescence during the

page_text: operation of heading by the passage therethrough of an electric current having the
requisite heating effect, substantially as described.
10. The herein-described improved method of riveting, consisting in heating
the rivet or rivet-blank electrically while in place and then heading either or both
5 ends of the same.
In testimony whereof I have signed my name to this Specification in the
presence of two subscribing witnesses, this 7th day of January 1892.
Witnesses:
LEOPOLD RIES.
HERMAN RIES.
ELIAS ELKAN RIES.