Improvements in Rivetting and Apparatus therefor.
Year: 1891

page_text: Date of Application, 12th May, 1891-Accepted, 1st Aug., 1891
COMPLETE SPECIFICATION.
Improvements in Rivetting and Apparatus therefor.
A communication from ELIAS ELKAN RIES, of 430, South Broadway, Baltimore,
State of Maryland, United States of America, Electrician.
I, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
M.I.M.E., 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 :-
This invention has reference to improvements in rivetting apparatus designed for
practising the process of rivetting in which the rivets are inserted into the holes in
a cold state, are 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 upsetting or heading the rivet.
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 like heavy structures; but by reason of the
contact of those heated rivets witli 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 occupy 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 blacksmiths' tongs, has to be carried some
considerable distance to the work under process, passed from hand to hand into the
interior of a 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 the electrical process of rivetting 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.
The apparatus for practising this process may assume a great variety of forms
and while I have shown in the drawings forming part of this Specification, certain
organized machines embodying the invention, my correspondent is in no manner
confined to the identical construction shown. All this will more fully appear from
the following detail description with reference to the accompanying drawings
in which
Fig. 1 is a side elevation of one form of rivetting machine embodying the
invention in which a generator or inductional transformer forms an integral part of
the frame of the machine.
Fig. 1B is a side elevation of another form of rivetting machine embodying
features of this invention.
Fig. 2 is a side elevation with parts in section of still another form of rivetting

page_text: machine embodying features of the invention and designed more especially for
large work.
Fig. 3 is a front view of the anvil and its supporting bracket shown in Fig. 1A.
Fig. 4 is an enlarged front view partly in section of the anvil and heading die
with adjacent parts shown in Fig. 1B and
Fig. 5 is a section on the line - of the heading die shown in Fig. 4.
Like numerals of reference indicate like parts all throughout the drawings.
Referring more particularly to Fig. 14 there is shown a heavy bar 1 of copper
or other good conductor of electricity, bent to a circular shape as indicated by
dotted lines, with the free ends turned outward and parallel forming two brackets 2, 3
one above the other, to support a rivetting mechanism composed of an anvil and
heading-die hereinafter referred to.
The bar 1 constitutes the secondary conductor of an inductional transformer the
primary coil 4 of which is composed of fine wire which is placed parallel with and
against the bar 1. The primary coil is bent into a loop between the two
brackets 2, 3, as shown so as to leave additional room for the work which latter is
shown in the form of two plates 56, to be rivetted together. A shell or shield 7
of magnetic material and composed of two similar castings (one only being shown)
which are provided on the inner and outer edges with flanges 7 through which
pass bolts 8 for securing the two castings together, encloses the circular portion of
both the primary and secondary of the transformer, and serves to concentrate the
magnetic lines of force within the transformer and thereby increases its efficiency.
The shell sections are provided with cars 9 projecting from the outer flanges 71 for
attaching the transformer to a suitable frame or for supporting it in any desired
position.
If found desirable the rigidity of the transformer may be increased by a tie-
od 10 indicated in dotted lines. The bracket 2 supports a heading die or tool 11
which in this instance consists of a bolt with a threaded shank extending through
a suitable nut in the said bracket and a hand-wheel 12 or other suitable device
whereby the bolt may be turned and thus elevated or depressed. The lower end of
the die is frusto-conical in shape, as shown at 13, and has a cavity of suitable shape
formed in its face to receive and mould the free end of the rivet-shank. The bracket 3
carries an anvil which as shown in Figs. 14 and 3 consists of a block or body 14
having an expanded upper end or head 15 with a broad flat face in which is a cavity
to receive or mould the head on one end of the rivet, and on the said face is a
layer 17 of insulating material, not however extending into the cavity provided
for the reception of the rivet-blank head. This facing may be made of asbestos
cloth, soap-stone, obsidian, agate, mica, or other insulating and refractory substance.
Extending through a nut in the bracket 3 is a screw-threaded rod 16 with its
upper end engaging the under side of the body 14 of the anvil and supporting the
latter. The rod 16 is turned by means of a hand-wheel 17 on its lower end, to
elevate or lower the anvil. On the body 14 of the anvil are depending side
wings 15 straddling the bracket 3 to prevent the said body from turning when
moved by the rod 16.
It will be understood however that other forms of die and anvil and means for
adjusting and actuating them such for instance as shown and hereinafter described
in connection with the other figures of the drawing may be used.
Depending from the bracket 2 are fixed legs 16 at the sides of the heading-die
and provided at their lower ends with insulating material 17' of the kind described
with reference to the facing 17. If now the plates to be rivetted together be
placed on the head 15 of the anvil with the shank of a rivet-blank in the rivet holes
in the plates and its head in the cavity in the anvil then the anvil may be elevated
by manipulating the screw-rod 16 until the said plates are clamped between the
expanded head 15 of said anvil and the legs 16' depending from the bracket 2.
The fine wire primary coil 4 receives alternating high tension electric currents
by wires 18 18 from a suitable source such as a dynamo, connecting with con-
ductors 19 19. One wire 18 includes a suitable current regulator within easy

page_text: reach; and as shown this regulator is a reaction rheostat composed of a series of
resistance coils 20 a series of contact plates 21 to which the terminals of the coils
are connected, a soft iron core 22, within the coils, and a switch-lever 23 arranged
to make contact with the plates 21 and with an idle contact plate 24.
The wire 18
is connected to the switch lever and a continuation 18' of said wire leading to the
coil 4 is connected to the end plate of the series of contact plates 21.
The operation of rivetting with a machine constructed as shown in Fig. 1ª will
now be understood.
A rivet 25 is placed with its head or if there be no head, with one end of its
shank, in the cavity in the face of the anvil, and the shank itself engaging the rivet
holes in the plates 5, 6. The operator then manipulates the rod 16 to elevate the
anvil together with the plates and rivet thereon, until the said plates are clamped
against the lower ends of the legs 16 and held firmly thereto during the entire
operation of rivetting. The heading die is then screwed downwards until in contact
with the upper or free end of the rivet shank and the switch-lever of the current-
regulator is turned from the idle contact plate onto the other plates, and from one
to the other of the latter until the requisite current is passed through the rivet to
bring it to the desired degree of incandescence after which the heading-die is further
depressed to upset the softened end of the rivet shank and form a head thereon which
is moulded by the cavity in said die.
The current may be maintained throughout the rivetting operation or it may be
regulated as desired, or be turned off at any time during the operation of rivetting,
as the character of the work may require.
In the machine thus far described the framework constitutes the proximate source
of the heating current, being in fact an inductional transformer the induced or
secondary circuit of which is composed of a single heavy bar of copper or other good
conductor of heat and electricity. The machine may thus be transported and set up
at any place without in any way or manner disturbing its electrical connections
except that the two feeding conductors 18 18 must be disconnected from and then
again connected with the main charging circuit 19 19.
In addition to this advantage there is the further advantage of utilizing the
material unavoidably used for the framework of the machine for the important
purpose of transforming the currents of high tension furnished by the primary
source, such as a dynamo into currents of the requisite low tension.
After the rivetting operation has been repeated a number of times the heading-die
and anvil become heated partially from the passage of the heating current through
their contiguous ends and partially from contact with the incandescent rivets. The
heating of the die and anvil is very objectionable and renders the operation of
rivetting inconvenient and uncomfortable; and to overcome this objectionable
feature a cooling medium is applied to the said die or anvil or to both of them in
any suitable manner. In Fig. 14 there is shown a pipe 26 leading from a source of
cold air supply (not shown) and provided with a nozzle 27 constructed to direct an
air-jet against the lower end of the heading-die, and there is also shown another
pipe 26 leading from the same source of air-supply and provided with a nozzle 27'
for directing an air-jet against the upper end or head of the anvil. It will be under-
stood that I am in no manner confined to the use of air-jets for cooling the heading-
die or anvil; and in lieu thereof such means may be used as are hereinafter described
in relation to other forms of rivetting machines or any other means may be used for
the purpose since this invention in this particular is designed to prevent undue
heating of the heading-die or anvil.
Referring now more particularly to Fig. 1B together with Figs. 4 and 5 of the
drawings there is shown a casting 28 provided with projecting arms or brackets 2, 3
and 29 one above the other. The arm 3 carries an anvil 14 similar to the anvil
shown and described in relation to Fig. 1A, that is it has an expanded head 15
with an insulating facing 17 and a cavity for receiving a rivet head, depending
side wings 15 straddling the bracket 3 and an adjusting screw-rod 16 with its
hand-wheel 17 for raising and lowering the anvil. In the present instance how-

page_text: ever the anvil is insulated from its support by a bushing 30 of insulating material
seated in the bracket 3 and through a nut in said bushing the screw-rod 16 extends,
and the inner faces of the wings 15' are covered with insulating material as indicated
by heavy lines.
The anvil is provided below the head 15 with a perforation for the reception of
the end of a conductor 31 and a set screw 32 entering said perforation serves to
bind the conductor firmly in the said perforation in the anvil.
As stated before with reference to Fig. 14 any suitable means may be employed
to cool the anvil during the operation of rivetting and in the apparatus shown in
Fig. 1 the anvil is provided for this purpose with two perforations 30¹ connected
together at one end by a coupling pipe 31' and at the other end connected respectively
to an inlet pipe 32' and an outlet pipe 33¹.
A cooling agent such as water or ammonia coming from a reservoir not shown
is made to flow through the pipe 32 from whence it will pass through one of the
perforations 30 and by means of the coupling 31 to the other perforation 30¹
from which it will escape through the pipe 331; the cooling agent will absorb heat
from the anvil and will maintain the latter at a moderate temperature during the
operation of rivetting.
The arm or bracket 2 serves as a guide for a reciprocating heading-die 33
reduced at its lower end to a frusto-conical form and there provided with a cavity
for moulding a rivet-head similar in this respect to the heading-die 11 shown in
Fig. 1A and at the upper end the heading-die is attached to one link of a
toggle 34 the other link of which is pivoted to the arm or bracket 29 of the
casting 28. The toggle is connected for operation with a piston-rod 35 driven by
a suitable piston within a cylinder 36 formed in the casting 28.
Steam or compressed air is admitted to the cylinder through a pipe 37
having a valve 38 of the familiar globe type and provided with a hand-wheel 39.
In the pipe 37 between the cylinder and the valve 38 is another valve 40
constructed to admit steam in front of or behind the piston when actuated by a
valve-ro 41.
Depending from and secured to the bracket 2 by bolts or screws 42 is a
jacket 43 surrounding and enclosing a portion of the heading-die and having a
perforation in the bottom through which the die passes and at which point the
jacket is provided with a gasket 44 to form a fluid-tight connection between the said
jacket and die at the perforation.
A cooling agent such as water or ammonia is introduced into the jacket by means
of a supply pipe 45 coming from a reservoir or pump (not shown) and entering the
jacket near the bottom and after circulating around the portion of the die enclosed
by the jacket the fluid escapes through a pipe 46 from which it is returned to the
said reservoir or pump and is allowed to waste.
It will be readily understood that the cooling agent constantly flowing
through the jacket will absorb the heat generated in the die during the operation of
rivetting and the die will thereby be maintained at substantially the normal
temperature.
Air-jets, hereinbefore described in the machine shown in Fig. 1B, may with
advantage be used in place of the liquid-circulating devices or any other suitable
means may be used for the purpose.
Near the lower end of the heading-dic is a perforation for the end of a
conductor 47 which is held therein by a set-screw 48. Embracing the lower end
of the heading-die are two laterally curved legs 49 having their lower edges coated
with insulating material 50. These legs do not entirely encircle the die there being
a space between their opposing edges for the passage of the conductor 47 as
clearly shown in Fig. 5, and the said legs extend downward from the bottom of the
jacket 43 being either integral therewith as shown or attached thereto in any
suitable manner.
The casting 28 together with the anvil and die carried thereby is secured on
the top of a suitable table 51 one of the end supports or legs 52 of which is shown.

page_text: Supported between the legs of the table is an inductional transformer 53 from the
thick wire secondary coil of which extends the conductors 31 and 47, and the
fine wire primary coil of the transformer receives the current from the derived
circuit wires 54 54 leading from the main dynamo circuit 19 or in any other suitable
manner.
One of the wires 54 includes a current regulator which may be identical with
that shown in Fig. 14 and is supported by a plate 55 depending from the end
of the table 51. On the face of this plate is mounted the switch-lever 23 and the
series of contact plates 21 which latter are connected with resistance coils mounted
on the inner face of the plate 55 and hidden from view thereby. The regulator is
provided with an idle contact-plate 24, and the lever 23 and contact-plates 21 are in
circuit with one of the feeding-wires 54 and its continuation 54' leading to the
transformer respectively.
Binding-posts 56 on the leg 52 and plate 55 and forming the terminals of the
regulator and one of the terminals of the transformer are provided for convenience
in attaching the feeding wires. Below the transformner and within convenient reach
is a pedal 57 pivoted at one end between the legs 52 of the table 51 in any suitable
manner (not shown) and at the other or free end provided with a step 58. This
pedal is connected to the valve-rod 41 controlling the valve 40 and is held
normally elevated by a spring 59 attached to some fixed portion of the frame of the
machine.
When the treadle is elevated the valve 40 is in a position to admit steam
in front of the piston in which case the toggle will be actuated to elevate the
heading-die, and when the treadle is depressed the valve 40 is moved to admit
steam behind the piston, in which case the toggle will be actuated to depress the
heading-die.
The operation of the machine shown in Fig. 1B will now be understood.
.
The plates 5, 6 to be rivetted together with the rivet-blank in position are placed
on the anvil and elevated with the same by turning the hand-wheel 17 until
clamped against the lower insulated ends of the legs 49 in the same manner herein-
before described with reference to the operation of the machine shown in Fig. 1 of
the drawing.
The treadle is now slightly depressed and moves the valve 40 in a direction to
admit sufficient steam or compressed air behind the piston to actuate the toggle and
depress the heading-die until in contact with the free end of the rivet blank.
The circuit now being completed through the secondary coil of the transformer
conductors 31 and 47 the anvil heading-die and rivet-blank the circuit through the
primary coil of the said transformer being preferably maintained closed a heating
current of electricity is passed through the rivet-blank in the manner hereinbefore
described.
When the rivet-blank has been raised to the desired temperature or degree of
incandescence the treadle 57 is further depressed to admit more steam behind the
piston so as to forcibly move the heading-die down upon the softened rivet-blank
and upset the latter the cavity in the die moulding a head on the end of said blank
while at the same time the shank of the rivet is upset to completely fill the rivet-
holes in the plates 5 and 6; the entire operation being usually completed by one
stroke of the die.
If the heading of the rivet is not completed by such operation the die may be
raised and again forcibly depressed by a suitable manipulation of the treadle and
repeated if necessary until the heading of the rivet is satisfactorily accomplished.
During the operation the current may be regulated as hereinbefore stated or the
current may be discontinued by moving the switch lever to the dead contact or in
any other desirable manner.
As stated above the circuit through the primary is preferably maintained.always
closed through the coils of the regulator; current begins to flow through the rivet
the moment contact is completed with the dies and the secondary current is then
increased by moving the switch lever to cut out the regulator coils thus reducing

page_text: .
the counter electro-motive force generated thereby and permitting more current to
flow through the primary coil which of course, increases the current in the
secondary.
The regulating switch may also be set to a certain point for given sized rivets
and the entire heating operation be left to itself. As the ends of the rivet make
better contact with the dies as they assume the proper shape the resistance is
gradually diminished and the current automatically increased.
Referring now more particularly to Fig. 2 of the drawings there is shown a
rivetting machine adapted for heavy work such as rivetting steam-boiler plates and
the like. There is a heavy U-shaped frame 60 with legs 61 62 normally extending
in a horizontal position and this frame is suspended by chains 63 secured to the
upper leg 61 and passing around pulleys 64 mounted in a truck frame 65 from
whence the chains are returned to winding-drums or windlasses 66 journalled
between standards 67 rising from the said upper leg 61 of the frame 60. Each
drum is rotated by means of a crank 68 of one of the ends of the drum-shaft 69 and
is held against a reverse movement by a ratchet-wheel 70 on the said drum-shaft
and a pawl 71 on the adjacent standard 67.
The truck-frame 65 has the pulleys 64 mounted on its under side near the ends
and directly above said pulleys on the upper side of the frame are mounted truck-
wheels 72 constructed to move on a rail or rails 73.
Chains 74 are attached to the ends of the truck-frame 65 and extend to some
convenient point where power may be applied to move the truck frame together
with the frame 60 along the track in either direction to the desired position.
It will be understood that the drums 66 may be manipulated to raise or lower
the frame 60 or incline it to any desired angle within the vertical plane marked by
the chains 63 and by the two legs of the frame 60.
To the free end of the lower leg 62 is secured a bracket 75 carrying a cylinder 76
in which is a piston 77 fitted for reciprocation therein. The piston is actuated by
steam or compressed air admitted through a pipe 78 into a valve chamber 79 from
whence it is directed above or below the piston by a slide valve 80 controlled by a
valve rod 81 which may be manipulated by hand or otherwise. The cylinder
together with the piston and means for admitting steam to the cylinder being of
common and well-known construction no further description thereof is necessary.
The anvil 14 in this machine is cylindrical in form and constitutes the piston rod
entering the cylinder 76 through a stuffing-box 82 and at its lower end being
reduced and passed through the piston and clamped thereto by a nut 83 which
latter is screwed onto the lower end of the anvil stem which is screw-threaded as
shown for the purpose. The anvil is insulated from the frame 60 by a bushing 84
of insulating material interposed between the reduced end of the anvil and the
piston through which it passes and by another bushing 85 of insulating material
which may also serve as packing surrounding the anvil stem where it passes through
the stuffing-box.
The upper end of the anvil has formed on it an expanded head 151 having a
facing 17 of insulating material and a cavity for the head or end of a rivet-blank
similar to and for the same purpose as hereinbefore described with reference to
the anvils shown in Figs. 14 and 1.
Below the head 15¹ the anvil is provided with a perforation for the reception of
the end of a conductor 86 leading from a source of electricity capable of producing
a low tension current of great quantity and which may be a transformer similar to
either of those shown in Figs. 14 and 1B or of any other suitable form or a suitable
dynamo or secondary battery. The conductor is clamped to the anvil by a set
screw 87 entering the aforesaid perforation in the anvil.
To the free end of the upper legs 61 of the frame 60 is secured a bracket 88
having an upwardly and a downwardly projecting arm 89 and 90 respectively.
The arm 89 of the bracket 88 carries a steam cylinder 91 constructed to cause the
automatic reciprocation of a steam hammer 92 forming the piston and piston rod
when steam or compressed air is admitted to the cylinder 91 through a pipe 93.

page_text: It is not necessary to describe in detail the construction of the steam hammer
since the same forms no necessary part of this invention; for the purposes of which
it is of no consequence how this steam hammer is constructed so long as it is
reciprocated under the action of the steam or compressed air admitted by the
pipe 78. I have therefore shown in the drawing a steam hammer of ordinary
construction which may be changed in various ways without affecting the
principle of operation which forms the basis of this invention.
The steam hammer cylinder 91 is provided with a neck 94 through which extends
the rod 95 forming a part of the hammer and the free end of which.constitutes the
hammer-head.
The arm 90 of the bracket 88 is provided with a horizontal extension 96 having
a vertical passage for a heading-dic 97 the latter consisting of a cylindrical body
reduced at the lower end to a frusto-conical shape and there provided with a head-
moulding cavity indicated by dotted lines and at the upper end above the
extension 96, the said die is provided with a buffer 98 of raw hide or other noise-
deadening material in line with the head of the hammer 92.
I
Below the buffer 98 the die is encircled by a collar or flange 99 against the top
of which bears the lower end of a coiled spring 100 encircling the said die and
bearing at its upper end against the lower end of the neck 94; the said spring
tending at all times to depress the dic.
Projecting from one side of the die near its lower end is a pin 101 extending
through a slot 102 in the side of the extension 96 of the bracket arm 90 and in the
path of the shorter arm 103 of an angle lever 104 pivotted to the said arm 90 and
constructed to be manipulated by hand. The lever 104 is held with its shorter
arm in a normally depressed position by a retractile spring 105 as shown.
It will be evident that when the longer arm of the lever is depressed the shorter
arm will be raised and acting upon the pin 101 will elevate the heading-dic against
the action of the spring 100 and above the position shown in the drawing.
Depending from the extension 96 of the bracket arm 90 are two legs 106 cach
with a facing 107 of insulating material on their lower ends. These arms constitute
the fixed member of a clamp the movable member being the anvil before described
and it will now be understood that two plates 5, 6 to be rivetted together may
be placed over the anvil with a rivet-blank in place in matched rivet-holes in the
said plates and that steam or compressed air may be introduced into the cylinder 76
below the piston 77 when the anvil will be raised and force the said plates against
the insulated lower ends of the legs 106 and thereby clamp them firmly together
between the said anvil and legs.
A conductor 108 leading from a transformer or other source of electric energy
from which the conductor 86 before mentioned leads, is connected to the upper
leg 61 by a set screw 109 or otherwise.
To ensure good electric connection between the movable heading-die and the
portion of the bracket 88 through which it is passed and which is in circuit with
the conductor 108 there are contact brushes 110 secured to the bracket extension 96
at the sides of the heading-die and bearing at their free ends directly on the said
heading-die so as to have a sliding contact therewith when the heading-die is
moved in a longitudinal direction. The operation of a rivetting machine constructed
as shown and described with reference to Fig. 2 is as follows:-
The entire apparatus is first adjusted by means of the supporting truck and the
windlasses in the manner before described until the anvil is below matched rivet
holes in the plates in which a rivet-blank is inserted. The heading-die is then
elevated by manipulating the lever 104 after which steam or compressed air is
admitted into the cylinder 76 below the piston 77 and the anvil is raised thereby
clamping the plates firmly against the insulated lower ends of the legs 106.
The lever 104 is now moved to its normal position and the heading-die is forced
downward by the spring 100 into intimate contact with the upper or projecting end
of the rivet-blank.
When the parts are in the position just described there is an electric connection

page_text: from the conductor 86 to and through the anvil, rivet and heading-dic and by the
contact brushes 110 to the upper leg 61 and the conductor 108. The current is now
turned on and controlled by a suitable regulator (not shown) which may be
constructed in the same manner as those described with reference to Figs. 14 and 18
until the rivet is heated to the desired state of incandescence.
Steam or compressed air is now admitted through the pipe 93 to the cylinder 91
and the hammer is automatically reciprocated in a manner well understood and a
rapid succession of heavy blows is struck on the upper end of the heading-die thus
upsetting the softened rivet-blank and forming a head thereon.
In order to maintain the heading-die and anvil at an approximately normal
temperature air-jets are directed against them by pipes 26 26 respectively which
may be similar to those described with reference to Fig. 14 of the drawings and
are provided with nozzles adjacent to the said die and anvil, but any other suitable
means may be used for the purpose of cooling the anvil and die and I am there-
fore not confined to the use of air-jets in connection with the machine illustrated
in Fig. 2.
It will be observed that in each machine herein before described the face of the
anvil and the lower ends of the legs forming the two members of the clamp for
holding the plates together are shown with a facing of insulating material which
however may be applied directly to the plates around the rivet-holes; a coating of
mineral paint or other similar substance giving good results. By this means the
current passing between the anvil and heading-die is confined to the rivet and the
plates therefore remain comparatively cold during the operation of rivetting and
are not compressed nor distorted when the rivet-blank is upset.
In the use of the different forms of apparatus hereinbefore described the anvil
and heading-die being used at the same time as the terminals of the circuit carrying
current of great quantity for heating the rivet are themselves readily heated and
unless provision were made for cooling these dies and anvils they would soon soften
to such extent as to render their continued use impracticable; for this reason the
heat abstracting or refrigerating devices hereinbefore described are used and it.
will be understood that my correspondent is not at all confined to the use of the
refrigerators shown in this case since any other means for abstracting the heat from
the dies and anvils may be employed.
In order to prevent as much as possible the heating of and to more readily abstract
the heat from the working ends of the dics and anvils the same are preferably made of a
metal of high conductivity for both heat and electricity and especially when possible of
greater conductivity for heat and electricity than the rivets employed. If iron rivets
are used the working ends of the die and anvil may be made with advantage of
phosphor-bronze, aluminium bronze, or any other suitable alloy of copper and in
all cases the cross-sections of both the die and anvil are made much larger than
that of the rivet. My correspondent also found it practicable to use ordinary
commercial copper in place of an alloy of copper for the anvils and heading-dies
and generally speaking the only condition to be satisfied is that the metal of the
dies and anvils have greater specific electrical conductivity than the metal of the rivet.
Having now particularly described and ascertained the nature of the said inven-
tion, as communicated to me by my foreign correspondent, and in what manner
the same is to be performed, I declare that what I claim is :-
1. The method of and means for rivetting by electricity substantially as described.
2. In an electric rivetting apparatus the combination with a heading die of an
anvil adjustable to and from the die and an electric circuit including said die and
anvil substantially as described.
3. In an electric rivetting apparatus the combination with a heading-die and
anvil of a clamp for the articles to be rivetted and an electric circuit including the
said die and anvil substantially as described.
4. In an electric rivetting apparatus the combination with a heading-die of an
anyil adjustable to and from the die a clamp for the articles to be rivetted one jaw

page_text: of which clamp is formed by the anvi and an electric circuit michuting sam are and
anvil substantially as described.
5. In an electric rivetting apparatus the combination with a heading-die of a
clamp for the articles to be rivetted one jaw of the clamp consisting of legs at the
sides of the die an anvil adjustable to and from the die constituting the other
jaw of the clamp and an electric circuit including said die and anvil substantially
as described.
6. In an electric rivetting apparatus the combination with a beading-die of an
anvil a clamp for the articles to be rivetted one jaw of which clamp is formed by
the anvil a layer of insulating material interposed between the working faces of the
clamp jaws and the articles clamped and an electric circuit including the die and
anvil substantially as described.
7. In an electric rivetting apparatus the combination with a heading-die of an
anvil a clamp for the articles to be rivetted one jaw of which is formed by the said
anvil and provided with a layer of insulating material on the working face
of each jaw and an electric circuit including the anvil and die substantially as
described.
8. In an electric rivetting apparatus the combination with a heading-dic and
anvil forming the terminals of an electric circuit of a refrigerator for cooling said
dic and anvil substantially as described.
9. In an electric rivetting apparatus the combination with a heading-die and
anvil forming the terminals of an electric circuit of pipes provided with nozzles for
directing a cooling agent against the working ends of said dies and anvil substantially
as described.
10. In an electric rivetting apparatus a framework consisting of a ring-shaped
bar of metal constituting the secondary of an inductional transformer having the
primary applied to it and a shell or envelope of magnetic material enclosing the
transformer in combination with an anvil and a heading-die forming the terminals
of the secondary of the transformer substantially as described.
11. In an electric rivetting apparatus the combination with an inductional
transformer constituting the framework of the apparatus of an anvil and heading-dic
forming the terminals of the secondary conductor of said transformer substantially
as described.
12. In an electric rivetting apparatus the combination with an inductional trans-
former constituting the framework of the apparatus and consisting of a fine wire
primary coil and an open frame forming the secondary conductor of an anvil &
heading-die forming the terminals of said secondary conductor substantially as
described.
13. In an electric rivetting apparatus the combination with an inductional
transformer constituting the framework of the apparatus and consisting of a finc
wire primary coil an open frame forming the secondary conductor and a shell of
magnetic material for the said primary and secondary of a heading-die and anvil
forming the terminals of said secondary conductor substantially as described.
14. In an electric rivetting apparatus the combination with an inductional
transformer composed of a fine wire primary coil and a secondary conductor with
adjacent projecting ends of an anvil and heading-die carried by said ends and a
clamp for the articles to be rivetted one jaw of which is formed by said anvil
substantially as described.
15. In an electric rivetting apparatus the combination with an inductional
transformer constituting the frame of the apparatus and provided with a secondary
conductor having adjacent projecting ends of a heading-dic and adjustable anvil
carried by said ends and a clamp for the articles to be rivetted one jaw of which is
formed by the said anvil substantially as described.
16. In an electric rivetting apparatus a heading die and anvil constituting the
terminals of an electric circuit and composed of metal of high electric conductivity
substantially as described.
17. In an electric rivetting apparatus a heading-die and anvil constituting the
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page_text: terminals of an electric circuit and composed of metal of a higher electric con-
ductivity than that of the rivet operated upon substantially as described.
18. In an electric rivetting apparatus a heading-die and anvil constituting the
terminals of an electric circuit and composed of metal of higher conductivity
of heat and electricity than that of the rivet operated upon substantially as
described.
19. In an electric rivetting apparatus a heading-die and anvil constituting
the terminals of an electric circuit composed of an alloy of copper having
higher specific conductivity than the metal of the rivet operated upon substantially
as described.
20. In an electric rivetting apparatus the combination of a heading-die and
anvil composed of a metal of higher specific, conductivity than that of the rivet
operated upon, with guides and supports for the anvil and die composed of a metal
of inferior electric conductivity substantially as described.
21. In an electric rivetting apparatus a heading-dic and anvil composed of
aluminium bronze having higher specific conductivity than the metal of the rivet
operated upon substantially as described.
Dated this 12th day of May 1891.
W. P. THOMPSON & BOULT,
Agents for the Applicant.