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Патент USA US2412069

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Dec. 3, 194a.
w. TRINKS
2,412,069
DRIVING MEANS FOR ROLLER ELECTRODES AND THE LIKE
' Filed June 16; 1944
WlLLlBALD TRINKS
Patented Dec. 3, 1946
2,412,069
UNITED STATES PATENT OFFICE
2,412,069
DRIVING MEANS FOR ROLLER ELECTRODES
'
AND THE LIKE
Willibald Trinlrs, Pittsburgh, Pa., assignor to The
Taylor-Win?eld Corporation, Warren, Ohio, a
corporation of Ohio
Application June 16, 1944, Serial No. 540,622
10 Claims.
1
This invention relates to electric resistance
welding apparatus and more particularly to such
apparatus employing a pair of opposed roller elec
(01. 219-4)
2
in which a plurality of roller electrodes are main
tained in pressure engagement with the work
to be welded and have relative movement with
respect to the same which is operative to trans
mit a driving force through at least a pair of the.
trodes which are operative to engage the work
between them and to weld the work along a line
or seam. In seam welding generally it is often
desirable to maintain a ?xed predetermined rate
of progression of the work with respect to the
electrodes while keeping the peripheral speeds of
welding electrode or electrodes or vice versa and
along a line or seam, for example, both the 'eleo-g
the electrodes of this pair exactly the same. Thus
in welding equipment performing series welds
in the case of seam welding machines employ 10 trodes effecting each pair of series welds maybe
ing a roller electrode rotatable about a normally
driven in a positive manner to aidv in ‘effecting
?xed axis it has been proposed to elTect this mode
the desired constant relative movement between
of operation by driving the roller electrode by
the work and the electrodes.
means of an arrangement which is inherently
Another object of the invention is the provision
operative to maintain a ?xed peripheral speed re 15 of improved arrangements and devices for driving
gardless of the wear and consequent decrease in
a pair of roller electrodes in electric resistance
diameter of the electrode. A commonly used ar
seam welding apparatus whereby substantial
rangement for this purpose comprises a steel driv
driving forces may be transmitted through each
ing wheel the diameter of which remains sub
of the electrodes while the peripheral speeds of
stantially ?xed throughout its life and the pe 20 the respective electrodes are yet maintained sub-'
riphery of which is maintained in pressure en
stantially the same. In accordance with this
gagement with the periphery of the roller elec
more speci?c object of the ‘invention I provide
trode.
The driving wheel is readily driven at
a multiple roller electrode driving system which
constant speed and in this manner the peripheral
operates in such manner that the torque applied
speed of the roller electrode remains ?xed regard 25 to rotate the respective electrodes is automatically
less of the extent of wear of the electrode but
correlated in respect to the diameters of the re
the arrangement has the serious disadvantage of
spective electrodes so that the frictional forces
limited power transmission and excessive elec
transmitted by the peripheries of the respective
trode wear.
electrodes to the work are substantially equal.
In seam welding machines employing a pair
The work, of course, presents relatively ?xed
of driven roller electrodes adapted to have simul
surfaces for contact with the peripheries of the
taneous engagement with the work the problem of
respective electrodes and in this manner syni
maintaining the peripheral speeds of the elec
chronization of the peripheral speeds of the re
spective electrodes is insured.
.
trodes equal is difficult due to unavoidable varia
tions in the rate of wear between the respective 35
The above and other objects and advantages
electrodes. This is particularly true if it is desired
of the invention will become apparent upon con
to transmit substantial propelling forces through
sideration of the following detailed speci?cation
and the accompanying drawing wherein there is
to undue Wear. It is the primary object of the
disclosed certain preferred embodiments of the
present invention to provide an improved electric 40 invention.
resistance seam welding apparatus of the type
In the drawing:
the electrodes without subjecting the electrodes
employing a pair of driven roller electrodes for
Figure 1 is a schematic representation of a mul
engaging opposite sides of the work to be welded
tiple roller electrode driving arrangement for
which is operative to keep the peripheral speeds
seam welding apparatus constructed in accord
of the two roller electrodes exactly the same 45 ance with the principles of the invention; and
whereby the rate of progression of the work
Figure 2 is a schematic representation of a
through the welding throat of the apparatus or,
modi?ed form of multiple electrode driving ar
conversely, the rate of progression of the welding
rangement constructed in accordance with the
throat along the work may be accurately main
principles of the invention.
tained at a predetermined ?xed value and where 50
Referring to Figure 1, reference numerals l0
by the contact between the work and the elec
and II designate upper and lower‘roller elec
trodes is always rolling contact.
.trodes, respectively, of an electric resistance seam
A further and more general object of the in
welding apparatus of the kind in which rotation
vention is the provision of an improved electric
of the electrodes may be relied on to move the
resistance welding apparatus of the general type
work through the welding throat of the appa
2,412,069
3
4
ratus. By way of illustration work pieces I2 and
The full shunt ?eld winding, consisting of sec
tions I8 and I9, of the motor I4 is connected
across the principal current supply line through
conductors 23, 36, 3'! and 26. The tap dividing
I3 to be welded together are shown as being posi
tioned between the roller electrodes I0 and I I and
it will be readily understood that in actual prac
sections I8 and I9 is connected to a contact 38
tice suitable means, not shown, will be employed
by means of conductor 39 and upon downward
to apply welding current and welding pressure to
movement of the armature 3| the contact 38 is,
these electrodes. Electrode I0 is arranged to be
by means of a contactor 32 and a conductor 3%},
driven by an electric motor I4 through suitable
connected directly to the conductor 25. This, of
speed reducing gearing shown schematically at I5
while electrode II is driven by a similar electric 10 ‘course, has the effect of short circuiting the wind
iIlg section 13 whereupon the motor I4 will at
motor I6 through similar gearing H, In the pre
once begin to draw more current and attempt to
ferred and illustrated embodiment of the inven
pick up speed. Similarly the complete ?eld wind
tion the motors I4 and I6 are of the direct cur
ing, consisting of both sections '20 and 2|, of the
rent shunt wound type although as will appear
motor I6 is connected across the supply line
more fully hereinafter motive means of other
through conductors 28, 40, 4i and 26 while the
types may readily be employed in their stead, all
- tap dividing the two sections is connected to a
within the purview of the invention.
switch contact 42 by means of conductor 43, As
The shunt ?eld winding of the motor I4 is
shown, upon upward movement of armature 3|
tapped to provide sections I8 and I9 while the
shunt ?eld winding of the motor I6 is similarly 20 contact 42 is, by means of contactor 32 and con
ductor 39, connected directly to line 26 so that
tapped to provide the winding sections 2c and 2 I.
upon this occurrence section 2i is short cir
A suitable source of direct current comprising the
cuited.
line conductors LI and L2 is provided and, in ac
In operation of the apparatus described above
tual practice, the current ?owing into the line LI,
L2 may be either automatically or manually con 25 the speeds of the respective motors I4 and I6
will normally be limited and controlled by the
trolled according to the nature of the control
connection of their full shunt ?eld windings
system of the complete machine in which the
across the current supply line and, assuming
features of the present invention are incor
ideal conditions, the armatures of the motors will
porated.
be drawing the same current so that the arma
In series with the armature of motor I4 across
ture 3I will be in neutral position and the con
the line L1, L2 is a solenoid 22, the circuit being
tactor 32 ?oating between the contacts 38 and
traceable from line L2 through conductor 23, the
42. If new one of the roller electrodes, electrode
armature of motor I4, conductor 24, solenoid ‘22,
It for example, should tend to lose speed the ar
and conductors 25 and 26 to line conductor LI.
mature current drawn by motor I4 will become
Axially aligned with solenoid 22 is a similar sole
less and solenoid 22 will be overpowered by sole
noid 21 which is in series with the armature of
noid 27 thereby short circuiting ?eld winding
motor I6 across the current supply line, the cir
section I8 to speed up motor I4. As soon as this
cuit being traceable from line conductor L2
motor reaches its normal speed its armature will
through conductor 23, conductor 28, the arma
ture of motor I6, conductor 29, solenoid 2?, and 40 again take its normal current and the contactor
32 will move away from contact 38 to reestablish
conductors 30 and 26 to line conductor LI. Ex
normal operating conditions in the assembly.
tending into the lower portion of solenoid 22 and
Conversely, loss of speed in motor IE will take
the upper portion of solenoid 2‘! is an armature
out section 2| of its shunt ?eld winding to re
3| to which is connected a contactor 32 and a ?oat
33 having a horizontal disk or ?n 34 immersed in 7 establish normal operating speed. It should be
observed, however, that this control is not based
a bath of ?uid contained in a vessel 35. Sole
on maintaining any predetermined ?xed speed of
noids 22 and 21 are oppositely poled so that nor
the two motors but in maintaining the speed in
mally they exert the same force on the armature
relation to the then existent diameters of the
3I. The buoyancy of ?oat 33 may be made of
su?icient value to carry the weight of armature 50 connected roller electrodes whereby the work out
put of the respective motors is kept equal and
3| and the parts connected to it so that the dif
more or less constant. As explained above, this
ferential relay comprised of the solenoids 22 and
mode of operation insures the maintenance of
21 will be sensitive in operation. The forces ex
equal peripheral driving speeds of the two roller
erted by the respective solenoids on the armature
electrodes employed.
7
3| are equal in the manner indicated above when
In the modi?cation illustratedin Figure 2 there
the motors I4 and I6 are drawing equal current.
is interposed in the lines of drive between motor
Inasmuch as the voltage applied to both the mo
I4 and electrode I0 and between I6 and electrode
tors is exactly the same the amount of current
II a switch carried by a part 45 which may be
drawn by the respective motors is an indication
of the amount of work being done by the respec GO rigidly connected to the motor end of the drive
and an operator 46 for the switch which is rigidly
tive motors. This should be distinguished from
connected to the electrode end of the drive. These
the torque applied to the drive shafts of the elec
couplings are so constructed that limited relative
trodes by the motors since an indication of torque
movement may occur between the parts 45 and
would not accurately re?ect the actual frictional
48 and the switch is so arranged that it is open
force exerted by the peripheries of the welding
when the direction of drive is from the motor to
wheels on the work. Thus it will be observed that
the electrode, If, however, either electrode over
if, for example, the peripheral ‘frictional force ex-'
takes its driving motor the switch connected to
erted by the wheel electrode II becomes less the
that particular electrode is closed. The opening
amount of current drawn by the motor I6 must
and closing of these directional switches are uti
necessarily also be less. Upon this occurrence
lized to control the energization of the respective
solenoid 22 overpowers solenoid 21 and the arma
driving motors I4 and I6 in a manner now to be
ture 3I is moved upwardly. This unbalance of
‘described.
the relay is utilized to correct the mechanical
The armature of motor I4 is connected across
output of the motors in the manner now to be
described.
7
>
- the current supply line LI, L2 by means of con
2,412,069
ductors 41 and 48 while the armature of motor
I6 is connected across this line by means of con
ductors 49 and 50. Field winding 5| of motor
I6 is connected directly across the line Ll, L2
While the ?eld winding 52 of the motor I4 is con
nected in series with a variable resistance 53
across this line. The value of the resistance 53
which is in this ?eld circuit is determined by the
6
resistance method of Figure 2 as will be readily
understood.
It should now be apparent that I have provided
improved methods and devices for driving a pair
of roller electrodes having simultaneous pressure
engagement with the work to be welded which
accomplish the objects initially set out. By em
ploying separate driving means for each of the
electrodes and controlling these means in such
position of a movable contact 54 which is moved
back and forth by the reverse and forward ro 10 a manner that they both deliver the same amount
tation, respectively, of a small reversing motor
of work there can be no slippage between the
55. I provide reversing contacts for the motor 55
electrodes and the work since the peripheral
actuated by the relays 56 and 51 which, in turn,‘
speeds of the electrodes must be alike. The pres
are operated by the opening and closing of the
ent invention is based upon this inventive thought.
switches carried and operated by the couplings 45 _
Inasmuch as many changes in the above spe
and 46. These switches, designated by reference
ci?cally described embodiments of the invention
numeral 58 each have two leads which are con
may be made without departing from the spirit
nected to a pair of slip rings 59 which are car
or scope of the invention, these embodiments
ried by and revolve with the drive shafts. When
should be considered as illustrative only. For
a particular switch is closed the slip rings 59 con
example, the speci?c switching arrangement
nected to this switch are interconnected electri
shown in Figure 1 for controlling the relative
cally, otherwise they are insulated from each
other.
speeds of the motors i4 and I6 by selectively short
circuiting portions of their shunt ?eld windings
The coil of relay 56 is in a circuit which may
may, as well, be replaced by an arrangement
be traced from line conductor L2 through con 25 whereby one of the motors normally operates at
ductor 60, the coil of relay 56, conductor 6|, rings
a predetermined ?xed speed while suitable means,
59 (suitable brushes being provided), and con
operated by the armature 3|, varies the voltage
ductors 62 and 49 to line conductor LI. Actu
applied to the shunt ?eld winding of the other
ation of relay 56 connects the armature of motor
motor up or down as required to effect the proper
55 across the line Ll, L2 with such polarity that 30 corrective action in the speed of the other motor.
the contact 54 is moved to the left, as viewed in
Such means may comprise a linear resistance
Figure 2, to increase the series resistance in the
element attached to the armature 3| and extend
?eld circuit of motor [4 thereby causing this
ing into a normally ?xed bath of mercury. As
motor to draw more armature current and speed
the armature moves downward the resistance
up. The coil of relay 51 is in a circuit which 35 then in series with the shunt ?eld winding of
may be traced from line conductor L2 through
such other motor diminishes thus reducing the
conductor 53, the coil of relay 51, conductor 64,
speed of the motor. Further, while I have chosen
rings 59 (suitable current carrying brushes being
direct current shunt wound electrode driving
provided), and conductors 64 and 49 to line con
motors for simplicity of illustration motive means
ductor Ll. Upon energization of relay 5'! the 40 of other types may be employed equally as well.
armature of motor 55 connected across the line
I may, for example, employ a single alternating
Li, L2 with such polarity that the contact arm
current motor with a ?xed drive to one of the
54 is moved to the right, as viewed in Figure 2,
roller electrodes and a variable speed transmis
to decrease the resistance in series with the shunt
sion in the drive to the other of the electrodes.
winding 52 of the motor l4 thereby decreasing the ‘. The means responsive to variations in the relative
speed of the motor l4 and allowing motor IE to
speed of the electrodes would then be utilized to
catch up and again drive its connected elec
control the ratio of the variable speed transmis
trode II.
sion. Reference should therefore be had to the
The operation of the modi?ed system illustrated
appended claims in determining the scope of the
by Figure 2 is such that the motors l4 and i6 50 invention.
normally take an equal load, the adjusted or
What I claim is:
neutral position of the resistance contact arm
1. In electric resistance seam welding apparatus
54 being selected to effect this mode of operation.
having a pair of roller electrodes adapted to have
If new the speed of one of the motors, motor £6
simultaneous engagement with the work to be
for example, should fall behind the electrode H 55 welded the combination of means to drive both
will tend to drive the coupling part 45 through
said electrodes and to synchronize the peripheral
the coupling part 46 thereby closing the attached
speeds thereof comprising a shunt wound direct
switch 58 which, in turn, will energize relay 5‘!
current motor for each of said electrodes and
through the circuit above described to energize
having driving connection thereto, means com
motor 55 for rotation in the direction which will 60 prising the ?eld windings of said motors to vary
decrease the resistance 53 in the shunt circuit of
the driving speeds of said motors, and means
the motor 14 to slow down the latter and thus
responsive to variations in the armature current
bring both the motors back into driving synchro
drawn by the respective motors in control of said
nism.
means to vary whereby the mechanical energy
It should be apparent that in the system of 65 delivered by said motors is maintained equalized
Figure 2 the variable resistance method for cor
thus synchronizing the peripheral speeds of said
relating the speeds of the motors may readily be
electrodes.
replaced, if desired, by the short circuiting ar
rangement of Figure 1—involving the use of a
plurality of ?eld winding sections for each of the
motors and contactors or switches for shorting
out certain of the sections as explained. Likewise,
in the embodiment of Figure 1 the short circuit
ing method of correlating the speeds of the
motors may readily be replaced by the variable
2. Apparatus according to claim 1 further char
acterized in that said responsive means comprises
a diiferential solenoid having winding sections
arranged to conduct current in proportion to the
current drawn by the armatures of the respective
motors, an armature in said solenoid, and means
responsive to movement of said last mentioned
75 armature in control of said means to vary.
2,412,069
8
,3. Apparatus according to claim 1 further Y
characterized in that said responsive means
comprises a differential solenoid having winding
sections arranged to conduct current in propor
tion to the current drawn by the armatures of
the respective motors, an armature in said sole
noid, damping means connected with said last
mentioned armature, and means responsive to
of said driving means whereby the peripheral
driving speeds of the electrodes will be main
tained substantially equalized.
7. In electric resistance seam welding appa
ratus having a pair of roller welding electrodes
adapted to have simultaneous engagement with
the Work to be welded, a driving element for
each of said electrodes, said driving elements be
ing connected to said electrodes radially inward
movement of said last mentioned armature in
10 of the peripheries thereof, driving means for
control of said means to vary.
each of said driving elements, a torque respon
4. In electric resistance seam welding appa
sive switch in each of the lines of drive inter
ratus having a pair of roller welding electrodes
adapted to have simultaneous engagement with
the work to be welded the combination of a driv
ing element for each of said electrodes, said
mediate said driving means and said driving
elements, and means responsive to actuation- of
driving elements being connected to said elec
trodes radially inward of the peripheries there~
tween said driving means.
said switches in control of the speed ratio be
7
8. In electric resistance seam welding appa
ratus having a pair of electrode wheels adapted
of, differential means to drive each of said ele
to have simultaneous engagement with the work
ments, and means to control said driving means
in accordance with the tractive eiiort being ex 20 to be Welded, an electric motor for each of said
erted by the respective electrodes whereby the
peripheral driving speeds of the electrodes are
wheels for driving the same, opposing solenoids
connected in- series in the armature circuits of
maintained substantially equalized.
said motors, a common armature for said sole
noids, and means operative in response to move
ment of said common armature to maintain the
power output of the two motors substantially
5. In electric resistance seam welding appa
ratus having a. pair of roller welding electrodes
adapted to have simultaneous engagement with
the work to. be welded the combination of a
driving element for each of said electrodes, said
equal.
.
'
9. Apparatus according to ‘claim 8 further
characterized in that said motors are of the
driving elements being connected to said elec
trodes radially inward of the peripheries thereof, 30 shunt wound type and in that said last men
differential means to drive each of said elements,
and means responsive to variations in the ratio
of the total mechanical energy delivered to the
tioned means is operative to reduce the shunt
?eld strength of the motor having less power
respective driving elements by said driving
10. In electric resistance seam welding appa
means in control of the operation of said driv
ratus having a pair of roller welding electrodes
adapted to have simultaneous engagement with
ing means whereby the peripheral driving speeds
output.
'
of the electrodes are maintained substantially
the work to be welded, a driving element for each
equal.
of said electrodes, said driving elements being
connected to said electrodes radially inward of
,6. In electric resistance seam welding appa
-ratus having a pair of roller welding electrodes 40 the peripheries thereof, driving means for each
of said driving elements, a torque responsive de
adapted to have simultaneous engagement with
vice in each of the lines of drive to the respec
the work to be Welded the combination of means
tive electrodes, and means controlled by said
to drive each of said electrodes, a torque re
torque responsive devices to control the spee
sponsive switch in each of the lines of drive
'
intermediate said driving means and the respec 45 ratio between said driving means.
tive electrodes, and means responsive to actua
tion of said switches in control of the operation
WILLIBALD TRINKS. ~
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