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Патент USA US2133152

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Oct. 11, 1938.
Filed May 2, 1935
mm“.vw outnm
by Wm
Patented Oct. 11, 1938
wannmc wrrn surnanurosnn men
Iwane Schigyo, Tokyo, Japan, assignor to Gen- 2
eral Electric Company, a corporation
of New
Application May 2, 1935, Serial No.‘ 19,479
In Japan June 8, 1934
4 Claims.
(CI. 21948) '
My invention relates to welding with superim
posed high frequency.
former is connected through conductors "and
In the various forms of electric welding it 'has'
been proposed to superimpose upon the welding
5 electrodes a‘ high frequency alternating current.
In resistance welding this high frequency current
is of su?lcient voltage to establish and stabilize
the ?ow of welding ‘current through the work in
serted between the welding electrodes as soon as
10 ‘the electrodes engage the work irrespective of
the surface condition of the work at the point of
welding. In arc welding the voltage of this su
I8 and a switch l9 to a source of supply 20.
A high frequency generator 2| is connected to
supply a relatively small high voltage high fre
quency current to the welding circuit |2, |3
through conductors 22, 23.
Conductors 22, 23 are _
connected through low frequency stopping con
densers 24 to the secondary 25 of a high fre
quency transformer 26 whose primary 2'! forms
part of a circuit adapted to oscillate at high fre
to strike the welding arc although its principal
function is to stabilize the welding arc and thus
quencies. The condenser 28 and spark. gap 29
connected to the primary 2] of the high fre
quency transformer 26 complete the oscillating
circuit. This circuit is energized by being con
in the case of alternating current arc welding
render the operation more easy to perform es
whose primary 32 is connected through conduc
perimposed high frequency is generally su?icient
pecially where low current
greater than necessary for usual welding oper
ations which are for the most part intermittently
performed. Thus for example in arc welding if
25 the generator were maintained in operation after
the welding operation, had been interrupted for
the adjustment of work or for some other pur
pose, unnecessary wear of the generator is occa
sioned. ‘Particularly is this so in the case ‘of
30 generators of the gap discharge type where oper
nected to the secondary 3|] oi’ transformer 3| 35
tors I‘! and it and control contacts 33 of a time
element relay 35 to the source of supply 20. The
operating coil 35 of the relay 34 is connected
through, conductors 36 and '31 and conductors,
22 and 23 to the welding circuit l2, l3. Its op
crating coil‘ is thus responsive to the voltage
across the electrodes I0 and H. The relay 34 is
of the time delay type and operates after ‘a pre
determined length of time in response to volt
ages across the electrodes I0 and H which are
greater than the arcing voltages employed during
The system above described operates as'follows:
ation-of the generator imposes considerable wear. When the switch I9 is; open, the various circuits 30
above described are deenergized and relay 34 as
on the gap electrodes.
sumes the position illustrated in the drawing.
It is anobiect of my invention to provide weld
When switch I9 is closed, transformers IS-and 3|
ing apparatus embodying a high frequency gen
- erator, with means for energizing the generator
only while the welding operation is in progress
and to deenergize the generator a predetermined
_ time after the welding operation has been com
.' The predetermined time may be made
adjustable if so desired.
- Y
The accompanying drawing diagrammatically
illustrates arc welding apparatus embodying my
In the drawing the welding electrodes are illus
trated at it and I]. The electrode “I may be a
fusible electrode or an electrode of the non-con
are energized by being connected to the source of v
supply 20 through conductors l1 and | 8. If the
welding electrodes Ill and | | are not brought into 35
engagement with one another to strike a welding
are or if a welding arc is not established between
these'electrodes the relay 34 is su?iciently ener
gized to open its contacts 33 after- a predeter
mined time interval and thus disconnect the
transformer 3| from the. source of supply 20.
This will-deenergize the high frequency generator
2| and until a welding operation is initiated this
generator will remain deenerglzed.
If the welding operator brings the electrode ||l
suming type, and the electrode II-may be the .into engagement with the work II to strike and
work upon which the welding operation-is being thereafter maintains a welding arc, the voltage
performed. These ‘electrodes are connected to a applied to the operatinglcoil 35 of the relay 34
supply of relatively large lowvoltage low fre will be insu?icient to operate the relay and dur
quency welding current through a welding circuit ing welding the high frequency generator 2| will 50
l2, l3. In the particular arrangements illustrat
consequently remain connected through conduc
ed this source is the secondary ll of a welding
55 transformer l5. The primary ID of this trans
tors l1 and | 8 to the source of supply20. Ifduring
welding the welding circuit is opened bythe are
being momentarily interrupted or interrupted for
quency generator connected to said welding cir
a predetermined short length of time, the relay
_" will not be sufliciently energized’ for a long
enough period of time to open its contacts, 33 and
the-high frequency generator will be continu
ously energized and thus furnish high frequency
current to the welding circuit l2, it to assist in
striking the arc and to stabilize its operation
cuit for supplying a high frequency are stabilizing
current thereto, a time element relay having an
operating coil and control contacts, means in
cluding said control contacts of said relay for
after it has once been ignited. The period of
time during which the high frequency generator
is energized after- a welding operation has been
deenergizing said high frequency generator, and
means for connecting said operating coil of said
relay with said welding circuit to control its ener
gization to close said, control contacts of said
relay during a welding operation and to open
said control contacts of said relay a predeter
interrupted or discontinued is determined by mined time after a‘ welding operation has been
the time element relay 34. This time may be completed;
made adjustable in order to adapt the welding
2. Arc welding apparatus comprising a plurality
system to various types of work by using a relay of welding electrodes adapted to strike and main
tain a welding arc‘, means for supplying welding
3‘ having a time adjustment.
Although a time element relay operating in current to said electrodes, means for supplying a ‘
response to the'voltage of‘ the welding circuit ' high voltage high frequency starting and stabiliz
ing current to said electrodes, and means includ 2.0
-has been illustrated in the embodiment above de
ing a time element relay having an operating coll
scribed, it is to be understood that a current re
sponsive' relay connected in the welding circuit connected to be responsive to voltages across said
20 may be used for accomplishing the same desired
electrodes for deenergizing ‘said last-mentioned
controL- In fact, any time element relay con
means 'after a predetermined length of time in
response to voltages greater than arc welding
‘ nected to be responsive to a characteristic of the
welding circuit may be employed for energizing
3. An arc welding apparatus comprising a pair
and deenergizing the high frequency generator
in accordance with my invention.
of arc-forming electrodes, meansfor delivering
It is apparent that my invention is not limited " low frequency current to such electrodes, means
in its application to high frequency generators for delivering high frequency current to such elec 30
of the type described above since other types trodes, and a relay energized by the ?rst-men
of generators may be used. It is also apparent tioned means and controlling the last-mentioned
30 that my invention is not limited in its applica
means, whereby interruption of the low frequency
tion to alternating current welding but may be current entails interruption of the high frequency
applied equally well to direct current welding.
Thus, while I have illustrated and described but
one embodiment of my invention, it is to be
35 understood that my invention is of general appli
cation to all types of welding employing super
imposed high frequency current.
What I claim as new and desire to secure by
Letters Patent of the United States is: t
1. Are welding apparatus comprising welding
electrodes adapted to strike and maintain a weld
- ing arc, a circuit connected to said electrodes for
supplying welding .current thereto, a thigh fre
4. An 'arc welding apparatus comprising a pair
of arc-forming electrodes,- means for delivering
low frequency'current to such electrodes, means
for delivering high frequency current to such elec
trodes, and a relay energized by the‘iirst-men
tioned means and.v controlling the last-mentioned
means, whereby interruption of the low frequency
current entails interruption of the high frequency
current, the relay having a retarded action.
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