Note: Descriptions are shown in the official language in which they were submitted.
~L~5~39
~ he presen-t invention relates to resistance bu-tt -
weldi.ng o~ piping and has particular reference to devices
~or removal of e~ternal circular fins ~rom the joints o~ the
pipes being welded together.
Known in the art îs a device ~or removing e~ternal
circular ~ins from the a oints of -the pipes being welded to- ;
gether, comprising a base, a hollow rotor with a ~aceplate,
running i~ the base bearings, carriages mounted on -the rotor
~aceplate, a mechanism for a radial traverse o~ the carria-
ges, having a holder ~it-ted on the rotor so as to rotate
with respect thereto, as well as the drive o~ the rotor and
o~ the carriage radial iraversing mechanism. ..
A cardinal disadvantage inherent in such devices ~or
removing external circular ~ins resides in an incomplete -;;
removal of ~ins whenever the pipe joints are found to have `~:
an oval shape, inasmuch as the cutting tools (cutters) are ~ .
held in the carriages which describe strictly predetermined .
orbital paths around the pipes being welded and there~ore are :~
incapable o~ tracing the pipe surface which in ~act departs
~rom a true circumference.
In the known device the cutter is ~ed at a constant
rate, therefore when removing an external circular fin having
a cross-sectional shape approximating the triangular one, the - ~
cu-tting ~orce applied and the power consumed are essentiall~ :
~ariable values.
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~i3~39
~ his results in overloadin~ the drive when the tool
is fed at high rates and, accordin~ly, in the drive under~
loading at lower feed rates o~ the cutter To obviate said
disadvantage said known devices provide for manual cutter
feed control in the course o~ operation, which badly affects
the productive e~ficiency of the device and deteriorates the
quality o~ ~achining.
Moreover, the device incorporates two self-contained
drives, viz. 9 the rotor drive and the carriage radial traver-
~se drive. ~herefore, special mechanisms must be provided to
bring the rotational speeds o~ both drives in synchronism.
~his still more adds to the buliness of the device and makes
its construction and service costs still higher.
In addition, said mechanisms fail to provide a programmed:
misalignment of the rotor and holder ro-tational speed to suit
particular operating conditions. At best, they would be able
to to perform a preset program under given operating condi-
tions; whenever the latter vary, the e~tire ~eed drive would ~
need resettin~. :
It is there~ore a prima~ and essential object of the
present invention to provide such a device ~or removal o~ ..
external circular fins from the joints of the pipes ~eing
welded together that would feature higher productive effi- ~ .
ciency compared to the known de~ices of a similar type.
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It is another obaect o~ the present invention to provide
such a device f`or removal o~ external circular fins ~rom pipe
joints that would make provision for a uniform fins removal
round the entire joint irrespective of whether the shape o~
the pipe bei~g welded together is a t.rue circumference or
departs therefrom. ~:
It is still another object of the present invention to
pro~ide such a device for remoYal of external circular fins
from the joints of the pipes being welded to~ether that would :
be capable of removing fins ~orming in the course of welding, .
having any cross sectional shape, the drive of the de~ice
being under constant load. .
Said and other objec-ts are accomplished in a device for .
removing e~ternal circular fins from pipe joints made by a ::
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resistance butt welding, comprising a base; a hollow rotor
with a faceplate, said rotor being mounted in the base; car~
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ria~es mounted on the rotor faceplate; a mechanism for a ra~
dial traverse o~ the carriages, said mechanism having a hol- ~
der fitted on the rotor rotatabl~ with respect thereto; and ~: :
a drive of the rotor and o~ the carriage traversing mecha-
nism, wherein according to the invention each of the car-
riages has its own rollex adapted to trace over the surface `~:
of the pipes being treated, while the mechanism for a radial
travers of the carriages is eomposed of links with one o~ : `
-their ends articulated -to -the holder and with the other end,
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to slide blocks, each o~ which is housed in a boring of the
respective carriage with.a possibility of radial movemen-t ..
therein and is connected to a spri.ng gauged for the
cutting ~orce, the other end o~ which spring thrusts against
-the bottom of the boring in the carriage, wheres the drlve ~.
of the rotor and of the carriage traversing mechanism has :.
two output shafts, of which one is kinematically associated
with the rotor, and the other, with the holder, and is provi-
ded ~ith a mechanism for program control o~ the difference ;.
between the rotational speeds o~ said sha~ts.
Due to the provision of a roller on each of the carriage~.:
adapted to trace over the surface o~ the pipes under trea-t-
ment, the proposed device is able to completely and uniformly
remove eæternal circular ~in round -the entire pipe joint ir-
respective of whether the shape of the pipes being welded
together is a true circumference or departs therefrom.
~ urthermore, the proposed device enables the speed syn-
chronism of the rotor and of the carriage radial traversing
mechanism.
It is expedient that the mechanism for program control
of the dif~erence between the rotational speeds of the shafts
kinematically associated with the rotor and holder~ respecti-
vely a be made as a di~ferential drive interconnecting said
shaft~ the housing of said drive being essentially an in- -
ternal~and-external rim gear loosely rotating round the
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shaft kinematically associated with the holder. The external -
gear rim of the differential drive housing is in mesh with the
gear set on the shaft kinematically associated with the rotor,
while the internal gear rim of said housing is in mesh, through
planet pinions, with the differential drive sun gear set on the
shaft kinematically associated with the holder. The carrier of the
planet pinions is made as a gear loosely running round the shaft
kinematically associated with the holder, while the rim of the - ~
planet pinion carrier is in mesh with the rack engaged with the -
piston of a hydraulic cylinder that controls the traverse of the
carriages.
In an aspect of the present invention there is ; `
provided-a device for removing external circular fins from pipe
joints made by the resistance butt welding, comprising: a base;
a hollow rotor mounted in said base; a faceplate of said rotor;
carriages mounted on said faceplate, each of said carriages having
a boring; a roller made fast on each of said carriages and
adapted to trace over the surface-of the pipes under treatment;
a holder fitted on said rotor ~otatably therearound; springs gauged
for the cutting force, with one of their ends thrusting against ;
the bottom of the boring in said respective carriage; slide blocks,
each of which is housed in the boring of said respective carriage
with a possibility of radial movement therein and with its one end
interconnected with the other end of said spring; a mechanism
for radial traverse of said carriages; links, with one of their
ends articulated to said holder and with the other end, to said
slide blocks; a drive for the rotor and for the carriage radial
traversing mechanism; an output shaft of said drive for the rotor
and for the carriage radial traversing mechanism, kinematically
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associated with said rotor; another output shaft of said drive for
the rotor and for the carriage radial traversing mechanism,
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kinematically associated with said holder: a mechanism forprogram control of the difference between the rotational speeds
of said output shafts, said mechanism being incorporated into
said drive for the rotor and for the carriage radial traversing
mechanism.
In what follows the present invention will now be
disclosed in a dekailed description of an illustrative embodi-
ment thereof with reference to the accompanying drawings, wherein:
Fig. 1 is a general longitudinal~section view of a
device for removing external fins, according
to the invention;
Fig. 2 is a general view of a carriage, according to
the invention:
Fig. 3 is a sectional elevation facing ~-A in Fig. 2
Fig. 4 is a longitudinal-section view of a drive for
the rotor and for the mechanism of radial
traverse of the carriages, according to the
invention, and -
Fig. 5 is a sectional elevation facing B-B in Fig. 1.
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The herein-proposed device ~or removing external circu-
lar ~ins ~rom the joints o~ pipes made by a resistance butt :
welding comprises a base (~igs. 1,2) in bearings 2 o~ which :.~
axe mounted a rotor 3 with a faceplate 4. Carriages 5 (four ,...:
in number a~ illustrated in Fig. 1) are mounted on the ~'a- ~ .
ceplate 4 and in the recesses thereo~0 Each o~ the carriages ~ '~, .,
carries cut-ting tools 6 held therein. Besides, each of the ':
carria~es is provided with a roller 8 adapted to traGe over
the sur~ace o~ a pipe 7 under treatment. ~he mechanism ~or
/ radial -traversing of the carriages 5 is composed of links ,~ .
9 with one of their ends articulated to a holder 10 and with .' ..
the o~her ends connected to slide blocks 11. Each of the ..
slide blocks 11 is accommodated in a boring o~ the corres- : ,
ponding carriage 5 with a possibility of radial movement the-' :
rein. A spring 12 gauged for the cutting force is located `'
between the bottom of' the boring and the butt end o~ the :
slide block 11. The holder 10 is free to rotate round the ro-' -
tor 3. ~he rotor 3 receives drive ~rom a sha~t 13 through ,:~'.
matched gears 14 and 15, the latter being rigidly set on -the .. ...
2 xotor 3. ~he holder 10 obtains drive ~rom a shaft 16 through
matched gears 17 and 18, the latter being rigidly fitted on ', .~
the holder 100 Drive 19 o~ the rotor 10 and o~ the traversin~,, ... -,.-
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mechanism o~ the carriages 5 has t~o output sha~ts 20 and 21 ;'
interconnected with the respective sha~ts 13 and 16 through .;
couplings. ~he drive 19 makes use o~ Q single motor 22 (eit~
her electric or hydraulic) which is connected to a shaft 23
o~ the drive 19 through a coupling. ;~
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The drive 19 t~igs . 3 ,4) comprises a housing accommodat-
ing a gearing consisting of matched gears 24 and 25~ the for-.
er being rigidly ~itted on -the shaft 23, while the latter
is rigidly set on the sha~t 20. A gear 26 is also rigidly ~et.
on the sha~t 20, said gear being i~ mesh with the external
gear rim of a dif~erential drive housing 27. ~he latter is `.
essentiall~ an inte~nal-and-external rim gear 27 loosely ro-
tatable round the sha~t 21 on which a gear 28 is rigidly set;`
being in fact the sun gear o~ the di~ferential drive. A pla~
/0 net pinion carrier 29 (~ig. 5) of the di~erential drive is
a gear loosely rotatable round the sha~t 21. Plane-t pinions ~ ,
31 are se~ on pins 30 o~ the carrier 29, said pinions being . .
in mesh with the in-ternal gear rim of the housing 27 and
with the gear 28 at a time. A gear rack 32 is mounted in the
housing of -the drive 19, capable of longitudinal motion, said
rack meshing the gear rim o~ the pinion carrier 29. ~he rack
32 is rigidly connected to a piston 33 o~ a hydraulic cylin~ .
der 34 that controls the traverse of the carriages 5.
With the device operating, the pipe joint is ~ed under
~o the cutting tool 6. To keep the pipes against rotation a ,`~
special arrangement i~ provided (not ~hown). Then the mo-tor
22 is turned in to impart rotation to the shaft 20 via the
gears 24 and 25, ~rom whence rotation is transmitted through
the coupling to the shaft 13 and ~urther, -through the match-
ed gears 14 and 15 to the rotor 3. Concurrently with the
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shaft 20, rotation is translated t~rough the gear 26 to
the dif~erential drive housing 27. With the pinion carrier
29 locked, rotatio~l is transmitted through the planet pinions
31 meshed with the sun gear 28 a~d the housing~ 27 to the.s~r ~.
21. '~he gear ratio of the dlf~erential drive is so selected
that with the pinion carrier 29 locked, the sha~t 21 runs at .::
a synchronous speed with the shaft ~0. ~otation ~rom the `~ .
sha~t 21 i~ transmitted through the coupling to the shaft 16
from whence rotation is imparted throug~h the matched gears
~o 17 and 18 to the holder 10. ~he gear ratio of the gears 17,
18 and o~ the gears 14y 15 is the same. Since the speed o~ :
the sha~ts 16 and 13 is the same with the pinion carrier 29
locked, the speed o~ the rotor 3 and the holder 4 is the sa-
me as well.
~ o impart ~eed motion to the cutting tools towa.rds the
pipe being maehined~ oil is force-~ed into the c~linder 34
with the result that the pisto~ 33 travels and urges the rack
32 to move and rotate the pinion carrier 29 round the sha~t ;~
21. Rotati~n o~ the pinion carrier 29 imparts some e~tra -.:
~o speed to the gear 28, thus resulting in di~feren-t speeds o~
the sha~ts 16 and 20. On that account the holder 10 starts
to advance the rotor 3 for an angle~ ~he result is that the
links 9 move the slide blocks 11 which urge through the
spring~s 12 to move the carriages 5 with the tools 6 towards ~ ~
the ce~tre o~ the joint being treated. As oil is ~ed into the .~ .
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cylinder 34 the tools bi-te into the ~in until the .rollers
8 star-t ri.ding over the pipe sur~ace, thus tracing the lat-
ter. In case of an elliptical pipej the cu-tting force will .-
rise when passing from the major semiaxis of the ellipse to
the minor semiaxis thereof, to eæceed the magnitude ~or
which the spring 12 is gauged, with the result that the :
spring 12 will be compressed, thus raising the carriage 5
above the slide block 11 and9 consequently, tracing the pipe
surface9 Upon ceasing the oil feed to the hydraulic cylinder
34, the ~eed motion o~ tha tools 6 discontinues, -too~ ~hus,
by varying the oil flow rate one can control the tool ~eed
rate. ~o return the tools 6 into the initial position, oil
~rom the hydraulic cylinder 34 is discharged, and the piston
32 is returned into the initial position, thus rotating the
carrier 29 o~ the planet pinions 31. ~hereupon the motor 22
is turned out.
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