Note: Descriptions are shown in the official language in which they were submitted.
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There are many machining or fabricating operations .
requiring a workpiece of irregular shape to be held secuxely on
a rotating support means, such that a portion o the workpiece i~
subjected to rotation about a predetermined axis of xotation.
When the wo.rkpiece has a regular ~hape, such as is the case for
cylindrical workpieces, there i~ no par~icular probl m involved
in holding the woxkpiece, ~or example, in the chucking headstocX
of a lathe or othex machine tool~ while effecting a acing opera-
tion, cutting a tread, or the like on the other end o~ the work-
piece, or placing a bead of welding material around the periphery
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¦ o~ the workpiece. ~wever, when the workpiece ha~ a shap~ other
¦ t:han a true cylindrical ~hape, BUCh a~, for example, when a
¦ workpiece i~ a pipe elbow, cson~iderable d.if~lcul'c~e~ are enco~n'cex
¦ ed in holding and centering the wor~piece ~uch as to ca~e ~e
¦ workpiece ~o rotate true aroun~ an a~i~ o~ rotation, w~ile ~ing
¦ 3ecurely held on the end o a rotatable ~pindle ~uc~ as a la'che
¦ head~tocac or ~he like.
A typical example o m~chining operation ox fabricating
. ¦opera~ion in whic~ conventional ahucking ix~ures are inappropri~
¦ate is one invvlving ~olding securely a pipe elbow o~ ~he end of
a rotatable ~pindle, for exampleO ~or f acing O beveling or ~hread-
ing one end of ~he elbow orO more partiaularly, for welding on
the end o~ the elbow a ~econd elb~w or a length of pipe by means
I c>f an arc or flame welder held in a fixed po~ition~ ~he 1:wo
¦ member~ to be connected being rotated in clo~e proximity to the
welder head
As it i~ not po~sible` to hold a pipe elbow9 for example~
by way of conventional c~ucking ~ixture~, such as conventional
lathe headstock chucks, holding flxtures have been contempla'ced
in t~he past consi~iting of an angle plate mounted in the lathe
chuck at an appropriate eccen~ri~ position~ and ~upporting ~he .
pipe elbow by ~ack welding ~he pipe elbow to ~he angle pla~e.,
Such an arrangemeIlt pre~ient~ ~nany inconve~ierlces~ he se~-up
must be changed fc~r each size of pipe elb~w., Tack welding of the
elb~w to ~he angle plate is a time-consuming and delicate
operation whidh sequire~i 6hiseling ~r grinding to seE~ara'ce t~he
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elbow ~rom the an~le plate at the ~nd o~ ~he machinlng or ,
fabricating operation. In addit~on, the ~urace o~ the elb~w .
iq marred, ~truatural integrity o~ tlle workpiece i~ jeop~rdized
and,when part specifications call for a part~culax m~tallu~gical
. 5 compo~ition o~ the elbo~ material~ ~uch a3 ~or ~me ~aînle~
steel materials, con~amination o~ the material may occur throug~
transfer of mate~ial- from ~he angle plate or due to the compo~i-
- tion o~ the weld u~ed ~or tack we~ding. Furthermore, non-
metallic pipe elbcw cannot ~e read~ly held in the fixture by tacX
weldingO
It is also rea~ily apparent that the ho7ding ~trength ia
dependent on the ~uality of the tack welding~ and that it may
happen that the taak weld breaks during a madhining operationO
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The disàdvantage ànd in~onvenierlce~ o the prior art are .
eliminated by the pre~ent inventi :>n ~ w~ich provide3 an aligning an
h~ lding ~ixture for an irregularly shaped workpiece, ~u~h as pipe
elbow~ and the like, ~or mounting su~h workpiece in a conven-
tional chucking arrangement or holding mean~, and permitting the
20 end or the portion of the workpiece on whic~h a machining or
fabricatislg operation is to be efected to be ac~urately aligned .
around a predetermined axis of rotation, ~ich provides s~urdy. .
clamping of l~he workpiece in po3iltion and which permits rapid
s:lamping and unclamping of~ ffie workpiece. ~he pre~ent inventio
accompli~he its purpose~ by mean~ of a holding ixt:ure in the
~orm o~ a aylindri~al member p~ovided at one end wi~h an
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appropriately angled and shaped ~eat portion enca~ing ~ por'cion
----- ~of the periphery o~ the workpiece, and wi1,h manually opera~le
clamp means in the form o~ a link chain, strap or 'ch~ liXe
capable o bein~ wrapped about a corre~ponding pc~rtion o~ t~e
S workpiece peripheral surface. q!he end o th~ clamp mean~ i~
provided with a ~hreaded mem1~er engageable between t~e branches ,
of a bifurcated bracket. A female threaded member provided with
manual grasping means, 8uch as a T-handle or ~e like ~ i~
threaded over t~e male ~hreaded me~er for dra~ing in t}~e clamp-
ing link chain or strap against t~he ~ur~ace o lthe w~rkpiece wi~h
enough pressure to hold ~he lat~er securely in position on the
holder seat.
. q~he diver e object~ and advantage~ of the invention will
become apparent to tho8e skilled in the art when the follo~ing
description of ~ome of the ~t mode~ oontempla'ced for practicing
~he invention is read in conju~ction with the ac!companying .
d.rawing wherein-
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FI&. 1 is a perspective view of an example o~ holding
2~ f~xture for irregular ~hape workpiece according to the pre ent
invention, mounted for rotation by a conventional ohucking
device;
FIG. 2 is a side elevation view ~hereo~, ~howing a
workpiece clamped on the end o~ the ix~ure;
2 5 FIG . 3 i~ a sec:tioll ~hexeof along line 3 -3 of ~IG . 2;
F~G ~ 4 is a ~ imilar ~o FIG. 3 but shawing a modif ica ~
tiorl 1~hereo ~ and . .
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¦ FIG. S i~ a view ~rom line 5-5 of FIG. 4. . ,
I ~eferring naw 'co the drawing, and more pa~ti¢ulaxly to
¦FIG. 1 thereo, an example o~ wor~piece ~uppor~ ~ix~ure 10
¦according to the present invention comprises an elongated membe~
¦or mandrel 12, aircularly cylindrical and pre~exably tubular
¦ having an end 14 ~or remova~le mounting be'cween t~ jaw~ 16 o~
¦ a conventional ahucking device 18, ~uc:~ as the headstoc3c chuck
1 of a machine lathe or t~he like. i~he cylind~ al member or mandre
10 ~ 12, when mounted in the c:huc~ing devi e 18 i~ adap~ed 'co be
l rotated thereby concentric about a rotation axis, shswn by dot
¦ and dash line 20 a~ FIG. 2 .
q~he free end 22 of the cyiindrical member or mandrel 12
I i5 cut along a pla~e di~posed generally at 45O with the longitu-
¦ dinal axis 20 o~ rotation of ~he cylindrical member or mandrel
12, and thu3 forms an annular ~ur~ace, generally ellipsoidal in
plane projection, de~ining a sealt 24 whic~ i~ preferably æhaped
` ¦ slightly concave as ~hown at 26 to ensure better engagement
¦ with a convex peripheral ~urface porSion of a wor~piece, such a~
¦ a workpiece 28, FI~S. 2 and 3.
The illustra~ed workpiece 28 i~ a 90 tubular or pipe
elbow 30~ l~he tllbular el~ow 30 i~ held in position on the.~eat 24
on the end of the cylindrical m~mber or mandrel 12 by mean~ of an
adjustable clamp mechani~m 32 which~ a~ trated at E~IGS. 1-3,
consists of a llnk chain 34 hingedly conn~cted at one end to a
block 369 FI~5. 1 as~d 3, by m~an~ o~ pivo~ pin 37. ~e blc:~c~c 36 .
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¦ i~ welded, for example, to the peripheral sur~ce o the cylind~1-
¦ cal member or mandrel 12 at an appropriate loca~ion proximate
¦ the seat 24, such tha~ the plane of :bending o~ the lin~c c~ain 3
¦ i~ ~ubstarltially or~hogonal ~co ~he ~eneral plane o:e the eç!at ~4.
S ¦ The free end of the link c~a:in 34 i~ provided with a ~hreaded ~tuc
¦ 38 hinged thereon, a3 ~hown at 40. ~ ~emale member Qr ~leeve
1 42 t:hread~ on the end of the threaded 8tud 38. For that purpo~e,
¦ the ~leeve 42 is internally ~readed or~ alters~atively, arld as
l illustrated in ~he drawing, the sleeve 42 may be provided on an
¦ end with a nut 44 welded ~ereon, which alone engag~ t~he t~read
f the threaded stud 38, the other end of ~he ~leeve 42 being
provided wi~h a T-ha~dle ~5 for manual grasp ~n aligned b~x
brackek 46 i~ welded on the pèripl~ery of the cylindrical mem ~ r
I or mandrel 12 proximate the ~eat 24, and the box braeket ~6 is .
¦ provided with a baqe plate 48 having a ~lot 50 a~ceptir~g the .
¦ threaded ~tud 38 there~hrough.
When it i8 desired to place a workpiece 28 suc~h a~ the
pipe elbow 3û in ~he holding ixture lO~ t~he pipe elb~w 30 is
. I positioned on the seat 24 in the position ~hown at FIG. 2, the
1 hinged link chain 34 i3 wrapped around 'che peripheral ~ur~ace of
the pipe el}~ow and the threaded stud 38 i5 engaged in the slot :
50 of the face plate 48 of ~he b~x bracXec 46.. ~he T~handle 45
i8 rotated 8UCll a~ to draw the threaded ~tud 38 and ~u~ apply
I the link chain 34 tightly around the periphery o~ th~ p~pe elbow
30. The ?ipe elbow 3û may be s:~lamped on the seat 24 on the end
o~ the holding ~ixture 10 with only enougl~ pre~sure ~o allow .
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~ligh~ lateral and longitudinal adjustment, a~ i8 generally done
when clamping a cylindrical workpiece in the c~ua~ing mem~er o~
la machine ~athe, to en~ure that; for example, the end ~or~ion 51
¦of the pipe elbow 30 rotates true relative to the axis 20 sf
¦rotation. Appropri.ate positioning gauges or rest~ may be used
to ~implify and make speedier the centering operation. Once th~
pipe elbow 30 i~ appxopriately centered, by rotating ~he T-~andle
45 addi~ional clamping pres-~ure may be exerted ~o ~ecurely hold
. ¦it on the eat 24.
¦ ~fter the workpiece 28, such a3 the pi~e elbow 30, is
securely and precisely mounted on the end of the holding ~ixture
¦ 10, any appropriate ma~hining operation, 5uch as ~acing, thread-
¦ ing, chamfering, or knurling may be effected on the end o~ the .
I elbow b~ appropriate tool~, while rotating ~e holding fixture 10
- 15 ¦ around its.~axis o~ rotation 20. It can alQo be seen ~hat the
l holding and aligning fixture 10 o ~he invention may be u~ed for
¦ holding an irregular shape workpiece such as the elbow 30, in
¦ alignment wi~h~ ~or example, a length of pipe~52, shown in phanto~
I line at FIG. 2. By rotating the pipe elbow 30 and th~ len~h of
¦ pipe 52 in unison, a weld bead may be deposited at thP junction
between the ~wo parts by mean~ of a ~tati~nary welding head.
The other end o the length of pipe 52 may be held in a rotatable
chucking mechanism, not sho~n~ rotated in uni~on with the
chuckiny mechanism 18 holding the holding fixture 10. In t~e .
25 alternative, ~he leng~h of pipe 52, supported by appropriate
re~t3, may b~ al~gned wit:h 'che axi~ 20 sf rotation, and ta~k
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welded to the end 51 o~ the pipe elkow 30, prior to ~eing rotated
in uni~on with the holding i~ture 10 a full xevolution rotati~n,
or any number o~ re~uired revolution~, o~ applying an app~opria~
weld bead at the junction be~ween ~he part~. Wh~n the o~h~x ¢nd
of ~he length o~ pipe i8 already provided with a~ elb~w, o~
where it i~ de~ired to weld together end to ~nd two elba~, t~e
o~her elbow may be held in a rotatable chucking mec~ani~m by
mean~ o~ second holding fix ure 10.
~ s an alternate ~tructure, ~he link chain 34 may be
replaced ~y a strap, ei~her ~lexible ~uc~ a~ to wrap firmly
around She exposed peripheral surfa~e of ~he workpiece, or rigid
a~ he rigid U-~haped strap 53 o~ FIGS. 4-S, hinged at one end
to a support block 37" and provided on it~ other end with a
threaded stud 38 having a bifurcated end 54 connected to the
~trap 53 by means o~ a hinging pin 55~, ~he remaining etructuxe
being the same a~ hereinbe~ore explained in detail~ The inner
sur~ace o~ ~he strap 53 may engage directly the peripheral ~
3urface o~ the pipe elbow 30, or, a~ ~hown at F~G. 4, it may be .
provided with a plurality of peds 56 for engaging such peripheral
~ur~ac~. The pads 56 may be made of so~t material or may be made .
c~f material-e having the same composition a~ ~he material making. u~ ,
the pipe elbow 30, such as to avoid contamination of the material
o~ the pipe elbow when the elb~w i~ heated during welding,, where
ContamirlatiQn i8 'CO be avoided a~, for ex~mple, while a}: rica t:i ng
a piping ~ystem fox critical chemiæa} or refine~in~tallations,
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¦ Although the holding fLxture 10 ha~been ~escribed and
¦ illu~trated as comprising a tubular member 12 o constant diame~
~er ~ro3r~ end to end, ~t will be apprec:Lated that where lt i~
~ desired to manuacture holding ~lxture~ ~or holdlrlg wo~piec~s
I of large 3iæes, and the opening of the chuc~ing mec~ani~m holdin~
¦ the ~ixture is limited, a tubular or mas~ive cylindrical member
l o~ a diameter which can be accon~nodated by the ~ihucking mechanism
¦ i9 provided on it8 end w~.th a tubular member o~ larger diameter
¦welded or o~herwise astened thereon, the tubular member o~
. 10 ¦ largex diame~cer beingO in turn provided with thP appropriate seat
24 ;Eor recelving and holding in clamping a~rangement a workpiece
of irregular ~hape. It will al80 be readily appreciated that
the principle o~ ~he invention i9 adaptable to holding workpieces
l other than 90 elbows, such a~, for example elbow~ o~ angles .
¦ othex ~han 900 and other irregular ~hape wor~pieces the orien-
tation o~ ~he ~everal plane of She workpiece receiviny seat being
a function of the shape o t~e workpiecè and of ~he alig~ment
l o-the portion o~ the workpiece which it is desired to rotate
¦ concentria to a predetermined axi~ of rotation.-----~
~aving thus de~c~be~e~inven~ion by way of examplQs
-o~-~-s~tructural embodiment t~hereof~, modificatiorls whereo~ will he.
apparent ts~ thos~ skilled in ~he ar~, wh t i~ claimed as new i~
as ollcws.
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