US2515752A - Stretcher press - Google Patents

Description

Sheet-s-Sheet l My 18, 1950 w. A. WEIGHTMAN STRETCHER PRESS Filed Dec. 13, 1944 W. A. WEIGHTMAN `July 1s, 195o STRETCHER PRESS `Fi1ed nec. 15, 1944 2 Sheets-Sheet 2 1 INVENToR WilumAM/eghman 7. Zwzvmm uw O -1L/WIFI:

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A TTORNE Y Patented July 18, 1950 STRETCHER PRESS William A. Weightman, Philadelphia, Pa., as-

signor to The Budd Company, Philadelphia, Pa., a corporation of Pennsylvania Application December 13, 1944, Serial No. 567,983

7 Claims. (Cl. 153-32) The invention relates to astretcher press and more particularly to a machine of this type adapted for simultaneously bending and stretching proles into curved forms.

Among the objects of the invention is a machine of the indicated type which is easily operated and which allows the production of a great variety of shapes including shapes with curvatures in more than one plane. y

Another object of the invention is amachine'ljg) of the indicated type which can easily and speedily be adapted or changed to the production of differently shaped articles.

The aforesaid objects and other objects and advantages are achieved' by a machine having `pairs of power driven independently movable the embodiment illustrated in the attached 30 drawings and described in the following.

In the drawings:

Figure 1 is a plan view of a machine showing diagrammatically the control circuits for the r different movable elements, certain parts being broken away; f

Figure 2 is a section on a larger scale along lline 2-2 of Figure 1` withone of the armsrswung about 90 from the positionshown inFigure 1;

Figure 3 is a section throughone of the arms 30 along line 3-3 of Figure 2 on a still larger scale; and

Figure 4 is a fragmentary section along line 4-4 of Figure 1 on a scale larger .than thatWil of Figure 2. Y A l V e#SI5 A floor I9 supports a base plate II. Part of the plate II coversy a well I2 in the floor II) the side walls of which are formed by beams I3. An upright wall I4 has its lower margin secured to a reinforcement l5 of the base plate and its w40 upper margin to a table top IB.. Webs I1, I8 and I9 interbrace said wall |4said reinforcement |5 and said top I6.` The web |8= is arranged along the vertical center line of the ,5 members II, I4, I5 and I6. The webs Hand the wall I4 are further interbraced by horizontal webs 20.

The upper side of the top plate I6 is' adapted for the securement thereto of a bending die 2|, ..250 as by means of bolts 22. The free edge of the top I6 running parallel to the wallA I4 is reinforced by an upwardly directed ange 23. `The latter has screw threaded therein bolts 24 serving for the adjustment of the"`die 2|. The die -55 plate l l.

2| and its'use will be described more fully later Secured to the bottom plate is a pair of gibs 25 which run parallel to each other and to the wall I4. Another gib 26 is secured to the wall I4 and extends horizontally on both sides of the web |8.

A pair of generally U-shaped structures 21 engage with mating gibs 28 and 29, respectively, the aforesaid gibsl 25 and 26 so that the structures 21 are slidably guided on the structure formed by the plate II and the wall I4. Each structure 21 has a vertical web 3|) carrying the gibs'29, a lower horizontal arm 3| of considerable length carrying the gibs 28 and a short horizontal upper arm 3|. The lower arm'is in the form of a circle segment and has secured to its. periphery a rack 32. I

Secured to the underside of the plate I I and arranged inthe well I2 is an electric motor 33 which `through gears 34 drives a short shaft 35 rotatably supported in bearings 36 secured to -the top of the plate II and which is controlled by the diagrammatically illustrated switch 33'. The shaft extends parallel to the hereinbefore described gibs 25 and is arranged co-axially with a pair of screw threaded shafts 31 the outer ends of which are supported rotatably but axially immovably in'bearings 38 likewise secured to the The vscrew threaded portions of the shafts 31 engage nut members 39 secured to the arms 3|. Between the inner end of each shaft 31` and the `adjacentouter end of the shaft 35 is arranged a coupling 40. The two couplings 40 are independently controllable, as by linkage and lever systems 4|, 42. l

- -f A pair of generally horizontally arranged arms 43 `have their inner 'ends journalled rotatably about'a vertical axis to the arms 3| and `3| of the` structure 21 at 44.l At some distance from the journal 44, each arm 43 rests by means of rollers 45 on the top surface of a horizontal extension 46 of thearm 3|. Each arm carries a motor 41 which through gears 48 drives a pinion 49 engaging one of the racks 32. The motors 41 of the two arms are controllable independently of each other by a pair of control means diagrammatically illustrated at 50'in Figure 1. Each arm 43 extends outwardly beyond the roller support 45, 46 and has itsv extended portion' provided with apair of horizontally spaced vertical gibs 5|."The gibs 5| are engaged by correspondingly shaped gibs 52 provided on a horizontal beam structure 53. Each beam structure 53 carries an electric-motor 54V which through `gears 55, drives a horizontal shaft 55 rotatably supported in bearings 51 on downward extensions 58 of the beam structure 53. The shaft 56 has secured thereto near each of its ends a Worm 59 which is in driving engagement with a worm wheel 60. Each worm Wheel 60 is held between lugs 6| of the extension 58 and is secured to a screw threaded shaftr62. TheL-screwwthreads of the shaft *62 engagethe correspondingly screw threaded interior of a lug 63 formed integrally with the respective arm 43. Here again each of the two motors 54 is independentlyscontrollable by a pair of control means 64 diagram-- matically illustrated in Figure-1.

Each beam structure 53-'carniesin bearing's'165' rotatably but axially stationarily a second "shaft B6 which is screw threaded:foversthe/greater part of its length. The shaft 65 is in driving connection with a motor 61 by means of gears. "'T-he motor El' is supported by the respective beam 'structure 53 :controllable :independently f the corresponding motor on the other arm .by the` control means GBL-'diagrammatically shown iin Figure l. A

' Acpairaoffsleds '1n rare 'slidingly supported by gibs :1l lformed :thereon and .correspondingly shaped guideways 12 of the beam'structures 53. lEaclfiisled i110 is in.fscrew':threaded engagement Vwithcwonesof the/shafts :15.6 `so *that -rotationfnf the-latter causes'fthe sled to move along-its suptporiting beam structure 2:53.

nf-hydraulic cylinder 13 isjOurnalled at'w'M fto zlugs '11.1.5crintegrally:securedtoza the. asled 119. vThe -opposite end vof the :cylinder 13 `has' rollersfI-S which :irun on :a =rsegment shaped :portion 11 of fthelisled`1'll. iA piston `18 in' the interior of A.the icyl-inclerzzlS'sis connectedfvto a rod 19 `which carries a vise ll swingably .around-:anhorizontal bolt 581|.

Thevisess `are .adapted for'rm fbut releasable engagement :ofrrone xendeach Yfof a workpiece'BZ by 'means of jaws '83. .The tdrawings'show.l an angle section workpiece but. itshouldv be understood :that a ygreat variety `.pi'ffcross'-:sections may ibe bentfbyzthe illustrated machine. Of. course, 'the jaws of the '.vi'ses 8l 'andtheidle: 25Il'xlf1ave 'lto` :be shapedzinraccordancewith thecross-section oflthe workpiecezato be'made.

Pressure Amedium may be :admitted to andadis- ``charged `-from the cylindersJS-by means o'f the zpiperlines- Stand .thezvalvesflB `andfthe return V.of -the'pistons ymayiber effected yby .springsul #The :pressure imediunixis supplied :'by the A.pump :ll-'l driven by motori88. The ldrawing clearly :shows the :substantially symmetrical construction offfthel machine Arela- '.tive'to fa verticaletransverse .planeand 4.the .proiy-.ision Iim most elements' in :.pairs.-.even though, .ticcasionally `for,rsimplicityssake, one .of the. Ielements'onlyqhasbeen `'referredto in fthe foregoing description.

:The Aoperation of the newrmachineunder-dif- .ferent fconditionsfwill .nowibel briefly described.

-If,:. as -in Lthe 'illustrated embodiment, the fdie lfhas azworkingsurfacewhlich .is curved in: one pl'anelonly and whichisesymmetrical to a `center =line,':theidie .is placed in the:machine. sof'l:hat its centerline coincidesr iwith the. center line fofthemachine. .'Ilhe .location of the journals #Agris adjusted bysmeans-.o'f the motor 33 and the .transmissions .driven thereby. 'The fs'leds i 10 are movedbyzmeans of Ithe motors 61 along the beams 53ste positions -at which the `viseswall arecat-a distancel from each other v:equaling about fthe length :of .theI workpiece :82. .Alsowthefheight of the visesy is adjusted so that they are at the same level with the working surface of the die 2l; this adjustment lis done by the motors 5A and the transmissions between them and the beam 53.

5 After these adjustments the workpiece 82 isplaced with its ends in the Vises 80 and secured therein while the arms 43 are in the position illustratedfinfliigure 1. Pressure medium is now admitted'to the cylinders 13 so 'thatthe worklo piece 82 is stretched and, while the workpiece 'sis under tension, the arms 43 are swung toward `each other about their pivots 44 by means of 'their motors @1, the transmissions 48, the pinions .lfllgfzand the vracksflil The tension of the work- *bend-ing "operation by reference to a pressure .gaugeattachedtothe cylinders 13, to any part of the conduits for the pressure medium or to the-pump 81.

If the working surface is more complicated fthanizillustratcd, for :instance longer, non-'symcmetrical; and inradditioncurved lin vertical direcvtion; differently: oncboth Ysides of its middle plane, then each arm andthe elementsattached thereto-:havelto'be .moved independently of eachother 4by means ofiithe--hereinbeiore 'described motors v:and controlmechansmsm64, 69. For instance,

one vise fall. may be moved-upward by. means of the motor .5A fwith its supporting. beam-53rand esledflftothe position illustrated by-dot-and-.dash 'ilinesinjzFigure 2,lwhereasfthe other vise fallmay .belkcpt .dependentali-pon' the .form :of the die, fon

the original level:.or.may even ,bemoved'downwa-rdly: :by -itsf motorr54- 'Similarlyfeach. ofthefarms 133 may be independently .moved according to laws .dictated by the formlof the die. This :independentfmeve- .mentfdoes notfonly sapply. to the .swinging Labout .-the.journa1s 44, :but even the location-offthe 40 rjournads may be-'changedduring .thefbendingand stretching '.operation.

No attempt is made to illustrate-and .describe .inf-.detail i Aany n of thoseamany. .forms which :may .be made on. the newmachlineby proper. coordina- .tionf of the different ...independent Emovements. Anybody skilled in the art knows theproblems ,and ...will .easily .recognizemthe Ipossibilities .off ered l,bythenew machine and how. to operate it so ras .to cope. with .any .one ofsuch` problems.

.Theinvention is vnot: restricted to thedetails .oftheillustrated embodiment. For instance, .oer-

tain parts of the machine may be omitted while nthersmay. .be .,substituted. by equivalent. means. Consequently, .protection .sought for the .inven- .55 tion as broadly as covered by the spirit-andy the .language of .theattached claims.

Whatis .claimed ist 1. In astretching. andy bendingmachine, a base structure, means on saidbase structure for. sup- 50 ,portinfz an arm swingable .about an axis, atormingdie stationarily supported on said base structure inthe region ofsaid axis, an elongated .structure coextensive with at least a major ,portion of 'said armand-'supported thereby moi/ably' back and forth vin a fdirectionjgenerally,parallel to said "axis of rotation, a sled slidable on said structure yback -an'dfforth'radially with respect to said' axis, means supported on said sled for firmly holding -a-woi'*k-piece,4 and means for `holding a workpiece .at a distance. from lthe -pointheld bythe aforesaid. holding means.

i2.In a stretchingr and bending machine,1a base 'structure-:means on rsaid base structure for supporting an arm swingable about anlaxis, a 'form- :ing diestationarily supported on saidf-lbase'structure in the region of said axis, an elongated structure coextensive with at least a major portion of said arm and guided thereon movably back and forth in a direction generally parallel to said axis of rotation, a sled slidable on said elongated structure back and forth radially with respect to said axis, means supported on said sled for iirmly holding a workpiece, means for holding a workpiece at a distance from the point held by the aforesaid holding means, a motor supported by one of said arm and said elongated structure, a transmission between said motor and other of said elongated structure and said arm so as to move said elongated structure on said arm during the operation of the machine.

3. In a stretch forming machine: a support and a forming die mounted thereon, a pair of means for rmly holding a workpiece in two spaced regions thereof and for stretching the workpiece between said means, an arm rotatable about an axis relative to said support, means on said arm for supporting only one of said holding means movably in a direction extending about parallel to the axis of rotation and at a distance from said die mounted on said support, while said workpiece is held by said pair of holding means in stretched condition in contact with said die.

4. In a machine for stretching and bending, a base, and a forming die supported thereon, a pair of devices for immovably engaging spaced points of a workpiece and for stretching it between them, means for supporting said devices on said base, said supporting means being adapted for moving the devices independently of each other in three diiTerent directions relative to said die supporting means which directions define co ordinate planes of a spacial coordinate system, while said workpiece is held by said engaging devices in stretched condition in contact with said die supported on said base.

5. In a machine for stretching and bending, a base, and a forming die supported thereon, a pair of devices for immovably engaging spaced points of a workpiece and for stretching it between them, means for supporting at least one of said devices on said base and for moving it independently of the other device in three coordinate planes relative to said die supporting means while said workpiece is held by said engaging devices in stretched condition in contact with said die supported on said base.

6. In a stretching and bending machine, a supporting structure, a forming die supported thereon, a pair of arms swingable about generally parallel axes relative to said structure, means on each of said arms for gripping and stretching a workpiece, a supporting device and power actuated means for each of said gripping means adapted for moving the latter in the direction of its respective arm, and power means controllable independently of said first-named power operated means for moving said gripping means relative to said supporting structure in a direction generally parallel to the direction of said axes, while said workpiece is held by said gripping and stretching means in stretched condition in contact with said forming die.

7. In a machine for stretching and bending, a base, a forming die supported thereon, a pair of devices for holding and stretching a workpiece between them, means for supporting at least one of said devices on said base for movement independently of the other device in three intersecting directions defining three coordinate planes, and three separate and separately controllable motors each of which is adapted for moving the respective device in one of said different directions while the workpiece is held by said stretching devices in contact with said forming die supported on said base.

WILLIAM A. WEIGHTMAN.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 537,550 Schacht Apr. 16, 1895 716,555 King Dec. 23, 1902 957,200 Gail May 10, 1910 1,447,299 Freeman Mar. 6, 1923 1,710,261 Kellogg Apr. 23, 1929 1,968,010 Bailey July 31, 1934 2,155,160 Bruno Apr. 18, 1939 2,190,423 I-Ienricson Feb. 13, 1940 2,255,867 Wisckol Sept. 16, 1941 2,305,850 Drysdale Dec. 22, 1942 2,357,027 Seifried Aug. 29, 1944 2,370,329 Seifried Feb. 27, 1945 2,431,173 Hawkes Nov. 18, 1947 2,446,089 Hochreiter July 27, 1948 FOREIGN PATENTS Number Country Date 482,769 Great Britain Apr. 5, 1938

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