US1149356A

US1149356A - Metal-bending machine.

Info

Publication number: US1149356A
Application number: US76497813A
Authority: US
Inventors: John M Fedders
Original assignee: Fedders Manufacturing Co Inc
Current assignee: Fedders Manufacturing Co Inc
Priority date: 1913-05-02
Filing date: 1913-05-02
Publication date: 1915-08-10
Anticipated expiration: 1932-08-10

Description

L M. FEDDERS.

METAL BENDING MACHINE. AEPLICATION FILED MAY 2, 1913*.

4 SHEETS-SHEET l'.

l. M. FEDDERS.

METAL BENDING MAcHlNE.

APPLICATION FlLED MAY 2| 1913,

Patented Aug. 10,1915;

Lmma.

NIQ

' by @qua/z 5% ATTDRNEY;

J. M. FEDDERS.

METAL BENDING MACHINE.

APPLICATION man, MAY2,191a

M L z-Fh, D W W Mm )N N Mw... 4 l T m HN! A m n n M e\\, www lm, uw mu hm* :l 0N F BQN m.\ i@ QN. x@ W QR @m N@ n@ R m l nu.. m .Eh 5 M ww .W w Km QMS www 5 1 l E b -Hwa wm \m 530m/ w Il k :H E uw m mb Q@ .mi M @L QB F. @L kN. m@ m l .m .mi .M W W w Cit JOHN' M. FEDIJERS, 0F BUFFALO, NEW YORK, ASSIGNOR, BY MESNE ASSIGNMENTS, T0

FEDDERS MANUFACTURING COMPANY, INC., OE BUFFALO, NEW YORK, A CORPORA- TION F NEVI YORK.

Specification of Letters Patent.

METAL-ENDING MACHINE.

Application led May 2, 1913. Serial No. 764,978. l

. of laterally projecting plaits and also longitudinal offsets so that these strips may be used in the manufacture of Water cooling radiators for automobiles.

In the accompanying drawings: Figure 1 is a perspective view of a metal bending machine embodying my improvements. Fig. 2 is a fragmentary horizontal section showing part of the mechanism for operating the locking device for one section of the die. Figs. 3, 4, 5, 6 and 7 are fragmentary vertical longitudinal sections of the die and punch of the bending machine showing the parts of these'members in the different positions which they occupy during the operation of producing a radiator strip. Fig. 8

is a vertical transverse section taken in line 8 8, Fig. 3 and showing the radiator strip disengagedfrom the die and punch. Fig. 9 is a bottom plan view of the punch. Fig. 1() is a top plan view of the die.- Figs. 11 and 12 are fragmentary vertical longitudinal sections taken in the correspondingly numbered lines in Fig. 8. Fig. 13 is a perspective view of a portion of the radiator 'strip which is produced by the metal bending machine of this invention. Fig.` 14 is a vertical section showing the manner of assembling two of these radiator strips for producing a plurality of air tubes.

Similar characters of .reference indicate corresponding parts throughoutV the several' views.

Although my improved metal bending machine may be utilized for. producing strips of metal which have been bent into various forms the machine illustrated in the drawings is designed more particularly for producing a radiator strip of sheet metal which in its finished condition comprises a succession of transverse webs 1 which are arranged lengthwise side by side "in a longitudinal row, a pluralitv of laterally projecting plaits 2 the walls of which are connected at their outer edges while ltheir inner edges'are connected respectively with the opposmg'transverse edges of two'adjacent webs, outwardly projecting offsets or beads 3 arranged longitudinally at opposite lateral edges o f the webs and in a direction lengthwise of thestrip, and afplurality of outwardly projecting beads 4 each of which is arranged lengthwise on the central part of each web and forms a longitudinal groove or seat on the inner side of the respective web, as shown in Fig. 13. In the assembled condition of two strips of this character each plait of one strip is arranged between two plaits of the other strip and engages its free edge with the groove or seat on the web of the other strip between the two plaits thereof, thereby forming a row of air tubes 5 between the two strips, as shown in Fig. 14. The longitudinal beads on the outer sides of the strips engage with corresponding beads on the strips of adjacent rows of air tubes, thereby forming intervening channels or conduits between adjacent rows of air tubes as shownv in Fig. 14 through which the water liows and is cooled by the air passing through the tubes.

punch or upper member thereof which is movable vertically toward and lfrom the die isindicated as a whole by the numeral 7. The die is mounted on the stationaryholder, support or table 8 forming a part of the main frame of the machine while the punch is mounted on a vertically movable head or holder 9 which is guided in any suitable manner on a standard 1() forming part of the main frame-and projecting upwardly from the rear part of the table. Although the punch may be operated by any suitable means the same -is represented in the drawings as beingY raised and lowered by means ofl a crank shaft l1 journaled horizontally and transversely in the upper part of the standard and having its crank connected by :means of a pitman or connecting rod 12 with the punch holder as shown in Fig. 1.

The die in its general organization jcomlil) prises a body having a horizontal main base 13, a horizontal sub-base 14 resting upon the main base, a front cross bar 15 mounted on the frontfpart of the sub-base, a rear cross bar preferably constructed of two sections 16, 17 which are mounted transversely on the rearpart of the sub-base, and two longitudinal side bars 18 connecting corresponding ends of the front and rear bars so as to produce, in effect, a body having a rectangular socket in its upper side. lVithin this socket of the body are arranged the main or workingsections of the die which comprise a front die section 19 arranged immediately in rear of the front cross bar, and a rear die section or holding section 20 arranged in rear of the front die section andengaging its rear side with the frontv face of the front section 16 of the rear cross bar. The rear die section is capable only of vertical movement while the front' die section is capable only of horizontal movement toward and from the rear die section for the purpose of decreasing andV increasing the space between the opposing vertical faces of these die-sections and -operating upon the strip of metal in a manner which will presently appear.

Normally the rear die section is yieldingly held in its elevated position in which the upper side of the same is above the level of the front die section and the cross`bars of the die body. The preferred means for holding the rear die section in this positionas shown in the drawings comprisey a supporting rod 21 secured with its upper end to the underside of the mainfbase of the die body, a supporting disk 22 mounted on the lower end of this supporting rod, a lifting spring 23 engaging its lower end with the supporting disk, a lifting disk 24 engaging with the upper end of the lifting spring, and two lifting rods 25 guided vertically in ways formed in the main and sub-bases of the die body and engaging their lower ends with the upper side of the lifting disk while their upper .ends engage with the underside of the rear die section. The upward movement of the rear die section under the action y of the lifting spring 23 is limited by engagement of the lifting disk 24 with the underside of the main base. The rear die section* is guided on the body of the die by constructing its opposite ends of tapering or V-shaped form, as shown at 26 in Fig. 10, and 'engaging the same with correspondinglyshaped vertical grooves or ways in the adjacent partsl of the inner 'sides of the longitudinal'bars of the from being lifted out of theV die body by means of stop pins27 projecting laterally fromM-,Opposite .ends thereof into vertical slots 28 formed in the adjacent portion of thebody side bars, as shown in Fig-8. On

die body., The rear die 'section is` further guided and also prevented its upper side the rear die section is pro-l vided in the central part thereof with a transverse rib 29 and near opposite ends thereof with longitudinal'ribs 30.

Normally the front die section 1s yield-l adjacent part of the respective longitudinal bar, as shown in Fig. 10. Means are provided for holding the rear die section, when depressed, temporarily in this position and means are also provided for moving the front die section toward the vrear die section while the latter is in its depressed p0- sition, said locking mechanism for the rearA die section andv the means for shifting the front die section rearwardly being preferably combined and constructed as follows:

35 represents two locking openings formed lengthwise in the rear die section and adapted when this section is in its lowered position to be arranged in line with corre. sponding locking openings 36,' 37 formed` respectively in thev front die sectionfand in the front section of the rear cross bar of the body. l a

38 represents two horizontally and longitudinally movable locking pins or rods which in their foremost position have their ings of the front die section, as'shown 1n rear end'sarranged within the guide openy Fig. 3, but which in,their rearmostposition enter the locking open/ings on the rear die section and/the reaecrossbar and hold the rear die section in its d epressed position, as shownrin Figs. 5y and Adjacent to its front end. each of the locking pins is provided w'ith a rearwardly facing shoulder y39 which is adapted to engage with the front` side of the front die section; In the foremost or retracted position of each locking pin its shoulder 39 is disengaged from the front side of the front die section, as repre'- sented in'Figs. 3 and-1. After the locking pin' during its rearward movement has passed through the respective locking opening of the rear die section .and has entered thel locking opening 'o f the rear cross bar the shoulder 39 of the locking pinengages 1 l with'the front side "of the' front die section, as shown in Fig. 5, so that during the last portion locking pin its shoulder causes the front die section tol be moved rearwardly toward therear die section, as shown in Fig. 6.

The reciprocating movement ofthe two 12's of the rearward movement ofthe l locking pins for locking and unlocking the a pin 44 depending rear die section in its loweredl position and also moving the front die section toward the rear die section and permitting the springs 33 to again move the front die section into its forward position may be eiiected by various instrumentalities but preferably by the means which are shown in the drawings and which are constructed as follows: represents a longitudinally movable slide which is guided in horizontal ways on the front part of the main base of the die body and to the rear end of which the locking pins 38 are adjustably secured preferably by providing the front ends of the locking pins with screw threads which engage with correspondingly threaded openings in the rear end of the longitudinal slide and lockingnuts 41 applied to the screw threaded portions of the locking pins and engaging the rear end of the longitudinal slide. 42 represents a horizontally and transversely movable slide guided in a .way formed on the Afront part vof the die base below. the longitudinal slide 40 andprovided with an'oblique slot 43 forming a cam which receives from the front end of the longitudinal slide.= 45 represents a rotatable cam mounted on the adjacent end of the crank shaft of the machine and proj vided on its outer side with a cam groove 46. 47 represents an upright rock lever pivoted on the standard of the machine and provided on its upper arm with a roller 48 which engages with the groove of the rotatable cam while its lower arm is operatively connected with the transversely movable slide 42, as shown in Fig. l. During each operation of the machine the rotatable cam 47l moves the transversely movable slide for-v ward and backward whereby the cam slot 43 causesthe llongitudinal slide to make a forward and backward stroke, the movements of these parts being so timed that they harmonize with the movements of other parts of the machine with which they cooperate. The upper side or face of the .front die section is provided on its central part with a transverse rib 48 and adjacent to its opposite ends wit-h longitudinal'ribs 49 which are-in line with the longitudinal ribs of the rear die section.

Means are provided for ejecting or lifting the strip of sheet metal from the front and rear die sections after each stamping operation which means are preferably constructed as follows: 5,0 represents two vertical ejector pins arranged between the front and rear die sections and each guided with its lower part in a guideway formed in the adjacent parts of the sub-base and the main base of the die body, as shown in F ig. 1l. Each of these ejector pins is yieldingly held inits elevated position in which its upper end is near the top of the die section by 'in F ig. 11,. In order to permit the front die section to approach the rear die section without interfering with the ejector pins the opposing vertical faces of these die sections are provided 'with

recesses

53, 54 in line with each ejector pin which provide the necessary clearance adjacent to these pins and prevent the same from being pinched between the front and rear die sections as the front section moves toward the rear section.l

In its general organ1zat1on the punch comprises a body having abase 55 which is secured to the vertically movable punch holder, a punch block 56 secured to the underside of the punch base, a forming blade 57 fixedly mounted on the central part of the punch block so as to project downwardly from the underside thereof vertically in line with the space between the front and rear die sections, a front punch section 58 arranged on the underside of the punch block vertically in line with the front part of the face of the front die section, an intermediate punch section 59 capable of vertical motion relatively to the punch block and arranged between the front punch section and the forming blade and vertically'in line with the rear part of the front die section, a rear punch section or'holding section 60 movable'vertically relatively to the forming blade and the punchbody and arranged in rear of the forming blade and vertically in line with the rear diesection, and a gage blade 61 mounted transversely on the rear yside of the rear punch section vertically in yparts ofthe longitudinal ribs fof the front die section. r.Phe main part df the face of the intermediate punch section isflat and adapted to coperate with the flat rear part of the face of the front die section and near its opposite endsthe same is provided with longitudinal groot/es 64 which ,are adapted to cooperate with the rear parts of the longi.

tudinal ribs of the front die section. rI`he intermediate punch section is `gulded in a 66 and guided in a pocket-68 formed partly' in the adjacent part of the punch block and in the punch base and a spring 69 arranged in the pocket 68 and bearing at its upper end'against the bottom of this pocket and at its other end against the head lof this shifting pin, as shown in Fig. 12. The

downward movement of the intermediate punch section relatively to the front punch section is limited by means of a downwardly facing shoulder 70 formed Aon the intermediate punch section and engaging with an upwardly facing shoulder 71 on the` punch block, as shown in Figs. 3 and 12.

The rear punch section or holding section is guided in a suitable way 72 on thel underside of the punch block and is yieldingly held ina depressed position relatively thereto so that the .face thereof is below. the face of the front punch section and also be- -low the forming blade, this being preferably eected by means of two shifting pins 73 guided in suitable openings in the upper cally in a pocket 75 formed in the adjacent.

part of the punch block and each connected at its lower end with the rear punch'section, a head v"ill secured to the upper end of each of these shifting rods and movable vertiupper part of the punch block and the punch base and a Vspring 76 arranged in this pocket, and bearing at its lower end against the head 74 and a't its upper end against said pocket. The downward movement of the rear punch section relatively 4to the punch a clear space between the same and the die block is limited by the heads the shifting pins 73 engaging with the lower ends ,of the pockets 7 5, as shown in Fig. 3. The underside or face of the rear punch section is provided on its central part with atransverse groove 7 7 which is adapted' to coperate with the transverse rib of the rear die section and adjacent to its opposite ends 'the same is provided with longitudinal grooves 7 8 which are adapted to cop'erate with the longitudinal ribs ofthe rear die section.

Retaining means are provided for holding the sheet metal strip in place on the rear die section preparatory to engaging the strip by the parts of the die' and punch which change the shape of the s ame. These retaining means preferably comprise two.

vertical retaining rods 79`each of which is arranged in correspondlng vertical openings formed inthe intermediate punch section while its upper end engages with the upper end of said pocket. In the normal position of each retaining p1n the same is moved downwardly relatively to the intermediate punch section so that its lower end projects below the lower edge or face of this punch section, the downward movement of this pin in this direction being limited by the bearing head 80 at its upper endengaging with the lower end of its companion pocket S1, as shown .in Fig. 3. p Y A Various means may be provided for s upplying the strip of sheet metal from which the radiator section is made those shown in the drawings for this purpose being suitable and constructed as followsz'83 represents an arbor or spindle upon which a roll 84 of the sheet metal strip is mounted and which is journaled atits opposite ends lin bearings 85 mounted on the main frame of the machine. From the roll 84 the strip of metal passes forwardly between two feed rollers 86, 87, mounted insuitable bearings on the frame. One of these feed rollers, preferably the lower one is provided with a ratchet wheel 88 which is engaged by a feed pawl 89 mounted on a rocking feed lever 90 which is pivoted concentrically with vthe ratchet wheel. A rocking motion is imparted to the ratchet lever -by means of a connecting rod 91 vconnected at its lower end with the free end of the rock lever while its upper 'end is pivoted by means of a crank pin 92 to the outer side of the rotatable cam on one side of the center of the crank shaft. This-strip feed mechanism is so timed that when the punch is elevated so as to provlde the strip of sheet metal is advanced one step after which the strip of metal is permitted to remain at rest until the same is operated upon by the punch and die.

After each operation of the machine and while the punch is raised the 'strip of metal is advanced one step and placed with the last formed plait against the rear side of the rear die section, the last formed transverse -bead in engagement -with the rib of the rear die section, and the last formed longitudinal bead over 'the longitudinal r1bs of the rear .die section, as shown by full lines in Fig. 3. At this time the locking pins are in their foremost position,the front die section is in. its forward position, the rear die section is elevated, the intermediate -punchsection is projected below the front rear punch section projects below the forming blade. The punch now descends and during the first part -of this movement the plungers 7 9 engageA first with the sheet and then the gage blade engages with the previously formed plait, the rear punch section engages with the top of the sheet metal blank so that the same is gripped between this punch section and the rear die section and the retaining rods 79 engage with the strip in frontof the rear die section and are caused to' retract upwardly into thel punch, as shown by dotted lines in Fig. 3, therebyobtaining a firm grip upon the strip of metal for reliably holding the same in place preparatory to performing the next stamping and bending operation on the same. During the next portion or step of the downward movement of the punch, the forming blade and the intermediate and front punch sections move downwardly while the rear punch section and gage blade remain at rest,'this being due to the greater strength of the main lifting spring. Q3 which holds the rear die section in its elevated position as compared with4 the spring 76 which tends to depress the' rear punch section. During this second downward step of the punch the forming blade bends the sheet metal strip Idownwardly along the front vertical side of the rear die section, thereby forming the rearwall of one of the plaits, as shown in Fig. 4. During the next portion or third step ofthe downward movement of the punch the rear punch section moves downwardly Vin unison with the punch block and forming blade by reason 'of the upper end ofthe rear punch section being engaged by the upper end of its guideway, thereby causing the rear die vsection to be depressed and the strip of sheet metal to be bent downwardly along the rearv side of the front die section for forming the front wall of the plait, as shown in Fig. 5. The stock for thus forming the front wall of the plait is supplied by the strip of metal moving forward at this time without restraint between the front die section and the front and intermediate punch sections so that no stretchiing of the metal occurs while forming a plait in the same. Immediately after the forming blades completes the plait the punch effects the final step of its downward stroke whereby the intermediatepunch section recedes into the punch body but is pressed with its face against the rear part of the front die section by engagement of the upper end of this die section with the upper end of its guideway in the punch block, thereby forming the rear parts of the longitudinal beads'and the front punch section engages with the front part of the front die section and forms the transverse bead on the strip and also the front portions of the longitudinal beads, as shown in Fig.

5. As the rear die section begins its downward movement the locking pins also begin their rearward movement and after the rear die section completes its downward movement the 4locking pins enter the locking openings of the rear die section and the locking openings of the rear cross bar, as shownvin Fig. 5, thereby locking the rear die section in its depressed position. During the first part of the subsequent rising movement of the punch the forming blade is withdrawn from between the front and rear die sections, the rear punch section and gage blade remain in engagement with the .strip of metal and the locking pins complete their rearward stroke so that their shoulders engage with the front side of the front die section and push the same rearwardly 'toward the rear die section, whereby the partly formed plait is now completed by pressing the two walls of the same together, as shown in Fig. 6. The punch is now raised to its highest position and its parts assume their normal position to permit'the sheet of metal to be fed forward another step either by hand or mechanical means as indicated in Fig. 7 and then the locking pins are moved forwardly so as to first permit the front die section to recede from the rear die section and release its grip upon the plait which has just been formed. 0

During the operation of forming the plait in the sheet of metal by bending the latterv downwardly between the front and rear die sections the upper ends of the ejector pins are engaged and these pins are depressed in opposite directions to the resilience of their springs but the instant the front die section recedes from the rear die section the ejector pins are quickly raised by their springs and 'engage the lower edge` of the plait which has been formed and lift the strip above the die sections so that the strip is free to be fed forwardly another step by the strip feed mechanism. The plaited part of the strip is Araised by its resilience above the die section of the press so as to be free to pass forward between the die andpunch sections l when the latter areseparate but .if desired this may be aided by hand or mechanical means. During the last part of the -forward movement of the locking pins the same are withdrawn from the rear die section and the latter is raised into engagement with the underside of the strip by the spring 23. The machine lnow begins another series of operations for producing the next following plaits and transverse and longitudinal beads in the strip of metal, the several steps above described being repeated for each cycle ofy operations of the machine. f

In the operation of this machine the strip of sheet metal is always under perfect control, and the same is at no time free to become displaced, thereby insuring absolute uniformity in bending and plaiting the same, ,whereby when two finished strips of this'character are assembled they will fit each other accurately and permit of producing rows or tiers of radiator' tubes which are of uniform construction and permit of producing a radiator which is regular and neat in appearance.

I claim as my invention:

1. A sheet metal bendingmachine comprising a die having a rear die section which is movable vertically, a front die section which is movable horizontally toward and from the rear section, a punch having a blade adapted to bend a part of the sheet metal between said front and rear die sections, and means for lockingsaid rear die section temporarily in its depressed position comprisingva horizontally movable locking pin movable in corresponding openings in said die sections. l

2. A sheet metal bending machine comf prising a die having a rear die section which is movable vertically, a front die section which is movable horizontally toward and from the rear section, al punch having a blade adapted 'to bend a part of the sheet metal between said front and rear die sections, and means for locking said rear die section temporarily in its depressed position comprising a horizontally movable locking lpin movable in corresponding openings in said die sections, a longitudinally movable slide carrying said locking pin and provided with a shifting pin, Va transversely movable slide having a cam slot which receives the shifting pin, a rotatable cam, and a rock lever having one arm-connected with said transversely movable slide while its other arm is operated on by said cam.

3. A sheet metal bending machine comprising a die having a rear die section which .ismovable* vertically, a front die section whichl is movable horizontally toward and from the rear section, a punch having a blade adapted to bend a part of the sheet metal between said fron-t and rear die sec.

tions, means for locking said rear die section temporarlly 1n its depressed position and rec1procating said Afrontdie section comprising a horizontally reciprocating locking pin' engaging with openings in said front and rear die sections and provided with a shoulder for engaging said front die section 'and moving the same toward the rear`die section. 4. A sheet metal bendingmachine comprising a die having a rear die section which is movable vertically, na front die section which is movablehorizontally toward and from the rear section, a punch having a blade adapted to bend a part'of the sheet metal between said front and rear die sections, means orlocking said rear die section temporarily in'its depressed position and reciprocating said front vdie vsection comprising a horizontally 4reciprocating locking pin engaging with openings in said front and rear die sections and provided with a shoulder for engaging said front die section and moving the same toward the rear die section, and a spring device for moving the front die section away from the rear die section. y

5. A `sheet metal bending machine com prising a die having a fixed body section provided with a locking opening, a rear vertically' movable die section having a locking opening, va front die section movable horizontally toward and from the rear die sec tion and having a'locking opening, a horizontally movable locking pin guided in the y plaiting blade adapted to move into and out of the space between the front and rear die sections.

6. A sheet metal bending machine comprising a die having a rearI die section which is movable vertically, a frontdie section which is movable horizontally toward and from the rear section, a punch having a blade adapted to bend a part of the sheet metal between said front and rear die sections, means for locking said rear die section temporarily in its depressed position and a4 spring device for holding said rear die section yieldingly in an elevated position when released.

7. A sheet metal bending machine comprising a die having a rear die section which is movable vertically, a' front die section which is movablehorizontally toward and from the rear section, a punch having a blade adapted to bend a part of the sheet metal between said front and rear die sections, means for locking saidrear die section temporarily in its depressed position, and a vertically movable ejector pin arranged between said die sections.

8. A sheet metal 'bending machine comprising a die having` a rear die section which is movable vertically, a front die section which is movable horizontally toward and from the adapted to engage with said recesses of said,

die sections and to move the sheet metal blank upwardly out of the space between said die sections.l f

9. A sheet metal bending `machine compris- 'ing a die having a vertically movable rear section, and a vertically movable punch having a body section adapted to coperate with .the horizontally movable die section, a blade fixed on the body of the punch and adapted to pass between the front and rear die sections, and a holding-section mounted yieldingly on the body of the punch and adapted to coperate with the'rear die Isection.

10. A sheet metal bending machine comprising a die having avertically movable rear die section, and a horizontally movable` front section, and a vertically movable punch having a body section adapted to cooperate with the horizontally movable die section, a blade fixed on the body of the punch and adapted to pass between the front and rear die sections, a holding section mounted yieldingly yon the body of the punch and adapted to. coperate withv the rear die section and a holding section yieldingly mounted on the punchv body and adapted `to engage with the front die section.

1l. Asheet metal bending machine comprising 'a die'having a vertically movable rear die section, and-a horizontally movable. f front section, and al vertically movable punch having a body section adapted to c0- operate with the horizontally movable die section, a blade fixed on the bodyyof the punch and adapted to pass between the front and 4rear die sections, a holding section mounted yieldingly on the body of the punch and adapted to coperate with the rear die section, and a gage blade mounted on said holding section and adapted to engage with a plait in the sheet metal blank in rear of the rear die section.'

l2. A sheet metal bending machine comprising a die having a vertically movable rear die section, and a horizontally movable front' section, and a vertically movable punch having a body section adapted to coperate i with the horizontally movable die section, a y'45 blade ,fixed on the body of the` punch and adapted to pass between the front and rear die sections, a holding section mounted yieldingly on the body of the punch and adapted to coperate with the rear die section, a holding section yieldingly mounted on the punch body and adapted to engage and a gageblade section and adapt- With the front die section, mounted on said holding ed to engage with a plait-in the sheet `metal blank in rea-r of the reardie section.

l13. A sheet metal bending machine comprising a die having a vertically movable rear die section, and a horizontally movable .front section, and a verticallyl movable.

punch having a bodysection adapted to cooperate with the horizontally movable die section, a blade iXed on the bodyv of the punch and adapted to pass between the front and rear die sections, a holding section mounted yieldingly on the body of the punchand adapted to coperate with the rear die section, a holding section yieldingly mounted on the punch body and adapted to engage with the front die section, blade mounted on said holding section and adapted to engage with a plait inthe sheet metal blank in rear of the rear die section, and a locking device for temporarily holding the rear die se tion.

14. A sheet metal bending machine comprising a vertically movable rear die section, a horizontally movable front die section, means for temporarily locking the rear die section in its depressed position and moving the front die section toward the rear die section, a rear punch section movable toward and from the rear die section, a gage blade movable with the rear punch section and past the rear side of the rear die section, a

4forming blade movable independently of said rear punch section and between said front and rear die section, an intermediate punch section movable independently of said JOHN M. FEDDERS.

Witnesses: l l

Timo. L. PoPP, v Arnal;-l HEIGIS.

ction in its depressed posia gage i 'zo l