US2577021A - Apparatus for notching can body blanks - Google Patents

Description

Dec. 4, 1951 E. LAXO I APPARATUS FOR 'NOTCHING- CAN BODY BLANKS Filed April 29, 1947 2 SHEETS-SHEET l 5 h\ m w MA 4 I V/- m V w W Dec. 4, 1951 E. LAXO 2,577,021

APPARATUS FOR NOTCHING CAN BODY BLANKS Filed April 29. 1947 2 swam-swam 2 F76. 4 INVENTOR.

Patented Dec. 4, 1951 APPARATUS FOR NOTGHING'CAN BODY 'BDANKS Ed..Laxo,..0akland, Calif assignorto Atlas ImperiallDiesel' Engine'C0., Oakland, Calif., a corporation of. Delaware Application April 29, 1947, -Serial"No.- 7445681 N "'2 Claims.

.The present invention pertains tocan body making apparatussan'dv is more particularly directed toa-pparatus for performing certain metal working operations onbodyblanks. preparatory to-their forming i-nto' asideseamedcylindrical body member.

Inthe formation-of can bodies, the cornersof theibody blanks are-notched and slit preparatory to'bending the oppositely arranged sideedges into hooks, whichare interlockedafter the blank is formed into-cylindrical shape 'on thel formi-ng mandrel:- :of the bodyimaking, equipment. Heretofore,-. thespu-nches'for. 'notching 'andslitting-the blanks have been mounted. on a-slidetcapablev of reciprocating insa-guide to-and from -acooperating 'die. Suchslidenecessarily overhung the supporting guide bya considerable extent. inview of the need; for. the guide ways to clear'theside edges-of the blanks.

Sincesuch'jpunclr and 'die equipment operates at' ai relatively high speed (often in excess of 400 body bla-nks per minute) the slide: must: have! a relatively loose fit in the guide ways: for. proper running clearance. Asa consequence; it is practically impossible'to maintain the. punches and dies in proper adjustment, resultin inthe formation of corner: notch contours and slit lengths which vary among thewcan blanks aand-even between adjacent 'canblanks passing: through the machine. Moreover, the excessive play-of the slide in therways makes it diflicult for the corners of the'body blanks to be cut'cleanly. It is readily apparent thatathe shearing edges of: the punches and diesiarecdifiiculfi toearran'ge accurately with respect" to 'each otheriinv view of the necessity for allowing 'for the play in the parts; otherwise, there. is' the hazard of dulling or breaking the cuttingparts after operating upon onlya relatively few :blan'ks. The-net result-of the-looseness of the-slide intheways'is toidullthe punches and 'di'es prematurely, formingburred corners of improper: configuration in the b1anks;rendering it difficult to produce a tight can body sea-m, andisometimes causing the apparatus. to' jam.

Accordingly, it 'is an :object' orthe: present invention tofprovide a machine for operating on can body blanks, the; punches and dies of such machine being supported accurately with respect to eachother; the punch being. movablealongla predetermined path by amounting member operating with substantially no: looseness on its cooperable support.

'turth'er object'of the 'inventionwis'to provide aJ -metar working: machine whose :punch and die areisuppor-tect and-relativelymoved in such man- ;-.2 ner as to. provide clean cut or formed can. body blank cornersof accurate contouranddimensions.

Anotherobject of the inventionis to provide for the readyassembly and adjustability of a can body. blank punch onla supporting and operating member.

Yet. another objectofthe invention is to provide an. improved manner of. securely holding a can body blank. die onthe frameof theforming or notching machine.

Still-anotherobject of the invention. is to provide. a machine for forming can bodies, said machine having an improved manner of rigidly securing a, punch to. its mounting and operating member.

One form which the invention may assume is exemplified in the following description and illushated by way of example in the-accompanying drawings, in which:

Fig. 1 is a cross-section through the'notchingstation ofa can body making machine, parts of themachine being. omitted for thepurpose of clarity.

Fig. 2- is a top. planview ofpartof the punch mechanismat the left. side ofthe-machine as viewed-in Fig.1.

Fig. 3 is-a partial section taken along the line 3-3-on.Fig..1,- disclosing the manner of clamping a punch to its holder.

Fig.4 is a partial plan view of the die block and bed of the machine as seengenerally along the line 4-4 on-Fig. 1.

The apparatus disclosedin the drawings constitutes the mechanism for notch-ing and slitting the cornersof can body blanks. B, which may have other operations performed upon them prior totheirfeeding to the notching station of the body maker. The grain of the body metal may first be broken to make the blanks more amenable to-formation-into-a cylindrical container, and the blanks may then be fed to a blanking or impression station (not shown) wherein provision is made for performing certain operations prior to delivering the blanks to the notching tools. For example, the corners of the body blank may be bent slightly'so that it will more closely follow the curvature of a mandrel about which the blank is subsequently formed, and allow the finishedside seam to be p ov ded i a relatively thin lap requiringa minimum of solderand having a greater holding strength.

"The body blanks are fed. from the blanking orim'p'ression station to-the. notchingstation by opposed; parallel feed bars l0. having the usual fingers (not shown) for engaging the rear edge of a body blank and moving it intermittently and in proper timed sequence from station to station along the length of the body making machine. These feed bars are slidably mounted on opposed side frames of the apparatus, which may be adjustably mounted on the base l2 of the machine to and from one another for the purpose of accommodating body blanks of different widths designed to provide cylindrical can bodies of various diameters. Since this feature forms no part of the present invention, the details are not disclosed herein.

Inasmuch as the mechanisms on the side frame II are virtual duplicates of each other, although oppositely arranged, a detailed description of one side of the machine will suflice for both sides.

Each side frame II has a bed portion IS on which the feed bar I!) is adapted to slide. It also is provided with an inner side member l4 secured thereto in any suitable manner, as by means of cap screws |5, and having an inwardly extending shoulder It on which a plate I! is mounted, which plate extends across the machine and also rests upon the shoulder IS on the opposite side, the plate being secured to the shoulders by countersunk screws I8 or the like, with its top surface Ila lying in the same-plane as the upper surface Illa of the feed bars I0. The inner member M has an intermediate outwardly projecting, longitudinally extending tongue |9 engageable within a companion groove in the feed bar. Mounted on the side frame adjacent the feed bar is a longitudinally extending die block 2| resting within a channel shaped groove 22 in the frame, and engaging the base 23 and outer side surface 24 of the groove. In effect, the die block 2| and inner member |4 form guide ways for preventing lateral movement of the feed bar ID.

The die block 2| is held in snug engagement with the bottom 23 and outer side 24 of the channel 22 by one or more diagonal screws 25, each extending through an enlarged diagonal bore 26 in the side frame into threaded engagement with a threaded diagonal hole 21 in the die block. Tightening of the screw so as to engage its head 28, or intervening washer 29, with the inclined outer surface 30 of the side frame draws the die block 2| downwardly and outwardly in the channel, in order to position the outer surface 2|a of the die block snugly against the companion outer surface 24 of the channel and its bottom surface 2|b snugly against the bottom 23 of the channel. Any necessity for the die block 2| to shift during tightening of the screw 25 is permitted since the screw may shift laterally of its axis within the enlarged bore 26. Longitudinal movement of the die block 2| along the channel 22is prevented by countersunk screws 3| passing through the end portion of the block and into the side member provision being made, of course, by any suitable means (not shown) well known in the art to allow transverse movement of the die block 2| when screw 25 is tightened.

The upper surface 2 |c of each die block lies in the same plane as the upper surfaces Illa, Ila of the plate and feed bar in order to support the body blank B in plane fashion and without distortion thereon. Each die block 2| has a pair of oppositely arranged, longitudinally spaced die cavities 32 for the reception of cooperable punches 33 designed to notch or slit the corners of a body blank placed in appropriate registry with respect to the cavities by a registering mechanism (not shown). It is to be understood that the cavities 32 in the die block on one side of the machine may be different from the cavities in the die block on the other side of the machine, since different configurations and operations on the corners of the body blank are to be made on one side of the blank than on the other side of the blank. In general, the blank corners on one side of the machine, as the left of the machine as seen in Fig. 1, may be notched, whereas the corners .on the other side of the machine may be slit.

During the feeding and registering of the body blanks along and at the notching station, their side edges are appropriately guided and supported by guide plates 34 suitably secured to the dies 2|, as by cap screws 35 or the like. These guide plates are notched so as to avoid interference with the punches 33 as they move into and out of the die block cavities 32.

One punch is provided for each cavity, and it is adjustably mounted in a punch holder 36 which is clamped to a rocking lever 3'! oscillat able upon a shaft 38 fixed to and extending between bearings 39 at the upper ends of supporting uprights 40 secured to the side frame ll of the machine. Needle or other suitable anti-friction bearing elements 4| are interposed between the shaft 38 and lever 31 to insure free pivotal movement of the latter. The outer end of the rocking lever 31 is adapted to receive a stud or pin 42 suitably clamped thereto. As disclosed in the drawings, the outer arm of the rocking lever is split to provide spaced ears or lugs 43 adapted to be moved toward each other by a cap screw 44 extending through one ear and threaded into the other car, which action clamps the split end of the arm around the stud 42. The stud extends outwardly of one face of the rocking lever and has one end of a connecting rod 45 mounted thereon through the intermediary of needle bearings 46, or other suitable anti-friction bearings. Endwise movement of the connecting rod from the stud or pin is prevented by a retainer cap 41 engaging the end face of the connecting rod 45 and suitably secured in position by a cap screw 48 threaded into the pin with its head engaging the exterior of the cap.

The connecting rod 45 depends from the rocking lever 31, its other end being formed as a strap 49 encompassing an eccentric 50 secured to a drive shaft 5| rotatable at the proper rate of speed by a suitable electric motor and inter vening gearing (not shown). It is to be understood that there is a drive shaft and connecting rod mechanism on each side of the machine and that such members move in unison to effect simultaneous movement of the punches 33 toward and away from the cooperable dies 2| to effect simultaneous notchinggand slitting of the body blank corners.

Each punch 33 of the pair of punches at each side of the apparatus is mounted for individual adjustment on its holder 36, which has a generally vertically extending slot or groove 52 in which the punch is snugly received, the upper end of the punch being adapted to bear against a set screw 53 extending through an inwardly projecting top wall 54 of the holder, which screw may be locked in any selected adjusted position by a nut 55 threaded thereon and adapted to bear against the upper surface of the top wall. When the set screw 53 has been appropriately threaded into the top wallfi in oidertwproperly(position the lower end or'the punch- 33 with" respect tel-the die block 2 l the punch' may'- beclamped in" suchadju'std position'by a. plate- 56 engaging its surface and held snugly thereagainst. to" hold the punch firmly against the'base ofithe groove- '52 by a pmrality of cap screws 5'5 extending through the plate Eli-and threaded intothe ho'lder 36.

There is one punch holder- 36' for each punch 33 and this punch :h'olderds adjustably mounted in the inner armor the rocking lever 3! to permit longitudinal movement or: the punch-longitudinally of the die block for accuratelylocating the punch in alignment with the-die cavity. Specifically, "the punch "holder" has "a flat rear face 58 adapted to *engagea companion backing 'face 59 formed in the rocking lever. "The punchholder also has a 'downwardly and outwardly! inclined lower surface '6 adapted --to cooperate with a companion inclined suriace" 6| formed on the upper side of a ledge 62 projecting from the "rocking lever inwardly beyond its 'backing-face 59. In effectf' theside 6|- of-the ledge andbacking face 59 form an acute angle withrespect-toeach other, or a: v shaped groove into which-the corresponding- 'lower' v sh'aped portion of the punch holder 36=is receivable.

The-upper end of each punch holder is also provided with an upper surface 63 diverging with respect to' its'lower surface-60, that is, such upper surface is inclined upwardly and outwardly to form arr acute angle with'its outer face 58. A cap piece' fi i' is adapted to be clamped 'to the upper end of the rocking 'l'ever 31-and against the upper portion of thepunchh'older 36 by ascrew 65 extending through the cap piece. This cap piece has an'inner projecting ledge 66 providing a tapered face 61 companion to the punch holder face 63 and also a short depending leg 68 adapted to be received Wit-11in'an LPShapedlinOtbh 69 at the outer upper corner of the rocking lever 31; the inner surface of thelegfifishouldering against the adjacent surface of the notch 69.

It is apparent that tightening of the cap screws 65' moves the cap li i'downwardly'toward the rocking lever 31; andin'sddoing 'forces the lower inclined" surface 60 ofthe punch holder'36 down along the companionsurface 6| of the projecting ledgefiz and theupp'er tapered surface 61 of the cap 64 down alongthe 'upper tapered surface" 63 of the holder, all ofwhich forces the holder 36 snugly against 'theba-ckingface' 59 of the rocking lever and effectsitsse'cure clamping to such lever. The punch" holder'36 maybe adjusted longitudinally alongthe'rockingdever' 3'lzinro'rder to locate the punch 33 accurately. inalignment with the die: cavity prior to securingof the cap piece 64 in place and the firm gripping of the punch holder between the backing face 59, ledge 62 and tapered portion 66 of the cap piece.

As stated above, there is a separate punch holder 36 for each punch and also a separate clamp piece 64 for each holder, in order that the parts may be appropriately adjusted and held securely in such adjusted position.

As the drive shafts on both sides of the machine rotate in synchronism with one another, the rocking levers 31 are oscillated on their supporting shafts 38 and the punches 33 on both sides of the machine are moved at the proper time into and out of the die cavities 32, effecting accurate notching of the corners of the body blanks B as they are fed to the notching station and appropriately registered thereat by the registering mechanism described in my above identified app1ication, "or1 by: any other suitable" registering mechanism. ."Themechanism may be operated at relatively high speed without any necessity for providing-for play' in theparts. Since there is an absence of re'ctilinearly moving members, there is no need for providing excessive operating-clearance, as is essential inconnection with reciproeating slide and guide way devices. All that is requirediis to provide the normal close bearing clearance between the shaft 38 and the antifriction bearingM, which produces very little; if any, deviation of the punches 33 from their intended'path ef-movement with respect to the die block ca'vities32. Asaresult, notching and slitting is performedaaccurately-and consistently as the-bodyblanks are fed through the machine.

-It-is also to beinoted that despite the relatively greatoverhang: betweenzthe rocking lever support 38 andthe punch 33; parts are alllof substantial dimensionsfandi extremel rigid'introducing no deflection which might: otherwise imoairiaccurate functioning:off the mechanism. 1 Moreover, a simple andieffective means hasbeen provided for: quickly and. accurately adjusting the punches 33- with respect tow the' punch holder "36" and? the punch holder with respect to-the supporting-lever 31. I In addition a': simple: manner of appropriate1y-adiusting the die blocks "2! through the simple expedient of the diagonally arranged screws-=25 has beenprovided,all' of which contributes to tl'ie lnroduction: of'aclean shearing action of the body metaras the punches engage its-upper si1rface and are: forced therethrough into the: die block cavities.

line-horizontal axes ofthe rocking lever shafts are'positioneda slight'distance y'ab'ove the plane of. the: surface 2 lo oftthe clieiblocks. Such distance-maybe equaL-to-the thickness of thebody blank B in .orderz that. thetpunches 33 be moved downwardlyhin anarc with their lowerends engagingthe metal andthen swinging ina direction awayfrom onoutwa-rdly-of the inner shearing-edge-ot the die; in effect, drawingthe punches 33 away'fromlthediell as they pass-this shearing edge and making it unnecessary to undercut the-faoe-of thedie'below such shearing edge to provide. clearance -for movement of the punch withimthe die cavity. This provides for a much stronger=-shearing edge onthe-die as compared with the acute. angle edge which undercutting would produce.

iVJhilevthe-invention has been described with specific reference to the notching and slitting of-the cornersof-v can: body blanks, it. isto be understood that-ices applicable to mechanisms performing other formingoperations onthe body blankswas, forexamplal-in connection with the operation .at thev blanking or impressing. station immediately preceding the notching station, or at the folding station forforming the body hooks immediately following the notching operation. The punches and dies would be similarly mounted, as specifically described herein in connection with the notching and slitting operations, and the punches would be rocked or oscillated to and from the cooperable forming dies in substantially the same manner as described herein.

It is, accordingly, apparent that a can body blank machine has been provided in which the punches and dies may be rigidly and accurately supported, with provision being made for their movement with a minimum of play to and from one another in eifecting the required operations on the body blanks. When specifically applied to the notching station, assurance is had that clean cut body blank corners of accurate contour and dimensions will be provided. The mechanism is readily adjustable to permit operations upon a variety of body blank sizes.

While I have shown the preferred form of my invention, it is to be understood that various changes may be made in its construction by those skilled in the art without departing from the scope of the invention as defined in the appended claims.

Having thus described my invention, What I claim and desire to secure by Letters Patent is:

1. An apparatus for forming can bodies including a frame, a stationary die member supported on the frame with its upper working surface disposed in a horizontal plane, an oscillatory lever mounted on the frame to oscillate about a horizontal axis so as to move one end thereof in a vertical plane toward and away from the horizontal working surface of the stationary die member, said end of the lever being formed with a flat backing face disposed in a plane parallel to the axis about which the lever oscillates and substantially perpendicular to the working face of the stationary die member at the time the punch engages one of said bodies, an upwardly and outwardly inclined projecting ledge extending along the lower terminus of the backing face on said lever, a punch holder having a flat surface to seat against the flat backing face and having a downwardly and inwardly inclined lower surface complemental to said ledge and an upper surface tapered upwardly and inwardly, a clamp mounted on the lever at the upper terminus of the backing face and formed with a tapered surface complemental to the tapered upper surface of the punch holder, screw means engaging the clamp and the lever to fix the clamp to the lever in a manner clamping the punch holder against the flat backing surface and between the ledge and the clamp, a punch secured to the punch holder, and means for oscillating said lever to move said punch toward and away from the working surface of the die member.

2. An apparatus for forming can bodies including a frame, a stationary die member supported on the frame with its upper working surface disposed in a horizontal plane, an oscillatory lever mounted on the frame to oscillate about a horizontal aXis so as to move one end thereof in a vertical plane toward and away from the horizontal working surface of the stationary die member, said end of the lever being formed with a flat backing face disposed in a plane parallel to the axis about which the lever oscillates and substantially perpendicular to the working face of the stationary die member at the time the punch engages one of said bodies,

an upwardly and outwardly inclined projecting ledge extending along the lower terminus of the backing face on said lever, a punch holder having a fiat surface to seat against the fiat backing face and having a downwardly and inwardly inclined lower surface complemental to said ledge and an upper surface tapered upwardly and inwardly, a clamp mounted on the lever at the upper terminus of the backing face and. formed with a tapered surface complemental to the tapered upper surface of the punch holder, screw means engaging the clamp and the lever to fix the clamp to the lever in a manner clamping the punch holder against the flat backing surface and between the ledge and the clamp, said punch holder having a recess formed therein extending inwardly from the face of the punch holder opposite the face thereof engaging the fiat backing face with the inner face of the recess parallel to said flat backing face, a punch member fitting said recess, means securing the punch member in said recess but operable to permit adjustment of the punch member in said recess in a direction parallel to the plane of said backing surface, said punch holder having a fixed rigid portion overlying said recess and the punch member therein at the upper end thereof, an adjustment screw threaded through said fixed portion and capable of adjustment coaxially of the punch member to adjust its position along said recess, and means for oscillating said lever to move said punch member toward and away from the working face of the die member for performance of an operation on a can body blank placed upon said. die member.

ED LAXO.

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

UNITED STATES PATENTS Number Name Date 59,541 Austin Nov. 13, 1866 236,613 Nelson Jan. 11, 1881 934,090 McLean Sept. 14, 1909 942,939 Sanborn Dec. 14, 1909 1,020,550 Graham 1 Mar. 19, 1912 1,192,132 Spiegel July 25, 1916 1,351,115 Morse Aug. 31, 1920 2,300,177 Richmond Oct. 27, 1942 2,333,293 Cartlidge Nov. 2, 1943 2,383,025 Taylor Aug. 21, 1945 FOREIGN PATENTS Number Country Date 624,096 Germany Jan. 13, 1936

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