US1473306A - Reciprocating knife can opener - Google Patents

Description

Nov. 6 1923. 1,473,306

J. T. M GRATH RECIPROCATING KNIFE CAN OPENER Filed Ana. 6. 1921 Patented Nov. 6, 1923.

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JOHN THOMAS MCGRATH, or nroorrmerou, ILLINOIS.

REC-IPBOCATING KNIFE CAN OPENER.

Application filed August 6, 1921. Serial No. 490,429.

had to the accompan in drawin s and to a n b the characters of refs nee marked thereon, which form a part of this specification.

T his invention relates to improvements in can openers of that type which is provided with a reciprocating knife by which to sever the can end or top from the body, so that the can end or top may be wholly or partially removed to discharge the contents through the opening formed by the partial or entire removal of the top wall or head of the can.

My improvements are herein shown as adapted to a type of machine inwhich the knife is carried by a reciprocating part that is mounted for reciprocation at a given station, and wherein the can itself is turned on a support therefor below theknife sothat successive areas of the can may be presented to the action of the cutting knife by feed movement of the can. In this respect the machine is adapted to open cans of different cross sections, as cylindric cans, square cans, oblong cans, and the like, inasmuch as the can may be readily directed to the single operating position of the cutting knife.

Among the objects of the invention is to provide an exceedingly simple, efiicient, and durable and rapidly operable can opening machine which is capable of adjustment to operate on cans of different heights, and

which is also capable of operating on cans of varying cross sections.

A further ob ect of the inventlon 1s to provide an improved mounting for the cutting knife by which the said knife can be adjusted to round or square. cans, and in this respect said machine is provided with a knife holder, to which the knife can be fixed thereon as a straight cutting knife for cut t ng the heads of oblong or square cans, and is also constructed with means to permit the body of the knife to be curved so that the trailingcutting edge of the knife can be curved inwardly towards the can center when operating on round or oval cans and thus enable'the knife to cut closely to the edge of the can. head while avoiding an an gular position thereof that .would cut through the seam by which the can head is locked: to the can body.

A further object of, the invention isto-provide-a novel means for supporting and guiding the knife holder on a bracket which. is constructed to vertically reciprocate the holder in straight direction through the medium of a swinging operating handle.

Another object of the invention is to'pro- I 'vide in a machine having these chara'cteris tics, means for adjusting the height ofthe bracketrelatively to the standard which supports thesame, and thereby adapt themachine to'cans of different heights.

A further object of the invention is to provide a novel'gui'de or gauge for u e in connection with round cans, adjustable to hold cans of diflerent diameters in proper relation to the cutting knife.

I Further objects of the invention are to improve and simplifycan openers, and the invention consists in the combination and arrangement of the parts shown in the drawings and described in the specification, andis pointed out in the appended claims.

In the drawings-z Figure l is a side elevation of a can opener embodying my invention, showingin section the vertical table or support for the can. Figure 2 is an enlarged section taken on the line 22'of Figure 1.

Figure 3 is a horizontal section taken on the line 3.3 of Figure 1.

Figures e and 5 are horizontal sections on the line -l 4 of Figure 1, showing the parts in different positions of adjustment.

F ignre 6 is. a. perspective view of the reciprocating knife holder. I Figure 7 is aperspectiveview of the cutter knife-when adjusted to operate on round cans, showing a portion of the can in dotted lines. p

As shown in the drawings, 10 designates a standard that may be fastened toth 'e-ledgeof a table or like'support 11 by a suitable form of jaw clamp 12,.having a clamping screw 13. The table 11 constitutes a support'for the can C, Whose head or end Q is adapted to be cut to 0 en'the can. 14 designates a bracket; that 11s slidably mounted to the standard 10 for vertical adjustment of the bracket relatively to the support 11, and

said bracket can be locked to the standard in different vertical positions by a locking screw of any suitable form.

16 designates a vertically reciprocating plunger which is adapted to slide in a verti cal opening 17 at the inner end of the bracket which overhangs the can to be opened. Said plunger is arovided on its lower end with a knife supporting head 18 which can be made of any suitable shape at its sides and rear end. In accordance with one phase of the invention, the inner .ace 19 of the knife supporting head is laterally concave to form at the corners of the head at each side of the concave portion relative sharp knife supporting edges 19. Said concave face is provided with one or more threaded openings 20 to receive cutting knife locking screws, will hereinafter more fully appear. Said headis further provided with a downwardly facing shoulder 21 adapted to bear against the upper edge of the cutting knife.

The said plunger 16 is surrounded by a spiral expansion spring 22 which is interposed between the upper face of the bracket 14 and an abutment 23 formed by a cap fixed to the upper end, of the plunger. The tendency of said spring is to hold said plunger upwardly with the knife carried thereby above its cutting position. 24 designates a plunger operating lever which is hinged to a horizontal pin 25 that is fixed in the outer end of the bracket 2%. Said handle extends inwardly over the can support to afford the required leverage to operate the reciprocating knife supporting plunger. 26 designates a link which is hinged at its lower end, as by means of a pin 27, to a part of the hand lever 24 abreast the bracket 14.. Said link is also hinged at its upper end, as by means of a pin 28, to "the upper end of the plunger 16, said pin extending through an opening in the upper end of the plunger and through registering openings of the hollow abutment 23, which latter is made tubular to fit down over the top of the plunger. The lower portion or skirt 30 of said abutment is made of somewhat larger internal diameter than the external diameter of the plunger to receive the upper end of thespring 22, as shown in Figure 2, which said spring bears at its lower end squarely against the apertured guide bracket 14; for the plunger.

32 designates a cutting knife which is adapted to be clamped on the concave face .19 of the head by means of a screw or screws 33 which extend loosely through openings in the body of the knife and into and are threaded in tlie'tlii'eaclecL opening or openings 20 of the knife supporting head. The said knife is so adjusted to the head that its upper edge bears againstthe downwardly facing shoulder 21 formed on the inner side 'to the height of the can.

of the head above the concave Portion 19 thereof, so as to thereby relieve the screw or screws 33 of shearing strains when the knife depressed to cut the can head. Said knife is formed with a lower, cutting point 35, an advance cutting edge 36, and a trailing cutting edge 37 somewhat longer than the advance cutting edge. Said cutting edges are formed by beveling the rear margins of the knife.

When cutting straight marginal portions of square or oblong cans, the knife 32 is adjusted to the position shown in Figure That is to say, the clamping pressure of the screw or screws 33 and the elasticity of the blade will be suiiicient to hold the rear margins of the knife against the edges 19 of the concave face of the head 18. With this adjustment of the knife, a square or oblong can placed on the support 11, with the cutting knife in line with that portion of the can head to be cut or severed, and the height of the knife mounting is properly adjusted The plunger is then forced downwardly by the hand lever 24: to force the knife through the can head, and upon release of the hand lever the spring 22 raises the knife supporting plunger and knife away from the can so as to permit the can to be advanced along in a straight line to present another portion of the margin thereof to the action of the knife, this operation being continued throughout the straight side of an oblong or rectangular can. The can is then turned on the support 11 to bring the adjacent margin under the knife and these operations are continued until the can head is completely severed, or sufiiciently severed to pull the same away from the can body to empty the contents through the opening formed by cutting the head away;

When operating on round or oval cans, the clamping screw or screws 33 are turned inwardly sufiicientto curve the cutting knife along its median vertical, axis in the manner shown in Figures 5' and 7. 'Such deformation of the blade at the point where it is borne upon by the head or heads of the clamping screw orlscrews 33 or other suitable curving means, is carried throughout the length of the blade so to thereby curve the cutting end of the knife in the manner shown in Figure 7, or with the trailing cutting edgev 37 turned inwardly towards the center of thecan head; a By thus vertically curving the cutting knife the trailing cutting edge thereof will be turned inwardly beyond the adjacent seam of the can that joins the body and head so as to enable the knife to sever the can head closely adjacent to said seam without striking the latter. It will be understood from what has been said that if the cutting knife were in the adjustment shown in Figure 4, when cutting'the head of 'iii a round or oval can, the round head-of the can could not be severed close to its margin, without the trailing edge of the knife striking the lock seam between the head and body. Therefore, to use a straight knife adjustment, as is shown in "Figure 4, the head would necessarily need to be cut or severed an objectionable distance inwardly from the lock seam. With the adjustment shown in Fignre however, andwhichis made possible by curving the inner face of the knife head and using a resilient blade, the cutting point of the knife may be made to attack the margin of the head closely adjacent to the lock seam, while at the same time avoiding the trailing edge of the knife encountering said seam.

When the machine is operatin t on round cans, it will be desirable to provide a guiding gauge of such character as to permit the can to be readily turned by hand on the vertical axis of the can. Such gauge is shown in Figures 1 and 3. It comprises a. curved bearing shoe 4O struck on an arc to correspond with the average size round an, and provided with outwardly extending lock and guide arms 41, 42, which are adapted to extend through horizontal openings in lugs 43, 44, formed on the lower end of the standard 10. The said gauge member thus constructed may be locked in adjusted positions by means of a set screw 45 that is threaded through one of the lugs 44 and against the corresponding arm 41 of the gauge. Thus the gauge can be readily adjusted towards and from the center of the can and can be fixedly locked by reason of the set screw and of the guiding engagement of the parallel arms in the guide lugs 43, 44.

It will be noted that I have provided a very simple, effective, light, and yet durable construction and one which may be said to be universal, in that it can be operated to open both round and square cans. The details of the construction whereby the functions set forth are effected, may be varied within the spirit and scope of the claims hereto appended, and the invention, therefore, is not l'nnited to the particular construction shown except as specifically set out in the appended claims and as imposed by the prior art.

I claim:

1. A can opener comprising a standard having means to fir; it to a support, a bracket vertically adjustable on said standard, and provided at its inner end with a plunger bearing. with means to lock it in vertical adjustment on said standard, a plunger slidable in said bearing and provided below said bearing with a knife mounting head. and above said bearing with an abutment, a spiral spring surrounding theplunger between said bracket and said abutment to hold said head upwardly against the bracket,

a lever pivoted to said bracket, and a link connected to said lever and extending there from for'connection to said plunger 2. A can opener comprising a. st: having means to fix it to a support, bracket vertically adjustable on said standard, and provided at its inner end with a plunger bearing, with means to lock it in vertical adjustment on said standard. a plunger slidable in said bearing and provided below said bearing with a knife mounting head, and above said bearing with an abutment, a spiral spring surrounding the plunger between said bracket and said abutment to hold said head upwardly against the bracket, a lever pivoted to said bracket, and a link connected to said lever and ex-- tending upwardly therefrom for connection to the upper end of said plunger, said abutment having a depending skirt portion which encloses the upper end'ot said spring.

3. A can opener comprising a standard having means to fix it to a support, a bracket adjustable on said standard, and provided at its inner end with a plunger bearing, with means to lock it in vertical adjustment on said standard, a plunger slidable in said bearing and provided below said. bearing with a knife mounting head, and above said bearing with an abutment, a spiral spring surrounding the plunger between said bracket and said abutment to hold said head upwardly against the bracket, a lever pivoted to said bracket for operating said plunger, and a can gauge carried by and extending laterally from the lower end of saidstands ard and having locking means to adapt it to end of the standard, and having a concave face against which the can is held while turning it to present new areas of the can headto the cutting knife. 1

5. A can opener comprising a standard. having means to it to a support,'a bracket vertically adjustable thereon by means to lock it fixed to the standard to overhang the support, a reciprocating. guided plunger supported 7 on said bracket and provided with a knife head, means for reciprocating .said plunger. and a round can gauge adjustably' mounted on the lower end of the standard, said gauge comprising a curved bearer member and parallel locking and guiding arms operatively &

supported at the base of said standard, lugs at the base. of the plunger through which said arms are adapted to slide, and a set screw piercing one of said lu s and imping- 5 ing against one of said arms.

6. A can opener comprising a a bracket fixed thereto a reciprocating, guided plunger supported on said bracket and provided with a knife head, means for reciprocating said plunger; and a round can gauge comprising a curved bezner parallel arms, lugs at the base of the plunger through which said arms are adapted to slide and means for lOCking one of said arms to one of said lugs.

7. In a can opening machine, a knife support, formed with a concave face flank-l by backing edges, a resilient knife adap l to span said concave face and rest against said edges and having an off-center point flanked by cutting edges. and pressure means to fasten said knife on said support, said means bearing against the portion of the knife opposite to said concave face to hold the knife against said edges and acting;

increased pressure to concave said knife towards said face ane to thereb deform said cutting edges.

8. The combination with a knife niounting, and a resilient blade having .a cutting point, an advance cutting edge and a lone trailing edge, of means to fasten the l i on said support, said fastening means ating to transversely curve said 7 through its cutting edge to cause the traniny edge to be curved towards the advance cutting edge.

9. in a can opener, a transversel" wincave knife mounting having lateral lznfic backing edges flanking a transverselv curved face, a knife and threaded means to pierce the longitudinal center of said knife to fasten the knife flativise on the mounting; and adapted to be threaded into the deeper part of the curved face of the mounting to transversely curve said knife.

In Witness whereof I claim the foregoing as my invention, 1 hereunto append my nature this 27 day of duly 1921.

JOHN THOMAS? MQGRATK?

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