US1427152A - Metal container and the like - Google Patents

Description

A. B. A. FICH.

METAL CONTAINER AND THE LIKE.

- APPLICAHON FILED SEPT. 20, 1920.

1,227,152. 2 Patented Aug. 29, 1922.

Ayn z 26 7/22]; /2 am 22%,

unites ALFRED BERTHOLD ANDREAS FIGHT, OF COPENHAGEN, DENMARK.

Specification of Letters Patent.

Patented Au 29,1922.

Application filed September 20, 1920. Serial No. 411,490.

To all whom it may concern:

Be it known that I, ALFRED BERTHOLD ANDREAS F1011, subject of the King of Denmark, residing at Islands Brygge 11, Copenhagen, Denmark, have invented new and useful Improvements Relating to Metal Containers and the like, of which the following is a specification.

As it is well known, it is common to open tin cans for preserved goods and the like by tearing open the cover of the can, or the can itself, either with or without the use of a special key, and the tearing is rendered possible by reason of the material of the can being weakened in certain lines along which the tearing is intended to be effected.

It is well known, however,that tear fre quently fails to follow the weakened lines but will diverge therefrom before the operation is finished in satisfactory manner. When such improper tearing results, it is frequently necessary to mutilate the contents of the same in removing it.

According to the present invention, the

weakening of the said lines in tin covers is effectedby rendering the material brittle along the said lines. And further, according to this invention the material is compressed instead of being scratched or cut down in thickness as heretofore. By this compression, which is one of the distinguishing features, of the present invention, the material which is usually soft becomes brittle, as above stated, and experience has shown that if the material is reduced to a suitable minimum thickness, for instance 0.06 to 0.1 millimeter, then the tin cans whose material is weakened in this manner will be exceedingly easy to open, as the percentage of error, that is to say the number of cans in which the process of opening fails, is less than one per cent of the total number of cans. The principal reason for this .is that the weakening produced by the compression is extremely uniform, and that. it is very much easier to produce a uniform thickness of metal all along the weakened lines by the said compression than by means of scratching or cutting tools, which practically all make an incision of definite depth in the material. Differences in the thickness and hardness of the material conse-,

actly similar to the lines to be weakened, is blunt. I

The drawing represents one embodimen of the invention,

Fig. 1 showing the upper die and Fig. 2 the lower die in a press adapted to perform the. above mentioned operation, while Fig. 3 shows the bottom die in top view,

and Figs. 4: and 5, respectively, show a to view and a longitudinal section of a modified -construction of the die with a steel strip inserted.

The upper die consists of a hardened stopping die member 1 which is shaped as a ring and encircles a'plate 2 which is held, in suitable known manner, in the die holder 3. The die plate 2 supports a form plate 4: whose lower face is shaped according to the cover or the like which is to be treated in the press, so that during the pressing operation the cover is contained in a space between this plate 1 and a corresponding plate 5 in the bottom die. The said plate 5 is encircled by a ring 6 which is So much larger than the plate 5 that a narrow slot is formed between the latter-and the said ring, so that a hardened steel strip 7 may According to the invention this steel edge, whose shape isex-' be driven down into this slot and held in I position there. The height of the ring 6 is such that the steel strip 7 projects slightly, for instance 0.25 to 0.3 millimeter beyond the'top surface of the ring, and the ring 1 in the top die is'of such height that when the top die is moved down towards the bottom die, the motion of the top die will be stopped by the said ring 1 meeting a fixed stop 8 on the bottom die, so that there will be left, between the blunt top edge of the steel strip 7 and the working surface 9 of the die plate 2 in the top die, a very small space equalling the thickness of metal in the weakened grooves in the treated .tinplate. The rings 1 and 6, the die plate 2 and the steel strip 7 must be ground in such a manner that the opposite faces on the rings 1 and 6, respectively, and on :the

strip 7 and the die plate 2 are perfectly fiat and parallel. treated is placed on the disc 5 in such a mannerthat-it covers the steel-strip 7 whose shape .correspondsexactly to the shape of the lines which are to be weakened inthe tinplate.

The top die .is now moved down towards .thebottom die and, as mentioned above, the latter will be stopped in such a position that-there will .be left, between the top surface .of. the strip 7 and the bottom 'face 9 ofthe plate 2 adefinitely-determined slight space which determines the thickness of metal in the lines weakenedthereby in the tinplate.

it is not necessary to take any kind of precautions in order to avoid the possibility of .unevennesswin the weakening of the c ov ers. The press works with absolute accuracy, without regard to the thickness of the material used, and the lifeof one single steel strip is exceedingly long,-so that one single steel strip may be used for several years during continuous operation of the 'whichisexceedingly slight in comparison with the costs heretofore incurred in repaarmg'presses of'the present kmd, when the working tools have been damaged.

If-it be desired to increase the weakeninsomezpaperor metal .foil, of a thickness cori responding 'to the increase of the compression, must "be inserted between the die plate 2 andEthe: pressing head or die holder 3 and, if itu-be desired to reduce the depth of the weakening, ::paper or metal foil of a thick nesscorresponding to the decrease must be inserted between the ring l and the press ingihead The tinplate or'cover to be The only member I The die into which the strip 7 is inserted may obviously also be used as the top die instead of as the'bottom die.

In the construction shown in Figs. 4 and 5., the steel strip 7 ends-blindly at both ends, the strip being inserted into and pass .ing back and forth through two essentially parallel slots converging at one end in such a manner that when for instance a tinplate cover is being weakened, there Will'be impressed therein two mainly parallel weakened lines convergin at one end.

Having now particularly described and ascertained the nature of my Sitld invention and in what manner the same is to be per-f formed, I declare that what I-claim is 2- l. An apparatus for producing weakened lines in metal tin plate comprising a die;-

a-nd an edgewise disposed steel strip inserted 1n said die, said strip=hav1ng aworlnngiedge rectangular throughout and projecting beyond the pressing face of said die, said rectangularworking edge being entirely ffree from any adjacent members so as to insure that the'entireedge will act upon the me'ta'l plate worked upon and will exert a -compressing action,as distinguished from a dis placingaction, along the lines to be Weak ened in said plate.

'2. An apparatus for producing weakened lines in metal plates comprising a diefsaid 'ul'ar' die" strip having a working edge recta n throughout and projecting beyond "said and entirely free from any adjacent m'embers a hardened I steel member engaging the rear edge of said steel str'ipya ringyencircling the steel strip andsecuring the latter to the hardened steel member; and a plate encircling said ring, there being between" sald ring andsaidxplate a 'narrow slotto *receive the steel strip.

Zip-An apparatus for producingweake ned lines in' metal plates comprising a'die, said strip having a working edge rectangular throughout and projecting beyond said die and entirely free from any adjacent mem-{ bers; a hardened steel mem 'ber engaging the rear edge of :said steel :strip; a ring encircling the steel strip and securing the latter to the hardened steel member; and a plate encircling :said ring, there :being between said ring and said plate a 11arr0W" SlOt -t0 receivetlie steel strip, saidpla'tehaving a perforation in order-to facilitateahe separation of the ring and the plate.

a. An apparatus for forming closures --for metal "containers comprising a die and a companion die member means tolimi't :the movement of said die and die member td ward each other so that the majorj-portions of the die and'die member will not compress the metal worked upon; and portions I on said die and die member b etween wlrich fflthe metal worked npon is adapted to be compressed by the relative movement bemy name in the presence of two subscribtween the die and mfimber, saiddportions ing witnesses. comprisin a fiat wor in face a a ted to compress %he metal with ut displacihg the ALFRED BERTHOLD ANDREAS 5 same in a direction perpendicular to the WVitnesses:

direction of the compressing force. HENRIK WOLFE,

In witness whereof I have hereunto signed CARL HEMMINGSEN.

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