US3037255A - Covered separable fastener - Google Patents

Description

June 5, 1962 Filed May 1, 1957 E. RYSER 3,037,255

COVERED SEPARABLE FASTENER 4 Sheets-Sheet 1 June 5, 1962 E. RYSER 3,037,255

COVERED, SEPARABLE FASTENER Filed May 1, 1957 4 Shets-Sheet 2 4 Sheets-Sheet 3 Filed May 1, 1957 il hi,

in IIHI EEE June 5, 1962 E. RYSER COVERED SEPARABLE FASTENER 4 Sheets-Sheet 4 Filed May 1, 1957 United States Patent 3,037,255 COVERED SEPARABLE FASTENER Ernst Ryser, Via Turconi, Mendrisio, Switzerland, assignor of one-half to Bertrand Voumard, La Chaux-de-Fonds,

Switzerland Filed May 1, 1957, Ser. No. 656,306 Claims priority, application Switzerland Mar. 5, 1957 7 Claims. (Cl. 24-2051) This invention relates to covered separable fasteners having interlocking fastener members attached to stringer tapes.

It is known to provide at least one of the stringers of a fastener arrangement with a covering strip which completely covers the fastener members at the outer side thereof when the separable fastener is in closed condition. On the other hand, it is also known to give the fastener members an asymmetric hook-shaped form with respect to a longitudinal center plane of the fastener extending transversely to the stringer plane, the stringer tapes being inserted into the interior of the hooks of these members. The hook ends about which pass the stringer tapes are in this case arranged so that in the closed position of the fastener the two stringer tapes contact each other in the said longitudinal center plane of the fastener at the front side thereof and thus cover the fastener members against being seen from the outside.

It has been found in actual practice that a one-sided covering of the fastener members does not suffice in many fields of application. Therefore it is an object of the invention to provide a separable fastener that is covered on both sides. According to the present invention the fastener members of the separable fastener are for this purpose symmetrically formed with respect to the stringer tape plane, in which arrangement at the level of the longitudinal center plane of the fastener situated at right angles to the plane of the stringer tape at each side of the head of each fastener member a portion of the stringer tape retained in the latter and associated with this fastener member emerges in such a manner, that when the fastener is closed, the stringer tape leaving the fastener members of one of the rows of members, and the opposite stringer tape leaving the members of the other row make contact in the longitudinal center plane of the separable fastener.

The separable fastener according to the present invention therefore is covered on both sides owing to the above described formation.

It is a further object of the invention to provide a separable fastener having two rows of fastener members anchored to stringer tapes, each stringer comprising two tape portions each of which is attached by an edge bead in the fastener members of the associated rows and emerges at both sides from these fastener members. When the portions of each stringer tape emerging at both sides from the clasp members remain disengaged and are together secured for example to an article of clothing only during insertion of the separable fastener into said article, it may occur that the fastener members of one row, when the fastener is open, are not tightly gripped by the stringer portions and thus are able to move relatively to each other out of the plane of the fastener. When sub sequently individual fastener members have been brought to a sufiicient extent out of alignment with the remaining 3,037,255 Patented June 5, 1962 members of the row, the slide fastener can no longer be closed at this point, since in operating the usual slider the members will only be urged further out of their position of alignment, which may then lead to damaging the fastener.

It is still another object of the invention to overcome the above disadvantage in that the stringer tapes are folded back over the legs of the associated fastener members and are firmly interconnected immediately behind the legs of the members remote from the head thereof.

In this manner a stringer sleeve is produced which snugly surrounds the legs of the fastener members of each row and prevents adjacent members from mutually moving to an excessive degree transversely to the plane of the fastener.

It is also an object of the invention to produce a separable fastener in which the slider of the fastener comprises two plates which are situated each at one side of the fastener and are interconnected by a central core piece, said plates being also provided with lateral guide members which travel solely on the two stringer tapes. Thereby a smooth quiet travel of the slider is obtained, and the latter is prevented from sticking to the fastener members, which may lead to damaging the fastener.

The invention is fully disclosed in the following specification of which the accompanying drawings form a part and represent a number of embodiments of the invention given merely by example, and in which:

FIG. 1 is a plan view of a fastener member of a first embodiment, prior to the insertion of the stringer tapes,

FIGS. 2 and 3 are sections of lines lI-II and IIII'II, respectively, in FIG. '1,

FIG. 4 shows the fastener member according to FIG 1, with the stringer tapes inserted therein,

"FIG. 5 is a sectional view of the first embodiment of the covered separable fastener according to the invention,

FIG. 6 shows a section through a second embodiment of the fastener,

FIG. 7 is a view similar to FIG; 4 illustrating a fastener member of a third embodiment,

FIG. 8 is a view similar to FIG. 4 illustrating a fastener member of a fourth embodiment,

FIG. 9 is a view similar to (FIG. 4 illustrating a fastener member of a fifth embodiment,

FIGS. 10 and 11 show a fastener member of a sixth embodiment of the invention before and after the insertion of the stringer tapes, respectively,

FIGS. 12 and 13 show a fastener member of a seventh embodiment before and after the insertion of the stringer tapes, respectively,

FIGS. 14 and 15 show a fastener member of an eighth embodiment before and after the insertion of the stringer parts, respectively,

FIGS. 1-6 and 17 show a fastener member of a ninth embodiment before and after the insertion of the stringer tapes, respectively,

FIGS. 18 and 19 show a fastener member of atenth embodiment before and after the insertion of the stringer tapes, respectively,

FIGS. 20 and 21 show a clasp member of an eleventh embodiment before and after the insertion of the stringer parts, respectively,

FIGS. 22 and 23 show a fastener member of a twelfth embodiment before and after the insertion of the stringer tapes, respectively,

FIGS. 24 and 25 illustrate a stringer tape used in the fastener according to FIG. 23 in plan view and in transverse section, respectively,

FIG. 26 is a fastener member of a further modification of the invention after the stringer tapes have been inserted,

FIGS. 27 and 28 show a stringer tape of the embodiment according to FIG. 26 in plan and sectional views, respectively,

FIGS. 29 and 30 show a fastener member of a further embodiment before and after the insertion of the stringer tapes, respectively,

FIGS. 31 and 32 show a stringer tape of the embodi ment according to FIG. 30 in plan and sectional views, respectively,

FIGS. 33 and 34 show a fastener member of a further embodiment before and after the insertion of the stringer tapes, respectively,

FIG. 35 is a fastener member of a further embodiment of the invention after the insertion of the stringer tapes,

FIG. 36 shows the fastener member of a further embodiment, which is die-cast directly upon a stringer tape,

FIG. 37 illustrates, in plan view, a fastener member of a further embodiment, which member also is die-cast upon a stringer tape.

FIG. 38 is a fragmentary plan view of a separate fastener according to the invention,

FIG. 39 is a modification of the fastener member shown in FIG. 1,

FIG. 40 shows in a sectional view the separable fastener provided with fastener members according to FIG. 39 and with a slider,

FIG. 41 is a plan view of a separable fastener covered on both sides,

FIG. 42 shows, on enlarged scale, a section along line IV-IV of FIG. 41,

FIG. 43 shows, on enlarged scale, a section along line V-V of FIG. 41, and

FIG. 44 shows, on enlarged scale, a section along line VI-VI of FIG. 41.

The fastener members 1 shown in FIGS. 1 to 5 are in known manner produced by a stamping operation. These members comprise a coupling head 2 which is provided with a recess 3 and a coupling projection 4. Each fastener member 1 has formed thereon two outwardly bent hook-shaped legs 5 and is symmetrically shaped with respect to the plane a of the stringer tape (see FIG. 4). The lateral surfaces of the head 2 of the fastener member are slightly beveled at the edges. The two stringer tapes 6, which carry the fastener members, are formed in two parts. Each part of the stringer has an edge bead 7. The two stringer parts 6 are inserted each with their edge head 7 in one of the hook openings, the leg 5 being pressed against the head 2 of the fastener member 1 in such a manner that the stringer tape portion surrounding the end portions of the hooks emerges from the member 1 approximately at the position of the longitudinal center plane I) of the separable fastener extending at right angles to the stringer tape plane a. As illustrated in FIG. 5, this arrangement results in that the opposite stringer tapes 6 contact each other laterally of the coupling heads 2 in the longitudinal center plane b of the separable fastener when the latter is in closed position. Obviously, a separable fastener covered on both sides is thereby obtained, in which the fastener members are covered-up by the stringer tapes themselves and not by cover-strips attached to the latter.

In order to provide a more continuous transition of the tape portions, laterally emerging from the fastener members 1, into the outer tape portion used for attaching the fastener, the members 1 of the embodiment according to FIG. 6 are tapered at their end remote of the head 2 and terminate into a slightly rounded tip. Otherwise, the fastener members 1 of this example are formed similar to the first described example and are likewise secured to two-piece stringer tapes 6.

The fastener members 1a, 1b illustrated in FIG. 7 is formed in two pieces while the stringer tape 8 provided in this design is made of a single continuous band. The hooks 9 provided on the part 1b of the fastener member enter with their projections 9a into corresponding recesses in the part 1a of the fastener member, whereby a safe connection between the two member parts 1a, 1b is insured. The hook ends surrounds by the stringer portions are disposed so that the two stringer tape ends emerge from the fastener member laterally of the head 2 approximately at the level of the longitudinal center plane b of the separable fastener. As in the first described cxample, the result is thereby obtained that the opposite stringer parts emerging from the fastener members at both sides of the head 2 contact each other in the longitudinal center plane b of the fastener when the latter is in closed position.

The two following examples illustrated in FIGS. 8 and 9 are built in analogous manner. Also in this embodiment of the invention the fastener members 1a, 1b are formed of two parts while the stringer tapes 8 each are in one piece. The hooks 9 of the fastener member part 1b engage corresponding recesses of the part 111 by means of the projections so that a secure union of the two fastener member parts 1a, 1b retaining the stringer tape 8 between themselves will be obtained. In the example according to FIG. 8, the stringer tape is of the same thickness throughout its length, an additional projection 9b provided on the part 1b engaging a corresponding recess in the part 1a of the fastener member in order to insure that the stringer tape is positively locked in place between said parts of the fastener member. In contradistinction to this arrangement, the stringer tape 8 of the example shown in FIG. 9 has a thickened portion 8a which insures a safe anchoring of the stringer tape between the parts of the fastener member.

The one-piece fastener member 1 shown in FIGS. 10 to 15 is stamped from sheet metal strips. The member 1 shown in FIG. 10 comprises two fastening legs 10 which are symmetrically arranged with respect to the stringer plane d of the separable fastener and slightly spread apart in outward direction. Inserted between these legs 10 and the head 2 of the fastener member 1 are the two parts of the edge head 11!: thereof positioned in a corresponding recess provided in the fastener member. The legs 10 are then forced against the head 2 of the fastener member, thereby gripping the end portions of the stringer so tightly within said member that they leave the fastener member 1 approximately at the level of the longitudinal center plane b of the separable fastener. The same holds true for the example shown in FIGS. 12 and 13. Also in this case the fastener member 1 comprises initially somewhat spread-apart fastenings legs 10 which are arranged symmetrically with respect to the stringer plane a and will be forced inwardly against the head 2 of the fastener member after the stringer parts 11 have been inserted. The length of the legs 10 is again selected so that the stringer parts 11 emerge from the fastener members 1 approximately at the level of the longitudinal center plane b of the separable fastener.

In order to produce the legs 10 of the fastener member 1, in the example shown in FIG. 14, slots 10a are punched into the blank and extend in outwardly inclined direction towards the longitudinal center plane b, into which slots the edge bead 11a of the parts of the two-piece stringer tape 11 will be inserted. Then the legs 10 are inwardly urged so that the stringer parts leave the fastener member 1 approximately at the level of the longitudinal center plane b of the separable slide fastener (FIG. 15).

The previously described examples of fastener members for separable fasteners covered on both faces according to the invention have the advantage of necessitating only a relatively small deformation of the hook or legs of the fastener members after the stringer tapes have been inserted, since the free ends of the hooks or legs are already directed towards the longitudinal center plane b of the separable fastener prior to the insertion of the stringer parts.

Another form of fastener member is provided in the examples according to FIGS. 16 to 32.

According to FIG. 16 the fastener member 1 initially comprises two legs 12 projecting from the head 2 and symmetrically formed with respect to the stringer plane a. Between head 2 and legs 12 the member 1 has a lateral contraction 13 into which the two parts of the two-piece stringer tape 14 are inserted with their respective edge beads 14a. The two legs 12 are subsequently outwardly bent by approximately 180 in order to provide hooks tightly clamping the stringer parts against the fastener member 1 so that the stringer parts emerge from the fastener member 1 laterally of the head 2 approximately at the level of the longitudinal center plane b of the separable fastener (FIG. 17). An analogous arrangement is used for the examples shown in FIGS. 18, 19 and 20, 21. Apart from the somewhat different formation for head 2, contraction 13 and fastening legs 12, the fastener members shown here are formed similar to the one illustrated in FIGS. 16, 17.

One-piece fastener members and two-piece stringer tapes have been provided in the examples described last. In contradistinction to that, the examples according to FIGS. 22 to 32 have one-piece fastener members 1 and also one-piece stringer tapes 15. The fastener member 1 indicated in FIG. 22 has shoulders 16, formed by a reduced width of the section below the head 2, and fastening legs 17 initially projecting from the head 2 and symmetrically arranged with respect to the plane a of the Stringer tape. These legs 17, in producing the separable fastener according to the invention, are slipped through a slot 18 provided in the one-piece stringer tape 15 (see FIGS. 24, 25) and then are laterally bent in upward direction to such an extent that the free ends thereof and the stringer parts, respectively, emerging from the fastener member will be positioned approximately in the longitudinal center plane b of the separable fastener (FIG. 23). The stringer tape 15 employed in this case is of equal thickness throughout its entire width, contrary to the stringer tape 15 which is provided in the example according to FIGS. 26 to 28 and has formed therein a thickened portion 19 on each side of the slots 18. The thickened portions 19 tightly gripped between the shoulders 16 and the upwardly bent legs 17 of the fastener member 1 insure a safe connection of the fastener members 1 with the stringer tape.

The fastener member 1 provided in the example shown in FIGS. 29 to 32 initially has a form (FIG. 29) almost similar to the one of the previously described fastener member according to FIG. 22. The legs 17 are here slipped each through a slot 20 in the stringer tape 15 and laterally bent in outward direction towards the longitudinal center plane b so that the two marginal portions of the stringer will emerge from the fastener member 1 approximately on the level of the longitudinal center plane b. Located between the two rows of slots 20 the stringer tape 20 has in this case a center bead 21 which is positioned at the outside of the fastener member 1 between the two upwardly turned legs 17.

The FIGS. 33 to -35 illustrate two examples having two- piece fastener members 1a, 1b and two-piece stringer tapes 25. According to FIG. 33 the part 1a of the fastener member has a head 2 from which project two fastening legs 22 symmetrically situated with respect to the plane a of the stringer. In assembling the two parts 1a, 1b of the fastener member, the free ends of the legs 22 are outwardly bent at right angles (FIG. 34) so that on the part 1a of the fastener member a contraction is formed into which the projections 23 provided on the arms 24 of the second part 1b of the fastener member are able to enter. The two stringer parts 25 are clamped between the free ends of the arms 24 of the part 1b and the head 2 of the part 1a of the fastener member in such a manner that these par-ts 25 emerge from the fastener members 1a, 1b laterally of the head 2 approximately at the level of the longitudinal center plane b of the separable fastener.

The fastener member part 1a of the fastener member shown in FIG. 35 comprises a head 2, a neck 26 and a foot 27, the part 1b of the fastener member surrounding the neck 26 of the part In and simultaneously urging the two stringer parts 25 against the head 2 of the part 1a of the fastener member. The whole arrangement is again such as to cause the stringer parts 25 to emerge laterally of the head 2, approximately at the level of the longitudinal center plane b, from the faster member of the separable fastener.

Previously only embodiments of the invention have been described in which the fastener members are shown to be clamped against the stringer tapes. In con-tradistinction to this design, the FIGS. 36, 37 show fastener members which are die-cast directly upon the stringer tapes. In the example according to FIG. 36 a one-piece stringer tape 28 is provided which has two series of longitudinally spaced slots 29 and also a center bead 30 separating the two series of slots 29. Fastener members 1 disposed symmetrically with respect to the stringer plane a are die-cast upon this tape in such a manner that the marginal portions of the tape 28 emerge on both sides of the head 2 approximately at the point of the longitudinal center plane of the separable fastener.

The fastener member 1 according to FIG. 37 is also die-cast upon a one-piece stringer tape 28 symmetrically to the stringer plane a, said tape 28 comprising a thickened center portion and a row of longitudinally spaced slots 31. Also here the arrangement is such as to cause the two marginal portions of the stringer tape 28 to leave the fastener member 1 laterally of the head approximately at the level of the longitudinal center plane b of the separable fastener.

The modification of the fastener member shown in FIGS. 39 and 40 differs from that shown in FIGS. 4- and 5 in that the heads 2 are provided with nose-shaped edges 2a at their side facing the foot of the fastener member, which edges together with the nose-shaped projections 5a of the hooks '5 insure that the edge beads 7 of the two-piece stringer tape 6 are securely locked in place within the fastener member 1. Since in addition between the arms of the hooks 5 and the projections 5a thereof a transition contour is provided which shows an obtuse angle and not an acute angle as in the fastener member shown in FIG. 1, the edge bead 7 perfectly fills the entire space left between the hook 5 and the foot of the fastener member. As shown in the FIGS. 39 and 40, the heads 2 of the fastener member are not symmetrically beveled with respect to the longitudinal center plane b at their respective sides, but formed so that the inclined surfaces 32, situated at the head side remote of the legs of a fastener member I of one of the rows, are somewhat set back with respect to the inclined surfaces 33 provided at the head side facing the legs of a member of the other row (FIG. 40).

As indicated in FIGS. 38 and 40 the slider 34 with its top and bottom plate exclusively slides over the tape portions 6. This fact results in a smooth travel of the slider which is elfectively prevented from sticking to the fastener members, a defect often leading to damaging the closure member in separable slide fasteners of conventional design.

Obviously, all described separable fasteners have fastener members which are symmetrically formed with respect to the plane of the stringer and secured to the stringer tapes such that their free end portions emerge from the fastener members laterally of the coupling heads approximately at the level of the longitudinal center the opposite stringer parts of the two stringer tapes of the fastener contact each other in the said longitudinal center plane of the fastener (FIG. 38). Consequently a separable fastener is produced which is perfectly covered on both sides. The interlocking heads 2 of the fastener members 1 of the two rows are embedded between the stringer parts 6 in such a manner that they will not come out of engagement even if the separable fastener is sharply bent in its longitudinal direction. Such a separable fastener may easily be used with either side facing outwardly since it obviously has in its closure position no distinct inside and outside. A separable fastener covered on both sides according to the invention is also suitable for use on such articles of clothing (e.g. fiying suits) or containers which are to be subjected to internal pressure. This becomes immediately clear when viewing the fastener member arrangement shown in FIG. 5. If for instance an internal pressure acts upon the separable fastener in the direction of the arrow A, then the mutually contacting stringer parts situated at the outside of the fastener (in FIG. the top side) are urged apart from each other, which fact thus would automatically lead to leakiness of the separable fastener in case of a fastener being covered only at one side thereof. However, as may be easily understood, in the present case the mutually contacting inner stringer parts are tightly forced against each other by the internal pressure so that the separable fastener can be kept in perfectly sealed condition.

In the separable fastener shown in FIGS. 41 to 44, the numerals 35a, 35b represent the two parts of one of the stringer tapes while 36a, 3611 indicate the two parts of the other stringer tape. A row of fastener members 1 is secured to each of the two stringers. The leg of the fastener members 1 forms at each side a hook 37 (FIG. 44) as in the previously described examples. By means of these books 37 the edge beads 38 of either stringer tape are tightly clamped, so that the two stringer parts laterally emerge from the fastener members approximately in the zone of the coupling axis of the separable fastener. Thereby it is obtained that the opposite parts of the two stringer tapes contact each other in the longitudinal center plane b (FIG. 43) of the fastener extending at right angles to the plane of the fastener, when the separable fastener is in closed position.

The two stringer parts 35a, 35b and 36a, 36b, respectively, which emerge out of the fastener members 1 at the side thereof, are turned back over the leg or the hooks 37 of the members 1 and are rigidly connected to each other by a quilting seam 39 immediately behind the end face of the leg remote of the head 2. Consequently the leg of each row of fastener members are locked in place each snugly fitting into a sleeve portion formed by the two parts of the stringer tape. It is understood that a plurality of quilting seams 39 extending parallel to each other could also be used; in place of the quilting seams 39 any other connection, e.g. by stitching or adhesive means, could also be provided. The same connection of the respective stringer parts may also be provided in case of all the previously described separable fasteners.

At that end of the separable fastener where the slider 34- is positioned when the fastener is closed, the two parts 35a, 35b and 36a, 361), respectively, of the stringer tapes are securely connected to each other each by means of an end piece 40 (FIGS. 41 and 42) surrounding and clamping together the edge beads 38. At the other end of the separable fastener where the slide will be located when the fastener is in open position, the mutually opposite parts 35a, 36a, and 35b, 3612, respectively, of the two stringers tapes are securely connected to each other each by means of an end piece 41 (FIGS. 41 and 43) surrounding and clamping together the edge beads 38. Thereby the rows of fastener members are perfectly closed at their ends; in addition the traveling path of the slide 34 will be limited particularly during opening of the separable fastener, whereby it is practically impossible to open up the fastener to an excessive extent. Since the clamping end pieces 41 immovably fix the two rows of fastener members in their mutual position, at any time the correct interengagement of the co-acting fastener members of the two rows is insured even after the fastener has been opened to its maximum extent.

t-is understood that the described arrangement could also be made in case of a separable fastener which is not covered.

The slide 34 of the shown separable fastener comprises two plates 34b each situated at one side of the closure member, whichv plates are connected to each other by a central core piece 34a. The lateral edges of these plates 34b are provided with guide members 34c facing each other. As distinctly shown in FIG. 44, the slide 34 exclusively travels along the two stringer tapes 35a, 35b and 36a, 36b, respectively, and its plates 34b provided with the guide members 340 surround the fastener members enveloped by the stringer parts.

It is understood that a separable fastener, which is covered only at one side or not at all and in which the stringer parts though also emerging laterally from the fastener members but contacting each other only at one side or not at all in the longitudinal center plane when the fastener is closed, may be provided with a slide of the described kind traveling exclusively upon the stringer tapes.

What I claim is:

1. A covered separable fastener comprising stringer tapes including opposite edge portions and interlocking fastener members secured in longitudinally spaced relation to said opposite edge portions of said tapes, said tapes defining a stringer tape plane, said members being symmetrical with respect to the stringer tape plane said fastener members each comprising a coupling head, a neck portion narrower than said coupling head, a shoulder coupling said neck portion and said coupling head and a pair of tape engaging legs, each of the legs including a straight portion and a nose portion on said straight portion, said nose portion being laterally adjacent said coupling head and directed towards said neck portion to subtend an acute angle with respect to said straight portion, said coupling head having at each side thereof an outwardly divergent side surface cooperating with said nose portion of said legs for securing said stringer tapes to said members, said stringer tapes engaging the whole side surface of said neck portion and shoulder and the side surfaces of said tape engaging the legs and in locked relation therewith, said stringer tape emerging from both sides of said fastener members laterally of said coupling head and said nose portion on the level of the longitudinal center plane of said fastener members and extending at right angles to said first-mentioned plane with said nose portions holding said stringer tapes in engagement with said outwardly divergent side surfaces of said coupling head to contact positively the whole outwardly divergent side surfaces of said coupling head, so that with the fastener closed the tape emerging from the fastener members of one stringer is in fluid-tight contact with the tape emerging from the fastener members of the other stringers.

2. A separable fastener according to claim 1, in which the fastener members of each stringer are each constituted by a single piece and said stringer tapes each comprise two connected pieces.

3. A separable fastener according to claim 1, comprising a slider on the separable fastener and sliding along the stringer tapes emerging from the fastener members.

4. A separable fastener according to claim 1, comprising a slider including top and bottom plates positioned each at one side of the fastener, a central core piece, said plates being connected to each other by said central core piece, and lateral guide members on said plates exclusively traveling along the two stringer tapes.

5. A separable fastener as claimed in claim 1 wherein said shoulder is substantially normal to the neck portion, said tapes including an enlarged portion between the neck portion and the tape engaging legs whereby relative movement between the fastener member and the tapes in a direction normal to said shoulder is prevented by said shoulder and said nose portion.

6. A fastener as claimed in claim 1 wherein each said tape is provided with a series of longitudinally spaced slots through which said neck portions extend.

7. A fastener as claimed in claim 1 wherein each said tape includes two separate tapes each including an edge portion engaged by the nose portions of the associated fastener member.

References Cited in the file of this patent UNITED STATES PATENTS 2,791,017 M-ulka May 7, 1957 FOREIGN PATENTS 262,850 Italy Feb. 22, 1929 585,731 Germany Nov. 7, 1931 214,594 Switzerland July 16, 1941 884,335 Germany July 27, 1953

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