CA1043077A - Molded snap fasteners - Google Patents

Abstract

Abstract of the Disclosure This invention is a dual element, molded snap fastener assembly for bags, raincoats, cartons, portfolios and the like. Each fastener element in the assembly is sealed to one side of its supporting material with its coupling member, i.e. a stud or socket, projecting through an aperture in the material to the other side of the material where the coupling member is interengaged by the cooperating member of the other element in the assembly.

Description

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~ he present invention relates to snap fasteners and more particularly the invention is directed to snap fastener elements molded from plastic material. The invention also relates to fasteners attached to a supporting member to form a complete assembly of two joined members.
Heretofore, snap fasteners were usually made of metal but it has now been recognized that when such fasteners are made of a plastic they have certain advantages as compared to metal snap fasteners in respect to economy and ease of manufacture, enhanced appearance, adaptability to be colored as desired for any application, and ease of securing to a supporting member.
It is the general object of the invention to provide such a plastic snap fastener possessing the aforesaid advantages while at the same time to provide an improvement over the snap ~astener of the type as shown in U.S. Patent Nos. 3,083,429 issued to N.M.
~arlow et al on April 2~ 1963, 3,243,858 issued to E. Melanson on April 5, 1966 and 3,270,385 issued to E. Melanson on September 6, 1966. Each of these patents shows a strip of snap fastener components of the stud and socket type, and, in the latter two patents, the components are dielectrically heat sealed to a supporting member whereas the components in the former patent are secured to supporting member by a high frequency heat sealing method.
Another object of the invention is to provide a plastic snap fastener in which the separable elements are effec-tively aligned and securely heat sealed to supporting members for repeatedl~ joining and dis~oining the members with ease thus providing5for example, an improvement over the fastener disclosed in U.S. Patent No. 3~152,376~ issued to R.J. Boser et al on October 13 ~ 1964.

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D'77 ~ccprdingly th0 snap fa~tener ass,embly of the ,invention :~or jo~ning together supporting material or substrates compr~ses (a) first and second elemen~s comprising a heat sealable thermoplastic material; (b) each of said elements comprising a circular base with a cylinder projecting therefrom; ~c) each of said cylinders bei,ng smaller in diameter than its respective base; ~d) the cylinder of the first element being solid and having a peripheral rib near the free end thereof; (e) the cylinder of the second element being hollow with its free end open said second element cylinder having an interior wall surface with a peripheral rib located thereon near the free end of said second element cylinder; ~f) the inner diameter of said second cylinder being greater than the outer diameter of the first cylinder said elements being secured by the interaction of their respective ribs whereby the first element can snap fasten thereinto; ~g) a pair of : superimposed substrates having apertures which complement and receive the element cylinders, said substrates each comprising material which is heat sealable to said fastener elements; (h) the cylinder of the first element projecting through one of said apertures and the cylinder of the second ele-ment projecting through said other aperture in a manner to permit said first element to snap fasten into said second element and join said substrates;
and, ~i) a heat seal between the surface of the base of each element from which the cylinder projects and the peripheral area of the aperture in each substrate, said seal being the sole means of securing each element to each substrate.
~he fastener elements are heat sealed to the superimposed substrates in a manner to permit joining and disjoining the substrates without placing excessiveorce directly on the seal securing the elements to their respective substrates.
In the drawings which are attached hereto and made a part of this specification:
Figure 1 is a top plan view of an element made in accordance with the first embodiment of the present in~ention;

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Figu~e 2 ls a section vie~ along lipes 2 2 of Fîgure 1, ~ ure 3 ~s a cro~s~eC~ n V~e~; throug~the elements o~ t~e ~irst em~odiment of the ~l~vent~on ~ho~ng the elements inte~engag~d;
~gure 4 is a top plan v~e~ of an element made in accordance ~t~ t~e ~eco~d em~od~ment o~ tae p~e~ent invention;
~gure 5 i~ a 6ectlonal vie~ along line~ 5-5 o~
Yigu~a 4;
~gure 6 is a cross ~ection vie~ through the elements 1~ Of the second embodiment of the invention se~ured to a substrate ~ho~ing the elements interenga~ed;
Fi~ure 7 i~ a perspective view o a bag embodying the invention; and, Figure 8 is a top plan vie~ of a fastener according to the pre~ent in~ention attached to fllm and ~howîng the seal securing the fastener to the film.

DESCRIPTION OF THE PREFERRED EMæODIMENT

In Figures 1 and 2~ element 1 of the faste~er assembly or unit of the first embodiment is shown which includes a single, molded~
piece of plastic having a rela~iv ly wide and preferably circular base 3 with a stud which i8 prefer~bly a solid cylinder 4 located centrally thereo. As shown in ~igure 2 ther~ i8 a ridge or rib 6 at least partially around the outer periph2ry of the open end of the cylinder.
~a can ~e fiaen in Figure 3, a complementar~ element o~ t4~ ~nap astener aasembl~ ia o~ a s~milar configuration~ i.e.9 a ~aae 5 aaVipg a cy~inde~ 7 pro~ect~n~ from the center thareof ~it~ a r~ 8 on t~e ~nner per~p~er~ o~ t~e open cnd of the c~linder.

3a 1~3077 The inner diameter of element 2 ia greater than the outer diameter of element 1 to th~ extel~t to pe~mit the ri~ of element 1 to en~er past tRe ~nner r~ o~ element 2 in anap engagement as- 8hown In ~gure 3. T~e crlinders may be any 6hape, preferably circular, a~ long ~s the c~llnder~ of cooperat~ye elements o~ a fastener assem~ are ~e same shape or are geometr~call~ compat~le to permit the joining and disjoining t~ereof. The natural res-tlienc~ of thermoplastic material~ makes such materials preferred for the snap fasteners o~ this ~n~Qntion as such resiliency perm~ts easy ~oining and dis~oining o~ t~e snap fastener elements.
Re~erring now to ~igures 4-69 ~here i~ seen the similarity of the elementc or parts and the operation of same of the first and ~econd em~odiment~ of this invention. Element~ 11 and 12 of the snap fastener unit or aasem~ly of the second embodimen~
~nclude bases 13 and 15 with goIid and hollow cyl~nders 14 and 17 re~pectively proJecting up~ardl~ therefrom, eac~ having a rib~
16 and 18, respectively. A6 s~own~ ri~ 16 ia around the uppermoat part of the outside wall of c~linder 14 of element ll, and rib 18 i3 around t~ uppermost part of the inner wall of the cyllnder.
Baaes 13 and 15 have a raised portion or collar 20 and 22 immediately ad~acent and surrounding cyllnder~ 14 and 17, reapectivel~.
The ~nap fastener elementa are each formed of heat ~ealable type plastic which i~ auitable for molding and has the required rigiditr after lding. Such plaatic~ are well ~nown in the art and include auch ma~erial~ as ma~ be derivad from polyethylene, polyprop~lene~ polyvinyl c~loride, or ~lends or combinations of an~ o~ the~e or o~her known ~hermoplastic resin~.
3a ~5-~L043077 Referring to Figure 6, there i6 illustrated an a6sembly or unit embod~ing the invention wherein the elements of the second embodiment are shown interengaged and attac~ed to superimposed layers of a su~strate or supporting ~en~er A. rt i3 to be understood that the ele~ents of ~ot~ em~od~ments mar be attached in th~e ~ame manner, ~ut for t~e 6ake of B~ev~t~ onl~ the elements o~ th~ aecond emaodiment will Be de~cr$bed.
T~e ~uperimposed la~er~ of substrate or article A have colnc~dent apertures t~rough which ~e c~linder and collar o the 1~ respect~ve elemante pro~ect. The base of the elemen~ may be secured to the supporting me~ber in any suitable manner, preferably 'heat sealed. As shown in Figure 6 heat 6eal B may be completely or partially around the collar; i.e., it may ~e a horse shoe-shsped- sea~ or part of a circle. (See, e.g. seal B in Figure 8.) From Figure 6 several par~lcular advan~ages of the present invention may be appreciated. First, each fastener element iR adhered onl~ to one side of the film with its coupling or fastenlng member, i.e. stud or socket, pro~ecting through an aperture ~o that the force of unsnapping the element is carried by the whQle upper surface of t~e base of the element bearing again~t the film ~o that the seal itself does not have to be subjected ~o such force. In some prior art snap fasteners in which the ~ase and the coupling member are on the same side of the ~ film, the ~eal itself carries all of the force of the unsnapplng operation. In such fastener6, ~he seal can easily be broken and the fastener pulled from the film. The film ma~ even tear as heat ~ealing operations ~11 of~en weaken the seal around ~he ~aa~ener.

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In other p~ior art snap asteners in which the base has twq aections, each o~ t~e twa ~ase sections ~elng on opposite sides of t~e ~ilm and the two ~ections ~ng ~o~ned b~ multiple penetrations of t~e f~lm, t~e ~orce of d~,sengaging or unanapping the elemen~s is carried' throu~ ta~ penetrations. Eaca penetrat~on w~ea~ens t~e film and often the penetra~ions serve as ipit~,at~ng point~ from ~ch a tear will propagate. Also the incraas~ng num6er of component~ for`eac~ snap faatener makes t~e process of securing t~e fa~teners to the bag slower and more lQ cumbersome. T~e snap fastener assembl~ of the present invention overcome~ the above mentioned disadvantages in t~e prior ar~; and, as can be seen in Figure 6,, a m~numum numt~er of film penetrations are re~uired and the uncoupling force is di6tributed over a relatiYal~ wide area.
F~gure 7 shows a reclosable thermoplastic bag 30 having a flap 32 and a ~od~ 34 with the ele~ents of the fastener assembl~ attached thereto. Either one of t~e cooperative element~
ma~ be attached to the flap and thQ other cooperating element attached to t~e ~ody of ~e ~ag to permit the clo~ing and opening

2~ of t~e bag; but, it i~ preferable for stud 11 to be on the 1ap 32.
The article or bag 30 ma~ ~e made of an~ ~uitat~le heat sealable material a~ lis~ed heretofore; pre~erably, the bag and ~le~ent~ are made of the same type thermopla6tic material.
Fig~re 8 i3 a view looking down on a fragment of film ~; A which can be a bag wall to which the base 15 of a snap fastener projecting through aperture 24 is sealed b~ seal B at least pa~tiall~ around the aperture 24. T'~e portion of tha snap fastener Wh~c~ pro~ect~ t~roug~ t~e aperture ~s ~ne ~ e coupl~ng m~mbers, .~ .

i.e. either a stud or a socket, which as illustrated, is a socket 17. When thermoplastic bag material i5 employed with a thermoplastic fastener, it is often desirable that the upper surface of the base 15 in the area to which the seal B is to be made be roughened. This roughening may be a regular grid-like pattern or it may be a randomly roughened surface. The purpose of the rough-ened surface is to provide more sealing surface area and to allow the pro-jections caused by roughening to penetrate somewhat the film surface thus promoting better adhesion.
In repeated use or in using automatic closing machinery, it has been found desirable to make stud member 11 a solid cylinder rather than a hollow cylinder as the thin wall of a hollow cylinder could be easily cracked if too much force is applied when, in closing, the elements are misaligned.
The preæent invention can be used wherever it is desired to tempor-arily join two supporting materials, particularly supporting materials which are sheet-like in nature whether they be flexible or substantially rigid.
Besides bags, the invention can be used for raincoats, shower curtains, ca-rtons, portfolios, and the like.

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Claims (2)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A snap fastener assembly for joining together supporting material or substrates comprising:
(a) first and second elements comprising a heat sealable thermo-plastic material, (b) each of said elements comprising a circular base with a cylinder projecting therefrom;
(c) each of said cylinders being smaller in diameter than its respective base;
(d) the cylinder of the first element being solid and having a peripheral rib near the free end thereof;
(e) the cylinder of the second element being hollow with its free end open and second element cylinder having an interior wall surface with a peripheral rib located thereon near the free end of said second element cylinder;
(f) the inner diameter of said second cylinder being greater than the outer diameter of the first cylinder said elements being secured by the interaction of their respective ribs whereby the first element can snap fasten thereinto;
(g) a pair of superimposed substrates having apertures which complement and receive the element cylinders, said substrates each comprising material which is heat sealable to said fastener elements;
(h) the cylinder of the first element projecting through one of said apertures and the cylinder of the second element pro-jecting through said other aperture in a manner to permit said first element to snap fasten into said second element and join said substrates; and, (i) a heat seal between the surface of the base of each element from which the cylinder projects and the peripheral area of the aperture in each substrate, said seal being the sole means of securing each element to each substrate.

2. The snap fastener assembly of claim 1 wherein said superimposed substrates are respectively the flap and body of a reclosable bag.