Integrally molded surface fastener

Abstract: The surface fastener comprises a pair of upper (male) and lower (female) engaging members (2,3) of the same structures, which are molded integrally and provided with a plurality of rows of hook elements (4) on the surfaces of engaging base plates (21,31). This arrangement unit has successively two hook elements (4,4) of predetermined pitches and a spacing (5) of two pitch lengths and is repeated in order continuously. The spacing (5) means that one hook element is not present. Due to these spacings (5), a hook element (4) of one engaging member is inserted between two hook elements (4,4) of the other engaging member, respective two hook elements (4,4) are easily elastic- deformed in the separating direction to provide reliable engagement of the opposed hook elements (4,4) even if positions of the opposed hook elements do not match perfectly.

Description: 1. Field of the Invention : This invention relates to a surface fastener molded integrally of synthetic resin comprising a pair of upper and lower engaging members as defined in the preamble of claim 1, in which a plurality of rows of hook elements are integrally molded of synthetic resin on surfaces of respective engaging base plates and which adopt the same structures to facilitate the manufacture and the control of products and to ensure uniform distribution of engaging strength and durability. 2. Description of Prior Art : The usual surface fastener is known as a so-called velvet type fastener comprising a pair of male and female tapes, wherein engaging element of male tape is formed as hook-like projection cutting a part of a loop in the fastener made of knitted cloth, or engaging element of male tape is formed as hook-like, mushroom-like, anchor-like projection in the fastener molded integrally of synthetic resin, and engaging element of female tape is mainly formed of a loop of a loop knitted cloth. As stated above, the other engaging element or female element is formed of the loop of the loop knitted cloth to provide high engaging ability, however, the female element has weaker strength and is too flexible. As a result, the female element has not been used as the industrial material since it does not meet the demand of positioning function and the durability. The conventional surface fasteners made of synthetic resin are disclosed for example in United States Patent No. 2499898, Japanese Utility Model Unexamined Publication No. S 52-71808, and No. H 2-127205. Each of these surface fasteners comprises a pair of upper and lower (or male and female) engaging members which are respectively molded integrally of synthetic resin, so that these fasteners provide excellent positioning function and high strength of engaging elements in comparison with using female members of loop knitted clothes. However, the above-mentioned surface fasteners comprise male and female engaging elements of mainly mushroom-shape. When the engaging element has a mushroom shape, the construction of the engaging element provides engaging strength weaker than that of the engaging element of hook-shape. When engaging and disengaging of the male and female elements are repeated, the engaging strength falls off in a short time, so that the fastener will be hardly usable. EP-A-0 421 295, which forms the basis of the appended claim 1, discloses a surface fastener comprising a pair of upper and lower engaging members of the same structure. This surface fastener is composed of upper and lower engaging members which are respectively provided with a plurality of rows of hook elements. The hook elements of upper and lower engaging members are oriented in the mutually opposite directions and the pitch of hook elements is uniform. The backface of the raised portion of each hook element extends straight from the engaging base plate. SUMMARY OF THE INVENTION It is therefore an object of this invention to provide a novel surface fastener comprising a pair of engaging members which are respectively integrally molded together with hook elements of the same structures to ensure high engaging strength and sufficient durability to be used repeatedly, to promote making efficiency, and to provide easy controlling and attaching works in the stock and shipment. In order to accomplish the above-mentioned object, the surface fastener of this invention comprises a pair of upper (male) and lower (female) engaging members with features as defined in the characterising portion of claim 1. Preferably, adjacent rows of hook elements of each engaging member are oriented in the mutually opposite directions. Hook elements on upper and lower engaging base plates are formed as wavy shapes on the beach and are arranged oppositely as shown in FIG. 1 and FIG. 2. In engagement of fastener, two hook elements of the upper engaging member confront opposing two hook elements of the lower engaging member as being shifted by one pitch. One hook element is pressed onto mating two hook elements while the tip face of the hook-like engaging portion FP of one hook element is contacted with the tip face of the hook-like engaging portion FP of one of the two mating hook elements and with the back face ba of the other mating hook element ajacent in row direction, to open these mating hook elements and is smoothly guided between the mating hook elements and engaged since the spacings are arranged between respective set of two hook elements to allow easy elastic deformation of the hook elements. And the mating hook elements are deformed in the same way, so that the confronting hook elements of both engaging members are engaged more surely. Accordingly, all hook elements of the upper and lower engaging members are mutually engaged uniformly and smoothly to ensure desire engaging strength without being rough or rugged when engaged. To disengage the engaged surface fastener, a disengaging force beyond a locking force of mating engaging members is applied to the engaged surface fastener, so that the tip ends of the engaged hook-like engaging portion FP are twisted slightly sideward and simultaneously opened in the mutually separating direction to provide easy disengagement. Further objects and advantages of the invention will be apparent from the detailed description hereinbelow set forth, together with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an illustrative view showing an engaging principle of integrally molded surface fastener according to this invention; FIG. 2 is a plan view showing an arrangement of the integrally molded surface fastener of a first embodiment of this invention; FIG. 3 is a side view showing every row of engaging elements of the surface fastener; FIG. 4 is a plan view showing another arrangement of the integrally molded surface fastener of a second embodiment of this invention; and FIG. 5 is a side view showing every row of engaging elements of the surface fastener of the second embodiment. DETAILED DESCRIPTION Firstly, the engaging principle of the surface fastener of this invention will be illustrated with reference to FIG. 1. As stated above, a first feature of this invention is that upper and lower engaging members 2, 3 of the surface fastener 1 have the same structure. A second feature of this invention is that a hook element of specific shape is adopted as an engaging element. The shape of the hook element comprises, as well as the precedent proposed hook shape, a raised portion SP having a back face ba extending with a gentle slope from a flat base plates 21, 31 and a vertically standing front face fr, a hook-like engaging portion FP extending forwardly from the end of the raised portion SP, and ribs c formed on the both sides of the raised portion SP. Each hook element 4 has a sectional area which increases gradually from the tip end of the hook-like engaging portion FP to the root d of the raised portion SP. Accordingly, in this embodiment, the hook element 4 has the maximum area at the root d thereof. However, said area may be the same from the tip end of the hook-like engaging portion FP to the root d of the raised portion SP, or the front face fr may be formed to have an arcuate shape, so that this invention has various modifications. And the rib c is not an essential component of this invention. A third feature of this invention is that two hook elements 4, 4 4 with a predetermined pitch and a spacing 5 which occupies the length of two pitches and wherein a hook element 4 is not disposed, are successively arranged in a row on a base plate, and this unit arrangement is successively repeated in the longitudinal direction. The first feature is to form upper (male) and lower (female) engaging members as the same structure in the manufacture of a surface fastener molded integrally so as to provide easy forwarding and stocking work and so as to ensure easy attachment of the surface fastener. The second feature is further to ensure easy molding, reliable engaging and disengaging, and sufficient durability for repeated use. The third feature is furthermore to provide reliable engaging of opposed upper and lower hook elements 4 by disposing spacing 5 which makes respective two hook elements 4, 4 to be easily elastic-deformed in the separable direction even if the positions of the opposed hook elements 4 do not mutually match in the row direction as shown in FIG. 1 (a) and (b) when the hook element 4 of the one engaging member is inserted between the two hook elements of the opposite engaging member. This invention is characterized by the above-mentioned three features, however, a further aspect of this invention is now described. The adjacent rows of hook elements which are arranged on respective surfaces of engaging base plate 21, 31, are oriented in the mutually reverse directions, whereby being prevented from having orientation in engaging strength in the row direction. A surface fastener 1 of this invention is an integrally molded article of synthetic resin materials. As shown in both figures 1(a) and 1(b), the upper and lower engaging members 2 and 3 have the same structure respectively. A plurality of rows of the hook elements 4 are linearly arranged and protrude on the surfaces of the engaging base plates 21, 31 at the above-mentioned regular arrangement. According to the first embodiment shown in FIG. 2 and FIG. 3, the hook elements 4 are repeatedly arranged by the same patterns of every six rows A, a, B, b, C, c. Three rows A, B, C of hook elements 4 are oriented in the same direction, and other three rows a, b, c of hook elements 4 are oriented in the reverse direction relative to the rows A, B, C of hook elements 4. Of course, every row of hook elements 4 is repeatedly arranged in order at the above-mentioned unit arrangement including two hook elements 4 of predetermined hook pitch and a spacing 5 of two hook pitches. Every one pair of adjoining rows A, a ; B, b ; C, c of hook elements 4 are respectively shifted by one half (1/2) of one hook pitch, and an adjoining pair of rows c, A ; a, B ; b, C of hook elements 4 is arranged at positions shifted by one and a half (3/2) hook pitches in the same direction. When one of two engaging members having the same structure is rotated by 180 degrees in the same plane and the surfaces having projected hook elements 4 are pressed toward each other, the hook elements 4 of the two engaging members are mutually engaged as follows; When hook elements 4 having vertical cross sections of wavy shapes on the beach are arranged as mentioned above on upper and lower engaging base plates 21, 31, the hook elements 4 of the upper and lower engaging members 2 and 3 are engaged in the face-to-face relation as shown in FIG. 1 and FIG. 2. During engagement, a set of two hook elements 4, 4 of the upper engaging member 2 is shifted by one pitch relative to a set of two hook elements 4, 4 of the lower engaging member 3. While the tip face of the hook-like engaging portion FP of one hook element 4 is contacted with the tip face of the hook-like engaging portion FP of the one of the mating hook elements 4, 4 and with the back face ba of the other mating hook element 4 adjoined in the same row, the one hook element is pressed and is guided smoothly between the adjacent mating hook elements 4, 4 due to the spacing 5 to provide reliable engagement between the upper and lower engaging members. Thus, the hook elements of the whole hook surfaces of the upper and lower engaging members 2, 3 are uniformly and smoothly engaged to ensure desired engaging strength without being rough. In case of disengaging the engaged surface fastener 1, when a force stronger than the engaging force between both engaging members 2 and 3 is applied to both engaging members 2 and 3 in the separating direction, the tip ends of the engaged hook-like engaging portions FP are twisted slightly sideward and simultaneously opened in the separating direction to provide easy disengagement. FIG. 4 shows an arrangement pattern of hook elements of a second embodiment of this invention. FIG. 5 is a side view showing every row of hook elements of the second embodiment. According to this second embodiment, the arrangement of the hook elements 4 repeats the same patterns at every six rows A, D, B, D, C, D and the hook elements 4 of the D-rows are disposed always in the same pattern and with the hook being oriented in the same direction. The hook elements 4 of the other A, B, C-rows are arranged between the D-rows and oriented in the reverse direction relative to the D-rows. Two hook elements 4, 4 of three rows A, B, C are arranged as a whole at an obliquely figured textile. Of course, in this example, two hook elements 4, 4 of predetermined pitches respectively and a spacing 5 of two pitch lengths are repeatedly arranged in order as stated above. When two engaging members of the above-mentioned structure are used as upper and lower surface fastener 1, it is possible to ensure reliable engaging strength as well as the above-mentioned first embodiment and further to provide easy engaging and discoupling of the surface fastener. As stated hereinabove, in accordance with this invention, advantageous results can be obtained as follows; Since a pair of engaging members of surface fastener have the same structures of integrally molded article, it is possible to ensure high engaging strength and sufficient durability for repeated use, to promote high manufacturing efficiency, and to provide easy controlling and attaching work in the stocking and shipment. Since the hook elements are rationally arranged on the engaging members, the surface fastener can be uniformly engaged with each other to provide uniform strength throughout the surfaces. Since the hook element has a specific shape of a generally wavy cross section and the hook elements of the first and second engaging members are oriented in the reverse directions relative to each other, the engaging and disengaging operation of the surface fastener can be smoothly carried out without damaging the hook elements. Accordingly, the surface fastener of this invention may be widely used in various fields and especially in the industrial material field which requires strong and uniform engagement.

Claims: A surface fastener molded integrally of synthetic resin comprising a pair of upper and lower engaging members (2,3) which are respectively molded integrally and provided with a plurality of rows of hook elements on engaging base plates (21, 31), each of said hook elements (4) having a raised portion (SP) having a back face (ba) extending from said engaging base plate and a front face (fr), and a hook-like engaging portion (FP) extending from the end of said raised portion (SP) forwardly, characterized in that (i) the back face (ba) of the raised portion (SP) of each of said hook elements (4) extends with a gentle slope from the engaging base plate (21, 31); (ii) two hook elements (4, 4) and a spacing (5) without a hook element which occupies a length of twice as long as a pitch of said hook elements (4, 4) are successively arranged in order in every row on each engaging member (2,3); and (iii) adjacent rows of hook elements (4) are mutually shifted by predetermined pitches. A surface fastener molded integrally of synthetic resin according to claim 1, characterized in that adjacent rows of hook elements ( 4 ) of each engaging member ( 2, 3 ) are oriented in mutually opposite directions. A surface fastener molded integrally of synthetic resin according to claim 1, characterized in that the sectional area of said hook element ( 4 ) is increased gradually from the tip end of said hook-like engaging portion ( FP ) to the root ( d ) of said raised portion ( SP ).

Inventors: MURASAKI RYUICHI, MURASAKI, RYUICHI
Applicants: YKK CORP, YKK CORPORATION
Application year: 1993
Main classification: A44B18
IPC codes: A44B18