US3735468A

US3735468A - Apparatus for making flexible strips of material having a pile of hook-shaped elements

Info

Publication number: US3735468A
Application number: US00234235A
Authority: US
Inventors: G Rutland
Original assignee: American Velcro Inc
Current assignee: American Velcro Inc
Priority date: 1970-11-18
Filing date: 1972-03-13
Publication date: 1973-05-29
Anticipated expiration: 1990-05-29
Also published as: US3665584A

Abstract

An apparatus is disclosed for making the hook or loop part of a seperable hook and loop type fastener by bending a flexible base strip having a plurality of unbroken hook-shaped rails protruding from one surface thereof into a generally tubular form with the rails extending radially inwardly thereof; and thereafter progressively subjecting spaced-apart cross-sectional segments of each rail alternately and periodically to a rotational cutting action to transform each rail into a row of individually spacedapart resilient hooks or loops.

Description

ilnite late-s aet [191 Erh [54] APPARATUS FOR MAKHNG FLEXIBLE STRHPS 0F MATERIAL HAVING A PILE OF HOOK-SHAPED ELEMENTS [75] Inventor: George H. Erb, Rutland, Vt.

[73] Assignee: American Velcro, Inc., New York,

[22] Filed: Mar. 13, 1972 [21] App]. No.: 234,235

Related U.S. Application Data [62] Division of Ser. No. 90,710, Nov. 18, 1970, Pat. No.

[52] US. Cl ..29/207.5, 29/410 [51] Int. Cl ..A41h 37/06, B23p 19/04 [58] Field of Search ..29/4l0, 207.5, 207.5 D, 29/558, 408

[451 May 29, 1973 [56] I References Cited UNITED STATES PATENTS 3,665,584 5/1972 Erb ..29/410 Primary ExaminerThomas H. Eager Atl0rneyDean S. Edmonds, Willis H. Taylor Jr.

and DavidJ. Toomey [57] ABSTRACT An apparatus is disclosed for making the hook or loop part of a seperable hook and loop type fastener by bending a flexible base strip having a plurality of unbroken hook-shaped rails protruding from one surface thereof into a generally tubular form with the rails extending radially inwardly thereof; and thereafter progressively subjecting spaced-apart cross-sectional segments of each rail alternately and periodically to a rotational cutting action to transform each rail into a row of individually spaced-apart resilient hooks or loops.

3 Claims, 9 Drawing Figures ll APPARATUS ron MAKING FLEXIBLE STRIPS or MATERIAL HAVING A PIILE or nook-SHAPED ELEMENTS This is a division, of application Ser. No. 90,710, filed Nov. 18, 1970, now US. Pat. No. 3,665,584.

BACKGROUND OF THE INVENTION This invention relates to separable fastening devices of the type wherein one part of the fastener has a multiplicity of small outwardly projecting loops of thin filamentary material and the other surface is provided with a multiplicity of curled or hook-like resilient projections. Such fasteners have been described in US. Patents Nos. 2,717,437 and 3,009,235.

It will be understood that when two layers of this type are pressed into face-to-face contact, their respective hooks and loops interengage one within the other thereby securing said layers into locking engagement. Separation of the two layers requires a force of considerable magnitude when attempting to effect the separation of a large number of hooks and loops at once, but separation may be quite readily effected by progressively peeling the layers apart.

Fasteners constructed with interlocking hooks and loops of the type described find a wide variety of applications. For instance, they can be substituted for existing closing devices such as buttons, buckles, clasps, slidable fasteners of the type popularly termed zippers, or like attachments which are currently used in many diverse type of wearing apparel. In addition, they serve a useful function reciprocating many particular environments where it is desired to fasten one object to another in a quick and efficient manner.

In the past, the hooked surface of these fasteners has been formed by subjecting a multiplicity of loops to the cutting action of a device consisting of a comb of tapered needles having mounted thereon small rapidly needles scissors-like cutters which clip each loop at a pre-determined point thereby resulting in a hook and stub formation which, due to the resilient nature of the filamentary loops, to a great extent resembles a snap hook configuration.

It is a principal object of this invention to provide an apparatus for producing a hooked surface of the type described which further utilizes an extruded starting material employed several possible hook-like forms or alternatively a loop form.

SUMMARY OF THE INVENTION action wherein selected spaced-apart cross-sectional segments of each inwardly extending rail are periodically removed to transform each rail into a row of individually spaced-apart resilient hooks or into rows of loops.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of the starting tape according to the invention;

FIG. 1a is a cross-sectional view taken in the direction of arrows la-la of FIG. 1;

FIG. 2 is an elevational view of the starting tape of FIG. 1 formed into a tube and subjected to internal cutting by an apparatus;

FIG. 3 is a top view of the starting tape and apparatus of FIG. 2;

FIG. 4 is a cross-section taken in the direction of arrows 4-4 of FIG. 2;

FIG. 5 is a fragmentary perspective view of the hook fastener tape material produced according to the present invention; and

FIGS. are cross-sections of tape material showing different configurations of hook and loop elements formed in accordance with the present invention.

DESCRIPTION OF PREFERRED EMBODIMENTS I With reference initially to FIGS. 1 and 1a of the drawing there has been disclosed a starter material 10 having a backing 11 and a series of rails 12 extending therefrom. In the illustrated embodiment the rails (as shown in FIG. lla) are hook-like extentions which are integral with the backing rail 11 and are extruded integrally therewith of a suitable plastic material.

Referring to FIG. 2, the starter material 10 is passed along an endless belt 14 through a frusto-conical shaped forming die 16 which causes the starter material 10 gradually to be formed into a. generally tubular shape. As the starter material moves in an axial direction in the direction of arrow 17, it will gradually ride up on the tapering circular inner surface of the die 16 to emerge from the smaller end 16a in a generally tubular form. The diameter of the smaller end of the die is slightly larger than the diameter of the circle which would be formed if the side edges 11a and 11b were brought into abutting contact.

This arrangement provides a tubular form with a gap which permits the tubular form to pass without interference with the gearbelt 21 connecting the cutter 20 to the motor 22. The cutter 20 is formed as a helix so that as the starter material 11 progresses past the cutter, the rails 12 will be cut progressively and will produce a series of upstanding hooks 12a as shown in FIG. 5. In the particular, illustrated embodiment, there has been provided a cooling means schematically indicated as surrounding the forming die 16 which will increase the rigidity of rails 12 so that these may be cut more readily. After cutting, the material 10 and hooks 12a will pass through a suitable heating means 36 which will return the material to its original or ambient temperature.

It should be noted that the term hook-shaped rail as used in the specification and claims is intended to signify any upstanding unbroken rail which whencut in the manner herein disclosed will produce a row of individual, spaced apart, and upstanding elements which are suitable for use as the hooks of the hook member of a hook and loop type separable fastener. For instance, as shown in FIG. 6 upstanding rails 24 are shaped respectively as arrowheads, and in FIG. 7 the rails 25 are formed as double-hooks.

In the foregoing description of this invention, reference has been made to the fact that the transverse bending of the starting tape into a tubular form and movement of the tubular form longitudinally in partially en-circling relationship to the fixed rotary cutter is accomplished simultaneously. It should be noted, however, that these steps may be performed sequentially. Thus, the starting tape may be bent into a generally tubular form and secured in a fixed position on a stationary table. Thereafter the rotating cutter may be moved axially through the tubular form to remove spaced-apart cross-sectional segments of each rail in the manner described above. Alternatively, the starting tape may be first bent into a tubular form and thereafter moved past a fixed rotating cutter in partial encircling relationship thereto, to produce the ultimate hooks. It should further be appreciated that while bending of the material into tubular form is a preferred method, nevertheless the material can be cut in accordance with the broad principles of the invention while it is flat.

It should also be understood that while the method herein disclosed has been described with particular reference to producing the hook member of a separable hook and loop type fastener, it should also be recognized that the method of this invention is equally well suited to producing the loop member of a separable hook and loop type fastener. When the method of this invention is so used, the upstanding hook-shaped rails may be merely replaced by a series of unbroken and upstanding loop-shaped rails 26 shown in FIG. 8.

While a preferred specific embodiment of the invention has been heretofore described, it is to be clearly understood that various modifications, in addition to those specifically mentioned, can be made in the details of the invention described herein without departing from the spirit of the invention and the scope of the appended claims.

What is claimed is:

1. An apparatus for making a member of a separable hook and loop type fastener comprising, means for bending a base material having a plurality of upstanding, longitudinal rails generally into tubular form with said rails extending radially inwardly, means for cutting said rails at discrete uniform intervals into separate sections spaced longitudinally apart and means for returning said base material to a flattened condition.

2. The apparatus according to claim 1 wherein the cutting means is a helical cutter.

3. The apparatus according to claim 2 wherein a cooling means is provided for cooling said base material during cutting.