METHOD OF PENETRATING MATERIAL WITH A FASTENER DISPENSING NEEDLE

Abstract

A method for penetrating a material with a fastener dispensing needle includes the steps of partially penetrating the material using a first penetration stroke, partially withdrawing the needle from the material using a first withdrawal stroke and, in turn, fully penetrating the material using a second penetration stroke. Once fully penetrated, a plastic fastener is dispensed from the fastener dispensing needle. Thereafter, the fastener dispensing needle is fully withdrawn from the material. Additional partial penetration and withdrawal strokes could be incorporated into the needle penetration cycle in a repeating pattern, as needed, with each penetration stroke preferably having a stroke length which is twice the length of each withdrawal stroke. The use of an oscillating, back-and-forth, linear needle penetration cycle serves to minimize the risk of lateral needle deflection which can result in bending or breakage of the needle as well as damage to the penetrated material.

Claims

1. A method for penetrating a material with a fastener dispensing needle, the material having a first surface and an opposing second surface, the fastener dispensing needle having a leading end with a sharpened tip, the method comprising the steps of: (a) partially penetrating the material with the fastener dispensing needle using a first penetration stroke; (b) after the partial penetration step, partially withdrawing the fastener dispensing needle from the material using a first withdrawal stroke; and (c) after the partial withdrawal step, fully penetrating the material with the fastener dispensing needle using a second penetration stroke.

2. The method as claimed in claim 1 wherein the first penetration stroke extends from the first surface of the material to a first location in the material between the first surface and the second surface.

3. The method as claimed in claim 2 wherein the first withdrawal stroke extends from the first location in the material to a second location in the material between the first surface and the first location.

4. The method as claimed in claim 3 wherein the second penetration stroke extends from the second location in the material to beyond the second surface.

5. The method as claimed in claim 1 further comprising the step of, between the partial withdrawal step using the first withdrawal stroke and the full penetration step using the second penetrations stroke, partially penetrating the material with the fastener dispensing needle using a third penetration stroke.

6. The method as claimed in claim 5 further comprising the step of, between the partial penetration step using the third penetration stroke and the full penetration step using the second penetration stroke, partially withdrawing the fastener dispensing needle from the material using a second withdrawal stroke.

7. The method as claimed in claim 6 wherein the full penetration step occurs immediately after the partial withdrawal step using a second withdrawal stroke.

8. The method as claimed in 1 wherein each of the first penetration stroke and the first withdrawal stroke has a length, the length of the first penetration stroke being approximately twice the length of the first withdrawal stroke.

9. The method as claimed in claim 8 wherein the first penetration stroke has a length of approximately 0.25 inches.

10. The method as claimed in claim 9 wherein the first withdrawal stroke has a length of approximately 0.12 inches.

11. The method as claimed in claim 1 wherein the fastener dispensing needle penetrates the material during the first penetration stroke along a first linear path.

12. The method as claimed in claim 11 wherein the fastener dispensing needle withdraws from the material during the first withdrawal stroke along the first linear path.

13. The method as claimed in claim 12 wherein the fastener dispensing needle penetrates the material during the second penetration stroke along the first linear path.

14. The method as claimed in claim 1 wherein, after the full penetration stroke, a fastener is dispensed from the fastener dispensing needle.

15. The method as claimed in claim 14 wherein, after the fastener dispensing step, the fastener dispensing needle is fully withdrawn from the material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In the drawings wherein like reference numerals represent like parts:

[0023] FIG. 1 is a fragmentary, front perspective view of a length of continuously connected ladder stock that is known in the art, the ladder stock being shown with an individual plastic fastener separated therefrom;

[0024] FIG. 2 is a front perspective view of a fastener dispensing device that is known in the art, the fastener dispensing device being shown with a length of the fastener stock in FIG. 1 fed thereinto, the fastener dispensing device being shown with a portion of its housing removed therefrom;

[0025] FIGS. 3(a)-(c) are enlarged front perspective, top plan, and front plan views, respectively, of the fastener dispensing needle shown in FIG. 2;

[0026] FIGS. 4(a)-(c) are a series of front views depicting a conventional method in which the needle shown in FIG. 3(c) penetrates through material during normal operation of a fastener dispensing machine, the material being shown in section; and

[0027] FIGS. 5(a)-(e) are a series of front views depicting a novel method in which the needle shown in FIG. 3(c) penetrates through material during operation of a fastener dispensing machine, the method being taught in accordance with the teachings of the present invention, the material being shown in section.

DETAILED DESCRIPTION OF THE INVENTION

[0028] Referring now to FIGS. 5(a)-(e), there is shown a series of views depicting a novel method for penetrating a material 81 with a fastener dispensing needle 59, the method being taught in accordance with the teachings of the present invention. As will be explained in detail below, in the method of the present invention, needle 59 is penetrated through material 81 using an oscillating, or reciprocating, linear penetration cycle in order to minimize the risk of damage to the needle or to the material.

[0029] As defined herein, material 81 represents any substance that is commonly applied, or otherwise tagged, with a plastic fastener, such as clothing fabrics, cardboard display cards, paper-based merchandise tags and the like. Further, it should be noted that material 81 is represented herein as a single layer for simplicity purposes only. However, it is to be understood that material 81 may represent multiple layers of material that are intended to be secured together using a plastic fastener, such as prior art fastener 18.

[0030] Additionally, in the description that follows, the method of the present invention is described in connection with the penetration of material 81 using a single fastener dispensing needle 59. However, it should be noted that the method of the present invention is not limited to needle 59, but rather could be utilized with other types of needles that are commonly used in fastener dispensing applications. Additionally, it is to be understood that the method of the present invention could be similarly applied to fastener dispensing machines which include multiple needles 59 (e.g., fastener dispensing machine 30) using the principles explained in detail below.

[0031] Referring now to FIG. 5(a), in the first step of the needle penetration method of the present invention, needle 59 is oriented vertically downward with sharpened tip 79 positioned close in relation to first surface 83. Through motorized displacement of head 57, each needle 59 is driven linearly downward so as to partially penetrate material 81, as represented by arrow P in FIG. 5(b). As can be seen, partial penetration stroke S.sub.F of needle 59 extends from first surface 83 (or in close proximity thereto) to a first location 91 in material 81 between first surface 83 and second surface 85.

[0032] Immediately thereafter, each needle 59 is partially withdrawn from material 81 along the same linear path, as represented by arrow W in FIG. 5(c). As can be seen, partial withdrawal stroke S.sub.R of needle 59 extends from first location 91 to a second location 93 in material 81 between first surface 83 and first location 91.

[0033] Upon completion of the partial withdrawal step, each needle 59 is driven linearly downward along the same linear path so as to fully penetrate material 81, as represented by arrow P in FIG. 5(d). As can be seen, full penetration stroke S.sub.F of needle 59 extends from second location 93 to a third location 95 disposed slightly beyond opposing surface 85 (i.e., with enough clearance that a fastener cross-bar can exit bore 73 though leading end 77).

[0034] Preferably, the length of full penetration stroke S.sub.F is approximately equal to partial penetration stroke S.sub.F. In this manner, a needle penetration cycle with a common, or fixed, forward stroke can be easily implemented into a fastener dispensing system.

[0035] Upon ejection of the fastener cross-bar through leading end 77 of needle 59 and, as such, through material 81, needle 59 is fully withdrawn from material 81, as represented by arrow W in FIG. 5(e). As can be seen, full withdrawal stroke S.sub.R of needle 59 extends from third location 95 (i.e., slightly beyond surface 85) back to surface 83 or in close proximity thereto. With needle 59 fully withdrawn, a small hole 97 may remain in material 81 due to the needle penetration process, as will be explained further below.

[0036] In summation, the oscillating linear needle penetration cycle as set forth in detail above includes a partial penetration stroke S.sub.F, a partial withdrawal stroke S.sub.R, a full penetration stroke S.sub.F, and a full withdrawal stroke S.sub.R. Preferably, the length of partial penetration stroke S.sub.F is approximately twice the length of partial withdrawal stroke S.sub.R.

[0037] For instance, in a preferred embodiment, partial penetration stroke S.sub.F has a length of approximately 0.25 inches and, in turn, partial withdrawal stroke S.sub.R has a length of approximately 0.12 inches. However, it is to be understood that the stroke lengths set forth above could be adjusted to suit the needs of the particular application (e.g., to accommodate different types and thicknesses of materials 81).

Features and Advantages of the Present Invention

[0038] The oscillating linear needle penetration cycle set forth in detail above introduces a notable advantage over traditional fastening methods. Specifically, it has been found that the use of a back-and-forth linear penetration motion minimizes the risk of lateral needle deflection (i.e., drifting of needle 59 from its ideal linear path). As a result, the oscillating linear needle penetration cycle as set forth above limits the likelihood of both (i) permanent bending or breakage of needle 59 as well as (ii) significant widening of hole 97. In fact, the aforementioned needle penetration cycle essentially renders hole 97 approximately equal in transverse cross-section to needle 59, thereby limiting the damage to material 81, which is a principal object of the present invention.

Design Modifications and Alternative Embodiments

[0039] The method described above is intended to be merely exemplary and those skilled in the art shall be able to make numerous variations and modifications to it without departing from the spirit of the present invention. All such variations and modifications are intended to be within the scope of the present invention as defined in the appended claims.

[0040] For instance, it should be noted that the material penetration method of the present invention is not limited to the four-stroke needle penetration cycle described in detail above (i.e., partial penetration, partial withdrawal, complete penetration, and complete withdrawal). Rather, it is to be understood that additional partial penetration and partial withdrawal strokes could be incorporated into the above-described needle penetration cycle, prior to the complete penetration step, in order to accommodate for materials of considerable thickness or density. For instance, utilizing a partial penetration stroke of 0.25 inches and a partial withdrawal stroke of 0.12 inches, the partial penetration and partial withdrawal component of the linear oscillating pattern could repeat multiple times, as necessary, until needle 59 fully penetrates the material (i.e., a first partial penetration of 0.25 inches, a first partial withdrawal of 0.12 inches, a second partial penetration of 0.25 inches, a second partial withdrawal of 0.12 inches, etc.).

[0041] It should also be noted that the material penetration method of the present invention is not limited to holding material fixed and, in turn, linearly driving needle through material (e.g., by programming a controller so as to operate the motor for the fastener dispensing device in accordance therewith). Rather, it is to be understood that the material penetration method of the present invention could be similarly applied by holding needle 59 stationary and, in turn, displacing material 81 linearly in relation to needle 59 using the above-described, oscillating linear path (e.g., by moving material 81 using a motor-driven stage).