RESILIENT PLASTIC STAPLE

• US 3,757,629 A
• Filed: 05/10/1971
• Issued: 09/11/1973
• Est. Priority Date: 05/10/1971
• Status: Expired due to Term

• Current Assignee: Robert Jerome Schneider
• Original Assignee: Robert Jerome Schneider
• Inventors: Schneider, Robert J.
• Primary Examiner(s): Parsons, Jr., Marion
• Application Number:
  US05/141,746
• Time in Patent Office: 855 Days
• Field of Search: 85/49,13,31,23,26
• US Class Current: 411/443
• CPC Class Codes: F16B 15/0015 Staples
• CPC Class Codes: Y10S 411/92 Staple

Abstract

A fastener or staple is formed of a resilient plastic material which has an elastic memory. The staple has legs, a crown integrally joining the legs, and retaining means such as barbs on the legs. The staple is formed so that normally the legs of the staple are non-parallel. The staple legs are displaced while being driven into the material to be stapled so that the legs are parallel, and after being driven into the material the legs return or tend to return to their normal non-parallel position due to the elastic memory of the plastic from which the staple is made. Thus the barbs or other retaining means are biased by the legs, which tend to return to their non-parallel position, into engagement with the material being stapled to retain the staple.

Claims

1. A staple formed from a resilient plastic material having an elastic memory and adapted to be driven by a stapling gun or the like for use in fastening relatively soft work material such as cellular or foam plastic, corrugated cardboard, and the like, said staple comprising:

a pair of preformed, substantially straight, and normally nonparallel leg portions; and

a preformed crown portion integrally connecting said leg portions so that said leg portions are each normally inclined from parallel position at an angle of up to about 25*;

each of said leg portions having a preformed reversely extending barb projecting angularly in substantially rigid relation from the free end of the leg portion and defining a sharp point at said free end for penetrating the work material during driving of the staple, said barb being adapted to form a clearance between the leg portion and the surrounding work material as the leg portion penetrates the work material;

each of said barbs being integrally joined with its leg portion solely at the outermost surface of the leg portion; and

said leg portions being deflectable momentarily to substantially parallel relation before and during penetration of the staple into the work material and thereafter returning toward their normal non-parallel position, by reason of said elastic memory, and thereby embedding said barbs in the work material, the return of said leg portions toward their non-parallel position being facilitated by the clearances formed by said barbs during penetration of the leg portions into the work material.

2. The staple of claim 1 further characterized in that said crown portion is normally curved or bowed and is adapted to be flexed toward a straight position during driving of the staple, thereby enhancing the resilient force urging said leg portions to their normal non-parallel position.

3. The staple of claim 1 further characterized in that said barbs lie generally in the plane of the staple formed by said leg portions and said crown portion.

4. The staple of claim 1 further characterized in that each of said leg portions has a pair of oppositely projecting barbs lying generally in the plane of the respective leg portion.

5. The staple of claim 1 further characterized in that said leg portions in their normal non-parallel position are inclined outwardly away from each other.

6. The staple of claim 1 further characterized in that said leg portions in their normal non-parallel position are inclined inwardly toward each other.

7. The staple of claim 1 further characterized in that a plurality of said staples are provided in the form of a strip or stick adapted to be inserted in a staple-driving tool.

8. The staple of claim 1 further characterized in that each of said leg portions has at least one additional prefoRmed barb projecting angularly in substantially rigid relation from the leg portion and spaced from the first-mentioned barb, said additional barb also being integrally joined with the leg portion solely at the outermost surface of the leg portion without diminishing the effective cross-sectional area of the leg portion.