A staple for installation in a wood support having a U-shaped body defined by a pair of rod-like legs in fixed parallel spaced-apart relationship terminating at one end with the opposite ends of an arcuate member and each leg terminating its respective other end in a chamfered, cut-away point. Each leg is further provided with a notched barb outwardly extending beyond the surface of each leg defining a rounded ramp on its side nearest the point and a step on its other side. A sleeve of insulative material is disposed on the inside of the staple adjacent to the arcuate member.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to fastening devices and, more particularly, 
to a novel fastening device of a staple type having means for 
substantially locking the legs of the staple to a supporting base so that 
the staple cannot be removed from its installation. 
2. Brief Description of the Prior Art 
In the past, it has been the conventional practice to employ staples having 
a pair of prongs joined by a center section which, when driven by an 
impact member, causes the prongs to enter a supporting material such as 
wood or the like. Generally, a wire length such as fence wire is 
positioned between the prongs and is substantially captured by the cross 
member of the staple when the staple is fully driven into the support 
member. 
Although such conventional staples have been effective for holding a wire 
to the supporting member, difficulties and problems have been encountered 
which stem largely from the fact that, after time, the staple tends to 
withdraw from its installation in the wood base. Also, any undue stress or 
pressure against the wire will cause the staple to withdraw from its 
installation. Additionally, electrical problems are sometimes encountered 
when metal staples are used in combination with metal fence wire. Such 
problems include antenna interference so that television or radio 
reception is adversely affected at nearby locations. 
Also, it is to be particularly noted that when driving a conventional 
staple into a wood base, the prongs are pointed to permit easy 
penetration; however, the prongs are parallel to one another in fixed 
spaced relationship so that extraction from installation can be readily 
achieved. Such extraction is not necessarily of benefit and greatly 
reduces the effectiveness of conventional staples. 
Therefore, a long-standing need has existed to provide a novel staple 
wherein the prongs cannot be readily withdrawn from the installation and 
which will be suitably insulated from wire or other members that are being 
held by the staple so that electrical interference or adversities are not 
encountered. 
SUMMARY OF THE INVENTION 
Accordingly, the above problems and difficulties are obviated by the 
present invention which provides a novel staple adapted to be installed in 
a wooden base or support and which includes a pair of prongs having 
pointed tips at one end and joined at their opposite end with the ends of 
an arcuate cross member. An insulative sleeve or solid member is 
insertably disposed on the inside surface of the arcuate cross member 
which spaces the arcuate member from wire or other objects intended to be 
supported by the staple. Means for preventing the withdrawal of the staple 
from an installed position are provided on the outside surface of the 
prongs and, in one form, take the shape of an extended barb outwardly 
projecting from each of the prongs and adapted to engage with the wood of 
the support member or base. A notch or pocket is provided immediately 
above the barb on each of the prongs which is filled with the base 
material so that the staple cannot be removed from its installation. 
A feature of the invention resides in forming the points of each of the 
prongs at the tip of a ramp surface whereby the ramp surfaces on each 
prong cooperate with one another to expand the prongs as the staple is 
driven into the support material. 
Therefore, it is among the primary objects of the present invention to 
provide a novel staple having means for preventing the withdrawal of the 
staple from its installation in a wooden support or base. 
Another object of the present invention is to provide a novel staple with 
at least an outwardly extending barb carried on a prong of the staple 
which will prevent the removal of the staple upon its installation in a 
soft, malleable material. 
Still another object of the present invention is to providea novel 
non-removable staple having an electrically insulative sleeve or solid 
member insertably carried on the inside of the staple to engage wire or 
other articles intended to be held in position on a support member or 
base. 
Yet another object of the present invention is to providea novel spike or 
staple having at least one hook formed in its prong that will readily hold 
the spike or staple in an installed position when attempts are made to 
remove it.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIG. 1, the novel staple of the present invention is shown 
generally at 10 and includes a pair of prongs 11 and 12 which are arranged 
in parallel fixed spaced-apart relationship terminating at one end in 
points 13 and 14 and joined at their opposite ends by means of an arcuate 
cross member 15. The distance between the points 13 and 14 is indicated by 
the letter D showing the fixed dimension between the points prior to 
staple installation. The points 13 and 14 are formed by chamfers 
constituting sloping ramps, as indicated by numerals 16 and 17, which are 
substantially flat surfaces. The flat surfaces or ramps 16 and 17 are 
angled with respect to one another so that upon insertion into the 
supporting base or member, the prongs will be slightly urged away from one 
another. 
The primary feature of the present invention resides in the provision of 
hooks or barbs such as indicated by numerals 20 and 21 carried on the 
exterior surface of each of the prongs 11 and 12 respectively. It is to be 
particulary noted that each barb provides a step, such as step 22 
associated with barb 21, which merges with a notch or pocket 23 within the 
main body of the prong. Therefore, upon insertion into a malleable or 
pliable material base or member, portions of the base or member 1 occupy 
the pocket so as to provide a build-up of material the step behind the 
barb to prevent removal of the staple from installation. 
FIG. 1 further illustrates the employment of an electrically insulative 
sleeve or solid member 24 which is substantially U-shaped in plan view so 
as to be conformal with the shape of the arcuate cross member 15 and a 
portion of the inside of the prongs 11 and 12. Preferably, the exterior 
end of the spacer 24 includes a to receive the inside surface of the cross 
member 15 and the prongs 11 and 12 respectively. 
Referring now in detail to FIG. 2, it can be seen that the barb 21 includes 
the step 22 on one side and that the step is substantially horizontal or 
normal to the longitudinal access of the prong. Also, the underside of the 
barb is rounded as is indicated by the numeral 25 and the rounded 
underside of the barb lies beyond or outwardly extended from the exterior 
of the prong. 
Referring now in detail to FIG. 3, it can be seen that the flat ramps 16 
and 17 are not parallel and that they are angularly disposed with respect 
to one another. Such provision results in a spreading of the prongs 
slightly as the staple is driven into the base member. 
Referring now in detail to FIG. 4, a typical installation of the staple is 
illustrated in connection with holding an article 26 in position against a 
wooden support base 27. The points 13 and 14 have penetrated into the wood 
27 to the point where the prongs are substantially embedded into the wood 
and the lower end of the insulator sleeve 24 bears against the external 
surface of the wood 27. The article 26 is captured by the staple in the 
installation and is not free to move. As the prongs travel through the 
wood composition under the impact of a hammer on the cross member 15, the 
wood will compress as the rounded portion 25 of each barb engages the 
wood. After penetration of the prong, the compressed wood will expand 
beyond the barb and occupy the pockets 23 behind the step 22. Therefore, 
the staple cannot be removed since the material behind the barb will 
prevent extraction. Also, inasmuch as the ramp surfaces 16 and 17 are 
angularly disposed with respect to each other, the prongs will have a 
tendency to spread when driven into the wood composition so that the 
dimension between the points 13 and 14 are represented by the dimension 
D'. Thus, the distance D' is increased over the distance D as shown in 
FIG. 1. 
Referring now in detail to FIGS. 5 and 6, another embodiment of the 
invention is illustrated generally at 30 and is substantially similar to 
the version shown in FIG. 1 with the exception that the flat ramp surfaces 
ind-cated by numerals 31 and 32 are arranged on opposite sides of the 
prongs 33 and 34 respectively. The barbs 35 and 36 are similar to the 
barbs shown with respect to the earlier version and operate in the same 
manner as described with respect to FIG. 4. It is to be noted that the 
barbs are formed past the midsection of the prongs adjacent to the upper 
edge of the ramps 31 and 32 with respect to version 30. The same 
relationship is disclosed with respect to the prongs 20 and 21 in the 
version of FIG. 1. Furthermore, it is to be understood that the barbs or 
hooks may be placed on the inside diameter of the prongs as opposed to the 
outside diameter as illustrated. In most instances, it is desirable to 
retain the prongs on the outside as illustrated so that the barbs or hooks 
will not interfere with the article 26 during the driving of the staple 
into the wood composition 27. 
Referring now in detail to FIG. 7, another version of the invention is 
illustrated which takes the form of a spike having a single prong. The 
spike is indicated generally 37 at and includes prong 38 having hook or 
barb 40 carried thereon. The end of the spike is pointed at numeral 41 
while the opposite end carries a flanged head 42. The spike 37 may be used 
in connection with steps for telephone poles or in connection with 
railroad ties. 
In view of the foregoing, it can be seen that the novel staple of the 
present invention cannot be removed after installation into the wood 
composition 27. The barbs will permit the prongs to pass into the 
composition but will prevent extraction since the composition will reside 
immediately behind the barbs in the pocket provided therein. Also, the 
resiliency of the prongs will maintain the prongs at the dimension D' as 
opposed to the dimension D in the unstressed position. The sloping ramps 
will provide for a slight spreading of the prongs during the forcible 
urging of the staple and its prongs into the wood composition 27. 
While particular embodiments of the present invention have been shown and 
described, it will be obvious to those skilled in the art that changes and 
modifications may be made without departing from this invention in its 
broader aspects and, therefore, the aim of the appended claims is to cover 
all such changes and modifications as fall within the true spirit and 
scope of this invention.