Paper clip and binder device

An improved sheet binding device for fastening together a plurality of sheets having pre-punched, spaced-apart openings, comprises an elongated backing member extending between such spaced-apart openings; and, attached to the backing member at spaced-apart positions corresponding to the spacing between such openings, a plurality of fastening elements, each comprising a connecting portion for insertion into such openings, and at the end of said connecting portion remote from said backing member, locking means movable between (1) a collapsed position in which the fastening element is insertable into such opening, and (2) an expanded position in which the locking means is effective to preclude removal of such sheets from said fastening element. This structure can be integrally molded from plastic material. In a preferred embodiment, the structure is substantially self-locking. Single-hole embodiments suitable as replacements for conventional brass head fasteners are also disclosed.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to an improved paper clip and binder, and, in 
particular, to a self-locking clip or binder which can preferably be 
integrally molded of plastic material. 
2. History of the Art 
One of the most popular paper binding devices in current use is the 
two-part metal binder. In substance, this binder comprises an elongated 
metal backing portion, a pair of elongated metal insert tabs disposed at 
opposite ends, and an elongated, grooved metal front portion having 
tab-receiving apertures at opposite ends and a pair of slidable locking 
members. In operation, the backing member is placed under a pile of papers 
to be secured and the metal tabs are inserted through pre-punched 
spaced-apart holes in the paper. The tabs are then secured to the locking 
portion by inserting them through the receiving apertures. The tabs are 
then bent down into the groove, and the locking members are slid over 
their respective ends. In some fasteners of this type, the backing member 
is also provided with pointed, bendable teeth for securement to a cover. 
The difficulties associated with the use of these binders are manifold. To 
be used and re-used, two separate parts must be assembled and 
disassembled. Re-use is limited because the metal insert tabs tend to take 
on permanent deformations after successive bendings. In addition, in use 
the separate front portions are frequently removed and lost or misplaced. 
All of the metal components are thin and have relatively sharp edges which 
can cut the paper being bound, underlying files, and the fingers of users. 
Moreover, the sliding locking members do not provide reliable locking and 
are as likely to slide off the insertion tabs as they are to stay there. 
In addition, the manufacture of these fasteners is inherently inefficient 
as compared to integral molding. Four separate parts must be stamped out 
of sheet metal, the back, the front, and two slide strips, and the slide 
strips must be assembled onto the front member. 
SUMMARY OF THE INVENTION 
In accordance with the invention, an improved sheet binding device for 
fastening together a plurality of sheets having pre-punched, spaced-apart 
openings, comprises an elongated backing member extending between such 
spaced-apart openings; and, attached to the backing member at spaced-apart 
positions corresponding to the spacing between such openings, a plurality 
of fastening elements, each comprising a connecting portion for insertion 
into such openings, and at the end of said connecting portion remote from 
said backing member, locking means movable between (1) a collapsed 
position in which the fastening element is insertable into such opening, 
and (2) an expanded position in which the locking means is effective to 
preclude removal of such sheets from said fastening element. This 
structure can be integrally molded from plastic material. In a preferred 
embodiment, the structure is substantially self-locking. Single-hole 
embodiments suitable as replacements for conventional brass head fasteners 
are also disclosed.

DETAILED DESCRIPTION OF THE DRAWINGS 
Referring to the drawings, FIGS. 1A and 1B are side and top views 
respectively of a sheet binding device in accordance with the invention 
comprising a backing member 10, which can be an elongated plastic strap, 
extending between the pre-punched, spaced-apart openings 11A and 11B of a 
plurality of aligned paper sheets 12; and, attached to the backing member 
at spaced-apart positions corresponding to the spacing between openings 
11A and 11B, a pair of fastening elements 13A and 13B. Each fastening 
element comprises a connecting portion, here a pair of pillar-like members 
14, connecting the backing member to a locking means 15 which is movable 
between a collapsed position 16, in which the fastening element is 
insertable into the pre-punched openings, and an expanded over-center 
locking position in which the locking means is effective to preclude 
removal of the sheets from the fastening element. 
In a preferred arrangement, each locking means comprises a pair of 
substantially rigid arms 17 connected to pillar-like members 14 and 
connected to each other on a longitudinal axis of the fastener by a 
relatively thin integral strap 18 so as to be removable towards and away 
from each other in a plane including the longitudinal axis 19. 
Preferably backing member 10 extends beyond each fastener and the arms of 
each fastener are so shaped or curved that in their locking position, they 
resiliently bias the paper into contact with the extended backing member. 
Such resilient contact substantially reduces stresses on the paper 
surrounding the prepunched apertures and greatly reduces the frequency of 
torn-out holes commonly observed in conjunction with the use of 
conventional fasteners. 
These fasteners can conveniently be fabricated as integrally molded 
structures of resilient plastic, such as polypropylene. They can be made 
by molding them with the fasteners in the open position in a multi-cavity 
mold using conventional injection molding techniques. 
Second Embodiment (FIGS. 2A, 2B, and 2C) 
FIGS. 2A, 2B, and 2C are side, top, and enlarged portion views of an 
alternative embodiment of a sheet binding device which is substantially 
self-locking. This embodiment is substantially the same as that shown in 
FIGS. 1A and 1B, except that the connecting portion comprises a pair of 
criss-crossing pillar-like members 24, each extending from the backing 
member on one side of the longitudinal axis of the fastener, crossing the 
longitudinal axis, and connecting to an arm on the other side of the axis. 
These criss-crossing members provide a spring force for biasing the arms 
into an over-center locking position after their insertion through the 
pre-punched holes in the collapsed position. 
Third Embodiment (FIG. 3) 
FIG. 3 is a side view of an alternative embodiment of a sheet binding 
device which is particularly suitable for binding thick layers of sheet 
material. This embodiment is substantially the same as that shown in FIG. 
1, except that here the connecting portion comprises an elongated 
strap-like member 34, which is preferably molded as an integral part of 
the binding device. 
Fourth Embodiment (FIGS. 4A and 4B) 
FIGS. 4A and 4B illustrate an alternative embodiment of a sheet binding 
device in accordance with the invention which is adjustable for binding 
different thicknesses of layers of sheet materials. While this device is 
similar to that described in connection with FIG. 3 above, it utilizes as 
connectors, an adjustable resilient strap member 44 which can be 
adjustably secured at various discrete lengths to a connector base element 
45 attached to the backing member. Advantageously, the connector base is 
of a suitable transverse cross section to fit within the pre-punched paper 
openings. Such adjustable securement can be obtained, for example, by 
providing strap 44 with a plurality of longitudinally spaced-apart regions 
of transverse enlargement 46 and providing each connector base element 45 
with a strap slot 47 having one or more receiving areas 48 of 
corresponding enlargement for securing the strap against longitudinal 
pullout. 
To adjust the strap for different thicknesses, one need merely pull the 
strap sideways from the connector base and reinsert it at the appropriate 
position. The fastener is then inserted into the pre-punched holes for the 
sheet material and these holes surround the connector base, preventing 
accidental sideways removal of the strap. 
This embodiment is made by separate injection moldings of the backing 
members (including connector bases) and the resilient strap members 
(including the locking means). 
Fifth Embodiment (FIG. 5) 
FIG. 5 is a perspective portion view of an alternative form of an 
adjustable sheet binding device in accordance with the invention. Here 
instead of being attached to a flexible strap, the locking means is 
connected by a pillar-like member 54 to a pillar-like connector base 55. 
For connection, one of these pillar-like members, in this case 54, can be 
provided with a plurality of spaced apertures 57, and the other, here 55, 
can be provided with a retaining stud 58. 
The total length of the connector comprising pillars 54 and 55 can be 
readily adjusted by transversely removing the stud from one aperture and 
putting it into another. Accidental removal can be prevented by choosing 
the stud length such that the circumference of the pre-punched paper holes 
prevents complete transverse separation of the stud and aperture, when 
paper is loaded into the fastening device. 
While each of the multiple-hole binder devices of FIGS. 1-5 have been 
described in relation to two-fastener embodiments appropriate for binding 
sheets with a pair of spaced pre-punched holes, it is clear that three, 
four, or more fasteners can be provided on a single backing member to bind 
sheets having a corresponding number of spaced holes. 
Single-Hole Embodiments (FIGS. 6, 7, 8, 9, and 10) 
FIGS. 6, 7, 8, 9, and 10 illustrate alternative embodiments of single-hole 
sheet binders in accordance with the invention. 
The embodiment of FIG. 6 is substantially the same as that shown in FIGS. 
1A and 1B, except that here the backing member is shortened to include but 
a single fastener and displaced, as by bending or curving, towards the 
locking arms in order to resiliently bias the paper between the backing 
and the locking arms. Alternatively, the arms could be displaced towards 
the backing member to effect the desired resilient biasing. 
The embodiment of FIG. 7 also includes a shortened, single-fastener backing 
member. In this embodiment, however, the fastener is of the criss-cross 
type described in connection with FIGS. 2A, 2B, and 2C. This fastener can 
be locked in the expanded position by the insertion of an elongated 
retaining means 70 such as a self-threading screw or other retaining stud 
along the longitudinal axis, as shown. 
In the embodiment of FIG. 8, the fastener is of the extended strap type 
described in connection with FIG. 3. 
In the embodiment of FIG. 9, the fastener is of the adjustable strap type 
described in connection with FIGS. 4A and 4B. 
And in the embodiment of FIG. 10, the fastener is of the adjustable pillar 
type described in connection with FIG. 5. 
While the invention has been described in connection with a small number of 
specific embodiments, it will be understood that these are merely 
illustrative of the many other specific embodiments which also utilize the 
principles of the invention. For example, while the device has been 
described as binding sheets of paper, it can also be utilized for binding 
sheets of other material such as plastic, wallboard, plywood, fiberboard, 
and the like, and for fastening objects to such sheets. Thus, numerous and 
varied devices can be made by those skilled in the art without departing 
from the spirit and scope of the present invention.