Ring binder carrier rail

A carrier rail for a ring binder which is provided with a plurality of ribs along the longitudinal axis of the rail.

This invention relates to ring binders which hold paper and the like for 
loose-leaf binders, files, folders and the like. 
Carrier rails in prior art ring binders have the tendency, firstly to be 
bent when a ring member is attached thereto during assembly, and secondly 
to twist excessively along the longitudinal axis of the rail when the ring 
binder is opened and closed. 
it is an object of this invention to overcome one or more of the 
abovementioned problems. 
In accordance with the invention, a carrier rail for a ring binder is 
provided with one or more longitudinal ribs. 
Such an arrangement is particularly useful, since the provision of ribs 
prevents any excessive bending occurring when ring members are attached to 
the rail during assembly, and secondly prevents any or excessive twisting 
movement along the longitudinal axis of the rail occurring when the ring 
binder is actually being opened and closed, thereby allowing for easier 
closing and opening of the ring members, since the ring binder is more 
integral. 
The bending problem prevents easy assembling of ring binders by machines, 
and this leads to wastage of rails of at least 17% during the assembly 
process. It has been found in tests, that with the provision of ribs, no 
rails are wasted whatsoever. 
Holes may be provided in the rail in order to act as guiding means for the 
rail during actual assembly of the ring binder, and the provision of such 
holes in the rail makes the twisting effect worse. The provision of the 
longitudinal ribs on the rail overcomes this additional twisting problem 
as well. 
Suitably a plurality of ribs are provided along the longitudinal axis of 
the rail. 
Suitably these ribs can be the same length or different lengths. 
Advantageously the ribs are formed by a pressing function. 
Preferably the rib has a base parallel to the rest of the rail, at least 
one side sloped relative to the rest of rail in the longitudinal 
direction, and one side sloped relative to the rest of the rail in the 
transverse direction. Such has the advantage that the center length and 
width of the rail are effectively made longer and wider due to the 
indented ribs when compared to a completely flat rail, and accordingly the 
rail has greater stiffness.

In the drawings a ring binder 10 is shown for a loose-leaf binder 
comprising a base member 12, three ring members 14 spaced along the base 
member (only one of which is shown in FIG. 1), and an opening and closing 
mechanism 20 at each end of the base member (again only one of which is 
shown in FIG. 1). The base member 12 comprises a housing member in the 
form of an upper rigid structure 24 which is curved in cross-section and 
which supports between its two overlapping sides 26 a pivotable lower 
structure 30 comprising two carrier rails 32 pivotable to each other along 
the longitudinal axis of the binder 10. 
The ring members 14 are mounted on the pivotable lower structure 30 and in 
particular, one of the ring components (i.e. component 14a) of each ring 
member is mounted on the carrier rail 32 while the other ring component 
(not shown) of each ring member is mounted on the other carrier rail (also 
not shown). 
Fastening means 34, meanwhile, are also provided on the upper structure 24 
in order to secure the ring binder 10 to a paper folder or the like. 
The two carrier rails 32 are movable (i.e. pivoted about lugs 35) relative 
to each other between a lower position and an upper position due to the 
action of the opening and closing mechanism 20 on each end of the carrier 
rails. 
The opening and closing mechanism 20 is pivotably supported on each end of 
the upper rigid structure 24 and is in engagement with each end of the 
pivotable lower structure 30 in order to position the opening and closing 
mechanism 20 between the upper and lower structures. 
The carrier rail 32 is shown in greater detail in FIG. 2, and in particular 
is shown having a number of longitudinal ribs 36 of varying lengths and 
each of trough-like shape. 
It will be noted from FIGS. 3 and 4, that the ribs 36 are deformed and/or 
pressed relative the rest of the rail 32 such that extra stiffness is 
provided to the rail. In particular, the base of the ribs 36 is deformed 
and/or pressed such that it is parallel to the rest of the rail 32. The 
ribs 36 are also provided with two sides 42 which are sloped relative to 
the rest of the rail in the longitudinal direction, and two sides 44 which 
are sloped relative to the rest of the rail in the transverse direction. 
Such provides the advantage that it prevents bending of the rail when the 
ring member 14a is attached to a corresponding hole 38 provided in the 
rail during assembly of the ring binder, and also prevents twisting of the 
rail 32 during opening and closing of the ring members 14 when the ring 
binder is in actual use. 
Regarding twisting of the rail 32, when the ring binder is forced open at 
one end, the rails are twisted under torsion, and if the rails are not 
rigid enough to transmit the torsion to the other end of the binder, the 
ring members 14 will simply not open. The provision of ribs 36 effectively 
increases the height of the rails thereby increasing the rigidity of the 
rail. 
A particular advantage of providing the ribs is by increasing the stiffness 
of the rail, the thickness of the rail can be minimized thereby saving 
material. In particular, the thickness of each rail can be lowered by 0.1 
mm. 
It has been found in calculations that the torque increase for the improved 
rail in the x direction is 1.34% whilst the torque increase for the rail 
in respect of the y axis direction is 1.3%. The total torque increase for 
the modified rail compared to prior art arrangements is thus 2.647%, and 
this is equivalent to a prior art rail with a thickness increased by 1%. 
The whole content of the two co-pending patent application Ser. No. 
08/055,968 and co-pending patent application Ser. No. 08/056,300, filed on 
the same day as this case by the same applicant are incorporated into this 
case by reference thereto.