Universal Sheet Lifter

Abstract

A sheet lifting device for looseleaf ring binders with any number of rings or ring spacing. The lifter has two parts each with a single aperture for receiving a binder ring and flexibly interconnected across the ring to maintain an alignment while permitting pivoting with covers of the binder. Inclined surfaces on the two parts engage portions of sheets carried by the rings and move the sheets about the ring when the binder covers are closed.

Description

This invention relates to sheet lifters or followers which are used to facilitate the closing of looseleaf binders.

Looseleaf binders are manufactured and used in a variety of styles and sizes. These styles and sizes vary in ring diameter, ring spacing and/or the number of rings used.

Typically, in looseleaf binders, a sheet lifter is secured to the rings of the binder adjacent each cover. The sheets held by the binder rings are positioned between the two sheet lifters. The function of the sheet lifters is to help move the sheets along the rings when the covers of an open binder are closed. This prevents the sheets from being caught at the base of the rings, between the rings and the covers, which tears the apertures of the sheets and makes it difficult to close the covers.

While sheet lifters for standard two and three ring binders are standard items carried by stationery suppliers, binders with a greater number of rings or with other than the standard ring spacing require custom made lifters. These lifters are made in smaller quantities than lifters for standard binders and are therefore more expensive and replacements are often unavailable. Moreover, while certain improved features have been developed in connection with the construction of sheet lifters (see, for example, U.S. Pat. No. 3,366,118 issued Jan. 30, 1968 to Lewis R. Beyer, and entitled "Sheet Lifter"), these improved features are typically available only on sheet lifters for standard 2 and 3 ring binders where relatively high production justifies the high initial equipment costs necessary for manufacture. For example, improved lifters of the type disclosed in the aforementioned patent are preferably formed of plastic by injection molding techniques, which require relatively expensive dies. Custom made lifters, therefore, are usually limited to the flat, cardboard-type lifter that can be individually cut to length and punched to accommodate the desired spacing and number of binder rings. Flat lifters do not function in a satisfactory manner at best, and the larger number of closely spaced rings typical of special binders make it all the more difficult to close the covers of the binder. Even for standard binders, the need for different sheet lifters for the two- and three-ring binders requires separate manufacture, handling, and larger inventories.

The present invention overcomes the above problems by providing a universal lifter, that is, a lifter that is usable with looseleaf ring binders having any number of rings or any spacing, and that can be constructed for use with rings of any diameter. The preferred sheet lifter device of the present invention incorporates inclined surfaces to effectively slide the sheets carried by the rings of the binder upward along the sheet lifter and about the rings as the covers of the binder are closed, so that resistance to closing of the covers and pinching or tearing of the sheets is avoided.

Briefly, the universal sheet lifting device of the present invention is comprised of two sheet lifter parts that are relatively small and are secured to a single ring of a binder rather than extending along a binder in the conventional manner. The two parts are aligned with each other across a single ring and across the ring back of the binder, one part being adjacent each cover of the looseleaf binder. Each part is comprised of a flat body portion with an upwardly offset back portion. An aperture in each part is provided adjacent the back portion to receive the ring of a binder. The aperture is elongated toward the front of the associated part to permit pivoting of the part with the cover. A gradually inclined surface extends upward and rearward from the flat body portion of each part toward the back portion preferably adjacent the aperture, and serves to effectively slide sheets outward along the lifter and about the rings when the lifter is pivoted during the closing of the binder cover. The two parts of the sheet lifting device are connected together at back portions in a manner that prevents the two parts from pivoting out of alignment with each other across the ring, i.e., from pivoting about the ring in the plane of the lifter or cover, but which permits pivoting about axes parallel to the cover hinges. Typically, two such sheet lifting devices are used on two-spaced rings, one adjacent each opposite end of a looseleaf binder. In the case of relatively small binders, a single such device used on a ring in the middle of the binder is adequate. Different ring diameters are accommodated by an expandable connection between the two parts that permits the distance between the back edges of the parts to be varied.

Accordingly, it is an object of this invention to provide a sheet lifter that can be used with ring binders having essentially any number of rings and any ring spacing.

Another object of this invention is to provide a lifter with two parts adapted to associate with opposite covers of a ring binder, and which is secured in use to a single ring of a binder and in which the two parts will pivot with the associated binder covers but will remain aligned with each other across the ring back.

Another object of this invention is to provide a lifter with two sheet lifter parts flexibly interconnected so as to extend across a ring of a ring binder, the flexible interconnection being constructed so that the space between the two parts can be varied to accommodate different diameter rings.

Another object of this invention is to provide a lifter, as described above, that has inclined surfaces to effectively lift sheets when the two parts are pivoted with the covers of a binder.

These and other objects, as well as the various features and advantages of this invention, will become better understood by reference to the following detailed description when taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a perspective view of a sheet lifter embodying the present invention, shown associated with a ring of a looseleaf ring binder;

FIG. 2 is an end elevational view of the sheet lifter and ring binder of FIG. 1;

FIG. 3 is an end elevational view of the sheet lifter and ring binder of FIG. 2, showing the relationship of the parts with the ring binder in a closed position;

FIG. 4 is an end elevational view similar to FIG. 2 showing the sheet lifter of FIG. 2 with a ring binder having rings of larger diameter;

FIG. 5 is an end elevational view similar to FIG. 2, showing a sheet lifter of a modified construction; and

FIG. 6 is an end elevational view similar to FIG. 5 showing another modified construction of a sheet lifter embodying the present invention.

Referring now to the drawings, in particular to FIG. 1, a preferred embodiment of the sheet lifter of this invention is indicated generally by the reference numeral 10 and is shown in operative association with a ring 12 of a looseleaf binder 14. The binder 14 is conventional and includes a backing or spine 15 to which two cover leaves 16, 17 are hinged as at 18, 19. The binder includes two or more rings 12, only one of which is shown, and each of which comprises two arcuate segments with uppermost portions that mate when the rings are in closed position. The lowermost portions of the rings are connected to a spring mechanism (not shown) to provide the conventional snap-action ring operation. The spring mechanism is housed by longitudinal cover plate 20 securely attached to the inside surface of the binder backing 15. The cover plate 20 has an outer surface 21 through which the binder rings 12 project. For illustrative purposes, loose sheets typically carried by the rings 12 in the binder 14 have been omitted from FIG. 1, but are shown in FIGS. 2 and 3. The sheets S are typically paper, and include holes through which the binder rings extend.

Typically, with a binder having a center ring (e.g., a three-ring binder) a single lifting device is associated with the binder on the center ring. In other binders without a central ring, such a two-ring binder, two lifting devices are used on rings adjacent opposite ends of the binder to assure a balanced lifting force on the sheets. As shown in FIG. 2, when the looseleaf binder 14 is open, the sheet lifting device 10 extends outward in opposite directions from the binder backing 15 and cover plate 20 of the ring assembly, along the inside surface of the covers 16, 17, beneath the sheets S of paper. As shown in FIG. 3, when the looseleaf binder 14 is closed, the sheet lifters rest on the cover plate 20 and extend upward along the covers 16, 17, with the sheets S moved to an upper position on the rings 12.

The lifter 10 is a unitary device, preferably molded of plastic, such as polypropylene, linear polyethylene, or the like that will form a relatively stiff sheet lifter but which is flexible and tough if thin so that integral hinged portions that will withstand repeated flexing can be provided by forming grooves in the material. The lifter 10 includes two parts 26, 28 of identical construction secured by an integral connector 29. Because the two parts 26, 28 are identical, only part 26 will be described in detail. Corresponding portions of part 28 will be identified by similar reference numerals, with a prime designation.

The sheet lifter part 26 includes a flat, bladelike body portion 30 with a front edge 32, a back edge 34, a top surface 36 and a bottom surface 38. The thickness of the front edge 32 is tapered upwardly and outwardly as best shown in FIG. 2. In the preferred embodiment, the front and back edges are parallel.

The body portion 30 includes a front part 30a that contacts the cover of the looseleaf ring binder with which the lifting device is used, has a back part 30b narrower than the front part to accommodate its use with a binder in which the rings are relatively closely spaced, and the narrower back part 30b includes an upwardly inclined terminal portion 30c so that the back edge 34 is upwardly offset from the flat body portion comprised of parts 30a, 30b. Preferably, the inclined portion 30c extends at an obtuse angle from the flat part 30b. The substantial width of the front edge 32 tends to either position the lifter, or maintain the lifter already positioned, with the front edge parallel to the binder cover hinges as soon as pivoting forces are applied to the lifter by the cover. This is because the forces are applied primarily against the front edge and are equalized across the width when the edge is parallel to the binder hinge.

A single aperture 40 is formed in the body portion 30 and is contained partially in the inclined portion 30c and is elongated along the flat body portion 30b in a direction toward the front edge 32. The aperture 40 is wide enough to receive a ring 12 of the binder and is elongated between a back edge 46 and a front edge 47 a distance sufficient to permit the sheet lifter part 26 to pivot with the adjacent cover of the binder to a closed position, without necessitating travel of the lifter about the binder ring. See FIG. 3.

Narrow tracks 42, 43 extend upward from the top surface 36 of the sheet lifter part 26 along opposite sides of the elongated aperture 40. Each track 42, 43 has an upper inclined surface 44, 45, respectively, that extend from the flat body portion 30b to the upwardly inclined portion 30c and which terminate adjacent the upper back edge 34. In the preferred embodiment shown, the lower forward edge of each inclined surface 44, 45 is located slightly to the rear of the front edge 47 of the elongated aperture 40. A continuation 48, 49 of each track 42, 43, respectively, extends from the end of the inclined surfaces 44, 45 toward the front edge 32 of the body portion 30 and projects a slight distance above the top surface 36. The continuations 48, 49 are optional and serve only as stiffening elements.

The connector 29 between the two parts 26, 28 of the lifter 10 joins the two back edges 34, 34'. The connector 29 is flexible in a direction that permits pivoting of the two parts 26, 28 with the covers of a looseleaf binder and is relatively stiff in a transverse direction to inhibit pivoting of the two parts in the planes of the flat body portions 30, 30' so that the two parts remain aligned across the backing 15, in proper relationship with the associated ring 12 to pivot with the binder covers. To provide the above features, the connector 29 is advantageously formed of a thin, relatively wide, ribbon of suitable length to permit the parts 26, 28 to be spaced across the back 15 and to be located one on each side of the associated ring 12. The ribbonlike connector 29 preferably has a hinged connection to the parts 26, 28 formed by a score line or groove 52, 52' at the juncture with each back edge 34, 34', to assure flexibility about axes parallel to the hinges 18, 19 of the binder 14. The substantial width of the ribbonlike connector 29 makes it difficult for the parts to pivot about the ring in the plane of the flat body portions 30.

If the sheet lifting device is to be used for a particular ring size, the length of the connector 29 can be selected to accommodate the particular ring diameter. Such a construction is shown at 10a in FIG. 6, in which a connector 29a is provided that is relatively flat or straight and which locates the inner ends of the two parts 26, 28 in proper location for a particular ring diameter. The connector is hinged to the parts 26, 28 at score lines or grooves 52a, 52a'. For a completely universal sheet lifting device that can be used not only with binders of different ring spacing and ring number, but also with binders of different diameter rings, the connector 29 is provided of sufficient length to permit the inner edges 34, 34' of the lifter parts 26, 28 to be spaced sufficient to accommodate the largest diameter rings in popular demand. The connector constructions shown in FIGS. 1 to 5 will accommodate varying ring diameters. Preferably, the connectors are constructed to be above the back edges 34, 34' of the lifter parts, as shown in FIGS. 2 and 5, so that the back edges will be located against the cover plate 20 of the ring binder when the covers are closed, as shown in FIG. 3. This maximizes the ring space available for sheets S.

A preferred construction shown in FIGS. 1 to 4 utilizes an accordion pleated ribbonlike connector 29 to provide maximum expansion for large diameter rings while maintaining the connector compact so that it will fit within small diameter rings, without interfering with the inner edges of sheets carried by the rings or with the rings themselves. The connector 29 is initially molded or otherwise formed to a compact condition as shown in FIGS. 1 and 2 and can be stretched to an expanded condition for use with large rings. Hinges formed by score lines or grooves 54 between flat sections 55 of the pleated connector 29 facilitate expansion. FIG. 4 illustrates the lifter 10 of FIG. 2 associated with a ring 12' of larger diameter than the ring 12, and illustrates the manner in which the ribbonlike accordion pleated connector 29 expands to accommodate the larger ring diameter. A sheet lifter 10b is shown in FIG. 5 with a curved connector 29b of sufficiently small radius to provide adequate sheet space within rings of relatively small diameters while allowing for limited expansion to accommodate larger diameter rings. The connector 29b is hinged to the parts 26, 28 at score lines or grooves 52b, 52b'.

The connectors 29, 29b are preformed to a compact configuration suitable for use with small rings, such as the standard size rings of 1 inch diameter, and are stretched when used to the greater spacing required for larger diameter rings, as shown in FIG. 4. The expandable connectors need not be resilient, since the sheet lifters are typically used with the same binder, once installed, and need not return to a compact configuration.

In operation, the purpose of the sheet lifting device is to lift the inner edges of the sheets of paper in a looseleaf binder from a position adjacent the bottom of the binder rings, as shown in FIG. 2, to a position adjacent the upper central portion of the rings, as shown in FIG. 3, when the binder covers are closed. When the two parts 26, 28 of the lifter 10 are pivoted from a flat, open, position as shown in FIGS. 1 and 2 to an upright closed position as shown in FIG. 3, the front edge 32 of each slides along the inner surface of the associated cover leaf of the binder and each part 26, 28 pivots relative to the ring 12, adjacent the back edge 34, 34'. The back edges 34, 34' move slightly downward during this pivoting and as the relatively flat body portions 30a, 30b swing upward toward the vertical, the ring 12 partially extends through the elongated apertures 40. Preferably, the front edge 47 of the aperture 40 is spaced a sufficient distance from the back edge 46 of the aperture so that it does not contact the outer surface of the ring 12 and limit the pivoting. Typically, the back edge 46 of the elongated aperture in the inclined portion 30c will contact the inside surface of the ring 12. As long as the front edge of the aperture does not contact the ring 12, there is no tendency for the sheet lifter to travel about the ring to a higher position.

As each part 26, 28 of the lifter 10 is pivoted upward, a camming action of the upper inclined surfaces 44, 45 of the narrow tracks 42, 43 on opposite sides of the aperture 40 against lower portions of the sheets S moves the sheets outward relative to the sheet lifter and about the ring 12 away from the back edge 34 of the associated sheet lifter. This prevents the sheets from being pinched or caught between the curvature of the ring 12 and the flat body portion 30 of the lifter. At all times during the pivoting of the two parts 26, 28 of the lifter 10, they are maintained in proper alignment across the ring binder by the connector 29 so that they properly pivot with the covers of the binder.

It will be readily apparent that the sheet lifter device 10 is installed by opening the ring 12 with which it is to be used and inserting each spaced end of the open ring into an aperture 40, 40' with the connector 29 between the spaced ends of the ring. Sheets S are then placed on the ring and the ring is closed. With large diameter rings, the accordion pleated spacer 29 or the curved spacer 29b is expanded during installation to accommodate the greater distance across the ring so that the back edges 34, 34' are adequately spaced to lie adjacent the lower inner portions of the ring 12 rather than more centrally, where the effective length of the apertures 40, 40' would be shortened.

While a preferred embodiment of this invention has been described with particularity, it will be readily appreciated that various modifications and alterations can be made therein without departing from the spirit and scope of the invention, as set forth in the appended claims. For example, while narrow tracks 42, 43 have been provided and are advantageous from the standpoint of reducing the friction between the inclined surfaces 44, 45 and the sheets S, the tracks need not be narrow. In fact, the body of the sheet lifter itself may be formed essentially of two planar members, one corresponding to the flat body portion 30a and the other extending therefrom at an obtuse angle corresponding with the upper inclined surfaces 44, 45 of the tracks 42, 43. The aperture 40 can be formed directly in this inclined surface. Moreover, while it is advantageous to locate the inclined surfaces 44, 45 adjacent the aperture 40, so that they act on the sheets directly on opposite sides of each ring, a single track 42 or 43 at each ring is generally sufficient and if desired the camming surface could be spaced somewhat from the aperture. It must also be recognized, that while the preferred inclined surfaces 44, 45 are straight, a surface slightly concave or slightly convex will also function in a similar manner to accomplish substantially the same result. The straight surface is preferred because a convex surface occupies more space between the rings when the notebook is closed and a concave surface does not move the sheets as effectively as the distance increases from the inner sheet edges to the back edge of the sheet lifter part. It will also be apparent that the particular shape of the flat portion of the lifter parts, especially the portions 30a, 30b may be varied from that shown, but a substantial width of the front edge portion 30a, somewhat wider than the back portion 30b, is desirable to help keep the lifter aligned across the binder. The back portions 30b and 30c should be wide enough for adequate strength, but otherwise must be sufficiently narrow to fit between the closest rings of looseleaf binders with which the lifter is to be used. Rigidity of the narrow back portion 30b is enhanced by the preferred construction in which the inclined surfaces are provided by tracks perpendicular to the flat surface, which increase the section modulus.

Claims

I claim:

1. A sheet lifter device for use with a looseleaf ring binder and adapted to be secured in the binder only by a ring of the binder that extends through apertures of the device, said device comprising:

a. two similar sheet lifter portions, each having

1. a substantially flat portion, for contacting covers of a looseleaf ring binder, which has a peripheral edge portion that forms a front edge of the lifter portion,

2. a back edge offset from the flat portion in an upward direction, when the flat portion is horizontal, forming the highest part of the associated lifter portion and spaced from but adjacent to the back edge of said other sheet lifter portion,

3. an inclined portion adjacent said back edge, extending at an obtuse angle from said flat portion in a rearward and upward direction, and adapted to engage sheets carried by a ring with which the device is associated, and

4. only a single aperture located adjacent said back edge and inclined portion and elongated in a direction toward said front edge for receiving a ring of a looseleaf binder, said single aperture of each said sheet lifter portion serving with the ring of a binder as the only means by which said device is secured to a binder,

b. a connector strip between and secured only to said back edges to inhibit swinging of said sheet lifter portions in the plane or planes of said substantially flat portions about a ring received in said apertures,

c. two spaced, parallel, hinge lines, each in said connector strip at the back edge of a different one of the two sheet lifter portions, said hinge lines being thinner than the part of the connector strip and sheet lifter portions immediately adjacent thereto and providing localized flexibility permitting the sheet lifter parts to pivot about separate axes along the hinge lines, and

d. said connector strip and sheet lifter portions being of one piece plastic construction.

2. A sheet lifting device as set forth in claim 1, wherein the connector strip is flexible in areas between as well as adjacent the back edges of the sheet lifter portions and has a length greater than the straight-line distance between said two sheet lifter portions, to permit varying the distance between said back edges.