Adjustable locking binder

#1. Field of the Invention

#This invention relates to an improved paper binder and in particular to an adjustable interlocking binder that can be adjusted to hold any plurality of sheets of paper, but that can be locked tightly so that the sheets are not loosely bound as with a ring binder. The components of the adjustable locking binder are preferably molded of plastic material, are interchangeable, can be provided for two or more holes in prepunched sheets, and can be readily unlocked to add more sheets of paper. Further, the shape of the locking strap is such that it will allow threading of the paper sheet onto the element without prepunching. The binder locks by means of interlocking elements or teeth in both components of the binder.

#2. Description of the Prior Art

#The accompanying drawings illustrate complete preferred embodiments of the present invention according to the best modes presently devised for the practical application of the principles thereof, and in which:

#FIG. 1 is an exploded perspective view of a two hole cover with locking strands and top receiver.

#FIG. 2 is a section cut according to FIG. 1, showing the locking strand being pushed into place into the top receiver.

#A typical application of the present invention is shown in FIG. 1. A standard two hole cover with top and bottom generally indicated as 2 contain prepunched holes 3 at standard spacing. A locking strand assembly 16 contains a restraining button or plate to prevent the strand from being pulled through prepunched holes 3. A transition stem 5 is connected to plate 4 and interlocking teeth 7 and base strip 8 which continue along the length of strand 16. A lifting tab 13 is connected at the end of the locking strand 16. The tab is of thin profile so that it may easily be lifted to release the strand after it is in place and to allow paper sheets to be pressed over the strand in the event the sheet is not prepunched with holes. The locking strands 16 pass through holes 3 and through holes in the ends of the top receiver assembly 15 where they are pressed into groove 11, to engage compatible teeth 9 and lock into slot 10. An end block 12 provides a finished end to the assembly 15.

#FIG. 2 is a sectional view illustrating how the locking strand 16 is interlocked to the top receiver assembly 15. The strand assembly 16 is inserted from the bottom of the covers 1 and paper sheets 2, through prepunched hole, 3 and into receiver hole 6. The paper sheets can be locked tightly together by simultaneously pulling up on the locking strand and pushing down on the top receiver. The locking strand 16 is then pushed over transition radius 14 in the top receiver groove 11. While holding the end of the strand up with one hand and pushing down and sliding a finger or object along the strand length, the strand interlocking teeth 7 are caused to rotate and engage top receiver interlocking teeth 9. It can be seen in the illustration that by bending the strand in a shallow to steep angle that the teeth 7 are caused to rotate sufficiently to disengage or engage the teeth 9 of the top receiver. Further more, once the locking strand teeth have engaged the top receiver teeth 9, the shapes of the two teeth hold the locking strand in place in the top receiver groove 11 and will not allow it to move horizontally or vertically relative to the top receiver. Additionally, pressure exerted on the strand plate 4 by the bound paper sheets causes the teeth 7 and 9, by virtue of their shape, to be more tightly locked together. Pressures placed on the strand by the bound paper are resisted by shear forces in the bases of teeth 7 and 9 and tensile forces in strand base strip 8. Referring also to FIG. 8 and 9 it can be seen that continuous slot 10 in the side of groove 11 receives a locking button or nipple 19 on the side of the locking strand at the end near the release tab 13 so that the strand will not accidentally be pulled and released from the top receiver. FIG. 3 is a similar sectional view showing the locking strand fully engaged in the top receiver groove 11. Referring to FIG. 4, FIG. 8, and FIG. 9 it can be seen how the locking strand 16 is removed from the top receiver 15. Release tab 13 is lifted upward so that it may be grasped by the fingers. Pulling up further causes the locking nipple to be pulled from slot 10, by causing side wall 18 to slightly deflect outward, releasing the locking strand. By pulling the strand upward and slightly backward, the strand teeth 7 are caused to rotate away from the top receiver teeth 9 and so disengage the strand from the top receiver. FIG. 5 is a sectional view showing how the locking strand and top receiver allow addition of paper sheets. As described above, the strands 16 are disengaged from the top receiver, the top receiver and cover removed, additional sheets of paper added, the cover and top receiver replaced over the locking strands 16, through receiver hole 6 and strands 16 are reengaged into the top receiver as described above. The locking strand automatically adjusts to the paper depth by sliding down the receiver groove 11 an equal distance. The paper is held in place as long as a certain minimum number of interlocking teeth 7, 9 are available to engage each other. Locking strands of varying length are readily substituted to accommodate additional layers of paper sheets.

#FIG. 6 is a partial perspective view showing the top receiver assembly 15 and locking strand assemblies 16. Top receiver interlocking teeth 9 are shown in receiver groove 11. A mirror imaged set of receiver interlocking teeth 9a are shown in an adjacent groove 11. Referring also to FIG. 7, a top view of the receiver, the interlocking teeth and mirrored image teeth can be seen. The orientation of the teeth allow identical locking strands to be used in the binder. The locking strands are inserted through receiver hole 6 with the teeth 7 of the strand facing the row of receiver teeth 9 and then pushed into place as previously described. As can be seen the locking strands are slightly off center in the prepunched holes of the paper sheets and covers so that they may bypass each other in the receiver grooves 11 of the top receiver 15. Referring simultaneously to FIG. 7 and FIG. 8 it can be seen how the locking strand end is held in the locked position. FIG. 7 is a sectional view of the top receiver with the locking strand in place. Nipple 19 is engaged into locking slot 10, which is made possible by small deformations and deflections of side wall 18. Grooves 11 are generally formed of side walls 18, center wall 17, and bottom 12. FIG. 9 is a side view of the locking strand end detailing the release tab 13 and locking nipple 19. The release tab is ordinarily in a flat position, so it cannot be inadvertently lifted. Once lifted, it provides sufficient grip to pull the locking strand up and disengage nipple 19 from locking slot 10.