Patent GB-589875-A (GB)
Title: Improvements in or relating to loose-leaf thong binders
IPC: B42F9/00
Filed: 1944-11-28
Abstract: 589,875. Loose-leaf thong binders. JEFFORD, P. F. Nov. 28, 1944, No. 23704. [Class 146 (i)] A loose-leaf thong binder having at least one pair of thongs of less width than the width of the openings of the sheet slots is provided with means for producing limited relative lateral movement between the thongs in order to lock them in the slots or to enable direct release of the slots from the thongs. In one form of the invention, a box-like metal frame member d, Fig. 1, is guided in grooves on the cover c for free relative sliding, and thongs a, b are connected to the member d by tension springs e and pivoted at f to links g pivoted at their other ends to a nut-like member h slidable in guides on the member d and urged relatively thereto, towards the cover hinge by compression springs i. Slotted links j controlled by compression springs 12 are pivoted at f and have detent notches k for engagement with pins m. The thongs a, b are attached to the cover n by tension springs o and pivoted links p. The sheets v are provided with undercut slots and are held between clamping bars u. Traversing the member h is a threaded rod s carried in bearings on the cover c and rotated by a lug engaging a squared end t. In operation, sheets are inserted between the bars u and on to the thongs, and the rod s is rotated to move the member h away from the hinge so as to thrust the ends of the thongs adjacent the member d laterally outwards so as to lock the thongs in the slots. In the open position the pins m engage the notches k, and on closing the member h trips the ends of the links j and they move into the position shown, under the action of the springs e, thus allowing the thongs to move apart. To open the binder, the rod s is rotated in the other direction, forcing the member h towards the hinge, until the rollers carried on pins q attached to the cover c enter slots in the member d and abut the links g, thereby pulling the thongs inwards to release the sheets, the notches k at the same time engaging the pins m. In another form of the invention, the rod s, Figs. 2 and 3, is threaded through the member d, to which the thongs are attached by springs e and links 8. The rod s operates bell-crank levers v pivoted to strap members w encircling the thongs. The other end of the rod s is provided with a thread 4 of opposite hand to the main thread and engaging an internally threaded sleeve 5 furnished with a square end 6 for actuation by a key. The sleeve 5 has serrations 10 adapted to engage serrations 11 on the rod s. To open the binder, the key is turned clockwise, whereupon the rod s is drawn, without rotating, to the right, carrying with it the member d, whereby the thongs are pulled inwards by the members wand links 8 to release the sheets. When the serrations 10, 11 interlock, the rod s rotates and is wound out of the member d, carrying the cover c away from the leaves. To close, the key is rotated in the opposite direction, to draw back the cover towards the leaves, the serrations 10, 11 being held in engagement by the pressure of a spring x. According to the Provisional Specification, the thongs pass over roller bearings, preferably supported on springs, in clamping bars.