Stitcher system with out of wire detector

A stitcher system includes a stitcher mechanism for stitching collations of documents and adapted to form stitches from a conductive wire moved into the stitcher mechanism. A non-conductive spool is mounted for rotation on a spindle. A conductive wire is wound on the non-conductive spool. The conductive wire has a tail end adjacent to the non-conductive spool and a lead end remote from the spool. The spool rotates when the conductive wire is moved into the stitcher mechanism to provide conductive wire to be used by the stitcher mechanism to form stitches. A sensing circuit is provided with a circuit path that includes the conductive wire wrapped on the non-conductive spool and a conductive member mounted to engage the wire. The sensing circuit path becomes open when the conductive wire is not wrapped on the non-conductive spool to thereby detect an out of wire condition.

FIELD OF THE INVENTION

The present invention relates to a stitching (i.e., stapling) apparatus and, more particularly, to a stitcher system with an out of wire detector system.

BACKGROUND OF THE INVENTION

There are many applications known in which documents are fed along a paper path and then collated for further processing. Generally, the documents must be properly aligned when the collation is formed before further processing, such as stitching or insertion into an envelope, can be performed. In some applications, such as, for example, photocopying machines, the collation is formed and then stitched at a stacking area. Typically, stitching is done either at the leading edge or at the trailing edge of a collation. In either case the collation is stopped adjacent to the stitching mechanism and stitched. The formation and processing of stitching collations can be carried out at high processing speeds where large number of collations are stitched, for example, at speeds of 20,000 stitched collations per hour.

Stitcher systems are known in the art and are available in paper handling systems for a variety of applications in which stapling of documents is required. Stitcher systems employ a continuous wire moved from a spool into a stitcher mechanism, where a suitable length of wire is cut and then used to form a stitch for a collation of documents. The stitch may be bent into the form of an open rectangle or U-shape prior to further bending at the time of clinching (e.g., closing the stitch to secure the collation). The open rectangle consists of a two vertical legs and a substantially perpendicular leg connecting one end of each of the two vertical legs to form the open rectangle. Various wire bending shapes may be employed.

Depending on the orientation of the stitcher mechanism and its position in relation to the collation to be stitched, the open end of the formed rectangle or U-shape may have an orientation extending downwardly from the top side of the collation (a top stitcher) or upwardly from the bottom side of the collation (a bottom stitcher). The open end of the stitch is driven through the collation and, after clinching, the stitch may be in the form of a rectangle that is almost closed or fully closed on the bottom or the top of the collation, as the case may be. In such case the two vertical legs are clinched somewhere between their ends so that they face each other and form a substantially closed rectangle and secure the collation together by the formed stitch. The height of the stitch is the difference between the top side and the bent sections of the two legs.

SUMMARY OF THE INVENTION

In the following description, certain aspects and embodiments of the present invention will become evident. It should be understood that the invention, in its broadest sense, could be practiced without having one or more features of these aspects and embodiments. It should also be understood that these aspects and embodiments are merely exemplary.

In accordance with the purpose of the invention, as embodied and broadly described herein, one aspect of the invention relates to a stitcher system including a spindle, a non-conductive spool mounted for rotation on the spindle, and a conductive wire wound on the non-conductive spool. In one embodiment, the conductive wire has a tail end adjacent to the non-conductive spool and a lead end remote from the non-conductive spool.

In another aspect, the stitcher system includes a stitcher mechanism receiving the lead end of the conductive wire and forming stitches from the wire for stitching collations of documents and a sensing circuit having a circuit path. In an embodiment, the circuit path includes the conductive wire wound on the non-conductive spool and a conductive member mounted to engage the conductive wire wound on the non-conductive spool. In a further embodiment, the circuit path becomes an open circuit when the conductive wire is not wrapped on the non-conductive spool to thereby detect an out of wire condition.

In a further aspect, the invention relates to a method of detecting an out of wire condition in a stitcher system, comprising providing a spindle and rotatably mounting on the spindle a non-conductive spool on which a conductive wire is wound. The conductive wire may have a tail end adjacent to the non-conductive spool and a lead end remote from the non-conductive spool. In another aspect, the method comprises receiving the lead end of the conductive wire in a stitcher mechanism and forming stitches from the wire for stitching collations of documents, and providing a sensing circuit having a circuit path. In an embodiment, the circuit path comprises the conductive wire wound on the non-conductive spool and a conductive member mounted to engage the conductive wire wound on the non-conductive spool, wherein the circuit path becomes an open circuit when the conductive wire is not wrapped on the non-conductive spool to thereby detect an out of wire condition.

Aside from the structural and procedural arrangements set forth above, the invention could include a number of other arrangements, such as those explained hereinafter. It is to be understood that both the foregoing description and the following description are exemplary only.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

As shown inFIG. 1, a paper handling system2includes an accumulator4and a stitcher mechanism6. The stitcher mechanism6includes a stitcher head8into which a wire10is fed. The stitcher head8draws the wire10into the stitcher head, cuts the wire, bends the wire into a suitable shape, such as an open rectangle or U-shape, for example, and thereafter forces the wire through papers, such as an collation, to be driven against the clincher12. The wire is fabricated from a conductive material, such as steel. Other conductive materials may also be used. The clincher12functions as an anvil for the forced shaped wire and causes the open ends of the shaped wire to be bent and to form a stitch for the collation. Various collations, such as collation13,14, and16are moved into an operative engagement with the stitcher mechanism6, so that a stitched collation, such as collation18with a stitch20, is formed. The stitch20is essentially a staple securing the collation together.

Wire10is drawn off a spool22, which is mounted to rotate on a spindle24. The spindle24is angled at approximately 15 degrees from the horizontal to provide a force that prevents the spool22from coming off the spindle24as the wire is drawn off the spindle24. Other angles may also be used. The spool22is made out of a non-conductive material, such as plastic. Other non-conductive materials may also be used. The spindle24rotates in the direction of arrow26as the wire10is drawn off the spool22.

This is normally a desirable direction of rotation for this equipment when the spool is mounted at the bottom portion of the paper handling equipment. The wire is drawn off the spool and fed in an upward vertical direction. However, as shown inFIG. 3, the direction of rotation may be reversed when the spool is mounted at the top of the paper handling equipment. The wire in that case is drawn off the spool and fed in a downward vertical direction. As shown, the spool22rotates in the direction of arrow28. This enables the stitch to be placed so that a top stitch or bottom stitch may be implemented as desired by the user to present the top of the stitch, as opposed to the legs of the stitch.

In the illustrated embodiments, several brushes comprising non-conductive bristles are mounted around the periphery of the spool22to contain the wire10as it is drawn off the spool22. In one embodiment, the bristles comprise nylon, although other materials may also be used. Thus, a mounting bracket30supports a nylon bristle brush32, which engages the wire10wrapped around the hub of the spindle-mounted spool22.

In a like manner, a mounting bracket34supports a nylon bristle brush38and a mounting bracket36supports a nylon bristle brush not shown inFIG. 1. The brushes both contain the wire10on the spool22to prevent the wire from becoming loose and possibly tangling as it is drawn off the spool, and also contain the wire as the spool is being loaded. Other numbers and arrangements of brushes may also be used.

In the embodiment shown inFIG. 1, a pivotable, spring-biased mounting bracket40supports a conductive bristle brush42. In one embodiment, the bristles comprise brass. Other materials may also be used. The mounting bracket40and the conductive bristle brush42are part of a brush assembly, shown generally at43inFIGS. 1 and 2. The conductive bristle brush42is part of a circuit, which is employed to sense an out of wire condition of the conductive wire10on the non-conductive spool22.

The conductive bristle brush42both contains the wire on the spool and also allows detection of when the out of wire condition occurs by interrupting a circuit. In the embodiment shown inFIG. 2, the pivotable mounting bracket40is biased by a torsion spring44, such that the bracket40rotates on a shaft46to cause the conductive bristles of the brush42to be urged against the conductive wire10on the spool22. Like the non-conductive bristle brushes, the conductive brush42also operates to contain the wire10on the spool22to prevent the wire from becoming loose and possibly tangling as it is drawn off the spool. When the wire10on the spool is depleted and an out of wire condition occurs, the conductive bristles of brush42are urged against the hub of the spool22, which is non-conductive. This breaks a circuit path through the conductive wire10and the conductive bristle brush to signal that there is no more wire on the spool22.

Because the conductive wire10and the conductive bristle brush42are part of a sensing circuit58, the support bracket48that supports the pivotable mounting bracket40is insulated so as to be isolated from other conductive paths that may affect the operation of the sensing circuit58. The support bracket48supports both the shaft46and the mounting bracket40. An insulating spacer, such as a plate50and washers52and54also made out of insulating material, electrically isolate the conductive bristle brush42and the mounting bracket40from the rest of the mounting frame structure, such as the plate56. The plate50and washers52,54may comprise phenolic, nylon, or other insulating materials.

The sensing circuit58is connected by a wire60or other means to the conductive brush42, for example, through the mounting bracket40. When the wire10is depleted and an out of wire condition exists, the circuit path is broken and it becomes an open circuit. Thus, the circuit path through the wire10, the conductive brush42, and the bracket40is interrupted due to the out of wire condition. The out of wire condition functions similar to the opening of a switch63shown inFIG. 4.

One of the boards, for example, board59in the sensing circuit58, has a 5-Volt input. A wire is connected from the board to the brush assembly43. The input is at 0 Volts as long as there is an unbroken circuit to the grounded stitcher head8. The stitcher head ground is shown at9. The switch63shown inFIG. 4represents the wire/no wire condition. The switch63is open when there is no wire10connecting the brush assembly43and the stitcher head8. When there is no wire, the input is at 5 Volts, since the voltage cannot go the ground. This changed voltage condition is employed to initiate the operator alarm61, shown inFIG. 1.

In a further embodiment, the information from the sensing circuit58is provided to a paper handling control system62, which is connected to control the accumulator4and the stitcher mechanism6to stop operation. This prevents the feeding of collations that would not be stitched due to the absence of wire10. When the sensing circuit58detects the out of wire condition, it triggers an operator alarm61to notify an operator of the out of wire condition and of the need to load a new spool of wire in the stitcher apparatus. The operator alarm may be audible, visual, or a combination, providing both an audible and visual out of wire alarm.

In some embodiments, the stitcher mechanism6may be stopped by the paper handling control system62with wire still in the stitcher head8. In that case, collations that are not stitched do not move out from stitcher mechanism6. Moreover, the task of reloading the new wire spool and feeding the wire into the stitching mechanism is facilitated since residual wire10is left in the stitcher head8from the out of wire spool. The residual wire10can be pulled out of the stitcher head8using the tail end of the wire from the out of wire spool. New wire from a new spool can be fed easily into the stitcher head8.

It will be apparent to those skilled in the art that various modifications and variations can be made to the structure and methodology described herein. For example, it should be recognized that the conductive bristle brush42may be any conductive member and need not a brush, provided such conductive member is in engagement with the conductive wire and is connected to be part of an out of wire sensing circuit. Moreover, the conductive member may be positioned to engage the wire after it is pulled off the spool and before it is fed into the stitcher mechanism head, whereby an out of wire condition of the spool would also be sensed.

Thus, it should be understood that the invention is not limited to the examples discussed in the specification. Rather, the present invention is intended to cover modifications and variations.