Signature Feeders

Abstract

Improved operation of a cyclically operable signature gathering machine is achieved by latching the gripper, which feeds a signature from a hopper, against the signature pile in response to a command signal that signatures are not to be fed from the hopper.

Description

This invention relates to signature gathering machines in which successive signatures are fed to and collected into a book on a conveyor.

Books, including magazines, are composed of signatures which are simply folded sheets bearing the printed matter. The signature may present pages of the usual kind, or it may be a special size insert. The individual signatures which compose the book are fed from corresponding hoppers or so-called pockets and the signatures for each book are eventually collected one atop another, or one aside another as the case may be, on a conveyor and are transported by the conveyor to a station in the machine where the signatures are joined into a book by stitching (e.g. staples) or by gluing, depending upon how the book is bound.

A gathering machine for thus composing a modern day magazine may have up to 30 or more hoppers. This is especially so in the instance where various inserts such as recipes, data sheets, return mail advertisements, expiration notices and the like are to be inserted at the proper place among the signatures in the course of gathering the signatures into the book.

It is now postulated that magazine editions will be subjected to so-called demographic controls. This is explained as follows:

For the most part, signature gathering machines as constructed today operate on the principle of zone mailing. For example the signatures may be gathered and the books completed sequentially on the basis on the entire mailing to a particular city, and such mailing will include the newsstands, residential subscribers, institutional subscribers subscribers, so on in that particular zone. In terms of residential mailing the books emitting from the machine are usually in alphabetical order for a particular zone, but some publishers have proposed that there be so-called demographic separation of subscribers in terms of professional groups, student editions, and so on, regardless of zone. Demographic separation may be founded on such differences as subject matter content, advertisements and so on.

A more sophisticated approach to demographic controls is to prepare a control tape, strictly alphabetical in character without regard to an alphabetical list of doctors, then an alphabetical list of housewives, then an alphabetical list of students and so on. Rather, all subscribers in a zone would be arranged alphabetically on the tape, and the tape would then be coded to specify that the particular subscriber is to receive signatures from all hoppers except, say, hopper No. 1, while the next subscriber on the list (perhaps a doctor) is to have a book containing all signatures except the signature in hopper No. 23.

The more sophisticated approach to demographic preparation of books thus assumes the need for individual control over each hopper or pocket, which is to say for example that in a given run of the machine there will be constant enabling and disabling of the feeding of signatures from any group of active hoppers or pockets.

In a much more simplified illustration of the need to disable a hopper in a signature gathering machine, it can be assumed, in a given run of the machine, that all books going to one area of the country the run for that zone will include one or more signatures which are not to be included in those books, produced in the next zone run of the machine intended for mailing to another geographical part of the country.

The primary object of the present invention is to enable signatures to be fed from a hopper only on demand, and to so construct the controls for the signature feed gripper as to enable this to be accomplished in a reliable and inexpensive manner. More specifically, it is an object of the present invention to allow the signature gripper to operate normally in the ordinary fashion during a stroke in one direction to first grip a signature in the signature pile and then to withdraw it from the hopper and then to release it incidental to delivering the released signature to the conveyor for transportation to another station of the machine, whereafter the gripper is returned for a repeat operation, while at the same time constructing the machine to include a latching device which upon delivery of a demand signal will latch a part associated with the means which reciprocate the gripper. Yet specifically it is an object of the present invention to include in the machine a solenoid operated latch arm which, when the solenoid receives a signal, will be shifted into position where a latching element thereon engages an arm which reciprocates with the gripper.

Other and further objects of the present invention will be apparent from the following description and claims and are illustrated in the accompanying drawings which, by way of illustration, show a preferred embodiment of the present invention and the principle thereof and what we now consider to be the best mode contemplated for applying that principle. Other embodiments of the invention embodying the same or equivalent principle may be used and structural changes may be made as desired by those skilled in the art without departing from the present invention.

In the drawings:

FIG. 1 is a diagrammatic view of a signature gathering machine in which the present invention may be used;

FIG. 2 is a diagrammatic view of signatures in the course of collecting by the conveyor;

FIG. 3 is a schematic view, accompanied by a legend, showing the nature of demographic mailing aspects characterizing operation of a signature gathering machine; and

FIG. 4 is a side elevation of the signature feed structure characteristic of the present invention, and taken on the line 4-4 of Fig. 5 but with certain parts added;

FIG. 5 is an end elevation at one side of a hopper showing the stop-feed mechanism of the present invention; and

FIG. 6 is a bottom view taken on the line 6-6 Of FIG. 5.

FIG. 1 illustrates diagrammatically the general operation of a cyclically operable signature-gathering machine in which individual signatures or sheets may be contained in an indefinite number of hoppers, hopper Hl through hopper H32. During any given run, the machine may only include three operating hoppers, or it may include 12 operating hoppers, or as many as 32 as shown.

The signatures advanced from each hopper in successive cycles of the machine are eventually collected on a conveyor, FIG. 1, and in the instance of so-called saddle stitching the signatures may be dropped one atop another, one after another, along the length of the conveyor, being supported on a stationary saddle SD, FIG. 2, where signatures S1, S2 and S3, respectively fed from hoppers Hl, H2 and H3, are superimposed one on another in the order shown.

The signatures in the course of collection into a book are fed forwardly along the saddle SD by means of a pin as P, FIG. 2, projecting upwardly from an endless chain C, and through a slot in the saddle SD. There are of course many pins, each pushing its own group of signatures as the signatures are gathered into a book.

The gathered signatures which compose the book are fed by the conveyor to a stitcher where the book is bound as by staples, but of course the binding may be otherwise.

For purposes of disclosure, it may e assumed that the book being produced, FIG. 1, is a magazine of monthly edition, but the publisher may want to vary the edition by way of special inserts, or the omission of such inserts, in terms of broad geographical differences or even difference among the subscribers themselves. Referring to FIG. 3, this shows schematically a mailing tape that will be separately prepared and applied to the magazines representing the books of FIG. 1. The fragment of the mailing tape illustrated in FIG. 3 includes three doctors and two students. The upper margin of the mailing tape may bear codes (magnetically sensed or otherwise) represented in this instance by black squares. According to the code shown, signatures from hopper Hl are not to be included in the magazine for each doctor in the mailing zone or region "60," and the students' magazines are to exclude signatures from hoppers Hl and H3.

It will be appreciated that what is illustrated in FIG. 3 is purely arbitrary and illustrative only of the principles of demographic separation manifest in an edition of the magazine being varied as to content. In any event, the code on the tape for each person is sensed, and a signal is generated for a hopper from which a signature is not to be fed.

In accordance with the present invention, each hopper of the signature gathering machine may be so constructed as to be responsive to such a demand signal, however originated, signifying that a signature is not to be fed from the hopper. In actual practice, the signal may be originated in many different ways, and in most instances the signal will be stored or registered until the book for the subscriber is immediately under preparation in terms of signatures being gathered on the conveyor.

In FIG. 4 the reference character H is generally applicable to any one or all of the hoppers shown in FIG. 1 from which signatures are fed, and it may be noted that the signatures will be in a generally horizontal stack with their bottom edges or backbones at level L and with the front page of the forwardmost signature engaging the face of a front plate 10. The front plate 10 extends downward only part way, leaving a large gap at the front of the hopper H where the lower portion of the leading signature is exposed to the action of a feeder in the from of a suction gripper 12.

Suction grippers of the kind involved for feeding signatures from a hopper are well known in the art, and their operation is well understood. It need therefore only be briefly noted that the suction gripper 12 is supported at the lower end of a reciprocating arm 14 affixed to a horizontal support shaft 15. The support shaft 15 and the arm 14 are provided with passages for communicating vacuum to the gripper cup 13, and effective suction or negative pressure is controlled by valves (not shown) in such a fashion that when the arm 14 is in the position shown in FIG. 4, presented to the front page of the leading signature, negative pressure is established and held during the time interval that the gripper arm 14 is rocked counterclockwise to withdraw the signature from the hopper H. In the course of its counterclockwise stroke, the gripper is effective to present the withdrawn signature to other feed elements (not shown) incidental to the eventual deposit of the signature on the conveyor for transportation elsewhere in the machine. For each hopper, there are usually at least two suction grippers as 12, operating in the manner described.

Shaft 15 is carried at the upper end of one arm 19 of a bellcrank 20. Bellcrank 20 is supported for pivotal movement on a rock shaft 21. The opposite arm 22 of the bellcrank serves as an anchor for a return spring 23 which cooperates with a cam 25 in controlling the operation or reciprocal motion of the gripper arm 14 in opposite strokes. Further to this end, a gripper-operating lever 26 is provided at its upper end with a split block 27 adapted to e clamped to the rock shaft 21 so that any angular movements imparted to the operating lever 26 are also imparted to the bellcrank 20. The lever 26 is provided at its lower end with a cam follower 30, FIG. 5, being rotatably supported by a stud 31 thereon.

The cam 25 is disposed opposite the cam follower 30, being fixed to a cam shaft 32, and in the course of cyclical operation of the machine the lobe 25L of the cam is repeatedly presented to the cam follower 30. On the other hand, when the dwell or low part of the cam 25 is presented to the follower 30, spring 23 is effective to rock the bellcrank so that the follower 30 will follow the contour of the cam characterizing the signature-withdrawing stroke of the gripper mechanism. Of course, when the gripper is in its signature-releasing position, the vacuum supplied thereto is interrupted by the vacuum control means, and this condition prevails in the course of cam lobe 25L being effective to return the gripper to the signature pile in a clockwise stroke as viewed in FIG. 4. The vacuum control means, which control gripping and release of the signatures, are cyclically operable with the machine.

In accordance with the present invention, an electrically controlled latch is operated when a signature is not to be fed from a hopper as H by the signature gripper, and the latch is effective to hold the gripper 12 in the position shown in FIG. 4, at the end of its clockwise stroke, so long as a corresponding command signal prevails. The suction cup will be applying suction throughout this duration to the leading signature in the hopper, but the gripper is prevented from moving until the command signal ceases, whereupon the latch is disabled allowing the gripper to operate in a normal manner until a new signal is originated.

The manner in which such a signal originates has been explained above in connection with FIG. 3 and is transmitted to an electromagnet in the form of a solenoid 40, FIGS. 4 and 5.

The solenoid 40 is secured to a support base plate 41 located at one side of the hopper H, and the armature or plunger 42 of the solenoid extends downward and is articulated to a depending spring housing 43 by a pair of pins 44 and 45 in conjunction with an interposed connector link 46 in the fashion obvious in FIGS. 4 and 5.

The housing 43 contains a coil spring 50 and a headed plunger 51, the head 52 thereof resting on the upper end of the spring 40. The lower end of the plunger 51 is free of the housing 43 and is connected to a link 52 by means of a pin 53. Link 52 is bifurcated, and in turn is pivotally connected to a latch arm 60 by a pin 61. The plunger and spring combination cushions the latch effect hereinafter described.

As shown in Fig. 4 the link 52 is connected to the latch arm 60 medially of the latter. One end of the latch arm 60 is pivotally supported on a stud 62 extending outward from the near side of the base plate 41 as viewed in FIG. 4, and the opposite end of the latch arm is provided with a notch or seat 65 in the upper edge thereof adapted to receive a roller 66 carried at the lower end of the control lever 26, coaxial with the cam follower 30.

The latch 60 is shown in its effective or enabling position in FIG. 4, which is to say that solenoid 40 has been energized to present the latch seat 65 to the detent or roller 66. Until this event occurred the latch arm 60 was in the dotted line position of FIG. 4 in a released or disabled state allowing free normal action of the gripper in cyclical response to the controls 23-25. Delivery of the latching signal to the solenoid 40 is so timed as to be coterminal with arrival of the gripper in the position shown in FIG. 4, so that when the solenoid is energized the gripper is in its normal sheet gripping position, FIG. 4, in which position it will be held until the solenoid is deenergized. In the meantime, the cam 25 continues to turn idly.

The deenergization of the solenoid 40, characterizing a demand that the signature is to be delivered from hopper H, will be timed to occur contemporaneously with the passage of cam lobe 25L off the follower 30, whereby the gripper is freed to the action of the return spring 23, allowing the follower 30 to follow the contour of the cam 25 for all subsequent cycles of cam shaft 32 in which the demand is to continue the delivery of signatures from the hopper H.

It will be appreciated that the exact form of the signature gripper is not important, but only that there be a reciprocal or oscillating means in the machine for withdrawing the signatures from the hopper and eventually releasing the signatures for delivery to another station in the machine, and that this means be capable of being latched or held inoperatively at some position of its stroke. Nonetheless, the form of the invention herein disclosed is preferred in that the lobe 25L of the cam 25 does represent something of a time dwell allowing ample time to operate The solenoid and the latch arm to trap the gripper-operating lever 26. Therefore absolute timing does not become a critical factor, nor do vacuum controls represent a critical factor. In its normal or ineffective position, the latch arm engages a stop pin 70 and is urged to that position by a torsion spring 71 associated with the pivot stud 62.

Hence while we have illustrated and described the preferred embodiment of our invention, it is to be understood that it is capable of variation and modification by those skilled in the art.

Claims

We claim:

1. In a cyclically operable signature-gathering machine where sheets are fed one by one from a hopper, eventually to be deposited on a conveyor for transportation to another station in the machine: gripper means operative in reverse strokes during repeating cycles of the machine to grip a sheet in the hopper at one end of a stroke and to withdraw the gripped signature from the hopper and to release the signature at the opposite end of the stroke incidental to the released signature being delivered to the conveyor, controls means for reversing the gripper at the opposite ends of its stroke, means to latch the gripper at an end of its stroke thereby to disable the gripper from feeding a signature, and means to operate the latch means only in response to a command signal so to do.

2. A machine according to Claim 1 in which the latch means is effective on an operating lever which operates the gripper.

3. A machine according to Claim 2 in which said control means includes a cyclically operable cam engageable with a cam follower on said lever.

4. A machine according to Claim 1 in which the latch is carried by a latch arm operated by a solenoid, reverse strokes being imparted to the gripper by an operating lever, said operating lever having an element engageable by the latch, and cam means for reciprocating said operating lever.

5. In a cyclically operable signature-gathering machine where signatures or the like are fed one by one from a hopper, eventually to be deposited on a conveyor for transportation to another station in the machine: gripper means operative in repeated reverse strokes during repeating cycles of the machine to grip a signature in the hopper at one end of a stroke and to withdraw the gripped signature from the hopper and to release the signature at the opposite end of the stroke incidental to the released signature being delivered to the conveyor, control means for reversing the gripper at the opposite ends of its stroke, means to disable the gripper at an end of its stroke thereby to disable the gripper from feeding a signature, and means to operate the disabling means only in response to a command signal.