Collator

Abstract

A collator intended for use with a high speed photocopy machine for automatic assembly of copies of a multi-page document including a conveyor and tray assembly with respective deflectors and in which passage of a copy sheet into a given tray serves to trigger the next deflector in the series. Means are provided for utilizing a hiatus in the flow of copy sheets from the photocopy machine to achieve automatic reset of a commutator to an initial reference condition to begin a new collating series. It is one of the important features of the invention that means are provided for detecting a condition of incipient jamming and for promptly and automatically disabling the conveyor and shutting off the flow of incoming copy sheets from the photocopy machine. One means for detection of an incipient jamming condition includes the provision of sensors along the conveyor path at a spacing which corresponds to the gaps between the sheets flowing in the conveyor path. Failure of one sensor to respond simultaneously with the others following passage of each copy sheet, indicating that the sheets are out of step with one another, produces automatic shut down. Also, failure of a sheet to pass promptly and completely into one of the receiving trays, a prolific source of jamming in conventional collators, is sensed to produce automatic shut down before a jam can occur. In this connection it is one of the features of the invention to utilize a single light source and photocell, servicing as many as 20 or more trays, for both commutation and jam detection. One of the features of the invention is the novel utilization, for jam detection, of a timer circuit which is constantly and repeatedly reset by the sensors under normal operating conditions but which, upon time-out, triggers the shutdown mode.

Description

The tendency in office photocopiers has been to go to higher and higher speed, particularly for machines which are intended for producing multiple copies of a multiple page document. Such a high speed machine, capable of producing copies at the rate of more than 60 a minute, using flash techniques, is disclosed in Newcomb U.S. Pat. No. 3,815,990 issued on June 11, 1974. To fully achieve the advantages of high speed operation it is necessary to use a collator, but collators of conventional design have been highly susceptible to jamming. It will be understood that when a jam does occur it is much more serious at high speed because of the rapid and destructive pile-up of sheets and the possibility of breaking or deforming some critical mechanical element.

It is, accordingly, the primary object of the present invention to provide a collator which is capable of detecting, while still in incipient state, those conditions which are found to lead to a jamming situation, with prompt shutdown so the condition may be corrected. More specifically it is an object to provide means for insuring that the copies to be collated, and flowing from a photocopy machine, are in a precise and evenly spaced sequence, with uniform and well defined gaps between adjacent copies thereby to insure that the sheets can be reliably diverted into successive trays. Moreover, it is an object of the present invention to provide novel means for insuring that each sheet which is diverted into a collecting tray passes promptly and completely into the tray into a position well clear of the following sheets. In this way the two conditions which are responsible for almost all of the failures of a collating machine are detected in the incipient stages to produce automatic shutdown without any care or attention on the part of the operator. Shutdown occurs at a stage when the condition is easily corrected without loss or copy sheets and before any wedging or crushing of copies can occur.

It is a more specific object of the present invention to provide a collator in which a sensor at a receiving tray serves to index a commutator switch so that the next copy is deposited in the next tray until there is a hiatus in the flow, whereupon the switch is snapped into a reference starting condition to begin a new commutating series. It is, accordingly, an object of the present invention to provide a collator which does not require any presetting by the operator to establish the length of a collation sequence, with the possibility of the collator s getting out of step. Nor is it necessary to provide any instruction to the collator by means of a wired connection from the copy setting knob on the associated photocopy machine.

It is a more detailed object to provide means for establishing a predetermined shutdown sequence which occurs after a period of non-use or upon pressing the "stop" button with assurance that any copies in transit will be cleared from the machine.

It is a still further object of the present invention to provide a collator which may be close coupled to a high speed photocopy machine and which includes provision for diverting copies within the latter upon occurrence of an incipient jamming condition, but which is otherwise independent of the photocopy machine and thus may be successfully used with high speed photocopy machines of radically different designs on the current market.

Finally, it is an object of the present invention to provide a collator which, notwithstanding all of the above, is nevertheless of simple and inexpensive construction, which is inherently long lived and maintenance free.

Other objects and advantages of the invention will become apparent upon reading the attached detailed description and upon reference to the drawings in which:

FIG. 1 is a perspective view of a collator and associated photocopy machine embodying the present invention.

FIG. 2 is a top view, with top cover removed, looking along line 3--3 in FIG. 3.

FIG. 3 is an elevational view, with front cover removed, taken along line 3--3 of FIG. 2.

FIG. 3a is a horizontal section taken along the line 3a--3a of FIG. 3.

FIG. 3b is a section taken along the line 3b--3b of FIG. 3.

FIG. 4 is a fragmentary elevation showing the registered coupling between the collator and photocopy machine.

FIG. 5 is a fragmentary elevation showing the construction of the diverters used at the lips of the respective trays.

FIG. 6 is a perspective view of the conveyor belt and vacuum assembly with portions being broken away.

FIG. 7 is a fragmentary top view of a typical diverter actuator viewed along the line 7--7 in FIG. 5.

FIGS. 8a-8c, taken together, form a schematic control diagram employed in the present machine.

FIG. 8d is a simplified diagram of a typical timer used in the above circuit.

FIG. 9 is a diagram showing the developed conveyor path and the sensor positions as related to the gaps between adjacent sheets.

While the invention has been described in connection with a preferred embodiment, it will be understood that we do not intend to be limited to the particular embodiment shown but intend, on the contrary, to cover the various alternative and equivalent forms of the invention included within the spirit and scope of the appended claims.

Turning now to the drawings, and particularly to FIGS. 1-3, there is shown a typical photocopy machine 20 of a type capable of producing multiple copies of a succession of original documents at a high rate of speed on the order of, say, one copy per second. Reference may be made to the above-mentioned Newcomb application for a disclosure of such a machine. Superimposed upon the photocopy machine illustrated in FIG. 1 is an "operator assist" mechanism 21 on which a stack of original documents may be placed, for example the pages of a multi-page booklet, the sheets being fed automatically to a transparent platen where the original sheet is retained long enough to expose the desired number of copies, following which the sheet is discharged into a collector 22 for removal. The illustrated machine is of the type in which the individual copy sheets are severed from a supply roll and individually, but in succession, charged, exposed, developed and fixed, the fixed sheets being discharged at a discharge opening 23 which is located near the top of the machine at its left-hand side (see FIGS. 3 and 4). In accordance with the present invention the photocopy machine is preferably of the type which is capable of diverting the flow of copy sheets from the regular discharge opening into an auxiliary collector tray. Thus, referring to FIG. 4, the final conveyor on which the copy sheet is transferred upwardly, indicated at 25, feeds the sheet between a pair of driven rollers 26. Arranged above the rollers 26 is a diverter 27 connected to a solenoid 28 and which, during normal operation of the machine, occupies the dotted position so that copies are directed to the left into a pair of expeller rollers 29 which eject the copies laterally through the discharge opening 23. As will be described, the solenoid 28 is connected in the circuit of the collator so as to be normally energized, but when the solenoid is deenergized, the deflector 27 discharges the photocopies, instead, into an auxiliary collector tray 30. For this purpose the solenoid is provided with a return spring 31 which, when the solenoid is deenergized, shifts the diverter 27 to the full line position in which the sheets are directed to the right through a pair of auxiliary expeller rollers 32 and into the collector tray 30.

The photocopy machine, it will be understood, has a start button 33 and a stop button 34. The present collator system, in addition to making use of the diverter 27 within the photocopy machine, controls the circuit which is actuated by the stop button 34 so that the collator is capable, under certain circumstances, of automatically turning off the copying machine to which it is connected.

Turning next to the structural aspects of the collator, indicated at 40, it will be noted (FIG. 4) that it includes an inlet opening 41 which, when the machines are coupled side by side, registers with the discharge opening 23 of the photocopy machine. Because of the functional integration of the photocopy machine and the collator it is, of course, desirable that the two units be mechanically coupled together in a way which will insure that the discharge opening of the first machine is in register with the inlet opening of the second, as illustrated in FIGS. 3 and 4; for example, a suitable latch, such as that indicated at L in FIG. 3, may be employed. The sheets entering the inlet opening 41 are driven, by the expeller rollers 29 in the photocopy machine, through a pair of wire guides 42 which define a curved path into engagement with a conveyor 50. The conveyor serves to convey the copies along a vertically elongated, U-shaped path, the copies flowing along the "downside" 51, about a 180.degree. turnaround 52, and then vertically upward along the "upside" 53. The copies conducted upwardly on the conveyor are diverted, on a commutated basis, into respective receiving trays. Prior to reference to the tray assembly and diverters, more detailed attention may be given to the conveyor.

In accordance with one of the aspects of the invention the conveyor is in the form of a hollow rectangular vacuum box (FIG. 6) which is surrounded by a series of endless transport belts 55 vertically extending and spaced edge to edge. The belts are trained about a pair of rollers 56 at the top and about a drum 57 at the bottom, the drum thus serving as a "turnaround" to cause the copy sheets to reverse their direction. The drum, and the belts which engage it, are power driven by a drive 60 which includes a pulley 61, a belt 62 and pulley 63, the latter being rotated by an electric motor 64. It will be understood that the speed of the motor and the diameter of the rotating elements are such that the belt speed is nominally the same as the speed at which copies are ejected from the photocopy machine.

For the purpose of causing the copy sheets to adhere to the belts, ports 65 are formed on the face of the box in the regions between the belts, and means are provided for evacuating the box to a degree sufficient to insure reliable transport. It will be understood that the opposite side of the box is similarly ported. For evacuating the box a centrifugal vacuum pump 66 is used, driven by a motor 67 and having an inlet duct 68. To insure that the sheets are guided into close engagement with the belts, a set of idler rollers 71 (see FIGS. 3 and 3a) are used. Spaced slightly away from the belts are vertical guide wires 72. At the lower end of the conveyor, in the region where the sheet leaves the region of vacuum, auxiliary rollers 73 are provided (FIG. 3b). The copy sheet is conformed to the drum by a set of curved guide wires 74 and the leading edge of the sheet is fed into a second set of auxiliary rollers 75. This insures that the leading edge of the sheet is again subjected to vacuum on the back, or upside, of the box for intimate contact with the belts.

The the extreme upper end of the conveyor idler rollers 76, physically the same as rollers 71, assist in propelling any sheet remaining onn the belt upwardly between guide wires 77 and expeller roller 78 into an overflow compartment 79. Means (not shown) are provided for driving the expeller rollers at copy speed.

In carrying out the invention we provide, along the upside 53 of the conveyor, a tray assembly 80 which is formed of a vertically stacked tier of shallow, copy receiving trays which may, in a practical case, be twenty in number; however, only the first two of these trays 81, 82, have been given a reference numeral. The trays are compactly integrated into a light boxlike frame which includes vertical members 85 notched at regular intervals. The trays are accessable for individual emptying through a "window" 86 formed in the front wall of the collator housing. During normal operation the trays are close coupled to the conveyor so that the lips thereof, typically indicated at 91, 92, extend close to the conveyed sheets.

For the purpose of diverting copies arriving in a closely spaced series into respective ones of the trays, each tray is provided, at its lip, with a deflector which is actuated selectively, and in sequence, to direct one of the copies of the series into the corresponding tray. Typical deflectors shown at 101, 102 cooperate with lips 91, 92. Taking the deflector 101 by way of example, as shown in FIGS. 3b, 7 and 5, it includes a transversely extending shaft 103 having a stop member 104 and a series of axially spaced deflector elements or fingers 105. The deflector shaft is urged into nondeflecting position by a spring 106. For the purpose of rotating the deflector into deflecting position, a solenoid 107 is provided which is coupled to the shaft by means of a link 108 of light construction. It will be apparent, then, that when the solenoid 107 is energized, tension on the link 108 rotates the shaft 103 so that all of the deflecting fingers 105 are rotated into the position illustrated in FIG. 5, thereby engaging the leading edge of the sheet at spaced points and camming the leading edge away from the conveyor so that it strikes the lip 91 and passes, along a downwardly curving path, into the tray 81 where the sheet is deposited on top of copy sheets which have been previously collected. FIG. 5 shows that the tray lips have side walls, which have, for simplicity, been omitted in FIG. 3.

Similar deflector assemblies are provided, one for each tray, constructed in the same way. By actuating the deflectors successively it will be understood that successive copies forming a series of identical sheets will be deposited in the successive trays, beginning with the first, the structure being capable of extension to include any number of trays.

Since the primary features of the present invention have to do with the scheme of control, reference will next be made to the schematic control diagram which is set forth in composite FIGS. 8a-8c. Power is derived from an AC power source via a power plug 110 which supplies lines 111,112. For adjusting the voltage of the AC lines an auto transformer 113 is used. The conveyor drive motor 64 and the motor 67 which drives the vacuum pump both receive current from the AC lines. Connected across the same lines are a twelve volt AC power supply 114, which energizes low voltage AC lines 115, 116, and a twelve volt DC power supply 117 which energizes low voltage DC lines 118, 119.

In accordance with the present invention a stepper switch is provided for commutating the solenoid coils 107 which actuate the deflectors, with the stepper switch being forwardly stepped by impulses from a sensor located at the lips of the trays so that passage of a copy sheet into a tray causes the stepper switch to advance one step with the result that the next copy sheet is diverted into the next tray in the series.

Referring to FIG. 8c, the stepper switch 130, which is diagrammatically shown, includes a ratchet wheel 131 having ratchet teeth 132 which are engaged by a ratchet 133 actuated by a stepping coil, or solenoid, 135 and to which is connected a return spring 134. Retrograde movement is controlled by a keeper pawl 136. The ratchet wheel 131 has a moving contact or wiper 137 which steppingly engages a series of contacts 138. Current to actuate the connected solenoids 107 is supplied through a stepper input lead 139.

In accordance with the invention, means are provided for directing a light beam adjacent the lips of the receiving trays in a position to be cut by a photocopy flowing into any one of the trays. A photocell is provided for receiving the beam and for pulsing the stepping coil 135. Thus referring to FIGS. 3 and 5, a light source 140 is mounted at the lower end of the tray assembly for directing a narrow, pencil-like beam of light of high intensity, indicated at 141, through registering openings 142 in the lips of the trays, with the beam being received at the top of the tray assembly at a photocell 143. It is one of the further features of the invention that the same beam of light which serves to pulse the stepping switch serves also as a sensor to detect tardy or incomplete passage of a copy sheet into any one of the receiving trays, thereby to detect a condition of incipient jamming to shut down the conveyor. Attention will first be given to the stepping circuit which includes the photocell, and the manner in which it is coupled to the stepping coil.

Thus referring to the central portion of the schematic diagram, the light source 140 is in the form of a high intensity lamp connected across the low voltage AC lines 115, 116. The photocell 143 is connected across low voltage DC lines 118, 119 in series with a relay 150 having a normally open contact 150-1 in series with the stepping coil and a normally closed contact 150-2. Initially, when the collator has been turned on, lighting the lamp 140, but before any copies start to flow, the beam of light 141 striking the photocell 143 energizes the relay 150, closing the contact 150-1. No current flows to the stepping coil, however, because of the necessity to close the normally open contact which is in series with it, and to which reference will shortly be made.

In accordance with one of the features of the present invention, a series-responsive sensing means is provided which enables the stepping switch to perform its commutating function as long as copy sheets arrive at the inlet opening in a closely and evenly spaced series; however, when there is a hiatus in the series of sheets, indicative that a change has been made in the original document in the photocopy machine, the sensing means disables the stepper switch by cutting off the voltage to it and, at the same time, energizes a reset line which causes the stepper switch to be reset to an initial reference condition. More specifically in accordance with the invention the sensor means includes a series-responsive timer having a reset line which is successively energized by the incoming copies so that the timer is constantly reset as long as the copies continue to flow in a closely spaced series; but when the timer times out, due to a hiatus in the received copies, the stepping switch is placed in the reset mode. Thus, referring to the top portion of the circuit diagram, an input sensing switch 155 is provided which is physically located close to the inlet opening 41 and in a position to be closed by the successively received copy sheets. This sensing switch controls a timer 160, which is representative of the timers employed in the present circuit and which is shown in greater detail in FIG. 8d. It will be noted that the timer has main terminals 161, 162 and a reset line 163. The latter serves to energize a delay 164 having a normally open contact 165 which is in series with terminals 161, 162. The relay contact is coupled to a time delay device 166 which, as indicated by the legend, provides time delay on drop-out. In operation, application of voltage to the relay coil 164 by the normally open sensor contact 155, or equivalent, immediately closes, or "resets" the contact 165. However, when the sensor contact opens, the relay contact 165 does not immediately drop out; instead, there is a time delay on drop-out which is of a fixed but adjustable amount. In the case of the timer 160 the delay on drop-out is on the order of 3 seconds. The details of the delay device 166 have, for the sake of simplicity, been intentionally omitted since such details are not part of the present invention and since commercial relays are available capable of making immediate contact upon energization but providing the desired fixed time delay on drop-out.

Connected in series with the timer 160, and controlled by it, is a relay 170 having a normally open contact 170-1 and a normally closed contact 170-2. The normally open contact is in series with the stepping coil 135 and the normally closed contact is in series with a reset coil 171 which is capable of releasing the keeper pawl 136 on the stepper switch. The ratchet wheel 131 of the stepper switch is biased by a torsion spring 172 to the reference starting position against a stop 173.

Thus when the first copy sheet of a series enters the inlet opening 41 closing sensor switch 155, the reset line 163 of the timer 160 is energized, turning on relay 170. This closes the contact 170-1, completing a circuit to the stepping coil 135 through contact 150-1 which, as previously noted, is closed by reason of the light striking photocell 143. Thus the stepping coil 135 is pulsed, advancing the ratchet wheel forwardly one step against the restoring force of the spring 172 so that the wiper 137 engages the first one of the step contacts 138 connected to the first one of the deflector solenoids 107. Such solenoid rotates the deflector 101 around into deflecting position illustrated in FIG. 5 so that the first copy sheet of the series engages the first lip 91 and is deposited in the first tray 81 (see FIG. 3). It is true that when the first sheet leaves the sensing switch 155, the opening of the switch causes the timer 160 to begin to time. However, since the timer is set for an interval on the order of two or three seconds, the timer does not time out, and closure of the switch 155 by the leading edge of the second sheet immediately resets the timer to its start position so that the contact 170-1 remains closed. Consequently, when the first sheet breaks the light beam as it passes into the first tray, the photocell relay 150 is momentarily deenergized, pulsing the contact 150 open and then closed again, thereby pulsing the stepping coil 135 and advancing the stepping switch to the next, or second, contact. This deenergizes the first deflector 101 (FIG. 5) and energizes the next, or second, deflector 102 so that the second sheet upon arrival is promptly diverted into the second tray.

This process is repeated for each copy sheet in the closely spaced series, the timer 160 being repeatedly reset by the arrival of successive sheets so that it does not, during the series, have opportunity to time out.

However, after a predetermined number of copies have been made, depending upon the setting at the photocopy machine, the closely spaced series comes to an end and there is a hiatus of several seconds because of the time that it takes to switch original documents in the photocopy machine. It may be assumed in a practical case that this requires more than three seconds. As a result, the sensor switch 155 is not actuated soon enough to reset the timer 160 before it times out, deenergizing relay 170 and closing contact 170-2. This energizes the reset coil 171, freeing the pawl 136, so that the ratchet wheel returns to its beginning, or reference, position. Opening of contact 170-1 isolates the stepping switch from the righthand supply line so that the deflectors are not energized in reverse order during the return swing of the wiper.

When, after a period of three seconds, a new series of photocopy sheets begins to be fed into the inlet of the collator, the sensor switch 155 resets the timer, turning on relay 170 which closes contact 170-1. This provides an initial conditioning impulse to the stepping coil 135 so that the wiper 137 is stepped from its reference position to its first contact position, energizing the deflector 101 which is then in readiness to divert the first copy into the first tray. When this happens the light beam is momentarily broken, impulsing the stepping coil which then turns off the first deflector and turns on the second, this process being repeated for all of the copy sheets in the series, until this series, too, comes to an end, causing the timer 160 to drop out to reset the stepper for a third series, and so on.

As has been noted, the stepping switch, acting as a commutator, does not require any instruction from the operator. It takes its instruction, to reset, only from the hiatus which exists between successive series of copy sheets.

One of the most common causes of malfunction in a collator is the failure of each sheet to pass fully into the tray which is to receive it. When this happens the succeeding copies frequently get "hung up" on the errant copy. It is one of the features of the present device that the same light beam which is employed for commutation is used to insure that each copy passes immediately and completely into a receiving tray. Thus means are provided for measuring the period that the beam is cut off by a copy and for shutting down the machine if such period of cut-off is more than momentary. More specifically, a timer is employed having a short time out period, on the order of two seconds or less, which is periodically reset by restoration of the beam, but with lack of restoration for the two-second period being interpreted as an incipient jam. Thus a relay 175 is provided connected in series with the normally closed contact 150-2 which is opened by the light beam. The relay controls a normally closed contact 175-1 and a normally open sealing contact 175-2, to which reference will be later made. Under the control of the contact 175-1 is a two-second "tray traverse" timer 180 having terminals 181, 182 and a reset line 183, the contact 175-1 being in series with the reset line. A relay 185, connected to the timer 180, has normally open contact 185-1 in series with the conveyor drive, a normally closed contact 185-2, upon timing out of the tray traverse timer, completes a connection to the "off" circuit of the photocopy machine, indicated diagrammatically at 186. The nature of the connection 186 will, of course, depend upon the specific photocopy machine with which the collator is used. The connection 186 may, for example, consist of a relay having a normally closed contact which is in series with a normally maintained holding circuit in the photocopy machine, in which case energization of the relay by interrupting the holding circuit will serve to turn the photocopy machine off. This is a matter well within the skill of the art.

The companion, normally open, contact 185-3 accomplishes, by its opening, an analogous result, namely, the deenergization of the diverter in the photocopy machine so that any copies which are "in process" in the photocopy machine are diverted into the auxiliary collector tray 30, previously referred to, rather than continuing to flow into the collator. It will be understood that during normal operation the contact 185-3 associated with the tray traverse timer 180 will be closed, thus completing a circuit to the diverter, so that the diverter (FIG. 4) is energized to direct copies out of the photocopy machine outlet opening 23. An incipient jam at the collator tray both turns off the collator conveyor and prevents flow of any further copies to the conveyor. This will be made clear upon considering a typical sequence of operation:

Under normal circumstances, with copy sheets flowing promptly into their respective trays, the light beam will be interrupted only momentarily. That is to say the light beam contact 150-2, which is normally held open by the presence of the beam, will be closed momentarily thus energizing the relay 175 momentarily and momentarily opening its contact 175-1. In other words, during normal operation, contact 175-1 in the reset line of the timer 180 is closed almost all of the time, being opened periodically only for a brief interval which is substantially less than two seconds, so that the timer 180 never has opportunity to time out. However, in the case that a copy sheet does not pass completely into a tray with the required promptness, the light-responsive contact 150-2 remains closed and its associated relay 175 remains energized for a longer period of time, thereby holding open the reset contact 175-1 for a period which exceeds the two-second time out period of the timer, causing deenergization of the timer relay 185 to signal that an incipient jamming condition exists. Three separate effects are produced. In the first place the contact 185-1 in series with the conveyor drive motor 64 and vacuum pump motor 67 opens so that no further copies are conveyed. Secondly, closing of the contact 185-2 completes a circuit to the device 186, thereby to turn off the photocopy machine so that no further copies are produced. However, in a conventional photocopy machine having a conveyor, the conveyor continues to run for a few additional seconds to clear from the conveyor any copy sheets which are in the "pipeline". In order to insure that such residual copy sheets are not fed into the collator, drop out of the contact 185-3 serves to disable the diverter 27 in the photocopy machine so that such residual copies are deposited in the auxiliary collector tray 30.

Thus with both the collator and photocopy machine fully shut down, the offending copy or copies at the lip of the tray may be removed.

In accordance with one of the features of the invention means are provided for making the tray assembly movable between an operating position in which the lips of the trays are closely adjacent the conveyor and a retracted position in which there is several inches of separation to provide easy access. As shown in FIG. 3 the tray assembly 80 is not fixedly mounted within the housing but is, instead, mounted upon a set of rollers supported on a bracket 190, the rollers being indicated at 191, 192. Access may be provided to the housing by hinging the entire front wall of the collator housing.

It may be noted that while the conveyor is stopped by reason of the incipient jamming condition, the power supplies 114, 117 continue to be energized. Thus when the offending sheet is removed, the light beam will be immediately reestablished. In order to prevent this from restarting the conveyor prematurely, a latching circuit is provided to keep relay 175 energized which, in turn, keeps the reset contact 175-1 open so that the timer 180 is not reset. The latching circuit is connected in parallel with the photocopy shut-off device 186 via a diode 194. Thus even though the light responsive contact 150-2 may open, the circuit through the diode and sealing contact 175-2 keeps the relay 175 in the energized state to prevent the timer from resetting. Prior to describing the start-up procedure, following an incipient jam, reference will be made to a further means, provided in the collator, for detecting, and responding to, an incipient jamming condition.

Thus in accordance with the present invention sensors are provided along the conveyance path, with the sensor-to-sensor spacing being the same as the spacing between the gaps which separate the adjacent copies in a series. For present purposes the gap spacing may be considered as the distance from the center of one gap to the center of the next, the distance being indicated at S in FIG. 9. This figure shows the U-shaped conveyor path in diagrammatic "developed" form in which the path is considered to be straight rather than curved. In this figure the sensors, shown at 201-204 inclusive will be considered to consist of sensitive switches of the normally open type and capable of being "thrown" to the closed condition upon engagement by a passing sheet. The copy sheets are indicated at C.sub.1 - C.sub.5, evenly spaced to define gaps G between them which, in a practiced case, may be on the order of 4 inches. In practicing the invention, by spacing the sensors at the same spacing as the gaps, all of the sensors respond simultaneously to the presence of gaps during normal flow of a series of copy sheets. Means, including a timer, are provided for detecting any failure of all of the sensors to periodically respond to the presence of respective gaps. More specifically in accordance with the invention, simultaneously response of all of the sensors to the passage of respective gaps is utilized to periodically reset a timer. Upon failure of the sensors to respond simultaneously, the timer times out, placing the circuit in a shut down mode as discussed above in connection with the action of the light beam.

In the present collator using a total of four sensors 201-204, the sensor 201 is located right at the entry way adjacent the sensor 155 previously referred to. The sensor 202 is positioned at the bottom of the conveyor assembly, adjacent the turn-around 52. The sensor 203 is positioned approximately half way up the conveyor on the tray side 53 and, finally, the sensor 204 is positioned at the end of the conveyor at the top of the tray assembly.

It would have been possible, in carrying out the invention, to place a further sensor midway between the sensors 201, 202 which would, indeed, have completed the pattern. However, because of the reliability of the illustrated conveyor there is very little likelihood that the transported sheets will get out of time between the sensors 201, 202. Moreover, it is one of the features of the present invention that while the sensors are spaced at gap spacing, it is not essential to have a sensor at each gap position. Consequently, the term "gap spacing" or "reference spacing" as used herein shall be understood to mean the distance S illustrated in FIG. 9 or any integral low order multiple thereof. One advantage of using the present gap sensing arrangement is that a sensor responds to the same degree to "nothing" as it does to an actual gap between adjacent copies. Thus the system is effective regardless of whether the conveyance path is fully, or only partially, occupied with copies. Indeed, the system permits use of a gap sensor 204 which, while forming an integrated part of the sensing system, will not sense any actual inter-sheet gaps until such time as overflow occurs.

We have found that the simplest mode of practicing the invention is to connect all of the normally open sensor switches 201-204 in parallel with one another, with the paralleled circuit being employed to control a relay having a normally closed contact in the reset line of a short period timer, conveniently referred to as a "gap-responsive" timer. Thus we provide a relay 205 having a normally closed contact 205-1 and a normally open contact 205-2 which is used for sealing purposes. The normally closed contact controls a timer 210 having terminals 211, 212 and a reset line 213, the contact being in series with the reset line. The timer controls a relay 215 having a normally open contact 215-1, a normally closed contact 215-2 and a normally open contact 215-3. By reason of these three contacts the same three shut-down functions are performed as discussed above. That is, drop-out of the relay 215 deenergizes the collator, turns off the photocopy machine and drops out the diverter 27 in the photocopy machine so that any residual copies are deposited in the auxiliary collector tray.

Such operation will be apparent upon considering a typical sequence. In normal operation, all of the sensor switches will, because of their spacing, respond at the same instant, momentarily dropping out the relay 205 and momentarily opening the reset contact 201-5. Such contact will, however, be closed again sufficiently promptly to reset the timer 210 which may, for example, be adjusted for a 2 to 3 second time-out. Thus the relay 215 will continue to be energized to maintain the collator in operation.

However, in the event of overlapping copy sheets in the conveyance path, or in the event a copy sheet gets out of time because of slippage or the like, all of the sensors 201-204 will not respond at the same instant. Failure of simultaneous response, because of the parallel connection, maintains the relay 205 energized and causes the contact 205-1 to remain open. As a misplaced copy sheet proceeds along the conveyance path, it will not only affect one of the sensors but it will affect successive sensors so that the contact 205-1 will remain open for a period which is sufficiently long to cause time-out of the timer 210 and drop-out of the relay 215. Opening of the contact 215-1 shuts off the conveyor motor and the vacuum pump motor. Closure of contact 215-2 sends a shut down signal to the photocopy machine, and opening of contact 215-3 drops out the diverter 28 in the photocopy machine so that residual copies are safely disposed of.

After clearing such incipient jamming condition, all of the contacts 201-204 will be in open condition. To prevent premature energization of the machine, sealing voltage is applied via a diode 216, which is connected in parallel with the device 186, to relay 205, the sealing contact 205-2 of such relay being closed, so that the relay 205 is held in notwithstanding the clearing of the offending sheet or sheets, thereby disabling the timer 210 until such time as the collator is intentionally restarted.

It will be seen, then, that the collator responds promptly to an incipient jamming condition in the only two regions where jamming can occur, either along the conveyance path or at the lips of the respective trays. It is to be particularly noted that the collator does not wait for a jam to occur before shutting itself down since this would, in most cases, be too late, but it responds, instead, to incipient conditions and with sufficient promptness so that there is no possibility of pile up of sheets anywhere within the machine.

It is one of the further features of the invention that the collator turns itself off if it remains unused for periods in excess of a minute. More specifically in accordance with the invention, two timers are employed for shut off, a 52 second "shut-off" timer and an eight-second "clearance" timer which are effectively connected in series with one another to provide a total delay of 60 seconds. For intentional shut-off, an "off" push button is effectively interposed between the two timers to provide an 8-second delay sufficient for clearing any copies from the conveyor before the machine finally shuts itself off.

The sensor 220 which is utilized for shut off purposes is mounted at the inlet (FIG. 3) and controls a normally open contact 221 and an associated normally closed contact 222. The contact 221 controls a timer 230 having terminals 231, 232 and a reset line 233, the contact being arranged in series with the reset line. A relay 235 is connected to the output terminal 232 of the timer, serving to control a normally open contact 235-1 as well as normally open and normally closed contacts 235-2 and 235-3. The latter are connected in series with "on" and "off" indicator lamps 236, 237 respectively.

For the purpose of coupling the timer 230 to the second timer for sheet clearance purposes, the relay 235 has a normally open contact 235-4. The latter controls a clearance timer 240 having terminals 241, 242 and a reset line 243. The output terminal of the timer is connected to a relay 245 having a normally open contact 245-1.

In operation, then, the two timers 230, 240 will be assumed to be both turned on, and, as long as a copy sheet is received within a 52 second interval, the sensor control 221 closes, resetting the timer 230, so that both it and the associated timer 240 remain turned on.

However, in the event that the machine is left unattended or if, for any reason, no sheet enters the collator for a period of time in excess of fifty-two seconds, the sensor contact 221 will remain open longer than the period of the timer 230 so that the timer will time itself out, deenergizing the relay 235 and opening the contact 235-4 in the reset line of the timer 240. Eight seconds later such timer will time itself out dropping out the relay 245 and opening contact 245-1. With both contacts 235-1 and 245-1 open, the low voltage AC and DC power supplies will be deenergized. In carrying out the invention deenergization of the DC power supply is caused to turn off the conveyor drive and vacuum pump motor. This is accomplished by a relay 250 which is placed across the output of the DC power supply, as shown, and which controls a normally open contact 250-1 in series with the conveyor drive motor. Consequently, the conveyor drive motor is, by reason of the opening of contact 245-1, and via the relay 250, turned off.

The interposition of the intentional "off" switch between the two timers will be made clear by considering the "off" push button 255 having a normally open contact 255-1 which is connected in series with a relay 256 having a normally closed contact 256-1 and a normally open sealing contact 256-2. The normally closed contact 256-1 is so connected as to functionally bypass the shut-off timer 230. Such bypassing is brought about by connecting the normally closed contact 256-1 in series with the timer terminal 231.

Thus assuming that the machine is in normal operation, with the conveyor running, and that it is desired to turn it off, the push button 255 is depressed closing the contact 255-1 and energizing the relay 256 which immediately seals itself in through contact 256-2 so that the push button may be promptly released. Energization of the relay 256 opens contact 256-1, thereby opening the output circuit of the shut-off timer 230 to drop out the relay 235. The latter opens contact 235-1, but this has no effect since the contact 245-1 in parallel therewith is still closed. Opening of contact 235-2 extinguishes the "on" lamp 236 while closure of contact 235-3 lights the "off" lamp 237. The opening of contact 235-4 causes the eight second timer 240 to time and, eight seconds later, relay 245 drops out, opening contact 245-1, turning off the AC and DC low voltage supplies, and, through relay 250, also turning off the conveyor drive and vacuum. The final eight second time delay provides adequate time for discharge into the receiving trays of any copies which may be in transit.

It is one of the more detailed features of the present invention that the same timer circuit which is employed for automatic shut off is utilized in putting the collator into operation. Thus an "on" push button 257 is provided having a normally open contact 257-1, a second normally open contact 257-2 and a normally closed contact 257-3. The normally open contact 257-1 is effectively connected in parallel with the inlet sensor contact 221. The contact 257-2 serves to turn on the low voltage AC and DC power supplies.

Having understood the manner in which the various portions of the circuit carry out their intended functions, the highly integrated nature of the control circuit will be apparent by considering in brief and summary form a complete cycley beginning with operation of the "on" push button 257. Before such push button is pressed, but with the power plug 110 plugged in, the transformer 113 will operate idly but all of the other components will be deenergized with all contacts in the conditions shown.

Pressing the push button 257 closes contacts 257-1 and 257-2. Closure of the latter energizes the two low voltage power supplies. The resulting energization of relay 250 closes contact 250-1. Closure of contact 257-1 resets (initiates) the 52 second timer 230 energizing relay 235. This closes contacts 235-1 and 235-2, with the latter serving to turn on the "on" lamp 236. Moreover, closure of contact 235-4 energizes the eight-second timer 240 which turns on relay 245, closing contact 245-1, which closure is, however, redundant.

Since, initially, timer 160 is in the "off" condition, the relay 170 which it controls is deenergized so a circuit is completed, through contact 170-2, to the reset coil 171 of the stepping switch, thereby insuring that the latter is restored to its reference starting condition.

Since the AC power supply 114 is energized, the lamp 140, which is connected across it, is lit to create a pencil of light through the lips of the trays. Such light, striking the photocell 143, turns on the associated relay 150, closing contact 150-1 and opening contact 150-2, but operation of such contacts is idle since contact 170-1, in series therewith, is in open condition. However, it is to be noted that this does not prevent the tray traverse timer 180 from being energized, such timer being turned on by reason of the normally closed contact 175-1. The latter energizes relay 185 which closes contact 185-1, so that two contacts in series with the conveyor drive motor are now closed, with a third awaiting closure. Since there is no copy sheet in the system, all of the spaced sensors 201-204 are open so that relay 205 connected thereto is in the deenergized state with contact 205-1 thereon being closed. As a result the gap responsive timer 210 is turned on immediately when the DC power supply is energized, thereby energizing the relay 215 and closing contact 215-1. This completes a circuit to the conveyor drive motor 64 and vacuum pump motor 67 so that the conveyor begins to move at normal speed and with vacuum in readiness.

Energization of the relay 215 has the further effect of closing contact 215-3 so that the diverter 27 in the photocopy machine (FIG. 4) is energized so that any copies produced by the machine are directed out of the discharge opening 23, rather than into the auxiliary tray 30.

Nothing further occurs until such time as the associated photocopy machine is put into operation to produce copy sheets in a closely and evenly spaced series.

The first copy sheet arriving at the entry way 41 promptly closes sensors 155, 201 and 220.

Closure of sensor 155 turns on the series-responsive timer 160, energizing the associated relay 170 and closing contact 170-1. Since contact 150-1 is at this time closed by reason of existence of the light beam, the effect is to apply current to the stepping coil 135 so that the stepping switch is advanced one step, making contact with the first of the step contacts to energize the first solenoid winding 107 to place the first deflector 101 in its deflecting position in readiness for receipt of the first sheet at the first tray.

At the same time, closure of the sensor switch 201 complete a circuit to the associated relay 205, opening the normally closed contact 205-1 in the reset line of the gap responsive timer 210 so that the timer starts its timing function.

Before the timer 210 can time out (which requires 3 seconds) the sensor switch 201 drops into the gap following the first sheet. This drops out the associated relay 205, momentarily closing the contact 205-1, and resetting the timer 210.

Moreover, arrival of the leading edge of the second sheet at the sensor 155 causes the timer 160 to be reset before it has had an opportunity to time out. Thus the timers 210 and 160 are constantly reset, the former by the gaps between the successive copy sheets and the latter by the leading edges of the successive copy sheets. Thus the conveyor transports a series of evenly spaced copy sheets along its "downside" 51, around the turn-around 52 and up the tray side 53.

When the leading edge of the first copy sheet strikes the first diverter (FIG. 5) the sheet is cammed away from the transport belts and into the first tray 81. This breaks the light beam causing the photocell 143 to deenergize the associated relay 150 which drops out to close the contact 150-2, thereby energizing the associated relay 175 to open contact 175-1 in the reset line of timer 180 so that the timer begins its timing function. However, provided that the sheet promptly clears the light beam, the photocell turns on its relay 150, reopening contact 150-2 which permits the relay 175 to drop out, so that the timer 180 is promptly reset and is thus ineffective.

As stated, breakage of the light beam by the first sheet, and its subsequent restoration, causes momentary opening of the contact 150-1 which is in series with the stepping coil so that the coil is pulsed to advance the stepping switch from the first contact to the second, restoring the first deflector 101 to its idle position and actuating the second deflector 102, so that the next sheet on the conveyor, which is the second sheet, is promptly deposited in the second tray.

Such sequence continues, with each copy sheet, by brekage of the light beam, serving to index the stepper switch so that corresponding copy sheets are deposited, one by one, in quick succession in corresponding trays.

During normal flow of the copy sheets, the spaced sensor switches 201-204 are periodically and simultaneously opened by the gaps between the sheets so that the gap responsive timer 210 is constantly reset before it can time out. Thus the copy sheets are commutated to respective trays until there is a hiatus in the series. Such hiatus is detected by failure of the sensor switch 155 to reclose within a period of three seconds. Such failure, by timing out of timer 160 and energization of relay 170, causes the stepping switch to be reset to its reference starting condition so that when the next copy sheet arrives it is directed to the first tray, and the commutation process is repeated.

Failure of any copy sheet to enter its prescribed tray promptly, by breakage of the light beam for more than the permitted amount of time, causes the reset line of the tray traverse timer 180 to be held in open condition until the timer times out, thereby dropping out the relay 185 to put the circuit in the shut down mode, resulting in stopping of the conveyor, turning off of the associated photocopy machine, and diversion of any residual copies therein into the auxiliary tray 30.

Similarly, in the event of any overlap or other mis-timing of the gaps between adjacent sheets, the spaced sensor switches 201-204 will not open simultaneously and periodically so that the relay 205 will continue to be energized and the contact 205-1 thereof, which is in the reset line of timer 210, will remain open beyond the interval of time-out of the timer 210, causing the latter to drop out the relay 215, which is also effective to put the circuit in the shut down mode.

Assuming normal operation, failure of the sensor 220 to be actuated for a period of 52 seconds, as previously discussed, causes timing out of the shut down timer 230 and the eight second, or "clearance", timer 240 for automatic shut-down when the machine is unused or unattended.

Finally, the machine is turned off during normal operation by pressing the "off" push button 255 which, by overriding the 52 second timer, starts the timing function of the 8-second timer with the result that any copies in transit are deposited in successive trays followed by shut down of the machine.

While the invention has been described in connection with a preferred embodiment, reasonable changes may be made without departing from the invention. For example, although an electro-mechanical stepping switch has been disclosed to facilitate understanding the operation, it will be understood that a commutating device of the solid state type, and capable of reset, may quite readily be substituted. Also while we prefer to use simple, normally-open gap sensor switches at reference spacing, normally closed switches might be substituted, changing the circuit from parallel to series and with use of an inverting relay. Indeed, the illustrated switch type sensors may be replaced by a light beam and photo cell with mirrors arranged so as to cause the light beam to traverse the sheet path at positions which are spaced at the reference spacing. This would make it unnecessary for the sheets to do the work of switching which would be particularly useful when making copies on thin paper stock.

While the collator of present design is intended to be constructed as a unit for coupling to a photocopy machine, with the outlet of one registered with the inlet of the other, it will be understood that the two machines may, if desired, be integrated within the same housing, in which case the path may be continuous and the two "openings" may be considered to be at any point along the transfer path.

It is convenient to construct the device as illustrated, with an elongated U-shaped conveyance path since this permits acceptance of copy sheets at a point near the top surface of a photocopy machine and permits commutated upward distribution to vertically stacked trays. It will be apparent, however, that the invention in certain of its aspects is not limited to this "vertical" arrangement and that the term "vertical" as used herein is intended to be interpreted in a relative fashion. When the invention is used with other than vertically stacked trays, corresponding changes will be required in the shape of the conveyance path.

Claims

What is claimed is:

1. In a collator intended for close coupling into an office photocopy machine having means for delivery of multiple copies of an original document in a closely and evenly spaced series comprising, in combination, a frame, a tray assembly formed of a stacked tier of trays and set of commutated deflectors for deflecting copy sheets into the respective trays in sequence, a driven copy sheet conveyor for receiving copies from the photocopy machine and for conveying them to the tray assembly along an extended conveyance path in an evenly spaced series defining gaps between adjacent copy sheets and with the gaps having a reference spacing, a set of gap sensors arranged along the conveyance path for sensing the gaps, the sensors being spaced at reference spacing so that periodically all of the sensors will have momentary simultaneous response to presence of respective gaps thereby to indicate that the copy sheets are all being normally conveyed, and means triggered by failure of any gap sensor to have periodic response simultaneously with the other sensors for automatically shutting down the conveyor, the sensors being in the form of switches which are momentarily opened upon passage of gaps between adjacent sheets and in which all of the switches are connected in parallel, circuit means responsive to failure of the parallel connected circuit to periodically open for producing an output signal, and means responsive to the output signal for shutting down the conveyor.

2. A collator intended for close coupling to an office photocopy machine having means for delivering multiple copies of an original document in a closely and evenly spaced series comprising, in combination, a housing having an inlet for registering with an outlet on the photocopy machine, a tray assembly formed of a stacked tier of trays with alined entrance lips, a copy sheet conveyor for conveying copies in a closely spaced series from the inlet of the collator along a conveyor path closely adjacent the lips of the trays, deflectors at the lips of respective trays and capable upon actuation of diverting an approaching copy sheet into the associated tray, means for commutating the deflectors so that successive copies are deposited in successive trays starting with the first, an automatic shut-off timer having a time delay on the general order of 52 seconds and having a reset line, a clearance timer having a time delay on the order of 8 seconds and having a reset line, the two timers being effectively connected in series with one another so that timing out of the shut-off timer initiates timing in the clearance timber, means controlled by timing out of the clearance timer for turning off the conveyor, a sensor adjacent the inlet and connected to the reset line of the shut-off timer for sensing arrival of a copy sheet at the inlet so that the shut-off timer is ineffective as long as the period of adjacent copy sheets is less than the time delay for which it is set, but with a period of greater duration serving to initiate timing by the clearance timer so that upon passage of an additional eight seconds the conveyor is turned off, and means including a manual "off" control effectively interposed between the shut-off timer and the clearance timer for directly initiating timing by the clearance timer so that the conveyor is turned off approximately 8 seconds after pressing of the "off" control thereby to insure that any copies being conveyed within the collator by the conveyor have an opportunity to clear the conveyor before the latter stops its motion.