US3152681A

US3152681A - Code responsive systems

Info

Publication number: US3152681A
Application number: US112707A
Authority: US
Inventors: Richard J Byrnes; James T Pence; Barney O Rae
Original assignee: Cutler Hammer Inc
Current assignee: Cutler Hammer Inc
Priority date: 1961-05-25
Filing date: 1961-05-25
Publication date: 1964-10-13
Anticipated expiration: 1981-10-13
Also published as: GB971347A

Description

Oct. 13, 1964 R. J. BYRNEs E'rAL 3,152,681

' com: RESPONSIVE SYSTEMSv Filed May 25. 1961 4 Sheets-Sheet l CON VES/OE Laax/El 6 Oci- 13 1964 R. J. BYRNEs ETAL 3,152,681

CODE RESPONSIVE SYSTEMS Oct. 13, 1964 R. J. BYRNr-:s ETAL. 3,152,681

coni: RESPONSIVE sysfrEMs Filed May 25, 1961 4 sheets-sheet s L cc L2 3o I I 32 8 9 l 1/ 7 a .VA'AVAV I *'{A'A' I 34 L T5 36 G, H9 Eff D I 7 Ocf- 13 1964 R..J.-BYRNEs ETAL y 3,152,681

conE RESPONSIVE SYSTEMS Filed May 25, 1961 4 Sheets-Sheet 4 Q. 6 L] cc/ L2 /O COMMON 'en o IVO, 2

United States Patent() 3,152,681 CODE RESPONSIVE SYSTEMS Richard J. Byrnes, West Allis, James T. Pence, Milwaukee, and Barney O. Rae, Shorewood, Wis., assignors to Cutler-Hammer, Inc., Milwaukee, Wis., a corporation of Delaware Filed May 25, 1961, Ser. No. 112,707 8 Claims. (Cl. 198-38) This invention relates to code responsive systems and more particularly to control systems which respond to control signals from code responsive moving-article detectors and control the routing of the articles.

While not limited thereto, the invention is especially applicable to conveyor systems and the like for controlling the routing of articles or article carriers.

William D. Brand and Harold S. Montgomery copending application Serial No. 8,628, filed February l5, 1960, now Patent No. 3,034,634, issued May l5, 1962, relates to a coded card controlled system for controlling the routing of articles or article carriers and employs a contact linger type detecting and identifying device. This invention relates to improvements thereover and more particularly relates to control systems of the universal type which are usable with either contact finger type code detectors or with proximity type code detectors or combinations thereof.

An object of the invention is to provide improved code responsive systems.

A more specitic object of the invention is to provide improved control systems operable with and responsive to diverse types of code sensing devices.

Another specific object of the invention is to provide improved routing control systems which are arranged to reduce to a minimum the misdirection of articles in the event of failure and reestablishment of the system power supply.

Another specific object of the invention is to provide improved routing control systems which are arranged so that it is impossible for an article destined for one station to be diverted to a preceding station.

Another object of the invention is to provide improved routing control systems having or logic code functions to render the same responsive to either one of two coded article detector signals.

Another object of the invention is to provide improved routing control systems having and logic code functions to render the same responsive to two simultaneously occurring coded article detector signals.

Another object of the invention is to provide improved routing control systems having a plurality of groups of article detecting devices for a respective plurality of routn ing control circuits wherein one of the article detecting devices is common to the plurality of groups thereof.

A further specific object of the invention is to provide improved transistor controlled routing control systems operable immediately after initiating the diverting of an article to reset into readiness for controlling the diverting of another article.

Other objects and advantages of the invention will hereinafter appear.

According to the invention, there are provided article routing control systems for automatically routing articles traveling along a main conveyor to predetermined destination branch conveyors in accordance with predetermined codes carried by such articles. Articles or article carriers such as trays or the like carry code-bearing cards which may be of the contact bridging type or may have electrically conducting elements thereon in coded positions for activating proximity detecting devices. A card reader is mounted at the side of the main conveyor for reading the codes on the cards. The card reader may have contact fingers for sensing the coded cards or may have proximity probe devices for detecting the passage of coded conducting members thereby. Control circuits readily connectable to either of the aforementioned types of readers are provided for storing the read code until the article approaches its destination branch conveyor. At this point, the article operates ya switch to utilize the stored code to operate a diverter to turn and divert the article to the destination branch conveyor and to operate the branch conveyor to move such article away from the diverting junction. Another switch on the branch conveyor is engaged by the article to restore the system to normal condition and to stop the branch conveyor. The system is constructed and arranged so that it is physically impossible to divert an article intended for a succeeding branch conveyor to a preceding branch conveyor and to reduce to a minimum the misdirection of articles in the event of system power failure.

The above mentioned and other objects and advantages of the invention and the manner of obtaining them will best be understood by reference to the following detailed description of exemplary embodiments of routing control systems taken in .conjunction with the accompanying drawings, wherein:

FIGURE 1 is a top view of an article conveyor and diverter control system constructed in accordance with the invention;

FIG. 2 is a circuit diagram of a diverter control system operable by a single proximity detector device to control diversion of articles from a main conveyor to a branch conveyor;

FIG. 3 is a .circuit diagram of a diverter control system having an and logic circuit operable in response to simultaneous signals from two proximity detector devices.

FIG. 3a is a simplified illustration of the circuit of FIG. 3;

FIG. 4 is a circuit diagram of a diverter control system having an or logic circuit operable in response to either one of two proximity detector devices;

FIG. 4a is a simplified illustration of the circuit of FIG. 4;

FIG. 5 is a circuit diagram of a diverter control system having an or logic circuit operable in response to either one of two contact linger detector devices;

FIG. 6 is a circuit diagram of a routing control system having three proximity detector devices for controlling two diverter control systems;

FIG. 6a is a simplified illustration of the system of FIG. 6; and

FIG. 7 is a circuit diagram of a routing control system having three contact fingers for controlling two diverter control systems.

Referring to FIG. l, for illustrative purposes, there is shown a main conveyor 2 having a pair of branch conveyors 4 and 6 extending laterally in parallel relation or the like from one side of the main conveyor. Diverter mechanisms 8 and 10 are mounted at the junctions between main conveyor 2 and the respective branch conveyors 4 and 6. Each such diverter mechanism is operable when actuated to its diverting position shown in dotted lines to turn and divert an article or article carrier such as tray 12 or the like onto the associated branch conveyor. These diverter mechanisms are operated into their diverting positions by suitable means such as iluid means or electromagnetic means having operators such as solenoids or the like and are spring returned to their normal non-diverting positions. Each such diverter mechanism comprises the aforementioned electromagnetic operator mounted at the side of main conveyor 2 and a row of skate wheels or the like for diverting articles.

For a more detailed disclosure of the diverter mechanism, reference may be had to Richard I. Byrnes, Robert N. Eck, Clyde F. Robbins and Norbert Sadowski copending application Serial No. 37,611 led June 2l, 1960 now Patent No. 3,058,567, dated October 16, 1962.

A code reader 14 is mounted at one side of main conveyor 2 ahead of the first diverter mechanism 8. The function of the `code reader is to detect and identify the code on a card 16l1eld in a slot in the side of tray 12 and to control diversion of the tray to its predetermined branch conveyor destination. While a card 16 is shown for exemplary purposes, the code can be applied by other means to an article or article carrier. Card 16 may be of the laminated type having an electrically conducting inner layer and electrically insulating outer layers. The insulating layer exposed to the code reader is provided with a plurality of cut-out portions in coded positions to expose the conducting layer to engagement by contact fingers mounted on the code reader whereby to electrically connect the contact fingers to one another. For a more detailed description of the contact finger type code reader and laminated card, reference may be had to the aforementioned William D. Brand and Harold S. Montgomery `copending application.

Alternatively, code reader 14 may be of the proximity switch type comprising a plurality of detector members or proximity probes extending therefrom a short distance over the side of the main conveyor. To operate the proximity probes, card 16 is provided in predetermined coded locations thereon with metallic elements of electrically conducting material such as copper or the like. When a coded article passes the reader such that the conducting elements match the positions of the probes on the reader, a control is initiated to divert the tray to its pre-determined branch conveyor destination. For a more detailed description of the proximity probe, reference may be had to Richard I. Byrnes, Walther Richter, Robert W.y Spink and Merle R. Swinehart copending application Serial No. 112,716, filed May 25, 1961.

Limit switches LS1 and LS2 are mounted on main conveyor 2 immediately ahead of the respective diverter mechanisms 8 and 10. The function of each such limit switch when operated by a moving tray is to cause actuation of the associated diverter mechanism into its diverting position provided the .code reader has indicated that the associated branch conveyor is its correct destination. Limitfswitches LS1 and LS2 provide gating for proper diverter operation such that article carriers in close proximity with each other are not misdirected. Another functionof each such limit switch is to start operation of the associated branch conveyor.

Limit switches LS3 and LS4 are mounted on the respective branch conveyors 4 and 6 at least one tray length from the main conveyor. The function of each such limit switch when operated by a diverted tray is to restore the associated control circuit to normal condition and to maintain operationl of the associated branch conveyor until the diverted tray has cleared such limit switch.

Referring to FIG. 2, there is shown a control circuit enclosed in broken lines and indicated generally as CC. Control circuit CC is supplied with alternating current power through power supply lines L1 and L2 and is provided with four terminals a, b, c and d adapted for connecting a code discriminating device of a selected type thereto as hereinafter described.

The code discriminating device shown in FIG. 2 comprises a proximity probe PP enclosed in broken lines and provided with terminals A, B, C, D and E adapted for connecting the same in a variety of ways to one or more control circuits CC and to other proximity probes as hereinafter more fully described. A portion of the circuit of proximity probe PP is shown in FIG. 2. The reference `characters identifying the elements of the proximity probe :are similar to those employed in the aforementioned Richard J. Byrnes, Robert W. Spink, Walther Richter and Merle R. Swinehart application. Proximity probe PP comprises a transistor T4 having an emitter-base junction E-B which is normally controlled to effect current flow through emitter-collector junction E-C thereof. The transistor is supplied with unidirectional voltage from terminals A and E so that the current flowing through the transistor also flows through resistor R7 in series. Terminals B, C and D are output control terminals and terminal B is utilized in the connection shown in FIG. 2. When transistor T4 conducts, it effectively shunts terminals A and B to transmit a first control to control circuit CC. When the proximity probe senses conducting material, transistor T4 is rendered non-conducting to transmit a second control to control circuit CC as hereinafter more fully described.

Control circuit CC is provided with low voltage means which responds to the `control received from the proximity probe to initiate a further control function. This low voltage means comprises a transistor amplifier AMP enclosed in broken lines and a low voltage relay LVR connected to the output of the amplifier. The low voltage circuit is supplied with power from a transformer TR having its primary winding connected across lines L1 and L2. The secondary winding of transformer TR is connected to alternating current supply terminals 18 and 20 of amplifier AMP. The amplifier is of the static type which is adapted for potting in thermo-setting material and is provided externally thereof with

control terminals

22, 24 and 26 and an additional terminal 28. Terminal 28 and terminal 2i) constitute unidirectional current output terminals for the amplifier.

Amplifier AMP is provided with a rectifier circuit for providing unidirectional voltage to a transistor T5. This rectifier circuit comprises a unidirectional diode RTS connected from terminal 18 to emitter E of transistor T5, collector C of the transistor being `connected to output terminal 28. Amplifier AMP is provided with a filter circuit for filtering the rectified voltage. This filter circuit comprises a capacitor C1 connected from the junction of diode RTS and emitter E to output terminal 20 and a pair of voltage divider resistors RS and R9 connected in series across capacitor C1. The junction of resistors R8 and R9 is connected to amplifier terminal 22 and therethrough to terminal a of control circuit CC. Emitter E of transistor T5 is connected to amplifier terminal 24 and therethrough to terminal b of control circuit CC. Base B of transistor T5 is connected to amplifier terminal 26 and therethrough to terminal c of control circuit CC. A control resistor R10 is connected between emitter E and base B of transistor T5. The operating coil of relay LVR is connected across output terminals 28 and 20 of the amplifier. A unidirectional diode RT6 is connected across output terminals 2t) and 28 to provide a discharge path for the induced voltage of the operating coil of relay LVR.

Control circuit CC is also provided with means for maintaining relay LVR energized after the input control to amplifier AMP terminates. This means comprises a maintaining circuit for the operating coil of relay LVR in shunt of amplifier AMP and extending from terminal 24 through a normally closed contact 1 of a control relay CR and a normally open contact 1 of relay LVR to terminal 28.

There is also provided in control circuit CC means for storing the input control signal until it is utilized when the tray reaches the diverting device associated with the destination branch conveyor. This means comprises control relay CR and circuits therefor. Relay CR is provided with an operating circuit extending from line L1 through a normally closed contact 1 of limit switch LS1, a normally open contact 2 of relay LVR and the operating coil of relay CR to line L2. -Relay CR is also provided with a self-maintaining circuit extending from line L1 through a normally open contact 2 of relay CR, a normally closed contact 1 of a relay DCB and the operating coil of relay CR to line L2.

Control circuit CC is also provided with means responsive to a moving article leaving the code reader for controlling routing of the article to the destination indicated by the code reader. This means comprises a pair of diverter control relays DCA and DCB and circuits therefor and limit switch LS1. Relay DCA is provided with an operating circuit extending from line L1 through contact 2 of relay CR, a normally open ycontact 2 of limit switch LS1 and the operating coil of relay DCA to line L2. Relay DCA is also provided with a self-maintaining circuit extending through a normally open contact 1 thereof in shunt of contact 2 of relay CR. Relay DCB is provided with an operating circuit extending from line L1 through contact 2 of relay CR, contact 2 of limit switch LS1, a normally open contact 2 of relay DCA and the operating coil of relay DCB to line L2. A counter CTR is connected for energization in parallel with the operating coil of relay DCA for registering the number of articles assigned by the code reader to the branch conveyor destination. A diverter DIV is connected for energization through a normally open contact 3 of relay DCB across lines L1 and L2.

Control circuit CC is further provided with means under the control of the aforementioned routing control means for controlling operation of the branch conveyor. This means comprises a branch conveyor control relay CCR, a motor forward contactor F, a branch conveyor motor BCM, limit switch LS3 and circuits therefor. Relay CCR is provided with an operating circuit extending from line L1 through contact 1 of relay DCA, a normally open contact 2 of relay DCB and the operating coil of relay CCR to line 2. A self-maintaining circuit extends from line L1 through a normally closed contact 1 of limit switch LS3, a normally open contact 1 of relay CCR and the operating coil of relay CCR to line L2. Forward contactor F is provided with an operating circuit extending from line L1 through a normally closed stop switch ST, a normally open contact 3 of relay CCR, a normally closed contact 2 of a reverse contactor R and the operating coil of forward contactor F to line L2. A maintaining circuit for contactor F extends through a normally open Contact 2 of limit switch LS3 in shunt of contact 3 of relay CCR.

There are also provided manual means for operating motor BCM comprising a motor forward operating control manual switch FOR connected in shunt of contact 3 of relay CCR for operating forward contactor F independently of relay CCR and limit switch LS3.

A reverse contactor R is provided for operating motor BCM in the reverse direction. Contactor R is provided with an operating circuit extending from line L1 through stop switch ST, a normally closed contact 2 of relay CCR, a manual reverse switch REV, the operating coil o contactor R and a normally closed contact 1 of contactor F to line L2. A self-maintaining circuit for contactor R extends through its normally open contact 1 in shunt of manual switch REV.

The operation of the system of FIG. 2 will now be described. A reduced voltage is applied by transformer TR to amplier AMP. This voltage is rectified by diode RTS and filtered by the filter network comprising capac itor C1 and resistors R3 and R9. The resulting ltered unidirectional voltage is applied across the emitter-col lector junction of transistor T 5 and the operating coil of relay LVR in series. Normally relay LVR remains deenergized because transistor T5 does not conduct. This is for the reason that the base voltage of transistorTS is at the same level as the emitter voltage thereof. Normally current flows from the left-hand end of the secondary winding of transformer TR through terminal 1S, diode RTS, terminals 24, b :and A, the emitter-collector junction of transistor T4, resistor R7 and terminals E, d and 20 to the right-hand end of the secondary winding of transformer TR. As a result, transistor T4 functions in effect as a closed switch and shunts resistor R10 and diode RT3. Consequently, transistor T5 remains nonconducting. As transistor T4 when conducting is not a perfect short circuit but has a small voltage drop thereacross, diode RTS is employed in series with resistor R10. The forward voltage drop of diode RTS is substantially equal to the voltage drop across the emitter-collector junction of transistor T4 to maintain the base voltage of transistor T5 at the same level as the emitter voltage thereof.

When proximity probe PP senses :a conducting element passing thereby, transistor T4 is momentarily rendered non-conducting and functions in effect as an open switch to interrupt the shunt circuit across resistor R10. As a result, current ows through resistor R10 and diode RTS. The voltage drop across resistor R10 renders the Voltage at base B negative relative to the voltage at emitter E of transistor T5 to cause current flow through the emittercollector junction of transistor T5 to energize the operating coil of relay LVR. Relay LVR closes contact 1 to maintain energization thereof through contact 1 of relay CR after transistor T5 is rendered non-conducting. As will be apparent, as soon as the conducting element passes proximity probe PP, transistor T4 is -again rendered conducting and shunts resistor R10 to render transistor T5 non-conducting.

Relay LVR also closes its contact 2 to energize the operating coil of relay CR through contact 1 of limit switch LS1. Relay CR closes its contact 2 to complete a self-maintaining circuit through contact 1 of relay DCB. Relay CR also opens its contact 1 to interrupt the maintaining circuit of relay LVR. Amplilier AMP and relay LVR are now restored to their normal condition into readiness to receive another input signal. The input control signal that has been received is stored on relay CR until the tray which has been sensed by code reader 14 in FIG. l engages limit switch LS1.

Engagement of limit switch LS1 by the tray causes opening of contact 1 land closure of contact 2 thereof. Contact 1 of limit switch LS1 interrupts the original energizing circuit of relay CR .to prevent registration of another input signal thereon until the signal stored thereon has been used. Contact 2 of limit switch LS1 completes an energizing circuit through contact 2 of rel'ay CR for relay DCA and counter CTR in parallel. As a result, counter CTR counts the tray assigned to the branch conveyor. Relay DCA closes its contact 1 to complete a self-maintaining circuit in shun-t of contact 2 of relay CR and closes its contact 2 to energize relay DCB. Relay DCB opens its contact 1 to interrupt the maintaining circuit of relay CR to cause relay CR to restore. Relay CR yrecloses contact 1 and reopens contact 2. The signal stored on relay CR has now been transferred to relays DCA and DCB. Relay DCB also closes its contact 3 to energize diverter DIV which is similar to diverter mechanism S in FIG. 1 thereby to actuate the diverter wheels to the dotted line position. As a result, the tray is turned and diverted to the branch conveyor. Relay DCB also closes its Contact 2 to energize relay CCR through contact 1 of relay DCA. Relay CCR closes its contact 1 to complete a self-maintaining circuit through contact 1 of limit switch LSS. Relay CCR also opens its contact 2 to prevent energization of reverse contactor R and closes its Contact 3 to energize forward contactor F through stop switch ST and Contact 2 of contactor R. Contactor F closes suitable contacts to operate motor BCM in the forward direction whereby the branch conveyor carries the tray therealong toward limit switch L83.

As isoon as the tray disengages limit switch LS1, contact 1 :thereof recloses to render relay CR ready to store another input signal. Limit switch LS1 also reopens contact 2 to interrupt energization of relays DCA and DCB and counter CTR. Relay CCR, however, remains energized through its maintaining circuit until the diverted tray engages limit switch LS3.

When the tray engages limit switch LS3, contact 1 thereof opens and contact 2 thereof closes. Contact 2 of limit switch LS3 completes an energizing circuit for contacter F in shunt of contact 3 of relay CCR. Contact 1 of limit switch LS3 interrupts energization of relay CCR to restore the latter. As will be apparent, contact 2 of limit switch LS3 maintains the branch conveyor running following restoration of relay CCR until the tray clears such limit switch thereby to move the tray away from the diverting junction. When the tray disengages limit switch L83, contact 1 thereof recloses without effect and contact 2 thereof reopens to deenergize contacter F and stop the branch conveyor.

If it is desired to run the branch conveyor under manual control, switch FOR is pressed to energize contactor F through stop switch ST and contact 2 of contactor R. As a result, the branch conveyor runs in the forward direction until switch FOR is released to allow it to reopen. Depression of manual switch REV energizes contacter R through stop switch ST, contact 2 of relay CCR and contact 1 of contactor F thereby to cause motor BCM to run the branch conveyor in the reverse direction. Contacter R closes its contact 1 to complete a 'self-maintaining circuit in shunt of switch REV to maintain the branch conveyor running in the reverse direction following release of switch REV until stop switch ST is pressed to stop the motor or until relay CCR is energized in response to the routing of a tray to the branch conveyor. If the branch conveyor is running in the reverse direction when a tray is automatically being routed thereto, relay CCR opens its contact 2 to interrupt the circuit of contractor R and closes its contact 3 as hereinbefore described to energize contacter F. As a result, the branch conveyor operation is automatically changed from reverse operation to forward operation to prevent the incoming tray from jamming at the diverting junction.

Referring to FIG. 3, there is shown a diverter control circuit having mcdied input control means. In FIG. 3, reference characters like those in FIG. 2 have been ernployed for like parts. Control circuit CC is similar to that in FIG. 2 and only a portion thereof has been shown in detail to avoid duplication. The modification in FIG. 3 comprises an and logic circuit, that is, two proximity probe devices PPI and FP2 are connected to control circuit CC iand to one another in such a manner that the control circuit operates only in response to a signal from devices PP1 and FP2. In other Words, operation of the control circuit requires concurrent output control from both of the probe devices and the control circuit cannot be operated by either probe device alone.

For this purpose, probe device PPI is connected to control circuit CC in the same manner as probe device PP was connected in FIG. 2. That is, terminals A, B and E of probe device PP1 are connected directly to terminals b, c and d of the control circuit, respectively. Terminals A, B and E of probe device PP2 are also connected to terminals b, c and d, respectively. In addition, terminal D of probe device PPI is connected to terminal D of probe device PPZ.

In FIG. 3, transistors T4 of probe devices PPI and PPZ normally conduct current in the manner hereinbefore described and stop conducting when the probe device senses conducting material adjacent to the tip of Ithe probe. Let it be assumed that probe device PPI alone senses conducting material to render transistor T4 thereof non-conducting. Current iiows from the positive side of the direct current source through terminal b,

terminal A and transistor T4 of probe device FP2 and then in parallel branches to the negative side of the direct current source. One branch extends through resistor R7 and terminal E of probe device FP2 to terminal d of control circuit CC and the other branch extends through terminal D Aof probe device PP2 and terminal D and resistor R7 and terminal E of probe device PPI to terminal d of the control circuit. This maintains resistor R10 ef -fectively shunted so that transistor T5 does not respond.

8 However, if transistors T4 of both probe devices are rendered non-conducting simultaneously, the shunt across resistor Riti is interrupted to cause control circuit CC to respond as hereinbefore described.

The circuit of FIG. 3 is shown in simpliiied form in FIG. 3a wherein transistors T4 of probe devices PP1 and PPZ are represented as switches SW1 and SW2, respectively. It will be apparent that connection of terminals D of the probe devices together connects switches SW1 and SW2 in parallel across resistor R10. Therefore, to obtain current ow through resistor R10, it is necessary to open both switches SW1 and SW2 at the same time.

Referring to FIG. 4, there is shown a diverter control circuit having modified input control means. In FIG. 4, reference characters like those in FIG. 3 have been employed for like parts. The modification in FIG. 4 cornprises an or`logic circuit, that is, two proximity probe devices PPI tand PP?. are each connected to control circuit CC in the isame manner as shown in FIG. 2 and either probe device is capable of controlling circuit CC. The modification in FIG. 4 differs from the arrangement of FIG. 3 in that the connection between terminals D of the probe devices has been omitted.

The circuit of FIG. 4 is shown in simplilied form in FIG. 4a. Referring to FIG. 4a, it will be apparent that when switches SW1 and SW2 corresponding to transistors T4 of probe devices PPI tand PFZ, respectively, are closed, current iiows through these switches in parallel to shunt resistor R10. If switch SW1 is opened, current continues to flow from the positive side of the source through switch SW2 and resistor R7 of probe device PPZ to the negative side. However, opening of switch SW1 causes current iiow through resistor R10, diode RTS and resistor R7 of probe device PPI to the negative side. Also, if switch SW2 is opened While switch SW1 remains closed, current flows from the positive side of the source through resistor R10 and diode RTS and resistor R7 of probe device FP2 to the negative side of the source. Diodes RT3 isolate the probe devices from one another so that either probe device is capable of controlling transistor T5. Of course, concurrent opening of switches SW1 and SW2 also causes transistor T5 to become conducting.

Referring to FIG. 5, there is shown a diverter control circuit having different input control means. In FIG. 5, reference characters like those in FIG. 2 have been employed for like elements. The circuit in FIG. 5 comprises an or logic circuit arrranged so that either one of two input control signals is capable of controlling control circuit CC. Terminals F and G of contact linger code reader 3d 'are respectively connected to terminals a and c of control circuit CC to form a first input connection. Terminal I-I of code reader 3i) is connected to terminal G thereof so that terminal I-I forms with terminal F a second input connection.

Code reader 30 is similar to the code reader disclosed in the aforementioned William D. Brand and Harold S. Montgomery copending application and comprises a supporting member or base 32 mountable at the side of a conveyor lso that

electrical contact fingers

34, 36 and 38 extend over the conveyor. A coded card 40 is held in a slot in a tray or the like fand is engaged by the contact lingers as the tray is conveyed past the reader station. Card 4d may be of the laminated type or the like having an electrically conducting inner layer and electrically insulating outer layers. The insulating layer exposed to the contact fingers is provided with cutout portions in coded positions to expose the `conducting layer for engagement by the contact lingers whereby to electrically connect two or more of the contact lingers. As will :be apparent, in the arrangement shown in FIG. 5, contact linger 34 forms a common connection and connecting thereof either to contact linger 36 or contact finger 38 causes operation of transistor T5.

Connection of

contact fingers

34 and 36 completes a circuit frompositive voltage through resistor R10, terminals c and G, contact finger 36, card 40, contact finger 34, terminals F and a and resistor R9 to the negative Voltage. As a result, the voltage drop across resistor R10 is applied to the emitter-base junction to render base B negative relative to emitter E thereby to cause transistor T to conduct and energize relay LVR. Connection of

contact fingers

34 and 38 completes a similar circuit therethrough to control transistor T5. Of course, connection of

contact fingers

34, 36 and 33 to one another also causes transistor T5 to conduct. Comparison of FIGS. 4 and 5 will show that control circuit CC is of the universal type and is adapted to function with either the proximity probe type sensing devices of FIG. 4 or the contact linger type sensing devices of FIG. 5.

Referring to FIG. 6, there is shown a routing control system having three proximity probe devices PPI, PP2 and PPC, probe device PPC being common to the other two probe devices. These three probe devices are connected for selectively controlling two control circuits CCI and CC2. In FIG. 6, reference characters like those in FIGS. `2, 3 and 4 have been employed for like elements.

Terminals A of probe devices PPI, PP2 and PPC are connected to one another and to terminals b of both control circuits CCI land CC2. These connections provide positive voltage to the three probe devices in parallel and connect the positive sides of the sources to one another. Terminals E of probe devices PPI, PP2 and PPC are connected to one another and to terminals d of control circuits CCI and CC2. These connections provide negative voltage to the three probe devices and connect the negative sides of the sources to one another. Terminal B of probe device PPI is connected to terminal c of control circuit CCI as in FIGS. 2, 3 and 4. Terminal B of probe device PP2 is similarly connected to terminal c of control circuit CC2. These connections constitute control connections from probe devices PPI and PP2 to the respective control circuits CCI and CC2. Terminals C of probe devices PPI and PP2 are connected to one another and to terminal D of probe device PPC. These connections render common probe device PPC operable with either probe device PPI or PP2 to operate control circuit CCI or CC2. That is, when probe devices PPI and PPC sense conducting material and render their transistors T4 non-conducting, control circuit CCI is operated. Similarly, probe devices PP2 and PPC operate control circuit CC2.

FIG. 6a shows the circuit of FIG. 6 in simplied form and transistors T4 of the probe devices are represented therein by switches SWI, SW2 and SWC. If switch SW1 alone is opened, current continues to flow through switch SWC, diode RT4 and resistor R7 of probe device PPI in shunt of resistor R of control circuti CCI so that transistor T5 of this control circuit remains non-conducting. Also, opening of switch SW2 has no eiiect because current fiows through switch SWC, diode RT4 has no effect because current ows through switch SWC, diode RT4 and resistor R7 of probe device PP2 in shunt of resistor R10 of control circuit CC2. However, when contacts SW1 and SWC open at the same time, current flows through resistor R10 of control circuit CCI and diode RT3 and resistor R7 of probe device PPI to render transistor T5 of this control circuit conducting. Diode RT4 of probe device PP2 isolates this probe device from control circuit CCI. When switches SW2 and SWC open at the same time, current flows through resistor R10 of control circuit CC2 and diode RT3 and resistor R7 of probe device PP2 to render transistor T5 of control circuit CC2 conducting. Diode RT4 of probe device PPI isolates this probe device from the control circuit CC2 so that it cannot interfere with operation thereof. It will be apparent that probe device PPI and common probe device PPC sense a first code to operate control circuit CCI which may control routing of articles to branch conveyor 4 in FIG. I. Also, probe device PP2 and common probe device 10 PPC sense a second code to operate control circuit CC2 which may control routing of articles to branch conveyor 6 in FIG. 1. All three probe devices may be mounted on a reader such as I4 in FIG. l to sense conducting members on a card 16 held in a slot on tray I2.

Referring to FIG. 7, there is shown a routing control system having a contact finger type code reader similar to that in FIG. 5 for selectively controlling two control circuits CCI and CC2. The system in FIG. 7 is similar to the system in FIG. 6 except that contact fingers are employed instead of proximity probe devices. In FIG. 7, reference characters like those in the prior figures have been employed for like elements.

In FIG. 7, common contact finger 34 is connected from terminal F to terminals a of control circuit CCI and CC2. Contact finger 36 is connected from terminal G to terminal c of control circuit CCI and contact finger 38 is connected fromterminal H to terminal c of control circuit CC2.

When card 40 bridges or electrically connects

contact fingers

34 and 36, current flows from the positive side of the source in control circuit CCI through resistor R10, terminals c and G, contact finger 36, card 40, contact finger 34, terminals F and a and resistor R9 to the negative side of the source. Current normally flows through resistors R8 and R9 so that connection of

contact fingers

34 and 36 through card 40 causes the voltage drop across resistor R8 to be applied across resistor R10 to cause current ow through the latter. As a result, the voltage drop across resistor R10 is applied to the emitter-base junction of transistor T5 to render transistor T5 conducting and to energize relay LVR. Relay LVR then controls the associated diverter and operates the associated branch conveyor 4 to effect routing of an article to the latter in the manner described in conjunction with FIG. 2.

When card 40 bridgescontact lingers 34 and 33, the voltage drop across resistor R8 of control circuit CC2 is applied across resistor R10 therein to cause current flow through resistor R10, terminal c of control circuit CC2, terminal H of reader 30, contact finger 38, card 40, contact finger 34, contact F of reader 30, terminal a of control circuit CC2 and resistor R9 to the negative side of the source. As a result, transistor T5 in control circuit CC2 is rendered conducting to energize relay LVR and to control routing of the article to branch conveyor 6 in FIG. 1.

It will be apparent that control circuit CC shown in detail in FIG. 2 is constructed so that it may be employed with either contact finger type sensing devices or proximity type devices. A plurality of control circuits CC may be controlled by employing a contact finger or proximity device for each thereof and one additional common contact finger or proximity device. The control circuit such as CC in FIG. 2 is constructed so that it receives a control signal when reader 14 in FIG. l senses a code and stores the signal until tray I2 engages the limit switch LSI or LSZ associated with the branch conveyor destination of the tray.

Branch conveyors 4 and 6 are preferably spaced close to one another and branch conveyor 4 is preferably spaced close to code reader 14 such that a single code reader can be employed to control diversion of articles to two branch conveyors. The spacing between branch conveyors 4 and 6 and the spacing between branch conveyor 4 and code reader I4 relative to the length of trays 12 being conveyed is preferably such that a preceding tray cannot be between the associated limit switch LS1 or LS2 and code reader 14 at the time that the code on a succeeding tray is being read. That is, the distance between limit switch LS2 and code reader I4 is preferably less than a tray length. This prevents the reading of the succeeding tray from misdirecting the preceding tray in accordance with such reading. If this distance were greater than a tray length, it would be necessary either to space the trays or to use a separate reader for each branch conveyor. The aforeamasser mentioned spacing of limit switch L32 and code reader 14 from one another ailows control of trays which are not spaced from one another. After a preceding tray engages limits switch L82, which corresponds to limit switch LS1 in FIG. 2, contact ll thereof maintains the energizing circuit of relay CR open so that an input signal from the code reader in response to a succeeding tray cannot cause misdirection of the preceding tray.

In the event of power failure, only a tray which has been sensed by reader ld or read but not diverted would be st, that is, the stored sgnel for controlling its destination would be canceled. A tray in any other position on the conveyor system will, upon restoration of power, be routed to its correct destination. A tray which happened to be between reader ld and the limit switch LSlL or LSZ of its destination branch conveyor when power fails will, upon restoration of power, travel along conveyor 2 and enter the last branch conveyor (not shown). In this manner, the system is adapted to reduce to a minimum the misdirection of articles in the event of power failure.

While the systems hereinbefore described are effectively adapted to fulfill the objects stated, it is to be understood that we do not intend to coniine our invention to the particular preferred embodiments of code responsive systems disclosed, inasmuch as they are susceptible of various modifications Within departing from the scope of the appended claims.

We claim:

l. In a system for identifying and responding to different codes carried by moving articles to energize electroresponsive load devices:

a code reader mounted at la point adjacent the path of travel of the articles and having a plurality of sensing means;

one of said sensing means being common to the others and each of the other sensing means forming with said common sensing means a different coded combination;

a plurality of switching means each being effective to operate when the code on an article matches a respective coded combination of sensing means;

and a control system comprising a plurality of like control circuits responsive to operation of the respective switching means for controlling operation of respective electroresponsive load devices;

each said control circuit comprising means responsive to operation of the respective switching means for providing lan output signal;

means for storing said output signal until it is utilized;

and means responsive to operation of said storing means for releasing said output signal providing means so that it can be reoperated by the switching means when the code on another `article is read.

2. In a system for identifying and responding to different codes carried by moving articles to energize electroresponsive loads:

a code reader mounted at a point adjacent the path of travel of the articles and having a plurality of coded sensing means;

said code reader comprising a plurality of switching means each being effective to operate when the code on an` article matches a code sensing means; l

and a control system comprising a` plurality of like control circuits responsive to operation of the respective switching means to operate electroresponsive loads; p

each said control system comprising a low voltage amplifier responsive to operation of said switching means for providing an output signal;

means responsive to s-aid output signal for storing the same;

and means responsive to said article at a predetermined fur-ther point in its path of travel for utilizing said stored signal to operate said electroresponsive load;

l2 i each said ampliiier being provided with input circuit means and a group of terminals connected to said input circuit means for adapting said ampliiier for operation with either one of two different types of code readers one of which is provided with a normally closed switching device normally shunting the input circuit means of the ampliiier to render it ineffective and being operable to unshunt said input circuit means when the code on the article matches said coded sensing means to render said amplifier operative to provide an output signal;

and the other type of code reader being provided with a normally open switching device normally interrupting the input circuit means of the amplifier to render it ineiective and being operable to close said input circuit means when the code on the article matches said coded sensing means to render said amplifier operative to provide an output signal.

3. ln a system for identifying and responding to different codes carried by moving articles to energize electroresponsive loads:

a code reader mounted at a point adjacent the path of travel of the articles and having Ia plurality of coded sensing means;

said code reader comprising a plurality of switching means each being effective to operate when the code on an article matches a coded sensing means;

and a control system comprising sa plurality of like control circuits responsive to operation of the respective switching means to operate electroresponsive loads;

each said control system comprising a low voltage ampliiier responsive to operation of said switching means for providing an output signal;

means responsive to said output signal for storing the same;

and means responsive to said article at a predetermined further point in its path of travel for utilizing load stored signal to operate said electroresponsive load;

each said amplifier being provided with two input circuits and a group of terminals connected to said input circuits to adapt said amplifier for operation with either one of two diiferent types of code readers when connected to predetermined input terminals;

one ofsaid code readers being of the type having a normally closed switching device connectable to rst terminals of said group thereof normally to shunt a first one of said input circuits to render said amplifier inelfective and being operable to unshunt said rst input circuit when the code on the article matches said coded sensing means to render said ampliiier operative to provide an output signal;

and .the other of said code readers being of the type having a normally open switching device connectable to second terminals of said group thereof normally to interrupt the second input circuit to render said ampliier ineffective and being operable to complete said second input circuit when the code on the article matches said coded sensing means to render said amplier operative to provide an output signal.

4. In a conveyor system having va main conveyor for conveying articles therealong and a plurality of branch conveyors extending from the main conveyor and diverter devices mounted on the main conveyor at the respective branch conveyor junctions for selectively diverting articles from the main `conveyor onto the branch conveyors, the improvement comprising a control system for automatically controlling routing of articles from the main conveyor .to .the branch conveyors in accordance with predetermined codes, `said control system comprising a code reader stat-ion mounted at one side of the main conveyor ahead of the branch conveyor junctions, code bearing elements carried by the articles past said code reader station, said code reader station comprising code discriminating means for detecting and identifying different codes and comprising a first detecting member for each branch conveyor and a second detecting member common to said branch conveyors, each rst detecting member in combination with said common detecting member forming a 'code discriminating device for a respective branch conveyor, a lpluralty of control circuit-s for the respective branch conveyors, means connecting said code discriminating devices to said control circuits whereby each code discriminating device affords an output control to its associated control circuit in response to identification of a code on a code bearing element passing thereby, means in each said control circuit for receiving said output control from the associated code discriminating device, means for registering said output control and for restoring said receiving means whereby to retain a record thereof after the code bearing element has passed by the associated code discriminating device, a plurality of limit switches one for each ycontrol circuit and mounted on the main conveyor immediately ahead of each diverter device for operation by the articles, means in each control circuit for operating the associated diverter device from a non-diverting position to a diverting position wherein it is effective to divert an article from the main conveyor to the associated branch conveyor, and means responsive to operation of one of said limit switches associated with a control circuit having said record therein for controlling the associated diverter device operating means.

5. The invention defined in claim 4, wherein said output control receiving means comprises a transistor amplifier having a control resistor connected across its emitter-base junction, means in said code discriminating device normally shunting said resistor to maintain said transistor non-conducting, and means in said code discriminating means responsive to identification of a code for interrupting said shunt to render `said .transistor conducting.

6. The invention defined in claim 4, wherein said out- 14 put control receiving means comprises a transistor ampli- Vfier having a control resistor connected across its emitterbase junction, a source of voltage connected to said resistor, means in said code discriminating means normally interrupting the circuit from said source to said resistor, and means responsive to identification of a code for completing said circuit to said resistor to cause current flow through the latter and to render said transistor conducting.

7. The invention defined in `claim 4, wherein the last mentioned means comprises means operable concurrently with operation of said diverter device for starting the associated branch conveyor running, yand a plurality of limit switches one lfor each branch conveyor and being mounted ythereon a predetermined distance from the junction thereof with the main conveyor for operation by the diverted articles to maintain operation of the associated branch conveyor and to stop the latter when the article has disengaged `such limit switch.

8. The invention defined in claim 4, wherein the distances between said code reader station and said limit switches are less than the length of the articles ibeing conveyed whereby to prevent a succeeding article at said code reader station from causing misdirection of a preceding article.

References Cited in the file of this patent UNITED STATES PATENTS 1,937,303 Worrall Nov. 28, 1933 2,719,629 Robinson Oct. 4, 1955 2,795,328 Tyler et al. June 11, 1957 2,862,617 Brown Dec. 2, 1958 2,877,718 Mittag Mar. 17, 1959 2,993,596 Steinbuch I-uly 25, 1961 3,003,629 Henderson Oct. 10, 1961 3,019,883 Jones Feb. 6, 1962 3,075,653 Wales etal Jan. 29, 1963

Claims

1. IN A SYSTEM FOR IDENTIFYING AND RESPONDING TO DIFFERENT CODES CARRIED BY MOVING ARTICLES TO ENERGIZE ELECTRORESPONSIVE LOAD DEVICES: A CODE READER MOUNTED AT A POINT ADJACENT THE PATH OF TRAVEL OF THE ARTICLES AND HAVING A PLURALITY OF SENSING MEANS; ONE OF SAID SENSING MEANS BEING COMMON TO THE OTHERS AND EACH OF THE OTHER SENSING MEANS FORMING WITH SAID COMMON SENSING MEANS A DIFFERENT CODED COMBINATION; A PLURALITY OF SWITCHING MEANS EACH BEING EFFECTIVE TO OPERATE WHEN THE CODE ON AN ARTICLE MATCHES A RESPECTIVE CODED COMBINATION OF SENSING MEANS; AND A CONTROL SYSTEM COMPRISING A PLURALITY OF LIKE CONTROL CIRCUITS RESPONSIVE TO OPERATION OF THE RESPECTIVE SWITCHING MEANS FOR CONTROLLING OPERATION OF RESPECTIVE ELECTRORESPONSIVE LOAD DEVICES; EACH SAID CONTROL CIRCUIT COMPRISING MEANS RESPONSIVE TO OPERATION OF THE RESPECTIVE SWITCHING MEANS FOR PROVIDING AN OUTPUT SIGNAL; MEANS FOR STORING SAID OUTPUT SIGNAL UNTIL IT IS UTILIZED; AND MEANS RESPONSIVE TO OPERATION OF SAID STORING MEANS FOR RELEASING SAID OUTPUT SIGNAL PROVIDING MEANS SO THAT IT CAN BE REOPERATED BY THE SWITCHING MEANS WHEN THE CODE ON ANOTHER ARTICLE IS READ.