US3272353A

US3272353A - Article sorting system

Info

Publication number: US3272353A
Application number: US335172A
Authority: US
Inventors: Karl T Wilder
Original assignee: ECD IND
Current assignee: ECD IND
Priority date: 1964-01-02
Filing date: 1964-01-02
Publication date: 1966-09-13
Anticipated expiration: 1983-09-13

Description

P 13, 1956 K. T. WILDER ARTICLE SORTING SYSTEM 5 Sheets-Sheet 1 Filed Jan. 2, 1964 FIG.|

46 33d. n w a In 46-] INVENTOR. KARL T. WILDER ATTORNEY p 1966 K. "r. WILDER ARTICLE SORTING SYSTEM 5 Sheets-Sheet 2 Filed Jan. 2, 1964 soiwu/ soN PIC-3.5

I 5 L L 535 3 FIG.6

45 (STEP DOWN] r' 50(5TEP oowm FIG.7

INVENTOR. KARL. T. WILDE R BY (NF ATTORNEY United States Patent 3,272,353 ARTICLE SORTING SYSTEM Karl T. Wilder, Randolph Township, N.J., assignor t0 ECD Industries, Mountainside, N.J., a partnership Filed Jan. 2, 1964, Ser. No. 335,172 24 Claims. (Cl. 214-11) This invention relates to article sorting systems.

More particularly, it relates to such systems of the type where articles are conveyed to successive discharge stations and are respectively discharged at selected stations.

In one such type of prior art system, the articles themselves, or their related holders, carryusually in coded formthe address of their intended discharge station. An automatic reader at each station reads the address information of each article and is effective to initiate discharge at that station of any article whose address corresponds to the station.

Another type of prior art system involves a separate coded information strip carrying the article addresses. The strip is moved in synchronism with the movement of the articles. The strip is sensed by respective reading devices provided for each discharge station. When the address information corresponds to the intended station, the reading means initiates discharge of the article at that station.

The foregoing types of systems are complex and therefore costly to build and expensive to maintain. Both require a separate automatic information reader for each discharge station. Further, the second typehaving the synchronous information strip-necessitates the provision of means for encoding on the strip the address of each article entering the system.

The system of the present invention is a different and simpler type. Selection means is provided for selection of a discharge station for any article. Operation of the selection means uniquely conditions control circuitry. As the articles move through the system in the same sequence in which the selections were made, the fact of article movement past each station will 'be detected, and the articles will be automatically discharged at their intended stations. There is no synchronism involved as in the information strip system, nor are automatic readers needed.

Furthermore, despite its simplicity the present system permits the same discharge station to be selected for different articles even though the first article selected for that station has not yet reached it. It is only necessary that the articles move through the system in the same sequence in which the selections are made.

It is therefore a major object of the present invention to provide a novel article sorting system.

It is a further object to provide such a system which is relatively inexpensive to construct and maintain.

It is a further object to provide such a system which, while simpler than prior art systems, nevertheless has comparable desired selection flexibility.

It is a more specific object to provide such a system wherein the same discharge station can be selected a number of times even before the first article intended for that station has not yet reached it.

It is a further object to provide novel control circuitry for achieving the preceding objects.

The above and other objects, features, and advantages of the invention will be apparent to those skilled in the art from the following detailed description when read in conjunction With the accompanying drawings, in which:

FIG. 1 is a schematic top plan view of one form of the novel sorting system of the invention.

FIG. la is a detail view of a station selecting button and the contacts it controls.

FIG. 2 is a diagram of the interlock circuit.

3,272,353 Patented Sept. 13, 1966 FIG. 3 is a diagram of the stacking relay circuit.

FIG. 4 is a circuit diagram showing a portion of the control circuitry, and particularly how a stepping switch for each discharge station is operated and controls the corresponding respective stepping switches for preceding stations.

FIG. 5 is a diagram showing certain control circuitry for the stacking stepping switches for any one discharge station.

FIG. 6 is a circuit diagram showing the interconnection of the various stepping switches for any one discharge station.

FIG. 7 is a diagram of the circuit means for any one station whereby the movement of an article to that station causes its stepping switches to step back.

FIG. 8 is a diagram of other portions of the control circuitry of the invention.

FIG. 9 is a schematic top plan view of a second form of the system of the invention, provided with plural loading points and plural selection control panels; and

FIG. 10 is a circuit diagram of the system of FIG. 9, for any one discharge station.

Referring now to FIG. 1, the reference characters 1, 2, n, designate a number of unloading or discharge stations disposed along the path of movement of a conveyor belt 10 on which are carried the articles 11 to be selectively unloaded at these various stations. The details of the conveyor itself and its drive form no part of the present invention, and may be of any suitable construction.

As seen in the top plan view of FIG. 1, the conveyor belt 10 is driven from left to right. The articles 11 thereon are first carried past a selecting station 12 (or can be placed on the belt at the station 12) at which is provided a control panel 13 having a number of selector push buttons 14 each corresponding to a different related one of the discharge stations 1, 2, n. The operator at the selecting station 12 decides at which discharge station the article is to be unloaded, and depresses the corresponding button 14. The particular characteristic or parameter of article 11 upon which the selection is based is immaterial so far as the present invention is concerned.

As will be described in detail shortly, the depression of the selector button 14 uniquely conditions the control circuitry of the present invention. As the article 11 is carried toward the right past the selector station 12, it first traverses a light beam projected by lamp 15 onto a starting photocell 16. Until the article passes the start photocell 16, the selector buttons 14 will be ineffective for a further discharge selecting operation.

Each discharge station includes a discharge arm or lever 20 which is normally held in the ineffective position of FIG. 1 out of the path of the moving articles. Just upstream of its discharge arm, each discharge station includes a related photocell 21 on which is projected a beam of light by a lamp 22. As each article 11 is carried along toward the right by belt 10, it successively blocks the beam of light falling on each photocell 21. Each such photocell-passing movement of the article 11 causes a change in the condition of the discharge control means of the invention.

As soon as article 11 passes the photocell 21 of the particular station which has been selected for that articles discharge (by previous depression of one of buttons 14), an operating solenoid 23 at that station will swing the discharge arm 20 clockwise so that the arm now lies in the path of movement of the article. The operated position of one of arms 20 is shown in broken lines in FIG. 1. Accordingly, as the feed belt 10 continues its rightward movement, the article 11 will be diverted onto 3 a lateral discharge chute 24 or other suitable receiving structure.

Extension 23a of the armature of each solenoid 23 operates discharge arm 20 through an intermediate link 25. The latter is fixed to a rotatable shaft 26, as is arm 20. A tension spring 27 biases the just-described mechanism to its normal, unoperated position.

As was mentioned earlier, one feature of the invention resides in the fact that the same discharge station can be selected for several different articles being carried along by the conveyor belt. For example, FIG. 1 shows three articles 11 on belt 10. With the present system, station 2 can be selected for discharge of the rightmost article, station 1 for the next trailing article, and station 2 again can be selected for the leftmost article, even before the leading (rightmost) article 11 has been discharged at station 2. The nature of the present invention is such that the same discharge station can be selected for various articles moving down the belt as many times as desired either before or after the first of such articles has even reached the discharge gate. Furthermore, such selection need not even necessarily be of articles traveling in immediate consecutive order on belt 10. This stacking capacity of the system is theoretically unlimited. In the actual design of a given system, it is achieved by repeating certain control circuitry, shortly to be described, the desired number of times.

Electric control circuitry The control circuitry of the invention will now be described.

At this juncture, it may be mentioned that each station selecting button 14 controls a number of

electrical contacts

30, 41, 46. As shown in FIG. 10, when any button 14 is operated to select a discharge station, it will close these three contacts.

Contact 30 is effective to operate an interlock circuit. This circuit will prevent all of the selector buttons 14 from being effective for discharge selection until the article 11 for which a selection has previously been made by operation of a button 14, passes the start photocell 16. This will prevent possible errors which could arise if a button 14 were operated with no corresponding article placed or present on belt 10, and another button 14 then depressed.

Interlock circuit Referring to FIG. 2, the interlock contacts 30 of all the selector buttons 14 are connected in parallel with each other and in series with a relay 31. (The numeral 30 is employed to designate generally the interlock contact for any discharge selector button 14. However, the same numeral followed by a dashed number specifically designates the contact for the discharge station corresponding to the dashed number. For example, 30-1 refers to the interlock contact associated with the first discharge station, etc. Similar nomenclature will be employed in connection with other parts.)

Operation of any one of the contacts 30, by depression of a related button 14, will energize relay 31 which will immediately lock in through its normally open contact 31a, and a normally closed contact 32a of a relay 32. When the article 11 for which a gate selection has just been made passes the start photocell 16, cutting off its light beam, the photocellwhich is in parallel with relay 32will rise in resistance in usual fashion, whereby relay 32 will operate. When relay 32 operates, its normally closed contact 32a will open, deenergizing relay 31. Until relay 31 is deenergized, its normally closed contact 31b (FIG. 3), to the stacking relays 40 (whose function will be described shortly) will be open, preventing the stack-, ing relays from operating in response to depression of a selector button 14.

A relay 33 (FIG. 2) is energized through normally open contact 310 of relay 31 so long as the latter is on. Normally closed contacts 33a (FIG. 4) of relay 33 accordingly prevent operation of stepping switches 45, with which they are in series, until relay 31 opens, and thereby causes relay 33 to open. As described later, stepping switches 45 are set in response to operation of the discharge selector buttons 14, and control discharge of the article at the appropriate station.

If desired, an additional, normally open contact 31d (FIG. 2) of relay 31 may be provided in series with a signal light or bell 34. Signal 34 will be on whenever relay 31 is in energized condition. This will indicate to the operator that a discharge selection cannot be made again until the signal light goes oif.

Stacking control As was briefly mentioned earlier, the present system provides that the operator can select the same discharge station as the exit point for several articles 11 being carried by the feed belt 10, even though the first of the articles intended to discharge at that station has not reached it by the time the operator again selects it for subsequent articles. For this purpose, there are provided for each discharge station a number of stacking relays 40 (FIG. 3). The number of stacking relays at each station is equal to the maximum number of articles 11 to be selected for discharge at that station, prior to the time the first of the articles intended for that station is discharged there. Stated difierently, there are as many stacking relays at a station as the desired maximum capacity to select that station to discharge articles coming toward it.

The stacking circuitry is arranged and operates as follows. Each discharge selector button 14, when operated, closes its associated contact 41 (FIGS. 1a, 3). Contact 41 is in series with the above-mentioned interlock contact 31b of relay 31, and is thence connected in series with the various stacking relays 40I, 40H 40N, for that discharge station through isolation diodes 42. (N, of course, represents the stacking capacity of the station.) Furthermore, a normally open contact of each stacking relay connected between all the next successive stacking relays 40 of that station and the contact 41. Thus, there will be no such contact for the first relay 401; there is a contact 40I-II of relay 401 in series with relay 40II; the third stacking relay (if any) will have in series with it normally open contacts of the second and first relays; the fourth stacking relay (if any) will have in series with it normally open contacts of the third, second, and first relays; and so on.

From the foregoing it will be seen that operation of any given station selector button 14 and consequent closure of its contact 41 will energize the first stacking relay 40I, assuming of course that the aforedescribed interlock relay 31 is deenergized whereby its contact 31b is in its normal, closed condition. Operation of relay 40I will cause it to latch in through its normally open contact 40Ia and a normally closed contact 62a of a related relay 62 (FIG. 8). Operation of relay 40I will also cause closure of its normally open contact 40I-II in the primary energizing circuit (through contact 41) for the next stacking relay 40II of the same discharge station. Thereafter, if the operator again selects the same station for another article carried by feed belt 10 behind the first article for which that station was selected, the consequent closure of contact 41 will cause the second relay 4011 to operate since contact 40I-II is closed. In similar fashion, relay 4011 will lock in through its latching contact 40IIa and a normally closed contact 625: of another, related relay 62, and will also condition the primary energizing circuit of the next stacking relay of that station for operation. Then, if the same station is again selected as the discharge point for another article before the first article selected therefor has been discharged at that station, the third stacking relay will be energized and latched in, thereby conditioning the next following stacking relay for operation, and so on.

Each successive energized stacking relay 40 corresponds to a difi'erent article 11 selected for discharge at that Station. As described later, the discharging operation includes energizing of the related relay 62, thereby opening its contact 62a and thus deenergizing the related stacking relay. However, this will not deenergize any of the energized following stacking relays of that station, since they are held in through their latching circuits. Also, if the same station is then again selected for article discharge, this will result in energizing the first relay 40 (of that station) which stands unenergized. This is because, as set forth above, the primary energizing circuit of any stacking relay includes a normally open contact of all preceding stacking relays of that station.

Stepping switches Referring to FIG. 4, there is provided for each discharge station a stepping switch 45. It will be recalled that each discharge selector button 14, when operated, will mechanically close its contact 46 (FIG. 1a). Each contact 46 (FIG. 4) is connected to a corresponding one of the stepping switches 45 through respective normally closed contacts 33a of the previously described interlock relay 33. Whenever any given selector button 14 is operated, it will cause the related stepping switch 45 to advance one step. As further shown in FIG. 4, each contact 46 is connected to all the stepping switches for the stations which lie upstream thereof. Therefore, operation of any discharge selector button 14 will cause not only the associated stepping switch 45 to advance one step, but will also advance all the preceding stepping switches one step. It will be understood that the diodes 47 are provided merely for the purpose of preventing sneak circuits.

There are also provided for each stepping switch 45, i.e., for each discharge station, a number of additional stepping switches 50. There is one such stepping switch 50 for each of the stacking relays 40 of a discharge station. FIGS. 5 and 6 show the various stepping switches associated with one discharge station, the arrangement being the same for all stations. The stepping switches 45 and 50 for any one discharge station are interconnected in the manner shown in FIG. 6. That is to say, the various contact points, ten for example, of the stepping switch 45 are each respectively connected to the corresponding points of all the stepping switches 50 for that discharge station. Each stepping switch 50 itself is, as shown in FIG. 5, connected across the applied power potential through a re spective normally open contact 4% of a related one of the stacking relays 40, a normally closed contact 53a of a relay 53 (FIG. 6), and a normally closed interrupter contact 50a of the stepping switch itself. There is a separate relay 53 for each stepping switch 50. Therefore, when any given stacking relay 4% is operated as described earlier, the related stepping switch 50 will continue to step until its commutator arm 51 (FIG. 6) reaches the same stepped position at which the commutator arm 52 of stepping switch 45 stands. This will complete the circuit for the relay 53, energizing the latter whereby its normally closed contact 53a will open, breaking the circuit for that stepping switch 50. It should be noted, however, that there is no electrical interconnection between

commutator arms

50 and 51 when they are in their home positions,

Briefly reviewing the discussion to this point, depression of any given discharge selector button 14 by the operator will cause the following circuit conditioning functions to occur: the stepping switch 45 for the selected discharge station will advance or step up one step, as will all previous (upstream) stepping switches 45; a given stacking relay 40 for the station will operate; and the commutator arm of stepping switch 50 corresponding to the one stacking relay 40, of the selected station, which is operated, will continue stepping until its commutator arm 51 is at the same position as the commutator arm 52 of stepping switch 45.

The operated relay 53 will lock itself in through its own normally open contact 53b in series with an off normal contact 54 of stepping switch 50. This latter contact is conventionally provided in commercially available stepping switches. It is normally open when the stepping switch is at its home position, but is otherwise closed. Therefore, relay 53 once energized will remain energized until the commutator arm 51 of stepping switch returns to home position.

The selection of a discharge station having been made as described above, the article 11 for which that selection was made is carried by conveyor belt 10 past each station photocell 21; and will be automatically ejected at the selected station as follows. As the article passes each photocell 21, the momentary blockage of light falling on that photocell causes a corresponding respective relay 60 (FIG. 7) to be energized because of the rise in the photocells resistance. Operation of relay 60 will close its normally open contact 60a which is effective to step all stepping switches 45 and of that station back one step. At this point, it should be mentioned that stepping switches 45 and 50 are provided with both conventional step up and step down means. In the usual commercial form, such a stepping switch includes a first coil effective to operate a count-up pawl; and a second coil effective to operate a count-down pawl. The contact a of relay 60 is in series with the step-down coils of stepping switch 45 and stepping switches 50. Therefore, the switches will be stepped back one step each time an article 11 carried by the conveyor belt 10 passes the photocell 21 for that station.

Each stepping switch 50 includes a second level having a commutator arm 61 (FIG. 8). When, and only when, the stepping switch is in its home position, this second arm 61 will complete the circuit for a related relay 62 through a normally open contact 530 of the previously mentioned relay 53. It will be recalled that this latter relay is energized so long as the associated stepping switch 50 is at other than home position.

Operation of any one of the station relays 62 is effective to cause the discharge of the article at that station, whose photocell 2 1 the article has just passed, by operating that stations discharge solenoid 23, as follows. As seen in FIG. 8, respective normally open cont-acts 62b of the various relays 62 for the given station are all arranged in parallel with one another and in series with the discharge solenoid 23 for that station. It will be recalled that there is provided a separate relay 62 for each stepping switch 50, and that there are as many of the latter as there are stacking relays 40 for the given gate. Accordingly, it will be seen that operation of any one of the relays 62 will energize solenoid 23 thereby swinging the related deflector arm 20 (FIG. '1) into the path of the article 11 on the belt 10. The article 11 is thus discharged from the belt at that station.

The foregoing system provides that each article 11 Will be automatically discharged at the station corresponding to the previously depressed selector button 14. A particular example will now be given. Assume that the system has at least five discharge stations; and that stations 5, 3, and 5 are selected, in that order, for three consecutive articles 11 on belt 10 by operating appropriate ones of buttons 14. The first selection sets up the following condition in the control circuitry for station 5: its stepping switch 45 advances one step from home position, as do switches 45 for stations 1, 2, 3 and 4; while the first stepping switch 50 (501) for station 5 also advances one step from home position.

The subsequent selection of station 3 advances stepping switches 45 for gates 3, 2, and 1 another step, so that these switches stand at two steps from home, although switches 45 for stations 4 and 5 remain at their one-step positions; and also advances the first stepping switch 50 (501) for gate 3 one step from home.

The following repeated selection of gate 5 advances the stepping switches 45 for all five stations an additional step. They, therefore, now stand advanced as follows: station 5-two steps; station 4-tw0 steps; stations 3, 2,

1three steps. This second selection of discharge station also causes the second stepping 50 (5011) of station 5 to move from home to the same stepped position as stepping switch 45, i.e., two steps.

The following events will take place as the various articles 11 for which the above selections were made are carried downstream past the photocell 21 of each discharge station. It is important to recall here two things: (1) each article movement past a station photocell 21 steps all the associated previously stepped stepping

switches

45 and 50 of that station back one step; and (2) when any switch 50 at a station steps back into its home position, it causes discharge of the article at that station.

The first article, destined for station 5, in passing each station photocell 21 will cause the stepping switches for the various stations to step back one step to the following positions rfirom home: switches 45 of stations 1, 2, 3two steps; switches 50 of stations 1, 2, 4no change, since they have not previously been stepped from home position; switch 50I of station 3one step; switch 501 of station 5 to home position, thereby causing discharge of the article at thevstation, as selected, by operation of the associated relay 62 which causes operation of the station discharge solenoid 23.

The second article passing each station photocell 21 causes the stepping switches to be stepped down to the following positions: switches 45 of stations 1, 2, 3one step; switches 50 of stations 1, 2no change; first switch 50 of station 3ho-me position, thereby causing discharge of the article at that station, as selected.

The third article: switches 45 of stations 1, 2, 3to home position; switches 45 of stations 4, 5one step; switches 50 of stations 1, 2, 3, 4no change; second switch 50 (5011) of station 5 to home, thereby discharging the article at the station, as selected.

Normalizing A separate, normally on, relay 63 is provided for each discharge station. As seen in FIG. 8, this relay is connected in series with a normally closed contact 620 of all the relays 62 of the station. In parallel with relay 63 are fixed resistance 64, variable resistance 65 and a capacitor 66, to provide an adjustable slow release time for the relay. When any one of relays 62 is operated as aforedescribed to operate the discharge solenoid 23, opening of its contact 620 will break the circuit to relay 63 so that the [latter will start to release. Earlier, mention was made of relays 53 (FIG. 6), one of which was energized when the related stepping switch 50 stepped to the same position as stepping switch 45. Each relay 53 is provided with a latching circuit through off normal contact 54 of the associated stepping switch 50, and also through contact 63a of relay 63. The fact that the stepping switch 50 has previously returned to home position opened the contact 54. However, relay 53 up to this point has remained latched-in through an associated normally open contact 63a of normally energized relay 63. However, the .fact that relay 63 has now dropped out opens contact 63a, whereby relay 53 is deenergized. This will cause cont-act 53c thereof to open, thereby deenergizing the one of relays 62 which had caused the discharge solenoid 23 to operate through the contact 62b. The latter contact will now open, deenerigizing solenoid 23, thereby allowing the deflector arm 20 to return to its unoperated position under the bias of spring 27. The operated relay 62 having now been deenergized, its normally closed contact 620 will now be closed reestablishing the energizing circuit for relay 63 whereby the latter returns to its normal, operated condition.

If desired, means can be provided to normalize the stepping switches 45- and 50 to home position, under manual control, as follows. Referring to FIG. 4, a push botton resetting switch has a first normally open contact 70a connected in series with all the stepping switches 45 through respective 01f normal contacts 71 of the various switches 45, and also respective interrupter contacts 72 of switches 45. Operation of contact 70 will therefore complete the circuit for any stepping switch 45 which is out of home position. The switch will step until it is at home position, at which time its oil normal contact 71 will open. Another contact 70b (FIG. 7) of the reset switch is provided for each station, connected to stepping switches 50 through an interrupter contact 73. It will be obvious from the foregoing description that at any one time two or more of the articles 11 can be between successive discharge stations.

FIGS. 9 and 10 show another species of the system in which the principles of the invention can be embodied. In the system of FIGS. 1-8, all the articles 11 are placed on the conveyor belt 10 ahead of the first discharge station. In the species of FIGS. 9 and 10, however, the articles can be loaded on conveyor 10 at various points between discharge stations.

Referring to FIG. 9, there are provided various sections S along the direction of movement of belt 10'. Each sector includes one or more discharge stations, and also is provided with a discharge selection panel 13'. Each selection panel 13 has selector push button 14' for selecting not only the discharge stations of that sector, but also that discharge stations of subsequent (downstream) stations.

Each discharge station of FIG. 9 is provided with discharge control circuitry as described previously in connection with FIGS. 1-8. Each selector button 14' controls the stepping switches 45 of the sector S in which its control panel 13' lies in the same manner as aforedescribed.

In addition, however, any selector button 14' for selecting a station lying in a subsequent sector controls further circuitry now to be described. Each downstream sector S is provided with a a stepping switch (FIG. 10). The various stepped positions of the switch s commutator arm 81 each correspond to a different discharge station within the sector. Respective contacts 82 each operated by a related button 14' of any upstream sectors control panel 13' are connected to switch 80 of the downstream sector containing the station corresponding to the button, through any suitable conventional control circuit 83, such as that used to self-step a stepping switch to a desired position. The arrangement is such that operation of a button 14 to select a station lyin in a downstream sector will step the latters sector switch 80 to its position corresponding to the selected discharge station within that sector.

The beginning of each sector S is marked by a light beam from a light source 84 falling on a photocell 85. An article moving from one sector to another will interrupt the light beam, whereby photocell 85 will cause operation of a respective related relay 86 provided for each sector. A normally open contact 86a of relay 86 is connected to the commutator arm 81 of stepping switch 80. The various contact points of the latter are respectively connected to relays 90 each provided for a discharge station within the sector. A normally open contact 90a of each relay 90 is connected in parallel with the contact 41 (FIGS. 3, 10) of each related discharge station. It will be recalled that closure of contact 41 operates one of the stacking relays 40 for the selected station.

Another contact 90b, of each relay 90 is in parallel with the contact 46 (FIGS. 4, 10) of each related discharge station. It will be recalled that closure of contact 46 operates stepping switch 45.

Assume that an article has been placed on belt 10 in one sector and the selector button 14' (of that sectors control panel 13) for a discharge station of the following sector is depressed. Operation of button 14' advances commutator arm 81 of stepping switch 80 of said following sector to its contact point corresponding to the selected station, so that the arm is now connected to the associated station relay 90. Then, as the article enters the next sector, which contains the selected discharge station, it will block the light falling on the sector photocell 85, operating relay 86 whereby its contact 86a now closes. This completes the circuit for the relay 90. Its

contacts

90a and 90b close, completing the circuits for stacking relays 40 and stepping switches 45, which will thereupon operate as described earlier in connection with FIGS. 1-8.

It will be seen from the foregoing that photocell 85 and stepping switch 80 serve to delay operation of the stacking relays (and therefore of stepping switches 50) and stepping switch 45 until the article has entered the sector containing the discharge station selected for it.

For stacking purposes, each sector is provided with plural stepping switches 80 controlled by related relays (not shown) in substantially the same manner as the stepping switches 50 and their stacking relays 40.

The foregoing description sets forth in detail specific embodiments of the invention. It will be understood, however, that various changes can be made in practice without departing from the broad principles of the in vention. For example, the selection means could be operated automatically as by sensing a punched card attached to each article entering the system. The system of FIGS. 910 could be in the form of a completely closed conveyor loop. Numerous other modifications can be effected while still making use of the inventions principles.

Accordingly, it is intended the foregoing detailed disclosure be illustrative only and not in any way limitative of the following claims.

I claim:

1. In an article sorting system having a plurality of successive article discharge stations; means for conveying articles successively to said stations; and selectively operable discharging means at each station: one selection means for selecting any one of a number of said discharge stations; control means for effecting operation of a stations discharging means when an article is at the station selected for that articles discharge; said control means including means, responsive to repeated selection of the same given discharge station for different given articles before the first of said given articles has been discharged at said given station, for causing the discharge means of said given station to operate only when said given articles are at said given station; said control means comprising a plurality of control devices for each discharge station, each of said control devices being adjustable to a number of different conditions including a discharge-effecting condition; said control means further including means, operable in response to operation of said selection means to select a station for an articles discharge, for causing adjustment of at least one of the control devices for that station before said last-mentioned article has arrived at the first of said plurality of stations.

2. The combination according to claim 1, wherein each of said control devices comprises a counting means.

3. The combination according to claim 2, wherein each counting means comprises a stepping switch.

4. The combination according to claim 1, wherein said control means comprises: a control element for each discharge station, with control element being adjustable to a number of different conditions; adjusting means responsive to the selection of a given discharge station for adjusting the control element for said station, and means connecting the control devices for said station with the control element for said station in such manner that the adjustment of said control devices is controlled by the adjustment of said control element.

"5. The combination according to claim 4, wherein said adjusting means, in response to selection of a given discharge station, also effects adjustment of the control elements for stations preceding the said given station.

6. The combination according to claim 5, wherein said connecting means causes one of said control devices to be adjusted to the same condition as the related control element in response to operation of said selection means to select the given station.

7. The combination according to claim 6, wherein the aforementioned adjustments of said control devices and control element are in one sense; and including means operable in response to the presence of an article at a discharge station for adjusting all adjusted control elements of that station in the opposite sense.

8. The combination according to claim 5, wherein said control devices and control element each comprises a step counter.

9. The combination according to claim 8, wherein said control devices and control element each comprises a step counter.

10. In an article sorting system having a plurality of successive article discharge stations; means for conveying articles successively to said stations; and selectively operable discharging means at each station: selection means for selecting a discharge station; control means for effecting operation of a stations discharging means when an article is at the station selected for that articles discharge; said control means including a control element for each discharge station, each control elemen-t being adjustable to a number of different conditions; adjusting means, responsive to the selection of a given discharge station, for adjusting the control element for that station and for at least one preceding station.

11. The combination according to claim 10, further comprising means for effecting an opposite adjustment of only the control element of a given station in response to movement of an article to said given station.

12. The combination according to claim 11 wherein each control element comprises a step counter.

13. The combination according to claim 10 wherein said system includes only a single selection means for selecting all the discharge stations of said system.

14. The combination according to claim 10 wherein said system includes plural selection means each for selecting at least some of said discharge stations starting with a different given upstream station.

15. The combination according to claim 7 wherein said system includes only a single selection means for selecting all the discharge stations of said system.

16. The combination according to claim 7 wherein said system includes plural selection means each for selecting at least some of said discharge stations starting with a different given upstream station.

17. The combination according to claim 1; further comprising not more than a single sensing means provided for each separate discharge station for sensing the presence of an article at said discharge station to control said control means; and wherein said control means is effective to cause discharge of articles at the respective discharge stations selected therefor even though a number of articles are disposed on said conveying means between two successive discharge stations.

18. In an article sorting system having a plurality of successive article discharge stations; means for conveying articles successively to said stations; and selectively operable discharging means at each station: one selection means for selecting any one of a number of said discharge stations; control means for effecting operation of a stations discharging means when an article is at the station selected for that articles discharge; said control means including means, responsive to repeated selection of the same given discharge station for different given articles before the first of said .given articles has been discharged at said given station, for causing the discharging means of said given station to operate only when said given articles are at said given station; said control means comprising a plurality of control devices for each discharge station, each of said control devices being adjustable to a number of diiferent conditions including a discharge-effecting condition; said control means further including means, responsive to the aforementioned repeated selection of the same, given station by said selection means, for causing adjustment of diflerent respective ones of said control devices of said given station.

19. The combination according to claim 18, including means for sensing the presence of an article at each discharge station.

20. The combination according to claim 19, wherein each said sensing means comprises a photocell and a source of radiant energy so arranged that the articles carried by said conveying means move therebetween.

21. The combination according to claim 19, wherein said control means includes means for changing the adjustment of at least some of said control devices for a station in response to the sensing of an article at that station by said sensing means.

22. The combination according to claim 21, wherein the adjustment of said control devices caused by said sensing means is opposite in sense from the adjustment caused by said selection means.

23. In an article sorting system having a plurality of successive article discharge stations; means for conveying articles successively to said stations; and selectively operable discharging means at each station: selection means for selecting a discharge station; control means for etfecting operation of a stations discharging means when an article is at the station selected for that articles discharge; said control means including a control element for each discharge station, each control element being adjustable to a number of different conditions; adjusting means, responsive to the selection of a given discharge station, for adjusting the control element for that station and for a plurality of preceding stations.

24. The combination according to claim 23; wherein said plurality of preceding stations comprises all the stations which precede said given discharge station.

References Cited by the Examiner UNITED STATES PATENTS 3,075,653 1/1963 Wales 214-11 3,084,784 5/1963 Zouibek 2l411 X 3,128,867 4/1964 Karcher 21411 3,141,540 7/ 1964 Burkhardt 198-38 3,152,681 10/1964 Byrnes 19838 MARVIN A. CHAMPION, Primary Examiner.

WILLIAM B. LA BORDE, GERALD M. FORLENZA,

' Examiners. M. TEMIN, 'Assistwnt Examiner.

Claims

1. IN AN ARTICLE SORTING SYSTEM HAVING A PLURALITY OF SUCCESSIVE ARTICLE DISCHARGE STATIONS; MEANS FOR CONVEYING ARTICLES SUCCESSIVELY TO SAID STATIONS; AND SELECTIVELY OPERABLE DISCHARGING MEANS AT EACH STATION; ONE SELECTION MEANS FOR SELECTING ANY ONE OF A NUMBER OF SAID DISCHARGE STATIONS; CONTROL MEANS FOR EFFECTING OPERATION OF A STATION''S DISCHARGING MEANS WHEN AN ARTICLE IS AT THE STATION SELECTED FOR THAT ARTICLE''S DISCHARGE; SAID CONTROL MEANS INCLUDING MEANS, RESPOSNIVE TO REPEATED SELECTION OF THE SAME GIVEN DISCHARGE STATION FOR DIFFERENT SELECTION ARTICLES BEFORE THE FIRST OF SAID GIVEN ARTICLES HAS BEEN DISCHARGED AT SAID GIVEN STATION, FOR CAUSING THE DISCHARGE MEANS ON SAID GIVEN STATION TO OPERATE ONLY WHEN SAID GIVEN ARTICLES ARE AT SAID GIVEN STATION; SAID CONTROL MEANS COMPRISING A PLURALITY OF CONTROL DEVICES FOR EACH DISCHARGE STATION, EACH OF SAID CONTROL DEVICES BEING ADJUSTABLE TO A NUMBER OF DIFFERENT CONDITIONS INCLUDING A DISCHARGE-EFFECTING CONDITION; SAID CONTROL MEANS FURTHER INCLUDING MEANS, OPERABLE IN RESPONSER TO OPERATION OF SAID SELECTION MEANS TO SELECT A STATION FOR AN ARTICLE''S DISCHARGE, FOR CAUSING ADJUSTMENT OF AT LEAST ONE OF THE CONTROL DEVICES FOR THAT STATION BEFORE SAID LAST-MEMTIONED ARTICLE HAS ARRIVED AT THE FIRST OF SAID PLURALITY OF STATIONS.