Electronic Counter Memory Means For Sorting Systems

Abstract

A memory means for a sorting system which includes conveyors which have separate article carrying means of the type having mechanisms for discharging articles when the article carrying means reach predetermined locations along the path of conveyor movement. The memory means comprise electronic counters operated in conjunction with the conveyor movement. The counters are connected to discharge mechanisms associated with the respective discharge locations situated adjacent the conveyor. Each counter is designed to operate the discharge mechanisms when a code unique to that counter is applied at a coding station and after the conveyor has moved a specified distance. Each counter has a plurality of terminals which may be alternatively selected to thereby vary the discharge position by distance increments.

Description

This invention relates to a memory means designed for use in conjunction with sorting systems employing conveyors adapted to carry articles and to discharge the articles at preselected locations along the conveyor path.

Memory systems have previously been devised for operation in conjunction with conveyors. A description of a memory system if found, for example, in Harrison et al. U.S. Pat. No. 3,167,192. This system involves the use of a memory timer employing a series of balls which may be successively dropped into a channel in response to successive operations of a solenoid which is controlled by keys on a selector board. The balls can then be subjected to a stepping operation with the movement of the balls being controlled in phase with the movement of individual conveyor trays. The actuation of tripping means for a particular tray will depend upon the number of balls inserted in the channel since the balls will serve as contacts in a circuit including a solenoid. Speaker U.S. Pat. No. 3,034,665 also discloses a memory system used for tripping conveyor means.

In copending application Ser. No. 776,074, filed on Nov. 15, 1968, and entitled "Memory System For Conveyors," now Pat. No. 3,482,260, issued on Dec. 2, 1969 there is described a memory means which is greatly simplified when compared with prior devices and which is compact and relatively simple in construction so that installation and maintenance can be carried out on an efficient basis. The system includes a memory wheel which is synchronized for movement with the conveyor. A magnetic writing head applies a code to the wheel when an article is loaded on the conveyor, and a plurality of reading heads are located in spaced relationship relative to the writing head. The writing head and reading heads are associated with electronic counters, and the system is synchronized so that the code for a particular reading head will reach that head at the same time that the conveyor reaches a discharge location assigned to the reading head. Circuit elements operate discharge means for the discharge location in response to reading of the code by the reading head.

It is a general object of this invention to provide a memory system which improves upon the system described in said application and which provides ideal means for controlling the discharge of articles from individual conveyors, for example conveyors of the type employed in systems described in the aforementioned patents.

It is a more specific object of this invention to provide a memory system which is simple in construction and compact so that only a small amount of space is required for installation of the system, which is characterized by a relatively simple operating principle, and which includes relatively simple operating parts so that unduly complicated operating and maintenance problems will not develop.

It is a more particular object of this invention to provide a memory system which is simple in construction and compact so that only a small amount of space is required for installation of the system, which is characterized by a relatively simple operating principle, and which includes relatively simple operating parts so that unduly complicated operating and maintenance problems will not develop.

It is a more particular object of this invention to provide memory means which provide circuit elements individually associated with a plurality of discharge locations along a conveyor path, each of the circuit elements being individually adjustable whereby the exact point of discharge at a particular location can be easily adjusted independently of each of the other discharge locations.

These other object of this invention will appear hereinafter and for purposes of illustration, but not of limitation, a specific embodiment of the invention is illustrated in the accompanying drawings in which:

FIG. 1 is a schematic illustration of circuit elements and conveyor means utilized in the system of the invention;

FIG. 2 is a schematic illustration of coding means employed in the construction;

FIG. 3 is a schematic illustration of connections for discharge actuating mechanisms;

FIG. 4 is a table indicating terminal connections and distances for various discharge points;

FIG. 5 is a circuit diagram for a read output module; and

FIG. 6 illustrates synchronizing means employed at a loading station.

The memory means of this invention is associated with a sorting system which includes a plurality of spaced apart article carrying means having conveying devices associated therewith. A loading station is provided for depositing articles on the article carrying means, and a plurality of discharge locations are positioned along the path of conveyor movement.

Memory means of the type including a coding device which operates when an article is deposited on a conveyor are provided. The memory means is associated with a discharge device, for example a solenoid operated tripper for a conveyor tray, and the memory means operates so that the discharge device will be actuated when the conveyor carries an article to a discharge station related to the code applied to the memory means.

In accordance with this invention, the memory means comprises individual electronic counters associated with each discharge location. Each counter is provided with a plurality of terminal means, and actuating means for the discharge device are connected to selected terminals. Pulse generating means are connected to each of the electronic counters, and when a code assigned to a particular counter is introduced to the counter, the counter becomes receptive to pulses. The pulses are introduced at a rate related to the conveyor speed. Accordingly, when a sufficient number of pulses has been introduced, the counter will operate the discharge device for that station, and the article deposited and assigned to that station will be removed from the conveyor.

An operator may be employed for applying codes each time an article is located on a conveyor. For example, a keyboard may be positioned at a loading station, and a particular electronic counter will be made receptive to pulses depending upon the keys actuated. The system of this invention is, however, highly suited for an automated sorting operation wherein a code is displayed on a package or other article, and is adapted to be read by computer equipment. The code can then be fed directly to the counters.

By providing a system which includes counters having a plurality of separate terminals which can be connected in various ways to discharge means, the specific point of discharge at a particular discharge location can be readily adjusted. Thus, the number of pulses required to operate a particular discharge device may be increased or decreased by switching to a different terminal of the counter. In accordance with a preferred form of this invention, the pulses are introduced to the counter from separate sources at different frequencies with the conveyor travel per pulse being different. This provides different degrees of adjustment thereby increasing the ease of incorporating the system in various installations.

FIG. 1 of the drawings illustrates schematically a conveyor path 10 having a plurality of discharge stations 12 situated on either side of the conveyor path. A loading station 14 is provided adjacent the path of movement of trays 16 which form a part of the conveyor. For purposes of this description, it may be assumed that the trays 16 are of the type shown in the aforementioned patent wherein tripping means operated by solenoids are actuated by the memory means when a tray reaches a predetermined discharge location. As will be explained, the circuit elements of this invention are designed to operate solenoids located at the respective discharge locations 12. It will be appreciated, however, that the output of the circuits connected to the memory means could be employed for operating other means designed to achieve a discharging operation.

FIG. 1 also illustrates an operator 18 stationed adjacent keyboard 20. The keyboard 20, as shown in FIG. 1, is connected to a pulse generator 22. The generator 22 may be connected as shown in FIG. 1 to a sprocket or the like 24 associated with a chain or other means moving in synchronism with the conveyor trays. Any suitable means may be employed for utilizing the mechanical output of the conveyor to generate electrical pulses, for example by driving a notched wheel by tying the wheel to a conveyor sprocket. A proximity sensor, for example, of the type manufactured by National Acme Company, may be positioned adjacent the notched wheel whereby a pulse will be produced each time a notch moves past the sensor. The frequency of the pulses for a particular notched wheel will, therefore, depend directly on the speed of the conveyor. Different frequencies can be obtained by using different wheels or by interposing gear reduction.

In the specific form of the invention to be described, pulses from the pulse generator 22 are fed to read output module 26 through line 28. One pulse is produced for each 3 inches of conveyor travel.

Pulses are also fed from the generator 22 through line 30 to the divide-by-nine divider 32. Pulses from this divider are then passed through line 34 at a frequency of one pulse for every 27 inches of conveyor travel. A two-phase converter driver 36 is employed for delivering these pulses in two phases to the read output module 26. As will be explained, this two-phase input to the read output module 26 is required where shift registers of the type requiring a two-phase clock are employed. It will be understood that the references to one-phase or two-phase input to the read output module are for illustration purposes since the concepts of the invention may involve the use of signals of all one phase or of various combinations depending upon the circuit elements utilized.

The keyboard 20 operates to send signals through line 38 to the read output module 26. As will be explained, the code input through the line 38 makes the read output module responsive to the clock pulses, and when a specified number of pulses have been introduced, a signal is then delivered through line 40 to discharge mechanism. A read output module is associated with each discharge station along the conveyor path. In the specific arrangement to be described, 62 stations are provided. It will be apparent, however, that the number of these stations can be varied considerably without departing from the concepts of the invention.

FIG. 2 illustrates the manner in which a plurality of read output modules 26 are tied to a coding mechanism. In this particular illustration, the coding mechanism comprises binary code input lines 42 connected to the binary to decimal converter 44. 17 converter input lines 46 are provided for connection with the read output module code input lines 38. The lines 46 represent the single digits 0 through 9, and the double digits 00 through 60. A 2-input AND gate is provided for each read output module 26 and, therefore, some combination of two of the 17 lines 46 must be connected to each read output module. In practice, the 00 line is connected to the modules for each of the stations one through 9 along with the single digit. The 0 line is connected along with the appropriate double digits for the stations 10, 20, etc. For the stations 11 through 19, 21 through 29 etc., the double digit is connected along with the appropriate single digit.

The lines 42 are connected to a translator 48 which is in turn connected to the keyboard 20. In a typical use of a construction of the type described, an operator may punch a series of numbers on the keyboard, for example a particular zip code, if the apparatus is used for sorting packages in a post office. The translator 48 will be programmed to determine which discharge location is applicable for this zip code. The binary output of the translator is then fed to the converter 44.

After the operator punches the keyboard 20, the package or other article is moved onto the conveyor. In order to synchronize the conveyor movement with the pulse counting operation, the translator 48 preferably stores the code until a pulse is received from the 27-inch driver 36 through line 50. A switch 52 is included in the line 50, and this switch may be connected to an electric eye 54 (FIG. 6). The beam of the eye will be interrupted by the article 56 being coded thereby maintaining the switch 52 in the open position. When the article is then moved onto the conveyor, the switch 52 will close, and the code will be stored until the next pulse is delivered through line 50. The initiation of code input to a particular read output module can then be precisely timed in accordance with the position of the conveyor.

Instead of the system described, the input to the lines 46 may be provided by a keyboard directly connected to these lines. A similar technique for delaying transfer of the code to synchronize the pulses with the transfer may be provided.

FIG. 3 illustrates a plurality of tripper solenoids 62 of the type which may be associated with the various discharge locations along the conveyor path. The solenoids are connected to the lines 40 extending from the read output module. A control switch may be provided for each solenoid so that any particular discharge station may be deactivated.

A read output module 26 which embodies the concepts of the invention is shown in FIG. 5. The lines 38 for this module extend to a 2-input AND gate 66 so that the module can be made receptive to pulses only if a signal is received simultaneously in both lines 38. The flip-flop 68 is activated when such signals are received to thereby send a pulse through transistor 70 and to the shift registers 72, as data "in" entry.

Clock pulses are continuously fed through the 27-inch clock lines 74 from the converter driver 36. The first pulse through the transistor 70 makes the registers receptive to these clock pulses, and this input continues until a count is completed throughout the registers 72. The first pulse through the lines 74 also serves to reset the flip-flop 68 but on the trailing edge of that pulse.

The shift registers 72 are all "16-bit" registers and with 10 of these being provided, a total of 160 pulses are fed in before these registers are cleared. An additional 8-bit register 76 is included in the same series, and eight additional pulses are required to clear this register.

An 8-bit register 78 is also connected to the 27-inch clock lines 74. Eight additional pulses are required for clearing this register.

The 3-inch clock line 28 is connected to the 8-bit register 80. Eight pulses are also required for clearing this register once a pulse from the line 28 is fed in.

The 10 16-bit registers 72 are connected, respectively, to one of the output terminals 80. The 8-bit register 76 is connected to terminals 80. The 8-bit registers 78 and 80 are provided with 8 selectable output terminals 84 and 86, respectively.

As shown at the far right of FIG. 5, the line 40 which extends to the tripper solenoid is connected through transistors 88 and 90 to the line 92. When a signal is generated by the read output module, this signal is sent through line 92 for energizing the attached solenoid 40. The particular time that a signal is sent through the line 92 will depend upon which of the terminals for the shift registers are connected to this line. The terminals to be connected depend upon the distance between a particular discharge station and the loading station for the conveyor. FIG. 4 comprises a table which illustrates how particular terminals are selected for particular discharge points.

The first discharge point in the assembly is located 19 feet 3 inches away from the induction or loading station. Since the conveyor will move 27-inch clock, the input for each pulse delivered from the 27-inch clock, the input from this clock is connected to the input 94 for the 8-bit register 78. This is accomplished by connecting the 0 line 96 from the transistor 70 directly to the input 94.

As indicated in column 3 of the table in FIG. 4, the -8 terminal of the register 78 is employed. Eight pulses must be introduced before there is an output signal at this terminal. During this period, the conveyor will travel 18 feet.

The output signal from the -8 terminal is then applied to the input line 98 for the register 80. This input line extends to diode 100 which forms an AND gate with the diode 102. Accordingly, the combination of signals from the 27-inch clock input, the input line 98, and the 3-inch clock 28 will activate the register 80. As indicated in column 6 of the table in FIG. 4, the -5 terminal of the register 80 is employed. When five 3-inch pulses have been introduced, the conveyor will have moved an additional 15 inches to provide the desired 19 feet 3 inches of travel. The output signal from the -5 terminal of the register 80 is applied to the driver line 92 so that the solenoid will operate at this point.

The output modules 26 for the other discharge locations are connection in a similar fashion depending upon their distance from the induction point. In the case of the -62 discharge point, a distance of 382 feet 10 inches must be traveled before discharge takes place. To accomplish this, each of the 16-bit registers 72 is utilized by employing the -160 output line 80. 160 pulses are required before a signal is applied to this line during which time the conveyor will have moved 360 feet. The output from the -160 terminal is applied to the 8-bit register 76 to achieve an additional 18 feet of travel. The output from this 8-bit register is then applied to the input line 94 of the register 78 and a signal is then taken off the -2 terminal of this register to provide an additional 4 feet 6 inches of travel. This signal is then applied to the input of the register 80 through line 98 and a signal is taken from the -1 output of this register and applied to the driver line 92. This additional 3 inches provides a total travel of 382 feet 9 inches. It will be observed that the system described, by employing increments of 3 inches for fine adjustment, will never be more than about 11/2 inches away from a discharge point which is calculated to be the ideal discharge point for a particular operation.

The ability to select a particular terminal arrangement for each output module 26 permits the installation of a conveyor system which does not depend upon the location of discharge points in a particular pattern. Thus, the system described can easily accommodate a conveyor system which has discharge points located in completely random fashion. Obviously, the reference to 27-inch and 2-inch increments is provided only for purposes of illustration since any relationship between the pulses and conveyor travel may be selected, including a system having more than two increments. As in the described case, however, the number of smaller increment terminals should be sufficient to permit selection of discharge positions throughout the range of a larger increment.

In addition to permitting random location of discharge points, the memory system easily accommodates changes in discharge points. If it is found desirable to move a station a few feet or to adjust the position of the tripper operation, this can be accomplished by simply changing the terminal connections. Preferably each of the modules 26 is mounted in a single housing, and they can be made easily accessible to greatly simplify such procedures.

Solid state components are available for use whereby maintenance problems and adjustments are virtually eliminated. The entire system can also be placed in a very compact housing and located in a remote position relative to the conveyor.

In the event of a malfunction at one discharge location, the remaining portions of the system are completely unaffected. The plug-in module for the particular location can be disconnected and maintenance work carried on without in any way disrupting the operating capabilities of the other discharge systems.

It will be understood that various changes and modifications may be made in the above-described system which provide the characteristics of this invention without departing from the spirit thereof.

Claims

I claim:

1. In a sorting system wherein a plurality of spaced-apart article carrying means are associated with a conveyor, a loading station for depositing articles on the article carrying means, a plurality of discharge locations positioned along the path of conveyor movement, discharge means at said locations and memory means including means for receiving a code as an article is deposited on the conveyor, the memory means initiating automatic operation of discharge means for said articles when the articles reach a discharge location related to the code, the improvement wherein said memory means comprises an electronic counter associated with each of said discharge locations, a plurality of terminal means for each of said counters, pulse generating means connected to said electronic counters, said counters operating to deliver signals to said terminal means in sequence depending upon the number of pulses counted, means for connecting selected terminal means to said discharge means, coding means connected to each of said electronic counters and means for making the individual counters receptive to pulses from said pulse generating means depending upon the code applied by said coding means, said electronic counters initiating operation of an associated discharge means when the pulses introduced are sufficient to deliver a signal to the terminal means connected to the associated discharge means.

2. A system in accordance with claim 1 wherein the pulse frequency is directly related to the speed of the conveyor whereby a specific distance of conveyor travel occurs for each pulse introduced into a counter.

3. A system in accordance with claim 2 wherein separate pulse sources are provided, the frequency of one source being such that a substantially greater distance of conveyor travel occurs per pulse than is the case with the other source.

4. A system in accordance with claim 3 wherein a plurality of separate terminals are provided for counters connected to each pulse source whereby multiples of a greater distance and multiples of a shorter distance may be combined for each discharge location.

5. A system in accordance with claim 3 including means for delaying the input of pulses from said other source until after all pulses from said one source have been counted by associated counters.

6. A system in accordance with claim 4 wherein said counters comprise shift registers connected for operation in series, a portion of said registers having a single output terminal whereby a plurality of pulses are required for developing one output signal, and a portion of said registers having a plurality of output terminals whereby an output signal is available for each pulse introduced to said last-mentioned registers.

7. A system in accordance with claim 6 wherein the shift registers having a single output terminal receive pulses at a frequency allowing the greater distance of conveyor travel, and wherein the shift registers having a plurality of output terminals receive pulses at a frequency allowing both a greater and lesser distance of conveyor travel.

8. A system in accordance with claim 1 wherein the means for making the counters responsive to pulses from said pulse generating means include a signal transmitted from said coding means, and including means for synchronizing the input of said signal from said coding means with a pulse from said pulse generating means.

9. A system in accordance with claim 8 including means for storing a code immediately after operation of said coding means, said storing means operating to release said code to said counters upon introduction of a pulse from said pulse generating means into said storing means to thereby synchronize release of said code with a pulse from the pulse generating means.

10. A system in accordance with claim 9 wherein articles are deposited on the conveyor adjacent a coding station, means for sensing the presence of an article being coded at the coding station, and wherein said storing means operates to delay release of said code to said counters until the article coded is moved away from said sensing means and onto the conveyor.