US3440972A - Sorting apparatus - Google Patents

Description

April 969 E. SIDEBOTHAM ET AL 3,440,972

SORTING APPARATUS Filed Jan. 5, 1967 Sheet of 3 COLUMN NO: 1 I 2 g 3 i 4 5 i 5 i t 1 E '5 E E 1 g 1 /MB U {:1 [E5] U U U U Ail J ICE] U [U1 U U 1 m m m U MAGNET BOX 52 2] H 3 mg MOT/UN E U U Q E/i353 U mum [E51 [E35] [3 m UNIT y M R3 L/L R5 M 0005 E 1 i 1 '3 1 0 1 '5 F G .1.

0/6/77 0/1311 2 015/7 3 DIG/7' 4 DIG/T 5 11) (1) 10) (1) R7 51/?2 52 R3 53 R4ms4 R T L3 L3 UNLOAD/NG APPARATUS April l969 E. SIDEBOTHAM ET L 3,440,972

SORTING APPARATUS Filed Jan. 5, 1967 Sheet 3 of s FIG. 3.

. i se a 52 12 gin 9 Iv SD QE'JEIEEDEICJ fi [EV R 7 April 29, 1969 E. SIDEBOTHAM E 2 SORT ING APPARATUS 7 Filed Jan. 5, 1967 Sheet 3 of s FIG. 5.

United States Patent 3,440,972 SORTING APPARATUS Eric Sidebotham, Gadby, and George James Human, Leicester, England, assignors to Associated Electrical Industries Limited, London, England, a British company Filed Jan. 3, 1967, Ser. No. 606,961 Claims priority, application Great Britain, Jan. 7, 1966, 850/66 Int. Cl. B61b 9/00; 361i 3/04; B61l 1/00 US. Cl. 10488 5 Claims ABSTRACT OF THE DISCLOSURE Sorting apparatus for controlling carriers of goods or materials moving along a guided path to required destinations in which an array of coded magnets on the carriers or at the destinations operates corresponding switches at the destinations or on the carriers, the code switches being in series so that a control circuit is completed if the correct combination is operated.

The code switches are two-way switches and the code is set up by two-way selector switches in series with associated code switches so that the control circuit is only completed if the correct combination of code switches had been operated and provided that no unwanted code switches have been incorrectly operated.

BACKGROUND OF THE INVENTION F Md 0] the invention This invention relates to sorting apparatus for con trolling carriers of goods or materials moving along a guided path to required destinations.

This invention relates to sorting apparatus and has an important application in apparatus for controlling carriers moving along a guided path to arrive at selected destinations.

Such requirements arise for instance in conveyor apparatus in which conveyors move along a track to various destinations. In such apparatus it is necessary to provide selector apparatus on the carriers which register with apparatus when the various destinations are reached; the apparatus, however, is coded so that a carrier is only stopped or discharged at the correct destination. It is known to provide catches on the carriers which operate banks of switches at the destinations, the switches being coded so that the correct combination must be operated to discharge or stop the carrier. However such arrangements have the disadvantage that the apparatus is subject to mechanical wear which after a while may lead to failure.

It has also been proposed to use magnetic or electrical devices in place of the mechanically operated switches; however these have required complicated logic circuitry.

The main object of the invention is to provide an improved arrangement which is both simple and reliable.

According to the present invention apparatus for controlling carriers moving along a guided path to required destinations comprises an assembly of series connected switches on each carrier or at each destination as the case may be, and a corresponding array of magnets at each destination or on each carirer, the switches and magnets being so positioned that when a carrier is at a destination the magnets operate corresponding switches, the individual switches and magnets being similarly coded so that when a carrier is at its correct destination the combination of switches operated completes a control circuit to divert and/or unload the carrier.

Preferably the magnets are permanent magnets, they may, however, in some cases be electromagnets.

According to a preferred embodiment the code switches are two-way switches and in series with each magnet operated code switch is a two-way selector switch whereby the code to which the control circuit responds may be preset.

Such an arrangement is simple and hence reliable since the electrical circuit is only completed when the correct combination of switches has been operated and it is not necessary to have complicated circuitry to effect the selection.

Preferably the magnets are arranged in rows parallel to the direction of relative motion the rows being either filled or vacant in accordance with a binary code. To avoid fortuitous closure of the circuit there may be an additional row, referred to as a strobe, and which is located at the midposition of the array of rows of magnets. The strobe ensures that the circuit can only be completed when the carirer is in its midposition at a destination, this helps to avoid chance operation of a combination of switches which completes the circuit.

In order that the invention may be more clearly understood reference will now be made to the accompanying drawings in which:

FIG. 1 shows an example of the arrangement of the magnets in the magnet box;

FIG. 2 shows an example of the electrical control circuit arranged to be used in the magnet box of FIG. 1;

FIG. 3 is a plan view of a portion of track at a destination according to one arrangement;

FIG. 4 is an elevation to an enlarged scale of the end of the carrier in the arrangement shown in FIG. 1;

FIG. 5 is a plan view of a portion of track at a destination showing another arrangement of the control apparatus, and

FIG. 6 is an elevation of the end of the carrier in the arrangement of FIG. 5.

The embodiment shown in the drawings comprises two parts. One part, the magnet box, contains an assembly of magnets arranged in coded formation, the code representing the address in binary form. The other part, the pickup unit, contains an assembly of magnetically biased reed switches. One part is mounted on each carrier, shown in the drawings as a vehicle, the others on the track in such a manner that as the vehicle moves along the track the magnets and pickup units are brought into register at a destination. The reed switches respond tothe field of the magnets and take up positions corresponding to the code.

Associated with each of the reed switches is a manual presetting switch. The desired code is set up on these manual switches. When the reed switches assume positions corresponding to the code, and at no other time, a circuit is completed through the contacts of all the reed switches and all the manual switches in series. T his circuit, which is completed only when a pickup unit is in register with a magnet box containing the same code as is set up on the pickup unit manual switches, can be used to control any required function, such as operation of points.

A magnet box suitable for a 5-digit code could be arranged as shown in FIG. 1. The magnets are arranged in a number of columns, one more than the number of digits in the code. The extra column is used for a strobe signal. In this case there are six columns, of which the first five are used to represent the code. Column 6 represents the strobe.

Magnets may be placed in each column. The presence of magnets in a column represents a l in the code, their absence represents a O. In the example shown there are magnets in columns 1, 2, 3, and 5 but not in 4, the code is therefore B1 101.

Patented Apr. 29, 1969 A number of magnets is used in each column, all arranged With the same polarity, to provide a substantially uniform field in the longitudinal direction. But it should be noted that magnets in adjacent columns have opposed polarity. The pickup unit has a number of reed switches R R arranged in positions corresponding to the columns of the magnet box. The polarising magnets of these reed switches have polarities which alternate from column to column, and which are opposed to the polarities of the magnets in the corresponding columns of the magnet box.

It will be seen that if pickup unit and magnet box are superposed, the polarising of those reed switches which are in register with 1 columns will be cancelled by the fields from the magnet box, and these relays will change over. Reed switches over columns will not have their polarisation cancelled and will not change over.

The lpickup unit and the magnet box are kept in accurate register laterally by the guidance means of the vehicle. This accurate alignment combined with the alternating of polarities from column to column gives high adjacent channel rejection, i.e., there is very little risk of the reed switch in one column being affected by magnets in adjacent columns.

At either end of the magnet box, there exists a firinge field which is the field first encountered by the pickup unit as the two come into proximity. When the reed switches are in this fringe field there is a possibility of them chattering or of one changing over before or behind the rest. False codes may be set up, or the correct code set up momentarily and lost again. To prevent false energisation of the external circuits by these elTects, the strobe system is provided. The last column, i.e., column 6 in the magnet box is always fitted with a number of magnets which is less than the number fitted in an address column (of the order of one-third). The address columns therefore overlap the strobe column at both ends. By the time the strobe reed switch comes under the influence of the magnets in the strobe column and changes over, the address reed switches are in the area of uniform field, and have taken up their correct settings. A contact of the strobe reed switch is included in series with the output circuit of the pickup unit, so that the external circuit cannot be energised until the strobe reed switch is operated.

FIG. 2 shows an arrangement of the control circuit of the pickup unit. The switches R R are reed switches operated by the magnets and the switches S S are manually operated presetting switches, both the switches S and S are two-way switches and this ensures that the correct combination of switches R etc., must be operated and that not only must all the necessary switches be operated but that switches not in the code must not be operated or the circuit will not be completed.

Assuming that a binary code is used and that a switch must be down for a 1 and up for a 0. FIGS 1 and 2 show the conditions for a code of 11101. It will be seen that with this code set up on the manual switches, no through circuit is possible until the code reed switches corresponding to the 1st, 2nd, 3rd and 5th digits and the strobe reed switch have operated, and the fourth code reed switch is not operated.

The code used for the addresses may be straight binary, binary coded decimal, or any other form of binary code, the basic requirement being a unique code for each address. The switches on the pickup unit may be single pole changeover manual pushbutton or toggle switches, on which the address code may be setup in binary form. It is preferable to set up the address in decimal form and convert this to binary, since a decimal code is less liable to error, particularly with unskilled operators. This can be done by using multipole decade rotary switches or pushbuttons. If the switches have a number of banks equal to the number of digits in the code, circuits can be arranged over the switch contacts which will convert the 4 decimal input into the appropriate binary form, and effectively produce the circuit of FIGURE 2.

It will be noted that either the magnet box or the pickup unit can be mounted on the vehicle, the other being mounted on the track. Which method is selected will depend on the requirements of the particular application.

One application is to a system for the shipping of goods to a number of destinations. A closed loop of track passes through a loading area and past the ends of a multiplicity of shipping bays. Tracks in the bays are connected to the loop through points, which are normally set for motion along the loop. Vehicles can be connected to a continuous chain which moves them around the loop. If a point is set to divert a vehicle into a shipping bay, the coupling to the chain is automatically disengaged. Levels are arranged so that the bays fall away from the main loop, and the carrier runs into the bay by gravity. Each bay is allocated to one destination.

In this case it is more convenient to have the pickup unit on the truck. Goods arriving in the loading area may be for any destination. A vehicle is loaded with goods for one shipping bay, the address of that bay set up on the :pickup unit, and the vehicle coupled to the chain. In the track, just ahead of the point leading to each bay, is a magnet box containing the code for that bay. When the vehicle reaches the magnet box of the bay to which it is addressed, the recognition circuit in the pickup unit is made up. This causes a signal to be extended to the points operating mechanism and the vehicle is diverted into the bay, the points being reset again behind it.

In this application it is necessary to pass a signal from the moving vehicle to the points operating mechanism attached to the fixed track. This can be done in a variety of ways. For example, an accoustic transducer on the truck may emit a narrow beam of energy when the pickup unit recognises its address, this signal being picked up by a microphone associated with the corresponding points mechanism. The use of a narrow beam at low power eliminates any possibility of accidentally triggering point mechanisms other than the one intended.

It is also necessary to carry on the vehicle a power supply for the supersonic transducer or other signalling means. The power level will be low since the signal is only required to be effective over very small distances, commonly a few inches, and is only required when the pickup unit recognises the correct magnet box. Therefore the power can be obtained from dry batteries which Will have a long life due to the small and very intermittent drain.

FIGS. 3 and 4 show such an arrangement, a carrier shown as a vehicle V moves from right to left along a track comprising rails R. At a destination the vehicle V can be diverted by points P into a siding D.

The control apparatus for operating the points comprises a magnet box MB on the track, this magnet box may for instance be as shown in FIG. 1 and cooperates with a pickup unit PU on the vehicle.

The pickup unit PU may be as shown in FIG. 2 and is arranged when the control circuit is completed, to energise a supersonic transducer SD. The supersonic output is picked up by a microphone MIC on the track and the electrical output feed to an amplifier AMP which is arranged to generate a signal sufiicient to operate a motor M to change over the points P and divert the vehicle into the siding D.

Clearly the microphone must be of a type which responds only to supersonic sound and not to audible sound otherwise there would be a risk of the apparatus being incorrectly operated by noise.

FIG. 4 is an enlarged view looking at the left end of the vehicle it will be seen that the presetting box is graduated in a decimal code, this as explained above is for simplification, the decimal code would be converted to a binary code by means of apparatus which is well known and the binary code signals produced would be used to actuate switches S S as shown in FIG. 2. It will be noted that the pick up unit is set to the decimal number 29 and this corresponds to the binary number 11101, which is the binary number to which the magnet box is set in FIG. 1. With the above arrangement the pickup unit will only respond to the correct magnet code and when this happens it will actuate the supersonic generator SD. Since the unit SD will at this time be positioned over the microphone MIC the points will be changed over. Such an arrangement has the advantage that most of the apparatus is located on the ground and there is minimum of equipment on the vehicle.

In the application above described, any vehicle may be sent to any address, and also a particular vehicle may well be sent to difierent addresses on successive occasions. Therefore it is necessary to have the pickup unit, which can be set up for any address, on the vehicle. Other applications can be visualised in which vehicles are required always to home to a fixed address. (Difierent vehicles might well have different home addresses.) In this case it would be preferable to carry the magnet box on the vehicle and mount the pickup unit on the track. No additional equipment is required on the vehicle and the pickup unit can operate point control circuits, etc., directly.

FIGS. 5 and 6 show such an arrangement in which only the magnet box MB is mounted on the vehicle and the pickup unit PU on the ground. In this arrangement there is no supersonic link and the magnet box operates the pickup unit which sends a signal direct to the amplifier and points motor.

The magnet box and pickup unit can each be complete ly self-contained. Neither require any power supplies in themselves, though power is required for the external apparatus controlled by the pickup unit. The only components required are magnets, magnetically polarised reed switches and manual switches, all of which have very long lives. The magnet box and the reed switch assembly of the pickup unit may be potted in resin, making it virtually impossible for the magnets and reed switches to change their relative positions.

Any form of binary codemay be employed. Addresses may be set up in decimal notation, with consequently little risk of error, and change to the required binary form by the prewired arrangement of switch contacts.

The system is not susceptible to extenal interference. Good adjacent channel rejection is achieved by alternating the magnet polarities. The use of a strobe signal avoids false addresses being read as the pickup unit approaches a magnet box.

Whilst the above embodiments concern vehicles running over a track the invention is not limited to such arrangements but is applicable to the overhead type of track in which loads are suspended from bogies moving along an overhead rail.

The propulsion means could well be an endless chain moving along the main loop and provided with dogs which engage the carriers or bogies, when a carrier is diverted 011 the main line the lateral movement automatically moves the carrier out of engagement with the dog.

It will also be appreciated that in some cases the carriers may merely be off-loaded at a destination Without being diverted from the track.

We claim:

1. Sorting apparatus for controlling carriers moving along a guided path to required destinations including an assembly of series connected two-way code switches, a coded array of magnets, means whereby said magnets are brought into operative relationship with associated code switches when a carrier is positioned at a destination, a two-way selector switch in series with each code switch for presetting the code, a strobe switch in series with the code switches, additional magnet means arranged to operate the strobe switch for a part of the time during which the code switches are operated and means whereby a control circuit is completed if the correct combination of code switches and the associated strobe switch are actuated and control apparatus operated if the control circuit is completed.

2. Sorting apparatus for controlling carriers moving along a guided path to required destinations comprising: an assembly of: two-way code switches, a coded array of magnets, means responsive to the positioning of a carrier at a destination for bringing said magnets into operative relationship with associated code switches, a two-way selector switch associated with each code switch for presetting the code, a series control circuit in which the code switches are connected alternately with the associated selector switches so that all the switches are in series, and control means operated if the control circuit is completed by actuating only the correct combination of code switches.

3. Sorting apparatus as claimed in claim 2 comprising: apparatus actuated by the control means and effective to divert a carrier from the guided path at a destination if the control circuit is completed by actuating only the correct combination of code switches.

4. Sorting apparatus as claimed in claim 2 comprisings: apparatus actuated by the control means to unload a carrier at a destination if the control circuit is completed by actuating only the correct combination of code switches.

5. Sorting apparatus for controlling carriers moving along a guided path to required destination comprising: a first set of apparatus comprising a coded array of magnets, a second set of apparatus comprising a series control circuit including two-way code switches connected alternately with two-way selector switches so that the switches are all in series, one of said sets of apparatus being mounted on a carrier and the other of said sets being mounted in a fixed position at a destination, means responsive to the positioning of a carrier at a destination for bringing the magnets into operative relationship with associated code switches, and control means operated if the control circuit is completed by actuating only the correct combination of code switches.

References Cited UNITED STATES PATENTS 3,100,040 8/1963 Kleist 198-38 3,158,710 11/1964 Paglee 104-88 3,173,533 3/1965 Zuck 198-38 3,214,003 10/1965 Wilson 19838 3,328,597 6/1967 De Witt 19838 ARTHUR L. LA POINT, Primary Examiner.

DANIEL F. WORTH III, Assistant Examiner.

U.S. Cl. X.R. 104-172

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