US 3141123 A
Description (OCR text may contain errors)
July 14, 1964 E. E. OLSON SELECTION DEVICE 2 Sheets-Sheet 1 Filed Aug. 16, 1962 INVENTOR. A /mar Z 4 ark) [Car/er if/ame /a.
July 14, 1964 E. E. OLSON SELECTION DEVICE 2 Sheets-Sheet 2 Filed Aug. 16. 1962 Q i i S E 0 a a. 2 :i E:
United States Patent 3,141,123 SELECTION DEVICE Elmer E. Olson, Nashotah, Wis, assignor to G. B. Lewis Company, Watertown, Wis, a corporation of Wisconsin Filed Aug. 16, 1962, Ser. No. 217,474 4 Claims. (Cl. 318-467) This invention relates to a selection device.
One purpose of the invention is a selection device which automatically determines the shortest path for the selected member to travel to a predetermined point.
Another purpose is a selection device of the type described in combination with a moving shelf arrangement, whereby a selected shelf travels the shortest path to a predetermined point.
Another purpose is a new and improved memory switch arrangement for use in a selection device of the type described.
Other purposes will appear in the ensuing specification, drawings and claims.
The invention is illustrated diagrammatically in the following drawings wherein:
FIGURE 1 is an electrical schematic diagram of the selection device,
FIGURE 2 is a perspective of a moving shelf arrangement, and
FIGURE 3 is an enlarged view of the controls of FIGURE 2, with parts in section.
Considering the circuit of FIGURE 1, a pair of multiposition selector switches 28 and 22 are contained in a housing indicated at 18, and are ganged together for simultaneous operation, as indicated by the broken line 24. Each of the switches and 22 has a number of terminals or positions, with the number of terminals on each switch being the same. As an example, each switch has terminals numbered 1 through 13. Switch 20, in addition, has five terminals, un-numbered, which are di rectly connected to terminals 9-13 as will be described hereinafter.
A rack or bank of two-position switches, for example microswitches, is indicated at 26 and includes microswitches numbered 1 through 13 to correspond to terminals 1 through 13 on the multiposition switches 20 and 22. Each of the microswitches has a terminal a and a terminal I), with each switch normally being closed to terminal I), as indicated in FIGURE 1. The third terminals 0 of each microswitch are connected together by a wire 28,-wire 28 in turn being connected to the secondary 30 of a transformer indicated generally at 32. The primary 34 of the transformer 32 may be connected to a suitable source of power.
The secondary 30 of the transformer 32 is connected by a wire 36 through a coil 38 to a start switch 40. The lower terminals 42 of the start switch 40 are connected to pointer 44 on the multiposition switch 20. It should be noted that the pointer 44 actually is in the form of a segment and connects together a number of terminal positions, when in anyone position on the switch. The number of positions connected together is, important in determining whether a selected member should move in a forward or reverse direction to take the shortest distance to a predetermined point, and should always be half or less than half of the total number of available positions. For example, in the example illustrated herein, there are 13 positions and 13 microswitches. Accordingly, the segment 44 connects together six positions, when in any one position on the switch. If there were a total of 14 positions around the switch 20, then the segment 44 would connect seven of these positions.
Wire 36 also connects to a forward and reversing starter in which the reversing coil for the starter is indi- 'ice cated at 46 and the forward coil for the starter is indicated at 48. Connected to the reversing coil 46 is a pair of contacts 50, which are normally closed, and which are opened by the passage of current through relay coil 38. Connected to the forward starting coil 48 is a pair of contacts 52, which are normally open, and which are closed by operation of relay coil 38. Contacts 50 and 52 are both connected to one of the upper terminals 54 of start switch 40. Wire 56 runs from the other upper terminal 54 to the far side of a pair of normally open contacts 58, the operation of which is controlled by the forward starting coil 43. When current passes through the forward starting coil 48, to start the motor hereinafter described in a forward direction, contacts 58 will close to lock in the operation of the motor. In like manner, normally open contacts 60' will be closed by operation of the motor in the reverse direction with current flowing through the reverse coil 46. A stop switch 62, which may be used for emergency stops, is connected to the normally open contacts 53 and 60 and to a pointer 64 on multiposition switch 22.
It should be noted that each of the terminals 1-13 on multiposition switch 20 are connected to terminal a of one of the two-position switches 1 through 13. This connection is important. For example, terminal 1 on switch 20 is connected to terminal a of two-position switch 13. Terminal 2 on switch 20 is connected to terminal a on two-position switch 1. In like manner the remaining terminals on multiposition switch 20 are connected to one of the terminals a of the switches 1 through 13. Each of the terminals on multiposition switch 22 is connected to a terminal b on the switches 1 through 13. In this case terminal 1 is connected to terminal b on switch 1, and terminal 2 is connected to terminal b on switch 2, etc.
FIGURES 2 and 3 illustrate a moving shelf conveyor which may use the selection device of FIGURE 1. Upper and lower frame members 66 and 68 may be held together by suitable vertical frame members 70. On top of the upper frame member 68 is a suitable motor or the like 72, which can operate in both the forward and reverse direction and is controlled by the motor starter illustrated in FIGURE 1. The motor 72 may drive a suitable belt or other flexible drive member 74 which runs around a grooved wheel 76, the wheel in turn being integrally joined with an upper sprocket wheel 78. A suitable chain or the like may pass around the upper sprocket wheel, of which there is a similar wheel on the opposite side of the assembly, and then around a lower sprocket wheel 82. Suitable guardsor the like 84 may be positioned along both sides of the shelf to shield the chain and keep it from becoming entangled. Mounted to the movable chains are shelf units indicated generally at 86. As shown herein each shelf unit consists of two spaced shelves, fixed together and swingably mounted to the chains 80. The invention should not be limited to this type of structure as merely a single shelf 'finds wide application. In any event, there are .the same number of shelves as there are two-position switches or microswitches.
The rack or bank of microswitches 26 is fastened to the framework of the shelf unit and extends between the back and front shelves. Extending rearwardly from the back of each shelf unit is a projection or tab or ear 88. It should be noted that the projections on each shelf unit vary in position and as the shelf units move down by the rack of microswitches 26, the projection on each shelf unit will strike the microswitch with which it is associated. In this way each shelf unit will be stopped at a predetermined location, normally approximately waist level for easy removal of the contents of the shelf. As
=3 soon as the projection 88 strikes the arm of the microswitch and moves the microswitch from terminal b to terminal a the shelf unit will stop as there no longer will be power to the motor.
The use, operation and function of the invention are as follows:
Although the selection device of this invention has been shown in conjunction with a movable conveyor shelf arrangement of the type shown in copending application Serial No. 199,736, filed June 4, 1962, the invention should not be limited to this application. The selection device has wide application and can be used wherever there are a number of movable members to be selected and where movement of the selected members can be used to start and stop the device as shown herein.
The operation of the conveyor shelf of FIGURES 2 and 3 will be utilized to described the operation of the selection device. Assuming that the shelf arrangement has stopped with shelf number I at the predetermined point or at the access position, microswitch number 1 will have its arm moved to terminal a, rather than in the normal position of terminal b. It should be pointed out that the shelf arrangement will always be stopped, unless there is an emergency stop, with one of the shelves at the access position. In this case on of the microswitches ll through 13 will always be in a closed position in which its arm has been moved from terminal b to terminal (1. Assuming now that the operator desires access to shelf number 5, the pointers 64 and 44, which are ganged together for simultaneous operation, are moved to position 5. When the start button 4th is pushed, the lower pair of contacts 42 will close first, prior to the closing of the upper contacts, as shown in FIGURE 1. As soon as contacts 42 are closed, there will be a circuit completed through relay coil 38, segment 44, and the line connecting terminal 2 on switch 29 to terminal a of microswitch number 1. Relay 38 will operate and contacts 5t) will be opened and contacts 52 will be closed.
Once terminals 54 of switch 46 are closed a circuit will be completed through the forward starting coil 48, and contacts 52, and the motor 72 will be driven in the forward direction. As soon as there is current flow through the forward starting coil 48, contacts 58 will be closed to lock in the operation of the motor in the forward direction. The shelves will now move until the projection 88 on shelf number 5 strikes microswitch number 5 and moves its arm from terminal b to terminal a. As soon as this happens there is no longer a circuit through switch 22 and pointer 64, and the motor will stop.
The shortest distance shelf 5 can move to come to the access point is in the forward direction. If instead of shelf 5 it is desired to have shelf 9 moved to the access position, when again shelf 1 is in this position, the two switches are moved to position 9. In this case, relay coil 38 will not operate as there is no connection through switch 20 to terminal b of switch number 1. Because relay 38 is not operated, the motor will be driven in the reverse direction, and there will be current flow through reverse starter coil 46, and contacts 50. As soon as there is current flow through reverse starter coil 46, contacts 60 will close to lock in the operation of the motor in the reverse direction. The shelves will now move in the reverse direction until shelf number 9 is in the proper position and its projection has moved the arm of microswitch number 9 from terminal b to terminal a to stop operation of the motor.
The arrangement of the switch 20 determines whether the motor should run in the forward or reverse direction. There are 13 positions on the switch. Accordingly, the
shortest distance from any one position to any other posi tion should be through no more than six positions. For example, if shelf number 8 is in the access position, shelves 9, 10, 11, 12, 13 and 1 can be reached by going in the forward direction as that is the shortest distance. That is, the next six shelves can be best reached by going in the forward direction. To reach shelves 7, 6, 5, 4, 3 or 2, the motor should be driven in the reverse direction as that is the shortest path to these shelves. The segment 44 connects together six positions when in any one position around switch 20. If instead of 13 positions on switch it there were 14, then seven positions would be connected together. If there were 15 positions on switch 29, again seven positions would be connected together. In other words, the segment 4-4 always connects together at least one-half of the allotted positions. It is the combination of the segment 44 and the particular electrical connections with the microswitches that permits the switch it to function as a memory switch and determine which is the shortest path for any particular shelf to take to reach a predetermined position. The memory switch is mechanical rather than electrical.
'hereas the preferred form of the invention has been shown and described herein, it should be realized that there are many modifications, substitutions and alterations thereto within the scope of the following claims.
1. A selection device including a plurality of twoposition switches, said switches adapted to be moved from one position to another by arrival of selected members at a predetermined point, a pair of multi-position selector switches, ganged together for simultaneous operation, and each having the same number of positions as there are two-position switches, each terminal of one selector switch being connected to a terminal on a twoposition switch, each terminal of the other selector switch being connected to the other terminal on a two-position switch, a forward and reverse motor connected to said one selector switch, each of said two-position switches adapted to be connected to a power source and normally being in a position to connect said motor to the power source, and means on the other selector switch for connecting said motor for either forward or reverse operation including means for connecting the selected position on said other selector switch with a number of consecutive adjacent positions on the switch, the number of connected positions being no greater than half the total number of positions on the switch and all being on the same side of the selected position, whereby the member selected is moved through the shortest distance to the predetermined point.
2. The structure of claim 1 further characterized in that said consecutive adjacent positions are behind the selected position.
3. The structure of claim 1 further characterized in that the means for connecting the selected position on said other selector switch with a number of consecutive adjacent positions on the switch include a solid segment fixed to and movable with said other selector switch.
4. The structure of claim 1 further characterized in that said motor is normally connected for reverse operation.
References Cited in the file of this patent UNITED STATES PATENTS 2,935,367 Crawford May 3, 1960 3,059,984 Handel Oct. 23, 1962 3,062,997 Loyd Nov. 6, 1962 FOREIGN PATENTS 599,535 Canada June 7, 1960