US 3762066 A
At one side of a table on which silk screen printing is done is a wicket conveyor which indexes a step at a time to deliver the objects on which the printing is performed. At the opposite side of the table is a wicket conveyor which takes the objects away after one color has been applied thereto and carries them through a dryer. For applying the next color the direction of movement of the two conveyors is reversed and the first named conveyor then carries the objects on which the second color has been applied through a second dryer. Transfer conveyors are employed between the table and the two wicket conveyors. The controls for the conveyor includes switches at each side of the table that are actuated by movement of an object to that side, thereby initiating the conveyor movement.
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Description (OCR text may contain errors)
United States Patent 1 1 Key I451 Oct. 2, 1973 1 1 APPARATUS FOR USE IN SILK SCREEN PRINTING OR THE LIKE John W. Key, 21 Duxbury, Rolling Meadows, Ill. 60008 22 Filed: July 27,1972
211 App]. No.: 275,722
' 198/134  Int. C1.B65g 17/12, B65g 15/00, B05c 11/00  Field of Search 34/150, 149, 148,
[ 5 6] References Cited 2,722,197 Robert 118/324 Primary ExaminerMeyer Perlin Assistant Examiner-Paul Devinsky Attorney-Howard H. Dabbo et al.
 ABSTRACT At one side of a table on which silk screen printing is done is a wicket conveyor which indexes a step at a time to deliver the objects on which the printing is performed. At the opposite side of the table is a wicket conveyor which takes the objects away after one color has been applied thereto and carries them through a dryer. For applying the next color the direction of movement of the two conveyors is reversed and the first named conveyor then carries the objects on which the second color has been applied through a second dryer. Transfer conveyors are employed between the table and the two wicket conveyors. The controls for the conveyor includes switches at each side of the table that are actuated by movement of an object to that side, thereby initiating the conveyor movement.
6 Claims, 7 Drawing Figures PATENTEDBBT 2W 3; 762.066
SHEEF 30? 3 104,812 10 912 ii0b APPARATUS FOR USE IN SILK SCREEN PRINTING OR THE LIKE BACKGROUND AND SUMMARY OF THE INVENTION While the present invention will have a number of applications, it was primarily devised for use in connection with the silk screening of a plurality of colors onto a plurality of objects. For example, decorative colors and designs are to be applied to a plurality of sheets of glass which are to form a part of a pinball machine, a bowling type game, a juke box, etc. These colors must be applied one at a time and then the paint (or other fluid decorative material) dried before the next color is applied.
The present practice is for the individual who is doing the silk screening to pick up the objects one at a time and lay them down at a location at which the screening operation is performed. As each object is deposited at that location it is screened with one color. It is then picked up and moved to a rack for the drying operation to take place. The removed object is replaced by a successive object which then has color applied to it and is in turn moved away to thedrying rack. After the initially applied color has dried, the objects are again moved back to the location, one at a time for the application of the second color. After the color is applied they are carried one at a time to a drying rack where the second color is dried before the third color is applied in a similar fashion.
It will be readily apparent that there is a great amount of hand labor involved in moving the objects in succession to the point of color application and then moving them to the drying racks and back again. The objects must be carefully handled so as not to smear the wet paint or damage them in other respects (e.g. break the glass the forms the object). Often they are heavy and bulky. This not only is tiresome for the worker or workers involved, but is expensive to the manufacturer to have such hand labor taking place. The principal object of the present invention is to provide a simple and effective apparatus for eliminating this hand labor of carrying the objects to and from the location at which the color is to be applied thereto as by mean of silk screen- DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of an embodiment of the invention;
FIG. 2 is a front elevation of the embodiment of FIG.
FIG. 3 is a perspective view looking at the front of the printing table, one transfer conveyor and the end of a wicket conveyor;
FIG. 4 is a perspective view of the rear of a transfer conveyor and the printing table;
FIG. 5 is a perpsective view of the rear of transfer conveyor;
FIG. 6 is a schematic diagram of an embodiment of the electrical controls; and
FIG. 7 is a schematic diagram of an alternative embodiment of the electrical controls.
DESCRIPTION OF SPECIFIC EMBODIMENT The following disclosure is offered for public dissemination in return for the grant of a patent. Although it is detailed to ensure adequacyand aid understanding,
the other this is not intended to prejudice that purpose of a patent which is to cover each new inventive concept therein no matter how others may later disguise it by variations in form or additions or further improvements.
The illustrated embodiment includes a table 10 on which the silk screen operation is performed on a plurality of objects 11. To the rear of the table 10 is a superstructure I2 which carries the frames 13 which support the silk screens that are moved over the objects 11 in the course of doing the printing thereon. This is conventional structure.
At one side of the table 10 is a wicket conveyor, generally 15. At the other side is a wicket conveyor, generally 16. Between the table and the two wicket conveyors are transfer conveyors, generally 17 and 18. Conveyor l5 includes an endless chain 20 which moves about Sprockets on shafts 21, 22, 23 and 24. On this endless chain are a plurality of rows of wickets 25. Each row comprises four wickets and each row is closely adjacent the other rows at the proximal ends of the wickets. The path of movement of the chain and wickets as defined by the shafts 21-24 has an ascending portion 26 followed by a generally horizontal portion 27. A drying oven 28 encloses a part of the horizontal path 27. Oven 28 has an inlet duct 29 through which heated air is introduced and an exhaust duct 30 through which the air carrying the volatile material picked up duringthe drying process is discharged. The wickets are relatively rigid and a row thereof are capable of supporting an object laid there across.
The structure of the wicket conveyor 16 is identical to that just described with respect to conveyor 15. Consequently, the same parts have been identified by the same numbers with primes thereafter. The two wicket conveyors are driven by an electric motor 33. The motor is mounted on and drives a gear box 34. From this gear box there are two shafts 35 and 35 going to the two conveyors l5 and 16 respectively. At the conveyor end of the shafts is a gear box such as 36' having a sprocket 37 onits output shaft. A chain 38 connects sprocket 37' to a sprocket 39 on shaft 21'. The operation is such that when the wickets of one conveyor are ascending at the transfer end (e.g. 26) the wickets of the other conveyor are descending at the transfer end (e.g. 26). I
The transfer conveyor 17 includes shafts 41 and 42 on which are a plurality of pulleys 43. Belts 44 are from a separate motorelectrically connected in parallel with motor 45, or separately controlled by its respective electrical controls.
Immediately at the left side of table 10 is an electric switch 50 having an actuator 51. When an object 11 is manually moved to the left side of table 10, and just slightly extending over the side onto belts 44, the weight of that object will depress actuator 51 to operate switch 50. There is a similar switch 52 immediately to the right of the table 10. At the pickup and discharge point of conveyor 15 (the effective end of transfer conveyor 17) is an electric switch 53. At the pickup and discharge point of wicket conveyor 16 is an electric switch 54. These switches, like switch 50, have actuators that cause a change of the switch position when an object 11 arrives at the respective pickup and discharge point.
in the schematic of the control apparatus of FIG. 6, the transfer switch 50 has a switch arm 50a and two contacts 50b and 50c. The transfer switch 52 has a switch arm 52a and two contacts 52b and 52c. The wicket switch 53 has a switch arm 53a and two contacts 53b and 53c. The wicket switch 54 has a switch arm 54a and two contacts 54b and 540. There is a condition reversing switch, generally 55, which comprises nine individual switches ganged together for simultaneous operation. These include the following: switch arm 56a with two contacts 56b and 56c; switch arm 57a with two contacts 57b and 576; switch arm 58a with two contacts 58b and 58c; switch arm 59a with two contacts 59b and 590; switch arm 60a with two contacts 60b and 60c; swtich arm 61a with two contacts 61b and 610; switch arm 62a with two contacts 62b and 620; switch arm 63a with two contacts 63b and 630; switch arm 64a with two contacts 64b and 64c. There is a main power switch having a switch arm 65a and a contact 65b. There are two normally open relay switches, one having a switch arm 66a and a contact 66b, the other having a switch arm 67a and a contact 67b. The relay has an operating solenoid 68.
Power input wire 71 connects to switch arm 65a. Power input wire 72 connects to one end of solenoid 68, switch arm 56a and contacts 63b and 64c. A wire 73 connects contact 56c, contact 57b and one side of motor 45. A wire 74 connects contacts 57c, 56b and the other side of motor 45. A wire 75 connects switch arm 52a, switch arm 57a, switch arm 66a and relay solenoid 68. A wire 76 connects contact 52c, contact 59b and contact 61b. A wire 77 connects contact 52b and contact 60b. A wire 78 connects contact 58c, contact 500 and switch arm 60a. A wire 79 connects contact 67b and switch arm 58a. A wire 80 connects contact 66b and switch arm 59a. A wire 81 connects contact 65b, switch arm 67a, switch arm 50a and switch arm 620. A wire 82 connects contact 50b and switch arm 61a. A wire 83 connects contact 536 and contact 62c. A wire 84 connects switch arm 53a and contact 63c. A wire 85 connects switch arm 54a and contact 62b. A wire 86 connects contact 54c and contact 64b. A wire 87 connects switch arm 63a and one side of motor 33. A wire 88 connects switch arm 64a and the other side of motor 33. The motors 33 and 45 are reversible. Alternatively, electrically operated clutches with reversing drives could be employed.
Condition switch 55 is set for movement from the left to right as viewed in FIGS. 1 and 2. Assume that conveyor 15 is full of objects and an object 11 is on table 10. One color application has been made to that object. The operator slides that object or glass plate just off the table edge to the right. This causes an actuation of switch 52. Thus switch arm 52a moves from contact 52b to contact 52c. Assuming that the main switch 65 is closed, power is applied to motor 45 through wire 81, switch arm 50a, wire 82, switch arm 61a, wire 76, contact 52c, switch arm 52a, wire 75, switch arm 57a, motor 85, switch arm 56a to the other power line 72. This starts motor 45. At the same time, solenoid 68 is energized, being across the lines 75 and 72 to which power has been just applied, so that the two switch arms 66a and 67a move to the respective contacts 66b and 67b. Switch arm 66a completes a holding circuit which shorts out the connection between switch arm 52a and contact 52c. Thus, as the transfer conveyor 18 moves the plate 11 to the right, and off of switch 52, the switch 52 can return to its position against contact 52b without interrupting the flow of power to motor 45. The holding circuit is established as follows, there is a circuit from wire 81 through switch arm 50a, switch arm 61a, wire 76, contact 59b, switch arm 59a, contact 66b, switch arm 66a to wire 75 maintaining the application of power to that latter wire.
When the object 11 arrives at the pickup and discharge point of wicket conveyor 16, it operates switch 54. This moves switch arm 54a onto contact 540. This completes a circuit from wire 81 through switch arm 62a, wire 85, switch arm 54a, wire 86, switch arm 64a and wire 88 to energize wicket motor 33. This starts the movement of wicket conveyors 15 and 16. Conveyor 16 picks up the object 11 that had been at the pickup and discharge point of that wicket conveyor. The conveyor movement transfers a succeeding row of wickets into position to receive the next object and, at the same time, opens switch 54 by reason of having lifted up the object that was depressing that switch. Switch arm 54a moves away from contact 54c to deenergize motor 33.
During the time that motor 33 was operating and thereby driving wicket conveyor 15, the latter conveyor moved in a downward direction as related to its pickup and discharge point to deposite an object 11 on the transfer conveyor at that pickup and discharge point. That object 11 closed switch 53, but this has no effect. The motor 45 has continued to run so that the transfer conveyor 17 moves the object that had been deposited upon it from conveyor 15 toward the table 10. As that object reaches the table 10, it depresses the actuating lever 51 of switch 50. This moves switch arm 50a from contact 50b to contact 500. This breaks the circuit that had existed through contact 50b so as to deenergize solenoid 68 and to deenergize motor 45. Thus all of the conveyors are now stopPed.
The operator moveS the object 11 from transfer conveyor 17 onto table and again performs an application of one color thereto. After having done so he slides the object 11 across the table top to the right to operate switch 52 and repeat the process. After one color has been applied to all of the objects, those objects are all stored in wicket conveyor 16. This wicket conveyor is indexed to the right so that all of the objects pass into the drying oven 28'. Part of this indexing will have been performed by the objects 11 as they were moved into the wicket conveyor 16. The remaining objects (those last received by the wicket conveyor 16) can be indexed through the drying oven by the operator holding switch 54 closed so that the wicket conveyors continue to run. To facilitate this operation, a manual switch 90 may be connected in parallel to switch 54 and positioned at a readily accessible location.
After the paint, etc., on all of those objects has been adequately dried, the operator prepares to apply a second color to those objects. After adjusting his silk screening apparatus he moves the condition selecting switch to its alternate position. That is, the switch arms 56a 64a are moved from contacts 56b 64b to contacts 56c 64c respectively. The switch arms 56a and 57a reverse the connections to motor 45 so that it drives in the opposite direction. Likewise, the switch arms 63a and 64a move to their alternate position to reverse the connections to motor 33 so that it will drive in the opposite direction.
Now the operator momentarily closes switch 53a. This completes a circuit from the main power switch.65 through wire 81, switch arm 62a, contact 620, wire 83, switch arm 53a, wire 84, contact 630, switch arm 63a, wire 87 to energize the motor 33. The motor 33 drives the wicket conveyor 16 so that the wickets are moving downwardly in portion 26' of the path of movement. The wicket conveyor thereby deposits an object at its pickup and discharge point on conveyor 18. That object is then slid onto table and an application of the second color made thereto.
The operator then moves the object 11 off the table to the left actuating switch 50. When switch arm 50a moves onto contact 500 a circuit is completed from wire 81 through switch arm 50a, switch arm 60a, switch arm 52a to wire 75. This energizes motor 45 through switches 56 and 57 and also energizes solenoid 68. When the solenoidcloses switch arm 67a onto contact 67b, a holding circuit bridging switch arm 50a and contact 500 is created so that when the latter two separate, the solenoid and motor remain energized. The object on transfer conveyor 17 moves to the left to operate switch 53. This completes a circuit corresponding to that previously described to energize motor 33. Motor 33 in turn causes the wicket conveyor to pick up the object on transfer conveyor 17 and causes wicket conveyor 16 to deposit a successive object on transfer conveyor 18."The object on conveyor 18 moves to the left until it reaches switch 52. Upon actuating switch 52 the circuit to wire 75, and thus motor 45 and solenoid 68, is broken so that the transfer conveyor is stopped. Thus the objects can be moved back and forth with successive applications of color made thereto and the color dried with little effort on the part of the operator. All of this makes his work substantially more productive and less laborious.
In the embodiment of FIG. 7, the condition switch, generally 92, comprises eight individual switches, namely: switch arm 93a, contacts 93b, 93c; switch arm 940, contacts 94b, 94c; switch arm 95a, contacts 95b, 95c; switch arm 96a, contacts 96b, 96c; switch arm 97a, contacts 97b, 97c; switch arm 98a, contacts 98b, 98c; switch arm 990, contacts 99b, 99c; switch arm 100a, contacts 100b, 1006'. Switches 101 and 102 are ganged together and positioned to operate as did switch 53. These two switches comprise switch arm 101a, contacts 101b, 1010 and switch arm 102a, contacts l02b and l02c. Switch 103 comprising switch arm 103a and contacts 103b and 103C corresponds to switch 50, previously described. Switch 104 corresponds to switch 52, previously described, and comprises switch arm 104a, contact 104b and contact 1040. The ganged switches 105 and 106 functionally correspond to switch 54 and comprise switch arms 105a, 106a and contacts 105b, 1050, 106b and 106c respectively. The holding relay comprises four switches, i.e. switch arm 107a, contact 107b, switch arm 108a, contact 108b, switch arm 109a, contact 109b, switch arm 110a, contact 110b, all operated by a solenoid 111.
. 'One power supply wire 112 connects to switch arm 102a, switch arm 101a, contact 107b, contact 110b, switch arm 105a and switch arm 106a. The other power supply wire 113 connects to contacts 95c, 96b, 99c,
100!) and solenoid 113. Wire 114 connects contacts 102C and 100C. Wire 115 connects switch arm 96a to motor 45. Wire 116 connects switch arm a to motor 45. Wire 117 connects switch arm a to motor 33. Wirc 118 connects switch arm 99a to motor 33. Wire 119 connects contacts 960 and 95b and switch arms 103a, 104a, 108a and 1090. Wire 120 connects switch arm 94a and contact l03b. Wire 121 connects switch arm 93a and contacts 1030 and l08b. Wire 122 connects contact 1010, contact 94b and switch arm 107a. Wire 123 connects contact 101b and contact 930. Wire 124 connects contact 104b and switch arm 98a. Wire .125 connects contact 104c and contact 10% and switch arm 97a. Wire 126 connects contact 98c, contact 1050 and switch arm 110a. Wire 127 connects contact 97b and contact 10Sb.
Again, the condition switch 92 as illustrated is set for movement to the right in FIGS. 1 and 2. As the object is moved off the edge of the table, it operates switch 104. This creates a circuit from wire 112, switch arm a, wire 127, switch arm 97a, contact 1040, switch arm switch 104a to energize wire 119. The energizing of wire 119 energizes solenoid 111 and, through switch arm 95a it energizes motor 45. The energizing of motor 45 causes the transfer conveyor 18 to move the object to the right. When the object arrives at the pickup and discharge point of wicket conveyor 16, it operates switch 105. This switch breaks the circuit previously described which extended through contact 105b thereby stopping the transfer motor 45 and deenergizing solenoid 111.
At the same time that switch 105 is operated switch arm 106a moves onto contact 106c. This then energizes motor 33 from wire 112 through the two direction switches 99 and 100. With motor 33 energized, the wicket conveyor 16 moves until it picks up the object, thereby opening switch 106a. Simultaneously with the movement of wicket conveyor 16, wicket conveyor 15 operated to deposit an object at its pickup and discharge po int, thereby actuating switches 101 and 102. The actuation of switch 102 has no effect. The movement of switch arm 101a to contact 101c creates a circuit from wire 112 to wire 122, switch arm 94a, wire 120, switch arm 103a to again energize wire 119. This starts motor 45 and energizes locking solenoid 41. Solenoid 41 closes switch arm 107a onto contact 107b thus establishing a holding circuit across switch arm 101a contact 1016.
The transfer conveyor now runs to move the object on conveyor 17 to the right. When the object arrives at table 41 it operates switch 103 thereby breaking the circuit just described to deenergize solenoid 41 and stop motor 45. Color is applied to this next object and the operator then moves that object to the right of table 10 to repeat the above described process.
When the function switch 92 is moved so that all of its switch arms 95a 100a are moved to the contacts 93c 1000, the motors 33 and 45 are reversed. Also,
when the object on table 10 is moved off the left side thereof to operate switch 103, the switch arm 103a is moved to contact 103C to create a circuit from wire 112, switch arin 101a, wire 123, contact 93c, switch arm 93a, wire 1.21, contact 1030, switch arm 103a to wire 119. This starts motor 45 and by energizing solenoid 111 closes holding switch 108a, 108b so that the opening of switch 103a, 103c does not deenergize that circuit. 'That circuit isdeenergized by the object arriving at the left end of transfer conveyor 17 and thereby operating switch 101a. Simultaneously, with the operation of switch 101a, switch 102a is operated to energize wicket motor 33 and move the two wicket conveyors in the opposite of the previously described direction. Conveyor picks up the object from transfer conveyor 17 and wicket conveyor 16 deposits an object on transfer conveyor 18. The latter object operates switches 105 and 106. Switch 106 is ineffective, but switch 105 creates a circuit from wire 112 to wire 119 through switch arm 105a, contact 1050, wire 126, contact 98c, switch arm 98a, wire 124, contact l04b and switch arm 104a. This energizes motor 45 to move the object to the left in FIGS. 1 and 2. It also energizes solenoid 111 to create a holding circuit (switch arm 110a and contact l10b) across switch arm 105a and contact 1050. When the object arrives at the table, it operates switch 104 thereby breaking the previously described circuit from wire 112 to wire 119.
1. In an apparatus having a printing table on which a plurality of separate fluid applications are made to a plurality of objects with the fluid on each object being dried between each application, the improvement comprising:
two wicket conveyors each trained for movement along a respective path, one position along each of said conveyors defining a common pickup and discharge point for the respective conveyor;
drying means positioned along each of said paths;
a first transfer conveyor extending from one side of said table to said pickup and discharge point of one of said wicket conveyors;
a second transfer conveyor extending from the opposite side of said table to said pickup and discharge point of the other of said wicket conveyors;
power means connected to said transfer conveyors for running the conveyors in one direction and in the other direction;
power means connected to said wicket conveyors for running the conveyors in one direction and in the other direction; and
control means connected to said power means for selectively establishing alternative first and second conditions, which in said first condition said first transfer conveyor runs from said one side toward said one wicket conveyor and said one wicket conveyor runs from said pickup and discharge point thereof toward said drying means and said other wicket conveyor runs toward the pickup and discharge point thereof and said second transfer conveyor runs from the latter point to the opposite side of said table, and in said second condition all of said directions of conveyor movement are reversed.
2. ln an apparatus as set forth in claim 1, wherein each wicket conveyor comprises an endless member and a plurality of relatively rigid wickets secured thereto and projecting therefrom, said wickets being in rows along said member, there being a plurality of wickets in each row with the wickets in each row being spaced from each other;
each transfer conveyor comprising a plurality of endless belts, at said transfer and pickup point said belts interdigitating with the spaced wickets.
3. In an apparatus as set forth in claim 2, wherein said belts are relatively horizontal at the pickup and discharge points, and the paths of said wicket conveyors are aligned to move the wickets in a generally vertical direction at said pickup and discaharge points, the arrangement being such that as a transfer conveyor is moving from the table toward the respective point the respective wicket conveyor is moving the wickets upwardly at said respective point, and as the transfer conveyor is moving from the respective point toward the table the respective wicket conveyor is moving the wickets downwardly at said respective point.
4. In an apparatus as set forth in claim 3, wherein said control means includes switch means at said one side of said table and positioned to be actuated by an object moved to said one side of said table to initiate the movement of the first transfer conveyor during said first condition, switch means at the wicket conveyor end of said first transfer conveyor and positioned to be actuated by an object arriving at the respective pickup and discharge point to initiate the movement of the wicket conveyors, and switch means at said other side of said table and positioned to be actuated by an object moved to said other side of said table to stop the movement of the second transfer conveyor during said first condition.
5. In an apparatus as set forth in claim 4, wherein said control means includes switch means at said other side of the table and positioned to be actuated by an object moved to said other side of the table to initiate movement of the second transfer conveyor during said second condition, switch means at the wicket conveyor end of said second transfer conveyor and positioned to be actuated by an object arriving at the respective pickup and discharge point to initiate the movement of the wicket conveyors, and switch means at said one side of the table and positioned to be actuated by an object moved to said one side of said table to stop the movement of the first transfer conveyor during said second condition.
6. In an apparatus as set forth in claim 1, wherein said control means includes switch means at said one side of said table and positioned to be actuated by an object moved to said one side of said table to initiate the movement of the first transfer conveyor during said first condition, switch means at the wicket conveyor end of said first transfer conveyor and positioned to be actuated by an object arriving at the respective pickup and discharge point to initiate the movement of the wicket conveyors, switch means at said other side of the table and positioned to be actuated by an object moved to said other side of the table to initiate movement of the second transfer conveyor during said second condition, switch means at the wicket conveyor end of said second transfer conveyor and positioned to be actuated by an object arriving at the respective pickup and discharge point to initiate the movement of the wicket conveyors, and manually operable condition changing means connected to said switch means to alternatively establish the switch means for said first condition and for said second condition.