Screen printing machine with oval rail for indexing pallets

Abstract

This disclosure is directed to a screen printing machine having an oval track or rail about which a series of pallets supporting a work piece are indexed from station to station. The arrangement is such that the pallets travelling about the oval rail are always disposed or maintained in a common plane. A printing head assembly having one or more color stations is operatively associated for movement into and out of printing relationship with one or more of the pallets as the pallets are indexed and maintained in a common plane.

What is claimed is: 
     
       1. A screen printing machine comprising a suporting frame means,   an oval shaped rail mounted on said frame .Iadd.means, .Iaddend.   a plurality of pallet means disposed in a common plane circumferentially spaced about said oval rail,   drive means operatively interconnecting said pallet .Iadd.means .Iaddend.for indexing said .[.pallets.]. .Iadd.pallet means .Iaddend.about said oval rail in said common plane, and   
     
     
       .[.a.]. printing head means mounted on said frame means for movement between an operative printing position and an inoperative non-printing position, .Iadd.said pallet means having substantially coplanar movement as they approach, traverse and depart said printing head means, .Iaddend. indexing means connected to said drive means for indexing said .[.pallets.]. .Iadd.pallet means .Iaddend.about said oval rail,   said indexing means .[.including a.]. .Iadd.includes .Iaddend.ram stop means,   a ram stop cam follower operatively associated with said drive means, .Iadd.and .Iaddend.   .[.and an.]. activating means for moving said ram stop means into and out of operative position relative to said cam follower to effect the indexing of said .[.pallets.]. .Iadd.pallet means .Iaddend.about said oval rail.   
     
     
       2. The invention as defined in claim 1 wherein said printing head means includes: a head frame pivotally mounted to said supporting frame means,   a carriage movably mounted on said head frame,   a squeegee means mounted on said carriage,   a screen holder disposed below said carriage and .Iadd.said .Iaddend.squeegee means mounted thereon,   said screen holder having one end pivotally mounted to said support frame means, and   a connecting link supporting the other end of said screen holder from said head frame,   and means on said link connected end .Iadd.of said screen holder .Iaddend.for effecting a predetermined amount of lost motion between said head frame and carriage mounted thereon.[.,.]. and said screen holder as said printing head is pivoted between an operative printing position to an inoperative non-printing position.   
     
     
       3. The invention as defined in claim 2 and including: a flood bar mounted on said carriage,   means for normally biasing said flood bar toward operative flooding position in the non-printing position of said head means, and   means for overcoming said bias on said flood bar in the printing position of said .Iadd.printing .Iaddend.head.   
     
     
       4. The invention as defined in claim 1 wherein said interconnecting drive means .[.including.]. .Iadd.includes .Iaddend. an endless flexible member,   said .[.pallets.]. .Iadd.pallet means .Iaddend.being connected to said endless flexible member at spaced intervals therealong, and   .[.a.]. means for effecting the drive of said endless flexible member.   
     
     
       5. The invention as defined in claim 4 wherein said drive means comprises: a drive shaft having a driving sprocket connected thereto,   said flexible member being threaded about said driving sprocket, .Iadd.and .Iaddend.   .[.a.]. motor means operatively connected to said drive shaft to effect the drive thereof.   
     
     
       6. A screen printing machine comprising: a supporting frame means,   an oval shaped rail mounted on said frame,   a plurality of pallet means disposed in a common plane circumferentially spaced about said oval rail,   means operatively interconnecting said pallet means for indexing said pallet means about said oval rail in said common plane,   a printing head means mounted on said frame means for movement between an operative printing position and an inoperative non-printing position, .Iadd.said pallet means having substantially coplanar movement as they approach, traverse and depart said printing head means, .Iaddend.   said interconnecting means including an endless flexible member,   said pallet means being connected to said endless flexible member at spaced intervals therealong,   a drive means for effecting the drive of said endless flexible member,   .[.and.]. indexing means operatively connected to said drive means for indexing said pallet means from station to station about said oval rail,   said indexing means including:   .[.a.]. ram stop means,   a ram stop cam follower operatively associated with said drive shaft to rotate therewith, .Iadd.and .Iaddend.   .[.and.]. an activating means for moving said ram .Iadd.stop .Iaddend.means .[.stop.]. into and out of operative position relative to said cam follower to effect the indexing of said pallet means about said oval rail.   
     
     
       7. The invention as defined in claim 4 and including registration means operative to register said pallet .Iadd.means .Iaddend.in the printing position. 
     
     
       8. The invention as defined in claim 7 wherein said registration means are operatively associated with said printing head so that said registration means are rendered operative when said .Iadd.printing .Iaddend.head is disposed in printing position. 
     
     
       9. A screen printing machine comprising: a supporting frame,   an oval shaped rail mounted on said supporting frame whereby the plane of said oval rail is substantially horizontally disposed,   a sprocket rotatably journalled adjacent each end of said oval shaped rail,   an endless flexible driving chain threaded about said sprocket,   a plurality of pallets connected to said chain at spaced intervals therealong,   guide rollers connected to each of said pallets, .[.said.].  .Iadd.   said .Iaddend.guide means being disposed in rolling engagement with said oval rail,   .[.a.]. drive means operatively connected to one of said sprockets to effect the drive thereof, whereby said pallets are moved in a common plane about said oval rail,   indexing means operatively associated with said drive means for indexing said pallets about said oval track,   said indexing means including .[.a.]. ram stop means,   a ram stop cam follower operatively associated with said drive means, .Iadd.and .Iaddend.   .[.and an.]. activating means for moving said ram stop means into and out of operative position relative to said cam follower to effect the indexing of said pallets about said oval rail,   a printing head assembly mounted on said supporting frame for .[.moving.]. .Iadd.movement .Iaddend.between an operative printing position and an inoperative non-printing position, .Iadd.said pallet means having substantially coplanar movement as they approach, traverse and depart said printing head means, .Iaddend..[.and.].   .[.a.]. registration means operatively associated with said printing head means, .Iadd.and .Iaddend.   said registration means operating on said pallets to effect accurate registration of said pallets with said printing head assembly in the operative printing position thereof.   
     
     
       10. A screen printing machine comprising: a supporting frame means,   an oval rail mounted on said frame means whereby the plane of said oval rail is substantially horizontally disposed,   a sprocket rotatably journalled on said supporting frame adjacent each end of said oval rail,   an endless flexible driving chain threaded about said sprocket,   a plurality of pallets connected to said chain at spaced intervals thereabout, said pallet having a locating means on one end thereof,   guide rollers connected to each of said pallets,   said guide rollers being disposed in rolling engagement with said rail,   .[.a.]. drive means including:   a drive shaft connected to one of said sprockets,   a motor means having an output shaft,   a second sprocket mounted on said drive shaft,   a flexible driving member coupling said motor shaft to said second sprocket to effect the drive of said drive shaft when said motor means is activated,   .[.an.]. indexing means including:   a ram stop cam follower connected to said second sprocket,   a ram stop pivotally mounted on said frame for movement into and out of engagement relative to said cam follower,   .[.a.]. ram stop activating means operatively connected to said ram stop to effect actuation of said ram stop,   means responsive to the actuation of said ram stop for effecting the actuation of said motor means,   a printing head assembly mounted on said frame for movement between a printing and non-printing position,   said printing head assembly including a head frame pivotally mounted on said support frame means,   said head frame including opposed side rails,   a carriage mounted on said side rails,   a carriage drive means for traversing said carriage along said side rails,   a squeegee means supported on said carriage,   a screen holder adapted to support a printing screen disposed below said squeegee,   said screen holder being pivotally mounted to said supporting frame means adjacent one end thereof,   an interconnecting link .[.supporting.]. .Iadd.supportingly connecting .Iaddend.the other end of said screen holder to said head frame,   said interconnecting link including means for effecting a predetermined amount of lost motion between said head frame and said screen holder as said printing head assembly moves between a printing and non-printing position,   .[.and a.]. registration means for accurately positioning said pallet in the printing position,   said registration means including a locating bar pivotally mounted on said supporting frame, .Iadd.and .Iaddend.   .[.and a.]. linkage means interconnecting said locating bar to said head frame whereby said locating bar is moved into registration with the locating means of said pallet in the printing position of said head assembly and out of registration with the locating means of said pallet in the non-printing position of said head assembly.   
     
     
       11. The invention as defined in claim 10 and including a flood .Iadd.bar .Iaddend.movably mounted on said carriage,   .[.a.]. spring means for normally biasing said flood bar toward .[.a.]. .Iadd.said .Iaddend.printing screen, .Iadd.and .Iaddend.   .[.and.]. means operatively connected to said flood bar for overcoming the bias of said spring in the printing position of said .Iadd.printing .Iaddend.head assembly.   
     
     
       12. The invention as defined in claim 11 wherein said latter means .Iadd.includes .Iaddend. .[.includes.]. a flood roller connected to said flood bar,   a flood bar bridge supported below said head side rails, .Iadd.and .Iaddend.   said flood roller being disposed in rolling engagement with said bridge in the printing position of said head assembly for maintaining the associated flood bar off the printing screen in the printing position. .Iadd. 13. A screen printing machine for textile materials comprising:   a supporting frame,   a rail having a predetermined peripheral geometric configuration,   a plurality of pallet means disposed in a substantially common plane and spaced in a predetermined manner about the periphery of said rail, said pallet means being capable of having textile workpieces positionally disposed thereon,   drive means including indexing means operatively interconnecting said pallet means for repeated automatic movement of said pallet means about said rail in said common plane and in only a single predetermined direction during a given printing sequence,   said indexing means moving said pallet means by predetermined distances such that when said pallet means is disposed at a printing station it is in proper position for printing without any further additional indexing movement,   printing head means for multicolored printing upon said textile workpieces being mounted on said supporting frame for movement between an operative printing position and an inoperative non-printing position, and   said pallet means having substantially coplanar movement as they approach, traverse and depart said printing means..Iaddend. .Iadd. 14. A screen printing machine in accordance with claim 13, wherein   said indexing means includes ram stop means,   a ram stop cam follower operatively associated with said drive means, and   activating means for moving said ram stop means into and out of operative position relative to said cam follower to effect the indexing of said pallet means about said rail. .Iaddend..Iadd. 15. A screen printing machine in accordance with claim 13, wherein   said pallet means are spaced from one another to define a plurality of spaced stations,   said indexing means operatively indexing said pallet means from station to station about the periphery of said rail, and   registration means operable to register said pallet means in the printing position. .Iaddend. .Iadd. 16. A screen printing machine in accordance with claim 15, wherein   said registration means are operable subsequent to said indexing means. .Iaddend..Iadd. 17. A screen printing machine in accordance with claim 15, wherein   said registration means is operatively interconnected between said supporting frame and said pallet means. .Iaddend..Iadd. 18. A screen printing machine in accordance with claim 15, wherein   said registration means is operatively associated with said printing head means so as to render said registration means operative when said printing means is disposed in the printing position. .Iaddend..Iadd. 19. A screen printing machine in accordance with claim 13, wherein   said rail includes at least one peripheral portion having an arcuate traverse path. .Iaddend. .Iadd. 20. A screen printing machine in accordance with claim 19, wherein   the peripheral end portions of said rail are of an arcuate configuration. .Iaddend..Iadd. 21. A screen printing machine in accordance with claim 17, wherein   said registration means includes a locating member movably mounted on said supporting frame,   said registration means also including locating means formed in said pallet means, and   said locating member being movable into registry with said locating means to effect registration of said pallet means. .Iaddend. .Iadd. 22. A screen printing machine in accordance with claim 21, wherein   said locating member is movable into registry with said locating means in the printing position of said printing head means and out of registry with said locating means in the non-printing position of said printing head means. .Iaddend..Iadd. 23. A screen printing machine in accordance with claim 22, wherein   said locating member comprises a locating bar pivotally mounted on said supporting frame. .Iaddend..Iadd. 24. A screen printing machine in accordance with claim 23, wherein   said locating means comprises a notch of predetermined configuration formed at one end of said pallet means and disposed on the underside thereof. .Iaddend. .Iadd. 25. A screen printing machine in accordance with claim 22, including   linkage means interconnecting said locating member and said printing head means. .Iaddend.