Vacuum pallet type screen printing machine with registration means

Claim 2

A screen printing machine comprising a frame, a printing head defining a printing station mounted on said frame, a track means on said frame extending along the length of said frame, a pallet means movably mounted on said track, said pallet means including spaced apart upper and lower plates and connected end walls defining therebetween a vacuum chamber, said upper plate having a series of apertures formed therein, means connected to said pallet means for drawing a vacuum on said chamber, spaced apart roller means connected to said pallet means disposed in rolling contact with said track means, a flexible endless drive disposed along each side of said frame, said endless drive including an upper flight and a lower flight, a flexible coupling connecting said pallet means to each of said endless drives, motor drive means connected to said endless drive to effect the actuation thereof for moving the connected pallet toward and away from said printing station, means for effecting registration of said pallet means with said printing head when in the printing station, and transfer means adjacent each end of said endless drives for effecting movement of said pallet means between said upper and lower flights, said transfer means always maintaining said pallet means face up.

Claim 3

The invention as defined in claim 1 and including an electric track, and a sliding contact engaging said electric track, said contact being connected in circuit to said vacuum drawing means, whereby said latter means is energized when said sliding contact is disposed in electrical contact with said track.

Claim 4

The invention as defined in claim 1 wherein said registration means includes a locator having a notch carried on said pallet means, and a cooperating follower positioned on the frame to engage said locator notch, and means for activating said follower.

Claim 5

The invention as defined in claim 1 wherein said transfer means includes a transfer sprocket adjacent one end of said machine, and a transfer guide means at the other end of the machine, means formed on the periphery of said transfer sprocket for receiving said rollers whereby said sprocket when engaged by said rollers functions to transfer said pallet means, face up, between said flights.

Claim 6

The invention as defined in claim 1 and including indexing means connected to said motor drive means to limit the movement of said pallet means to said printing station.

Claim 7

The invention as defined in claim 1 and including means for decelerating the speed of said motor drive means as said pallet means approaches said printing station.

Claim 8

The invention as defined in claim 1 wherein said pallet means includes roller means, and said transfer means at one end of said flight comprising: a transfer sprocket, means for driving said transfer sprocket in unison with said drive means, said transfer sprocket having means formed about the periphery thereof for engaging the roller means connected to said pallets, whereby said transfer sprocket co-acts with said drive means to lift said pallets from the lower flight to the upper flight.

Claim 9

In a screen printing machine including a frame having a feed end, and a screen printing head mounted on said frame for movement between printing and non-printing position, the improvement comprising: pallet means, said pallet means having an upper and lower member defining a chamber therebetween, said upper member having aPertures formed therein, a drive means for effecting the movement of said pallet means toward and away from a printing station located below said printing head, said drive means comprising an endless flexible drive moving in an endless path along spaced apart upper and lower flights, means connecting said pallet means to said endless flexible drive to be driven along said endless path, transfer means disposed adjacent the opposed ends of said endless path for effecting the transfer of said pallets between said flights, said transfer means maintaining said pallets in a face-up position throughout the travel thereof along said endless path, a vacuum producing means connected to the chamber of said pallet means for drawing a negative pressure on said chamber as said pallet means moves along said endless path, a registration means operatively associated with said pallet means for effecting registration of said pallet means with said printing head when in the printing position beneath said printing head.

Claim 10

In a screen printing machine including a frame having a feed end, and a screen printing head mounted on said frame for movement between printing and non-printing position, the improvement comprising: pallet means, said pallet means having an upper and lower member defining a chamber therebetween, said upper member having aPertures formed therein, a drive means for effecting the movement of said pallet means toward and away from a printing station located below said printing head, said drive means comprising an endless flexible drive moving in an endless path along spaced apart upper and lower flights, means connecting said pallet means to said endless flexible drive to be driven along said endless path, transfer means disposed adjacent the opposed ends of said endless path for effecting the transfer of said pallets between said flights, said transfer means maintaining said pallets in a face-up position throughout the travel thereof along said endless path, a vacuum producing means connected to the chamber of said pallet means for drawing a negative pressure on said chamber as said pallet means moves along said endless path, a registration means operatively associated with said pallet means for effecting registration of said pallet means with said printing head when in the printing position beneath said printing head.

Claim 11

The invention as defined in claim 8 wherein said pallet connecting means includes a resilient coupling to provide for limited relative movement between said pallet means and its flexible drive.

Claim 12

The invention as defined in claim 9 wherein said drive means includes: a pair of spaced apart endless flexible driving means extending along the longitudinal sides of said frame, said resilient coupling means comprising opposed connecting links disposed to opposed sides of said pallet, one end of said link being connected to the adjacent flexible drive means, a resilient bearing member connected to the other end of said link, and a bearing housing connected to the sides of said pallet means for receiving said resilient bearing member.

Claim 13

The invention as defined in claim 9 wherein said drive means including a pair of opposed endless flexible drives, said pallet being disposed between said flexible drives, said resilient coupling means are oppositely disposed on said pallet means to form a connection with the respective endless drives whereby said flexible drives pull said pallet therebetween to and from a printing station when actuated, and said registration means comprising a locating means connected to said pallet and, a complementary follower positioned on the frame to engage said locating means, and means for activating said follower to effect registration of said pallet means in the printing station.

Claim 14

The invention as defined in claim 8 and including a feed table disposed to one side of the pallet means at the feed end of said machine, said feed table extending slightly over the side of said pallet means in overlying relationship thereto, and means on said table for properly orientating a work piece on said pallet means whereby the workpiece is partly supported on said feed table and partly on said pallet means at the feed end.

Claim 15

The invention as defined in claim 8 wherein said pallet means includes roller means, and said transfer means at one end of said flight comprises a transfer guide means positioned to receive the roller means of said pallet, and to cooperate with said drive means for effecting transfer of said pallet means between the upper and lower flight in said face-up position.

Claim 16

The invention as defined in claim 8 and including means for maintaining said vacuum producing means actuated as said pallet means is moved toward and away from said printing station.

Claim 17

In a screen printing machine having a frame and a plurality of printing heads mounted on said frame to define a plurality of printing stations, each of said printing heads being adapted to support a printing screen and an associated squeegee, the improvement comprising, a plurality of pallet means supported on said frame by drive means having endless vertically spaced aparts flights, said endless drive means for effecting the movement of said pallet means from station to stAtion along said flights in an endless path, means for flexibly coupling each of said pallet means to said endless drive means at spaced intervals along said endless drive means, means for effecting the registration of said pallet means with its respective printing head when disposed in said printing stations, each of said pallet means including spaced apart upper and lower members defining a chamber therebetween, said upper member having apertures formed therein, a vacuum producing means connected to each of said pallet means for drawing a negative pressure on the associated pallet chamber, means for maintaining said vacuum producing means activated as said pallet means advances through the respective printing stations, and transfer means adjacent each end of said endless path for maintaining said pallet means in a face-up position through the entire travel thereof about said endless path.

Claim 18

In a screen printing machine having a frame and a plurality of printing heads mounted on said frame to define a plurality of printing stations, each of said printing heads being adapted to support a printing screen and an associated squeegee, the improvement comprising, a plurality of pallet means supported on said frame by drive means having endless vertically spaced aparts flights, said endless drive means for effecting the movement of said pallet means from station to stAtion along said flights in an endless path, means for flexibly coupling each of said pallet means to said endless drive means at spaced intervals along said endless drive means, means for effecting the registration of said pallet means with its respective printing head when disposed in said printing stations, each of said pallet means including spaced apart upper and lower members defining a chamber therebetween, said upper member having apertures formed therein, a vacuum producing means connected to each of said pallet means for drawing a negative pressure on the associated pallet chamber, means for maintaining said vacuum producing means activated as said pallet means advances through the respective printing stations, and transfer means adjacent each end of said endless path for maintaining said pallet means in a face-up position through the entire travel thereof about said endless path.

Claim 19

The invention as defined in claim 15 wherein said endless drive means comprises: opposed flexible endless drives extending along the adjacent longitudinal sides of said frame, and said flexible coupling means including oppositely disposed links, a resilient bearing connected to one end of each of said links, said resilient bearing being coupled to said pallet means, and said registration means including a locator on each of said pallet means and an associated follower located on said frame at each printing station, a means for activating said follower to effect registration of said follower with said locator on said pallet means in a printing station.

Claim 20

The invention as defined in claim 16 wherein the direction of movement of said follower is substantially normal to said locator on said pallet means.