Rotary Screen Printing Machine

Abstract

A carousel screen printing machine which includes a stationary column supporting a plurality of print heads; a rotatable carousel mounted on said column supporting a plurality of pallet support arms and drive means located at or above said carousel for indexed movement of said carousel about said stationary column. Indexation and registration is achieved using bushes on the carousel rotor to cooperate with complementary pins at an indexing station and at a registration station. The location of the motor makes the machine more stable during rotation and is easier to access. The registration and indexing system is simpler and uses fewer parts than in the prior art. In one embodiment an additional print head is used in association with a dual purpose load unload station.

Description

DETAILED DESCRIPTION OF THE INVENTION

A preferred embodiment of the invention will be described with reference to the drawings in which:

FIG. 1 is a plan view of the stator and rotor of this invention;

FIG. 2 is a side view of the indexing system according to this invention;

FIG. 3 is a side view of the indexing and registration system of this invention.

FIG. 4 is a plan view of a 10 station carousel printing machine incorporating the improvements of this invention;

FIG. 5 is a plan view of an 8 station stator according to this invention;

FIG. 6 is a side view of the stator of FIG. 5.

In the machine illustrated the pallets rotate in an anticlockwise fashion but it is equally possible for the machine to function with clockwise rotation of the pallets. The screen printing machine comprises a rotatable set of pallet arms 21 which are mounted for rotation about a central column 15. Each pallet arm 21 carries a garment pallet 22. Garments are fitted onto the pallets.

Above the pallets are a set of print heads 24 mounted on fixed print head support arms 23 which also radiate from a stator 19 fixed to the central column 15. A print carriage motor 28 is shown in FIG. 1. Conventionally and the load station L and the unload station UL are located between the first and last printheads. A control panel is located above the stations L and UL.

As shown in FIGS. 2 and 3 the stator incorporates a control arm 59 and control station 60 located above the load and unload station. The pallet arms 21 rotate in an anticlockwise direction. Each rotation is indexed so that each pallet moves sequentially from one print head station to the next. The registration station 50 is mounted on the stator 19.

The pallet arms are secured to a rotor disc 31 driven by motor 33 programmed to rotate the disc through 45° which is one indexation. The motor 33 and its gear assembly 32 is mounted on the stator 19. As can be seen the motor is easily accessable for maintenance. The mechanism 32 may be of the same general design as the indexing mechanism disclosed in U.S. Pat. No. 4,934,263. Because the drive system for the rotor disc 31 is located at the level of the pallet arms, which are attached to the disc 31, there is no stress which was a problem with prior art machines where the indexing motor was located adjacent the base some distance below the pallet arms.

The rotor disc 31 contains a series of bushes 34 in the peripheral ring 35 of equal number to the number of pallet arms. The indexing station 41 is mounted on an arm 42 which is fixed to the central column 15 and does not rotate. The arm 42 extends from the bearing assembly 44 which does not rotate but is raised with the disc 31 when the pallet arms are raised for indexation with the print heads. Instead of pins and bushes any other suitable locating and indexing mechanism may be employed.

As the rotor reaches the end of the indexation, the pin 43 of the indexing station is urged into one of the bushes 34.

At this point the vertical pin 51 of registration station 50 is located over another bush 34 on the opposite side of the disc 31. When the rotor disc 31 and pallets are raised toward the stator 19, the pin 51 enters the bush 34 and locks the pallets into registration with the print heads.

FIG. 4 illustrates a 10 station machine with an innovation that is made possible with the present invention namely a dual purpose unload/load UL/L station which increases the number of printing/curing stations by one, to nine in this 10 station machine. If separate load and unload stations are required one of the printhead arms 23 adjacent to the UL/L station may be removed. The components of the machine are the same as those described with reference to FIGS. 1 to 3.

In FIGS. 5 and 6 an eight station stator is illustrated and the components of the machine are the same as those described with reference to FIGS. 1 to 3. The control panel 60 is located on the control panel arm 59 which in this embodiment is adjustable in elevation by means of the lever 61 and pivot point 62. Print arms with associated print heads are attachable to each of the print arm supports 23 so that 7 active print stations are available for 8 pallets. The pallet located below the control panel 60 is the load/unload station.

From the above those skilled in the art will realize that the present invention provides an inexpensive and easy to build base that provides added rigidity and stability to screen printing machines. Those skilled in the art will realize that this invention may be utilized in a number of embodiments other than those described, without departing from the core teaching of this invention.

Claims

1. A carousel screen printing machine which includes a) a stationary column supporting a plurality of print headsb) a rotatable carousel mounted on said column supporting a plurality of pallet support armsc) drive means located at or above said rotatable carousel for indexed movement of said carousel about said stationary column.

2. A screen printing machine as claimed in claim 1 in which said rotatable carousel incorporates bushes which cooperate with pins at an indexing station mounted on said stationary column so that on each indexed rotation a pallet arm is located below a print arm.

3. A screen printing machine as claimed in claim 2 in which a registration mechanism is mounted on said stationary column and incorporates a pin mechanism to cooperate with one of said bushes on said rotatable carousel to register the pallet arm in a fixed position relative to a print arm.

4. A carousel screen printing machine which includes a) a stator supporting a plurality of print headsb) a rotor supporting a plurality of pallet support armsc) said rotor being mounted for rotation about said statord) drive means for said rotor located at or above the level of said rotore) bushes or pins on said rotor to cooperate with complementary pins or bushes at an indexing station and at a registration station.

5. A carousel screen printing machine as claimed in claim 4 in which bushes are located in said rotor and an indexing station and a registration station are located on said stator and the indexing and registration mechanisms include pins which engage said bushes.

6. A carousel screen printing machine which includes a) a stationary column supporting a plurality of print arms adapted to support print headsb) a rotatable carousel mounted on said column supporting a plurality of pallet support armsd) the carousel being arranged for indexed movement to bring each pallet arm successively into registration with each print heade) there being one less print head than the number of pallet arms so that the pallet arm without an associated print head may be loaded or unloaded.

7. A screen printing machine as claimed in claim 6 in which a control panel is located on one print arm to replace a print head and the pallet below the control panel is the load and unload station.

8. A screen printing machine as claimed in claim 4 or 5 in which the drive means for the rotatable carousel is mounted at or above said rotatable carousel.