US3026794A

US3026794A - Silk screen press

Info

Publication number: US3026794A
Application number: US828377A
Authority: US
Inventors: Jerome J Nicholson
Original assignee: KUBIN NICHOLSON CORP
Current assignee: KUBIN NICHOLSON CORP; KUBIN-NICHOLSON Corp
Priority date: 1959-07-20
Filing date: 1959-07-20
Publication date: 1962-03-27
Anticipated expiration: 1979-03-27

Description

March 27, 1962 J. J. NICHOLSON SILK SCREEN PRESS '7 Sheets-Sheet 1 Filed July 20, 1959 INVENTOR. JEROME J. NICHOLSON BY 2 7 ATTORNEY N .o w 3 w I ...+...l...... wjulvvnauwlsnfiufl ww mm o 5 8 mm m 2?? o I N NQ m on g N.

March 27, 1962 J. J. NICHOLSON SILK SCREEN PRESS 7 Sheets-Sheet 2 Filed July 20, 1959 INVENTOR. Janene J. \QHQLSON;

ORNY

March 27, 1962 J. NICHOLSON 3,026,794

SILK SCREEN PRESS Filed July 20, 1959 7 Sheets-Sheet 3 mmvrm JEROME J.N\cH0Lson BY I ATTGRNEY March 27, 1962 J. J. NICHOLSON SILK SCREEN PRESS 7 Sheets-Sheet 4 Filed July 20, 1959 INVENTOR.

O 0 n Janene J. Nucuousou ATTORNEY March 27, 1962 J. J. NICHOI SON SILK SCREEN PRESS 7 Sheets-Sheet 5 Filed July 20, 1959 g mm NQ mm INVENTOR. JEROME J. NICHOLSON ATTORNEY March 27, 1962 J. J. NICHOLSON 3, ,7

SILK SCREEN PRESS Filed July 20, 1959 '7 Sheets-Sheet 6 I I I l I I I I I l I I I I l I I [I I I I .l l I I l I I 9 |o6 VENTOR.

I JEROME J. NmHoLsoN A-r-rgnuav March 27, 1962 J. J. NICHOLSON SILK SCREEN PRESS 7 Sheets-Sheet 7 Filed July 20, 1959 INVENTOR. JEROME J. NlCHOLSON ATTORNEY United States Patent 3,026,794 SILK SCREEN PRESS Ierome J. Nicholson, Milwaukee, Wis, assignor to Kubin- Nicholson Corporation, Milwaukee, Wis., a corporation of Wisconsin Filed July 20, 1959, Ser. No. 828,377 7 Claims. (Cl. 101-123) This invention relates to an automatic silk screen press.

Silk screen printing is limited in its application to the small order type of job due to its slow rate of hand operation. Since silk screen printing is a manual operation, economy of operation is dependent on the ability of the operator. In all attempts to increase the rate of production of the operator, semi-automatic devices have been used primarily to aid the operator in various phases of the printing process such as opening and closing the screen and carrying away the printed material after printing. Attempts at using fully automatic devices have been generally unsatisfactory because of the problem of registering successive sheets of material in the same place in the printer. Since silk screen printing requires two or three printings on the same sheet to obtain the various color patterns, it is extremely important that each time the sheet of material is placed under the screen it is registered in exactly the same place.

The primary object of this invention is to provide a fully automatic silk screen printing press.

Another object of this invention is to provide an automatic silk screen printer that has positive registry over a long period of operation.

A further object of this invention is to provide an automatic silk screen printer that increases the rate of output per man hour.

Other objects and advantages will be pointed out in, or be apparent from, the specification and claims, as will obvious modifications of the single embodiment shown in the drawings, in which:

FIGURE 1 is a side elevation of the present invention with the bed and screen closed.

FIGURE 2 is a side elevation of the present invention with the bed and screen open.

FIGURE 3 is taken on line 33 of FIGURE 2 showing the grippers between the open bed and screen.

FIGURE 4 is taken on line 4-4 of FIGURE 1 showing the position of the grippers with the bed and screen closed.

FIGURE 5 is a plan view of the present invention with the screen removed showing the grippers with the paper on the bed.

FIGURE 6 is taken on line 6-6 of FIGURE 1 showing the drive mechanism for the present invention.

FIGURE 7 is taken on line 77 of FIGURE 5 showing the position of the gripper with the screen and bed closed.

FIGURE 8 is a view of the grippers abutting the cam opener.

FIGURE 9 is a top view-of FIGURE 8.

FIGURE 10 is a top view of the gripper.

FIGURE 11 is taken on line 11-1l. of FIGURE 10 showing the gripper in a closed position.

FIGURE 12 is a side elevation of the gripper showing the cam and cam actuator in dotted line.

FIGURE 13 is a front view of the gripper in a closed position.

FIGURE 14 is taken on line 14l4 of FIGURE 11 showing the spring actuator for the finger.

FIGURE 15 shows the cam actuator engaging the cam to open the gripper.

The printing mechanism for this device consists of a bed It) and screen 12 which are both moveable by means of linkage system 14 actuated by earns 16. The

3fi26fl9i Patented Mar. 27, 1962 ice cams are mounted on shaft 18 and rotated by motor 20 and chain drive 22. The linkage system includes bell cranks 24 pivoted on pin 26. Cam follower 3i} rotatably secured to the bell crank rides on the surface of the cam actuating drive rod 32 having one end attached to the bell crank and the other end attached to shaft 36 through link 34. Eccentric arms 38 are rigidly secured to each end of the shaft 36 and have an arm 40 attached to one end and an arm 42 attached to the other end. Arms 40 are connected to the bed iii and arms 42 are connected to the silk screen frame 12. For each half revolution of the cam 16 arm 32 will move outward from the cam rotating shaft 36. Eccentric arms 38 will rotate with shaft 36 moving bed 10 downward and silk screen frame 12 upward. During the other half revolution of the cam, the bed and silk screen frame will be closed. Cams 16 are provided with rapid rise-rapid fall cam surfaces so that the outward and return movements of the bed and silk screen frame are completed in a minimum of time.

During the outward movement of the bed and frame, a sheet of material 28 is carried to a position intermediate the bed and frame by grippers 50. The grippers are secured to drive chains 62 in sets, the number of grippers in each set being dependent on the width of the Sheet to be printed. The grippers are mounted on

rods

56 and 58, the former of which is rigidly secured to end members 60 and the latter is rotatably mounted in the end members. The end members are connected to the drive chain by boss 64 so that the gripper rods are transverse to the planes of the chains. The drive chains are mounted on sprockets 66 and run between the silk screen frame and the bed to sprockets 68 on the end of take-off table 70. The chain then runs to drive sprockets 72 around chain tightener 74 and back to sprockets 66. The drive sprockets are mounted on the ends of shaft 92 which is secured to one-way clutch 90. Motor 29 actuates a wheel and ratchet arrangement 76 through rods 80 producing a reciprocating rotary motion in the wheel. This motion is carried to the clutch by chain 88 and the clutch transmits one direction of rotation to shaft 92 advancing the drive chain and free wheels in the other direction of rotation. The drive chain is thus advanced in a step by step manner and in the embodiment shown in the drawings one complete revolution will be completed in five steps.

The grippers are rigidly secured to rod 56 and are provided with apertures 57 in which rods 58 are rotatably positioned. A cam E6 secured to the end of rod 58 is ac tuated on the downward movement of the silk screen frame by an actuator 94 (FIG. 15). Rotation of rod 58 will rotate pin Q8 moving index member 61 upward against finger 100. The finger is rotatably mounted on rod 56 and biased downward by pin and spring arrangement 1G2 against knurled roller 52. The upward movement of the index member rotates the finger about rod 56 exposing the face 78 of the index member. A sheet of material is aligned with a number of adjustable blocks 47 on the edge of feed table 46 and is inserted between the finger and roller until it abuts the face of the index. It can be seen that with a set of grippers mounted in a line ('FIG. 5) the sheet of material is registered in the grippers while the printer is printing on the preceding sheet of material. On the upward movement of the frame and actuator 94, the bias of the pin and spring arrangement 102 on the finger will rotate rod 58 and cam 96 to the initial position while closing the finger on the roller. The sheet of material will be clamped between the finger and roller and will be carried by the grippers into the printing mechanism when the drive chain is advanced to the next position.

There are five sets of grippers provided on the chain drive, one for each step of movement. It will be appreciated that any number of sets of grippers could be used depending only on the number of steps required to complete one cycle in the operation of the device. In the first step of operation a sheet of material is aligned with blocks 47 and registered on the faces 78 of the index members in the grippers. When the silk screen frame moves upward, the sheet of material will be clamped in the grippers. As the frame reaches the top of its movement, the ratchet and wheel drive will reverse, advancing these grippers with the sheet of material into the printer. (The movement of the chain will be stopped with the grippers aligned along the edge of the bed10.) Since the grippers were aligned with the feed table so that the index faces in the grippers provide an identical registration point for each sheet of material inserted therein, positive registration is assured on the bed if the chain is moved an identical distance from the feed table to be bed in each step of movement. The chain will then be stopped with the grippers aligned along the edge of bed 10.

The bed and frame will then close on the sheet with the grippers lying below the plane of the surface of the ed (FIGURE 7). The bed is of the conventional vacuum type and will hold the sheet of material until the vacuaim is released as the bed and screen are opened. The sheet will be pulled from the screen so that the grippers can carry it to the take-off table 70 when advanced to the next position.

As the grippers are moved across the take-off table, cam 96 will engage stationary cam actuator 106 momentarily opening the grippers in movement (FIGURE 8). The sheet of material will be released from the grippers and drop onto a plurality of continuously moving bands 110 on the take-off table. The grippers will be stopped on sprocket 68 below the surface of the take-off table so that the printed sheet will be carried clear of the table. The grippers will then be moved in three steps back to the starting position.

In operation motor 20 is driven at a continuous rate of speed which can be varied depending on the capabilities of the operator. For approximately one-half revolution of the motor the screen and bed are closed while a standard mechanical squeegee is drawn across the screen. The details of mechanical squeegees are conventional and are therefore not shown. During this half revolution of the motor, the drive from the ratchet and wheel is being absorbed by the free wheeling action of the clutch. Just prior to the end of this half revolution of the motor, the bed and silk screen frame will be opened to allow the grippers to move therebetween and Will close on the sheet registered therein. As the direction of motion of the ratchet changes, the clutch will drive the grippers forward one step. As the grippers approach the edge of the bed nearest the take-off table, the bed and frame will start to close on the sheet of material. The grippers are then stopped and the paper is disposed in a plane over the bed so that the bed and screen close with the sheet therebetween.

The reach of the drive chain from the feed table to the point of register with the bed is tight at all times, assuring positive registration from one position to the other. It is conceivable that the grippers be raised over the bed but this would introduce some slack in the chain which will reduce the possibility of obtaining positive register in each step of operation. It will be appreciated that there must be some vertical motion of either the bed or the chain to allow for proper clearance for the grippers.

After the printing operation the bed and frame are opened to allow the grippers to move across the take-off table carrying the printed sheet out from the bed. The sheet will have a tendency to stick to the silk screen and by moving the screen away from the printed sheet the vacuum bed has a tendency to peel the material from the screen. This peeling effect can be increased by raising the silk screen frame at an angle rather than horizontally as shown by increasing the length of eccentric arms 38 at the gripper end of the bed so that one end of the frame is moved through a greater distance than the other end. The preferable arrangement is to have the end next to the gripper raised the highest so that the motion of the grippers will pull the sheet from the screen. The grippers are momentarily opened by actuator 1% as they are moved across the take-01f table releasing the printed sheet. The sheet will then be carried clear of the grippers by the bands to an automatic dryer.

This device can be used for material other than paper, such as cardboard or even metal sheets. As presently set up, the grippers can handle stock from three-thousands of an inch to the thickness of corrugated board without any adjustment. It is possible to increase this to quarter inch stock with a very minor adjustment in the grippers.

Although but one embodiment of the present invention has been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.

I claim:

1. In a sill; screen printing device for producing successive inked impressions in like predetermined locations on each of a plurality of sheets of stock comprising, a fiat bed defining a hard smooth upper surface for receiving and supporting one of said sheets, printing means positioned in a plane parallel to the plane of the bed, means for raising the bed vertically upward and lowering the printing means vertically downward into engagement simultaneously, means for registering a sheet in a predetermined position on one side of the bed, said registering means including means for clamping the sheet, means secured to the printing means and movable therewith for actuating the clamping means to receive one of said sheets only When the bed and printing means are in engagement, said clamping means closing on the sheet when the bed and printing means are opened, and means for moving the registering means to a printing position between the bed and printing means, said bed and printing means closing on the sheet when the registering means is in the printing position.

2. In a silk screen printing device according to claim 1 wherein the clamping means comprises a number of grippers positioned on a pair of bars, one of said bars being rotatable within the grippers, a cam on the end of said rotatable bar actuated by the actuating means, an index block in each gripper connected to the rotatable rod and movable by said cam to open the gripper, said blocks presenting an indexing surface for registering said sheet when the gripper is opened by the actuating means.

3. In a silk screen printing device for producing successive linked impressions in like predetermined locations on each of a plurality of sheets of stock comprising, a fiat vertically movable bed defining a hard smooth upper surface for receiving and supporting a sheet, vertically movable silk screen printing means positioned over the bed, means for registering one of said sheets on one side of the bed, means on the other side of the bed for transporting the sheets away from the bed, means for intermittently moving the bed and printing means vertically into and out of engagement, a pair of endless chains mounted to move in one direction past the registering means, between the bed and printing means and over the transporting means, means for advancing the chain in a step by step manner, said advancing means being operable only when the bed and printing means are out of engagement, gripper means mounted between the chains at intervals so that one section is aligned with the registering means, one section is aligned with the bed, and one section is aligned with the transporting means at the end of each step of movement, means supported by the printing means and movable therewith for actuating the gripper means while aligned with the registering means, so that one of said sheets on the registering means can be clamped within the gripper, whereby on opening of said printing means the gripper will close on the sheet and carry the sheet between the bed and printing means and on the next step of movement the sheet will be carried to the transporting means.

4. An automatic silk screen printer comprising a movable bed, a silk screen mounted above the bed in a plane parallel to the plane of the bed, said screen being connected to the bed to move oppositely to the movements of the bed, means for actuating the connecting means to move the bed and screen simultaneously towards each other to a closed position and away from each other to an open position, a pair of continuous chains mounted to ro tate in planes parallel to each other and transverse to the planes of the bed and screens, a plurality of gripper sections having one end attached to each chain, means carried by and movable with the screen for opening one of the gripper sections to receive a sheet of blank material when the bed and screen are in the closed position said means for actuating the connecting means advancing the chain simultaneously with the opening of the bed and screen so that the sheet of material is positioned between the bed and screen during the period of time it takes to move the bed and screen from the closed position to the open position and back to the closed position.

5. A printer according to claim 4 wherein the actuating means includes a ratchet and wheel, means for reciprocally actuating the ratchet and wheel, a one-way clutch mounted to actuate the chain, and means connecting the ratchet and wheel to the one way clutch so that the chain is advanced intermittently by the clutch.

6. An automatic silk screen printer comprising a movable bed, a movable screen positioned in a plane parallel to the plane of the bed, means for moving the bed and screen relative to each other, a pair of continuous chains movable in planes parallel to each other and transverse to the planes of the bed and screen, means for advancing the chain in stages, a gripper section secured to the chains in each stage of movement, each gripper section having a pair of parallel rods mounted transverse to the planes of the chain, a plurality of grippers rigidly secured to one of said rods, the other rod being rotatable, a cam secured to the end of the rotatable rod, a finger rotatable on the stationary rod, a spring biasing the finger toward the rotatable rod, an index block slidable within the gripper operatively engaging the finger, a pin secured to the rotatable rod and engaging the block so that on actuation of the cam the rod will rotate and the pin will force the block upward against the finger, said block providing an indexing means for aligning sheets of blank material, means mounted on the silk screen for actuating the cam upon closing the screen, said means releasing the cam when the silk screen is open so that the fingers will grip the sheet of material, and said advancing means advancing the grippers to a position between the bed and the screen.

7. In a silk screen printing device for producing successive inked impressions in like predetermined locations on each of a plurality of sheets of stock comprising, a flat bed for receiving and supporting one of said sheets, a silk screen positioned over and connected to the bed, registration and gripping means movable to a station for reception of material, means for moving the registration and gripping means to a predetermined location with respect to the bed so that a sheet carried by the gripping means will be positioned in a predetermined location, means for closing the bed and screen while the sheet is on the bed, said closing means opening the bed and screen after printing by raising the end of the screen adjacent the grippers to a greater height than the other end of the screen, and means for moving the sheet to a discharge point for releasing the sheet to a take-off means the motion of moving means being effective to peel the sheet from the screen.

References Cited in the file of this patent UNITED STATES PATENTS 1,589,546 Nichols June 22, 1926 1,966,416 Parmele et a1. July 10, 1934 2,196,678 Klopfenstein Apr. 9, 1940 FOREIGN PATENTS 800,680 France July 16, 1936