US3094921A - Machines for printing or decorating articles of ware - Google Patents

Description

June 25, 1963 D. R. JAMES 3,094,921

MACHINES FOR PRINTING OR DECORATING ARTICLES OF WARE Filed Aug. 3.7, 1960 3 Sheets-Sheet 1 l Nv ENTOR 04km fi/c/mneo 5/4415:

ATTORNEY June 25, 1963 D. R. JAMES 3,094,921

MACHINES FOR PRINTING OR DECORATING ARTICLES OF WARE Filed Aug. 17, 1960 3 Sheets-Sheet 2 F J Fla. 3.

\NVENTOR fl/W/D K/eH/Mo JAMES A TORNEY June 25, 1963 D. R. JAMES 3,094,921

MACHINES FOR PRINTING OR DECORATING ARTICLES 0F WARE Filed Aug. 17, 1960 3 Sheets-Sheet 5 INVENTQR ATTORNEY at the inking station.

United States Patent Ofice 3,084,921 Patented June 25, 1963 3,094,921 MACHINES FOR PRINTENG OR DECORATING ARTIQLES F WARE David Richard James, Covertside, Hasfield, England, as-

signor to Murray Curvex Printing Limited, Gloucester, England Filed Aug. 17, 1960, Ser. No. 50,275 Claims priority, application Great Britain Aug. 18, 1959 11 Claims. (Cl. 101-44) This invention relates to machines for the off-set printing or decorating of articles, for example articles of ware, of the type in which colour is transferred from a plate having the design formed thereon to the article to .be printed or decorated by means of a resilient pad which is first pressed against the plate and then against the article.

The object of the invention is to provide a novel machine of the above type which can readily be designed for printing or decorating articles of ware capable of being stacked, for example back-stamping plates and the like.

According to the invention a machine for the offset printing or decorating of articles comprises a printing head movable between an inking station and a printing station and transfer means movable between said printing station and a third station, means being provided to effect such movements automatically in timed relation whereby the transfer means will transfer an article between the printing and third stations during movement of the printing head so that a fresh article to be printed or decorated is always positioned at the printing station ready for printing or decorating when the printing head reaches the printing station. [Preferably the printing head comprises a resilient pad which is pressed against a design plate at the inking station.

The transfer means preferably comprises a suction cup which grips the articles, and it may be arranged to grip the top article of a stack of unprinted articles at the third station during a printing operation of the printing head at the printing station and release that article at the printing station during an inking operation of the printing head Thus a stack of articles to be printed positioned at the third station are transferred one by one for printing to the printing station at which the printed articles are stacked. Alternatively, the transfer means may operate in the reverse manner, so that a stack of articles at the printing station are transferred one by one to the third station after printing and in sequence with successive printing operations. Thus the third station becomes a stacking station for the printed articles.

Preferably both the printing head and the transfer means, which may be a pick-up head, are arranged for reciprocatory movement during the printing and inking operations, and the accompanying picking-up and delivering operations, respectively. The heads may be mounted on the piston rods of fluid-pressure operated power cylinders, conveniently arranged for vertical reciprocation, and they may be mounted on a common column for rocking movement between said stations when in a raised inoperative position.

The arrangement may be such that automatic operation of the machine ceases when the stack of articles to be printed is exhausted, and the machine may come to rest with the printing head positioned above the inking station ready for its downward ink-ing stroke at the commencement of the next machine cycle. The machine operator can now remove the stack of printed ware and place a fresh stack of unprinted were in position ready for printing, although in many cases it will be found that the operator .can do this without stopping the machine.

Means for automatically applying paint or ink to the plate at the inking station and for removing excess paint or ink therefrom may be operated automatically in timed relation to the rocking movement of the column on which the printing and pick-up heads are mounted.

The invention will now be further described with reference to the accompanying drawings which illustrate, by way of example, one form of printing machine in accordance with the invention, designed for back-stamping articles of ware such as plates and the like, and in which:

FIGURE 1 is a plan view of the machine,

FIGURE 2 is a front view partly sectioned on the line II-II in FIGURE 1,

FIGURE 3 is a side view partly sectioned on the line 1I III'I in FIGURE 1, and

FIGURE 4 is a circuit diagram of a pneumatic control circuit of the machine.

The machine comprises a vertical column 1 on which are mounted a printing head 2 and transfer means, comprising a pick-up head 3, for movement along arcuate paths of equal radius during rocking movement of the column 1. The printing head 2 comprises a resilient pad 4 mounted at the lower end of the piston rod 5 of a vertical double-acting power cylinder 6, and the pick-up head 3 is similarly mounted on the lower end of a vertical double-acting power cylinder 7. The cylinders 6 and 7 are respectively fixed at the outer ends of arms 8 and 9 clamped to the column by a clamp bolt 10.

The column 1 is mounted on a base 12 behind a table 13 which is also mounted on the base 12. The table 13 has two upstanding pegs 14 adjustable along slots 15 and against which a stack of ware to be printed is placed so as to be correctly positioned for printing. Rocking movement of the column 1 is produced automatically during operation of the machine by a doubleacting power cylinder 16. Such rocking movement serves to move the printing head from a position (as shown particularly in FIGURE 1) above an inking station, at which is positioned a horizontal plate 17 formed with the design to be transferred to the articles, to a postion above a printing station on the table '13 and back again, the pick-up head 3 at the same time moving between the printing station and a third or loading station defined by the pegs 14 on the table 13.

The power cylinder 16 isconnected to a crosshead 18 linked to the column 1 by a work arm 19 and connected to inking and do-ctoring means 20 (shown in section in FIGURE 2) mounted at the front of the crosshead 18 which is attached to the piston of the power cylinder 16 and slides in a fixed forward bearing 21. An inking member 23 of the means 20 is pivotally mounted on an arm 24 bolted to the front of the crosshead and provides a downwardly directed surface 25 above the design plate 17. An inclined doctor blade 26 bolted to the front of the member 23 has a lower doctor edge parallel to the surf-ace of the plate 17.

In use ink in the reservoir formed between the plate 17 and the surface 25 is spread over the plate 17 during a forward stroke of the crosshead which moves the printing head 2 from the inking station to the printing station. During the return stroke of the crosshead 18 the doctor blade 26 automatically removes ink from the plate 17.

The member 23 is connected to a lever arm 27 which is urged by a compression spring 28 into a resting position in which the doctor blade 26 is held slightly clear of the plate 17 during an inking stroke. An adjusting nut 29 enables the tension in the spring 28 to be adjusted. Adjacent each upper corner of the arm 27 a piston 29, which bears on the rear surface of the arm 27, is mounted in a corresponding cylinder bore in a member 30 mounted on the crosshead. A connection 32 leads to both the cylinder bores and enables pressure to be applied thereto, in a manner described hereinafter, to displace the pistons 29 outwardly to overcome the spring 28 and urge the doctor blade 26 into engagement with the plate 17 during each return or doctoring stroke of the crosshead 18.

Automatic cycling of the machine is achieved by means of the pneumatic control circuit which will now be described: In the resting position of the machine (as shown in the drawings) the printing and pick-up heads 2 and 3 are fully raised above the inking and printing stations respectively with the ink applying means 20 in a position in which ink has been spread on the plate 17 and the latter doctored.

Movement of the crosshead controls five auxiliary control valves V1, V2, V3, V4 and V of the circuit. As shown particularly in FIGURE 1, V1 is a trip valve which is tripped by the crosshead 18 as the latter passes through an intermediate position midway between its terminal positions, V2 and V5 are operated by an upstanding pin 32 on the crosshead 18, and V3 and V4 are respectively operated by adjustable tappets 33 on the arm 19. In the resting position of the crosshead 18, V4 is held open against spring loading and V5 held in its actuated terminal position. V3 is also spring loaded to its normal resting position; and V1, V2 and V5 are of a type which can be reset by the application of pressure air to corresponding operating cylinders of these valves.

To operate the machine a push-pull start valve V6 is pulled to close the latter and admit pressure air from 'an inlet 34, through a restrictor R1 and the trip valve V1 to the inlets of V3 and V4. As V4 is open the air passes therethrough to an operating cylinder 35 of a springloaded head-control valve V7 controlling the cylinders 6 and 7. This valve is spring loaded towards a terminal position in which a line 36 leading to the upper ends of the cylinders 6 and 7 is connected to exhaust, and a line 37 leading to the lower ends of these cylinders is connected to a pressure air inlet 38 which merely supplies air for operation of the cylinders 6 and 7. Thus the spring loading of V7 acts to retain the heads 2 and 3 in their raised positions and the application of pressure air to the valve cylinder 35 changes over V7 to lower the heads 2 and 3 simultaneously.

A spring-loaded foot-operated valve V8 supplied from a further air inlet 34a is connected to V6 in such manner that V6 and V8 can be used at will to control the machine, according to whether hand or foot operation is the more convenient.

The speed of lowering of the printing head 2 is controlled by an exhaust restrictor R2 in circuit with the power cylinder 6, and that of the pick-up head 3' by inlet and exhaust restrictor's R3 and R4 connected in circuit with the power cylinder 7. An adjustable regulator valve V9 enables the final load on the printing head 2, i.e., the normal printing pressure, to be preset at a value providing satisfactory printing without damaging the articles of ware. At the end of its downward stroke the head 2 contacts the design plate 17 and picks up any ink which may be left thereon, and the pick-up head 3 during this initial machine cycle idles above the printing station.

At the same time as pressure is applied to the valve cyl in der 35 it is also applied through a line 39 to one end of a reservoir 40. This reservoir is in the form of a hollow cylinder'containing a free piston 42 so that, in effect, two

separate reservoirs are respectively provided on opposite sides of the piston 42. The pressure builds up in the reservoir 40 and in the power cylinders 6 and 7 until it reaches a prearranged value which operates a normally closed spring-loaded sequence valve V which opens to apply pressure air to the valve cylinders 43, 44, and 45 of V1, V2 and V5. As a result V1 and V2 are reset, but not V5 which is held in the actuated position by the crosshead pin 32.

Resetting of V1 exhausts the valve cylinder 35 through V4, so that V7 is changed over by its spring loading to reverse the power cylinders 6 and 7 and raise the printing and pick-up heads 2 and 3. At the same time the reservoir 40 is exhausted through the line 39 while the opposite end of the reservoir is supplied with pressure air through a line 46 at a rate controlled by the restrictor R1. Pressure builds up at this end of the reservoir 40 while the heads 2 and 3' are being raised, and continues to build up until it reaches a value at which it operates a second normally closed spring-loaded sequence valve V11.

Opening of Vll supplies air through V5 to a line 47 connected to an operating cylinder 48 of a double-acting column-control valve V12 and an operating cylinder 49 of a double-acting doctor control valve 13. The other operating cylinders 50 and 52 respectively of V12 and V13 are connected to V5 by a line 53 which in the reset position of V5 is connected to exhaust, so that opening of the sequence valve V11 applies pressure air through V5 to change over V12 and V13. V12 then connects a pressure air inlet 54 to the inner end of the power cylinder 16 through a line 55 and exhausts the other end of the power cylinder 16 through a line 56 to rock the column and bring the printing and pick-up heads 2 and 3 respectively into position above the printing and stacking stations. The speed of such movement is controlled by restrictors R5 and R6 respectively connected in the lines 55 and 56, and change over of V13 exhausts the cylinders of the pistons 29 so that the latter are moved inwardly by the spring 28 and the pressure of the doctor blade on the plate 17 is relieved.

Movement of the crosshead 18 resulting from changing over of V12 acts to ink the plate 17, in the manner already described, and releases V4 and V5 so that the former is reset by its spring loading. At the midpoint of the crosshead stroke V1 is tripped while at the end of the stroke V3 is opened against its spring loading and V2 closed, opening of V3 again applying pressure air to the valve cylinder 35 to operate V7 against its spring loading and bring about a downward printing stroke of the printing head 2 and a corresponding stroke of the pickup head 3 on to the stack of unprinted articles previously placed at the loading station against the pegs 14. As before, operation of sequence valve V10 reverses the power cylinders 6 and 7 and brings about operation of the sequence valve V11. Opening of the latter now admits pressure air through V5 to the line 53, again changing over V12 and V13. This reverses the power cylinder 16 to produce a return'movement of the column 1 and applies pressure air to the pistons 29 through a restrictor R7 from an air inlet 51, so that the doctor blade 26 is urged against the design plate 17 and the ink previously spread on the latter is doctored during the return crosshead stroke.

During the downward movement 'of the pick-up head 3 above the loading station a vacuum is built up in a suction cup 57 of the head 3 when the latter contacts the uppermost article at the stacking station. The headal'so comprises a cylinder member 58 to the lower end of which the cup 57 is attached; the cylinder member 58 and the cup 57 communicate through a port 57a. Within the cylinder member 58 slides, with a degree of lost motion, a piston 59 mounted at the lower end of the piston rod 60 of the power cylinder 7. The piston 59 includes an upwardly concave cup seal 59a and the cylinder member 58 is urged downwardly away from the piston 59 by a compression spring 58a. Thus continued downward movement of the piston rod 60 after the cup 57 has engaged an article at the stacking station moves the piston 59 within the cylinder member 58 to compress the spring 58a and to exhaust the cylinder member 58 around the edge of the cup seal 59a and through a vent (not shown) in the upper end of the cylinder member. The next upward movement of the piston rod 60 initially permits movement of the piston 59 within the cylinder member 58 under the influence of the spring 58a until the partial vacuum so formed in the cup 57 and the cylinder member 58 is sufficient to lift the uppermost article assuming that V2, which forms a suction control valve, is closed. V2 is connected to the interior of the cylinder member 58 by a line 62.

When the crosshead reaches the terminal position which brings the pick-up head above the loading station V2 is closed as already described, so that the next upward movement of the pick-up head creates a vacuum in the cup 57 and the uppermost article is gripped and raised bodily with the head 3. During the return movement of the crosshead 18 which brings the pick-up head 3 and the gripped article above the printing station V2 remains closed, as it does during the next downward stroke of the power cylinder 7, so that the vacuum in the cup 57 is not relieved and the article is lowered at the printing station while still gripped by the cup 57. However, the next operation of the sequence is that valve V applies pressure air to the valve operating cylinder 44 to change over V2 which is thus opened to relieve the suction in the cup 57 and release the article previously gripped.

A line 63 connects V2 to the line 36, and as a result relief of the suction in the cup 57 is assisted by a positive pufi of exhaust air along the line 63 from the power cylinders 6 and 7. This relieves the suction in a positive manner and moreover tends to blow dust and grit from the surface of the article as it is released. This cleans the surface ready for printing during the next machine cycle and also reduces the dirt and grit picked up by the printing head 2 during the next printing operation which would otherwise be transferred to the plate 17 and increase wear of the latter and the doctor blade 26.

It will be clear from the above description that as long as V6 is not reversed by hand, or V8 released when the machine is foot controlled, the machine will continue cycling, picking up articles in turn from the loading station and depositing them at the printing station for printing by the head 2. Single cycle operation can be achieved merely by suitable foot operation of V6. A check valve V14 in parallel with V9 is provided to allow air exhausted from the upper end of the power cylinder 6 to escape to atmosphere through V7 more easily, and pressure test points such as 64 are provided at suitable positions in the circuit to allow the pressure at such points to be checked with a suitable pressure gauge. All the pressure inlets such as 34 are arranged for connection to a common source of controlled pressure air.

In the embodiment illustrated the design plate 17 is clamped in position by clamping nuts 74 which retain it between side strips 75 with its rear edge located below an undercut locating strip 76. This arrangement enables the design plate 17 to be removed and replaced, if desired by a plate bearing a fresh design.

If desired, the printing head may comprise a resilient pad having a design thereon in cameo, the design being inked at said inking station. The inking station may comprise a plate upon which ink is spread with a roller or it may comprise a porous pad impregnated with ink, in either case the cameo design is inked at the station and then transferred to the printing station to print.

I claim:

1. A machine for the ofi-set printing of staclcable articles comprising an inking station, a printing station constructed to receive a stack of said articles, a third station constructed to receive a stack of said articles, a printing head movable automatically between said inking station and said printing station, and transfer means movable automatically in timed relation to the movement of the printing head to transfer articles one at a time between a stack of articles at the printing station and a stack of articles at the third station as the printing head moves between the inking station and the printing station, the printing head printing the article at the top of the stack of articles at the printing station between its movement to and from the inking station, and the transfer means, which comprise a pick-up head including a suction cup, being arranged to pick up the top article of the stack of unprinted articles at the third station during a printing operation of the printing head at the printing station and to release that article at the printing station during an inking operation of the printing head at the inking station,

whereby said machine may be loaded with a stack of unprinted articles at the printing station and after printing said articles may be removed in a stack from the third station.

2. A machine for the off-set printing of stack-able articles comprising an inking station, a printing station constructed to receive a stack of said articles, a third station constructed to receive a stack of said articles, a printing head movable automatically between said inking station and said printing station, and transfer means, which comprise a pick-up head including a suction cup, movable automatically in timed relation to the movement of the printing head to transfer articles one at a time between a stack of articles at the printing station and a stack of articles at the third station as the printing head moves between the inking station and the printing station, the printing head printing the article at the top of the stack of articles at the printing station between its movement to and from the inking station, and said pick up head being arranged to pick up the top printed article of a stack of othenvw'se unprinted articles at the printing station during an inking operation of the printing head at the inking station and to release that article at the third station during a printing operation of the printing head at the printing station.

3. A machine for the off-set printing of stackable articles comprising an inking station, a printing station constructed to receive a stack of said articles, a third station constructed to receive a stack of said articles, a printing head movable automatically between said inking station and said printing station, and transfer means, which comprise a pick-up head including a suction cup adapted to grip the articles, movable automatically in timed relation to the movement of the printing head to transfer articles one at a time between a stack of articles at the printing station and a stack of articles at the third station as the printing head moves between the inking station and the printing station, the printing head printing the article at the top of the stack of articles at the printing station be tween its movement to and from the inking station, and both the printing and pick-up heads are arranged for re ciprocating movement during the printing and inking operations, and the accompanying picking up and releasing operation, respectively.

4. A machine according to claim 3, comprising two fluid-pressure operated power cylinders having piston rods on which said printing and pick-up heads are respectively mounted.

5. A machine according to claim 3, wherein the printing and pick-up heads are arranged for vertical reciprocation.

6. A machine according to claim 5, comprising a common column on which the printing and pick-up heads are mounted for movement between said stations when in a raised inoperative position.

7. A machine according to claim 6 comprising means to cause cessation of automatic operation of the machine when a stack of articles to be printed is exhausted.

8. A machine for the ofi-set printing of stackable articles comprising an inking station, a printing station constructed to receive a stack of said articles, a third station constructed to receive a stack of said articles, a printing head movable automatically between said inking station and said printing station, and transfer means movable automatically in timed relation to the movement of the printing head to transfer articles one at a time between a stack of articles at the printing station and a stack of articles at the third station as the printing head moves between the inking station and the printing station, the printing head printing the articles at the top of the stack of articles at the printing station between its movement to and from the inking station, and the transfer means, which comprises a pick-up head including a suction cup, being arranged to pick up the top article of the stack of unprinted articles at the third station during a printing operation of the printing head at the printing station and to release that article at the printing station during an inking operation of the printing head at the inking station, a control circuitrcontrolling automatic operation of the machine being arranged to stop the latter with the printing head positioned at the inking station ready for an inking movement at the commencement of the next machine cycle.

'9. A machine according to claim 8, wherein the control circuit is pneumatic in operation.

10. A machine for the off-set printing of stackable articles comprising an inking station, a printing station constructed to receive a stack of said articles, a third station constructed to receive a stack of said articles, a printing head movable automatically between said inking station and said printing station, and transfer means, which comprise a pick-up head including a suction cup, movable automatically in timed relation to the movement of the printing head to transfer articles one at a time between a stack of articles at the printing station and a stack of articles at the third station as the printing head moves between the inking station and the printing station, the printing head printing the article at the top of the stack of the articles at the printing station between its movement to and from the inking station, and means for automatically applying ink to a design bearing plate at the inking station and for removing excess ink therefrom which are operated automatically in timedrelation to the movement of the printing and pickup heads between said stations.

11. A machine according to claim 10, comprising a common column on which the printing and pick-up heads are mounted, a crosshead and a fluid-pressure operated power cylinder connected to said orosshead movement of which produces rocking movement of the column and operates the means for automatically applying ink and removing excess thereof.

References Cited in the file of this patent UNITED STATES PATENTS 1,359,807 Huber Nov. 23, 1920 1,440,856 Wescott Jan. 2, 1923 1,599,918 Ohara Sept. 14, 1926 2,493,953' Emerson Jan. 10, 1950 2,692,552 Conkle Oct. 26, 1954

Claims (1)

1. A MACHINE FOR THE OFF-SET PRINTING OF STACKABLE ARTICLES COMPRISING AN INKING STATION, A PRINTING STATION CONSTRUCTED TO RECEIVE A STACK OF SAID ARTICLES, A THIRD STATION CONSTRUCTED TO RECEIVE A STACK OF SAID ARTICLES, A PRINTING HEAD MOVABLE AUTOMATICALLY BETWEEN SAID INKING STATION AND SAID PRINTING STATION, AND TRANSFER MEANS MOVABLE AUTOMATICALLY IN TIMED RELATION TO THE MOVEMENT OF THE PRINTING HEAD TO TRANSFER ARTICLES ONE AT A TIME BETWEEN A STACK OF ARTICLES AT THE PRINTING STATION AND A STACK OF ARTICLES AT THE THIRD STATION AS THE PRINTING HEAD MOVES BETWEEN THE INKING STATION AND THE PRINTING STATION, THE PRINTING HEAD PRINTING THE ARTICLE AT THE TOP OF THE STACK OF ARTICLES AT THE PRINTING STATION BETWEEN ITS MOVEMENT

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