US2120471A - Apparatus for drying printing plates - Google Patents

Description

June 14, 1938. .1. PETERSA ET AL APPARATUS FOR DRYING PRINTING PLATES Filed June 14, 1955 2 Sheets-Sheet l June 14, 1938. J. EETEE'E ET AL 2,120,471

' APPARATUS FOR DRYING PRINTING PLATES Filed June 14, 1955 2 sheets-sheet 2 BY d m ATTORNEYS Patented June 14, 1938 UNITED STATES PATENT OFFICE APPARATUS POR DRYING PRIN TIN G PLATES John Peters, Teaneck, N. J., and Harold M. Crosby, Jackson Heights, N. Y., assignors to News Syndicate Co. Inc., New York, N. Y., a corporation of New York Application June 14, 1935, Serial No. 26,552

5 Claims.

the plate is turned more rapidly, after the supplyv of heat has been shut olf.

Another object of our invention is to provide apparatus whereby the supply of heat is automatically shut off after a predetermined interval and the plate is then whirled or otherwise agitated at a higher speed.

Another object of our inventionis to provide an improved control whereby gas heat can be utilized, the supply of gas being automatically shut off after a specified time interval and the whirling of the plate being then continued at a higher speed for an additional and predetermined time interval.

Another object of our invention is to provide improved time-switch means for said apparatus.

Other objects of our invention will be set forth in the following description and drawings which illustrate a preferred embodiment thereof, it being understood that the above statement of the objects of our invention is intended to generally explain the same Without limiting it in any manner.

Fig. 1 is an elevation of the improved apparatus.

Fig. 2 is a diagrammatic representation of the printing plate which is to be dried.

Fig. 3 is a top plan view on the line 3-3 of Fig. 1.

Fig. 4 is a sectional view on the line 4-4 of Fig. 1.

Fig. 5 is ya diagrammatic representation of the wiring circuits.

Fig. 6 illustrates a detail of the mechanism.

Heretofore and in preparing photo-mechanical printing plates, it has been customary to dry said plates after they have been cleansed, by whirling said plates in a heated atmosphere. According to previous practice, the plate has been whirled about a vertical axis, with the wet coating material at the bottom surface of the plate.

According to our improved method the plate is whirled in a heated atmosphere, and the supply of gas or other heating medium is then discontinued, and the whirling of the plate is continued until the temperature to which the plate is exposed has dropped from about 50 C. to 35 C. In treating the plate according to our improved method, the plate is-whirled about a verticalaxis in the usual manner and the coating solution or material may be at the bottom surface y of the plate.

The improved machine has aframe F, provided at its top with a cylindrical' compartment 56a,

-which has an open portion 56 at the front thereof. A slidable doorflJ can be provided if desired, and this door D can be moved vertically in guides 5I.

The door D may be closed or it may be held open or partially open, while the apparatus is being used.

The upper end of the apparatus is provided with a motor 2, which may be a three-phase electric motor. Said motor may have two speeds, as will be later more fully described.

The time switch 3 is also mounted at the top of the frame.

The motor shaft S is connected to a collar 5 by means of a suitable pin, so that the collar 5 turns with the motor shaft S. At its lower end the collar 5 is provided with a pin 33, which is located in the slot 32 of a shaft extension 4. The shaft extension 4 can be moved up and down relative to the collar 5, and the engagement of the pin 33 with the slot 32 of the shaft extension 4, causes said shaft extension 4 to turn in unison with the shaft S.

'I'he shaft extension 4 is connected by a universal -jolnt 6 with a second shaft extension 4a. Said shaft extension 4a has a reducedbottom portion, which is located within the groove of a third shaft extension 4b, so that the members 4b and 4a turn in unison. The shaft extension 4b is provided with a collar I4, which is clamped thereto by means of a screw I5.

The collar I4 rests upon the upper end of a cylindrical bearing I2. If desired, any suitable antifriction means can be used, in order to permit the collar I 4 to turn freely relative to the bearing I2. 7

As shown in Fig. 4, the cylindrical bearing I2 is connected to the outer end of a rod 8, which is slidable in a sleeve 1a. Thesleeve 1a is connected to the interior wall of the compartment 56a, by means of an arm or bracket 1..

The slidable rod 8 is provided with a reduced shank Il, which is provided with a head I0. A coil spring 9 surrounds the reduced shank II. One end of the coil spring 9 abuts the head I0,

and the other end of the coil spring 9 abuts a. shoulder of the sleeve 1a. The coil spring 9 therefore yieldably retains the slide rodf8 in the position shown in Fig. 4, but said slide rod 8, together with the bearing I2, can be pulled outwardly, if desired.

As shown in Fig. 6, the rod 8 is provided with an extension 8a which fits within a corresponding groove of the sleeve 1a, when the parts are in the position shown in Fig. 4 and Fig. 6. However, when the rod 8 is pulled to lits outer posil tion, the extension 8a moves out of said groove of sleeve 1a, so that the sleeve 8 can be turned in unison with the head I0. If desired, the shank II could be made turnable relative to the head I0, so as to eliminate friction. Hence the vertical cylindrical bearing I2 can be turned around an axis which is perpendicular to the plane of Fig. 1, if the shaft member 4a is released from the shaft member 4b. The shaft member 4a can be released from the shaft member 4b by pushing the shaft member 4a upwardly, this being permitted by the pin 33 and the grooves or slots 32.

When the shaft member 4a is moved upwardly so as to release the collar I4, the shaft member 4a can be turned by means of'the universal joint 6, until said shaft member 4a is engaged by the resilient latch-member 36. This makes it possible to turn the bearing I2, in the manner previously stated.

Referring to Fig. 4, the lower end of the shaft member 4b is integral with a slotted arm I5.

Clamping members I1 are slidably mounted in the slots or grooves of the slotted arm I5, and said members I1 can be clamped in position relative to the slotted arm I5.

As shown in Fig. 1, the clamping members I1 are provided with anges I8 which engage the underside of the printing plate I. Hence the printing plate I can be clamped firmly in position at the bottom of the shaft member 4b.

The compartment 56a is provided with a series of gas burners I9 and it is also provided with a ue 50, in order to permit the escape of the products of combustion. The burners I 9 are connected by means of hand operated valves 20, to a gas pipe 2I. The gas pipe 2| is connected to a gas supply pipe 22, and a hand operated valve 3| can be operated in order to shut oi the supply of gas to the burners.

The supply of gas to the burners is also controlled by an automatically operated valve 30, this being operated by a solenoid or by other suitable electro-magneticmeans. A pilot light 23 is aso provided and. this is connected to the pipe 2 v By means of this apparatus it is possible to whirl the printing plate I in a heated atmosphere so as to thoroughly dry the same. 'I'he electric motor 2 is provided with current through the lcable 24 which passes through a conduit 26.

'I'he apparatus is provided with a hand switch 25 for opening and closing the circuit of the motor. A

As shown in Fig. 3, a cable which is locate in a conduit 1li, connects the motor to the switches which are diagrammatically shown in Fig. 5, and which are located in a switch casing 21. The conduit 10 carries the six leads from the two switches in the control box to the windings of the motor. y

On the other side of the switch casing 21, a. conduit 28 is provided for the cable of a branch control circuit to which the solenoid 61 (shown in Fig. 5) is connected.

The wiring diagram shown in Fig. 5 may be analyzed as follows:-

Since the specific embodiment has a threephase motor, we have shown three leads A, B, and C. A switch 31, having three arms, is connected to a rod 38 which is operated by means of the usual solenoid 38. When the switch 31 is in the operative position the three arms thereof contact with the three contact points 31a.

Another and similar switch 60 is provided, and this is operated by means of a rod 6I, which is operated by means of the solenoid 62. When the switch 60 is in the circuit-closing position, its three arms contact with the points 63.

The lead A passes through the time switch 3 and its circuit includes the armature 64 which is operated by means of the solenoid 65. Said parts 64 and 65 diagrammatically illustrate a time-delay relay which may be of any suitable conventional construction, so that a predetermined period of time must elapse before the relay 64 is moved so as to close contact between the points 66, when solenoid 65 is energized.

When the armature 64 is in the circuit-closing position which is illustrated in Fig. 5, the current passes through solenoid 38, to the lead C. Hence, when the time switch 3 rst closes the circuit, the solenoid 38 is energized, thus moving the rod 39, so that the switch 31 moves to the circuit-closing position, in which position the coils 2a of the 'motor 2 are in circuit, thus driving the motor at a relatively low speed, of about 600 R. P. M., for about one-half minute. Of course this period of one-half minute can be varied, in order to meet any given conditions.

While the coils2a are in circuit, the solenoid 61 is energized, in order to operate the magnetically controlled gas supply 30, so as to supply heat to the apparatus. When the relay armature 64 is operated, it closes the circuit between the relay points 66, and it `opens the circuit between the relay points 64a.

The coil 38 is now cut out of the circuit and the solenoid coil 62 is now put into the circuit, so that the switch 31 will open, and the switch 60 will close, so that its arms touch the points 63. This will de-energize the solenoid 61 so that the gas control valve 30 will move to the closing position. The open position of said gas control valve is shown in Fig. 5.

Current is now supplied to the motor coils 2b, thus driving the motor at a relatively higher speed, as for example about 1200 R. P. M. 'I'he motor can be driven at this higher speed, while the supply of heat is shut oi, for any desired periodfwhich may be from two minutes to two and a half minutes. In any event the period during which the motor is operated while the heat supply is shut off is preferably longer than the rst period.

After the predetermined period of operation, the time switch 3 moves to open the circuit completely.

In order to protect the pipes I9 from the dripping of liquid, said pipes are covered by a pan P which becomes heated by the gas burners and this heat is transmitted upwardly.

The bottom of the compartment 56a, is provided with a drain pipe Wl through which the Waste liquid can escape.

The apparatus and method specified herein CII can be utilized for drying any printing plate, which is subjected to a coating` operation, etc.

The advantage of the double speed whirling is that while the lower speed is being used, the heat sets some of the coating solution on the plate. The subsequent high speed whirls-of the excess of the solution, and the coating is thor= oughly dried during said high speed operation. Hence a more even coating is secured by the twostage operation, than by whirling the plate at a uniform and low speed.

While we have specified the whirling of the plate in the description and claims, it is to be understood that this is intended to include any suitable mechanical movement whereby the mois ture is driven off by mechanical force.

We have shown preferred embodiments of our invention, but it is clear that numerous changes and omissions can be made without departing from its spirit.

We claim:

1. Apparatus for drying a printing plate, comprising an electric motor having a shaft, means for clamping a printing plate to said shaft, said electric motor having first driving means and also having second driving means, first switch mechanism for controlling the circuit of the first driving means, second switch mechanism for controlling the circuit of the second driving means, said switches being normally in the open position, first electro-magnetic means for moving the first switch to the circuit closing position, second electro-magnetic means for moving the second switch to the circuit closing position, the circuit of said motor also including a time switch, a time-delay relay having an armature which closes the circuit of the first electro-magnetic means when in normal position, said armature being moved to a position in which it closes the circuit of the second electro-magnetic means after a predetermined interval which is less than the effective interval of saidl time switch, said timedelay relay opening the circuit of the first electro-magnetic means when it is moved to the last mentioned position, heating means adapted to heat the atmosphere in which the printing plate is located, and electromagnetic means for shutting off the supply of heat and in circuit with the first driving means.

2. Apparatus for drying a printing plate, comprising an electric motor having a shaft, means for clamping a printing plate to said shaft, said electric motor having iirst driving means and also having second driving means, first switch mechanism for controlling the circuit of the first i driving means, second switch mechanism for controlling the circuit of the second driving means, said switches being normally in the open position, first electro-magnetic means for moving the rst switch to the circuit closing position, second electro-magnetic means for moving the second switch to thecircuit closing position, the circuit of said motor also including a time switch, a time-delay relay having an armature which closes the circuit of the first electro-magnetic means when in normal position, said armature being moved to a position in which it closes the circuit of the 'second electro-magnetic means after a predetermined interval which is less than the effective interval of said time switch, said time-*delay relay opening the circuit of the first electro-magnetic means when it is moved to the last mentioned position, heating means adapted to heat the atmosphere in which the printing plate is located, and electro-magnetic means for shutting off the supply of heat and in circuit with the first driving means, the second driving means being adapted to turn the motor at a higher speed than the first driving means.

3. In apparatus for drying a printing plate, a vertical shaft and means for turning the same, a first shaft extension vertically movable relative .to said shaft and turnable in unison therewith,

a second shaft extension turnably in unison with the first shaft extension, the second shaft extension being turnable relative to the rst shaft extension around an axis which is inclined to the axis of rotation of said shaft, a third shaft extension anda bearing therefor, the second shaft extension being reieasably connected to the third shaft extension, said third shaft extension having clamping means for clamping a printing plate thereto, and time-control mechanism for controlling the turning of said vertical shaft in two stages having different speeds.

4. In apparatus for drying a printing plate, a vertical shaft and means for turning the same, a first shaft extension vertically movable relative to said shaft and turnable Vin unison therewith, a second shaft extension turnable in unison with the first shaft extension, the second shaft extension being turnable relative to the first shaft extension around an axis 'which is inclined to the axis of rotation of said shaft, a third shaft extension and a bearing therefor, the second shaft kextension being releasably connected to the third shaft extension, said third shaft extension having clamping means for clamping a. printing plate thereto, said bearing having turnable means supporting the same, said turnable means being turnable around an axis which is perpendicular to the central axis of said bearing, and timecontrol mechanism for controlling the turning of said vertical shaft in two stages having different speeds. 1

5. In apparatus for drying a printing plate, a vertical shaft and means for turning the same, a first shaft extension vertically movable relative to said shaft and turnable in unison therewith, a second shaft extension turnable in unison with the first shaft extension, the second shaft extension being turnable relative to the first shaft extension around an axis which is inclined to the axis of rotation of said shaft, a third shaft extension and a bearing therefor, the second shaft extension being releasably connected to the third shaft extension, said third shaft extension having clamping means for clamping a printing plate thereto, said bearing having turnable means supporting the same, said turnable means being turnable around an axis which is perpendicular to the central axis of said bearing, and means for holding said supporting' means in fixed position, and time-control mechanism for controlling the turning of said vertical shaft in two stages having different speeds.

JOHN PETERS. HAROLD M. CROSBY.

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