US2172394A

US2172394A - Surfacing of inking rolls

Info

Publication number: US2172394A
Application number: US752647A
Authority: US
Inventors: Wells A Lippincott; Bruce W Hubbard
Original assignee: Ideal Roller and Manufacturing Co
Current assignee: Ideal Roller and Manufacturing Co
Priority date: 1934-11-12
Filing date: 1934-11-12
Publication date: 1939-09-12
Anticipated expiration: 1956-09-12

Description

Sept. 12, 1939. w; A. L IPPINCOTT Er Al. 2,172,394

SURFACING OF INKING ROLLS Original Filed NOV, l2, 1954 Qr//e ou i @UHR Patented Sept. l2, 1939 UNITED STATES SURFACING F INKING ROLLS Wells A. Lippincott and Bruce W. Hubbard, Oak

Park, Ill., assignors to Ideal Roller & Manufacturing Company, Chicago, Ill., a corporation of Illinois Application November 12, 1934, Serial No; 752,647 f Renewed June27, 1938 Claims.

This invention relates to the surfacing ofthe inking rolls for printing presses with a film of printers composition and has more particular reference to the formation of such a coating by a method wherein the entire roller surface is at one time submerged in a body of the composition in a molten state.

The primary object of the invention is to provide a method of the above character by which a coating of uniform thickness may be formed over the entire roller surface, and rollers may be coated at a comparatively high rate of production.

Another object is to provide for the effective elimination of air cells in the coating formed on a roller by the above method.

The invention also resides in the novel character of the apparatus for carrying out the foregoing objects.

Other objects and advantages of the invention will become apparent from the following detailed description taken in connection with the accompanying drawing, in which Figure 1 is an elevational view of an apparatus by which the invention may be practiced.

Fig. 2 is a side elevational view of the apparatus shown in Fig. 1.

Fig. 3 is a fragmentary view partially in section of a part of the drive mechanism shown in Fig. 2.

Fig. 4 is a fragmentary sectional view illustrating a modification.

The invention is susceptible of various modifications and therefore we do not, by the present exemplary disclosure, intend to limit the invention, but aim to cover all modifications and alternatives falling within the spirit and scope of the invention as expressed in the appended claims.

Generally stated, the invention contemplates coating or surfacing an inking roller by a method which involves submerging the entire roller surface in a body of molten printers composition maintained at the proper temperature and subjecting different parts of the surface to said body for different lengths of time such as to produce uniform draining of the excess composition from the roller surface when the roller is removed, thereby leaving a congealed film of uniform thickness on the surface. Accordingly, the invention consists in supporting the roller in vertical position during the draining of the vexcess of composition therefrom and exposing successive longitudinal sections of the roller surface to the molten composition for progressively increasing intervals of time beginning at the upper end o1' the roller. During such exposure, the lower 1ongitudinal sections of the surface onto which cooling composition drains down from above are heated by the molten composition to a greater degree than the upper sections onto which there is less drainage. As a result of the natural drainage of the excess composition under these conditions, the tendency toward the formation of a lm which increases in thickness toward the lower end of the roller may be overcome resulting inthe formation of a coated roller of a diameter substantially uniform throughout its length.

Preferably, though not necessarily.. the improved method involves supporting the roller to be coated with its axis in upright position above a confined body of molten composition maintained at a substantially constant level during the coating operation, lowering the roller in an endwise direction and at a gradual and uniformly maintained rate into the composition, withdrawing the roller from the bodyprogressively and at a uniformly maintained rate, and rotating the roller at least during such withdrawal.

One form of apparatus for practicing the method as above setforth is shown in the drawing wherein the numeral 6 indicates a cylindrical heat-insulated tank adapted to conne a body l of molten printers composition greater in length and diameter than the rollers to be coated. Preferably, the lower part of the tank is connected through the medium of a pipe 8 and a power driven gear pump 9 with the lower end of a storage tank lll in which a body ofjcomposition greater than the amount required to fill the tank 6 may be contained. The composition may be heated by water within a jacket il and maintained at the usual temperature'of from 140 to 160 degrees Fahrenheit by an electric heater l2 controlled by a thermostat I3. If, as will be described later, the coating operation is performed without circulation of the molteny comy position through the tank .6,` the composition in the latter may be maintained at the desired temperature by a suitable thermostatically controlled electric heater Il.

Disposed in vertical position alongside of the tank 6 is a standard I6 providing a vertical slideway for a carriage I8 which overlies the tank and supports a vertical rotary shafti9 having a coupling socket 20 by which the roller 2i to be coated may be suspended in vertical position from one end of its shaft 22. An electric motor 23 mounted on the carriage is arranged to rotate the roller through appropriate speed reduction gearing 2l and a belt 25 connecting cone pulleys 26 and shiftable into different positions to permit adjustment of the speed of rotation of the roller.

To provide means for moving the roller inta and out of the tank 6, a lead screw 21 extends alongside the upper part of the standard i6 with its opposite ends supported by brackets 28.' Encircling the screw 21 is a nut 29 journaled in bearings 30 supported by the carriage. To enable the nut to be rotated in opposite directions, suitable reversing mechanismy may be employed.

Ilv

clutch collar I2 which may be shifted into clutchi ing engagement with either of two beveled gears 3l which are loose on the shaft ll and mesh with a gear 34 driven from the motor .by means such as the belt 35. The clutch may be shifted by mampulation of a handle 38 operating a yoke which engages the collar 32. rChanges inthe rate of entry and withdrawal ofthe roller may be effected in any desired way. For example, where a directcurrent motor is used, the speed thereof may be adjusted by changing the position of a rheostat controller 31 governing the motor circuit.

For a purpose to more fully appear later, a trough 3B completely surrounds the upper end of the tank 6 and constitutes'an overflow receptacle from'which the'excess of composition delivered to the tank 6 may be returned to the storage tank I0 through a pipe 39.

Preparatory to a coating operation, the roller to be coated is suspended from the shaft I9.' as shown in Figs.'1 and 2, and after the tank 6 has been filled by operation of the pump 9 and a uniform temperature attained, the motor. 23 is started and the -clutch lever 36 shifted into a position to cause lowering of the'. roller. Downvward endwise movement of the roller at a slow and uniform rate continues until the entire roller surface has been submerged. Then the drive mechanism is conditioned for raising the roller at the `desired rate after which the clutch is shifted to initiate -withdrawal of the roller from the tank.

. As the roller rises, the excess of molten composition retained on each longitudinal section rising above thelevel of the composition drains downwardly onto lower portions of the roller, the excess. composition nally being returned to the tank.l Itwill be observed that by lowering and raising theroller in the manner above described, the lowerend of the roller surface will be ex-l posed to -the composition for a substantially longer time interval than the upper end. For this reason, vveach succeeding section toward the upper end of the roller will be exposed, to the heated composition for a shorter time interval and therefore will become heated to a lesser degrec; But inasmuch as the rate of endwise movement is -maintained uniform, the amount of heat imparted to the roller will be changed progressively from one end of the roller to the other. Thus, as the excess of composition on one section drains down onto the section below, the additional heat available at the latter pointy will be returned to the adhering composition serving to maintain'the latter at the proper viscosity for insuring continued draining to the proper degree. As a result, the excess drains off from the roller in a manner such-as to leave a film of approximately uniform thickness over the entire surface even though the excess applied to the upper p0rtions of the roller flows down over the lower parts while it is cooling and its viscosity is thereby decreasing.

To produce a film of the desired uniformity in thickness, relative movement between the roller and the level of the composition in the tank 6 should occur at a rate which is suillciently slow to allow for proper progressive heating of the roller surface in the manner above described. With printers composition of the formula ordinarily used and where a constant level is mainauasa'i' t tained in the tank` B throughout the coating operation, a coating of the desired uniformity will be produced, for example, when the roller is lowered into and withdrawn from the composition at a rate oi' fteen inches per minute. Slower rates may be used and the maximum permissible rate of movement of the roller will of course vary with other factors such as the viscosity of the composition sed as determined by the proportions of its ingredients and the temperature at which it is maintained.

The maintenance of a continuous overflow throughout the coating operation is advantageous in that the level of the composition in the tank 6 does not vary appreciably in spite of the displacement of composition by the rollers. Thus, a tank 6 of comparatively small volume may be employed, and the same rate of roller movement usedin coating all sizes of rollers. If a continuous overflow is not maintained, the level of the composition in the tank will vary according to the relative diameters of the roller and the tank, so that unless an objectionably large tank 1' is used, .the relative diameters of the roller and the tank must be considered in determining the maximum permissible rate at which the roller is lowered and raised. If, instead of lowering the roller into the composition gradually, it is immersedv quickly, the withdrawal should preferably be at a correspondingly lower rate in order to produce proper progressive heating of the` roller surface. y

By maintaining a continuous overflow from the tank 6 while the roller is being lowered into andwithdrawn from the body of molten composition, air bubbles or cells are effectually eliminated from the film retained on the roller surface. This is due to the fact that the composition at the surface of the body in the tank Vis constantly moving outwardly from the roller surscribed, foam accumulating at any point on the composition surface will be carried in difi'erent directions from the roller into the overflow outlet thereby becoming trapped-in the tank Il.

face. With the overflow arranged as above det By rotating the roller during withdrawal thereof from the tank 6, the elimination of air cells from the final coating is materially facilitated. This is because the rotating roller' produces a swirling of the composition within the tank resulting in removal of the bubbles trapped on the roller surface by a mechanical brushing action of the composition. These and any bubbles which might be in the composition as delivered to the tank rise to the surface of the composition and vare eiectually removed by overflow action above described. The rate of vrotation of the roller may vary considerably. However, it should not be so fast as to agitate the molten composition unduly or result in the formation of a wavy surface on the coating.

If desired, mechanical means may be provided for assisting in the removal of .air bubbles which may be trapped on the roller surface as it is immersed. This means may take the form of brushes I0 on a carrier li which is supported within the tank 6 below the level of the composition. The brushes are spaced to engage and wipe across vthe roller surface as the rotating roller is lowered into the tank.

' While it is preferred to move the roller into and out of the composition within the tank O, it will be apparent that the same relative movement between the roller and the level of the comenvases position may be obtained by flowing the composition from the tank I into the tank B and then withdrawing the composition at a uniform rate. Flowing of the composition in this manner may be effected by the pump S which may be arranged to be driven by a reversible motor so that its direction of discharge may be reversed.

We claim as our invention:

1. 'Ihe method of coating an inking roller with the axis of the roller disposed in vertical position which comprises maintaining a confined body of molten composition, gradually lowering the roller endwise and at a predetermined rate into the composition until the entire surface to be coated has been submerged, gradually withdrawing the roller from said body at a uniform rate, and withdrawing molten composition from said body during said lowering and supplying molten composition to the body during said withdrawal to maintain the composition in said body at a constant level.

2. The method of coating an inking roller which comprises supporting the roller with its axis in vertical position, moving the roller and the level of a body of molten printers composition relative to each other vertically in a direction to immerse successive longitudinal sections of the roller surface and submerge the entire surface, withdrawing said roller from the composition at a predetermined rate, and continuously supplying molten composition to said body at a rate sufficient to maintain a substantially constant depth thereof during withdrawal of the roller therefrom.

3. Apparatus for coating a roller with printers' composition comprising, in combination, a tank adapted to contain molten composition and having a depth and diameter greater than the roller surface, means at the upper end of said tank providing for overflowing of the composition indifferent radial directions, means by which the roller may be lowered into said tank and withdrawn therefrom at a slow predetermined rate to permit draining of the excess composition, and means for supplying molten composition to the tank to maintain a continuous overflow in said diiferent directions away from the roller during withdrawal thereof.

4. Apparatus for coating a roller with printers composition comprising, in combination, a tank adapted to contain'molten composition and having a depth and diameter greater than the roller surface, an overflow receptacle at the upper end of said tank constructed to induce the flow of the surface composition outwardly in different directions from the center of the tank, means byl which the roller may be lowered into said tank and withdrawn therefrom at a slow predetermined rate to permit draining of the excess composition, an auxiliary storage tank containing molten composition and adapted to receive composition from said overflow receptacle, and means operable during withdrawal of the roller from said first mentioned tank to withdraw composition from below the level ln said storage tank and deliver the composition to the rst mentioned tank below the level in the latter and in quantities sumcient to maintain a constant overflow into said receptacle.

5. Apparatus for coating a roller with printers composition comprising, in combination, a tank adapted to contain molten composition and having a depth and diameter greater than the roller surface, an overflow receptacle at the upper end of said tank extending substantially around the entire periphery of the tank, means by which the roller may be lowered into said tank and withdrawn therefrom at a slow predetermined vrate to permit draining of the excess composition, and means for supplying molten composition to the tank to maintain a continuous overow therefrom during withdrawal of the roller.

6. Apparatus for coating a roller with printers' composition comprising, in combination, means for supporting a roller with its axis disposed in upright position, a recepticle arranged to contain a body of composition encircling said roller whereby to apply a coating thereto during relative vertical movement between the receptacle and roller, means for rotating the roller, and mechanical means positioned to wipe against the roller surface below the level of the composition within said receptacle whereby to remove air cells trapped on the roller surface.

'7. Apparatus for coating a roller with printers composition comprising means to support the roller with its axis in upright position, a receptacle adapted to contain a body of molten composition in which the roller may be submerged, means for effecting relative movement between said body of composition and said roller in a direction endwise of the latter, means operable during at least a part of said relative movement to deliver molten composition to said receptacle at a point below the level of the composition therein, an overflow outlet for said receptacle operable during the delivery of composition to the receptacle to induce the movement of the surface composition in different directions away from the roller surface, and means for effecting relative rotary motion between the composition in said receptacle and said roller whereby to remove trapped air cells from the roller surface.

8. 'I'he method of forming a film of printers composition on the peripheral surface of an' inking roller which comprises maintaining a conned body of said composition in a molten state, submerging the peripheral surface of said roller in said molten composition progressively from one end to the other, and wiping said surface progressively from one end to the other while the engaged longitudinal portions of the surface are submerged in said body whereby to remove air cells trapped on the surface.

9. The method of forming a film of printers' composition on the peripheral surface of an inking roller which comprises maintaining a confined body of said composition in a molten state, immersing the peripheral surface of said roller in said molten composition, and wiping each portion of said peripheral surface while the latter is submerged in said body whereby to remove air cells trapped on the surface.

10. Apparatus for forming a film of printers composition on the periphery of an inking roller comprising means for supporting a roller, a receptacle arranged to contain a body of molten composition encircling said roller whereby to apply a coating of the composition to the roller surface during relative movement of the receptacle and said roller axially of the latter, and mechanical means operable during such relative movement to wipe against the roller surface submerged in said composition whereby to remove air cells trapped on the roller surface.

WELLS A. LIPPINCOIT. BRUCE W. HUBBARD.