US2692575A - Moistener for duplicating machines - Google Patents

Description

Oct. 26, 1954 R. M. FORD ETAL 2,692,575

MOISTENER FOR DUPLICATING MACHINES Filed June 4, 1952 3 Sheets-Sheet l INVENTOZS.

m Aceems Get. 26, 1954 R. FORD ETAL MOISTENER FOR DUPLICATING MACHINES 3 Sheets-Sheet 2 Filed June 4, 1952 \NVENTORS 26, 1954 R. M. FORD ET AL 2,692,575

MOISTENER FOR DUPLICATING MACHINES Filed June 4, 1952 3 Sheets-Sheet 3 FIGE. 51-5 E g 3-6 \28 i INVENTORS BY Q 2 WANN m AGIENTS Patented Oct. 26, 1954 MOISTENER FOR DUPLICATING MACHINES Ronald Max Ford and Denis Percy Crane, Olton, Birmingham, England; said Crane assignor to Frank R. Ford Limited, Sparkbrook, Birmingham, England, a British company Application June 4, 1952, Serial No. 291,762

Claims priority, application Great Britain June 9, 1951 8 Claims. 1

This invention relates to duplicating machines of the kind in which means such as a master cylinder are provided for supporting a master sheet upon which is carried the matter to be reproduced, such matter appearing on the master sheet in reverse or mirror image, and copy sheets are fed into pressure contact with the master sheet after being suitably moistened by means provided for this purpose on the machine.

One object of the present invention is to provide in such machines, hereinafter referred to as being of the kind specified, new or improved means for moistening the copy sheets as they pass into pressure contact with the master sheet.

A further object of the invention is to improve the control exercised over the quantity of mois ture applied under varying conditions of consumption by providing a fabric moistening strip extending transversely of the feed path along which the copy sheets pass to the master cylinder, this strip having a receiving portion disposed in operative relation to a liquid distributing device, an extraction portion which is in contact with a porous or absorbent body to maintain a flow of moistening liquid under capillary action along the strip from the receiving portion tothe extraction portion, and a transfer portion lying effectively between the receiving and extraction portions and associated operatively with means for effecting transference of liquid to the copy sheets, the transfer portion of the strip being in contact with an absorbent pad of substantially larger capacity than the strip itself so as to maintain progression of liquid through the strip thereby reducing fluctuations in the flow of liquid through the strip caused by varying consumption on to the copy sheets.

Yet another object of the invention is to provide improved means for urging the transfer portion of the moistening strip into contact with a transfer roll.

A further object of the invention is to provide improved means for initially confining the re" ception of moistening liquid to the receiving portion of the strip so that it may inherently be capable of being absorbed into the strip to flow along it through the transfer portion thereof.

Still another object of the invention is to pro vide improved means for collecting any surplus moistening liquid which may, notwithstanding the improved means for confining liquid fed to the receiving portion of the strip, ultimately be discharged therefrom, such collecting means being adapted to perform the auxiliary function f r in he strip into ontact with the transfer roll.

(Cl. 1l.8-260) The invention will now be described with reference to the accompanying drawings illustrating by way of example the embodiment of same and wherein:

Figure 1 shows in side elevation one construc tion of duplicating machine of the kind specifled incorporating moistening means according to the present invention.

Figure 2 is a view of the same machine also in side elevation and on an enlarged scale with one of the side plates removed to show the general arrangement for feeding and moistening copy sheets and in which some of the parts are shown in section.

Figure 3 is a fragmentary view in side elevation on a still larger scale and in cross section along a vertical longitudinal plane showing the arrangement of moistening strip, liquid distributing means and trough.

Figure 4 is a perspective exploded view showing details of the distributing means, trough and moistening strip.

Figure 5 is a fragmentary view showing one arrangement of duct elements constituting the liquid distributing device with the orifice groups extending along opposite lateral zones of the moistening strip.

Figure 6 is a similar view but illustrating a different arrangement of orifice groups.

Figure 7 is a fragmentary view in cross section showing the arrangement of liquid tank and feed pump, this view being taken in cross section on a vertical longitudinal plane through the tank, and

Figure 8 is a fragmentary view in cross section on the line 38 of Figure '7.

In the construction illustrated in the drawings and particularly in Figures 1 and 2 the duplieating machine comprises a rotary master cylin der Ill journaled between side plates H and engaged by a pressure roll !2 which forms a printing couple with the master cylinder through which copy sheets are passed along the feed path indicated by the broken line [3.

The master cylinder is adapted to carry a master sheet 14 hearing the matter to be reproduced in a suitable medium such as hectographic carbon, this matter appearing on the exposed face of the master sheet in reverse or mirror image and the master sheet is held in place by means of a suitable grip [5 provided on the master cylinder. A bulk supply of copy sheets as illustrated at i6 is supported on a suitable table I! at the front of the machine and after passage into a guide opening !8 enters the nip between a moistener transfer roll [9 and associated feed roll 20 spring loaded into engagement with the transfer roll moistener, the copy sheets being eventually discharged after passage through the printing couple on to a receiving tray or table 2.

Thus far described the machine is of conventional construction and the detailed form and arrangement of the various component parts may be varied widely without in any way departing from the scope of the invention.

Referring now more specifically to Figures 3 and 4 the moistening means provide for moistening the copy sheets prior to passage to the printing couple comprising in combination with the transfer roll G9 a moistening strip indicated generally at 2! having a transfer portion 22 in contact with the transfer roll I 9 and a receiving portion 23 disposed in operative relation to a liquid distributing device indicated generally at this transfer strip also having an extraction portion 25 which is in contact with an absorbent body in the form of a felt pad 58. The moistening means further comprise a trough like receptacle 21 for collecting any surplus liquid supplied to the receiving portion of the moistening strip from the liquid distributing means 24 and also serving as a backing member for the strip.

Considering now the various component parts of this moistening means in more detail the liquid distributing device comprises a duct system including a pair of spaced parallel duct e1ements 28 and 29 in the form of tubes, these being closed at their ends 36 and 3| respectively and connected at their other ends 32 and 33 respectively to individual pipes 34 and 35 (Figure 1) by means of which moistening liquid such as a spirit is conveyed to the duct elements.

Each of the duct elements is provided with one or more orifice groups which extend across different fractional width zones of the moistening strip the latter extending for the whole or substantially the whole width of the feed path along which copy sheets pass.

In the arrangement illustrated in Figure the duct element 28 has an orifice group consisting for example of five longitudinally spaced orifices 36 which occupy one lateral zone and the duct element 29 has a similar group of five longitudinally spaced orifices 31 occupying the other lateral zone.

In the alternative arrangement illustrated in Figure 6 the duct element 28 has an orifice group 38 extending across a central zone while the duct element 29 has a pair of separate orifice groups 39 and 40 which register with relatively narrow lateral zones on either side of the orifice groups 38.

The purpose of providing two or more duct elements each having one or more orifice groups and of feeding these duct elements by means of individual supply pipes is to obviate or reduce any lack of uniformity in the amount of fluid discharged from the individual orifices and thus to ensure a substantially uniform moistening of the receiving portion 23 of the moistening strip either across its whole width or across a selected fractional zone. In the latter case it will be understood that one or more of the individual duct elements may have its supply of liquid cut on or reduced as may be required by the particular operating conditions in which the machine is used.

The liquid for supplying to the duct system is contained in a tank 4| which may as illustrated be secured externally to one of the side plates (Figure l) and in association with this tank is provided a pressure feed device such as the pump illustrated in Figure 7.

The pump comprises a cylindrical body 42 which extends through the tank and in which operates a piston 43 driven from a cam 44 on the master cylinder spindle this cam coacting with a rotary follower 45 carried at the upper end of piston rod 46 the latter being spring loaded in the upward direction by means of a coiled compression spring 41 disposed on the piston rod and operating between a cross pin 48 and a closure cap 49 on the upper end of the cylindrical pump body 42.

Near its lower end the pump body is provided with one or more inlet orifices 58 preferably surrounded by a filtering sleeve 5| and at its lower extremity which projects from the base of the tank pipes 34 and 35 communicate with a common outlet orifice 52.

The pump body 42 is rotatable about its own axis with respect to the tank by means of an operators control lever 53 secured to or formed with the closure cap 49 and the pipes 34 and 35 are received in a fixed closure cap 54 at the lower end of the pump body so that by rotating the pump body either the pipe 34 or the pipe 35 or both may be placed in communication with the outlet orifice 52 or both pipes may be shut off from orifice 52 as may be required.

The pipes 34 and 35 are provided with nonreturn valves one of which is indicated at 55 (Figure l) and forms a feed control device which ensures that the lengths of both pipes 34 and 35 between the closure cap 54 and these nonreturn valves are always full. On the other side of the non-return valves length of pipe and duct element measured between the non-return valves and the first orifice in each duct element are made equal in each case to ensure that equal quantities of liquid are delivered from both the duct elements 28 and 29 for each stroke of the pump when both the pipes 34 and 35 are placed in communication with the outlet orifice 52.

The moistening strip 21 is preferably formed of velvet or other suitabl pile fabric with the pile presented outwardly against the surface of the transfer roll 19 and the receiving portion of this strip is lapped round the distributing device or duct system so that it assumes the tubular form illustrated in Figure 3 with the duct system disposed in the interior of the tubular portion.

Preferably the orifice group or groups of one duct element 29 are directed upwardly as indicated in Figure 3 at 31 so that the liquid issuing from this orifice group is directed on to the under-surface of the upper ply of the tubular portion whilst the duct element 28 has its orifice group 36 directed downwardly on to the upper surface of the lower ply of the tubular portion.

For supporting the duct elements and for collecting any surplus liquid which may drip or drain from the receiving portion of the moistening strip the trough like receptacle 21 is provided and the duct elements may be secured to the upper rim of this by means of suitable clamping members as shown at 56 (Figure 4).

The trough is received in a downwardly tapering wedge shaped seating defined by an arcuate supporting member 51 of plate form and the opposed portion of the transfer roll 19. The supporting plate 51 also serves to carry an absorbent body of substantial bulk this body being in the form of a felt pad 58 against the upper face of which one convex arcuate side wall 59 of the trough bears.

The opposite side wall 60 of the trough is also of arcuate form but its outer face is concave and has a curvature corresponding to that of the transfer roll so that the trough presses uniformly against the two plies of the moistening strip constituting the transfer portion which are interposed between the trough and the transfer roll.

The extraction portion 25 of the moistening strip which is disposed beneath the trough and is connected to the transfer portion by a part of the moistening strip which extends around a downwardly projecting tongue 8! of the trough is suitably secured as for example by means of a fastening element 62 to the lower margin of the felt pad 58 and consequently there is a progression of liquid from the receiving portion 23 of the moistening strip through the intermediate portion 22 and thence to the extraction portion 25 where any surplus moisture is drained off into the absorbent felt pad from which it evaporates. It will be observed more especially from Fig. 3 that the cross-sectional area and hence the volume of the felt pad substantially exceeds that of the moistening strip itself and consequently the former will afford a substan tially greater capacity for absorbing liquid than the moistening strip itself, thus ensuring the progression of liquid through the moistening strip from the receiving portion to the extraction portion independently of such consumption of liquid as takes place by virtue of a proportion of the liquid to the transfer roll [9.

Part of the liquid will of course be applied to the transfer roll 99 but the amount of liquid consumed in this way may vary somewhat depending upon the area of the copy sheets fed to the machine and consequently the presence of the extraction portion and felt pad acts as a stabilizing influence preventing excessive accumulation of liquid in the transfer portion 22 and reducing or avoiding over dampening of the transfer roll.

The transfer roll is driven rotatably in the direction indicated by the arrow 63 and consequently it tends to move the trough downwardly in the tapering wedge shaped seating thus augmenting the pressure already applied by the trough to the transfer portion of the moistening strip by virtue of the seat of the trough and the tapering conformation of the walls of the seating.

A cover preferably of sheet metal as illustrated at 65 serves to enclose the components of the moistening means this cover being pivotally supported by means of a rod 55 on which it is pivotally mounted the cover may be provided with a wiper pad 56 the function of which is to remove or reduce any surplus liquid remaining on the transfer roll after it has engaged with a copy sheet.

What we claim then is:

1. In a duplicating machine of the kind specifled means for moistening copy sheets comprising, a tank for containing moistening liquid, a duct system operatively connected to said tank and extending transversely of the copy sheet feed path said duct system having liquid distributing means extending along its length, a fabric moistening strip arranged with its Width extending lengthwise of said duct system and having a receiving portion disposed on the delivery path of said distributing means, said strip also having an extraction portion extending at least approximately parallel to said receiving portion but spaced therefrom in the direction of the length of the strip, an absorbent body in contact with said extraction portion and having a substantially greater capacity for absorbing liquid than the moistening strip thereby to maintain flow of liquid under capillary action along the length of the strip and said strip having a transfer portion lying effectively between said receiving and extraction portions and means for effecting transference of liquid from said transfer portion to the copy sheets.

2. In a duplicating machine of the kind specified means for moistening copy sheets comprising a tank for containing moistening liquid, a duct system operatively connected to said tank and extending transversely of the copy sheet feed path said duct system having liquid distributing means extending along its length, a fabric moistening strip, means for supporting same transversely of the copy sheet feed path with one transversely extending marginal zone uppermost and disposed in the operative range of said distributing device to form a receiving portion of said strip and with the other transversely extending marginal zone situated below said receiving position and in contact with an absorbent body and having a substantially greater capacity for absorbing liquid than the moistening strip thereby to form an extraction portion of said strip for maintaining a flow of liquid across its width under capillary action, said strip also having an intermediate portion connecting said receiving and extraction portions and positioned to coact with means for effecting transference of liquid to the copy sheets.

3. In a duplicating machine of the kind specified mean for moistening copy sheets comprising, a tank for containing moistening liquid, a duct system operatively connected to said tank, and extending transversely of the copy sheet feed path, said duct system having liquid distributing means extending along its length, a fabric moistening strip, a transfer roll mounted in the machine adjacent to said strip and disposed with its axis transversely of the copy sheet feed path and a backing member for said strip extending parallel with said transfer roll and adjacent thereto this backing member having a concave part-cylindrical face directed towards said transfer roll said strip having a transfer portion disposed between said concave face of the backing member and said transfer roll and at the upper and lower edges respectively of said transfer portion said strip having a receiving portion disposed in the operative range of said distributing device so as to be moistened thereby, an extraction portion, an absorbent body in contact with said extraction portion and having a substantially greater capacity for absorbing liquid than the moistening strip thereby to maintain flow of liquid under capillary action across the Width of the strip, and means for urging said backing member towards said transfer roll to compress said transfer portion of the strip.

4. In a duplicating machine of the kind specified means for moistening copy sheets comprising a tank for containing moistening liquid, a duct system operatively connected to said tank and extending transversely of the copy sheet feed path said duct system having liquid distributing means extending along its length, a fabric moistening strip, a transfer roll mounted in the machine adjacent to said strip and disposed with its axis, transversely of the copy sheet feed path and a backing member for said strip extending parallel with said transfer roll and adjacent thereto, this backing member having a concave part-cylindrical face directed towards said transfer roll, a supporting member for said backing member having a supporting face therefor which is inclined from its upper end downwardly and towards the opposed face of the transfer roller so as to define in conjunction therewith a downwardly tapering wedge-shaped seating in which said backing member is supported, said strip having a transfer portion disposed between said concave face of the backing member and said transfer roll, a receiving portion disposed in the operative range of said distributing device so as to be moistened thereby, and an extraction portion, and an absorbent body in contact with said extraction portion and having a substantially greater capacity for absorbing liquid than the moistening strip thereby to maintain flow of liquid under capillary action across the width of the strip.

5. In a duplicating machine of the kind specified' means for moistening copy sheets comprising, a tank for containing moistening liquid, a duct system operatively connected to said tank and extending transversely of the copy sheet feed path said duct system having liquid distributing means extending along its length, a fabric moistening strip, a transfer roll mounted in the machine adjacent to said strip and disposed with its axis transversely of the copy sheet feed path and a backing member for said strip extending parallel with said transfer roll and adjacent thereto this backing member having a concave part-cylindrical face directed towards said transfer roll, a supporting member for said backing member having on its face which is directed towards the transfer roll an absorbent body having a liquid absorbing capacity greater than that of the moistening strip and presenting towards said transfer roll a upporting face for the backing member which face is inclined from its upper end downwardly and towards the opposed face of the transfer roll so as to define in conjunction therewith a downwardly tapering wedgeshaped seating in which said backing member is supported, said strip having a transfer portion disposed between said concave face of the backing member and said transfer roll and at the upper and lower edges respectively of said transfer portion said strip having a receiving portion disposed in the operative range of said distributing device so as to be moistened thereby and overlying the upper part of the backing member which has a cavity forming a receptacle for collecting any surplus liquid delivered to said receiving portion, and said strip having an extraction portion in contact with said absorbent body which thereby maintains the flow of liquid across the width of the strip from said receiving portion to said extraction portion to prevent the accumulation of a surplus in said transfer portion.

6. In a duplicating machine of the kind specified means for moistening copy sheets comprising, a liquid distributing device a fabric moistening strip extending transversely of the copy sheet feed path and having a receiving portion of tubular form enveloping said distributing device said distributing device including at least two duct elements one of which has an orifice group extending across a central zone of the copy sheet feed path and the other of which has an orifice group extending across each of the lateral zones of said path, said duct elements being connected at their adjacent ends to a pressure feed device said strip also having a transfer portion, means for effecting transference of liquid from said transfer portion to the copy sheets and a receptacle positioned adjacent to said receiving portion for collecting any surplus liquid delivered to said receiving portion.

7; In a duplicating machine of the kind specifled means for moistening copy sheets comprising, a liquid distributing device, a fabric moistening trip extending transversely of the copy sheet feed path and having a receiving portion of tubular form enveloping said distributing device said distributing device including at least two duct elements having respective orifice groups extending across opposite lateral zones of the copy sheet feed path said duct elements being connected at their adjacent ends to a pressure feed drive, said strip also having a transfer portion, means for effecting transference of liquid from said transfer portion to the copy sheets, and a receptacle positioned adjacent to said receiving portion for collecting any surplus liquid delivered to said receiving portion.

8. In a duplicating machine of the kind specified means for moistening copy sheets comprising, a liquid distributing device, a fabric moistening strip extending transversely of the copy sheet feed path and having a receiving portion of tubular form enveloping said distributing device said distributing device having separate feed inlets serving different portions thereof, these inlets being connected individually by substantially equal length pipes to a common pressure feed device, said strip also having a transfer portion, means for effecting transference of liquid from said transfer portion to the copy sheets and a receptacle positioned adjacent to said receiving portion for collecting any surplus liquid delivered to said receiving portion.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,012,619 Ritzerfeld Aug. 27, 1935 2,225,421 Marchev Dec. 17, 1940 2,241,554 Lang et a1 May 13, 1941 2,299,994 Kokay Oct. 27, 1942 2,465,160 Levenhagen et a1. Mar. 22, 1949 2,533,574 Gerlach Dec. 12, 1950

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