GB2156276A - Ink discharge regulation blades - Google Patents

Abstract

An ink quantity regulator for a printing press in which an ink discharge regulation blade is positioned adjacent an ink roller and is acted on by members positioned at a predetermined pitch in accordance with a number of zones, which vary the gap between the edge of the blade and the ink roller has an ink discharge regulation blade shaped into the form of a large number of cantilevered reed members by slits 32 in a metal sheet at the predetermined pitch, and elastic members 34 are fitted into at least the slits, thus allowing independent regulation without allowing ink to ooze between the reed members. The elastic members may be united by en elastic coating along one face of the blade (Fig 10, not shown). <IMAGE>

Description

SPECIFICATION Ink discharge regulation blades This invention relates generally to an ink quantity regulator for use in a printing press. More particularly, the present invention relates to an ink discharge regulation blade which consists of a large number of cantilevered reed members produced by providing slits in a metal sheet at a predetermined pitch, and then fitting elastic members into the slits between the reed members, and which completely eliminate any leakage of ink.

in order to regulate the ink quantity supplied to each zone (usually 32 zones) in an ink regulator for a printing press, such as an offset printing press, a device such as that shown in the sectioned side view of Figure 1 is provided. In the drawing, reference numeral 10 represents a rotating ink roller and reference numeral 12 a doctor bed. One edge of an ink discharge regulation blade 14 is fixed to the doctor bed 12 with the other edge thereof free.

The tip of a regulation member 16, such as a threaded pin, is brought into contact with the free edge of the ink discharge regulation blade 14, and this regulation member 16 is moved back and forth to push and thus operate the free edge of the ink discharge regulation blade 14. Accordingly, the gap between the edge of the blade 14 and the outer circumference of the ink roller is varied to increase or decrease the ink feed quantity for each zone.

In the ink quantity regulator of the kind described above, a flat strip of metal sheet, such as that shown in the perspective view of Figure 2 and the sectioned view of Figure 3, is conventionally used as the ink dishcarge regulation blade. Although simple in construction, a regulation blade 18 consisting of a single sheet has the problem that portions adjacent to a portion which need adjusting are readily affected. In other words, assume that the regulation member represented by reference numeral 20 in Figure 3 is the regulator for a zone that needs adjusting.This regulation member 20 is always affected by the positions of adjacent regulators 22 and 24, regardless of how the regulation member 20 alone is moved back and forth independently to try to push and operate only that portion of the regulation blade, and it is difficult to operate independently only specific parts of the regulation blade so that it is not possible to accurately adjust the ink quantity for each zone.

To eliminate this problem with the single-sheet blade, Japanese Utility Model Laid-Open No.

89630/1980 (which was eventually rejected) disclosed a construction in which shallow grooves 28 are provided in the lower surface of a blade 26, as shown in the sectioned view of Figure 4, at a pitch corresponding to the pitch of units of the blade 26, so that the blade 26 can be pushed and operated easily and independently for each zone. Although the operating performance of regulation blade equipped with these grooves is improved, its intrinsic mechanical strength drops, and the righting moment which returns the units to their original state deteriorates so that changes with time are likely to occur. Moreover, the so-called "zero position", at which ink discharge is zero, can not be obtained. Basically, it has been found difficult to use blades consisting of a flat strip of metal sheet for the independent regulation of the ink discharge quantity for each zone.

In view of the background described above, split blades such as that shown in the perspective view of Figure 5 and in the sectional view of Figure 6 have been proposed. In accordance with this proposal, the blade 30 is essentially split in accordance with the pitch of the zones (which is predetermined), so that a blade for each zone is independent of the others. This prior art device makes it possible to independently regulate the blade for each zone, it is true, and there are no problems concerning the discharge regulation function itself. However, since the blade for each zone is independent, the work of locating the boundary surfaces of adjacent blades is difficult.

Moreover, since it is necessary to adjust the fitting position of each blade with respect to the ink roller, an extremely high level of skill and a large number of steps are required for the fitting and adjustment operations. Because there is nothing on the boundary surfaces between the blades, and these portions are left as gaps, the ink is likely to ooze out and present problems concerning the operation of each blade which requires extremely delicate movements (of the order of 1/100 millimeter in answer to the advance or retreat of the regulation members). However delicately the blades may be assembled in order to eliminate the problem of the oozing of ink, this requires a large number of steps, but does not essentially solve the problems.

To eliminate these problems with the split blade, another blade is usually added. In other words, another, auxiliary blade, not shown, is fitted separately from the split blade by a magnet or rubber so as to prevent the oozing of ink from the boundary surfaces. However, the use of such an auxiliary blade can not completely prevent the ink oozing, makes the construction complicated, and is troublesome to produce.

Other prior-art embodiments of the ink discharge regulation blades include those which use eccentric pins and independently-driven blades, disclosed in Japanese Utility Model Publication No.

101036/1982, although these are somewhat different technically from those described above. However, with the eccentric pin type of blades, there is no problem concerning the adjustment itself, but the construction is complicated and a "zero region" of ink always occurs. In the independentlydriven type of blades, their complicated construction is a serious problem.

It is therefore a principal object of the present invention to provide an improved ink discharge regulation blade.

It is another object of the present invention to provide an ink discharge blade in wh ich an independent operation can be effected for each zone without any adverse affect on adjacent zones, but oozing or leakage of ink is still completely pre vented.

it is still another object of the present invention to provide an ink discharge regulation blade which has a simple construction and which can be easily fitted, and whose position can be easily adjusted.

To accomplish the objects set out above, the present invention provides slits in a single sheet of metal at a pitch corresponding to the pitch of the zones so as to form a large number of cantilevered reed members, and fits flexible elastic members into these slits.

These and other objects and features of the present invention will become more obvious from the following description to be taken in conjunction with the accompanying drawings. It is to be noted, however, that the following embodiments are merely illustrative, they do not limit the present invention in any way.

Figure I is a sectioned side view of an ink quantity regulator for a printing press; Figures 2 and 3 are perspective and sectioned views of the most basic ink discharge regulation blade; Figure 4 is a sectioned view of a blade equipped with shallow grooves; Figures 5 and 6 are perspective and sectioned views, respectively, of a split type of blade; Figure 7 is a perspective view of one embodiment of an ink discharge regulation blade in accordance with the present invention; Figure 8 is a section taken along the line VIII Villi of Figure 7; Figure 9 is a sectioned view thereof which is useful for explaining the operation; Figure 10 is a perspective view of another embodiment of the present invention; and Figure 11 is a section taken along the line XI - XI of Figure 10.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

Figure 7 is a perspective view of an ink discharge regulation blade in accordance with one embodiment of the present invention, and Figure 8 is a section taken along the line VIII - VIII of Figure 7.

Slits 32 are defined in a single sheet of metal at a predetermined pitch in agreement with the pitch of the zones (which is constant), and an elastic member 34 is fitted into each slit 32. (Needless to say, the metal sheet could have a length corresponding to the total length of the 32 zones, but the present invention can also be worked by dividing the sheet into a suitable number of blocks.) The metal sheet is a thin sheet of steel or a nonferrous metal which has an appropriate flexibility, and is a few millimeters thick. The slits 32 are formed in this thin sheet at a predetermined pitch.

The transverse width of each slit 32 is approximately of the same order as the thickness of the metal sheet. Since the slits 32 are formed therein, the single sheet of metal has the structure of a large number of cantilevered reeds which are independent of one another.

An elastic member 34 which is capable of deforming is fitted tightly into each slit 32. The elastic members 34 are preferably made of a material which has a deformation resistance which is as small as possible, but still has an ink-sealing function and durability. Urethane rubber and rigid rubber are particularly preferred examples of this material. The elastic members 34 must withstand deformation stress and the chemical influences of the ink and solvent, and be integrally connected to the metal sheet during the use of the printing press for an extended period of time, so that they are preferably attached to the metal sheet by the use of an adhesive such as epoxy resin, or by printing.

The operation of the embodiment described above will now be explained with reference to Figure 9 which is a section thereof. Each of the cantilevered reeds which are separated by the slits 32 is pushed entirely independently by a regulation member 16. In other words, a specific reed member is pushed and operated only by the regulation member 16 corresponding to it, whatever the state of the adjacent reed members 34 or regulators 16.

In this case, the elastic members 34 fitted into each slit 32 freely deform with a deformation resistance as small as possible, and hence they provide an ink-sealing function so as to prevent the oozing or leakage of ink, without restricting the movement of each reed member. Since the gap between the ink roller 10 and the blade of each zone can be adjusted, the ink discharge quantity is set entirely independently for each zone.

Another embodiment of the present invention is possible, it is illustrated in Figures 10 and 11 which are a perspective view and a second taken along the line Xl - XI of Figure 10, respectively. In this emboidment, an elastic member 36 made of a material such as urethane rubber is attached as a sheet, by printing or the like, onto one side surface of the metal sheet which not only has a large number of slits 32, but is also shaped to have a cantilevered reed construction. (The elastic member need not extend over the entire surface of that one side of the metal sheet but may be local.) In this emboidment, since the elastic member 36 is fitted onto one side surface so as to join together the elastic members 34 in the slits 32 and increase their binding area, the strength against any peeling force can be increased and the service life of the blade can be prolonged. Thus, this embodiment eliminates any possible problem with the first embodiment in that, since the elastic members 34 are independent, their anti-peeling strenght is rather low. The embodiment also completely eliminates any leakage of ink through the slits 32.

While the embodiments described above represent preferred forms of the present invention, it is to be understood that various changes and modifications may be made by those skilled in the art without departing from the spirit and scope of the invention.

Claims (6)

1. In an ink quantity regulator for a printing press of the type in which an ink discharge regula tion blade is positioned in the proximity of an ink roller, and is pushed and operated by regulation members positioned at a predetermined pitch in accordance with a number of zones so as to vary the gap between the edge of said ink discharge regulation blade and said ink roller, an ink discharge regulation blade characterized in that said blade is shaped in the form of a large number of cantilevered reed members produced by defining slits in a metal sheet at a predetermined pitch in accordance with the pitch of said zones, and elastic members are fitted into at least said slits.

2. The ink discharge regulation blade as defined in claim 1 wherein said elastic members are fitted not only into the large number of said slits, but also as a sheet on one side surface of said metal sheet which has said cantilevered reed structure.

3. The ink discharge regulation blade as defined in claim 1 or 2 wherein said elastic members are made of urethane rubber.

4. The ink discharge regulation blade as defined in claim 1 or 2 wherein said elastic members are made of rigid rubber.

5. The ink discharge regulation blade as defined in claim 1 or 2 wherein said elastic members are bonded to said metal sheet.

6. The ink discharge regulation blade as defined in claim 1 or 2 wherein said elastic members are printed onto said metal sheet.