Year: 1888

page_text: I, JULES MICHAUD, of 96 Rue d'Assas, Paris, France, Engineer, do hereby declare
the nature of this invention, and in what manner the same is to be performed, to
be particularly described and ascertained in and by the following statement :-
My invention relates to improvements in the apparatus for damping the stones or
the zinc plates of either flat or cylindrical lithographic or zincographic printing
presses.
These improvements consist :-
Ist. In a new construction of the dampers or wetters for the stones or zinc plates,
and
2nd. In an automatic feeding apparatus for such dampers.
The new construction of damper consists essentially in the employment of strips of
velvet, cloth, india rubber, or other tissue of flexible material, to be used either singly
or combined, such strips being held between two flat metallic, wooden, or other suitable
strips, connected one to the other.
These flat and flexible dampers are applied, in any suitable numbers, directly to
holders fixed on the frame of the press behind the cylinder.
They possess the following advantages over the rollers clothed with flannel, or other
form of damper hitherto employed:
1. The damping of the stones or plates is more uniform, even though they are not
perfectly true. But little friction is exerted on the drawing or other matter to be
printed, thus ensuring less wear, and consequently enabling a larger number of
impressions to be taken than with cylindrical dampers.
2. The cost of keeping the dampers in proper condition is reduced.
3. The dampers occupy less space and permit the stone to travel a sufficient distance
to ensure the constant damping of its ends, so that they will not be soiled by the
inking rollers. An economy is thus effected in the cost of keeping the blankets and
moleskins, which cover the cylinder of the machine, in proper condition, and which
are quickly destroyed by any ink deposited on the edges of the stones.
4. The noise produced by cylindrical dampers is entirely avoided.

page_text: Fig. 1 is a side elevation of the improved damper.
Fig. 2 a plan view, and
Fig. 3 a cross section of same.
Fig. 4 is a vertical section of a flat press, showing three of the improved dampers
applied thereto, as well as the apparatus for automatically supplying water to the
dampers.
Fig. 4 is a plan view of such automatic feeding apparatus.
Fig. 5 is a cross section of one of the dampers composed of an outer strip and an
inner strip of more elastic material.
Fig. 6 is a vertical section of a cylindrical machine with three of the improved
dampers applied thereto.
Fig. 7 shows, in side and end elevation, a ratchet and pawl arrangement for
rotating the roller of the automatic apparatus for supplying water to the dampers.
Fig. 8 shows, in side elevation and transverse section, a cam and ball arrangement
for actuating such roller.
The damper shown in Figs. 1, 2 and 3 consists of a strip a of flexible material,
folded and held between two flat metallic plates M and N. The fabric is of such width
that the fold rests upon the whole width of the stone, which passes beneath it in
travelling to and fro.
The metallic plate M is longer than the other plate, and its ends M³, M2, are
engaged (Fig. 4) in the holders m secured to the frame of the press behind the
cylinder Č.
One or more dampers are thus mounted freely on the machine, and take up
moisture from the damping table arranged on the stone carrying bed, at the opposite
end to the inking table.
The dampers can be readily placed in position or removed for repairs or other
purpose with the greatest ease. The dampers further possess all the advantages
hereinbefore mentioned.
I do not limit myself to the particular construction, form or shape of the dampers
above described, nor to the employment of any particular flexible and supple material
for same; and further, any suitable number of such dampers may be employed, such
number necessarily depending upon the kind and size of machine to which they are
to be applied.
In Fig. 5 I have shown a damper composed of two materials, the inner one being
more elastic than the outer one, so as to ensure the return of the damper to its normal
position after the passage of the stone or plate.
Fig. 6 shows a cylindrical machine with three of the dampers applied thereto.
I will now describe the apparatus for automatically supplying water to my improved
dampers.
In order to effect this I arrange upon the stone carrying bed (Fig. 4) beyond the
damping table A, a trough B, in which a damping roller C, clothed with taffeta,
velvet, or other suitable material, can turn freely, and which dips a certain distance
into the water contained in the trough.
The axis of roller C₁ revolves in suitable bearings, and on one end is mounted a
suitable arrangement D, which on each return movement of the bed comes in
contact with tappet E serving to actuate same, and thus cause roller C¹ to
revolve.
According to the position of this tappet the extent of the rotary movement of the
roller can be regulated. For this purpose the tappet consists of a screw working
through an angle piece F secured to the frame of the machine. By turning the screw
in one direction or the other the roller (, when actuated thereby, is caused to turn
more or less, and consequently a smaller or greater quantity of water is supplied to
the straight dampers, which absorb same and spread it over the damping table A.
This table might be dispensed with if desired.
In either case, it will be seen that it is easy to regulate at will the supply of

page_text: moisture for damping the stone, according to its size, the temperature, the nature of
the paper to be printed upon, etc.
When the ratchet arrangement for actuating roller C¹ has been acted upon by
the tappet E, a spring causes it to return to its normal position, against a fixed
stop.
It will be understood that the trough B, roller C, and the arrangement for actuating
the latter, may be of any suitable construction; and also the regulating tappet E
described, which in place of a screw may be in the form of a cam, or any other suitable
arrangement may be employed.
Fig. 7 shows a ratchet and pawl mechanism for actuating roller 0, and Fig. 8 an
arrangement of cam and balls for the same purpose, the action of both of which will
be apparent, and which are only shown as examples of the manner in which such roller
may be actuated.
Having now particularly described and ascertained the nature of the said inven
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. The improved damping device for the stones or zinc plates of either flat or
cylindrical lithographic or zincographic printing presses, consisting in either fixed or
movable rectilinear dampers, composed of a strip of fabric or flexible material a, for
supplying moisture to the stones or plates, substantially as specified.
2. The combination with the damper or dampers a, of the roller C, which is caused
to rotate in a trough B containing water, and is carried by the travelling bed of the
machine, so as to automatically supply the dampers a with the necessary amount of
water for damping the stones or plates of lithographic or zincographic printing presses,
the amount of water being capable of being regulated at will by varying the speed of
rotation of such roller, substantially as specified.