close

Вход

Забыли?

вход по аккаунту

?

Патент USA US2114288

код для вставки
April 19, 1938.
2,114,288
A. B. DAVI$
PRINTING PLATE AND METHOD OF MAKINGTHE SAME
Filed Aug. 22, 1935
4 Sheets-Sheet 1
April 19, 1938. ‘
A, 5. mm
. ,
2,114,288
PRINTING PLATE AND METHOD OF MAKING THE SAME}
Filed Aug. 22, 1935
4 Sheets-Sheet 2
NVE NTOQ/
(?r/7w)" )3. J90 ws
@7 fab, M‘ 3x3,“ ‘W
'
(ATTOQN Egys
April 19, ‘1938. ' ‘
2,114,288
I A. B. DAVIS
PRINTING PLATE AND METHOD OF MAKING THE SAME
Filed Aug. 22, 1955
4 Sheets-Sheet 3
- Am! 19, 1938.
I
A. B. DAVIS \
PRINTING PLATE AND METHOD OF MAKING THE SAME
Filed Aug. 22, 1935
' M6
40
2,114,288
4 Sheets-Sheet 4
‘Patented Apr. 19, 1938
' 2,114,288
UNITED‘ STATES PATENT OFFICE
2,114,288
PRINTING PLATE AND IWETHODOF MAKING
' '
THE SAME
\Arthur B. Davis, Spring?eld, Ohio
Application August 22, 1935, Serial No. 31,319
5 Claims. (CI. 41-25)
'This invention relates generally to printing
Fig. 10 is a view' similar to Fig. 8 illustrating
plates which constitute reproductions of! the the method of forming a modi?ed form of print.
type surface of a type form, engraving or they ing plate.
like, and has more particular reference to the
Fig. 11 is a fragmentary sectional view of the
5 formation of printing plates composed in part modi?ed plate attached to a printing press cyl- ~5
of moldable material such as synthetic resin.
The general object of the'invention is to provide a new and improved printing plate comprising a layer of resinous material having
‘10 molded type projections and itself adhesively
secured in the molding operation to the surface
of an imperforate metalv sheet by which the
plate as a whole may be fastened properly to a
inder.
.
Fig. 12 is an elevational view of the preferred ‘
form of make-ready‘ sheet.
.
Fig. 13 is a section taken along the line
|3-l3 of Fig. 12.
10
The invention is susceptible of various modi
?cations and therefore I dotnot, by the present
exemplary disclosure, intend to limit the in
printing press support.
15
Another object is to provide for the novel
treatment of the printing plates during the
vention, but‘ aim to cover all modi?cations and
alternatives falling within the spirit and scope 15
of the invention as expressed in the appended
molding operation to incorporatev make-ready
therein so that in the use of the plates in printing selected solid areas of the type will be emphasized and the pressure on selected high light
claims.
_
'In the drawings, the invention is illustrated
as applied to the formation of a printing plate
It comprising areas ll of molded resinous ma- 20
20 areas relieved.
.
‘
terial adhesively secured to an imperforate metal
A further object is to provide a method of
reproducing the type surfaces of original forms
or engravings which providesfor the elimina-
mounting sheet l2 and having'projections l3
standing out in relief and de?ning surfaces H
corresponding to the characters or other con
25 tion, in a novel manner. of the parts corre- ?gurations to be printed. The areas ll may be 25
sponding to the so-called "dead metal” ordi- ' composed‘ wholly of resinous material or of av
wnarily provided in the engraving.
Other objects and advantages of the lnvention willbecome apparent from the following
39 detailed description taken in connection with
mixture of a base or ?ller ingredient combined
with a resin binder. While any preferred mold
able resinous material may be used, it is pre
ferred, in order to permit the plate to be bent- 30
the accompanying drawings, in which
' readily to the proper curvature, to employ a
Figure 1 is a perspective view of the improved resin having thermoplastic characteristics such ‘
printing plate in the process 'of attachment to a as that sold under the trade name of Vinylite.
as.
printing press cylinder. Fig. 2 is a fragmentary sectional view of the
printing plate attached to the cylinder.
Fig. 3 is a plan view of a make-ready sheet
used in the treatment of the plate.
Fig. (i is a plan view of a sheet used in condd nection with the removal of the resin from the
"dead metal” areas of the plate.
Fig. 5 is a fragmentary perspective view of
the mold from which the printing plate is made.
Fig. 6 is a fragmentary perspective view of “an
45 original type form or engraving to be reproduced.
.
Fig. 7 is a fragmentary perspective view of
the mold with one form of make-ready sheet
attached to the underside thereof.
50
Fig. 8 is a fragmentary sectional view illustrating the arrangement of the parts preparatory to the molding operation.
Fig. 9 is a perspective view of the ?nished
plate illustrating the method of removing the
55 resin from the non-type areas.
,
The relatively ?exible plate thus vconstructed
may be attached to the printing press support 35.
or cylinder l6 through the” medium of a backing
or saddle which,v for purposes of illustration, is
shown as comprising two plate sections H and
l8 hinged together at l9 and adapted to engage .
at their remote side edges with shoulders in the 40
form of ?anges 20 formed on the carrying sheet
92. The section I8 is adjustably secured against
the surface of the cylinder it by clamps 2i.
When the narrower section ll is swung down
wardly against the cylinder with the plate iii-45
positioned as shown v‘in Fig. 1, the ?anges 20
will be spread apart and the plate stretched over
the saddle , the free edge of the- section i‘i being ‘
later fastened, down by means of clamps 22.
The printing surfaces of the plate above de-'_ 50
scribed constitutes a molded reproduction of the
surfaces of an engraving 23 or other type'form
well known in the printing art. To obtain an
accurate replica so that all of the dots for ob
taining the'di?erent color shades may be repro- 55
2
2,1 14,288
duced accurately, a mold 24 formed from the
engraving is used in molding the printingrareas. '
For a piu'pose to appear later, the mold pref
erably comprises r'a layer 25 of ductile metal,
such as lead, having cavities 26 therein corre
sponding to the type projections to be formed
and attached through the medium of a sheet 21
of steel or other reinforcing material to a sheet
28 of ductile metal having a ?at machined sur
face 29 disposed in a plane parallel to the roots
of the type cavities. The mold may be formed
in the manner described in my copending appli
cation Serial No. 736,222, ?led July 20, 1934.
The plate molding operation is carried on in a
15 suitable press preferably operated hydraulically
and having platens 30 and 3| heated as by gas
?ames 32 to the temperature necessary for soft
ening the resin ingredients to the degree required
for molding. During molding, the mold is sup
20 ported on the lower platen 3| and covered with a
layer '33 of the resin ingredients su?icient in
amount to more than ?ll all of the mold cavities
when in the plastic state. The carrying sheet 62
may be fastened by a ?ller plate 34 against which
25 the upper platen 30 acts. ‘With the parts thus
assembled, the platens are ?rst maintained in
close proximity to each other until the resin has
been softened properly. Then the platens are
moved together under pressure to compress the
30 plastic ingredients to a thickness determined by
bearers 35 after which the resin is allowed to set
with the back surface of the sheet l2 thus accu
rately maintained in parallel relation to the type
surfaces. Upon cooling, the ?nished plate may be
35 stripped from the'mold and thereafter bent read
ily to the proper curvature by reheating to a
temperature su?icient to soften the resin slightly.
The surface of the carrying sheet I2 is treated
in a manner such as to cause ?rm adherence of
40 the plastic resin thereto so that the resin areas
will not be displaced during bending of the plate
or under the stresses applied thereto during print
ing. This may be accomplished by covering the
surface of the sheet 0 2 with cl0th‘36 such as mus
45 lin to which the resin will adhere readily and
which in turn may be cemented to the metal by
means of a suitable adhesive such, for example,
as water glass cement.
'
'
Provision is made for ready removal from the
50 molded plate of those areas of the resinous mate
rial corresponding to the non-type or so-calle‘d
“dead metal” areas 23“ of the engraving thereby
avoiding the costly operation of routing out these
areas to prepare the plate for use in printing.
55 For this purpose, the invention contemplates the
introduction between the resin ingredients 33 and
the muslin surface of the sheet I2 of a'parting
medium corresponding in shape and position to
the non-printing areas and acting during the
60 molding operation to prevent the plastic resin
material from coming into contact with the
selected areas of the treated surface.
Herein this parting medium takes the form of
a sheet 31 (Figs. 4 and 8) of manila paper out out
to form openings 38 corresponding in shape to but
slightly larger than the type areas. To facilitate
formation of this mask, a printed impression of
the engraving 23 may be formed on the paper
sheet 31 in a proving press and the printed areas
then cut out to form the mask. The latter is
secured detachably to the cloth covered surface
of the carrying sheet l2 or placed in proper posi—
tion above the resin ingredients 33 preparatory to
,molding. As indicated at 50, the resin adheres
75 to the mask which, after molding, may be stripped
off from the carrying sheet. In this operation,
the thin section 39 of the resin material immedi
ately surrounding the type areas is ?rst scored
with a. knife so that it will break readily as the
thicker areas are bent away from the plate as
illustrated in Fig. 9. Thus, in the ?nished plate,
only the printing areas proper and the thin
border 39 therearound remain on the cloth sur
face. Where there is a dead metal area 5| (Fig.
6) completely surrounded by type areas, the cor 10
responding portion of the resin may be removed
by applying a properly shaped piece 52 of paper
(Fig. 4) to the resin layer or muslin sheet before
the molding operation.
Where several similar printing plates are re
quired, it is the present practice to provide for in
creasing the printing pressure on the so-called
“solid” areas of the plate and relieving the pres
sure on the “high light” areas through the use
during printing of make-ready sheets individual 20
to the separate plates. The present invention
contemplates a substantial reduction in the cost
of the make-ready treatment of a series of dupli
cate plates through the association with the mold
from which the plates are madeof a single make
ready sheet which operates automatically during
the molding of each plate to properly prepare the
25
plates for printing and in effect incorporate the
make-ready details in the plate itself. For this
purpose, advantage is taken of the inherent ?ex
ibility possessed by the mold 24 when constructed
as above described to enable the heights of the
selected printing areas formed thereby to be va
ried relative to each other during the molding
operation by the action of a built-up underlay 40 35
positioned against the ?at back surface 29 of the
mold.
As illustrated in Fig. 7, the underlay 40 is in
the form of a paper sheet having indentations
4| therein disposed opposite the mold cavities 40
corresponding to “solid" printing areas upon
which the pressure is to be increased during
printing. Paper patches 42 may be secured to
the underlay sheet opposite the cavities corre
sponding to the’ “high light” areas on which the
printing pressure is to be relieved. During mold
ing of the ?rst plate, those parts of the mold
‘which are in register with the underlay sheet
will be supported by the latter while the parts
opposite the indentations 4| will be depressed by 50
it is subjected. Accordingly, the printing sur
faces of the type formed in the depressed cavi
ties will, in the ?nished plate, project a greater
distance from the sheet l2 than the surrounding
printing surfaces, this difference in the heights
of the printing surfaces being determined by the
depth of the indentations 4|. Thus, in the use
?exure of the mold under the pressure to which
of the plate in printing, the pressure on the higher
areas will be increased, and the “solids” corre 60
sponding to the size and shape of the depres
sions 4! will be emphasized properly. Similarly
the printing pressure on selected “high light"
areas may be reduced to the desired degree
through the provision of the patches 42 of the 65
proper size and shape. Under the molding pres
sure, these patches ?ex the mold and raise the
roots of the type cavities in register therewith
thereby causing the corresponding printing sur
faces of the ?nished plate to be spaced closer .70
to the sheet l2 than the surrounding. surfaces.
Owing to the ?exible and ductile character of
the lead of which the mold is constructed, the
printing areas of the ?nished plate which are af
fected by the action of the make-ready details 75
2,114,288By constructing
2 correspond accurately in size and shape to the
As a. result, ‘
indentations 4i and the patches 42.
su?icient precision may be attained in the make
ready treatment to substantially avoid the neces
3
and molding printing plates
as above described, itwill be observed that a high
degree of accuracy may be obtained in spacing
the printing surfaces from the back of the carry
ing sheet l2 and in maintaining true parallelism
sity of any further treatment in the use of the therewith‘. Owing to the thinness of the sheet
plate in printing. The lead of the mold will of and the resin layer in which the types are molded,
course/take a set in the initial‘ plate molding op
the plate possesses sufficient ?exibility to respond,
eration, but will nevertheless respond to changes under the pressure used in printing, to make
10
in the underlay sheet that maybe added subse
“ready details located between the sheet l2 and
quently.
the
backing
plate
51,18.
In
this
way,
any
addi
10
To facilitate formation of the underlay 40 and tional corrections that may be required to make
"proper location of the details, it is preferredto' the plate ready for printing may be applied
build up the details on a printed impression of readily.
'
the subject matter involved. If, as illustrated
Where the printing plate is to be used for pro 15
in Figs. 3 and 7, the details are to be added after longed runs in the printing press, it is some
15
the impression has been attached to the ?at back ' times desirable to provide a printing surface
surface 29 of the- mold, an offset proof 43 is taken which is more resistant to wear and the action
from the original form 23 preferably on manila of the inks than a surface composed wholly of
paper and cemented, printed side outward, onto the synthetic resins now available. To adapt the 20
20 the back of the mold with the different printed plate for such severe use, the surface of the plate
areas located with the aid of calipers or the like including type projections in the resin layer H
in proper register with the corresponding parts may be covered with a thin metallic shell ‘45 .
of the mold surface. The indentations 4| corre
(Fig. 11) approximately .005 of an inch in thick
sponding to the “solid” areas are then formed
25 and located by taking a second offset proof 44
on paper of the required thickness~ and cutting
out the proper parts so as to leave indentations
of the proper depthwhen the second proof is
pasted onto the ?rst one with the corresponding
30 parts in proper register. Then, the patches 42 are
cut out from additional proofs or plain paper
and pasted on the proof 44 or directly on the
proof 43 in'case there are no -“solids” to be em
phasized.
Byv building up the make-ready de—
03 GH tails‘ on the separate proof 43, location of the
details regardless of their shape is facilitated.
The cost of the make-ready treatment can be
reduced still further by building up the underlay
‘40 as a separate unit in a spec'al department of
40 the printing shop.
To this end, a direct proof
Bl (Fig. 12) is taken from' the original 23 on
heavy manila paper. A second similar proof 48
cut out to form the indentations 4i correspond
ing to the “solid” areas is then pasted onto the
ness. This may be of any metal desired such as
25
chromium electrodeposited on the mold 24 prior
to the molding operation which is carried on with
out removing the shell from the mold, the parts
?rst being arranged as shown in Fig. 10 after 30
which the heat and pressure is applied in the
manner above described. After molding, the plate
assembly is stripped from the mold and the side
edges 46 of the shell bent around the ?anges
20 to form a unitary plate which may be attached 35
to the press cylinder in the same manner as the
resin surfaced plate ?rst described.
I claim as my invention:
1. For use in reproducing from an original type ,
form a printing plate comprising type areas of
molded, resin adhering to a metal carrier sheet,
the method which comprises, forming a mold
from said type face, covering said mold face with
a layer of_moldable material, placing said carrier
sheet over said layer with a parting medium in
s40
terposed therebetween to expose said material 45
the corresponding printed parts in - to areas of said sheet corresponding in size and
proof
4'!
with
45
register. Thenepatches 42 are added for the shape to the type indentations in said mold, ap
“high light” areas. The underlay thus formed plying pressure to said mold and carrier sheet
is trimmed to the proper size so that when its whereby to cause setting of said material with
the molded type areas onhr adhering to said 50
carrier sheet, and stripping o? said parting
face 29 of the mold, the printed parts wili regis
medium and the material adhering thereto.
ter accurately with the corresponding cavities of
2. Themethod of making a printing plate re
the mold. In the assembly of the parts for the production of an original form type surface which
molding operation, an underlay of this character comprises forming a mold from said type face, 55
making a printed proof of said form on a paper
55 would be placed printed side up on the lower
press platen 3i and the mold laid thereon as sheet, cutting out the printed areas from said
shown in Fig. 8, these parts being retained in sheet, applying a layer of resin ingredients to
‘proper matched relation by the bearers 35 or the indented face of said mold, placing said paper
sheet on said resin layerwith the cut-out por
other suitable guides.
The method above described for treating the tions matching with the corresponding type areas
60
plates to incorporate make-ready therein auto
of said mold, heating said resin layer to a mold
matically in the molding operation is especially ing temperature, and pressing said resin layer
advantageous in that it avoids individual treat
and said proof sheet between said mold and a ,
ment of the several plates whch are ordinarily ' carrier sheet whereby to cause only the resin 65
made from a single engraving in the larger print~ opposite said cavities to adhere to said carrier
65
ing shops. This advantage results from associa
sheet, and stripping o? said paper sheet and the
tion of the make-ready details with the mold resin adhering thereto.
from which anyv number of plates may be made.
3. For use in making a printing plate compris
No additional equipment is necessary, and no ing a molded resin layer on a sheet of metal hav 70
special skill is required in forming and locating ing a surface treated for the adherence of plastic
the make-ready details all of which operations resin thereto, the method which comprises form
may be performed outside of the press room. ing a metal surfaced mold having cavities therein
Manufacturing costs are thus reduced substan
corresponding to the type to. be molded, masking
edges are .matched with those of the mold 24
50 with the patches 49 lying against the back sur
75
tially as compared with methods ordinarily used
in making printing lates ready for printing.
the portions of said treated surface correspon
4
2,114,288
to the non-type areas of said mold, covering the
face of said mold with a layer of resin ingredients,
locating said sheet with the exposed treated sur
face thereof in register with the type areas of the
mold, pressing said mold and sheet together with
said ingredients heated to a molding temperature,
and stripping the resin off from the masked areas
of said sheet.
4. For use in making a printing plate compris
10 ing a molded resin layer one sheet of metal hav
ing a surface treated for the adherence of plastic
resin thereto, the method which comprises form
ing a metal surfaced mold having cavities therein
corresponding to the type to be molded, masking
the portions of said treated surface correspond
ing to the non-type areas of said mold, and press
ing a layer of resin ingredients between the face ‘
of said mold and said sheet whereby to mold the
type on the exposed areas of sheet.
5. The method of forming a printing plate
which comprises forming a mold having cavities
therein corresponding to the type to be formed,
covering the face of the mold with moldable
material, covering said material with a. carrier
sheet having selected portions thereof corre
sponding to the type areas of said mold adapted
for the adherence of the molded material there
to, and the remaining areas adapted for the non
adherence of the molded material and molding
said material in said mold under pressure.
ARTHUR B. DAVIS.
5
15
Документ
Категория
Без категории
Просмотров
0
Размер файла
798 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа