Improvements in Gripper Attachments for Platen Printing Presses.
Year: 1898

page_text: Date of Application, 9th Sept., 1898-Accepted, 22nd Oct., 1898
COMPLETE SPECIFICATION.
Improvements in Gripper Attachments for Platen Printing Presses.
I, ANDREW WRIGHT KNOX, of Nos. 56 and 58, Grand Street, in the Borough of
Manhattan, and City, County, and State of New York, United States of America,
Manufacturer, 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:-
This invention relates to the class of devices employed on platen printing
presses for stripping the sheet from the form as the platen withdraws after the
impression, such devices being commonly called grippers. Usually such grippers
are simple bars, two in number, arranged to take behind the blank portion or
margin of the sheet at the respective sides. Such bars must, of course, be adjusted
laterally of the platen to suit sheets and type-forms of different widths, and this
setting of the bars for each job requires considerable time. Moreover, there are
some jobs where it is not easy to employ such grippers satisfactorily at all.
None of these grippers attain what I seek to accomplish by my invention,
which will now be described with reference to the accompanying drawings, which
illustrate embodiments thereof. In said drawings
Figure 1 is a plan view, on a small scale, of the platen of a printing press
having my improved gripper devices applied thereto.
Figure 2 is an edge view of one of the gripper-bars showing the clamps thereon.
Figure 3 shows one of the clamps, B, detached.
Figure 4 is a cross-section of a gripper-bar A, showing a clamp B, thereon.
Figure 5 is a plan and side view, and Figure 6 an end view of the clip which
secures the pin or wire d adjustably on the transverse strips C, C.
Figures 7, 8, 9, 10 and 11 illustrate a somewhat modified form of the invention.
Figure 7 shows the gripper-bars on the platen; Figure 8 shows the clip in per-
spective; Figures 9 and 10 are sectional views of the clip, and Figure 11 shows a
grooved gripper-bar in edge and plan views.
In Figure 1, X represents the platen of an ordinary printing press, and a a
sheet placed thereon up to the usual gage-pins, to receive the impression. Z is
the slotted plate to which the two gripper-bars, A, A, are secured, each by a bolt
engaging the slot in the plate in the usual way.
B are spring clamps on the respective gripper-bars for holding and securing
thereto, adjustably, the relatively stiff bands or strips, C, which tie the two bars A
together. As shown in Figure 1 there are two of these tie-bands. Preferably
the tie-band or strip C will be flat, and of thin but rather stiff metal, and it is
secured adjustably to the bars A by the clips B, in such a manner that it may be
adjusted lengthwise of the bars A, and also so that the latter may be adjusted
laterally across the platen, the tie-band C sliding through the clips.
Figures 3 and 4 show the construction of the clip B. It is of spring sheet metal,
the curved crown plate, b, thereof, which bears on the face of the bar A, being a
spring, and the flanges, . thereof, which are bent down so as to embrace the
edges of the bar A, having formed in them dovetailed keepers, 3, one of which is

page_text: seen in Fig. 3, to receive the band C, which latter is beveled at its edges to fit said
keepers. The spring crown-plate of the clip draws the band C up elastically
against the opposite face of the bar A and thus holds the parts together friction-
ally but permits of the adjustments before stated.
is
There are two wires or pins, c. and d, which are adapted to extend across the
space enclosed by the gripper-bars A, A, and the tie-bands C, C. The pin
secured frictionally and adjustably to the bars A, A, by spring clips, B', substan-
tially like the clips B, and it extends across the space parallel to the bands C;
the pin d extends across the space parallel to the bars A, and is secured adjustably
and frictionally to the bands C by spring clips, e, as seen in Figures 5 and 6.
Both of these pins c and d are shown in use in Figure 1, but obviously one may be
used without the other under certain circumstances. Indeed the same pin may be
used in either position, and they may be of stiff, steel. wire and have small heads
like long pins. In using these pins care must be taken that they cross the form
of type along blank spaces or lines so that in making the impression they will
not injure the faces of the types. In a set of these gripper devices the printer will
be supplied with all the parts seen in Figure 1, and will use such of them as may.
be needed in each particular case.
In the modified construction of Figures 7 to 11, the bar A is grooved length-
wise, as seen at a, and the clip B is constructed somewhat differently from that
herein before described. The clamp takes over the bar A and has keepers, like
the keepers 63, to receive the strip C; but it has secured to it a plate, b¹, which
plays along the channel a in. the gripper-bar, and through this plate is driven a
screw 2, which bears on the bottom of the slot and serves to draw the clip B up
snugly against the lower face of the gripper-bar.
In Figure 7 only one strip C is shown mounted on the bars A, and only one is
needed on some work.
It will be noted that the use of the tie-band C avoids the necessity of shifting
the bars A laterally throughout a great range of work, and provides a stripper
which takes under the upper margin of the sheet throughout its entire width.
This is important as being the proper point to take under the sheet for detaching
it from the form. The lower end of the sheet takes under the lips of the gage-
pins which serve to a good extent as detaching devices, and the band C takes
under the upper margin of the sheet, as described. Another advantage of the
tie-band is that it holds the bars A in place and prevents them from shifting
laterally, as they are liable to do if they become loosened at their lower ends.
In Figures 1 and 7 the bands C and c are represented as resting or extending
over the sheet, but it will be understood that during the impression it will be
under the sheet, or between the sheet and the bed on which the type-form rests,
as in all gripping devices for the purpose of detaching the sheet from the form
when the platen draws back. The strip or band C may be made from any strong,
tough and stiff material; metal is preferred. The bands c and d may be long
pins of steel wire.
My device may be applied to any of the ordinary platen presses.
Of course the use of the tie-bands do not prevent the bars A, one or both, from 4
being made to take beneath or behind the side-margin or margins of the sheet.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is: :―
5
1. A gripper attachment for a platen printing press, comprising two laterally
adjustable gripper-bars adapted in all positions to bear on the face of the platen
when the impression is made, and a tie-band or strip of stiff material extending
across the platen from one of said bars to the other and secured adjustably to
the latter, whereby the strip may be set at different points along the bars, substan- 5
tially as set forth.

page_text: 2. A gripper attachment for a platen printing press, comprising two laterally
adjustable gripper-bars adapted in all positions to bear on the face of the platen
when the impression is made, a tie-band or strip C, of stiff material extending
across the platen from one of said bars to the other, said strip having bevelled
edges, and clamps on said bars having keeper grooves to receive said tie-band
and means for securing the latter to the bars in the position set thereon, substan-
tially as set forth.
3. The combination with the platen of a printing press, of a gripper attach-
ment comprising a pair of gripper-bars AA, mounted adjustably on said platen
so that they may be shifted laterally over the latter, a strip C, of stiff material
extending across from one of said bars to the other and secured in an adjustable
manner thereto, and clamps which secure the strip to said bars in a manner to
permit the latter to be moved both transversely, and longitudinally over the bars,
substantially as set forth.
4. A gripper attachment for platen printing presses, having a spring clamp, B
or B', as shown in Figures 3 and 4, for use on a gripper-bar to hold a tie-band,
as C or pin, as c, substantially as set forth.
5. A gripper attachment for platen printing presses, having tie-bands C,
secured to the gripper-bars, and a pin or wire a, secured to said bands, parallel
with and between the said gripper-bars, substantially as set forth.
G. A gripper attachment for platen printing presses having gripper-bars, tie-
bands adjustably connected to said bars, and a pin or wire secured adjustably
to said tie-bands or bars by clips and adjustable laterally thereon, substantially
as set forth.
7. The spring clip for securing the tie-band to the gripper-bar substantially
as described and as shown with reference to Figure 3 of the accompanying
drawings.
8. The clip for securing the tie-band to the gripper-bar substantially as
described and as shown with reference to Figure 8 of the accompanying drawings.
Dated this 8th day of September 1898.
STEPHEN WATKINS,
Wolverhampton, Agent for the Applicant.