MOUNTING STRAP FOR A PRINTING PLATE

BRIDE DE FIXATION DE CLICHE

English Abstract

MOUNTING STRAP FOR A PRINTING PLATE
ABSTRACT OF THE DISCLOSURE
A mounting strap for a printing plate which is
fixed to a flexible saddle for mounting on a rotary drum,
the saddle being engagable by its leading edge with a slot
in the drum and having at least one aperture adjacent its
trailing edge. The strap has an elongated resilient body
with a rigid flange fixed at one end of the body and a rigid
hook fixed at the other end. The hook has a shoulder ex-
tending downwardly and rearwardly from the body and a tongue
extending forwardly from the shoulder, the shoulder being
engagable with the rim of the aperture when the tongue is
inserted therethrough.

Claims

I CLAIM:
1. For use with a printing plate fixed to a
flexible saddle mountable on a rotatable drum, the saddle
having means along its leading edge for engagement with a
slot in the drum and adjacent the trailing edge of the
saddle at least one aperture with a circumscribing rim, a
strap comprising an elongated resilient body, a rigid flange
fixed to one end of the body and a rigid hook fixed to the
other end of the body, the hook having a shoulder projecting
downwardly and rearwardly from the strap and a tongue pro-
jecting forwardly from the free end portion of the shoulder,
the hook being insertable through the aperture whereby the
shoulder is engagable with the rim thereof.
2. A strap as claimed in claim 1 in which the hook
comprises a plate member fixed to said other end of the body
of the strap, a pin extending downwardly from the plate member
to form the shoulder, and a tongue member extending laterally
from the free end of the pin parallel to the plate member and
projecting forwardly of the body.

Description

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FIELD OF THE INVENTION
This invention relates to a mounting strap for
a printing plate mountable on a rotary printing drum.
BACKGROUND OF THE INVENTION
For printing corrugated containers and the like,
a large rotary printing drum is used on which a printing plate
is removably mounted. the printing plate comprises a flexible
saddle with a printing block fixed on the saddle.
A device for mounting the saddle on the roll is
disclosed in United States Patent No. 3,295,443 issued January
3, 1967 in the name of Harry J. Devon. In that device an
elastic strap is used to fasten the saddle to the drum. The
saddle is first positioned on the drum with the flanged leading
edge engaging a slot in the drum. To secure the saddle in this
position on the drum the hooked leading edge of the strap en-
gages an aperture in the trailing edge of the saddle and the
flanged trailing edge of the strap engages a further slot in
the drum. The problem with the Devon device is that the hook
of the strap must be forced open to engage the aperture in
the saddle and repeated use weakens the material which may
break in use and seriously damage the expensive printing press.
It is an object of the present invention to
provide a strap, for engaging the flexible saddle of a printing
plate, which has an improved means for interconnecting with
the saddle.
SUMMARY OF THE INVENTION
In its broadest aspect the invention consists
of a strap for use with a printing plate fixed to a flexible
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saddle mountable on a rotatable drum, the saddle having
means along its leading edge for engagement with a slot in
the drum and adjacent the trailing edge of the saddle at
least one aperture with a circumscribing rim, the strap
comprising an elongated resilient body, a rigid flange fixed
to one end of the body and a rigid hook fixed to the other
end of the body, ~he hook having a shoulder projecting
downwardly and rearwardly from the strap and a tongue pro-
jecting forwardly from the free end portion of the shoulder,
the hook being insertable through the aperture whereby the
shoulder is engagable with the rim thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
An example embodiment of the invention is shown
in the accompanying drawings in which:
Figure l is a perspective view of a rotary drum
having mounted thereon, by means of ~a strap, a printing plate
fixed on a saddle;
Figure 2 is a perspective view of the mounting
strap of Figure 1;
Figure 3 is a perspective view of one end of the
strap of Figure 2; and
Figure 4a, 4b and 4c are side views, partly in
cross-section, showing one end of the strap of Figure 2 in
sequential steps of engagement with the saddle of the printing
plate of Figure l.
DETAILED DESCRIPTION OF THE INVENTION
In the example embodiment shown in the drawings
a printing plate 10 is mounted on a rotary drum 12 by means
of a saddle 14 on which the printing plate is fixed, the
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saddle being detachably mounted on the drum by a mounting
strap 16.
Saddle 16 has a leading edge 18 carrying a flange
20 which is engagable in a slot 22 extending parallel to the
rotational axis of drum 12 in the surface of the drum. The
trailing edge portion 24 of saddle 16 has a row of apertures
26 each having a circumscribing rim 27.
Mounting strap 16 comprises an elongated
resilient body 28 carrying a rigid flange 30 fixed at one end
of the body and a rigid hook 32 fixed at the other end. Flange
30 is angled to be engagable with a further slot 34 in the
surface of drum 12 parallel to slot 22 as seen in Figure 1
of the drawings. Hook 32 comprises a pin member 36 projecting
downwardly and rearwardly from a plate member 37 fixed against
the end portion of strap 16 to form a shoulder 38, and a
tongue 40 projecting forwardly from the free end portion of
! - pin member 36, pin member 36 and tongue 40 being receivable
in aperture 26 of saddle 14.
Body 28 of mounting strap 16 is elastic in the
direction of arrows 42 as seen in Figure 2 and also flexible
in a direction perpendicular to the plane of the strap.
Body 28 is preferably made of buna rubber while flange 30
and hook 32 are preferably made of styrene for rigidity, the
flange and the hook being fixed to body 28 by suitable
adhesive.
In the use of mounting strap 16, saddle 14 of
printing plate 10 is laid against drum 12 and flange 20 is
engaged in slot 22. Hook 32 of strap 16 is then brought into
engagement with aperture 26 of saddle 16 by allowing tongue
40 to be inserted at an angle through the aperture, as seen
in Figure 4a of the drawings. Body 28 is moved towards drum

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12 as seen in Figure 4b to allow pin member 36 to enter
aper~ure 26. Finally body 28 is stre-tched to engage flange
20 in slot 34 of drum 12, causing shoulder 38 of pin member
36 to bear against rim 27 of aperture 26, as seen in Figure
4c, thus securing strap 16 to saddle 14 and the saddle on
i drum 12.
To remove strap 16 from saddle 14 and to remove
the saddle from drum 12 the reverse procedure is followed.
It will be appreciated that the mounting strap
of the present invention allows quick and easy mounting and
removal of a printing plate on a rotary drum while providing
a device which will not fracture on repeated use.