CA1177690A

CA1177690A - Mounting strap for a printing plate

Info

Publication number: CA1177690A
Application number: CA000399626A
Authority: CA
Inventors: Arthur J. London
Original assignee: Individual
Current assignee: Individual
Priority date: 1981-04-08
Filing date: 1982-03-29
Publication date: 1984-11-13

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.

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 ~17~7690 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 :~ - 2 -117~690 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 117'i'690 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.

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.