# US 4,391,193 A · Plate holding device for offset duplicator

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- Number: US 4,391,193 A
- Document ID: US4391193A
- Status: Granted
- Kind: A
- Application number: 06/251,450
- Filed: 1981-04-06
- Granted: 1983-07-05
- Earliest claimed: 1980-04-17
- Assignees: Ryobi Ltd.
- Inventors: Koji Ishii; Takahiko Shinmoto; Kenso Maehara
- Web page: https://patentgrep.com/patent/US4391193A

## CPC

- B41F 27/1218: {comprising printing plate tensioning devices}
- B41L 29/14: Clamping devices
- B41F: PRINTING MACHINES OR PRESSES (manifolding devices or office printing machines B41L)
- B41L: APPARATUS OR DEVICES FOR MANIFOLDING, DUPLICATING OR PRINTING FOR OFFICE OR OTHER COMMERCIAL PURPOSES; ADDRESSING MACHINES OR LIKE SERIES-PRINTING MACHINES (printing presses or machines for industrial purposes B41F; stamps, stamping or numbering devices B41K)

## Abstract

A printing plate holding device for an offset duplicator. The device includes a base slidably positioned on one side of a grooved portion of a plate cylinder of the duplicator. A clamp plate is secured to the base and a clamp lever is attached to the clamp plate. A latch is loosely secured to a pin attached to the clamp lever and connected to a spring to provide a plate clamping force upon the clamp plate. A guide plate and a plate release preventing plate are attached to an outer longitudinal side of the base. An axial displacement control device is positioned at one longitudinal end of the cylinder while a circumferential displacement control device is positioned at the other longitudinal end thereof.

## Claims

### Claim 1

A printing plate holding device for an offset duplicator, said holding device being positioned in a grooved portion of a plate cylinder and confronting a tail clamp device, said holding device comprising: a base positioned along one side of said grooved portion and slidably secured thereto in a horizontal plane; a clamp plate pivotally secured to said base and provided with a first pin; a clamp lever fixed to said clamp plate and provided with a second pin; a latch loosely secured to said second pin of said clamp lever and connected to a spring so as to provide a plate clamping force to said clamp plate, said latch being engageable with a bracket of said base so as to maintain said clamp plate at an open position; a guide plate and a plate release preventing plate both fixed to an outer longitudinal side of said base; axial displacement control means positioned at one longitudinal end of said cylinder; circumferential displacement control means positioned at the other longitudinal end of said cylinder; said axial displacement control means comprising a first knob rotatably extending through a slot formed in a first bracket fixed to said base, said first knob being threadingly engaged with said plate cylinder; and said circumferential displacement control means comprising a second knob rotatably extending through a slot formed in a second bracket fixed to said cylinder, said second knob being threadingly engaged with a third bracket fixed to said base.

### Claim 2 (depends on 1)

The printing plate holding device of claim 1 wherein said plate cylinder comprises a slide base portion extending inwardly from an outer surface of said plate cylinder and wherein said base has a slot formed at approximately its longitudinal center, and further comprising a third pin for loosely securing said base portion to said slide base, said third pin extending through said slot.

### Claim 3 (depends on 1)

The printing plate holding device of claim 1 wherein said slot formed in said first bracket extends substantially perpendicular to the axial direction of said plate cylinder.

### Claim 4 (depends on 3)

The printing plate holding device of claim 3 wherein said first knob is threadingly engaged with said plate cylinder.

### Claim 5 (depends on 3)

The printing plate holding device of claim 3 wherein said first knob is engaged with said plate cylinder through a fourth bracket.

### Claim 6 (depends on 1)

The printing plate holding device of claim 1 wherein said slot in said second bracket extends parallel to the axis of said plate cylinder.

### Claim 7 (depends on 1)

The printing plate holding device of claim 1 wherein said plate release preventing plate is provided with a plurality of thrust pawls projecting outwardly for securing a printing plate.

### Claim 8 (depends on 1)

The printing plate holding device of claim 1 further comprising a second guide plate and a printing plate abutment, said second guide plate and said printing plate abutment being secured, respectively, to upper and lower surfaces of said clamp plate.

### Claim 9 (depends on 1)

The printing plate holding device of claim 1 further comprising a torsion spring for urging a recessed portion of said latch toward an interlocking position with said bracket of said base.