US4231292A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Safety interlock for offset printing press
Assignee: White Consolidated Industries Inc
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Filing: 1978-08-25
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Granted: 1980-11-04
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Expires: 1998-08-25
Abstract
Abstract A two-color offset printing press having two plate cylinders simultaneously engageable with a single blanket cylinder is disclosed. The plate cylinders and the blanket cylinder are rotatably mounted on a printer head fixed to the mainframe of the press. A first set of dampening and inking rollers is mounted on the printer head and engageable with one of the plate cylinders. A second set of dampening and inking rollers, engageable with the other plate cylinder, is mounted on a ball bushing supported carriage linearly movable to and from the printer head along a pair of parallel rails fixed to the mainframe. Image registry between the two plate cylinders is established by an operator-accessible adjustment mechanism for shifting one of the plate cylinders back and forth along its axis of rotation. An electrical safety interlock system precludes operator access to the carriage-associated plate cylinder during predetermined operating modes of the press.
Inventors
- 👤 James R. Stolle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 19:12
CPC Classifications
B; B41; B41F; B41F7/00; B41F7/02; B41F7/08; B41F33/00; B41F33/0018
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
328 words
In an offset printing press having a mainframe, a printer head fixed to the mainframe, the printer head including a blanket cylinder and a plate cylinder, the plate cylinder and the blanket cylinder being rotatably supported by the printer head, the plate cylinder being movable into and out of an engagement position with the blanket cylinder wherein the plate cylinder is rotatably driven by a drive means at said engagement position, and a carriage mounted on the mainframe and linearly movable to and from the plate cylinder, the carriage including dampening and inking rollers, a safety interlock system for electrically deenergizing a motor mounted on the mainframe and driving the drive means, comprising: a pair of power lines across which the press motor is connected for electrical energization; a relay connected across the power lines, the relay being in electrically parallel relation with the press motor, the relay including at least one pair of relay contacts which are normally open when the relay is deenergized, the relay contacts being electrically series-interposed between the motor and one of the power lines; and a switch means electrically connected in series relation between the relay and one of the power lines, the switch means being responsive both to carriage movement to and from the printer head over a predetermined distance and to the plate cylinder movement into and out of its engagement position, wherein movement of the carriage away from the printer head for the predetermined distance, when the plate cylinder is in its engagement position, opens the switch means to deenergize the relay and electrically open the pair of relay contacts wherein the motor is electrically disconnected from one of the power lines, movement of the plate cylinder out of its engagement position closing the switch means and reenergizing the relay to electrically close the pair of relay contacts wherein the motor is reconnected to the power lines when the carriage is at the predetermined distance from the printer head.
Claim 2
Dependent Claim
328 words
In an offset printing press having a mainframe, a printer head fixed to the mainframe, the printer head including a blanket cylinder and a plate cylinder, the plate cylinder and the blanket cylinder being rotatably supported by the printer head, the plate cylinder being movable into and out of an engagement position with the blanket cylinder wherein the plate cylinder is rotatably driven by a drive means at said engagement position, and a carriage mounted on the mainframe and linearly movable to and from the plate cylinder, the carriage including dampening and inking rollers, a safety interlock system for electrically deenergizing a motor mounted on the mainframe and driving the drive means, comprising: a pair of power lines across which the press motor is connected for electrical energization; a relay connected across the power lines, the relay being in electrically parallel relation with the press motor, the relay including at least one pair of relay contacts which are normally open when the relay is deenergized, the relay contacts being electrically series-interposed between the motor and one of the power lines; and a switch means electrically connected in series relation between the relay and one of the power lines, the switch means being responsive both to carriage movement to and from the printer head over a predetermined distance and to the plate cylinder movement into and out of its engagement position, wherein movement of the carriage away from the printer head for the predetermined distance, when the plate cylinder is in its engagement position, opens the switch means to deenergize the relay and electrically open the pair of relay contacts wherein the motor is electrically disconnected from one of the power lines, movement of the plate cylinder out of its engagement position closing the switch means and reenergizing the relay to electrically close the pair of relay contacts wherein the motor is reconnected to the power lines when the carriage is at the predetermined distance from the printer head.
Claim 3
Dependent Claim
37 words
A safety interlock system according to claim 1, wherein the carriage is movable between two end positions, the switch means electrically opening only when the carriage is moved toward its end position farthest from the printer head.
Claim 4
Dependent Claim
35 words
A safety interlock system according to claim 2, wherein the switch means includes a switch mounted on and fixed to the mainframe, the carriage mechanically engaging and actuating the switch to an electrically closed condition.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-11-04 | 1984-05-05 | 1984-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-11-04 | 1988-05-05 | 1988-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-11-04 | 1992-05-05 | 1992-11-04 | $7700.00 | Window Closed / Lapsed |