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Publication numberUS3682551 A
Publication typeGrant
Publication dateAug 8, 1972
Filing dateOct 28, 1971
Priority dateOct 28, 1971
Publication numberUS 3682551 A, US 3682551A, US-A-3682551, US3682551 A, US3682551A
InventorsThomas E Bradley, Walter Spadt Jr
Original AssigneeBethlehem Steel Corp
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Contact printing apparatus
US 3682551 A
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Description  (OCR text may contain errors)

Edited States Patent Bradley et al.

[54] CONTACT PRINTING APPARATUS [72] Inventors: Thomas E. Bradley, Bethlehem; galter Spadt, Jr., Emmaus, both of Assignee: Bethlehem Steel Corporation Filed: Oct. 28, 1971 Appl. No.: 193,408

US. Cl. ..355/120, 355/93, 355/120 lnt. Cl. ..G03b 27/04 Field of Search .......355/93, 120

[56] References Cited UNITED STATES PATENTS 2,210,726 8/1940 Mazzocco ..355/93x [15] 3,682,551 [451 Aug. 8, 1972 2,534,784 12/1950 Maxwell ..355/93 X 2,534,794 12/1950 Powers, Sr. ..355/93 X 3,106,145 10/1963 Hutchins ..355/93 Primary Examiner-Samuel S. Matthews Assistant Examiner-Richard M. Sheer Attorney-Joseph .l. OKeefe [5 7] ABSTRACT Improved printing apparatus having a tiltable printing frame with a first light source for use when the printing frame is in a horizontal position and a second light source for use when the printing frame is in a vertical position and apparatus to automatically deenergize the first light source and energize the second light source and further apparatus to automatically position the second light source.

6 Claim, 3 Drawing Figures PATENTED 9 C I J 4 I INVENTORS Thomas E Bradley B Walter Spad/ Jr.

7 rrouzv 1 CONTACT PRINTING APPARATUS BACKGROUND OF THE INVENTION This invention relates generally to contact printing apparatus and more particularly to an improved dual purpose exposure unit.

Recent developments in photosensitive material provide a fast, good quality method of instant image proofing. Existing equipment, however, is not readily adaptable to use with the instant image proofing photosensitive material. Most commercial equipment, rollthrough or other exposure units are not dual purpose, being limited to standard operations such as exposing composite negatives wherein the light source is a quartz lamp. The recently developed photosensitive material is exposed to ultra violet cool light source employing 1 volts.

It is an object of this invention therefore to provide a dual-purpose unit capable of use in standard proofing operation and instant image proofing operation.

It is a further object of the invention to provide automatic switching means between the operations.

It is a still further object of the invention to automatically position the light source in the instant image proofing operation.

SUMMARY OF THE INVENTION BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of the equipment showing the apparatus in one position of operation;

FIG. 2 is a view similar to FIG. 1 but with parts removed to expose more clearly details of the invention showing the apparatus in an alternate position; and

FIG. 3 is a schematic wiring diagram.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the FIGURES, the contact printing apparatus 10 of the instant invention is seen to generally comprise a frame or support structure 11, a printing frame 12 pivotable about pivot point 13, first light source 14, second light source 15 and carriage 16. The support structure 11 includes a frame 17 which is mounted thereon and extends to the rear therefrom.

The first light source 14, e.g. a quartz lamp, is used when the printing frame 12 is in a horizontal position for use in standard ofiset procedures. The second light source 15 comprises a bank of 12 closely spaced ultra violet tubes mounted on a sheet of plywood covered with sheet asbestos and reflective aluminum foil. The aluminum foil is grounded to encourage proper ionization of the gas in the tubes. Sheet metal housing 26 prevents stray ultra violet rays from emitting into the room. The second light source 15 is used when the printing frame 12 is pivoted to a vertical position as shown in FIG. 2. The bank of lights of light source 15 is bracketed to a set of rollers 18 riding in twin channels 19 pennitting second light source 15 to move toward or away from the printing frame 12.

Printing frame 12 which as shown is of conventional design, including a glass frame 21 and blanket frame 22, has cam follower means 23 mounted at the rear thereof on either side, the purpose for which will be presently described.

Pneumatic damper 24 is mounted on frame 17 and is connected to carriage 16 to provide the power to move carriage 16 toward the printing frame 12 under pneumatic action similar to a door check. The pneumatic damper 24 also provides a damping effect to the movement of the carriage 16 to prevent jarring of the bank of ultra violet tubes of light source 15 and consequent damage thereto as will be understood from the description of the operation of the apparatus.

Referring now to FIG. 3 which shows a schematic wiring diagram of the electrical control system for the automatic operation of the equipment when the printing frame 12 is in a horizontal position. The electrical control system is seen to generally comprise v supply, on-off switch 30, timer or exposure control means 31, first limit switch 33, second or master limit switch 32, including contacts 32a and 32b, first light source 14 and second light source 15. All components are wired into the system through junction box 35 of FIG. 1. Limit switch 33 located at the front of support structure 11 is actuated when the printing frame 12 is laid down in the horizontal position, the contacts of limit switch 33 being closed when the switch is depressed by the weight of the printing frame 12 resting on it. Master limit switch 32 is located at the rear of support structure 11 and mounted thereon to be activated when the printing frame 12 is pivoted to the vertical position. As will be understood by subsequent description herein, the arrangement of limit switches permits the deenergization of one light source while the other light source is energized, thus conveniently providing a dual purpose exposure unit.

In operation: the contact printing apparatus 10 of the instant invention as hereinbefore described is a dual purpose exposure machine. The printing frame 12 located in the horizontal position as seen in solid lines in FIG. I is used for standard ofiset procedures and a first light source 14, e.g., a quartz lamp, is provided for exposure purposes. Timer 31 is also connected in the system as seen in FIG. 3 and is manually set to provide a timed exposure of said first light source 14 and said second light source 15.

The exposure of instant image proofing photosensitive material to a second light source 15, e.g., a bank of 110 V ultra violet tubes, is accomplished by tilting the printing frame 12 about pivot point 13 to a vertical position. The cam followers 23 mounted on the printing frame 12 at the rear thereof are in contact with the housing 26 of the bank of lights of second light source 15 when the printing frame is in the horizontal position and thus space the second light source 15 to the rear of the printing frame 12 when the printing frame is horizontally disposed. As the printing frame 12 is tilted or pivoted to the vertical position the cam followers 23 roll down wear plate 27 mounted on the face of the housing 26 until they are free from contact with the bank of lights of light source 15 intermediate the horizontal and vertical positions of the printing frame 12 as seen in phantom lines in FIG. I. The printing frame will continue rotation about pivot point 13 until it has reached the vertical position.

The bank of lights 15 mounted on carriage 16 is advancedby the pneumatic damper 24 toward the now vertical printing frame 12 until contact is made once again with the cam followers 23 which act as a stop and space the bank of lights from the printing frame the desired distance as shown in FIG. 2. During the short time while the cam followers 23 mounted on the rear of printing frame 12 are free from contact with wear plate 27 of housing 26 the carriage 16 is under the control of pneumatic damper 24 and is biased toward the vertically disposed printing frame 12 on rollers 18 and twin channels 19. Pneumatic damper 24 is normally fully extended by the force of the cam followers 23 against the bank of lights 15 when the printing frame 12 is horizontal. The printing frame 12 is released from contact with wear plate 27 of housing 26 of the light source 15 as the cam followers 23 rotate about an arc described about pivot point [3 as a center.

The damping effect of pneumatic damper 24 hereinbefore referred to controls the movement of carriage 16 toward the printing frame 12 so that as the printing frame 12 is raised toward a vertical position the printing frame 12'becomes separated from wear plate 27 of housing 26 of the light source 15 for a time to allow the printing frame to reach its vertical position before contact is made again between the aforementioned printin g frame and wear plate. The cam followers 23 act as a stop for the movement of the carriage 16 against the vertically disposed printing frame 12. The damping effect prevents jarring of the bank of lights of second light source 15.

When the printing frame 12 is in a vertical position, the bank of lightsof light source 15 is spaced about 3 inches from the face of the printing frame 12. This space can be adjusted as desired by moving the cam followers 23 or installing a stop (not shown) between support 11 and housing 26, as desired. Metal housing 26 provides means to prevent the emission of stray ultra violet light from around the periphery of the printing frame 12.

Referring to FIGS. 1 and 3 for a detailed description of the switching arrangement it is presumed that the printing frame 12 is laid down in the horizontal position for exposure to the first light source .14. The on-off switch 30 connected to the 1 V power source is actuated and timer 31 which is normally open (NO) is manually set by the operator to the desired exposure time. The limit switch 33 is actuated by virtue of contact made by the horizontally disposed printing frame 12 thus closing the contacts in limit switch 33 to energize the quartz lamp or first light source 14. It is understood that contacts 32a are closed.

Master limit switch 32 is designed so that when the printing frame 12 is pivoted to a vertical position for instant image proofing and contact is made between the limit switch 32 and the rearrnost portion of the printing frame 12 as seen in FIG. 2, contacts 32a are opened and contacts 32b are closed thus energizing the plurality of ultra violet tubes a to 15n inclusive when the timer 31 is set. The contacts in limit switch 33 are opened immediately upon release of the horizontally disposed printing frame 12 from contact therewith when pivoting the frame 12 toward the vertical position, thus deenergizing first light source 14. Second light source 15 is energized as described above when the printing frame 12 reaches the vertical position and the timer is set. I

We claim:

1. In contact printing apparatus having a support structure, a printing frame pivotally mounted on said support structure for movement between a horizontal and a vertical position'and a first light source for use with said printing frame when said printing frame is in the horizontal position, the improvement comprising:

a. a second light source for use when said printing frame is in the vertical position,

b. means on said support structure to automatically position said second light source relative to said printing frame when said printing frame is pivoted to the vertical position, and

c. means on said support structure to automatically energize and deenergize said first light source only when said printing frame is in the horizontal position and said second light source only when said printing frame is in the vertical position.

2. Contact printing apparatus according to claim 1 wherein the means described in subparagraph (b) comprises a pneumatic damper mounted on said second light source to move said second light source horizontally toward said printing frame when said printing frame is in the vertical position.

3. Contact printing apparatus according to claim 1 wherein the means described in subparagraph (c) comprises first and second limit switches activated by movement of said printing frame, and a timer.

4. Contact printing apparatus according to claim 1 wherein the means described in subparagraph (b) comprises a pneumatic damper mounted on said support structure and connected to said second light source to move said second light source toward said printing frame when said printing frame is in the vertical position, and the means described in subparagraph (c) comprises a first limit switch activated by pivoting said printing frame above the horizontal position to deenergize said first light source, and

a second limit switch activated by pivoting said printing frame to a vertical position to energize said second light source,

5. Contact printing apparatus according to claim 1 wherein the means described in subparagraph (b) comprises a carriage supporting said second light source mounted on said support structure for movement toward and away from said printing frame,

cam followers mounted on said printing frame in rolling contact with said carriage, and a pneumatic damper mounted on said support structure and connected to said carriage to move said carriage toward said printing frame when said printing frame is raised.

6. Contact printing apparatus according to claim 5 wherein the means described in subparagraph (c) comprises a first limit switch activated by pivoting said printing frame above the horizontal position to deenergize said first light source, and

a second limit switch activated by pivoting said printing frame to a vertical position.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3771869 *Feb 26, 1973Nov 13, 1973Douthitt CorpPrinting plate maker
US4111549 *Jun 6, 1977Sep 5, 1978Cazel Thomas RPlatemaker and contact frame exposure indicator
US4721383 *Jan 21, 1987Jan 26, 1988Simon Michael JProofing machine
US5400118 *Nov 18, 1992Mar 21, 1995Publishers Press, Inc.Process and apparatus for printing periodicals and the like
US5737065 *May 17, 1995Apr 7, 1998Fotodyne IncorporatedDual light source transilluminator and method of transillumination
Classifications
U.S. Classification355/120, 355/93
International ClassificationG03B27/06
Cooperative ClassificationG03B27/06
European ClassificationG03B27/06