US 2774289 A
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Description (OCR text may contain errors)
Dec. 18, 1956 c. B. COLLINS PRINTING DEVICE Filed Jan 9, 1952 INVENTOR. Farrell 17. 60111146 I? TTORNET United States atent' PRINTING DEVICE Carroll B. Collins, Pittsburgh, Pa., assignor to Peerless Photo Products, Inc., Shoreham, N. Y., a corporation of New York Application January 9, 1952, Serial No. 265,556
Claims. (Cl. 95-76) The present invention relates generally to printing devices and more particularly to one which utilizes a flexible sheet of material for holding material against a supporting surface.
One of the difficulties in reproducing letters, drawings or other items, is that of putting the items and a sheet of sensitized material into smooth contact with a supporting surface and so holding them during printing. If smooth uniform contact is not obtained between the supporting surface, the sensitized printing material and the negative or item to be reproduced, resulting prints will lack the desired sharpness and clarity; they are likely to show objectionable blurred or foggy areas where wrinkles or bulges have been present in the negatives or printing material. Attempts have been made to overcome .such difficulties by placing a rubber sheet over the negative and withdrawing air from beneath the rubber sheet. These attempts have not solved the difliculty, however, as wrinkles, bulges or folds in the negatives and printing material frequently occur during placing of the rubber sheet thereover.
The present invention aims to overcome the above and other 'dilficulties by providing a new and improvedprinting device which is adapted to remove or prevent formation of objectionable bulges, wrinkles and the likexin both the items to be reproduced and the printing material, and which holds the items and printing material in smooth contact with each other and with a supporting surface. The invention further contemplates the provision of means for facilitating operation of the printing device by minimizing the effective weight ofcertain of its parts and maintaining them in any adjusted position.
An objectof the present invention is to provide a new and improved printing device.
Anotherobject of the invention is to provide an improved printing device adapted to prevent or minimize wrinkles, bulges or the like in both items to be reproduced printing device embodying improved means for minimizingthe weight of certain of its parts and facilitating positioning thereof.
Other and further objects of the invention will be obvious upon an understanding of the illustrative embodiment about to be described, or will be indicated in the appended claims, and various advantagesnot referredto herein will occur to one skilled in the art upon employment of-the invention impractice.
A preferred embodiment of the invention has been chosen for purposes of illustration and description and is shown in the accompanying drawings, forming a part of the specification, wherein:
Fig. 1 is a perspective view showing a preferred embodiment of the present invention;
Fig. 2 is a sectional view taken along line 2-2 of Fig. 1;
Fig. 3 is a fragmentary end view of the portion of the device illustrated in Fig. 2; v
Fig. 4 is a sectional view taken along line 4-4 of Fig. 2;
Fig. 5 is an enlarged fragmentary perspective view showing a portion of the device illustrated in Fig. 1; and
Fig. 6 is a sectional view taken along line 66 of Fig.5.
Referring more particularly to Figs. 1 and 2, the present device is shown comprising a box-like body portion 2, which will be referred to as a cabinet, supported on legs 3. The upper part of the cabinet carries a plate 4 of transparent or translucent glass, plastic, or other suitable material forming a supporting surface for sheets of printing material 6 and negatives 5 such as letters or other items to be reproduced. Various electric switches and operating handles 7 may be provided at the front part of the cabinet 2 for controlling any suitable fluorescent illuminating lamps, automatic timing mechanism, and vacuum pump and motor. The lamps and any reflectors for them are normally positioned inside the cabinet 2 so that illumination may pass up through the glass plate 4 and expose the sheet of printing material 6 to letters or other negatives 5. Representations of the negatives are transferred to the printing materiale and the latter may be treated in any well known manner to develop and fix a representation of the negative thereon.
A sheet of printing material 6 and letters or other material 5 are smoothed down into uniform contact with the upper surface of the plate 4, and into such contact with each other, by a vertically swingable opaque blanket 10, which may be a sheet of flexible material such as rubber or fabric. i
" The sheet of flexible material 10 is shown connected adjacent a rear edge thereof with the cabinet 2 at rear edge of the glass plate 4 and adjacent an opposite front edge thereof with a rotatably mounted member or frame 11. Side edges 13 of the flexible sheet are preferably free of connection with the frame member 11 so that the sheet is free to sag under its own weight between its rear and front portions 14 and 15. V
The length of the flexible sheet between its front and rear portions is preferably such that it covers the glass plate 4 without buckling in any way, when the frame member 11 is down against the upper surface of the cabinet 2. The frame member Ellis so mounted, however, that in elevated positions the flexible sheet 10 becomes slack and sags down toward the .glass plate 4 (see Figs. 1 and 2).
As the frame member 11 is pulled downwardly from some such position as that shown in Fig. l, the sagging flexible sheet 10 gradually rolls forwardly over the glass plate 4 and any material thereon. The flexible sheet 10 rolls gently down without disturbing negatives and printing material on the glass plate and'yet applies sulfici ent pressure to hold them in place. As the flexible sheet 10 moves down the advancing sag gradually pushes air out from between its under surface and upper surfaces of the glass plate printing material and negatives.
The flexible sheet 10 may be moved away from the glass plate material thereon by rotating the frame 11 upwardly about its connection with the cabinet. In raised position sheets of printing material 6 and items 5 to be reproduced may be readily placed on the glass plate. It will beunderstood that the position of the printing material 6 and negatives" may be interchanged so that the latter overlies the former.
When the frame member 11 and flexible sheet are down adjacent the glass plate 4, air may be withdrawn from the underside of the flexible sheet. In Fig. 2 this is shown obtained by a conduit 17 which connects with the underside of the flexible sheet 10 through lateral conduits 18. Conduit 17 may be connected with a vacuum pump (not shown) so that air is withdrawn from beneath the flexible sheet through the conduits. When vacuum is effective at the underside of the flexible sheet, the latter is forcibly and uniformly pushed down by atmospheric pressure against the glass plate and materials thereon; no hold-down clamps or latches are required.
A rib or ridge 12 may be provided on the flexible sheet 10 to project down into contact with the glass plate 4 or edges 8 of the glass plate and into Contact with upwardly facing surfaces of the cabinet to thereby minimize leakage of air in under the flexible sheet when a partial vacuum exists thereunder. v
The frame member 11 is shown with a projecting arm 22 that is rotatably secured to a portion of the cabinet 2 at a location below the glass plate 4. When the frame member is down close to the upper surface of the glass plate 4 the flexible sheet 10 lies substantially fiat against the glass plate without objectionable slack therein. As the frame member is rotated upwardly from such a lower position, slack is provided in increasing amounts. The slack difference between the amount of slack present when the frame member is substantially upright and when it is substantially horizontal is indicated generally by the upper and lower positions shown by dot-dash lines in Fig. 2.
The amount of slack provided in the flexible sheet 10 when the frame member 11 is fully raised is roughly equal to the distance between the frame members rotatable support and the rear portion 14 of the flexible sheet 10.
A separate arm member 22 and the associated structure about to be described, is preferably provided at each end of the cabinet 2; since the construction of each end is the same, a description of one will suflice for both. As shown in Figs. 2-4 the arm 22 is aflixed to an apertured bracket 25 that is rotatably supported on a cross-shaft 26. The end of shaft 26 fits into an aperture in plate member 28, which is in turn screwed to an end wall of the cabinet 2.
To facilitate movement of the frame member 11 and automatic retention of an adjusted position thereof, there is preferably provided the balancing and retaining mechanism illustrated in Figs. 2-4. As there shown the arm 22 extends downwardly and rotatably connects with a reciprocable member 30 through any suitable rotatable connection 31. 'A bracket 32 extends laterally from the reciprocable member 30 and is yieldably connected with a side bracket afiixed to a cabinet end wall, 34, through spring 35. The spring 35 is adapted to exert a force about equal and opposite to that exerted by the frame member 11 and its associated elements. When the frame member 11 is in an upper position; the spring 35 is stretched a comparatively small amount and hence exerts a small force on the arm 22; since little force is required to retain the. frame in its upper position this small spring force is ample'to maintain the frame in position. As the frame moves downwardly toward the glass plate 4, the lower part of arm 22 is rotated in clockwise direction and the spring 35 is stretched a greater amount, which causes it to exert greater force in opposition to movement of the arm 22 and frame member 11; thus, here again a counthe spring 35 and the frame member 11 at different positions thereofis taken care of by braking the reciprocable member 30. In Fig. 2 the undersurface of the reciprocable member 30 is shown supported on the upper surface of a brake shoe 38 mounted on a bracket 39 secured to the side of the cabinet 2. The braking surface of the shoe member 38 may be wood, brake lining, or any other suitable material. It will be noted that the force exerted by the spring 35 tends to rotate the reciprocable member 30 in clockwise direction about the rotatable connection 31, the effect of which is to press the reciprocable member 30 down against the upper surface of the brake member 38. This brake construction tends to hold the reciprocable member 36 against longitudinal movement in either direction, which in turn tends to maintain the arm 22 and connected frame member 11 in any position to which it is selectively adjusted.
When loading the printing device, the frame member 11 is preferably pulled part way down toward the glass plate 4, which allows the flexible sheet to sag against the glass plate adjacent the rear portion thereof. Printing material 6 and any items 5 to be reproduced may then be pushed back under the sheet so as to be held between it and the glass plate. If the device is to be loaded with letter size or other small originals, the rear row may be pushed under the sagging part of the flexible sheet, then the frame moved down further, and then the next adjacent front row pushed in under the sagging sheet.
It will be seen that the present invention provides a new and improved printing device which is adapted to press sheets of sensitized printing material and items to be reproduced, into firm and uniform contact with a supporting surface. As the flexible member moves downwardly toward a supporting surface, air is gradually pushed out from between the flexible sheet and the supporting surface. The sheet sags downwardly into contact with the supporting surface and any materials placed thereon, and provides what may be termed a rolling action, but which does not actually require unwinding an annular roll of material over a supporting surface. The present flexbile sheet is at all times accurately in position at front and rear edges thereof and no excess slack is present to disturb printing operations when the sheet and its supporting frame member are fully down in printing relationship.
. The frame member which carries the flexible sheet of material is counterbalanced by relatively simple mechanism located at the interior of the cabinet and this mechanism effectively retains the frame member and blanket at-any position of adjustment. When vacuum is applied to the underside of the flexible sheet the latter is pulled down firmly and evenly at all portions and substantial uniform and smooth contact is obtained throughout the entire surface of the supporting surface.
As various changes may be made in the form, construction and arrangement of the parts herein without departing from the spirit and scope of the invention and without sacrificing any of its advantages, it is to be understood that all matter herein is to be interpreted as illustrative and not in a limiting sense.
Having thus described my invention, I claim:
1. In a device for photographic printing, the combination of a support having a substantially horizontal surface area for supporting the material to be reproduced, a flexible sheet having an operative area coextensive with said surface area and having its rear portion connected to the .rear portion of said surface area, a frame member having connected to its front portion the front portion of the sheet, means pivotally connecting the rear portion of said frame member to the support on an axis located behind the rear end of said surface area and substantially below the level of said surface area whereby when the frame member moves from a vertical position to a horizontal position a sagging portion of the sheet will move progressively into contact with substantially the whole area of said surface until the frame member reaches fully closed position on said surface area.
2., The. device as claimed in claim 1, ineludinga friction brake means to releasably hold said frame member in any position.
3. The device as claimed in claim 1, including a friction brake means to releasably hold said frame member in any position, and brake force controlling means on said brake means to increase the brake force as the frame is swung toward a horizontal position.
4. The device as claimed in claim 1 in which a conduit communicates with the underside of said flexible sheet to conduct air away from the underside of said sheet when it overlies said surface area.
5. The device as claimed in claim 1 including a brake comprising a reciprocable member pivotally attached to the frame below the pivotal connection of the frame to the support, a brake shoe fixedly mounted on said support to frictionally engage said reciprocable member, and spring tension means to force said members into frictional engagement, said tension means having one end connected to said reciprocable member and its other end connected to said support whereby the friction brake force is increased in accordance with movement of the frame about its pivotal connection to position more of the flexible sheet in engagement with the surface area.
References Cited in the file of this patent UNITED STATES PATENTS 799,266 Renkel Sept. 12, 1905 844,135 Jungkind Feb. 12, 1907 1,144,014 Westman June 22, 1915 1,466,696 Brack Sept. 4, 1923 1,589,811 Mathes June 22, 1926 2,170,622 Sussin Aug. 22, 1939 2,173,168 Hughes Sept. 19, 1939 2,257,581 Ulsheimer Sept. 30, 1941 2,494,282 Campbell Jan. 10, 1950 2,600,580 Sabel et al June 17, 1952 2,638,827 Leavittet al May 19, 1953 FOREIGN PATENTS 245,915 Germany Apr. 20, 1912 133,225 Switzerland Aug. 1, 1929 571,617 Germany Mar. 3, 1933