US3236488A

US3236488A - Photographic apparatus

Info

Publication number: US3236488A
Application number: US261126A
Authority: US
Inventors: Dennis E Wilson
Original assignee: Individual
Current assignee: Individual
Priority date: 1963-02-26
Filing date: 1963-02-26
Publication date: 1966-02-22
Anticipated expiration: 1983-02-22

Description

Feb. 22, 1966 D. E. WILSON 3,236,488

PHOTOGRAPHIC APPARATUS Filed Feb. 26, 1963 INVENTOR DENNIS E. WILSON AGENT United States Patent 3,236,488 PHOTOGRAPHIC APPARATUS Dennis E. Wilson, 914 Wheeler St., Troy, Ohio Filed Feb. 26, 1963, Ser. No. 261,126 7 Claims. (Cl. 248-343) This invention relates to a device for supporting sheets, films, and the like in position for reproduction. In particular, this invention is directed to a combination of apparatus for holding a sheet of material to be photocopied in firm and intimate contact with a support device by means of a vacuum.

According to this invention, a sheet of photographic print paper or the like is held in place by application of a vacuum to the passageway of a supporting device which has a plurality of openings on its surface in communication with the passageway. The applied vacuum will cause a valve means located in each of the individual openings to move into firm engagement with the supporting device and the passageway and thereby establish a complete vacuum seal throughout the supporting device. A sheet of the material to be reproduced will then be placed on the face of the supporting device so as to cover either a portion of the individual openings or, if desired, the entire surface of the supporting device. When the sheet is so placed, the valve means will be forced to move out of its firm engagement with the vacuum passageway and the wall of the supporting device, thereby breaking the vacuum seal over that portion of the passageway.

'In the preparation of newspapers and similar publications such as magazines of large page units which are made up of standardized columns and standard overall dimensions, it is extremely important that the individual units be maintained in very rigid contact with the supporting surface. Accurate and rigid contact is essential in order to successfully subject the units to the mass reproduction techniques commonly used. Numerous devices have been proposed by the prior art for fulfilling this requirement (for example, U.S. Patents 2,133,518, 2,317,348, and l,813,690). None of these devices have satisfactorily solved this problem, however. All of these devices are incapable of providing the precision contact and rigidity which is required. The failure of these devices may be ascribed to numerous reasons, such as only providing for means to hold the sheet at its margin or failing to provide for means to control application of the vacuum to the individual openings on the surface of the support.

Another prior art device is that of US. Patent 2,910,- 265, directed to supporting a film of photo sensitive paper in a large photographic camera. According to this patent, a valve means is provided with a group of openings within the facing plate of a laminated support structure. This patent utilizes the pressure equalization technique, i.e., the patent provides for a bypass hole within each group of openings. These holes will insure that pressure will always be applied to the group of openings and thus tend to equalize the pressure within the openings and the vacuum passageway. While this de vice may perform satifactorily in photographic apparatus such as cameras, it is not suitable for usage in the makeup type of reproduction, such as newspapers, or other large publications of large page units. For such usage, it is necessary to have more accurate control of the application of the vacuum to the surface openings. The design of this device (that is the support facing plate and the bypass holes) precludes sufiiciently close spacing of the vacuum holes to insure the requisite rigid contact of the sheet of material with the surface of the support. In addition, the attendant cost of manufacturing such a device with the extra support layer and the addi- 3,236,488 Patented Feb. 22, 1966 lCC tional holes makes the utilization of such economically undesirable.

It is an object of this invention therefore to provide a combination of apparatus which solves the above mentioned problems of the prior art. It is a specific object of this invention to provide a vacuum support device so constructed and arranged that a plurality of different size sheets or filrns may be held in rigid engagement with the operative face thereof. Other objects, advantages, and features of this invention will become apparent to those skilled in the art in view of the following more detailed description of the invention.

These and other objects are achieved by means of this invention in which a novel and improved vacuum supporting structure for sheets, films, and the like is provided. According to this invention, a sheet of material to be reproduced is accurately aligned and firmly held in contact with the surface of a vacuum supporting device by applying a vacuum to the passageway of the supporting device, which has a plurality of individual openings on its surface in communication with the passageway. When the vacuum is applied, a valve means within each of the individual openings will be caused to move into firm engagement with the supporting device and the passageway which communicates with the opening, thereby completely closing off the passageway from the opening and establishing a complete vacuum seal throughout the supporting device. The valve means will be subsequently forced to move out of its firm engagement with the passageway by placing a sheet of material to be reproduced on the face of the supporting device, thereby breaking the vacuum seal over that portion of the passageway. It is thus seen that the essential feature of this invention is the provision of valve means within each individual opening on the surface of the support member. By providing for a valve means within each individual opening, it is possible to establish accurate and precise control over the vacuum applied throughout the surface of the supporting member. The utilization of a valve means within the individual openings also makes it possible to use a lower vacuum pressure and decreases the possibility of an uneven application of the pressure which would produce a movement or wrinkling of the sheet.

The invention will be better understood by referring to the accompanying drawing. It is to be understood that the drawing is but an illustrative embodiment of the invention and is not to be considered as a limitation of same.

FIGURE 1 is a plan view of the improved support of this invention. FIGURE 2 is a plan view of the valve construction drawn to an enlarged scale and showing further details of the construction of the support and the valve organization therewithin. FIGURE 3 is a vertical section taken on line AA of FIGURE 2 and shows further details of the construction of the support and the valve arrangement.

Referring now in detail to the drawings, a vacuum support device is shown designated 'by the numeral 1. Surrounding the support 1 is a vacuum channel 2 connected to a standard vacuum source such as a pump, not shown. Vacuum passageways 3 are shown within the support 1 which are in communication with the vacuum channel 2 and the individual openings 4 spaced uniformly throughout the surface of the support device 1. The vacuum passageway 3 has a plurality of tributary passageways 5 which are in direct communication with the surface openings 4. Referring more particularly now to FIGURES 2 and *3, the details of the valve construction will be shown. Within each surface opening 4 there is positioned a ball type valve member 6. Within each opening, there is an intersection 7 between the supporting device and the tributary passageway which provides a valve seat for the ball valve 6. This valve seat, if desired, may be established by the provision of a recess within the supporting device. It has been found, however, that it is preferable to form the valve seat using only the natural (unbeveled) contour formed by the intersection of the openings in the supporting device and the vacuum passageway. Experiments have demonstrated that any other configuration tends to be somewhat detrimental to the efiiciency of the support in that the valve will be attracted to the valve seat and against the material being held in position. This has been found to be particularly true when the mechanism is operated in the vertical position.

Also shown in FIGURE 3 is a retaining lip 9, formed on the surface of support 1 at opening 4. This retaining lip must be of such contour to retain the valve 6 within the opening 4, but also to allow valve 6 to seat perfectly at valve seat' 7 without interference, i.e., without contact of the retaining lip against the valve. For additional assurance of the perfect seating of the valve, the depth of opening 4 is preferably only slightly greater (approximately to 25%) than the diameter of valve 6, and vacuum passageway 5 positioned such that its center is slightly less than the radius of the valve from the working surface.

In the operation of this device, a vacuum is applied through'channel 2 to vacuum passageways 3 and the tributary passageways 5 to the individual openings 4 on the surface of the supporting device 1. As shown in FIGURE 3, the application of the vacuum through a tributary passageway 5 will force the ball valve 6 to move into its valve seat 7 in which position it extends slightly above the plane of the working surface of support 1, thereby completely closing off the vacuum passageway from the surface opening and establishing a vacuum seal within that opening. When a sheet of material 8 is placed over a portion of the supporting device 1, the ball valve 6 will be forced to move out of its firm engagement with its valve seat 7, thereby breaking the vacuum seal over that portion of the passageway and accurately aligning and retaining the sheet of material in place for reproduction. The operator would then place additional sheets on the supporting device and in this manner make up the page of the newspaper or other publication which was to be reproduced. A photographic camera, not shown, would then be brought into position and photograph the page of the publication supported on the vacuum supporting device. In this manner, a completely integrated composing and photographing operation would be provided.

As shown in this-invention, the valve means provided in each of the surface openings comprises an extended, walled section formed in the opening. The valve means also contains a valve seat formed by the intersection of a tributary vacuum passageway 5 withthe supporting structure 1. This is shown on the drawing at numeral 7. This valveseat converges very slightly in the direction of the air flow created by the application of a vacuum to the openings through the passageway. Retained in this section is a ball valving member that moves along the lower surface of the section to and from a position of firm engagement with the wall of the supporting device in which position the surface opening would be completely closed off from the vacuum passageway and a complete vacuum seal would be established. Conversely, the ball valving member may move down this surface and out of firm engagement with the wall of the supporting device thereby establishing communication between the vacuum passageway and the surface opening and the sheet of material placed on this opening. When a portion of the supporting device which is. not being used, that is when no sheet of material is placed over the opening, the ballvalve will be retained in tight engagement with thesurface of the supporting device. When the valve is inthis closed position, it is effective to prevent the flow of air. through the passageway, thereby making it unnecessary for' the vacuum to do the unnecessary work that i would be required if the passage were left unrestricted.

Although this invention has been disclosed as being intended for usage primarily in the make up of pages of newspapers or other large scale publication-s, it is to be understood that the utility of this invention is not to be limited thereto. It is to be understood that the device and process of this invention will find application in the field of art Work, either in original or photo print form, and prescreened half-tone copy. The device andprocess of this invention may also find application as a film holder in photographic cameras, as a copyboard, a contacting frame, a silkscreen processing platen, or numerous other applications in the graphic arts field. This invention Will also have extensive utility in other fields for various holding functions where flat surfaces are to be handled and held in intimate contact with a supporting device.

-It is to be understood that many equivalent modifications will be apparent to those skilled in the art from a reading of the foregoing disclosure without a departure from the intended concept of the invention.

I claim:

1. In a support structure for sheets, films, and the like, the combination comprising a support plate having a plurality of individual openings distributed over its surface area, a passageway in direct communication with each of said openings through which a vacuum may be applied to retain a sheet in contact with said support plate, valve means positioned within each of said openings in communication with said passageway, said valve means comprising a ball member retained in each of said openings and a valve seat in said support structure at the intersection of said passageway with each of said openings, whereby said valve means will be firmly retained against said valve seat by the application of a vacuum, said valve seat being formed by the natural contour of the intersection of said opening and said passageway, said passageway comprising a first main passageway and a plurality of tributary passageways, each of said tributary passageways being in direct communication with one of said openings and valve means, and each of said tributary passageways positioned such that its center is less than the radius of said ball member from the working surface.

2. The combination of claim 1 wherein the first main passageway comprises a plurality of such passageways.

3. A support structure for sheets, films, and the like, comprising a plate for engaging .and supporting such sheets, films and the like having a plurality of individual openings distributed over its surface area against which such articles are engaged and supported, a passageway in direct communication with each of said openings through which a vacuum may be applied to retain a sheet in contact with said support plate, and valve means within each of said openings in communication with said passageway, said valve means comprising a ball valve member in each of said Openings and a valve seat in the support structure at the intersection of said passageway With each of said openings, said valve member functioning without any mechanical agency. other than the material being supported and the pneumatic force which is applied, the valve seats being formed by unbeveled intersections of said openings and said passageways.

4. The support structure of claim 3 in which the depth of said openings is approximately 10 to 25 percent greater than the diameter of said ball valve member.

5. The support structure of claim 3 in which the center of the passageway in immediate communication with each of said openings is less than the radius of the valve member from the working surface.

6. A support structure for sheets, films and the like comprising a support plate having a plurality of individual openings distributed over its surface area, a passageway in communication with each of said openings through which a vacuum may be applied to retain a sheet in contact with said support plate, and valve means within each of said openings in communication with said passageway, said valve means comprising a ball member in each of said openings and a valve seat in the support structure at the intersection of said passageway with each of said openings, the center of said passageway in immediate communication with each of said openings being less than the radius of said ball member from the working surface.

7. A support structure for sheets, films, and the like comprising a support plate having a plurality of individual openings distributed over its surface area, a passageway in direct communication with each of said openings through which a vacuum may be applied to retain a sheet in contact with said support plate, and valve means positioned with each of said openings in communication with said passageway, said valve means comprising a ball member retained in each of said openings and a valve seat in the support structure at the intersection of said passageway with each of said openings, said valve seat being formed by the natural contour of the intersection of said opening and said passageway, the depth of said openings being approximately 10 to 25 percent greater than the diameter of said ball valve member, and the center of said passageway in direct communication with each of said openings being less than the radius of said ball valve memher from the working surface.

References Cited by the Examiner UNITED STATES PATENTS 2,425,921 8/1947 Crockett 248--363 2,753,181 7/1956 Anander 248-363 X 2,910,265 10/1959 Anander 248-363 CLAUDE A, LE ROY, Primary Examiner.

Claims

1. IN A SUPPORT STRUCTURE FOR SHEETS, FILMS, AND THE LIKE, THE COMBINATION COMPRISING A SUPPORT PLATE HAVING A PLURALITY OF INDIVIDUAL OPENINGS DISTRIBUTED OVER ITS SURFACE AREA, A PASSAGEWAY IN DIRECT COMMUNICATION WITH EACH OF SAID OPENINGS THROUGH WHICH A VACUUM MAY BE APPLIED TO RETAIN A SHEET IN CONTACT WITH SAID SUPPORT PLATE, VALVE MEANS POSITIONED WITHIN EACH OF SAID OPENINGS IN COMMUNICATION WITH SAID PASSAGEWAY, SAID VALVE MEANS COMPRISING A BALL MEMBER RETAINED IN EACH OF SAID OPENINGS AND A VALVE SEAT IN SAID SUPPORT STRUCTURE AT THE INTERSECTION OF SAID PASSAGEWAY WITH EACH OF SAID OPENINGS, WHEREBY SAID VALVE MEANS WILL BE FIRMLY RETAINED AGAINST SAID VALVE SEAT BY THE APPLICATION OF A VACUUM, SAID VALVE SEAT BEING FORMED BY THE NATURAL CONTOUR OF THE INTERSECTION OF SAID OPENING AND SAID PASSAGEWAY, SAID PASSAGEWAY COMPRISING A FIRST MAIN PASSAGEWAY AND A PLURALITY OF TRIBUTARY PASSAGWAYS, EACH OF SAID TRIBUTARY PASSAGEWAYS BEING IN DIRECT COMMUNICATION WITH ONE OF SAID OPENINGS AND VALVE MEANS, AND EACH OF SAID TRIBUTARY PASSAGWAYS POSITIONED SUCH THAT ITS CENTER IS LESS THAN THE RADIUS OF SAID BALL MEMBER FROM THE WORKING SURFACE.