US3545860A

US3545860A - Zone control valve for vacuum film holder

Info

Publication number: US3545860A
Application number: US744891A
Authority: US
Inventors: Loren W Hutchins
Original assignee: DOUTHITT CORP
Current assignee: DOUTHITT CORP
Priority date: 1968-07-15
Filing date: 1968-07-15
Publication date: 1970-12-08
Anticipated expiration: 1987-12-08

Description

Dec. 8, 1970 1.. w. HUTCHINS ZONE CONTROL VALVE FOR VACUUM FILM HOLDER 2 Sheets-Sheet 1 Filed July 15, 1968 \\\l I I mwwx r02 IIIMII 5 lNVENTOR LOREN W- HUTCHINS BY q $71M,

ATTORNEYS De. 8, 1970 L. w. HUTCHINS 3,545,350

ZONE CONTROL VALVE FOR VACUUM FILM HOLDER Filed July 15, 1968 2 Sheets-Sheet 3 (D INVENTOR I LOREN W. HUTCHINS 4%, JAM, @M

ATTORNEYS United States Patent 3,545,860 ZONE CONTROL VALVE FOR VACUUM FILM HOLDER Loren W. Hutchins, Detroit, Mich., assignor to Douthitt Corporation, Detroit, Mich. Filed July 15, 1968, Ser. No. 744,891 Int. Cl. G03b 27/20 US. Cl. 355-91 4 Claims ABSTRACT OF THE DISCLOSURE An open face vacuum film holder having a'vacuum source and a vacuum board which includes a pan and a series of partitions therein defining a plurality of concentric vacuum chambers, each having a vacuum inlet. A rigid porous sheet is sealed over said pan and partition to define a series of independent vacuum zones. A slide valve is provided under and bearing against the pan, has an inlet connected to the vacuum source and a stepped zone control chamber. Manually controlled movement of the valve selectively connects the vacuum source with one or a plurality of said zones successively. Heretofore in vacuum holders of this nature, a photosensitive unexposed film of a predetermined dimension is centrally applied to the open face vacuum board being correctly located for its dimension. There is directly applied to the said film a positive or a negative print and wherein by the use of the vacuum bed both are pulled flat against each other and fiat against the bed during the exposure process using a high intensity lamp for a short predetermined period.

In holders of this type, the print may be of a small size as for example 4 x 5 inches, 5 x 7 inches or 8 x 10 inches, or may be larger in the range of 14 X 17 inches, 20 x 24 inches or 32 x 32 inches.

It is an object of the present invention to provide an open face vacuum film holder which has within its vacuum board a series of concentric rectangular zones selectively connected to a vacuum source so that if a small size print is employed, the entire vacuum communication is directed to that zone and wherein valve means are provided by which for increasingly larger prints additional concentric vacuum zones may be activated so that the full vacuum strength is directed only to those zones over which the print lies for the exposure process.

It is another object of the present invention to provide a novel slide valve construction manually operable by which the total vacuum source directs full vacuum to the areas or zones employed during the printing process, but wherein means are provided whereby zones exterior to the boundaries of the print during printing cut off from a vacuum source which would otherwise be open to the atmosphere.

It is a further object to provide a novel form of slide valve control for regulating the delivery of vacuum from the vacuum source of the printer selectively to the zone or adjacent zones over which the print is centrally located to thus provide for the best utilization of the vacuum source, and wherein a very small powered pump may be utilized regardless of the zones selected.

DETAILED DESCRIPTION An illustrative embodiment of the invention is disclosed in the attached drawings in which FIG. 1 is a front elevational view of the present open face vacuum film holder.

FIG. 2 is a plan view on an increased scale and partly broken away for illustration.

3,545,860 Patented Dec. 8, 1970 "ice- FIG. 3 is a section taken in the direction of arrows 3-3 of FIG. 2.

FIG. 4 is a section taken in the direction of arrows 4-4 of FIG. 2; and,

FIG. 5 is a fragmentary section taken in the direction of arrows 5-5 of FIG. 2.

Referring to the drawing, the present open face film holder 11 includes housing 12 with legs 13 and incorporating a shelf 14 and front panel 15 mounting the off and on switch 16 for interconnecting power source 17 with vacuum pump 18 mounted upon shelf 14.

A vacuum board 19 overlies and is coextensive with the top of housing 12 and includes upon its undersurface the adjustable zone control slide valve 20 having a vacuum inlet fitting 21 and attached thereto the flexible hose 22 which connects the vacuum pump or other vacuum source.

The vacuum board includes a preferably metallic pan 23 which includes a peripheral upright side wall and a pan bottom, FIG. 3.

A series of continuous

upright partitions

24, 25 and 26 mounted within said pan are coextensive with its side wall and thus define with said pan a plurality of concentric preferably rectangular vacuum chambers A, B, C and D, FIG. 2.

Applied to the side wall of the pan 23, as well as the top edge of the

partition

24, 25 and 26, is a continuous strip of sponge rubber 27 which has adhesive on its opposite sides in order to adhere to the pans side wall and partitions and at the same time compressively and cooperatively and sealingly engage the undersurface of the rigid porous sheet or strip 28. In the illustrative embodiment of the present device, the sheet is constructed of a sintered Steel and is porous throughout.

Applied to the top surface of the said porous sheet 28 and correctly centered, are suitable indicia 29, FIG. 2, which correspondingly define the respective corners and location points for film and prints depending on their sizes and corresponding respectively to the outer boundaries of the respective chambers B, C and D to thus assist in correct location of the film and print over the vacuum board for an exposure process.

Within the bottom wall of pan 23 are a series of vacuum inlets 30 arranged in a row, FIG. 2, which communicate respectively with each of the vacuum zones or chambers A, B, C and D.

By the present construction, the porous sheet which is coextensive with the top surface of the pan thus defines with the pans side wall and the said chambers, a series of independent vacuum zones A, B, C and D.

The present slide valve or zone control valve generally indicated at 20 includes a generally rectangular valve body 31 having a Teflon top sheet 32 and a metallic bottom plate 33. The body includes upon its interior stepped zone control chamber 34, which is adapted for cooperative registry selectively with one or more of the vacuum inlets 30 upon the undersurface of the pan 23.

The said slide control valve is slidably mounted upon the undersurface of the said pan with the Teflon top plate of the valve body sealingly and slidably engaging with reduced friction the undersurface of said pan bottom.

As viewed in FIG. 2, the zone control chamber has a series of steps by which it is seen in the position of the valve body shown in FIG. 2, that the control chamber is in communication only with the vacuum inlet 30 registering with vacuum chamber D. It is seen furthermore that should the valve body be moved from its present position rearwardly a short distance, an additional vacuum inlet to chamber C would be in communication with the valve control chamber 34. Further, longitudinal adjustment of the valve body in the same direction exposes in addition to the first mentioned two inlets 30 the additional inlet 30 which communicates with vacuum zone B. Furthermore, on further longitudinal adjustment in the same direction of the valve body the fourth vacuum inlet 39 in the pan would be in communication with the zone control chamber to thus establish vacuum communication to all of the vacuum chambers A, B, C and D. This would be a situation where the largest size negative or print is employed which is substantially coextensive with the outer boundaries of the vacuum bed 28.

The slide mounting of the vacuum control valve upon the undersurface of pan 23 includes a pair of opposed spaced Z-shaped channels, guides 35, FIG. 4, upon which the slide valve is movably mounted for transverse adjustment as shown in FIG. 2.

For this purpose, the link 36 is pivotally connected at one end to the valve body at 37 and at its opposite end is pivotally connected as at 40 to the free end of the selector control arm 38.

The latter arm is pivotally mounted upon the undersurface of the pan as at 39 with its free end, FIG. 2, projecting through control plate 41 which is suitably slotted and notched as at 42 to thereby determine the angular adjustments of the selector arm 38 from the position shown in FIG. 2 to the extreme dotted line position shown therein, and wherein vacuum communication would be established to all of the zones A, B, C and D.

It is noted that the slot formed within the control plate 41 isof such length as to limit the angular movements of the selector arm 38 and also to predetermine the four locations thereof which correspond to the respective zones A, B, C and D to which it is desired that vacuum be directed.

In use, if the negative and print involved is of a dimension of a smaller nature such as 4 x 5 inches, 5 x 7 or 8 x 10 inches, then the same is located with respect to the indicia 29 so as to overlie only the vacuum zone D. In the position of the slide valve in FIG. 2, only that zone is in full communication with the vacuum source.

Should the next size print be employed such as 14 x 17 inches, then it is necessary to adjust the selector arm 38 to register with the first notch 42. This would cause a corresponding sliding movement of the valve 20 so as to expose the second vacuum inlet to the vacuum control chamber 34.

The valve body 20 upon its undersurface has secured thereto the inlet fitting 21 which is suitably connected to the vacuum source by flexible conduit 22, FIG. 1.

For a larger print such as the size 20 x 24 inches, then it is necessary that the selector arm 38 be moved further along the slot within the plate 41 to the second notch. At this location, the slide valve 20 would be so moved that vacuum communication is now established to all three of the chambers D, C and B, etc.

Having described my invention, reference should now be had to the following claims.

I claim:

1. In an open face vacuum film holder;

a housing mounting a vacuum source;

a horizontally disposed vacuum board on said housing including a pan having a bottom and a peripheral wall;

a series of continuous upright partitions within said pan coextensive with said wall and defining with said pan a plurality of concentric rectangular vacuum chambers;

there being a series of spaced inlets in said pan bottom and communicating with said chambers respectively;

a rigid porous sheet coextensive with and overlying said pan in sealing registry with the pan wall and said partitions separating said chambers into a series of independent vacuum zones;

a slide valve on the exterior of and bearing against the pan bottom and guidably mounted thereunder for reciprocal movements in a direction at right angles to said row of inlets;

said valve including an apertured body having a top wall and a bottom wall with a vacuum fitting, said body having a portion with a series of longitudinal steps defining in said body a stepped zone control chamber, adapted on adjustment for establishing communication of vacuum from said chamber progressively with said inlets;

a conduit interconnecting said fitting and said vacuum source;

and a selector arm intermediate its ends pivotally mounted upon said pan, at one end pivotally connected to said valve and at its other end projecting laterally of said pan for manual movements for establishing full vacuum communication to one vacuum zone and successively to additional vacuum zones as required depending upon the size of the negative to be printed.

2. In the film holder of claim 1, said body including a metal bottom wall mounting said vacuum inlet fitting, and a Teflon top wall sealingly engaging said pan.

3. In the film holder of claim 1, the connection of said selector arm and valve including a link;

and an apertured arm support at one edge of and depending from said pan guidably receiving said selector arm, and including a plurality of spaced arm control notches.

4. In the film holder of claim 1, a series of concentric printing sheet locating indicia of rectanugular shape applied to said porous sheet, corresponding to and in registry with each of said vacuum zones respectively.

References Cited UNITED STATES PATENTS 2,799,205 7/1957 Bacsik 35576 2,895,706 7/1959 Blatherwick 35573X 2,905,428 9/1959 Ribesehl et al. 35573X 3,222,051 12/1965 Bevilacqua et al. 35576X 3,229,953 l/l966 Muir 35573X JOHN M. HORAN, Primary Examiner R. L. MOSES, Assistant Examiner US. (:1. X.R. $-73, 7