US3537371A

US3537371A - Processing apparatus having specially configured pressure applying members

Info

Publication number: US3537371A
Application number: US714690A
Authority: US
Inventors: Patrick L Finelli
Original assignee: Polaroid Corp
Current assignee: Polaroid Corp
Priority date: 1968-03-20
Filing date: 1968-03-20
Publication date: 1970-11-03
Anticipated expiration: 1987-11-03
Also published as: DE1914033A1; DE1914033C3; NL6904305A; FR2004334A1; DE1914033B2; GB1214113A

Description

United States Patent Inventor Patrick L. Flnelli Sudbury, Massachusetts Appl. No. 714,690

Filed March 20, 1968 Patented Nov. 3, I970 Assignee Polaroid Corporation Cambridge, Massachusetts in corporation of Delaware PROCESSING APPARATUS HAVING SPECIALLY CONFIGUREI) PRESSURE APPLYING MEMBERS 8 Claims, 5 Drawing Figs.

U.S.Cl

' 95/89 Int. Cl. G03d 3/00 95/13,

Field of Search Y 89/(lnquired) [56] References Cited .UNITED STATES PATENTS 2,845,850 8/1958 Bing et a1 95/13 2,854,904 10/1958 Bishop 95/13 Primary ExaminerNorton Ansher Assistant Examiner-Richard L. Moses Anomeys- Brown and Mikulka, William D. Roberson and Leonard S. Selman ABSTRACT: A pair of rigid spreader members, for use in a self-developing camera, having adjacent portions spaced apart and resiliently urged toward one another to form a pressuregene'rating gap through which photographic sheet materials are movable to effect the spreading of a processing fluid as a layer therebetween. The sheet contacting surface of each spreader member is provided with a convex curvature extending the length of the gap, the degree of curvature of one such surface being substantially greater than that of the other such surface.

CROSS REFERENCE TO RELATED APPLICATIONS The processing apparatus of the present invention is related to the subject matter disclosed in copending-U.S. Pat. applications Ser. No. 655,831 filed July 25, l967; Ser. No. 655,832 filed July 25, 1967; Ser. No. 655,833 filed July 25, 1967; Ser. No. 655,834 filed July 25, 1967; Ser. No. 655,835 filed July 25, 1967 now US. Pat. No. 3,498,196; and Ser. No. 687,183 filed Dec. 1, 1967, all assigned to the same assignee.

SUMMARY OF THE INVENTION The present invention is directed to a device whichmay be incorporated in a self-developing camera wherein'a photographic transfer image is produced by moving a pair of film sheets including an exposed negative photosensitive sheet and a superposed positive receiving sheet, between apair of juxtaposed pressure-applying members for distributing a processing liquid or developer between and in contact with the sheets which are later separated. The preferred embodiment of the invention as disclosed herein provides a narrow gap between a pair of spring-mounted sheet metal members through which the sheets are moved while the liquid introduced between the sheets is spread uniformly between and in contact with the entire facing surfaces of the sheets in a direction opposite the movement of the sheets relative to'the pressure-applying sheet metal members.

The spreader system which incorporates the present invention has many advanced features including its integral-precise construction resulting in important savings in cost of manufacture, its compactness and-lightweight and its removability for cleaning or repair from the photographic cameras designed for its use therewith. The preferred embodiment of the spreading apparatus more particularly includes a pair of sheet metal spreaders bent precisely to form a pair of small-radius edge means having a precisely defined gaptherebetween through which the sheets are pulled thereby rupturing a processing liquid-containing pod carried by the sheets andspreading the liquid between thesheets. The sheet metal spreader members are permanently joined to a pair of springs which serve the dual function of supporting the spreader members in exactly aligned juxtaposed relation to one another and further to urge said spreader members toward each other with just enough force to provide a uniform spread of processing liquid between the photographic sheets with as small a pull force as is feasible.

This invention is particularly related to the shape of the gapforming members and in particular their profile along the length of the gap. The shape of the gap is constantly changing as the film material is moved therethrough. In the initial stage the gap must be such that the film leader may be easily guided between the spreader members so that it extends outside the camera body in position to be grasped manually. During rupturing of the pod and cleaning out of the processing liquid therefrom as well as during the spreading of the processing liquid between the film sheets the gap configuration plays a critical role in providing a uniform spread of the processing liquid.

In the preferred embodiment of the invention the profiles of the sheet-contacting surfaces as determined along the length of the gap have a convex curvature and the degree of curvature or convexity is deliberately greater on the positive sheetcontacting surface than on the negative sheet-contacting surface. This curvature provides a gap configuration which appears slightly "pinched" in the middle. The spreader members forming the gap between them are supported at either end by spring members and those unsupported areas especially at the center experience a certain amount of deflection due to the forces thereon. These forces include the damming force of the processing fluid as it is spread between the film sheets after rupture of the pod as well as the forces due to spring load and friction on the spreading members. The convex curvature of the sheet-contacting surfaces prevent the deflection of the surfaces from widening the gap more than a predetermined amount across the length of the gap. The curvature of the sheet-contacting surfaces, however, are actually greater than that required for deflection compensation alone. For best results the surface contacting the positive sheet which is relatively thicker and stiffer than the negative sheet should have a slightly greater degree of convexity than does the sheet-contacting surface contacting the thinner, more flexible negative sheet.

The convex curvatures of the sheet-contacting surfaces improve the completeness of coverage of the actualpicture area of the film sheets by the processing fluid. They also contribute to the uniformity of the thicknessof the processing fluid layer. For example, if eithersheet-contacting surface were initially flat or concave, the deflection of the surface during the spreading operation would result in an excess of processing fluid flowing to the widened part of the gap. This may cause a mottling in the final print or even failure of the fluid to completely cover the picture area since the amount of processing fluid is limited. The convex curvatures of the sheetcontacting surfaces, especially atthe ends of the gap, also relieve and control certain damming forces acting on the fluid due to the effective sealing of the longitudinal edges of the film sheet to prevent fluid leakage as the film sheets are moved through the gap between the spreader members.

Accordingly, it is an object of this invention to provide photographic apparatus having an improved liquid-distributing device in position to spread a processing liquid in a uniform layer ofpredetermined thickness between a pair of photographic sheets. I

It is another object of this invention to provide improved liquid-distributing photographic apparatus including apair of juxtaposed pressure-applying nonrolling spreader members having a gap therebetween through which a pair of photographic sheets are movable while processing liquid is spread therebetween, the pressure-applying members on either side of said gap each having convex curvatures extending substantially the entire length of said gap and cooperating with the respective photographic sheet contacted by each to provide improved spreading performance.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the apparatus possessing the construction, combination of elements and arrangement of parts which are exemplified in the following detailed disclosure, and the scope of the application of which will be indicated in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of a camera having mounted within and shown in cross section,'the liquid-distributing processing apparatus of the preferred embodiment of the invention including the spring-mounted sheet metal spreader members having a gap therebetween through which the photographic sheet may'be drawn. 1

FIG. 2 is a perspective view of the processing apparatus shown removed from a camera.

FIG. 3 is an enlarged front view of the processing apparatus showing the gap between the spreader members and the configuration of the sheet-contacting surfaces of the spreader members along the length of the gap.

FIGS. 4 and 5 are fragmentary cross-sectional views along lines 4-4 of FIG. 2 showing the respective sheet-contacting surfaces of the spreader.

DESCRIPTION OF THE PREFERRED EMBODIMENT The photographic apparatus of the present invention including the processing liquid spreader has many advantages including removability of the spreader from the camera for easy cleaning, repair or replacement as well as economy of manufacture. This invention is directed, however, to the spreading function and in particular with the configuration or profile of the sheet-contacting surfaces as measured along the length of. the gap between spreader members as described in the following detailed description.

FIG. 1 shows the spreader apparatus 10 mounted in operable position inside a photographic camera. The film sheets as shown in FIG. 1 are in processing position ready to be removed from the camera. U.S. Pat. No. 2,991,702 shows a plurality of such film sheets stacked in a film pack as they are 'used in many of the present day self-developing cameras. ln

picture-taking position, the negative sheet 12 with its photosensitive surface faces the open front of the film pack and the taking lens and then is pulled around and on top of the positive sheet 14 by tab 16 as shown in FIGS. 1 and 2 in superposed position ready for processing. Tab 16 pulls the leader 18 through the gap between the sheet

metal spreader members

20 and 22 which are supported and biased toward one another by

spring members

24 and 26. The leader 18 is then manually grasped and the photographic material including the negative I sheet 12 and the positive sheet 14 and the processing liquidcontaining pod 28 is pulled through the gap whereby the pod is broken and the processing liquid 30 is uniformly spread between the positive and negative sheets.

FIG. 2 is a detailed perspective view of the processing apparatus removed from the camera illustrating features of the apparatus which are the subject of the aforementioned applications, including the spring separating means 32, the spring restraining means 34, the platform relief 36 and the edge control means 38.

FIG. 3 is a front view of the preferred embodiment of the spreading apparatus showing in an exaggerated manner, for purposes of clarity, the curvature of the sheet-contacting

surfaces

40, 42 of the

rigid spreader members

20 and 22. To initially provide a gap between the pair of rigid spreader members so that the film leader 18 may be manually pulled through the gap by means of tab 16, a pair of raised surfaces 44 and 46 are provided on spreader member 20 at both ends of the gap. The sheet-contacting surface 40 of spreader member 20, which contacts the stiffer positive sheet 14 as shown in FIG. 4, is shown as having a greater degree or radius of convex curvature than that of the curved sheet-contacting surface 42 on member 22 which contacts the more flexible negative sheet 12. This points up an important aspect of the invention; the degree of convexity of each curved sheet-contacting surface is significantly related to the flexibility of the sheet that it actually contacts. Thus, the surface contacting the stiffer positive sheet is made to have the specific contour to most effectively react in conjunction with that particular sheet to control and direct the flow of processing liquid which is to be spread between the film sheets as the sheets are forceably drawn between the gap-forming members. It is important to note that even seemingly minute changes in the shape of the sheet-contacting surfaces can easily make the difference between acceptable and on nonacceptable spread control. Thus making provision for the flexibility for the particular sheet contacted by making these slight changes in degree of convexity can and does remarkably effect the performance of the spread system. In the preferred embodiment, as shown in FIG. 3, the end-toend contour of each sheet-contacting surface constitutes a circular arc symmetrical about center line C.

FIG. 4 shows the film material including the processing liquid-containing pod 28 and the positive and

negative sheets

14 and 12 in position to be moved between the

spreader members

20 and 22. FIG. shows the film after the pod 28 has been ruptured and the liquid 30 is being spread between the thicker, less flexible positive sheet 14 and the thinner, more flexible negative sheet 12 by the positive sheet-contacting surface 40 and the negative sheet-contacting surface 42 on the respective spreader members.

The convex curvature of

surfaces

40 and 42 may constitute a circular arc, as previously described, but is not limited thereto and may also comprise other curves and may even change slightly in degree of curvature along the length of the An example of a specific embodiment of the invention as described above has a pair of sheet-contacting surfaces of 9.23 cm. in length with the center points of the positive and negative sheet-contacting surfaces extending .0 l 75 mm. and .0125 mm. into the gap, respectively, (as measured from an imaginary flat sheet-contacting surface) and a spring load of 2.8 lbs. per side on the spreader members.

The preferred embodiment as described above is directed toward use with certain film sheet materials having predetermined thicknesses and flexibility. Other film materials which may have positive and negative sheets differing in these pro perties may require greater or less curvature of the sheet-contacting surfaces forming the gap between the spreader members. However, in all cases it has been found that the convex curvature of both of said surfaces is required to control the flow of the processing fluid.

Thus the improved configuration of the sheet-contacting surfaces provide in a simple structure a means which greatly and to an unexpected extent improves performance in all stages of the movement of the film sheets through the gap and especially in the uniform spreading of the processing fluid between the positive and negative sheets.

Since certain changes may he made in the above device without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

lclaim:

l. Photographic apparatus for distributing a liquid in a layer between two layers of photographic sheet material, said apparatus comprising:

a pair of substantially rigid'members having adjacent portions predeterminedly spaced apart to form a narrow pressure-generating gap through which said sheet material is movable, a sheet-contacting surface on each of said rigid members located at said narrow gap and extending coextensively the length of said gap, said sheet-contacting surfaces each having a convex curvature extending substantially the entire length of said gap, the degree of curvature of one of said sheet-contacting surfaces being greater than the degree of curvature of the other of said sheet-contacting surfaces; and

means for urging said members toward one another in a manner to effect the spreading of said liquid in a layer between the sheets of said photographic material during movement of said material through said gap.

2. Photographic apparatus for distributing a processing liquid in a layer between two layers of photographic sheet material, said apparatus comprising:

a pair substantially rigid nonrolling members having adjacent portions predeterminedly spaced apart to form a narrow pressure-generating gap through which said sheet material is movable, and a pair of facing surfaces on said members converging angularly toward each other to define a narrow throat to guide said sheet material toward said narrow gap, a sheet-contacting surface on each of said rigid members located at said narrow gap and extending coextensively the length of said gap, said sheetcontacting surfaces each having a convex curvature extending substantially the entire length of said gap, the degree of curvature of one of said sheet-contacting surfaces being greater than the degree of curvature of the other of said sheet-contacting surfaces; and

means for urging said members toward one another in a manner to effect the spreading of said liquid in a layer between the sheetsof said photographic material during movement of said material through said gap. v

3. Photographic apparatus for distributing a liquid in a layer between two layers of photographic sheet material, said apsaid rigid members located at said narrow gap and extending coextensively the length of said gap, said sheetcontacting surfaces each forming a convex circular arc extending substantially the entire length of said gap, the radius of curvature of one of said sheet-contacting surfaces being greater than the radius of curvature of the other of said sheet-contacting surfaces; and

means for urging said members toward one another in a manner to effect the spreading of saidliquid in a layer between the sheets of said photographic material during movement of said material through said gap.

4. Photographic apparatus for distributing a processing liquid in a layer between two layers of photographic sheet material, one of said layers comprising a relatively flexible sheet and the other of said layers comprising a relatively stiff sheet, the liquid being dispensed ina measured quantity and spread between the sheets, said apparatus comprising:

a pair of substantially rigid members having adjacent portions predeterminedly spaced apart to form a narrow pressure-generating gap through which said sheet material is movable, sheet-contacting surfaces on each of said rigid members located at said narrow gap and each of said sheet-contracting surfaces having a convex curvature extending substantially the entire length of said gap, the degree of convexity of said sheet-contacting surface contacting said relatively stiff sheet of photographic material being greater than the degree of convexity of said sheetcontacting surface contacting said relatively flexible sheet of photographic material; and

means for supporting and aligning said members in juxtaposed relation to one another so that said gap is formed between them and for urging said members toward one another so that asvtlie photographic sheets are moved through said gap the processing fluid is spread in a uniform layer between said sheets.

5. Photographic apparatus for distributing a processing liquid in a layer between two layers of photographic sheet material, one of said layers comprising a thin relatively flexible negative sheet and the other of said layers comprising a less flexible positive sheet, the liquid being dispensed in a measured quantity and spread between the sheets, said apparatus comprising:

a pair of substantially rigid members having adjacent portions predeterminedly spaced apart to form a narrow pressure-generating gap through which said sheet-material is movable, and a pair of facing surfaces on said members converging angularly toward each other to define a narrow throat to guide sheet material toward said narrow gap, a positive sheet-contacting surface on one of said rigid members located at said narrow gap and a negative sheet-contacting surface on the other of said rigid members at said gap, said positive and negative sheet-contacting surfaces each having a convex curvature extending substantially the entire length of said gap and the degree of curvature of said positive sheet-contacting surface being greater than the degree of curvature of said negative sheet-contacting surface; and

means for supporting and aligning said members in juxtaposed relation to one another so that said gap is formed between them and for urging said members toward one another so that as the photographic sheets are moved through said gap the processing fluid is spread in a uniform layer between said sheets.

6. Photographic apparatus for distributing a processing liquid in a layer between two layers of photographic sheet material, one of said layers comprising a relatively flexible negative sheet and the other of said layers comprising a relatively stiff positive sheet, the liquid being dispensed in a measured quantity and spread between the sheets, said apparatus comprising:

.a pair of substantially rigid members having adjacent portions predeterminedly spaced apart to form a narrow pressure-generating gap through which said sheet material Is movable, and a pair of facing surfaces on said members converging angularly toward each other to define a narrow throat to guide sheet material toward said narrow gap, a positive sheet-contacting surface on one of said I rigid members located at said narrow gap and a negative sheet-contacting surface on the other of said rigid members at said gap, said positive and negative sheet-contacting surfaces each forming a convex circular are extending substantially the entire length of said gap, the radius of curvature of said positive sheet-contacting surface being greater than the radius of curvature of said negative sheet-contacting surfaces;and

means for supporting and aligning said members in juxtaposed relation to one another so that said gap is formed between them and for urging said members toward one another so that as'the photographic sheets are moved through said gap the processing fluid is spread in a uniform layer between said sheets.

7. Photographic apparatus for distributing a processing liquid in a layer between two layers of photographic sheet material, one of said layers comprising a thin relatively flexible negative sheet and the other of said layers comprising a less flexible positive sheet, a processing liquid-containing pod carried by one of said sheets in advance of said positive sheet and adapted to be ruptured by said apparatus and the liquid spread between the sheets, said apparatus comprising:

a pair of substantially rigid nonrolling members having adjacent portions predeterminedly spaced apart to form a narrow pressure-generating gap through which said sheet material is movable, and a pair of facing surfaces on said members converging angularly toward each other to define a narrow throat to guide sheet material toward said narrow gap, a positive sheet-contacting surface on one of said rigid members located at said narrow gap and a negative sheet-contacting surface on the other of said rigid members at said gap, said positive and'negative sheetcontacting surfaces each having a convex curvature extending substantially the entire length of said gap and the degree of curvature of said positive sheet-contacting surface being greater than the degree of curvature of said negative sheet-contacting surface; and

a pair of spring means fastened to at least one of said rigid members at respectively opposite ends of said narrow gap for supporting and aligning said members in juxtaposed relation to one another so that said gap is formed between them and for urging said members toward one another so that as the photographic sheets are moved through said gap the processing fluid is spread in a uniform layer between said sheets.

8. Photographic apparatus for distributing a processing fluid in a layer between two layers of sheet material, said apparatus comprising:

a pair of substantially rigid members having adjacent portions predeterminedly spaced apart to form a narrow pressure-generating gap through which said sheet material is movable, a sheet-contacting surface on each of said rigid members located at said narrow gap and extending coextensively the length of said gap, each of said sheetcontacting surfaces having a convex curvature extending substantially the entire length of said gap, the degree of curvature of one of said sheet-contacting surfaces being greater than the degree of curvature of the other of said sheet-contacting surfaces; and

means for urging said members toward one another in a manner to effect the spreading of said liquid in a layer between said layers of sheet material during movement of said material through said gap.