Apparatus for production of photographic elements

Claim 2

Apparatus for coating a layer of liquid photographic coating composition on a continuous web in the manufacture of a photograhic element, said apparatus comprising: a coating hopper having a cavity for holding said coating composition and a narrow elongated horizontally-disposed discharge slot communicating with said cavity for discharging a substantially uniform thin layer of said coating composition, means defining a continuous inclined slide surface which adjoins said slot and is disposed to receive on the upper surface thereof the coating composition discharged from said slot and which extends downwardly to a lip; whereby the coating composition discharged from said slot flows by gravIty down said slide surface, where it is distributed by the action of gravity to provide exact thickness uniformity across the flowing layer, and over said lip to form a vertical freefalling curtain of coating composition having exact thickness uniformity, guide means defining edge guide surfaces adjacent each edge of the path of said free-falling curtain for engaging the edges of said curtain to establish the curtain width, said guide means comprising a pair of rods each vertically mounted with the upper end adjacent said lip and the lower end terminating above the plane along which said web is moved and resilient extensions on the lower end of each rod for engaging said web, means for moving said web along a predetermined path spaced below and transversely of said lip to intercept the freefalling curtain and form on said web a layer of said coating composition, and shield means depending downwardly from said coating hopper upstream of said free-falling curtain and extending to a position above but closely adjacent the plane along which said web is moved, for protecting said free-falling curtain from air currents and reducing the resistance of the barrier layer of air on the moving web to penetration by said free-falling curtain.

Claim 3

Apparatus as described in claim 1 additionally comprising means for varying the speed at which said web is moved.

Claim 4

Apparatus as described in claim 1 additionally comprising means for varying the vertical spacing between said lip and said web.

Claim 5

Apparatus as described in claim 1 additionally comprising means for rigidly supporting said web as it passes beneath said lip.

Claim 6

Apparatus as described in claim 1 additionally comprising a vacuum manifold operatively connected to said shield means for drawing air from the surface of said web.

Claim 7

Apparatus as described in claim 1 additionally comprising deflector means mounted to move between a position where it extends across the path of said free-falling curtain above the path of said web and a position where it is outside the path of said free-falling curtain.

Claim 8

Apparatus as described in claim 6 additionally comprising liquid receiving means positioned to receive coating composition deflected into it by said deflector means.

Claim 9

Apparatus for coating a layer of liquid photographic coating composition on a continuous web in the manufacture of a photographic element, said apparatus comprising: a coating hopper having a cavity for holding said coating composition and a narrow elongated horizontally-disposed discharge slot communicating with said cavity for discharging a substantially uniformly thin layer of said coating composition, means defining a continuous inclined slide surface which adjoins said slot and is disposed to receive on the upper surface thereof the coating composition discharged from said slot and which extends downwardly to a lip; whereby the coating composition discharged from said slot flows by gravity down said slide surface, where it is distributed by the action of gravity to provide exact thickness uniformity across the flowing layer, and over said lip to form a vertical free-falling curtain of coating composition having exact thickness uniformity, guide means defining edge guide surfaces adjacent each edge of the path of said free-falling curtain for engaging the edges of said curtain to establish the curtain width, said guide means comprising a pair of rods each vertically mounted with the upper end adjacent said lip and the lower end terminating above the plane along with said web is moved and resilient extensions on the lower end of each rod for engaging said web, means for moving said web along a predetermined path spaced below and transversely of said lip to intercept the free-falling curtain and form on said web a layer of said coating composition, means for varying the speed at which said web is moved, means for rigidly supporting said web as it passes beneath said lip, means for varying the vertical spacinG between said lip and said web, and shield means depending downwardly from said coating hopper upstream of said free-falling curtain and extending to a position above but closely adjacent the plane along which said web is moved, for protecting said free-falling curtain from air currents and reducing the resistance of the barrier layer of air on the moving web to penetration by said free-falling curtain.

Claim 10

Apparatus for coating a layer of liquid photographic coating composition on a continuous web in the manufacture of a photographic element, said apparatus comprising: a coating hopper having a cavity for holding said coating composition and a narrow elongated horizontally-disposed discharge slot communicating with said cavity for discharging a substantially uniformly thin layer of said coating composition, means defining a continuous inclined slide surface which adjoins said slot and is disposed to receive on the upper surface thereof the coating composition discharged from said slot and which extends downwardly to a lip; whereby the coating composition discharged from said slot flows by gravity down said slide surface, where it is distributed by the action of gravity to provide exact thickness uniformity across the flowing layer, and over said lip to form a vertical free-falling curtain of coating composition having exact thickness uniformity, guide means defining edge guide surfaces adjacent each edge of the path of said free-falling curtain for engaging the edges of said curtain to establish the curtain width, said guide means comprising a pair of rods each vertically mounted with the upper end adjacent said lip and the lower end terminating above the plane along with said web is moved and resilient extensions on the lower end of each rod for engaging said web, means for moving said web along a predetermined path spaced below and transversely of said lip to intercept the free-falling curtain and form on said web a layer of said coating composition, means for varying the speed at which said web is moved, means for rigidly supporting said web as it passes beneath said lip, means for varying the vertical spacinG between said lip and said web, and shield means depending downwardly from said coating hopper upstream of said free-falling curtain and extending to a position above but closely adjacent the plane along which said web is moved, for protecting said free-falling curtain from air currents and reducing the resistance of the barrier layer of air on the moving web to penetration by said free-falling curtain.