US3609875A - Dryer for processed photographic paper and method of transporting paper therethrough - Google Patents

Abstract

THE INVENTION DISCLOSED HEREIN RELATES TO A DRYER FOR PROCESSED PHOTOGRAPHIC PAPER AND PARTICULARLY TO A DRYER HAVING A WARM AIR CIRCULATING SYSTEM WHICH INCLUDES A HOLLOW UPSTANDING VACUUM STACK OVER WHICH THE PAPER TO BE DRIED TRAVELS (UP ONE SIDE AND DOWN THE OTHER) AND INTO WHICH THE DRYING AIR IS DRAWN BY THE INTAKE OF A CIRCULATING BLOWER, THE STACK BEING PROVIDED WITH A PLURALITY OF VENT OPENINGS AND PAPER ENGAGING SPACER AND RETARDING ELEMENTS TO KEEP THE PAPER SPACED FROM SAID VENTS, THE VENT OPENINGS BEING DESIGNED SO THAT THE VELOCITY OF THE AIR TRAVELING INTO THE STACK IS GREATER THAN THE VELOCITY OF THE MOVING AIR OUTSIDE THE STACK TO HOLD THE PAPER AGAINST THE SPACER ELEMENTS AND FRICTIONALLY RETARD THE FREE END OF THE WEB AT THE END OF EACH ROLL OF PAPER TO POSITIVELY PREVENT SAID FREE END FROM FALLING AWAY FROM THE STACK AS IT DESCENDS ON THE DOWN SIDE THEREOF.

Description

Oct. 5, 1971 c RElD 3,609,815

DRYER FOR PROCESSED PHOTOGRAPHIG PAPER AND METHOD OF TRANSPORTING PAPER THERETHROUGH Filed June 6, 1969 [WWW M A lrroklwv United States Patent Ghee DRYER FOR PROCESSED PHOTOGRAPHIC PAPER AND METHOD OF TRANSPORTING PAPER THERETHROUGH Norman C. Reid, Minneapolis, Minn, assignor to Pako Corporation, Minneapolis, Minn. Filed June 6, 1969, Ser. No. 831,017 Int. Cl. F26!) 13/06 US. Cl. 34-159 4 Claims ABSTRACT OF THE DISCLOSURE The invention disclosed herein relates to a dryer for processed photographic paper and particularly to a dryer having a warm air circulating system which includes a hollow upstanding vacuum stack over which the paper to be dried travels (up one side and down the other) and into which the drying air is drawn by the intake of a circulating blower, the stack being provided with a plurality of vent openings and paper engaging spacer and retarding elements to keep the paper spaced from said vents, the vent openings being designed so that the velocity of the air traveling into the stack is greater than the velocity of the moving air outside the stack to hold the paper against the spacer elements and frictionally retard the free end of the web at the end of each roll of paper to positively prevent said free end from falling away from the stack as it descends on the down side thereof.

It is an object of the present invention to provide a dryer for processed photographic paper which is specifically designed to maintain feeding and driving control over the entire length of the paper web including the free end at the end of each roll thereof.

It is another object to provide a vacuum stack within a dryer for processed photographic paper which is designed to hold the paper against spacing and retarding elements by means of a vacuum effect produced by the drying air as it is circulated through the vacuum stack into the intake of the circulating blower.

These and other objects and advantages of this invention will be apparent from the following description made in connection with the accompanying drawing wherein like reference characters refer to similar parts throughout the several views, and in which:

FIG. 1 is a vertical sectional view of a dryer embodying my invention; and,

FIG. 2 is a fragmentary horizontal section taken substantially along the line 22 of FIG. 1.

A dryer is illustrated in the accompanying drawing which is adapted to dry a web of photographic print paper 4 after the same is processed through the various processing solutions. The dryer includes a housing 5 with a paper inlet opening 5a and discharge opening 5b. A stack unit 6 is mounted inside the dryer housing 5 and is provided with a plurality of horizontally spaced apart rows of vertically spaced intake vents each having an outwardly extending louver 7. A transport belt 8 travels in the unobstructed area between the horizontally spaced rows of louvers. A circulation blower 9 is mounted in the bottom of the housing 5 with its intake 9a in communication with the stack 6. The discharge from the blower passes over a heating element 10 and is circulated upwardly within the housing 5 in contact with the paper being dried. Each of the stack openings adjacent the louvers permits air to be drawn into the stack to provide the sole means for supplying the intake of the blower 9. A pair of driven rollers 11 and 12 operating at the same speed are respectively provided at the intake and discharge openings 5a and 5b. These rollers are meshed with the perforated transport belt 8 in a manner similar to that disclosed in 3,509,875 Patented Got. 5,, 1971 my copending application filed of even date herewith and entitled Method and Apparatus for Processing Photographic Prints. Idler rollers 13, 14 and 15 guide the paper 4 and the belt 8 around the stack 6 as illustrated and a belt receiving groove is provided at the center portion of the upper roller 14 to receive the belt and permit contact between the paper and said roller.

As the air passes into the stack through the restricted openings behind each of the louvers 7 the velocity is increased from the velocity of the air being blown upwardly around the stack 6 within the housing 5. This higher velocity produced on the air passing through the louvers and downwardly within the stack 6 reduces the pressure on the back side of the paper causing the paper to be attracted toward the stack and held in engagement with the outer edges of the louvers 7. This vacuum attraction against the edges of the louvers provides sufficient resistance to the paper to maintain control of the free end of each paper roll being processed as it descends on the down side of the stack and prevents this trailing free end from falling away from the stack which could damage the paper. A pair of vent openings 16 are provided at the top of the housing 5 to permit a portion of the hot moisture-filled air to escape. This air is also released from the housing through the discharge opening 5b.

It will, of course, be understood that various changes may be made in the form, details, arrangement and proportion of the parts without departing from the scope of the invention, which generally stated, consists in the matter set forth in the accompanying claims.

What is claimed is:

1. A dryer for separate strips of web material comprising:

a housing having a web inlet opening and a web discharging opening,

a hollow upstanding stack unit mounted within said housing and having a plurality of spaced apart vent openings, and a plurality of web-engaging portions,

means for guiding the web through a fastooned path within said housing and around said stack unit, and

means for drawing air into said stack unit through said vent openings to produce a vacuum effect and hold said web against said web-engaging portions to prevent the trailing of each web strip from falling out of said festooned path within said housing as it travels therethrough.

2. The structure set forth in claim 1 and said webengaging portions comprising means extending outwardly from said stack unit between the surface thereof and the web material for maintaining a spaced relation between the web and the adjacent stack surface to control the air flow therebetween and into the vents.

3. The structure set forth in claim 2 wherein said spacing means comprises a plurality of web engaging and retarding louvers adjacent at least certain of said vent openings.

4. The structure set forth in claim 1 wherein the guiding means is comprised of a transport belt to which the leading ends of unspliced webs of material is secured, the belt constituting a continuous structure drawn through the festooned path in said dryer from inlet opening to discharge opening.

References Cited UNITED STATES PATENTS 2,439,722 4/1948 Dreisel 34159 2,597,999 5/1952 Knopp 34-159 X 2,780,878 2/1957 Sanborn et a1. 34159 2,920,399 1/1960 Fry 34-159 3,405,456 10/1968 Shepherd 34-155 EDWARD J. MICHAEL, Primary Examiner

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