US3092005A - Photographic copying apparatus - Google Patents

Description

I Q m m w a HWHHMHHH MHH June 4, 1963 w. LIMBERGER PHOTOGRAPHIC comma APPARATUS 2 Sheets-Sheet 1 Filed July 1'7, 1959 W.Limberger INVENTOR.

GENT.

June 4, 1963 Filed July 17, 1959 W. Ll-MBERGER PHQTOGRAPHIC COPYING APPARATUS 2 Sheets-Sheet 2 AGENT-' United States Patent f 3,092,005 PHDTOGRAPHIC COPYING APPARATUS Walter Limberger, Hamburg, Germany, assignor to Lumoprint Zindler K.G., Hamburg, Germany, a corporation of Germany Filed July 17, 1959, Ser. No. 827,833 Claims priority, application Germany Aug. 16, 1958 15 Claims. (Cl. 95-75) The invention relates to a photographic copying apparatus in which positive and negative prints of an original, or master copy, to be reproduced are made on respective blanks of initially sensitized sheet material which are drawn from separate stacks upon the insertion of the original.

The invention has as one of its objects the provision of means for facilitating the insertion particularly of the negative print sheets from their stack into the operative part of the apparatu in which they are transported by suitable feed means through an exposure device and a developing device, thereby eliminating the need for removing these highly photo-sensitive sheets from their holder outside of the protective confines of the apparatus.

Another object of the invention is to provide improved means for simultaneously passing the two copy sheets through the developing bath.

In accordance with a feature of the invention, the stack for the negative blanks disposed at the underside of the apparatus is accessible from its front end through a shutterable opening and arranged in relation to a transport unit in such a manner that the leading edge of the accessible uppermost negative blank lies close enough to an element of that unit so as to be capable of engagement therewith if pulled forwardly a short distance through the aforementioned opening.

In accordance with another feature of the invention, an oblique backing surface is arranged at the stack of negative blanks in such manner that the top blank is forwardly offset with respect to the underlying sheets.

In a preferred embodiment, the transport device comprises a roller which may consist of a plurality of coaxial individual roller members and which is partially surrounded by one or more guiding surfaces pressed elastically against at least a portion of the roller. The area of engagement between the roller and the associated guiding surface or surfaces advantageously lies in front of or above the stack of negative blanks. .According to a more specific feature of the invention, two roller members and guide surfaces are provided on opposite sides of the shutterable opening to give convenient acces to the stack of negative blanks. Advantageously, the holder for this stack is provided with a double bottom to accommodate a flexible shutter which may, if desired, be urged into closed position by means of springs. This arrangement eliminates such bulky element as outside covers or flaps which might unduly obstruct other parts of the apparatus when in open position.

In their stack the blanks lie with their photosensitive surfaces facing downwardly. The access opening to the stack preferably is arranged in a downwardly sloping lower surface of a projection at the front side of the apparatus, the upper surface of this projection serving as a supporting table for the original.

According to a further feature of the invention, the apparatus is provided with a removable storage shelf for the copies issuing from the developing device. This shelf is formed by a storage container for the developing liquid which can be detachably secured to the rear end of the apparatus housing. The container is connected to the developing tank by means of two flexible conduits opening at diiferent levels into the developing tank. The latter advantageously is equipped, pursuant to still another 3,092,005 Patented June 4, 1963 feature of the invention, with guide consisting of several vertical sheets spacedly arranged alongside on another and rising, in the case of the guides for the negative blanks, from the bottom of the tank to provide a receptacle for the sludge.

Further advantages and features of the invention will become apparent from the following description of an embodiment of the invention given with reference to the accompanying drawing in which:

FIG. 1 is a sectional side-elevational view of the apparatus and FIG. 2 is a front view of the apparatu with part of the housing broken away.

The apparatus shown in the drawing comprises a fiat housing 1 having at its underside a holder 2 for a stack 3 of negative blanks. Another holder 4 for a stack of positive blanks is provided at the upper side of the housing. In the illustrated embodiment, holder 4 ascends obliquely toward the rear of housing 1.

At its front end, shown on the left in FIG. 1, the housing 1 has a slot 5 for the insertion of the original or master copy. This slot is limited from below by a projection 6 protruding from the front side of the housing. The upper side 7 of the projection slope upwardly into the interior of the apparatus and serves as a supporting table for the master copy. Its lower limiting wall 8 slopes downwardly towards the rear and is provided with a shutterable opening 37 giving access to the stack of negative blank as more fully described later on.

The apparatus is equipped with an exposure device 9, consisting of a transparent cylinder 10 containing a light source 10 and three rollers 11, 12, 13 around which elastic pressure belts 14 are guided in parallel relation to one another.

Furthermore, the apparatus contains a developing de vice =15, consisting of a tank 16 in which guide paths 17, .18 for the negative blanks from holder 2 and for the positive blanks from holder 4 are formed between the suitably curved upper and lower edges of three groups 19, 2t), 21 of guiding elements in the form of stamped leaves which are arranged side-by-side, standing upright and spaced from one another. The group 19 defines the lower boundary of the guide path 17 and rises from the bottom of the tank 16. The group 20, consisting of sickle-shaped leaves, is situated between the guide paths 1.7 and 18. Above the guide path 18, the group of guiding elements 21 is arranged. The guiding elements are fastened to the walls of tank 16 by means of rods 19, 20, '21 and spacers 19", 20", 21". This design of the guiding elements has the advantage that the guide paths may be manufactured with great exactitude by inexpensive means. Moreover, the guiding elements 19 form compartments within which sludge may accumulate on the bottom of the tank 16 without interfering with the passage of the treated blanks along their guide paths. In addition, positive separation is insured between the two blanks so that both will be adequately wetted by the developer.

The tank 16 is connected with a storage container 24 for the developing liquid via flexible conduits 22 and 23.

Beyond the guide paths 17, 18 a pressure and transport roller pair 32, 3 3 is provided for the purpose of establishing temporary contact between the sensitized surfaces of the two wetted sheets and thereafter ejecting both the finished positive print and the negative copy from the housing through the slot 34.

Between the exposure device 9 and the developing device 15, there are provided means for guiding the blank toward the tank 16 and for separating it from the master copy which is then ejected from the apparatus. For the last-named purpose, a separating roller pair consisting of the rollers 25-, 2 6 is provided. The rollers are rotating in the same sense. Together they define a gap whose Width corresponds to at least the thickness of the negative blank but is smaller than the combined thickness of the negative blank and the master copy. In particular the roller 26 has a roughened surface so as to drive the leading edge of the master copy upwardly, thereby discharging the latter through the slot 27 onto the upper side of the housing 1. Guide surfaces 28, 29 and 33, which for instance are fastened by angle irons to the side walls of the housing, serve to direct the master copy and the negative blank in the desired manner. The guide surface 28 extends close to the exposure cylinder 1% in order to strip both the master copy and the negative blank from the exposure device 9. The guide surface 29 leads the negative blank into the guide path 17.

The separating rollers 25, 26 are positively driven, as indicated by the arrows, from a suitable motor (not shown) together with the associated transmission means situated in the housing part 31. Preferably, all moving parts are operated by one and the same motor by gear, chain and/or belt drives, some of which are visible in FIG. 2.

At its rear end, i.e. on the right-hand side of the apparatus as viewed in FIG. 1, the holder 2 is provided with a sloping internal abutment 35 for the negative blanks of stack 3. The front face 36 of the holder 2 is inclined in the same direction and lies in the same plane as the lower face 8 of the projection 6. As a result, the upper sheets of the stack 3 are forwardly displaced in relation to the bottom blanks. The opening 37 at the center of face 8 extends into the holder wall 36 as clearly seen in FIG. 2. This opening may be closed by a flexible shutter 35' of the rolltop type which is guided at its edges along the aligned wall portions 8, 36 of the apparatus housing and of the holder 2. The latter comprises a double bottom in which the shutter is received when the opening 37 is uncovered.

The upper edge of the shutter is provided with a handle 4-0. Deflection rollers for the shutter are designated 43.

The holder 2 is designed as a drawer lodged in a frame 75 and adapted to be extracted from it in forward direction. The abutment 35 forms the rear edge of the drawer. A sealing strip 73' is arranged at the front Wall 36 of the drawer to insure a light-tight closing.

Above the front edge of the stack 3, within the projection 6, there are positioned a pair of rough-surfaced, co-axial transport rollers 41, 42 flanking the opening 37. The transport rollens, which have a common shaft 76, are furthermore surrounded by respective portions 43 43 of a guide plate 43 which extend around their upper and front surfaces. The lower edge of the guide plate, in the illustrated embodiment, is situated approximately in front of the forward edge of the top blank of the stack 3. The upper edge of the guide plate is extended above a feed table 46, as shown at 44', underneath the exposure device 9. The guide plate 43 is hingedly supported solely at its extension 44 while its depending fiap portions 43, 43 may be elastically deflected. These resilient guide portions are arranged and formed in such a manner that they surround in spaced relation the upper and, to some extent, the front part of the rollers 41, 42 While contacting the rollers with their lower ends and projecting tangentially beyond these rollers toward the stack 3. An elastic contact pressure is provided for this purpose by suitable rneans here shown as a weight 47 attached to each guide portion 43', 4-3 at its forward bulge. This loading insures that the lower edge of the guide plate is placed against a portion of the lower forward quadrant of the rollers i1, 42.

This arrangement represents a simple and eflicient system for the guidance of the negative blank to the sup porting table 4 6 without necessitating a removal of the blank from the apparatus and exposure thereof to light. After the shutter 39 has been pulled downwardly in order to expose the opening 37, the top sheet of the stack 3 4i may easily be seized by the operator between the rollers 41, 42 and be pulled upwardly and forwardly until it enters between the lower edge of the guide portions 43, 43 and the rotating rollers d1, 4-2 whereupon the sheet is entrained by the roughened surface of these rollers. The sheet then advances along the guide plate 4 3 and over the supporting table 46, underneath a roller 49, until it abuts a stop 5% pivotable about the shaft of this roller.

In some instances it will be desirable to insert between the stack 3 and the transport device 4143 a single-sheet feeder, consisting of a driven roller opposite a guide plate in order to insure the supply of only one blank at a time to the transport device even if by chance two blanks have been gripped by the operator. Such a singlesheet feeder has been illustrated at 66, 67 in the path of the positive blanks from holder 4 and will be described in greater detail hereinafter.

The roller 49 carrying the stop 50 has a gear meshing with a gear on a roller 77 whose shaft serves as the pivot of another stop 51 projecting into the guide path for the original. If the stop 51 is deflected as the result of the insertion of a master copy, the stop 50 is lifted and the rollers 41, 42' push the negative blank between the rollers 12 and 52 simultaneously with the arrival of the master copy between these rollers. Behind the rollers 12 and 52, a guide plate 53 overlies the gap between the rollers and surrounds the roller 12 to guide the negative blank and the master copy between the exposure cylinder 10 and the belts 14 running over the roller 12.

Even if the original or master copy is a very thin sheet, proper actuation of the stop 51 is insured by the fact that the original is pressed against the transport belts 14 of the exposure device via a roller 54 and guided between these belts and a shelf surface 55 to the rollers 12 and 52. Below the supporting table 46, a screen 56 is located to prevent the passage of light from the exposure device to the stack 3.

In the inlet of the guide path 17 of the developing device 15 there is provided a stop 57 for the negative blank to be developed, this stop being carried on one end of a double-armed lever, swingable about a horizontal axis, Whose other end bears a stop 58 lying in the supply channel for the positive blanks which are stacked in the holder 4. The stack of these blanks, not shown in the drawing, is situated on a plate 62 which is hinged to the holder at its upper end 61 and is urged against a lower stop ledge 64) by the force of a spring 59. Spaced from the stop ledge 60 is a preferably transparent front guide plate 63 which is rigidly secured to the side Walls of the stack holder 4.

When a positive blank is to be fed, the front blank of the stack is seized through the upper open end 64 of the holder 4, lifted and dropped whereby this blank drops into the slot 65 between the guide plate 63 and the stop ledge 60. Underneath the slot, the aforementioned single-sheet feeder device is located in order to prevent the feeding of more than one blank if two blanks have inadvertently been dropped. This feeder comprises a guide plate 66, secured to the side walls of the housing 1, and a roughsurfaced roller 67 rotating in anticlockwise direction as viewed in FIG. 1. The gap between the members 66 and 67 is of such limited width that only one positive blank may pass at a time.

The positive blank drops down so far that it comes to rest on the stop 53. The stop 58 lies, looking from the location of the stock holder 4, ahead of a transport roller pair 68, 69 which precedes the insertion end of the guide path 18 of the developing device :15. If a negative blank coming from the exposure device 9 and traversing the transport roller pair 25', 26 deflects the stop 57, the stop 58 movable in a peripheral slot of the roller 6? is retracted sideways so-that the positive blank ready to start its travel drops into thegap of the transport rollers 68, 69 and is fed by them into the developing device 15.

The storage container or reservoir 24 for the developing liquid in the illustrated embodiment has a rectangular cross section. Apart from the ports of the flexible conduits 22, 23 the container is closed on all sides. On its narrow side, the container has a bracing arm 70 which may be bifurcated to straddle the conduits 22, .23 and extends level with the lower container surface toward the rear wall of housing 1. The upper surface of the container 24 has a projection 71 formed as a plate having at its front end a hook 72 which may be hooked into the rear edge of the exit slot 34. The container 24 can thus be operatively positioned, in the illustrated manner, so that its upper side together with the platelike projection 71 forms a storage shelf for the treated sheets ejected from the housing. In this position the container 24 automatically discharges into the tank 16.

It will be seen that the container may be readily lifted out of its operative position. Then, the flexible conduits 22, 23 allow for an inoperative positioning of the container at a lower level, e.g. behind the apparatus or in a compartment situated for instance between the feet 74 of the housing 1 underneath the box 2. The developing liquid then returns automatically from the tank 16 into the container 24-, so that oxidation of the liquid is safely avoided. This arrangement at the same time offers the advantage that the supporting shelf provided by the container Z4 is available only when the apparatus is in operation, so that the dimensions of the apparatus during nonuse are substantially reduced.

The operation of the container 24 with its two flexible conduits 2Q, 23 resembles that of a so-called chicken-coop trough. The location of conduit 22 along the height of the container 24 and the capacity of the latter relative to that of tank 16 are so selected that the flow of liquid from this container into the tank 16 will stop soon after the liquid therein has risen above the lower port of tube 22. When the liquid level in the tank 16 decreases to expose once more this lower port, liquid may flow into the tank 16 through the conduit 23 as a corresponding amount of air enters the container 24- through the conduit 22.

It will be seen from FIG. 2 that the housing 1 is wider than the stack holder 4 to provide room for the driving and transmission mechanism as previously described. Naturally, the invention may. also be realized with an apparatus where housing 1 extends, for example, to only one side of the stack holder 4.

A socket 78 atop the housing 1 serves as a means for removably maintaining the holder 4 in its slanting position above the entrance slot to feeder 66, 67. Such slanting positioning is, however, not essential and other means for supporting the holder 4 may be provided in lieu of the arrangement shown. Again, the holder 2 for the negative blanks may be an integral part of the housing instead of being removable therefrom as herein disclosed. Other modifications of the particular apparatus described and illustrated, such as for example a further mechanization of the blank-feeding process through the inclusion of additional automatic transport means known per se, are of course also possible without departing from the spirit and scope of the invention as defined in the appended claims.

What is claimed is:

l. A photographic copying apparatus comprising a housing, a holder on said housing adapted to carry a stack of photosensitive blanks, exposure and developing means for said blanks in said housing, transport means in said housing for advancing successive blanks from said holder through said exposure and developing means, said housing being provided with an opening giving access to an uppermost blank of said stack whereby said uppermost blank can be manually brought into engagement with said transport means within the confines of said housing, closure means for covering said opening, said transport means comprising a pair of coaxial rollers rotatable about a horizontal axis and flanking said opening, guide means 6 adjacent said rollers, and loading means resiliently urging said guide means into contact with said rollers, said holder being located substantially horizontally underneath said rollers in a position in which an edge of the uppermost blank is adjacent the lower surface of said rollers.

2. An apparatus according to claim 1 wherein said guide means comprises a flexible plate partly enveloping said rollers, said plate surrounding an upper portion of said rollers with clearance while being normally maintained in contact with a lower part of said rollers by said loading means.

3. An apparatus according to claim 2 wherein said plate has an upper portion attached to said housing and a pair of spaced-apart lower portions respectively enveloping said rollers.

4. An apparatus according to claim 3 wherein said loading means comprises a weight on said plate tending to bend the free edges of said lower portions toward said rollers.

5. A photographic copying apparatus comprising a housing, a generally horizontal holder on said housing adapted to carry a stack of discrete photosensitive blanks, exposure and developing means for said blanks in said housing, transport means in said housing for advancing successive blanks from said housing through said exposure and developing means, said housing being provided with an opening giving access to an uppermost blank of said stack, said transport means including a pair of coaxial horizontal rollers above said holder flanking said opening and positioned close enough to said opening and said stack to enable an edge of said uppermost blank to be manually brought into contact with said rollers within the confines of said housing, guide means in said housing adjacent said roller for holding said blank engaged by the surface of said rollers, said transport means including drive means for rotating said rollers in a sense conveying the blank so engaged toward said developing means, and closure means for covering said opening upon such engagement of said blank by said rollers, said guide means including a flexible plate partly enveloping said rollers, said plate surrounding with clearance an upper part of said rollers and being provided with loading means urging respective spaced-apart edge portions of said plate into contact with lower parts of said rollers.

6. An apparatus according to claim 5 wherein said housing is provided with a forward projection having a rearwardly sloping lower face, said holder having a sloping forward face aligned with said lower face, said opening being provided partly on said lower face and partly on said forward face, said forward face having a top portion lying forwardly and above said opening.

7. An apparatus according to claim 6 wherein said holder comprises a drawer on the underside of said housing, said drawer being formed at its rear with a sloping internal abutment substantially paralleling said forward face whereby the blanks of said stack are staggered relatively to one another with the topmost blank positioned more forwardly than the others.

8. In a photographic copying device, in combination, a housing, an exposure device in said housing, developing means in said housing, first holder means at the bottom of said housing adapted to contain a stack of negative blanks, second holder means at the top of said housing adapted to contain a stack of positive blanks, said housing being provided with several slots including an entrance slot for a master copy to be reproduced, a discharge slot for said master copy and an exit slot for said blanks, first transport means for feeding a negative blank from said first holder together with said master copy past said exposure device and thereupon ejecting said master copy through said discharge slot, second transport means for feeding a positive blank from said second holder together with said first blank through said developing means and thereupon discharging both said blanks through said exit slot, said first transport means including a horizontal defleeting roller positioned underneath said entrance slot and above the level of said first holder, said housing having a forward projection accommodating said deflecting roller and forming an upwardly sloping feed table for said master copy leading to said entrance slot, said forward projection having a rearwardly sloping lower face below said roller provided with an access opening enabling the top blank in said first holder to be gripped from without and to be pulled forward into engagement with said deflecting roller, and closure means for covering said opening.

9. The combination according to claim 8, further comprising supporting means rearwardly of said projection for removably maintaining said second holder in a slanting position atop said housing.

10. A photographic copying apparatus comprising a housing, a holder on said housing adapted to carry a stack of discrete photosensitive blanks, exposure and developing means for said blanks in said housing, transport means in said housing for advancing successive blanks from said housing through said exposure and developing means, said housing being provided with an opening giving access to an accessible blank of said stack, said transport means including a roller positioned close enough to said opening and said stack to enable an edge of said accessible blank to be manually brought into contact with said roller within the confines of said housing, guide means in said housing adjacent said roller for holding said blank engaged by the roller surface, said transport means including drive means for rotating said roller in a sense conveying the blank so engaged toward said developing means, and closure means for covering said opening upon such engagement of said blank by said roller, said guide means including a flexible plate partly enveloping said roller, said plate surrounding with clearance a part of said roller relatively remote from said stack and being provided with loading means urging an edge portion of said plate into contact with a part of said roller relatively close to said stack.

11. A photographic copying apparatus comprising a housing, a holder on said housing adapted to carry a stack of discrete photosensitive blanks, exposure and developing means for said blanks in said housing, transport means in said housing for advancing successive blanks from said housing through said exposure and developing means, said housing being provided with an opening giving access to an accessible blank of said stack, said transport means including a pair of coaxial rollers flanking said opening and positioned close enough to said opening and said stack to enable an edge of said accessible blank to be manually brought into contact with said rollers within the confines of said housing, guide means in said housing adjacent said rollers for holding said blank engaged by the surface of said rollers, said transport means including drive means for rotating said rollers in a sense conveying the blank so engaged toward said developing means, and closure means for covering said opening upon such engagement of said blank by said rollers, said guide means including a flexible plate partly enveloping said rollers, said plate surrounding with clearance parts of said rollers relatively remote from said stack and being provided with loading means urging respective spacedapart edge portions of said plate into contact with parts of said rollers relatively close to said stack.

12. A pnotographic copying apparatus comprising a housing, a generally horizontal holder on said housing adapted to carry a stack of discrete photosensitive blanks, exposure and developing means for said blanks in said housing, transport means in said housing for advancing successive blanks from said housing through said exposure and developing means, said housing being provided with an opening giving access to an uppermost blank of said stack, said transport means including a horizontal roller above said holder positioned close enough to said opening and said stack to enable an edge of said uppermost blank to be manually brought into contact with said roller within the confines of said housing, guide means in said housing adjacent said roller for holding said blank engaged by the roller surface, said transport means including drive means for rotating said roller in a sense conveying the blank so engaged toward said developing means, and closure means for covering said opening upon such engagement of said blank by said roller, said guide means including a flexible plate partly enveloping said roller, said plate surrounding with clearance an upper art of said roller and being provided with loading means urging an edge portion of said plate into contact with a lower part of said roller.

13. A photographic copying apparatus comprising a housing, a holder in said housing adapted to carry a stack of photosensitive blanks, exposure and developing means for said blanks in said housing, transport means in said housing for advancing successive blanks from said holder through said exposure and developing means, said housing being provided with an opening giving access to an uppermost blank of said stack whereby said uppermost blank can be manually brought into engagement with said transport means within the confines of said housing, and a flexible shut-ter behind said opening for covering the latter, said holder being provided with a double bottom adapted to receive part of said shutter in a withdrawn position of the latter.

14. A photographic copying apparatus comprising a housing, a holder on said housing adapted to carry a stack of photosensitive blanks, exposure and developing means for said blanks in said housing, transport means in said housing for advancing successive blanks from said holder through said exposure and developing means, said housing being provided with an opening giving access to an uppermost blank of said stack whereby said uppermost blank can be manually brought into engagement with said transport means within the confines of said housing, said housing having a forward projection with a rearwardly sloping lower face, said holder having a sloping forward face aligned with said lower face, said opening being provided partly on said lower face and partly on said forward face, said holder comprising a drawer on the underside of said housing formed at its rear with a sloping internal abutment substantially paralleling said forward face whereby the blanks of said stack are staggered relatively to one another with the uppermost blank positioned more forwardly than the others, and a shutter for said opening withdrawable into said holder.

15. A photographic copying apparatus comprising a housing, a holder on said housing adapted to carry a stack of photosensitive blanks, exposure and developing means for said blanks in said housing, transport means in said housing for advancing successive blanks from said holder through said exposure and developing means, said housing being provided with at opening giving access to an uppermost blank of said stack whereby said uppermost blank can be manually brought into engagement with said transport means within the confines of said housing, a flexible shutter for covering said opening, said holder being substantially horizontally positioned underneath said transport means and open at the top, and sloping abutment means within said holder adapted to maintain said blanks in a relatively staggered position whereby the uppermost blank projects more forwardly than the others, said transport means being disposed adjacent the forward edge of said topmost blank.

References Cited in the file of this patent UNITED STATES PATENTS 1,203,657 Sheckler Nov. 7, 1916 2,435,720 Land Feb. 10, 1948 2,732,778 Limberger Jan. 31, 1956 2,792,768 Ludwig May 21, 1957

Claims (1)

1. A PHOTOGRAPHIC COPYING APPARATUS COMPRISING A HOUSING, A HOLDER ON SAID HOUSING ADAPTED TO CARRY A STACK OF PHOTOSENSITIVE BLANKS, EXPOSURE AND DEVELOPING MEANS FOR SAID BLANKS IN SAID HOUSING, TRANSPORT MEANS IN SAID HOUSING FOR ADVANCING SUCCESSIVE BLANKS FROM SAID HOLDER THROUGH SAID EXPOSURE AND DEVELOPING MEANS, SAID HOUSING BEING PROVIDED WITH AN OPENING GIVING ACCESS TO AN UPPERMOST BLANK OF SAID STACK WHEREBY SAID UPPERMOST BLANK CAN BE MANUALLY BROUGHT INTO ENGAGEMENT WITH SAID TRANSPORT MEANS WITHIN THE CONFINES OF SAID HOUSING, CLOSURE MEANS FOR COVERING SAID OPENING, SAID TRANSPORT MEANS COMPRISING A PAIR OF COAXIAL ROLLERS ROTATABLE ABOUT A HORIZONTAL AXIS AND FLANKING SAID OPENING, GUIDE MEANS ADJACENT SAID ROLLERS, AND LOADING MEANS RESILIENTLY URGING SAID GUIDE MEANS INTO CONTACT WITH SAID ROLLERS, SAID HOLDER BEING LOCATED SUBSTANTIALLY HORIZONTALLY UNDERNEATH SAID ROLLERS IN A POSITION IN WHICH AN EDGE OF THE UPPERMOST BLANK IS ADJACENT THE LOWER SURFACE OF SAID ROLLERS.

Images