NO169682B - DEVICE FOR DISPLAYING THE SINGLE SHEETS IN A SHEET STACK, SPECIFICALLY A PHOTO VIEWING EXCHANGE - Google Patents

Description

This invention relates to a device for displaying the individual leaves in a stack of leaves, in particular a device in the form of a so-called photo viewing changer. The starting point for an invention is such a device that includes the elements that appear in the introduction in the following patent claim 1.

A device of this kind and in the form of a device designed to change between paper and cardboard images,. slides, advertising texts etc., are known from DT-PS 873 908. However, this device is not suitable for reliable switching of relatively thin sheets, which also have relatively large dimensional tolerances, such as e.g. normal photos.

US-PS 3,377,727 and 3,783,540 also indicate devices for cyclically restacking sheets that are stacked in a sheet stack. A single leaf is taken from one end of such a stack through

a first slit or slot when a pusher is pulled out, after which the same blade is brought back to the other end of the stack when the pusher is subsequently pushed in. In this way, a new leaf will appear at the top of the stack, as this top leaf can be viewed through a transparent cover or viewing window. In order to separate each blade from the top end of the stack, the other blades of the stack are kept locked by a wall in an element that delimits an outlet slot and has an extension normal to the main plane of the stack blades. The disadvantage here lies in the fact that the separated blade at the outlet can collide with the vertical wall and the edge and become deformed.

The difficulties that arise when you want to acquire

considering a photo viewing changer of the kind mentioned at the outset, which functions reliably, is as simple as possible and can be manufactured at a reasonable price, is primarily based on the fact that photos as a changer must be released for consideration in a such photographic imagers, despite their uniform format, differ in many respects, depending on the manufacturer from which the paper and developing chemicals are supplied and according to which copying facility the finished images are produced from these materials.

The photos delivered by the copying facility not only have different image formats, of which the final formats are 9 x 9 cm (more precisely 8.9 x 8.9 cm), 9 x 11.5 cm as well as 9 x 11.7 and

9 x 13 cm are the most used, but within these nominal values

final formats have relatively large dimensional tolerances which can amount to as much as 5 mm and i.a. is written from the fact that the photographs have been brought to the final format in a variety of ways, e.g. by punching, cutting, cutting from paper rolls etc. Furthermore, depending on the make, the thickness of the photographs can vary relatively greatly. The nominal thickness of photographs is usually between 0.25 and 0.3 mm, but larger and smaller thicknesses • can also occur. In addition, the photographs may have right-angled or round corners and the image edges may, depending on the nature of the image's final format, be differently shaped and they may possibly have degrees after cropping.

Finally, the different photographs can be strongly curved differently and in different directions, because the so-called photographic papers in reality do not consist of paper but of a plastic carrier that looks like paper, on which a large number of different chemical layers are embedded or stored in gelatin. Gelatin is a natural product and therefore in terms of properties subject to very strong fluctuations. In particular, gelatin is relatively strongly hygroscopic, while the plastic carrier is significantly less hygroscopic, so that depending on the humidity different tensions arise between the plastic carrier and the gelatin layers, which lead to the most diverse bending and twisting of the photographs. These bends are also affected by the aforementioned chemical layers which are embedded in the gelatin and which consist of at least a light protection layer, a filter layer, a fixing layer, a protective layer and three color layers as well as any further layers, which again depends on which manufacturer supplies the photographic papers and which special chemical processes are the basis for their production.

When one considers in this context that there are at least five large photographic paper manufacturers, namely the companies Kodak, Agfa, Fuji,

3M and Sakura, which respectively produce other photographic papers, and that there are a number of copying facilities that process the photographs with a wide variety of devices, especially bringing them to the final format, it will be clear that the main problem with

the acquisition of a reliably functioning photo viewing changer consists in the fact that it must be able to work with a wide variety of photographs, even if these are nominally the same format. One like that

photo viewing changers must therefore meet the requirement to function equally reliably with all these different photographs. Particularly. it must meet the following requirements for at least one of these: (1) The most different photographs in a stack of photographs must, despite their diversity, be distinguishable from each other with the same reliability.

(2) The transport of the various photographs away

from the stack must, despite their diversity, function with the same security.

(3) Reintroduction of a separated photograph to the other end side of the stack (upper or lower stack side) must take place reliably. (4) The photographs must be pressed against a viewing disc so that they can be viewed flat. (5) During the viewing of a photograph in the view changer and during the operation of this changer, no photograph must fall out and more precisely regardless of the position in which the view changer is held and operated. (6) The operation of the photoview changer' should be possible in any position, e.g. also if the observer is lying on his back. (7.) The photographs must be able to be filled into the photo viewing changer individually or as a stack or be removed from this. (8) The photoreflection exchanger must function in any state of filling, i.e. e.g. both when it is completely filled with e.g. 25 photos, as well as when this same photo viewer only contains two or three photos. (9) The photo viewing changer must be "foolproof" when it comes to operation, in particular the photographs must not be damaged by only partial operation of the mechanism in the changer, be pressed together or bumped, chlorinated or in any other way condition-

hurt.

(10) If desired, the photographs must also be able to be viewed continuously, for which it is required to be able to line them up or hang them up using the photo viewing switcher.

(11) The photo-viewing exchanger must be stackable

a proper or suitable form.

(12) The photo viewing changer must be "pocket-friendly", so that it is possible to put the photographs together with the photo viewing changer in your pocket, preferably in a suit pocket or handbag, and for this purpose the photo viewing changer must be as flat as possible, rounded at the corners and designed to be touch-friendly . (13) In addition, a simple and cost-effective manufacturability of the photoreflection exchanger shall be required and, more specifically, it should be possible to produce it as automatically as possible and likewise to assemble it in this way. Its parts must be suitable for injection molding, so that they can be molded by spraying plastic. (14) The changeover mechanism must function so reliably that it always takes out exactly one photograph and feeds it back into the stack, i.e. never, with correct and complete operation, two photographs change at the same time or even no photograph at all. (15) The photographs must be protected against finger contact and dust using the photo view changer. (16) It must be required that the photo viewing exchanger is compact, i.e. only has a small space requirement and that a large part of its volume, preferably the predominant part of this volume, can be filled up by the photographs themselves. (17) Of the respective displayed photographs, preferably the entire image surface should be visible, i.e. little or none of the image surface should be covered. (18) The possibility of subtitles for the purpose of indicating the content should be present. (19) The filling of photographs in the viewing changer must also be mechanically possible, in particular with automatic machines for the filling of photographs, the closing of the photo viewing changer and a function check. (20) The photo viewing changer's mechanism should enable different forms of execution, as in one embodiment it should be possible to take out the photographs at the top of the stack and put them back in at the bottom, while in another embodiment the reverse should be possible to take out the photographs at the bottom of the stack and put them back in at the top. If necessary, there should be a mechanism by which it is possible to take out a photograph inside the stack.

The same requirements that are listed above and which apply to viewing changers for photographs in paper or cardboard design, should preferably also apply to other plate-shaped objects which in the following can be called "sheets" for simplicity's sake, e.g. cards with food recipes, orientation cards for ski slopes, hiking trails etc., and index cards for small index cards, to name just a few examples. In addition to this, the above-mentioned requirements also apply, at least in part, to exchangers for cards that do not have visible records. Thus, it is e.g. conceivable that with a changer of the type mentioned at the outset, magnetic cards, on which language lessons are located, can alternately be brought in front of a simple, e.g. battery-powered magnetic head scanning mechanism which can optionally be permanently mounted on the switching mechanism.

Consequently, the invention does not exclusively relate to a photo-inking exchanger, although it is preferably used for photographs, but it generally relates to a device for displaying the individual sheets in a stack of sheets. More specifically, the aim of the invention is a device of this kind, with which at least some, however preferably all of the preceding requirements are met and the disadvantages of the above-mentioned state of the art are overcome.

The device produced by the invention, which is built up in the manner mentioned at the outset, is distinguished according to the invention by the features that appear in the characteristic of claim 1.

To make up for the disadvantages stated at the outset

for the known constructions described in US 3 377 727 and 3 783 540 it is therefore ensured that the stack's blade edge construction surfaces are at an angle in relation to the main plane for the individual planes in the stack and thus also in relation to the counter pressure surface, whereby the stack is shifted laterally into a trapezoidal shape and so that the edge of the top leaf to be separated from the stack will slide upwards along an inclined surface and is more easily guided up from the underlying leaf in the stack. The sloping formation of the stack also allows for easier lifting of the top leaf with a hook or similar.

With this design, in particular, a safe separation of a respective single leaf from the leaf stack is achieved without there being any danger of either no leaf being separated from the stack at all or several leaves being separated at the same time. the stack. This device also functions reliably when

the blades have relatively large surface dimensions and thickness tolerances.

The leaf counter-pressure surface .. which presses the leaf stack against the house's viewing window in the form of a clear plate or a transparent cover can be arranged in the bottom of the house or essentially formed by this, while the contact surface against which the leaf stack is pressed up can be the transparent cover itself or be arranged on the inside of this.

The blade counter-pressure surface can be on the upper side of a counter-pressure plate which holds the blade stack spring-loaded against the overlying contact surface.

A particularly space-saving and well-known construction occurs if a conical spiral spring is arranged on the underside of the plate to push the counter pressure plate upwards and which faces away from the blade stack, because such a spiral spring can be compressed completely, whereby it only gets the height of one spring turn. Other known ways can be to let the counter-plant surface be the surface of one, two or more rollers or rollers, especially rubber rollers or rubber rollers.

For semi- or fully automatic reintroduction of an out-

taken blade, the device according to the invention is designed in such a way that a pusher is arranged which is movable perpendicular to the relationship

to an outlet slot so much that it completely occupies the separated blade. In detail, the pusher is stored and guided for its forward

and backward movement on the blade stack's holding device or on a housing formed by it or placed on it.

The pusher has a frame that extends along the side edges of the blade stack running in the direction of movement of the pusher.

For the purpose of inserting and removing the blade stack, an opposing blade edge installation surface can be arranged on a rotatable structural part, preferably an essentially wedge-shaped construction part, which is pivotable about an axis parallel to the blade edge and whose surface opposite the opposing blade edge installation surface preferably forms a side wall in the device housing. The removal of the blade stack becomes easier if the wedge-shaped component has one or more parts which, in the normal position of this component, grip over the adjacent edge area of the blade stack.

On the pusher, there are springs in the area of the side edges of the withdrawn blade, particularly leaf springs which extend in the direction of movement of the pusher and which press the separated blade through the withdrawal slot.

A gripper can be arranged on the pusher, which takes with it the second leaf present on the side of the withdrawal slot in the leaf stack. The gripper can be designed in different ways, e.g. have a suction device which is connected to a vacuum pump that can be operated and controlled by means of the pusher's movement. However, a particularly simple construction results when the gripper is designed as a projection that engages with the rear edge of the end blade in the stack on the side of the outlet slot present in the area of the counter blade edge installation surface.

For pre-sorting or pre-separation of that leaf

which is to be carried along, from the underlying leaf, the counter-leaf edge installation surface in the area of the rear edge of the decorative leaf on the outlet slot side has two step or stair-like ledges.,

with a step height somewhat greater than the thickness of a blade.

The step-like ledges can be arranged on the above-mentioned, rotatable, particularly wedge-shaped building part.

The device's sliders can be designed in such a way that the housing's

at least partially transparent lids or covers at the same time can only be pulled out parallel to the main plane of the blades so far

that in its furthest extended position it still remains in the housing, as one or more parts are arranged which grip over the adjacent edge of the leaf stack, possibly over its two opposite edges.

The part or parts secure the blade stack on one side against falling out when the pusher is pulled out to the maximum and the housing opening is turned downwards, which e.g. may be the case when the sheets, such as photographs, are viewed by a person lying on their back.

In these cases, difficulties arise due to the parts that catch over, in taking the blade stack out of the housing or inserting a blade stack into an empty housing, even when the pusher is pulled as far as possible out of the housing.

It should be noted here that the invention is not only applicable to a device as stated above, but on the contrary in principle can be used as a generally applicable device for individually displaying leaves in a stack of leaves.

In principle, the invention can even be advantageously assigned to all devices that hold a leaf stack or a single leaf against two opposite surfaces by means of overarching elements such as projections, edges or the like, of which one element is stationary, while the other according to the invention is placed on a pusher that can go under the name additional pushers.

The operation of the device of the invention will now be reviewed, and reference is made to the associated figures, where fig. 1a shows a perspective representation of an embodiment of a photo-viewing exchanger, fig. 1b and 1c show an alternative embodiment which enables a reinsertion of a removed blade without the need for the blade springs shown in fig. 1a, fig. 2a shows a longitudinal section of another embodiment according to FIG

the invention and which enables a fully automatic removal and reinsertion of a blade, fig. 2b is a perspective view of the embodiment in fig. 2a seen obliquely from above and partly in section, fig. 2c is a compared to fig. 2a is a larger-scale view of a rotatable, wedge-shaped component for the device in fig. 2a and 2b, fig. 2d is a larger scale representation of a gripper

for the device in fig. 2a and 2b, fig. 2e is a section of a modified embodiment of the cover for the housing present on the pusher in the device of fig. 2a and 2b, fig. 2f is a perspective partly in section and on a larger scale compared to fig. 2a and which shows a partial view of the device produced there, fig. 2g is a perspective view of a counter pressure element made of wire which can replace corresponding elements in the device shown in fig. 2a,

fig. 3a and 3b are partially schematic drawings of yet another example of

an embodiment of the invention, where the separation of the respective leaf to be taken out takes place with the aid of a suction device, as fig. 3a is a perspective view, partly in section, and fig. 3b is a schematic longitudinal section, fig. 4a shows a longitudinal section of a pusher which has a locking device,

as part of the house is visible, which can occupy one. blade stack and where the locking device is in the position in which it prevents the pusher from being pulled out of the housing, fig. 4b is a plan view of the pusher with the locking device and of part of the housing seen from above, without blade stack, the pusher being in the position shown in fig. 4a, fig. 4c is a plan view of the pusher and part of the housing seen from below and, more specifically, also in the locked position of the pusher, fig. 4d is a section similar to fig. 4a, where, however, the pusher has been pulled out of the housing almost as far as possible, and fig. 4e is a plan view corresponding to fig. 4b, where the pusher has the position shown in fig. 4d,

fig. 5a - 5c show different positions of a movable carrier element, by means of which the uppermost leaf in a leaf stack is brought along in the first phase exclusively by means of a binding element and in the second phases by means of a hook, and fig. 6a and 6b is an embodiment that can be produced particularly well in one piece, and more specifically, fig. 6a a longitudinal section

of this device with an upturned cover and fig. 6b a plan view of the device.

In fig. 1a shows a first embodiment of the device, where a pusher 39 is arranged which can be pulled almost completely

'out of the housing 40 (except for a short section) and which on both sides respectively have a leaf spring 41 which presses the exiting leaf upwards against the contact surfaces of the pusher.

The advantage of this design is that when reinserting the removed blade you do not need to "aim", so that the reinsertion position of this blade is secured and takes place semi-automatically.

In fig. 1b and 1c show another embodiment which makes the springs 41 redundant. Here it is. at the end of the pusher which is at the rear in the pusher's withdrawal direction, a comb-like elevation 39a is arranged in the pusher bottom, approximately at 39b in fig. 1a, and the part on which the blade edge installation surface 11 is located and which is denoted here by 39c, as well as e.g. is triangular in cross-section, but can also have a different cross-section, is rotatable about an axis 39d in the 39e of the arrow. direction and more specifically mOt the elastic force of a spring, e.g. a torsion spring. The part 39c can be called a turning wedge.

When the comb-shaped elevations 3 9a abut against the one in fig. 1b lower edge of the turning wedge 39c when reinserting, they turn the wedge in the direction of the arrow 39e, whereby the blade 39f to be inserted is deflected upwards along the face of the turning wedge (see fig. lc) and is pushed into it here did not show insertion slot 16 when further pushing the pusher 39 into the housing. As will be seen, a "brush" consisting of the turning wedge 39c and the comb-shaped elevation 39a is provided to some extent.

In fig. 2a - 2f shows a further form of embodiment of the invention, by means of which the fully automatic removal of the blades from the blade stack and their reintroduction into the blade stack is possible, by simply pulling out a pusher 43 from the housing 42 and pushing it back into the house.

The pusher 43 is movable so far vertically on a take-out slot 10 arranged at the top in this embodiment that it occupies the respective leaf 44 coming out of the latter completely on transport surfaces 45 arranged thereto, over which it is again pushed into the insertion slot 16. However, the pusher is secured against full extraction of the house using corresponding estimates.

During its reciprocating movement, the pusher 43 is guided in the housing 42, for which purpose it has a. frame 46 with pusher parts 47 which extend in the direction of movement of the pusher and which are slideable in corresponding recesses 48 in the inner walls and/or bottom of the housing 42. The slider can be guided in the housing in many different ways and can also be designed in different ways, e.g. be telescopically extendable.

The pusher 43 is preferably partially guided along contact surfaces on the guide parts, so that the manufactured blade is secured against falling out laterally from the pusher.

In the example of execution shown in fig. 2a - 2g, the pusher 43 also includes a mainly transparent cover 49 on the housing, the cover can include a clear plate 50 which is fixed in a frame 51 (see fig. 2f). So that the blades in the extended state of the pusher, in which they practically lies open, should not be able to fall out, the pusher is only so far extendable in the housing 42 that the unextractable rear edge of the frame 51 covers the corresponding edge of the blade stack 1. At the other end of the housing, tongue-shaped parts 52 are arranged which can be called hold-down tongues and are designed to grip over the top blade with its edge area and hold it down with a contact surface, i.e. preventing it from springing up or falling out of the housing 42 when the pushers 43 are pulled out.

The pusher 43 is extended on the operating side below in the direction of the housing 42 by means of a tab 53. This tab protrudes when the pusher 43 is pushed in a suitable length, e.g. 10 - 14 mm, into the bottom of the housing, which at this point has a corresponding recess 54. The purpose of the tab 53 is to serve as a gripping surface.

For the removal of a blade and its reinsertion, the blade edge installation surface 11 is arranged on a construction part 55 permanently connected to the housing 42 which can be called a wedge or separator and which respectively limits one side of the removal slot 10 and the insertion slot 16. The other side of the removal slot 10 is formed by the inner side of the slider cover 49,

and the other side of the insertion slot 16 is completely or partially formed by the pusher parts 47 which extend in the direction of movement of the pusher. A separator is formed by respective one on the sides of the pusher arranged spring 56 (of which in fig. 2a only one is visible) and more specifically of their in the pusher's

extraction direction front bow 57. These springs, which are also referred to as retaining springs, have the further task of transferring the blade 44 emerging through the withdrawal slot 10 to the transport surfaces 45 arranged on the pusher, over which it is pushed into the insertion slot 16, whose insertion stop 58 is formed by one or more springy tongues which are arranged on a counter-pressure plate 59, which is under pressure from a spring 60 and thus presses the blade stack 1 against the inside of the pusher's cover 49.

The pushing out of a blade through the withdrawal slot 10 takes place with the help of a gripper 61 which is arranged at the rear end of the pusher's cover 49 and mainly has the shape of a nose, to which a gripper cavity 62 joins in the pullout direction of the pusher, which has the task of enabling a safe introduction of the edge of the blade coming into engagement with the gripper to be removed under the action of the counter pressure plate 59. The gripper cavity 62 can e.g. be a saving of approx. 3 mm width and 0.5 mm depth. In this way, the gripper edge is extended to a certain extent towards the "harmless" side, i.e. upwards, where the second top image could not be touched.

This is above all an advantage when the edge of the blade that engages with the gripper is bruised in the form of an injury, i.e. extended. This prevents further damage to the blade.

The safe functioning of this system is based on the commonly occurring fact that the images preferably used as sheets have an acute section angle on the edge area of the image side and an obtuse section angle on the opposite edge area.

The pivot wedge 63 is rotatable about the shaft 64, so that the down-holding tongue 52 completely releases the blade stack 1 in the area of it in fig. 29 showed the left edge when the turning wedge is turned out of its rest position. In this way, it is possible to remove the blade stack 1 from the housing 42 when the pusher 43 is pulled out. In particular, this enables a simple and automatically implementable

..filling the housing 42 with a leaf stack 1.

So that the pivot wedge is in its normal position as shown on

fig. 2a is held securely, a locking device is provided. This is mainly formed by a planar surface 66 present on the inside of the bottom of the housing and by a counterplanar surface 67 present on the opposite side of the turning wedge 63, the planar surface 66

and the counterplane surface 67 67 rest elastically against each other, which e.g. can be achieved by means of the inherent elasticity of the correspondingly designed bottom of the housing. The counter-plane surface 67 transitions in the direction of the outer side of the housing into a curved surface 6 8 whose radius of curvature r increases up to a radius r+Ar, whereby r is equal to the distance from the pivot shaft 64 to the flat surface 66. On the other side of the pivot wedge, a nose ends 65 itself to the flat surface 67 which grips under the adjacent edge of the blade stack 1 and by turning the turning wedge 6 3 lifts the blade stack at the edge from its normal position so that it can be removed more easily.

At the upper end, the turning wedge has two step-like ledges 100 and 99, the height of which is approximately equal to the blade thickness. These step-like ledges cause pre-sorting in the sense that the gripper 61 can practically only grip the edge of the uppermost leaf and more specifically for the following reason: When the pusher 4 3 is pushed in again after removing a leaf, in order to push in again this extracted blade through the insertion slot sen 10 down, it will simultaneously happen that the cover 49 placed on the pusher 4 3 exerts a frictional force on the top leaf in the stack with the help of its inner side, which force is partly transferred to the underlying leaves. This frictional force leads to > that the uppermost blade which, when the previous blade was removed by friction against the latter, has been taken along in the direction of the blade edge installation surface 11, is now pushed back again. When it is pressed upwards by the counter-pressure plate 59, it can only be pushed back to the first landing because it is prevented by this from a continued movement in . direction of the opposite blade edge installation surface 30. In contrast, the next top blade is pushed back further up to the second step-like ledge 99 because, to the extent that it comes into contact with it at all in fig. 2a and 2c lower edge of the step-shaped ledge 100, can slide away over this edge, because it is made slanted or rounded.

The opposite blade edge installation surface 30 is, as already evident from its designation, the counterpart of the blade edge installation surface 11. Consequently, both of these surfaces 11 and 30 are preferably designed complementary to each other.

This pre-sorting also works with corresponding dimensional tolerances to which the leaves are exposed and because of which it may happen that the top leaf is shorter or longer than the next top leaf or the same length as this. This shall be described in more detail. (a) When the uppermost blade is shorter than the second uppermost blade, it may indeed happen that the first step-shaped ledge 100 comes into contact with the edge of the second uppermost blade before the uppermost blade has reached it. Since, however, the movement transmitted by the frictional force between the sliding cover 49 and the top blade is significantly greater than between the top blade and the second top blade, the latter is finally displaced by the top blade and pushed over the rounded edge of the first step-shaped ledge 100 further back to the second step-shaped ledge 99. (b) When the uppermost and the second uppermost blade are of the same length, pulling out the pusher during the withdrawal of the previous blade will cause the one in fig. 2a rear edge of the top leaf at the beginning of the new insertion of the pusher lies further to the right than the corresponding edge of the second top leaf, so that the edge of the second bottom leaf first comes into contact with the first step-shaped ledge 100 , is then displaced by the edge of the upper blade and finally is pushed back to the second step-shaped ledge 99. (c) If finally the upper blade is longer than the upper one, its blade edge first engages the first step-shaped ledge 100, while the corresponding edge of the next top leaf will lie further to the right. Also in this case, the blade edge of the top blade that is gripped by the gripper is securely separated from that of the next top blade.

The error-free function of the gripping edge 61 and the step-shaped landings 100 and 99 used for pre-sorting is ensured by the fact that the retaining tongues 52, on which the two step-shaped landings are arranged, are doubly secured at the exact, correct height, namely first by means of the above-mentioned locking device , by means of which the turning wedge is held securely in its normal position, and secondly by the hold-down tongues 52, by means of recesses 84 in the sliding cover 49, also being held at exactly the correct height, so that

the flawless functioning of the step-shaped ledges and the gripping edge is ensured.

The conical spiral spring 60 is thus designed or arranged so that it exerts a stronger pressure on the one in fig. 4 showed

left part of the counter pressure plate 5 9 than on the right part. Thereby it is achieved that the respective blade edge can be securely pressed into the gripper cavity 62 at the rear end of the pusher and that an obstruction of the front arc 57 of the retaining spring 56 which supports the separation is avoided.

It should also be mentioned that the counter pressure plate 59 and the springy insertion stop 58 can consist of a single part of springy metal or synthetic material, which can also have tongues punched out inside to be able to replace the effect of the springs 60. The springy insertion stop 58 must be as wide as possible so that bent leaves do not hang up when reinserted. In addition, its elasticity is such that even when there is no leaf or only a few leaves in the housing -42, it extends to the bottom of the housing or almost up to it so that a leaf that is to be inserted into the housing at a low degree of filling is not pushed under the counter pressure plate.

The counter-pressure plate 59 can also be designed with the help of a "wire rack" made of spring steel or springy plastic round material, as shown in one embodiment, e.g. on fig. 2g. Such a part can be formed from a single length of wire and, more specifically, it is bent in such a way that in the corners of an imaginary rectangle lies a respective spiral spring 60å which replaces the spiral spring 60 and can also possibly be conically designed. These spiral springs 60a are connected to each other by means of intermediate steps 59a which constitute extensions of the spiral springs, and these intermediate steps are located at the upper level of the ends of the springs 60a, so that they replace to a certain extent the contact surfaces for the blade stack 1 as in fig. . 2a is formed by the counter pressure plate 5^. The two front coil springs 60a in fig. 2g are connected to each other by means of an intermediate step 58a which likewise forms an extension of the spiral springs and extends obliquely downwards from the upper side of the springs, so that it has the function of an insertion stop 58 and at the same time by its inclined rise deflects respectively guides the incoming blade in the insertion slot 16, more precisely as the front end of the insertion stop 58 as in fig. 2a is not specified in more detail, but which also extends to the bottom of the house and rises obliquely into the house.

In fig. 2d shows a section of the cover 49 on the pusher 43 at the end of the gripper 61, where a strip 62a of a material with a relatively high coefficient of friction, e.g. of rubber, whose free surface 62b, which is preferably flat, is displaced in the direction of the interior of the cavity 62 in relation to the lower edge 49b of the gripper, and more specifically a height h which is preferably 0.1 mm.

Instead of the strip 62a, a small magnetic rod or the like can also be arranged, when one or more fixed elements are placed on the blades of the blade stack 1, on the edge area on the gripper side of each blade, e.g. strips, of iron or another magnetically attractive material, which e.g. located on the undersides of the leaves. In this case, the magnetic force is so dimensioned that it can mainly only take the top blade with it. Even if the next blade is also drawn along to a certain extent by the magnetic force, which is however significantly weaker, this blade is held back by means of the wedge 55.

Finally, in fig. 2e shows a section of the housing cover 49, where the springs 56 are replaced by a springy and transparent plate 56a which in the unloaded state has a bend 56b that corresponds to the insertion stop 58. From a production point of view, it is of great advantage because the housing cover 49 and the springy plate 56a in in this case, transparent plastic can be sprayed twice, preferably of the same material in one work operation.

The plate 56 has at 56b (like the spring 56 in the area 57) a. relatively flat, bent area 56c, so that the respective blade is loaded with pressure over a relatively large length area. In addition, it is relatively strongly bent at 56d and also at 56e.

Furthermore, in fig. 3a and 3b show a device where the separation and pushing out of the blade to be taken out is effected by a suction device 90 which is connected to a vacuum pump 91. This vacuum pump is operated and controlled by means of a pusher.

Now with reference to fig. 4a - 4e describe in more detail a device for collective removal of the leaf stack. In these figures, only the respective pusher is shown, which could also be designated as a drawer and later is so designated and which, in view of the designations used above and in the requirements, is the "additional" pusher, i.e. the pusher that is only operated for the removal of a stack of leaves of the house only partially shown,

while a pusher for changing the blades lying in the housing can be arranged on the not shown left side of the housing, which e.g. can be designed like the right side on

fig. 2a and 2b with the pusher 43 for changing the blades.

Fig. 4a - 4e are therefore in relation to those mentioned with the sides switched. If such an additional pusher is provided in the device of fig. 2a and 2b, the wedge 63 does not of course need to be rotatable. The view shown in fig.<4>a of a section along the line I-1 in fig. 4b shows part of a housing 101, and more precisely in fig. 4a a part of one of the two side walls 102, 103 in the house 101 is visible, while in this figure only some special parts of the bottom of the house 104 are shown, which will be discussed in more detail below.

In the housing 101, a leaf stack, not shown in detail, can be placed which is placed on the bottom 104 of the housing 101, so that the leaf surfaces extend parallel to the bottom and the leaf stack is enclosed on the sides by the side walls 102, 103 and the further side wall 105 as well as a not visible , last opposite side wall. On the side wall 105 are arranged holding fingers 106 that grip over the blade stack. On the side opposite the side wall 105, there are projections arranged on the housing 101 and/or on a pusher that serves for changing the blades in the blade stack, which grip over the blade stack in advance certain length, when the latter pusher for changing blades is pulled as far as possible out of the housing. As a result, the leaf stack cannot be easily removed from the housing from above, nor is it possible to insert a leaf stack into the empty housing from above.

In order for this possibility to be brought forward, the side wall 105 in the housing 101 is placed on a pusher which is held by means of a locking device in the housing 101.

The locking device comprises a latch 108 arranged on the pusher 107 which, in the locked state of the pusher 107, engages in a locking stop 109 arranged on the housing 101, more precisely in the bottom 104 of the housing, so that the pusher 107 in this state cannot be moved out of the housing 101 towards right seen in fig. 4a - 4e.

The holding catch 108 is placed on a tongue 110 and

can by swinging the tongue in the direction of the arrow 111, i.e. inwards into the housing 101, be brought out of engagement with the locking stop 109. So that the engagement between the retaining pawl 108 and the locking stop 109 does not come loose. in one case, the tongue 110 is arranged and placed on the pusher 107 in such a way that, by its own elasticity, it keeps the retaining pawl 108 in engagement with the locking stop 109, if no pressure is exerted in the direction of the arrow 111 from below on the tongue 110.

If the tongue 110 is swung upwards in the direction of the arrow 111, the upper side of the tongue engages with the leaf stack, not shown, and in order for the tongue to be able to take the leaf stack with it when the pusher 107 is pulled to the right, an engagement surface 112 with high friction is arranged on the tongue and more specifically in the present embodiment by a friction element 113, e.g. a small rubber plate, is applied to the upper side of the tongue.

For the reasons already mentioned above for the tongue

110 sensitivity and in order to avoid an accidental operation of the same, a finger engagement recess 114 is arranged on the underside of the tongue (see in particular also fig. 4c). In the present example, this finger engagement recess 114 is only slightly removed from a gripping surface 115 which is preferably knurled and serves to hold the housing 101 when one does not exactly want to pull out the pusher 107. For that purpose, quickly move the user's holding fingers from the gripping surface 115 over for the finger engagement recess 114, the latter can also be arranged immediately next to the gripping surface 115.

In the example shown, the pusher 107 comprises a tongue-shaped guide part 116 which, as can be seen in fig. 4b and 4e> extend into the area of the gripping surface and are attached to or made in one piece with the remaining part of the pusher 107. The tongue 110 is thus located in a longitudinal recess 117 in the guide part 116 and the latter is displaceable in the bottom of the housing 104 in the direction of movement of the pusher 107, as it is stored on its side edges in guide surfaces 118 in the bottom of the housing 104. The guide rafts 118 can e.g. form a dovetail guide which is otherwise arranged and designed in such a way that the guide part 116 on its edge areas 119 on the sides can neither come out of engagement with the guide rafts 118 inwards or outwards.

A stop 120 is arranged on the guide part 116, which e.g. can be designed in the same way as the retaining latch 108, but which can also have any other shape and cooperate with a counterstop 121 on or in the bottom of the housing 104. Thereby the movement of the pusher 107 out of the housing 101, i.e. in the direction of the arrow 122 on fig. 4a, limited and more specifically to a slightly greater length than the above-mentioned predetermined length, with which the blade stack was gripped onto the opposite side of the housing 101 in relation to the pusher 107. When, as a result, a sufficient pressure is exerted on the tongue 110 in the direction of the arrow 111, the blade stack is taken by the pusher 107 with the help of the friction element 113 when it is pulled out and on it in fig. 4a - 4e not shown (left) side of the housing 101 pulled forward under the projections or other overlapping parts that are located there on the housing and/or on a pusher that serves to change the blades in the blade stack. When, on the other hand, the leaf stack in the area of the opposite side wall 105 is held by means of the holding fingers 106, i.e. here despite the pressure on the tongue 110 cannot move upwards, the latter pressure acts in the direction that only the one in fig. 5d the left side of the leaf stack is lifted, which is however fully sufficient and otherwise even advantageous because thereby preventing the leaf stack from being pushed out of the housing 111 uncontrolled by too strong pressure on the tongue 110 and falling to the floor or otherwise dissolving into individual leaves which again must be joined together.

After you have taken out the stack of blades that was previously in the housing 1.01, you release the tongue 110 again and possibly put another stack of blades into the housing 101, after which you push the pusher 107 back into the housing of the retaining catch 108 due to its own elasticity intervenes in the estimate 109.

In cases where the house does not already

can be opened from the top by means of a pusher arranged for changing blades, it is naturally required that the pusher that serves for collective withdrawal, which is referred to below as a drawer, has a greater extension length that is at least dimensioned so that the stack of blades is pulled out as far as possible drawer can be removed without difficulty.

same. If for some reason this friction is not entirely sufficient, then the blade 15 can only move so far in relation to the part 219 until it engages with the hook-like projection 231 which, however, can then no longer grip the next blade in the stack 1 All in all, there is a secure hold on the top leaf 15 which is thus removed from the stack 1. The leaf spring 227 has the task, in the case of leaves with small deviations from the plane, to always ensure a good engagement between the binding element 22 8 and the hook-like projection 231 on one side and the top blade 15 on the other side. When the pusher 43 is reinserted into the housing 42, the hook-like projection 231 causes the top blade not to be touched by the binding element 228, i.e.

that the blade stack 1 can be moved past under part 219 without significant resistance.

An element which can be called a driver element 233 and which e.g. has a chin-like projection 234 and an e.g. binding element 235 consisting of rubber is shown in fig. 5a - 5c. The binding element 235 and the hook-like projection 234 are arranged on the circumference of a roller 236 one after the other in the circumferential direction and this roller is pivotable about its axis 237 which extends parallel to the blade stack 1. The turning movement of the roller 236 about the axis 237 is controlled by an edge 238 fixed to the roller 236 and a cam guide part 239 which in turn is stationary in relation to the roller 236. The roller shaft 237 can e.g. be stored on the pusher 43 on the device in fig. 2a instead of the gripper 61, in which case the cam guide part 239 is arranged on the housing 42.

The operation of the driver element 233 is obvious from the three positions shown in fig. 5a - 5c. The driver element 233 is indeed controlled so that when the top leaf 15 is withdrawn from the stack 1 in the direction of the arrow 240, only the binding element 235 engages with this leaf in the first instance. This position shown in fig. 5a, has the task of creating a step-off between the top leaf 15 and the following leaf in the stack i, the top leaf 15 due to the bond between it and the binding element 235

is shifted a bit laterally.

After this displacement, the cam 2 38 engages with the cam guide part 239, whereby the driver element 233 is turned a predetermined angle clockwise, and more precisely so that the hook-like projection 234 engages with the rear edge of the blade 15 and takes the blade with it. further. This hook-like projection 234 is kept in the same position during the entire transport of the blade 15 by means of the straight, plate-like cam guide part 239, which is such that the hook surface of the projection 234 that engages with the rear edge of the blade 15 extends perpendicular to the blade edge . As will be apparent from this mode of operation, the height h of the hook can easily be greater than the thickness of a blade because the hook-like projection 23 4 only engages with the rear edge of the blade 15 when this has already been displaced a little in relation to the stack 1 , so that the hook-like projection 234 has absolutely no possibility of gripping a further blade edge. As a result, a very secure gripping effect of the hook-like projection 234 is made possible.

In the return run of the driver element 233 shown in fig. 5c, the driving element is turned about the axis 237 by means of the cam 238 and the cam guide part 239 in the opposite direction, i.e. clockwise, so that both the hook-like projection 234 and the binding element 235 become ineffective and the roller 236 with a sliding surface 241 which is smooth and e.g. consists of plastic, can slide over the blade stack in the direction of the arrow 242.

It should also be mentioned here that a resilient contact pressure is constantly maintained between the stack 1 and the driver element 233. Furthermore, it should be pointed out that the driver element does not necessarily have to be in the form of a roll, but that in principle any corresponding rotatable part that has a convex surface facing the leaf stack *1, on in which the hook-like projection 234, the binding element 235 and the sliding surface 241 are arranged one after the other in the direction of movement.

In fig. 6a and 6b show an embodiment which is designed in such a way that it can be produced together in one piece of transparent plastic. This means that the housing 2 with its cover 2a and with the parts 2b that have the blade edge installation surface 11

and respectively on one side: delimits the outlet slot 10 and the insertion slot 16, consists of one piece, as the cover, which can be closed in the direction of the arrow 2c, is connected by a plastic link 2d to the other part of the housing 2. The outlet slot 10 is formed here by a recess in the bottom of the house 2 which in the middle area of the house has another one running into the house

extension 2e, through which the lower blade can be grasped with a finger and moved in the direction of the withdrawal slot 10 and thus can be taken out of the housing as indicated in fig. 6a.

It should be pointed out here that the individual features in one or the other of the described embodiments can be transferred to any other of the described embodiments to the extent that it is technically appropriate with regard to their cooperation in the respective, freely selectable blade change operation or in another way, or if they do not touch this leaf-changing operation at all, e.g. such as the special design of the pivot key or the arrangement of the housing cover on the pusher or on the housing.

It is e.g. especially possible to replace the transport elements used to solve the transport problem (extraction of a leaf), e.g. gripping edges or similar, mutually or with other elements that are effective for gripping or hold or by friction against the blade to be removed. Thus, e.g. as an element that should grip a blade, instead of a gripping edge or 1 instead of a negative pressure driver, a row of brushes with a free-wheel effect is used, i.e. with brushes that stand at an angle in the direction of extraction and when a blade is extracted "strikes against" the underside of the blade,

while when pushing in the blade slides without force on the underside of the blade, Instead of the brush, one can also be used consisting of a series of saw-tooth-like protrusions made of metal or another sharp material, whose saw-tooth edges point obliquely in the direction of extraction of the pusher, so that they to a to some extent "stick into" the underside of the blade, while when the pusher is reinserted into the housing they slide away over the underside of the blade.

Claims (4)

1. Device for displaying the individual sheets (15, 44) in a stack of sheets (1), in particular a device in the form of a so-called photo viewing switcher, comprising: - a housing (2, 40, 42, 101) and a pusher (39) , 43, 107) which can be moved back and forth in relation to the housing in a direction parallel to a main plane of the blades (15, 44) in the blade stack (1), as this, when inserted into the device, is enclosed by the pusher and the housing , whereby at least one blade (15, 44) is separated from one end of the stack (1) during the pull-out movement of the pusher (39, 43, 107) in relation to the housing (2, 40, 42, 101) and is led out through a withdrawal slot (10) , after which one or each separated blade (15, 44) is again fed to the stack (1) during the pusher's subsequent push-in movement, now via an insertion slot (16) and to the opposite end of the stack, - a blade edge installation surface (11) arranged between the slots (10, 16), and on/in one of the building elements housing (2, 40, 42, 101) or sliders (39, 43, 107), and a corresponding counter blade edge installation surface (30) on/in same building element, and - a blade counter-pressure surface against which the stack (1) can be pressed, CHARACTERIZED BY the fact that both blade edge installation surfaces (11, 30) are arranged at an angle in relation to the counter-pressure surface so that the blade edges on two mutually opposite sides of the stack (1) are displaced horizontally in relation to each other. 2. Device according to claim 1, CHARACTERIZED BY the fact that the opposite blade edge installation surface (30) sits on a mainly wedge-shaped construction part (63) which can be rotated about a shaft (64) whose longitudinal axis lies parallel to one edge of the blades (15, 44), and that the construction part (63)'s opposite side in relation to the counter blade edge installation surface (30) has a surface which forms a side wall in the housing (42). 3- Device according to claim 2, CHARACTERIZED BY the fact that the wedge-shaped component (63) has one or more parts (52) which, in this component's normal position, grip over the adjacent edge of the blade stack. 4. Device according to one of the preceding claims, CHARACTERIZED IN THAT the opposite blade edge installation surface (30) in the area of the rear edge of the end blade on the outlet slot side has two step-like ledges (100, 99) with a step height that is approximately equal to the thickness of a blade.