Apparatus for stacking individual sheets

The invention relates to an individual-sheet stacking apparatus including a frame, a support which is displaceably guided at the frame and which is fitted with a rest surface for the individual sheet stack and having a pressurizing spindle to alternatingly shift and release the support. The pressurizing spindle consists of a pressurizing shaft rotatably supported at the frame, two pressurizing spindle lateral elements affixed to the pressurizing shaft, and at least two glide shafts configured in a fixed or rotatable manner at the pressurizing spindle lateral elements, the glide shafts being fitted with glide rollers. A drive means drives the pressurizing spindle into rotation.

BACKGROUND OF THE INVENTION

The present invention is based on an apparatus stacking sheets, in particular money bills.

The state of the art of the German patent document 101 01 563 A1 discloses an apparatus delivering and accepting individual sheets. The singularization and stacking of the individual sheets is implemented by the cooperation of a stack support fitted with a drive, two transport rollers and a sector cylinder with several sector rollers. In order to feed an individual sheet to a stack resting on said support, this individual sheet is pulled in by the two transport rollers and inserted along a guide surface into a slit between the sector cylinder and the end stack surface. To secure enough space for the individual sheet between the sector cylinder and the stack end surface, the drive pulls back said support. Next, the individual sheet is moved toward the stack. This design incurs the drawback that not only the transport rollers and the segment drum must be driven, but also the support. In other words, a first drive must be provided for the rollers and cylinder and a second one for the support. Moreover, the drive requires a control fitted with a commensurate sensor system. As a result, not only is apparatus manufacture costly, but energy also must be applied to both drives to operate the apparatus, entailing further costs.

The objective of the present invention is to create an individual sheet stacking apparatus of lower costs of manufacture and operation than are incurred in the apparatus of the state of the art.

BRIEF SUMMARY OF THE INVENTION

Compared to the state of the art, the apparatus of the present invention includes on one hand a displaceably guided support with a rest surface for a stack of individual sheets and on the other hand a pressurizing spindle to alternatingly shift and release the support. In a first position, the support is situated directly against the pressurizing spindle before any sheet lies on the support. When inserting individual sheets into a stack at the support, the same is displaced by the pressurizing spindle at every individual sheet by exactly that distance which corresponds to the individual sheet's thickness. This shifting motion is implemented solely by the pressurizing spindle. A further drive is not needed. The support is displaced until the stack is full. The support will be in its second position at the end of stacking. In this second position, the spacing between the support and the pressurizing spindle does correspond to the stack's thickness. After removing the stack, the support is returned into its first position directly against the pressurizing spindle. This motion may be manual or automated.

The pressurizing spindle, alternatingly displacing and releasing the support, consists of a pressurizing shaft rotatably supported on the lateral parts of a frame of the apparatus, of two pressurizing spindle lateral elements affixed to the pressurizing shaft and at least two glide shafts with glide rollers mounted on pressurizing spindle lateral parts at equal radial distances and parallel to the pressurizing shaft. The glide rollers may be configured rotatably or in fixed manner on the pressurizing spindle lateral parts. The glide rollers in turn may be configured rotatably or in a fixed manner on the glide shafts. Advantageously, the glide rollers are mounted rotatably on the fixed glide shafts. At least either the glide shafts or the glide rollers should be rotatable to preclude that, when the glide rollers roll off the uppermost individual sheet of the stack, this sheet should be shifted. The positions of the individual stack sheets should remain unchanged when an additional individual sheet is added. The pressurizing spindle is merely used to displace the support to make room for the individual sheets to be admitted into the stack. The individual sheets are not moved by the pressurizing spindle. To make sure, the surfaces of the glide rollers should be as smooth as possible. This condition minimizes the friction between the glide rollers and the individual sheets. Advantageously, a limiting element is configured above the pressurizing spindle to avert shifting the individual sheets upwards.

In an especially preferred manner, three or four glide shafts with glide rollers are mounted on the pressurizing spindle lateral parts. By selecting this number of glide shafts, the gap is large between the glide shafts with their associated glide rollers available for an individual sheet, on one hand, and on the other, the sequence of alternating displacements and releases will optimally match the feeding of the individual sheets.

The guide assures that the support shall be consecutively displaced with each inserted individual sheet and that the displacement is rectilinear. Because of the inertia of the system constituted by the support and the guide, the support shall be displaced each time only as far as it is moved through the pressurizing spindle. Displacement over a larger distance or in the opposite direction is precluded short of applying an external, additional force. In this manner, the support shall advance each time only by the length corresponding to the thickness of one sheet.

Thanks to the cooperation between the support and the pressurizing spindle, only one drive is needed for said spindle. The support being displaced by the pressurizing spindle, a support drive to stack the individual sheets is superfluous. Additional control means and associated sensors can be dispensed with.

One advantageous design of the present invention includes a transport roll to seize a sheet being fed to it in the direction of motion of the individual sheet in front of the pressurizing spindle. The transport roll includes a transport shaft rotatably resting on the lateral frame parts parallel to the pressurizing shaft. Several mutually apart disks that are coaxial with the pressurizing shaft are mounted on the transport shaft. The transport shaft cooperates with one or more guides. These guides are straight or curved plates affixed to the frame. They are mounted in such a manner on the frame that when an individual sheet is being moved, at least one plate shall be positioned above and at least one plate underneath said individual sheet. Advantageously the apparatus of the present invention may be additionally fitted with a guide spindle which also cooperates with the transport roll. The guide spindle consists of a shaft and several transport disks configured coaxially with and on the shaft. The plates are configured mutually spaced apart as a result of which the guide spindle may act by means of the transport disks between the plates in order to move an individual sheet. The individual sheet is frictionally displaced between the individual sheet and the transport disks. The transport disks of the transport shaft preferably are connected rigidly to the transport shaft. The surface of the displacing disks is rough to prevent the individual sheet from slipping along the displacing disks. In one advantageous embodiment mode of the present invention, the transport spindle is driven via a gear by the same drive acting on the pressurizing spindle.

In another further embodiment of the present invention, one or more individual sheet guides are configured underneath the pressurizing spindle in front of the support. The individual sheet guides assure that an individual sheet's edge pointing forward in the direction of advance shall be moved—after having been released from the transport roll or from another conveying element—to that zone wherein the pressurizing spindle touches the support or the stack resting against the support. The single sheet guide may run as an integral part over the full length of the pressurizing spindle or be configured in the form of strip-like, individual single sheet guides between the transport disks or the glide rollers of the pressurizing spindle. Preferably, the individual sheet guides are leaf springs. Advantageously too, the individual sheet guides shall rise at least to a height corresponding to that of the pressurizing shaft. In an especially preferred manner, the individual sheet guide length seen in the direction of advance corresponds to that of the individual sheets in the direction of advance. As a result, an individual sheet shall be reliably guided even when there are creases in it before it is inserted into the conveying system.

A further advantageous embodiment of the present invention comprises a brush roll to pressurize the edges of the individual sheets configured in the stack. This feature precludes protrusion of the stack's individual sheet edges facing an individual sheet being inserted. Again, as a result, the approaching individual sheet shall always be inserted at the front on the stack, not behind the uppermost or another individual stack sheet. Also, the brush roll forces the edge pointing to the rear as seen in the direction of advance of the individual sheet to be inserted against the stack when said edge is released by the transport roll or another transport element. The brush roller is fitted with a bristle shaft supported at the lateral frame parts parallel to the pressurizing shaft. A plurality of bristle bundles pointing radially outward are affixed to the brush shaft. Advantageously, the brush roll is driven by means of a gear unit by the same drive as is the pressurizing spindle and where called for the transport roll. The bristles may be replaced by impellers mounted on a driven shaft. The impellers project radially outward. The resiliency of the particular impellers is implemented by using, for instance, materials such as thermoplastic elastomers. The impellers improve the transport in the direction of advance of a single sheet's rear edge.

In another advantageous embodiment of the present invention, the guide system comprises a beam firmly affixed to the support. The beam is guided at the two lateral parts of the frame. For that purpose the lateral parts are fitted with elongated holes or elongated slits engaged by the beam's ends. In such a design the weight of the support and beam bears on the lateral parts. The support advantageously is mounted rigidly to the beam at an angle to the vertical and at a slant.

In another embodiment mode of the present invention, the support guide comprises at least one belt and two pulleys for each belt. The support is firmly connected to the belt(s). An additional affixation means may be provided. Illustratively, the belts also may be affixed to the beam. The belt(s) running around the pulleys move in respectively opposite the direction of motion. They act as stop surfaces to the lower edges of the individual stack sheets. Advantageously, the belt surface facing the stack and the support shall be roughened.

In a further advantageous embodiment mode of the present invention, the belts are toothed belts and the pulleys are toothed belt pulleys. Because of the geometric interlocking of the belts and the toothed pulley(s), the belt(s) cannot slip relative to the pulleys. As a result, the pressurizing spindle always must drive the belts and the associated toothed pulleys to displace the support.

In a further advantageous implementation of the present invention, the belt(s) is/are guided by the pulleys in part above and in part below the base. That part above the base rests against it. In this manner this portion of the belt(s) together with the support and an optionally additional fastener can rest on the base.

In a further advantageous embodiment of the present invention, one of the belt pulleys is fitted with a belt drive to allow—following removing a stack out of the apparatus—moving the support out of its second position back into its first position at the pressurizing spindle. Preferably, the drive is fitted with a propulsion spring or a spiral spring. The spring forces the support against the pressurizing spindle. The support is fitted directly or indirectly with a stop-advance element. Merely by unlocking it, the support may be moved from its end position—which corresponds to a full stack—back into its initial position near the pressurizing spindle.

Further advantages and advantageous designs of the present invention are defined in the description below, the appended drawings and the claims.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1 through 5show individual sheet stacking apparatus comprising two lateral parts1and2, a base3, a support4, a pressurizing spindle5and a transport roll6. The support4substantially consists of a rectangular plate with a central cutout affixed to a beam7while oblique to the vertical. The beam7is guided in two long slits8and9of the lateral parts1and2. Two toothed belts11and12are affixed to the beam by screws10. The teeth of the toothed belts cannot be seen in the drawing. The toothed belts run on toothed pulleys13,14, and15. The two rear toothed pulleys13and14are shown inFIGS. 1,2and4.FIG. 3additionally shows one of the two toothed pulleys15. The second front toothed pulley is absent from all Figures.

The pressurizing spindle5comprises a pressurizing shaft16rotatably supported in the two lateral parts1and2. Two pressurizing spindle side elements17and18are affixed to the pressurizing shaft16. Said side elements are cross-sectionally square. A glide shaft19is affixed at each end of the pressurizing spindle lateral parts, so that a total of four glide shafts19are configured at the pressurizing spindle. Each glide shaft is fitted with a total of four glide rollers20. The glide rollers20are rotatably connected to the glide shafts19.

A transport roll6is configured underneath the pressurizing spindle5. Said conveying spindle comprises a transport shaft21rotatably supported on the two lateral parts1and2. A total of six transport disks22are affixed to the transport shaft21. The transport disks22are rigidly connected to the transport shaft21. Several individual sheet guides are configured in the region of the pressurizing spindle5and the transport roll6. A first individual sheet guide23runs in the advance direction from the front end of the two lateral parts1and2as far as the region of the front toothed pulleys15. This feature is shown especially clearly inFIG. 3. The first individual sheet guide23runs perpendicularly to the direction of advance, further over the full width of the frame between the two lateral parts1and2. The first individual sheet guide23follows, at least partly, the shape of the transport disks22, as a result of which only a small guidance gap remains between said transport disks and the first individual sheet guide. In the region ahead of the transport roll6, the first individual sheet guide23is covered above by a second individual sheet guide24. A gap is subtended between the first and the second individual guide somewhat larger than the thickness of an individual sheet. In this manner an approaching individual sheet arrives as far as the transport spindle without encountering excessive friction that would be entailed by a too narrow gap. As seen in the direction of advance, as soon as the individual sheet, by its front edge, reaches the region of the transport roll6, it will be forced by the transport disks37of a guide spindle36against the transport disks22. The guide spindle36and the transport disks37of the guide spindle36are shown inFIG. 5. Because of the friction entailed between the transport disks22and37on account of their rough surfaces on one hand and the individual sheet on the other, said individual sheet is gripped and transported. The force required for significant friction is generated by the transport disks37of the guide spindle36. Third individual guides25are configured above the transport roll6. Said guides run as seen in the direction of advance from the transport disks22of the transport roll6as far as into the region above the glide rollers20of the pressurizing spindle5near the support4. This path is shown inFIG. 3.FIG. 5shows the position of the third individual sheet guides25perpendicular to the direction of advance. These third individual sheet guides25extend width-wise in the gaps between the transport disks22and the glide rollers20.

A limiting element42is configured above the pressurizing spindle and prevents the individual sheets from being pushed upward. Said element moreover is covered upward as a whole by a cover44. It limits the upward stack height. The cover is affixed by a hinge and a lock to a housing43enclosing the apparatus. Both hinge and lock are omitted from the drawing.

A brush roll26is configured underneath the support4and behind the transport roll6. This configuration is shown inFIG. 3. The brush roll comprises a brush shaft27rotatably supported in the two lateral side parts1and2. Numerous bundled bristles28are configured on the brush shaft and distributed over its entire length and entire circumference.

The pressurizing spindle16, the transport shaft21and the brush shaft27are fitted at their ends projecting beyond the lateral part2with gears29,30,31and32. Another gear33rotatably configured at the lateral part2transmits the rotation of the gear29to the gear30. The gear31engages the gear32. The gears29through33constitute a gear unit. To drive into rotation the pressurizing spindle, the transport roll and the brush roll, no more need be done than to connect one of the gears or the associated shaft to a drive. The drive is not shown in the drawing.

The two rear toothed belt pulleys13and14are mounted on a common toothed pulley shaft34rotatably supported in the two lateral parts1and2. A propulsion spring is configured at the toothed belt shaft34in the region of the lateral part1. A spiral spring may also be used instead of a propulsion spring. Such a drive is used to force the support4against the pressurizing spindle. A stop-advance element38shown inFIG. 2and configured at the toothed pulley shaft34assures the support4shall be pushed stepwise by the pressurizing spindle from an initial position near the pressurizing spindle into a final position near the toothed pulley shaft. This stop-advance element precludes the possibility of a displacement in the opposite direction while receiving the individual sheets into a stack. The stop-advance element38is connected by a serration not visible in the drawing with a lever39. This lever is forced by a tension spring40against the serration of the stop-advance element38. Said lever rests by means of the shaft41against the housing. When the lever39is pivoted out of its initial position shown inFIG. 2, into a second position and in the process is rotated about the shaft41, the serration of the stop-advance means will be disengaged. The propulsion spring assures that the support4is returned from its rearmost position—especially following removal of a complete stack of individual sheets not shown in the drawing—back into its initial position near the pressurizing spindle5. This initial position of the support4is shown inFIGS. 1 through 5.

The individual sheets are stacked as follows:

In the beginning the support4is in its initial position or first position directly at the pressurizing spindle5. Therein the glide rollers20of one of the glide spindles19do touch the support4at its surface. No individual sheets yet are situated at the support. Next, an individual sheet is fed in-between the first and second individual guides23and24. As soon as the individual sheet (omitted from the drawing) is situated between the transport disks22of the transport roll6and the transport disks37of the guide spindle36, it shall be moved upward by the transport roll6. For that purpose and as shown inFIG. 3, the transport roll6is rotated counter-clockwise. As soon as the front edge—as seen in the direction of advance—of the individual sheet has been released by the transport spindle, it arrives in the region of the third individual sheet guides25. Part of the individual sheet still remaining between the transport disks22of the transport roll6and the transport disks37of the guide spindle36, said individual sheet will further be pushed upward. The third individual sheet guides25assure that said sheet's front edge reaches the region wherein the glide rollers20touch the support4. The distance subtended in the circumferential direction of the pressurizing spindle between the glide rollers of different glide shafts and the ensuing gap between the support4and the glide rollers20allows placing the individual sheet's front edge against the support. Moreover the transport spindle assures that the individual sheet shall be pushed upward. The third individual sheet guides25above the pressurizing spindle5ensure that an individual sheet shall remain duly near the stack. This is especially the case regarding crumpled individual sheets because of their own stresses. As soon as the individual sheet front edge rests against the support, the glide rollers20of a further glide shaft19and because of the pressurizing spindle rotation touch the guided individual sheet and ensure that the support shall be exactly moved back by the distance corresponding to the individual sheet's thickness. The guide rollers, being rotatable relative to the glide shafts, and moreover having a smooth surface, said individual sheet shall not be moved, or only negligibly so, by the glide rollers. To preclude that on account of excessive friction an individual sheet being deposited on the front stack edge be pushed upward excessively, the limiting element42is configured above the pressurizing spindle5. The pressurizing spindle is rotated counter-clockwise. After the rear edge of an individual sheet has passed the guide spindle36, further transportation is implemented by the pressures from the bristles28of the brush roll26on the individual sheet and hence on the transport roll6. As soon as the rear edge—as seen in the direction of advance—of the individual sheet has been released by the transport roll6and the first individual sheet guide23, the lower region of said sheet is seized by the bundles of bristles28of the brush roll26and forced against the support4. In the process said individual sheet orients itself in a manner that it shall rest by its full surface on the support4. The next individual sheet is fed in the same manner. This procedure is repeated until either the stack does contain the desired number of individual sheets or the support4is in its rearmost position near the toothed pulley shaft34. After the stack has been removed, the lever39is pivoted and released from the serration of the stop-advance element38. Next, the propulsion spring35causes the support4jointly with the beam7to be returned into its initial position at the pressurizing spindle5. Optionally, the support also may be manually returned into its initial position at the pressurizing spindle5. Stacking may then begin again.

As soon as several individual sheets have been received in a stack, the support4is situated a distance from the pressurizing spindle5corresponding to the stack thickness. In that position the stack's individual sheets rest by their lower edges on the two toothed belts11and12. The support4being firmly connected by the beam7and the screws10to the two toothed belts11and12, the individual sheets standing on the toothed belts are entrained by them when the support4is shifted. As a consequence when the stack is displaced jointly with the support4and the belts, no friction arises between the stack's individual sheets and a substrate. The force by which the pressurizing spindle5must shift the support4and the stack ever larger and heavier with each new sheet therefore changes only slightly.

All features of the present invention may be construed being inventive per se or in arbitrary combinations.

LIST OF REFERENCES