Abstract:
A paper dispenser contains a receiving compartment for a dispenser roll, a transport path leading from above into the receiving compartment, a hold position for a spare roll being defined in the transport path by a blocking device, and a transfer device for the paper of the spare roll once the paper of the dispenser roll is used up. The width of the receiving compartment is smaller than the diameter of the spare roll, and a sensor element for the diameter of the spare roll releases the blocking device not before the diameter of the spare roll has been reduced to the width of the receiving compartment.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This is a continuation application, under 35 U.S.C. §120, of copending international application No. PCT/AT2009/000186, filed May 4, 2009, which designated the United States; this application also claims the priority, under 35 U.S.C. §119, of Austrian patent application No. A 703/2008, filed May 5, 2008; the prior applications are herewith incorporated by reference in their entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The invention relates to paper dispensers having a housing, in which the following are provided: a receiving compartment for a dispenser roll, a guide track leading from above into the receiving compartment for a spare roll that can move from an upper waiting position into the receiving compartment, and a device for transferring the paper from the spare roll, which is dispensed once the dispenser roll has been used up. 
     A paper dispenser of this type is known, for example from U.S. Pat. No. 4,844,361. There, the diameter of the dispenser roll is monitored and, when a minimum diameter of the dispenser roll is determined, a blocking device for the waiting position is released. As a result, the spare roll is transferred downward into the dispensing position, so that further paper can be drawn off this roll and a new spare roll can be inserted from above at some time before the spare roll is used up. This requires a dispenser housing in the lower dispensing part of which there is space for a full diameter roll. As a result, the housings become relatively voluminous, in particular when cutting devices, electric drives, battery compartments or further internal fittings are intended to be present. 
     SUMMARY OF THE INVENTION 
     It is accordingly an object of the invention to provide a paper dispenser which overcomes the above-mentioned disadvantages of the prior art devices of this general type. 
     With the foregoing and other objects in view there is provided, in accordance with the invention a paper dispenser for dispensing paper. The paper dispenser contains a housing, a receiving compartment for a dispenser roll disposed in the housing, and a guide track leading from above into the receiving compartment for a spare roll that can move from an upper waiting position into the receiving compartment. The guide track is disposed in the housing. A device is disposed in the housing for transferring the paper from the spare roll, which is dispensed once the dispenser roll has been used up. A waiting position is delimited by a narrow passage through which the spare roll can move into the receiving compartment only when the spare roll has a reduced diameter. The narrow passage is disposed in the housing. 
     The invention has now recognized that the width of the receiving compartment for the dispenser roll can be smaller than the diameter of the spare roll if the waiting position is delimited by a narrow passage, through which the spare roll can move into the receiving compartment only when the roll has a reduced diameter. The reduced width of the receiving compartment also means that the height is reduced, so that space is created for additional constituent parts of the dispenser. The starting point is the thought that refilling is not carried out anyway immediately after the dispenser roll has been used up but at a time interval thereafter and during this time period it is naturally of no importance whether the new roll is lying in a lower dispensing position or still in the upper waiting position of the spare roll. 
     The narrow passage can be formed between the guide track and a housing part, for example the rear wall of the latter, i.e. the spare roll rests with the circumference on the rear wall and cannot fall down, since the guide track is narrower than the diameter of the spare roll or because, in the case of rolls which are provided with bearing journals projecting at the ends, which slide or fall in groove-like guide tracks, the bearing journals are still at a distance from the section leading downward. If the spare roll is gradually used up, then the diameter of the spare roll or the distance of the bearing journals from the section of the guide track leading downward decreases. For instance, after half has been used up, that diameter which allows the spare roll to slip downward can then be reached. 
     Since the paper rolls are normally neither dimensionally accurate nor exactly cylindrical, it is possible for the cross-sectional area of the roll not to be circular but slightly elliptical, so that the roll jams as it slips down or moves down, or the two bearing journals do not enter synchronously into the groove sections leading downward. 
     In order to avoid faults caused as a result, a preferred embodiment provides for a blocking device to be provided in the narrow passage, which is released only when the diameter of the spare roll has been reduced below the width of the narrow passage. 
     For the registration of this once more somewhat smaller diameter of the spare roll, the latter is preferably directly or indirectly assigned a movable sensing element. In a first embodiment, the direct diameter registration can be carried out by the movable sensing element resting on the circumferential surface of the spare roll. 
     In a further embodiment, the diameter registration is carried out indirectly by sensing the migration of the roll axis, in particular of the bearing journal along the initial section of the guide track, which takes place as a function of the reduction in the diameter. For instance, a pivotable sensing element can rest on the bearing journal and, after the appropriate distance has been reached, can fall away, the blocking device being unlocked mechanically. 
     This can be done, for example, by the pivoting movement of the sensing element being converted into a linear movement of the blocking device which, in this case, is formed in particular by a slide, the end of which projects into the guide track. 
     In a second embodiment, provision can be made for the blocking element provided to be a swinging arm that can be moved downward, the end of which projects into the guide track and is released by the moving sensing element. 
     If the paper dispenser according to the invention has a lid that can be pivoted up, provision is preferably made in a further embodiment for the sensing element also to pivot upward therewith, in order to be able to insert the spare roll more easily. When the lid is closed, the sensing element also falls down again and rests on the inserted spare roll. 
     A further preferred embodiment of a paper dispenser having a receiving compartment for a dispenser roll, having a guide track leading from above into the receiving compartment, in which track a waiting position, defined by a blocking device, for a spare roll is provided, and having a device for transferring the paper from the spare roll after the paper from the dispenser roll has been used up, is characterized in that the width of the receiving compartment is smaller than the diameter of the spare roll, and a sensing element for the diameter of the spare roll is provided, which releases the blocking device only when the diameter of the spare roll has been reduced to the width of the receiving compartment. 
     Other features which are considered as characteristic for the invention are set forth in the appended claims. 
     Although the invention is illustrated and described herein as embodied in a paper dispenser, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. 
     The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
         FIG. 1  is a diagrammatic, side view of an upper region of a paper dispenser with a lid open according to the invention; 
         FIG. 2  is a diagrammatic, longitudinal sectional view through the paper dispenser according to  FIG. 1 ; 
         FIG. 3  is a diagrammatic, side view of the upper region with a spare roll that has already been largely reduced in size; 
         FIG. 4  is a diagrammatic, longitudinal sectional view through the paper dispenser according to  FIG. 3 ; 
         FIG. 5  is a diagrammatic, side view of the upper region showing a waiting position for a spare roll unlocked; 
         FIG. 6  is a diagrammatic, longitudinal sectional view through the paper dispenser with a blocking device drawn up completely and a spare roll that has fallen downward; 
         FIG. 7  is a diagrammatic, perspective view of two side walls of a second embodiment of a paper dispenser having a roll carrier in the dispensing position and a roll carrier in the waiting position; 
         FIG. 8  is a diagrammatic, side view of an upper region of the side wall from  FIG. 7  with a schematically inserted spare roll, similar to  FIG. 1 ; 
         FIG. 9  is a diagrammatic, side view of the upper region of the side wall from  FIG. 7  with the waiting position for the reduced size spare roll already unlocked, similar to  FIG. 5 ; 
         FIG. 10  is a diagrammatic, side view of the upper region of the side wall from  FIG. 7 , the spare roll having moved downward part of the way; and 
         FIG. 11  is a diagrammatic, perspective view of the two side walls with the two roll carriers in the positions according to  FIG. 10 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the figures of the drawing in detail and first, particularly, to  FIGS. 1 and 6  thereof, there is shown a dispenser for paper from a dispenser roll  17  that has in a housing  1  an upper receiving compartment for a spare roll  13 , which is accessible after a lid  2  has been pivoted up. The dispenser has mutually opposite guide tracks  11  in the form of side wall grooves, in which bearing journals  19  projecting from roll carriers  12  at the ends engage. As can be seen from  FIG. 6  or  8 , a full spare roll  13  almost fills the upper part of the dispenser housing  1 . Formed in the guide track  11  is a narrow passage  20 , which defines a waiting position for the spare roll  13 . Provided in the narrow passage  20  is a blocking device  9 , which projects with one end into the guide track  11  and can be removed from the latter in order to permit the spare roll  13  to slip or move downward. 
     Provided in the lower part of the dispenser housing  1  is a receiving compartment  16  for the dispenser roll  17 , from which the paper web is drawn off, passing through a conveying device, not specifically explained. A width B of the receiving compartment  16 , as can be seen from  FIG. 6 , is substantially smaller than the diameter of a spare roll  13 , preferably only about half the width thereof, so that other components of the paper dispenser can be accommodated in the space saved. In order then to be able to continue to remove paper from the dispenser after the paper from the dispenser roll  17  has been used up, a device  18 —merely indicated—is provided ( FIGS. 6 ,  7 ), which feeds the paper start of the spare roll  13  following the end of the dispenser roll  17  to the conveying device, through which the paper web from the spare roll  13  is then drawn down. In the process, the spare roll  13  first remains in the waiting position in the upper part, in which, since it cannot pass through the narrow passage  20 , it rests on the rear wall of the housing  1 , and in which the bearing journals  19  of the roll carrier  12  are prevented from moving by the blocking device  9 . 
     In the embodiment according to  FIGS. 1 to 6 , a sensing element  15  in the form of a pivoting bow or the like, which is dynamically coupled to the blocking device  9 , rests on the spare roll  13 .  FIGS. 1 ,  3 , and  5  reveal that on the pivot axis  4  that bears the sensing element  15  there is provided an approximately triangular control part  7 , to which the upper end of the blocking device  9  is attached at a distance from a pivot axis  4 . A hinge pin  10  thus moves on a circular arc, since the sensing element  15  pivots downward when the diameter of the spare roll  13  becomes smaller. The arrangement is made in such a way that, at the start of the pivoting movement of the sensing element  15 , the hinge pin  10  moves over an angle of about 60° on a “horizontal” curve, i.e. that the end in the guide track  11  does not release the spare roll over this range, since the directional component directed upward is small. 
       FIGS. 3 and 4  show the position of the sensing element  15  and of the blocking device  9  shortly before the spare roll  13  has been used up to such an extent that the diameter thereof has been reduced to the width B of the receiving compartment  16  and the spare roll can be transferred downward. The sensing element  15  is still just lying on the spare roll  13  and—as soon as some more paper has been drawn off—will pivot through into the release position for the blocking device  9 , as can be seen from  FIG. 6 . As the sensing element  15  pivots through, the hinge pin  10  pivots outward on a steeply rising curve since, over this angular range, the lifting component has become substantially greater and the blocking device  9  is drawn up. The remaining part of the spare roll  13 , the diameter of which is now minimally smaller than the width B of the receiving compartment  16 , can then fall or slip downward without jamming, so that it continues to function as a new dispenser roll  17 . Then, until the new dispenser roll  17  has been used up, a spare roll can be put in at the top. Hooked into the control part  7  is a tension spring  8 , the other end of which is fixed to a spring holder  6 , so that the sensing element  15  is pressed onto the spare roll  13 . In order to make it easier to insert the new spare roll, the spring holder  6  is not fixed to the housing  1  but to a curved extension  3  of the lid  2 , which slides in a pivoting guide  5  of the housing  1 . As the lid  2  is pivoted, the tension spring  8  is therefore relieved of tension, since the spring holder  6  is moved concomitantly, and the sensing element  15  is likewise moved upward. 
     In the embodiment according to  FIGS. 7 to 11 , the registration of the diameter of the spare roll  13  and the release of the blocking device  9 ′ are not carried out by a sensing element pressing directly against the circumference of the spare roll  13  but by a sensing element  15 ′ which can likewise be pivoted and which rests on one of the two bearing journals  19  sliding or rolling in the grooves of the guide track  11 . As can be seen from  FIGS. 7 to 11 , the sensing element  15 ′ extends above the first section of the guide track  11 , which falls slightly rearward, and is mounted such that it can pivot about an axis  21 . The sensing element  15 ′ engages in the guide track  11  and is raised by the bearing journals  19  of the spare roll  13  when the latter is inserted into the paper dispenser. As  FIG. 8  shows, in the waiting position the spare roll  13  rests on the rear wall of the housing  1  before the bearing journal  19  comes to lie above the section of the guide track  11  that continues downward. The sensing element  15 ′ has a control part  7 ′ projecting in the manner of a hook, on which a blocking projection  23  is formed. 
     Paper is dispensed as required from the dispenser roll  17  lying in its lower dispensing position, which roll rests with a bearing journal  19  on a bearing lug  31  that can be pivoted out. Once the paper from the dispenser roll  17  has been used up, paper from the spare roll  13  in the waiting position is gripped and output by a non-illustrated device. Transfer devices  18  needed for this purpose ( FIG. 7 ) are known in various embodiments and belong to the general prior art, so that it is not necessary to discuss them in more detail here. They are not important to the understanding of the invention treated here. 
     Dispensing the paper from the spare roll  13  leads to a reduction in the diameter, and the roll carrier  12  or the bearing journal  19  come closer to the region of the section leading downward, until the position shown in  FIG. 9  is reached, which represents the end of the waiting position and in which the bearing journal  19  has entered the release position  22  of the control part  7 ′. 
     The blocking element  9 ′, which can be pivoted downward about the axis  24 , engages in both guide tracks  11  and blocks both bearing journals  19 , has a side part  25 , on which there is provided a stop  26  interacting with the blocking projection  23 . 
     In the position according to  FIG. 9 , the blocking projection  23  has been lowered together with the sensing element  15 ′, so that the stop  26  is free and can pivot downward with the blocking element  9 ′.  FIG. 10  shows a position of the individual elements at about half the pivoting travel. The bearing lug  31  mentioned above has on its swinging arm  30  a lateral elevation  32 , onto which the blocking element  9 ′ runs, the empty roll carrier  12  of the dispenser roll  17  that has been used up losing its support, so that it is able to tilt downward, as can be seen from  FIG. 11 , and slips out of the opposite guide track  11 . As the blocking element  9 ′ is pivoted further downward, the bearing lug  31  returns into its position and is once more able to support the spare roll  13  slipping down, which therefore becomes the new dispenser roll  17 . 
     Then, the blocking element  9 ′ is repositioned in the position according to  FIG. 9  by a non-illustrated spring, so that when a new spare roll  13  is inserted, the control part  7 ′, which, according to  FIG. 8 , has been raised again with the sensing element  15 ′, once more defines the waiting position, since the stop  26  is blocked by the blocking projection  23 .