referring now to the figures of the drawing in detail and first , particularly , to fig1 and 2 thereof , there is shown a paper dispenser that has a housing , in a lower region of which a receiving space for a dispensing reel 10 and a conveying roll pair 4 , 5 which contains a knife arrangement are arranged . the conveying roll pair 4 , 5 can be driven manually by pulling on the paper , by an external crank or preferably in a sensor controlled manner by an electric motor . the conveying roll pair has a smaller conveying roll 4 in the embodiment shown , over which conveying roll 4 a paper web 25 of the dispensing reel 10 is guided into the nip 6 with the second larger conveying roll 5 which is mounted below the conveying roll 4 and can contain the knife arrangement . the second conveying roll 5 has a circumferential groove 7 which is assigned a sensing element 11 which is mounted behind the nip 6 in the conveying direction f such that it can be pivoted about an axis 9 . the sensing element 11 can be provided with a bracket 8 which lies upright at an angle , is indicated only diagrammatically in fig2 and via which the resetting of the sensing element 11 can take place into the position shown in fig1 . a paper dispenser according to fig3 to 9 has a housing 1 which is provided with a non - illustrated cover panel which can be pivoted up . here too , a receiving space for a dispensing reel 10 and a conveying roll pair which contains , in particular , a knife arrangement are arranged in the lower region of the dispenser , which conveying roll pair is driven manually by pulling on the paper , by an external crank or preferably in a sensor controlled manner by an electric motor . the second conveying roll 5 has a circumferential groove 7 which is assigned a sensing element 11 which is mounted behind the nip 6 in the conveying direction such that it can be pivoted about an axis 9 . the sensing element 11 is provided with a control bracket 8 which lies upright at an angle and by which the movement of the sensing element 11 is transferred during entry into the circumferential groove 7 . after the insertion of the reel into an upper receiving space , a paper start 24 of the reserve reel 13 is fixed on mandrels 16 of a holding device 14 which is formed by a hoop which can be pivoted about an axis 17 , and is held at a spacing from the nip 6 between the conveying rolls 4 , 5 by a latching lever 18 which can be pivoted about an axis 19 . the front end of the latching lever 18 lies on a projection 22 ( fig7 , 8 ) of a side part of the holding device 14 , and the rear end rests with an inclined slope 21 ( fig7 , 8 ) on the control bracket 8 of the sensing element 11 . furthermore , the side part of the holding device 14 carries a lug 20 which , during approach to the nip 6 , comes into contact with the spring loaded restoring element 12 which is configured in the form of a slide and the other end of which is articulated on the control bracket 8 of the sensing element 11 . the function will now be explained in greater detail with reference to fig4 to 9 : as can be seen from fig4 , the paper web 25 from the dispensing reel 10 is guided over the conveying roll 4 through the nip 6 and over the conveying roll 5 , the sensing element 11 resting on the paper web 25 behind the nip 6 . if the paper is finished , the sensing element 11 falls into the circumferential groove 7 of the conveying roll 5 ( fig5 ) under the action of gravity and assisted by the spring 23 which is assigned to the restoring element 12 . here , the upright control bracket 8 pivots forward ( to the left in the drawing ), pushes the restoring element 12 forward with the assistance of the spring 23 and presses the rear end of the double armed latching lever 18 upward , the front end of which latching lever 18 slides off from the projection 22 on the side part of the holding device 14 . the holding device 14 can therefore pivot about the axis 17 as a result of gravity and assisted by the tension spring shown , with the result that the wedge - shaped threading lug of the transverse web 15 of the holding device 14 approaches the nip 6 with the paper start of the reserve reel 13 attached to it . before the nip 6 is reached , the lug 20 comes into contact with the advanced restoring element 12 and pushes the latter back into the starting position ( fig6 , 8 ) again . since the restoring element 12 is articulated on the control bracket 8 , the latter pivots backward ( to the right in the drawing ) and raises the sensing element 11 out of the circumferential groove 7 of the conveying roll 5 . as soon as the threading lug of the transverse web 15 has reached the nip 6 , the paper start 24 is gripped by the surface of the two conveying rolls which has , in particular , a rubber coating at least in regions , is detached from the mandrels 16 and is pulled into the nip . the further path for the paper web 24 is free thanks to the resetting of the sensing element 11 . fig8 and 9 show these positions in a side view and in cross section . after a defined service time , the diameter of the reserve reel 13 has been reduced to such an extent that it can fall or slide along the guide track 2 out of the waiting position downward into the receiving space ( fig6 ). since there are no disruptive fixtures in the transfer region 27 ( fig4 , 5 ) and the sensing element 11 which is required for the paper web 25 lies on the outside , this change can take place without the assistance of a service person . fig5 shows the region p , in which the paper web is moved from 24 to 25 . the automatic change can take place , for example , by diameter sensing of the reserve reel 13 in the upper position , which reserve reel 13 then falls or slides downward in the guide track 2 in the case of a correspondingly reduced diameter . fig1 to 12 show essential parts of a third embodiment of the dispenser 1 . the two conveying rolls 4 , 5 which delimit the nip 6 are shown , of which the larger conveying roll contains a knife arrangement which cuts the paper web into sections . the sensing element 11 is mounted such that it can be rotated about the axis 9 and falls into the circumferential groove 7 of the conveying roll at the end of the paper web ( not shown in fig1 to 12 ). it is also the case in this embodiment that the paper web is sensed behind the nip 6 in the paper conveying direction f . the holding device 14 for the start of the paper web of the reserve reel is configured in the manner of a hoop as described . two stops 28 and 29 are formed on at least one side part 30 of the holding device 14 . in the waiting position shown in fig1 , the side part 30 rests on the restoring element 12 which projects upright from the sensing element 11 , and the transverse web 15 is held at a spacing from the nip 6 . as soon as the paper end of the dispensing reel 10 is detected , the sensing element 11 falls into the circumferential groove 7 and the restoring element 12 pivots forward or to the left in fig1 . as a result , the holding device 14 is released ( fig1 ) and pivots downward about the axis 17 , the second stop 28 coming into contact with the restoring element 12 shortly after the triggering , with the result that the restoring element 12 is pivoted back after conclusion of the pivoting movement of the holding device 14 and , as a result , the sensing element 11 is raised out of the circumferential groove 7 again ( fig1 ). as a result , the path for the paper web of the reserve reel is free again , which paper web is threaded in by the holding device 14 . during insertion of a new reserve reel , the holding device 14 is pivoted up again out of the position according to fig1 , with the result that the end of the restoring element 12 comes to lie under the stop 29 again . the free end of the restoring element 12 is resilient perpendicularly with respect to the plane of the drawing , with the result that it can evade the stop 29 during the return pivoting movement .
a paper dispenser dispenses paper from a dispenser roll lying in a dispensing position . the paper dispenser contains two transport rollers for the web of paper , the rollers defining a gap , and a mobile sensor element for identifying the end of the web of paper . the sensor element being arranged between the two transport rollers downstream of the gap in the direction of transport of the paper .