Cassette having a press roller

1. A cassette ( 10 ) comprising first and second mutually connectable cassette trays ( 11 , 12 ), between which a tubular bag ( 20 ) to be emptied is suspendingly held and is emptiable in a largely residue-free manner by means of a press roller ( 30 ), wherein the tubular bag has an outlet opening, wherein the press roller ( 30 ) includes a cylindrical metal core ( 31 ) having mounted thereon a hollow-cylindrical casing ( 32 ) made of foamed, elastically compressible plastic, and wherein the core ( 31 ) is on both sides provided with respective rotationally fixedly mounted gearwheels ( 34 ), and wherein in the second cassette tray ( 12 ), on an inner side thereof, are arranged two parallel toothed racks ( 26 ) aligned with and matched to the gearwheels ( 34 ), characterized in that the gearwheels ( 34 ) have thereon respective freely rotating running wheels ( 41 ), which running wheels each have a larger diameter than the gearwheels, and wherein the first cassette tray ( 11 ), which in the closed state lies opposite the second cassette tray ( 12 ), has therein tracks ( 27 ) for the running wheels ( 41 ).

2. The cassette as claimed in claim 1 , characterized in that each of the running wheels ( 41 ) has a running surface which overtops the teeth of a corresponding one of the gearwheels ( 34 ).

3. The cassette as claimed in claim 1 , characterized in that each of the gearwheels ( 34 ) is part of a double-walled hub ( 35 ) including inner and outer concentric pipe sections ( 36 a , 36 b ) which are fixedly connected to each other via a radially running connecting wall ( 37 ), wherein the inner pipe section ( 36 a ) has an internal diameter which is matched to a diameter of the core ( 31 ) of the press roller ( 30 ) such that the core ( 31 ) of the press roller ( 30 ) fits with press fit into the inner pipe section ( 36 a ) of the double-walled hub, while a ring gear, which forms a corresponding one of the gearwheels ( 34 ), is molded onto the outer pipe section of the double-walled hub ( 35 ).

4. The cassette as claimed in claim 3 , characterized in that the inner pipe section ( 36 a ) of the double-walled hub ( 35 ) has an end wall which at least partially covers the inner pipe section and which forms a cover surface ( 38 ) which, in a direction of mounting, forms a stop for the core ( 31 ).

5. The cassette as claimed in claim 3 , characterized in that the inner pipe section ( 36 a ) is longer than the outer pipe section ( 36 b ).

6. The cassette as claimed in claim 3 , characterized in that the inner pipe section ( 36 a ) of the double-walled hub ( 35 ) has a plurality of radially outwardly springing tongues ( 39 ), wherein each of the tongues ( 39 ) has a radially outwardly directed retaining boss ( 43 ).

7. The cassette as claimed in claim 4 , characterized in that the running wheels ( 41 ) each include a tubular bearing bushing ( 40 ), onto an end of which a corresponding one of the running wheels ( 41 ) is integrally molded as a flange, wherein an internal diameter of the bearing bushing is matched to an external diameter of the inner pipe section ( 36 a ) of the double-walled hub ( 35 ) such that the bearing bushing runs rotatably on the hub.

8. The cassette as claimed in claim 6 , characterized in that the bearing bushing ( 40 ) has an annular groove or a step-like offset ( 42 ), in which the flexible tongues ( 39 ) engage.

9. The cassette as claimed in claim 1 , characterized in that the cassette trays ( 11 , 12 ) are made of plastic and the toothed racks ( 26 ) are integrally molded onto the second cassette tray ( 12 ).

10. The cassette as claimed in claim 9 , characterized in that tracks ( 27 |) are integrally molded in the first cassette tray ( 11 ).

11. The cassette as claimed in claim 10 , characterized in that the tracks ( 27 ) are shaped as flange grooves, in which the running wheels ( 41 ) travel.

12. The cassette as claimed in claim 1 , characterized in that the first and second cassette trays ( 11 , 12 ) are articulately connected to each other via a hinged connecting joint ( 14 ).

13. The cassette as claimed in claim 12 , characterized in that the first and second cassette trays ( 11 , 12 ) are connected to each other via a film hinge.

14. The cassette as claimed in claim 10 , characterized in that the first and second cassette trays ( 11 , 12 ) each have a bottom face wall ( 18 ) and a circumferential side wall ( 19 ), and wherein the toothed racks ( 26 ) and/or the tracks ( 27 ) are shaped as corresponding thickenings or thinnings of the bottom face wall ( 18 ).

15. The cassette ( 10 ) as claimed in claim 10 , characterized in that a minimum nominal measure between one of the tracks ( 27 ) and a tooth root of a toothed rack ( 26 ) on the same side of the closed cassette ( 10 ) maximally exceeds by half a height of a tooth of the toothed rack.