Cutting unit for cutting sheet material

Abstract

The present invention relates to a cutting unit for cutting sheet material. The cutting unit includes a unit body having a lower side, and a rotary cutting device coupled to the unit body. The rotary cutting device has a circular knife mounted rotatably about a shaft. The circular knife is movable between a raised initial position and a lowered cutting position via an actuation device. When the circular knife is in the cutting position, it is shiftable into a cutting location for a cutting operation. The circular knife is movable relative to the lower side such that in the initial position the circular knife does not project beyond the lower side, and in the cutting position does project beyond the lower side. The cutting operation is producible by moving the entire cutting unit over the sheet material.

Description

The invention is illustrated in more detail, with reference to an exemplifying embodiment, in the drawings, in which:

FIG. 1 is a side view of the cutting unit according to the present invention with a view of the cutting portion;

FIG. 2 is a side view of the cutting unit according to FIG. 1, rotated 90° counterclockwise;

FIG. 3 is a top view of the cutting unit according to FIGS. 1 and 2;

FIG. 4 is a side view of the cutting unit according to FIGS. 1 to 3, but inverted with respect to FIG. 1;

FIG. 5 is a bottom view of the cutting unit according to FIGS. 1 to 4;

FIG. 6 is a perspective view, obliquely from above, of the cutting unit according to FIGS. 1 to 5, showing the cutting portion (reduced in size);

FIG. 7 is a perspective view, obliquely from below, of the cutting unit according to FIGS. 1 to 6 (reduced in size);

FIG. 8 is an exploded view of the cutting unit according to FIGS. 1 to 7;

FIG. 9 is a cross section through the cutting unit according to FIGS. 1 to 8;

FIG. 10 is a cross section through the cutting unit according to FIG. 9, but in a plane through the cutting portion with a circular knife in the cutting location;

FIG. 11 is a cross section through the cutting unit according to FIG. 10, but placed on a sheet of paper and in a downwardly pressed state, i.e. in the cutting location;

FIG. 12 is an oblique view of the cutting unit according to FIGS. 1 to 11, showing the cutting portion with the circular knives in the initial position;

FIG. 13 is a side view of the cutting unit according to FIG. 12, but with the upper housing part rotated 60° clockwise and with one circular knife in the cutting position;

FIG. 14 is a side view of the cutting unit according to FIG. 13 in the cutting location during the cutting operation;

FIG. 15 is a side view of the cutting unit according to FIGS. 1 to 14, placed on a guide bar;

FIG. 16 is a bottom view of the cutting unit according to FIG. 15, with a horizontal section through the guide bar.

Claims

1. A cutting unit for cutting sheet material, having the following features: a) the cutting unit has a unit body and a lower side;b) the cutting unit comprises a single rotary cutting device;c) the rotary cutting device has a single circular knife;d) the circular knife is mounted rotatably about an at least substantially horizontal shaft;e) the circular knife is movable between a raised initial position and a lowered cutting position;f) the circular knife that is in the cutting position is shiftable into a cutting location for a cutting operation;g) the cutting unit comprises an actuation device for movement of the circular knife between the initial position and cutting position; characterized by the following features:h) the circular knife is movable with reference to the lower side of the cutting unit in such a way that in the initial position the circular knife does not project beyond the lower side of the cutting unit, but in the cutting position does project beyond the lower side of the cutting unit, at least after occupation of the cutting location;i) in the cutting position, the circular knife is fixed with respect to the cutting unit in such a way that a cutting operation is producible only by moving the entire cutting unit over the sheet material.

2. The cutting unit according to claim 1, wherein the actuation device comprises a rotary member which is mounted rotatably with reference to the unit body and to which a rotary motion, with which the circular knife is movable between an initial position and cutting position, can be imparted from outside.

3. The cutting unit according to claim 2, wherein the rotary member is rotatable about a vertical axis.

4. The cutting unit according to claim 2, wherein the circular knife is arranged on the unit body and an operative connection exists between the rotary member and circular knife such that by rotation of the rotary member, the circular knife is movable between the initial position and cutting position.

5. The cutting unit according to claim 2, wherein the circular knife is arranged on the rotary member.

6. The cutting unit according to claim 5, wherein the rotary cutting device is arranged movably on the rotary member, and there is provided, between the circular knife and unit body, a guidance device which is embodied in such a way that the movement of the circular knife between the initial position and cutting position is producible by rotation of the rotary member.

7. The cutting unit according to claim 5, wherein the guidance device is embodied as a guideway against which the circular knife abuts directly or indirectly under spring preload.

8. A cutting unit (1) for cutting sheet material (68), having the following features: a) the cutting unit (1) has a unit body (2) and a lower side;b) the cutting unit (1) comprises a single rotary cutting device;c) the rotary cutting device has multiple circular knives (17, 33, 34);d) the circular knives (17, 33, 34) are each mounted rotatably about an at least substantially horizontal shaft (35, 36, 37);f) the circular knives (17, 33, 34) are movable selectably from a raised initial position into a lowered cutting position;g) the particular circular knife (17, 33, 34) that is in the cutting position is shiftable into a cutting location for a cutting operation;h) the cutting unit (1) comprises an actuation device (6) for movement of the circular knives between the initial position and cutting position; characterized by the following features:i) the circular knives (17, 33, 34) are movable with reference to the lower side of the cutting unit (1) in such a way that in their respective initial positions the circular knives (17, 33, 34) do not project beyond the lower side of the cutting unit (1), but in the cutting position do project beyond the lower side of the cutting unit (1), at least after occupation of the cutting location;j) the particular circular knife (17, 33, 34) brought into the cutting position is fixed with respect to the cutting unit (1) in such a way that a cutting operation is producible only by moving the entire cutting unit (1) over the sheet material (68).

9. The cutting unit according to claim 8, wherein each circular knife is coupled to a respective actuation element with which the associated circular knife is movable between an initial position and the cutting position.

10. The cutting unit according to claim 9, wherein the actuation device comprises a rotary member (6) which is mounted rotatably with reference to the unit body (2) and to which a rotary motion, with which the circular knives (17, 33, 34) are movable between an initial position and the cutting position, can be imparted from outside.

11. The cutting unit according to claim 10, wherein the rotary member is rotatable about a horizontal axis and the circular knives are arranged distributed over the periphery of the rotary member at angular distances.

12. The cutting unit according to claim 10, wherein the rotary member (6) is rotatable about a vertical axis.

13. The cutting unit according to claim 12, wherein the circular knives are arranged on the unit body, and an operative connection exists between the rotary member and circular knives such that by rotation of the rotary member, one of the circular knives is respectively movable between the initial position and cutting position.

14. The cutting unit according to claim 10, wherein the circular knives (17, 33, 34) are arranged on the rotary member (6), there being provided between the circular knives (17, 33, 34) and the unit body (2) a guidance device (50) which is embodied in such a way that by rotation of the rotary member (6), one of the circular knives (17, 33, 34) is movable into the cutting position.

15. The cutting unit according to claim 17, wherein the guidance device is embodied as a guideway (50) against which the circular knives (17, 33, 34) abut directly or indirectly under spring preload.

16. The cutting unit according to claim 2, wherein the unit body (2) is embodied in a hat shape, and the rotary member (6) is mounted substantially inside the unit body (2).

17. The cutting unit according to claim 16, wherein the rotary member (6) protrudes downward out of the unit body (2), and comprises grip elements (7, 8, 9) there with which the rotary member (6) is rotatable with respect to the unit body (2).

18. The cutting unit according claim 8, wherein the circular knives (17, 33, 34) are movable in such a way that they can all be brought, by means of the actuation device (6), into initial positions in which none of the circular knives (17, 33, 34) does project beyond the lower side of the cutting unit (1).

19. The cutting unit according to claim 1, wherein the lower side comprises at least one flat sliding surface (14, 15, 16) for nontilting support of the cutting unit on the sheet material.

20. The cutting unit according to claim 1, wherein the unit body (2) comprises, in the region in which a respective circular knife (17, 33, 34) is in the cutting position, a cutout (5) which is dimensioned so that the circular knife (17, 33, 34) that is in the cutting position can be replaced through the cutout (5).

21. The cutting unit according to claim 20, wherein each circular knife (17, 33, 34) is completely covered externally by a respective removable cover cap (51, 52, 53).

22. The cutting unit according to claim 1, wherein on the lower side of the cutting unit (1), at least in the region of the circular knife (17, 33, 34) that is in the cutting position, a protective element (10) is provided to cover said circular knife (17, 33, 34) on at least one side, the protective element (10) being guided movably between a lower protective position in which the circular knife (17, 33, 34) does not project beyond the protective element (10) even in the cutting position, and an upper enabled position in which the circular knife (17, 33, 34) projects beyond the protective element (10).

23. The cutting unit according to claim 22, wherein the protective element is embodied as a protective disk (10) that forms the lower side of the cutting unit (1).

24. The cutting unit according to claim 22, wherein the protective element (10) is spring-loaded toward the protective position.

25. The cutting unit according to claim 24, wherein the spring loading is stronger than the weight of the cutting unit (1) without the protective element (10).

26. The cutting unit according to claim 1, wherein the circular knife or knives (17, 33, 34) is/are encapsulated on both sides in the initial position.

27. The cutting unit according to claim 1, wherein the particular circular knife (17, 33, 34) that is in the cutting position is snap-locked.

28. The cutting unit according to claim 1, wherein the circular knife or knives (17, 33, 34) is/are snap-locked in the initial position.

29. The cutting unit according to claim 1, wherein the cutting unit (1) is graspable by a human hand.

30. The cutting unit according to claim 1, wherein the cutting unit (1) comprises guidance protrusions (11, 12, 13) on its lower side, and there is associated with the cutting unit (1) a guide bar (72) that can be laid onto a sheet material (68) and onto which the cutting unit (1) is placeable, the guidance protrusions (11, 12, 13) fitting around the guide bar (72), when put in place, on both sides and at the top but not at the bottom.

31. The cutting unit according to claim 30, wherein at least three guidance protrusions (11, 12, 13) are present, two guidance protrusions (12, 13) being provided for surrounding the guide bar (72) on one side, and one guidance protrusion (11) for surrounding the guide bar (72) on the other side between the two aforementioned guidance protrusions (12, 13).

32. The cutting unit according to claim 30, wherein the guide bar (72) is equipped at least on one side with a horizontally extending bracing strut.

33. The cutting unit according to claim 30, wherein the guide bar (72) is embodied in straight, curved, or circular fashion.