Power-Tool Cutting Device

Abstract

A power-tool cutting device includes at least one cutting strand, at least one guide unit configured to guide the cutting strand, and at least one deflecting unit. The guide unit together with the cutting strand forms a closed system. The deflecting unit is arranged on a drive-remote side of the guide unit and has at least one movably mounted deflecting element configured to deflect the cutting strand at least while the cutting strand revolves about the guide unit. The deflecting element includes at least one contact surface for an at least temporary contact with the cutting strand. The deflecting element is configured to be at least substantially free from an extension for engagement in the cutting strand.

Claims

1. A power-tool cutting device, comprising: at least one cutting strand; at least one guide unit configured to guide the cutting strand, the guide unit together with the cutting strand forming a closed system such that the guide unit and the cutting strand are connected together in an at least substantially non-releasable manner; and at least one deflection unit arranged on a drive-remote side of the guide unit, the deflection unit including at least one movably mounted deflection element configured to deflect the cutting strand during rotation of the cutting strand around the guide unit, wherein the deflection element includes at least one contact surface configured to temporarily contact cutting elements of the cutting strand during rotation of the cutting strand around the guide unit, and wherein the deflection element is configured as a sprocket that is pivotably mounted about a non-roller bearing.

2. The power-tool cutting device as claimed in claim 1, wherein: the sprocket includes a plurality of continuations projecting away from the non-roller bearing configured to engage the at least one cutting strand; and the sprocket includes a respective contact surface between each adjacent pair of continuations, and the contact surfaces are configured to contact the cutting strand.

3. The power-tool cutting device as claimed in claim 1, wherein the non-roller bearing is formed by a bearing element that is arranged in a recess defined in the deflection element and configured such that the deflection element rotates around the bearing element.

4. The power-tool cutting device as claimed in claim 1, wherein the guide element comprises a curvature at an end of the guide element that faces the deflection element.

5. The power-tool cutting device as claimed in claim 3, wherein the guide element delimits a receiving region in which the deflection element is received.

6. The power-tool cutting device as claimed in claim 4, wherein the guide element has a longitudinal axis, and the guide element is symmetric relative to the longitudinal axis.

7. The power-tool cutting device as claimed in claim 1, wherein the deflection element is not mounted with a roller bearing.

8. The power-tool cutting device as claimed in claim 1, wherein the contact surface configured to temporarily contact the cutting elements is configured at least in part in a friction-reducing manner.

9. The power-tool cutting device as claimed in claim 1, wherein the contact surface includes a surface treatment that reduces friction between the cutting elements and the contact surface.

10. A power tool system, comprising: at least one power-tool cutting device including: at least one cutting strand; at least one guide unit configured to guide the cutting strand, the guide unit together with the cutting strand forming a closed system such that the guide unit and the cutting strand are connected together in an at least substantially non-releasable manner; and at least one deflection unit arranged on a drive-remote side of the guide unit, the deflection unit including at least one movably mounted deflection element configured to deflect the cutting strand during rotation of the cutting strand around the guide unit, wherein the deflection element includes at least one contact surface configured to temporarily contact cutting elements of the cutting strand during rotation of the cutting strand around the guide unit, and wherein the deflection element is configured as a sprocket that is pivotably mounted about a non-roller bearing; and at least one portable power tool which comprises at least one coupling device for one or more of positive locking and friction locking coupling with the power-tool cutting device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Further advantages are produced from the following description of the drawing. Four exemplary embodiments of the disclosure are shown in the drawing. The drawing, the description and the claims include numerous features in combination. The expert will also look at the features individually in an expedient manner and combine them to form sensible further combinations.

[0022] In which:

[0023] FIG. 1 shows a schematic representation of a portable power tool according to the disclosure having a power-tool cutting device according to the disclosure,

[0024] FIG. 2 shows a schematic representation of a view of a detail of a first exemplary embodiment of a power-tool cutting device according to the disclosure,

[0025] FIG. 3 shows a schematic representation of a view of a detail of a second exemplary embodiment of a power-tool cutting device according to the disclosure,

[0026] FIG. 4 shows a schematic representation of a view of a detail of a third exemplary embodiment of a power-tool cutting device according to the disclosure and

[0027] FIG. 5 shows a schematic representation of a view of a detail of a fourth exemplary embodiment of a power-tool cutting device according to the disclosure.

DETAILED DESCRIPTION

[0028] FIG. 1 shows a portable power tool 42a having a power-tool cutting device 10a according to the disclosure which together form a power tool system. The portable power tool 42a comprises at least one coupling device 44a for positive locking and/or friction locking coupling with the power-tool cutting device 10a. The coupling device 44a can be realized as a bayonet closure, a snap lock and/or as a different coupling device which appears sensible to an expert. The power-tool cutting device 10a or the portable power tool 42a comprises at least one torque-transmitting element 46a. The torque-transmitting element 46a can be realized as a toothed wheel, in particular as a pinion. The power-tool cutting device 10a includes at least one cutting strand 12a and at least one guide unit 14a for guiding the cutting strand 12a. The guide unit 14a together with the cutting strand 12a forms a closed system. The torque-transmitting element 46a is provided for transmitting a driving force of a drive unit 48a of the portable power tool 42a to the cutting strand 12a.

[0029] The portable power tool 42a comprises at least one power tool housing 50a which surrounds the drive unit 48a and a gear unit 52a of the portable power tool 42a. The drive unit 48a and the gear unit 52a are operatively connected together in a manner already known to an expert for generating a driving torque, which is transmittable to the power-tool cutting device 10a. The gear unit 52a is realized in a preferred manner as an angular gear. The drive unit 48a is realized in a preferred manner as an electric motor unit. However, it is also conceivable for the drive unit 48a and/or the gear unit 52a to comprise another configuration which appears sensible to an expert, such as, for example, a configuration of the gear unit 52a as a worm gear etc. The drive unit 48a is provided for the purpose of driving the cutting strand 12a of the power-tool cutting device 10a via the gear unit 52a in at least one operating state. The cutting strand 12a is moved in the guide unit 14a of the power-tool cutting device 10a along a cutting direction 54a of the cutting strand 12a in the guide unit 14a, in particular relative to the guide unit 14a.

[0030] FIG. 2 shows a power-tool cutting device 10a according to the disclosure, in detail. The power-tool cutting device 10a includes a cutting strand 12a and a guide unit 14a for guiding the cutting strand 12a which, in particular, together with the cutting strand 12a, forms a closed system. The power-tool cutting device 10a includes at least one deflection unit 18a, which is arranged on a drive-remote side 16a of the guide unit 14a and comprises at least one movably mounted deflection element 20a for deflecting the cutting strand 12a at least during rotation of the cutting strand 12a around the guide unit 14a, which deflection element includes at least one contact surface 22a for contacting the cutting strand 12a at least temporarily. The deflection element 20a is realized at least substantially free of a continuation for engagement in the cutting strand 12a. In a preferred manner, the deflection element 20a, when viewed in a direction transversely to the movement axis 60a of the deflection element 20a, in particular when viewed transversely to a rotation axis 74a of the deflection element 20a, is realized at least substantially free of teeth. The deflection element 20a is mounted at least substantially free of a roller bearing. The deflection element 20a is realized as a deflection disk 24a. In said exemplary embodiment, the deflection element 20a comprises a recess 56a, into which a bearing element 58a of the deflection unit 18a is inserted to form a movable bearing arrangement of the deflection element 20a. The bearing element 58a is realized in the form of a bolt. The deflection element 20a is mounted so as to be rotatable about the bearing element 58a. The rotation axis 74a of the deflection element 20a runs at least substantially perpendicular to the cutting plane of the cutting strand 12a. A direction of rotation 62a of the deflection element 20a is at least substantially parallel to a cutting direction 54a of the cutting strand 12a. The deflection element 20a is arranged at least substantially symmetrically with reference to a longitudinal axis 34a of the guide unit 14a. It is equally conceivable for the deflection element 20a to be arranged in an alternative configuration at least substantially asymmetrically with reference to a longitudinal axis 34a.

[0031] The deflection element 20a, when viewed along a direction perpendicular to the longitudinal axis 34a, comprises a diameter of at least substantially half the width of the guide unit 14a. The deflection element 20a comprises an at least substantially circular configuration. A diameter of the deflection element 20a, when viewed in a plane parallel to the cutting plane of the cutting strand 12a, comprises an at least substantially constant dimension in all directions. For contacting the cutting strand 12a at least temporarily, the deflection element 20a includes the contact surface 22a. The contact surface 22a is aligned at least substantially perpendicular to the cutting plane of the cutting strand 12a. The contact surface 22a, when viewed along the direction of rotation 62a of the deflection element 20a, runs at least substantially along an outer extent 68a of the deflection element 20a. The cutting strand 12a includes individual cutting strand segments 64a which, when put together, form the cutting strand 12a. The individual cutting strand segment 64a comprises a contact area 66a for contacting the deflection element 20a. The contact area 66a comprises a rounded configuration. The deflection element 20a and the individual cutting strand segment 64a can abut against one another at least substantially via the contact surface 22a and via the contact area 66a. The contact surface 22a is preferably provided such that the individual cutting strand segment 64a, with the contact area 66a provided for that purpose, can move parallel to the cutting plane of the cutting strand 12a at least substantially relative to the deflection disk 24a when rotating around the guide unit 14a. The contact surface 22a is realized at least in part in a friction-reducing manner. The guide unit 14a comprises an inlet region 30a for the cutting strand 12a which adjoins at least substantially the deflection element 20a and an outlet region 32a for the cutting strand 12a which adjoins at least substantially the deflection element 20a, the inlet and outlet regions being realized differently. The inlet region 30a is preferably configured in such a manner that at least one outer line 70a of the inlet region 30a runs at least substantially in the direction of the outer extent 68a of the deflection element 20a and/or is curved at least substantially in the direction of the outer extent 68a of the deflection element 20a and approaches the same. The outer line 70a of the inlet region 30a runs at least substantially in the tangential direction of the deflection element 20a. In particular, the outer line 70a approaches a tangent of the deflection element 20a. The outlet region 32a is at a greater distance relative to the deflection element 20a compared to the inlet region 30a. The guide unit 14a comprises at least one guide element 36a which is realized asymmetrically to the longitudinal axis 34a and which delimits a receiving region 38a for the deflection element 20a. It is equally conceivable for the guide unit 14a to comprise more than one guide element 36a, which are realized asymmetrically to the longitudinal axis 34a and which delimit a receiving region 38a for the deflection element 20a. The guide element 36a, on an end that faces the deflection element 20a, comprises a curvature which runs at least substantially parallel to the outer extent 68a of the deflection element 20a. The guide element 36a delimits the receiving region 38a for the deflection element 20a on one side by means of the end that faces the deflection element 20a. The guide element 36a comprises a transfer continuation 40a which is provided for the purpose of making possible, when the cutting strand 12a moves relative to the guide element 36a, an at least substantially seamless transition of the cutting strand 12a from the guide element 36a to the deflection element 20a. The transfer continuation 40a is arranged at least in part in the inlet region 30a. The transfer continuation 40a runs at least substantially tangentially in the direction of the outer extent 68a of the deflection element 20a. The guide element 36a forms the inlet region 30a and/or the outlet region 32a.

[0032] FIGS. 3 to 5 show further exemplary embodiments of the disclosure. The following descriptions and the drawings are limited substantially to the differences between the exemplary embodiments, it also being possible, in principle, to refer to the drawings and/or the description of the other exemplary embodiments, in particular of FIGS. 1 and 2, with reference to identically designated components, in particular with reference to components with identical reference signs. To differentiate between the individual exemplary embodiments of the disclosure, the letters a to d follow the respective reference signs in FIGS. 2 to 5. In the exemplary embodiments in FIGS. 3 to 5, the letter a is replaced by the letters b to d.

[0033] FIG. 3 shows a second exemplary embodiment of a power-tool cutting device 10b according to the disclosure in detail. In said exemplary embodiment, the deflection unit 18b includes at least one further deflection element 26b, which is surrounded at least in part by the deflection element 20b. The further deflection element 26b is movably mounted and comprises a sliding surface 28b which is provided for the purpose of making possible a sliding movement of the further deflection element 26b relative to the deflection element 20b. The further deflection element 26b is surrounded completely by the deflection element 20b along the direction of rotation 62b. The further deflection element 26b and the bearing element 58b are arranged in the recess 56b of the deflection element 20b. The deflection element 20b and the further deflection element 26b are mounted so as to be rotatable about the bearing element 58b. The further deflection element 26b is mounted with the deflection element 20b at least substantially concentrically. The further deflection element 26b and the deflection element 20b are arranged at least substantially symmetrically with reference to the longitudinal axis 34b. The further deflection element 26b is movable relative to the bearing element 58b, to the deflection element 20b and to the cutting strand 12b. The sliding surface 28b of the further deflection element 26b is arranged perpendicular to the cutting plane of the cutting strand 12b at a border of the further deflection element 26b that faces the deflection element 20b. The sliding surface 28b runs at least substantially parallel to the contact surface 22b for contacting the cutting strand 12b of the deflection element 20b at least temporarily. The sliding surface 28b is realized at least substantially in a friction-reducing manner. With regard to further features and functions of the power-tool cutting device 10b shown in FIG. 3, reference may be made to the description of the power-tool cutting device 10a shown in FIGS. 1 and 2.

[0034] FIG. 4 shows a third exemplary embodiment of a power-tool cutting device 10c according to the disclosure in detail. The deflection element 20c is mounted on a roller bearing 72c of the deflection unit 18c. The roller bearing 72c includes rolling elements which are realized as balls in said exemplary embodiment. It is equally conceivable for the deflection element 20c, in an alternative exemplary embodiment, to be mounted in another manner which appears sensible to an expert, such as, for example, on cylindrical elements. With regard to further features and functions of the power-tool cutting device 10c shown in FIG. 4, reference may be made to the description of the power-tool cutting device 10a shown in FIGS. 1 and 2.

[0035] FIG. 5 shows a fourth exemplary embodiment of a power-tool cutting device 10d according to the disclosure in detail. The deflection element 20d comprises at least one continuation 76d for engagement in the cutting strand 12d. The deflection element 20d is mounted at least substantially free of a roller bearing. The deflection element 20d is realized in a star-shaped manner, in particular it is realized as a sprocket nose 78d or pinion. The contact surface 22d for contacting the cutting strand 12d at least temporarily runs at least substantially parallel to the contact area 66d of the individual cutting strand segments 64d. The deflection element 20d and the cutting strand 12d are moved together at least substantially homogeneously when rotating around the guide unit 14d by means of engagement of the continuation 76d in the cutting strand 12d. The outer line 70d of the inlet region 30d for the cutting strand 12d runs at least substantially in the direction of the bearing element 58d. The inlet region 30d for the cutting strand 12d and the outlet region 32d for the cutting strand 12d comprise at least substantially the same configuration. The guide element 36d is realized at least substantially symmetrically to the longitudinal axis 34d and delimits at least substantially the receiving region 38d for the deflection element 20d. The guide element 36d comprises a curvature on an end that faces the deflection element 20d. The guide element 36d delimits the receiving region 38d for the deflection element 20d at least substantially on one side by means of the end that faces the deflection element 20d. With regard to further features and functions of the power-tool cutting device 10d shown in FIG. 5, reference may be made to the description of the power-tool cutting device 10a shown in FIGS. 1 and 2.