| WO/1990/011873 | FILAMENT HOLDER FOR A ROTATING FILAMENT VEGETATION CUTTER |
| JPS5925133 | [Title of the device] Coded type cutting blade apparatus |
| WO/1985/004548 | CUTTING HEAD FOR YARN CUTTING DEVICE |
| WO2003020008A1 | 2003-03-13 |
| DE4005879C1 | 1991-03-21 | |||
| DE19817883C1 | 1999-11-25 | |||
| DE19632721A1 | 1998-02-19 | |||
| US4054993A | 1977-10-25 | |||
| FR2793648A1 | 2000-11-24 | |||
| US4186239A | 1980-01-29 | |||
| EP0764398A1 | 1997-03-26 | |||
| EP1170406A1 | 2002-01-09 |
Patent Claims
1. A flexible mowing unit, characterised by the fact that the surface (1) of that unit of a fixed or variable cross section is provided with bosses (5) and/or cavities (6) of a fixed and/or variable height, which have at least one cutting edge.
2. A flexible mowing unit according to the Claim 1 , characterised by the fact that bosses (5) and/or cavities (6) are in the form of regular circumferential protrusions (8) and/or hollows (9).
3. A flexible mowing unit according to the Claim 1 , characterised by the fact that bosses (5) and/or cavities (6) are in the form of irregular circumferential protrusions (8) and/or hollows (9).
4. A flexible mowing unit according to the Claim 1 , characterised by the fact that bosses (5) and/or cavities (6) are in the form of regular axial protrusions (8) and/or hollows (9).
5. A flexible mowing unit according to the Claim 1 , characterised by the fact that bosses (5) and/or cavities (6) are in the form of irregular axial protrusions (8) and/or hollows (9).
6. A flexible mowing unit according to the Claim 1 or 4, characterised by the fact that bosses (5) and/or cavities (6), situated along the longitudinal axis, have a fixed pitch t.
7. A flexible mowing unit according to the Claim 1 or 5, characterised by the fact that bosses (5) and/or cavities (6), situated along the longitudinal axis, have a variable pitch I 1 .
8. A flexible mowing unit according to the Claim 1 or 2, characterised by the fact that bosses (5) and/or cavities (6), situated along the longitudinal axis, are perpendicular to that axis.
9. A flexible mowing unit according to the Claim 1 or 2, characterised by the fact that bosses (5) and/or cavities (6), situated along the longitudinal axis, are diagonal to that axis.
10. A flexible mowing unit according to the Claim 1 or 2 or 3, characterised by the fact that bosses (5) and/or cavities (6), situated along the longitudinal axis, are in the form of a spiral.
11. A flexible mowing unit according to the Claim 1 or 10, characterised by the fact that bosses (5) and/or cavities (6) have continuous cutting edges.
12. A flexible mowing unit according to the Claim 1 or 10, characterised by the fact that bosses (5) and/or cavities (6) have interrupted cutting edges.
13. A flexible mowing unit according to the Claim 1 or 2 or 3 or 10 or 11 or 12, characterised by the fact that bosses (5) and/or cavities (6), situated along the longitudinal axis, are in the form of a thread. |
FLEXIBLE MOWING UNIT
The object of the invention is a flexible mowing unit intended for use in mechanical scythes with electric or combustion drive for mowing grass, trimming lawn edges at flower beds, kerbs, around trees, bushes and places inaccessible for regular lawn mowers.
To date, smooth-surface plastic lines of a circular section have been most commonly used in mechanical scythes as a cutting unit. Those lines are popularly used for mowing grass and other plants of low. resistance to cutting forces. While for cutting lignified shoots or plants of bigger stem section, shears made of metal or other material of considerable hardness are used.
Sometimes lines of polygonal section are also used, since due to their structure they have some cutting edges.
Plastic lines that have been used so far in mechanical scythes as a cutting unit are most usually made of polyamide plastics known under nylon and tarnamid trade names and due to the smooth surface of those lines they have little cutting properties. Those properties depend on a line diameter and the number of rotation of the scythe's head that the line is wound on. Cutting effect on grass or other plants being mowed results from the action of a resultant force originating from centrifugal force and a force tangent to a curve as taken by the line during the head rotation. As a result of that dynamic action, the section of a cut surface is irregular, close to tearing effect. Effectiveness of that process is the highest at the loose line end. In case of such a mowing process, mowing efficiency can be increased only by using longer line and adopting higher rotational speed of the
cutting head. Using a longer line results in increase of its casing size, which also increases the scythe's weight, whilst increasing rotational speed of the head considerably increases mowing costs due to higher outlays needed to cover the increased expenditure of energy and the scythe's wear.
The aim of the invention is to increase mowing efficiency of mechanical scythes and broadening their cutting possibilities by developing a flexible mowing unit with a surface provided with cutting edges.
The flexible mowing unit according to the invention is characterised by the fact that on its surface of a fixed or variable section there are bosses and/or cavities provided with at least one cutting edge. Bosses and/or cavities are in the form of regular circumferential protrusions and/or hollows. Bosses and/or cavities are in the form of irregular circumferential protrusions and/or hollows. Bosses and/or cavities are in the form of regular axial protrusions and/or hollows. Bosses and/or cavities are in the form of irregular axial protrusions and/or hollows. Bosses and/or cavities placed along the longitudinal axis have a fixed pitch. Bosses and/or cavities placed along the longitudinal axis have a variable pitch. Bosses and/or cavities placed along the longitudinal axis are perpendicular to it. Bosses and/or cavities placed along the longitudinal axis are diagonal to it. Bosses and/or cavities placed along the longitudinal axis are in the form of a spiral and they have continuous and/or interrupted cutting edges. Bosses and/or cavities placed along the longitudinal axis are preferably in the form of a thread.
The advantage of the flexible mowing unit is that due to the use of cutting edges, mowing action proceeds in a similar way as in case of cutting with a saw, and therefore, mowing process is more effective, more precise, faster and more productive, even when mowing pliant plants. Mowing can be implemented using smaller diameter lines and at a lower rotational speed of the cutting head.
The object of the invention is presented in the example product in the drawing, where Fig. 1 shows a head of a mechanical scythe provided with a
flexible mowing unit; Fig. 2 presents the flexible mowing unit of a surface with fixed or variable section which is provided with bosses and/or cavities situated along the longitudinal axis and which are perpendicular to that axis and provided with at least one cutting edge in the form of regular circumferential protrusions and/or hollows; Fig. 3 presents the flexible mowing unit of a surface with fixed or variable section which is provided with bosses and/or cavities situated along the longitudinal axis and which are perpendicular to that axis and which are in the form of irregular circumferential protrusions and/or hollows; Fig. 4 presents the flexible mowing unit of a surface with fixed or variable section which is provided with bosses and/or cavities which are in the form of regular axial protrusions and/or hollows; Fig. 5 presents the flexible mowing unit of a surface with fixed or variable section which is provided with bosses and/or cavities which are in the form of irregular axial protrusions and/or hollows; Fig. 6 presents the flexible mowing unit of a surface with fixed or variable section which is provided with bosses and/or cavities, situated along the longitudinal axis, which have a fixed pitch; Fig. 7 presents the flexible mowing unit of a surface with fixed or variable section which is provided with bosses and/or cavities, situated along the longitudinal axis, which have a variable pitch; Fig. 8 shows the flexible mowing unit of a surface with fixed or variable section which is provided with bosses and/or cavities, situated along the longitudinal axis and diagonal to that axis; Fig. 9 presents the flexible mowing unit of a surface with fixed or variable section which is provided with bosses and/or cavities, situated along the longitudinal axis, which are in the form of a spiral with continuous cutting edges; Fig. 10 presents the flexible mowing unit of a surface with fixed or variable section which is provided with bosses and/or cavities, situated along the longitudinal axis, which are in the form of a spiral with interrupted cutting edges.
As it is presented in the drawing, the flexible mowing unit of a fixed or variable section, wound on a reel 2 of a head 3 of a scythe 4 has a surface 1 provided with bosses 5 and/or cavities 6 which have at least one cutting edge 7. Bosses 5 and/or cavities 6 are in the form of regular or irregular circumferential protrusions 8 and/or hollows 9. Bosses 5 and/or cavities 6 are in the form of
regular or irregular axial protrusions 8 and/or hollows 9. Bosses 5 and/or cavities 6i situated along the longitudinal axis, have a fixed pitch t or variable pitch U. Bosses 5 and/or cavities 6J 1 situated along the longitudinal axis, are perpendicular or diagonal to that axis. Bosses 5 and/or cavities (B 1 situated along the longitudinal axis, are in the form of a spiral, preferably a thread, with continuous or interrupted cutting edges.