阅读说明：本技术 用于安装在割灌机的驱动轴处的线绳收割头 (Cord harvesting head for mounting at the drive shaft of a brush cutter ) 是由 A·雷塔伯 于 2020-08-28 设计创作，主要内容包括：本发明涉及一种用于安装在割灌机(1)的驱动轴(2)处的线绳收割头。该线绳收割头包括壳体(7)、用于切割线绳(6)的带有至少一个卷筒壁(11、12、13)的线绳卷筒(9)、壳体盖(8)和串接装置(19)。线绳卷筒(9)在运行位置(30)中通过端部止挡(20)与壳体(7)抗扭地连接。线绳卷筒(9)可从运行位置(30)在转动轴线(10)的方向上调整至非运行状态(31)下。串接装置(19)包括转动止挡(23),该转动止挡将线绳卷筒(9)相对于壳体(7)的旋转限制至非运行状态(31)下。转动止挡(23)构造在线绳卷筒(9)的卷筒壁(11、12、13)中的狭槽(24)处。(The invention relates to a cord harvesting head for mounting at a drive shaft (2) of a brush cutter (1). The cord harvesting head comprises a housing (7), a cord drum (9) for cutting a cord (6) having at least one drum wall (11, 12, 13), a housing cover (8) and a tandem arrangement (19). The cable drum (9) is connected in a rotationally fixed manner to the housing (7) in the operating position (30) by means of an end stop (20). The wire drum (9) can be adjusted from an operating position (30) in the direction of the axis of rotation (10) into a non-operating state (31). The tandem connection (19) comprises a rotation stop (23) which limits the rotation of the wire drum (9) relative to the housing (7) to a non-operating state (31). The rotation stop (23) is formed at a slot (24) in a drum wall (11, 12, 13) of the line drum (9).)

1. Cord harvesting head for mounting at a drive shaft (2) of a brush cutter (1), comprising: a housing (7), a cable drum (9) for cutting a cable (6) having at least one drum wall (11, 12, 13), a housing cover (8) and a tandem arrangement (19), wherein the cable drum (9) is rotatably mounted about a rotational axis (10) and is held in the housing (7) and the housing (10) such that it can be displaced in the direction of the rotational axis (10)Between the covers (8); a spring element (14), wherein the cable drum (9) is preloaded by the spring element (14) into a running position (30) of the cable harvesting head (5), wherein the tandem arrangement (19) comprises an end stop (20), and the cable drum (9) is connected in a rotationally fixed manner in the running position (30) by the end stop (20) to the housing (7), wherein an actuating force (F) acting on the tandem arrangement (19) is exerted_B) -the line drum (9) is adjustable from an operating position (30) in the direction of the axis of rotation (10) into a non-operating state (31) of the line harvesting head (5) for replenishing the cutting line (6) wound onto the line drum (9), wherein the tandem arrangement (19) comprises a rotation stop (23) which limits the rotation of the line drum (9) relative to the housing (7) into the non-operating state (31),

characterized in that the rotation stop (23) is configured at a slot (24) in a drum wall (11, 12, 13) of the wire drum (9).

2. Cord harvesting head according to claim 1, characterized in that an engagement element (25) cooperating with the slot (24) in a non-operative state (31) is arranged at the housing (7).

3. Cord harvesting head according to claim 1, characterized in that the slot (24) is configured as an opening (27).

4. The cord harvesting head according to claim 1, characterized in that the cord drum (9) has an upper drum wall (11) adjacent to the housing (7), wherein the slot (24) is configured at the upper drum wall (11) of the cord drum (9).

5. Cord harvesting head according to claim 1, characterized in that the slot (24) extends in an arc around the axis of rotation (10) over an angular section (δ), wherein the angular section (δ) is between 30 ° and 70 °.

6. Cord harvesting head according to claim 1, characterized in that a structural protrusion (36) is provided at the rotation stop (23) of the slot (24).

7. Line harvesting head according to claim 1, wherein the line drum (9) comprises a hub section (76) for supporting the line drum (9) relative to the housing (7) and a line chamber section (77) coupled to the hub section (76) for winding the cutting line (6), wherein the slot (24) is configured in the line chamber section (77).

8. The cord harvesting head according to claim 1, characterized in that an end stop (20) of the tandem arrangement (19) is arranged at the housing cover (8) and the tandem arrangement (19) comprises a counterpart stop (22) arranged at the cord drum (9).

9. Cord harvesting head according to claim 8, characterized in that the counter-stop (22) engages with the end-stop (20) in an operating position (30) for a torque-proof connection between the cord reel (9) and the housing (7).

10. A cord harvesting head according to claim 1, characterized in that the tandem arrangement (19) is configured such that with manipulation of the tandem arrangement (19) into a non-operative state (31), the cord drum (9) is rotated with respect to the housing (7) by a first rotation angle (α) until the rotation stop (23) hits at the engagement element (25).

11. A cord harvesting head according to claim 10, characterized in that the cord drum (9) is rotated with respect to the housing (7) by a second angle of rotation (β) starting from the impact of the turn-stop (23) at the engagement element (25) until the impact of the counterpart-stop (22) at the end-stop (20), wherein the total angle of rotation (μ) corresponds to the sum of the first angle of rotation (α) and the second angle of rotation (β).

12. Cord harvesting head according to claim 1, characterized in that the manipulation force (F)_B) Is applied to the tandem arrangement (19) via an actuating element (15), wherein the actuating element (15) extends from an opening (16) of the housing cover (8) away from the housing (7).

13. The cord harvesting head according to claim 1, characterized in that the cord drum (9) is pretensioned towards the housing cover (8) by means of the spring element (14).

14. The cord harvesting head according to claim 1, wherein the slot (24) is defined by a circumferential wall (60) surrounding the slot (24).

15. The cord harvesting head according to claim 1, characterized in that the cord drum (9) comprises a cord channel (61) for introducing, in particular for threading, a cutting cord (6).

Technical Field

The invention relates to a cord harvesting head (Fadenmaehkopf) for mounting at a drive shaft of a brush cutter (Freischneider).

Background

The brush cutter is used for harvesting grass, shrubs and the like. For this purpose, the wire harvesting head with the tool is driven in rotation about the axis of rotation of the wire harvesting head, whereby the grass is cut off when it comes into contact with the tool. As a tool, use is often made in particular of a cutting cord, which is subject to a certain wear during the operation of the cord harvesting head. This wear results in the cutting cord shortening during its operation and the cutting function being impaired. With too short a cutting cord grass, bushes and the like can be harvested only barely or even no longer. Therefore, the cutting cord must be replaced by a new cord. String cutting heads with stringing devices are known, which, after their actuation, unwind the cutting string wound on the string drum and extend the portion of the cutting string protruding from the string cutting head again. This in turn produces the cutting function of the cord harvesting head.

In order to be able to avoid a too frequent, complete reloading of the cutting cord onto the cord reel and thus also to avoid interruptions in the use of the brush cutter, the cord reel is designed with a correspondingly large winding volume. The aim here is to be able to wind as much cutting cord as possible onto the cord reel. As a result, the structural dimensions of the cord reel and of the cord harvesting head increase, in particular in the axial direction with respect to the axis of rotation. However, such dimensions of the cord reel have a negative effect on the cutting height of the cord harvesting head. Due to the axial configuration of the cord reel, the spacing between the ground and the cutting cord where the cutting cord protrudes from the housing of the cord harvesting head is also increased. The grass to be harvested can no longer be cut in the desired height.

Disclosure of Invention

The object of the invention is to provide a cable harvesting head for mounting on a drive shaft of a brush cutter, which has a compact design and at the same time has a large winding volume for accommodating a cutting cable.

This object is achieved by a cord harvesting head for mounting at a drive shaft of a brush cutter, comprising: a housing, a cable drum for cutting a cable with at least one drum wall, a housing cover and a coupling device (weiterschultvorichtung), wherein the cable drum is rotatably mounted about a rotational axis and is held displaceably in the direction of the rotational axis between the housing and the housing cover; a spring element, wherein the cable drum is prestressed by means of the spring element into an operating position of the cable cutting head, wherein the coupling device comprises an end stop and the cable drum is connected in the operating position in a rotationally fixed manner to the housing by means of the end stop, wherein the cable drum can be adjusted from the operating position in the direction of the axis of rotation by applying an actuating force acting on the coupling device into a non-operating state of the cable cutting head for the purpose of supplementing a cutting cable wound onto the cable drum, wherein the coupling device comprises a rotation stop which limits the rotation of the cable drum relative to the housing into the non-operating state, wherein the rotation stop is formed at a slot (Schlitz) in a drum wall of the cable drum.

Set up to, the cotton rope harvesting head includes: a housing, a cord reel for cutting a cord with at least one reel wall, a housing cover, and a tandem. The tandem connection includes an end stop. The cable drum is connected in a rotationally fixed manner to the housing in the operating position by an end stop. By applying an actuating force acting on the tandem arrangement, the cable drum can be adjusted from the operating position in the direction of the axis of rotation to a non-operating state of the cable harvesting head for the purpose of supplementing the cutting cable wound onto the cable drum. The tandem connection device includes a rotational stop that limits rotation of the cord reel relative to the housing to a non-operational state. The rotation stop is configured at a slot in the drum wall of the cord drum.

The most common concatenation devices for string cutting heads on the market form such a rotation stop by means of a local ridge (Erhoehung), i.e. a configuration of the drum wall, into which a mating element can engage. By configuring the rotation stop as a slot, it is integrated into the drum wall. Thus eliminating the need for a ridge in the direction of the axis of rotation of the cord harvesting head. The overall height of the cable drum can thereby be reduced while maintaining the same winding volume, thereby achieving a compact overall size of the cable harvesting head.

Preferably, an engagement element is arranged on the housing, which in the inoperative state interacts with the slot. The engaging element engages into the slot when transitioning from the operating position to the non-operating state. The cord reel is rotated relative to the housing until the engagement element hits a circumferential wall of the slot forming a rotation stop and the cord reel is restricted from further rotation relative to the housing in the non-operational state.

The slot is preferably configured as an opening. Thus, the slot does not include a bottom. By configuring the slot as an opening in the drum wall, the engagement element can engage even deeper into the slot. Thereby, when the engagement element hits the rotation stop configured by the circumferential wall of the slot, higher forces and moments can be transferred from the housing to the cord reel.

An opening, i.e. a slot without a bottom, is thus formed in the drum wall, as a result of which the engagement element can engage even deeper into the slot and a better force or torque transmission between the drum and the housing is ensured.

The housing preferably has a substantially horizontal section which is substantially perpendicular to the axis of rotation of the cord harvesting head. The cable drum advantageously has an upper drum wall adjacent to the housing, in particular adjacent to the horizontal section of the housing, wherein the slot is preferably formed at the upper drum wall of the cable drum. The horizontal section advantageously merges into a circumferential section of the housing, which extends coaxially to the rotational axis of the cable harvesting head. The engaging element can thus also be arranged directly at the housing, in particular at a horizontal section of the housing, whereby a structurally simpler construction of the cord harvesting head can be achieved.

The slot preferably extends in an arc around the axis of rotation over an angular section, wherein the angular section is preferably between 30 ° and 70 °. By actuating the tandem arrangement into the inoperative state, the engaging element is sunk into the slot and moved along the slot until it strikes against a rotation stop of the slot. As a result of the engagement element hitting the rotation stop, the drum is braked in its relative rotation with respect to the housing. In this case, the cable drum is rotated approximately over an angular section (which is preferably between 30 ° and 70 °) relative to the housing. The engaging element has a stretch (ausdehnnung) extending in a tangential direction with respect to the axis of rotation. In order to allow the engaging element to sink directly into the slot at the moment of the application of the actuating force, the slot must accommodate at least a part of the tangential stretch. Thereby causing the slot to elongate at its end remote from the rotation stop. The angular section of the slot and the first rotation angle of the wire drum differ by this magnitude.

Advantageously, a structural projection (strukturerhebbung) is provided at the rotation stop of the slot. This structural projection causes a reduction in the pressure per unit area at the rotation stop upon impact of the engaging element. The contact area between the engaging element and the rotation stop is increased by the structural projection, thereby reducing the pressure per unit area. Thereby avoiding material fatigue and improving the running strength of the cord reel. The structural elevation has a significantly smaller axial height than the follower placed on the rope drum, so that it hardly influences the structural height of the rope drum.

It is advantageously provided that the cable drum comprises a hub section (Nabensegment) for supporting the cable drum relative to the housing and a cable chamber section coupled to the hub section for winding the cutting cable, wherein the slot is configured in the cable chamber section. Preferably, the slot has a minimum spacing from the axis of rotation, measured in a radial direction with respect to the axis of rotation, corresponding at least to the spacing of the narrowest coil of wire (fadenwick) from the axis of rotation. The spacing is advantageously at least 20%, in particular at least 25%, preferably about 30%, of the diameter of the cord reel. This facilitates the transmission of forces and moments between the housing and the rope drum. The maximum spacing of the slot from the axis of rotation is advantageously less than the spacing between the largest possible winding of the cord and the axis of rotation. The slot is thus in the area of the rope drum, which limits the winding of the rope in the axial direction. This likewise facilitates the transmission of forces and moments between the housing and the cable drum.

The end stop of the tandem arrangement is preferably arranged at the housing cover. The tandem connection preferably comprises a mating stop arranged at the line rope drum. Advantageously, the counterpart stop engages with the end stop in the operating position for a rotationally fixed connection between the rope drum and the housing. In the operating position of the tandem arrangement, the end stop of the housing cover contacts a counterpart stop of the line drum, as a result of which the line drum is connected in a rotationally fixed manner to the housing cover and thus also to the housing in the direction of rotation of the line harvesting head. The cord reel is moved by its counterpart stop by the end stop of the housing cover by a rotational movement of the housing cover. The cord reel and the housing jointly rotate in the direction of rotation of the cord harvesting head in the operating position.

It is advantageously provided that the tandem arrangement is configured such that with the tandem arrangement being manipulated into the inoperative state, the wire drum is rotated by a first rotation angle relative to the housing until the rotation stop hits the engagement element. After the tandem has been switched to the inoperative state and the cable drum has been rotated together with the slot until the engagement element has collided at the rotation stop of the slot, the cable drum is moved by the spring element in the axial direction towards the housing cover back into its initial position in which the counterpart stop and the end stop overlap in the axial direction. In this case, the engagement element is axially remote from the slot of the cord reel, thereby eliminating a tangentially effective connection between the rotation stop at the slot and the engagement element at the housing. The wire reel braked by the engaging element hitting the rotation stop may continue its relative rotation with respect to the housing.

It is advantageously provided that the cable drum is rotated by a second angle of rotation relative to the housing starting from the impact of the rotation stop at the engaging element until the impact of the counterpart stop at the end stop, wherein the total angle of rotation corresponds to the sum of the first angle of rotation and the second angle of rotation. The rotation of the cable drum relative to the housing is now continued until the end stop of the housing cover strikes against a counterpart stop of the cable drum and restricts the relative rotation of the cable drum. This state of the tandem arrangement (in which the rope reel is axially remote from the engagement element of the housing and continues to rotate relative to the housing until abutting against an end stop of the housing cover) is another part of the non-operating state. In the other part of the non-operating state, the wire drum is rotated over a second rotation angle of the wire drum. As soon as the counterpart stop on the cable drum strikes against the end stop of the housing cover and a rotationally fixed connection is again established between the housing cover and the cable drum in the direction of rotation of the cable take-up head, the tandem arrangement is transferred from this further part of the inoperative state into the operative position.

With each actuation of the tandem, the wire drum is rotated relative to the housing, preferably by a total rotational angle relative to the housing. The total angle of rotation corresponds to the angle obtained by the angular spacing of the mating stops or end stops. In the circumferential direction with respect to the axis of rotation, adjacent counter stops or end stops have an equal angular spacing, so that in the case of four, an angular segment of 90 ° results. Preferably, the number of end stops or counter stops also corresponds to the number of rotation stops or engagement elements. The rotation stop and the engagement element are matched in their arrangement with the counterpart stop and the end stop in such a way that, when the tandem arrangement is actuated, the tandem arrangement is switched from the operating position into the inoperative state, into another part of the inoperative state and finally into the operating position again. The total rotation angle is an angle at which the wire drum rotates relative to the housing upon application of one manipulation force. The total angle of rotation is divided here into a first angle of rotation of the wire drum and a second angle of rotation of the wire drum which the wire drum experiences in its inoperative state. The second rotation angle of the wire drum, i.e. the rotation in the other part of the non-operational state, corresponds to the difference of the total rotation angle and the first rotation angle. The first angle of rotation is advantageously smaller than the second angle of rotation. By selecting the first angle of rotation to be smaller than the second angle of rotation, a stable web width (Stegbreite) is created between adjacent slots configured in the drum wall.

The actuating force is preferably applied to the tandem arrangement via an actuating element, wherein the actuating element extends from the opening of the housing cover away from the housing. The operating element is thus very well accessible to the operator. The cord reel is preferably pretensioned against the housing cover by means of a spring element. This results in the actuating direction of the tandem connection device in the direction of the horizontal section of the housing. The steering direction lies parallel to the axis of rotation of the harvesting head and is oriented towards the drive shaft. For actuating the actuating element, it is sufficient to press the cord cutting head with its bottom surface against the ground. Since the actuating element projects from the housing cover, the actuating element contacts the ground and is pressed in against the spring force. In this way, the cable drum operatively connected to the operating element is moved in the axial direction, thereby releasing the relative movement of the cable drum with respect to the housing. This process can also be carried out during operation of the cord cutting head, whereby unwinding of the cutting cord from the cord reel can be effected in a simple manner.

The slot is preferably defined by a circumferential wall surrounding the slot. The circumferential wall thus delimits the slot in the circumferential direction outwardly and inwardly from the axis of rotation. In an alternative embodiment, the slot can also be a slot which is open on the circumferential side. In other words, the slot can open out in the radial direction from the axis of rotation.

The cord reel preferably comprises a cord channel for introducing (in particular threading) the cutting cord. In this way, the cutting cord can be inserted (in particular threaded completely) into the cord channel and subsequently wound up on the cord reel by rotating the cord reel. The cable channel is advantageously formed in a drum wall, in particular an intermediate drum wall, of the cable drum. In the region of the cord channel, the drum wall is thickened, so that the construction of the cord channel is at the expense of the volume of the cord chamber. The cutting cord may be wound in a cord cavity. By having the concatenation device at least partly utilize the structural space of the existing wall, the axial structural space thus obtained in the housing is attributed to the height of the cord chamber and at least partly compensates for the loss of volume of the cord chamber.

By having the concatenation device in the cord chamber section of the cord reel, i.e. inside the cord chamber in the radial direction, the cord chamber can be pulled in the radial direction to the housing, whereby a relatively large maximum winding diameter can be achieved and thus a large volume of cord can be stored on the cord reel.

It may be expedient alternatively or additionally to configure the counterpart stop as a slot and the end stop as an engaging element. In this case, the slot will be arranged in the drum wall below the line rope drum and the engaging element will be arranged at the housing cover.

It is also expedient if the actuating element does not project through an opening in the housing, but is in operative connection with the housing itself instead of with the cable drum. Accordingly, the housing is removed in the axial direction relative to the cable drum when the actuating element is actuated. Thereby bringing the end stop and the counter stop out of contact, the housing and the wire drum perform a relative movement accompanied by a first and a second rotation of the housing similar to the already described first and second rotation of the wire drum.

Drawings

Embodiments of the invention are explained below with reference to the drawings. Wherein:

FIG. 1 shows a schematic view of a brush cutter held by an operator;

FIG. 2 shows a side view of an embodiment of a cord harvesting head;

fig. 3 shows a cross-sectional view of the cord harvesting head according to fig. 2 in an operating position;

fig. 4 shows a cross-sectional view of the cord harvesting head in the direction of the arrow iv according to fig. 3;

fig. 5 shows a cross-sectional view of the cord harvesting head in the direction of the arrow v according to fig. 3;

fig. 6 shows a cross-sectional view of the cord harvesting head according to fig. 2 in a non-operating position and with the cord reel undergoing a first angle of rotation;

fig. 7 shows a cross-sectional view of the cord harvesting head in the direction of the arrow vii according to fig. 6;

fig. 8 shows a perspective view from above of a cord reel with a clamping loop;

fig. 9 shows a partial perspective view of a slot of a cord reel;

fig. 10 shows a cross-sectional view of the cord harvesting head according to fig. 6, already in an axial initial position;

fig. 11 shows a cross-sectional view of the wire harvesting head in the direction of arrow xi according to fig. 8 and with the wire drum undergoing a second rotation angle;

fig. 12 shows a perspective view from below of a cord reel with a clamping loop;

FIG. 13 shows a cross-sectional view of the cord harvesting head with a cut cord channel;

fig. 14 shows a perspective view of the housing cover.

Detailed Description

Fig. 1 shows a brush cutter in a schematic view. The brush cutter 1 is held by an operator 64. The brush cutter 1 has a rear end with a rear housing 65 from which projects a drive shaft, not shown, and a front end. A rod 67 connects the rear end and the front end. At the lever 67, a handle 68 for controlling the brush cutter 1 is arranged. A wire harvesting head 5 is coupled to the front end of the brush cutter 1. The wire harvesting head 5 is fixed at the drive shaft and is driven in rotation about the rotation axis 10 in a rotation direction 29 by a drive motor, not shown. The drive motor is arranged in the rear housing 65, wherein the drive shaft extends in a rod 67. It may be provided that the drive shaft in the rod is connected directly to the drive shaft for the wire harvesting head 5, and thus no transmission is coupled in between. In an alternative embodiment, not shown, the drive motor, in particular the electric motor, can also be arranged on a not shown front housing 66 arranged at the front end. Advantageously, a transmission is also present in the front housing. The cord harvesting head 5 is covered by a protective cover 69 at the side which in operation faces the operator 64. The cord harvesting head 5 has at least one cutting cord 6 for cutting a cutting object such as grass, brush or the like. At the cable harvesting head 5, a bottom surface 4 is formed which in operation faces the ground 70 and is arranged at the side of the cable harvesting head 5 facing away from the shaft 67. The top surface 3 of the cord harvesting head 5 is constructed at the side of the cord harvesting head 5 facing the pole. The protective suit to be worn by the operator 64 for the operation of the brush cutter 1 is not shown in the simplified illustration in fig. 1.

The cord harvesting head 5 is shown in a side view in fig. 2. Only the housing 7, the housing cover 8, the axis of rotation 10 and the actuating element 15 of the cord harvesting head 5 are shown in this illustration. The housing 7 is basin-shaped and in this embodiment comprises a horizontal section 62 oriented approximately perpendicular to the axis of rotation 10 of the cord harvesting head 5. In a preferred embodiment, the horizontal section 62 transitions into a circumferential section 63 of the housing 7 which extends substantially coaxially with the axis of rotation 10 of the cord harvesting head 5. At the circumferential section 62 of the housing 7 two opposite cord openings 72 are provided through which the cutting cord 6 protrudes from the housing 7. In an alternative embodiment of the cord harvesting head 5, it may be expedient to provide a different number of cord openings 72. Two latching openings (rasoeffnung) 41 are formed at the circumferential section 63 of the housing 7. The housing cover 8 comprises two latching projections 42 which engage in latching openings 41 of the housing 7 when the housing cover 8 is fixed. The latching projections 42 form, together with the associated latching openings 41, a releasable snap connection (Schnappverbindung)40, by means of which the housing cover 8 is firmly connected to the housing 7. "firmly connected" here means that they are fixed relative to one another in all spatial directions. In a preferred embodiment, a snap connection 40, which is formed in each case by a latching projection 42 and a latching opening 41, is provided, as a result of which a sufficient holding force between the housing 7 and the housing cover 8 is achieved. In an alternative embodiment of the cord harvesting header 5, other numbers of snap connections 40 may also be suitable. If the housing cover 8 is fixed to the housing 7, the mechanism with the associated components located in the cord harvesting head 5 is protected from dirt.

As shown in fig. 2, the housing 7 has a plurality of grip surfaces 43 at the circumferential side of the housing 7. The gripping surface 43 is designed as a toothing, wherein each toothing extends approximately in the direction of the axis of rotation 10. The gripping surface 43 serves to better retain the cord harvesting head 5. When the cable harvesting head 5 is fastened to the drive shaft 2, which is schematically indicated in fig. 2, the cable harvesting head 5 is screwed onto the drive shaft 2 in the installed state. The grip surface 43 at the housing 7 enables the operator 64 to grip at the housing 7 in a slip-proof manner and thus makes it easy for the operator 64 to screw the wire harvesting head 5 onto the drive shaft 2 and to loosen the wire harvesting head 5. In the preferred embodiment, four gripping surfaces 43 are provided, evenly distributed around the circumferential side of the housing 7. Alternatively, other numbers of gripping surfaces 43 may be suitable. The gripping surface 43 may have other configurations.

The cord harvesting head 5 is shown in cross-section in fig. 3. A receptacle (Aufnahme)45 is formed in the housing 7 of the cable harvesting head 5, via which receptacle the cable harvesting head 5 is fastened to the drive shaft 2. In the preferred embodiment, the receptacle 45 is formed by a nut 46 oriented coaxially with the axis of rotation 10 in the housing 7. In this exemplary embodiment, the housing 7 has, in addition to its horizontal section 62 and its circumferential section 63, a hollow cylindrical section 50 which is oriented coaxially to the axis of rotation 10. A twelve-sided hole 47 is formed in the hollow cylindrical section 50, in which the nut 46 is arranged and is held rotationally fixed relative to the housing 7. In the direction of the axis of rotation 10, the nut 46 is supported by a housing shoulder 49 towards the top face 3 of the harvesting head 5 and is secured via a toothed disk 48 towards the bottom face 4. Furthermore, the cable harvesting head 5 has an opening 51 at its top face 3, through which the drive shaft 2 is passed and subsequently screwed with the nut 46 in order to fix the cable harvesting head 5. In an alternative embodiment, it may also be expedient for the drive shaft 2 to be connected in a rotationally fixed manner to the cable drum 9 and for the housing 7 to be fixed relative to the cable drum 9 via the connecting device 19.

As shown in fig. 3, the cord take-up head includes a cord reel 9 for winding and unwinding the cutting cord 6. Furthermore, in this exemplary embodiment, a tandem arrangement 19 is provided, which, when actuated, rotates the cable drum 9 by a predetermined angle relative to the housing 7 and in this case causes the cutting cable 6 to be unwound from the cable drum 9.

As shown in fig. 3, the cable drum 9 is held on a hollow cylindrical section 50 of the housing 7 so as to be movable in the direction of the axis of rotation 10. The wire drum 9 comprises a hub 44 which is mounted on a circumferential side 53 of the hollow cylindrical section 50 so as to be axially displaceable in the direction of the axis of rotation 10.

As shown in fig. 3, the web strip 54 extends from the hub 44 of the cable drum 9 in the radial direction of the axis of rotation 10 and merges into a longitudinal wall 55 extending in the direction of the axis of rotation 10. In this exemplary embodiment, the wire drum 9 has a plurality of drum walls 11, 12, 13, namely an upper drum wall 11, a lower drum wall 13, and an intermediate drum wall 12 arranged between the upper drum wall 11 and the lower drum wall 13. The upper drum wall 11 is arranged adjacent to the horizontal section 62 of the housing 7, and the lower drum wall 13 is arranged adjacent to the housing cover 8. The drum walls 11, 12, 13 are connected to each other via a longitudinal wall 55. The cable drum 9 has a cable chamber 56 for winding the cutting cable 6, which is delimited in the direction of the axis of rotation 10 by an upper drum wall 11 towards the top surface 3 of the cable take-up head 5 and by a lower drum wall 13 towards the bottom surface 4 of the cable take-up head 5. In a radial direction towards the axis of rotation 10, a cord chamber 56 is defined by the longitudinal wall 55 of the cord harvesting head 5. The cutting cord 6 may be wound around the entire cord chamber 56 between the upper and lower drum walls 11, 13, except for the intermediate drum wall 12. As shown in fig. 7, the cord reel 9 may be divided into a hub cavity section 76 and a cord cavity section 77 in a radial direction with respect to the rotation axis 10. Here, the definition of the cord lumen section 77 also corresponds to the definition of the cord lumen 56. Thus, the web strip 54 of the cord reel 9, as well as the hub 44 of the cord reel 9 itself, may be associated with the hub cavity section 76. The slot 24 with the rotation stop 23 is configured in the area of the cable chamber section 77 at the cable drum 9.

As shown in fig. 4, an end stop 20 is provided on the housing cover 8, which end stop is arranged on the cover inner side 58, i.e. on the side of the housing cover 8 facing the housing 7. A counterpart stop 22 is provided on the lower drum wall 13 at the cable drum 9, said counterpart stop being arranged on the side facing the housing cover 8. The end stop 20 and the counterpart stop 22 are part of the tandem connection arrangement 19. In the operating position 30 of the coupling 19 shown in fig. 3, the end stop 20 at the housing cover 8 acts in the direction of rotation 29 of the cable harvesting head 5 on the counterpart stop 22 of the cable drum 9.

The end stop 20 and the counterpart stop 22 come into contact in the stop face 59, whereby the cable drum 9 is carried along by the housing cover 8 in the direction of rotation 29 of the cable harvesting head 5. The end stop 20 and the counterpart stop 22 form a positive connection in the direction of rotation 29 of the cable harvesting head 5. Thereby, the wire drum 9 and the housing cover 8 and thus also the wire drum 9 and the housing 7 are connected to each other in the direction of rotation 29. In this operating position 30 of the tandem arrangement 19, the string harvesting head 5 can be used by the operator 66 for cutting grass, bushes or the like.

As shown in fig. 12, the counterpart stop 22 at the lower drum wall 13 of the line drum 9 is inclined in the direction of rotation 29. This produces a sort of ramp 71 of the counterpart stop 22. Similarly, the end stop 20 is also inclined against the direction of rotation 29 in the form of a ramp 71. The cord reel 9 and the housing cover 8 are thus held in a form-fitting manner in the direction of rotation 29, but can be rotated relative to one another counter to the direction of rotation 29, since the end stop 20 and the counterpart stop 22 slide over their ramp 71. There is no positive connection against the direction of rotation 29 due to the end stop 20 and the counterpart stop 22.

As shown in fig. 4, in a preferred embodiment, four end stops 20 and four counterpart stops 22 are provided, which are respectively arranged at equal intervals to the axis of rotation 10 and are distributed uniformly about the axis of rotation 10. With a uniform distribution of the four end stops 20, a total angular spacing of adjacent end stops of 90 ° about the axis of rotation 10 results. The same applies to the counterpart stop 22 at the line drum 9. In an alternative embodiment, other numbers of end stops 20 and mating stops 22 may also be suitable. The number of end stops 20 at the housing 7 corresponds to the number of counterpart stops 22 at the cord reel 9. By means of the four pairs of end stops 20 and the counterpart stops 22, a high torque can be transmitted from the housing cover 8 to the cord reel 9.

As shown in fig. 3, the cord harvesting head 5 comprises a spring element 14 arranged between the housing 7 and the cord reel 9. The cable drum 9 is prestressed by means of the spring element 14 against the bottom 4 of the cable harvesting head 5, in other words against the housing cover 8.

In a preferred embodiment, the spring element 14 is embodied as a helical spring, wherein the helical spring is arranged coaxially to the axis of rotation 12. The housing 7 has an inner side 37 facing the housing cover 8, against which the spring element 14 is supported. Toward the bottom surface 4 of the cable take-up head 5, the spring element 14 rests against a rest plate 38 arranged on the web 54 of the cable drum 9. In this case, the spring element 14 presses the abutment plate 38 against the web 54, as a result of which the cable drum 9 is clamped toward the housing cover 8. The spring element 14 is prestressed in the operating position 30 of the tandem arrangement 19. Spring element 14, supported on housing 7, is biased with spring force F against housing cover 8_FActing on the cord reel 9.

As shown in fig. 2 and 3As shown, the actuating element 15 is arranged on the bottom surface 4 of the cable cutting head and serves for actuating the tandem arrangement 19. The housing cover 8 has an opening 16, which is oriented coaxially with the axis of rotation 10 and through which the actuating element 15 projects. The actuating element 15 is thus accessible to the operator 66 in the mounted state of the line harvesting head 5. The actuating element 15 has a shoulder 52 which extends in the radial direction from the axis of rotation 10. The lower drum wall 13 of the cable drum 9 rests against the shoulder 52 of the actuating element 15 and presses it against a clamping surface 57 of the housing cover 8, which clamping surface is formed adjacent to the opening 16. The actuating element 15 is thus passed via the cable drum 9 by the spring element 14 with a spring force F_FClamped towards the housing cover 8.

As is shown in fig. 6 and 7, the cable drum 9 has a plurality of rotation stops 23, which interact with a corresponding number of engagement elements 25 formed on the inner side 37 of the housing 7. The engagement element 25 and the rotation stop 23 are also part of the tandem connection arrangement 19.

As is shown in fig. 7 and 8, four rotation stops 23 are arranged on the upper drum wall 11 of the cable drum 9, which are each formed in a slot 24 in the upper drum wall 11. The rotation stop 23 is formed at the end of the slot 24 in the direction of rotation. In the inoperative state 31, the wire drum 9 is rotated relative to the housing 7 counter to the direction of rotation 29 in an opposite direction of rotation 78. The rotation stop 23 is located at the downstream end of the slot 24 with reference to the opposite rotation direction 78 of the cord harvesting head 5. The slot 24 is in each case struck with its downstream end against an engaging element 25 which is sunk in at its upstream end. The slot 24 extends around the axis of rotation 10 over an angular section δ, wherein the angular section δ is approximately 30 ° to 70 °. In this exemplary embodiment, adjacent slots 24 have an angular spacing s, measured about the axis of rotation 10, wherein the angular spacing s is at least 15 °, in particular at least 30 °, preferably approximately 40 °. The angular spacing epsilon should be chosen such that sufficient material for high structural strength is provided between the two slots 24 at the upper reel wall 11. In the case of fewer than four slots 24 in the upper drum wall 11, it is also possible to adjust between two slots 24 to a significantly greater angleAnd (3) separating epsilon. Similar to the end stop 20 and the counterpart stop 22, the rotation stop 23 is spaced at a total angle of 90 °And (4) arranging. In an alternative embodiment of the cord harvesting head 5, other numbers of rotation stops 23 may also be suitable, and thus other total angular intervalsMay also be suitable. The slot 24 has a spacing b from the axis of rotation 10, measured in a radial direction with respect to the axis of rotation 10, wherein the spacing b corresponds to at least 20%, in particular at least 25%, preferably approximately 30%, of the diameter a of the wire drum 9. Furthermore, the slot 24 has a width c, measured in radial direction with respect to the axis of rotation 10, which corresponds to at least 5%, preferably at least 10%, preferably about 15% of the diameter a of the cord reel 9.

The slot 24 is rounded at its ends in the circumferential direction. Thereby increasing the contact area limited by the wall thickness of the wire drum 9 and thereby reducing the pressure per unit area. Furthermore, the notch stress concentration effect (Kerbwirkung) is reduced.

As shown in fig. 6 and 7, a plurality of engagement elements 25 are arranged in a horizontal section 62 on the inner side 37 of the housing 7. The number of engaging elements 25 and the total angular spacing of adjacent engaging elements 25 from each otherCorresponding to the rotation stop 23. In the preferred embodiment, the engagement elements 25 are configured as U-shaped projections which extend from the inner side 37 of the housing 7 in the direction of the axis of rotation 10 towards the bottom surface 4 of the cord harvesting head 5. Due to the U-shaped configuration of the engagement element 25, it rests flush against the slot 24 when it comes into contact with the rounded rotation stop 23. As can be seen in fig. 3, the engaging element 25 is inclined against the direction of rotation 29.

As shown in fig. 8 and 9, in a preferred embodiment, the slot 24 is configured as an opening in the upper drum wall 11. The slot 24 in the sense of the invention may thus be a slot with a bottom, but also a slot 24 without a bottom, i.e. an opening. In a preferred embodiment, the slot 24 is defined by a circumferential wall 60 that surrounds the slot 24. The circumferential wall 60 thus defines the slot 24 on the circumferential side radially inwardly and outwardly with respect to the axis of rotation 10. In an alternative embodiment, the slot 24 can also be a slot which opens out on the circumferential side. In other words, the slot can open out in the radial direction from the axis of rotation 10. The web webs formed between adjacent slots 24 here, however, advantageously do not project radially beyond the lower drum wall 13 of the cable drum 9.

As can be seen in fig. 8, 9 and 10, at the end of the slot 24 in the direction of rotation 29, a structural projection 36 is provided which reduces the pressure per unit area at the rotation stop 23 when contact is made between the engagement element 25 and the rotation stop 23. The load on the rotation stop 23 is thereby reduced, whereby the operating life of the wire harvesting head 5 is increased.

The unwinding process of the cutting cord 6 when handling the stringing device 19 is explained below:

fig. 3 shows the tandem arrangement 19 in its operating position 30. The end stop 20 of the housing cover 8 and the counterpart stop 22 of the rope drum 9 are in engagement and form a form-fitting connection in the direction of rotation 29 of the rope harvesting head 5. Fig. 6 shows the tandem arrangement 19 in the inoperative state 31, in which the wire drum 9 has also undergone the first rotation angle α (fig. 5). The actuating element 15 is actuated by an actuating force F_BAgainst spring force F_FIs pressed and in this case pushes the wire drum 9 towards the top surface 3 of the wire harvesting head 5, i.e. towards the drive shaft 2. In this case, the effective connection between the end stop 20 of the housing cover 8 and the counterpart stop 22 of the cord reel 9 is eliminated. At the same time, the engaging element 25 at the housing 7 sinks into the slot 24 at the drum wall 11 above the wire rope drum 9. In this case, the engagement elements 25 engage axially from above into the slots 24, i.e. in the direction of the axis of rotation 10 from the top side 3 toward the bottom side 4. The cord reel 9 is rotated counter to the direction of rotation 29 relative to the housing 7Until the engagement element 25 of the housing 7 hits the rotation stop 23 of the slot 24. By the centrifugal force acting on the cutting cord 6, the cutting cord 6 is pulled tangentially to the cord reel 9, whereby the cord reel 9 rotates in the relative rotation direction 78 relative to the housing 7. Upon a relative movement between the cord reel 9 and the housing 7, the cutting cord 6 is unwound from the cord reel 9 by a respective angular section corresponding to the first rotation angle α of the cord reel 9. The first angle of rotation α is slightly smaller than the angular section δ of the slot 24, since the engaging element 25 first sinks into the slot 24 and can therefore only be rotated by the length of the slot 24 (minus the inherent length of the sinking of the engaging element 25). As soon as the engagement element 25 abuts against the rotation stop 23 of the slot 24, a relative movement of the cable drum 9 extending in the relative direction of rotation 78 of the cable drum 9 counter to the direction of rotation 29 of the cable harvesting head 5 is braked. In fig. 5, the engaging element 25 is sunk into the slot 24. The wire drum 9 must be rotated in the relative rotation direction 78 through a first rotation angle α in order for the rotation stop 23 of the wire drum 9 to impinge on the engaging element 25 of the housing 7. In fig. 7, the wire drum 9 with the rotation stop 23 is rotated a first rotation angle α, whereby the rotation stop 23 is in contact with the engaging element 25. The slot 24 shown in dashed lines indicates the position of the cord reel 9 with the slot 24 before the first rotation a. In this position, as long as the actuating force F is no longer present_BThe cable drum 9 is pressed again by the spring element 14 against the bottom surface 4 of the cable harvesting head 5 and clamped against the housing cover 8. As is shown in fig. 10, the tandem arrangement is then in the other section 32 of the inoperative state, in which the cable drum 9 is rotated further by the second rotation angle β of the cable drum 9 relative to the housing 7 (fig. 11) until the counterpart stop 22 of the cable drum 9 contacts the end stop 20 of the housing cover 8. In a further section 32 of the inoperative state 31 of the tandem connection 19, the cable drum 9 is rotated relative to the housing 7 by a second rotation angle β of the cable drum 9 counter to the rotation direction 29 in the relative rotation direction 78 of the cable drum 9. Then, the position of rotation in the direction of rotation 29 is again reached (i.e. the operating position 30) and the cutting wire 6 is wound off by the corresponding total angular distance. In this case, the total angular intervalCorresponding to the sum of the first rotation angle alpha of the wire drum 9 and the second rotation angle beta of the wire drum 9.

A reduced overall height of the cable take-up head 5 is thereby obtained, i.e. the slot 24 is formed in the drum wall 11 above the cable drum 9. The structure of the upper drum wall is thus subjected to relatively high stresses. In order not to exert excessive forces and damage the upper drum wall 11 when the engagement element 25 comes into contact with the rotation stop 23 in the inoperative state 31 of the coupling device 19, the slot 24 must be designed to be correspondingly short. This results, on the one hand, in the web between adjacent slots being kept as large as possible and, on the other hand, in the cable drum 9 being accelerated only relatively briefly until the rotation stop 23 of the cable drum 9 strikes against the engagement element 25, as a result of which the force at the moment of impact of the engagement element 25 against the rotation stop 23 can be kept small. Thus not damaging the upper drum wall 11.

In an embodiment not shown, the same operating principle of forming the rotation stop 23 at the slot 24 can also be applied to the end stop 20 and the counterpart stop 22. The counterpart stop 22 of the lower drum wall 13 can thus also be arranged at a slot formed at the lower drum wall 13, so that the end stop 20 engages in the slot.

As shown in fig. 13, the cord harvesting head 5 comprises a cord channel 61 which extends over the entire diameter d of the cord reel 9. As the cutting cord 6 is wound onto the cord reel 9, the cutting cord 6 is pushed through the cord channel 61 and is centrally oriented towards the rotation axis 10. The cord reel 9 can then be rotated relative to the housing 7 against the direction of rotation 29. By means of the ramps 71 at the end stop 20, the counterpart stop 22 and the engaging element 24, the respective stops slide over one another and thus allow a relative movement of the wire drum 9 relative to the housing 7 against the direction of rotation 29. This is possible due to the axial movability of the cord reel 9 with respect to the housing 7. In an alternative embodiment of the cable harvesting head 5, which is not shown, it may be expedient to provide two cable channels instead of one cable channel 61, which do not extend over the entire diameter b of the cable drum 9. Such alternative cord channels may also be configured as blind holes.

As is shown in particular in fig. 8 and 12, a clamping ring 18 for preventing an unintentional unwinding of the cutting cord 6 is arranged at a circumferential side 60 of the cord reel 9. Thereby retaining the cutting cord 6 between the longitudinal wall 55, the drum walls 11, 12, 13 and the gripping loop 18. In order to enable the cutting cord 6 to pass through the cord openings 72, the clamping ring 18 also has a corresponding number of openings 73. The cutting cord 6 projects from the cord reel 9 through the opening 73 of the clamping ring 18 and out through the cord opening 72. In order to arrange the opening 73 of the clamping ring 18 in superimposition with the cable opening 72 at the housing 7 in order to be able to mount the cutting cable 6 from outside the housing 7, the clamping ring 18 is held in a form-fitting manner at the housing 7. A plurality of shoulders 74 are formed on the clamping ring 18, which shoulders bear in a form-fitting manner on the inner wall of the housing 7 at corresponding counter shoulders 75, extending around the rotational axis. This results in the clamping ring 18 being connected to the housing 7 in a rotationally fixed manner when the cable drum 9 is rotated, rotating relative to the cable drum 9 and thereby retaining the cutting cable 6 in the cable chamber 56 of the cable drum 9.

Fig. 14 shows the housing cover 8. In this figure, the opening 16 of the housing cover 8 through which the actuating element 15 projects in the mounted state of the cable harvesting head 5 is again clearly shown. Furthermore, a latching projection 42 of the housing cover is shown, which together with a latching opening 41 of the housing forms a latching connection 40. Further shown are four end stops 20 which co-act with mating stops 22 of the cord reel 9.