DE102022131543A1 - Attachment head - Google Patents

Abstract

An attachment head (100) has a first and a second clamping element (102, 104), wherein the clamping elements (102, 104) are designed such that at least one flexible elongated processing element can be inserted between the clamping elements (102, 104). The two clamping elements (102, 104) have fastening elements (112, 130) that can be brought into engagement with one another and that fix the two clamping elements (102, 104) to one another. The second clamping element (104) comprises a base plate (134) with a plurality of axial through-openings that are designed to receive flexible elongated processing elements. This design improves the attachment head (100) structurally and functionally.

Description

The invention relates to an attachment head according to the preamble of claim 1, which is designed in particular as a mowing head for a brush cutter or a lawn trimmer.

Brush cutters or lawn trimmers are often used to maintain green areas, e.g. to cut or remove grass or weeds. Replaceable cutting lines are clamped into their mowing heads for this purpose. It is helpful if the cutting lines can be mounted on the mowing head so that they protrude radially, but also axially downwards. In this way, for example, a horizontal cut on grass and plants is possible, but it can also be used to clear growth from joints.

Since the cutting threads wear out over time, they should be easy to replace.

The invention is based on the object of structurally and/or functionally improving an attachment head mentioned above.

The problem is solved with an attachment head having the features of claim 1.

In summary and in other words, the invention thus results in, among other things, an easy-to-handle attachment head, since only the two clamping elements need to be moved to replace the flexible, elongated processing elements (hereinafter also referred to as "processing elements"). Since these can be fixed directly to one another using their fastening elements, there is no need to handle other individual parts, such as screws. To insert the processing elements, the second clamping element is simply detached from the first clamping element, the processing elements are inserted according to the desired orientation and the second clamping element is re-attached to the first clamping element. The through openings in the base plate specify the position of the axially extending processing elements, which simplifies the adjustment of the processing elements when inserting them into the attachment head. The clamping elements preferably form the two main components of the attachment head.

The respective fastening element can be firmly connected to the remaining clamping element, so that when replacing the processing elements only the two clamping elements and no other components need to be moved. In particular, the fastening elements can be designed as one piece with the remaining clamping element. The respective fastening element can be made in one piece and/or in one piece with the respective clamping element, i.e. they can be made from one part. Alternatively, the respective fastening element can be pressed onto the respective clamping element. The attachment head can consist of the two clamping elements.

The flexible, elongated processing elements can be replaceable wearing parts. They can be made of a suitable plastic and/or metal, e.g. a wire. In particular, conventional cutting threads for brush cutters or lawn trimmers can be used as processing elements. However, the use of wire strands and/or wire brushes is also conceivable.

The attachment head can be used in particular as a mowing or brushing head for a hand-held device, for example a brush cutter or lawn trimmer, and/or be designed for this purpose. Depending on the arrangement and/or type of processing elements inserted, various functions can be implemented with the attachment head, especially a cutting and/or brushing function. For example, mowing grass, cutting plants, cleaning floor joints, but also general cleaning or processing of surfaces is possible.

During operation, the attachment head can be attached to a rotating shaft of the handset or can be attached to it for this purpose.

For this purpose, the first clamping element can preferably have a suitable receptacle for the shaft. This can in particular be a standardized mounting opening running along a rotation axis on a side opposite the fastening element of the first clamping element. For example, the mounting opening has a diameter of 20 mm (¾ inch) or 25.4 mm (1 inch).

The longitudinal direction of the attachment head can coincide with its axis of rotation during operation.

In a preferred embodiment, the clamping elements can be designed in such a way that flexible, elongated processing elements can be guided through the through holes in the base plate and/or clamped between axial contact surfaces on both clamping elements. In order to achieve an axial alignment of the processing elements for a brushing function, the two ends of a processing element can be inserted through adjacent through holes in the base surface. For a cutting function with a radial alignment of the processing The machining element can be arranged parallel to the surface of the base plate and/or clamped between the two clamping elements.

In order to obtain the smoothest possible outer contour of the attachment head, the contact surfaces of the two clamping elements can preferably lie flat and/or gap-free on top of each other when equipped exclusively with processing elements inserted into the through openings.

The outer peripheral edge of each of the contact surfaces can also lie in a single plane all the way around, whereby the outer peripheral edges of the two contact surfaces can have identical contours. This results in the outer surface of the attachment head being as smooth as possible.

Preferably, the clamping elements can be designed so that the processing elements can be placed directly between the two clamping elements. This enables the processing elements to be mounted in the desired radial and/or axial alignment without the use of intermediate elements such as spacers or deflection nuts. This simplifies handling and reduces the time required to replace the processing elements. With just the two clamping elements, any arrangement of radial and/or axially aligned processing elements can be realized. For example, purely radial or purely axial assembly is possible, but also a mixed assembly of radial and axially aligned processing elements.

The first clamping element can preferably have a groove running around the fastening element. The middle, e.g. curved, sections of the processing elements running inside the attachment head in the through holes in the base plate can then be accommodated in the groove between the two clamping elements. The processing elements can also be deflected axially towards the base plate by the outer edges of the groove. The processing elements can thus be held securely in the attachment head and/or, in the case of purely axial assembly, can be completely covered by the clamping elements with the exception of their ends protruding outwards through the through holes. It has been found that this also results in improved running behavior of the attachment head.

The groove can preferably extend radially completely over the through openings. The groove can be limited by the axial contact surface of the first clamping element, so that the contact surface can lie radially outside the groove. The contact surface of the second clamping element can then preferably lie radially outside the through openings.

In a preferred embodiment, the fastening elements of the two clamping elements can have interlocking threads. Left-hand threads are advantageously provided here in order to prevent the two clamping elements from coming loose from one another during operation of the attachment head.

The fastening element on the second clamping element can preferably be an axial projection provided with an external thread. The projection can have several receiving openings for processing elements. The fastening element on the first clamping element can have an internal thread. The internal thread can receive the projection. In this way, the two clamping elements can be detached from one another and reconnected to one another by a simple rotational movement of the second clamping element relative to the first clamping element.

Instead of the external thread, the projection could also be provided with other suitable fastening components, for example locking elements/locking sections of a locking connection. The first clamping element then has no internal thread, but rather corresponding complementary locking elements/locking sections. Fastening components of a bayonet lock would also be conceivable.

The receiving openings can preferably be axial slots that are open at the free end of the projection so that the processing elements can be easily inserted from above. The processing elements can be arranged as desired. The receiving openings can be so high in the longitudinal direction that several processing elements can be inserted on top of one another in order to be able to implement a mulching function, for example.

The through-openings in the base plate can preferably be arranged in such a way that adjacent through-openings are offset from one another in the circumferential direction and/or in the radial direction. For example, an arrangement in at least two concentric circles can be provided, with the through-openings of radially adjacent circles being offset from one another in the circumferential direction. The offset arrangement of the through-openings can improve the brushing function. The number of brushes mounted on the base plate can also be reduced. can be maximized by using editable elements.

In order to generally protect the attachment head from wear, a rotatably mounted wear protection element can be arranged on the underside of the attachment head. The underside of the attachment head can be understood to be the side of the attachment head that faces a work surface, e.g. the ground, when the attachment head is in operation. In the embodiments described above, this can correspond to a side of the base plate facing away from the first clamping element. The wear protection element can thus be arranged at the point on the attachment head that most frequently comes into contact with the ground during operation. The wear protection element can thus prevent other rotating areas of the attachment head from coming into contact with the ground. The rotatable mounting of the wear protection element can reduce abrasion on the wear protection element itself and/or can thus increase its service life.

The wear protection element can be made of a harder and/or tougher material than the second clamping element. For example, the wear protection element can be made of stainless steel, while the clamping elements are made of a plastic or aluminum.

Preferably, the wear protection element can be a ball. This makes it easy to create a rotating bearing. In addition, a relatively large distance can be created between the underside of the attachment head and the outermost point of the wear protection element. In this way, the attachment head can also be protected from contact with the ground up to a greater inclination of the attachment head.

The bearing of the wear protection element can, for example, be formed directly in the underside of the attachment head.

The invention makes it possible to create a compact, easy-to-use attachment head that consists of just two main components. To change the processing elements, the second clamping element only has to be detached from the first clamping element and then reconnected to it after the processing elements have been inserted. The connection between the two clamping elements can be released and closed again in particular by a rotating movement of the entire second clamping element relative to the first clamping element. The processing elements can optionally be mounted in any combination of radially extending and axially extending processing elements without the attachment head having to be modified.

Advantageous embodiments and/or further developments are the subject of the subclaims.

• 1 einen erfindungsgemäßen Aufsatzkopf in einem teilweise auseinander geschraubten Zustand;
• 2 den Aufsatzkopf aus 1 mit montierten Bearbeitungselementen, die sich axial erstrecken;
• 3 den Aufsatzkopf aus 1 mit montierten Bearbeitungselementen, die sich radial erstrecken;
• 4 eine perspektivische Ansicht eines ersten Einspannelements des Aufsatzkopfs aus 1;
• 5 eine weitere perspektivische Ansicht des ersten Einspannelements des Aufsatzkopfs aus 1 und 4;
• 6 eine perspektivische Ansicht eines zweiten Einspannelements des Aufsatzkopfs aus 1;
• 7 eine weitere perspektivische Ansicht des zweiten Einspannelements des Aufsatzkopfs aus 1 und 6;
• 8 eine weitere perspektivische Ansicht des zweiten Einspannelements des Aufsatzkopfs aus 1, 6 und 7; und
• 9 eine Darstellung einer Unterseite des Aufsatzkopfs aus 1 mit einem Verschleißschutzelement.

In the following, embodiments of the invention are described in more detail with reference to figures, which show schematically and by way of example:

• 1 an attachment head according to the invention in a partially unscrewed state;
• 2 the attachment head 1 with mounted machining elements that extend axially;
• 3 the attachment head 1 with mounted machining elements that extend radially;
• 4 a perspective view of a first clamping element of the attachment head from 1 ;
• 5 another perspective view of the first clamping element of the attachment head from 1 and 4 ;
• 6 a perspective view of a second clamping element of the attachment head from 1 ;
• 7 another perspective view of the second clamping element of the attachment head from 1 and 6 ;
• 8th another perspective view of the second clamping element of the attachment head from 1 , 6 and 7 ; and
• 9 a representation of the underside of the attachment head 1 with a wear protection element.

For reasons of clarity, not all similar components of a figure are always provided with reference symbols.

1 shows an attachment head 100 for a hand-held device (not shown), in particular a brush cutter or a lawn trimmer.

The attachment head 100 is composed of a first clamping element 102 and a second clamping element 104.

In general, the clamping elements 102, 104 can consist of a suitable plastic or a suitable metal, for example aluminum.

Between the two clamping elements 102, 104, several flexible elongated machining elements 106 can be inserted (see 2 and 3 ). When the attachment head 100 is in operation, the processing elements 106 are used, for example, to remove plant parts or to clean curb joints, as is conventionally known from such devices. However, they can also be used generally for cleaning or processing surfaces.

The first clamping element 102 is closer to the 4 and 5 shown. It is designed in an approximately bell-shaped manner here. A central section 108 has the shape of a hollow cylinder with an internal thread 110 and forms a fastening element 112 of the first clamping element 102. The central section 108 is essentially rotationally symmetrical with respect to a longitudinal axis A, which represents the axis of rotation of the attachment head 100 during operation.

At one end, the central portion 108 has a radial widening 114, on the inside of which there is a groove 116 which runs annularly around the central portion 108 (see 5 ).

An axial contact surface 122 is formed between an outer edge 118 of the groove 116 and an outer peripheral edge 120 of the first clamping element 102. In this embodiment, the outer peripheral edge 120 of the first clamping element 102 is smooth all the way around, so that it lies completely in a single plane. An axial surface is understood here to mean a surface that is aligned perpendicular to the longitudinal axis A.

The first clamping element 102 is formed in one piece so that the central section 108 and the widening 114 are firmly connected to one another.

At the end opposite the widening 114, the first clamping element 102 has a standardized assembly opening 124, which serves to connect the attachment head 100 to a hand-held device. If necessary, further components are present for releasably fixing the attachment head 100 to a rotatable shaft of the hand-held device. However, these are not involved in the actual function of the attachment head 100, in particular not in inserting and replacing processing elements 106, and are therefore not considered further here.

The second clamping element 104, which is closer to the 6 to 8 is shown, in this example comprises an axially extending, central projection 126, which here has an external thread 128. The projection 126 with the external thread 128 forms a fastening element 130 of the second clamping element 104.

The external thread 128 is formed complementarily to the internal thread 110 of the first clamping element 102, so that the two clamping elements 102, 104 can be screwed together using their fastening elements 112, 130. Both threads 110, 128 are left-hand threads. In this embodiment, the fastening and loosening of the two clamping elements 102, 104 to one another takes place purely by a relative rotation between the two clamping elements 102, 104. Additional fastening means are not provided.

In the projection 126, several receiving openings 132 (here 6) are arranged distributed over its circumference. In this example, the receiving openings 132 are designed as slots that run from the free end of the projection 126 down to a surface of a base plate 134. The receiving opening 132 is designed to receive one or more processing elements 106 one above the other.

The projection 126 is arranged centrally on the base plate 134. The projection 126 and the base plate 134 are formed integrally with one another.

The base plate 134 has a plurality of axial through-openings 136 which run along the longitudinal direction A and serve to receive processing elements 106. With the exception of the projection 126 and the through-openings 136, the side of the base plate 134 facing the first clamping element 102 is flat and shaped without projections or recesses.

Adjacent through-openings 136 are arranged offset from one another along the circumferential direction U and along the radial direction r. The position of two through-openings 136 adjacent in the circumferential direction U therefore always differs both in the circumferential direction U and in the radial direction r. In this example, the through-openings 136 are arranged in two concentric circles around the projection 126, with the through-openings 136 of both circles being offset from one another in the circumferential direction U. Overall, an even number of through-openings 136 is provided here. For example, both circles can each have 14 through-openings 136. However, the number can be varied at the discretion of the expert.

A circumferential, axial contact surface 138 is formed radially outside the through-openings 136. This contact surface 138 corresponds in shape to the contact surface 122 of the first clamping element 102 and is oriented opposite to it. An outer peripheral edge 140 of the base plate 134 at the edge of the contact surface 138 is shaped identically to the outer peripheral edge 120 at the widening 114 of the first clamping element 102.

The central portion 108 of the first clamping element 102 and the projection 126 of the second clamping element 104 extend in the longitudinal direction A. The two fastening elements 112, 130 are arranged centrally with respect to the widening 114 and the base plate 134.

In this embodiment, an overall outer contour of the attachment head 100 is essentially rotationally symmetrical.

If the attachment head 100 is to be equipped with processing elements 106, the two clamping elements 102, 104 are separated from one another by disengaging their fastening elements 122, 130. In the embodiment shown, the two clamping elements 102, 104 are unscrewed.

Processing elements 106 are, for example, inserted into the receiving openings 132 of the projection 126. They can be guided, for example, in such a way that they enclose a web formed between two receiving openings 132, or extend more or less straight through two opposite receiving openings 132. Several processing elements 106 can also be arranged one above the other in a receiving opening 132. The ends of the processing elements 106 protrude radially from the attachment head 100 in this configuration, as shown in 3 is shown.

In another option, processing elements 106 are guided with their ends through a through-opening 136, whereby a middle part of the respective processing element 106 then runs over the base plate 134 (not shown). With this configuration, the ends of the processing elements 106 protrude outward through the base plate 134 in the longitudinal direction A from the attachment head 100. This is shown in 2 shown.

Both types of equipment can be combined as desired.

In the embodiment shown, no additional components such as intermediate disks are used.

Once all processing elements 106 to be used have been inserted, the second clamping element 104 is again fastened to the first clamping element 102 by engaging the threads 110, 128 on the respective fastening elements 112, 130 and screwing the second clamping element 104 to the first clamping element 102 again.

The groove 116 now lies over the sections of the processing elements 106 that run over the base plate 134. In this example, the groove 116 is designed and arranged such that it covers all of the through openings 136 in the radial direction r. The edges of the groove 116 support the deflection of the processing elements 106 into the through openings 136.

If only axially extending processing elements 106 are provided, i.e. only processing elements 106 that are guided through through openings 136, the contact surfaces 122, 138 of the first and second clamping elements 102, 104 lie directly on one another without a gap in the assembled attachment head 100. The outer peripheral edges 120, 140 have no projections or recesses in the longitudinal direction A. This shows 2 . It can also be clearly seen there that an outer contour of the widening 114 merges smoothly and continuously into an outer circumference of the base plate 134. The middle sections of the processing elements 106 are completely covered by the two clamping elements 102, 104. The processing elements 106 only protrude from the attachment head 100 on an underside 142 thereof and are not exposed at any other point on the attachment head 100.

If only or also machining elements 106 are mounted which extend radially, they run between the two contact surfaces 122, 138 and are clamped between them. This is in 3 shown.

In the embodiment shown here, a wear protection element 144 is arranged on the underside 142 of the attachment head 100. The underside 142 of the attachment head 100 is formed in this example by the underside of the base plate 134, which is opposite the side of the base plate 134 facing the first clamping element 102.

The wear protection element 144 is rotatably received in a bearing 146, which is formed in the underside 142. In this example, the wear protection element 144 is a ball. This consists in particular of a harder and/or tougher material than the second clamping element 104, e.g. of stainless steel.

The bearing 146 can be formed in any way. For example, the wear protection element 144 can be held by a flanged peripheral edge of the bearing 146. It is also possible to design the bearing 146 in such a way that the wear protection element 144 can be replaced.

The wear protection element 144 protrudes in the longitudinal direction A beyond the rest of the underside 142. Therefore, the wear protection element 144 forms the most likely contact point between the attachment head 100 and a work surface, for example the ground when mowing plants. Even when the attachment head 100 is inclined, usually only the wear protection element 144 touches the ground.

Such a wear protection element 144 can also be used on attachment heads other than those described above, such as mowing heads. In particular, the arrangement of the wear protection element 144 is independent of the design of the clamping elements of the attachment head.

The terms “can”, “preferably” and “preferably” refer in particular to optional features of the invention. Accordingly, there are also further developments and/or embodiments of the invention which additionally or alternatively have the respective feature or features.

If necessary, isolated features can also be selected from the combinations of features disclosed here and used in combination with other features to define the subject matter of the claim, dissolving any structural and/or functional connection that may exist between the features.

Reference symbols

100

Attachment head

102

first clamping element

104

second clamping element

106

Processing elements

108

Middle section

110

inner thread

112

Fastener

114

Expansion

116

Groove

118

Outer edge of the groove

120

Outer peripheral edge

122

Contact surface

124

Mounting opening

126

head Start

128

External thread

130

Fastener

132

Receiving opening

134

Base plate

136

Passage opening

138

Contact surface

140

Outer peripheral edge

142

bottom

144

Wear protection element

146

storage

Claims (10)

Attachment head, in particular for a hand-held device, with a first and a second clamping element (102, 104), wherein the clamping elements (102, 104) are designed such that at least one flexible elongated processing element (106) can be inserted between the clamping elements (102, 104), wherein the two clamping elements (102, 104) have fastening elements (112, 130) which can be brought into engagement with one another and which fix the two clamping elements (102, 104) to one another, characterized in that the second clamping element (104) has a base plate (134) with a plurality of axial through-openings (136) which are designed to receive flexible elongated processing elements (106). Attachment head after Claim 1 , characterized in that the clamping elements (102, 104) are designed such that flexible elongated processing elements (106) can be guided optionally through the through openings (136) in the base plate (134) and/or clamped between axial contact surfaces (122, 138) on both clamping elements (102, 104). Attachment head after Claim 2 , characterized in that when equipped exclusively with flexible elongated processing elements (106) inserted into the through openings (136), the contact surfaces (122, 138) of the two clamping elements (102, 104) lie flat and gap-free on one another. Attachment head according to at least one of the Claims 2 and 3 , characterized in that an outer peripheral edge (120, 140) of each of the contact surfaces (122, 130) lies circumferentially in a single plane, wherein the outer peripheral edges (120, 140) of the two contact surfaces (122, 130) have identical contours. Attachment head according to at least one of the preceding claims, characterized in that the clamping elements (102, 104) are made of are arranged such that the flexible elongated processing elements (106) can be placed directly between the two clamping elements (102, 104). Attachment head according to at least one of the preceding claims, characterized in that the first clamping element (102) has a groove (116) running around the fastening element (112). Attachment head according to at least one of the preceding claims, characterized in that the fastening element (130) on the second clamping element (104) is an axial projection (126) provided with an external thread (128) which has a plurality of receiving openings (132) for flexible elongated processing elements (106), and the fastening element (112) on the first clamping element (102) has an internal thread (110). Attachment head according to at least one of the preceding claims, characterized in that the through openings (136) in the base plate (134) are arranged such that adjacent through openings (U) are offset from one another in the circumferential direction (U) and in the radial direction (r). Attachment head according to at least one of the preceding claims, characterized in that a rotatably mounted wear protection element (144) is arranged on an underside (142) of the attachment head (100). Attachment head after Claim 9 , characterized in that the wear protection element (144) is a ball.

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