DE3432461A1 - ATTACHING A WOODEN HANDLE - Google Patents

Description

The invention relates to a fastening of a plastic sleeve, the one longitudinal opening for receiving a coupling nipple or the like. and a transverse threaded hole for receiving a screw, on a wooden handle.

It is already known (DE-PS 26 17 622) for attachment of a garden tool provided with a coupling nipple, insert a plastic sleeve into a piece of pipe and to push the piece of pipe at its opposite end onto a wooden handle.

To improve the attachment between a tubular sleeve and a wooden handle, it is known (DE-PS 26 39 016), a Insert connecting element in the form of an approximately U-shaped bent flat material strip between the tube and the stem.

Both mounting options have proven themselves. she however, require the production and availability of a relatively large number of items.

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The invention is based on the object of creating a handle attachment that is easier to manufacture the connection properties are improved, the number of parts and thus the manufacturing and storage costs can be reduced and which is better sealed against water ingress.

To solve this problem, the invention provides that the plastic sleeve has a portion formed integrally with her around an axial end region of the wooden handle is arranged around and directly connected to this. This means that there is only one additional component needed for the wooden handle that is attached directly to the wooden handle. The plastic can be one Act thermoplastic, but reactive resins are also possible, which are glued or foamed around the end area can. It has been found that the connection of the plastic with the wood is extremely good because the wood has a relatively rough, fiber-rich surface, so that there is a good bond with the plastic comes. It is particularly favorable if the plastic is injected around the end area of the wooden handle.

In a further development it can be provided that the end area of the stem has a reduced diameter. In this case it is possible that the molded plastic area runs flush with the rest of the handle so that there are no edges in which to hold dirt or moisture can fix. The reduced diameter of the stem can be achieved by a simple milling, which at the same time has the advantage that the surface is relatively rough. This in turn leads to improved adhesion between the plastic and the wood.

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The invention provides that the length of the end region of the stem or of the molded section of the plastic sleeve is at least about twice as long, preferably three times as long as the diameter of the stem. this leads to a mechanically good connection, as the adhesion surface is sufficiently large.

To further improve the durability of the attachment can be provided that the plastic sleeve in a End area of the stem surrounding and over the stem end protruding tube and into the space between the Tube and the stem is introduced, preferably injected. This leads to increased mechanical stability. The tube can advantageously consist of metal, in particular aluminum, but it can also consist of an optionally consist of differently composed plastics. The tube increases the bending moments to be transmitted and holds the plastic sleeve firmly clamped.

Here, too, it can be provided that the outer diameter of the tube is at least in the area overrunning the stem corresponds roughly to the outside diameter of the stem in its remaining area. This will make a smoother Transition between the outside of the tube and the adjoining area of the stem created so that no dirt can settle.

In a further development it can be provided that the stem in its end region has at least one annular groove. With the help of this ring groove, which is filled by the plastic is, an increase in tensile strength is achieved. Two such annular grooves are expediently provided.

In a further development it can be provided that the tube in his a reduced area protruding over the stem

Has diameter. In this tube area, in which the handle does not engage, is the longitudinal opening for receiving a coupling nipple arranged. The drilling diameter can be reduced by the known method of pulling in a pipe, for example an aluminum pipe. The reduced diameter does it Among other things, it is possible to only have to make the pipe as thick in this area as is necessary for inserting the coupling nipple, with wooden handles of different sizes Thickness can be used.

The invention proposes to improve the security against rotation about an axis running in the longitudinal direction of the fastening before that the tube is ribbed inside in its area spanning the stem. While the plastic on the If the fibrous surface of the wood adheres sufficiently firmly, the inner ribbing of the pipe makes it a special one good adhesion of the pipe to the plastic achieved in the direction of rotation. In addition, the ribbing creates the separating surface enlarged between pipe and plastic. A particularly favorable type of ribbing is given when the pipe has longitudinal grooves formed from the outside in this area, the corresponding ribs on the inside of the pipe form. So there are grooves formed in the outside of the pipe, which push through on the inside. The material thickness of the tube remains the same everywhere, so that the corresponding webs are formed inside without that the material is weakened. The application of the grooves from the outside of course has advantages in terms of manufacturing technology.

The invention further provides that the tube has an opening of enlarged diameter in the area of the threaded hole of the plastic sleeve, with the plastic sleeve

an approach penetrating the opening to the outside is formed. This allows, for example, the length of the thread, in which the locking screw is arranged, enlarge. This leads to better guidance of the screw and a longer service life. In addition, this of course also leads to the connection being secured again between plastic and pipe. During production, the molding tool can have a corresponding shape at this point exhibit. The approach can be used with advantage to a cooperating with the screw device with the help of which the screw is held captive. For example, the approach can be a snap-on collar and optionally have radially extending slots that allow easier deformation of the snap-on collar. Such a protection against loss is known from DE-GBM 79 16 056.

The invention also proposes a method for producing a handle attachment in which a plastic sleeve is connected with a wooden handle. This handle attachment can be designed as described above became.

According to the invention, the stem with its axial end region placed in a mold and then plastic in the space between the mold and introduced into the end of the stem. The plastic can, provided it is, for example, a thermoplastic is, be injected, but it can also be introduced and cured in some other way, or else be foamed.

It is particularly favorable if the plastic is injected.

The axial end region of the stem can be selected as required, it being useful that its length is at least about two to three times the diameter of the stem.

For better axial locking between the plastic and the handle it can be provided that before insertion of the handle, at least one, preferably two, annular grooves are milled or screwed into the end area of the handle will.

To ensure a smooth transition between the outside of the plastic sleeve and to ensure the outside of the stem, it can be provided that the end portion of the stem is in front its insertion into the molding tool is brought to a reduced diameter, in particular is milled off. Included it may be possible, for example, to reduce the area Form slightly conical in diameter, the diameter increasing in the direction of the end of the stem. Even this enables a good interlock between wood and plastic to be achieved.

In a further development it can be provided that a tube is inserted into the molding tool in such a way that it forms the end region of the stem and protrudes beyond its end, and that the plastic in the space between the tool and End of the stem is introduced. The resulting connection is hereby further improved, since the plastic sleeve is surrounded on the outside by the pipe.

In the transition area between the end of the tube and the handle of the wood, the tool can according to the invention on the Wooden handle can be pressed, the pressing up to Inner diameter of the pipe can be done. In this way

it is achieved that the plastic does not escape from the corresponding end of the tube and is therefore invisible from the outside is.

However, it is also possible, as is further proposed by the invention, in the transition area between Tube and handle to form a plastic collar. In this case, the molding tool can be designed so that it does not protrudes inwards beyond the outer diameter of the pipe.

In a further development it can be provided that a molding tool is used with at least one cavity in the area of the federal government. The cavity can be opened through a narrow opening be connected to the collar area, so that after completion of the handle attachment in the area of the collar balls or the like. are formed, which are connected to the federal government via narrow webs. These narrow ridges can be removed immediately break off so that the ball-like projections can be removed. This training has the advantage that on one Blick can be used to check whether the spraying process has proceeded without errors.

It is particularly favorable when a tool with a low Radial spacing in the region of the end of the pipe is used. The plastic is introduced under pressure so that under its pressure, the pipe is due to the small radial distance of, for example, 0.2 mm slightly outwards can deform. This deformation must still be in the elastic range of the pipe material used. When hardening some shrinkage of the plastic may occur, but this is due to the elastic deformation of the pipe material is absorbed by its recovery, so that no loosening or the like occurs after hardening.

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The invention also provides that when the plastic sleeve is manufactured, a side opening of the tube is inserted Threaded approach is formed, in particular formed. The plastic sleeve is positioned for this purpose inserted into the tool so that its opening corresponds to the shape on the outside of the tube got.

The invention also provides for the pipe before it is inserted to taper in the molding tool in its protruding area over the stem. This can be done through the familiar Pulling in pipes is done. Furthermore, it can be provided that the tube before it is inserted into the molding tool is grooved. These grooves on the outside form similarly shaped grooves on the inside of the Tube, which when they run in the longitudinal direction, a particularly favorable rotation lock between the tube and the brought in plastic.

To produce the grooves, a ring with embedded balls can be placed over the tube and that Move along the pipe. Depending on the diameter of the circle inscribed on the spheres, each sphere a more or less deep groove is formed, both in the purely longitudinal direction and when the ring is rotated can be designed to run obliquely during the movement. This type of production of the grooves has the advantage that when a ball wears out it can easily be replaced.

Further features, details and advantages of the invention emerge from the claims and the following description preferred embodiments of the invention and based on the drawing. Here show:

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1 shows a longitudinal section through a handle attachment according to the invention;

FIG. 2 is a plan view of the arrangement in FIG. 1; FIG. Fig. 3 is a view of the arrangement from the left in Fig. 1; FIG. 4 shows a section along line IV-IV in FIG. 1; FIG. Fig. 5 is a section along line V-V in Fig. 1;

6 schematically shows the arrangement during the manufacture of a handle attachment;

FIG. 7 shows a diagram corresponding to FIG. 6 View of a different type of manufacture;

8 shows another type of production that has been modified again.

Fig. 1 shows in longitudinal section a fastening between a wooden handle 11, a plastic sleeve 12 and a one End region 13 and the plastic sleeve 12 overlapping Tube 14, which in the present example consists of aluminum. The length of the end region 13 of the wooden handle 11 is approximately three times as long as the diameter of the wooden handle 11. The end area 13 itself has a reduced diameter, wherein the free end 15 of the end region 13 is slightly frustoconical. Contains roughly in this area the end region 13 has a circumferential annular groove 16 which is approximately trapezoidal in cross section. A second such Groove 17 is arranged closer to the end of the tube 14. It also has an approximately trapezoidal cross-section.

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The plastic sleeve 12 is injected into the interior of the tube 14, wherein it has a first section 18 on the left in FIG. 1, in which it contains a longitudinal opening 19. the Longitudinal opening 19 has a circular cross-section towards the end 20 of the plastic sleeve 12, while further on the inside, individual webs 21 extending in the longitudinal direction extend. The longitudinal webs form contact surfaces for one in the Longitudinal opening 19 to be used coupling nipple.

Beyond the area 18 of the plastic sleeve 12, this forms a second section 22 which is integral with the Space between the end region 13 of the wooden handle

11 and the tube 14 is arranged. The plastic material extends into the annular grooves 16 and in this area 17 and connects due to the fibrous structure of the wooden handle 11 with the end portion 13, so that an absolute secure connection is established.

In the transition area 23 between the tube 14 and the wooden handle 11, the plastic of the section 22 forms the sleeve

12 a circumferential collar 24, which has a smooth transition forms between the tube 14 and the wooden handle 11. At the opposite end of the tube 14 is also a Collar 25 formed from the material of the plastic sleeve 12, which closes the handle attachment towards its free end.

At the top in Fig. 1, the tube 14 contains an opening 26, through which a projection 27 of the plastic sleeve 12 passes. The approach 27 includes a longitudinal bore 28 which transversely runs to the longitudinal opening 19 of the plastic sleeve 12. In In its area closest to the longitudinal axis of the tube 14, the longitudinal bore 28 contains a thread 29 on its outside contains the approach 27 a snap-on collar 30, the

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protrudes somewhat outwardly with respect to the otherwise cylindrical outer side of the projection 27. In this area If the extension 27 contains a total of four slots 31, the side walls 32 of which run approximately radially, see also FIG.

From Fig. 1 and 2 it can be seen that the tube 14 in the stem area an enlarged diameter and a reduced diameter in the area protruding over the handle Π having. In both areas, the tube 14 is cylindrical.

In the area of enlarged diameter, the tube, see FIG. 2, contains several longitudinal grooves 33, the boundary surfaces of which lie on an arc of a circle when viewed in cross section. The grooves 33 are by bending the Tube 14 produced so that it is also present on the inside of the tube 14 in the end region 13 of the stem 11 are.

3 shows the view of the handle attachment from the left in FIGS. 1 and 3. The tube 14 is not closed from the left see that the front side is formed by the collar 25. The webs 21 already mentioned in FIG. 1 simulate inwardly directed contact surfaces 34 on which adjacent surfaces of a hexagon can lay. The longitudinal opening 19 is penetrated at its end by a transverse web 35, which enables the insertion of a hexagonal coupling nipple limited. It is then acted upon transversely by a screw screwed through the shoulder 27 and the thread 29 pressed against the contact surfaces 34 of the longitudinal webs 21. This leads to a backlash-free mounting of a coupling nipple on the stem 11.

Fig. 4 now shows the section along line IV-IV in Fig. 1, the cut extending transversely through the extension 27. The shoulder 27 protrudes on the inside of the longitudinal bore 19 something into this, while it clearly protrudes on the outside of the tube 14 from this. On the outside the four slots 31 are available, which extend from the upper end of the extension 27 to the area just before the pipe 14 extend. Outside the tube 14, the projection 27 engages with a lip 36 around the outside of the opening 26 of the Tube 14, so that it is clearly defined here and prevents the ingress of liquid. The thread 29 is formed only in the lower region of the projection 27.

Fig. 5 shows a section through the tube 14 in the end region 13 of the wooden handle. The tube contains on its outside a total of eight grooves 33 evenly distributed over the circumference, which are delimited in cross section by a circular line. The grooves 33 correspond to the inside of the tube 14 corresponding part-circular ribs 37, which except for the Outside of the end region 13 of the wooden handle 11 reach. As a result, there are a total of eight approximately between the ribs 37 Trapezoidal spaces in the longitudinal direction of the wooden handle Π are created into which the plastic can penetrate and can reach the transition area 23 for the formation of the federal 24. After the plastic has hardened or solidified is therefore the tube 14 against rotation completely with the help of the plastic at the end portion 13 of the wooden handle 11 attached. The grooves 33 on the outside, which are produced with the aid of balls moved in the longitudinal direction, form In addition, there are recessed grips on the outside, which make it easier to grasp and manipulate the handle from its outside.

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Fig. 6 shows very schematically the arrangement of the end area 13 of the handle 11 in an only partially shown Forming tool 38. The tube 14 is already in the finished shape, i.e. with grooves 33 in its outside. Between the molding tool and the outside of the tube 14 is a small distance 39 is present, which when injecting the Plastic under pressure allows deformation of the aluminum tube 14 to the outside. The molding tool 38 includes a Step 40, which is directly at the free end 41 of the tube 14 is present. The depth of the step 40 corresponds to the thickness of the pipe 14. Behind the step 40 contains the molding tool a slightly curved portion 42 that extends outward. During the injection of the plastic, the Wooden handle 11 pressed down in this area, so that the plastic in the cavity 43 between the outside of the wooden handle 11 and the inside of the tube 14 can penetrate, but not via the free end 41 of the tube 14 can step out.

In the arrangement in FIG. 7, another tool 44 is used that does not have the step 40 shown in FIG. 6 having. The distance 39 can again be seen. The tool 44 runs in a straight line without a step into the area of the wooden handle 11 enlarged diameter, so that the entering the cavity 43 plastic beyond the free End 41 of the tube 14 can form the collar 24 which can be seen in FIGS. 1 and 2.

In the arrangement according to FIG. 8, the tool 45 contains an approximately spherical cavity 46 into which the plastic can enter from the cavity 43 and the formed collar 24 through a narrow opening 47. After hardening and removing the tool 45, a ball is formed on the collar 24 in the region of the cavity 46, which with the help of a

narrow web 47 is connected to the collar 24. If the ball is present at least in the area of the small opening 47 this means that the plastic has actually completely penetrated into the cavity 43. Due to the The balls can then be broken off in small ridges.

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Claims (24)

EXPECTATIONS 1. Attachment of a plastic sleeve (12) which has a longitudinal opening (19) for receiving a coupling nipple and a transverse threaded hole (29) for receiving having a screw on a wooden handle CIl), characterized in that the plastic sleeve (12) has a integrally formed with her portion (22) which around an axial end region (13) of the wooden handle (11) arranged around and connected directly to it is. 2. Fastening according to claim 1, characterized in that that the end region (13) of the stem (11) has a reduced diameter. Fastening according to claim 1 or 2, characterized in that that the length of the end region (13) of the stem (11) or the overmolded section (22) of the plastic sleeve (12) is at least twice as long, preferably at least three times as long as the diameter of the Handle (11). 4. Fastening according to one of the preceding claims, characterized in that the plastic sleeve (12) into a tube (14) surrounding the end region (13) of the handle (11) and protruding beyond the handle end (15) and is injected into the space between the tube (14) and the stem (11). 5. Fastening according to claim 4, characterized in that the outer diameter of the tube (14) is at least in the area encompassing the stem (11) approximately equal to the outside diameter of the stem (11) in the rest of the latter Area corresponds. 6. Fastening according to one of the preceding claims, characterized in that the stem (11) in his End region (13) has at least one annular groove (16, 17). 7. Fastening according to one of claims 4 to 6, characterized in that the tube (14) in its over the Stalk (11) protruding area has a reduced diameter. 8. Fastening according to one of claims 4 to 7, characterized characterized in that the tube (14) is ribbed on the inside in its area encompassing the stem (11). 9. Fastening according to one of claims 4 to 8, characterized in that the tube (14) in its the stem (11) encompassing the area from the outside formed longitudinal grooves (33), which on the inside of the pipe a Form ribbing (37). ^{A21505 / 6} - ³ - 3Λ32461 10. Fastening according to one of claims 4 to 9, characterized characterized in that the tube (14) has an opening (26) in the area of the threaded hole (29) of the plastic sleeve (12) Has enlarged diameter, and on the plastic sleeve (12) an opening (26) penetrating to the outside Approach (27) is formed. 11. Fastening according to claim 10, characterized in that the projection (27) one cooperating with the screw Has device for their captive holder. 12. Method for producing a handle attachment, at which is connected to a plastic sleeve (12) with a wooden handle (11), characterized in that the handle (11) with an axial end region (13) inserted into a molding tool (38, 44, 45) and then made of plastic is introduced into the space between the tool (38, 44, 45) and the handle end region (13). 13. The method according to claim 12, characterized in that that the plastic is injected. 14. The method according to claim 12 or 13, characterized in that that at least one annular groove (16, 17) is milled into its end region (13) before the handle (11) is inserted or is rotated. 15. The method according to any one of claims 12 to 14, characterized characterized in that before inserting the handle (11) its end region (13) to a reduced diameter is turned or milled off. A 21 505/6 - 4 - ο / οο / ei 343246 ι 16. The method according to any one of claims 12 to 15, characterized in that in the mold (38, 44, 45) a tube (14) is inserted so that it surrounds the end region (13) of the stem (11) and over the end thereof (15) protrudes, and that the plastic in the space between the tool (38, 44, 45) and the end area (13) of the stem (11) is introduced. 17. The method according to claim 16, characterized in that that in the transition area (23) between tube (14) and handle (11) the wood is pressed by the tool (38) will. 18. The method according to claim 16 or 17, characterized in that that in the transition area (23) between tube (14) and handle (11) a plastic collar (24) is formed will. 19. The method according to claim 18, characterized in, that a molding tool (45) with at least one cavity (46) in the region of the collar (24) is used. 20. The method according to any one of claims 16 to 19, characterized in that a tool (38, 44, 45) with a small Radi al distance (39) in the region of the end of the tube (14) is used. 21. The method according to any one of claims 16 to 20, characterized characterized in that when forming the plastic sleeve (12) a threaded extension (27) penetrating a lateral opening (26) of the tube (14) is formed. A 21 505/6 -5- ο / ο ο / c 22. The method according to any one of claims 16 to 21, characterized in that the tube (14) before its insertion into the molding tool (38, 44, 45) in its over the
Stalk (11) protruding area is tapered. 23. The method according to any one of claims 16 to 22, characterized characterized in that the tube (14) is provided with grooves (33) before it is inserted into the molding tool (38, 44, 45) will. 24. The method according to claim 23, characterized in that
that to produce the grooves (33) a ring with embedded balls is moved over the tube (14) in its longitudinal direction.