EP1542836B1 - Tool holding fixture - Google Patents

Abstract

The invention relates to a tool holding fixture, particularly for a hammer drill or chisel hammer, comprising a holding body (14) provided with: an insertion opening (16) for holding a tool shank (12); a locking element (22) for axially locking the tool shank (12) inside the insertion opening (16), whereby the locking element (22) can move between a locking position and an unlocking position, and; an arresting pin (36), which is mounted inside the locking element (22) while being able to be radially displaced between an arresting position and a release position. Said arresting pin axially arrests the locking element (22) in the arresting position thereof and axially releases it in the release position thereof.

Description

State of the art

The invention relates to a tool holder according to the preamble of claim 1, in particular for a hammer drill or a chisel hammer.

Out DE 34 21 811 A1 is a tool holder for drilling and chiseling known, which provides a simple and easy-to-use holder for positively recorded tools. The tool holder has a guide tube and a surrounding adjusting sleeve. The adjusting sleeve is displaceable or rotatable against the force of a spring element and has recesses for the radial disengagement of locking elements. A radially disengageable, consisting of a bolt and a ball latch is pressed by a spring ring radially inward. After removal of the insertion end of a tool from a receiving area of the tool holder, the adjusting sleeve is locked by the engagement of the ball in the radial bore. When inserting the insertion of a tool in the receiving bore of the bolt is pressed radially outward and the adjusting sleeve unlocked. Once the locking elements can engage in recesses of the insertion end, the adjusting sleeve is set back by the spring element back to its original position.

Out DE 100 26 021 A1 a tool holder for a drill bit is known, which allows a tool change one-handed operation. For this purpose, the tool holder on a receiving body with an insertion, into which a tool shank can be inserted axially. In the inserted state, the tool shank can then be locked axially by locking bodies, wherein the locking bodies engage in axially extending grooves in the tool shank, so that the tool shank in the locked state has a certain freedom of movement in the axial direction. In this case, a radial deflection movement of the locking body is prevented by an axially displaceable locking sleeve when the locking sleeve is in a locking position. In contrast, when the locking sleeve of the operator in an unlocked position is pushed, the locking body can dodge radially outward and the drill bit can be removed from the tool holder or inserted into the tool holder. The locking sleeve is in this case biased by a spring in the direction of the locking position to prevent inadvertent unlocking of the drill bit. To enable one-handed operation, however, the locking sleeve can be locked axially in the unlocked position, wherein the locking is effected for example by a leaf spring which engages from inside into the locking sleeve.

Advantages of the invention

In a tool holder according to the invention according to the type of claim 1, the mechanism for locking the locking sleeve is simple and robust.

Advantages of the invention

For this purpose, a locking pin is mounted in the preferably sleeve-shaped locking element, which is displaceable with respect to the insertion opening in the radial direction between a locking position and a release position.

In the locking position of the locking bolt, the locking element is then locked in the unlocked position, so that the tool shaft can be inserted into the tool holder or removed from the tool holder, without the user having to hold the locking element.

In the release position of the locking bolt, however, there is no locking of the locking element in the unlocked position, whereby the tool shaft is axially locked in the tool holder.

In a preferred embodiment of the invention, a spring element is provided which biases the locking pin in the direction of the locking position, wherein the locking pin rests in the locking position on an axial stop in the receiving body. The locking pin then slides independently due to the spring bias in the locking position when the user moves the locking element from the locking position to the unlocked position. In this case, no user intervention is required for locking the locking element in the unlocking position, whereby the operation is considerably simplified.

Preferably, the locking of the locking element can also be solved without a user intervention to further simplify the operation. In a preferred embodiment, it is therefore provided that the locking pin can be released from the locking position by the tool shank. Preferably, this solution of the locking takes place in that the movement of the tool shaft is transferred during removal from the tool holder or during insertion into the tool holder on the locking pin and thereby releases it from the locking position.

In this case, for example, a preferably spherical shape for transmitting power from the tool shank to the locking pin Transmission element may be provided which projects radially into the insertion opening of the tool holder and is displaced radially outwardly during insertion or during removal of the tool shaft and thereby presses the locking pin radially outward.

Preferably, the transmission element is a ball which is mounted radially displaceably in an opening in the receiving body. In this case, the opening preferably tapers conically inwards in order to prevent the ball from falling inwards when there is no tool shank in the tool holder.

The term used in the invention of a locking element is to be understood in general and not limited to the initially described locking sleeve, which surrounds the receiving body like a shell and is axially displaceable.

Preferably, a spring element is provided, which biases the locking element in the direction of the locking position to prevent unintentional unlocking of the tool shaft.

The displacement of the locking element can be done, for example, as in the known tool holder described above, by the user operates the locking element directly.

In a preferred embodiment, however, a separate control element is provided, preferably as a control sleeve is executed and the locking element advantageously surrounds shell-shaped. The operating element is preferably axially displaceable and biased by a spring element in the axial direction to define a rest position. A movement of the operating element can then be transmitted to the locking element, which can be done, for example, that the operating element entrains the locking element. However, it is alternatively also possible that the operating element is rigidly or elastically coupled to the locking element in order to transmit the movement of the operating element to the locking element.

The actual locking of the tool shaft in the tool holder can be done as in the known tool holder described above by blocking body, which engage in corresponding grooves in the tool shank. Preferably, however, are used to lock the tool shank radially displaceable locking rollers, which are much less wear.

Furthermore, the invention also includes a machine tool, such as a hammer drill or a chisel hammer, with a tool holder according to the invention.

drawing

Further advantages emerge from the following description of the drawing. In the drawings, two embodiments of the invention are shown. The drawings, the description and the claims contain numerous features in combination. The person skilled in the art expediently also the features individually consider and summarize to meaningful further combinations.

Fig. 1

eine Querschnittsansicht einer erfindungsgemäßen Werkzeugaufnahme in der Entriegelungsstellung beim Einführen eines Werkzeugschafts,

Fig. 2

eine Querschnittsansicht der Werkzeugaufnahme aus Figur 1 in der Verriegelungsstellung mit eingeführtem Werkzeugschaft,

Fig. 3

eine Querschnittsansicht der Werkzeugaufnahme aus Figur 1 in der Entriegelungsstellung bei der Entnahme des Werkzeugschafts,

Fig. 4a

eine Detailansicht der Werkzeugaufnahme aus Figur 1 im Querschnitt,

Fig. 4b

die Detailansicht aus Figur 4a in einer radialen Aufsicht sowie

Fig. 5

eine alternative Ausführungsform einer erfindungsgemäßen Werkzeugaufnahme.

Show it:

Fig. 1

a cross-sectional view of a tool holder according to the invention in the unlocked position during insertion of a tool shank,

Fig. 2

a cross-sectional view of the tool holder FIG. 1 in the locking position with inserted tool shank,

Fig. 3

a cross-sectional view of the tool holder FIG. 1 in the unlocked position when removing the tool shank,

Fig. 4a

a detailed view of the tool holder FIG. 1 in cross section,

Fig. 4b

the detail view FIG. 4a in a radial supervision as well

Fig. 5

an alternative embodiment of a tool holder according to the invention.

Description of the embodiments

The cross-sectional views in the FIGS. 1 to 3 show a tool holder 10 for a rotary hammer or a chisel, the tool holder 10 allows axial locking of a tool shank 12 with a predetermined axial range of motion and a simple one-handed operation when changing tools.

For this purpose, the tool holder has a substantially hollow cylindrical receiving body 14 with an insertion opening 16 into which the tool shank 12 can be inserted axially.

In the receiving body 14 a plurality of apertures are distributed over the circumference provided, in each of which a locking roller 18 is arranged, wherein the apertures in the radial direction taper inwardly to prevent the locking rollers 18 can fall inward.

The locking rollers 18 can engage the axial locking of the tool shaft 12 in an axially extending groove 20 in the lateral surface of the tool shank 12, whereby the tool shank 12 is locked with a predetermined axial movement margin.

Furthermore, the tool holder 10 has a locking sleeve 22, which between the in FIG. 2 shown locking position and in FIG. 1 shown unlocking position is axially displaceable.

In the in FIG. 2 shown locking position, the locking sleeve 22 covers the openings in the receiving body 14 and thus prevents a radial deflection movement of the locking rollers 18, whereby a removal of the tool shank 12 is prevented.

In the in the FIGS. 1 and 3 shown unlocking the apertures in the receiving body 14, however, by an elastic sleeve 26 is covered, which is attached to the inside of a stepped extension of the locking sleeve 22. The locking rollers 18 can then escape radially outward, so that the tool shaft 12 can be removed from the tool holder 10 or inserted into the tool holder 10.

The locking sleeve 22 is in this case biased by a spring element 24 in the direction of the locking position to prevent inadvertent unlocking of the tool shank 12.

The operation of the tool holder 10 is effected by an operating sleeve 28 which surrounds the locking sleeve 22 on the outside and is axially displaceable, wherein the operating sleeve 28 is biased by a spring element 30 in the axial direction. Upon a displacement of the control sleeve 28 in the direction of the locking sleeve 22, the control sleeve 28 abuts the locking sleeve 22, wherein the locking sleeve 22 is taken axially.

Furthermore, the tool holder 10 has an elastic, annular dust sleeve 32, which prevents the penetration of dust into the insertion opening 16.

In addition, the tool holder 10 has a locking mechanism, which locks the locking sleeve 22 in the unlocked position and thereby enables a one-hand operation during a tool change.

The locking mechanism consists inter alia of a steel ball 34 which is mounted radially displaceably in a radially extending aperture 35 in the receiving body 14. The opening 35 in the receiving body 14 tapers inward in the radial direction in order to prevent the ball 34 from falling out of the opening 35 inwardly into the insertion opening 16. The ball 34 can therefore only partially protrude inwards into the insertion opening 16, as in FIG FIG. 1 is shown.

Furthermore, the locking mechanism on a locking pin 36 which is mounted radially displaceably in a radially extending bore in the locking sleeve 22, wherein the locking pin 36 is biased by an annular spring 38 radially inwardly.

The locking pin 36 is guided in two axially extending grooves 40, 42, which are arranged in the lateral surface of the receiving body 14 on both sides of the opening 35 for the ball 34, wherein the workpiece-side groove 40 has a smaller groove depth than the tool-side groove 42. In the in FIG. 1 shown unlocking position of the locking pin 36 is therefore axially on the step between the two grooves 40, 42, whereby the locking sleeve 22 is axially locked.

The following will now be based on FIG. 1 describes how the tool shaft 12 is inserted into the tool holder 10 and then locked automatically.

Before inserting the tool shank 12, the locking sleeve 22 must first in the in FIG. 1 shown unlocked position can be brought. For this purpose, the user pushes the control sleeve 28 in the direction of the locking sleeve 22, wherein the locking sleeve 22 is axially entrained until the locking pin 36 finally engages behind the step between the two grooves 40, 42 and thereby locks the locking sleeve 22 axially.

Subsequently, the user can release the control sleeve 28, which then returns due to the bias of the spring 30 to its original position.

Upon axial insertion of the tool shank 12 into the insertion opening 16, the tool shank 12 then presses the locking rollers 18 radially outwardly until the locking rollers 18 then engage the grooves 20 in the tool shank 12.

Upon further insertion of the tool shank 12, the end face of the tool shank 12 then presses the ball 34 radially outward, the locking pin 36 also being pressed radially outward against the bias of the annular spring 38.

When the locking pin 36 is then raised above the step between the two grooves 40, 42, the spring 24 pushes the locking sleeve 22 axially into the in FIG. 2 illustrated locking position, wherein the locking pin 36 is guided in the groove 40. In the locking position, the locking sleeve 22 then covers with its inside the breakthrough for the locking rollers 18, which thus not can escape more radially outward and thereby axially lock the tool shank 12 with a predetermined range of motion.

The tool shank 12 is thus locked automatically when inserted into the tool holder 10, without the need for user intervention.

The following will now be based on FIG. 3 the removal of the tool shank 12 from the tool holder 10 described.

Before removing the tool shaft 12 from the tool holder 10, the locking sleeve 22 must first from the in FIG. 2 illustrated locking position in the in FIG. 3 shown unlocked position can be brought. For this purpose, the user pushes the control sleeve 28 axially from the position shown in Figure 1 in the direction of the locking sleeve 22, wherein the control sleeve 28, the locking sleeve 22 moves axially until the locking pin 36 tool side behind the ball 34 in the groove 42 and thereby on the ball 34 is present.

Then the user lets go of the operating sleeve 28, whereupon the operating sleeve 28 due to the restoring force of the spring 30 moves back to its original position.

However, the locking sleeve 22 is then axially locked by the ball 34 and the locking pin 36, since the locking pin 36 laterally abuts the ball 34, while the ball 34 is pressed by the lateral surface of the tool shank 12 to the outside. It should be noted that the groove 20 for the locking rollers 18 in the circumferential direction does not include the part in which the ball 34 is arranged. Thus, the ball 34 can not dodge inwardly into the groove 20, since this is arranged angularly offset relative to the ball 34.

The user can then pull the tool shank 12 axially out of the tool holder 10 until the tool shank 12 finally releases the ball 34, which then deflects radially inwards. The locking pin 36 is then no longer blocked by the ball 34, so that the locking sleeve 22 moves due to the bias of the spring 24 in the locking position shown in Figure 2.

This in FIG. 5 illustrated embodiment of a tool holder 10 'according to the invention is largely consistent with the tool holder 10 described above, so that reference is made in the following to avoid repetition of the above description and the same reference numerals are used for corresponding components, which are marked for distinction only by an apostrophe.

The peculiarity of this embodiment is that on the in the FIGS. 1 to 3 provided spring 30 is omitted to return the control sleeve 28.

Instead, the control sleeve 28 'in this embodiment, fixed to the locking sleeve 22' is connected, so that both are moved together.

reference numeral

10, 10 '

tool holder

12, 12 '

tool shank

14, 14 '

receiving body

16, 16 '

insertion

18, 18 '

locking roller

20, 20 '

groove

22, 22 '

locking sleeve

24, 24 '

feather

26, 26 '

cuff

28, 28 '

operating sleeve

30

feather

32, 32 '

dust boot

34, 34 '

Bullet

35

breakthrough

36, 36 '

locking bolt

38, 38 '

Ringfeder

40

groove

42

groove

Claims (14)

1. Tool holding fixture, in particular for a hammer drill or rotary demolition hammer, comprising a holding body (14) with an insertion opening (16) for holding a tool shank (12), comprising a locking element (22) for axially locking the tool shank (12) in the insertion opening (16), the locking element (22) being movable between a locking position and an unlocking position, and comprising an arresting pin (36) which is mounted in the locking element (22), is radially displaceable between an arresting position and a release position, and axially arrests the locking element (22) in its arresting position and axially releases it in its release position, characterized in that the arresting pin (36) is displaceably guided in the axial direction in grooves (40, 42) arranged in the holding body (14).
2. Tool holding fixture according to Claim 1, characterized in that the grooves (40, 42) merge into one another and have different groove depths, such that a step is produced.
3. Tool holding fixture according to either of Claims 1 and 2, characterized in that the holding body (14) has a radial through-bore (35) and in that the through-bore (35) is defined in the axial direction by in each case one of the grooves (40, 42).
4. Tool holding fixture according to one of the preceding claims, characterized by a first spring element (38) which preloads the arresting pin (36) in the direction of the arresting position, the arresting pin (36) bearing against an axial stop in the holding body (14) in the arresting position.
5. Tool holding fixture according to Claim 4, characterized in that the arresting pin (36) can be released from the arresting position by the tool shank (12).
6. Tool holding fixture according to Claim 5, characterized by a transmission element (34), mounted in the holding body (14) in a radially displaceable manner, for releasing the arresting pin (36) from the arresting position, wherein the transmission element (34) can be displaced radially outwards against the arresting pin (36) by the tool shank (12).
7. Tool holding fixture according to Claim 6, characterized in that the transmission element (34) is a ball.
8. Tool holding fixture according to one of the preceding claims, characterized in that the locking element (22) is sleeve-shaped.
9. Tool holding fixture according to one of the preceding claims, characterized by a second spring element (24) which axially preloads the locking element (22) in the direction of the locking position.
10. Tool holding fixture according to one of the preceding claims, characterized by an axially displaceable operating element (28) for the axial displacement of the locking element (22).
11. Tool holding fixture according to Claim 10, characterized by a third spring element (30) which preloads the operating element (28) in the axial direction.
12. Tool holding fixture according to Claim 10 and/or Claim 11, characterized in that the operating element (28) is sleeve-shaped and at least partly surrounds the locking element (22).
13. Tool holding fixture according to one of the preceding claims, characterized in that radially displaceable locking rollers (18) are arranged in the holding body (14) for the axial displacement of the tool shank (12), said locking rollers (18) engaging in grooves (20) in the tool shank (12) in the locking position of the locking element (22).
14. Power tool, in particular a hammer drill or rotary demolition hammer, comprising a tool holding fixture (10) according to one of the preceding claims.

Images