EP2260980B1 - Attachment for a hand tool - Google Patents

Description

The invention relates to an attachment for a hand tool according to the preamble of claim 1.

Such an article is for example from the WO 97/16123 out. In order to increase the possibilities of use for a hand tool, such as a screwdriver or drill, it is known from the prior art to attach an attachment to the power tool. The article may be, for example, an angular attachment whose output shaft is at an angle to the drive shaft of the power tool. Even eccentric essays with a parallel to the drive shaft of the power tool offset arranged output shaft are known The output shaft of the essay thereby drives a recorded in a tool holder of the essay insert tool, such as a screwdriver or Bohrerbit.

For releasably attaching an attachment to a housing of a power tool different types of attachment are known. Conventional essays are tightened on a clamping neck of the power tool housing. This requires an additional tool.

An alternative attachment for a tower is off DE 101 09 956 A1 known. The attachment described therein is clamped with a concentric to the drive shaft bayonet connection device in the axial direction against the housing of a power tool.

Out WO 97/16123 For example, a surgical instrument with a locking mechanism for attachment to a handle is known, wherein the locking mechanism comprises a fixed hub and a drive shaft. The hub can be attached to the handle by means of a latching hook.

Disclosure of the invention

The invention relates to an attachment for a hand tool according to claim 1, which is equipped with a rotatably mounted shaft and a locking unit. The shaft is indirectly or directly rotatably connected to a drive shaft of the power tool. The shaft of the attachment may e.g. with a tool holder for receiving an insert tool, e.g. a Schraubendreherbits be equipped so that via the shaft, the recordable in the tool holder insert tool is driven. The locking unit of the attachment is releasably attachable to a housing of a hand tool and fixed. It is proposed to provide the locking unit with at least one means for a latching connection. The releasable positive connection of the attachment with a housing of a hand tool is thus carried out by means of a latching connection. It is an elastic locking connection with at least one elastic locking means, which is designed as a leaf spring. A latching connection has the advantage that it is easy to handle, since no additional tool is needed as an aid for attaching or detaching the attachment.

The simple handling of the latching connection is particularly evident in an embodiment in which the at least one latching means is activated automatically, i. without further manual operation of the locking means or other means, is executed detent. This means that the axial attachment of the attachment to the housing of a handheld power tool engages the at least one locking means in corresponding means on the housing of the power tool detent already. The locking connection between the attachment and the housing of the power tool is fully automatic, i. without any other action or influence of any other means, effective (autolock function). This can be done for example by a resilient latching connection such that a resilient latching means, which is designed as a leaf spring is formed during assembly of the essay and the power tool forcibly against the force of the resilient latching means with a corresponding means on the housing of the power tool, e.g. a recess, is engaged.

Another advantage of a locking connection is that the engagement of the locking means, which is designed as a leaf spring, which is designed as a leaf spring, in corresponding means on the housing of the power tool can be audible, so that the operator of the power tool is indicated by a clicking sound when snapping that the article is completely and properly locked to the power tool.

To release the locking connection, and thus to remove the attachment of the power tool, the at least one locking means, which is designed as Blattfeden, manually operable. The locking means may be attached to the locking unit so that it directly from the outside or indirectly via an unlocking element, e.g. a release button in the form of a push button, a slider or the like. manually operable by the operator. In the case of a resilient locking connection, the operator of the power tool against the spring force of the resilient locking means has to apply force to bring the locking means with the corresponding means on the housing of the power tool disengaged.

According to one embodiment of the attachment according to the invention, the at least one latching means, which is designed as a leaf thread, effects at least one axial securing of the attachment on a housing of a handheld power tool. Thus, the article is held by the locking means at least in the axial direction. For example, may be provided on a housing of a power tool an annular groove, so that the locking means when attaching the attachment to a housing of a power tool with the annular groove is engageable.

To accommodate the forces acting on the attachment in the circumferential direction, different means may be provided. On the one hand, an axially acting locking means, which is designed as a leaf thread, be designed so that it also causes a rotation.

On the other hand, the rotation can also be effected by a separate means. According to one embodiment of the attachment according to the invention, the locking unit has engagement means for rotationally fixed engagement with a housing of a handheld power tool. For this purpose, corresponding engagement means are provided on the housing. The mutually associated engagement means are fixedly arranged on the locking unit of the attachment and on the housing of the power tool. In this case, the engagement means are in particular designed so that already during the axial attachment of the essay on the housing without any other manual operation, the engaging means of attachment and housing engage with each other. As a result, an effective in the circumferential direction positive connection can be produced when attaching the essay. In this embodiment of the article, the forces acting in the circumferential direction are transmitted by the engagement means to the housing of the power tool, while the axially acting forces are surmounted by the locking means. Thus, the forces acting in the circumferential direction and in the axial direction are absorbed by different means.

Preferably, the engagement means on the locking unit and on the housing of the power tool designed as a toothed ring is the teeth of the toothed ring formed accordingly feln, the article can be mounted in virtually any angular position relative to the housing of the power tool.

In the attachment according to the invention, the at least one latching means is a spring element, i. the locking means is resilient in itself.

The resilient latching means (spring element) is formed by a leaf spring. The at least one leaf spring is used in attaching the locking unit to a housing of a hand tool with suitable engaging means, e.g. an annular groove, automatically engaged. On the leaf spring, a resilient hook is formed, which engages audibly in the annular groove when attaching the attachment to a housing of a power tool. In this case, a first end of the leaf spring in the locking unit is fixed, while a second end of the leaf spring, which is designed as a hook, is arranged to be movable in the radial direction relative to the locking unit. Thus, when attaching the attachment of the hook of the leaf spring along a ramp of the housing is guided radially outwards, whereby the leaf spring is tensioned against its spring force.

The locking unit further comprises a locking ring, which is rotatably arranged in the locking unit, the locking ring can be brought by a manual rotational movement in a locking position or in an unlocked position. In the locked position prevents the locking ring unintentional release of the attachment of a housing of a power tool. In the unlocked position of the locking ring allows the removal of the attachment of a hand tool. This is achieved, for example, in that the locking ring has radially inwardly directed locking projections, which lie in the locking position in the radial direction of the at least one leaf spring and thus prevent a radial movement of the second end of the leaf spring outward against the spring force. In the unlatched position, however, the at least one leaf spring is opposite in the radial direction a free space, which permits a radial movement of the second end of the leaf spring outward against the spring force. To attach and detach the attachment, the locking ring must be brought into the unlocked position.

When attaching the attachment to a housing of a power tool also a drive shaft of the power tool is brought into rotationally fixed connection with a rotatably mounted shaft of the attachment. The rotationally fixed connection can take place immediately. For this purpose, the drive shaft at its free end, for example, a polygonal recess. On the other hand, a corresponding polygonal extension is formed on the shaft of the attachment, which is received positively by the polygonal recess of the drive shaft. When attaching the essay thus the drive shaft and the shaft of the attachment can be assembled rotatably without additional manual operation. Thus, the hand tool can be used without attachment, the polygonal Stirnausnehmung the drive shaft is shaped so that it can also act as a receptacle for an insert tool, such as screwdriver bit. However, the rotationally fixed connection can also indirectly via a transmission, such as an angle gear, or a clutch, such as a Überrastkupplung done. Then the article has an input shaft and an output shaft. Input shaft and output shaft are connected via a transmission or a clutch to each other in driving connection. In this embodiment, the output-side end of the drive shaft and the input-side end of the input shaft are provided with corresponding means to produce a positive rotational connection. If such an attachment attached to a hand tool, the input shaft and the drive shaft of the power tool rotatably mated.

The shaft of the attachment may further comprise at its output end a tool holder for receiving an insert tool, e.g. a screwdriver or Bohrerbits have. The tool holder may be a simple recess on the front side of the shaft. If the attachment has an input and an output shaft, the tool holder is correspondingly arranged on the end face of the output shaft.

The attachment may e.g. an angular attachment whose output shaft is at an angle to a drive shaft of the power tool, wherein the input shaft of the attachment is connected via an angular gear to the output shaft.

The attachment may also be e.g. an eccentric with a parallel to a drive shaft of the power tool offset arranged output shaft be.

The attachment may also be used e.g. be a torque cap, with which the operator of the power tool can set the maximum torque.

Another object of the invention is a hand tool, which contains an article according to the invention. The hand tool can be a battery-powered or network-bound screwdriver, drill, drill or the like. be.

Figur 1

einen Ausschnitt aus einer Handwerkzeugmaschine mit einer Antriebs- welle und einer Werkzeugaufnahme in perspektivischer Darstellung

Figur 2

eine Seitenansicht einer Ausführungsform eines erfindungsgemäßer Aufsatzes mit einer Welle sowie einer Verriegelungseinheit

Figur 3

ein Längsschnitt durch eine erfindungsgemäße Ausführungsform eines Aufsatzes mit einer Verrie- gelungseinheit, bestehend aus Grundkörper, Blattfedern als Rastmittel und Verriegelungsring

Figur 4

die Verriegelungseinheit nach Fig. 3 in perspektivischer Darstellung

Figur 5

die Verriegelungseinheit nach Fig. 3 in der Entriegelungsstellung in der Rückansicht

Figur 6

die Verriegelungseinheit nach Fig. 3 in der Verriegelungsstellung in der Rückansicht.

The invention will be explained in more detail with reference to the accompanying drawings. Show it

FIG. 1

a section of a hand tool with a drive shaft and a tool holder in perspective view

FIG. 2

a side view of an embodiment of an inventive article with a shaft and a locking unit

FIG. 3

a longitudinal section through an inventive embodiment of an essay with a locking gelungseinheit consisting of base body, leaf springs as locking means and locking ring

FIG. 4

the locking unit after Fig. 3 in perspective view

FIG. 5

the locking unit after Fig. 3 in the unlocked position in the rear view

FIG. 6

the locking unit after Fig. 3 in the locking position in the rear view.

In FIG. 1 a section of a hand tool 100 is shown, which is suitable, a top 30 according to the invention Fig. 2 ). At the in Fig. 1 Hand tool 100 shown is a screwdriver. In Fig. 1 only the parts of the power tool necessary for explaining the invention are shown. The hand tool 100 includes, seen in the direction of work, the front portion of a housing 10 from which a drive shaft 20 exits. The drive shaft 20 has on its front side a polygonal recess 22 for receiving an insert tool, such as a screwdriver bit (not shown). The hand tool 100 can be operated as such, ie without essay. For this purpose, for example, a screwdriver bit can be inserted as an insertion tool into the recess 22.

In Fig. 2 is shown as an example of an attachment 30 according to the invention a torque attachment for adjusting the torque. Which function the attachment fulfills, whether it is an angle, eccentric, torque or other attachment plays a minor role in the present invention. Therefore, it will not be discussed in detail here on the operation of the torque attachment.

The attachment 30 comprises a shaft 32, which on its output side has a recess 34 for receiving an insert tool 36, for example a Screwdriver bits having. If the attachment 30 is attached to the hand tool 100, the shaft 32 is in driving connection with the drive shaft 20 of the power tool 100. In the present case of a torque attachment, the shaft 32 forms an output shaft via an overrunning clutch (not shown) with an input shaft (not shown). The shaft 32 is indirectly in rotationally fixed connection with the drive shaft 20 of the power tool. The input shaft, not shown, is directly in driving connection with the drive shaft 20 of the power tool as soon as the attachment 30 is attached to the power tool. This can be achieved in a simple embodiment, for example, by a positive connection by the drive shaft 20, as in Fig. 1 shown, a polygonal end recess 22 has, and the input shaft of the attachment 30 on the input side with a complementary to the end recess 22 extension is provided with mehrkantigem cross-section (not shown). When assembling attachment 30 and hand tool 100, the extension of the input shaft is simply inserted without further action into the recess 22 of the drive shaft 20.

The attachment 30 further comprises a locking unit 40 for releasably attaching to a housing 10 of a hand tool 100. The attachment 30 according to the invention is characterized by a locking unit 40, which has at least one means 42 for an elastic locking connection, which is designed as Blattfeden. Such a locking unit 40 is in principle for all possible attachments, which are detachably attachable to a housing of a hand tool, such. Angled attachment or torque attachment, suitable.

In Fig. 3-6 an embodiment of a locking unit 40 is shown, which also has a locking means for attaching the attachment 30 to the housing 10 of a power tool. As a locking means serve in this embodiment, four evenly distributed over the circumference leaf springs 62nd

The forces acting in the circumferential direction are transmitted by the engagement means 43, 13 to the housing 10 of the power tool 100, while the axially acting forces are transmitted by the latching means 62. In the embodiment However, the latching means in the form of leaf springs 62, it would also be possible to include not only the axial forces, but also the forces acting in the circumferential direction by the leaf springs 62, provided that the leaf springs 62 would be fixed in the locked state on the housing 10 substantially free of play in the circumferential direction (not shown).

As locking means according to Fig. 3-6 four spring elements in the form of leaf springs 62 are provided. The four leaf springs 62 are substantially equidistantly distributed over the circumference of the main body 44 of the locking unit 40 The leaf springs 62 are formed so that they automatically when attaching the essay 30 to the housing 10 with corresponding means, here a circumferential annular groove 12 on the housing engage. If the leaf springs 62 are engaged in the annular groove 12, the attachment 30 is locked in the axial direction.

A first end 65 of the leaf springs 62 is fixedly disposed in the main body 44 of the locking unit 40, while a second end 67 of the leaf springs 62 is arranged to be movable in the radial direction relative to the main body 44 of the locking unit 40. The second end 67 of the leaf springs 62 is a hook educated. When the second, freely movable end 67 of the leaf springs 62 is moved outward in the radial direction, the leaf springs 62 come under tension. When the voltage is released, the free end 67 returns to its original position. The elasticity of the leaf springs 62 is used to effect an automatic latching. In the initial position, ie before attaching the attachment 30 to the housing 10, the leaf springs 62 are in a de-energized state. When attaching the attachment 30 to the housing 10, the leaf springs 62 are tensioned without further manual operation by the leaf springs 62 are forced along the housing 10. In order to facilitate the positive guidance of the leaf springs 62 on the housing 10, the surfaces 14 of the teeth of the toothed ring 13 are chamfered in the axial direction. When the leaf springs 62 come into engagement with the annular groove 12 on the housing 10, the tension of the leaf springs 62 is partially released. The engagement of the leaf springs 62 in the annular groove 12 causes a positive fit and prevents inadvertent release of the attachment 30 of the power tool 100 in the axial direction.

For locking and unlocking the locking unit 40 further comprises a locking ring 66 which is rotatably mounted on the base body 44. In Fig. 5 is the locking ring 66 in its unlocked position, in Fig. 6 shown in its locking position. The show FIGS. 5 and 6 the locking unit in the rear view.

The locking ring 66 can be brought by a manual rotational movement in the locked position or in the unlocked position. In the locked position, the locking ring 66 prevents unintentional release of the attachment 30 from a housing 10 of a hand tool. In the unlocked position, the locking ring 66 permits removal of the attachment 30. For this purpose, the locking ring 66 has on its inner surface a plurality of circumferentially uniformly distributed, radially inwardly facing locking projections 69 in the locking position according to Fig. 6 The locking projections 69 are radially opposed to the leaf springs 62 so as to block a radial movement of the second end 67 of the leaf springs 62 outward against the spring force. Thus, the leaf springs 62 can not get out of engagement with the annular groove 12.

In the unlocked position to Fig. 5 lie in the radial direction of the leaf springs 62 in each case a free space 68 on the inner surface of the locking ring 66 opposite. The clearance 68 allows radial movement of the second end 67 of the leaf springs 62 against the spring force to the outside. By pulling the attachment 30 in the axial direction away from the power tool, the leaf springs 62 disengage from the annular groove 12 so that the attachment 30 can be pulled off the power tool.

For attaching and detaching the attachment 30, the locking ring 66 must be brought into the unlocked position only by a manual rotational movement in the circumferential direction of the locking ring 66. The locking position and unlocking position of the locking ring 66 are each defined by a stop 49 or 50 on the main body 44 of the locking unit 40. In order to hold the locking ring 66 in the locking or unlocking position, in the locking ring 66 for the locking position and the unlocking position in each case a receptacle 61 for a spring-loaded Ball 63 is provided. In the sectional view to Fig. 3 only one picture 61 is shown. The base body 44 has for this purpose a ball 63 and a coil spring 64, wherein the coil spring 64 is supported on the base body 44 and the ball 63 presses substantially radially outwardly into the receptacle 61. The ball 63 is pressed by means of coil spring 64 in the locking position or unlocking position into the respective receptacle 61 in the locking ring 66. This prevents unintentional release of the locking ring 66 from its locking or unlocking position.

Claims (10)

1. Attachment for a portable power tool, comprising a locking unit (40) which can be releasably attached in a fixed position to a housing (10) of a portable power tool, and a rotatably mounted shaft (32) which can be connected to a drive shaft (20) of the portable power tool in a rotationally fixed manner, wherein the locking unit (40) has at least one means (62) for a latching connection, said means being in the form of a leaf spring, wherein a first end (65) of the leaf spring (62) is arranged in a fixed position in the locking unit (40) and a second end (67) of the leaf spring (62) is arranged such as to be movable in the radial direction in relation to the locking unit (40), characterized in that the locking unit (40) has a rotatably mounted locking ring (66) which prevents a radial movement of the second end (67) of the leaf spring (62) in a locking position.
2. Attachment according to Claim 1, characterized in that the at least one latching means (62) is configured to latch in place automatically.
3. Attachment according to either of Claims 1 and 2, characterized in that the at least one latching means (62) can be actuated manually in order to release the latching connection.
4. Attachment according to one of Claims 1 to 3, characterized in that the at least one latching means (62) at least axially secures the attachment to a housing (10) of a portable power tool.
5. Attachment according to one of the preceding claims, characterized in that the locking unit (40) has engagement means (43) for rotationally fixed engagement with a housing (10) of a portable power tool.
6. Attachment according to Claim 5, characterized in that the engagement means (43) are configured as a toothed ring.
7. Attachment according to one of the preceding claims, characterized in that the attachment is an angular attachment, the output shaft of which is at an angle to a drive shaft (20) of the portable power tool, wherein the input shaft of the attachment is connected to the output shaft via an angular gear mechanism.
8. Attachment according to one of the preceding claims, characterized in that the attachment is an eccentric attachment, the output shaft of which is arranged in a manner offset from and parallel to a drive shaft (20) of the portable power tool.
9. Attachment according to one of the preceding claims, characterized in that the attachment is a torque attachment for setting the maximum torque.
10. Portable power tool containing an attachment according to one of Claims 1 to 9.

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