WO2017092867A1

WO2017092867A1 - Power tool

Info

Publication number: WO2017092867A1
Application number: PCT/EP2016/002020
Authority: WO
Inventors: Mario EMMERICH; Stefan KURTENBACH; Mathias HÜSING; Burkhard Corves
Original assignee: Rheinisch-Westfälische Technische Hochschule Aachen
Priority date: 2015-12-03
Filing date: 2016-11-30
Publication date: 2017-06-08
Also published as: DE102015015562B4; WO2017092867A8; DE102015015562A1

Abstract

The invention relates to a power tool, in particular a hand-operated battery-powered screwdriver, comprising a motor unit (1) with a motor (2) and an output shaft (3) which can be driven by the motor (2) and comprising a contact region (4) which is arranged on the motor unit (1) and with which the motor unit (1) can be secured to the lower arm (5) of a person, in particular to the top of the lower arm, in a removal manner, preferably in an adaptively removable manner. A guidance mechanism (6), on the end of which a retaining element (7) is arranged, extends from the motor unit (1), and a tool holder (8), in particular a bit holder (8) or a chuck, is received in the retaining element (7) in a rotatable manner. The retaining element (7) has a finger receiving area (9), into which a finger (10), preferably the index finger (10), can be received, and a flexible or articulated shaft (11) extends between the tool holder (8) and the output shaft (3), said shaft being guided by the guiding mechanism (11) and being used to drive the tool holder (8) by means of the motor (2).

Description

power tool

The invention relates to a power tool, in particular a hand-operated cordless screwdriver comprising a motor unit with a motor and a

Output shaft which is driven by the motor and arranged on the motor unit contact area, with which the motor unit on a forearm of a person, in particular on the forearm top is releasably fastened.

Power tools of this type are known in the art, e.g. from the publication WO 2005/058554. The power tool described there can e.g. for the purpose of screwing, but of course also be used for drilling and this is attached to the forearm of a person. It is here described as positive that this tool does not have to be put out of hand, if e.g. only temporarily not used. It remains attached to the forearm, e.g. lashed by straps, as the invention can provide. The usual attachment of this device and also in the invention is such that the investment area on the forearm top, which in the

The back of the hand passes over, then laid on and then is lashed over said belt.

A disadvantage of this prior art is that on the output shaft of the motor unit directly a tool holder is attached, thus thus the direction in which screws set or holes can be created by the extension direction of the output shaft are pre-adjusted. Because the output shaft,

CONFIRMATION COPY as also preferred in the invention in the direction of extent with the

Extending direction of the forearm of a user using at least substantially coincidentally means that it is difficult

accessible places of this power tool can not be used, since the user must always be able to align his forearm in the required direction.

It is therefore an object of the invention to provide a power tool of the type mentioned, with which it is also possible to work in hard to reach places, in particular in which there is no need for the forearm in the direction of the longitudinal extent of the screw or to be set used to position drill.

This object is achieved in that a on the motor unit

Guide gear connects, at the end of a holding element is arranged and in the holding element, a tool holder, in particular a bit holder or chuck, is rotatably received and the holding element a

Finger receiving, in which a finger, preferably the index finger,

is receivable and a flexible or articulated shaft between the

Tool holder and the output shaft extends, which is guided by the guide gear, preferably with all the forces / torques are absorbed during use of the power tool and with which the tool holder is driven by the motor or is driven during operation.

The essential core idea of the invention is that the tool holder and the motor unit are flexibly or flexibly connected to each other, so that the orientation of the output shaft and the driven shaft of the tool holder need not necessarily be parallel, but also can. It is also essential for the invention that the tool holder can not assume any position to the output shaft, but is forcibly guided by the fact that the tool holder is accommodated in a holding element, which is connected via a guide gear to the motor unit. The position of the Retaining element is determined by the finger, preferably the index finger of a user's hand.

Preferably, the guide gear can be designed such that the

Retaining element can take all positions that the user can specify by the position of the fingertip or the last phalanx of the finger received in the finger receiving and lying in the plane in which the three finger members can be kinked to each other.

If necessary. It can also be provided that the holding element with the

Guide transmission can be moved outside this plane, e.g. in a solid angle range, which is defined by the buckling of the three finger members to each other and the mobility of the first finger member relative to the back of the hand. The holding element may also be concretely restricted by the guide gearing to the natural mobility of the last phalanx relative to the hand, e.g. so as to avoid finger or hand injuries.

The invention can provide that the finger receptacle is designed as a recess open in the direction of the motor unit, into which a finger can be inserted, at least with the fingertip, preferably the last phalanx of the finger. Thus, a user can attach the power tool to the forearm and insert the finger into the recess, without this having to be attached in a special way. For this, the recess on the retaining element is preferably underside

arranged, based on a mounting of the power tool on top of the forearm.

Preferably, the power tool has a handle that differs from the

Motor unit extends toward the holding element, wherein the handle has a handle member, in particular which is perpendicular to the output shaft, over which the palm of a hand of a user from the direction of the guide gear can be brought over. For the handle element is about half way between the output shaft de motor unit and the holding element below the guide gear and the guided flexible / articulated shaft arranged again, preferably in turn based on the aforementioned

Mounting position on top of forearm.

The grip element, which can be grasped by the palm and the remaining fingers, is more preferably by two laterally thereto

subsequent grip struts on the motor unit, in particular laterally attached thereto. In this case, the center of the handle element to the center axis of the

Be offset output shaft.

The handle can be asymmetric, especially with respect to the grip struts

be formed, in particular wherein the handle on the motor unit releasably and fastened in reverse orientation. This will ensure that both right-handed and left-handed people can easily operate the power tool.

Preferably, the guide gear and the flexible / articulated shaft are extended from an area between the grip struts into an area above the grip struts and above the grip element, in particular in the same direction as the fingers of a user's hand are guided over the grip element. This results in a course of the guide gear and shaft, which corresponds to the anatomical course of the extended used (pointing) finger.

In a further preferred embodiment, the handle element may have at its lateral end a switch for actuating the motor. This switch is more preferably located on the side opposite the thumb so that it can be used for operation. It is also possible to provide a reversing switch, preferably also on the gripping element, e.g. in addition to the operating switch or integrated in this.

The invention may also provide in another embodiment, however, that the engine is switched on and / or off automatically. For example, in the holding element, a pressure sensor or pressure switch may be integrated, by means of which the motor is switched on and / or over when a limit pressure acting on the tool holder is exceeded can be switched off. By pressing the clamped or inserted tool on a workpiece to be machined so switching can be effected.

The shaft, which is guided by the guide gear can be formed, for example, in a simple design as usual flexible spiral wound wire or ribbon.

In another, in contrast, preferred embodiment, the shaft is designed as an articulated shaft, the multiple homokinetic joints or

having spherical joints, in particular cardan joints. For example, or preferably with equal axial angles, two universal joints can follow one another, e.g. in Z and W configuration in the power transmission direction of the

Motor unit to the holding element follow each other. At least a portion of the shaft between spherical joints can be stored, especially in one

Bearings be stored, the bearing with the guide gear,

in particular one of its transmission links is rigidly connected.

The guide gear is preferably lockable in its mobility,

in particular by a force acting in the connecting direction between the holding element and motor unit force, in particular a stretching or upsetting force. For example, it can be achieved that the locking takes place automatically when a force is applied to the tool holder, in particular when the user brings the power tool in the working position and attaches to the workpiece.

The blocking takes place in such a way that the flexibility or flexibility is canceled, so the guide gear is rigid. This will ensure that the user's finger does not pass through the on the tool or workpiece

applied force is applied, but the power flow over the

Guide gear is done.

To effect the blocking, an embodiment may provide that along the orientation of the guide gear (especially the regularly not straight) extends a blocking element which causes by friction or positive locking, in particular due to a displacement, the blocking in a respective joint of the guide gear. A blocking element may be formed, for example, as a rope, preferably that runs in the interior of the guide transmission, wherein the guide transmission in the mobility can be blocked by a force applied to the blocking element.

Preferably, the guide gear in the connecting direction between the holding element and motor unit on a plurality of gear members, in particular at least three gear members. A gear member may be formed by a rigid element having on both sides of an adjacent gear member an articulated connection, which is at least about a rotation axis, if necessary. Also movable about a pivot point. In an articulation by an axis of rotation, this axis of rotation is preferably perpendicular to the output shaft and in particular parallel to the handle element, whereby a parallelism results to the hinge axes of the used Finder, which is inserted into the receptacle on the holding element.

The invention may also provide that the guide gear in his

Mobility can be blocked by a shift of the gear members relative to each other. For this, e.g. a hinge axis between two gear members relative to at least one of the two gear members in one direction

be displaceable perpendicular to the axis of rotation, e.g. in a slot recording, in which the Drehachsenenden einhegen. It can thereby be achieved that e.g. at least one of the transmission members is variable in length or at least positionally variable within the guide transmission within the connecting direction. This change can block the entire

Guide gear can be achieved, for example, characterized in that the change causes a displacement of a blocking element, as already mentioned above. Due to the change, however, only the articulation of the considered changed transmission element can be influenced relative to the adjacent one, ie blocked. In one embodiment, the invention may provide that at least one of the gear members has a juxtaposition of an even number of intermeshing gears with or without the use of a belt drive. This has the advantage that set over two joints across the same angle (W or Z arrangement) and thus the uniform

Rotary motion transmission is ensured.

A further preferred embodiment may provide that the position of the hinge axis or the hinge point between the last gear member and the holding member is variable. As a result, the position of the axis or the point can be adapted to the position of the hinge axis of the last finger member of a user, so that the holding element can be moved particularly comfortable by the finger used.

The invention thus causes a total that the orientation of the tool holder in the retaining element can be changed at least in the context of the mobility of the guide gear relative to the output shaft of the drive unit.

An embodiment of the invention will be described with reference to the following figures. Since both figures the same version of different

View directions shows a common description.

The figures show an inventive power tool, here with battery operation. In the motor unit 1, a motor 2 is arranged, and here at the rear end, a battery pack for power supply. However, the power supply can in principle also be arranged externally.

On the underside of the motor unit 1, a contact area is provided with which the motor unit can be placed on the forearm top of a user. By not shown here straps can be attached to the forearm.

The motor unit has an output shaft 3, whose alignment with the

Alignment of the forearm matches. Through the output shaft 3, an articulated shaft 11 is set in rotation during operation of the motor, the on a Tool holder, which is received in a holding element 8, is transmitted. This holding element, in turn, is connected to the motor unit not only by the shaft 11 but also by the guide gear 6, comprising a plurality of gear elements 6a, 6b, 6d. Also between the motor unit 1 and retaining element 8 is a connection between the shaft 3 and guide gear 6 via the

Connection element 6e given, so that the possible position of the

Holding element 7 relative to the motor unit in total by the

Guiding gear is forcibly guided.

From the motor unit 1, two gripping struts 14a and b continue to extend on the right and left in the direction of the holding element 7, which are connected to one another at the front end by a gripping element 13 and form a handle 12 as a whole. A user may place his hand over the handle member 13, e.g. and preferably insert the index finger with the last finger member in a finger holder 9 on the holding element 7. In another embodiment, a one-sided grip strut is right or left possible, at the end of which is then a cantilever handle member 13 is located.

By moving the index finger, the orientation of the tool holder 8 relative to the output shaft 3 can be changed. A user can virtually point with the pointing finder on the workpiece to be machined and perform the machining, e.g. screw in a screw or drill a hole, depending on

Equipping the tool holder 8.

An articulation is within the guide transmission by several

Gear members 6a, 6b, 6c given, which are hinged together. The articulated connection takes place here by rotary axes, all parallel to

Gripping element 13 lie and are aligned perpendicular to the output shaft 3.

In order to achieve a force transmission from the lower arm 5 to the retaining elements 7, in which the power flow does not occur, or at least not substantially via the finger, the invention provides that the mobility of the guide transmission can be blocked. In this embodiment, the axis of rotation between the Gear members 6b and 6d mounted in a slot, so that the transmission member 6b within the guide gear in the position is changed, for example, the transmission member 6b slidably einliegen in the connecting element 6e and by shifting the position of the gears 6c of the gear member 6a change each other, for example so that a rotational inhibition of the gears takes place. Provided that the change in position of the gear member 6b and a rotational inhibition between the gear members 6b and 6d is carried out as a whole, the guide gear can be made rigid. It then absorbs acting forces in the connection between the holding element and the motor unit.

A user can turn on the engine by a switch 15 located on the

Handle member 13 is disposed at one of the lateral ends.

Claims

claims

1. electric tool, in particular hand-operated cordless screwdriver,

full

a. a motor unit (1) having a motor (2) and an output shaft (3) which can be driven by the motor (2),

b. a contact area (4) arranged on the motor unit (1) with which the motor unit (1) can be detachably fastened to a forearm (5) of a person, in particular on the forearm upper side, preferably adaptably,

characterized in that

c. extends from the motor unit (1) a guide gear (6), at the end of a holding element (7) is arranged and

d. in the holding element (7) a tool holder (8), in particular a bit holder (8) or chuck, is rotatably received and e. the holding element (7) has a finger holder (9) into which a finger (10), preferably the index finger (10), can be received and f. a flexible or articulated shaft (11) extending between the

Tool holder (8) and the output shaft (3) extends, which is guided by the guide gear (11) and with which the tool holder (8) by means of the motor (2) is drivable.

2. Power tool according to claim 1, characterized in that the finger receptacle (9) is designed as a in the direction of the motor unit (1) open recess into which a finger (10) at least with the fingertip, preferably the last finger member can be inserted.

3. Power tool according to one of the preceding claims, characterized

characterized in that of the motor unit (1) has a handle (12) in Direction to the holding element (7), wherein the handle (12) a

Has grip element (13), in particular perpendicular to the output shaft (3) is aligned over the palm of the hand of a

User from the direction of the guide gear (11) can be folded over.

4. Power tool according to claim 3, characterized in that the

Handle element (13) by means of a one-sided or two-sided

Handle bars (14a or 14 b) on the motor unit (1), in particular laterally attached.

5. Power tool according to claim 4, characterized in that the guide transmission (6) and the flexible / articulated shaft (11) from an area between the handle struts (14) into an area above the grip struts (14) and above the grip element (13 ) are extended,

in particular in the same direction as the fingers (10) of a user's hand are guided over the grip element (13).

6. Power tool according to one of the preceding claims 3 to 5, characterized in that the handle element (13) at its lateral end a switch (15) for actuating the motor (2).

7. Power tool according to one of the preceding claims 3 to 6, characterized in that the handle (12), in particular in terms of

Handle bar (14) is formed asymmetrically, in particular wherein the handle (12) on the motor unit (1) releasably and in reverse orientation can be fastened.

8. Power tool according to one of the preceding claims, characterized

in that the articulated shaft (1) is formed by a plurality of spherical joints (11a), in particular those in Z and W configuration follow one another.

9. Power tool according to one of the preceding claims, characterized

characterized in that the guide gear (6) in its mobility can be blocked, in particular by a force acting in the connecting direction between the holding element (7) and the motor unit (1), in particular stretching or compressive force acting.

10. Power tool according to claim 9, characterized in that along the direction of extension of the guide gear (6) a

Barrier element extends, in particular a rope, preferably in the interior of the guide gear (6), wherein by a force applied to the locking element, the guide gear (6) is lockable in the mobility.

11. Power tool according to one of the preceding claims, characterized

characterized in that the guide gear (6) in the

Connecting direction between the holding element (7) and motor unit (1) a plurality of gear members (6a), in particular at least two

Gear members (6a, 6b) has.

12. Power tool according to claim 11, characterized in that the guide transmission (6) is lockable in its mobility by a displacement of the gear members (6a, 6b) relative to each other.

13. Power tool according to claim 11 or 12, characterized in that at least one of the gear members (6b) is variable in length.

14. Power tool according to one of the preceding claims 11 to 13, characterized in that at least one of the gear members (6a) has a juxtaposition of an even number of meshing gears (6c).

15. Power tool according to one of the preceding claims 11 to 14, characterized in that the position of the hinge axis or the

Hinge point between the last gear member (6a) and the

Retaining element (7) is changeable, in particular to its position on the Adjust the position of the hinge axis of the last phalanx of a user.

16. Power tool according to one of the preceding claims, characterized

in that a pressure sensor or pressure switch is integrated in the holding element (7), by means of which the motor (2) can be switched on and / or off when a limit pressure acting on the tool holder is exceeded.