CN210025091U

CN210025091U - Electric screwdriver with anti-swing screwdriver head

Info

Publication number: CN210025091U
Application number: CN201920671526.0U
Authority: CN
Inventors: 李东厚; 潘立波
Original assignee: Suzhou Weister Intelligent Technology Co Ltd
Current assignee: Suzhou Weister Intelligent Technology Co Ltd
Priority date: 2019-05-11
Filing date: 2019-05-11
Publication date: 2020-02-07
Anticipated expiration: 2029-05-11

Abstract

The utility model discloses an criticize first electronic screwdriver of preventing putting belongs to the screwdriver field, and it includes the casing, sets up the link in the casing and is located housing end's output shaft, be equipped with the motor in the casing, output shaft both ends opening and inside separate for criticizing first groove and holding tank through the baffle, the one end of casing is connected with the installation lantern ring, the link is located the installation lantern ring, the link is equipped with the connection boss that inserts to the holding tank towards one side of holding tank, be equipped with the inserting groove in the connection boss, the spindle of motor passes the diapire of the installation lantern ring and inserts to the inserting groove in, the steerable link of motor rotates with the output shaft is synchronous. The utility model discloses have the swing phenomenon when can improving screwdriver head and rotate, keep better concentricity when making screwdriver head and motor spindle synchronous rotation, required elasticity power is littleer, and is lower to the damage of motor with the output shaft, and operation process is more smooth, and the noise of production is lower effect also.

Description

Electric screwdriver with anti-swing screwdriver head

Technical Field

The utility model relates to a technical field of screwdriver, in particular to criticize first anti-swing electronic screwdriver.

Background

A driver is a tool used to turn a screw to force it into place, having a driver head which can be inserted into a slot or recess in the head of the screw, the head having primarily a straight line and a cross, and often also having a hexagonal shape, including both an inner hexagonal shape and an outer hexagonal shape. Screwdrivers are generally classified into manual screwdrivers and electric screwdrivers, which use an electric motor to install and remove screws instead of a human hand.

Chinese patent publication No. CN107791188A discloses a precision electric screwdriver, which comprises a screwdriver head, a housing and a motor, wherein a composite mechanism for realizing manual and automatic mode switching is arranged between the screwdriver head and the motor, and the composite mechanism comprises: the support comprises a back plate and an extension arm, a linkage shaft hole is formed in the back plate, and a motor shaft penetrates through the linkage shaft hole and then can drive the support to rotate.

The above prior art solutions have the following drawbacks: under the clamping and limiting action of the balls, the support and the output shaft rotate together when the motor crankshaft rotates normally, and the screwdriver head is driven to rotate. However, the bracket is fixed to the end of the motor shaft, and the screwdriver head gradually deviates from the axis of the motor shaft under the action of centrifugal force, so that a swing phenomenon occurs, and the swing phenomenon is more obvious when the end of the screwdriver head is far away from the shaft end of the motor shaft, so that the problem needs to be solved urgently.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide an electronic screwdriver of head anti-swing of criticizing has the swing phenomenon when can improving the screwdriver head and rotate, keeps the effect of better concentricity when making screwdriver head and motor spindle synchronous rotation.

The above technical purpose of the present invention can be achieved by the following technical solutions:

the utility model provides an criticize first electronic screwdriver of preventing putting, includes the casing, sets up the link in the casing and is located the output shaft of housing end portion, be equipped with the motor in the casing, output shaft both ends opening and inside are separated for criticizing first groove and holding tank through the baffle, the one end of casing is connected with the installation lantern ring, the link is located the installation lantern ring, the link is equipped with the connection boss that inserts to the holding tank towards one side of holding tank, be equipped with the inserting groove in the connection boss, the spindle of motor passes the diapire of the installation lantern ring and inserts to the inserting groove in, the steerable link of motor rotates with the output shaft is synchronous.

Through adopting above-mentioned technical scheme, at first utilize the connection boss to insert inside the output shaft, the connection stability between the multiplicable two, the synchronism improves during the motion, when the screwdriver head inserts to criticizing the head inslot, can make the screwdriver head, the output shaft, link and motor spindle form a whole, and the outline of four is circular, higher concentricity and true circularity have during the rotation, the connecting boss can also supply the spindle of motor to insert simultaneously, the interval between spindle axle head and the output shaft axle head has been shortened, thereby can further reduce the screwdriver head and make the distance of deviating from the spindle axis when rotary motion, make the screwdriver head difficult emergence horizontal hunting when the elasticity screw, required elasticity is also littleer, damage to motor and output shaft is lower, the operation process is more smooth, the noise that produces is also lower.

The utility model discloses further set up to: the mounting sleeve ring is in splicing fit with a bearing frame, and the end face, far away from the bottom wall of the mounting sleeve ring, of the bearing frame is not lower than the end face, far away from the bottom wall of the mounting sleeve ring, of the output shaft.

Through adopting above-mentioned technical scheme, can hide the output shaft in the bearing bracket completely, both can play the guard action to output shaft itself, when can prevent again simultaneously that the output shaft from rotating, people's hand takes place to touch rather than directly to the safety in utilization has been improved.

The utility model discloses further set up to: the outer side wall of the output shaft is provided with a resisting step along the periphery thereof, the outer profile of the cross section of the end part of the output shaft facing the connecting frame is provided with a circular arc surface and a notch surface which are continuously and alternately arranged, the periphery of the connecting frame is extended along the radial direction thereof with at least two extension arms, one ends of which are butted with the resisting step;

work as when connecting in the boss inserts the holding tank, the lateral wall of extension arm and the inside wall laminating of bearing bracket, be formed with between breach face and the bearing bracket inside wall and cut off the space, be equipped with the round pin post in cutting off the space, upwards in week the round pin post is located between the adjacent extension arm, maximum distance between the lateral wall of breach face and the inside wall of bearing bracket equals the diameter of round pin post, distance between the lateral wall of arc surface and the inside wall of bearing bracket is less than the diameter of round pin post.

By adopting the technical scheme, the connecting frame, the output shaft and the motor shaft can be controlled to synchronously rotate by utilizing the matching relation of the pin column, the arc surface and the notch surface, and meanwhile, when the motor stops rotating, the connecting frame and the output shaft cannot rotate under the action of external force, so that the switching of two working states of a screwdriver electric mode and a manual mode can be realized.

The utility model discloses further set up to: the lateral wall of bearing frame evenly is equipped with the inserted block along its circumference, the mounting groove has been seted up to installation lantern ring lateral wall, the inserted block card is gone into to the mounting groove in.

Through adopting above-mentioned technical scheme, the joint cooperation of grafting piece and mounting groove can realize the firm connection between bearing bracket and the installation lantern ring and can dismantle the function.

The utility model discloses further set up to: the relative lateral wall integrated into one piece of mounting groove has the joint protruding, two the joint is protruding to be formed with the direction breach with the installation lantern ring between the terminal surface towards the output shaft.

Through adopting above-mentioned technical scheme, when the grafting piece inserted to the mounting groove in, the setting of direction breach can play the guide effect to the operation of being connected between bearing bracket and the installation lantern ring has been made things convenient for.

The utility model discloses further set up to: the installation lantern ring is equipped with the positioning flange towards the one end lateral wall of casing, the casing overcoat is equipped with the dustcoat, the lateral wall integrated into one piece of casing has the fastening strip, the dustcoat inside wall is equipped with location step and fastening groove, works as when positioning flange and location step butt, the fastening strip inserts to the fastening inslot.

Through adopting above-mentioned technical scheme, utilize the butt of location step and location flange to fix a position being connected between dustcoat and the casing, the cooperation of fastening groove and fastening strip also makes being connected between dustcoat and the casing more firm simultaneously.

The utility model discloses further set up to: the bearing bracket overcoat is equipped with the protective housing, the protective housing is with the inside wall butt of dustcoat, the terminal surface that installation lantern ring bottom surface was kept away from to the protective housing is not less than the terminal surface that installation lantern ring bottom surface was kept away from to the output shaft.

Through adopting above-mentioned technical scheme, the safety in utilization of screwdriver can further be improved in the setting of protective housing.

The utility model discloses further set up to: the protective housing is made of transparent materials, and an LED lamp strip is clamped between the protective housing and the mounting lantern ring.

Through adopting above-mentioned technical scheme, LED lamp area can make the operator still can clearly see the condition in work area clearly when using the screwdriver in the place that light is bad, and the protective housing is made by transparent material simultaneously and also can concentrate the light that LED lamp area sent.

The utility model discloses further set up to: and a magnetic part is clamped between the groove bottom of the accommodating groove and the connecting boss.

By adopting the technical scheme, when the screwdriver head is inserted into the screwdriver head groove, the magnetic part can play a role in adsorbing and positioning the screwdriver head, and the stability of the screwdriver head after being accommodated is improved.

The utility model discloses further set up to: the outer contour of the cross section of the part of the output shaft, which is internally provided with the screwdriver head groove, is in a regular polygon shape.

By adopting the technical scheme, the output shaft is formed by the injection molding process, if the outer contour of the cross section of the output shaft is made to be circular, the exhaust of an insert of an injection mold is not easy, and meanwhile, the front temperature and the rear temperature of the molten injection molding material are high during flowing, so that the solidification is easy to occur, and the defects of edge collapse and the like are caused after the injection molding of the final product. When the cross section of the output shaft is made into a regular polygon, the injection molding material is instantaneously accelerated when being filled into the mold cavity when meeting the edge corner, so that the temperature difference between the front injection molding material and the rear injection molding material during filling is reduced as much as possible, and the forming quality of the output shaft is better.

To sum up, the utility model discloses following beneficial effect has:

1. through the arrangement of the connecting boss, the transmission distance between the motor shaft and the screwdriver head is reduced, the concentricity of the motor shaft, the connecting frame, the output shaft and the screwdriver head during rotation is enhanced, and the swing amplitude of the screwdriver head is reduced;

2. through the arrangement of the bearing frame, a necessary installation environment can be provided for the screwdriver to realize two working modes of manual operation and automatic operation, and meanwhile, the output shaft can be protected together with the protective shell, so that safety accidents caused by contact between an operator and the output shaft due to misoperation are avoided;

3. through the setting of splicing block, inserting groove and joint arch, can enough increase the firm degree of being connected between the bearing frame and the installation lantern ring, can also make things convenient for the change to bearing frame and output shaft, link simultaneously.

Drawings

Fig. 1 is a schematic diagram of an explosion structure for embodying the whole of the present invention;

FIG. 2 is a schematic structural view of the screwdriver head according to the present invention;

FIG. 3 is an enlarged view of the portion A in FIG. 1, for showing the connection relationship between the connecting frame and the output shaft;

fig. 4 is a schematic view of the present invention showing the matching relationship between the connecting frame, the pin, the output shaft and the bearing frame;

FIG. 5 is an enlarged view of the portion B in FIG. 1, for showing the structure of the mounting groove;

fig. 6 is a schematic view of the connection relationship between the housing and the outer cover according to the present invention.

In the figure, 1, a housing; 11. fastening strips; 2. a connecting frame; 21. connecting the bosses; 211. inserting grooves; 22. an extension arm; 3. an output shaft; 31. a partition plate; 32. a batch head groove; 33. accommodating grooves; 34. a resisting step; 35. a circular arc surface; 36. a notch surface; 4. a motor; 41. a crankshaft; 5. mounting a lantern ring; 51. mounting grooves; 511. clamping the bulges; 512. a guide notch; 52. a positioning flange; 6. a bearing bracket; 61. an insertion block; 7. a pin; 8. a housing; 81. a fastening groove; 82. positioning a step; 9. a protective shell; 10. an LED light strip; 12. a magnetic member; 13. a circuit board; 14. a battery; 15. and a reversing switch.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

Example (b):

as shown in FIG. 1, for the utility model discloses a batch head anti-swing electric screwdriver, including casing 1, dustcoat 8, output shaft 3 and bearing bracket 6. The outer cover 8 covers the shell 1, the outer cover and the shell are in inserted fit, and the length of the outer cover 8 is larger than that of the shell 1; the one end integrated into one piece of casing 1 has the installation lantern ring 5, defines the one end that casing 1 was equipped with installation lantern ring 5 as the near-end, and the other end is defined as the tail end, has set gradually motor 4, circuit board 13 and battery 14 along the direction of near-end to distal end in the casing 1.

As shown in fig. 2, both ends of the output shaft 3 are open, and a partition plate 31 is fixedly arranged inside the output shaft 3, the partition plate 31 divides the inside of the output shaft 3 into a batch groove 32 and a receiving groove 33, and one end of the output shaft 3, which is provided with the receiving groove 33, is located in the mounting collar 5. The screw head groove 32 is of an inner hexagon and is used for inserting a screw head; the cross-sectional outer contour of the output shaft 3 where the stub groove 32 is provided is a regular polygon, preferably a regular decagon in this embodiment. The connecting frame 2 is arranged at the bottom of the mounting sleeve ring 5 in a fitting manner, the connecting boss 21 extends towards the output shaft 3 at the center of the connecting frame 2, the extending arms 22 extend from the periphery of the connecting frame, and the number of the extending arms 22 is at least two, preferably three, along the circumferential direction of the connecting frame 2.

As shown in fig. 3 and 4, the side wall of the output shaft 3 near the bottom of the mounting collar 5 is composed of a circular arc surface 35 and a notch surface 36, which are continuously and alternately arranged, the circular arc surface 35 is convex, the notch surface 36 can be a straight surface or an arc surface, and is concave when used as an arc surface, in this embodiment, the notch surface 36 is a straight surface. The outer side wall of the output shaft 3 is provided with a retaining step 34 along the circumferential direction at a position close to the mounting sleeve ring 5, the bearing frame 6 is sleeved on the outer side of the output shaft 3, the bearing frame 6 is in insertion fit with the mounting sleeve ring 5, and a stepped inner cavity (see fig. 2) is formed in the bearing frame 6 to be matched with the insertion position of the retaining step 34 for positioning the bearing frame 6 and the mounting sleeve ring 5. When the connecting boss 21 is inserted into the accommodating groove 33 (see fig. 2), the outer wall of the extension arm 22 is attached to the inner side wall of the bearing frame 6, the inner wall of the extension arm 22 is attached to the arc surface 35, a partition space is formed between the notch surface 36 and the inner side wall of the bearing frame 6, and a pin 7 is arranged in each partition space (namely, the pin 7 is inserted between the notch surface 36 and the bearing frame 6 in the radial direction, and the pin 7 is positioned between adjacent extension arms 22 in the circumferential direction); one end of the pin 7 abuts against the abutting step 34, and the other end abuts against the bottom wall of the mounting collar 5. The maximum distance between the outer side wall of the notch surface 36 and the inner side wall of the bearing frame 6 is equal to the diameter of the pin 7, and the distance between the outer side wall of the arc surface 35 and the inner side wall of the bearing frame 6 is smaller than the diameter of the pin 7.

As shown in fig. 1 and 2, a D-shaped insertion groove 211 (see fig. 3) is formed at one end of the connection boss 21 facing the bottom of the mounting collar 5, and the crankshaft 41 of the motor 4 penetrates through the bottom wall of the mounting collar 5 and is inserted into the insertion groove 211. The screwdriver of the embodiment has an electric mode and a manual mode, the outer cover 8 is provided with the reversing switch 15, and the reversing switch 15 is electrically connected with the circuit board 13 and used for controlling the forward and reverse rotation of the crankshaft 41 of the motor 4. In the electric mode, the motor 4 drives the connecting frame 2 to rotate, and the pin 7 drives the output shaft 3 to rotate under the driving action of the connecting frame 2; in the manual mode, when the output shaft 3 rotates, the pin 7 is clamped between the notch surface 36 of the output shaft 3 and the bearing frame 6, and the output shaft 3, the bearing frame 6, the pin 7 and the shell 1 are relatively fixed.

The method specifically comprises the following steps: under the electronic mode state, select to screw up or remove the screw through reversing switch 15 regulation motor 4's positive and negative rotation, reversing switch 15 driving motor 4 work, motor 4's spindle 41 drives link 2 rotatory, the extension arm 22 drive round pin post 7 of link 2, round pin post 7 card supports the regional of the nearly arc surface 35 of breach face 36 of output shaft 3 and drives output shaft 3 and rotate, extension arm 22 has circumferential effort to round pin post 7, because the diameter of round pin post 7 is greater than the distance between arc surface 35 and the bearing bracket 6, so this effort accessible round pin post 7 acts on output shaft 3, this output shaft 3 finally drives the screwdriver head rotation of placing in screwdriver head groove 32 and carries out work.

Under the manual mode state, when motor 4 is out of work or under meticulous operation requirement operating mode, directly manually screw up or remove the screw, when screwdriver head rotatory screw, the screwdriver head has the effort to output shaft 3, and output shaft 3 can produce a small segment rotary displacement and make round pin post 7 block support in the space that the breach face 36 of output shaft 3 and bearing frame 6 formed. Because the distance between the arc surface 35 and the bearing frame 6 is smaller than the diameter of the pin 7, an acting force is generated on the pin 7 when the output shaft 3 rotates, the acting force applied to the pin 7 faces the bearing frame 6, the output shaft 3, the pin 7 and the bearing frame 6 are mutually clamped and relatively fixed under the acting force of the output shaft 3, the bearing frame 6 and the shell 1 are fixed, so the output shaft 3, the pin 7, the bearing frame 6, the shell 1 and the screwdriver head are relatively fixed, and the screwdriver is consistent with the using method of a common screwdriver at the moment.

As shown in fig. 2, a magnetic member 12 is further disposed between the connection boss 21 and the partition plate 31 in the accommodation groove 33, the magnetic member 12 is a cylindrical magnet, and when the screwdriver bit is inserted into the screwdriver bit groove 32, the magnetic member 12 can perform an effect of adsorbing and positioning the screwdriver bit, thereby further reducing the shaking of the screwdriver bit. Meanwhile, compared with the magnetic part 12 arranged in the screwdriver head groove 32, the magnetic part 12 has the shortest distance with the crankshaft of the motor 4 and the screwdriver head in the screwdriver head groove 32, the magnetic adsorption force is larger, and even under the clamping action condition without the pin 7, the motor 4 can still synchronously rotate with the output shaft 3 through the magnetic part 12, so that the function of basic loosening and tightening screws of the screwdriver is realized.

As shown in fig. 1 and 5, the specific insertion fit manner of the bearing frame 6 and the mounting collar 5 is as follows: the side wall of the mounting lantern ring 5 is symmetrically provided with mounting grooves 51 along the axis, the opposite side wall close to the groove of the mounting groove 51 is integrally formed with clamping protrusions 511, and a guide notch 512 is formed between the two clamping protrusions 511 and the end face of the mounting lantern ring 5 facing the output shaft 3; the lateral wall that is located bearing frame 6 is provided with two grafting blocks 61 along its axis symmetry, and the longitudinal section of grafting block 61 is isosceles trapezoid. The end with the smaller width of the insertion block 61 is inserted into the installation groove 51, the minimum distance between the clamping protrusions 511 is slightly smaller than the minimum width of the insertion block 61, and the minimum distance is limited by the clamping protrusions 511 so as to fix the relative position of the installation lantern ring 5 and the bearing frame 6.

As shown in fig. 2, a protective shell 9 made of transparent plastic is further sleeved outside the bearing frame 6, one end of the protective shell 9 is embedded into the outer cover 8 and abutted to the positioning flange 52, a flexible LED strip 10 is further clamped between the protective shell 9 and the end face of the mounting lantern ring 5, and when the output shaft 3 rotates, the LED strip 10 can emit light by power supplied from a battery.

As shown in fig. 2, in order to prevent the output shaft 3 rotating at a high speed from being scratched due to an operator's misoperation, the end surface of the bearing bracket 6 away from the bottom surface of the mounting collar 5 is designed not to be lower than the end surface of the output shaft 3 away from the bottom surface of the mounting collar 5, and the end surface of the protective housing 9 away from the bottom surface of the mounting collar 5 is also designed not to be lower than the end surface of the output shaft 3 away from the bottom surface of the mounting collar 5. Utilize bearing frame 6 and protective housing 9's double-deck guard action, hide output shaft 3 in protective housing 9 completely to the safety in utilization has been improved.

As shown in fig. 6, the specific connection manner between the housing 1 and the outer cover 8 is as follows: the lateral wall integrated into one piece of casing 1 has the cross section to be personally submitted half circular arc's fastening strip 11, and the installation lantern ring 5 is equipped with location flange 52 towards the one end lateral wall of casing 1, and the dustcoat 8 inside wall is equipped with location step 82 and fastening groove 81, and the notch of fastening groove 81 extends to location step 82 department. When the housing 1 is inserted into the housing 8 and the positioning flange 52 abuts against the positioning step 82, the fastening strip 11 is also inserted into the fastening groove 81.

The present embodiment is only for explaining the present invention, and it is not limited to the present invention, and those skilled in the art can make modifications to the present embodiment without inventive contribution as required after reading the present specification, but all of them are protected by patent laws within the scope of the claims of the present invention.

Claims

1. The utility model provides an electronic screwdriver of head anti-swing, includes casing (1), sets up link (2) in casing (1) and is located output shaft (3) of casing (1) tip, be equipped with motor (4), its characterized in that in casing (1): output shaft (3) both ends opening and inside are separated for criticizing first groove (32) and holding tank (33) through baffle (31), the one end of casing (1) is connected with the installation lantern ring (5), link (2) are located the installation lantern ring (5), link (2) are equipped with connection boss (21) of inserting to holding tank (33) towards one side of holding tank (33), be equipped with inserting groove (211) in connection boss (21), shaft (41) of motor (4) pass the diapire of the installation lantern ring (5) and insert to inserting groove (211), motor (4) steerable link (2) and output shaft (3) synchronous rotation.

2. The electric screwdriver as claimed in claim 1, wherein: the mounting sleeve ring (5) is spliced and matched with a bearing frame (6), and the end face, far away from the bottom wall of the mounting sleeve ring (5), of the bearing frame (6) is not lower than the end face, far away from the bottom wall of the mounting sleeve ring (5), of the output shaft (3).

3. The electric screwdriver as claimed in claim 2, wherein: the outer side wall of the output shaft (3) is provided with retaining steps (34) along the periphery thereof, the outer contour of the cross section of the end part of the output shaft (3) facing the connecting frame (2) is provided with arc surfaces (35) and gap surfaces (36) which are continuously and alternately arranged, the periphery of the connecting frame (2) is radially extended with extension arms (22) of which one ends are abutted against the retaining steps (34), and at least two extension arms (22) are arranged;

work as connect boss (21) when inserting to holding tank (33) in, the lateral wall of extension arm (22) and the inside wall laminating of bearing bracket (6), be formed with between breach face (36) and bearing bracket (6) inside wall and cut off the space, cut off and be equipped with round pin post (7) in the space, circumferentially go up round pin post (7) are located between adjacent extension arm (22), the maximum distance between the lateral wall of breach face (36) and the inside wall of bearing bracket (6) equals the diameter of round pin post (7), distance between the lateral wall of arc surface (35) and the inside wall of bearing bracket (6) is less than the diameter of round pin post (7).

4. The electric screwdriver as claimed in claim 2, wherein: the lateral wall of bearing frame (6) evenly is equipped with plug block (61) along its circumference, mounting groove (51) have been seted up to the installation lantern ring (5) lateral wall, plug block (61) card is gone into to mounting groove (51) in.

5. The electric screwdriver as claimed in claim 4, wherein: the relative lateral wall integrated into one piece of mounting groove (51) has joint arch (511), two joint arch (511) and installation lantern ring (5) are formed with direction breach (512) towards between the terminal surface of output shaft (3).

6. The electric screwdriver as claimed in any one of claims 3 to 5, wherein: the mounting sleeve ring (5) is equipped with positioning flange (52) towards the one end lateral wall of casing (1), casing (1) overcoat is equipped with dustcoat (8), the lateral wall integrated into one piece of casing (1) has fastening strip (11), dustcoat (8) inside wall is equipped with location step and fastening groove (81), works as when positioning flange (52) and location step butt, fastening strip (11) insert to fastening groove (81).

7. The electric screwdriver as claimed in claim 6, wherein: bearing frame (6) overcoat is equipped with protective housing (9), the inside wall butt of protective housing (9) and dustcoat (8), the terminal surface that installation lantern ring (5) bottom surface was kept away from in protective housing (9) is not less than output shaft (3) and keeps away from the terminal surface of installation lantern ring (5) bottom surface.

8. The electric screwdriver as claimed in claim 7, wherein: the protective housing (9) is made of transparent materials, and an LED lamp strip (10) is clamped between the protective housing (9) and the end face of the mounting lantern ring (5).

9. The electric screwdriver as claimed in claim 1, wherein: and a magnetic part (12) is clamped between the bottom of the accommodating groove (33) and the connecting boss (21).

10. The electric screwdriver as claimed in claim 1, wherein: the outer contour of the cross section of the part, in which the screwdriver head groove (32) is arranged, of the output shaft (3) is in a regular polygon shape.