JPH11267937A - Device for locking shaft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of damage based on actuation of a lock function during rotation of a shaft. SOLUTION: In this device, a shaft 10 rotatably supported in a casing 11, especially the tool spindle of a motor-driven hand machine tool is locked. Two engageable lock members 12 and 13 are provided. The first lock member 12 of the lock members 12 and 13 is non-rotatably arranged in the casing 11 and the second lock member 13 is non-rotatably arranged on the shaft 10. In this case, a separation member is provided to forcibly separate the two lock members 12 and 13 from each other when the shaft 10 is rotated. The separation member is differently constituted according to constitution of the lock members 12 and 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The invention relates to a shaft rotatably mounted in a casing, in particular a hand-held drilling machine, an accumulator screwdriver, etc., of the type described in the preamble of claim 1. The present invention relates to a device for locking a tool spindle of a simple electric hand-held machine tool.

[0002]

2. Description of the Related Art Such a locking device locks a tool spindle during machine stop, as a so-called spindle locking function, for example, in the use case of an electric hand-held machine tool, in order to tighten and release a coated tool chuck. .

[0003] In the case of a known locking device for an electric hand-held machine tool of the type described above (German Patent No. 43 05 967), in order to realize a so-called locking function,
A spindle gear meshing with a drive gear on the output shaft of the electric motor, which non-rotatably engages the tool spindle, is used as a second locking member, which is provided for this purpose by a number of axial notches. have.

The first locking member is configured as a locking switch having a gripping recess on its upper surface, the locking switch being movable parallel to the tool spindle and having a locking rod. The locking rod can form-fit into one of the notches of the spindle gear and thus fix the tool spindle to the casing in a non-rotatable manner.

[0005] In order to avoid that the locking function is activated by the operation of the lock slider during rotation of the machine and thus damages the machine, measures are taken to prevent the movement of the lock switch when an electric motor is connected. I have. In this measure, the locking rod is guided backwards to the electrical switching area of the motor and is connected to the slide there. The slide is released and moved by the adjusting ring only when the brush adjusting device occupies a de-energized central position for the electric motor.

In the case of similarly known locking devices for percussion drilling machines, a manual switching lever for the operating types "perforation" and "percussion drilling" sets the third pivot position in which the locking function is realized. Have. In this pivoted position of the switching lever, a locking pin fixed to the movably mounted housing moves against the return force of the return spring and, in the same manner, in one of the axial cutouts of the spindle gear. Formally engage. The tool spindle is driven by an electric motor via the spindle gear.

In this case as well, in order to avoid malfunction, the transfer of the switching lever to the third switching position is effected by tightening the return spring, which returns immediately when the switching lever is released. Return the switching lever. As a result, the locking function is removed again immediately after the tool change, and one of the operating modes "perforation" and "percussion perforation" can be activated when the electric motor is connected.

[0008]

SUMMARY OF THE INVENTION The object of the invention is to further improve a locking device of the type mentioned at the outset.

[0009]

According to the invention, the object is achieved by a locking device having the features of claim 1.

[0010]

The advantage of the locking device according to the invention is that the manual execution of the locking function is not prevented at a given point in time,
At the same time, damage to the device and the shaft due to the actuation of the locking function is avoided with relatively low construction costs. This is because the separating member according to the present invention, which works only during rotation of the shaft, forcibly separates the lock member when the lock member is engaged or engaged by the lock function operation. This eliminates all complex measures that have to be interrupted for manual operation.

[0011] Advantageous further configurations and improvements of the device for locking a shaft according to claim 1 result from the further claimed configuration.

Advantageous configurations of the invention for realizing the advantageous configuration of the locking device are, optionally, claims 7, 8 and 15.
It is described in.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The various embodiments of the device for locking a shaft 10 rotatably mounted in a housing 11, shown in cross-section in FIGS. 1 to 6, are advantageously hand-held. Used in the case of electric hand-held machine tools such as drilling machines, accumulator screwdrivers, etc. and used to fix the tool spindle forming axis 10 when the machine is stopped;
In this case, a coated clamping chuck, which receives a tool such as a drill or a screwdriver and is non-rotatably connected to a tool spindle, is tightened or released for tool change. In this case, the casing 11 forms a machine casing of the electric hand-held machine tool.

In principle, all illustrated embodiments of the locking device have two locking members 12, 13 which engage with one another, of which the first locking member 1
2 is a non-rotatable and second locking member 1 in the casing.
Numeral 3 is arranged on the shaft 10 so as not to rotate. The mutual engagement of the two locking members is effected by manual operation of a first locking member 12 which is arranged in the casing and projects partly from the casing 11 for operation. When both lock members are engaged, the shaft 10 is fixed to the casing 11 so as not to rotate.

The connection of the drive for the shaft 10 allows the shaft 10, in order to prevent the motor, the locking device or the shaft 10 from being damaged when an electric motor is connected, for example in the case of an electric hand-held machine tool. A separating member is provided which, when rotated, causes the locking members 12, 13 to be forcibly separated. In the various embodiments according to FIGS. 1 and 2 or 3 and 4 or 5 or 6, the separating element is realized in a different manner according to the different configuration of the locking elements 12, 13. Is done.

In a first embodiment of the locking device, shown in a different sectional view in FIGS. 1 and 2, a first locking member 12 is provided.
Has a locking ring 14 surrounding the shaft 10 and movably guided into the casing 11, and an operating member 16 protruding from the casing 11 for moving the locking ring 14 along the shaft 10. A locking body 15 is formed on one ring surface of the locking ring.

As is apparent from FIG.
4 is guided by two diametric guide projections 17 in two U-shaped cross-section guide rails 18 formed in the casing 11 and extending in the axial direction parallel to the axis. The second lock member 13 includes a locking ring 1.
A locking body 19 is also formed on the end face of the lock member facing 4, and this locking body is a locking body 1 of the locking ring 14.
Ring 14 corresponding to 5 and within guide rail 18
Are engaged with each other by the movement of.

To move the locking ring 14 in the axial direction, the operating member 16 acts on a transmission ring 20 which is mounted in front of the locking ring 14 and loosely engages the shaft 10. Between the transmission ring 20 and the locking ring 14, there are arranged a number of pressing springs 21 having a spring axis extending parallel to the axis and uniformly distributed over the circumferential direction. The spring end of the pressing spring 21 is provided with an axial recess 22 of the locking ring 14 and an axial recess 2 of the transmission ring 20.
3 is received in a form-fitting manner. These recesses are provided on mutually facing end faces of the locking ring 14 and the transmission ring 20.

The operating member 16 has a sliding button 24 guided movably in the casing 11 in the radial direction with respect to the shaft 10 and a sliding wedge 25 integrally connected to the sliding button in the moving direction of the sliding button. And the sliding wedge engages the shaft 10 in a fork-like manner. The sliding wedge 25 is formed with a wedge surface 26, which is locked with respect to the axis of the sliding button 24 during the inward movement of the sliding button 24 toward the shaft 10. It is configured to cause a movement movement of the transmission ring 20 and the locking ring 14 towards the member 13.

For this purpose, the transmission ring 20 is subjected to the spring force of the pressing spring 21 by a slope 27 formed on the ring surface facing the sliding wedge 25 and extending in parallel to the wedge surface 26 so as to receive the wedge surface. Touch 26. Sliding button 2
4 is associated with a return spring 28, which is supported at one end by the slide button 24 and at the other end by the casing 11, and is contracted during the radial inward movement of the slide button 24. You.

When the sliding button 24 is pressed manually (by hand), the sliding wedge 25 moving toward the shaft 10 is moved through the wedge surface 26 of the sliding button 24 and the inclined surface 27 of the transmission ring 20. The transmission ring 20 is moved to the left as viewed in FIG. 1, whereby the locking ring 14 is moved via the pressing spring 21 and the locking members 15 and 19 of the locking ring 14 and the second locking member 13 are moved. Engage with each other.

When the shaft 10 rotates, the two lock members 1
The separating element mentioned at the beginning, which causes a forced separation of the two and 13 and thus prevents damage, forms a torque release means (Ueberrastmoment) provided between the locks 15 and 19. The magnitude of the unlocking torque of this means depends on the locking body 1
5 and 19, which are defined by the shaping and the hardness of the pressing spring 21 and are designed as follows: when the shaft 10 stops, the unlocking torque is, for example, when the tool chuck of the tool spindle is disengaged. Is designed to be smaller than the torque acting on the shaft 10 caused by the rotation.

When the shaft 10 rotates, the torque releasing means forms a ratchet mechanism between the locking ring 14 and the second locking member 13, whereby the sliding button 24 is pushed in despite the pushing. The shaft 10 can rotate.

In the various embodiments shown in cross-section in FIGS. 3 and 4, the first locking member 12 is movable into the casing 11 radially with respect to the shaft 10 for manual operation. It has a guided sliding button 30, which at its end facing the shaft 10 has a locking projection 3.
One. A return spring 32 is associated with the sliding button 30 and is supported at one end by the sliding button 30 and at the other end by the casing 11, for radial inward movement of the sliding button 30. Sometimes austere.

The second lock member 13 is fixed to the shaft 10 via the keyway / coupling member 33 so as to be non-rotatable and movable in the axial direction. In this case, the axial movement is performed against the spring force of the return spring 34, and the return spring 34
The spring axis is supported between the second lock member 13 and the casing 11 with the spring axis oriented parallel to the axis 10. Second
In the axial section of the lock member 13, locking grooves 35 uniformly distributed in the circumferential direction are arranged, and the locking grooves 35 correspond to the locking projections 31 of the sliding button 30. ing.

At the basic position of the second lock member 13 on the shaft 10, since the locking groove 35 is located in the movement trajectory of the locking projection 31, the sliding button 30 is provided in the casing 11.
Is pressed by hand against the spring force of the return spring 32, the locking projection 31 is engaged with one of the locking grooves 35 in the circumferential direction by shape coupling, and thus the second lock member 13 and the shaft. 10 is fixed to the casing 11 so that it cannot rotate.

When the shaft 10 rotates, the two lock members 1
In the present embodiment, the separating member for forcibly separating the lock members 2 and 13 includes a pin 36 corresponding to the first lock member 12 and a shaft provided with the wave profile 38 formed on the second lock member 13. Section 37 is provided. Pin 3
6 protrudes from the locking projection 31 in the radial direction with respect to the shaft 10 under the spring force of the pressure spring 39 which is movably guided within the sliding button 30 and presses the pin 36 against the stopper 301 of the sliding button 30. It reaches the shaft section 37 at a slight radial distance. Therefore, when the sliding button 30 is pushed into the casing 11,
The pin 36 engages with the wave profile 38 much earlier than the engagement protrusion 31 engages with the engagement groove 35.

The wave profile 38 is formed as follows, ie, the pin 36 which is protruded when the shaft 10 rotates rotates the second lock member 13 against the spring force of the return spring 34. The locking groove 35 is located outside the movement trajectory of the locking projection 31, so that the locking projection 31 engages in the locking groove 35 at the end of the inward movement of the slide button 30 to cause locking. Not so formed.

For this purpose, in particular, the wave profile 38 having the peaks 381 and the valleys 382 is provided in the shaft section 37 of the second locking member 13 such that the peaks 381 are formed on the annular end 371 of the shaft section 37. Is cut so as to be on the same plane as
Is rotated, and rides on the end 371 and contacts the end 371 on the peripheral surface and thereby the second locking member 1
3 so as to move against the spring force of the return spring 34,
It engages behind the shaft section 37.

In order to obtain a sufficient amount of movement of the second lock member 13, the depth of the wave profile 38, that is, the distance between the peak 381 and the valley 382 is determined from the movement trajectory of the locking projection 31. The second necessary for guiding the retaining groove 35 away from the
Is slightly larger than the moving distance of the lock member 13.

When the shaft 10 is stopped, the pin 36
Also strikes the wave profile 38 during the inward movement of the sliding button 30. If the pin 36 cannot enter the intermediate space of the wave profile 38, the pin 3
6 moves inward against the spring force of the compression spring 39 of the sliding button 30, the movement of the sliding button 30 is such that the locking projection 31 projects into the locking groove 35, and consequently the shaft 10 is moved. Continue until locked.

In the third embodiment of the locking device shown in FIG. 5, a second locking member 1 which is non-rotatably arranged on a shaft 10 is shown.
3 has two externally engaging teeth 40 and the first locking member 12 has two correspondingly configured shut-off levers 41 rotatably mounted on the casing 11.
1 engages with the externally meshing teeth 40 by means of the locking projections 42 and thus makes the second lock member 13 unrotatable.
Fix to 1. Each breaking lever 41 has a breaking lever 41
The engaging projection 42 is always inserted into the tooth space of the outer meshing tooth 40 by receiving the spring force of the leg spring 43 because the leg spring 43 is loaded in the engaging direction.

When the shaft 10 rotates, the two lock members 1
In the present embodiment, the separating member for forcibly separating 2 and 13 has two electromagnets 44, and each electromagnet 44 is arranged corresponding to one shut-off lever 41. When the exciting coil 45 of the electromagnet 44 is energized, the correspondingly arranged shut-off lever 41 is pulled and turned. In this case, the locking projection 42 is lifted from the external meshing tooth 40.

The electronic control mechanism 46 for reducing the on / off state of the switch for the drive unit of the shaft 10, that is, for detecting the on / off state of the electric motor in the case of the electric hand-held machine tool, uses the switch for the drive unit for the shaft 10. By closing, the excitation coils 45 of the both electromagnets 44 are energized, and the locking projections 42 lifted from the external meshing teeth 40 to separate the two lock members 12, 13 locked to each other in the electromagnet non-energized state.
This is used to rotate the shaft 10 without hindrance.

In the simple construction of the locking device shown in FIG. 5, one of the two shut-off levers 41 and the electromagnet 44 are omitted.

In a fourth embodiment of the locking device, shown in cross-section in FIG. 6, the second locking member 13 has an outer meshing tooth 50, while the first locking member has Member 12
Is a shut-off lever 51 provided with a locking projection 52 rotatably supported in the casing 11 and a slide which is movably supported by the casing 11 and which can be moved manually (by hand) into the casing 11. Operation button 53.

A spring with a leg 54 acts on the shut-off lever 51. The spring with the leg 54 loads the shut-off lever 51 in the counterclockwise direction as viewed in FIG.
To the sliding button 53. When the sliding button 53 is not operated, the sliding button 53 comes into contact with the inner wall of the casing 11 toward the stopper 111 by the preloaded shut-off lever 51. In this position, the locking projection 52 of the shut-off lever 51 is pushed out of the outer meshing teeth 50 of the second locking member 13 and is again moved to the locking position shown in FIG. In this position, the two locking members 12, 13 are non-rotatably connected to each other.

When the shaft 10 rotates, the two lock members 1
The separating member which causes the forced separation of the two, 13 is a cam disk 55 with a radially projecting projection 56 for engaging the shaft 10 by frictional coupling,
And a lifting cam 57 formed on the shut-off lever 51 on the lower side. The lifting cam 57 cooperates with the projection 56 and is limited by a stop 58 for the projection 56.

The lifting cam 57 has a cosine-shaped cam section 571. The distance between the cam section 571 and the projection 56 is such that when the projection 56 occupies the lowest section of the cam section 571, the shut-off lever 51 is closed. The locking projection 52 is designed to be able to protrude into the external meshing tooth 40 (see FIG. 6) and to be pushed out of the external meshing tooth 50 when the projection 56 occupies the highest section.

The stopper 58 is arranged at the end of the highest section of the cam section 571 when viewed in the rotation direction of the projection 56.
The direction of rotation of the shaft 10 is indicated by the arrow 59. In this case, the projection 56 of the cam disk 55 is
2 and the stopper 58.

When the shaft 10 rotates, the operator turns the shut-off lever 51 inwardly through the slide button 53, so that the locking projection 52 reaches the vicinity of the outer meshing teeth 50. When the projection 56 rotates along the lifting cam 57, the shut-off lever 51 is locked. in this case,
Since the projection 56 comes into contact with the stopper 58 after the specified rotation, and the cam disk 55 slips along the shaft 10,
When 0 rotates, the protrusion of the locking projection 52 into the outer meshing tooth 50 is prevented.

When the shaft 10 is stopped, the operator can slightly turn the shaft 10 by hand,
The cam disc 55 releases the shut-off lever 51 again and the shaft 10 can be locked by pressing the sliding button 53.

[Brief description of the drawings]

FIG. 1 is a partial sectional view of the device for locking a shaft rotatably mounted in a casing, taken along the line II in FIG. 2;

FIG. 2 is a sectional view taken along the line II-II of FIG. 2;

FIG. 3 shows a second embodiment of the locking device, corresponding to FIG.

FIG. 4 is a sectional view taken along the line IV-IV in FIG. 3;

FIG. 5 is a partial cross-sectional view of a third embodiment of the locking device.

FIG. 6 is a partial cross-sectional view of a fourth embodiment of the locking device.

[Explanation of symbols]

 10 shaft 11 casing 12, 13 locking member 14 locking ring 15, 19 locking body 16 operating member 17 guide projection 18 guide rail 20 transmission ring 21 pressing spring 22, 23 recess 24, 30, 53 sliding button 25 slides Wedge 26 Wedge surface 27 Slope 28, 32, 34 Return spring 31, 52 Locking projection 33 Keyway / coupling member 35 Locking groove 36 Pin 37 Shaft section 38 Wave profile 39 Crimping spring 40, 50 External meshing tooth 51 Shut-off lever 52 locking projection 54 spring with leg 55 cam disk 56 projection 57 lifting cam 58 stopper

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Robert Gin Switzerland Ekingen Bergstraße 4 (72) Inventor Stephan Keller Switzerland Solothurn Derenweg 10 (72) Inventor Matthias Winter Switzerland Zuffville Amselweg 50

Claims (17)

[Claims] 1. A device for locking a tool spindle rotatably mounted in a casing (11), in particular a tool spindle of an electric hand-held machine tool such as a hand-held drill machine, an accumulator screwdriver or the like. There is provided two lock members (12, 13) that can be engaged with each other, and a first lock member (12) of the lock members is non-rotatably disposed in the casing (11). In a type in which the second lock member (13) is non-rotatably disposed on the shaft (10), when the shaft (10) rotates, the two lock members (12, 13) are forcibly separated. A device for locking a shaft, characterized in that a separating member is provided for producing the shaft. 2. The first locking member (12) is connected to a shaft (1).
A locking ring (14) movably guided in the casing (11) surrounding the 0) and an operating member (16) projecting from the casing (11) for moving the locking ring (14). Having said locking ring (14)
A locking body (15) is formed on one of the ring surfaces,
A second locking member (13) supports a locking body (19) corresponding to the locking body (15) of the locking ring (14) on the end face facing the locking ring (14), and separates. 2. The device as claimed in claim 1, wherein the member is formed by a torque release means provided between the stops (15, 19). 3. An operating member (16) acting on a transmission ring (20) loosely engaging the shaft (10), wherein the shaft is located between the transmission ring (20) and the locking ring (14). 3. The device according to claim 2, wherein a pressure spring having a spring axis oriented parallel to the axis is supported. 4. A torque release means comprising: a locking member (15, 1);
4. The device according to claim 3, wherein the device is adjustable by the shaping of (9) and the hardness of the pressure spring (21). 5. The operating member (16) has a sliding button (24) movably guided to a casing (11) in a radial direction with respect to a shaft (10), wherein the sliding button is provided. In the moving direction, a sliding wedge (25) fork-like engaging with the shaft (10) is continued integrally, and the wedge surface (26) of the sliding wedge is aligned with the axis of the sliding button (24). , The wedge surface (2) during the inward movement of the axial slide button (24).
5. The device according to claim 3, wherein 6) is configured to cause a movement of the transmission ring (20) and the locking ring (14) towards the second locking member (13). 6. The transmission ring (20) is provided with a sliding wedge (2).
5) The wedge surface (2) of the sliding wedge (25)
6. The device according to claim 5, wherein the device has a slope parallel to (6). 7. The first locking member (12) includes a shaft (1).
0), a manually operated sliding button (3) guided movably in the casing (11) in the radial direction with respect to
0), wherein the sliding button has a locking projection (31) which can be inserted into a groove (35) formed in the circumferential direction of the second locking member (13) on the end face facing the shaft. ), Wherein the second lock member (13) is disposed so as to be axially movable on the shaft (10), and the separation member is disposed corresponding to the first lock member (12). A spring-loaded pin (36) movably guided in a sliding button (30) in the direction of movement of the locking member, said pin being mounted on a shaft (1).
0) protruding from the sliding button (30) in a radial direction with respect to the second locking member (1).
3) having a shaft section (37) formed in
The wave profile (38) of the shaft section is such that a pin (36) which projects radially into the shaft section (37) during rotation of the shaft moves the second locking member (13) against the spring force, The locking groove (35) is formed by the locking projection (3).
The device according to claim 1, wherein the device is formed so as to be located outside the movement trajectory of (1). 8. A peak (3) of a wave profile (38).
81) is an annular end surface (371) of the shaft section (37).
So that the pin (36) rides on and engages behind the end face (371) of the shaft section (37) during rotation of the shaft,
The device according to claim 7. 9. The depth of the wave profile (38) in the axial direction is changed from the movement trajectory of the locking projection (31) to the locking groove (3).
5) A second lock member (1
9. The moving distance is designed to be larger than the moving distance of 3).
The described device. 10. A second locking member (13) having a pressure spring (34) at the end face opposite the shaft section (37).
10. The device according to claim 7, wherein the device is supported on the housing via a housing. 11. A pin (36) projecting from the slide button (30) is provided by a crimp spring (39) with at least one stopper (30) formed on the slide button (30).
1), and the moving distance of the pin (36) against the pressure spring (39) is longer than the moving distance of the locking projection (31) until it protrudes into the locking groove (35). Any one of claims 7 to 10 wherein
Item. 12. A return spring (28; 32) is assigned to the slide button (24; 30), and said return spring is
12. A sliding button (24; 30) and a casing (11) supported on the sliding button (24; 30) and capable of contracting upon radial inward movement of the sliding button (24; 30). The described device. 13. The first locking member (12), wherein the second locking member (13) has external meshing teeth (40).
Has at least one shut-off lever (41) pivotally supported by the casing (11), which is engaged in the outer meshing tooth (40) by the locking projection (42) under spring force. The separating member comprises an electromagnet (44) that is excited during rotation of the shaft, lifting the at least one shut-off lever (41) from the external meshing teeth (40).
The described device. 14. Apparatus according to claim 13, wherein the shaft (10) is adapted to be driven by an electric motor, and the exciting coil (45) of the electromagnet (44) is connected to an intermittent switch of the electric motor. . 15. The first locking member (12), wherein the second locking member (13) has external meshing teeth (50).
Is a sliding button (5) protruding from the casing (11).
3), the externally meshing teeth (5)
0) is configured as a shut-off lever (51) which can be pushed into the housing, the shut-off lever being pivotably mounted on the casing (11), and the separating member being engaged with the shaft (10) by frictional coupling. Projections (5
6) a cam disk (55), and a shut-off lever (5).
1) a lifting cam (57) cooperating with the projection (56) formed on the projection (56).
2. The device according to claim 1, wherein the device is limited by a stop for use. 16. The lifting cam (57) has a cosine-shaped cam section (571), and the distance between the cam section (56) of the cam disk (55) and the projection (56) is equal to that of the projection (5).
When 6) occupies the lowest section of the cam section (571), the locking projection (52) of the shut-off lever (51) is engaged with the external meshing teeth (4).
0) and is designed to be pushed out of the external meshing tooth (50) when the projection (56) occupies the highest section, the stop (58) being arranged in the direction of rotation of the projection (56). 16. The device according to claim 15, wherein the device is located immediately after the highest section of the cam section (571) as viewed in (59). 17. A spring, preferably formed as a leg spring (54), acts on the shut-off lever (51),
The spring connects the shut-off lever (51) to the second locking member (1).
Apparatus according to claim 15 or 16, wherein the load is applied in the lifting direction of the locking projection (52) from the external meshing tooth (50) of 3).