EP2464806B1 - Gear mechanism - Google Patents

Description

The invention relates to a transmission according to the preamble of claim 1.

Such a transmission is through the DE 1 876 411 A1 known. There external attacks are preferably carried out in the form of spindle locks. They are used for one or both sides limiting the path of a Sonnenschutzbehangs, such as a blind or the like.

These blinds locknuts are located in the blinds upper box and generally consist of a threaded hollow spindle, on which a running nut runs, which prevents a co-rotation of the running nut by a positive connection to the blinds top box, but allows an axial movement of the same, and from at both ends of the spindle mounted adjusting rings, against which the running nut can strike. The hollow spindle generally has an internal profile which is adapted to be driven by the turning bar of the blind. When the blind is actuated, therefore, the hollow spindle rotates, while the running nut executes only an axial movement in the direction of the adjusting rings and upon reaching the same prevents further rotational movement. Now, if the curtain, for example, completely extended, so provided for this end position collar must be installed so that the running nut in conjunction with the collar further rotation of the curtain in this direction makes impossible. The same process is now repeated after the curtain has been moved in the opposite direction, ie at the very top to the desired end position. The adjustment of the collars is done by means of screws on the collars. The adjustment of the collars is complicated both in a default setting in the factory as well as a readjustment on site and due to the sometimes poor accessibility of the blinds difficult to implement.

For hangings that are wound on winding shafts, such. As blinds, awnings, etc., is usually located at one end of the winding shaft of the drive in the form of a transmission or engine; At the other end - if necessary - the spindle lock is inserted axially into the winding shaft. The threaded spindles of such spindle locks do not rotate and at the same time serve as a bearing axis for a pipe adapter, which is firmly connected to the winding shaft. The running nut is connected to the winding shaft so that it rotates with it, whereby it is axially movable in Wckelrohr.

With a rotating winding shaft, the running nut runs, for example, in the direction of a stop fixedly connected to the threaded spindle and stops the rotational movement as soon as the running nut has reached the stop.

A disadvantage of all spindle locks is that they have to withstand considerable forces both during engine operation and during manual operation via crank, cord or bead chain, since in motors with torque deactivation the spindle locks are acted upon each time with the switch-off of the engine. In manual mode, even higher forces can occur due to incorrect operation or forcible operation. To ensure safe operation, the spindle locks must therefore be very robust and generously dimensioned; this dimensioning is associated with corresponding costs.

By the DE 43 28 698 A1 a transmission for transmitting torque in both directions of rotation of a drive member rotatably drivable on a connected to an elevator shaft of a Sonnenschutzbehangs driven member, the transmission having a switchable coupling means by which the drive connection between these members is separable in the upper or lower Behangendstellung. However, the transmission is arranged in front of the curtain, and the whole drive of the sunshade needs a lot of space in the longitudinal direction. Since the load of the gear parts is limited to the forces occurring when mounting and lowering the curtain, the gear parts can be lighter, smaller and made of weaker materials. A setting of the end positions is easily possible on site, but only because the transmission is in line with the curtain and therefore is freely accessible.

The aim of the present invention is to provide a transmission referred to in the preamble of claim 1, in which an overload is made impossible by motor or manual operation in the end positions, which can be produced inexpensively, a simple installation in the factory and before Location allows, allows a simple end position adjustment on site, an alternative operation option by simply pulling out the curtain without adjusting the end positions allows and can still be installed to save space.

These objects are achieved by the features of claim 1.

It can be seen that the invention is in any case realized when the output member as the hollow spindle is hollow and forms a unit with this at the distal end of the drive member. In this case, the housing of the drive member is connected via a first disengageable coupling with a guide tube, which carries out the rotationally fixed mounting of the running nut in that it has a longitudinal groove in which a guide web of the running nut is guided. The drive member is connected via a second disengageable clutch with a freely running in the output member and the hollow spindle drive shaft. The drive shaft is coupled at its end remote from the drive member via a slip clutch with the output member.

Further expedient and advantageous embodiments of the invention will become apparent from the dependent claims.

All gear parts except the brake coil spring of the slip clutch can be made of plastic.

According to a further embodiment of the invention, the hollow spindle has an external thread and the running nut has an internal thread.

According to a further embodiment of the invention, the hollow spindle has an internal thread and the nut has an external thread. Hollow spindle and nut preferably have a metric thread.

According to a further embodiment of the invention, the running nut on its end face on at least one stop cam, which cooperates with a stop on the end face of the driven member.

According to a further embodiment of the invention, the output member at the outer end for receiving the slip clutch on an axial recess, in which adjacent longitudinal ribs for receiving a spring end of cooperating with the drive shaft brake coil spring of the slip clutch (26) are arranged.

According to a further embodiment of the invention, the output member has on its outer circumference a geometric shape for coupling to the winding shaft, which is designed to be complementary. It can be provided in a further embodiment of the invention that the first disengageable coupling is formed by an axially or radially acting coupling.

According to a further embodiment of the invention, the first disengageable coupling is formed by means of a disc connected to the guide tube with at least one locking lug on the drive member facing side and a perforated disc connected to the housing, which provided in the vicinity of its circumference with circular and evenly distributed holes is, in which the latching nose (30) can engage.

According to a further embodiment of the invention, a tool for keeping apart the disc and the perforated disc is provided.

According to a further embodiment of the invention, the second disengageable coupling is formed by means of a coupling sleeve connected to the drive shaft with a driving inner section and a freewheel inner section and by means of a connecting rod connected to the drive member, which engages in the sections.

A further embodiment of the invention is such that the driving internal portion has a relation to the freewheel inner section reduced radius and three distributed on the inner circumference longitudinal grooves whose bottoms are on the radius of the freewheel inner section, and that the coupling rod three distributed on its circumference cam for engaging in Has longitudinal grooves.

As a result, the following simple assembly and adjustment is possible: At the assembly site in the factory in the winding shaft to which the curtain is already fully wound, the transmission with the stop device according to the invention installed in the winding shaft, that the running nut on the stop of the output member located. Upon actuation of the drive member consequently the curtain can not be extended, since the stop device is located on the one end position at the stop and would trigger the slip clutch. This ensures transport safety. The winding shaft with the curtain and the gearbox with the stop device can now be installed in the plant at the factory, packed and delivered to the construction site.

There, the entire system is mounted to the building. By a suitable actuating mechanism, the output member is released from the drive member and the system is driven by the drive member to the desired end position down. As described above, while the complete stop device rotates together with the winding shaft, so that the running nut remains at the stop and performs no axial movement.

Alternatively, the curtain can be pulled out by hand to the desired lower end position with the driven member released. Since the drive member usually has a brake in the form of a gearbox or motor, the slip clutch slips when the hangers are pulled out. The advantage of this type of adjustment is that the installer can adjust the lower limit position if no control element, such as a crank, or no electrical supply of the engine is present.

In the lower end position, the output member via the said actuating mechanism is firmly connected to the drive member. As a result, in this end position, the end stop, whereby the setting of the end position is completed. Now, if the curtain moved by means of the drive member up, the nut moves on the thread of the spindle as intended axially away from the stop.

The release and connection of the output member from the drive member can be done for example by a detachable, axially disengaged connection between the drive member and output member.

Likewise, a two-piece, fixed stop is advantageous in which the first part is fixedly connected to the drive member and the second part is rotatably mounted and releasably connected to the first part. By means of a locking member such. B. a screw, the rotational movement can be prevented or allowed.

Further, an actuating mechanism in the form of a lever, printhead or a turntable can be provided, with which an axial or radial positive connection between the first fixed part of the output member and the second rotatably mounted part of the output member axially or radially can be engaged or engaged. The disengagement movement can take place, for example, by means of a cam disk or a wedge slide or a blocking member on the actuating mechanism, which is moved against an axial spring force or radially.

• Fig. 1 eine geschnittene Gesamtdarstellung der Ausführung mit Innengewinde an der Laufmutter,
• Fig. 2 eine geschnittene Gesamtdarstellung einer alternativen Ausführung mit Außengewinde an der Laufmutter,
• Fig. 3 verschiedene Ansichten des Getriebes der Fig.1,
• Fig. 4-6 verschiedene Ansichten der Laufmutter,
• Fig. 7-9 verschiedene Ansichten des in Fig.1 verwendeten Anschlagrohrs,
• Fig. 10-12 verschiedene Ansichten der in Fig. 1 verwendeten Antriebswelle,
• Fig. 13-15 verschiedene Ansichten des in Fig.1 verwendeten Führungsrohrs,
• Fig. 16-18 verschiedene Ansichten des in Fig. 1 verwendeten Bremszylinders,
• Fig. 19-21 verschiedene Ansichten der in Fig. 1 verwendeten Bremsschraubenfeder,
• Fig. 22 Ansichten des in Fig. 1 verwendeten Antriebsglieds,
• Fig. 23 eine perspektivische Ansicht eines Getriebes gemäß der Erfindung mit einer ersten ausrückbaren Kupplung in der ausgerasteten Einstellposition,
• Fig. 24 eine perspektivische Ansicht des Getriebes der Fig. 23, in der sich die erste ausrückbare Kupplung in der eingerasteten Betriebsposition befindet,
• Fig. 25 verschiedene Ansichten der in den Figuren 23, 24 verwendeten Scheibe der ersten ausrückbaren Kupplung mit dem Führungsrohr,
• Fig. 26 verschiedene Ansichten der in den Figuren 23, 24 verwendeten Lochscheibe,
• Fig. 27 verschiedene Ansichten der Distanzlasche,
• Fig. 28 eine perspektivische Explosionsansicht des Getriebes nach den Figuren 23, 24,
• Fig. 29 eine vergrößerte, perspektivische, geschnittene Ansicht der in Fig. 28 dargestellten, zweiten ausrückbaren Kupplung in der eingerückten Position und der Antriebswelle,
• Fig. 30 eine vergrößerte, perspektivische, geschnittene Ansicht der in Fig. 28 dargestellten, zweiten ausrückbaren Kupplung in der ausgerückten Position und der Antriebswelle und
• Fig. 31 eine perspektivische, geschnittene Ansicht des Getriebes nach den Figuren 23, 24.

The invention will now be explained in more detail with reference to exemplary embodiments. Show it:

• Fig. 1 a sectional overall view of the embodiment with internal thread on the nut,
• Fig. 2 a sectional overall view of an alternative embodiment with external thread on the nut,
• Fig. 3 different views of the transmission Fig.1 .
• Fig. 4-6 different views of the running mother,
• Fig. 7-9 different views of the in Fig.1 used stop tube,
• Fig. 10-12 different views of in Fig. 1 used drive shaft,
• Fig. 13-15 different views of the in Fig.1 used guide tube,
• Fig. 16-18 different views of the in Fig. 1 used brake cylinder,
• Fig. 19-21 different views of in Fig. 1 used brake coil spring,
• Fig. 22 Views of in Fig. 1 used drive member,
• Fig. 23 a perspective view of a transmission according to the invention with a first disengageable clutch in the disengaged setting position,
• Fig. 24 a perspective view of the transmission of Fig. 23 in which the first disengageable coupling is in the engaged operating position,
• Fig. 25 different views of the in the Figures 23 . 24 used disc of the first disengageable coupling with the guide tube,
• Fig. 26 different views of the in the Figures 23 . 24 used perforated disk,
• Fig. 27 different views of the spacer flap,
• Fig. 28 an exploded perspective view of the transmission according to the Figures 23 . 24 .
• Fig. 29 an enlarged, perspective, sectional view of the in Fig. 28 illustrated, second disengageable clutch in the engaged position and the drive shaft,
• Fig. 30 an enlarged, perspective, sectional view of the in Fig. 28 illustrated, second disengageable clutch in the disengaged position and the drive shaft and
• Fig. 31 a perspective, sectional view of the transmission according to the Figures 23 . 24 ,

In Fig. 1 is a complete view of the transmission with the stop device according to the invention in a sectional view to see. A drive member 2 is rotatably connected to a drive shaft 1, whereby the rotational movement of the drive member is transmitted to the drive shaft 1. The drive shaft 1 is coupled at its end remote from the drive member 2 via a slip clutch with a stop tube 12. The slip clutch has a brake coil spring 25 which sits on a brake cylinder 19 and the spring ends are held in the output member 12 ₁ . The brake cylinder 19 is in turn seated on a first square 18 at the left end of the drive shaft 1 and is held there. The stop tube 12 receives the drive shaft 1 and consists of two pipe sections 12 ₁ and 12 _second The first pipe section takes the brake coil spring 25 is referred to as a driven member 12 ₁ , because it is coupled on its peripheral side by means of a groove 14 with the winding tube, not shown, and is provided on its the drive member 2 facing end side with a stop 11. The adjoining in the direction of the drive member 2 to the output member 12 ₁ second pipe section receives the drive shaft 1 is formed as a spindle 12 ₂ and acts on the threaded side of the spindle with a provided with an internal thread nut 3 together. When rotating the drive shaft 1, the running nut 3 moves in a corresponding axial direction to a preset stop. This axial movement of the running nut 3 is possible in that the running nut 3 has a guide web 4, which is guided in a complementary guide groove 5 of a guide tube 6 connected to the housing 2 _{1 of} the drive member 2 and thus prevented from rotating. The running nut 3 has on the drive member 2 facing away from a stop cam 10 on. If the nut 3 accumulated with its stop cam 10 on the stop 11, so in the case of a violent further operation, the brake coil spring 25, ie, that by widening the brake coil spring 25, the coupling of the drive shaft 1 with the stop tube 12 repealed and thus overloading the drive train or the blind is prevented. When using a double brake spring, as from EP 09001269 is known, a different release torque can be specified in each direction.

By combining the stop device with an overload clutch, the slip clutch 26, it is possible, defying stationary or blocked drive member 2 the curtain, z. As a roller blind to pull out by hand. By pulling the roller blind, the stop tube 12 is set in a rotary motion. The brake coil spring 25 of the slip clutch slips on the drive shaft 1, since the drive shaft 1 is blocked by the generally self-locking drive member 2. The running nut 3 still runs with you until the stop cam 10 runs onto the stop 11 and blocks the movement. It is crucial that both in the Operation by the drive member 2 as well as by a train operation of the blind the end positions are not adjusted.

In the Fig. 2 an alternative embodiment of the transmission is shown, which has the same operation as the above-described embodiment, but differs in construction. So here is the thread on the nut 3 'attached externally, while the spindle 12 ₂ ' has an internal thread.

In the Fig. 3 a first embodiment of the transmission is shown, and that shows the Fig. 3 ₁ a side view that Fig. 3 ₂ an end view of the Fig. 3 ₁ from above and Fig. 3 _3rd a longitudinal section of Fig. 3 ₁ , Here is easy to see how a locking means 7 of the guide tube 6 is connected to a receptacle 8 in the housing 2 ₁ .

In the Fig. 4-6 the running nut 3 with an internal thread 9, a guide web 4 and a stop cam 10 is shown. With its guide web 4, the running nut 3 runs in the guide groove 5 of the guide tube 6, so that a rotational movement of the running nut 3 is prevented and an axial movement is generated. The stop cam 10 collides after reaching the running path in one direction with the stop 11 of the output member 12 _first

In the Figures 7-9 is the stop tube 12 with the external thread 13 having a spindle 12 ₂ shown that is compatible with the internal thread 9 of the nut 3. Also shown is the stop 11, which collides with the stop cam 10 of the nut 3, and a cam groove 14, which is compatible with an inner rib of the winding shaft, not shown, of the curtain. In place of the driving groove 14 is also any other geometric shape, which is complementary to the winding shaft of the blind conceivable. Also shown are adjacent longitudinal ribs 16 ₁ and 16 ₂ on the inner circumference 16 of the output member 12 ₁ , which serve to receive spring ends 17,17 'of the brake coil spring 25. At 15 is a Ring paragraph of the output member 12 ₁ denotes, while 23 represents the friction clutch side.

In the Fig. 10-12 the drive shaft 1 is arranged with a arranged at the right end, first square 18 for receiving a brake cylinder 19, which is fixed by means of a Seeger ring (32), not shown in these figures at a recess 20 of the square 18. On the opposite side of the drive shaft 1, a second square 21 is arranged, which serves as a drive receiving the drive member 2. Depending on the design of the drive member 2, the second square 21 may also be formed as a hexagon or have any other shape complementary to the drive member 2. Zeichnerisch not shown is the Fixierungsart of the second square 21, which can be fixed by screwing, Verklipsen or any other conceivable attachment. A disc 22 serves as an axial fixation of the drive shaft 1 in the output member 12 _first

In the FIGS. 13-15 the guide tube 6 is shown with its locking means 7, which acts complementary to the receptacle 8 of the drive member 2. Here also the groove 5 can be seen, which serves to receive the guide web 4 of the running nut 3.

In the Figures 16-18 the brake cylinder 19 can be seen with a receiving means 24 which serves for the complementary insertion of the first square 18 of the drive shaft 1. Again, every imaginable, complementary, geometric shape can be used both in the receiving means 24 and in the first square 18.

In the Figures 19-21 the brake coil spring 25 is shown with its ends 17 and 17 ', which together with the brake cylinder 19 forms a slip clutch and thus an overload clutch.

In the FIG. 22 the drive member 2 is exemplified with its receptacle 8, which may have a different shape depending on the drive member design.

In the FIG. 23 an embodiment of the transmission is shown with a stop device according to the invention. The transmission is different from the FIGS. 1 to 22 provided with disengageable clutches on the drive side and with a driver intermediate tube 38 on the output member 121. In Fig. 23 a first disengageable coupling is shown, which consists of a fixedly connected to the guide tube 6 disc 27, which may also be a flange of this guide tube, and connected to the housing 21 perforated disc 28. The disc 27 has at least one locking lug 30 in the vicinity of its circumference on the drive member 2 side facing. The perforated disc 28 has, in the vicinity of its circumference, uniformly distributed over these holes 34 whose diameters are adapted to the diameter of the latching lug 30. The locking lug 30 can penetrate into these holes 34 and thus couple the two disks together. The Fig. 23 shows the two discs in the disengaged state, in which the end positions can be adjusted. In order to maintain the disengaged state, a tool in the form of a spacer tab 29 is used. The disengagement takes place in the example illustrated here by the disk 27 and the perforated disc 28 are pulled apart and the spacer plate 29 is pushed therebetween to fix this position.

Not shown here are further, advantageous embodiments of the invention for disengaging and fixing the disc 27 on the perforated disc 28 by, for example, the position is fixed by means of a tension spring or a kind of bayonet lock or by a fixed clamping lever.

In a further advantageous, not shown embodiment of the invention, the locking lugs 30 on the disc 27 in favor of the circumference radially arranged recesses and projections in the manner of a spur toothing omitted. The perforated disc 28 has for this purpose the at least partially complementary radial counter contour in the manner of a ring gear, wherein the holes 34 can be omitted. This creates an axially removable and engageable coupling, with radially acting toothing.

As a further advantageous embodiment, not shown, the perforated disc eliminates 28 in favor of a fixed to the drive member 2 associated receptacle, which has a radially engageable locking member which can be switched on and disengaged from the previously described Stirnradverzahnug 27 of the disc.

As a further advantageous embodiment, not shown, the disc 27 instead of the spur gear toothing on a cylindrical surface, against which z. B. the aforementioned locking member acts in the form of a radially acting on the lateral surface screw and thus the disc 27 sets or allows a rotational movement.

Also advantageous is an axial locking connection between the drive shaft 1 and the output member 2 of the transmission, which is dimensioned so that two defined, axial positions are obtained, corresponding to the engaged or disengaged position of the disc 27. The engagement or disengagement can be done by hand, for example, by axial displacement of the winding shaft. This solution will be described in more detail.

These mentioned, additional embodiments of this invention have the advantage that no "loose" tool as the Distanzlasche 29 is more necessary.

in the FIG. 24 is the in FIG. 23 shown clutch 27, 28 in the engaged state, so to see in the normal operating condition.

In the Figures 25-27 are the necessary items for those in the Figures 23 and 24 illustrated embodiment of the transmission shown. In Fig. 25 views of the guide tube 6 and formed as a flange 31 disc 27 are shown. In Fig. 26 views of the perforated disc 28 are shown. The perforated disc 28 carries on the drive member 2 side facing 33 two projections 35 and has a central, circular opening 37. These means serve to fix the perforated disc 28 on the housing 2 ₁ . The side facing away from the drive member of the perforated disc is designated 36. In Fig. 27 views of the spacer tab 29 are shown. The spacer tab 29 is in the form of a flat lever provided with a claw 41 having an open end 40 at one end and an eyelet 42 at the other end.

In Fig. 28 is an exploded view of the transmission after the Figures 23 . 24 shown. In addition to the first disengageable clutch 27, 28, a second disengageable clutch can be seen, which consists of a coupling sleeve 43 connected to the drive shaft 1 and a coupling rod 44 engaging in this coupling sleeve.

Enlarged views of this second disengageable clutch are in the Figures 29 and 30 shown. The coupling sleeve 43 has inner sections, namely a driving internal section 43 ₁ and a freewheel inner section 43 ₂ . The driving internal portion 43 ₁ has a relation to the freewheel inner section 43 ₂ reduced radius and three distributed on the inner circumference longitudinal grooves 45, the bottoms of which lie on the radius of the freewheel inner section 43 ₂ . The coupling rod 44 is provided with three distributed on its circumference cam 44 ₁ for engagement in the longitudinal grooves 45. In the Fig. 29 the cams 44 _{1 are} engaged in the grooves 45, while these cams in the Fig. 30 are disengaged.

In Fig. 31 Finally, the transmission according to the invention with the first disengageable clutch 27, 28 and the second disengageable clutch 43, 44 shown in section.

LIST OF REFERENCE NUMBERS

1 drive shaft 2 drive member 3 running nut 4 guide web 5 guide 6 guide tube 7 latching means 8th admission 9 inner thread 10 stop cams 11 attack 12 stop tube 12 ₁ driven member 12 ₂ spindle 13 external thread 14 drive slot 15 annular shoulder 16 inner circumference 16 ₁ longitudinal rib 16 ₂ longitudinal rib 17 spring end 17 ' spring end 18 First square 19 brake cylinder 20 puncture 21 Second square 22 disc 23 Slip clutch side 24 receiving means 25 Brake coil spring 26 slip clutch 27 disc 28 perforated disc 29 Distance tab 30 locking lug 31 flange 32 Seeger ring 33 page 34 hole 35 head Start 36 page 37 opening 38 Mitnehmerzwischenrohr 39 (empty) 40 Open end (the spacer flap) 41 claw 42 eyelet 43 coupling sleeve 43 ₁ Take inner portion 43 ₂ Freewheel inner section 44 coupling rod 44 ₁ cam 45 longitudinal groove

Claims (12)

1. A gear mechanism, having a drive member (2) and a output member (12₁), the latter disposed in the windup shaft of a sun protection awning and having a stop device which has a hollow spindle (12₂), a traveling nut (3) cooperating with the hollow spindle, and stops (10, 11) for the traveling nut,
   characterized in that

   - the output member (12₁) is embodied as hollow;

   - the housing (2₁) of the drive member (12₁) is connected via a first disengageable clutch (27, 28) to a guide tube (6), which effects the retention in a manner fixed against relative rotation of the traveling nut (3) in such a way that

   - it has a longitudinal groove (5), in which a guide rib (4) of the traveling nut (3) is guided;

   - the drive member (2) is connected via a second disengageable clutch (43, 44) to a drive shaft (1) running freely in the output member (12₁) and the hollow spindle (12₂); and

   - the drive shaft (1), on its end remote from the bg2, is coupled to the output member (12₁) via a friction clutch (26).
2. The gear mechanism according to claim 1 for transmitting torques in both directions of rotation of the rotationally drivable drive member (2) to the output member (12₁) disposed in the windup shaft of a sun protection awning, having a stop device which has a hollow spindle (12₂) solidly connected to the output member (12₁), a traveling nut (3) cooperating with the hollow spindle and retained in a manner fixed against relative rotation, and stops (10, 11) for the traveling nut,
   characterized in that
   the output member (12₁) is embodied as hollow like the hollow spindle and, on the end of the hollow spindle remote from the drive member (2), forms a unit with the hollow spindle.
3. The gear mechanism according to claim 1 or 2,
   characterized in that
   the hollow spindle (12₂) has a male thread, and the traveling nut (3) has a female thread.
4. The gear mechanism according to one of claims 1-3,
   characterized in that
   the hollow spindle (12₂') has a female thread, and the traveling nut (3)' has a male thread.
5. The gear mechanism according to one of claims 1-4,
   characterized in that
   the hollow spindle (12₂, 12₂') and the traveling nut (3, 3') have metric threads (9).
6. The gear mechanism according to one of claims 1-5
   characterized in that
   the traveling nut (3), on its face end, has at least one stop cam (10), which cooperates with a stop (11) on the face end of the output member (12₁).
7. The gear mechanism according to one of claims 1-6,
   characterized in that
   the output member (12₁), on the outer end, for receiving the friction clutch (26), has an axial recess (16) in which longitudinal ribs (16₁, 16₂) located side by side are disposed, for receiving one end of a helical brake spring (25), cooperating with the drive shaft (1), of the friction clutch (26).
8. The gear mechanism according to one of claims 1-7,
   characterized in that
   the output member (12₁), on its outer circumference, has a geometrical shape (14) for coupling to the windup shaft, which shape is embodied in complementary fashion for that purpose.
9. The gear mechanism according to one of claims 1-8,
   characterized in that
   the first disengageable clutch is formed by means of a disk (27) connected to the guide tube (6) and having at least one detent lug (30) on the side toward the drive member (2), and by means of a perforated disk (28) connected to the housing (2₁), which perforated disk is provided in the vicinity of its circumference with circularly and uniformly distributed holes (34) which the detent lug (30) can engage.
10. The gear mechanism according to claim 9,
    characterized in that
    a tool (29) for keeping the disk (27) and the perforated disk (28) apart is provided.
11. The gear mechanism according to one of claims 1-10,
    characterized in that
    the second disengageable clutch is formed by means of a coupling sleeve (43), connected to the drive shaft (1) and having an inner slaving portion (43₁) and an inner freewheeling portion (43₂), and by means of a coupling rod (44) which is connected to the drive member (2) and engages the portions (43₁, 43₂).
12. The gear mechanism according to claim 11,
    characterized in that
    the inner slaving portion (43₁) has a reduced radius compared to the inner freewheeling portion (43₂) and has three longitudinal grooves (45) distributed on the inner circumference, the bottoms of which grooves are located on the radius of the inner freewheeling portion (43₂); and that the coupling rod (44) has three cams (44₁), distributed over its circumference, for engagement with the longitudinal grooves (45).

Images