EP1260322A1 - Angle type power nutrunner - Google Patents

Abstract

The invention relates to a power-driven angle screwdriver (10) with a housing (11) comprising a main housing part (12), in which a drive (32), a reduction gear (38) coupled to it and a spindle (40) driven thereby are accommodated, and with an angular head (20) which has a tool spindle (44) driven by the spindle (40) and arranged at an angle thereto for driving a tool and an angular head housing (19) which can be adjusted in angle with the main housing part (12) via an adjusting device (58) connected is. It is proposed that the reduction gear (38) has a reaction part (70) which receives a reaction torque with respect to the spindle (40), which is connected to the angular head housing (19) in a rotationally fixed manner and is coupled to the drive (32) via the adjusting device (58) (Fig. 2).

Description

The invention relates to a power-driven angle screwdriver with a housing comprising a main housing part in which a Drive, a reduction gear and a coupled driven spindle are accommodated, and with an angular head, the one driven by the spindle and angled to it arranged tool spindle for driving a tool and a Includes angular head housing, which with the main housing part an adjusting device is connected in an angularly adjustable manner.

Such an angle screwdriver is known from EP 691 185 A1.

Angle screwdriver with a rotatable angle head, in which one Tool spindle for driving a tool at an angle to one is arranged by a gear driven spindle compared to conventional power-driven screwdrivers, their Tool holder arranged directly on the spindle and thus is aligned in the longitudinal direction of the screwdriver, several Benefits. On the one hand, the angular head can be rotated different operating positions, which in particular often more ergonomic work in tight spaces becomes possible. Above all, however, that leads to the screwdriver Reaction moment when screwing in and loosening screws not to twist the screwdriver around its longitudinal axis, but to pivot the screwdriver around the angularly arranged Tool spindle axis. Such pivotal movements are much easier to pick up by an operator as rotations of the screwdriver around its longitudinal axis.

The angle screwdriver designed as a so-called rod angle screwdriver, which is known from EP 691 185 A1 mentioned at the outset a rotatable angle head, which is connected by a screw connected to a main housing part of the angle screwdriver is. A drive and a reduction gear are in the main housing part of the angle screwdriver fixed in a rotationally fixed manner. The Screw connection, which is located directly at the transition between the angle head and the main housing part is located secured against unintentional rotation by means of a lock nut. Because when operating the angle screwdriver between the angle head and relatively large torques occur to the main housing part, is a lock as an additional anti-twist device provided with the help of a locking pin. In a locking position the locking pin extends through holes in the Angle head and the main housing part in the area of the screw connection run in the radial direction and by mutual Twisting are brought into congruence. In this way, the Angular head in several positions so that it rotates relative to the Main housing part to be locked that during operation the angle screwdriver whose angle head is not inadvertently can adjust.

The object of the invention is an angled screwdriver of the beginning mentioned type to improve such that the rotatability between the angle head and the main housing part on constructive simpler and therefore cheaper way becomes.

The invention solves this problem with an angle screwdriver type mentioned in that the reduction gear a reaction part receiving a reaction torque with respect to the spindle has that rotatably with the angle head housing connected and coupled to the drive via the adjusting device is.

The non-rotatable connection of the reaction part to the angle head housing with simultaneous coupling to the drive via in other words, the adjusting device means that the Even then, the reaction part is non-rotatable with the angle head housing is connected when the adjusting device is completely released and thus the angle head can be rotated relative to the main housing part is. In the known angle screwdrivers, however, is the reaction part always immediately, i.e. not about the adjustment device, rotationally fixed with the drive or one of them fixed main housing part connected. This other stipulation of the reaction part relative to the two in relation to each other adjustable parts of the angle wrench has considerable Effects on the torques when operating the right angle screwdriver between the angle head housing and the main housing part act and taken up by the adjusting device Need to become.

For the sake of explanation, let us assume that the spindle passes through a tight screw is blocked, so that the drive generated torque completely from the housing parts of the Angle screwdriver must be included. Between the drive and the reduction gear then acts on what is generated by the drive Torque, on the one hand over the intermediate one Spindle section and on the other - as a counter torque - between the housing parts that with the reaction part of the reduction gear or the drive are connected. This Torque is about the reduction factor of the reduction gear smaller than that between the reduction gear and the angle head works. This allows the Adjustment device much easier and less massive to execute than the known adjustment devices, the one adjustable connection between the reaction part of the reduction gear and manufacture the angle head housing.

Due to the comparatively low torques that the Adjustment device must be included, it is even possible during the operation of the angle screwdriver or to turn the angle head even when the screw is stuck.

On lock nuts or additional locking mechanisms can therefore be dispensed with in principle. Instead, it is enough it, the adjustment device as a simple screw connection perform. Alternatively or in addition, it is natural it is also possible to provide a locking mechanism if e.g. defined Relative positions between the angle head and the Main housing part are desired. For torque transmission reasons is not such a locking mechanism required. If nevertheless such a, known per se Locking mechanism is desired, this can also be very be simple and easy to set up since it is not worth mentioning Torques need to be recorded.

Corresponding considerations naturally also apply to angle screwdrivers, where the reaction part of the reduction gear not immediately, but via a torque limiting clutch is fixed to the angle head housing.

In an advantageous embodiment of the invention, the An angle wrench therefore has a torque limiting clutch a first and a second coupling part, which when closed Torque limiting clutch are engaged, wherein the first coupling part with the angular head housing rotatably connected and coupled to the drive via the adjusting device is, and wherein the second coupling part rotatably with the reaction part of the reduction gear is connected.

Compared to torque limiting clutches that are directly between two sections of a drive train are arranged, this has the advantage that there is no rotational movement of the two coupling parts when the torque limiting clutch is closed. This acts on the coupling parts and possibly in between arranged rolling elements no significant centrifugal forces, which lead to increased wear. Because to solve the Torque limiting clutch the two coupling parts in axial direction against one generated by a compression spring Bracing must be removed from one another, either the first or the second coupling part is axially displaceable be arranged in the housing. Mutual rotatability of the two coupling parts must also be possible one of these parts can be rotatably arranged in the housing.

In an advantageous development of this embodiment the first coupling part is displaceable in the axial direction Housing is arranged and the reaction part opposite the housing freely rotatable.

In this way, the axial displaceability and the rotatability divided into different coupling parts, whereby their definition in the housing of the angle screwdriver simplified becomes.

It is also preferred if a switch to switch off of the angle screwdriver is provided by the first Coupling part is actuated.

In this way it is prevented that the angle screwdriver is driven after loosening the torque limiting clutch continues to act on the coupling parts and thus to a continued Circulation of the at least one rolling element between the leads both coupling parts.

It is further preferred if the reaction part has one or more Ring gear receiving planetary gear of a planetary gear is.

Planetary gears are special due to their distribution of forces reliable and durable and are therefore particularly suitable for power-driven angle screwdrivers in the commercial sector.

It is understood that the above and those below Features to be explained not only in each case specified combination, but also in other combinations or can be used alone, without the scope of to leave the present invention.

Fig. 1

einen erfindungsgemäßen Winkelschrauber in einer Seitenansicht;

Fig. 2

einen vorderen Abschnitt des in Fig. 1 gezeigten Winkelschraubers, wobei durch einen Gehäuseausschnitt schematisch angedeutete Teile im Inneren des Winkelschraubers erkennbar sind;

Fig. 3

einen axialen Schnitt durch einen Abschnitt eines Antriebsstrangs des in den Fig. 1 und 2 dargestellten Winkelschraubers, in dem ein Planetenradgetriebe und eine Drehmomentbegrenzungskupplung in teilgeschnittener Darstellung erkennbar sind.

Further advantages and features of the invention result from the following description of an embodiment of the invention with reference to the drawing. In it show:

Fig. 1

a side screwdriver according to the invention;

Fig. 2

a front portion of the angle screwdriver shown in Figure 1, wherein schematically indicated parts in the interior of the angle screwdriver can be seen by a housing cutout.

Fig. 3

an axial section through a portion of a drive train of the angle screwdriver shown in FIGS. 1 and 2, in which a planetary gear and a torque limiting clutch can be seen in a partially sectioned representation.

In Fig. 1 is a so-called rod angle screwdriver according to the invention executed angle screwdriver shown in a side view and designated a total of 10. The angle screwdriver 10 has a housing 11 with a main housing part 12 on which a grip section 16 is formed. From there is a Main switch 18 can be operated conveniently by an operator. On the front end of the main housing part 12 is an angular head housing rotatable 19 attached to an angle head 20, of which perpendicular to a longitudinal axis of the angle screwdriver 10 a Tool holder 22 protrudes.

At the transition between the angle head housing 19 and the Main housing part 12 is a rotating ring 28 rotatable relative to the main housing part 12 is arranged. By brought in Slits 30, of which only the one facing the viewer in FIG. 1 a tool can be inserted into the angle screwdriver 10 be introduced with the trigger torque of the angle wrench 10 can be set in a manner to be explained in more detail can.

Fig. 2 shows a part of the angle screwdriver shown in Fig. 1 10 with partially removed housing parts. By parts of the screwdriver that can be seen through the housing opening 10 are only indicated schematically.

The angle screwdriver 10 has, for example, an electric motor executed drive 32 on the opposite to one another the main housing part 12 fixed support sleeve 34 attached is. The drive 32 drives via an intermediate shaft 36 Reduction gear in the form of a planetary gear 38 which sets a spindle 40 in rotation on the output side. The Spindle 40 drives via an arranged in the angle head 20 Bevel gear toothing 46 on a tool spindle 44 on its free end carries the tool holder 22.

2 is a torque limiting clutch 50 shown schematically, which is a reaction moment against the spindle 40 receiving reaction part of the planetary gear 38 couples with an adjusting sleeve 52. The adjusting sleeve 52 is formed in one piece with an angle head housing 19 or connected non-rotatably to it via one or more intermediate parts. To twist the angle head 20, e.g. in the in Fig. 2 position shown in dashed lines, the entire angle head 20, i.e. the angle head housing 19 with housed therein Bearings 55 and 56 for the spindles 40 and 44 and the adjusting sleeve 52, opposite the housing-fixed carrier sleeve 34 along a here twisted adjustment device 58. When the torque limiting clutch is 50 also the reaction part of the planetary gear 38 opposite the angular head 20 fixed in rotation and via the adjusting device 58 coupled to the drive 32.

This definition of the planetary gear 38 on the angle head 20 with simultaneous coupling to the drive 32 via the adjustment device 58 has compared to the conventional definition on the main housing part 12 significant advantages, such as the following considerations.

It is assumed here that the spindle 40 is fixed by a tightened screw is blocked, so that the drive 32nd Torque generated entirely by the housing parts of the angle screwdriver 10 must be included. On the intermediate shaft 36 acts between the drive 32 and the planetary gear 38 then the torque generated by the drive 32. A corresponding one Counter torque of the same size is closed - at as assumed torque limiting clutch 50 - from the housing parts, namely the support sleeve 34 and the adjusting sleeve 52 added. This torque is around the reduction factor of the Planetary gear 38 smaller than the torque that between the planetary gear 38 and the angle head housing 19th acts. The adjusting device 58 can therefore be simple Screw connection to be carried out, the additional locking mechanism can have. For torque transmission reasons such a locking mechanism is not required. If nevertheless such a locking mechanism known per se is desired, it can also be very simple and easy be built up because it only absorb small torques needs.

3 shows in an axial section details of in FIG. 2 parts shown only schematically inside the angle screwdriver 10th

On a rotor connector 60 of the drive only indicated in FIG. 3 32, an intermediate shaft 62 is rotatably pushed on in one piece with a first sun gear 64 of the two-stage design Planetary gear 38 is formed. The first sun gear 64 meshes with three first planet gears 66 a first Planetary gear stage, of which only two can be seen in Fig. 3.

The first planet gears 66 are on a first planet gear carrier 68 rotatably attached and mesh with one at the same time Ring gear 70, which extends over the entire axial length of the planetary gear 38 extends. The first planet carrier 68 is formed in one piece with a second sun gear 72 or rotatably connected, which with second planet gears 74 combs. The second planet gears 74 are in turn on one second planet carrier 76 rotatably supported and also mesh with the ring gear 70. Planetary axles 82 on which the second planet gears 74 are guided, enforce the second planet carrier 76 and form on its gearbox-facing Side socket 80. These grip the wings of a driving wheel 84 that the spindle 40 drives and axially on one of one Snap ring 85 supports ring 87. The sockets 80 and driving wheel 84 form a play clutch 86.

The ring gear 70, which is opposite the intermediate shaft 62 and the Spindle 40 takes over a reaction moment and thus the reaction part of the planetary gear 38 is over a Bearing 88 rotatable in the support sleeve screwed to the drive 32 34 and the associated via the adjusting device 58 Adjustment sleeve 52 added. The ring gear 70 is on the Adjusting sleeve 52 (or a part connected to it in a rotationally fixed manner) the torque limiting clutch 50 set. This includes a cam ring 90 screwed non-rotatably into the ring gear 70, whose shoulder 92 protrudes over the ring gear 70 is also supported on the adjusting sleeve 52 via the bearing 88, as well as a switching ring 96 which against a compression spring 94 the cam ring 90 is clamped. The switching ring 96 is axial, i.e. in the longitudinal direction 95 of the spindle 40, displaceable, however rotatably in an intermediate sleeve connected to the adjusting sleeve 52 98 added.

The non-rotatable but axially movable arrangement of the shift ring 96 is 100 using first and second longitudinal grooves or 101 achieved on a circumferential surface of the switching ring 96 or are arranged on the inside on the intermediate sleeve 98 and cooperate with guide balls 102. About that in the first and second longitudinal grooves 100 and 101 rolling guide balls 102, the switching ring 96 and the intermediate sleeve 98th are shifted towards each other in the axial direction, one in the intermediate sleeve 98 inserted snap ring 105 from falling out the guide balls 102 prevented.

On the side of the switching ring 96 facing the cam ring 90 are circumferentially three rollers 104 rotatably mounted on axes 106. The rollers 104 can roll on a cam track 108, that on an end face facing the switching ring 96 of the cam ring 90 is formed.

The compression spring 94 is supported on the back of a tensioning disk 110 from which can be moved in the axial direction in the intermediate sleeve 98 is included. Act on the spring washer 110 four clamping bolts 112 evenly distributed over the circumference, that in bores 114 that in a shoulder of the intermediate sleeve 98 are attached, are guided and on a collar Support 116. The collar 116 can be on an outside the intermediate sleeve 98 applied thread section 118 in the Shift longitudinal direction 95 by twisting. A longitudinal shift of the collar 116 on the threaded portion 118 of the Intermediate sleeve 98 is on the clamping bolt 112 and the clamping washer 110 transferred to the compression spring 94, so that on this Way the preload between the switching ring 96 and the cam ring 90 can be changed. For actuating the adjusting ring 116 a tool, e.g. a screwdriver, through through one of the slots 30 in the rotating ring 28 (see FIG. 1) one of several sockets formed on the adjusting ring 116 122 introduced. Then the collar 116 together with the rotating ring 28 until the desired one Bracing the compression spring 94 and thus the triggering moment Torque limiting clutch 50 is reached.

The rollers 104 abut while a screw is being screwed in formed on the cam track 108 so that the reaction torque exerted on the ring gear 70 via the cams, the rollers 104 and the switching ring 96 on the intermediate sleeve 98 and thereby to the adjusting sleeve 52 connected to it in a rotationally fixed manner is transmitted so that the ring gear 70 during the screwing one screw rests. If the torque increases, it grows Torque acting on the cam ring 90 until there is Finally, the cam ring 90 begins to rotate and thereby the rollers 104 and thus the switching ring 96 counter to its cams the force of the compression spring 94 increases. With further rotation the cam ring 90 then runs under with its cams the rollers 104 away, so that the rollers 104 with the Switch ring 96 finally again under the pressure of the compression spring 94 lower.

During rotation of the cam ring 90 and the associated one Ring gear 70, the planetary gear 38 is no longer rotationally fixed set so that the drive 32 on the spindle 40th applied torque is practically reduced to zero. In which Lifting the switching ring 96 against the force of the compression spring 94 the switching ring 96 triggers a switch 124 which through the Intermediate sleeve 98 in a remaining above the switching ring 96 Free space 128 protrudes. Switch 124 interrupts the power supply for the drive 32 and thus provides sure that after the triggering torque is exceeded Do not turn cam ring 90 several times under switching ring 96.

Claims (6)

Power-driven angle screwdriver (10) with a housing (11) comprising a main housing part (12), in which a drive (32), a reduction gear (38) coupled thereto and a spindle (40) driven thereby, and with an angle head (20 ) having a driven from the spindle (40) and an angle thereto disposed tool spindle (44) for driving a tool and an angle head housing (19) which is connected to the main housing part (12) via an adjusting device (58) is angularly adjustable, characterized characterized in that the reduction gear (38) has a reaction part (70) receiving a reaction torque with respect to the spindle (40), which is connected to the angular head housing (19) in a rotationally fixed manner and is coupled to the drive (32) via the adjusting device (58). Angle screwdriver according to Claim 1, characterized by a torque limiting coupling (50) which has a first (96) and a second (90) coupling part which engage when the torque limiting coupling (50) is closed, the first coupling part (96) having the angular head housing ( 19) is connected in a rotationally fixed manner and is coupled to the drive (32) via the adjusting device (58), and the second coupling part (90) is connected in a rotationally fixed manner to the reaction part (70) of the reduction gear (38). Angle screwdriver according to Claim 2, characterized in that the first coupling part (96) is arranged in the housing (11) so as to be displaceable in the axial direction (95), and in that the reaction part can be freely rotated relative to the housing (11). Angle screwdriver according to claim 3, characterized by a switch (124) for switching off the angle screwdriver (10) which can be actuated by the first coupling part (96). Angle screwdriver according to one of the preceding claims, characterized in that the reaction part is a ring gear (70) of a planetary gear (38) receiving several planet gears (66, 74). Angle screwdriver according to one of the preceding claims, characterized in that the adjusting device (58) has a latching mechanism.

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