DE9421613U1 - Helical gear - Google Patents

Description

PATENT ATTORNEY ·" _L _ _u i 199-17

DiPL-ING. JM LEMKE '™ . &eegr;&kgr; **. *-

SCHMEDSTRASSEI.HAUSEN ^mico Society for

\ mSS p£!?!? _M Industrien Automation mbH

^x (08237)1005 D-73037 Goeppingen

FAX (08237)5787

23 January 1996

Spur gear

The innovation concerns a spur gear for adjusting windows, seats or the like, in particular in vehicles.

Such a spur gear is required to be as efficient as possible in order to achieve good operating comfort or, if driven by electric motors, to achieve the lowest possible energy consumption. On the other hand, one would like to prevent a window, seat or similar from being adjusted or displaced when force is applied to it, i.e. a blockage should occur when pressure is applied to the window (for example during a break-in attempt), especially in a motor vehicle, or when force is applied to the seat.

According to the innovation, this task is solved by a spur gear with a drive gear and an output gear, each of which has a helical gear with different pitch angles a and b, which are dimensioned in such a way that when an attempt is made to drive via the output gear, self-locking occurs, as a rotary drive

for adjusting windows, seats, etc.,
especially of vehicles.

Self-locking spur gears are well known.
Advantageously, both gears have an opposite
Helical gearing (heraldic gearing) which is dimensioned in such a way that an axial load for the respective connecting part (cable reel,
racks, swivel mechanisms, etc.) is avoided.

When used as a window regulator in a motor vehicle, the drive gear is conveniently driven by a crank or a
Electric motor driven, while the output gear is usually connected to a rope reel or other

Other possible output-side actuation mechanisms have already been mentioned,
although not exhaustive.

The innovation is illustrated below with reference to the drawing
illustrated preferred embodiments are explained in more detail.

It shows:

Fig. 1 shows a first embodiment of an innovative
Rotary drive with a rope drum output in oblique view;

Fig. 2 a second embodiment with a spindle output in
Very clear;

Fig. 3 shows a third embodiment with a rack and pinion output, also in oblique view.

In the first embodiment according to Fig. 1, the gear is mounted on a carrier plate 1. A torque can be introduced via a crank 2 or an electric motor (not shown), which drives a drive gear 4 via a shaft 3. This drive gear 4 drives an output gear 5 via a toothing 7. A cable drum 6 is flanged to the output gear 5, on which a wire rope, for example, can be wound.

If a torque is exerted on the driven gear 5 by pressure on, for example, a window (not shown) via a mechanism (not shown in detail here), in the present case for example via a cable (not shown) engaging the cable drum 6, the toothing 7 between the driven gear 5 and the drive gear 4 self-locks. The desired effect, namely high efficiency when driven via the crank 2 on the one hand and self-locking, i.e. blocking when attempting to drive backwards via the cable drum 6 on the other hand, is achieved by different helix or pitch angles a on the drive gear 4 on the one hand and b on the driven gear 5 on the other. Other elements for braking, blocking or maintaining position can be omitted by the innovative use of a self-locking spur gear for a window lifter or the like according to the design shown.

By designing the gearing 7 as counter-rotating helical gearing (heraldic gearing) and dimensioning accordingly, the axial forces arising in the gearing cancel each other out. Axial loads for the gears connected to the gearbox

subsequent parts are thereby avoided.

In the embodiment according to Fig. 2, a threaded rod 8, for example a trapezoidal thread spindle or a ball screw spindle, is connected as the output-side actuating mechanism instead of the cable drum 6. This embodiment could be used, for example, for a car seat adjustment.

In the embodiment according to Fig. 3, which is also intended for seat adjustment, the output element is formed by a rack 9, which is ultimately nothing other than the circumferential section of a fictitious output gear (see the output gear 5 in the embodiment according to Fig. 1) with an infinite diameter.

Claims (5)

Expectations 1. Spur gear with a drive gear (4) and an output gear (5), each having helical gearing with different pitch angles (a) and (b) which are dimensioned such that when an attempt is made to drive via the output gear (5), self-locking occurs, characterized by the design as a rotary drive for adjusting windows, seats or the like, in particular of vehicles. 2. Spur gear according to claim 1, characterized in that both gears (4, 5) have opposing helical teeth in the form of a herringbone toothing (7) with a dimension that avoids axial loading for the respective connecting part. 3. Spur gear according to claim 1 or 2, characterized in that the drive gear (4) is driven by a crank (2) and the driven gear (5) is clamped coaxially to a cable drum (6). 4. Spur gear according to claim 1 or 2, characterized in that the drive gear (4) is driven by a crank (2) and the driven gear (5) is clamped coaxially to a threaded rod (8). 5. Spur gear according to claim 1 or 2, characterized in that the drive gear (4) is driven by a crank (2) and the driven gear (5) is replaced by a threaded rod (9).