Rotary shafts – gudgeons – housings – and flexible couplings for ro – Fluid coupling
Reexamination Certificate
1999-07-13
2001-07-17
Browne, Lynne H. (Department: 3629)
Rotary shafts, gudgeons, housings, and flexible couplings for ro
Fluid coupling
C074S411000, C192S058300
Reexamination Certificate
active
06261181
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a drive means for a motor vehicle door lock or the like, but also to a motor vehicle rear hatch lock or rear door lock or tailgate lock, with an electric motor drive, a gearing having a drive side and a driven side, an actuating lever of a lock mechanism in driven connection with the gearing.
2. Description of Related Art
The known drive means for a motor vehicle door lock or the like has a simple structure and allows simple auxiliary actuation by hand when the electric motor drive fails U.S. Pat. No. 5,240,296). In this drive means the gearing is made as a worm gear pair with a worm and worm gear, projecting eccentrically from the worm gear in the axial direction a driving lug which fits into a fork-shaped receiver of an actuating lever and overthrows it into a safety or safety-released position. The driving lug is at rest outside the fork-shaped receiver so that then the actuating lever can be moved back and forth by hand between the safety and safety-released position. When the electric motor drive fails, therefore the lock can also be moved by hand into this rest position, i.e. for example, the safety can be engaged or released proceeding from a locking cylinder.
In this prior art stops for the safety position and the safety-released position are assigned to the actuating lever. Actual activation ofthe electric motor drive takes place by microswitches, not by striking these stops.
One problem in this drive means is the failure of electricity while the electric motor drive is running. Then it can happen that the driving lug on the worm gear remains within the fork-shaped receiver, is blocked there, and thus locks the entire door lock. Usually it is not possible to build the electric motor drive such that it does not self-lock in this situation, therefore can be reset by hand when the corresponding force is applied.
If the intention is to control the electric motor drive by so-called “block operation”, i.e. by fixing the power consumption when the driving lug strikes the stop surfaces laterally from the fork-shaped receiver published German Patent Application No. 44 39 479), it is admittedly advantageous in terms of motor and control engineering, but the aforementioned problem of drive failure during operation is thus not solved. In addition, the impact when the driving lug strikes the stop surface is hard; this can lead to considerable wear and premature failure of the drive means and briefly cause the current to rise very dramatically (6 to 8 A). Making the corresponding stops elastic does not always help the situation published European Patent Application No. (0 684 356).
SUMMARY OF THE INVENTION
The object of the invention is to embody and develop a drive means of the aforementioned type such that when the current fails or the voltage drops, therefore the electric motor drive fails, and/or with high self-locking of the gearing, actuation by hand or from the outside can be done as easily and permanently reliably as possible. At the same time quiet, soft starting of the electric motor drive and contact as soft as possible in the block will be ensured when block operation is underway.
The aforementioned object is achieved in a drive means for a motor vehicle door lock or the like by a variable coupling being provided between the driven side of the gearing producing a high degree of coupling at high rpm and a low degree of coupling at low rpm, having low slip at high rpm and high slip at low rpm and being a fluid coupling with a fluid of relatively high viscosity in which a coupling part moves.
Differently than in the existing gearing of drive means of the type under consideration, there is no fixed coupling between the drive side and the driven side, but coupling which can vary in degree of coupling. Therefore, depending on the rpm the gearing has slip of varying amounts. At high rpm the slip is low, at low rpm relatively high slip can be accomplished. How high the slip is depends of course on the counterforce acting at the time. The teaching of the invention is especially important when the coupling characteristic of the coupling is independent of the direction in which the force flows.
With the teaching as claimed in the invention, auxiliary actuation of a drive means which is not a problem in any respect for a motor vehicle door lock or the like can be accomplished. When the motor, especially the electric motor drive, starts with relatively high rpm, the coupling works with a high degree of coupling and the slip of the gearing is low or almost zero. A flow of force is established from the drive side to the driven side. The actuating lever or whatever drive element which transfers the driving motion into the lock mechanism is driven as designed. If the motorized, especially the electric motor drive fails, for example the actuating lever coupled to the driven side can be slowly moved by hand, for example starting from the locking cylinder; this corresponds to a low rpm on the driven side of the gearing. The low degree of coupling which then prevails or the large slip leads to the fact that the electric motor drive can nevertheless be stationary.
Therefore emergency actuation or auxiliary actuation is accomplished in case of a current failure or a voltage drop or otherwise sluggish gearing without any problem.
Another advantage is that when the electric motor drive starts the degree of coupling rises as the rpm increases, therefore soft starting is accomplished. If control of the drive means is accomplished by “block operation”, the contact of the corresponding driving lug or the like with the stop surface is greatly damped by the aforementioned coupling characteristic and the coupling acts like a stop damper.
In the following the invention is explained using only one embodiment.
REFERENCES:
patent: 1540453 (1925-06-01), Arave
patent: 1956188 (1934-04-01), Black
patent: 2613779 (1952-10-01), Milford
patent: 3220640 (1965-11-01), Kambs
patent: 4160389 (1979-07-01), Kubono
patent: 4770055 (1988-09-01), Chevance et al.
patent: 5240296 (1993-08-01), Kobayashi
patent: 5501183 (1996-03-01), Takayama
patent: 5564308 (1996-10-01), Hoshikawa et al.
patent: 5860501 (1999-01-01), Murata
patent: 44 13 719 (1995-10-01), None
patent: 0 064 942 (1982-11-01), None
patent: 0 287 860 (1988-10-01), None
patent: 2 026 592 (1980-02-01), None
patent: WO 96 20353 (1996-07-01), None
Patent Abstracts of Japan, vol. 97, No. 7, Jul. 31, 1997 & JP 09 088395 A (Aisin Seiki Co. Ltd.) Mar. 31, 1997—See Abstract.
Reichmann Siegfried
Wolf Erwin
Browne Lynne H.
Nixon & Peabody LLP
Robert & Bosch GmbH
Safran David S.
Thompson Kenn
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