Central locking system for door and lid fastenings of a motor vehicle

• US 4,848,509 A
• Filed: 08/29/1988
• Issued: 07/18/1989
• Est. Priority Date: 08/27/1987
• Status: Expired due to Fees

• Current Assignee: Daimler-Benz AG (Mercedes-Benz Group AG)
• Original Assignee: Daimler-Benz AG (Mercedes-Benz Group AG)
• Inventors: Fischer, Helmut, Weikert, Gunther, Deischl, Hans, Bruhnke, Ulrich, Schumacher, Josef, Feichtiger, Dieter, Korber, Jurgen, Claar, Klaus, Jobmann, Ingo
• Primary Examiner(s): Bertsch, Richard A.
• Application Number:
  US07/237,335
• Time in Patent Office: 323 Days
• Field of Search: 180/287, 123/198 B, 307/10 AT, 340/63, 340/64, 70/237, 70/264
• US Class Current: 180/287
• CPC Class Codes: E05B 77/50 by pneumatic or hydraulic means
• CPC Class Codes: Y10T 70/5889 For automotive vehicles

Abstract

A central locking system for motor vehicles, not only doors and tailgate and gas tank-cap lids, but also several flaps of containers arranged in the passenger space (gloveboxes, small luggage compartments). These locks can be released and locked jointly by a unitary switch signal, or for specific conditions, both the doors and lids and the flaps can respectively be locked and released separately in groups.

Claims

1. Central locking system for door and lid fastenings of a motor vehicle which are releasable and lockable by power-operated actuating elements, comprising:

multi-point operation of an electrical central control circuit, operating the actuating elements at least indirectly

(a) from outside by key actuation of first closing points located on doors and equipped with an identification means for key recognition and for generating a key recognition signal, and

(b) from inside by manual actuation of handles, arranged in the passenger space of the motor vehicle and belonging to the door fastenings, by first control switch means coupled to the first closing points and to the handles;

a change-over means connected between the central control circuit and at least one actuating element, for changing over when a key recognition signal is present and in a specific switch position, for isolating each following actuating element from the central control circuit;

a glovebox flap fastening lockable by the central locking system;

second closing point in the passenger space and to be brought into a released and a locked closing position by key actuation and coupled mechanically to a bistable second control switch means for operating the central control circuit and for changing over the change-over means controlled electrically by the central control circuit;

flap fastening actuating element assigned to the glovebox flap fastening and to flap fastenings of several containers accessible from the passenger space;

said change-over means being connected both between the door fastening and lid fastening actuating elements and the central control circuit and between the flap fastening actuating elements and the central control circuit;

in the locked closing position of the second closing point, the second control switch means applies a blocking signal to the central control circuit, and in response to the said blocking signal, said central control circuit prevents change-over of the Change-over means to a switch position connecting the flap fastening actuating elements to the central control circuit until the second closing point is in said released position;

in response to key actuating of the second closing point, said central control circuit changes-over the change-over means, at least for a set time, to the switch position isolating the door fastening and lid fastening actuating elements from the central control circuit and connecting the flap fastening actuating elements to the central control circuit to allow separate operation of the flap fastening actuating elements by the central control circuit;

said central control circuit, only when there is simultaneous key actuation of one of the first closing points and of released closing position of said second closing point, changes over the change-over means for a set time in response to the key recognition signal fed from the identification means to the central control circuit, to allow joint operation of the door fastening and lid fastening actuating elements, and of the flap fastening actuating elements by the central control circuit.

2. Central locking system according to claim 1, wherein:

said first closing points are actuated both by a master key and by a secondary key;

said identification means generates the key recognition signal when either key is used;

the central control circuit includes a storage circuit connected to the identification means, for assuming a setting state in response to a locking signal from one of the first control switch means, and allowing renewed operation of the central control unit only as a result of key actuating of one of the first closing points with the effect of release, the storage circuit being reset at the same time as the renewed operation, and said second closing point can be actuated only by said master key.

3. Central locking system according to claim 2:

including a third closing point actuated only by said master key and is on the tailgate lid of the vehicle and a third control switch at said third closing point for operating the central control circuit, both the third control switch and each of the first control switches being connected respectively to a terminal of the central control circuit, and

wherein the central control circuit includes logic means for activating the change-over means either for simultaneous occurrence of the key recognition signal from the identification means and release signals from the first control switches or for signals from the third control switch.

4. Central locking system according to claim 1:

including a dual pressure pump driven by an electric motor and with actuating elements operably fluid overpressure and fluid underpressure;

wherein said change-over means includes 3/2-way solenoid valve, to an input terminal of which is connected a delivery outlet of the dual pressure pump and which alternately connects to the delivery outlet of the dual pressure pump an external delivery line branch, to which the door fastening and lid fastening actuating elements are connected, and an internal delivery line branch, to which the flap fastening actuating elements are connected.

5. Central locking system according to claim 4, wherein the 3/2-way solenoid valve includes means for returning it automatically to its basic position connecting the door fastening and lid fastening actuating elements to the central control circuit.

6. Central locking system according to claim 4, including a pressure sensitive or underpressure sensitive switch device in each of the two delivery line branches, connected electrically to the central control circuit and feeds a threshold value switch signal to the central control circuit at a specific pressure level or underpressure level present in the respective delivery line branch, the pressure or underpressure level being set so that all the actuating elements connected to the respective delivery line branch have safely been actuated before this pressure level or underpressure level is reached;

and

said control circuit being responsive to said threshold value switch signal such that (a) when there is joint operation of all the actuating elements, a first threshold value switch signal causes a change-over of the change-over means, with the dual pressure pump continuing to run, and a second threshold value switch signal causes the final switch-off of the electric motor or of the dual pressure pump; and

(b) when there is separate operation of the actuating elements connected to a delivery line branch, the threshold value signal of the respective switch device causes the final switch-off of the electric motor.

7. Central locking system according to claim 4:

including an individual pressure sensitive or underpressure sensitive switch device fluidically between the dual pressure pump and the 3/2-way solenoid valve for feeding threshold value switch signals to the central control circuit, and

wherein said central control circuit being responsive to said threshold value switch signal such that (a) when there is joint operation of all the actuating elements, a first threshold value switch signal from the switch device, responding respectively later than the actuating elements, causes a change-over of the 3/2-way solenoid valve, with the dual pressure pump continuing to run, and a second threshold value switch signal causes the final switch-off of the electric motor or of the dual pressure pump; and

(b) when there is separate operation of the actuating elements connected to a delivery line branch, the first threshold value switch signal from the switch device causes the final switch-off of the electric motor.

8. Central locking system according to claim 1, wherein the change-over means includes two change-over elements which are electrically switchable independently of one another, one change-over element is in a connecting branch between the central control circuit and the door fastening and lid fastening actuating elements and the other change-over element is in a connecting branch between the central control circuit and the flap fastening actuating elements.

9. Central locking system according to claim 1, wherein:

first closing points are actuated both by a master key and by a secondary key;

the key recognition signal is generated by the identification means only when the master key is used;

the second closing point is actuated only by the master key, whereby after the central locking of the vehicle from one of the first closing points by the master key, even in a released switch position of the second closing point it is not possible for a holder of a secondary key to release the centrally locked flap fastenings.