GB2174452A

GB2174452A - A locking device operating by mechanical and electrical means

Info

Publication number: GB2174452A
Application number: GB08610594A
Authority: GB
Inventors: Hans Gerd Keller; Hermann Bartels
Original assignee: Ymos AG
Current assignee: Ymos AG
Priority date: 1985-05-03
Filing date: 1986-04-30
Publication date: 1986-11-05
Also published as: GB8610594D0; DE3515888A1

Abstract

The invention relates to a locking device, more particularly applicable to automobile doors, which operates using a mechanical and electronic system and having a lock housing (5), a rotable cylinder (2) therein with pin tumblers (3) which may be moved out of locking positions by means of a key (4), and an induction element (14) connected in an electrically conducting manner with an electronic device on the vehicle for the transmission of an electromagnetic field, the key (4) having an induction element (28) electrically connected with an electronic key circuitry (29) accommodated in the key for the transmission of an electromagnetic field. The key induction element (28) is located adjacent to the tip of the key (4) and the lock induction element (14) is located in a part of the locking device adjacent to the key tip after insertion thereof. <IMAGE>

Description

SPECIFICATION A locking device operating by mechanical and electrical means The invention relates to a locking device, more particularly applicable to automobile doors, which operates using a mechanical and electronic system and having a lock housing, a rotable cylinder therein with pin tumblers which may be moved out of locking positions by means of a key. The device has an induction element connected in an electrically conducting manner with an electronic device on the vehicle for the transmission of an electromagnetic field. The key has an induction element electrically connected with an electronic key circuitry accommodated in the key for the transmission of an electromagnetic field.

Mechanical locking systems with magnetically or electrically acting components are known as such. German Patent Publication (DE-OS) 2,546,542 discloses a magnetically operating lock, more especially in the form of a cylinder lock with a combined locking system, using a key with magnetic code or information carrying means for cooperation with a magnetic reading device and with an interrogating device provided in or on the lock. The reading device or the interrogating device detected the magnetic code. The interrogating device is connected with a controller programmed to a certain key information. If there is bilateral agreement, the electromagnetic latching device is unlocked. However, if there is no agreement, the latching device is kept locked. If desired, a warning signal would be generated.In this known lock the magnetic information carried in the key is the sole magnetic control signal for the reading device and for the interrogating device. The reading device is a Hall generator which on insertion of the key into the lock is exposed to the magnetic field lines of the key information. This key information is, for example, represented by magnetically encoded information in or on the back of a flat key which along its other narrow side had conventional cuts or serrations for operation of the tumblers. The magnetic information in this prior art locking device was embodied in the form of molecular alignments so that magnetic field lines ectend both in parallel to and also normal to the axis of the key.

This conventional locking device is, however, rather sensitive. It only operates satisfactorily if there is a very narrow air gap between the Hall generators and the key back carrying the key magnetic information. Even tolerances which are normal in profile cylinders, exceed the dimensions needed for the Hall generators so that such a combination of mechanical and electromagnetic components is difficult to manufacture. Furthermore this known locking system could not be constructed for use with double-bitted or reversable keys. A lock system for motor vehicles should however permit the use of doublebitted, reversable keys.

Accordingly one object of the invention is to devise a mechanically and electronically operated locking device having, due to the use of its electronic components, a greatly increased security compared to conventional purely mechanical locks.

A further aim of the invention is to devise such a lock system that may also be used with double bitted or reversable keys.

In order to achieve these or other objects becoming apparent in the course of the following specification, the key of the invention has an induction element adjacent to its tip while the lock has an induction element placed so as to be adjacent to the key tip after the insertion thereof.

The arrangement of the one induction element adjacent to the tip of the key makes possible a highly precise correlation of the induction element in the lock within the tolerance limits that must be maintained to make sure that the induction elements transmit the electro-magnetic field in the desired form. Furthermore, the selected form of arrangement of the induction elements makes it possible to use reversable or double bitted keys, since it is only necessary for this purpose to locate the induction element at the tip of the key symmetrically to the turning axis of the key.

The position of the key induction element in relation to the induction element in the lock is then independent of the direction of insertion of the double bitted key.

Further features of the invention will appear from the specification and the claims in conjunction with the drawings.

The invention will now be described, by way example, in more detail with reference to one working example as illustrated in the accompanying drawings, wherein: Figure 1 is a block circuit diagram of the separate. components; Figure 2 shows a large scale section through parts of the lock system after insertion of the key; Figure 3 shows a section as that of Fig. 2 but after turning of the key by 90 in a counter-clockwise direction; Figure 4 is a section taken on the line IV-IV of Fig. 2; and Figure 5 is a section taken on the line V-V of Fig. 2.

A mechanical-electronic locking device 1 intended particularly for motor vehicle doors, comprises a cylinder 2, which has tumblers 3 and which is able to be turned into its unlocked position in a housing 5 by a key 4.

The tumblers 3 and the respective channels 6 in the housing 5 constitute a mechanical and well-known security device.

The end of the cylinder 2 is fixed to a driver dog 7 having an arm 8 extending through a slot 9 in a lug 10 and is acted upon by respective different limbs of a spring 13 with two limbs. This spring 13 returns the cylinder after each locking operation into its center position as indicated in Fig. 2. The lug 10 operates the locking function as is conventional.

An induction element 14 in the cylinder 2 is connected with an electronic device 15 in the vehicle, whereby for example, two conductors 16 and 17 are provided for this purpose. The device 15 is a processing circuit located in the vehicle and connected in a known way with the battery 19 of the vehicle by a conductor 18. A locking device 21 is operated through conductors 20 so that dependent on the correct key code being used, the lock not shown is locked and unlocked by turning the key 4.

The induction element 14 in the cylinder, that is to say in the vehicle, is a coil with a soft iron core and is best placed in a bushing 22. This bushing 22 is arranged in the cylinder 2 and turns with it. Preferably the bushing 22 is located in the vicinity of the end 24 of the cylinder 2 remote from the head 23 of the cylinder 2. The bushing 22 surrounds the key 4 so that the conductors 16 and 17 are able to extend out of the bushing 22 coaxially to the cylinder axis and to the axis 25 of turning of the key. The induction element 14 is arranged in the cylinder 2 and in the bushing 22 respectively in the vicinity of the key tip 26 adjacent to the keyway 27. The induction element delimits the keyway 27, which stretches from the cylinder 2 as far as the bushing 22.

The key 4 also has an induction element 28 which is also a coil with a soft iron core and is furthermore electrically connected to key circuitry 29 by two conductors 30 and 31 which run through a longitudinal hole 34 in the key 4 and its shank 32.

The induction element 14 in the cylinder and the induction element 28 in the key are so arranged that when the key is inserted as shown in Figs. 2 and 3, they are closely adjacent to each other so that there is an optimum transmission of the electromagnetic fields produced and received by the induction elements 14 and 28, respectively. The induction element 28 is therefore at the tip 26 of the key.

The induction element 28 in the key 4 is arranged in a recess 33 in the shank 32 of the key directly adjacent to the key tip 26.

This recess extends in the length direction of the key transversely through the key shank 32 and is best fashioned as a rectangular opening as shown in Fig. 2. The longitudinal hole 34 for the two conductors 30 and 31 runs from the recess 33 to the key circuitry 29 which is preferably accomodated in the head 35 of the key.

Due to the position and arrangement of the induction element 28 in the key 4 the element is centred on the longitudinal axis 25 of the key and after insertion of the key it is also centred on the cylinder axis. The function and manner of operation of the mechanical electronic lock device 1 are as follows. The cylinder induction element 14 produces an electromagnetic field which is sensed by the key induction element 28 and is transmitted to the key circuitry 29.A key code specific to the vehicle stored in the key circuitry is generated by the circuitry and then returned by the key induction element 28 to the cylinder induction element 14 and thence returned to the vehicle electronic system 15 which it leaves as an operating signal for electrically operating the locking device 21, The invariable key code will consist for instance of a sequence of voltage values, which are transmitted by the key induction element 28 to the cylinder induction element 14 and then further through one of the conductors 16 and 17 to the processing circuit of the electronic system 15 of the vehicle. Either a voltage is applied permanently to the induction element 14 or the voltage is applied only when the correct key 4 is inserted into the cylinder 2.

However in both cases it is a question of the transmission of a signal or a key-related code without galvanic contact so that a comparison and evaluation may take place for operation of the locking device.

The part 40 is a holding ring iri the way of a spring- or snap ring, grasping into grooves of the cylinder 2 and the driver dog 7 and fixing it in axial direction.

Claims

1. A locking device, comprising a body, a cylinder mounted in said body and able to be turned therein by a locking key, a first induction element located within said cylinder for the transmission of an electro-magnetic field, a second induction element forming part of said locking key, key electronic circuitry in said locking key, said second induction element being arranged adjacent a tip of said locking key and being connected with said key electronic circuitry, and wherein said first induction element is arranged so as to be adjacent said key tip when said locking key is inserted.

2. The device of claim 1, wherein said second induction element is placed so as to be symmetrical to a turning axis of said locking key.

3. The device of claim 1, wherein said second induction element is placed in a recess in a shank of said locking key.

4. The device of claim 1, installed in a motor vehicle, wherein said first induction element forming part of-an electronic system of said motor vehicle, is arranged to turn with said cylinder.

5. The device of claim 4, wherein said first induction element is placed in a bushing adjacent to a keyway in said cylinder.

6. The device of claim 1, wherein each of said first and second induction elements comprises a coil with a soft iron core.

7. The device of claim 1, wherein electrical conductors leading to one of the said induction elements, leave the bushing at its end and axially.

8. The device of claim 1, wherein said bushing fits around a keyway in said cylinder.

9. The device of claim 1, wherein said electronic circuitry is arranged in a head part of said locking key.

10. The device of claim 1, having a lengthwise hole for electrical conductors in said locking key and extending from the second induction element as far as the electrical circuitry in the key head.

11. A locking device, substantially as hereinbefore described with reference to the accompanying drawings.