Integrated circuit key and connector notably for such a key

The disclosure relates to "chip" type electronic keys and the connectors designed to work with these keys. A bolting or blocking groove is provided in the face of the key opposite the one supporting the chip, in an intermediate position between this chip and the front end of the key. The key-blocking means therefore press the key towards the connection means which are located above the key. Thus, clearance is eliminated and the clogging of the contacts is avoided. The disclosure enables the use of the known standard of chip keys for the chip and its connection means.

BACKGROUND OF THE INVENTION 
The present invention relates to keys that incorporate an integrated 
circuit that can be used to replace the mechanical characteristics that 
usually constitute the originality and security of a key with electronic 
characteristics. It also relates to the connectors designed to receive an 
object such as a key of this type to set up the contacts with the 
electronic device forming, in this case, the main elements of the lock 
with which the key must be matched. 
The advantages of keys having an integrated circuit are well known, 
especially with regard to discretion and easy neutralization if the key 
should be lost. The various embodiments known to date nevertheless have a 
number of drawbacks related essentially to the matching of the key with 
the connector that forms the lock, so as to obtain operation that is as 
reliable as in the case of purely mechanical keys. 
SUMMARY OF THE INVENTION 
To overcome these drawbacks, the invention proposes an electronic key of 
the type comprising an elongated part designed to be inserted into a 
connector matched with the key, an integrated circuit provided with 
connection means that are flush with one of the faces of the elongated 
part and a locking groove transversal to this elongated part, wherein 
chiefly this groove is located on the face opposite to the one with which 
the contacts of the integrated circuit are flush. 
The invention also proposes a connector for an object provided with an 
integrated circuit, notably for an electronic key, of the type comprising 
a connection grid to get connected with connection means of the integrated 
circuit of the object, a mechanism to place the grid in contact with these 
connection means, bolting means designed to hold the object fixed in a 
determined way with respect to the connection grid, wherein chiefly the 
bolting means act in a direction opposite to the direction of operation of 
the contact-making mechanism.

MORE DETAILED DESCRIPTION 
An electronic key, in order to be used, is inserted like an ordinary key 
into the slot of a suitable lock comprising notably a special connector 
used to set up contacts with the connection points of the integrated 
circuit, generally called chips, inserted into the key. This connector 
includes several parts that can be made according to various methods, some 
of which are well known. There is notably a known way of using a guide 
into which the key is inserted, the withdrawal motion of the guide 
bringing into play various mechanisms which, in particular, set up contact 
with the chip of the key and the blocking of this key. 
In order to make it easier to describe the invention, FIG. 1 shows solely 
the guide proposed in the invention in a way that is both simplified and 
partial so as to make it easier to examine the drawing. 
This guide is formed by a plate 101 beneath which the key is inserted in 
its motion of being introduced into the lock, represented by the arrow 
102. After sliding beneath the face of this plate, the front end of the 
key abuts a snug 103 that is made by punching into the middle of the 
plate. The relative motion of the key and the plate then stops and the key 
is positioned with respect to the plate in such a way that the contacts of 
the chip contained in the key are at the center of a substantially 
rectangular scallop 104 opened in the rear end of the plate so as to 
enable access to these contacts to set up the necessary connections. At 
this point in time, the key is only half engaged in the lock. 
The penetrating motion of the key then continues and carries along the 
guide since it is fixed against the snug 103. The connector naturally 
includes elastic means, such as a spring, that enable the guide to be 
pushed back in the reverse direction to that of the motion 102 so as to 
firstly provide for the relative positioning of the key and of the guide 
and secondly push the guide back to its resting position when the key has 
been released. 
The guide furthermore has two side flanges 105 fixed to the sides of the 
plate 101, perpendicularly to the plane of this plate and in parallel to 
the motion 102. These flanges have slots that are inclined from top to 
bottom and from the rear to the front of the guide (by convention, the 
front is the side by which the key is inserted). These slots end in a 
substantially horizontal portion 107. 
These slots are used to maneuver a connection element shown in FIG. 2. This 
connection element has a support 201 with dimensions matching those of the 
scallop 104. The support is connected to the lower part of a horizontal 
bar 202. A contact grid 203 matching the connections of the chip of the 
key is fixed to the lower face of the support 201. A set of flexible 
connection wires, not shown in the figure, is used to connect this contact 
grid with the electronic elements of the lock which are known per se. The 
two ends of the bar 202 get engaged into the slots 106 of the flanges 105. 
They are joined to the fixed part (not shown) of the lock, in which the 
guide slides, so as to get shifted solely in the vertical direction. Thus, 
when the guide moves back under the effect of the key, the bar 202 will 
slide into the slots 106 and the inclination of these slots will cause the 
descent of the bar and of the support 201 that is connected to it towards 
the upper surface of the plate 101. At the end of this motion, the support 
201 gets housed in the scallop 104 and the bar 202 gets fixed in the small 
horizontal part 107 of the slot 106 which fixes the support 201 with 
respect to the plate 101. 
The key according to the invention, which is shown in FIG. 3, is made by 
the molding of a plastic material. There is only one shape for all the 
keys. This is one of the known advantages of electronic keys. This key has 
an elongated part 301 which generally has the shape of a rectangular 
parallelepiped but has its faces modified to fulfil different functions 
that shall be described here below. This elongated part plays the role of 
the bit in an ordinary mechanical key. It ends in a wider part 302 that 
serves as the handle of the key. 
The key is shown in this figure in cavalier projection in its position of 
normal use, and the upper face of the figure corresponds to the face 
which, according to the invention, will be located horizontally and on top 
when the key is used. 
On this upper face, there is made a substantially parallelepiped-shaped 
blind cavity 303 which will be used to house the integrated circuit 
containing the data elements that will be used to give the key its 
individual character and associate it with the lock that it will open. 
This integrated circuit is associated with a connection device, formed for 
example by an appropriately etched piece of printed circuit such as those 
used in so-called chip type bank cards. This connection system and its 
link with the chip are well known in this technique of chip cards. The 
unit is then placed in the cavity where it is sealed by means of a bonder 
adapted to this purpose, in the same way as in chip cards. The cavity 
itself is made so that the contacts are slightly withdrawn from the 
surface of the elongated part 301, in order to protect these contacts 
especially against friction with the lips of the aperture of the lock when 
the key is inserted into it. 
The location and the dimensions of the cavity 303 are determined so that 
the contacts get placed just below the scallop 104 when the key is fixed 
with respect to the guide by the snug 103. 
Thus, when the guide ends its motion, the contact grid fixed to the support 
201 penetrates the upper end of the cavity 303 to set up the contacts with 
the connections of the chip located in this cavity. 
The upward position of the opening of the cavity 303 and hence of the 
connection elements of the chip make it possible to prevent the connection 
grid located on the support 201 from getting clogged with various 
particles that would collect on itself if it were to be placed in the 
opposite direction with its contacts facing upwards. 
In order to enable the key to be inserted systematically in the right 
direction, the cross-section of the part 301 will be given a particular 
shape shown in the cross-sectional view of FIG. 5. This shape makes it 
possible, inter alia, to prevent mistakes by preventing the insertion of 
the key into the aperture of the lock, this aperture having the same shape 
as this cross-section. For this purpose, the lower corners of the part 301 
are folded back to obtain chamfers 501 having for example an angle of 
35.degree. to the horizontal, thus giving this cross-section a generally 
trapezoidal appearance. It can easily be imagined that if the aperture 
designed for the insertion of the key has the same shape, it will be 
possible to insert it in only one direction, with the cavity 303 upwards. 
Furthermore, this device makes it possible to concentrate the essential 
part of the wearing out of the faces of the key, arising out of friction 
with the aperture of the key, on the lower face of this key. This makes it 
possible, in the course of time, to maintain suitable tolerance values for 
the positioning of the upper face with respect to the contact grid. 
Furthermore, according to a generally chosen arrangement, there is 
provision for means to fixedly hold the key or keep it blocked in the lock 
throughout the time when information is being exchanged between the chip 
of the key and the electronic system of the lock so that this operation 
can be conducted with total security, especially in order to provide 
electrical protection to both the chip and the elements of the lock. 
These bolting or blocking means are shown schematically in FIG. 4 along 
with a longitudinal section of the front end of the part 301 of the key. 
These means have a roller 401 that gets engaged into a transversal groove 
402 made in the lower face of the part 301 and, hence, on the face 
opposite the one bearing the chip. This roller is preferably a horizontal 
roller born by a set of hinged arms 403 and 404 pushed upwards by a spring 
405. According to a first variant, when the key is pushed in, its end 
abuts the roller 401 which descends and then rolls on the lower face of 
the key and then rises to get engaged in the groove 402. This action 
occurs at the end of the motion of the key and bolts this key into the 
lock. In order to make it easier for the roller to descend when the end of 
the key abuts it, the lower face of this key is bevelled in order to form 
a clearance giving an inclined edge 406 forming for example an angle of 
35.degree. with the horizontal. 
According to a preferred variant, the vertical arm 403 has the shape of a 
two-pronged fork that gets engaged into lateral slots 108 made in the 
plate 101 by the punching of strips 109 curved upwards in an acute angle. 
These strips force the fork 403 to plunge in, carrying along the roller 
which therefore no longer abuts the inclined edge 406. At the limit of 
their travel, the prongs of the fork meet the apertures 110 made behind 
the slots 108. They penetrate these apertures enabling the roller 401 to 
rise and get engaged into the groove 402. Thus, the wearing out of the key 
and of the lock are diminished, making it possible for example to simplify 
the manufacture of the lock by replacing the roller with a horizontally 
elongated flat part of the bar 403. 
Under the effect of the spring 405, the roller 401 therefore leans on the 
walls of the groove 402 and places the key flat against the lower face of 
the plate 101 of the guide. This holds the two parts with respect to each 
other in a well-defined relative position and makes it possible to 
compensate for inevitable clearance. It is thus possible to obtain far 
greater precision at the contact gate supported by the plate 201 and hence 
to tolerate greater initial clearance values than if the lock were to be 
positioned on the top of the key, on the chip side. 
Furthermore, the invention also proposes the placing of the groove 402 
before the cavity 303 between this cavity and the front end of the key 
but, naturally, always on the face opposite the one containing this 
cavity. It is thus possible to use a spring 405 that is firm enough to 
hold the key very efficiently in the lock without any risk of deforming 
the key at the chip and of damaging it. 
When the exchanges of information between the chip and the electronic 
circuits of the lock are over, these circuits activate the interruption of 
the electrical connection. In particular, the supply voltage for the chip 
disappears and, to release the key, these very same electronic elements 
activate a motor 407, an electromagnet for example, that causes the 
rocking of the lever 404. This causes the roller 401 to come down again 
and enables the ejection of the key under the effect of the elastic means 
that push the guide backwards. 
For the sake of security, should this action fail, for example because of a 
malfunctioning of the electromagnet 407, it is furthermore provided, 
according to the invention, that the groove 402 will have a substantially 
trapezoidal section with flanks that are slightly inclined, by 16.degree. 
for example, towards the interior of the groove. In this way, it is always 
possible by pulling very hard on the key, to drag the roller 401 over that 
face of the groove 402 which is most inclined frontwards, thus forcing 
this roller to come downwards and enabling the key to be released 
mechanically. Naturally, the strength of the spring 405 shall be designed 
so that there is no risk of this action's causing the key to break. 
Finally, it is also provided according to the invention that the upper edge 
408 of the end of the key will be rounded, with a radius of 0.5 mm for 
example, so that it can be matched with the end of the snug 103. Indeed, 
the plate 101 as well as many other elements of the guide and the lock are 
preferably made by punching in order to reduce costs. Thus, the end of the 
snug 103, which is folded downwards, necessarily has a rounded portion on 
the inside with a radius that is relatively great while at the same time 
being defined with fairly low precision. If, therefore, the edge that this 
abutting at this position were to be sharp, the point of contact between 
the key and the end of the snug would be defined in a relatively imprecise 
way. This could give rise to poor contacts at the connection grid with the 
chip of the key. If this edge is sufficiently rounded, it no longer rests 
on the corner of the folded end of the snug and it is the flat part of 
this folded end that receives the flat part of the end of the key. This 
considerably reduces the tolerance values of positioning between the key 
and the snug and therefore between the key and the guide.