SWITCH ACTUATOR FOR AN ELECTROMECHANICAL LOCKING UNIT

COMMUTATEUR POUR SERRURES ELECTRO-MAGNETIQUES

English Abstract

A switch actuator for an electromechanical locking unit,
which locking unit includes a cylinder lock mechanism operated
mechanically by a key, a blocking device functionally dependent
on an electronic code to be fed from the key, and an electronic
control unit, which on the basis of the electronic code is
arranged to control the blocking device and which, under the
control of the switch actuator, is connectable to an electric
power source. The switch actuator comprises a permanent magnet
to be attached in association with the cylinder lock, a reed
switch located in the immediate vicinity of the permanent magnet
within the magnetic field provided thereby and a piece of
ferromagnetic material located in the key and arranged to be
placed in the vicinity of the permanent magnet when the key is
inserted into the cylinder lock so that it causes a change in the
magnetic field influencing the reed switch to provide a control
pulse, which is arranged to connect the electronic control unit
to the power source.

Claims

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Claims
1. An electromechanical locking unit comprising:
a cylinder lock mechanism defining a key channel,
a key having a key shank for insertion in the key channel
for mechanical operation of the cylinder lock mechanism, said key
embodying a code,
a blocking means for blocking operation of the cylinder lock
mechanism,
an electronic control unit responsive to a code to control
the blocking means,
a means for feeding the code embodied in the key
electronically from the key to the electronic control unit,
an electric power source for supplying operating current to
the electronic control unit,
a switch arrangement for controlling supply of operating
current from the electric power source to the electronic control
unit, said switch arrangement including a switch having an open
condition in which it isolates the control unit from the electric
power source and a closed condition in which it supplies
operating current from the electric power source to the control
unit, a magnet responsive means in the vicinity of the cylinder
lock mechanism for controlling the condition of the switch in
dependence on magnetic field influencing the magnet responsive
means, and a permanent magnet means establishing a magnetic field
in the vicinity of the magnet responsive means, and
a ferromagnetic means on or in the key, the ferromagnetic
means altering the magnetic field established by the permanent
magnet means such as to cause the magnet responsive means to
place the switch in the closed condition when the key shank is
inserted in the key channel.
2. An electromechanical locking unit according to claim 1,
wherein the switch is responsive to an electrical pulse to change
from its open condition to its closed condition, the switch
arrangement comprises a capacitor and the magnet responsive means
comprises a reed switch connected between the power source and
the capacitor, whereby a change in state of the reed switch

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causes the capacitor to supply an electrical pulse to the control
switch.
3. An electromechanical locking unit according to claim 2,
wherein the reed switch and the permanent means are mutually
located so that the magnetic field established by the permanent
magnet means biases the reed switch to an open state and the reed
switch changes to a closed state when the magnetic field
established by the permanent magnetic means is altered by the
ferromagnetic means when the key is inserted in the key channel.
4. An electromechanical locking unit according to claim 1,
wherein the permanent magnet means comprises two permanent magnet
elements angularly spaced about the key channel and wherein the
magnet responsive means is positioned substantially between the
two permanent magnet elements.
5. An electromechanical locking unit according to claim 4,
wherein the two permanent magnet elements are angularly spaced at
an included angle of at least about 120° and the magnet
responsive means is positioned in the included angle between the
permanent magnet elements.
6. An electromechanical locking unit according to claim 1,
comprising a protective element protecting the cylinder lock
mechanism from the exterior and wherein the magnet responsive
means and the permanent magnet means are located inside the
protective element and upstream of the cylinder lock mechanism
with respect to the direction of insertion of a key in the key
channel.
7. An electromechanical locking unit according to claim 6,
wherein the magnet responsive means comprises a reed switch and
the reed switch and the permanent magnet means are integrated in
a switch unit.

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8. An electromechanical locking unit according to claim 1,
wherein the key has a key bow from which the key shank extends
and the ferromagnetic means comprises a piece of ferromagnetic
material attached to the key shank at its end nearer the key bow.
9. An electromechanical locking unit according to claim 8,
wherein the ferromagnetic material is iron.
10. An electromechanical locking unit according to claim 1,
wherein the key has a key bow from which the key shank extends
and the ferromagnetic means comprises a sleeve-like piece of
ferromagnetic material fitted around the key shank at its end
nearer the key bow.
11. An electromechanical locking unit according to claim
10, wherein the ferromagnetic material is iron.
12. An electromechanical locking unit according to claim 1,
wherein the ferromagnetic means comprises a piece of
ferromagnetic material attached to the key.
13. An electromechanical locking unit according to claim 1,
wherein the switch is a pulse controlled switch and the locking
unit further comprises a control means for placing the pulse
controlled switch in its open condition after a locking operation
has been completed.
14. An electromechanical locking unit according to claim 1,
wherein the electric power source is a battery.
15. An electromechanical locking unit according to claim 1,
wherein the electric power source is a rechargeable battery.

Representative Drawing