BACKGROUND OF THE INVENTION
Field of the invention
[0001] This invention relates to a key-operated cylinder lock having a function of detecting
the presence and absence of the key.
Related Art
[0002] A key-operated cylinder lock, for instance, for an automobile door has not been put
in practical use yet which includes a detecting device for electrically detecting
whether the key is inserted into the rotor of the cylinder lock or it is removed therefrom;
i.e., the presence or absence of the key.
[0003] A key-operated cylinder lock of this type is liable to be adversely affected by external
conditions, because it is mounted on the outer surface of a vehicle; that is, it is
exposed outside. Hence, it is, in general, difficult for the key-operated cylinder
lock to have a detecting device for electrically detecting the presence or absence
of the key. On the other hand, it is not always impossible to provide such a detecting
device for the key-operated cylinder lock; however, the detecting device thus provided
is unavoidably intricate in structure and bulky.
SUMMARY OF THE INVENTION
[0004] In view of the foregoing, an object of this invention is to provide a key-operated
cylinder lock having a function of electrically detecting the presence or absence
of the key which is small in the number of components and is not bulky.
[0005] In view of the foregoing, another object of this invention is to provide a key-operated
cylinder lock which is relatively simple in construction and is able to electrically
detect the presence or absence of the key with higher accuracy.
[0006] The foregoing object of the invention has been achieved by the provision of a key-operated
cylinder lock which, according to the invention, comprises: a rotor casing including
a cylindrical main portion, and an engaging portion larger in diameter than the main
portion which is extended forwardly from the main portion; a rotor having a large-diameter
portion on the outer cylindrical surface of the front end portion, and a key inserting
channel opened in the front end face thereof, the rotor being rotatably arranged in
the rotor casing with the large-diameter portion engaged with the engaging portion;
a permanent magnet provided in the rotor near the key inserting channel; a magnetic
shutter swingably provided in the rotor in such a manner that when the shutter is
at a channel closing position to close the key inserting channel, the shutter is away
from the permanent magnet, and when the shutter is swung to a channel opening position
by a key inserted into the key inserting channel to open the key inserting channel,
the shutter approaches the permanent magnet to concentrate the magnetic flux of the
permanent magnet; a spring member adapted to urge the shutter towards the channel
closing position; an accommodating recess formed in the rear of the outer periphery
of the rotor casing in such a manner that the accommodating recess is located behind
the engaging portion and near the permanent magnet and that the accommodating recess
is opened only backwardly; a magnetic detecting element provided in the accommodating
recess, for detecting variations of the magnetic flux of the permanent; and a sealing
resin sealing the magnetic detecting element in the accommodating recess.
[0007] The foregoing object of the invention has been achieved by the provision of a key-operated
cylinder lock which, according to the invention, comprises: a rotor casing; a rotor
having a key inserting channel, which is
rotatably arranged in the rotor casing; a permanent magnet provided in the rotor near
the key inserting channel; a magnetic detecting element provided in the rotor casing
in such a manner that the magnetic flux of the permanent magnet acts on the magnetic
detecting element; a magnetic shutter swingably provided in the rotor in such a manner
as to open and close the key inserting channel, the shutter being made of a magnetic
material and adapted to interrupt the application of the magnetic flux of the permanent
magnet to the magnet detecting element when the shutter is swung to a channel closing
position to close the key inserting channel by a key inserted into the key inserting
channel; and a spring member provided in the rotor, which is made of a non-magnetic
material and is adapted to urge the shutter towards the channel closing position.
[0008] In the key-operated cylinder lock, it is preferable that in the case where a rotor
cover is provided on the front end portion of the rotor, the rotor cover is made of
a non-magnetic material. Furthermore, it is preferable that, in the case where a casing
cover is provided on the front end portion of the rotor casing, the casing cover is
made of a non-magnetic material.
[0009] In the key-operated cylinder lock of the invention, the magnetic detecting element
for detecting the variations of the magnetic flux of the permanent magnet is arranged
in the accommodating recess formed in the rear of the rotor casing. Therefore, it
is unnecessary to additionally provide a special casing for the magnetic detecting
element. Furthermore, since the accommodating recess is formed in the rear of the
engaging portion of the rotor casing which is larger in diameter than the main portion,
the engaging portion is substantially not inflated outwardly by the formation of the
accommodating recess containing the magnetic detecting element.
[0010] Until the key is inserted into the key inserting channel, the shutter is held at
the channel closing position, and the magnetic flux of the permanent magnet acts on
the magnetic detecting element. When, under this condition, the key is inserted into
the key inserting channel, the shutter is swung to the channel opening position against
the elastic force of the spring member; that is, the shutter approaches the permanent
magnet so that the magnetic flux of the latter is concentrated on the shutter. As
a result, the application of the magnetic flux of the permanent magnet to the magnetic
detecting element is interrupted.
[0011] As is apparent from the above description, the magnetic flux of the permanent magnet
acting on the magnetic detecting element is varied with the operation of the shutter.
Hence, the presence or absence of the key can be electrically detected by detecting
the variations of the magnetic flux.
[0012] In this detecting operation, the spring member urging the shutter towards the channel
closing position will not affect the magnetic flux of the permanent magnet acting
on the magnetic detecting element, because it is made of non-magnetic material.
[0013] In addition, both the rotor cover mounted on the front end portion of the rotor,
and the casing cover mounted on the front end portion of the rotor casing are made
of non-magnetic material. Hence, the rotor cover and the casing cover will not affect
the magnetic flux of the permanent magnet acting on the magnetic detecting element,
either.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014]
FIG. 1 is an enlarged fragmentary sectional view showing essential components of a
key-operated cylinder lock, which constitutes a second embodiment of this invention;
FIGS. 2 and 3 are a front view and a side view, respectively showing the key-operated
cylinder lock.
FIG. 4 is a rear view of a rotor casing in the key-operated cylinder lock;
FIG. 5 is a perspective view of lead wire holders in the key-operated cylinder lock;
FIG. 6 is an enlarged fragmentary sectional view showing essential components of a
key-operated cylinder lock of a first embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
First embodiment
[0015] First embiodiment will be now described with the reference to FIG. 6.
[0016] The body 1 of the key-operated cylinder lock comprises: a cylindrical rotor casing
2; and a rotor 3 with a key inserting channel 3a which is rotatably arranged in the
rotor casing 2. The rotor casing 2 comprises: a main portion 2a; and an engaging portion
2b extended from the former 2a, forming the front end portion of the rotor casing
2. The engaging portion 2b is larger in diameter than the main portion 2a. A step
2c is formed inside the engaging portion 2b, while a large-diameter portion 3b is
formed on the outer cylindrical surface of the front end portion of the rotor 3, so
that the large-diameter portion 3b of the rotor 3 is engaged with the step 2c to prevent
the backward movement of the rotor 3.
[0017] A magnetic shutter 4 is swingably provided inside the rotor 3, to open and close
the key inserting channel 3a. Furthermore, inside the rotor 3, a spring member 5 is
provided to urge the shutter 4 to close the key inserting channel 3a, and a permanent
magnet 6 is positioned near the spring member 5.
[0018] On the other hand, a magnetic detecting element, namely, a reed switch 7 is provided
on the outer cylindrical surface of the engaging portion 2b of the rotor casing 2
near the permanent magnet 6. More specifically, the reed switch 7 is set in its own
casing 8, which is covered by a casing cover 9 mounted on the front end portion of
the rotor casing 2.
[0019] In the case where the key 10 is not inserted into the key inserting channel 3a yet,
the shutter 4 is held at a channel closing position to close the key inserting channel,
and the reed switch 7 is held, for instance, turned off by the magnetic flux of the
permanent magnet 6.
[0020] When, under this condition, the key 10 is inserted into the key inserting channel
3a, the shutter 4 is swung against the elastic force of the spring member 5 to its
channel opening position (as indicated by the two-dot chain lines); that is, the shutter
4 approaches the permanent magnet 6, so that the magnetic flux of the latter 6 is
concentrated on the shutter 4. As a result, the application of the magnetic flux of
the permanent magnet 6 to the reed switch 7 is interrupted, so that the latter 7 is
turned on.
[0021] As was described above, the magnetic flux of the permanent magnet 6 acting on the
reed switch 7 varies depending on whether the shutter 4 is opened or it is closed.
Therefore, the presence or absence of the key can be electrically detected by detecting
the variations of the magnetic flux.
[0022] With the above-described key-operated cylinder lock, it is necessary to use the casing
8 to provide the reed switch 7, which increases the number of components as much.
Furthermore, since the casing 8 is greatly outwardly protruded from the engaging portion
2b of the rotor casing 2, the key-operated cylinder lock is bulky.
[0023] Moreover, in the above-described key-operated cylinder lock, the spring member adapted
to urge the shutter towards the channel closing position is a coil spring made of
a piano wire. The piano wire is generally of magnetic substance, and is positioned
near the permanent magnet, so that the magnetic flux of the permanent magnet is allowed
to pass through the spring member. Hence, when the shutter is positioned at the channel
closing position, a larger part of the magnetic flux passes through the spring member;
that is, the magnetic flux acting on the reed switch is decreased as much. As a result,
when the shutter is operated, the magnetic flux applied to the reed switch is less
varied. Hence, the detection of the presence or absence of the key is lowered in accuracy.
Second embodiment
[0024] In view of the forgoing the problem, a key-operated cylinder lock of a second embodiment
of the present invention applied to an automobile door will be described with reference
to FIGS. 1 through 5.
[0025] As shown in FIGS. 1 through 3, a cylinder lock body 11 mounted on an automobile door
comprises: a rotor casing 12; and a rotor 14 having a key inserting channel 13 which
is rotatably provided inside the rotor casing 12.
[0026] The rotor casing 12 comprises: a cylindrical main portion 12a; and an engaging portion
12b extended forwardly (to the right in FIG. 1) from the former 2a, thus forming the
front end portion of the rotor casing 12. The engaging portion 12b is larger in diameter
than the main portion 12a. A step 12c is formed inside the engaging portion 12b, while
a large-diameter portion 14a is formed on the outer cylindrical surface of the front
end portion of the rotor 14. When the rotor 14 is inserted into the rotor casing 12
from the front, the large-diameter portion 14a of the rotor 14 is engaged with the
step 12c of the engaging portion 12b to prevent the further backward movement of the
rotor 14. The rotor casing 12 and the rotor 14 are made of non-magnetic material,
zinc.
[0027] A rotor cover 15 is mounted on the front end portion of the rotor 14. The rotor cover
15 has a key inserting hole 15a which is communicated with the key inserting channel
13. A plurality of tumbler grooves 16 are formed in the outer periphery of the rotor
14, and tumblers (not shown) are movably arranged inside it in correspondence to the
tumbler grooves 16. The rotor cover 15 is made of non-magnetic stainless steel.
[0028] A shutter 17 is provided inside the rotor 14. More specifically, the shutter is located
beside the rotor cover 15. The shutter 17 is made of magnetic stainless steel, and
has side plates 18 on its both edges, and pivot pins 19 on its both ends through which
the shutter is mounted inside the rotor 14 in such a manner that it is swingable about
the pivot pins 19. As the shutter 17 is swung, the key inserting hole 15c and accordingly
the key inserting channel 13 are opened and closed. For this purpose, a spring member
20, which is a coil spring, is provided inside the rotor 14 to urge the shutter 17
to close the key inserting channel. The spring member 20 is made of non-magnetic material,
for instance, beryllium copper.
[0029] Furthermore, inside the rotor 14, a permanent magnet 21 is provided in contact with
the spring member 20. More specifically, the permanent magnet 21 is so positioned
that, when the shutter 17 is swung to its channel opening position as indicated at
the two-dot chain lines in FIG. 1, it is covered by the shutter 17.
[0030] On the other hand, a casing cover 22 having a circular hole 22a at the center is
mounted on the front end portion of the rotor casing 12 in such a manner that it covers
the rotor 14 from the front. The casing cover 22 is made of non-magnetic stainless
steel, similarly as in the case of the rotor cover 15.
[0031] An accommodating recess 23 is formed in the outer periphery of the rotor casing 12
in such a manner that it is located behind the engaging portion 12b and near the permanent
magnet 21 in the rotor 14 (cf. FIG. 4). In the accommodating recess 23, provided are
a printed circuit board 14, and a magnetic detecting element, namely, a reed switch
25 which is coupled to the printed circuit board 14. The printed circuit board 14
and the reed switch 25 are sealed in the accommodating recess 23 with sealing resin
26.
[0032] U-shaped lead wire holders 27 and 28 are formed on the outer cylindrical surface
of the main portion 12a of the rotor casing 12 in such a manner that, as shown in
FIG. 5, they are shifted from each other in the direction of axis of the rotor casing
12 and are confronted with each other, so as to hold a lead wire extended from the
aforementioned printed circuit board 24.
[0033] Now, the operation of the key-operated cylinder lock thus constructed will be described.
[0034] In the case where the shutter 17 is held at its channel closing position as indicated
by the solid lines in FIG. 1, the magnetic flux of the permanent magnet 21 acts on
the reed switch 25, so that the latter 25 is held turned off for instance.
[0035] When, under this condition, the key 30 is inserted into the key inserting channel
13 through the key inserting hole 15a, the shutter 17 is swung by the key 30 to the
channel opening position against the elastic force of the spring member 30 as indicated
by the two-dot chain lines in FIG. 1. That is, the shutter 17 approaches the permanent
magnet 21, so that the side plates 18 of the shutter 17 embraces the permanent magnet
21 from both sides; that is, the permanent magnet 21 is covered by the shutter 17.
[0036] When the shutter 17 is swung to the channel opening position, the magnetic flux of
the permanent magnet 21 is concentrated on the shutter 17, so that the application
of the magnetic flux to the reed switch 25 is interrupted. As a result, the reed switch
25 is turned on.
[0037] In the case where the predetermined key 30 is inserted into the key inserting channel
13 as was described above, the tumblers (not shown) are accommodated inside the rotor
14, thus permitting the rotation of the rotor 14. If, on the other hand, a key different
from the key 30 is inserted into the key inserting channel, then some of the tumblers
are protruded out of the tumbler grooves 16, thus inhibiting the rotation of the rotor
14.
[0038] In the above-described embodiment, as the shutter 17 is operated, the magnetic flux
of the permanent magnet 21 acting on the reed switch 25 varies. Therefore, the presence
or absence of the key 30 can be detected by detecting the variations of the magnetic
flux.
[0039] In the embodiment, the reed switch 25 for detecting the variations of the magnetic
flux of the permanent magnet 21 is arranged in the accommodating recess 23 formed
in the outer periphery of the rotor casing 12. Therefore, it is unnecessary to additionally
provide a special casing for the reed switch 25, which decreases the number of components
as much. Furthermore, the accommodating recess 23 is formed in the rear of the engaging
portion 12b of the rotor casing 12 which is larger in diameter than the main portion
12a. Therefore, the engaging portion 12b is substantially not inflated by the formation
of the accommodating recess; that is, the resultant key-operated cylinder lock is
not bulky.
[0040] Furthermore, in the key-operated cylinder lock thus constructed, the distance between
the permanent magnet 21 and the reed switch 25 is substantially equal to that in the
key-operated cylinder lock shown in FIG. 6. This means that the reed switch is high
in detecting performance.
[0041] Moreover, in the above-described embodiment, the spring member 20 adapted to urge
the shutter 17 towards the channel closing position is made of non-magnetic material.
Therefore, although the spring member 20 is provided in contact with the permanent
magnet 21, it will not affect the magnetic flux of the permanent magnet 21 acting
on the reed switch 25. This means that the reed switch 25 is improved in detecting
accuracy.
[0042] In addition, the rotor cover 15 mounted on the front end portion of the rotor 14,
and the casing cover 22 mounted on the front end portion of the rotor casing 12 are
both made of non-magnetic material. That is, the rotor cover 15 and the casing cover
22 will not affect the magnetic flux of the permanent magnet 21 acting on the reed
switch 25, which further improves the detecting accuracy of the reed switch 25.
[0043] As is apparent from the above-description, in the key-operated cylinder lock according
to the invention, the magnetic flux of the permanent magnet acting on the magnetic
detecting element is varied as the shutter adapted to open and close the key inserting
channel is operated, and the variations of the magnetic flux are detected with the
magnetic detecting element, so that the presence or absence of the key is detected.
In addition, the spring member adapted to urge the shutter towards the channel closing
position is made of non-magnetic material. Therefore, the reed switch 25 is improved
in detecting accuracy.
[0044] In the key-operated cylinder lock of the invention, the magnetic detecting element
is arranged in the accommodating recess formed in the outer periphery of the rotor
casing, which makes it unnecessary to additionally provide a special casing for the
magnetic detecting element, and reduces the number of components as much. Furthermore,
since the accommodating recess is formed in the rear of the engaging portion of the
rotor casing which is larger in diameter than the main portion, the engaging portion
is substantially not inflated outwardly by the formation of the accommodating recess.
[0045] In addition, the rotor cover mounted on the front end portion of the rotor, and the
casing cover mounted on the front end portion of the rotor casing are both made of
non-magnetic material. Thus, the magnetic detecting element is improved in detecting
accuracy.
1. A key-operated cylinder lock comprising:
a rotor casing;
a rotor having a key inserting channel, which is rotatably arranged in the rotor
casing;
a permanent magnet provided in the rotor near the key inserting channel;
a magnetic detecting element provided in the rotor casing in such a manner that
the magnetic flux of the permanent magnet acts on the magnetic detecting element;
a magnetic shutter swingably provided in the rotor in such a manner as to open
and close the key inserting channel, the shutter being made of a magnetic material
and adapted to interrupt the application of the magnetic flux of the permanent magnet
to the magnet detecting element when the shutter is swung to a channel closing position
to close the key inserting channel by a key inserted into the key inserting channel;
and
a spring member provided in the rotor, which is adapted to urge the shutter towards
the channel closing position.
2. A key-operated cylinder lock as claimed in claim 1, wherein the rotor includes a cylindrical
main portion, an engaging portion larger in diameter than the cylindrical main portion
which is extended forwardly from the cylindrical main portion and an accommodating
recess formed in the rear of an outer periphery of the rotor casing in such a manner
that the accommodating recess is located behind the engaging portion and near the
permanent magnet and that the accommodating recess is opened only backwardly.
3. A key-operated cylinder lock as claimed in claim 2, further comprising:
a sealing member for sealing the magnetic detecting element in the accommodating
recess.
4. A as claimed in claim 3, wherein the sealing member includes a sealing resin.
5. A key-operated cylinder lock as claimed in claim 1, further comprising:
a rotor cover on the front end portion of the rotor, the rotor cover being made
of a non-magnetic material.
6. A key-operated cylinder lock as claimed in claim 1, further comprising:
a casing cover on the front end portion of the rotor casing, the casing cover being
made of a non-magnetic material.
7. A key-operated cylinder lock as claimed in claim 5, further comprising;
a casing cover on the front and portion of the rotor cover, the casing cover being
made of a non-magnetic material.
8. A key operated cylinder lock as claimed in claim 1, wherein a spring member is made
of a non-magnetic material.