[0001] The invention relates to a self-holding key switch, wherein a switch is combined
with a lock adapted to be released by inserting a key and the switch is turned on
or off by rotating the inserted key.
[0002] In a key switch according to the Japanese Utility Model Laid-Open No. 1341/1981,
a rotor or rotatable cylinder of a lock main body is rotated by means of a key inserted
into the cylinder, and a microswitch fitted to the rear of the lock main body is turned
on and off by a cylindrical cam that rotates integrally with the cylinder. The cylinder
and the cam being freely rotatable in both directions by means of the key, accidental
or unintentional rotation of the inserted key by an operator can lead to the switch
being turned on or off, there being no necessity of rotating the key up to 360° in
order to turn of the switch. In particular, when the key has been rotated in the normal
operating direction to turn on the switch and is then unintentionally rotated in the
reverse direction through a small angle, the switch can return to the off state easily
within a short period of time.
[0003] The document DE-B-1 131 464 describes a key-operated combined ignition and starter
switch for an engine of a motor vehicle, the switch having the features described
in the prior art portion of claim 1. Insertion of a key into a cylinder lock and rotation
of the key in one direction brings a rotary switch from an off position into an ignition
position and then into an engine starting position, at which stage a spring mechanism
rotates the cylinder in the reverse direction to bring the switch back to the ignition
position. In order to prevent the switch from being inadvertently rotated a second
time to the starting position before being first returned to the off position, a separate
ratchet mechanism is provided, wherein two cam discs are fitted coaxially onto a rear
extension of the lock cylinder, the rear cam disc being rotated integrally with the
cylinder and the front cam disc being free to rotate with respect to the cylinder
and the rear cam disc within a limited angular range. In the off position of the switch,
two spring-loaded pawls, pivotally supported at the lock main body, each engage with
one of two slight recesses formed on opposite perimeter portions of the front cam
disc. Rotation of the cylinder to the ignition and engine starting positions first
allows only the rear cam disc to rotate, whereafter the front cam disc is constrained
to rotate in the same direction, the pawls being slid out of the slight recesses and
then dropping into cutout portions of the perimeter of the front cam disc to abut
against the perimeter of the rear cam disc. The subsequent spring-urged return of
the cylinder to the ignition position causes the rear cam disc to rotate and one of
the pawls to engage immediately with a tooth of the rear cam disc, so as to block
a return of the cylinder to the starting position. Further rotation of the cylinder
to the ignition position causes the other pawl to engage with a second tooth portion
of the rear cam disc, so as to block a return of the cylinder to the starting position
from a position close to or at the ignition position. Return of the cylinder to the
off position then rotates the front cam to slide the pawls out of engagement with
the rear cam disc and to engage the pawls with the slight recesses of the front cam
disc.
[0004] It is the object of the present invention to provide a self-holding key switch of
the type in which a cylindrical cam rotates integrally with the lock cylinder to push
or release the actuator of a switch to turn the switch on or off, wherein the switch
in the on state is prevented from being returned quickly to the off state owing to
an erroneous operation by an operator, so that the switch can be kept reliably in
the on state for a predetermined period of time, as necessary for the equipment for
which the key switch is used.
[0005] This object is achieved by a self-holding key switch having the features given in
claim 1.
[0006] Hereinafter, one preferred embodiment of the invention will be described with reference
to the accompanying drawings, in which:
Figure 1 is a front view of a key switch;
Figure 2 is a right-hand side view showing a part of the key switch in a longitudinal
section;
Figure 3 is a rear view with a rear seat plate being omitted; and
Figure 4 is a transverse sectional view of a cam used for the key switch.
[0007] Briefly stated, the invention resides in that a pawl 6 is disposed sideways of a
switch operating cam 5 for a switch 2 and is urged to rotate towards the peripheral
side surface 5a of the cam 5, and a tooth 7 for meshing with the tip of the pawl 6
is disposed on the peripheral side surface 5a of the cam 5, so that reverse rotation
of the cam 5 is prevented by the engagement of the pawl 6 with the tooth 7 when the
switch 2 is turned on by rotation of the cam 5 in the normal operating direction.
[0008] A fitting base plate 8 is fixedly mounted to the rear of a lock main body 1 by a
screw 9, and the microswitch type switch 2 is fixed to the fitting base plate 8 by
a rear seat plate 10 in cooperation with a nut 11. The front end portion of an interlocking
plate 13 is slidably inserted into the rear end portion of a key groove 12 formed
in a lock cylinder 3 in its axial direction, and the rear - end portion of this interlocking
plate 13 is fitted into a split groove 14 of the cylindrical cam 5 that extends in
the radial direction of the cam 5. The rear end portion of the interlocking plate
13 is fixed to the cam 5 by a spring pin 15. A compression spring 17 and a small ball
18 are disposed in a centre through-hole 16 of the cam 5. The front end portion of
the compression spring is in pressure contact with the interlocking plate 13, and
the small ball 18 is in pressure contact with a receiving hole 19 that is disposed
on the rear seat plate 10. Accordingly, the cam 5 is urged to slide towards the rear
surface of the lock main body 1.
[0009] The switch 2 is adapted to be turned on and off by engagement with the suitably formed
peripheral side surface 5a of the cam 5. On the peripheral side surface 5a of the
cam 5 a step portion 21 is formed into which an actuator 20 of the switch 2 fits.
When the actuator 20 is positioned at the innermost portion of the bottom surface
21 a of the step portion 21, the switch 2 is kept off. The tooth 7 described above
is formed at a portion of the peripheral side surface 5a of the cam 5 with which the
actuator 20 does not come into sliding contact, that is, at the front end portion
of the peripheral side surface 5a of the cam 5. The base end portion of the pawl 6
is rotatably fitted to a bolt 22 which is interposed between the fitting base plate
8 and the rear seat plate 10. One of the ends of the pawl 6 is thus anchored to the
fitting base plate 8, with the other being urged to rotate towards the peripheral
side surface 5a of the cam 5 by a twist coil spring 23 which is in contact with a
side surface at the tip of the pawl 6.
[0010] A spacer cylinder 24 is fitted onto the portion of the bolt 22 between the pawl 6
and the rear seat plate 10. Locking of the cylinder 3 to the lock main body 1 is effected
by use of a known disc tumbler mechanism, pin tumbler mechanism, or the like. This
embodiment employs the pin tumbler mechanism. A follower pin 27 and a driving pin
28 disposed in pin receiving holes 25, 26 in the radial direction of the cylinder
3 and the lock main body 1, respectively, are urged to slide by a compression spring
29 in the axial direction of the cylinder 3.
[0011] Next, the operation of the key switch will be described.
[0012] When the key 4 is inserted into the key groove
' 12 of the cylinder 3 to a predetermined length, the contact surfaces of the follower
and driving pins 27, 28 coincide with the outer peripheral surface of the cylinder
3, so that lock of the cylinder 3 to the lock main body 1 is released. When the key
4 is pushed in the axial direction of the cylinder 3, the interlocking plate 13 and
the cam 5, that have been placed at the positions represented by dash lines in Figure
2, are pushed by the tip 4a of the key 4 and move backwards to the position represented
by solid lines in Figure 2. Next, when the cylinder 3 is rotated clockwise in the
normal operating direction by the key 4, as shown by arrows in Figure 1, the interlocking
plate 13 and the cam 5 follow the rotation of the cylinder 3 and are rotated in the
same direction, so that the tip of the pawl 6 sequentially comes into sliding contact
with slope surfaces 7a, 7b, 7c of the tooth 7 and then with the peripheral side surface
5a of the cam 5. During the period in which the pawl 6 passes through the portion
of the tooth 7 in this manner, the actuator 20 is pushed by the bottom surface 21a
of the step portion 21 at the position P
1 in Figure 1, so that the switch 2 is turned on. The switch is kept turned on as the
actuator 20 comes into sliding contact with the peripheral side surface 5a of the
cam 5. When the cam 5 thus rotates the step portion 21 to the position P
2 in Figure 1, the actuator 20 drops into the step portion 21, so that the switch 2
is turned off. When rotation in normal operating direction is further continued until
the step portions 21 reaches the position P
o in Figure 1, the pin receiving holes 25 and 26 are aligned on the same line, so that
the key 4 can be removed from the cylinder 3.
[0013] After the switch 2 has been turned on at the position P
1 of the step portion 21, even if an attempt is made to rotate the key 4 counterclockwise,
as seen in Figure 1, and thus to rotate the cam 5 in the reverse direction, the cam
5 cannot be rotated reversely to the OFF range between the positions P
o and P
i, because the pawl 6 meshes with the tooth 7 and engages with the restricting slope
surface 7b thereof before the actuator 20 drops into the step portion 21. For this
reason, the operator must rotate the key in the normal operating direction in order
to remove the key 4 at the position P
o of the step portion 21.
[0014] As described above, the present invention guides or forces the operator to fully
rotate the cam 5 to 360° because of a ratchet mechanism that includes the pawl 6 and
the tooth 7. Thus, the switch 2 is reliably kept in the ON state from the position
P
1 to the position P
2 in Figure 1 for a predetermined period of time required for equipment with which
the key switch is used.
1. A self-holding key switch equipped with
-a lock main body having a rotatable cylinder (3) adapted to be unlocked from the
lock main body (1) by the insertion of a key (4) into a key groove (12) of the cylinder
(3) and to be rotated by means of the key (4), a fitting base plate (8) being mounted
to the rear of the lock main body (1),
-a switch (2) fixed to the rear of the lock main body (1) and adapted to be turned
on and off by rotation of the cylinder (3),
-a cam (5) adapted to rotate integrally with the rotatable cylinder (3) and having
a tooth (7) formed on its peripheral side surface (5a), and
-a pawl (6) disposed at the side of the cam (5), one of the ends of the pawl (6) being
rotatably fitted at the fitting base plate (8) and the other being urged to be swivelled
against the peripheral side surface (5a) of the cam (5) by spring (23), the tooth
(7) of the cam (5) being adapted to engage with the pawl (6) at a predetermined switch
position when the cam (5) rotates in a normal operating direction and being formed
in such manner that a reverse rotation of the cam (5) is prevented by the engagement
of the pawl (6) with the tooth (7),
characterized in that
-the cam (5) is a switch operating cam (5) having a step portion (21) into which an
actuator (20) of the switch (2) fits, the step portion (21) is formed on the peripheral
side surface (5a) of the cam (5), the switch (2) being kept off when the actuator
(20) is positioned at the innermost portion of the bottom surface (21a) of the step
portion (21),
-tooth (7) is formed at a front end portion of the peripheral side surface (5a) of
the cam (5) with which the actuator (20) does not come into sliding contact,
the arrangement is such that
-when the key (4) is inserted into the key groove (12) and the cylinder (3) is rotated
in the . normal operating direction, the cam (5) being rotated in the same direction,
the tip of the pawl (6) sequentially comes into sliding contact with slope surfaces
(7a, 7b, 7c) of the tooth (7) and then with the peripheral side surface (5a) of the
cam (5), and when the pawl (6) passes through the portion of the tooth (7) the actuator
(20) is pushed by the bottom surface (21a) of the step portion (21), so that the switch
(2) is turned on, and
-the switch (2) is kept turned on when the actuator (20) comes into sliding contact
with the peripheral side surface (5a) of the cam (5) and until the cylinder (3) has
been rotated in the normal operating direction almost to the position in which the
key (4) may be withdrawn from the cylinder (3), when the actuator (20) drops into
the step portion (21) on the peripheral side surface (5a) of the cam (5), so that
the switch (2) is turned off.
2. A self-holding key switch according to claim 1, characterized in that the front
end portion of an interlocking plate (13) is slidably inserted into the rear end portion
of the key groove (12) of the cylinder (3) and the rear end portion of the interlocking
plate (13) is fitted into a split groove
(14) of the cylindrical cam (5) extending in the radial direction of the cam (5) and
is fixed to the cam (5), the front end portion of a compression spring (17) being
in pressure contact with the interlocking plate (13), so that the interlocking plate
(13) is urged to slide towards the rear surface of the lock main body (1), and when
the key (4) is inserted into the key groove (12) and pushed in the axial direction
of the cylinder (3), the interlocking plate (13) and the cam (5) are pushed by the
tip (4a) of the key (4) and move backwards, and when next the cylinder (3) is rotated
in the normal operating direction by the key (4), the interlocking plate (13) and
the cam (5) follow the rotation.
1. Selbsthaltender Schlüsselschalter, ausgestattet mit
-einem Schloßhauptkörper mit einem drehbaren Zylinder (3), der durch Einführen eines
Schlüssels (4) in einen Schlüsselschlitz (12) des Zylinders (3) vom Schloßhauptkörper
(1) entriegelbar und mittels des Schlüssels (4) drehbar ist, wobei eine Befestigungsgrundplatte
(8) an der Rückseite des Schloßhauptkörpers (1) montiert ist,
-einem Schalter (2), der an der Rückseite des Schloßhauptkörpers (1) festgelegt und
durch Drehen des Zylinders (3) ein- und ausschaltbar ist,
-einem Nocken (5), der gemeinsam mit dem drehbaren Zylinder (3) drehbar und an dessen
Umfangsseitenfläche (5a) ein Zahn (7) ausgebildet ist, und
-einer an der Seite des Nockens (5) angeordneten Rastklinke (6), wobei eines der Enden
der Rastklinke (6) drehbar an der Befestigungsgrundplatte (8) angebracht ist und das
andere von einer Feder (23) gegen die Umfangsseitenfläche (5a) des Nockens (5) verschwenkt
gehalten wird, und wobei der Zahn (7) des Nockens (5) bei einer vorbestimmten Schalterstellung
mit der Rastklinke (6) in Eingriff kommt, wenn sich der Nocken (5) in normaler Betätigungsrichtung
dreht, und in der Weise ausgebildet ist, daß eine Drehung des Nockens (5) in der umgekehrten
Richtung durch den Eingriff des Rastklinke (6) mit dem Zahn (7) verhindert wird,
dadurch gekennzeichnet, daß
-der Nocken (5) ein Schalterbetätigungsnokken (5) ist, der einen stufenförmigen Teil
(21) aufweist, in den ein Betätigungsglied (20) des Schalters (2) hineinpaßt, der
stufenförmige Teil (21) an der Umfangsseitenfläche (5a) des Nockens (5) ausgebildet
ist und der Schalter (2) ausgeschaltet gehalten wird, wenn das Betätigungsglied (20)
an der innersten Stelle der Bodenfläche (21a) des stufenförmigen Teils (21) positioniert
ist,
-der Zahn (7) an einem vorderen Endteil der Umfangsseitenfläche (5a) des Nockens (5)
ausgebildet ist, mit dem das Betätigungsglied (20) nicht in gleitender Berührung kommt,
wobei die Anordnung derart ist, daß
-wenn der Schlüssel (4) in den Schlüsselschlitz (12) eingeführt und der Zylinder (3)
in normaler Betätigungsrichtung gedreht wird, wobei der Nocken (5) in gleicher Richtung
gedreht wird, die Spitze der Rastklinke (6) aufeinanderfolgend mit geneigten Flächen
(7a, 7b, 7c) des Zahns (7) und dann mit der Umfangsseitenfläche (5a) des Nokkens (5)
gleitend in Berührung kommt, und wenn die Rastlinke (6) den Teil mit dem Zahn (7)
durchläuft, das Betätigungsglied (20) von der Bodenfläche (21a) des stufenförmigen
Teils (21) angedrückt wird, so daß der Schalter (2) eingeschaltet wird, und
-wenn das Betätigungsglied (20) gleitend in Berührung mit der Umfangsseitenfläche
(5a) des Nockens (5) kommt, der Schalter (2) eingeschaltet gehalten wird bis der Zylinder
(3) in der normalen Betätigungsrichtung fast bis zu der Stellung, in der der Schlüssel
(4) aus dem Zylinder (3) herausziehbar ist, gedreht worden ist, wobei das Betätigungsglied
(20) in den stufenförmigen Teil (21) an der Umfangsseitenfläche (5a) des Nockens (5)
hineinfällt, so daß der Schalter (2) ausgeschaltet wird.
2. Selbsthaltender Schlüsselschalter nach Anspruch 1, dadurch gekennzeichnet, daß
der vordere Endteil einer Verriegelungsplatte (13) gleitbar in den rückwärtigen Endteil
des Schlüsselschlitzes (12) des Zylinders (3) eingeführt und der rückwärtige Endteil
der Verriegelungsplatte (13) in eine spaltartige Nut (14) des zylinderförmigen Nockens
(5), die sich in Radialrichtung des Nockens (5) erstreckt, eingesetzt und am Nocken
(5) festgelegt ist, wobei der vordere Endteil einer Druckfeder (17) sich in Druckkontakt
mit der Verriegelungsplatte (13) befindet, so daß die Verriegelungsplatte (13) zur
rückwärtigen Fläche des Schloßhauptkörpers (1) hin verschoben wird, und daß, wenn
der Schlüssel (4) in den Schlüsselschlitz (12) eingeführt und in der Axialrichtung
des Zylinders (3) gedrückt wird, die Verriegelungsplatte (13) und der Nocken (5) von
der Spitze (4a) des Schlüssels (4) geschoben werden und sich nach hinten bewegen,
und wenn danach der Zylinder (3) vom Schlüssel (4) in der normalen Betätigungsrichtung
gedreht wird, die Verriegelungsplatte (13) und der Nocken (5) der Drehung folgen.
1. Un interrupteur à clé à auto-maintien équipé
-d'un corps principal de verrou comportant un cylindre tournant (3) agencé pour être
déverrouillé par rapport au corps principal de verrou (1) par l'insertion d'un clé
(4) dans une rainure de clé (14) du cylindre (3) et pour être tourné au moyen de la
clé (4), une plaque de base (8) de montage étant montée à l'arrière du corps principal
de verrou (1),
-un interrupteur (2) fixé à l'arrière du corps principal de verrou (1) et agencé pour
être mis en position fermée et en position ouverte par rotation du cylindre (3),
-une came (5) agencée pour tourner solidairement avec le cylindre tournant (3) et
présentant une dent (7) formée sur sa surface latérale périphérique (5a), et
-un cliquet (6) disposé sur le côté de la came (5), l'une des extrémités du cliquet
(6) étant montée à rotation sur la plaque de base (8) de montage et l'autre étant
sollicitée pour basculer contre la surface latérale périphérique (5a) de la came (5)
par un ressort (23), la dent (7) de la came (5) étant agencée pour coopérer avec le
cliquet (6) pour une position prédéterminée de l'interrupteur quand la came (5) tourne
dans le sens normal de fonctionnement et étant formée de telle manière qu'une rotation
de la came (5) en sens inverse est empêchée par la coopération du cliquet (6) avec
la dent (7),1
caractérisé en ce que
-la came (5) est une came (5) d'actionnement de l'interrupteur présentant une partie
en gradin (21) dans laquelle s'adapte un élément d'actionnement (20) de l'interrupteur
(2), la partie en gradin (21) est formée sur la surface latérale périphérique (5a)
de la came (5), l'interrupteur (2) étant maintenu ouvert quand l'élément d'actionnement
(20) est placé dans la partie la plus intérieure de la surface de fond (21 a) de la
partie en gradin (21),
-la dent (7) est formée à la partie extrême avant de la surface latérale périphérique
(5a) de la came (5) avec laquelle l'élément d'actionnement (20) ne vient pas en contact
de glissement, l'agencement étant tel que
-quand la clé (4) est insérée dans la rainure de été (12) et que le cylindre (3) est
tourné dans le sens normal de fonctionnement, la came (5) étant tournée dans le même
sens, l'extrémité du cliquet (6) vient séquentiellement en contact de glissement avec
des surfaces inclinées (7a, 7b, 7c) de la dent (7), puis avec la surface latérale
périphérique (5a) de la came (5) et, quand le cliquet (6) traverse la partie de la
dent (7), l'élément d'actionnement (20) est poussé par la surface de fond (21a) de
la partie en gradin (21), de sortie que l'interrupteur (2) se ferme, et
-l'interrupteur (2) est maintenu fermé quand l'élément d'actionnement (20) vient en
contact de glissement avec la surface latérale périphérique (5a) de la came (5) et
jusqu'à ce que le cylindre (3) ait été tourné dans le sens normal de fonctionnement
presque jusqu'à la position pour laquelle la clé (4) peut être retirée du cylindre
(3) quand l'élément d'actionnement (20) tombe dans la partie en gradin (21) de la
surface latérale périphérique (5a) de la came (5), de sorte que l'interrupteur (2)
s'ouvre.
2. Un interrupteur à clé à auto-maintien selon la revendication 1, caractérisé en
ce que la partie extrême avant d'une plaque d'interverrouillage (13) est insérée de
manière coulissante dans la partie extrême arrière de la rainure de clé (12) du cylindre
(3) et la partie extrême arrière de la plaque d'interverrouillage (13) est adaptée
dans une gorge fendu (14) de la came cylindrique (5) s'étendant dans la direction
radiale de la came (5) et est fixée à la came (5), la partie extrême avant d'un ressort
de compression (17) étant en contact de pression avec la plaque d'interverrouillage
(13), de sorte que la plaque d'interverrouillage (13) est sollicitée à glisser vers
la surface arrière du corps principal de verrou (1) et, lorsque la clé (4) est insérée
dans la rainure de clé (12) et poussée dans la direction axiale du cylindre (3), la
plaque d'interverrouillage (13) et la came (5) sont poussées par l'extrémité (4a)
de la clé (4) et se déplacent vers l'arrière et, lorsque le cylindre (3) est à nouveau
tourné dans le sens normal de fonctionnement par la clé (4), la plaque d'interver-
rouillage (13) et la came (5) suivent la rotation.