Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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BACKGROUND OF INVENTION
Field of the Invention
The present lnvention relates to an improved
delay action time lock and wherein an electronic timer is
provided having adjustable features whereby to preset two
time delay periods, the first one being actuated by
turning a key cylinder or combination lock cylinder to an
open position, and the second being effectuated
immediately after the first time delay period is
terminated or as soon as a bolt retracting lever is
retracted to pull the lock bolt within the lock housing.
Description of Prior Art
Various delay action time locks are known
effect time delay counts prior to enabling a mechanism to
permit a lock to be opened. Most of these known locks
utilize complex mechanical cams and levers and timers and
many do not provide for an adjustment of the time period,
or if they do, this adjustment is very limited. Also,
these time locks are not very reliable and are difficult
to repair and service. Still further, the time locks are
not very precise in their time counts and this may have
certain disadvantages in specific applications of the
lock where very accurate time delays are required from
very short periods of a few seconds to long periods of
many hours.
SUMMARY OF INVENTION
It is therefore a feature of the present
invention to provide an improved delay action time lock
which substantially overcomes the above-mentioned
disadvantages of the prior art and particularly a time
lock which has an electronic timer which incorporates one
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or more timer modules which can be precisely set to
effectuate a very accurate time delay count, and to a
lock which is simple in construction, reliable, and which
provides easy adjustment of the timer within a very large
time scale.
Another feature of the present invention is to
provide an improved delay action time lock which is easy
to operate by the user and easy to service due to its
modular construction.
According to the above features, from a broad
aspect, the present invention provides a delay action
time lock comprising a lock housing having a spring
action bolt. A retracting cam is also provided and has a
retracting means for engagement with a bolt retracting
lever for retracting a locking end of the bolt in the
housing. Retracting cam actuating means is disposed
outside the housing for turning the cam. A motor
actuated support cam is provided for normally supporting
the bolt retracting lever in a disengaged position with
the retracting cam. Switch means is associated with the
retracting cam for enabling a timer circuit to initiate a
first preset time delay count. An electric motor is
connected to the retracting lever support cam. The timer
causes the motor to be energized after the preset time
delay whereby the motor will turn the support cam in a
first direction to cause the retracting lever to move to
an engageable position for engagement by the retracting
cam. The timer circuit initiates a second preset time
delay count after terminating the first count after which
the motor is energized to cause the support cam to turn
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in a reverse direction to support the retracting lever at
its disengaged position whether the retracting lever is
retracted or not by the retracting cam.
BRIEF DESCRIPTION OF DRAWINGS
A preferred embodiment of the present invention
will now be described with reference to the example
thereof as illustrated in the accompanying drawings, in
which:
FIGURE 1 is a perspective view illustrating the
modular construction of the delay action time lock of the
present invention with the electronic timer module
removably secured to the lock housing;
'FIGURE 2 is a rear view of the lock housing
illustrating the main components of the delay action time
.lock of the present invention;
FIGURE 3 is a view similar to Figure 2 but
showing the retracting cam turned to an actuating
position to enable the timer circuit;
FIGURE 4 is also a view similar to Figure 2 but
showing the retracting lever support cam in its
disengaged position with the retracting cam engaged with
the bolt retracting lever;
FIGURE 5 is also a view similar to Figure 2 but
showing the motor actuated support cam in its position
for maintaining the retracting lever in its disengaged
position once released by the retracting cam;
FIGURE 6 is a simplified top view of the basic
components of Figure 5; and
FIGURE 7 is a block diagram showing the
construction of the electronic timer of the present
invention.
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DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to the drawings, and more
particularly to Figure 1, there is shown the delay action
time lock of the present invention. This Figure
illustrates the modular construction of the lock and it
comprises a lock housing 10 in which is housed the
locking mechanism to retract the locking end 11' of the
lock bolt 11 into the housing 10 whereby to open a door
(not shown) to which the lock housing is secured. The
bolt end 11' is retracted by turning the key 12 which is
inserted in the keyhole 13 of the lock cylinder 14. A
timer housing 15 is secured to the lock housing at a
convenient location and is provided with a window opening
16 in which are disposed a plurality of dip switches 17
to provide adjustment of preset time delays of the timer
modules, which will be described later, provided in the
electronic timer circuit.
In operation, the key 12 is inserted in the
keyhole 13 and the key cylinder 14 is turned clockwise,
until the key is arrested. This initiates a first preset
time delay count by the timer circuit and after which
time a signal, either audible or visual, is generated to
indicate to the operator that the key can now be
positioned to retract the bolt end 11' into the housing.
As soon as the first preset time delay count is
terminated, the timer circuit initiates a second time
delay count and the lock bolt must be retracted by the
key within that period. If not, rotation of the key 12
will not engage the necessary levers to retract the
locking end 11' of the bolt within the housing. If the
lock bolt is retracted, then the second count is
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automatically cancelled and as soon as the lock bolt is
released, the key or the key cylinder is disengaged from
the bolt retracting mechanism.
Referring now additionally to Figures 2 to 6,
there will be described the detailed construction and
operation of the delay action time lock 10. As shown in
i Figure 2, the lock cylinder 14 is connected to a shaft 18
on which is secured a bolt retracting cam 19. The cam is
provided with a hook member 20, formed integral
therewith, and having an engaging end 21 whereby to
engage with a retracting notch 22 provided in a bolt
retracting lever 23 which is connected to the lock bolt
11. As herein shown, the lock bolt is a spring action
lock bolt and the bolt is biased outwardly by a helical
spring 24, in a manner well known in the art. The bolt
retracting lever 23 is connected to the bolt 11 on a
pivot pin 25. The bolt retracting lever 23 is biased
downwardly by means of helical spring 26.
The free end portion 27 of the retracting lever
23 is provided with a support pin 28 extending trans-
versely thereto (see Fig. 6) and on which a peripheral
edge portion 29 of the motor actuated support cam 30
abuts whereby to displace and support the bolt retracting
lever 23 at a disengaged position as shown in Figure 2.
Referring again to Figure 6, it can be seen
that the cam engageable pin 28 has a free end 31 which is
disposed in close proximity to a switch contact arm 32 of
a timer cancellation switch 34 constituted by a
microswitch. The free end 31 of the pin 28 is engaged in
frictional contact with the switch contact arm 32 when
the retracting lever 23 is retracted in the direction of
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arrow 33 when the lock bolt end 11' is retracted within
the housing. Disengagement causes the switch contact arm
32 to effect a switch closure to cancel the second preset
count of the timer.
In order to initialize the timer to effect the
first preset time delay count, as previously described,
the key 12 is inserted into the key slot 13 and the lock
cylinder 14 is rotated causing the bolt retracting cam 19
to turn in the direction of arrow 35 as shown in Figure
3. The cylinder or key 12 is turned until it is arrested
when the hook arm 20 of the cam 19 abuts with the switch
contact post 36. The switch contact post 36, as shown in
Figure 6, is provided in an electrically insulating
casing 37 and an insulated wire 38' is connected thereto
and to the appropriate connection in the timer circuit.
This contact closure initiates a first preset time delay
count and after this count, an appropriate indication,
either an audible or visual indication, is transmitted so
that the user is now aware of the expiration of the
first preset time delay count. At this time, the key 12
is turned to its initial position placing the bolt
retracting cam 19 to its position as shown in Figure 2.
This retraction could have been done also immediately
after the hook arm 20 has made contact with the contact
pin 36. Immediately after the first preset time delay
count has terminated, the timer circuit connects a
six-volt supply to the motor 38, which is connected to
the motor actuated support cam 30, causing the cam to
rotate a predetermined distance in the direction of arrow
39 (as shown in Fig. 3) whereby the cam 30 assumes its
position as shown in Figure 4, thereby disconnecting its
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support engagement with the support pin 28 of the bolt
retracting lever 23. Accordingly, the lever drops down
to its position as shown in Figure 4 due to the pulling
force exerted by the helical spring 26 and arrested at
this engageable position by abutment means (not shown).
The engaging end 21 of the bolt retracting cam 19 is now
engageable in the notch 22 so that by turning the key 12
again in the direction of arrow 35, the retracting lever
free end portion 27 is lifted upwards so that the free
end 31 of the pin is aligned with the switch contact arm
32. At the same time, the free end portion of the bolt
will move inwardly in the direction of arrow 40 (see Fig.
4) so as to cause the switch contact arm 32 to close and
effect a switch closure to cancel the second preset time
delay count.
As soon as the second preset time delay count
is terminated, the motor 38 is again actuated by the
timer circuit whereby to move the motor actuated support
cam 30 back to its initial position, as shown in Figure
5. Therefore, as soon as the key 12 is rotated back to
its initial position, the lock bolt 11 will move out of
the housing drawing the bolt retracting lever 23 to its
positlon as shown in Figure 2 and the support pin 28 now
rests against the support peripheral edge portion 29 of
the cam 30 with the retracting notch 22 positioned
outside the arc of displacement of the hook member 20 and
the lock bolt can no longer be retracted.
In the event that the bolt retracting cam 19 is
maintained in a position engaged with the contact pin 36
during the first preset time delay count, it is pointed
out that after the count is terminated, the hook member
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20 can still be positioned back at its original position
as shown in Flgure 2 by slmply rotatlng lt ln a
counterclockwlse manner. Because the bolt retractlng cam
19 ls dlsposed ln a common plane with the bolt retracting
lever 23, when rotating the bolt retracting cam in a
counter direction, the rear top edge 41 of the hook
member 20 will abut against the sloped wall 42 formed on
the lower edge of the free end portion 27 of the
retracting lever to push the bolt slightly upwardly so
that the hook member 20 can be positioned to engage the
notch 22. Also, if after the expiration of the second
time delay count, the key 12 has not been rotated to
effect a bolt retraction, then the support cam 30 is
automatically actuated by the motor 38 and thls engages
with the support pin 28 and pushes the bolt retracting
lever 23 back to its initial disengaged position as shown
in Figure 2. It is therefore necessary to again
reactivate the first preset time count of the electronic
timer and wait for the delay period before the retracting
lever can again be engaged.
As shown in Figures 2 to 5, the motor actuated
support cam 30 is a disc-shaped cam which has a circular
support cam portion 29 for engagement with the support
pin 28 and a cut-out portion 43 to liberate the bolt
retracting lever 23. The disc is also provided with a
slot 44 not to interfere with the contact pin 36. A disc
support cam is also offset from the plane of the bolt
retracting lever 23.
Referring now to Figure 7, there will be
briefly described the construction and operation of the
timer circuit 50. The timer 50 consists of a small
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electronic circuit connected to the servo-motor 38 and a
six-volt battery 51. It is in fact a double timer; the
first one 52 controls the time until the lock is
permitted to open, and the second timer 53, the time
during which the lock can be opened.
Initially, the timer circuit 50 is turned on by
rotating the lock key 12 clockwise and returning it to
its initial position. The timer 52 starts and, at the
expiration of its preset time, the motor's shaft 38'
rotates by 90 degrees. This allows a door to be opened
by the lock. Subsequently, the second timer 53 starts
and, at the expiration of the second preset time, the
motor returns to its initial position, and the timer
circuit turns itself off. If, during the second preset
time the door is opened by the lock, the motor 38
immediately returns to its original position and the
circuit turns itself off. The timer is then ready for
another cycle. The timers 52 and 53 are fully adjust-
able, anywhere from seconds to days. The accuracy of the
timer is excellent, with less than 10 seconds of error
per day.
As shown in Figure 7, the timer circuit 50 has
two sections: the first section consisting of the supply
and protection diode 54 and a flip-flop circuit 55 which
is continuously power~d from the six-volt battery. The
second one, the timer per se, is powered from the circuit
55. When the timer is off, the drain from the battery is
in the order of 10 micro-amperes and represents only a
fifth of the battery capacity over a one-year period.
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Flip-flop circuit 55 acts as an electronic
switch which is turned on by a contact closure with pin
36 operated by the lock key, and turned off by the timer
circuit itself at the end of a timing cycle.
An oscillator/counter integrated circuit 56 is
also provided and is controlled by a very stable crystal
57. The counter 56 has fifteen divide-by-two stages and
provides outputs at 60, 10 and 1 Hz. The 1 Hz output 58
is used as a clock for the entire circuit and is
distributed to integrated circuits U2, U4, U5 and U6. U2
and U3 form an 18- stage counter operated at 1 Hz. On
initial power-up, U7A clears U2, U3, U4B, U5A and U5B,
and sets U4A. U8 and U9 decode specific times by adding
the outputs selected by the dip switches. Timer 53 can
thus be adjusted from 1 to 255 seconds in steps of one
second, and timer 52 from 32 to 262, 143 seconds (72.8
hours) in steps of 32 seconds. Any gate input not
connected to the counter while a switch is open is pulled
up to +V by the resistor network 59.
At the expiration of timer 52, U9-9 drops low
and sets U4B and U5A thus enabling U8 in preparation for
the timing operation of timer 53. On the next positive
clock, 0.5 seconds later, U4A is reset. This signals the
motor to turn by providing a low on the drive signal to
U10. Simultaneously, the counters U2 and U3 are cleared
via U7C. Once the counters are cleared, U9-9 returns to
a high and 0.5 seconds later, U4A is set. This releases
the counters which are now timing the preset time of
timer 53. The setting of U4A would normally
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force the motor back to its original position but ~7D and
transistors Ql, Q2 insure that the power is only applied
to the motor for the duration of the drive signal.
At the expiration of timer 53, U4B is reset.
This disables T2 and resets U5A on the next positive
clock edge, enabling U7B. This causes the power to be
reapplied to the motor via U7D, Ql and Q2 returning it to
its original position. A second later, U6A toggles and
removes the power from the timer circuit.
If, during the preset time period of timer 53,
the "Open" line is pulled low by the opening of the lock
door, U4B is cleared. Again, this disables timer 53 and
resets U5A on the next positive clock edge, thus enabling
U7B. This causes the power to be applied to the motor
via U7D, Ql and Q2 which returns it to is original
position. A second later, U6A toggles and removes the
power from the timer circuit.
UlOA and UlOB are both power amplifiers
designed to drive the servo-motor. The feedback
potentiometer VRl is mechanically linked to the output
shaft of the motor. It drives the amplifier with a
voltage proportional to the shaft's position. When the
"Drive" signal is set low by the timer, UlOA forces some
current to the motor which rotates until the voltage at
VRl reaches a point corresponding to a 90 degree
rotation. On the other hand, when the timer sets "Drive"
high, UlOB forces current in the opposite direction until
the voltage at VRl has returned to its original value.
In any event, the power is only applied to the motor and
to U10 and VRl for the duration of half a clock period or
0.5 seconds.
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It is within the ambit of the present invention
to cover any obvious modifications of the preferred
example described herein, provided such modifications
fall within the scope of the appended claims. For
example, it is pointed out that although the lock
cylinder is hereinshown as a key operated cylinder, it is
also obvious to a person skilled in the art that this
cylinder could be operated by a combination lock using
tumblers whereby after a combination is preset, the knob
can be positioned in engagement with the shaft 18 of the
bolt retracting cam 19.
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