Note: Descriptions are shown in the official language in which they were submitted.
~:~S~ 4
The present invention relates generally to mechanical
digital locks and more particularly to a mechanical digital
lock that is operable through a series of mechanical operations
actuated by the depression of digital keys, comprising an
intellectual combination of essential mechanisms including a
plurality of key means, digital selecting means, identifying
means, locking means and automatic resetting means. The number
of digital combinations is enormous and the lock cannot be
opened unless the predetermined digitals are sequentially
depressed on the key board. Once the lock is opened, it is
automatically reset. A change of combination of digitals can
easily be effected manually without using any tool. With this
structure, the lock is highly reliable.
Most traditional key-depression digital locks are of
the electronic/mechanical type with complicated structure. Wiring
is usually necessary upon installation and the costs of both
manufacturing and installation are relatively high. The lock
will be dead during circuit problems or power failure, this being
the main drawback. Some types of key-depression digital locks
have been recently proposed. However, their structures are rather
complicated with unusually high cost and relatively low reliabili-
ty. The change of digital combinations can only be effected
by a skilled worker with special tools. sesides, only four
digits are usually adopted. Hence their number of combinations
is quite limited.
The present invention thus overcomes the aforesaid
drawbacks in conventional digital locks and provides a
mechanical digital lock of high reliability, comprising digital
selecting means having dial arm with changeable insertions
~hich can be easily relocated to change digital combination.
Further, six up to ten dlgitals are capable of being adopted, so
that the number of combination of digital becomes enormous. The
-1- ,~
S7~
lock digitals cannot be detected through hearing or touch.
The present invention also provides a mechanical
digital lock having mechanical means for identifying digital
sequence. Key depression of a wrong sequence that deviates
from the predetermlned order will result in a deadlock condition,
until it is manually reset, the lock wil~ not open.
The present invention further provides a mechanica'
digital lock having automatic resetting means whi~ch would o~erate
automatically after the lock is opened. The lock can be used
without additional operations.
The present invention again provides a mechanical
digital lock havin~ uni~ue design of lock core and latch which
is suitable both for use on doors of left and right swings.
The present invention also provides a mechanical
digital lock with simple construction for easier manufacturing
and installation, which is especially suitable for use on any kind
of door.
According to the present invention there is provided
a mechanical diyital lock for use on a door which opens and closes
within a frame, said lock comprising: a casing mountable on the
door, latch means carried by said casing and movable into and
from locking engagement with the door frame, manually actuable
handle means carried by said casing and accessible externally of
the casing, latch actuating means displaceably carried by said
casing and operably connected to said handle means and said latch
means so as to be displaced in response to actuation of said
handle means to move said latch means into and from said locking
engagement, a plurality of key means carried by said casing,
each key means including a manually displaceable key accessible
externally of said casing, a plurality of selecting means carried by
said casing and each arranged to be engaged and displaced by an
associated one of said key means when the key thereof is displaced,
identifying means carried by said casing and actuable by said
l~S~S79~
selecting means to permit displacement of said latch actuatirlg
means for moving said latch from said locking position, said
identifying means comprising: a plurality of independently
movable elements arranged to be engaged and moved to a release
mode by an assoclated one of sald selecting means when the latter
is displaced by its associated key means, each element
including gate means arranged to prevent displacement of said
latch actuating means to unlock said latch means unless said
element is in its release mode; all of said elements, except
an initially actuable one of said elements, including stop means
normally preventing movement to said release mode, all of said
elements, except a finally actuable one of said elements,
including stop-deactivating means response to movement of said
element to its release mode for deactivating the stop means of
the subsequent element to permit the latter to move to its
release mode, so that all of said elements can be moved to the
release mode only when actuated in proper sequence, retaining
means carried by said casing for releasably holding each of said
elements in a release mode, and resetting means carried by
said casing and operably connected to said handle means and
retaining means to release said retaining means when said handle -
means is moved to lock said latch for enabling said elements to
move out of said release mode.
In one embodiment of the present invention the
elements each comprise first and second slidable blocks, said
first block being engageable by an associated one of said
selecting means, said stop means normally connecting said second
block for movement with said first block and being moved to a de-
activated position by said stop deactivating means of a previous
by-actuated element to enable said first block to be displaced
relative to said second block to define said release mode for
such element.
1153S7~
Suitably, the second block when displaced together
with said first block is positioned to prevent displacement of
said latch actuating means to unlock said latch, and the retaining
means holds said first block and said second block when the
latter is displaced together with said first block.
In one particular aspect thereof, the present invention
~rovides a mechanical digitallock for use on a door whi~h ~pens and
closes within a frame, said lock comprising; a casing mountable
on the door, latch means carried by said casing and movable into
and from locking engagement with the door frame, manually
actuable handle means carried by said casing and accessible
external~y of the casing, latch actuating means displaceably
carried by said casing and operably connected to said handle means
and said latch means so as to be displaced in response to
acutation of said handle means to move said latch means into and
from said locking engagement, a plurality of key means carried
by said casing each key means including a manually displaceable
key accessible externally of said casing, a plurality of
selecting means carried by said casing and each arranged to be
engaged and displaced by an associated one of said key means
when the key thereof is displaced, each selecting means comprising:
a plurality of sets of selecting arms, the number of sets of
arms corresponding in quantity to the number of digits in the
lock combination, and a removable insert disposed upon one
selecting arm of each set and arranged to be engaged by one of
said key means, identifying means carried by said casing and
actuable by said selecting means to permit displacement of
said latch actuating means for moving said latch from said locking
position, said identifying means comprisina: a plurality of
independently movable elements arranged to be engaged and moved
to a release mode by an associated one of said selecting means
when the latter is displaced by its associated key means, each
57~L
element including yate means axrarlged to prevent displacement
of said latch actuating means to unlock said latch means unless
said element is in its release mode, retaining means carried
by said casing for releasably holding each of saia elements in
a release mode, and resetting means carried by said casing and
operably connected to said handle means and retaining means
to release said retaining means when said handle means is
moved to lock said latch.
The present invention will be further illustrated
by way of the accompanying drawings, in which:
Fig. 1 is a partial cutaway perspective view of a
preferred embodiment of the mechanical digital lock according
to the present invention;
Fig. 2 is a partial cutaway front view of the same
embodiment;
Fig. 3 is a partial cutaway side view of the same
embodiment;
Flg. 4 is a back view of the key panel;
Fig~ 5 is a perspective view of the digital selecting
means thereof;
Fig. 6 is an e~plodecl perspective view of the digital
selecting arms;
Fig. 7 is a perspective view of the digital identi-
fication means thereof;
Fig. 8 is a top view of the digital identification
means;
Fig. 9, which is on the same sheet as Fig. 4, is a
partial cutaway side view of the digital identification means;
Fig. 10 is a partial cutaway front view showing
the relation between the core plate and the latch means;
Fig. 11 is a partial cutaway side view showing the
relation between the core plate and the latch means;
~3~i7~
Fi~ 12 is a ~artial cuta~ay perspective view showing
the essential part of the resetting means;
Fig. 13 is a schematic view showing the installation
of the locls in concern; and
Fig. 14 (A) and (B) are side views showing the
operation of the lock in concern.
Referring to Figs. l to 3, the mechanical digital lock
of the present invention comprises a casing 1, frame 2, key
means 3, digital selecting means 4, identifying means 5, core
plate 6, latch means 7, resetting means 8, knob 9, inside
opening means 10, base plate 11 and face plate 12~
The casing l has an upper case la and a lower case lb,
and is detachably mounted by screws on the side walls of the
base plate 11. The casing encloses therein the whole mechanical
means M of the lock. The upper case la is detachably mounted
upon the upper end of the lower case lb with screws. The frame
2 comprises a pair of side walls 21-21 and two connecting plates
22 to hold a key panel box 31 tight with screws. Mechanical
means M is mounted within the frame 2.
The key means 3 is mounted at the uppermost section
of the frame 2 on the connecting plate 22 thereof. The key means
3 comprises a key panel box 31, a plurality of keys 34, say ten,
usually representing numerals 0-9 and/or characters as
reguired. The keys 34 are retained in key holes 33 provided in
the key panel box 31 and each biased from behind by a spring 32.
Key rod 35 extends from the back of each key 34 into the case l.
For the compactness of the layout, the ten keys are arranged into
two rows, five in the upper row and five in the lower row. Since
it is necessary to arrange the end of key rods 35 into a single
row to faci itate operation without conflict, the ends 36 of rods
35 are bent as shown in Fig. 4.
Digital selecting means 4 is disposed at a somewhat
~ 15;~7~L
lower position than key means 3, comprising a number of sets of
selecting arms 41 arranged parallel from front to rear. The number
of sets of arms chosen in this embodiment is six correspondin~
to a predetermined number of digits, six. Hence, each of six
inserts 42 is detachably and selectively inserted on the upper end
of one arm of each set of arms 41.
Each set of selecting arms 41, such as shown in Fiy. 5,
comprises a number of arms corresponding to the number of the keys,
in this case, ten. Each member of arm set 41 comprises an upward-
ly extended upper arm 41a, each set of arms 41 having a lower arm41b extending from just one of the lower end of the ten arms 41,
in the set. Since each lower arm, having forwardly bent tip 411,
extends from a different set of arms to avoid ~heir overlapping,
each of the six sets of arms is consolidated to provide axle plates
41c at their ends and with bearing socket 43 pivotally mounted on
the side wall 21 of the frame 2, so that each set of arms can
swing freely about the said axle plate 41c. For the compactness
of layout, the axle plates 41c are disposed at two diEferent
levels. In the meantime, to facilitate the lower tips 411 of
downwardly extended lower arm 4lb reaching the identifying means
which is prearranged in a single row, the upper/lower arms 41a/41b
of the arm 41, except the left-hand one (the first one), are bent
to a different extent in the shape " ~ " with various lengths of
horizontal spacing, so that the tips 411 can be within a same
plane where the identifying means is located.
Referring also to Fig. 6, it can be seen that each upper
arm 41a of the ten arms in the set has one or two positioning
holes 412 to facilitate the insertion of the inser's 42. The
position of the inserts is set by projected nipples 421 provided
inside the socket 42a of the inserts 42 to lock into the
- respective positioning holes 412. Each set of the six sets of
selecting arms 41 is provided with one of such inserts 42. Upper
~535i74
arm 42b of the insert 42 extends forwardly and is arranged to be
touched by the end 36 of rod 35 o~ a depressed key. A gap is
therefore maintained between the rod end 36 and the upper arm
42b of the insert 42. Since it is desired that the uppex arm
42b to be in alignment with the single row ends 36, the bend
of the upper arms 42b except the one closest to the key, into a
"~ " is necessary, and the extent of the bends varies with the
increasing length of the horizontal portion from left to right.
It is also necessary that the inserts 42 are so placed from the
set closest to the key to the rearest set according to the
predetermined order of digital numbers.
The ldentifying means 5 is located under the selecting
means 4, such as shown in Figs. 7 to 9. It comprises a front
fixing plate 51a, a rear fixing plate 51b, and a guide plate 52
fixed between the two plates 51a, 51b. A plurality of sets
(corresponding to the number of selecting arm sets 41, i.e. six
sets) of elements each element comprising a front sliding block
53a and a rear sliding block 53b which blocks are slidably
mounted as a pair on the guide plate 52. A claw 54 is pivotally
disposed on plate 52 and between adjacent pairs of block 53a-53b.
A stopper 55 is disposed on each front sliding block 53a except
on the first or left-hand block 53a. A return spring 56 is
provided between each front sliding block 53a and the front
fixing platè 51a, and a compression spring 57 is disposed between
the front and rear sliding blocks 53a, 53b, of each pair.
The ~ront fixing plate 51a and the rear fixing plate 51b
are both of "U" shaped cross section. However, plate 51a is
larger than plate 51b, the yuide plate 52 being clamped between
them and fixed by screws. ~uiding grooves 521 corresponding to the
number of selecting arm sets 41, i.e. six, are evenly spaced
on the guiding plate 52. The front and rear sliding blocks 53a,
53b are slidably mounted in palrs on the plate 52 with their
~iS3~
slidin~ channel formed on individual ~ates or legs 53a' and 53b'
inserted into the guiding groove 521. A recess 531 is formed in
the front wall of the front slidiny block 53a, a spring 56 with
its one end retained in said recess 531 and the other end pushed
against the front fixing plate 51a. Upon each front sliding
block 53a, disposed in front is a wedge-like projection 532 which
is opposite to a straight rear wall 533. At the back of said
rear wall 533, a spring retaining stud 534 is provided. While on
the front side of the wall 533, a hook like projection 535 is
disposed. setween projections 532 and 535, a stopper 55 is
mounted with a pivot pin 551. Biased by the force of spring 58,
the front end 552 of the stopper 55 tends to rotate .o the
left, yet ~he rear end 553 of the stopper 52 abuts against the
side surface of the projection 535 to ensure a limited projection
of the front end 552. An inclined surface 536 is formed in front
of the leg 53a' of the front sliding block 53a. At the bottom of
the inclination, a locking recess 537 is drilled.
The rear sliding block 53b has a rear wall 501. A
spring retaining stud 502 is disposed on the inner side opposite
the stud 534 on front sliding block 53a. A compression spring 57
is retained between the studs 502-534. An arm 503 extends
forwardly from the side of the rear sliding block 53b. A
triangular shaped stopper 504 is formed at the tip of the arm
503 to be almost in contact with the projected end 552 of the
stopper 55.
The hook shaped claw 54 is pivoted through a pin 541
to the guide plate 2 at a position between adjacent grooves 521,
and biased by a spring 542 to force its claw end 543 to have its
rear inclination 544 constantly pressed against the inclination
on projection 535. The front end 543 of the claw 54 keeps an
appropriate gap with the front end 552 of the stopper 55.
Lock core plate member 6 having a side cross section of
~L~$357~
" ~ " shape is disposed under the identifying means 5, such as
shown in Figs. 10, 11. The core plate member 6 comprises a
front plate 61, a back plate 62 and a bottom plate 63 On the
front plate 61, one lon~ claw 64 and short claw 65 are formed.
A toothed portion 66 having a plurality of teeth is formed on
the back plate 62, in a position under the blocks 53a, 53b,
with the projected teeth just engaging into a continuous groove
59 formed between the legs 53a', 53b' of the blocks 53a, 53b.
A rectangular aperture 68 with a vertical flap 67 punched out
along one side is disposed at the center of the front plate 61
of the core plate 6. A pair of arms 621, 631, extend from both
sides of the back plate 62 and the bottom plate 63, respectively,
and are slidably inserted into pairs of guides 23 provided on
side walls 21 of the frame 2 for supporting the core plate 6.
A return spring 69 is provided on the left arm 621 to bias the
core plate against the right side wall 21. A rotatable arm 60
is pivoted on a pin 601 on the inner center of the base plate 11,
with its upper and lower end engaged respectively with the latch
7 and the short claw 65 to provide for the door opening.
Latch means 7 is provided laterally across the central
part of the frame 2 and located between the selecting means 4 and
the identifying means 5. Latch 7 with its one end formed into
a wedge head 71 and the other base end 73 having a central recess
72 is slidably mounted into a pair of horizontal guides 24 formed
on the two side walls 21 of the frame 2. The base end 73 of the
latch 7 is slipped into a closed end nylon socket 25 inserted in
one of the horizontal guides 24. A spring 74 is retained between
the socket 25 and the central recess 72 to bias the latch to cause
its wedge head to extend out of the side wall 21. A follower
member 75 having a left plate 75a and a right plate 75b is
- detachably clamped to the middle of the latch 7. The bent end of
the long claw 64 extends at the right side of the left follower
1153S74
plate 75a, so that when the core plate 6 moves to the left, the
claw 64 pulls the follower member 75 to the left against the
spring 74 to cause the withdrawal of the wedge head 71 of the
latch 7 into the frame 2 to open the door. The core plate 6 thus
functions as a latch actuating means.
The resetting means is located under the identifying
means 5 and is parallel to the core plate 6 such as shown in
Fig. 12. It comprises a supporting rack 81 having an "S" shaped
cross section. The rack 81 with its two ends passes through two
vertical posts 82 and moves freely up and down thereon. The lower
end of each post 82 is fixed at the lower part of the frame 2
while its upper end passes through the bottom of the guide plate
52 and is limited by a snap ring 83. A spring 84 is provided at
the lower end of said post 82 in a position between the supporting
rack 81 and the frame 2 to bias the said rack upward. A spacing
sleeve is disposed on the post 82 between the guide plate 52
and the rack 81 to keep a constant distance therebetween. On
the said rack 81, a plurality of retaining or locking pins 86
corresponding to the position of the front sliding block 53a
are disposed with their upper ends passing through the guide
plate 52 and extending thereabove under the front inclination
536 of the block 53a, while their lower ends are allowed to extend
under the lower deck 81L of the rack 81 to a certain extent. A
snap ring 87 is provided at the middle section of the locking
pin 86 and just under the upper deck 81U of the rack 81. Between
the snap ring 87 and the middle deck 81M of the rack 81, a
spring 88 is provided to bias the pin 86 upward. ~hen the front
sliding block 53a moves forward, the pin 86 will fall in the
recess 537 and retain the sald block in position.
A knob means 9 is provided at the front center of the
frame 2, with a knob handle 90 disposed out of the face plate 12,
and socket sleeve 91 extending inwardly through the face plate 12,
1~5~574
base plate 11 to reach the core plate 6. A flange 92 is formed
at the inner end. From the center of the flange, a reset
actuating plate 93 is further extended through the aperture 68
to reach the lower deck 31L of the supporting rack 8. A core
actuating plate 94 is bent from the upper edge of the flange 92
to engage with the vertlcal flap 67. When the knob 9 is turned
counterclockwise, the core actuating plate 94 engages the flap
67 to force the core plate to move to the left to open the lock.
When the knob is turned clockwise, the reset actuating plate 93
forces the rack 8 to move downwardly to accomplish manual reset.
The inside opening means 10 is provided at the center
of the lower case lb. It comprises a turning knob 101 having a
shaft 102 retained by a bearing 103 fixed to the lower case lb
and passing into the frame 2. A cam 104 is provided at the end of
the shaft 102 to engage with the riaht plate 75b of the follower
member 75. When the knob 101 is turned, the cam 104 actuates
the follower 75 to directly open the door from inside without
the aid of the core plate 6. The base plate 11 serves to connect
the face plate 12 from outside as well as the whole frame 2, and
to fasten onto the inner wall of the door. The face plate 12 is
a metal cover for connection with the knob 90. A rectangular
opening 121 is provided to facilitate the display of the key
panel 34 of the key panel box 3. Three hollow posts stick out
from within to faci'ltate bolts extending from the base plate 11
passing through and fastening thereon. The variation in door
thickness can be accommodated by adjustment of the thread length
of the bolt.
Fig. 13 shows the way of installing the lock. According
to the template furnished by the manufacturer, a rectangular
opening hl, a round opening h2 and three bolt holes h3 are provided
on the door. The face plate 12 is installed from the outsiae
of the door with three threaded posts 122 thereon to pass through
1~ ~i35i74
the door thickness D. The base plate 11 is then installed from
inside. The socket sleeve 91 is then aligned with the knob 90,
and both thrusted to flt, A little turning is helpful to enable
the groove provided on the sleeve 91 to be matched exactly
with a projection provided inside the knob base. The three bolts
are passed from inside the base plate 11, through the
corresponding bolt holes formed on the base plate 11, and the bolts
are fastened into three threaded post 122 of the face plate 12,
so that the base plate 11 is fitted tightly against the face plate
12 with the door thickness inbetween. The fixation of the base
plate 11 on the door D is further reinforced by four wood screws.
~he pre-assembled frame including the key panel box, selecting
means, identifying means, resetting means, latch means, core plate
etc. is inserted from above so that the latch enters into the side
wall opening on the base plate 11. The whole fra~;~e is manually
forced in and door knob 9 is turned a little to enable a flap 67
on the core plate 6 to be close to the core plate actuating
plate 94 on the socket sleeve 91 of the knob 9. Both sides o
the frame 2 are hence enclosed in the side walls of the base plate
11. Three screws are then fastened on both sides, so that the
frame 2 and the base plate 11 are tightly connected. The case 1
is put on and again fastened with screws to the side walls of the
base plate 11. The installation of the lock is thus finished.
Exposed outside the door are the knob 9 and key panel 31. Wedge
head 71 of the latch sticks out at the side of door D into a latch
pit (not shown) provided on the door sash. When the combination
numbers are not depressed in a proper manner and the knob 9 is
turned left, since the core plate 6 is in locked condition, teeth
66 are hardened by the legs 53a' of sliding blocks 53a. Even
though the core plate actuating plate 94 is in contact with the
flap 67 and tends to force the core plate 6 toward the left, the
latch 7 cannot be moved and the door D cannot be opened.
1~53574
Now referring to Fig. 14 (A) and (B) when the keys 34
are depressed in a predetermined sequence, the key rods 35 in
turn push the corresponding inserts 42 of the selecting arm set 41,
then the lower arm tip 4lb swings about the axle center 41c and
presses the rear wall 533 of the front sliding block 53a,
forcing the block 53a to slide forward along the guide groove 521.
Since the first or left-hand block 53a is not provided with a
stopper 55, this block 53a is free to move independently forward
fromarest mode (Fig.14A) without affectingthe rear siidingblock 53b
and thereby defining a release mode of the element 53, 53b
(Fig. 14B). A gap "g" is then created between legs 53a'-53b' of
blocks 53a, 53b to admit passage of the teeth 66 of the core plate
6. When the first front sliding block 53a reaches a position
where the locking recess 537 thereunder is aligned with the
locking pin 86, the pin 86 is forced by the spring 88 into the
recess 537 thereby anchoring the block 53a, so that when the key
is released from the depression, the block 53a stays without being
returned by the spring 56, and the gap g is thus reserved for the
passing of teeth 66 of the core plate 6.
When the first front sliding block 53a moves fowardly,
the inclination of the projection 535 forces the claw 54 to move
about the pivot 541 to the right or the second front sliding
block 53a. The front end 543 of the claw 54 pushes the stopper 55
on the second front block 53a to the right, until said front end
543 abuts against the side wall of the second front block 53a
and forces the front end 552 of the stopper 55 to withdraw -
entirely. By then the front end 552 of the stopper 55 releases
the stopper 504 of the arm 503 extended from the rear sliding
block 53b. Thus, the claw 54 deactivates the stopper 55. There-
fore when the second digit of the combination is depressed on the
key panel 34, the corresponding selec'ing arm set 41 would repeat
the function as aforementioned. Its lower arm 41b pushes
1~ 53S7~
forward the second front block 53a to move ahead independently
and also to leave a gap "g" between legs 53a'-53b' of the second
set blocks 53a, 53b to admit passage of the teeth 66 of the
core plate 6. This process repeats until all of the six (or more)
predetermined digits are depressed on the key panel, six gaps "g"
thus formed allow the free passage of the teeth 66 of the core
plate 6, so that when the knob 9 is turned to the left to open
the lock, the latch 9 is forced to the left by the actuating
plate 94 through flap 67 (see Fig. 10) . The long ~:law 64 on
the core plate 6 in turn pushes latch 7 to the left against the
spring 74, wedge head 71 of latch 7 is thus withdrawn into the
case 1 and the ]ock is opened.
The identifying means 5 serves to automatically lock up
when the key is depressed in error or in a wrong sequence. More
particularly, the multi-sets of front/rear sliding blocks have to
be operated in a sequence from first, second, third .. tG the
last. A wrong depression or depressions following a wrong digital
sequence, such as to depress a second digit instead of a first,
the front sliding block corresponding to the key is pushed, i.e.
the second front block is moved forward along the guide groove 521.
Since the preceding or the first digital number was not initially
depressed, the first front block has not been moved forward, and the
first claw 54 stays unmoved, the second front block or the front
block of the wrongly depressed digit nurrber still keeps its
stopper 55 from releasing the stopper 504 of arm 503 extended from
the rear block 53b. The forward movement of the second front block
53a would move the rear block 53b at the same time. No gap "g"
will be created between le~s 53a~-53b' of blocks 53a, 53b. Even
if an attempt is made later on to depress a series of digits in
a right sequence, since the above fault has already blocked up the
- expected gap "g", the continuation of gaps "g" is broken and would
not let the core plate 6 get through. The block-up of the gap "g"
-15-
~Si3579~
would occur as many times as the key is wrongly depressed.
~ hen the lock is opened, all the blocks 53a remain
unreleased by the pins 86. After turning the knob 9 in a counter-
clockwlse direction, the resetting a_tuating plate 93 presses
down the rack 81 of resetting means 8, pins 86 in turn release
the front sliding blocks 53a to move backward. By then a part of
the teeth 66 are still retained between the front blocks and
rear blocks. The front blocks, although they have already been
released by the~pin~s 86, have not yet resumed their original
positions. When the knob 9 is turned to its dead end, the latch
7 withdraws fully into the case l and the door is opened. By
releasiny the knob 9, the core plate 6 biased by the spring 69
restores its original position, pins 86 stick out just as in the
original condition, and the front blocks biased by the spring 56
resume their original position. The resetting of the lock is thus
accomplished. The latch 7 again extends out of the case, and
automatically locks up the door. In case it is suspicious
whether the keys have been depressed by any party before the intend-
ed depression, a clockwise turniny of the knob before starting
depression, produces the downward action of the resetting
actuating plate 93, whereby the rack 81 is lowered to ~orce down
the pins 86 so that resetting can be achieved.
When it is desired to open the lock from within, turn
the knob lOl clockwise, the cam 104 in turn moves the follower 75
of the latch 7 without affecting the core plate 6 and the
identifying means 5 and directly withdraws the latch 7 to open
the door. sy releasing the knob 101, the latch 7 biased by the
spring 7~ resumes its position, and the knob lOl returns to its
original position also through the action of follower 75 and
cam 104.
The above illustration refers to a door with the lock
mounted on the right side as viewed from outside. The lock of
-16-
~S3~7~
the present invention is also capable of being installed to the
left side of the door, The al~ernation can be easily effected
by reversing the latch 7 with the nylon socket 25 replaced at
the other end. In other words, put the wed~e head ~f the latch
to the left and the base end 73 to the right and allow the socket
25to be covered at the base end 73. The follower member is
reversely relocated which can be readily done by the manufacturer.
The lock opening operation is then as follows: The
knob is still turned counterclockwise, the core plate moves to
the left accordingly. Since the follower member 75A is reversely
relocated, the plate on the follower member 75A is not moved
by the long claw 64, only the upper end of the revolving arm
60 engages the right side of the plate 75b. Hence, the short
claw 65 forces the lower end of arm 60 to move left, and arm 60
rotates about the center 601 to cause its upper end to move to the
right, and pushes the latch 7 to the right through plate 75b.
The latch 7 is withdrawn to open the lock. The revolving arm 60
was inactive in the right-mounted lock, since it did not engage
either of the pla~es 75a, 75b.
Combination change can be effected manually by changing
the positions of inserts 42. Open upper case la, take down all
the old inserts, then relocate them according to a new desired
digital number~ The inserts are placed on the upper ends 41a
of each arm set of ten 41, the location of the inserts in the
sets corresponding to the number sequence to be depressed on the
key panel. The upper ends 41a of the arm sets 41 can be marked
with the figures 0 - 9, for the convenience of recognition.
Feeling by touching may be attempted by a potenti~l
burglar to find out which number is active. Thus, false inserts
42 may be mounted to each of the blank upper ends 41a of the in-
active numbers, so that every push of a key 34 would give the
same touch, since behind rod 3~ of every key there is an insert 42.
3 ~S3574
However, eyen without the false inserts, the combination of six
out of ten keys is already complicated enough for a hurglar
to try out.
The lock gives an enormous number of combinations. Safe-
ty is assured through the provision of selectin~, identifying
means as well as the automatic resetting means. Its construction
is simpler than that of similar locks. It is more easily
manufactured, and the combination can be easily changed without
special tools. Since no conventional ke~,~ is provided, there is
no fear of losing the same.
_lR
