Note: Descriptions are shown in the official language in which they were submitted.
1 1560~3
RELAT~D APPLICATIONS
This specification is related to Canadian applica-
tion Serial No. 352~7~6r file~ on May 27, 1980 and entitled
~OC~ WITH IMPRQVED PROVIS}ONS FOR ~ITHSTANDXNG FO~CES
S APPLIED TO ~HE BOLT~
FIELD OF T~E INVENTION
.
The present invention is rela1:ed to loaks of
~he dead bolt type, and, more particularly, to the
connection between the bolt and the cylinder of such a
lo~k~
BACKGROUND OF THE INVEN'rION
A conventional dead bolt door lock is constructed
so that it can incorporate any of a large variety of
intercha~geable externally threaded lock cylinders that
lS are commercially available from a variety of sources~,
On the inner end of the cylinder, an ~ccentric cam i'3
xota~ably mounted, and a linkage must he provided that
causes recipricatory movemen~ of a bolt between re~racted
~nd ~xtended positions in re~ponse to movement o~ the cam.
A ~ide variety o~ a~rangement~ ~or transmitting
tha motion o~ ~h~ aam ~o ~he bol~ hav~ been propo~ed~
~ne importan~ re~ui~smen~ has been ~hat relativ~ly ~rong
~d hea~y compQnl3nt8 mu~t be used, en~bl ing th~ bolt ~o
~AJ
1 1~60~
18729
wi-thstand any effort to disable the lock by driving it
forcefully back toward its retracted position. These
connecting components are not only costly, but they
sometimes make the lock difficult to operate, offering
high resistance to bolt movement.
Another important disadvantage of conventional
dead bolt locks is tha~ it is generally possible to
rotate the cam in the wrong direction through a larye
angle, sometimes approaching a full turn. This makes
the operation of the lock confusing, particularly where
there are several locks on a single door so that it is
difficult for the user to deter~ine whether he or she
has properly actuated the bolt.
Another disadvantage of a conventional dead
bolt is that the key must be rotated in a first direction,
and then counterrotated, thereby returning to its
original position so that it can be withdrawn. In many
caces, the user does not rotate the key through a
large enough angle to fully extend the bolt before counter~
r~tating and removing it. The result is that the bolt
remalns in a partially extenclcd posltion and the door
h~s the appearance o~ heing locked, but the bolt o~ers
almos~ no reslstance i~ pushed toward its retracted po~ition
by an e~ernal force.
~ principal objective of the present invention
isto provide an improved dead bolt lock that overcomes the
a~ove-mentioned operational di~advantages of conventional locks.
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~ ~5~3 lB729
A further objective is to provide such a lock that is
particularly well suited for relatively inexpensive
lightweight construction and offers a minimum resistance
to operation without sacrificing the strength of the lock.
SUMMARY OF THE INVENTION
The present invention resides in a door lock
o~ the dead bolt type in which motion is transmitted rom
the cam of a lock cylinder to a bolt by a rotatable ring
concentric with the lock cylinder and a linkage that
extends from the ring to the bolt. As the cam is rotated,
it engages a deformation on the ring, thereby moving
the ring between first and second positions corresponding
to retracted and extended positions of the bolt.
Preferably, the ring is supported by the cylinder,
thus eliminating the need for any other ring-supporting
structure. It includes an engagement portion that extends
beyond the ~ylinder and carries the deformation. Most
advantageously, the deformation is a recess in which the cam
;,
is receivable~ opposite ends of the recess being engageable
2Q by tha cam to ratate the ring toward it~ ~ir~t and second
positions~ One or more sprinqs urge the ring toward either
o~ th~se po~itions.
rrhe ring and cam are shaped and dimenc;ioned so
tha~ ~he cam can make a comple~e revolu~ion within the ring,
2~ en~aging and disengaging the de~orma-tion as it does so. It
i~, there~ore, possible to operate ~he lock by inserting
the key, making a single revolution, and then removing the
key without counterrotating it. The construction o the
. ,,
1~72~
of the lock thus e~ ~ mir!ates the possibility that its user
will inadvertently leave the bolt in a partially extended
position as a result of having reversed the rotation of
the key without having first moved it through a sufficient
angle. In addition, the ring limits rotation of the key
away from -the deformation to less than one-half of a turn
so that the user will quickly become aware of his mistake
if he attempts to turn the key in khe wrong direction.
According to another aspect of the invention, the
structure described above is combined with a catch rnechanism
that opposes any force applied to the bolt in the direction
of its retracted position and prevents this force from being
transmitted to the ring. Because of this catch mechanism,
the ring and its associated components, which need not be
capable of withstanding a force applied to the bolt, can be
of a light, inexpensive and easily operated construction~
To accommodate the catch mechanism, the lock
includes a housing in which the bolt is reciprocable and an
abutment carried by the housing. The catch means includes
a prong that i~ forced upwardly by a pin-and-slot connection
into engagement wlth the abutment as the bolt is pushed
toward its retrac-ted position. A spring can be disposed
wlthin the bolt to facilitate the smoo~h operation of th~
catch mechanlsm while, simultaneously, urying the ring
toward its iirs~ and second positions.
Other Peatures and advantages of the present
invention will become apparent from the following de~ailed
~ 1560~3
18729
description, taken in conjunction with the accompanying
drawings which illustrate, by way of example, the principles
of the invention.
BRIEF DESCRIPTION OF TliE DRAr~INGS
FIG. 1 is a perspective view o~ a door lock of
the dead bolt type constructed in accordance with the
present invention, the lock being installed in a door,
a fragmentary portion of whi~h is illustrated, wi-th the
bolt of the lock shown in phantom lines in its extended
position;
FIG. 2 is a plan view of a portion of the lock
of FIG. 1 including the lock cylinder, ring, linkage and
bolt;
FIG. 3 is a cross-sectional view of the lock
taken along the line 3-3 of FIG. 1 but showing the bolt
in its extended position;
FIG. 4 is a cross-sectional view similar to
FIG. 3 but showing the bolt in its retracted position,
a portion of the linkage between the bolt and the ring
~0 bqing brok~n away to expose other componentsl the bolt
not. ~eing sectione~;
FIG, 5 is anvthqr cross~sectional viqw si~ilar
to FIG~ 3 hut illus~rating the lock as an extqrnal force
ls applied -to the bol~ drivin~ it toward its rctracted
posi~io~;
-- 6 --
..... ~
115l60~3 18729
FIG. 6 is a three-dimensional, exploded view
of the lock;
FIG. 7 is a plan view of a fragmentary portion
of the lock with the bolt in its retracted position;
FIG. 8 and 9 are similar to PXG. 7 showing the
lock in various intermedi~te positions as it moves toward
its extended position;
FIG. 10 is another view similar to FIG. 7
showing the bolt in its fully extended position; and
FI~. 11 is a perspective view of the ring and
~onnection pin of the lock.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
An exemplary door lock 10 of the dead bolt
type, illustrated in FIGS. 1 through 11 of the accompanying
drawings, embodies many novel aspects of ~he present
invention. In g~ne.ral, it i.ncludes a mountin~ ecured
to a doo~ 12, a lock cyllnder 13 supported by th~ mou;nting~
a ~humb-turn as~mbly 1~ suppor~ed by the moun~ing on the
opposi~e $ide of ~he doox ~rom ~he aylinder, a bolt lS
~nd hou~ing 16 mounted in an edge 17 o~ the door in
whiah the bolt 1~ receivea. The bolt aan xeciproca-te
between a retracted position within the door, as shown in
F~G. 4, and an ex~ended pOSi~iQn in which it projects into
a ~ocket lB in the door frame 19, as shown in FIG. 3.
, ~
1 1$60G3 18729
The mo~mting 11 includes two escutcheon plates
20 and 21 held against opposite sides of the door 1~ and
four through bolts 22. The bolts are positioned so that
their heads engage the interior escu~cheon plate 21
while they are threadedly received by sockets in the
exterior plate 20. A relatively large transverse opening
through the door 12 is aligned with a round aperture
23 in each escutcheon pla~e.
The cylinder 13t sometimes referred to as a
mortise cylinder, is of conventional construction and
is positioned within the door opening. It is threaded
to mate with the aperture 23 of the exterior escutcheon
plate 20 and has a flange 24 on its outer end to hold
an annular cylinder guard 25 and decorative cover 26
against the outer surface of the plate. The cylinder
is anchored against rotation by a pair of screws tnot
shown) that project vertically through the exterior
escutcheon plate 20 into grooves 31 that extend axially
across the threads of the cylinder~
The aperture 23 of the interior escutcheon plate
21 receives the thumb-turn assembly 14, opposing the
cylind~r 13, that is generally cylindrical having a
~lang~ ~7 that engage~ the oUter surEace of the e$cutcheon
plate and its de~rative cover 28. On the inside of the
thumb-turn assembly i9 a rotatable plate ~9 rigidly
connected to a thumb~turll handle 30 on the outside 5ide
o~ the interior escutcheon 50 that the plate can be rota~ed
by the handle.
~ 1~6~3 18729
On the cylindrical surface of the thumb-turll
assembly 14 is a slot 32 that faces the ed~e of 17 of the
door 12. A latch member 33 is slidably mounted on the
inside of the interior escutcheon plate 21 and biased
by a spring (not shown) into engagement with the slot
to prevent axial withdrawal of the thumb-turn assembly.
To release and remove the thu~-turn assembly, a tool can
be inserted from the edge of the door, after -the bolt 15
and its housing 16 have been removed, to grasp the latch
member by a depression 34 and withdraw it from the slot.
On the inner end of the cylinder 13 is an
eccentrically mounted cam 35 attached to a cylinder core
36 that can be rotated once a key has been inserted. As
is conventional in cylinders of this type, there is only
one position of the core in which the l;ey (not shown)
can be inserted and removed. With the core in this
position, the cam is symmetrically oriented on the inner
end of the cylinder (as shown in FIGS. 3, 4, 5, and 7)
and does not extend radially beyond the perimeter of the
cylinder. When the core is rotated, however, the cam,
because ol its ecc~ntricity, extends beyond the perimeter
o~ the cylinder ~ as shown in FTGS. ~ and 9, 10 and in
phantQm line8 of FIGS~ 3 and 4), i~s position o~ maximum
extension bein~ ~eparated from the key insertion po~ition
~5 by 180 deg~aes.
The ale~nt that interacts directly with the cam
35 to bxing about mo~ement o~ the bolt 15 is a ring 37
(~hown separately in FIG. 11) that is internally threaded
to receive the external threads o~ the cylinder 13. The
1~560~3 1872g
ring is freely rotatable on the cylinder by which it is
supported, and its rotation produces no significant axial
movement because of the fine pitch of the threads. It
includes an arcuate engagement portion 38 that extends
axially beyond the inner end of the cylinder, the inside
diameter of this engagement portion being equal-to the
diameter of the cylinder.
A lug 39 projects radially from the surface of
the ring 37 to engage either of two stops 40 and 41 that
are integrally formed on the exterior escutcheon plate 20
at the ~op and bottom of the aperture 23. A coil spring
42 in tension biases the ring so that, when free to
xotate, it will move to a position in which the lug
engages the nearest stop, the two stop engaging positions
being separated by 180 degrees. The spring is attached
at one end to the exterior escutcheon plate and at its
opposite end to a connection pin 42 that extends from the
ring to the rotatable plate 29 of the thumb-turn a~sembly
14. Thus, in addition to its function of securing the
spring, the connection pin fastens the ring to the th~ -
turn plate for joi~t rotation.
The engagement portion 38 o~ the ring 37 is
inkerrupted by a disconkinuity in the ~orm o a recess 44
pusi~ioned diagonally opposite the lug 39. T~le purpose
2S o~ this recess, a~ explained in greater detail below, is
to receiV~ ~he cam 35 to cause rotakion o~ the ring in
response to movement o~ the cam.
--10--
. ~,~ ~ .
~1S606~ 1872~
The holt 15 is a cylindrical steel mel~ber that
rides in a low friction plastic sleeve 45 within the bolt
housing 16. Extending from the inner end of the bolt is
an axial bore that receives a free-turning hardened steel
security pin 46. This pin will resist any effoxt to saw
through the bolt since it will rotate when engaged by the
teeth of a saw, preventing the saw from biting into the
steel. The security pin is biased away from the outer
end of the bolt by a compression spring 47 disposed between
the pin and the end of the bore.
At its inner end, the bolt 15 is bifurcated to
form two parallel vertical plates 48 connected by a
horizontal bolt pin 49 (best shown in FIG. 2) that extends
transversely with respect to the door 12. An elongated
bolt link 50 has a slot 51 in which the bolt pin is
received, the link having a round aperture in at its
opposite end in which the connection pin 43 is loosely
journaled. Thus, the ~olt pin, bolt link and connection
pin ~orm a linkage by which the bolt is connected to the
ring 37.
The slot 51 in the bolt link 50 is inclined
~rom the horizontal direction o~ bolt movement so that,
wi~h t~e bolt 15 in its fully extended position, the outer
~nd o~ the slo-t is hi~her than the inner end. One Eunction
o~ the compr~ssion sprinq 47 is to bias the bolt outwardly
away from the security pln 4~ so that the bolt pin ~9
remains at the raised ou-ter end of the slot.
.
1 ~ 560 ~ 3 18729
When the ring 37 occupies its first pvsition
abutting the first stop 40, the connection pin 43 is
located on the side of the cylinder 13 ~way from the
bolt 15 and the bolt is secured in its retracted position
(FIGS. 4 and 8). With the ring in its second position
abutting the second stop 41, however, the connection
pin is located on the side of the cylindler nearest the
bolt and the bolt link 50 then extends further from the
cylinder securing the bolt in its extencled position
(FIGS. 3 and 10).
~he operation of the lock 10 begins with the
bolt 15 in its retracted position (as shown in FIGS. 4
and 7), the ring 37 in its corresponding first position
with the lug 39 engaging the first stop 40 and the cylinder
core 36 in its key insertion position (FIG.l). The cam
35, which includes a lobe 52 that extends toward the
bolt, is located completely within the perimeter of the
cylinder 13. To lock the door 1~, the key i~ inserted
and the cam is caused to rotate counterclockwise ~with
~ reference to FIGS. 3-5 and 7-10). A~ter le~s than 90
degrees of rotation the lobe extends downwardly and almost
vertically into the recess ~ (FIG. 8). Continued rotatio~
0~ ~he ¢am, ~re~sincJ against one end of the rece~s~ ~orces
the ring ~o rot~te, -ther&by stretching the ~ension spring
~2. Qnce ~he rin~ has been displace~ about ~0 degrees
~FIG. 9) ~ th& sprinc3 will have been ~t.re~hed to tha
maximum extent and, upon .Eurther rotation, will begin
to pull the ring toward i~8 second po~i~ion.
1 1$6~63 18729
Whcn the recess 44 is located at the top of the
cyllnder 13, the lug 39 abuts the second stop 40 to halt
rotation of the ring 37 (FIG. 10). At -this point,
continued rotation of the cam 35 brings the cam lobe 52
hack within the perimeter of the cylinder and withdraws
it from the recess so that the cam can complete a full
revolution (FIG. 3), allowing the cylinder core 35 to
return to its original position in which the key can be
withdrawn.
To retract the bolt 15, the key is again inserted
but is rotated in the opposite direction so that the cam
lobe 52 rises to re-engage the ring 37, bearing against
the opposite end of the recess 44 from that which it
engaged when the bolt was being extended. The cam 35
then rotates clockwise (with reference to FIGS. 3-5
and 7-10) again stretching the tension spring 23 until
it passes the half-way point and the lobe 39 is again
,~
withdrawn from the recess as it reaches the downward
position. After a complete rotation of the cylinder core
36, the key can be withdrawn again. The ring then remains
in its first position, corresponding to the retracted
position of the bolt, with the lug 39 abutting the first
~op 40.
It is not po~ible to withdraw the key when the
bo}t lS is in a partially ex-tended posltlon; thc cylinder
core 36 must make a ~omplete revolution. It is, th~re~ore,
impossible to rota-te the cylinder core without moving the
ring 37 Eully from one o~ its two positions with the other.
, Sv~
1 ~ 5 ~ 0 ~3 13729
Another advantage of the lock lO is tha~ it
is not possible to inadvertently rotate the cylinder
core 36 as much as one-half of a turn in the wrong
direction. If, for example, an attempt is r,lade to rotate
the core clockwise (with reference to FIG. 7~ when the
bolt lS is in its retracted position, the cam 35 can be
displaced only about 45 degrees before its movement is
limited by the engagement portion 38 of the ring 37 (as
indicated in phantom lines in FIG. 7). ~ similar result
is obtained if an effortis made to rotate the cam so that
the lobe 52 moves downwardly away from the recess 44 when
the bolt is in its extended position.
It should be noted that the compression spring
47 urges the bolt lin~ 50 back into the door 12 and in
this way duplicates the function of the tension spring 29,
i.e., it biases the ring 37 toward its first and second
posîtions in which the lug 39 engages the stops 40 ancl 41.
AlthQugh it is advantageous to have two springs perorm
this ~unction, either spring alone could supply a suf~icient
biasing force.
A1-though the preferred embodiment of the loclc
10 de~aribed here includes a cingle key-operated c~lincler
13 and a ~hum~urn a~e~bly 14, tha principals a~ the.
invention can also be employed in a double cylinder lock~
~he two halve~ o~ the lock would ~hen be mirro~ images o~
e~ch other, and ~he lock would include two ~ings 37 joined
by the connection pln 43.
,. ,
~1~
1 ~ 560S3 18729
Preferably, the ring 37 lS made of plastic
and neither the ring nor the connection pin 43 need be
of sufficient strength to withstand a force that migh~
be applied to the bolt lS in an effort to disable the
lock by driving the bolt toward its retracted position.
A unique catch mechanism prevents any such forc~ from
being transmitted by the link 50 to the connection pin.
As part of the catch mechanisrn, a pointed, up-
wardly projecting prong 53 is formed on the outer end of
the link 50 and, when the bolt 15 is in its extended
position (FIG. 3), this prong is aligned with and
irNmediately below an opening 54 in the top of the housing
16. When the bolt is in its normal extended position
and the door 12 is locked, a force applied to the bolt
lS and tending to drive it toward its retracted position
(as indicated by the arrow A in FIG. 5) would push the
bolt pin 43 to the inner end of the slot 51 in the bolt
link.
Since the slot Sl i9 inclined at an angle to the
~0 hoxizontal, the bolt pin 49 moves t.oward -the inner end
oX the slot (FIG. 5) and the link 50 pivots on the
connection pin 43 rather than rnoving inwardly in a
reclpricatory manner. ~he outer end of the l.ink is
thus lifted so that the prong 53 enters the opening S4
ln the housin~ 16. The lnner ~nd oE ~he openin~ ~erve~
~: as an abutment engaged by the prong to oppose the force
applied to the bolt 15. Since the force is absorbed by
18729
~L ~ S60~3
the housing, it is not transmitted through the link
to the rislg 37 and connection pin 43. It should be
noted that there is enough looseness in the linkage to
pers~t the prong to move into firm engagement with the
housing without stressing the connection pin.
To further strengthen the lock lO and resist
inwardly directed forces applied to the bolt 15, the link
50 carries a downwardly projecting tab 55 which is disposed
immediately behind the inner end of the housing 16 when
the bolt is fully extended (FIG. 2). A force applied
to the link and, causing the link to pivot on the connection
pin 43 as the bolt pin 49 slides to the inner end of the
slot 51, will also cause the ~ab to engage-the bottom
inner end of the housing, as shown in FIG. 4. A second
- 15 abutment is thus provided whereby the housing resists
the force applied to the bolt and prevents that force
from being transmitted to the connection pin and the ring
37. If the prong 53 and tab do not engage their respective
abutments simultaneously 7 the connection pin will flex
slightly to allow engagement at both locations.
I~ a forcq sufficient to break the connection
pin43 shauld be applied to the extended bolt 15 in a
directlosl of m~vement from its xetracted to its extended
posi-~ion, as might happen in the case of a blow that tends
2S to open door 12, ~he ~o~ward end o~ the tab 55, tha~ ~orms
an inclined ramp sur~ace~ engages:the aligned abutment on
the inner bottom end o~ the housing 16. Simu:Ltaneously,
the prong 53 engages an abutment on the housing ~or~led by
-15-
,~ .. . . . .
1 ~5~0~3
18729
the outer end of the opening 54 so that the bolt link
SO becomes wedged in the housing. In this way, the force
applied to the bolt is resisted by the housing and is not
transmitted to the connection pin 43 and ring 37.
It will be apparent from the foregoing that the
lock 10 of the present invention is of simple construction
and is readily manufacturable. It has a smooth action that
offers little resistance to its operation, but, at the
same time, is highly secure and able -to withstand large
forces applied to the bolt.
While a particular embodiment of the invention has
been illustrated and described, it will also be apparent that
various modifications and changes can be made without departing
from the spirit and scope of the invention.
