U.S. patent number RE30,198 [Application Number 05/843,309] was granted by the patent office on 1980-01-29 for cylinder lock.
This patent grant is currently assigned to Mechanical Development Co., Inc.. Invention is credited to Elvis C. Flora, Roy N. Oliver, Paul A. Powell, Roy C. Spain.
United States Patent |
RE30,198 |
Oliver , et al. |
January 29, 1980 |
**Please see images for:
( Certificate of Correction ) ** |
Cylinder lock
Abstract
A cylinder lock with a key plug rotatably mounted in the
cylinder shell is described. The key plug has a plurality of
tumblers that are set by the V bits of a key inserted in the key
plug. The key is cut at three different levels and cut at three
different angles. Each tumbler in the key plug may be positioned by
the properly bitted key reciprocally to clear the shear line and
also positioned rotationally to allow the fence to be cammed out of
engagement with the cylinder shell. The key plug may then be
rotated. A side bar cylinder lock is also described with the same
key cut at three different levels and cut at three different
angles. The tumblers are positioned reciprocally and rotationally
by the properly bitted key to allow the fence to be cammed out of
engagement with the cylinder shell. The key plug may then be
rotated.
Inventors: |
Oliver; Roy N. (Salem, VA),
Flora; Elvis C. (Salem, VA), Powell; Paul A. (Salem,
VA), Spain; Roy C. (Salem, VA) |
Assignee: |
Mechanical Development Co.,
Inc. (Salem, VA)
|
Family
ID: |
27090381 |
Appl.
No.: |
05/843,309 |
Filed: |
December 13, 1977 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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Reissue of: |
627243 |
Mar 1, 1967 |
03499302 |
Mar 10, 1970 |
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Current U.S.
Class: |
70/494; 70/378;
70/406; 70/409; 70/419 |
Current CPC
Class: |
E05B
27/0082 (20130101); E05B 27/0039 (20130101); Y10T
70/7864 (20150401); Y10T 70/7881 (20150401); Y10T
70/7932 (20150401); Y10T 70/7701 (20150401); Y10T
70/761 (20150401) |
Current International
Class: |
E05B
27/00 (20060101); E05B 015/14 (); E05B 019/02 ();
E05B 027/04 () |
Field of
Search: |
;70/362,363,364R,364A,365,366,376,377,378,392,406,407,409,419,420,421 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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153145 |
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Apr 1938 |
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AT |
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381154 |
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Sep 1923 |
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DE2 |
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529771 |
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Jul 1931 |
|
DE2 |
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1462932 |
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Nov 1966 |
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FR |
|
207599 |
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Nov 1923 |
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GB |
|
Primary Examiner: Wolfe; Robert L.
Attorney, Agent or Firm: Sughrue, Rothwell, Mion, Zinn and
Macpeak
Claims
What is claimed is:
1. In a cylinder lock operated by a proper angularly bitted key, a
cylinder shell, a key plug rotationally mounted in said cylinder
shell to provide a shear line between said cylinder shell and said
key plug, at least one tumbler mounted in said key plug to
reciprocate and rotate therein as a whole, at least one driver
associated with said tumbler positioned by the reciprocal movement
of said tumbler upon engagement with the proper bitted key to clear
the shear line, and a fence member blockingly associated with said
tumbler and shaped so that the rotational positioning of said
tumbler upon engagement with the proper bitted key allows said
fence to clear the shear line.
2. The invention as claimed in claim 1 wherein said tumbler has a
true gate parallel to the axis of said tumbler, and said fence
member is blockingly associated with said true gate of said tumbler
and shaped so that the rotational positioning of said tumbler with
the proper angularly bitted key allows said fence member to clear
the shear line.
3. The invention as claimed in claim 2 wherein means are provided
for urging said fence member towards said cylinder shell, and a
.[.cammed.]. .Iadd.cam .Iaddend.surface on said fence member
normally urged into engagement with said cylinder shell so that
upon the proper rotational positioning of said true gates of said
tumblers the fence member may be cammed out of engagement with said
cylinder shell allowing said fence member to clear the shear
line.
4. A cylinder lock and properly angularly bitted key comprising, a
cylinder shell, a key plug rotationally mounted in said cylinder
shell to form a shear line, a proper angularly bitted key, at least
one tumbler reciprocally mounted in said key plug and rotatable
therein about an axis, a true gate on said tumbler parallel to the
axis of said tumbler, said tumbler and associated driver
reciprocally positioned upon engagement with a properly bitted key
to clear the shear line, a fence member, said fence member having a
first cam surface thereon, a second cam surface on said cylinder
shell adapted to cooperate with said first cam surface, means
normally urging said fence member towards said cylinder shell so
that said first cam surface normally engages said second cam
surface, said tumbler shaped to be rotationally positioned upon
engagement with said properly angularly bitted key to present said
true gate to said fence member so that torque applied to said key
plug will cam said fence out of engagement with said cylinder
shell.
5. A cylinder lock having a cylinder shell, a key plug rotationally
mounted in said cylinder shell, a key with bits formed so that it
raises and lowers tumblers and causes rotation of tumblers, at
least one tumbler as a whole capable of rotation and
.[.rseciprocal.]. .Iadd.reciprocal .Iaddend.movement in said key
plug, and a fence member, said tumbler shaped in its rotatable
position to either block or free said fence.
6. A cylinder lock, a cylinder shell, a key plug rotatably mounted
in said cylinder shell to provide a shear line between said
cylinder shell and said key plug, a key shaped with bits formed so
that its raises and lowers tumblers and causes rotation of
tumblers, at least one tumbler reciprocally mounted in said key
plug and rotatably mounted therein about an axis, said tumbler
having a first true gates thereof parallel to the axis of said
tumbler, a second true gate perpendicular to the axis of said
tumbler, and a fence member blockingly associated with said tumbler
and shaped so that the rotation and reciprocal positioning of said
tumbler upon engagement with the proper shaped key allows said
fence to clear the shear line.
7. A key blade having a longitudinal axis of insertion, said key
.Iadd.blade .Iaddend.having a plurality of V-shaped cuts, at least
one V-shaped cut .[.perpendicular.]. .Iadd.perpendicularly
.Iaddend.cut across the longitudinal axis of said key blade, and at
least one V-shaped cut skew cut across the longitudinal axis of
said key blade.
8. A lock, a key having a longitudinal axis of insertion, said key
having a plurality of V-shaped cuts of variable depths, said
V-shaped cuts .[.perpendicular.]. .Iadd.perpendicularly
.Iaddend.and skew cut across the longitudinal axis of said key,
.[.primary.]. said lock including a .Iadd.primary .Iaddend.locking
means activated by the perpendicular and skew cuts of said V-shaped
cuts.
9. A tumbler, said tumbler having a cylindrical body, a chisel
shaped lower portion, and a true gate thereon parallel to the
longitudinal axis of said tumbler, said true gate oriented to said
chisel shaped lower portion.
10. The tumbler claimed in claim 9 wherein there is a second true
gate thereon .[.perpendicular.]. .Iadd.perpendicular .Iaddend.to
the longitudinal axis of said tumbler. .Iadd. 11. A cylinder lock
having a cylinder shell, a key plug rotationally mounted in said
cylinder shell, a key with a plurality of bits including at least
one skew cut bit formed so that it raises and lowers pin tumblers
and causes rotation of said pin tumblers, at least one said pin
tumbler as a whole capable of rotation and reciprocal movement
about its own longitudinal axis in said key plug, and a fence
member, said tumbler shaped in its rotational position to either
block or free said fence. .Iaddend. .Iadd. 12. A key blade as
defined in claim 7 wherein there are a plurality of skew cuts.
.Iaddend..Iadd. 13. A cylinder lock as in claim 5 wherein the key
bits include skew cut bits. .Iaddend..Iadd. 14. A cylinder lock as
in claim 5 wherein the tumblers are pin tumblers and their rotation
and reciprocal movement is about their longitudinal axis. .Iaddend.
Description
This invention is directed to a cylinder lock, and specifically
directed to a new cylinder lock having a new and novel locking
arrangement.
Conventional cylinder locks have a plurality of tumblers
reciprocally mounted in the key plug. The key plug is rotationally
mounted to rotate in the cylinder shell of the cylinder lock. The
key plug is engaged in some manner with a locking mechanism with
the cylinder shell so that the key plug may not be rotated in the
cylinder shell. The reciprocally mounted tumblers operate the
locking mechanism. In a pin tumbler cylinder lock, the locking
mechanism consists of drivers associated with each tumbler. The
drivers are in a driver bible rigidly formed with the cylinder
shell. Driver springs normally urge the drivers and tumblers across
the shear line between the key plug and cylinder shell, keeping the
key plug from rotating in the cylinder shell. The drivers and
tumblers may be separated across the shear line by a properly
bitted key cut at a plurality of levels, so that the lock is
unlocked, and the key plug may be rotated.
A side bar cylinder lock uses a locking mechanism consisting of a
fence slidably engaged in a lateral slot in the key plug which is
normally urged into engagement with the cylinder shell to keep the
key plug from rotating within the cylinder shell. Each tumbler has
a circular groove which may be termed a true gate, at a
predetermined level so that by the insertion of a properly bitted
key cut at a plurality of levels, the tumblers may be reciprocally
moved to present all of the circular true gates to the fence. The
fence may then be cammed out of engagement with the cylinder shell
and the tip of the fence move in the true gates so that the key
plug is unlocked.
The number of key changes possible in these cylinder locks is
determined by the number of tumblers in the key plug, and the
number of bitting levels in the operating key. The number of key
changes refers to the number of different keys possible. For
instance, in a cylinder lock with five levels, and five tumblers,
it would theoretically be possible to have 3125 key changes. A
number of these possible key changes must immediately be struck
because backing of the key out of the lock would simultaneously
raise all of the tumblers to the next higher level and unlock the
lock in some combinations. Because of manufacturing tolerances and
undesirable key cuts, the actual number of key changes possible is
as low as one to two percent of the theoretically possible key
changes. Thus there may actually only be thirty to sixty actual key
changes in a five bitted level, five tumbler locks.
Due to conditions which arise in the construction of the lock parts
under customary manufacturing tolerances, it is possible to effect
minute rotary displacement of the key plug from its normal locked
positions and thereby produce a slight offset shoulder formation or
ledge by the key plug at the shear line between the key plug and
the wall of the key plug accommodating bore, which will catch and
support the edge of the lower end of the driver when tumblers are
elevated. This property of the locks is taken advantage of in lock
"picking" procedures by applying a special torque wrench to the key
plug to force or stress the key plug in an angular direction about
its axis of rotation and then manipulating the tumblers by a
picking tool inserted into the key slot to individually lift the
tumblers until the drivers catch on the shoulder or ledge formed
when the key plug is thus stressed. When all of the drivers have
been thus caught in the elevated position, the key plug can be
turned to unlock the lock.
The locks may also be opened by "key jiggling" a lock, using a
small group of select keys. These keys are then used by inserting a
selected key in the key hole, pushing it in and out, torqueing it,
with all of these motions carried out simultaneously, until one of
the select group of keys opens the lock.
It is therefore an object of this invention to provide a new and
improved cylinder lock having a significantly greater number of
actual key changes.
Another object of this invention is to provide a new and improved
cylinder lock which is difficult, if not impossible, to pick.
In summary, a new and improved lock with an accompanying key has
been described. The cylinder lock operated by a single cut key has
a cylinder shell, a key plug normally engaged in the cylinder
shell, a first locking means operated by the single cut of the key,
and a second locking means operated by the single cut of the key,
so that the first and second locking means operated by the single
cut on the key disengage the key plug from the cylinder shell.
A locking means is disclosed which may be operated by an angularly
displaced tumbler. The single cut key is bitted angularly from the
horizontal axis of the key.
This invention is set forth with particularity in the appended
claims. The principles and characteristics of the invention, as
well as other objects and advantages are revealed and discussed
through the medium of the illustrative embodiments appearing in the
specification and drawings which follow.
In the drawings:
FIG. 1 is a perspective view of an improved cylinder lock
constructed in accordance with this invention;
FIG. 2 is a perspective view of the improved cylinder lock showing
the different parts of the lock in separated positions;
FIG. 3 is a perspective view of the key constructed to operate the
cylinder lock shown in FIGS. 1 and 2;
FIG. 4 is an enlarged view of a portion of the key plug assembly
with tumblers and associated operating members and key;
FIG. 5 is a cutaway view of the key plug showing the tumblers in
position with the key withdrawn;
FIG. 6 is a cutaway view of the key plug similar to FIG. 5, but
with the tumblers in the position with the key engaged;
FIG. 7 is a longitudinal cross sectional view of the cylinder lock
showing the key properly engaged in the cylinder lock;
FIG. 8 is a transverse cross sectional view of the cylinder lock
with a proper insertion of a key to disengage and turn the key
plug;
FIG. 9 is an enlarged perspective view of a portion of the key plug
of a side bar cylinder lock;
FIG. .[.10.]. .Iadd.11 .Iaddend.is a transverse cross sectional
view of the side bar cylinder lock shown in FIG. 9;
FIG. .[.11.]. .Iadd.10 .Iaddend.is a top view of a tumbler.
Referring now to the drawings and specifically to FIGS. 1 and 2, a
cylinder lock 21 has a cylinder shell 23 formed with a bore 25 in
which an integrally formed head portion 27 and key plug 29 are
rotatably mounted. A longitudinal keyway 31 is formed in the key
plug 29 and head portion 27. The key plug 29 is formed at its rear
end with a stud 33. The stud rotates with the key plug 29 and may
be associated with any conventional mechanism, for example, a door
bolt retracting mechanism, which may be actuated by rotating the
key plug 29 with the proper key inserted in the keyway 31.
The key plug 29 is formed with a laterally opening slot 35,
extending substantially perpendicular to the keyway 29. In the slot
35 is a laterally inserted stop plate 37 with five tumbler stops
39a-39e. The five stops are positioned at the rear of each of the
five tumbler holes 41a-41e with the five stops 39a-39e parallel to
the keyway 31. The five tumbler holes 41a-41e communicate with the
longitudinally extending keyway. The tumbler stops 39a-39e function
to limit the rotational movement of the five tumblers 61a-61e in a
manner to be explained.
A fence member 45 of a substantial length is slidably engaged in
the laterally opening slot 35 so that it is laterally movable. A
plurality of springs 46a-46d are positioned between the fence 45
and the wall of the keyway 31 to normally urge the fence member 45
out of the fence slot 35. The fence 45 has five gate lugs 49a-49e
positioned on the fence 45 so that the five gate lugs 49a--49e may
be moved into the corresponding five tumbler holes 41a-41e in a
manner which will become evident later in the description. The
fence 45 also has an extending cam-like projection 51 at its outer
surface which is shaped to engage a cam groove 55 formed in the
inner wall of the cylinder wall 23.
The five tumbler holes 41a-41e are longitudinally positioned with
five corresponding drive holes 57a-57e in the driver bible 59 when
the key plug 29 is inserted in the cylinder shell 23. Five tumblers
61a-61e are inserted in the tumbler holes 41a-41e, five
corresponding drivers 60a-60e are inserted in the driver holes
57a-57e, and five corresponding driver springs 63a-63e are inserted
in the driver holes 57a-57e. A driver bible plate 65 is then
positioned over the driver bible to restrain the driver springs
63a-63e in the driver holes 57a-57e. The driver springs 63a-63e,
when restrained, urge the corresponding drivers 60a-60e and
tumblers 61a-61e toward the bottom of the corresponding driver
holes and tumbler holes.
The sum length of each tumbler and its associated driver is a
constant as is standard so that the proper key will raise each
driver and its associated tumbler to a position so that each driver
is urged into the driver bible 59, and each tumbler remains in the
key plug to clear the shear line.
As shown specifically in FIGS. 2, 5, and 6, each tumbler 61a-61e
has either two or three longitudinal notches. Each tumbler 61a-61e
has a wide notch 67a-67e in which a corresponding tumbler stop
39a-39e is positioned to stop the rotational movement of the
tumbler when the shoulders of the notches 67a-67e meet the
stationary tumbler stops 39a-39e. Each tumbler 61a-61e also has a
second longitudinal notch 69a-69e which is termed true gate. Each
true gate is wide enough and deep enough to completely engage the
corresponding gate lug 49a-49e on the fence 45 when the fence is
cammed towards the tumblers 61a-61e. The gate lugs 49e-49d cannot
engage the corresponding tumbler true gate 69a-69e until all the
tumblers are rotated to position the true gates at right angles to
the keyway 31 and are facing the fence 45.
Tumblers 61b, 61c, and 61e also have a third longitudinal notch
71b, 71c, and 71e which is termed a false gate. False gates 71b,
71c, and 71e are deep enough and wide enough to admit merely the
tip of corresponding gate lugs 49a, 49c, and 49e as shown in FIG.
6, and not the entire depth of the gate lugs.
In this particular embodiment described herein, the width of the
notches 67a-67e is 38 degrees plus the width of the tumbler lug
39a-39e. Thus in FIG. 5 there is a 19 degree separation between
each shoulder of a notch 67a-67e and its corresponding tumbler stop
39a-39e. The true gates 69a and 69d are positioned on their
respective tumblers so that they are at right angles to the keyway
31 and facing towards the fence 45 when the tumbler stops 39a and
39d are positioned in the center of notches 67a and 67d. The true
gates 69b and 69e are positioned on their respective tumblers so
that when tumblers 61b and 61e are rotated clockwise 19 degrees and
the tumbler stops 39b and 39e meet the right-hand shoulder of
notches 67b and 67e, the true gates 69b and 69e are at right angles
to the keyway 31 facing the fence 45. The true gate 69c is
positioned on its tumbler so that when tumbler 61c is rotated in a
counterclockwise direction 19 degrees and the tumbler stop 39c
meets the left-hand shoulder of notch 67c, the true gate 69c is
positioned at right angles to the keyway 31 facing the fence
45.
False gates 71b and 71e are positioned in the clockwise direction
from their associated true gates 69b and 69e so that a
counterclockwise rotation of their respective tumblers 61b and 61e
will rotate the false gates 71b and 71e to a position where they
will face their corresponding fence lugs 49b and 49e. False gate
71c is positioned in a counterclockwise direction from true gate
69c so that clockwise rotation of the corresponding tumbler 61c
will rotate the false gate 71c so that it will face its
corresponding fence lug 49c. The operation and function of these
true and false gates will become evident in the description of the
operation of the cylinder lock.
Each tumbler end 75a-75e in the keyway 31 end of the corresponding
tumbler hole 41a-41e is formed in a 90 degree chisel tip with the
chisel tip perpendicular to a line through the center of the
tumbler and the center of the 38 degree notch. The chisel tip is
also provided with a twelve degree angle from its center to pass
over the developed angles on the steeples of the key 24.
Referring now specifically to FIGS. 2 and 3 for a description of
the key 24 corresponding to the cylinder lock shown and described
above, the key bittings are cut to three levels, and five V bits
77a-77e are cut in the key 24. V bit 77e is cut to the second
level, V bit 77d is cut to the third level. V bit 77c is cut to the
first level, V bit 77b is cut to the second level, and V bit 77a is
cut to the third level.
The leading edge 79 of the key 24 is cut to a 90 degree angle with
the back of the key 24.
V bits 77a and 77d are cut in the conventional manner with the cut
perpendicular to the axis of the key 24. This cut will be termed
the center cut.
In accordance with this invention, V bits 77b, 77c, and 77e are cut
in a unique manner. These V bits are cut at an angle to the center
cut. V bit 77b is cut in a clockwise or left direction from the
center cut to form a valley 77b forming a 19 degree angle with the
center cut V bits 77a and 77d. V bits 77d is also cut in a
clockwise or left direction from the center cut to form a valley
77d forming a 19 degree angle with the center cut V bits 77a and
77d.
V bit 77c is cut in a counterclockwise or right direction from the
normal center cut to form a valley 77c forming a 19 degree angle
with the center cut V bits 77a and 77d.
In the manner described, a key 24 has been angularly bitted at a
plurality of angles.
OPERATION
The operation of the cylinder lock shown in FIGS. 1-9 and described
hereinbefore will first be described with the insertion of the
proper key into the keyway 31 and the resulting rotation of the key
plug 29 in the cylinder shell 23.
Key 24 is inserted into the keyway 31 with the perpendicular cut of
the leading edge 79 of the key 24 rotating the chisel end 75a-75e
of each tumbler 61a-61e to a position perpendicular to the axis of
the key 24 and keyway 31. In this manner also at the moment that
the leading edge 79 of the key meets the chisel end 75a-75e of each
tumbler 61a-61e, the tumbler is positioned so that the tumbler stop
39a-39e is in the center of the corresponding angular notch
67a-67e. This is illustrated well in FIG. 5.
The key 24 is inserted to its full length until the end 79 of the
key 24 is stopped by the end of the keyway 31.
Referring specifically to FIG. 7, tumbler 61e rests in the second
level of V bit 77e so that the top of the tumbler 61e is at the
shear line and the corresponding driver 60e is within the driver
bible 59. The force of the insertion of the key 24 has urged the
tumbler 61e and driver 60e against the driver spring 63e,
compressing the driver spring 63e.
Tumbler 61d now rests in the third level of V bit 77d so that the
top of the tumbler 61d is at the shear line and the corresponding
driver 60d is within the driver bible 59.
Tumbler 61c now rests in the first level of V bit 77c so that the
top of the tumbler 61c is at the shear line and the corresponding
driver 60c is within the driver bible 59.
Tumbler 61b now rests in the second level of V bit 77c so that the
top of tumbler 61b is at the shear line and the corresponding
driver 60b is within the driver bible 59.
Tumbler 61a now rests in the third level of V bit 77a so that the
top of the tumbler 61a is at the shear line and the corresponding
driver 60a is within the driver bible 59.
In the manner described, the key has been inserted and the tumblers
61a-61e now rest in the proper V bits .[.77c.]. 77a-.Iadd.77a
.Iaddend.of the proper key so that all of the tumblers 61a-61e are
at the shear line and the corresponding drivers 60a-60e are
contained completely within their corresponding driver holes in the
driver bible 59. Thus there are no tumblers nor drivers obstructing
or across the shear line between the cylinder shell 23 and the key
plug 29.
However, at this point the fence 45 is still urged away from the
keyway 31 by springs 46 so that the cam projection 51 engages the
cam groove 55. The key plug cannot be rotated unless the cam
projection 51 is moved out of the cam groove 55.
Referring specifically now to FIGS. 3, 4, and 6 for a description
of the disengagement of the cam projection 51 on the fence 45 from
the cam groove 55, bear in mind that three of the V bits of the key
24 are angularly displaced from the two center cut bits.
V bit 77a is a center cut bit cut perpendicular to the axis of the
key, so that the chisel end 75a of tumbler 61a rests perpendicular
to the keyway 31 as shown in FIG. 6, tumbler stop 39a is in the
center of the 38 degree plus retaining notch 67a, and the true gate
69a is perpendicular to the keyway 31 facing the fence lug 49a, so
that fence lug 49a may be moved into the true gate 69a.
At this point, note that one fence lug by itself cannot be moved
into its corresponding true gate, but all fence lugs must be moved
simultaneously into all corresponding true gates.
V bit 77b is a clockwise cut V bit so that the chisel end 75b of
tumbler 61b is rotated in a clockwise direction, rotating the
tumbler 61b and its corresponding true gate 69b, false gate 71b,
and angular notch 67b in a clockwise direction, so that the right
shoulder of angular notch 67b is stopped by the tumbler stop 39b.
The true gate is thus presented perpendicular to the keyway 31,
facing fence lug 49b so that the fence lug 49b may be moved into
the true gate 69b.
V bit 77c is a counterclockwise cut V bit so that the chisel end
75c of tumbler 61c is rotated in a counterclockwise direction,
rotating the tumbler 61c and its corresponding true gate 69c, false
gate 71c, and angular notch 67c in a counterclockwise direction, so
that the left shoulder of angular notch 67c is stopped by the
tumbler stop 39c. The true gate 69c is thus presented perpendicular
to the keyway 31, facing the fence lug 49c so that the fence lug
49c may be moved into the true gate 69c.
V bit 77d is a center cut V bit so that the chisel end 75d of the
tumbler 61d rests perpendicular to the keyway 31. Tumbler stop 39d
is in the center of the angular notch 67d, and the true gate 69d is
perpendicular to the keyway 31 facing the fence lug 49d so that
fence lug 49d may be moved into the true gate 69d.
V bit 77e is a clockwise cut V bit so that the chisel end 75e of
tumbler 61e is rotated in a clockwise direction, rotating the
tumbler 16e and its corresponding true gate 69e, false gate 71e,
and angular notch 67e in a clockwise direction, so that the right
shoulder of angular notch 67e is stopped by the tumbler stop 39e.
The true gate 69e is thus presented perpendicular to the keyway 31
and facing fence lug 49e may be moved into the true gate 69e.
As the proper key has been inserted, all tumblers and drivers now
meet across the shear line, and all of the true gates 69a-69e are
facing their corresponding fence lugs 49a-49e so that the fence
lugs may be moved into their corresponding true gates 69a-69e.
Torque may then be applied to the key 24. The torque urges the key
plug 29 either in a clockwise or counterclockwise direction camming
the cam projection 51 out of the cam groove 55, urging the fence 45
towards the keyway 31. As the true gates 69a-69e are all presented
properly, the fence lugs 49a-49e move into their corresponding true
gates 69a-69e, allowing a lateral movement of the fence 45 towards
the keyway 31 so that the cam projection 51 cams out of the cam
groove 55.
The cylinder lock described herein has thus been unlocked by the
combination of three level changes in the V bits of the key to move
the tumblers 61a-61e and corresponding drivers 60a-60e to the shear
line, and the angular displacement of the tumblers 61a-61e in three
angular positions to rotate the true gates 69a-69e so that the
fence lugs 49a-49e may be moved into the true gates 69a-69e by
camming a cam projection 51 on the fence 45 out of engagement with
a cam groove 55 in the cylinder shell 23.
When the key is rotated back to the locked position, and the key
removed, the tumblers 61a-61e fall back down so that drivers
60a-60e cross the shear line. When the key is rotated back to the
initial position, the springs again urge the fence 45 towards the
cylinder shell 23 so that the cam projection 51 engages the cam
groove 55 again.
The withdrawal of the key .[.center.]. .Iadd.leading edge
.Iaddend.79 from contact with the chisel end 75a-75e rotates the
tumblers 61a-61e back to a position where the chisel ends 75a-75e
are perpendicular to the axis of the keyway 31, and rotating the
true gates .[.69a-69e.]. .Iadd.69b, 69c, and 69e .Iaddend.so that
they are not presented to the corresponding fence lugs
.[.49a-49e.]. .Iadd.49b, 49c, 49e. .Iaddend.
The combination of the necessary reciprocating movement of the
tumblers and angular rotational movement of the tumblers 61a-61e
makes it impossible to engage in "key jiggling" and/or "key
picking" possible with cylinder locks where the only locking
mechanism is in the reciprocating movement of the tumblers. "Key
jiggling" with a standard key will only move the tumblers 61a-61e
up and down, and will not rotate the tumblers 61a-61e so that the
true gates 69a-69e will not be presented to their proper fence
lugs, and the cam projection 51 cannot be cammed out of engagement
with cam grooves 55.
The necessary rotational movement of the tumblers 61a-61e to
present their true gates 69a-69e also defeats the "picking," for
while the tumblers 61a-61e may be moved vertically by a "pick," it
is difficult, if not impossible. to also rotate the tumblers
61a-61e. To provide for an extra margin of safety to prevent
"picking," the false gates 71b, 71c, and 71e, previously described,
are provided. The false gates 71b, 71c, and 71e are large enough to
engage merely the tips of the fence lugs 49b, 49c, and 49e. If a
"pick" is successful in rotating one of the tumblers 61b, 61c, or
61e, the odds are that one or more of the false gates will be
presented to the corresponding fence lug 49b, 49c, or 49e, and upon
torque being applied to the key plug 29, the resulting camming
action will force the fence lug into the corresponding false gate.
The false gate will not allow the fence lug to completely enter the
false gate, so that the cam projection 51 cannot be cammed out of
the cam groove 55, and the key plug 29 cannot be rotated.
It can readily be seen that the cylinder lock constructed according
to this invention can be given a high number of key changes. The
secondary locking means resulting from the angular displacement of
the tumblers in three positions may be multiplied by the normal
primary locking means resulting from the level displacement. It
should be evident that the bitting levels of the key can be spaced
further apart than in ordinary bitting levels as it is possible to
use a smaller number of levels. This reduces the key changes lost
due to manufacturing tolerances. Thus it would be possible, for
instance, to use three bitting levels plus three angular
displacements disclosed herein to give nine changes. With nine
changes at each tumbler, using a five tumbler lock, it would be
possible to get approximately 60,000 useable lock changes. This is
significantly superior to the normal one to two percent useable
lock changes out of the theoretically possible lock changes in
locks constructed according to previous lock construction.
Referring now to FIGS. 9-11, the principles of this invention may
be applied to operate a side bar cylinder lock providing a primary
and secondary locking means with a single cut on the key. This
particular description is directed to a four tumbler, three level
bitted, side bar cylinder lock; however, the tumblers and levels
may be varied according to the specific desires and needs of an
application.
A side bar cylinder lock by its very nature does not have drivers,
driver pins, and a driver bible. The side bar cylinder lock does
not lock by positioning drivers in a shear line, but locks by
providing gates on the tumblers and a fence which may engage the
circular gates on the tumblers when the tumblers have been raised
to the proper levels by the insertion of a proper key. The fence
which is engaged with the cylinder shell may then be cammed out of
engagement with the cylinder shell and into engagement with the
properly leveled circular gates on the tumblers.
Referring now to FIGS. 9, 10 and 11, therefore a fence 81 is shown
positioned in a lateral slot 83 in a key plug 85. The key plug 85
may be rotated in the cylinder lock 87 when the cam slot 89 in the
fence is properly cammed into the lateral slot 83 by the bendable
cam 91. Bendable cam 91 extends into a recess 93 in the side wall
of the cylinder shell 87.
Bendable cam 91 is constructed so that it will cam the fence 81
inward, but it will bend or crush if torque is applied and the
fence 81 cannot be moved in towards the keyway 90. A projection 95
from the fence 81 with the cam slot 89 therein also normally
extends into the recess 93. A plurality of springs (only one of
which is shown) 99 urge the fence projection 95 into the recess
93.
The fence 81 has a top horizontal fence plate 97 with four fence
recesses 101a-101d therein, and four vertical fence lugs 103a-103d.
Each vertical fence lug 103a-103d is perpendicular to the center of
a corresponding horizontal fence recess 101a-101d. Only one tumbler
105 of the four tumblers is shown in FIGS. 9 and 10. The tumbler
105 has the two longitudinal notches shown in the tumblers for the
lock shown in FIGS. 1-8, and they perform the same function as
described therein. There is an angular notch 107 which is 38
degrees wide plus the width of a tumbler stop 109 and a true gate
111. A false gate is not used as the tumbler rests properly in a
center cut V bit.
In addition, there are three circular notches, a true circular gate
115, a false circular gate 117, and a false circular gate 119.
Tumbler spring 121 urges tumbler 105 down towards the keyway
90.
A key 123 with the proper V bitting angular displacements as
described with relation to the cylinder lock described and shown
with relation to FIGS. 1-8 is inserted in the keyway 90. The
angular displaced V bittings angularly rotate the chisel end of the
tumbler 105, rotating the tumbler 105, so that the angular notch
107 rests with the tumbler stop 109 at the center of angular notch
107. The true gate 111 is then presented at right angles to the
angular notch facing the vertical fence lug 103b. The other three
tumblers which are not shown are also angular displaced in the
angular V bittings so that they also are rotated to present their
true gates to their proper vertical fence lug.
The tumbler 105 is also positioned by the level of the V bit in
which the chisel end of the tumbler 105 rests. The proper level for
tumbler 105 is at level three so that the tumbler rests down in the
V bit in the key 123, presenting its true circular gate 115 at a
level parallel to the corresponding fence recess 101b.
The other three tumblers are also positioned by the level of the V
bit in the proper key 123 so that their circular true gates are
also presented at a level parallel to the fence recesses 101a,
101c, 101d.
The key 123 is then turned, applying torque, camming the cam slot
89 by cam 91, moving the fence 81 into the lateral slot 83 towards
the keyway 90. The vertical true gates are all presented to the
face lugs 103a-103d and the circular true gates are all presented
properly to the corresponding fence recess 101a-101d so that the
fence 81 can be cammed into the lateral fence slot 83.
The key plug 85 may then be rotated in the cylinder shell 87 and
the side bar cylinder lock has been unlocked by a primary and
secondary locking means.
This side bar cylinder lock constructed according to this invention
offers the same difficulties to "key jiggling" and/or "key picking"
that the cylinder lock shown in FIGS. 1-8 offers. In addition, it
should be noted that if torque is applied to rotate the key plug 85
without the insertion of the proper key to present all of the true
gates properly that the fence lugs and recesses can move into, the
cam slot 89 in the fence 81 will bend the bendable cam projection
91 instead of being cammed into the cam slot 83. Further rotation
of the key plug 85 will move the fence 81 into engagement with the
shoulders of the recess 93 in the cylinder shell 87. The key plug
83 may not be rotated any further so that the attempt to force the
lock has failed and a lock-out occurs.
The circular false gates 117 and 119 operate in a similar manner to
the horizontal false gates shown in FIGS. 1-8. The introduction of
a pick into the keyway 90 and the forceable movement of the
tumblers upward will tend to present a false gate as often as a
true gate.
The usual procedure in "key picking" and/or "key jiggling" a lock
is to use a small group of select keys. These keys are used in the
following manner. The selected key is inserted in the hole, pushed
in and out and torqued, with all of these motions carried out
simultaneously, until one of the select group of keys opens the
lock. In this lock constructed according to our invention, the key
bitting levels are spaced further apart than in conventional keys
(which takes care of manufacturing tolerances) and the tumblers
have to be angularly displaced. Thus it can readily be seen that
the above manipulation ("key picking" and/or "key jiggling") is not
practical. The tolerances allowed in the key constructed according
to this invention make the reciprocation movement of the tumblers
during the manipulation impractical, and the manipulation also
tends to spin the tupmblers to an off-gated position.
The combination of the smaller number of bitting levels, and the
necessary rotational movement of the tumblers makes the lock
difficult, if not impossible, to operate without the properly
bitted key.
In the lock constructed according to the principles of this
invention, due to the clearance between tumblers, drivers, and
their corresponding bores, it is usually possible with the key
removed to turn a key plug some eight to twelve degrees clockwise
or counterclockwise within the cylinder shell. .[.we.]. .Iadd.We
.Iaddend.use this motion to cam the fence member towards the center
of the key plug, forcing the projections or fence lugs against the
tumbler members themselves. Therefore, when picking attempts are
made, the tips or fence lugs of the fence member engage the true
and false gates and surfaces in the periphery of the tumblers due
to applied torque.
The engagement of the fence lugs of the fence member with the
periphery of the tumblers makes it extremely difficult to move and
position the tops of the tumblers and the bottoms of drivers to
clear the shear line.
If picking has been accomplished so that the tumblers and drivers
clear the shear line, it would now be necessary to rotate the
tumblers themselves to their correct position so that their true
gates would receive the fence lugs. To anyone familiar with this
procedure of "lock picking," this necessary positioning of the
tumblers and drivers to clear the shear line in combination with
the rotational positioning of the tumblers to present their true
gates to the fence lugs of the fence is highly improbable, if not
impossible.
While the invention has been explained and described with the aid
of particular embodiments thereof, it will be understood that the
invention is not limited thereby and that many modifications
retaining and utilizing the spirit thereof without departing
essentially therefrom will occur to those skilled in the art in
applying the invention to specic operating environments and
conditions.
* * * * *