U.S. patent number 3,857,263 [Application Number 05/385,230] was granted by the patent office on 1974-12-31 for pick resistant cylinder lock.
Invention is credited to Klaus W. Gartner.
United States Patent |
3,857,263 |
Gartner |
December 31, 1974 |
**Please see images for:
( Certificate of Correction ) ** |
PICK RESISTANT CYLINDER LOCK
Abstract
A pick resistant, key operated, cylinder type lock having a key
plug rotatable within a cylindrical shell and having a plurality of
segmented pin tumblers movable radially relative to the axis of
rotation of the key plug. The pin tumblers each have inner and
outer pin sections separated by a plane of separation adapted to be
alined by a proper key with the shear line between the plug and the
cylindrical casing, and a plurality of additional redundant lines
of separation along the inner section of each pin tumbler. An
additional locking member is coupled to each of the pin tumblers
and has leg portions projecting into openings in the casing and
plug, and provides one or more additional lines of separation at
the shear line between the plug and casing, to be alined with the
shear line when the pin tumblers are positioned by the key at the
proper positions.
Inventors: |
Gartner; Klaus W. (Rochester,
NY) |
Family
ID: |
23520565 |
Appl.
No.: |
05/385,230 |
Filed: |
August 3, 1973 |
Current U.S.
Class: |
70/493; 70/421;
70/419 |
Current CPC
Class: |
E05B
27/00 (20130101); Y10T 70/7944 (20150401); Y10T
70/7605 (20150401); Y10T 70/7932 (20150401) |
Current International
Class: |
E05B
27/00 (20060101); E05b 015/14 (); E05b
063/00 () |
Field of
Search: |
;70/364A,358,365,366,364R,419,421 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Wolfe; Robert L.
Attorney, Agent or Firm: Mason, Fenwick & Lawrence
Claims
What is claimed is:
1. A cylinder lock adapted to be unlocked by a key, comprising a
lock casing having a forwardly opening, axially elongated
cylindrical bore therein a cylindrical key plug rotatably disposed
in said bore for rotation about the bore axis having a key slot
therein and a cylindrical surface closely conforming to and located
immediately adjacent the bounding surface of said bore defining a
shear line at the interface therebetween, said lock casing and key
plug each having mating bore sections alinable along pin axes
intersecting the shear line at the locked position of the plug to
form tumbler bores, tumbler pin assemblies in each of said tumbler
bores each including a rigid pin locking segment resiliently biased
to a normal position extending into both said bore sections
crossing said shear line and a plurality of inner pin segments in
the plug bore section defining plural planes of separation for each
pin assembly spaced radially inwardly of the shear line, and
locking members for the respective pin assemblies coupled for
reciprocative movement with the associated pin assemblies along
paths generally paralleling and laterally spaced from the
associated pin axes and each having a rigid elongated locking leg
crossing said shear line to block rotary movement of the plug from
said locked position, said casing and plug having recesses alinable
at the locked position of the plug to receive said legs of said
locking members, and said legs having end surfaces positioned to
aline with said shear line when the pin assemblies are moved to a
release position alining selected planes of separation defined by
said pin segments with the shear line to release the plug for
rotation to unlocked position.
2. A cylinder lock as defined in claim 1, wherein said plug has
elongated bores alined with said legs along the paths of movement
of the legs communicating with the recesses for said legs, and
axially movable pin members in said last-mentioned bores
resiliently biased toward the end surface of the adjacent leg and
having an end surface to aline with said shear line when said pin
assemblies are disposed at said release position.
3. A cylinder lock as defined in claim 1, wherein said locking
segment of each pin assembly is the radially outermost pin portion
extending through a major portion of the casing bore section to a
plane of separation with the next adjacent pin segment spaced
radially inwardly of the shear line toward the axis of rotation of
the plug, and said pin segments defining several additional planes
of separation therebetween for each pin assembly spaced radially
inwardly of the outermost pin portion.
4. A cylinder lock as defined in claim 2, wherein said locking
segment of each pin assembly is the radially outermost pin portion
extending through a major portion of the casing bore section to a
plane of separation with the next adjacent pin segment spaced
radially inwardly of the shear line toward the axis of rotation of
the plug, and said pin segments defining several additional planes
of separation therebetween for each pin assembly spaced radially
inwardly of the outermost pin portion.
5. A cylinder lock as defined in claim 1, wherein said locking
members each comprise an integral U-shaped member having a
cross-piece centrally abutting the locking segment of its
associated pin assembly for movement therewith axially of its bore
and a pair of depending legs laterally flanking the associated pin
assembly each extending across the shear line into said plug to
form a pair of said leg members for each pin assembly.
6. A cylinder lock as defined in claim 2, wherein said locking
members each comprise an integral U-shaped member having a
cross-piece centrally abutting the locking segment of its
associated pin assembly for movement therewith axially of its bore
and a pair of depending legs laterally flanking the associated pin
assembly each extending across the shear line into said plug to
form a pair of said leg members for each pin assembly.
7. A cylinder lock as defined in claim 3, wherein said locking
members each comprise an integral U-shaped member having a
cross-piece centrally abutting the locking segment of its
associated pin assembly for movement therewith axially of its bore
and a pair of depending legs laterally flanking the associated pin
assembly each extending across the shear line into said plug to
form a pair of said leg members for each pin assembly.
8. A cylinder lock as defined in claim 4, wherein said locking
members each comprise an integral U-shaped member having a
cross-piece centrally abutting the locking segment of its
associated pin assembly for movement therewith axially of its bore
and a pair of depending legs laterally flanking the associated pin
assembly each extending across the shear line into said plug to
form a pair of said leg members for each pin assembly.
9. A cylinder lock as defined in claim 5, wherein said lock casing
includes a cylindrical shell portion having said cylindrical bore
housing said plug and a ridge portion projecting radially from the
shell portion having the casing bore sections therein housing said
pin locking segments, coil springs in said casing bore sections for
urging said pin assemblies axially inwardly toward the axis of
rotation of the plug, said ridge portion of the casing having
lateral slots transversely intersecting the casing bore sections,
and the crosspieces of said locking members extending through said
slots into abutment with ends of the pin locking segments
interposed between the latter and said coil springs.
10. A cylinder lock as defined in claim 6, wherein said lock casing
includes a cylindrical shell portion having said cylindrical bore
housing said plug and a ridge portion projecting radially from the
shell portion having the casing bore sections therein housing said
pin locking segments, coil springs in said casing bore sections for
urging said pin assemblies axially inwardly toward the axis of
rotation of the plug, said ridge portion of the casing having
lateral slots transversely intersecting the casing bore sections,
and the crosspieces of said locking members extending through said
slots into abutment with ends of the pin locking segments
interposed between the latter and said coil springs.
11. A cylinder lock as defined in claim 1, wherein said pin
assemblies are all disposed with said pin axes located in a common
plane along a radius of the axis of rotation of the key plug, and
said leg members being disposed with their axes paralleling said
pin axes spaced laterally from said common plane.
12. A cylinder lock as defined in claim 2, wherein said pin
assemblies are all disposed with said pin axes located in a common
plane along a radius of the axis of rotation of the key plug, and
said leg members being disposed with their axes paralleling said
pin axes spaced laterally from said common plane.
13. A cylinder lock as defined in claim 1, wherein said pin
assemblies are all disposed with said pin axes located in a common
plane along a radius of the axis of rotation of the key plug, and
said leg members being disposed with their axes paralleling said
pin axes in a pair of planes laterally flanking said common plane
along opposite sides thereof.
14. A cylinder lock as defined in claim 2, wherein said pin
assemblies are all disposed with said pin axes located in a common
plane along a radius of the axis of rotation of the key plug, and
said leg members being disposed with their axes paralleling said
pin axes in a pair of planes laterally flanking said common plane
along opposite sides thereof.
Description
BACKGROUND AND OBJECTS OF THE INVENTION
The present invention relates in general to cylinder locks, and
more particularly to key-operated pin tubler cylinder locks having
special provision for protecting the same against unauthorized
entry by the usual lock picking procedures.
One of the common types of key locks which have come into wise use
is the type known as a cylinder lock. Such cylinder locks comprise
a lock body or casing having a cylindrical bore opening through the
front surface of the lock body which rotatably houses a key plug or
lock plug having a key way or key slot opening through the front
surface of the plug and extending substantially the axial length of
the plug. A series of parallel tumbler bores are formed in the plug
and lock body along axes extending radially of the axis of rotation
of the plug and lying in a common plane when the plug is in locked
position. These pin tumbler bores house coil springs and sectioned
or segmented locking pins each comprising an inner section lying
entirely within the plug portion of the tumbler pin bore having an
end surface extending into the keyway to be contacted by the shaped
edge of the key, and an outer section which extends into the
portion of the tumbler bore lying in the outer lock body. The inner
pin section is in axially aligned abutment with its associated
outer pin section with the outer pin section normally extending
across the shear line or boundary zone between the plug and the
lock casing, thus restraining the plug against rotation. However, a
key of proper contour will elevate the pins proper distances to
locate the line of separation between the inner and outer pin
sections in alinement with the shear line between the plug and lock
casing, permitting rotation of the plug and the bolt connected with
the plug to unlock the closure protected by the lock.
Due to the conditions which arise in the construction of the lock
parts under customary manufacturing tolerances, it is possible to
effect minute rotary displacement of the plug from its normal
locked position to thereby cause the cylindrical surface portions
of the plug bounding the tumbler pin bores to form a slight offset
shoulder or ledge at the shear line between the plug and the
surface of the plug-accommodating bore, which will catch and
support the edge of the lower ends of the outer pin sections when
the tumbler pins are elevated. This property of the locks is taken
advantage of in lock picking procedures by applying a special
wrench to the plug to force or stress the plug in an angular
direction about its axis of rotation and then manipulate the
tumbler pin by a pick inserted into the keyway to individually lift
them until the outer pin sections catch on the shoulder or ledge
formed when the plug is thus stressed. When all of the outer pin
sections have been thus caught in the elevated position, the plug
can be turned through the appropriate arc to unlock the lock
without the use of a key.
Various means have been proposed for increasing the security of
such cylinder locks against picking. These means have variously
included secondary apparatus for preventing even slight relative
rotation of the plug in the lock casing so that the conventional
lock picking techniques of applying the torque to the plug and
hanging the outer sections of the tumbler pins is prevented. These
have included mechanisms blocking access to the keyway except when
they are in a particular position which prevents slight relative
rotation of the plug and lock casing.
An object of the present invention is the provision of a novel
keyoperated pin tumbler cylinder lock construction, having a lock
mechanism which resists unlocking of the lock by the usual lock
picking procedures.
Another object of the present invention is the provision of a novel
cylinder type key lock wherein each of the pin tumblers are
provided with a plurality of lines of separation, together with
means associated with each of the pin tumblers which restrain the
key plug against rotation for all but one of the plural planes of
separation of each tumbler pin.
Another object of the present invention is the provision of a novel
key operated pin tumbler cylinder lock wherein the portion of each
pin tumbler in the rotatable key plug is segmented to provide a
plurality of transverse planes of separation at different axial
positions along each pin, together with associated locking members
movable along axes paralleling each tumbler pin axis in flanking
relation thereto which normally locks the key plug against rotation
and releases the key for rotation only when one of the plurality of
planes of separation between the segments of each tumbler pin is
aligned with the shear line between the key plug and the wall of
the plug-accommodating bore in the cylinder lock casing.
Other objects, advantages and capabilities of the present invention
will become apparent from the following detailed description, taken
in conjunction with the accompanying drawings illustrating a
preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a front elevation view of a key operated pin tumbler
cylinder lock embodying the present invention;
FIG. 2 is a vertical longitudinal section view thereof, taken along
the line 2--2 of FIG. 1;
FIG. 3 is a vertical transverse section view taken along the line
3--3 of FIG. 2; and
FIG. 4 is an interrupted perspective view of the cylinder lock,
with an intermediate portion broken away to reveal the construction
of the locking mechanism.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
Referring to the drawings, wherein like reference characters
designate corresponding parts throughout the several Figures, the
cylinder lock of the present invention is indicated generally by
the reference character 10 and comprises a lock body or casing 11
of substantially conventional configuration including a lower
cylindrical lock case portion 12 and an upwardly extending ridge
portion 13 aligned with the medial vertical longitudinal plane of
the lock casing. The cylindrical lock case portion 12 has a
longitudinally disposed cylindrical bore 14 opening through the
front face or surface 15 of the lock body. The rearmost end portion
of the bore 14 may have a constricted bore portion opening through
the rear face of the lock body, in accordance with conventional
practice. A cylindrical key plug or barrel 16 conforming closely to
the diameter and curvature of the bore 14 is received in the bore
for rotation about the axis thereof and has a front face which is
projected slightly forwardly from the front face 15 of the lock
casing, and the plug may have a constricted rear portion projecting
through the constricted bore portion of the lock case to an exposed
position rearwardly of the lock case to be coupled by suitable
conventional means with a conventional bolt (not shown). The
cylindrical plug 16 is provided with the usual key slot or keyway
17 having an entrance end at the front face of the plug 16.
The ridge portion 13 of the lock casing is provided with a
longitudinally spaced, parallel, series of pin-accommodating bores
20 for housing the tumbler pin assemblies. Each of the bores 20
have their axes extending radially of the axis of rotation of the
plug 16 in a common plane, usually a vertical plane including the
axis of rotation of the plug, and the key 16 is provided with a
series of similar bores 21 extending from the periphery of the plug
16 to substantially the center of the key slot 17. The bores 21 are
adapted to be aligned axially with the bores 20 when the key 16 is
in locked position. The bores 20 and 21, in the usual fashion,
support and guide a series of tumbler pin assemblies 22, each made
up of an outer tumbler pin section 23 lying principally in the
bores 20 in the lock case, and an inner pin section 24 made up of a
plurality of pin segments 24a lying wholly or principally within
the bore 21 in the key plug 16. The tumbler pin assemblies 22 made
up of the outer pin section 23 and the segments forming the inner
pin section 24 are biased continuously to a bottomed condition
within their respective bores, biased toward the center of the key
slot 17, by the coil springs 25 within the bores 20 continuously
urging a resiliently biasing force against the upper ends of the
outer pin sections 23. The coil springs 25 may be held in the bores
20 by any conventional means, such as by the cover plate 26 fixed
in the recess 13a in the top of the ridge portion 13, or by
headless screws threaded into threaded top sections of the bores
20. The plane of separation between the outer pin section 23 and
the uppermost of the pin segments 24a forming the inner pin section
is spaced radially inwardly from the shear line or zone between the
cylindrical surface of the key plug 16 and the plug-accommodating
bore 14 so that this shear line occurs at an intermediate portion
of the outer pin section 23. Thus, the plurality of planes of
separation between the pin segment 24a of each tumbler pin assembly
and between the uppermost of these pin segments and the outer pin
section 23 form rendundant tumbler pin separation surfaces which
may be caught against the shoulder or ledge formed when the key
plug is stressed by the usual lock picking procedures, and thus the
person attempting to pick the lock is unable to determine which of
the separation planes is the correct one for unlocking the
lock.
Associated with each of the tumbler pin assemblies 22 is a U-shaped
tumbler member or locking member 27 having a cross piece or top
portion 28 extending transversely to and slidable in an associated
vertical slot 29' extending along the upper portion of each bore
20, with the center portion of the cross piece 28 bearing against
the top end of the outer tumbler pin section 23. A pair of
laterally spaced legs 29 depend from the cross piece through slots
30 in the cylindrical portion 12 of the lock case and into recesses
31 in the confronting portions of the key plug 16. As illustrated
in the drawings, the slots 30 in the shell or cylindrical lock case
portion 12 and the recesses 31 in the key plug 16 for accommodating
the locking legs 29 are somewhat larger than the cross-section of
the legs 29 to provide some clearance so that the slight rotation
of the key plug which is achieved when it is stressed in accordance
with usual lock picking procedures will not bring any shoulder
surface at the shear line between the plug and the case into
contact with the legs 29, thus avoiding the catching of the locking
members which is essential to unauthorized picking of the lock. As
illustrated, the U-shaped locking members 27 may be resiliently
biased upwardly to the normal positions occupied by them when the
lock is in locked condition by axially slidably cylidrical pins 32
seated in elongated cylindrical bores 33 in the plug 16
communicating with the recesses 31 and housing coil springs 34
which bear upwardly against the pins 32 urging them into upwardly
biasing engagement with the bottom surfaces of the locking member
legs 29.
It will be apparent that in order to unlock the lock, the
appropriate key which is inserted into the keyway 17 of the key
plug 16 must lift the tumbler pin assemblies 22 an appropriate
distance to aline the plane of separation between a pair of the pin
segments 24a or between one of such pin segments and the outer pin
section with the shear line between the plug 16 and the lock case
11, and must also aline the bottom ends of the locking member legs
29 with this shear line before the plug 16 is released for rotation
to the unlocking position. There are no shoulder or ledge
formations which can be formed adjacent and brought into contact
with the legs 29 because of the clearance provided by the slots 30
and recesses 31 relative to the legs 29, by which a person
attempting to pick the lock can determine the appropriate distance
to elevate the associated tumbler pin to achieve the proper setting
of the tumbler pin and associated lock member. Although the person
attempting to pick the lock can, by stressing the plug 16, produce
shoulder or ledge formations which can catch the tumbler pin
assemblies 22 at the various planes of separation between the pin
segments 24a or between the uppermost pin segment and the outer pin
segment 23, there are a plurality of such line of separations
provided for each tumbler pin so that the person using the pick has
no way knowning which one of the plural separation lines for each
tumbler pin is the proper one to elevate the locking member legs 29
to proper unlocking position. In the illustrated embodiment, five
of such planes of separation are provided for each tumbler pin
assembly 22, although it will be appreciated that a different
number of planes of separation for each tumbler pin assembly can be
used, without altering the underlying principal of operation. In
fact, each tumbler pin assembly can be made up entirely of a stack
of pin segments such as the pin segments employed for the inner pin
section of the specifically described embodiment.
* * * * *