U.S. patent number 3,756,049 [Application Number 05/172,991] was granted by the patent office on 1973-09-04 for axial pin tumbler lock assembly and combination reset key therefor.
This patent grant is currently assigned to Chicago Lock Co.. Invention is credited to William J. Kerr.
United States Patent |
3,756,049 |
Kerr |
September 4, 1973 |
AXIAL PIN TUMBLER LOCK ASSEMBLY AND COMBINATION RESET KEY
THEREFOR
Abstract
An axial tumbler lock assembly having a three-part cylinder
arrangement including a fixed rear part, a rotatable front part,
and a rotatable intermediate part, the three parts establishing
between them two interfacial planes. Three-piece split tumbler
arrangements are slidable in aligned bores in the cylinder parts
and normally project across both interfacial planes to thus prevent
relative turning of either rotatable cylinder part with respect to
the fixed cylinder part. A reset key is provided for releasing the
front cylinder part from the intermediate cylinder part without
releasing the intermediate cylinder part, thus effecting a new
alignment of tumbler pieces and a combination change so that a
different operating key is required for each combination change of
which the lock is capable. The reset key is incapable of effecting
unlocking operations.
Inventors: |
Kerr; William J. (Glenview,
IL) |
Assignee: |
Chicago Lock Co. (Chicago,
IL)
|
Family
ID: |
22630042 |
Appl.
No.: |
05/172,991 |
Filed: |
August 19, 1971 |
Current U.S.
Class: |
70/491;
70/382 |
Current CPC
Class: |
E05B
27/083 (20130101); Y10T 70/7729 (20150401); Y10T
70/7593 (20150401) |
Current International
Class: |
E05B
27/08 (20060101); E05B 27/00 (20060101); E05b
029/00 (); E05b 025/00 () |
Field of
Search: |
;70/340,363,382,383 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Champion; Marvin A.
Assistant Examiner: Staab; Lawrence J.
Claims
Having thus described the invention what I claim as new and desire
to secure by letters patent is:
1. An axial pin tumbler lock comprising, in combination, a
generally cylindrical open-ended tubular lock barrel having at its
front end a fixed inturned rim flange defining a front central and
circular key opening, a rigid, functionally one-piece lock shaft
projecting centrally and axially through said lock barrel and
embodying a front cylindrical section which projects forwardly and
terminates in the vicinity of said central key opening and
constitutes a centerpost for selective reception thereover of a
tubular reset key and a tubular operating key, a rear cylindrical
section which terminates adjacent to the rear end of the barrel and
embodies means between it and said rear end of the barrel to
prevent forward axial displacement of the lock shaft with respect
to said barrel, and an intermediate cylindrical section in the form
of a radial lock shaft flange the diameter of which is greater than
the diameter of either the front or rear cylindrical section and is
also equal to the internal diameter of the lock barrel, locking
means operatively connected to said rear cylindrical section of the
lock shaft exteriorly of the lock barrel, a non-rotatable
cylindrical rear tubular lock cylinder encompassing said rear
cylindrical section of the lock shaft within the barrel and fixedly
secured to the latter, a rotatable cylindrical front tubular reset
cylinder disposed within the front portion of the barrel and
encompassing said centerpost and through which the latter projects
axially and beyond which it projects forwardly, said rotatable
front reset cylinder, rotatable intermediate radial lock shaft
flange and non-rotatable rear lock cylinder being provided with
circumferentially spaced longitudinally extending bores which are
movable into and out of alignment with one another upon relative
angular shifting movement therebetween, follower tumblers, driver
tumblers and reset tumblers slidable in the bores in said
non-rotatable rear lock cylinder, lock shaft flange, and front
reset cylinder respectively, provided with spring means for urging
them forwards, and normally projecting across the interfacial
planes between said flange and cylinders and preventing relative
rotation between the radial lock shaft flange and each cylinder,
certain of said driver tumblers being of different length and
certain of said reset tumblers being of different length, said
front reset cylinder, except only for the provision of said reset
tumblers, being freely rotatable on said centerpost throughout an
arc of 360.degree., the front ends of said reset tumblers being
partially overhung by said fixed inturned flange, said driver
tumblers and follower tumblers being effective when meeting on the
interfacial plane between the radial lock shaft flange and the
non-rotatable rear lock cylinder to release the lock shaft flange
from said rear lock cylinder for rotation of the lock shaft as a
whole and also its associated locking means, said reset and driver
tumblers being effective when meeting on the interfacial plane
between the lock shaft flange and front reset cylinder to release
the latter from the former for rotation relatively thereto, a reset
key having a tubular body telescopically receivable over said
centerpost forwardly of the reset cylinder and having bitting
embodying shoulders which are engageable with said reset tumblers
and effective to shift said reset and driver tumblers to their
positions of reset cylinder release, and a plurality of similar
operating keys, each of which has bitting different from the other
operating keys and also from that of the reset key and embodies
shoulders engageable with the reset tumblers and effective through
said reset tumblers to shift the driver and follower tumblers to
their positions of lock shaft flange release, depending upon the
relative angular positions assumed by said reset cylinder and lock
shaft flange.
2. An axial pin tumbler lock as set forth in claim 1 and wherein
said inturned rim flange on the lock barrel is formed with an
alignment notch therethrough, each operating key is provided on its
body with an outwardly extending alignment lug designed to register
with the alignment notch in order to insure proper cooperation
between the key shoulders and reset tumblers at the time such
operating key is inserted into said forward central key opening and
adapted after full insertion of the operating key into place and in
connection with turning of such key to swing around the inner
surface of said inturned rim flange, and the body portion of the
reset key is devoid of any alignment lug whereby the shoulders on
its body portion may variously cooperate with said reset tumblers
at the time such recess key is inserted into said forward central
key opening and said reset key may be withdrawn from said forward
central key opening after turning thereof into any selected angular
position.
3. An axial pin tumbler lock comprising, in combination, a
generally cylindrical open-ended tubular lock barrel having at is
front end a fixed inturned rim flange defining a front central and
circular key opening, a centerpost of circular cross section
extending centrally and axially through the front end portion of
the lock barrel, terminating in the vicinity of said central key
opening and adapted for selective reception thereover of a tubular
reset key and a tubular operating key, a rigid functionally
one-piece lock shaft projecting centrally and axially through the
intermediate and rear end portions of said lock barrel and
embodying a rear cylindrical section which terminates adjacent to
the rear end portion of the barrel and embodies means between it
and said rear end portion of the barrel to prevent forward
displacement of the lock shaft with respect to said barrel, and a
radial lock shaft flange which is disposed between the centerpost
and the rear cylindrical section and the diameter of which is
greater than the diameter of the centerpost and said rear
cylindrical section and is equal to the internal diameter of the
lock barrel, locking means operatively connected to said rear
cylindrical section of the lock shaft exteriorly of the lock
barrel, a non-rotatable cylindrical rear tubular lock cylinder
encompassing said rear cylindrical section of the lock shaft within
the barrel and fixedly secured to the latter, a rotatable
cylindrical front tubular reset cylinder disposed within the front
portion of the barrel and encompassing said centerpost and through
which the latter projects axially and beyond which it projects
forwardly, said rotatable front reset cylinder, rotatable
intermediate radial lock shaft flange and non-rotatable rear lock
cylinder being provided with circumferentially spaced
longitudinally extending bores which are movable into and out of
alignment with one another upon relative angular shifting movement
therebetween, follower tumblers, driver tumblers and reset tumblers
slidable in the bores in said non-rotatable rear lock cylinder,
lock shaft flange, and front reset cylinder respectively, forming
three-part only tumbler arrangements, provided with spring means
for urging them forwards, and normally projecting across the
interfacial planes between said flange and cylinders and preventing
relative rotation between the radial lock shaft flange and each
cylinder, certain of said driver tumblers being of different length
and certain of said reset tumblers being of different length, said
front reset cylinder, except only for the provision of said reset
tumblers, being freely rotatable throughout an arc of 360.degree.,
the front ends of said reset tumblers being partially overhung by
said fixed inturned flange, said driver tumblers and follower
tumblers being effective when meeting on the interfacial plane
between the radial lock shaft flange and the non-rotatable rear
lock cylinder to release the lock shaft flange from said rear lock
cylinder for rotation of the lock shaft as a whole and also its
associated locking means, said reset and driver tumblers being
effective when meeting on the interfacial plane between the lock
shaft flange and front reset cylinder to release the latter from
the former for rotation relatively thereto, a reset key having a
tubular body telescopically receivable over said centerpost
forwardly of the reset cylinder and having bitting embodying
shoulders which are engageable with said reset tumblers and
effective to shift said reset and driver tumblers to their
positions of reset cylinder release, and a plurality of similar
operating keys, each of which has bitting different from the other
operating keys and embodies shoulders engageable with the reset
tumblers and effective through said reset tumblers to shift the
driver and follower tumblers to their positions of lock shaft
flange release, depending upon the relative angular positions
assumed by said reset cylinder and lock shaft flange.
Description
The improved axial pin tumbler lock assembly comprising the present
invention is primarily designed for use in connection with the door
of a vending machine cabinet where managerial policy dictates that
the pin tumbler combinations of the lock assembly shall be changed
frequently, usually on the order of at least once each week. The
invention is, however, capable of other uses, and lock assemblies
embodying the principles of the present invention may find wide
application in other fields as, for example, in connection with
parking meters, self-service gasoline dispensing pumps, safety
deposit boxes and other lock applications too numerous to
mention.
The invention is concerned primarily with a lock assembly of the
axial pin tumbler type wherein the split tumblers that are
associated therewith are circumferentially spaced about and extend
parallel to the central longitudinal axis of the lock barrel, are
spring-biased or pressed towards the front end of the lock barrel,
and are designed for cooperation with a key having
circumferentially spaced, tumbler-engaging shoulders which are
adapted, when the key is inserted into said front end of the lock
barrel, to engage the forward ends of the split tumblers and shift
or depress said tumblers rearwards. This type of lock assembly is
widely used in connection with vending machines which are installed
in public places such as subway stations and the like.
Heretofore, the changing of the pin tumbler combination of such a
lock assembly in the field has been hampered by the necessity of
having first to open the door of the cabinet or other structure to
which the lock assembly is applied and then to dismantle as much of
the lock assembly as is necessary to render the split pin tumblers
accessible for removal and subsequent substitution or replacement.
The workman or operator who is assigned to such combination
substitution work is obliged to carry with him various tools, as
well as an assortment of lock parts including split pin tumblers of
varying lengths. These pin tumblers must be cataloged so that the
operator will know their successive order of replacement in the
various lock assemblies and, therefore, an operator who is not only
skilled from the point of view of workmanship, but one who also has
the ability to perform a certain amount of bookkeeping work, must
be employed. An additional limitation resides in the fact that when
such an operator works from the back side of a cabinet door, the
necessarily open door is frequently a hinderance to people passing
by such as are encountered on a subway platform for example.
Finally, it is necessary that a trustworthy operator be employed
inasmuch as for all lock-changing operations that have heretofore
been adopted for large-scale lock-changing operations, the interior
of the cabinet has been accessible to the operator and invariably
access to the cabinet means access to its contents including such
money or other valuables as may have been deposited therein.
The present invention is designed to overcome the above noted
inconveniences that are attendant upon the changing of pin tumbler
combinations which are associated with axial pin tumbler locks and
toward this end, it contemplates the provision of a novel lock
assembly wherein the insertion of a special reset key into the
circular key-receiving opening in the front end of the lock barrel
and subsequent turning of such key throughout a predetermined angle
will automatically effect changing of the pin tumbler combination
so that after the reset key is withdrawn from the key-receiving
opening, the original key which formerly fitted the lock assembly
will no longer work and a different regular key will be required to
actuate the lock assembly.
An important feature of the present invention resides in the fact
that the special reset key does not have the ability to effect
unlocking operations, the lock assembly remaining in its locked
condition during combination changeover operations and the only key
to which the lock will respond is a key which has been cut
according to the combination which is brought about by use of the
special reset key.
Stated otherwise, the function of the special reset key is entirely
a resetting function and its use is accomplished simply by
inserting the same in the circular key-receiving opening in the
front end of the barrel of the lock assembly and turning the same
throughout a calculated or predetermined angle in order thereby to
effect within the lock barrel certain tumbler shifting movements by
means of which the existing combination of pin tumblers will be
destroyed and a new combination will be supplied. In using the
reset key, it is not necessary that the cabinet or other structure
to which the lock assembly is applied be opened, nor in fact is it
possible for the reset operator to open such cabinet unless he is
specifically supplied with an operating key which is cut for the
combination that is to be changed or for the new combination.
Ordinarily, where vending machines are concerned, the reset
operator will not be supplied with an operating key of any sort,
his only equipment being in the form of a single reset key. Neither
is it necessary for the operator to remove any portion of the lock
assembly and, in fact, it is not even necessary for the operator to
handle or even touch the lock assembly, his only function being to
insert the reset key into the circular key-receiving opening in the
front end of the lock barrel, then turn the key to the desired
combination change, then withdraw the reset key, and finally
proceed to the next vending machine which is to be processed.
The provision of a lock assembly and a special reset key therefor
such as has briefly been outlined above constitutes the principal
object of the invention. Other objects and advantages of the
invention not at this time enumerated will be apparent from a
consideration of the following detailed description.
The invention consists in the several novel features which are
hereinafter described and are more particularly defined by the
claims at the conclusion hereof.
In the accompanying two sheets of drawings forming a part of this
sepcification, one illustrative embodiment of the invention is
shown.
In these drawings:
FIG. 1 is a front elevational view of an axial pin tumbler lock
assembly embodying the principles of the present invention;
FIG. 2 is a longitudinal sectional view taken on the line 2--2 of
FIG. 1;
FIG. 3 is a transverse sectional view taken on the line 3--3 FIG.
2;
FIG. 4 is a fragmentary front perspective view of the lock
assembly;
FIG. 5 is a perspective view of an operating key for the lock
assembly of FIGS. 1 to 4, inclusive;
FIG. 6 is a perspective view of a reset key by means of which the
pin tumbler combination of the lock assembly may be changed;
FIG. 7 is a schematic developed homolographic projection of the
lock barrel, showing the split pin tumblers in the positions which
they assume when the lock assembly is in its locked condition by
reason of a prevailing initial pin tumbler combination;
FIG. 8 is a homolographic view similar to FIG. 7 but representing
the positions of the pin tumblers when a first and proper key is
inserted into the front end of the barrel of the lock assembly but
before the key is turned in a direction to effect unlocking of the
lock assembly;
FIG. 9 is a homolographic view similar to FIG. 7 but showing the
pin tumblers in the positions which they assume after the special
reset key of FIG. 6 is inserted into the lock barrel but prior to
turning of such key to effect a change of the tumbler
combination;
FIG. 10 is a homolographic view similar to FIG. 9 showing the
position of the pin tumblers after the reset key has been turned to
effect the combination change, but prior to withdrawal of such
special reset key from the lock;
FIG. 11 is a homolographic view similar to FIG. 10 but showing the
position of the pin tumblers after the reset key has been withdrawn
and with the new combination of pin tumblers prevailing; and
FIG. 12 is a homolographic view similar to FIG. 8 but showing the
pin tumblers in the positions which they assume when a proper key
conforming to the new combination has been inserted in the lock but
prior to turning of such key to effect unlocking of the
assembly.
Referring now to the drawings in detail and in particular to FIGS.
1 to 4, inclusive, a preferred form of lock assembly which is
constructed according to the present invention is designated in its
entirely by the reference numeral 10. A key for operating the lock
assembly to lock and unlock the same is shown in FIG. 5 and
identified by the reference numeral 12. A reset key which is
illustrated in FIG. 6 and is designated in its entirety by the
reference numeral 13 is capable of operating the lock assembly 10
for the purpose of changing the pin tumbler combination thereof,
but is incapable of either locking or unlocking the assembly. The
lock assembly 10 is of the axial pin-tumbler type, which is to say
that it is provided with an annular series of circumferentially
spaced split pin tumbler arrangements including tumblers which
extend in the axial direction of the lock barrel and are shiftable
endwise upon engagement of the front reset tumblers of the split
tumbler arrangements with outwardly facing tumbler-actuating
shoulders on the operating key 12, as will be described
presently.
The lock assembly 10 involves in its general organization a
cylindrical outer tubular barrel 14, the forward end of which is
formed with an outwardly turned radial rim flange 16. The barrel 14
is provided with an external screw thread 18 for reception
thereover of a nut 20 which cooperates with the rim flange 16 in
clamping the lock assembly in position on a cabinet door or the
like (not shown). The screw thread 18 is interrupted by the
provision of a pair of oppositely disposed flats 22 by means of
which the barrel may be gripped by a suitable turning tool such as
a wrench.
The barrel 14 of the lock assembly 10 serves to enclose a
three-part lock cylinder arrangement, the details of which will be
made clear subsequently, such arrangement being designated by the
bracket 24 in the homolographs constituting FIGS. 7 to 12,
inclusive. Said three-part lock cylinder arrangement includes a
fixed rear part and two rotatable parts in front of the rear part.
The fixed cylinder part is comprised of a lock cylinder proper 30
which is anchored to the barrel 14 by means of a radial pin 32, the
cylinder proper thus being non-rotatable and forms the fixed rear
part of the three-part lock cylinder arrangement 24. Rotatably
disposed within the barrel 14 is an elongated, longitudinally
extending lock shaft 34 embodying a rear clyindrical section 36
(see FIG. 2) which projects through and is coextensive with a
central bore in the lock cylinder proper 30. A front cylindrical
section 38 on the lock shaft 34 is formed with a rounded outer or
front end 40 and this lies within the confines of a circular
key-receiving opening 42 within an inwardly extending rim flange 44
at the front end of the barrel 14. This front cylindrical section
38 constitutes a key-centering post which, in connection with axial
tumbler-type lock assemblies, is commonly referred to as a
"centerpost." The lock shaft 34 is further provided with an
intermediate cylindrical section 46 in the form of a radial lock
shaft flange, the diameter of which is substantially equal to the
internal diameter of the barrel 14 and, consequently, to the outer
diameter of the lock cylinder proper 30. This intermediate section
46 constitutes one of the two rotatable parts of the lock cylinder
arrangement 24.
The rear end of the lock shaft 34 is provided with a short reduced
extension 48 which projects through the usual washer 50 and is
formed with a pair of diametrically opposite flats 52. The latter
cooperate with a radially extending locking cam 54 which turns with
the lock shaft 34 into and out of locking position as is well known
in the art. A nut 56 is threadedly received on the outer extremity
of the lock shaft extension 48 and serves to hold the locking cam
in a clamped position against the washer 50.
The lock cylinder proper 30 is provided with an annular series of
circumferentially spaced, axially extending cylindrical sockets 58,
each of which slidably receives therein a non-rotative follower
tumbler 60 of a three-piece split pin tumbler arrangement. The rear
ends of the sockets 58 are closed and the front ends of the sockets
are open. Each follower tumbler 60 is designed for cooperation with
a rotative driver tumbler 62 which forms the intermediate piece of
said three-piece tumbler arrangement and is slidably disposed in an
axially extending bore 64 in the intermediate cylindrical section
46 of the lock shaft 34. The bores 64 are arranged in an annular
series. They are open at both ends and correspond in number to the
sockets 58.
A reset cylinder 70 which constitutes the other rotatable part of
the three-part lock cylinder arrangement 24 is rotatable in the
barrel 14 and is disposed on that side of the intermediate
cylindrical section 46 of the lock shaft 34 that is remote from the
lock cylinder proper 30. It has a central circular hole for
receiving the front cylindrical section 38 of the lock shaft 34 and
is provided with an annular series of bores 72. The latter
correspond in number to the bores 64 in the intermediate
cylindrical section 46 of the lock shaft 34 and are movable into
and out of register with said bores 64. Each bore 72 slidably
receives therein a reset tumbler 74 which forms the third and front
piece of said three-part tumbler arrangement and, in effect,
functions as an interchangeable extension for the associated driver
tumbler 62. The reset tumblers 74 also function as driver tumblers
themselves in that, when they are depressed by the reset key 23,
they shift the positions of the driver tumblers 62 as well as the
follower tumblers 60. The reset cylinder 70 and the reset tumblers
74 which are carried thereby constitute the principal feature of
the present invention. The reset tumblers 74 normally bear
forwardly against an annular shoulder 76 which is established by
the inner face of the inwardly extending rim flange 44 on the front
end of the barrel 14, these tumblers being yieldingly biased
against said shoulder by means of an annular series of helical
compression springs 78. The latter correspond in number to and are
disposed respectively in the rear ends of the sockets 58 in the
lock cylinder proper 30. As best shown in FIG. 2, the springs are
piloted on posts 80 which are formed on the rear ends of the
follower tumblers 60. The compression in the springs 78 is
transmitted through the driver tumblers 62 to the reset tumblers
74.
From the above description, it will be observed that the lock
barrel 14 serves to enclose the three parts 30, 46 and 70 of the
lock cylinder assembly 24 and that these three parts establish
among themselves two interfacial planes which are designated,
respectively, in FIGS. 7 to 12 by the broken lines r--r and 1--1.
The interfacial plane r--r will be referred to as the "reset" plane
and the interfacial plane 1--1 will be referred to as the "locking"
plane. The reset plane is established by the interface between the
reset cylinder 70 and the intermediate cylinder section 46 of the
lock shaft 34. The locking plane is established by the interface
between the intermediate cylindrical section 46 and the lock
cylinder proper 30. As a prelude to a proper understanding of the
operation of the herein described lock assembly 10, it must be
borne in mind that when all of the splits which exist between the
driver tumblers 62 and the follower tumblers 60 lie in the
interfacial plane 1--1 as shown in FIGS. 8 and 12, the lock shaft
34 which carries the rotatable intermediate cylindrical section 46
may be turned with respect to the fixed lock cylinder proper 30 and
the barrel 14, thus effecting locking and unlocking operations in
the usual manner of operation of an axial pin tumbler lock. When
all of the splits which exist between the driver tumblers 62 and
the reset tumblers 74 lie in the interfacial plane r--r as shown in
FIGS. 9 and 10, the reset cylinder 70 is free to turn throughout an
arc of 360.degree. with respect to the intermediate cylindrical
section 46 of the lockshaft 34. As shown in FIGS. 7 to 12 of the
drawings, certain of the driver tumblers 62 are of different length
and certain of the reset tumblers 74 are of different length. This
is both important and necessary to proper workability of the
present lock assembly. Also as shown in the drawings, the follower
tumblers, the driver tumblers, and reset tumblers form three-part
only tumbler arrangements.
Shifting of the various tumblers 60, 62 and 74 endwise either for
lock operation or for lock resetting purposes may be effected by
selective use of the operating key 12 and the reset key 13. These
two keys are of similar construction, each of them being cut from a
commercially available axial tumbler lock key. As shown in FIG. 5,
the operating key 12 includes a cylindrical body portion 82, one
end of which is notched in order fixedly to receive the usual
manipulating wing 84. The body portion 82 of the regular operating
key 12 is tubular to the end that it has a deep internal axial
socket 86 which is designed for reception over the centerpost 38
(front cylindrical section of the lock shaft 34) in telescopic
relationship when the key is initially introduced into the lock
assembly through the circular key-receiving opening 42. The key 12
is privided with bitting which embodies an annular series of
forwardly facing shoulders 88 which are cut to different depths in
the outer periphery of the rim region of the body portion 82 of the
operating key 12 and these shoulders are adapted to engage the
extreme forward ends of the reset tumblers 74 for tumbler shifting
purposes. In order to insure entry of the key 12 into the lock
assembly 10 in the proper angular relationship so that alignment of
the shoulders 88 with their respective reset tumblers will take
place, an external alignment lug 90 is provided on the body portion
82 and is adapted to project into an inwardly facing notch 92 (see
FIGS. 1 and 4) in the inwardly extending rim flange 44 of the
barrel 14. After the alignment lug 90 has moved past the rim flange
44 and the key has been turned, the key will be constrained from
being withdrawn from the lock assembly 10 until such time as the
lug 90 is again restored or positioned to register with the notch
92. An internal lug 94 is provided on the rim portion of the key
body 82 and is designed for cooperation with a longitudinally
extending groove 96 which is formed in the centerpost 38 of the
lock assembly 10.
The reset key 13, except for its bitting, i.e., the various depths
to which the shoulders 188 are cut, and also for the absence of an
alignment lug such as the lug 90, is substantially identical to the
key 12 and, therefore, in order to avoid needless repetition of
description, similar reference numerals but of a higher order have
been applied to the corresponding parts as between the disclosures
of FIGS. 6 and 5.
The operation of the present lock assembly 10 may best be set forth
by reference to the homolographic views of FIGS. 7 to 12,
inclusive. In FIG. 7, the three-piece split pin tumbler arrangement
represents the condition of the cylinder arrangement 24 when a
first established tumbler combination prevails and the lock
assembly is in its locked condition with no key in the lock. In
order to facilitate a description of the manner in which various
tumbler move-ments take place under the control of either the
regular key 12 or the special reset key 13, the reset tumblers 74
are labelled A, B, C, D, E, F, G and H in FIG. 7, while the driver
tumblers 62 are labelled a, b, c, d, e, f, g and h. This same
labelling is preserved throughout all of FIGS. 7 to 12.
Furthermore, since these figures of the drawings are homolographic
views rather than structural views, further simplification of the
discussion may be obtained by referring to the reset cylinder 70 as
the "upper fill," the intermediate cylindrical section 46 of the
lock shaft 34 as the "intermediate fill," and the fixed lock
cylinder proper 30 as the "lower fill," the term "fill" being a
conventional term which has arisen and is currently used in the
lock industry to designate one of the tumbler-carrying strata of a
composite lock cylinder regardless of whether the same be
associated with an axial tumbler-type lock or any other tumbler
lock.
Returning to a consideration of FIG. 7 of the drawings, it will be
observed that several tumblers project across the interfacial
planes r--r and 1--1 so that no relative movement of the three
parts of the lock cylinder arrangement is possible and the lock
assembly 10 remains in its locked condition.
In FIG. 8 the various tumblers assume the positions to which they
are shifted when the proper operating key 12 is introduced into the
lock assembly, the shoulders 88 on the key being cut so that each
three-piece pin tumbler arrangement presents a split which lies in
the interfacial plane 1--1. However, one or more tumblers project
across the interfacial plane r--r so that no relative turning
movement between the upper reset fill and the intermediate fill is
possible. The two uppermost fills, however, may turn bodily as a
unit with respect to the lower fill for locking and unlocking
operations. In FIG. 8 the operating key 12 is shown as being
introduced into the lock assembly but not as yet turned. The net
result is that the intermediate and lower fills are released from
each other so that turning of the key will result in causing the
lock assembly 10 to be unlocked.
In FIG. 9 a condition is illustrated wherein the special reset key
13 has been introduced into the lock assembly 10 but has not yet
been turned for a reset operation. The upper fill and the
intermediate fill are thus released from each other while the
intermediate fill and the lower fill remain coupled to each other
by reason of one or more tumblers projecting across the interfacial
plane 1--1. The various shoulders 188 on the reset key have thus
pushed the three-piece pin tumbler arrangements inwardly in order
to bring the splits between the reset tumblers 74 and the driver
tumblers 62 into register with the upper and intermediate
fills.
In FIG. 10 of the drawings, a condition is illustrated where the
reset key 13 has been turned one increment of step so that the
upper fill has rotated throughout a small angle in order to bring
the reset tumbler A (one of eight) into register with the driver
tumbler b (also one of eight), the reset tumbler B into register
with the driver tumbler c, the reset tumbler C with the driver
tumbler d, and so on, the reset tumbler H finally registering with
the driver tumbler a.
Upon withdrawal of the special reset key 13, the various tumblers
assume the positions wherein they are shown in FIG. 11, the
compression springs 78 having forced the various three-piece pin
tumbler arrangements forwards until all of the reset tumblers 74
have moved into engagement with the annular stop shoulder 76 which,
as previously mentioned, is established by the inwardly rim flange
44 at the front end of the lock barrel 14 of the lock assembly 10.
Said lock assembly has at this time been reset to a different
combination so that the original key 12 is no longer capable of
operating the lock assembly by reason of the fact that the various
reset tumblers 74 are mated with different driver tumblers 62, each
reset tumbler constituting, in effect, an extension of its
associated driver tumbler and giving a new length value with
respect to the latter.
Since the combination of the lock assembly 10 has thus been changed
by the aforementioned manipulations of the reset key 13, a
different key is now required in order to effect locking and
unlocking of the lock assembly. Although such a key has not been
illustrated herein, it will be understood that the key will have
its tumbler-engaging shoulders cut so that when the key is
introduced into the circular key-receiving opening 42 of the lock
assembly, the mating reset tumblers 74 and driver tumblers 62 which
are variously disposed in the upper and intermediate fills will be
depressed to bring the splits which exist between the follower
tumblers 60 and the driver tumblers 62 into the interfacial plane
1--1, thus releasing the intermediate fill from the lower fill to
the end that turning of the new key will effect lock unlocking and
locking operations.
It will be understood that although only one specific reset
operation has been illustrated and described herein, various other
reset operations of a different character are available by further
turning of the reset key 13. For example, if desired, a different
pin tumbler combination will be attained if the reset key is turned
to bring the reset tumbler A into register with the driver tumbler
C, in which case the reset tumbler B will move into register with
the driver tumbler d, and so on.
It is obvious that because the reset key 13 is devoid of an
alignment lug such as the lug 90, the same is capable of being
inserted into the lock assembly in any selected angular position.
It is also capable of being withdrawn from the lock assembly in any
desired angular position. However, unless such reset key 13 is
introduced into the lock assembly 10 in the same angular position
which it assumed at the time it was last withdrawn from the lock
assembly, it cannot be turned for resetting operations inasmuch as
the shoulders 188 which are provided thereon must cooperate with
the reset tumblers 74 in such a manner as to depress such tumblers
to positions wherein their inner ends lie in the interfacial plane
r--r in order thus to release the upper fill from the intermediate
fill. Therefore, in order to facilitate proper introduction of the
special reset key 13 into the lock assembly 10, the front end face
of the barrel 14, i.e., the front rim thereof, may be provided with
numerical or other indicia such as are illustrated in FIG. 1 and
designated by the reference numeral 98.
The invention is not to be limited to the exact arrange-ment of
parts shown in the accompanying drawings or described in this
specification since various changes in the details of construction
may be resorted to without departing from the spirit or scope of
the invention. Therefore, only insofar as the invention is
particularly pointed out in the accompanying claims is the same to
be limited.
* * * * *