Note: Descriptions are shown in the official language in which they were submitted.
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BACKGROUND OF THE INVENTION
A need exists for a reasonably priced pin tumbler lock
that is substantially pick proof. Despite continuing efforts
to produce such a lock, all known pin tumbler locks are either
prohibitively expensive or may be violated, either by picking
or by shearing of the lock's pins with a strong tool inserted
into a keyway. It is the general object of the present inven-
tion, therefore, to provide a high security pin tumbler lock
which is of reasonably low cost.
SUMMARY OF THE INVENTION
The present lock includes a cylinder housing with a cir-
cular bore in which a cylindrical plug is eccentrically mounted.
On the plug there are mounted sleeve segments each having at
least one pinway. The componènts are arranged such that the
plug and sleeve segments form a concentric unit that can be
rotated on an axis with a proper key to open or clos2 the lock.
However, in the event that any pin is not at a proper shear
level and thereby restrains a sleeve segment, the plug may be
rotated only slightly before becoming bound to prevent opening
of the lock. Picking of the lock is prevented by the provision
in each sleeve segment of circumferentially extending recesses
coincident with the pinways. During a picking attempt the pins
become ledged in the recesses and relative rotational movement
between sleeve segments produces pinway misalignment that pro-
hibits further attempts to attain the proper shear. Mounted
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eccentrically on the plug is a circular face that is retained
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in a concentric face opening in the cylinder. Binding occurs -
between the plug face and cylinder opening in response to inde-
pendent rotation of the plug. This feature prevents opening of
the lock in the event a false shear line is attained at the
junction between the plug and sleeve segments.
In addition~ a diagonally contoured movable plate may be
utilized in a longitudinal recess in an extra eccentric sleeve
arrangement mounted on the plug. This sleeve has longitudinal ~
grooves or recesses in the outer surface and in the lower sur- ;-
face with corresponding apertured diagonal contoured plates
therein.
BRIEF DESCRIPTION OF THE DR~WINGS
Fig. 1 is a rear view~ without cam or other actuator, o
; the cylinder, plug and three intervening levels of eccentric
rings, bands and sleeve;
Fig. 2 is a sectional view taken on line 2-2 of Fig. l;
Fig. 3 is a view showing the plug face and potential areas
of binding stop;
Fig. 4 is a detail illustrating interengaging mPa~s be-
2Q tween the various rings or bands going to make up a sIeeve;
Fig. 5 is a side view o~ the plug;
Fig. 6 is an end view of the eccentric ring surrounding theplug;
Fig. 7 is a view in elevation looking in the direction of
arrow 7 in Fig. 6;
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~ Fig. 8 is an end view of the intermediate sleeve;
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Fig. 9 is a view in elevation looking in the direction of
arrow 9 in Fig. 8;
Fig. 10 illustrates the out-of-line position of the diago-
nal plate or plates utilized wlth the sleeve of Fig. 8;
Fig. 11 illus~rates diagona] contoured plates assuming an
out-of-line form when pressured out of pinway alignment by ro-
tary motion of the plug and longitudinal recess shoulder of
sleeve;
Fig. 12 is a front view of the outermost rings or bands;--
Fig. 13 is an assembly view looking in the direction of
arrow 13 in Fig. 12;
Figs 14 and 15 illustrate the action of the plug with thefirst ring on the plug in false opening positions;
Yig. 16 is a view on an enlarged scale s-;milar to that of
Fig. 1 and illustrating the top and bottom pin and the proper
shear point level when three intermediate plug surrounding mem-
bers are utilized;
Figs. 17 and 18 illustrate the action of the structure
shown in Fig. 16 in operable pssition showing different posi-
tions of the pin restraint of rings, bands and sleeves; and
Figs. 19-21 are front views of the lock illustrating or-
- bital movement of the plug within the cylinder.
PREFERRED ~MBODIMENTS OF THE INVENTION
A cylinder housing 10 has a cylindrical plug 12 eecentri-
cally positioned in a circularly cylindrical bore 11. The plug
12 defines a conventional key slot 14 therein. Surrounding the
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plug are a plurality of sleeves 16, 20, 32 forming a composite
circularly cylindrical sleeve rotatably mounted in the bore 11.
The plug 12 is rotatably mounted in a circularly cylindrical
passage 19 defined by the inner sleeve 16 and eccentric to the
axis of the bore 11. Formlng the sleeve 16 are a plurality of
ring segments 54, two of which are shown in Fig. 4. The seg-
ments 54 are interengaged by recesses 56 and tabs 58 that per-
mit relative rotational movement therebetween. It will be
noted that the segments are eccentric in that they are thinner
at one edge and gradually thicken to a maximum diametrically
opposite. There is also a groove or recess 52 in the thickest
position of each forming a composite elongated recess which is
indlcated at 18. The plug is correspondin~ly but reversely
eccentric relative to its circula~ face 40, as will be de-
scribed.
If desired, a second set of rings or bands may be used, or
in its place a sleeve 20 may be utilized about the rings or
bands 16 and this is also eccentrically made as described pre-
viously and has two longitudinal contoured recesses, one exte-
rior thereof as at 22 and one on the interior 24. This formsa contoured floor 26 separating the recesses in each of which
is a contoured diagonal apertured plate 28, 30, which lies di-
agonally in the groove or recess 22 and 24 but assume a rec-
tangular form when pressured out of alignment by the recessed
shoulder of the sleeve.
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Also, if desired, a third set of rings or bands 32 may be
app]ied to the exterior of sleeve 20 and they also are eccen-
tric and have longitudinal recesses 34. The various rings or
bands are arranged to have their thicker sides additive, the
plu~, however being cylindrlcal with a constant radius.
The cylinder housing 10, of course, has housing pinways 37
as shown in Fig. 2 and the sleeves, 16, 20 and 32 have aligned
sleeve pinways 39, 39a and 39b as shown in Figs. 6-12. The pin-
ways retain driver pins 36 biased inwardly by springs 41. Also
defined by the plug 12 are plug pinways 39c that retain tumbler
pins 36a longitudinally aligned with the driver pins 36. The
circular face 40 of the plug is inserted into a circular open-
ing 44 in the face 42 of the cylinder 10.
As shown in Fig. 5, the plug face 40 extends upwardly a
distance greater than it extends downwardly, see 46, and is
eccentric to a central axis running through the plug, but is
concentric with the bore 11 and the plug face opening 44 in
the cylinder 10. When a proper key is used in the keyway 14
and all the pins are raised, a shear point will be reached
wherein the tumbler pins 36a and the driver pins 36 meet along
the surface of engagement between the sleeve 32 and the cylin-
der housing 10 as shown in Fig. 16 In those positions, the
tumbler pins 36a engage the plug 12 with the sleeves 16, 26
and 32 forming a composite circularly cylindrical unit that is
not tied tc the housing 10. Consequently, the unit can turn
on the common axis of the bore 11 and the face plate 40 to
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unlock or lock the lock. During such operation of the lock, the
eccentric plug 12 moves in an orbital path about the axis of the
bore ll as illustrated by the different plug positions shown in
Figs. 19-21. However, should any of the pins 36 still be en-
gaged between the housing lO and any of the sleeves as shown in
Figs. 14, 15, 17 and 18, then the remaining parts of the unit
become eccentric with respect to the bore 11 and when this hap-
pens, and turning is attempted to be forced, binding occurs be-
tween the plug 12 and the engaged sleeves preventing rotation.
In the event that all of the driver pins 36 are out of the plug
pinways 39c and torque is applied to the plug 12, the face 40
turn~ on an eccentric axis relative to the opening 44 in the
cylinder7 and therefor~ will bindingLy engage on the opening's
edge 44 at points A, Figs. 1 and 3, and no further turning can
be imposed on the plug.
Referring now to Figs. 8, 9 and 10, it will be seen that
the plate 28 in the recess 22 of the eccentric sleeve 20 fits
snugly in the recess and it is apertured to receive the upper
pins 36 shown in Fig. 2. When the plug is attempted to be
turned and one or more pins restrain the plate, it will assume
a straight longitudinal position in its recess 22 and 24, re-
sulting in a pinway misalignment; see Fig. 10.
Fig. 14 illustrates the ledging and lodging of a top pin
36 in recess 18 of one segment 54 of the sleeve 16. Similar
positions are illustrated in Figs. 17 and 18 as to the ledging
and lodging action where the rings or bands 20 and 32 are
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utilized in the structure. These represent typical positions
that the driver pins 36 would assume during attempts to pick
the lock. For example, in accordance with known techniques, a
picker would sequentially apply upward pressure on each tumbler
pin 36a while simultaneously exerting torque on the plug 12 in
an attempt to ledge the associated driveE pin 36 at shear level.
However, before reaching actual shear level, the driver pins 36
would first reach false shear levels provided, for example, by
the recess 18 as shown in Fig. 14. In these positions concen-
tric rotation of the composite plug and sleeve unit is prevented
and opening of the lock is precluded. Consequently, after all
driver pins 36 have reached the positions illustrated in Fig.
urther picking is required ~o raise them to the actual
shear~position~. Such ~urther picking is precluded~ however,
because the amount of plug movemerlt required to ledge all the
driver pins 36 as shown in Figs. 14 will produce a misalignment
between the plug pinways 39c and one or more of the sleeve pin-
ways 39. The misalignment results from the relative rotational
movement that is possible between the individual segments 54 of
~j 20 the sleeve 16. Once misalignment of pinways 39 and 39c occurs,
the associated tumbler pin 36a which will have dropped back into
the plug 12 after picking pressure was released cannot be brought
into contact with its driver pin 36 and further picking opera-
tions are precluded. It will be obvious that attempts to ledge
`~ the driver pins 36 at other false shear levels such as those
illustrated in Figs. 17 and 18 will produce a similar result to
prevent further picking.
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Obviously, many modifications and variations of the pres-
ent invention are possible in light of the above teachings.
For example, it will be obvious that the lock could be modi-
fied to eliminate the outer sleeves 20 and 32 and the inner
segmented sleeve 16 would still function to subvert picking
operations. It is to be understood, therefore, that the in- :
vention can be practiced otherwise than as specifically de-
scribed .
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