Note: Descriptions are shown in the official language in which they were submitted.
CA 02630757 2008-05-06
PADLOCK HAVING A PRELOADED LOCKING MEMBER
FIELD
[0001] The present disclosure relates to padlocks.
BACKGROUND
[0002]The statements in this section merely provide background information
related to the present disclosure and may not constitute prior art.
[0003] One type of padlock is a combination padlock. This type of padlock
includes advantages over other types of padlocks, a padlock having a key
locking mechanism, for example, because combination padlocks do not require
carrying around a key. Instead, a memorized combination is used to unlock the
padlock.
[0004] Padlocks typically include a lock body and a lockable shackle that is
used to secure the padlock to a structure. Common structures include, but are
not limited to, sheds, trunks, lockers and lock boxes.
[0005]A particular kind of padlocks is a padlock having a movable locking
member that is used to lock the shackle in a secured position by engaging a
notch defined in the shackle, wherein the locking member is preloaded towards
the locked position. Pressing down the shackle into the lock body pushes back
the preloaded locking member momentarily until it springs forward again to
snap into and engage the notch. This procedure allows easy and fast
securement of the padlock to a structure.
[0006] Such padlocks, however, may be susceptible to direct mechanical
attacks, such as the use of a padlock shim which in some cases may release the
shackle without using a key or entering a combination by the authorized user.
CA 02630757 2010-10-29
2
[0007] One object of this disclosure is to provide a novel and improved
padlock which is
less susceptible to mechanical attacks.
SUMMARY
[0008] Accordingly, the present disclosure provides a padlock that comprises a
lock body
including at least one passage defined therein. A shackle is displaceable
between open and
secured positions, said shackle having at least one elongated leg, said at
least one leg being
slideable within said at least one passage and including a notch, said at
least one leg being
completely removed from said lock body when said shackle is in said open
position. A
locking member is accommodated within said lock body and displaceable between
unlocked and locked positions, said locking member being preloaded towards
said locked
position to engage said notch to inhibit movement of said shackle from said
secured
position into said open position wherein the locking member may be pushed back
from its
locked position into its unlocked position when the shackle is in its secured
position
independently of the position of a locking mechanism cooperating with the
locking
member. One of said at least one passage and said at least one leg defines at
least one
recess which extends in a transverse direction from its circumference relative
to a
longitudinal axis of said at least one leg. The other one of said at least one
passage and
said at least one leg defines at least one projection complementary in shape
to said at least
one recess that extends in the transverse direction from its circumference
relative to said
longitudinal axis of said at least one leg, at least a portion of said at
least one projection
being positioned in into said at least one recess when said shackle is in said
secured
position. At least a portion of said recess and said projection are aligned
with at least a
portion of said notch as viewed along said longitudinal axis of said at least
one leg when
said shackle is in said secured position.
[0009] In another feature, the at least one recess and at least one projection
are
arranged at that circumferential side of the at least one passage and said at
least one leg where the locking member selectively engages the notch.
[0010]In still another feature, the at least one passage and the at least one
leg
define a plurality of recesses, wherein the at least one passage and the at
least
one leg define a corresponding plurality of projections that engage a
respective
one of the recesses, and wherein the recesses and projections are arranged
along the periphery of the at least one leg and the at least one passage,
respectively.
[0011] In another feature, the at least one leg defines the at least one
recess,
wherein the at least one recess extends throughout that portion of the at
least
one leg that is disposed within the at least one passage in the secured
position.
CA 02630757 2008-05-06
3
[0012] In yet another feature, the at least one passage defines the at least
one
projection and an aperture in the lock body, wherein the at least one
projection
is arranged at least at the aperture.
[0013] In another feature, the lock body has an outer casing, wherein the at
least on projection is integrally formed with the outer casing.
[0014] The padlock of the present disclosure impedes that the preloaded
locking member can be pushed back by a padlock shim or the like when the
shackle is in the secured position and the locking member is in the locked
position. Customarily, a padlock shim comprises a cylindrical wall portion
made of sheet metal to be inserted into a typically ring-shaped gap between
the boundary of the at least one passage and the at least one leg near the
region where the locking member selectively engages the notch. If the
cylindrical wall of such a padlock shim reaches down to the locking member in
some cases the locking member can be pushed back to release the shackle by
rotating the cylindrical wall around its cylinder axis towards the locking
member. By providing the at least one recess and the at least one projection
that cooperates with the at least one recess said ring-shaped gap gets blocked
which in turn bars the padlock shim from revolving around its cylinder axis.
[0015] Further areas of applicability will become apparent from the
description
provided herein. It should be understood that the description and specific
examples are intended for purposes of illustration only and are not intended
to
limit the scope of the present disclosure.
DRAWINGS
[0016] The drawings described herein are for illustration purposes only and
are
not intended to limit the scope of the present disclosure in any way.
[0017] Fig. 1 is a perspective view of a padlock in accordance with the
present
disclosure according to a first embodiment;
CA 02630757 2008-05-06
4
[0018] Fig. 2 is a cross-sectional back view through the center of the padlock
of
Fig. 1;
[0019] Fig. 3 is a cross-sectional view of the padlock along line 3 - 3 of
Fig. 2;
[0020]Fig. 4 is a cross-sectional view as in Fig. 3 of a padlock according to
another embodiment; and
[0021] Fig. 5 is a cross-sectional view as in Fig. 3 of a padlock according to
still
another embodiment.
DETAILED DESCRIPTION
[0022] The following description is merely exemplary in nature and is not
intended to limit the present disclosure, application, or uses. It should be
understood that throughout the drawings, corresponding reference numerals
indicate like or corresponding parts and features.
[0023] Referring now to Fig. 1, a rotary combination padlock 10 is illustrated
and includes a lock body 12 and a U-shaped shackle 14 having first and second
legs 16, 18 that are slideably received in a respective one of first and
second
passages 20, 22 defined in the lock body 12. The lock body 12 has an outer
casing including a cylindrical side wall 24, a back plate 26 as well as a
front
plate 28. The front plate 28 carries an external single-dial rotary knob 30
including numbers.
[0024]Referring now to Fig. 2, the second leg 18 includes a notch 32 which is
selectively engaged by a locking member 34 accommodated within the lock
body 12 to inhibit displacement of the shackle 14 in the direction A. The
locking member 34 is displaceable between a locked position, which is shown
in Fig. 2, and an unlocked position, in which the locking member 34 is
retracted from the notch 32 thereby releasing the shackle 14. The locking
member 34 is preloaded towards the locked position by a spring member (not
shown). A locking member mounting 36 is pivotally mounted to a post 38 and
is adapted to slidingly accommodate therein the locking member 34. The
CA 02630757 2008-05-06
locking member mounting 36 is provided with a curved downwardly extending
protrusion 40.
[0025] To retract the locking member 34 from the notch 32 and thus to release
the shackle 14, a combination (i.e. sequence of numbers) must be entered by
5 using the single-dial rotary knob 30 to manipulate the rotational positions
of a
plurality of (usually three) parallel discs or cams accommodated within the
lock body 12. In Fig. 2 two discs 44, 46 are visible. Each of the discs 44, 46
has
an indentation 48, wherein the indentations 48 of the plurality of discs 44,
46
align when the correct combination is entered, thus allowing the protrusion 40
to fit into the indentations 48. This in turns allows the locking member
mounting 36 to rotate counterclockwise thereby retracting the locking member
34 from the notch 32.
[0026] To enable actuation of the discs the single-dial rotary knob 30
includes
an off-center positioned catch (not shown) on its back side and each of the
discs
includes an off center positioned catch (not shown) on each of its sides,
wherein
the catches facing each other may engage. As the single-dial rotary knob 30
rotates in a first direction, its catch connects to the front side catch of
the first
disc, thus causing the first disc to rotate with the single-dial rotary knob
30.
As the first disc rotates, its back side catch connects to the front side
catch of
the second disc, thus causing the second disc to rotate with the single-dial
rotary knob 30 and the first disc. This is continued until the last disc
rotates
with the single-dial rotary knob 30 and all other discs. The rotation is
stopped
when the last disc is in the correct position to allow protrusion 40 to fit
into the
last disc's indentation 48. Then the single-dial rotary knob 30 is rotated in
the
opposite direction to connect to all discs but the last one from the other
side.
The rotation is stopped when the last but one disc is in the correct position
to
allow protrusion 40 to fit into the last but one disc's indentation 48. This
procedure is repeated until all discs are in the correct position. The shackle
14
CA 02630757 2008-05-06
6
may now be pulled back from its secured position (shown in Fig. 2) into an
open position.
[0027] Starting from this open position the shackle 14 may at any time be
pushed back into the lock body to resume its secured position. This may be
done independently of the rotational position of the rotary knob 30 and the
discs 44, 46, since the locking member 34 is spring-loaded into its locked
position (so-called automatic locking function).
[0028] The above described mechanism for retracting a locking member from a
notch defined in a leg of a shackle is well known to the skilled practitioner
and
is described in US Patent 3,194,033, for example, the disclosure of which is
incorporated herein by reference in its entirety.
[0029]As explained above, the shackle 14 is displaceable between a secured
position, which is shown in Fig. 2, and an open position, in which the second
leg 18 is fully withdrawn from the second passage 22. The first leg 16 is
longer
than the second leg 18 and can not be fully withdrawn from the first passage
20. In the open position, the shackle 14 is displaced along direction A with
respect to its secured position.
[0030] The second leg 18 defines a groove 50 which extends axially with
respect
to the second leg 18. The groove 50 is formed on the inner side of the second
leg
18, i.e. on that circumferential section of the second leg 18 which faces the
first
leg 16. The locking member 34 is positioned between the first and second legs
16, 18. The groove 50 is thus formed on that side of the second leg 18 where
the locking member 34 selectively engages the notch 32. The groove 50 extends
throughout that axial portion of the second leg 18 that is disposed within the
second passage 22 in the secured position. In particular, the groove 50
extends
below and above notch 32.
[0031] The second passage 22 defines a projection 52 that juts into the groove
50 of the second leg 18. The projection 52 is integrally formed with the
cylindrical side wall 24 of the lock body 12 and extends downwardly from an
CA 02630757 2008-05-06
7
aperture 54 defined by the second passage 22 in the lock body 12 to a certain
point above notch 32.
[0032] Except for the groove 50 and the projection 52 each of the second leg
16
and the second passage 22 is circular in cross-section, as shown in Fig. 3,
but
in principle could be oval, square or exhibit any other shape just as well.
The
boundary of the second passage 22 and the second leg 18 define a substantially
ring-shaped gap 56 thereinbetween which ring-shape is interrupted by the
projection 52 that extends over the width of the gap 56 into the groove 50
(see
Fig. 3). Each of the groove 50 and the projection 52 is substantially
rectangular
in cross-section.
[0033] Alternatively, the second leg 18 may define the projection 52 and the
second passage 22 may define the groove 50 (see Fig. 5)
[0034]As can be discerned from Fig. 4, the padlock 10 may as well be provided
with a plurality of pairs of groove 50 and projection 52. In Fig. 4, the pairs
are
defined along the circumference of the second passage 22 and the second leg
18, respectively, to flank the circumferential region where the locking member
34 selectively engages the notch 32.
[0035]However, the padlock 10 may be provided with any other number of
pairs of groove 50 and projection 52, and these pairs may be defined at any
position along the periphery of the second passage 22 and the second leg 18.
In
addition, for one pair the groove 50 may be defined by the second leg 18 and
the projection 52 may be defined by the second passage 22, whereas for
another pair the groove 50 may be defined by the second passage 22 and the
projection 52 may be defined by the second leg 18. Further, the cross-section
of
the groove 50 and the projection 52 may be triangular, trapezoidal or exhibit
any other shape just as well.
[0036] By providing said at least one groove 50 and said at least one
projection
52 which extends into the associated groove 50 the spring-loaded locking
member 34 may not easily be pushed back into its unlocked position by means
CA 02630757 2008-05-06
8
of a flat tool inserted into the gap 56 between the boundary of the second
passage 22 and the second leg 18 when the shackle 14 is in its secured
position. Therefore, a higher degree of security is obtained.
[00371 Those skilled in the art can now appreciate from the foregoing
description that the broad teachings of the present disclosure can be
implemented in a variety of forms. Therefore, while this disclosure has been
described in connection with particular examples thereof, the true scope of
the
disclosure should not be so limited since other modifications will become
apparent to the skilled practitioner upon a study of the drawings, the
specification and the following claims.
