Patent Application
20090277230
The present disclosure relates to padlocks.
The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
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.
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.
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.
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.
One object of this disclosure is to provide a novel and improved padlock which is less susceptible to mechanical attacks.
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. The shackle has at least one leg. The at least one leg is slideable within the at least one passage and includes a notch. A locking member is accommodated within the lock body and is displaceable between unlocked and locked positions. The locking member is preloaded towards the locked position to engage the notch to inhibit movement of the shackle from the secured position into the open position. One of the at least one passage and the at least one leg defines at least one recess. The other one of the at least one passage and the at least one leg defines at least one projection that extends into the at least one recess when said shackle is in said secured position.
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.
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.
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.
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.
In another feature, the lock body has an outer casing, wherein the at least on projection is integrally formed with the outer casing.
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.
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.
The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.
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.
Referring now to
Referring now to
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 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
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 may now be pulled back from its secured position (shown in
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).
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 U.S. Pat. No. 3,194,033, for example, the disclosure of which is incorporated herein by reference in its entirety.
As explained above, the shackle 14 is displaceable between a secured position, which is shown in
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.
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 aperture 54 defined by the second passage 22 in the lock body 12 to a certain point above notch 32.
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
Alternatively, the second leg 18 may define the projection 52 and the second passage 22 may define the groove 50 (see
As can be discerned from
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.
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 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.
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.
