BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded perspective view of the combination lock of the present invention;
FIG. 2 is a partially exploded perspective view of the combination lock of the present invention;
FIG. 3A is a perspective view showing the structure of the sleeves of the present invention;
FIG. 3B is a perspective view showing the structure of the sleeves different to that shown in FIG. 3A;
FIG. 4 is a perspective view showing how the combination is retrieved via an auxiliary tool which is used to extend into each and every one of the threaded holes in the casing;
FIG. 5 is a perspective view of a conventional combination lock, wherein the casing is partially removed to clearly see the internal structure of the combination lock;
FIG. 6 is a perspective view of a different conventional combination lock, wherein the casing is partially removed to clearly see the internal structure of the combination lock;
FIG. 7A is a perspective view showing the relative position of the sleeve to the wheel;
FIG. 7B is an operational view showing that the sleeve is moved away from the corresponding wheel to start combination change procedure; and
FIG. 8 is a perspective view of a series of conventional sleeves.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to FIG. 1, it is noted that the combination lock (1) in accordance with the present invention includes a casing (11), multiple wheels (12) rotatably received inside the casing (11), sleeves (13) each movably received in a corresponding one of the wheels (12) and a latch (14) linearly movable relative to and received in the casing (11). All the elements described above are conventional in the art, details concerning the operation and associated structural relationship is thus omitted. The following description will then focused on the improvement of the present invention.
With reference to FIG. 2 and still using FIG. 1 for reference, it is noted that the casing (11) has multiple threaded holes (111) defined through a side face of the casing (11) to allow extension of threaded bolts (112). Further, each sleeve (13) has a notch (131) defined in a proximal end thereof and a cutout (132) defined in a distal end thereof. Because each of the sleeves (13) is rotatable relative to the casing (11), each cutout (132) is selectively aligned with a corresponding one of the threaded holes (111).
With reference to FIGS. 3A and 3B, it is noted that when the combination lock of the present invention is assembled for the very first time and in the unlocked status, positions of the sleeves (13) inside the casing (11) are fixed. That is, all the notches (131) are aligned with one another due to the movement of the latch (14). However, the positions of the cutouts (132) of the sleeves (13) are not necessary aligned with one another and with the notches (131). In other words, the manufacturer uses some (or all) of the cutouts (132) to align with some of the threaded holes (111) so as to determine a default combination for unlocking the combination lock.
There may be only one row of the threaded holes (111) defined in the side face of the casing (11) such that after the selected cutouts (132) are aligned with the threaded holes, the cutouts (132) are located at the same position. Due to the variety of selecting the cutouts (132), the sleeves (13) selected are not necessary to be close to one another.
For example, if the default combination is 1, 4, 5 and 8 (as shown in FIG. 4), the selected cutouts (132) will be aligned with the corresponding threaded holes (11). The non-selected cutouts (132) are not aligned with any of the threaded holes (111).
With reference to FIG. 4, it is noted that after the combination lock is manufactured with the default combination and has been implemented for quite some time, if the self-determined combination is lost or forgotten, an auxiliary tool (2) is required to unlock the combination lock. The auxiliary tool (2) is provided with a pre-engraved default combination for a certain combination lock (e.g. 1, 4, 5 and 8).
Before proceeding with the unlocking process, the user first remove the threaded bolts (112) located at the positions corresponding to the numerals, e.g. 1, 4, 5 and 8. Then a sharp end of the auxiliary tool (2) is extended into the threaded holes (111) corresponding to the numerals 1, 4, 5 and 8. Rotating the wheels (12) to drive the sleeves (13) to rotate accordingly. When the cutout (132) of the sleeve (13) is aligned with the sharp end of the auxiliary tool (2), the sharp end of the auxiliary tool (2) is able to extend into the cutout (132). Thus the user is able to know one of the default combination. The subsequent combination will thus be obtained by repeating the same process. The number of rows of the threaded holes (111) is based on the number of the wheels (12). That is, the more the wheels (12) are, the more rows the threaded holes (111) are.
It is concluded that when the user is trying to open the combination lock of the present invention, the user will have to follow the following steps to find out what the default combination is:
defining at least one row of threaded holes in the casing of the combination lock;
defining cutouts in distal ends of sleeves, which are opposite to notches defined in proximal ends of the sleeves;
selecting certain cutouts which are mis-aligned with the notches;
rotating sleeves to allow the cutout of each selected cutouts to align with a corresponding threaded holes; and
rearranging the notches to allow the notches to be in a linear arrangement.
Furthermore, an auxiliary tool is able to extend into the aligned cutout and one of the threaded holes to ensure the alignment therebetween. A threaded bolt is threadingly received in one of the threaded holes (111) so that when the threaded holes (111) are not required, the extension of the threaded bolts (112) in the corresponding threaded holes (111) ensures that the combination lock is free from damages caused by sand, liquid and other contaminants that enter the casing to cause mechanical malfunction.
It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
Patent Application
20080060399
