FIELD OF THE INVENTION

The present invention relates to locks general¬ ly and more particularly to locks with spring loaded locking assemblies.

BACKGROUND OF THE INVENTION

Various types of locks are known. One known type of lock includes a lock body having formed therein at least one bore for lockingly receiving therein a locking member. Inside the lock body there is provided a spring loaded locking assembly which, when actuated, lockingly engages the locking member.

Persons of ill repute have attempted to over¬ come locks of this type by inserting thin shims in the bore between the locking member and the lock body and subsequently displacing such elements about the periphery of the locking member in the bore.

SUMMARY OF THE INVENTION

The present invention seeks to provide a lock which defeats attempts to overcome locks having spring loaded locking assemblies.

There is thus provided in accordance with a preferred embodiment of the present invention a lock including a lock body having formed therein at least one bore for lockingly receiving therein a locking member and a biased locking assembly which, when actuated, lockingly engages the locking member, the lock being characterized in that said bore and said locking member each have a

non-circular cross-section.

Preferably, the non-circular cross-section includes a generally circular cross section having at least one protrusion. In accordance with a preferred embodiment of the present invention, the at least one protrusion extends radially inward.

Preferably the lock body includes a pair of radially inwardly directed protrusions at each bore and each locking member includes recesses of corresponding cross section.

It is a particular feature of the present invention that any unauthorized rotation of the locking members or of shims in the bores causes deformation of the protrusions, which deformation being testimony to an unauthorized attempt to remove the locking members from the lock body.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be understood and appreciated from the following detailed description, taken in conjunction with the drawings in which:

Figs. 1A and IB are simplified pictorial illus¬ trations of a lock, including a lock body and a shackle, constructed and operative in accordance with a preferred embodiment of the present invention, the shackle being respectively disengaged and engaged with the lock body;

Fig. 2 is a sectional illustration of the lock of Figs. 1A and IB, taken along lines II - II in Fig. IB, the shackle being in a locked engagement with the lock body;

Fig. 3 is a simplified illustration of a lock cylinder of the lock of Figs. 1A and IB, viewed along line III in Fig. 2;

Fig. 4 is a sectional illustration of the lock of Figs. 1A and IB, taken along lines IV - IV in Fig. IB,

the shackle being in an unlocked orientation with respect to the lock body;

Fig. 5 is a simplified illustration of bores of non-circular cross section provided in the lock body of the lock of Figs. 1A and IB, taken along lines V - V in Fig. IB;

Figs. 6A and 6B are simplified illustrations of bores of circular cross section in another lock, in respective locked and forcibly unlocked orientations; and

Figs. 7A and 7B are simplified pictorial illus¬ trations of a lock, including a lock body and a shackle, constructed and operative in accordance with another preferred embodiment of the present invention, the shack¬ le being respectively disengaged and engaged with the lock body.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Reference is now made to Figs. 1A and IB which illustrate a lock 10 constructed and operative in accord¬ ance with a preferred embodiment of the present inven¬ tion.

Lock 10 comprises a lock body 12 and a shackle 14. Shackle 14 preferably comprises a generally U-shaped element 16 having a pair of locking members 18 and 20, at least one and preferably both of which are formed with a notch 22. Lock body 12 preferably comprises a cover member 24, typically formed of plastic, which at least partially encloses a lock housing 26.

Shackle 14 is shown respectively disengaged and engaged with lock body 12 in Figs. 1A and IB.

Referring additionally to Fig. 2, it is seen that lock housing 26 comprises an enclosure 28 which defines a pair of bores 30 and 32 which accommodate locking members 18 and 20 respectively. Lock housing 26 also comprises a lock cylinder 34 and first and second

locking elements 36 and 38 which are biased by a biasing device, such as being spring loaded by a spring 40. First and second locking elements 36 and 38 are displaced by operation of lock cylinder 34 into and out of locking engagement with notches 22 on respective locking members 18 and 20, as described hereinbelow.

Referring additionally to Fig. 3, it is seen that lock cylinder 34 includes a cylinder housing 42 and a plug 44 rotatable within cylinder housing 42 and defin¬ ing a keyway 46 which accepts a key 48.

Referring additionally to Fig. 4, it is seen that key 48 may be used to rotate plug 44 to actuate a cam 50 which causes, as is known in the art, first lock¬ ing element 36 to move against spring 40 in the direction of arrow 52 and second locking element 38 to move against spring 40 in the direction of arrow 54, thereby displac¬ ing locking elements 36 and 38 out of locking engagement with notches 22 on respective locking members 18 and 20. Shackle 14 may now be removed from lock body 12.

Referring additionally to Fig. 5, it is seen that bores 30 and 32 each have a non-circular cross- section. Preferably, the non-circular cross-section includes a generally circular cross section having at least one protrusion 58. In accordance with a preferred embodiment of the present invention, protrusions 58 extend radially inward.

In the illustrated embodiment of Figs. 1A - 5, lock body 12 includes a pair of radially inwardly direct¬ ed protrusions 58 at each of bores 30 and 32 and locking members 18 and 20 include recesses 60 of corresponding cross section, as shown in Fig. 1A.

Reference is now made to Figs. 6A and 6B which illustrate a lock 100 identical with lock 10 described hereinabove, like elements being numbered with like numerals, with the exception that lock 100 is provided with bores 102 and 104 of generally circular cross sec-

tion. In Fig. 6A it is seen that first and second locking elements 36 and 38 are biased by spring 40 against notch¬ es 22 on respective locking members 18 and 20. Persons of ill repute may cleave the U-shaped body of shackle 14 in a region designated by reference numeral 106 (Fig. 2), so as to isolate locking members 18 and 20.

As shown in Fig. 6B, each locking member 18 and 20 may then be forcibly rotated in respective bores 102 and 104, such as in the direction of respective arrows 108 and 110, so as to cause first locking element 36 to move against spring 40 in the direction of arrow 52 and second locking element 38 to move against spring 40 in the direction of arrow 54, thereby displacing locking elements 36 and 38 out of locking engagement with notches 22 on respective locking members 18 and 20. This allows shackle 14 to be removed from lock body 12 without using key 48.

Alternatively, locking elements 36 and 38 may be displaced by persons of ill repute by inserting thin arcuate shims in respective bores 102 and 104 between respective locking members 18 and 20 and lock body 12. The shims may then be rotated about the periphery of each locking member in its respective bore, such as in the direction of arrows 108 and 110, as described hereinabove with reference to Fig. 6B, to displace locking elements 36 and 38 out of locking engagement with notches 22 on respective locking members 18 and 20.

Referring again to Fig. 5, it is appreciated that the non-circular cross sectional shape of bores 30 and 32 substantially prevents rotation of locking members 18 and 20 in respective bores 30 and 32, as well as rotation of shims therein, thereby substantially prevent¬ ing unauthorized removal of shackle 14 from lock body 12.

It is a particular feature of the present invention that any unauthorized rotation of locking members 18 and 20 or of shims in respective bores 30 and

32 causes deformation of protrusions 58, which deforma¬ tion being testimony to an unauthorized attempt to remove shackle 14 from lock body 12.

Reference is now made to Figs. 7A and 7B which illustrate a lock 120 constructed and operative in ac¬ cordance with another preferred embodiment of the present invention. Lock 120 is identical with lock 10 described hereinabove with reference to Figs. 1A - 5, except that lock 120 includes a lock body 122 shaped differently from lock body 12.

It will be appreciated by persons skilled in the art that the present invention is not limited to what has been particularly shown and described hereinabove. Rather, the scope of the present invention is defined only by the claims that follow: