Lock and protective cover assembly
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention generally relates to locks and, more particularly, to an improved lock and protective cover assembly. 
     2. Prior Art 
     A number of covers have been devised to protect locks against the elements. For the most part, such covers have been made of non-corrodable metal, such as aluminum or magnesium, or of relatively stiff and inflexible plastic to seal off the locks from moisture, dirt, rusting and the like. Such covers are normally comprised of two or more hinged or snapped together pieces. See, for example, U.S. Pat. No. 4,317,344 wherein there are disclosed a pair of top and bottom boots which clamp together over the lock body. In U.S. Pat. No. 3,848,440 a similar construction is disclosed with a lid snap fitted to a bottom casing. U.S. Pat. No. 3,858,419 discloses a similar arrangement, as do U.S. Pat. Nos. 4,224,813 and 3,983,725.  U.S. Pat. Nos. 4,134,280, 4,286,445 and 4,218,902 are also similar. 
     In each instance, two or more portions of the protective casing must be pulled apart or a hinged trap door therein must be opened in order to permit access to the lock keyhole for operation of the lock. Such devices tend to become very brittle and stiff in use, so that their components become difficult to separate and reassemble and have a tendency to wear rapidly. This is particularly true when the ambient temperature is very low, as in the winter in northern climates. Moreover, such devices require complicated fabricating techniques and are relatively expensive. 
     Accordingly, it would be desireable to provide an improved lock and cover assembly wherein the cover is easy to install and to remove and is inexpensive, durable and efficient in all kinds of weather to fully protect the lock. Such cover should be capable of being made in a single molding operation or simple forming operation and be unitary in structure. 
     SUMMARY OF THE INVENTION 
     The improved lock and protective assembly of the present invention satisfies all the foregoing needs. The assembly is substantially as set forth in the Abstract above. Thus, it includes a lock, the body of which is wholly enclosed in a flexible, resilient, stretchable unitary casing up from which the lock hasp or shackle loop protrudes. The casing extends well below the lock and includes a bottom normally closed slit which is automatically openable merely by squeezing two opposed sides of the casing lower portion at opposite ends of the slit towards each other, thus permitting a key to be inserted through the slit into the keyhole. Upon removal of the key, the slit automatically relaxes to the closed position. 
     The casing is unitary and preferably is fabricated of polyurethane plastic elastomer in a molding operation. It can include top collars tightly gripping the hasp, and an optional dessicant can be disposed in a container in the casing. Thus, the casing is much simplier, more efficient and durable and less expensive than conventional lock covers. Further features of the invention are set forth in the following detailed description and accompanying drawings. 
    
    
     DRAWINGS 
     FIG. 1 is a schematic front elevation, partly broken away, of a first preferred embodiment of the improved lock and cover assembly of the present invention; 
     FIG. 2 is a schematic side elevation, partly broken away, of the assembly of FIG. 1; 
     FIG. 3 is a schematic bottom plan view of the assembly of FIG. 1, shown with the bottom slit thereof in a relaxed closed condition; 
     FIG. 4 is a schematic bottom plan view of the assembly of FIG. 1, shown with the bottom slit thereof open to expose the lock keyhole; 
     FIG. 5 is a schematic top plan view, partly broken away, of the assembly of FIG. 1; 
     FIG. 6 is a schematic side elevation, partly broken away, of a second preferred embodiment of the improved assembly of the present invention; 
     FIG. 7 is a schematic front elevation, partly broken away, of the assembly of FIG. 6; 
     FIG. 8 is a schematic top plan view, partly broken away, of the assembly of FIG. 6; 
     FIG. 9 is a schematic side elevation, partly broken away, of a third preferred embodiment of the improved assembly of the present invention; 
     FIG. 10 is a schematic bottom plan view of the assembly of FIG. 9; 
     FIG. 11 is a schematic front elevation, partly broken away, of the assembly of FIG. 9; 
     FIG. 12 is a schematic front elevation, partly broken away, of a fourth preferred embodiment of the improved assembly of the present invention; 
     FIG. 13 is a schematic side elevation of the assembly of FIG. 12; 
     FIG. 14 is a schematic bottom plan view of the assembly of FIG. 12, shown with the bottom slit thereof in the closed relaxed condition; and, 
     FIG. 15 is a schematic bottom plan view of the assembly of FIG. 12, shown with the bottom slit thereof in the flexed open position, exposing the lock keyhole. 
    
    
     DETAILED DESCRIPTION 
     FIGS. 1-5. 
     Now referring to FIGS. 1-5, a first preferred embodiment of the improved lock and cover assembly of the present invention is schematically depicted therein. Thus, assembly 20 is shown, which comprises a lock 22 having a lock body 24 with a bottom keyhole 26 (FIG. 4) and an inverted U-shaped two runged hasp 28 extending up from body 24. 
     Body 24 is completely enclosed in a cover 30 comprising a thin unitary casing 32 of flexible, resilient, stretchable material which retains its properties over a wide temperature range, including winter conditions in northern climates. Such material may be an elastomer of natural or synthetic rubber or plastic, for example, polyurethane plastic, and can be conveniently formed in a single simple molding or forming operation. Casing 32 is sufficiently stretchable so that it can be easily put in place over lock body 24, and adheres closely thereto and can as easily be removed therefrom. Casing 32 includes at its top 34 a spaced pair of openings 36 and 38 (FIG. 5) defined by a pair of collars 40 and 42 integral with top 34 and extending up therefrom to tightly and sealingly grip rungs 44 and 46 of hasp 28. 
     Casing 32 includes a rectangular upper portion 48 comprised of interconnected vertical sidewalls 50, 52, 54 and 56 joined to horizontal top 34, and closely adjacent to lock body 24, and a lower portion 58 joined thereto by depending opposed inverted, triangular vertical walls 60 and 62 and opposed walls 64 and 66; all of which extend well below lock body 24. Walls 64 and 66 are rectangular and converge downwardly to meet at an inverted apex at the bottom 68 of casing, defining therebetween a bottom-opening normally closed slit 70 (FIG. 3) aligned below keyhole 26. 
     Thus, casing 32 seals lock body 24 fully against the elements in all kinds of weather. When it is desired to operate lock 22, walls 60 and 62 are gripped between the thumb and fingers of one hand and are urged toward each other, flexing and bellying slit 70 open (FIG. 4) to fully expose keyhole 26 and thus enable a key held in the other hand to be inserted through slit 70 into keyhole 36 to operate lock 22. The key can then be withdrawn and finger pressure can be removed from walls 60 and 62, allowing slit 70 to relax to the closed position of FIG. 3. 
     The area around slit 70 is also sufficiently stretchable to permit introduction of lock 22 therethrough and into casing 32 of cover 30. Other portions of casing 32 are also stretchable to permit positioning of rings 44 and 46 through openings 36 and 38 to the installed position shown in FIGS. 1-5, and to permit easy removal of cover 30 from lock 22. Thus, assembly 20 is of improved design and function, offering efficient all-weather protection of lock 22 at low cost. 
     FIGS. 6-8. 
     A second preferred embodiment of the improved assembly of the present invention is schematically depicted in FIGS. 6-8. Thus, assembly 20a is shown. Components thereof similar to those of assembly 20 bear the same numerals, but are succeeded by the letter &#34;a&#34;. 
     Assembly 20a is the same as assembly 20 except in three respects. Thus, slit 70a in bottom 68a of casing 32a of cover 30a is provided with a pair of downwardly and outwardly diverging curved lips 72 and 74 formed in walls 64a and 66a, respectively, to guide moisture away from slit 70a. Moreover, a slot 76 is disposed between and intersects collars 40a and 42a on top of 34a of cover 30a to allow lock body 24a to be easily installed through top 34a into casing 32a and to permit rungs 44a and 46a of hasp 28a to be easily installed in collars 40a and 42a. Slot 76 is protectively overlaid with a close-fitting flap 78 which extends to collars 40a and 42a, as shown in FIG. 8, to keep the elements from lock body 24. 
     Additional protective means are also provided in casing 32a at the sides thereof in the form of a pair of disposable containers 80 and 82 having vaporous walls 84 and 86, respectively, of cloth or the like, and containing a granular dessicant 88 such as calcium chloride or the like to trap any moisture which might reach lock body 24a in casing 32a. Accordingly, assembly 10a has the advantages of assembly 10, plus additional lock protective means. 
     FIGS. 9-11. 
     A third preferred embodiment of the improved assembly of the present invention is schematically depicted in FIGS. 9-11. Thus, assembly 20b is shown. Components thereof similar to those of assembly 20 or 20a bear the same numerals, but are succeeded by the letter &#34;b&#34;. Assembly 20b is identical to assembly 20, including lock 22 with body 24 disposed in cover 30 comprising casing 32, except that slit 70b in bottom 68b of casing 32b is covered by a protective overlapping lip 90. Lip 90 is a forward extension of wall 66b over wall 64b. Slit 70b is opened by squeezing walls 60b and 62b towards each other, in order to expose the keyhole (not shown) of lock body 24b so that hasp 28b can be opened and reclosed. Thus, assembly 10b operates in the same manner as assembly 20, but with additional moisture protection means. 
     FIGS. 12-15. 
     A fourth preferred embodiment of the improved assembly of the present invention is schematically depicted in FIGS. 12-15. Thus, assembly 20c is shown. Components thereof similar to those of assembly 20 bear the same numerals, but are succeeded by the letter &#34;c&#34;. Thus, assembly 20c is identical to assembly 20 except that the lower portion 58c of casing 32c is rectangular. Walls 50c, 52c, 54c and 56c of upper portion 48c of casing 32c merely continue perpendicularly down from horizontal top 34c to horizontal bottom 68c. Bottom 68c is well below body 24c of lock 22c, and bears a short slit 70c centered below keyhole 26c. Assembly includes hasp 28c extending up through collars 40c and 42c. When it is desired to open closed slit 70c from the relaxed position of FIG. 14 to the flexed position of FIG. 15 in order to expose keyhole 26c, the lower ends of walls 50c and 54c are squeezed toward each other (arrows of FIG. 15) until slit 70c bellies wide open. After lock 22c has been operated by a key inserted in keyhole 26c of lock body 24c, such key can be withdrawn. Then finger pressure can be removed from walls 50c and 56c and slit 70c, thereupon automatically closes to the sealed position of FIG. 14. Thus, assembly 20c thus is similar to assembly 20 in function and advantages. 
     Various other modifications, changes, alterations and additions can be made in the improved assembly, its components and parameters. All such changes, modifications, alterations and additions as are within the scope of the appended claims form part of the present invention.