Numerous lock constructions have been developed and are widely employed by individuals to prevent unauthorized persons from gaining access to any area which has been closed and locked. Although many locks are constructed to be opened by a key, numerous combination locks have been developed which are opened by knowledge of a particular combination.
One particular type of combination lock that has become very popular, due to it ease and convenience of use, is a combination lock which employs a plurality of rotatable independent dials, each of which comprises a plurality of indicia, usually numbers or letters, which define the combination for releasing the lock. Although locks of this general nature had been available for several decades, these prior art combination lock constructions are typically employed in low security areas, due to their inability to resist forced entries in which excessive force is applied to the lock.
In those areas wherein a high security lock system is required, prior art constructions have relied upon padlocks which require a key for operating the lock between its alternate open position and closed position. Due to the ease with which keys are often lost or misplaced, as well as the proliferation of the keys required for many individuals to carry, high security padlocks requiring keys for operation has become increasingly unpopular. However, prior art constructions have been incapable of providing a high security padlock incorporating a combination system for operating the padlock, either independently or in combination with a key.
In addition to prior art, high security padlock constructions relying upon key activation and operation, another problem which has consistently plagued prior art constructions is the cost of construction for producing and assembling prior art padlocks. In order to attain a padlock which provides all of the features desired by the users, prior art constructions typically incorporate numerous small components, each of which require inexpensive assembly procedures to produce the final product. As a result, these prior art high security padlock constructions are typically expensive to produce, thereby reducing the ability of these padlocks to reach a broader base of users.
Another problem commonly found with prior art high security padlocks is the inability of these prior art constructions to prevent contaminants from reaching the internal components of the padlock, thereby causing damage to these components and interfering with the ease of operation of the padlock by authorized personnel. Although numerous attempts have been made to reduce the adverse effect caused by contaminants reaching these components, such attempts have been incapable of satisfactorily eliminating this problem.
A further problem commonly found in prior art high security padlocks is the ability of these locks to be opened by unauthorized individuals using known picking techniques. In particular, since most prior art products employ keys for their operation, unauthorized entry is a common problem.
Therefore, it is a principal object of the present invention to provide a padlock construction which is specifically designed for effective operation in high security applications and is operable using a combination system, either independently or in combination with a key system.
Another object of the present invention is to provide a padlock construction having the characteristic features described above which virtually eliminates the ability of unauthorized persons from gaining access to the lock by attempting to pick the lock using known techniques.
Another object of the present invention is to provide a padlock construction having the characteristic features described above which employs a minimum of components and is quickly and easily assembled, thereby providing a lock capable of being constructed at a competitive price.
Another object to the present invention is to provide a padlock having the characteristic features described above which effectively seals the rotating components from external contamination and effectively prevents any external contaminants from reaching the rotating components and thereof.
Other and more specific object will in part be obvious and will in part appear hereinafter.