Combination lock

“ Having in the course of their inquiries examined the different existing modes in which locks may be picked, forced, or opened by false keys, the Committee have come to the conclusion that the parautoptic lock cannot be opened by any of the methods now practised, unless by a person in possession of the key by which it was locked, in the exact form of combination in which it was used for the purpose, or in the almost impossible case of the bits being adjusted to the skeleton key by accident in that very form. ”

“ In a complex Bramah lock, and in locks on the combination principle, the difficulty of picking is almost insuperable, so long as what may be termed the arithmetical method is adopted. It is perfectly true, as has been so often stated, that the varied combinations in the arrangement of the slides amount to millions and even billions, when the slides are in any degree numerous; and if a person attempt to pick the lock by ringing the changes on all these combinations, it would very likely require the lives of a dozen Methuselahs to bring the enterprise to an end. ”

“ Reuter, Aulic Councillor and Secretary of the Institute, directed your attention to a newly invented lock of Mr. Newell, of North America, which was represented as excelling all other changeable combination-locks hitherto known, and as being without a rival. ”

“ The inner cylinder can then be turned, by which the bolt is locked or unlocked. If, by the use of a false key, any pin be pushed in too far, it will be as ineffectual in opening the lock as if it were not thrust in far enough; and some of these locks having been made with as many as forty pins, the chances are very numerous against the right combination being hit upon. There is a combination of something like the Egyptian with something like the Bramah lock, here attempted. ”

“ The object of the invention is stated to be to have a time-movement guard, and operate in conjunction with a combination-lock, to prevent the action of the combination-lock until a time previously appointed by the setting of the time-movement shall have arrived, in the ordinary running of the time-movement, at which time, and not before, the combination-lock will come into action, when operated in the usual way, as if there were no time-movement. ”

“ The springs, which by the turning of the key must be raised together with the tumblers, are attached to levers, and press upon the latter at their centre of gravity, in consequence of which all crowding towards either side is prevented, and the key can be turned with facility, in spite of the many combination parts which it has to raise; and the springs themselves are by their positions so little called into action, that their strength can never be impaired by use.
The lock has also another very complete arrangement in the detector-tumbler, which is attached to the cap or covering of the lock. ”

“ The outer rings are moved with the finger, so as to throw the various interior grooves out of a right line, and thus prevent the withdrawal of the spindle. As each ring may be turned round through a large or a small arc, and all turned in different degrees, the variations of relative position may be almost infinite. The letters on the outer rings are to assist the owner to remember the particular combination which he had adopted in the act of locking; for no other combination than this will suffice to open the lock. ”

“ The letter of rejection said: 'Hollen shows the combination of a time-movement and a lock, with a lever constructed and located to render inoperative such lock until a predeterminate hour, the tumblers of the lock being free to rotate through the medium of a key, while the unlocking action of the lock is suspended by the lever. Rutherford shows (Figs. 1, 2, 3, 4, and 5, sheet 2) the combination of a time-movement and a lock, with a lever arranged to engage with the bolt of a lock and render inoperative such lock until a predeterminate hour. ”

“ No one who has the combination, whether obtained surreptitiously or otherwise, can open the lock when the time-movement is set, for the simple reason that no connection can be made between the tumbler or combination-wheels, the dog, angle-bar, or fence, the spindle, and the lock-bolt, or bearing. ”

“ When the key is inserted, and the fastening device thrown back, it will be seen that the rims of the wheels are held stationary by the key, while the centers may be turned to any different position by the spindle, thus setting the lock to a new combination. ”

“ The walls of steel or iron which separate the security parts from the tumblers, and the cylinder which revolves with the key, present formidable barriers to all descriptions of pick-locks, and render the lock a most positive and reliable security. The tumblers consist of rolled very smooth steel plates, in which the fire-crust has not been filed away, partly in order that the lock might not need oiling, as all these parts are very smooth, and partly that the [96] combination pieces might not easily rust, a thing to which the adhering fire-crust is not favourable. ”

“ Do not think it a task to change the combination often.
The old Louis Lillie combination locks, where the spindle dial could be unscrewed, and a few other makes of the present day, most of them antiquated,490 could be successfully manipulated. In fact, these locks were what I termed a “dead walk-over.” ”

“ The constructing a key having a groove in its shank to receive the detector tumbler.”
fig. 46. Movable stump.
When the American locks became known in England, Mr. Hobbs undertook the superintendence of their manufacture, and their introduction into the commercial world. Such a lock as that just described must necessarily be a complex piece of mechanism; it is intended for use in the doors of receptacles containing property of great value; and the aim has been to baffle all the methods at present known of picking locks, by a combination of mechanism necessarily elaborate. ”

“ We shall have occasion to shew presently, that if the number of tumblers (and consequently the number of bits in the key) be small—not exceeding six, for instance—the possession of the true key gives any one the power of opening the lock, provided he has time and patience to go through a few hundred changes of the bits of the key; for, as some one arrangement must have been that by which the lock was locked, it must again occur if the user takes care to make all the arrangements in turn, and tries the lock after each. ”

“ The stem, therefore, can be left by the principal of an establishment for locking up by a subordinate; but the bit, which is the essential part of the key required for opening the lock, need never be used or seen by any one but the principal himself. As the hole in the external door-plate for the stem of the key has a notch on one side only to admit the key stem, and the cylinder is prevented from making a complete revolution, the stem of the key cannot be withdrawn from the lock except when the bolt is shot ”

“ For if a lock of any given size be furnished with wards in as curious and complete a manner as it can be, those wards being necessarily expressed on what is termed by locksmiths the bit or web of the key, do not admit of a greater number of variations than can be expressed on that bit or web; when, therefore, as many locks have been completed of the given size as will include all the variations which the surface of the bit will contain, every future lock must be the counterpart of some former one, and the same key which opens the one will of course unlock the other. ”

“ His next remark on the subject is a sensible one: “Notwithstanding the large size of these locks, and all the apparatus with which they are provided, they correspond but ill with the solidity of the rest of the coffer. If we have given a representation of one, it is chiefly to shew how little confidence one could have in such a lock, and what are its defects, in order that we may avoid them.” It is not difficult, by tracing the action of the several levers, to see how one movement of the key, in the centre of the lid, would act upon all the bolts. ”

“ I do not state this circumstance as a point essential or of any importance to the purpose of the lock, but to prove more clearly what I have before observed upon its principle and properties; for if such difficulties occur to a skilled workman, as to render it almost, if not altogether impracticable to form a key when the lock is open to his inspection and its parts accessible to his hand, it pretty clearly demonstrates the impossibility of accomplishing it when no part of the movement can be touched or seen. ”

“ In relation to the opinion just given, it may be remarked that the American lock has shewn no tendencies to get out of [134] order; if well constructed (and good construction is a sine qua non in such mechanism) , the parts work into and upon each other with very little friction. In respect to expense, and to the size of the key, a bank-lock is not one in which economy would be much studied, security being the great desideratum. No attempt is made to produce a parautoptic lock of small size or for cheap purposes. ”

“ These are very good little padlocks, with an excellent lever action, 'dogged against detent,' as the technical phrase goes; so that only the key properly made for each lock will open it. They are so good, indeed, as locks, that it would be a waste of time to try picking them, when, because of their small size, it is so very easy to break them apart, just as you have done yourself, and just as I could probably have done in half the time, having had rather more experience. Now that is what has been done with your lock by the person who has your bonds. ”

“ PREVIOUS TO THE DATE OF THE GREAT EXHIBITION. It must be evident, even on a cursory glance at the past history of the lock-manufacture, that the prime motive for the introduction of novelties and improvements in construction is the desirability of producing a lock which no one can open without the proper key. From the earliest and simplest lock, down to the latest and most complex, this object has been constantly held in view; and every clear proof or evidence that this object has not been attained has led to the invention of some new contrivance. ”

“ By another contrivance it is rendered impracticable to move a pick or picks round in the lock more than a small distance, unless the tumblers could previously be all lifted to their right positions, which can only be done by the right key. ”

“ The particular construction of my lock is that the two time movements rotate a graduated dial so arranged that its motion oscillates, at certain regular, determinable intervals, a pivoted bent lever, which in turn, in one instance, for automatic locking, lifts the free part of, and thus oscillates on its stationary pivot a metallic dog or obstruction, so as to cause it to rest in the way, and prevent the retraction, of the sliding bolt-work ”

“ When a person who was outside wished to enter, it was necessary for him to insert the key in a little hole and to raise the bolt; and in time this species of fastening was improved by the insertion of the bolt in an iron frame or rim permanently attached to the door by a chain, and fastening the door by the insertion of the hasp, through the eye of which was forced the bolt inside the lock by applying the key. ”

“ Hence a person putting a false bit into one of these locks will not only infallibly lose it at the very first trial, but will do so without gaining any information as to the nature of its inaccuracy; for as the gatings of the levers cannot be seen or felt, all that can be told about the action of a false bit is, that it has failed to open the lock. In fact, a counterfeit bit passes under the levers, and through the lock, just like the true bit; and it is only the stoppage afterwards met with of the bolt that indicates the failure of the false bit, which is by that time gone beyond recovery. ”

“ The principles of mechanical science are also appreciated by many lock-makers. The lever, the inclined plane, the eccentric, the cam, the screw, the wheel and pinion, the ratchet, the spring,—all are brought to bear on the internal mechanism of locks, frequently in many novel combinations. ”

“ They have been too simple to require it, and too little varied to permit it. That some such fastenings must be employed wherever doors of any kind are used is sufficiently apparent; and there is a little (though only a little) information obtainable, which shews the nature of the fastenings adopted in early times. The bolt, the hasp, the chain, the bar, the latch, the lock, all were known, in one or other of their various forms, in those ages which we are accustomed to consider classical. Travellers, generally speaking, do not descend to locks, or rather they do not think about them ”

“ There is a mechanism of springs and levers to shoot the bolt when the pins in the plate are rightly adjusted. The arrangements in respect to the key are singular and somewhat awkward. The teeth which lock the bolt are not the same as those [63] which unlock it, the user having to change ends and adjust the bit to a socket-handle. This is one among many examples in which a lock embodies several principles, the inventor having set himself the task of combining the excellences of many diverse locks. ”

“ The numerous cases that have occurred of attempts to open locks by counterfeit keys, such as the remarkable instance previously referred to, show that even with the most practised hands it is next to impossible to make from a wax impression a key that will serve for opening a good lock the very first time it is tried ”