AMERICAN LOCKS.
The lock-manufacture in America has undergone some such changes as in
England. The insufficiency of wards to the attainment of security has
been for many years known; and the unfitness of even tumblers to attain
this end, without auxiliary contrivances, has been fully recognised for
a dozen years back. In this, and in other mechanical arts, the American
machinists depended primarily on the invention of the artisans in the
mother country, rather than on those of any continental European state.
But the development of the art in the United States has not been wanting
in originality; the varieties of locks have been very numerous, and many
of them exceedingly ingenious. It is not necessary, however, to describe
or depict any of those of simple form. The warded locks of different
countries very much resemble each other; the intricate warded locks
made in France in the last century have long fallen into disuse, in
consequence of the general conviction that no arrangement of wards,
however intricate, can afford the degree of security required in a good
lock. It will be more to the purpose, therefore, to proceed at once to a
notice of those American locks which, during the last few years, have
acquired some celebrity; first, however, noticing one of older date.
Stansbury’s lock, invented in the United States about forty years ago,
may be regarded as a modification of the Egyptian lock. It had a bolt,
case, and key-hole somewhat similar to those of modern locks; but there
were peculiarities of construction in other respects. There was a
revolving plate, pierced with a series of holes, and having a bit or pin
which moved the bolt. On the lock-case were a series of springs, each
having a pin at one end; and the arrangement was such that, when the
bolt was locked or unlocked, each pin would be pressed into some one of
the holes. Like as in the Egyptian lock (figs. 1 to 4), each pin had to
be pushed out, and all of them simultaneously, to allow the plate to
turn and move the bolt. The key was made with a barrel and bit; and on
the front end of the bit was a series of pins corresponding in position
with the holes in the plate. The mode of locking or unlocking was as
follows: the key was inserted in the key-hole, and turned to a certain
position; it was then pressed in with some force, until the pins on the
key met those in the plate; when the latter, yielding to the pressure,
left the plate free to turn and move the bolt. Modifications of the
Egyptian lock, more or less resembling this, have been brought out in
some variety on both sides of the Atlantic; but scarcely any have
equalled in simplicity the curious wooden relic of by-gone ingenuity in
the art of lock-making.
A lock made a few years ago by Mr. Yale, in the United States, somewhat
resembles the Bramah lock in having a cylinder or barrel, or rather two
concentric cylinders, one working within the other. These cylinders are
held together by pins which pass through them both into the key-hole. On
the back of the inner cylinder is a pin that fits into a slot in the
bolt, and moves it whenever the cylinder is turned. The pins that hold
the cylinders together are each cut in two; the pieces of the various
pins differing in lengths as irregularly as possible. The key is so
peculiarly formed, that, on inserting it in the key-hole, it thrusts the
pins radially outwards; each pin being pushed just so far that the joint
of the pin shall coincide with the joint between the two cylinders. 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.
One of the principal constructions adopted in America a few years back
for bank-locks is that of Dr. Andrews of Perth Amboy, in New Jersey. It
was up to that time (1841) believed that the best locks, both of England
and America, were proof against any attempts at picking derived from
knowledge obtained by inspection through the key-hole; but there still
remained the danger that the sight of the true key, or the possession
thereof, for only a few minutes, would enable a dishonest person to
produce a duplicate. It was to contend against this difficulty that Dr.
Andrews directed his attention; and he sought to obtain the desired
object by constructing a lock, the interior mechanism of which could be
changed at pleasure. The lock of his invention is furnished with a
series of tumblers and a detector. The tumblers are susceptible of being
arranged in any desired order; and the key has movable bits which can be
arranged so as to correspond with the tumblers. When the lock is fixed
in its place, no change can be made in the tumblers, and consequently
only one arrangement of the bits of the key will suit for the shooting
and withdrawing of the bolt. The owner can, however, before the fixing
of the bolt, adopt any arrangement of tumblers and bits which he may
choose. But though the tumblers cannot be actually re-arranged in any
new order within the lock while the latter is fixed, yet by an ingenious
contrivance the tumblers can be so acted upon as to render the lock
practically different from its former self. The purchaser receives with
his lock a series of small steel rings, each ring corresponds in
thickness with the thickness of some one of the bits of the key; so
that, by suitable adjustment, any one of the bits may be removed from
the key, and a ring be substituted in its place. The effect of this
substitution is, that the particular tumbler which corresponds with the
ring is not raised by it; it is drawn out with the bolt, as if it were
part of the bolt itself. Supposing the lock to be locked by this means,
the original key would not now unlock it; for one of the tumblers has
now been displaced, and can only be re-adjusted by the same ring which
displaced it. If an attempt be made to open the lock by the original
key, or by the key in its original adjustment, a detector is set in
action, which indicates that a false key or other instrument has been
put into the lock. One, or more than one, of the bits may be removed
from the key, and rings be substituted, and consequently one or more of
the tumblers may be disturbed in this peculiar way; so that the lock may
change its character in all those permutating varieties which are so
observable in most “safety-locks.” The shape of the tumblers is, of
course, such as to facilitate this action; they have each an elongated
slot, and also two notches; when a tumbler is raised by one of the bits
of the key, one of the notches closes around a stump fitted into the
case of the lock, and prevents the tumbler from being moved onward with
the bolt; but when a ring has been substituted for a bit on the key, the
tumbler cannot be raised at all; it is carried onward by a stump on the
bolt.
Dr. Andrews is also the inventor of a lock which he terms the
_snail-wheel lock_. In this lock a series of revolving discs, or wheels,
taking the place of the tumblers, are mounted on a central pin, on which
the pipe of the key is inserted. Each disc has a piece cut out of it,
into which the bit of the key enters, and in turning round moves the
discs according to the various lengths of the steps on the key. On the
outer edge of each disc is a notch, and by the turning of the key all
these notches are brought into a line, so that a moveable tongue, or
_toggle_, attached to the bolt, falls into the notches; the key is then
turned the reverse way, by which means the bolt is projected.
About the time when Dr. Andrews invented his first lock, Mr. Newell, of
the firm of Day and Newell of New York, constructed a lock which
possessed the same distinctive peculiarity as that of Andrews, viz. that
the key might be altered any number of times without rendering it
necessary to remove the lock or change its internal mechanism. This was
brought about, however, in a different manner. Instead of having, as in
the Andrews lock, a two-fold movement to every tumbler, Mr. Newell
employed two sets of tumblers, the one set to receive motion from the
other, and having different offices to fill, to be acted upon by the key
in respect to the first series, and to act upon the bolt in respect to
the second. Calling these two sets _primary_ and _secondary_, the action
of the lock may be briefly described as follows. A primary tumbler being
raised to the proper height by the proper bit in the key, raises the
corresponding secondary tumbler; the secondary tumbler is held up in a
given position during the locking, while the primary becomes pressed by
a spring into its original position. It results from this arrangement
that the bolt cannot be unlocked until the primary tumbler has been
raised to the same height as before, so as to receive the tongue of the
secondary tumbler. And as this is the case in respect to any one primary
and its accompanying secondary tumblers, so is it the case whether each
set comprises four, five, or any other number. The key may be altered at
pleasure, and will in any form equally well shoot the bolt; but the lock
can only be unfastened by that arrangement of key which fastened it.
It is, however, desirable to trace the course of improvements more in
detail, because every successive change illustrates one or other of the
several properties required in a good lock. Messrs. Day and Newell’s
lock was not finally brought to an efficient form without many attempts
more or less abortive. Mr. Newell conceived the idea of applying a
second series of tumblers, so placed as to be acted on by the first
series. Each of these secondary tumblers had an elongated slot, such
that a screw could pass through all of them; the screw having a clamp to
overlap the tumblers on the inside of the lock. The head of the screw
rested in a small round hole on the back of the lock, so placed as to
form a secondary key-hole, to which a small key was fitted. There was
thus a double system of locking, effected in the following way: when the
large key had been applied, and had begun to act on the primary
tumblers, the small key was used to operate on the clamp-screw, and thus
bind all of the secondary tumblers together, ensuring their position at
the exact heights or distances to which the primary key had caused them
to be lifted. The bolt was then free to be shot, and the first series of
tumblers reverted to their original position.
But such an arrangement has obvious inconveniences. Few persons would
incur the trouble of using two keys; and besides this, there were not
wanting certain defects in the action and reaction of the several parts;
for if the clamp-screw were to be left unreleased, the first series of
tumblers would be upheld by the second series in such a way that the
exact impression of the lengths of the several bits of the key could be
obtained through the key-hole while the lock was unlocked or the bolt
unshot. To remedy one or both of these evils was the next object of Mr.
Newell’s attention. He made a series of notches or teeth in each of the
secondary tumblers, corresponding in mutual distance with the steps or
bits of the key; and opposite these notched edges he placed a dog or
lever, with a projecting tooth suitable to fall into the notches when
adjusted properly in relation to each other. When the key was used, the
primary tumblers were raised in the usual way, and acted on the
secondary tumblers; these latter were so thrown that the dog-tooth
caught in the notches and held them fast, thereby rendering the same
service as the clamp-screw and the small key in the former arrangement.
No other relative position of the bits of the key could now unlock the
lock.
Still, improvement as it was, this change was not enough; Mr. Newell
found that his lock, like all the locks that had preceded it, was
capable of being picked by a clever practitioner; and candidly admitting
the fact, he sought to obtain some new means of security. He tried what
a series of complicated wards would do, in aid of the former mechanism;
but the result proved unsatisfactory. His next principle was to provide
a number of false notches on the abutting parts of the primary and
secondary tumblers, with alterations in other parts of the apparatus.
The theory now depended upon was this, that if the bolt were subjected
to pressure, the tumblers would be held fast by false notches, and could
not be raised by any lock-picking instrument. To increase the security,
a steel-curtain was so adjusted as to cover, or at least protect, the
key-hole. Great anticipations were entertained of this lock, but they
were destined to be negatived. A clever American machinist, Mr. Pettit,
accepted Messrs. Day and Newell’s challenge (500 dollars to any one who
could pick this lock); he succeeded in picking the lock, and thus won
the prize.
Once again disappointed, Mr. Newell re-examined the whole affair, and
sought for some new principle of security that had not before occurred
to him. He had found that, modify his lock how he might, the sharp-eyed
and neat-fingered mechanician could still explore the interior of the
lock in such a way as to find out the relative positions of the
tumblers, and thus adapt their means to the desired end. How, therefore,
to shut out this exploration altogether became the problem; how to make
a lock, the works of which should be _parautoptic_--to coin a word from
the Greek, which should signify _concealed from view_. The result of his
labours was the production of the American bank-lock now known by that
name. The details of this lock may now conveniently be given.
[Illustration: fig. 40. The American Parautoptic lock; bolt unshot.]
[Illustration: fig. 41. The same with the bolt shot.]
In fig. 40 the lock is represented in its unlocked state, with the cover
or top-plate removed; the auxiliary tumbler and the detector-plate are
also removed. In fig. 41 it is represented as locked, with the cover and
the detector-plate also removed, and the auxiliary tumbler in its place.
In these two figures, the same letters of reference apply to the same
parts, unless otherwise stated. B B is the bolt; T¹ are the first series
of movable slides or tumblers; _s_ shews the tumbler-springs; T² the
secondary series of tumblers; and T³ the third or intermediate
series--these latter coming between the first and secondary series; P P
are the separating plates between the several members of the first
series of tumblers; _s_¹ are the springs for lifting the intermediate
tumblers. On each of the secondary tumblers T² is a series of notches,
corresponding in mutual distance with the difference in the lengths of
the movable bits of the key. It thence happens that, when the key is
turned in the lock to lock it, each bit raises its proper tumbler, so
that some one of these notches shall present itself in front of the
tooth _t_ in the dog or lever L L. When the bolt B is projected by the
action of the key, it carries with it the secondary tumblers T², and
presses the tooth _t_ into the notches; in so doing, it withdraws the
tongues _d_ from between the jaws _j j_ of the intermediate tumblers T³,
and allows the first and intermediate tumblers to fall to their original
position. By the same movement, the secondary tumblers T² become held in
the position given to them by the key, by means of the tooth _t_ being
pressed into the several notches, as shewn in the closed state of the
lock (fig. 41). Now let us see what results if any attempt be made to
open the lock with any arrangement of key but that by which it has been
locked. In such case, the tongues _d_ will abut against the jaws _j j_,
preventing the bolt from being withdrawn; and should an attempt be made
to ascertain which tumbler binds and requires to be moved, the
intermediate tumbler T³ (which receives the pressure), being behind the
iron wall I I, which is fixed completely across the lock, prevents the
possibility of its being reached through the key-hole; and the first
tumblers T are quite detached at the time, thereby making it impossible
to ascertain the position of the parts in the inner chamber behind the
wall I I. K is the drill-pin, on which the key fits; and C is a
revolving ring or curtain, which turns round with the key, and prevents
the possibility of inspecting the interior of the lock through the
key-hole. Should, however, this ring be turned to bring the opening
upwards, a detector-plate D, fig. 42, is immediately carried over the
key-hole by the motion of a pin _p_¹ upon the auxiliary tumbler T⁴,
which is lifted by the revolution of the ring C, thereby effectually
closing the key-hole. As an additional protection, the bolt is held from
being unlocked by the stud or stump S bearing against the
detector-plate; and, moreover, the lever _l l_ holds the bolt, when
locked, until it is released by the tail of the detector-plate pressing
the pin _p_¹; _l_¹ is a lever which holds the bolt on the upper side,
when locked, until it is lifted by the tumblers acting on the pin _p_¹;
X are separating-plates between the intermediate tumblers T³; _u u_¹ are
the studs for preserving the parallel motion of the different tumblers.
[Illustration: fig. 42. The detector plate of the Parautoptic lock.]
Fig. 43 represents the key in two different forms, or with the bits
differently arranged. Either form will lock the lock, but the other will
not then unlock it. The end of the key is represented in fig. 44,
shewing the screw which fixes the bits in their places. The bits for a
six-bitted key are shewn separately in fig. 45.
[Illustration: fig. 43. Key of the Parautoptic lock.]
[Illustration: fig. 44. End view of the key.]
[Illustration: fig. 45. Separate bits of the key.]
In 1847 the parautoptic lock was exhibited at Vienna before the National
Mechanics’ Institute of Lower Austria; and towards the close of the year
Mr. Belmont, consul-general of Austria at New York, placed in the hands
of Messrs. Day and Newell a letter, a diploma, and a gold medal,
forwarded by the Institute. The letter was from the president of the
Institute to Mr. Newell, and was couched in the following terms:
“The Institute of Lower Austria, at its last monthly session, has passed
the unanimous resolution to award to you its gold medal, as an
acknowledgment of the uncommon superiority of the combination-lock of
your invention; and this resolution was ratified in its general
convention held on the 10th instant.
“Whilst I, as president of this Institute, rejoice in seeing the
services which by this invention you have rendered to the locksmith’s
art thus appreciated and recognised, I transmit to you, enclosed, the
said medal, together with the documents relating to it; at the same
time availing myself of this opportunity to assure you of my esteem.
“COLLOREDO MANNSFELD.
“Vienna, May 31st, 1847.”
The diploma and the medal were similar to other honorary distinctions of
the same class, and need not be described here; but the report of the
special committee may be given, as it expresses the opinions of the
Viennese machinists on the relative principles by which safety is sought
to be obtained in different kinds of locks.
REPORT
_Of a Special Committee on the new Parautoptic Permutation Lock of the
American Newell, made known to the Lower Austrian Institute by the
Councillor, Professor Reuter, and on the motions relating to it made
by the same and accepted by the Institute. Presented at the monthly
meeting, April 6th, 1847, by Mr. Paul Sprenger, Aulic Councillor on
Public Works, &c. &c._
GENTLEMEN:--At our last monthly meeting, Mr. 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 Special Committee which was intrusted with the examination of this
lock, and of the motions made by the said Secretary, and accepted by
the Institute, has conferred on me the honour of making you acquainted
with the results of its investigations.
The attention of your committee was chiefly occupied with the three
questions proposed by the said Aulic Councillor in relation to the
lock in question:
First: Whether the idea of Mr. Newell was of any practical value for
already existing and still-to-be-invented combination-locks;
Secondly: Whether the idea was of sufficient importance to be
published and minutely described in the transactions of the said
Institute; and
Thirdly: Whether the merits of the inventor were of sufficient
importance to entitle him to a distinction from the said Institute.
The deliberations on the first question, viz. the newness of the idea,
and of its practical value, would of necessity enlist the particular
attention of your committee, especially since by far the greater
number of its members are by their avocation called upon to be
interested in the execution of all kinds of locks.
It is therefore the unanimous opinion of your committee, that the
idea of the American Parautoptic Combination-Lock is entirely new and
without example.
The combination-locks with keys have, with few exceptions, such an
arrangement that a determinate number of movable parts (the so-called
combination-parts) must by the turning of the key be raised or lifted
into a certain position, if it is desired to project the bolt, or,
what is the same thing, to lock it out; consequently these parts, or,
as they are technically termed, tumblers, could not be transposed or
changed, from the circumstance that the key-bit was one solid piece,
with various steps or notches adapted to the several tumblers, and one
impression from it destroyed the security of the lock.
In order, however, to add more security to such a combination-lock,
and to make the key, in case it should be lost, or any counterfeit
made from a wax impression, useless for an unlawful opening of the
lock, another step was taken: the key-bit was made to consist of
several bits or movable parts, in such a manner that the owner of the
lock was enabled to change the bits, and to form, _as it were_, new
keys different from the former. But since the bolt of the lock can
only be projected whilst the combination parts or tumblers are in a
certain position, which position depends upon the order of the bits in
the key, it is evident that the owner, when changing the key, must at
the same time make a corresponding change in the position of the
tumblers in the lock itself, before the lock can be of any use for the
newly changed shape of the key, which rendered it troublesome, and
impracticable for the purpose designed, from the fact that no positive
change could be made in the lock, without taking it from the door, and
then taking the tumblers out of the case, to change them in a suitable
form for the key.
This principle of changing the lock is rarely adhered to, as few men
understand the machinery of a lock sufficiently to undertake the task;
and this circumstance rendered the lock quite as insecure as the
former one described.
Another step toward the perfection of combination-locks consisted in
this, that the key remains unaltered whilst the combination parts of
the lock can, before it is locked, be brought into different positions
by means of movable plates on the frame of the lock. These plates were
arranged by hand to certain figures, and depended on the memory for
adjustment at each time the bolt was to be locked out or in, the key
operating only on the bolt, to move it back and forth when the plates
were set in proper positions for the purpose; and should the owner
forget the arrangement of the plates, after projecting the bolt, his
key is of no use to him, and he must resort to the skill of the
locksmith to gain access.
The same case may occur in the far less perfect ring-lock of Reynier,
which is operated without keys, and is opened by means of the rings
being turned in a particular position; on these rings are usually
stamped letters, which, by introducing some word readily suggested to
the memory, thus point out the relative position of the rings.
But although in case of these ring-locks the owner is enabled to
produce a change in the rings in such a manner that the opening of
the lock can, as it were, only become possible by rightly arranging
the altered position of the letters, still this lock of Reynier’s does
not possess that safety and perfection which could have insured it
universal application.
M. Crivelli, formerly professor at Milan, has given a minute
description of the imperfection of ring-locks generally, in the annals
of the Imperial Royal Polytechnic Institute.
It is the unanimous conviction of your committee that the American
Lock of Newell surpasses, in the ingenuity displayed in its
construction, all other locks heretofore known, and more especially in
this, that the owner can, with the greatest facility, change at
pleasure the interior arrangement of his lock to a new and more
complex one, at every moment of his life, simply by altering the
arrangement of the bits in the key, and this is accomplished without
removing the lock or any part of it from its position on the door.
Its operation is as follows:--At the closing or locking of the lock,
whilst the bolt is projecting, the movable combination parts assume
precisely the position prescribed to them by the key, according to the
particular arrangement of its bits at the time the key is turned.
The combination parts do not consist in one set of tumblers only, such
as are found in all other locks, but there are three distinct sets or
component parts fitting into each other. When the bolt is projected,
it dissolves the mutual connexion of the constituent pieces, and
carries along with it such as are designedly attached to it, and which
assume the particular positions given them by the key in its
revolution. These parts are rendered permanent in their given form by
means of a lever adapted for the purpose, while the parts not united
with the bolt are pressed down by their springs to their original
places.
If now the bolt is to be returned again, _i. e._ if the lock is to be
unlocked, then the constituent pieces or tumblers which are in the
original state must, by means of the key, be again raised into that
position in which they were when the lock was closed, as otherwise the
constituent parts attached to the bolt would not lock in with the
former, and the bolt could not be returned. Nothing, therefore, but
the precise key which had locked the lock can effect the object.
This idea in itself, considered by your committee, is as ingenious as
it is new, and is accompanied by a perfection in its execution which
reflects the highest honour on Mr. Newell, the inventor and
manufacturer of the lock.
The lock is built strong and solid, and the several parts are
admirably adapted to the functions which they are designed to perform.
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 combination
pieces might not easily rust, a thing to which the adhering fire-crust
is not favourable. 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. This tumbler, on turning the key either way, closes the
key-hole, and not only prevents the use of false instruments in the
lock, but detects all attempts at mutilating its interior parts.
This lock is especially useful for locking bank-vaults, magazines,
counting-houses, and iron-safes, in which valuable effects, money, or
goods are to be deposited for safe keeping. When it is considered that
the bits of the key belonging to this lock can be transferred into
every possible form within its limits, and since the construction of
the lock admits of every combination of the slides resulting from the
changes of the key, therefore the lock in question is, in every
respect, deserving of the appellation given to it by the Secretary of
the Institute, namely, the Universal Combination Lock; and justly so,
when we consider that the ten bits attached to the key admit of three
millions of permutations, and upward; consequently forming that number
of different kinds of keys and locks.
If we consider further, that we need not be limited to the given bit,
but that others can be applied, differing in their dimensions from the
former; and again, if we consider that from every system arising from
a difference in their relative dimensions, a large number of new keys
differing from each other will result, and that this can be effected
in a space scarcely occupying a square inch,--then we cannot refrain
from confessing that the human mind, within this small space, has
shewn itself to be infinitely great.
After this preliminary and general exposition, your committee can
answer the three questions propounded to them the more briefly, as the
locks heretofore known have all been noticed.
To question first.--On the practical value of the invention of Mr.
Newell, your committee were unanimous and positive that the principle
on which it is based should be preserved.
To question second.--For this reason the committee deemed it desirable
that a drawing and description of the American lock in question should
be published in the Transactions of the Institute of Lower Austria.
To question third.--With regard to the claims of the inventor, Mr.
Newell, to an honorary distinction from the Institute of Lower
Austria, the committee recommend that he be presented with a Diploma
of honourable mention and a Gold Medal.
The members of your committee, consisting mostly of fellow-tradesmen
of Mr. Newell, experience great satisfaction in the fact that it has
fallen to their lot to vote to their colleague on the other side of
the ocean an acknowledgment of his successful ingenuity, and they
close the Report with the request that the Institute will transmit to
Mr. Newell of New York, in North America, the Diploma and Gold Medal,
together with a copy of this Report, according to the motion of the
Aulic Councillor and Professor Reuter.
[An exact copy of the original Report as preserved in the archives of
the National Mechanics’ Institute of Lower Austria.]
DR. SCHWARTZ,
_Assistant Secretary of the Institute_.
There are other circumstances connected with the American bank-lock, in
relation to events both in the United States and in England, to which
attention will be directed in a subsequent chapter.
The English patent for Messrs. Day and Newell’s lock, dated April 15,
1851, runs as follows: “The object of the present improvements is the
constructing of locks in such manner that the interior arrangements, or
the combination of the internal movable parts, may be changed at
pleasure according to the form given to, or change made in, the key,
without the necessity of arranging the movable parts of the lock by
hand, or removing the lock or any part thereof from the door. In locks
constructed on this plan the key may be altered at pleasure; and the act
of locking, or throwing out the bolt of the lock, produces the
particular arrangement of the internal parts which corresponds to that
of the key for the time being. While the same is locked, this form is
retained until the lock is unlocked or the bolt withdrawn, upon which
the internal movable parts return to their original position with
reference to each other; but these parts cannot be made to assume or be
brought back to their original position, except by a key of the precise
form and dimensions as the key by which they were made to assume such
arrangement in the act of locking. The key is changeable at pleasure,
and the lock receives a special form in the act of locking according to
the key employed, and retains that form until in the act of unlocking by
the same key it resumes its original or unlocked state. The lock is
again changeable at pleasure, simply by altering the arrangement of the
movable bits of the key; and the key may be changed to any one of the
forms within the number of permutations of which the parts are
susceptible.”
The “claims” put forth under this patent are the following:--
“1. The constructing, by means of a first and secondary series of slides
or tumblers, of a changeable lock, in which the particular form or
arrangement of parts of the lock, imparted by the key to the first and
secondary series of slides or tumblers, is retained by a cramp-plate.
“2. The constructing, by means of a first and secondary series of slides
or tumblers, of a changeable lock, in which the peculiar form or
arrangement of parts of the lock, imparted by the key, is retained by
means of a tooth or teeth, and notches on the secondary series of slides
or tumblers.
“3. The application to locks of a third or intermediate series of slides
or tumblers.
“4. The application of a dog with a pin over-lapping the slide or
tumblers, for the purpose of holding-in the bolt when the lock is locked
or unlocked.
“5. The application of a dog operated on by the cap or detector-tumbler
for holding the bolt.
“6. The application of a dog for the purpose of holding the internal
slide or tumbler.
“7. The application to locks of curtains or rings, turning and working
eccentrically to the motion of the key, for preventing access to the
internal parts of the lock.
“8. The application to locks of a safety-plug or yielding-plate, at the
back of the chamber formed by such eccentric revolving curtain or ring.
“9. The application to locks of a strong metallic wall or plate, for the
purpose of separating the safety and other parts of the lock from each
other, and preventing access to such parts by means of the key-hole.
“10. The application to locks of a cap or detective tumbler, for the
purpose of closing the key-hole as the key is turned.
“11. The constructing a key by a combination of bits or movable pieces,
with tongues fitted into a groove and held by a screw.
“12. The constructing a key having a groove in its shank to receive the
detector tumbler.”
[Illustration: 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. Such a lock must of
necessity be costly; but in order to supply the demand for a small lock
at moderate price, Mr. Hobbs has introduced what he calls a _protector
lock_. This is a modification of the ordinary six-tumbler lock. It bears
an affinity to the lock of Messrs. Day and Newell, inasmuch as it is an
attempt to introduce the same principle of security against picking,
while avoiding the complexity of the changeable lock. The distinction
which Mr. Hobbs has made between secure and insecure locks will be
understood from the following proposition, viz. “that whenever the parts
of a lock which come in contact with the key are so affected by any
pressure applied to the bolt, or to that portion of the lock by which
the bolt is withdrawn, as to indicate the points of resistance to the
withdrawal of the bolt, such a lock can be picked.” Fig. 47 exhibits the
internal mechanism of this new patent lock. It contains the usual
contrivances of tumblers and springs, with a key cut into steps to suit
the different heights to which the tumblers must be raised. The key is
shewn separately in fig. 48. But there is a small additional piece of
mechanism, in which the _tumbler stump_ shewn at _s_ in figs. 46 and 47
is attached; which piece is intended to work under or behind the bolt of
the lock. In fig. 47, _b_ is the bolt; _t t_ is the front or foremost of
the range of six tumblers, each of which has the usual slot and notches.
In other tumbler-locks the stump or stud which moves along these slots
is riveted to the bolt, in such manner that, if any pressure be applied
in an attempt to withdraw the bolt, the stump becomes pressed against
the edges of the tumblers, and bites or binds against them. How far
their biting facilitates the picking of a lock will be shewn further on;
but it will suffice here to say, that the movable action given to the
stump in the Hobbs lock transfers the pressure to another quarter. The
stump _s_ is riveted to a peculiarly-shaped piece of metal _h h_ (fig.
46), the hole in the centre of which fits upon a centre or pin in a
recess formed at the back of the bolt; the piece moves easily on its
centre, but is prevented from so doing spontaneously by a small binding
spring. The mode in which this small movable piece takes part in the
action of the lock is as follows: when the proper key is applied in the
usual way, the tumblers are all raised to the proper heights for
allowing the stump to pass horizontally through the gating; but should
there be an attempt made, either by a false key or by any other
instrument, to withdraw the bolt before the tumblers are properly
raised, the stump becomes an obstacle. Meeting with an obstruction to
its passage, the stump turns the piece to which it is attached on its
centre, and moves the arm of the piece _p_ so that it shall come into
contact with a stud riveted into the case of the lock; and in this
position there is a firm resistance against the withdrawal of the bolt.
The tumblers are at the same moment released from the pressure of the
stump. There is a dog or lever _d_, which catches into the top of the
bolt, and thereby serves as an additional security against its being
forced back. At _k_ is the drill-pin on which the pipe of the key works;
and _r_ is a metal piece on which the tumblers rest when the key is not
operating upon them.
[Illustration: fig. 47. Hobbs’s Protector Lock.]
[Illustration: fig. 48. The key.]
Another lock, patented by Mr. Hobbs in 1852, has for its object the
absolute closing of the key-hole during the process of locking. The key
does not work or turn on its own centre, but occupies a small cell or
chamber in a revolving cylinder, which is turned by a fixed handle. The
bit of the movable key is entirely separable from the shaft or stem,
into which it is screwed, and may be detached by turning round a small
milled headed thumb-screw. The key is placed in the key-hole in the
usual way, but it cannot turn; its circular movement round the stem as
an axis is prevented by the internal mechanism of the lock; it is left
in the key-hole, and the stem is detached from it by unscrewing. By
turning the handle, the key-bit, which is left in the chamber of the
cylinder, is brought into contact with the works of the lock, so as to
shoot and withdraw the bolt. This revolution may take place whether the
bit of the movable key occupy its little cell in the plate or not; only
with this difference--that if the bit be _not_ in the lock, the plate
revolves without acting upon any of the tumblers; but if the bit be in
its place, it raises the tumblers in the proper way for shooting or
withdrawing the bolt. It will be understood that there is only one
key-hole, namely, that through which the divisible key is inserted; the
other handle or fixed key working through a hole in the cover of the
lock only just large enough to receive it, and not being removable from
the lock. As soon as the plate turns round so far as to enable the
key-bit to act upon the tumblers, the key-hole becomes entirely closed
by the plate itself, so that the actual locking is effected at the very
time when all access to the interior through the key-hole is cut off.
When the bolt has been shot, the plate comes round to its original
position, it uncovers the key-hole, and exhibits the key-bit occupying
the little cell into which it had been dropped; the stem is then to be
screwed into the bit, and the latter withdrawn. It is one consequence of
this arrangement, that the key has to be screwed and unscrewed when
used; but through this arrangement the key-hole becomes a sealed book to
one who has not the right key. Nothing can be moved, provided the bit
and stem of the key be both left in; but by leaving in the lock the
former without the latter, the plate can rotate, the tumblers can be
lifted, and the bolt can be shot.