Ar In- PROVEMENT IN THE CONSTRUCTION OF LOCKS
Year: 1824

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
CHUBB, of Portsea, in the County of Southampton, Ironmonger, send
greeting.
WHEREAS His most Excellent Majesty King George the Fourth did,
by His Letters Patent under the Great Seal of that part of the United
Kingdom of Great Britain and Ireland called England, bearing date at
Westminster, the Fifteenth day of June, One thousand eight hundred and
twenty-four, in the fifth year of His reign, give and grant unto me, the said
Charles Chubb, my exors, admors, and assigns, His especial licence, full
power, sole privilege and authority, that I, the said Charles Chubb, my
exors, admors, and assigns, during the term of years therein mentioned,
should and lawfully might make, use, exercise, and vend, within England,
Wales, and the Town of Berwick-upon-Tweed, my Invention of "Ar In-
PROVEMENT IN THE CONSTRUCTION OF LOCKS;" in which said Letters Patent
there is contained a proviso that if the said Charles Chubb, shall not parti-
cularly describe and ascertain the nature of my said Invention, and in what
manner the same is to be performed, by an instrument in writing under my
hand and seal, and cause the same to be inrolled in His Majesty's High
Court of Chancery within two calendar. months next and immediately after
the date of the said Letters Patent, that then the said Letters Patent, and all
liberties and advantages whatsoever thereby granted, shall utterly cease, deter-

page_text: mine, and become void, as in and by the same, relation being thereunto had,
will more fully and at largo appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Charles Chubb, do hereby declare that the nature of the said Invention, and
the manner in which the same is to be performed, are particularly described
and ascertained in and by the Drawings which are hereunto annexed, and by
the following description thereof (that is to say) :-
My said Improvement in the Construction of Locks is applicable only to
that description of lock generally known under the denomination of Chubb's
Patent Detector Lock, and for which Letters Patent were granted to Jeremiah
Chubb, of Portsca, bearing date at Westminster, on or about the Third day of
February, in the fifty-eighth year of the reign of His late Majesty King
George the Third, and in the year of our Lord One thousand eight hundred
and eighteen. And in order that the application of my said improvement
may be distinctly understood, I will first briefly describe one of the said Patent
Detector Locks, furnished with what the Patentee denominated Detecting
Mechanism.
The detector is a detent or lever moving upon a fixed center pin, being
formed with a hook or catch adapted to interlock with a notch or stud in the
bolt of the lock, so as effectually to stop and resist the motion of such bolt
whenever the detector is moved on its center pin, so as to come into contact
with the bolt; but if the detector is moved on its center pin so as to be clear
of the bolt it will then make no opposition to its motion. The detector
spring is a spring applied to the detector in such a manner as to urge its hook
or catch towards the bolt when the detector is moved, so as to bring the said
hook or catch nearer to the bolt than a certain portion which may be called
the point of detection; at the same time the said detector spring will urge the
detector hook away from the bolt whenever the same is at a greater distance
from the bolt than the said point of detection. The detector is so placed as to
be operated upon by the tumblers of the lock when the whole or any of them
are raised, and if any of the tumblers is raised too high (that is to say), is
moved further from the center of motion of the key than the required position
in which the notch in such tumbler comes opposite to the stud of the main
bolt (in order that the main bolt may pass to open the lock), then such
tumbler which has been too much raised will move the detector beyond or
within the point of detection, in which case the detector spring will throw the
book of the detector into contact with the bolt, and the detector will thereby
effectually stop any motion of the bolt, even though the tumbler which occa
sioned the detection should be restored to its proper position; for though any

page_text: one of the tumblers which may be raised too high will operate against the
detector to throw its hook into the notch in the bolt, yet there is no connection
between such tumbler and the detector which can occasion the detector to
leave its then position. As the true key of the lock will raise each tumbler
to its required position, and no further, it will never throw the detector beyond
or within the point of detection, consequently the detector spring will always
keep the detector hook disengaged from the bolt; but if a false key or pick-
lock be employed to raise the tumblers, there will be every probability that
some one will be raised too high, and will move the detector beyond the point
of detection, so that the detector spring will then throw the hook into contact
with the bolt. In this state the lock is what is called detected, and the
possesser of the true key has evidence that an attempt has been made to
violate the lock, because the said true key will not now open it, for neither
the true key or tumblers have any means of communication with the detector
after it has passed within the point of detection. The remaining parts of the
detecting mechanism are for the purpose of regulating the lock, or releasing
its bolt from the hook of the detector; they are as follows:-The regulating
bolt is a slider within the lock, adapted to operate upon the detector in such
manner as to raise or remove the hook thereof away from the bolt of the lock
beyond the point of detection, and it is operated upon by an adjusting instru-
ment, which is called the regulating key, which may be similar in form to
other keys, but so made as not to open the lock, it being designed only to
discharge the detector and regulate the lock by restoring its parts to such a
state of adjustment that its own key will open it. For this purpose the
regulating key has a different arrangement of the steps on its bit, one of
which shifts or moves the regulating bolt. The regulating bolt may be placed
over or under the bolt of the lock, and has a pin or stud which projects from
it and applies against the tumblers of the lock, which are adapted to resist
the motion of this regulating bolt, unless cach one of the said tumblers is
raised or moved into a given position, and neither more or less, by means of
the several steps in the bit of the regulating key. The regulating key being
applied in its place in the lock and turned partly round, its several steps will
first raise each tumbler to its exact required position, and then it will move the
regulating bolt, by which means the detector will be moved without or beyond
the point of detection, and the detector spring will throw the hook of the
detector out of the reach of the bolt, which may be effected by a small
inclined plane or wedge upon the regulating bolt. By this means the lock
will be regulated or restored to its original state, and can be opened by its
true kev.

page_text: In another part of the said Jeremiah Chubb's Specification he described
plan whereby the same key may be made to serve for the true key and for
the regulating key by changing its position in the lock. This he effected by
having a small middle plate situated within the lock, having two keyholes
formed through it at right angles to each other, which operated as follows:-
When the lock had been detected by an attempt to violate it, or by any other
means, the true key was to be introduced into the keyhole, and after being
turned one quarter round upon its pin it was to be drawn outwards, or away
from the main lock plate, until its bit passed through the second keyhole
formed in the middle plate before mentioned. The key was then turned partly
round, in which position the steps upon its bit would operate upon the
tumblers and regulating bolt in a proper manner to regulate or restore the
lock to its original position, and when this had been effected the key was to
be pressed inwards and returned into its proper position for opening the lock.
All the methods which were described by the said Jeremiah Chubb for regu-
lating or restoring the state of the lock when it had been detected were found
to be attended with inconveniences, to obviate which has been the entire
object of my present improvement, as will be herein-after fully described.
detector moves.
Figures 1 to 6 (inclusive) upon the Sheet of Drawing which is hereunto
annexed, represent a lock with its parts adapted for a door. It is provided with
four tumblers, and is furnished with the aforesaid detecting mechanism, but the
regulating part is constructed according to my present improvement. Note,
the same characters or letters of reference are used to denote corresponding
parts upon the Figures whenever they occur. 1, the center pin upon which the
2, the tail or end of the detector, proceeding nearly down to
the tumblers B. 3, the hook which detains or holds the main bolt by falling
into the notches 4 cut therein. 5 is the detector spring; it is formed into a
triangular piece at the end which acts against the detector, the end of which
is also made in a triangular form. Now, if the proper key is introduced into
this lock it will raise the tumblers B upon their centre of motion D exactly to
the required beight for the stud 6 (upon the main or locking bolt A) and the
stud 10 (upon the regulating bolt 7) to pass through their respective openings
in the tumblers, as seen in Fig. 1 upon the annexed Drawing, and thereby
the main bolt may be withdrawn or unlocked; but if any key or other instru-
ment should be introduced into this lock for the purpose of opening or picking
it, by which any one or more of the tumblers B should be raised too high, they
will also raise the end 2 of the detector, and depress the end 3 until the
inclined plane or triangular piece of the detector falls under the triangular
piece of the spring 5, then the hook 3 will be instantly shot into one of the

page_text: notches 4 on the main bolt (as shewn at Fig. 2, where the lock is represented
in a locked position), and will retain it so effectually that the application even
of its proper or true key will have no effect to withdraw the main bolt, nor
can the same be moved until the detector has been returned to its original
position as aforesaid.
I have above described the nature of Jeremiah Chubb's Detector Lock suffi-
ciently to be enabled to explain clearly to persons conversant with works of a
similar description how my present improvement is to be applied thereto; and I;
the said Charles Chubb, do hereby declare that I make no claim to that detecting
mechanism which I have above above described, it having only been introduced
into this my Specification to shew clearly the application of my present improve-
ment, but I confine my claim entirely to the following particulars, that is to
say:-I form and apply the regulating bolt in such manner that the proper or
true key which is used to lock and unlock the lock may also perform the office of
relieving the detector to regulate the lock when it has been detected as afore
said, and that by simply turning the said key partly round upon its center pin
in the same direction that it is turned in the act of locking or throwing
the main bolt, as shewn by the direction of the small dart or arrow in Fig. 2.
This improvement is effected in the following manner:-The regulating
bolt 7, which is shewn in Fig. 3 upon the annexed Drawing as laying over
the main bolt A, is adapted to move or slide backwards and forwards along
with the main bolt in the act of locking and unlocking the same, for which
purpose it has a groove or opening cut through it, which slides upon the stud
D in the same manner as the main bolt does. The regulating bolt has also
an opening formed through it for the stud 6 of the main bolt to pass through;
and this opening is of such length in the direction of the bolt's motion that
the regulating bolt 7 can slide forwards in a slight degree upon the main
bolt A, even after the main bolt has been fully shot or locked, and it is this
extra sliding motion of the regulating bolt upon the main bolt which operates
to regulate the lock or return the detector to its original position after the
lock has been detected by any means as aforesaid. When the lock is in the
act of locking and unlocking the regulating bolt 7 is caused by the motion of
the key to slide backwards and forwards along with the main bolt by means
of a notch 8, which is made in its side for the bit of the key to take into,
similar to the notch in the main bolt. Now if an attempt is made to violate
or open the lock, and by that means the lock should become detected, as
shewn in the Fig. 2, its proper or true key, on being introduced and turned
round in the right direction for unlocking or withdrawing the main bolt will
be found not to perform its office, since the main bolt will be retained by the

page_text: hook 3 of the detector, and will thus intimate to the proprictor of the lock
that an attempt has been made to pick it, in which case he must slide
or move the regulating bolt in order that its inclined plane or wedge 9, before
mentioned, may force back or relieve the hook 3 of detector from its hold
upon the main bolt, to effect which he has nothing to do but simply to turn
the key in a backward direction, or in the same direction that it is turned in
the act of locking or shooting the main bolt, as shewn by the small dart or
arrow in Fig. 2, by which means the various steps upon the bit of the key
will first raise the different tumblers so that their openings 11 will correspond
with each other sufficiently to permit the stud 10 upon the regulating bolt to
enter; then by continuing to turn the key round a short distance further in
the same direction, its bit will enter the second notch marked 12 in the side
of the regulating bolt 7, and will advance or move the said bolt in a sufficient
degree for its inclined plane or wedge 9 to relieve the detector from its hold,
after which the key on being turned round in the proper direction for
withdrawing the bolt, as shewn by the arrow in Fig. 1. it will open the
lock. Note, the main bolt has two notches cut in its side, as shewn in the
Fig. 5 and 6, which represent two views of the main bolt as detached from the
lock. The second notch in the main bolt, marked 18, is made wider than the
notch marked 12 in the regulating bolt, in order that the bit of the key, when
moving the regulating bolt forwards in order to return the detector, might not
act upon the main bolt. This improvement, by enabling the true key to be
employed in such a simple manner for regulating the said Patent Detector
Locks, is found to possess considerable advantage over the modes which were
heretofore known and in use, and will, it is presumed, render those locks more
generally useful. The said improvement is equally applicable to all descrip-
tions of the Patent Detector Locks before mentioned, and may, from the
description above given, be easily adapted to them by persons conversant with
such works.
Figs. 7 to 12 inclusive upon the annexed Drawing represent a padlock with
its tumblers and appendages, being provided with detecting mechanism, similar
to what has been herein-before described, and with the regulating part con-
structed according to my aforesaid improvement. The same characters or
letters of reference which are used upon the various parts of this lock will be
found to correspond with those marked upon similar parts in the Figures of the
door lock; and, since its operation is nearly similar, it will not be necessary to
enter into a minute description of it, observing that the form and proportion of
the different parts may be varied according to the discretion of the workman
employed in constructing the same. The materials of which the same may be