CERTAIN IMPROVE- MENTS IN LOCKS AND LATCHES
Year: 1841

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THEODORE
FREDERICK STRONG, of Goswell Road, Middlesex, Engineer, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the Twenty-eighth day of September, in the fifth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Theodore Frederick Strong, Her especial licence, full power, sole privilege and
authority, that I, the said Theodore Frederick Strong, my exors, adññiors, and
assigns, or such others as I, the said Theodore Frederick Strong, my exors,
admors, or assigns, should at any time agree with, and no others, from time
to time and at all times during the term of years therein expressed, should
and lawfully might make, use, exercise, and vend, within England, Wales,
and the Town of Berwick-upon-Tweed, my Invention of "CERTAIN IMPROVE-
MENTS IN LOCKS AND LATCHES;" in which said Letters Patent is contained a
proviso, that I, the said Theodore Frederick Strong, shall cause a particular
description of the nature of my said Invention, and in what manner the same
is to be performed, to be inrolled in Her said Majesty's High Court of
Chancery within six calendar months next and immediately after the date
of the said in part recited Letters Patent, as in and by the same, reference
being thereunto had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Theodore Frederick Strong, do hereby declare the nature of my Improve-
ments to consist,-

page_text: Firstly, in the combination of a series of two or more tumblers attached to
the bolt of a lock, and one to another, each tumbler having its fulcrum on
the preceding tumbler of the series near the end opposite to the fulcrum of
that preceding tumbler, the first of the series having its fulcrum on the tail
plate or thin part of the sliding bolt. Thus the fulcrn of the tumblers are
alternately placed near the opposite ends of the tail plate, and consequently
the alternate tumblers rise, the one to the right hand and the other to
the left, when the lock is held up in a vertical position, whereby a great
complication of checks against the operation of a false key is obtained from
a few tumblers.
Secondly, in attaching a secondary bolt, sliding transversely in the main bolt
of a lock, and acting against an abutment to form a detent in addition to the
complicated effect of the alternating tumblers described as the first part of
my improvements, this transverse bolt being to be drawn back by one of the
tumblers before the main bolt can be withdrawn.
Thirdly, in the combination of the alternating tumblers with a secondary
bolt attached to the lock plate, and shooting into a notch in the main bolt
to prevent its being drawn back previous to the withdrawal of the bolt.
Fourthly, in adding to the combination of alternating tumblers a detecting
tumbler connected with the secondary bolt above described under the second
part of my improvements, which detecting tumbler, on being lifted too high
by a false key, is there detained by a spring catch until released by the
true key.
Fifthly, in the combination of a hooked catch piece with several tumblers
acting on one common fulcrum, the whole of the tumblers constituting a sub- 2
stitute for the bolt, whereby a greater number of tumblers of a given thickness
may be introduced into a thin lock than when the catch pieco is pierced
through in the manner of a staple.
Sixthly, in the application of a pair of links, one hinged to cach side of the
sliding bolt of a spring latch, each link terminated at the end opposite to the 3
hinge by a hook catching on upon the follower, whereby the followers,
whether turning right or left, act with very little friction in withdrawing
the bolt.
Seventhly, in the formation of a hinge by casting alone in parts of the
lock in which the motion on the joint is but small, for which purpose a notch S
is cast in one of the pieces of the hinge, of the form of about three fourths of
a hollow cylinder, into which notch a cylindrical protuberance or knuckle cast
with the other piece of the hinge fits and turns in a small are of a circle,
such a hinge being peculiarly applicable to the joining of the links to the

page_text: side view of the same. Figure 20, a view of the frame and back plate, in which
is shown by dotted lines the form and position of the driver of the transverse
bolt and detaining spring. Figure 21, a front and edge view of the driver
shown separately from the lock. Figure 22, a side and end view of the key.
It is to be remarked that the same letters and numbers of reference signify the
same parts in all these twenty-two Figures. a, the frame of the lock. 6, the
back plate fixed to and forming part of the frame, to which plate the works
are principally attached. c, the front plate, removeable at pleasure to expose
the works to view. d, the main bolt. e, the transverse bolt. f, the driver of
the transverse bolt turning on the neck of a screw in the back plate. 9, a
stud fixed in the driver to act in the crook of the transverse bolt, and slide it
up and down. h, a spring attached to the lock frame, having a hook at the
free end to fall into a notch in the end of the driver, and hold it in its resting
position. k, a bauking piece or abutment projecting from the frame for the
transverse bolt to catch against. 1, the tumblers. m, the fulcrum hole of
the tumbler. n, the stud on which the next tumbler of the series acts. p, the
springs which return the tumblers to their resting places. These springs aro
made of one plate of gilt steel, having three longitudinal incisions extending
the greater part of the length of the plate, dividing it into four parts, each
constituting a separate spring. q, a stud fixed in the tail of the main bolt, in
a mortice of which stud the end of the plate constituting the springs is firmly
held. r, two studs, cach fixed by one end into the back plate, the other end
being steadied by two apertures made in the front plate. These studs guide
the tail of the main bolt, and serve for abutments or bauking pieces for the
tails of the tumblers to act against. s, two slots in the tail of the main bolt
sliding upon the guide studs r. t, the fulcrum pin on which the first tumbler
hangs and turns. u, a screw to hold the transverse bolt in the groove of the
main bolt. v, a spring in the transverse groove of the main bolt pressing
against the side of the transverse bolt to keep it from falling by its own
weight. w, the notch in the side of the tail of the main bolt into which the
bit of the key enters to slide the bolt in or out. x, the latch bolt. y, a forked
stud fixed in the back plate in which the tail of this bolt slides. z, a spiral
spring on the body of the latch bolt acting against the forked stud y. 1, a
hinge piece fixed on the tail of the bolt. 2, two connecting links, each jointed
to the hinge piece by means of a solid cylinder forming one end of the link,
and acting in a notch in the hinge piece, of the figure of about three-fourths
of a cylinder, the other ends of the connecting links being formed into hooks.
3. the two followers. 4, the centre piece united with and turning the two
followers.

page_text: Sheet 2. Figure 1 represents a back view, Figure 2, an edge view, and
Figure 3 an end view of a lock to be fastened on against a door. Figure 4, a
view of the inner works of this lock as scen when the front plate is removed
and a secondary plate remaining, the bolt being shewn as thrown out.
Figure 5, a view of the inner works as seen when the secondary plate is
removed and the bolt withdrawn. Figure 6, a transverse vertical section
from E to F of Figure 5. Figure 7, front and edge view of the first tumbler
in the series, having its fulcrum at the right-hand end to work on a stud in
the right-hand end of the tail of the bolt. Figure 8, front and edge view of
the second tumbler of the series, having its fulcrum at the left-hand end to
work on a stud in the left-hand end of the first tumbler. Figure 9, front
and edge view of the third tumbler in the series, having its fulcrum at the
right-hand end to work on a stud in the right-hand end of the second tumbler.
Figure 10, front and edge view of the transverse bolt, shewn separately from
the lock. Figure 11, front and edge view of the detecting tumbler, shown
separately from the lock. Figure 12, front and edge view of the detecting
tumbler as attached to and working in the main bolt of the lock, and connected
with the transverse bolt. Figure 13, a section from G to II of Figure 12,
shewing the face of the detecting spring book. Figure 14, a front view of the
two edge views of a plate to
frame of the lock. Figure 15, inside view and
be screwed on to the door by four screws, and to which plate the frame of
the lock is secured by four hooks projecting from the face of the plate, and
catching under four lugs inside the frame of the lock, and there retained by
one screw in the end of the frame. It is further to be remarked, that the
same letters of reference signify the same parts in all the Figures of Sheet 2.
a, the frame of the lock. b, the back plate. c, the plate to be screwed on
against the door. d, the four hooks of the door plate to catch under the lugs
of the frame. e, the four lugs. f, the secondary plate to keep the works in
place. g, the main bolt. h, the studs for guiding the main bolt, and for
bauking or abutting the alternating tumblers. k, the alternating tumblers.
1, the detecting tumbler. m, the transverse bolt. n, the bauking piece or
abutment behind which the transverse bolt passes after the main bolt is thrown
out. p, the fulcrum of the detecting tumbler. 2, a stud fixed in and projecting
from the face of the detecting tumbler to take into the crook at the lower end
of the transverse bolt, and to work that bolt up and down. r, the bauking
stud for detaining the detecting tumbler. s, a spring catch to pass over the
top of the left-hand end of the detecting tumbler, if that tumbler should he
raised too high by a false key, in which case the lowest recess of the slot in
the tail of the tumbler would be forced up above the height at which the

page_text: tumbler could pass the bauking stud 7, the tumbler being there detained by
the spring hook until released by a backward motion of the true key pressing
upon the curved part t. t, the curved part of the detecting tumbler against
which the true key must be pressed in order to relieve that tumbler after
having been raised too high by a false key. u, a spring for throwing down
the detecting tumbler when not held up by the spring catch s. v, the screws
for fastening the secondary plate on upon the frame. w, two lug plates fixed
to the frame of the lock to which the secondary plate is screwed. x, three
springs made of one plate of gilt steel held in a stud fixed in the tail of the
main bolt.
Figure 12, two views of the lifting
Figure 18, two views of the forked
Figure 14, two views of
Sheet 3. Figure 1 represents a front view, Figure 2 an edge view, and
Figure 3 an end view of a mortice lock, containing also a lifting latch.
Figure 4, a view of the works when the front plate is removed and the latch
lifted, the bolt being withdrawn. Figure 5, a view of the same when the
latch is down and the bolt thrown out. Figure 6, a transverse vertical section
from I to K of Figure 5. Figure 7, two views of an ordinary tumbler, shewn
separately from the lock, but to be applied upon the tail of the main bolt as
an example of the combination of the new with old tumblers. Figure 8, two
views of the first of the series of the alternating tumblers, the fulcrum of this
being placed upon the same pin as the fulcrum of the ordinary tumbler.
Figure 9, two views of the second tumbler of the series. Figure 10, two
views of the third tumbler of the series. Figure 11, two views of the main
bolt, shewn separately from the lock.
latch, shewn separately from the lock.
connecting piece, shewn separately from the lock.
the followers, united by a central piece, shewn separately from the lock.
Figure 15, an inner view of the frame or case of the lock, with the studs fixed
to it. Figure 16, two views of the key. Figure 17 a front view, Figure 18
an edge view, and Figure 19 an end view of a chest lock, in which several
tumblers, turning on a common fulcrum, are combined to form a substitute for
the bolt. Figure 20, a front view of the works when the front plate is
removed. Figure 21, a vertical section from L to M of Figure 20. Figure 22,
three views of the catch piece. Figure 23, two views of one of the tumblers,
shown separately from the lock. It is also to be remarked, that the same
letters of reference signify the same parts in all the Figures of Sheet 3.
a, the frame of the mortice lock. b, the back plate. c, the front plate.
d, the main bolt. e, the studs for guiding the main bolt, and for bauking the
alternating tumblers. f, two slots in the tail of the main tumbler to work
over the studs e. y, the common tumbler. 1, the alternating tumblers.

page_text: k, the tumbler springs and stud in which they are fixed. 7, the fulcrum pin
in the tail of the lock bolt, on which hang the common tumbler and the first
of the series of alternating tumblers. m, the rising latch. n, the tail of the
latch. p, the fulcrum pin, on which the rising latch turns. 9, a spiral spring
to return the latch to its place of rest after having been lifted. r, the forked
picce hinged to the tail of the latch. s, the pair of followers. t, the centre
piece, uniting and turning the followers. u, the frame of the chest lock.
v, the tumblers, terminated at the top by a double hook, the right-hand side to
take into the hook of the catch piece for the purpose of locking, and the left-
hand side to act as a detent to the catch piece in case of the tumbler being
thrown too far by a false key. w, the catch piece with two hooks, the right-
hand hook for the locking, and the left-hand hook to prevent unlocking, when-
ever a false key turns any one of the tumblers too far, so that all the tumblers
must be turned far enough, and not one too far, in order to disengage the
catch piece. x, the springs which return the tumblers to their resting place.
These examples of the application of my improvements will be abundantly
sufficient to enable any skilful lockmaker to adapt some of them to the con-
struction of each variety of locks for gates, doors, cabinets, cupboards, chests,
drawers, bookcases, books and portfolios, and locks for other purposes; also
for padlocks, for which last kind of lock the tumblers and hooks described in
Figure 16, and the following Figures of Sheet 3, are particularly applicable.
And I hereby further declare, that I do not claim as my Invention the
various common parts of locks or latches shewn in the Drawings, and which
were necessarily introduced as foundations upon which my improvements
might be exemplified, such as the frames, the plates, the bolts, the springs, the
studs, the screws, the guide pieces, or the form of the tumblers. But what I
claim is, the alternate position of the fulcra of a series of two or more
tumblers, the first tumbler having its fulcrum on the thin part or tail of the
main bolt, the second tumbler having its fulcrum on the first tumbler near the
moveable end, the third tumbler having its fulcrum on the second tumbler
ncars its moveable end, and so on, to any convenient number of tumblers.
And I claim the combination of the alternating tumblers with a transverse
secondary bolt acting as a detent to the main bolt, whether the secondary bolt
be attached to the main bolt itself or to the lock plate.
And I claim the combination of the detecting tumbler with the secondary
bolt.
And I claim the combination of the hooked catch piece with several
tumblers acting on one common fulcrum, the tumblers forming together a
substitute for the bolt.

page_text: And I claim the application of a pair of hooked links, hinged to the sides of
a bolt of a spring sliding latch, the hooks catching on and drawn by the
followers.
And I claim the formation of a hinge by a protuberant cylindrical knuckle
acting in a hollow cylindrical notch.
And I claim the application of the forked picce between the followers and
the lifting latch; the particulars of all these claims being herein-before shewn
and described.
In witness whereof, I, the said Theodore Frederick Strong, have here-
unto set my hand and seal, this Twenty-sixth day of March, in the
year of our Lord One thousand eight hundred and forty-two.
MANBY, Extra.
THEODORE FREDERICK (L.S.) STRONG.
AND BE IT REMEMBERED, that on the Twenty-sixth day of March, in
the year of our Lord 1842, the aforesaid Theodore Frederick Strong came
before our said Lady the Queen in Her Chancery, and acknowledged the
Specification aforesaid, and all and every thing therein contained and specified,
in form above written. And also the Specification aforesaid was stamped
according to the tenor of the Statute made for that purpose.
Inrolled the Twenty-eighth day of March, in the year of our Lord One
thousand eight hundred and forty-two.