IMPROVEMENTS IN LATCHES, LATCH LOCKS, AND OTHER LOCKS FOR FASTENING
Year: 1847

page_text: CHUBB & HUNTER'S SPECIFICATION.
TO ALL TO WHOM THESE PRESENTS SHALL COME, JOHN CHUBB,
of Saint Paul's Church Yard, in the City of London, Patent Lock and Fire
Proof Safe Manufacturer, and EBENEZER HUNTER the elder, of Wolverhamp-
ton, in the County of Stafford, Lock Maker, send greeting.
WHEREAS we did, by Petition, humbly represent unto Her most Excellent
Majesty Queen Victoria that we had invented "IMPROVEMENTS IN LATCHES,
LATCH LOCKS, AND OTHER LOCKS FOR FASTENING;" and Her said Majesty, being
willing to give encouragement to all arts and inventions which may be for
the public good, was graciously pleased, by Her Royal Letters Patent under
the Great Seal of the United Kingdom of Great Britain and Ireland, bearing
date at Westminster, the Eleventh day of January (One thousand eight
hundred and forty-seven), in the tenth year of Her reign, for Herself, Her
heirs and successors, to give and grant unto us, the said John Chubb and
Ebenezer Hunter, our executors, administrators, and assigns, Her especial
license, full power, sole privilege and authority, that we or they, by ourselves
or themselves, or by our or their deputies, servants, or agents, or such others
as we or they shall agree with, and no others, during the term of fourteen
years from the date of the said Letters Patent, should and lawfully might
make, use, exercise, and vend our said Invention, within that part of Her
said Majesty's Dominions called England, Her Dominion of Wales, and
Town of Berwick-upon-Tweed, and the Islands of Jersey, Guernsey, Alderney,
Sark, and Man, and also in all Her Majesty's Colonies and Plantations
abroad, in such manner as to us, our executors, administrators, and assigns,
shall seem meet, and that we or they shall enjoy the whole profit and

page_text: advantage arising by reason of the said Invention during the said term of
fourteen years; and whereas the said Letters Patent contain a proviso
obliging us, the said John Chubb and Ebenezer Hunter, particularly to
describe and ascertain the nature of our said Invention, and in what manner
the same is to be performed, by an instrument in writing under our hands and
seals, or under the hand and seal of one of us, and to cause the same to be
enrolled in Her Majesty's High Court of Chancery within six calendar
months next and immediately after the date of the said 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
John Chubb, for myself and for the said Ebenezer Hunter, do hereby declare
that our said Invention is described and ascertained in manner following, and
by the aid of the two Sheets of Drawings hereunto annexed (that is to
say):
The object of that part of our improvements which relates to latches
and latch locks is to give security against the latches or spring latches or
spring bolts in latches and latch locks being forced open, or being unlatched
or withdrawn or unlocked by means of picklocks or false keys, such latches,
spring latches, or spring bolts aforesaid, as they are commonly constructed
and used, are adapted to latch or shoot by self-action of their own weight
or of their own springs when the door to which they are applied is shut.
But after having been so latched or shot by their own self-action the said
ordinary latches or spring latches or spring bolts (being then on the latch)
are not retained by any other means than by their own weight or their
own springs from being forced open or being unlatched or withdrawn or
unlocked by means of picklock or false keys, so as to allow the door to be
opened. And although it is common to apply tumblers to the latches or
spring latches or spring bolts, in some kinds of latch locks, nevertheless those
tumblers do not come into action when (by the shutting of the door) the latch
or spring latch or spring bolt becomes latched or shot by its self action as afore-
said; but in order to bring the tumblers into action, and' obtain any security
therefrom, it is requisite to apply a key, and by action thereof the spring
latch or spring bolt is shot further out than it had been previously shot by its
said self-action, and when so shot farther out it becomes securely locked and
retained by means of the tumbler or tumblers, from being withdrawn, except by
aid of the key. It is well known that the spring latch locks in ordinary use
for street doors of houses are insecure when left on the latch, that is, left in the
state which they will assume by their own self-action aforesaid, and unless such

page_text: spring latch locks are made without any keyhole at the outside of the door
they can be easily opened by picklock or false keys. And note, there are
latches of a peculiar construction known as Chubb's Patent Latches, which
fasten of themselves by self-action on the shutting of the door, and which,
when on the latch, possess the same kind of security as several tumblers would
give. They were invented by my late father, Charles Chubb, to whom
Letters Patent were formerly granted therefor, and were extensively manu-
factured by him, and, since his decease, by me. They can be made with a
keyhole at the outside of the door, so as to be unlatched by a key from the
outside, as well as by the usual mode of turning a knob handle at the inside of
the door, and are very secure against being so unlatched from the outside by
picklock or false keys. Now our present improvements (by different means
now about to be described) will give the same security to the latches or spring
latches, or spring bolts of latches, and latch locks.
Fig. 1, Sheet I., of the Drawings hereunto annexed, is an elevation of a latch
constructed according to part of our said improvements, the cover plate being
removed in order to shew the interior parts as they would appear when seen
from the inside of the door to which the latch is applied, supposing that door
to be transparent, so as to be seen through.
Fig. 2 is a horizontal section of the same latch viewed from above, to shew
the relative positions of the several tumblers and other interior parts.
Fig. 3 is an elevation like Fig. 1, but shewing interior parts which are
concealed in Fig. 1. A, A, is the rim or exterior case of the latch, consisting
of a back plate C, and four sides A as usual; and B, Fig 2, is the section of the
cover plate which fits into the said four sides A, and is fastened by screws so as
to form a complete box or case which encloses all the mechanism. The said
cover plate B applies against the inside of the door when the latch is fastened
by screws in its place against that inside. The keyhole is cut out through
the cover plate B suitably for the admission of the key K, when the same is
inserted from the outside of the door into a corresponding keyhole cut through
the thickness of the door. And note, the keyhole may also be continued
through the back plate C, as shewn at a, Fig. 1, suitably for the admission
of the key from the inside of the door, when required for double locking the
latch, so that the same cannot be unlocked by means of the knob handle E,
Fig. 2, at the inside, but the said keyhole at the inside is not an essential
part of the latch, as will be explained. G are the tumblers, one behind the
other, in Fig. 1, and h the fixed centre pin, serving as their centre of motion
about which they are all moveable, but quite independently one of the
.other. Six tumblers are shewn in Fig. 2, but the number may be varied.

page_text: I are the tumbler springs made of one piece of steel cut with nicks like the
teeth of a comb, so as to become divided into as many springs as there are
tumblers, and one of those springs acts upon each tumbler (in aid of the weight
thereof) to urge it to move downwards about its centre of motion h towards
the keyhole ȧ. When the key k is inserted into the keyhole, and turned
round therein, then the several steps on the bit d of the key, acting against the
lower edges of the several tumblers Ġ, will lift them all upwards in opposition
to their several springs 1, each tumbler G being thereby lifted to its own proper
intended height, so as that the long horizontal notches in all the several
tumblers G will coincide one horizontal notch with another, and will all cor-
respond with the stump m, which projects out forwards from the latch or
bolt I, which latch or bolt is applied flat against the back plate C, bebind all
the tumblers G, and is capable of being lifted up at the outer end i, and also
of sliding endways. The latch or bolt I is guided in its motions by the outer
end i passing through the end A of the rim, and by a slot (shewn dotted in
Fig. 8), through the inner end being fitted to a fixed stud which projects out
forwards from the back plate C. The outer end, where it passes through the
rim A, is cut away with a slope at the under side i, so as to permit that outer
end to descend when the latch or bolt I is withdrawn, as represented in Fig 3,
but when the latch or bolt I is shot out, as in Fig. 1, (or farther out than
is there represented), then the outer end i fills the opening through the end of
the rim A, so as to retain the latch or bolt I to move in an endway direction
only: S is a spring, and R a lever noveable about the fixed centre pin r,
for the purpose of transmitting the force of the spring S to the latch or bolt I,
with a tendency to shoot or move it endways outwards; but, at the same time,
in consequence of the upper end of the lever R acting against the upper part of
the latch or bolt I, at k (above the level of the fixed guiding stud in the
slöt ic), the said force of the spring S, which is so transmitted by the lever R,
will act in aid of the weight of the outer end i of the latch or bolt, with a
'tendency to urge that end i downwards (as far as the opening through the
end of the rim A will permit the said end i to descend), as well as with a
tendency to shoot the whole of the bolt or latch I endways; when the latch
or bolt I is withdrawn, as appears in Fig. 3, then the aforesaid slope, which
is cut away froin the under side i of the outer end of the latch or bolt I, will
allow that outer end to descend by the aforesaid action of the lever R atk, aided
by the weight of that outer end, so that a notch f at the under side of the bolt
I will catch upon a fixed stud g, which projects out from the back plate C, so
as to detain the latch or bolt I from being shot forwards endways by action
of the lever R, until the outer end i of the latch or bolt has been first raised

page_text: .
so much as to clear the notch f from the fixed stud 9, and then the latch
or bolt I will immediately shoot forwards for latching and fastening the door.
The extreme end p of the latch or bolt I always projects out beyond the end
of the rim A, even when the latch or bolt I is withdrawn, as in Fig. 3, as far
as it can go into the rim. And when the door is in the act of being nearly
closed that extreme end p acts against a fixed inclined plane or curve q, Fig. 2,
on the hasp or staple J, which is fixed to the doorpost, so that in the final
closing of the door the extreme outer end p of the latch or bolt will be forced
to ascend the said inclined plane or curve 2, and thereby the outer end i of
the latch or bolt I will be so much raised upwards as to disengage its notch f
from the fixed stud g, and then the whole of the latch or bolt I will suddenly
shoot forwards to the position shewn in Fig. I, by what has been mentioned
as self-action of the latch or bolt, but in reality being by reaction of the
spring S transmitted by the lever R. Note, a notch is cut out in the hasp J.
just above the fixed inclined plane or curve q, the size of that notch being
adapted to the size of the extreme end p of the latch or bolt, so as to
permit that end to enter into the hollow of the hasp J. When the said end
phas passed up to the summit of the inclined plane or curve q at the final
closing of the door, and when the latch or bolt I shoots forwards, the outer
endi, k, of the latch or bolt I, which then enters into the hollow of the hasp
J, is so much larger, and enters so much farther than the said notch, that the
said outer end i, k, of the latch or bolt I will obtain a secure hold in the
hollow of the hasp J, notwithstanding the said notch; and when the latch or
bolt is shot forwards as aforesaid into the position shown in Fig. 1, its
stump m will come opposite to the upper parts of the transverse notches = in
the tumblers G, and then each of those tumblers will descend by reaction of
the several springs l, so as to catch and interlock the stump m within those
upper parts of the transverse notches z, and thereby the latch or bolt I will
be detained and securely locked, so that it cannot be withdrawn or forced back
unless each one of the several tumblers G is previously lifted to its own!
proper intended height for bringing the horizontal notches of the several
tumblers to coincidence one with another, and all of them with the stump m, as
already mentioned. And also that being properly done without lifting any
one of the tumblers higher than its said intended height, for if any one of the
tumblers is over-lifted then the lowest part of its transverse notch z, which is
below the horizontal notch, will interlock with the stump m, so as to detain the
latch or bolt I, all which is only the usual means whereby tumblers givo
security to prevent a bolt being withdrawn or forced back, unless by action of
the true key; but hitherto, in ordinary latches or latch locks, the tumblers
that are sometimes applied therein are not operative (as is the case according

page_text: to this part of our improvements as aforesaid) when the latch or bolt has
been merely latched or shot out by its own self-action or spring action, and
(as already mentioned) it is only by subsequent action of the key in such
ordinary latches or latch locks, and thereby shooting the bolt further out than
.it had been previously shot by the said self or spring action, that the tumblers
are brought into operation for detaining the bolt from being withdrawn. And
when the latch, Fig. 1, is fastened as there represented, that is, with its latch
or bolt I latched or shot into the hollow of the hasp J by self or spring action
at the final closing of the shutting of the door, and the said latch or bolt
I is secured in that position by the tumblers G from being unlatched or
withdrawn, as already described, then, in order to unlatch or withdraw the
bolt I from the inside of the door, the knob handle E, Fig. 2, must be turned
partly round in the proper direction; or to do the same from the outside of the
door the key K. must be inserted through the keyhole in the door and in the cover
plate B, and turned partly round in the proper direction. In either. case the
follower H, or the key K, will act in a similar manner, first to lift or raise cach
one of the tumblers G to its proper intended height, but no higher, and after
having thereby brought the horizontal notches of all the several tumblers G to
coincide one with another and with the stump m, then the follower II, or the
key K, will come into action against one of the talons t or w of the latch or
bolt I, in order to draw the same back nearly to the position Fig. 3, but with
the outer end i, k, raised up as high as it can go, in which position it
will allow the door to be opened. The extreme end p then passing freely
through the notch in the hasp J, the stud m moves along without obstruction.
in the horizontal notches of the tumblers G, whilst the latch or bolt I is so
drawn back, and after the door is opened the turning action of the knob
handle E or of the key K being discontinued, then the outer end i, k, of the
latch or bolt I descends, so that the notch f catches into the stud 9 in order to
detain the latch or bolt I exactly in the position, Figure 3, in opposition to the
reaction of the spring S, as already explained, and the parts will remain in that
position after the action on the knobs or handle E, or on the key K, is wholly
discontinued, and after the key is withdrawn. But the parts being in the said
position, Figure 3, are ready for latching by self-action or spring action on the
final closing of the door, so as to fasten the same, as already explained. The
knob handle E is fastened on a square at the end of an axis or spindle v, which
passes through a round hole in the back plate C to the interior of the latch,
and a leaf or bit H, called the follower, projects out from the axis v, with
steps like those on the bit of a key, formed in a suitable manner for acting
against the tumblers G, and one of the talons t, of the bolt I, when the knob
handle E is turned partly round-with a similar action to that of the bit of a

page_text: key, except that the action against the tumblers is nearer to their centre of.
motion h, and the talon t is nearer to the end of the latch or bolt I than is
usual for the action of a key. The axis v is hollow like the pipe of a key,
and fits upon a fixed centre pin which projects out from the cover plate B, as
shewn by dotted lines Fig. 2, so. as to serve for the centre of motion of the
follower H. And note, the use of the keyhole a, Fig. 1, through the back
plate C, at the inside of the door, is for inserting the key K. for the purpose of
throwing the latch or bolt I an additional shoot beyond the position Fig. 1,
the bit of the key then acting against another talon which is formed in the
bolt for that purpose, as shewn by dotted lines between the talons t and w, as
before mentioned, all which is in the usual. and well-known manner of
adapting a bolt for being double locked by two successive turns of the key.
And also the tumblers G have their horizontal notches prolonged, with.
transverse notches sy at the ends, for catching and interlocking the stump m
when the latch or bolt I is thrown out, by means of the key, to the full extent.
of the said additional shoot, and then the talon t comes into such a position in
respect to the follower H that the latch or bolt I cannot be withdrawn from
that additional shoot by means of the knob-handle E, but only by means of the
key. And note, the said additional shooting of the latch or bolt I by the key'
can be performed from the outside of the door as well as from the inside, but:
when performed in either way the outer end i, k, of the latch or bolt enters
into the whole depth of the hollow in the hasp J, and renders the fastening of
the door very secure. The lever R comes to rest against a fixed stop pin'
when the latch or bolt has made its said additional shoot, so as then to have
no effect on the latch or bolt for giving any self-action or spring action thereto.
The said additional shooting of the latch or bolt I is no part of our present.
improvements, but by the circumstance of the latch or bolt I being securely
retained by its stump in interlocking into the transverse notches-z of the
tumblers G when the latch or bolt has latched of itself (or made its own shoot
by self-action or spring action) at the final closing of the door, as already'
described, all the security of a good tumbler lock is obtained by a latch which
is constructed according to this part of our improvements. And note, the
said additional shooting of the latch or bolt I is not a necessary part of the
latch Figures 1, 2, and 3, for the same may be made without any keyhole a at
5 the inside, and the tumblers g may be made without the aforesaid prolongation
of their horizontal notches G or any transvers notches y at the ends of those
prolongations; and it is when so constructed that it is properly called a latch
constructed according to part of our improvements, because it has the pro-
perties of a latch, videlicet, that it will latch of itself by self-action or spring

page_text: action in consequence of the end of its latch or bolt I being lifted up (when
the door is nearly closed) by action of the extreme end P of the latch or
bolt I against the fixed inclined plane or curve 9 of the hasp J, and, in
consequence of the reaction of its spring S being allowed to operate at the
final closing of the door, the latch or bolt will then shoot out suddenly, and
carry its outer end into the hollow of the hasp J for fastening the door; but,
by virtue of this part of our improvements, the latch or bolt, after so shooting
out of itself, will be securely detained by the tumblers G from being forced
back or from being withdrawn, except by aid of the key from the outside of
the door, or by turning the knob handle E at the inside thereof; but when
constructed as represented in Figures 1, 2, and 3, so as to be capable of an
additional shoot of the latch or bolt by means of the key, that is, with the
inside keyhole a, and additional transverse notches y in the tumblers G, and
an additional talon to the latch or bolt, as already described, then it is more
properly called a latch lock constructed according to this part of our improve-
ments (although, as already stated, that additional shooting forms part of our
improvements), because the double shooting of the latch or bolt, and the
security resulting therefrom, is performed by the key only, in the manner of
double shooting the bolt of a lock, without any of the self-action or spring
action which takes place in a latch. Note also, that the latch or latch lock,
Figures 1, 2, and 3, is represented with what is called a detector Z applied to
its latch or bolt, according to another part of our improvements herein-after
described, but such defector, although an additional security, is not a necessary
part, and may be omitted or introduced as may be preferred; V, Figure 2, is
a small finger knob at the outside of the back plate C (inside the door) for
giving motion to a cross bolt W, Figure 1, within the box or case of the latch
so as to catch into a notch in the under edge of the latch or bolt I for
detaining the same in the position Figure 3 when required.
Figures 4, 5, 6, and 7, Sheet I., represent another latch constructed
according to part of our improvements, Fig. 4 being an elevation with the
cover plate removed. Fig. 5 a section viewed from beneath, and Figures 6
and 7 are elevations, shewing different positions of the interior parts. The
same letters being used, as in Figures 1, 2, and 3, for reference to parts which
are similar or corresponding in the two latches, part of the preceding descrip-
tion will apply to the present Figures, viz, the rim A, cover plate B, back 3
plate C, the knob handle E at the inside of the door, with its axis v, and
follower H, the tumblers G with their fixed centre pin h, and springs 1, the
latch or bolt I, with its spring S and lever R on the fixed centre pin 1. The
outer end of the latch or bolt I is bevilled as represented in Fig. 5, and the

page_text: ก
fixed hasp J has an inclined plane or curve q, called a striking plate, with
which the bevilled end of the latch or bolt I comes in contact when the
door is nearly closed, so that by oblique action of p against q the latch or bolt
I will be pushed back, as shewn in Fig. 7, in opposition to the force of its
spring S, until the final closing of the door, when the bevilled end p of the.
latch or bolt, having passed by the fixed inclined plane or curve q, the latch or
bolt will then shoot suddenly out by self-action or spring action, so as to insert
its outer end into the hollow of the hasp J, and thereby fasten the door; and
when it is required to open the door from the inside, then, by turning the knob.
bandle E round in the proper direction, its follower I will act against the
talon t at the end of the latch or bolt T, so as to draw the same back in
opposition to its spring S into the position Fig. 7, and then it will permit the
door to be opened; or, in like manner, to open the door from the outside, the
key K, being inserted through the keyhole in the door and in the cover plate
B, as shown in Fig. 5, and turned round in the proper direction, the bit of the
key will act against another talon w of the latch or bolt I, to draw the same
back to the position Fig. 7. And note, the key K is made with a pipe to fit
upon a pin a, which projects out from the back plate C, and serves for the
centre of motion of the key which is not adapted to be inserted from the
inside of the door. And note, in case of the latch, Figures 1, 2, and 3, being.
constructed without the means of making the additional shoot already described,
it will not have any keyhole at the inside of the door, but only a keyhole at
the outside, and then the key may be made with a pipe to fit upon a fixed
centre pin projecting out from the back plate C, and thus far the aforesaid
operation of the latch, Figures 4, 5, 6, and 7, is as usual in ordinary latches,
wherein the latch or bolt I, when it is shot out, as in Fig. 4, by self-action
or spring action (for fastening the door) is not detained in that position by any
other means than by the force of the spring S for preventing it from being forced
or drawn back to the said position, Fig. 7, which will allow the door to be opened.
But according to this part of our improvements, the transverse notches in the
tumbler G interlock the stump m of the latch or bolt I, so as to detain it in
that position to which it has been shot out by its own self-action or spring.
action for fastening the door, and the latch or bolt I cannot be forced back or
drawn back to the position, Fig. 7 (so as to permit the door to be opened),
unless all the several tumblers G are brought with their horizontal notches to
coincide one with another and with the stump m, which may be done either by
turning the knob handle E at the inside of the door, or by inserting the key K
into the keybole at the outside of the door, and then turning the key, but
cannot be done by picklock or false keys. In the section, Fig. 5, fiyo tumblers,

page_text: G, appear side by side one behind another, but in fact there are only four
operative tumblers, and they are coloured orange, because that one Q,
Figures 5, 6, 7, which is next to the latch or bolt I, although it resembles the
others, does not act in the usual manner of a real tumbler, and it may be
more properly termed a detent Q; it is coloured yellow in the Figures, and it
has no spring applied to it, but, instead thereof, the detent Q has a spring S
applied to press against the extreme end of it, as shewn in Figures 4, 6, and 7,
in order to cause friction, and thereby keep the detent Q steady, without
moving from the position that may be given to it either by action of the stump
m of the latch or bolt I, when that stump is moving in the notch which is cut
through the detent Q, as seen in Figs. 6 and 7, or at other times by the.
bit d of the key K, or of the follower H, acting beneath the lower edge of the
detent so as to lift the same in like manner as a tumbler is lifted. For
instance, suppose the latch or bolt I is in the act of being drawn back to the
position Fig. 7, either by turning the knob handle E and follower H, or else
by turning the key K in a proper direction, whereby the bit of the follower H,
or of the key K, acts beneath the lower edges of the several tumblers G to lift
each one to its proper intended height, and also acts against the talon t or w of
the latch or bolt, for so drawing it back, and likewise the same bit, by acting
against the lower edges of the detent Q, lifts the same up about the centre of
motion h, and when the latch or bolt I is thus carried back to the position,
Figure 7, the door can be opened, and then the action on the knob handle E
and follower H, or on the key K, being discontinued, the latch or bolt
I will begin to move outwards again by reaction of its spring S, and the
talon t or w, then acting against the follower H or the key K, will turn
the follower or the key, which in. so. turning will act beneath the lower
edge of the detent Q at n or at o, so as to lift the detent Q up to the.
position Fig. 6, by the same time that the latch or bolt I has arrived at the.
position shewn in that Figure, and also in Fig. 4, when the stump m will be
intercepted by the catching part c of the notch in the detent Q, so as to s
prevent the latch or bolt I shooting any farther out, and it will continue in
that position, Figures 4 or 6, so long as the door continues open; but when
the door is nearly shut, then the bevilled end p of the latch or bolt I will come
into contact with the fixed inclined plane or curve 7 of the striking plate or
hasp J, so as by oblique action of such contact in the further closing of the s
door to push back the latch or bolt I to the position Fig. 7, and the stump m,
acting above the part e of the notch in the detent Q, forces the same down to
the position there shewn. After which, when the door is completely closed,
the latch or bolt I shoots suddenly outwards by self-action or spring action,

page_text: with its outer end far into the hollow of the hasp J for fastening the door, and
in so shooting outwards the latch or bolt I moves as inuch farther than the
position Fig. 4 as to carry the stump m opposite to the transverse notches
of the several tumblers G, which thereupon fall by action of their respective
springs, in order to interlock the stump m within the said transverse notches
, and thereby secure the latch or bolt I against being forced back or with-
drawn, or the door opened, until the tumblers G are lifted to the proper.
intended height for cach one, which (as already mentioned) can be done, and
the latch or bolt I withdrawn to the position Fig. 7 for opening the door,
either by turning the knob handle E at the inside of the door, or cise by
inserting the key K at the outside and turning it round, but cannot be done
by picklock or false keys. Note, when the latch or bolt I shoots farther out
than shewn in Fig. 4, as aforesaid, the catching part c of the notch in the
detent Qoffers no impediment to the motion of the stump m, because.
the detent Q continues in the position shewn in Fig. 7. The key K cannot
be turned all round in the latch, Figures 4, 5, 6, and 7, which as there
represented is a latch constructed according to part of our improvements,
the latch or bolt I of which can be always withdrawn by turning the knob
handle E at the inside of the door, or by applying the key K at the
outside and turning it round. But in case it is desired to prevent the latch
or. bolt I being so withdrawn by the key K from the outside, there is a
cross bolt W, Fig. 4, which, by means of a finger knob V, Fig. 5, at the
outside of the back plate c (inside the door), can be inserted into a suitable
notch in the upper edge of the latch or bolt I, so as to completely fasten
5 the same either from being withdrawn or else from being shot out, as may
be desired.
Figures 8 and 9, Shect II., represent another latch lock, constructed according.
to part of our improvements; and the same letters being used as in the fore-
going description for reference to similar or corresponding parts, it is unneces-
Osary to repeat the whole. The office performed, as already explained, by the
detent Q in Figures 4, 5, 6, and 7, is performed in Figures 8 and 9 by that
one of the tumblers which is adjacent to the latch or bolt I, and which is
shewn at Q, Fig. 9, the other tumblers G, Fig. 8, being removed from before
it. The tumbler Q has a projecting tooth u at its upper part, which tooth u
5 is adapted to be caught by the end of a spring catch s (the other end of which
is fixed to the back plate C), whenever the tumbler Q is lifted up, as shewn in
Fig. 9, so as to be a little higher than its true intended position as a tumbler,
(that said position being when its borizontal notch coincides with the stump m);
and when the tooth u is so caught by the spring catch s it prevents the tumbler

page_text: Qfrom descending again by reaction of its usual spring 1, until the spring
catch s is bended upwards so much as to let go the tooth u. The spring catch
s is situated opposite to a notch at the upper edge of the latch or bolt I, and
whenever the latch or bolt 1 is pushed back as far as it can go, then an inclined
parte of that notch will come to act beneath the end of the spring catch s, so
as to bend it upwards in order to let go the tooth u; but so long as the tooth u
remains caught by the end of the spring catch &, the tumbler Q will be held up
(as in Fig. 9) so much above its proper intended height as that the stump m
of the latch or bolt I will be intercepted by a catching part c in the notch of
the tumbler Q, so as to retain the latch or bolt I from shooting out any farther
than is represented in Fig. 9. But when the spring catch s is disengaged
from the tooth u, and the tumbler Q is therefore allowed to descend by reaction
of its spring to its proper intended position, then the catching part c will not
interfere with the stump m, and the latch or bolt I will be at liberty to shoot
farther out by self-action or spring action, so as to assume the position Fig. 8,
when the stump m having come opposite to the upper parts of the transverse
notches in the several tumblers G, they will descend by reaction of their
respective springs 1, so as to interlock the stump m into the said parts z, and
thereby the latch or bolt I will be prevented from being forced back or with-
drawn, unless each one of the several tumblers G is raised to its true intended
height, and no higher than that, as already explained respecting the other latches
and latch locks. The position, Fig. 8, is when the latch or bolt I is shot with its
bevilled end p out into the hollow of the hasp, suitably for fastening the door,
and the bolt or latch I can be withdrawn from that position, Fig. 8, either by
turning the follower H by means of its knob handle at the inside of the door
or by inserting the key K at the outside and turning it round. In either case
the bit of the follower H, or of the key K, will act beneath the lower edges of
the tumblers G to raise each one to its proper intended height for allowing the
stump m to move freely along within the horizontal notches in the tumblers G,
and then the said bit, coming to act against the talon t or wof the latch or bolt,
will draw the same back in opposition to its spring S, until the bevilled outer
end p of the latch or bolt I is wholly withdrawn from the hollow in the hasp,
and does not project beyond the end A of the rim, but allows the door to be.
opened. But note, when the bit of the follower or of the key had so with-
drawn the latch or bolt I some part of the way, it passed beneath a small
prominence at n, or at o, in the under edge of the tumbler Q. so as to overlift
that one tumbler Q beyond its proper height to the position Fig. 9, and
thereby cause its tooth 1 to be caught by the end of the spring catch s. After
the latch or bolt I has been wholly withdrawn, as aforesaid, and the door

page_text: opened, then the action on the knob-handle of the follower H or on the key
being discontinued, the latch or bolt I will shoot out again by the reaction of
its spring S, and whilst so shooting out the talon t or w, by re-acting against
the bit of the followor H or of the key K, will turn the follower or the key
round, and, in so turning, the said bit, passing beneath the prominences n or o,
Fig. 9, of the tumbler Q, will keep that tumbler raised (as there shewn.)
so that its tooth will be caught by the spring catch s, and then its catching
part c will intercept the stump m, thereby retaining the parts in the position
Fig. 9, so long as the door continues open; and when the door is nearly shut
the bevilled end p of the latch or bolt I coming in contact with the cor
responding fixed bevilled or inclined plano or curve on the striking plate or
hasp, the oblique action of such contact will force the latch or bolt back as far
as it can go a very little before the time when the door is completely closed,
and then at that time the latch or bolt I having passed by all the aforesaid
contact of its bevilled end p, with the corresponding fixed bevil of the striking
plate or hasp, the latch or bolt I will suddenly shoot out by self-action or
spring action, with its end into the hollow of the hasp, so as to fasten the door,
and assume the position Fig. 8, with the stump m securely interlocked into
the transverse notches of all the several tumblers G, and also of the
tumbler Q, for the latter became liberated from its spring catch when
the latch or bolt I was forced backed nearly as far as it can go, as aforesaid,
in consequence of the inclined part of the latch or bolt I then bending the
spring catch s so much upwards as to let go the tooth of the tumbler Q,
which being thereby left at liberty, and neither the bit of the follower H nor
of the key K being beneath cither of the prominences n or o, the tumbler Q
descended by reaction of its spring 1, and its catching part c, offered no impe-
diment to the motion of the stump m until the latter arrived beneath the
transverse notch of the tumbler Q, as well as of the other tumblers G, and
then they all descended, by reaction of their respective springs l, so as to
0 interlock the stump m, as appears in Fig. 8. And thus far the aforesaid
description of Figures 8 and 9 would be that of a latch, but those Figures
represent a latch lock because the horizontal notches in the tumblers G and Q
are prolonged, and have transverse notches y at the ends of the prolonged
notches for interlocking the stump m when the latch or bolt I is thrown
5 out an additional shoot by action of the key when turned round a second
turn, during which the bit of the key acted against another talon on the
latch or bolt I between the talons t and to, and after such additional shoot
of the latch or bolt I it becomes securely locked so that it cannot be with-
drawn by the follower II, and the talon t then assumes such a position

page_text: in respect to the follower H that the latter cannot be turned round, or
act at all for withdrawing the latch or bolt. The said second shooting of
the latch or bolt I, Figures 9 and 10, is nearly the same as already described
in reference to Figures 1, 2, and 3, but is no part of our improvements.
Figures 10 and 11, Sheet II., represent another latch constructed according
to part of our improvements, being nearly the same in its parts and their
mode of operation as Figures 8 and 9, but the latch, Figures 10 and 11,
is adapted for a drawer or till, and will fasten the same (with all the
security of a lock having several tumblers) by self-action or spring action,
when the drawer is closed without any assistance of the key K, which is only
required for withdrawing the latch or bolt, in order to open the drawer
or till. There is no knob handle or follower in Figures 10 and 11, and
only one set of transverse notches in the tumblers G and Q. The
tumbler Q, Fig. 11, which is nearest to the bolt I, has its catching place c,
projecting tooth u, and spring catch s, all the same as Figures 8 and 9,
and operating in the same manner as already described. Also the outer
end of the latch or bolt I, Figures 10 and 11, is bevilled, in order to
operate by oblique action against a corresponding fixed bevil on the striking
plate, so as to force back the latch or bolt I, in opposition to its spring S,
when the drawer or till is in the act of being shut, and the instant that it is
completely shut, then the latch or bolt I shoots out suddenly with its end into
the hole in the striking plate by self-action or spring action, for fastening the
'drawer or till, the latch or bolt I, when so shot out by self-action or spring
action, becoming secured by the tumblers in the manner already described, so
that it cannot be forced back or withdrawn except by action of the key K.
Also in Figures 10 and 11 the spring catch s is made to answer the double
purpose of such a catch and of a detector, which is newly applied, according
to another part of our improvement now to be described, and which may be
applied to the tumblers of locks of other kinds, as well as to those of latches
or latch locks.
İ
The object of that part of our improvements which relates more particularly
to locks (although applicable to such latches and latch locks as have tumblers)
is for giving greater security to the tumblers of such locks, latches, or latch
locks, by means of what is commonly termed a detector, which being applied
to the set of tumblers of a lock, then in case of any one of those tumblers
being overlifted or raised higher than its proper intended position during any
attempt to unlock such lock by the introduction of picklock or false keys,
the detector will come into action of itself to prevent one of the tumblers from
afterwards descending to its proper intended position, whereby the lock is

page_text: rendered more difficult to be picked or unlocked, in consequence of the said
action of the detector on that tumbler, and cannot be unlocked even by its
own key until a suitable manipulation has first been made with that key
for undetecting the lock and putting the detector out of action. The circum-
stance that the lock cannot be opened by its own key is information to the
person using that key that some attempt has been made to unlock the lock, by
introducing some kind of picklock or false key. Detector locks were originally
invented by my uncle, Jeremiah Chubb, who obtained Letters Patent
therefor, and were afterwards improved and brought into use by my late
father, Charles Chubb, under further Letters Patent granted to him, and the
detectors being subsequently simplified in construction and application, other
Letters Patent were granted therefor to him and to the said Ebenezer
Hunter, dated the Twentieth day of December, One thousand eight hundred
and thirty-three. Now this part of our present improvements relating to
detector locks is to dispose the detector above the tumblers, so as to operate
upon a projection at the upper part of one of the tumblers, the detector being
at the opposite side of the tumblers to that side thereof where the key operates
for lifting the tumbler, so that no instrument that can be introduced at the
keyhole can be inade to reach the detector for undetecting the same; whereas,
according to the same former Letters Patent of Charles Chubb and Ebenezer
Hunter, the detector was applied at the ends of the tumblers farthest from
their centre of motion, and operated upon projections from those ends, and the
detector in that situation was too near the keyhole to be perfectly secure from
being reached by some instrument introduced into the keyhole.
Figures 12 and 18, Sheet II., represent a tumbler lock with a detector Z
applied to it, according to this part of our improvements, above the set of
tumblers G. One of the tumblers M, Fig. 18, which is near (or nearest) to
the bolt I of the lock has a projecting tooth j at its upper side and near that
end of the tumbler which is mounted on the fixed centre pin h, which tooth j
is adapted to be caught by the end of the detector spring Z whenever the
tumbler M is overlifted above its proper intended height, and then the
catching of the tooth j, by the end of the spring Z, prevents the tumbler M.
descending again by reaction of its spring 1, but it will be retained per-
manently in its overlifted state, as shewn in Fig. 18, so as to keep the
stump m of the bolt I interlocked in the lower part of the transverse notch z
of the tumbler M, and thereby prevent the bolt I from being withdrawn, in
which state the lock is said to be detected, and it cannot be unlocked, even by
its own key K, because that can have no action whatever on the overlifted
tumbler M, which is detained in that state by the detector Z; and in

page_text: order that the lock may become so detected in case of any other of the
tumblers, instead of M, being so overlifted, the said tumbler M (in
addition to having the aforesaid projecting tooth j) has also a small pin Y
fastened into it, and projecting forwards from it over the upper edges of
all the other tumblers G (see Fig. 12), and therefore, if any one of those
tumblers is overlifted (as, for instance, by action of a picklock or false
key) then the upper edge of that tumbler which is so overlifted will
come into contact with the said pin Y, and by raising the same upwards
will overlift the tumbler M, into which that pin is fastened, so that the project-
ing tooth of the said tumbler will be caught by the end of the detector spring
Z in the same manner as if the said tumbler M had been itself overlifted by
action of the said picklock or false key. Wherefore any one of the tumblers
G or M of the set wherewith the lock is provided being overlifted will cause
the lock to become detected. And note, the said pin Y, and the manner of
its operation as aforesaid, is no part of our present improvements, being the
same as in Chubb and Hunter's former Patent aforesaid; and in order to
undetect the lock when it is found that its own proper key K will not unlock
it, and it is thereby made known that the lock has become detected, in conse-
quence of some attempt having been made to use a picklock or false key, then
the true key K, which cannot in such case be turned round in the proper
direction for unlocking, must be turned round the contrary way as if for double
locking the bolt L, by giving an additional shoot thereto, and then the bit of
the key K will come to act against another talon of the bolt I so as to urge
the same outwards; and the several steps of the key K having lifter each of
the tumblers to its proper intended height, the stump m will be at liberty to
move into the prolongation U of the horizontal notches of the several tumblers
G, so as to permit the bolt I to be moved outwards a little further than
appears in Figures 12 and 13, for the purpose of undetecting the lock. And
note, the said prolongation U in the tumbler M, Fig. 13, is so wide as to leave
the stump m at liberty to move forwards as aforesaid, although that tumbler 5
M continues in its overlifted state. And the said moving forwards of the bolt
I causes the lock to be undetected by means of a small inclined part L at the
upper edge of the bolt I acting beneath the extreme end of the detector
spring Z, when the bolt I moves forwards as aforesaid, so as to lift the detector
Z sufficiently upwards to disengage its catching end from the tooth j of the s
tumbler M, which thereupon descends by reaction of its spring 1, leaving the
lock undetected and ready to be unlocked by the usual action of the key K.
And note, the aforesaid mode of undetecting the lock is no part of our
improvements, except as regards the position of the inclined part L at the

page_text: upper edge of the bolt I, to correspond with the position of the detector spring
Z, and of the tooth j of the tumbler M, which parts Z, j, and L, according to
Chubb and Hunter's former Patent aforesaid, were disposed opposite to the
end of the tumblers, but the new position in which they are applied according
to this part of our present improvements gives an increased security by
rendering the detector Z wholly inaccessible from the keyhole.
Figures 14 and 15, Sheet II., shew a small padlock with tumblers, and a
detector Z applied above them. It is drawn the real size, and shows how the
detector spring Z may be disposed with its fixed end towards the inner end of
the bolt I, the catching end of the spring % being in such case a hook, adapted
to catch the toothj, which projects up from the tumbler M. The operation is
the same as alreadly described, that hooked end of the detector Z being
adapted to be lifted up by an inclined part of the upper edge of the bolt I
when the same is shot forwards for undetecting the lock. The hooked
detector spring Z, as in Figures 14 and 15, may be applied to large locks as
well as to small.
The latch or latch lock, Figs. 1, 2, and 3, Sheet I., is represented with a
detector spring Z applied to its tumbler M, Fig. 3. The foregoing descrip-
tion of the detector in Figs. 12 and 13 will apply to the detector Fig. 1, 2,
and 3. And it has been already mentioned respecting the latch, Figures 10
and 11, that the spring catch s therein answers the double purpose of a
spring catch (as previously described), and also the purpose of a detector. The
construction of the said spring catch s, Figures 10 and 11, and the manner of
its catching a tooth u which projects out from the tumbler Q, is very similar
to the detector spring Z and tooth j of the tumbler M, Figure 13, and so the
mode of removing the spring catch s, Figures 10 and 11, in order to let go
that tooth by action of an inclined part e of the latch or bolt I acting to bend
the spring catch s when the bolt moves endway is similar to the action of
bending the detector spring Z, Figure 13, by action of the inclined part L of
the bolt I, wherefore the parts and their operation being so similar they can
perform the double purpose aforesaid. And the said two purposes cannot
interfere one with another, because the spring catch s, Figures 10 and 11
(as previously described), is only required to be operative when the latch
or bolt I of the latch is drawn back, or is only partly shot forwards, as
appears in Figure 11, when the stump m not interlocked into the transverse
notches Z of the tumblers; whereas the defector spring Z is only required
to be operative when the latch bolt I is shot out to its full extent for fastening
the door, and the stump m is interlocked in the transverse notches z, as appears
in Figure 12. The tumbler Q, Figure 11, which has the projecting tooth u

page_text: for being caught by the end of the spring catch s, answers in every respect to
the tumbler M, Figure 18, and has like that a pin similar to Y, Figure 18,
projecting out from it for the same purpose of causing the latch, Figures
10 and 11, to become detected when any one of its tumblers G or Q is over-
lifted. The bolt or latch I, Figs. 10 and 11, has an inclined part L, the same
as the bolt I, Fig. 13, for the purpose of undetecting that part L, being
brought into contact with the spring catchs (which is also the detector spring),
when the latch or bolt I is thrown out somewhat further than the usual posi-
tion, Fig. 10, for the purpose of undetecting in the manner already explained,
and the notches of the tumblers G, Figures 10 and 11, are prolonged at U in
order to admit the stump m, when thrown further outwards than in Fig. 10,
for the purpose of undetecting. And note, our improvement herein-before
described in latches and latch locks are only applicable to those cases where
the outer end of the latch is bevilled suitably for being lifted up (as in Figures
1, 2, and 3), when the door is in the act of shutting, such lifting up being
caused by oblique action against a fixed inclined plane or curve on the hasp
or striking plate, or else the outer end of the latch or bolt being bevilled
suitably for being pushed back edways (as in Figures 4, 5, 6, and 7, Figures
8 and 9, and Figures 10 and 11), when the door or drawer or till is in the act of.
shutting, such pushing back being caused by oblique action of the said bevilled
end against a fixed inclined plane or curve on the hasp or striking plate.
. Having now described our said improvements, I, the said John Chubb, for
myself, and for the said Ebenezer Hunter, do hereby declare that the new
Invention, whereof the exlusive use is granted to us by the Letters Patent
herein-before recited, consists in the following particulars :-
First, the improvement herein-before described in reference to Figures
1, 2, and 3, Figures 4, 5, 6, and 7, Figures 8 and 9, also Figures 10 and 11,
in latches and latch locks, whereof the outer end of the latch or bolt is
bevilled suitably for being lifted up (as in Figures 1, 2, and 3), or for being.
pushed back endways (as in Figures 4, 5, 6, and 7, Figures 8 and 9, also
Figures 10 and 11) by oblique action of such bevilled outer end against a
fixed inclined plane or curve on the basp or striking plate when the door
or drawer or till or other moveable (to which the latch or latch lock is
applied) is in the act of shutting; the nature of the improvement being that
when the latch or bolt, after having been so lifted or pushed back by oblique
action as aforesaid, and then shoots out suddenly by self-action or spring
action at the final closing of the door, drawer, or till, or other moveable, for
fastening the same as usual in ordinary latches and latch locks, that the latch
.or bolt shall by virtue of the improvement become securely detained by means

page_text: of tumblers, which will prevent it from being withdrawn or forced back, and
thereby will prevent the door, drawer, till, or other moveable being opened;
those tumblers coming into operation of themselves in the manner and by
the means herein-before described at the time of the said sudden shooting
out of the latch or bolt by self-action or spring action aforesaid, without
requiring any use of a key or other manipulation for bringing the tumblers
into operation.
Secondly, the improvement herein-before described in reference to Figures
12 and 13, and Figures 14 and 15, in detector locks, also applicable to latches
or latch locks, of applying a detector spring of the kind herein-before described
at that side of the tumblers which is most remote from the keyhole, in order
to render such detector spring wholly inaccessible to any instruments which
can be introduced at the key whole.
Thirdly, the improvement hercin-before described in reference to Figures
10 and 11, in latches or latch locks, whereby some of the same parts which
operate to produce the first improvement in the latch or latch lock, as herein-
before described viz., (the spring catch s and tooth u and incline e, Figures
10 and 11), also serve the double purpose of a detector applied according to
the second improvement, so as to obtain the advantages of both the first and
the second improvements combined together without any additional parts
beyond such as would be required for performing either the first or the second
improvements alone without the other.
In witness whereof, I, the said John Chubb, for myself and for the said
Ebenezer Hunter, have hereunto set my hand and seal, this Tenth day
of July, One thousand eight hundred and forty-seven.
JOHN (L.s.) CHUBB.
AND BE IT REMEMBERED, that on the Tenth day of July, in the
eleventh year of the reign of Her Majesty Queen Victoria, the said John
Chubb came before our said Lady Queen in Her Chenor and coknowledmod
Inrolled the Tenth day of July, One thousand eight hundred and forty-
seven.