IMPROVEMENTS IN LOCKS AND LATCHES
Year: 1875

page_text: LETTERS PATENT to Charles Aubin, of Wolverhampton, in the
County of Stafford, Manufacturer, and John Frederic Wright, of
Wolverhampton aforesaid, Manufacturer, for the Invention of
"IMPROVEMENTS IN LOCKS AND LATCHES:"
.
* IMPROVEMENTS IN LOCKS AND LATCHES:"
Sealed the 26th October 1875, and dated the 4th August 1875.
PROVISIONAL SPECIFICATION left by the said Charles Aubin and
John Frederic Wright at the Office of the Commissioners of
Patents, with their Petition, on the 4th August 1875.
We, CHARLES AUBIN, of Wolverhampton, in the County of Stafford,
Manufacturer, and JOHN FREDERIC WRIGHT, of Wolverhampton afore-
said, Manufacturer, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN LOCKS AND LATCHES," to be as follows:-

page_text: In constructing according to Our invention Combined TOCAS au
latches for prisons and places where it is wished to prevent tampering
with the bolt or latch by the introduction of something into the staple,
we construct and arrange the parts as follows:-
The latch bolt is shot forward by a mainspring in the usual way, the
said latch bolt being retained in its withdrawn position by a spring, a
shoulder on which engages against a shoulder on the bolt. The end of
the said spring is turned at right angles and projects from the lock case.
When the door is closed the projecting end of the spring is pressed
inwards. The latch bolt is thereby disengaged from the retaining
spring when it is urged forward by the mainspring and bolts the door.
The lower edge of the bolt is provided with a series of depressions, the
last only of which is of sufficient depth to allow a latch bolt in the
secondary or warder's lock to advance sufficiently to permit the locking
of the said warder's lock, the said latch bolt, when in a partly shot
position limiting the motion of the small locking bolt. When, however,
the latch bolt is fully shot, the deep depression in its rear end being
opposite the end of the bolt of the warder's lock, the last named bolt
can be shot, and engaging behind a projection on the said latch bolt,
prevents its return. Hence when any obstruction is placed in the staple
the principal bolt cannot, on the shutting of the door, enter the staple
sufficiently far to enable the warder to turn the key of the warder's
lock, and he thereby discovers that some obstruction has been placed in
the staple. He is further informed of the obstruction by the position of
the handle of the lock.
In addition to the warder's lock there is a governor's lock, by which
the keyhole of the warder's lock can be covered or uncovered by the
governor.
In order to present a passage to the key through a solid block or
mass of metal to isolate the keyhole from the locking parts of the
lock and thereby frustrate the attempts sometimes made to injure the
interior of the lock by means of acids or by mechanical means, we
adopt the following arrangement:-We make the key-hole in a solid
block or curtain of metal, which is turned by the turning of the key.
A pin on the back of this curtain passes through a curved slot in a
fixed metal plate which isolates the other parts of the lock from the
curtain. The said pin engages in a slot in a tumbler at the back of the

page_text: isolating plate described, the slot in the tumbler crossing that in the
isolating plate. On turning the key through a certain angle the
tumbler described is raised until a keyhole in it is raised so as to
coincide with a keyhole in the isolating plate, this compound keyhole
making a considerable angle with the keyhole in the curtain. By
now pushing the key it can be made to pass through the compound key-
hole described and operate upon the lock in the usual way.
In order to increase the safety of locks in which the bolts engage in a
slot, in a plate, or in a staple, we so construct the bolt that when it is
partly shot its ends open out and engage in the slot or staple by a
hooking action. By this means the separation of the bolts from the
plate or staple by the insertion of a wedge or other like instrument
between them is prevented, as it is only on the withdrawal of the bolt
from the staple by the action of the key that the expanded end of the
bolt collapses sufficiently to allow its withdrawal. To effect this the
bolt is made of two similar flat plates with hooked ends. These plates
are placed on one another in a reversed position and turn upon a pin at
their rear end. When closed they constitute virtually a bolt of the
ordinary shape, that is, with a square end. On the lock plate is a pin
which engages in a slot in each of the bolt plates. These slots run
along the middle of the plates for the greater part of their length, but
their inner ends are inclined one on one side and the other on the other
side. When the bolt is so far shot that the inclined parts of the slots
are brought to the pin on the lock plate the hooked ends of the plates
open out and act in the manner described.
In order to make an ordinary spring latch lock itself, so that it
cannot be pushed back except by acting on the knob on the inside of
the door, we insert a flat spring in a slot in the bolt, the said spring
carrying at its end an incline nearly coinciding with the incline on the
end of the bolt. This spring also carries a pin, which, when the bolt is
shot, falls into a hole in the lock case and thereby fixes the bolt until
by raising the spring the pin is withdrawn from the hole in the lock
case. To effect this we give the knob a slight swivelling action, so that
when the hand presses it in the direction proper to withdraw the bolt it
first acts upon the spring so as to withdraw the pin from the hole in the
lock plate. The further action of the hand withdraws the bolt.
In order to reduce the size of the key in stock locks and other locks
we dispense with the bit of the key and effect the shooting and with-

page_text: drawing of the bolt by means of a rotating disc or barrel working inside
the lock. The shank of the key has a slit which enables it when
introduced into the lock to engage with the disc or barrel described.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Charles Aubin and John Frederic Wright in the
Great Seal Patent Office on the 27th January 1876.
TO ALL TO WHOM THESE PRESENTS SHALL COME, wc, CHARLES
AUBIN, of Wolverhampton, in the County of Stafford, Manufacturer,
and JOHN FREDERIC WRIGHT, of Wolverhampton aforesaid, Manu-
facturer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fourth day of August, in the year
of our Lord One thousand eight hundred and seventy-five, in the
thirty-ninth year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto us, the said Charles Aubin and Jolin
Frederic Wright, Her special license that we, the said Charles
Aubin and John Frederic Wright, our executors, administrators, and
assigns, or such others as wc, the said Charles Aubin and John Frederic
Wright, our executors, administrators, and assigns, should at any
time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully
might make, use, exercise, and vend, within the United Kingdom
of Great Britain and Ireland, the Channel Islands, and Isle of Man,
an Invention for "IMPROVEMENTS IN LOCKS AND LATCHES," upon the con-
dition (amongst others) that we, the said Charles Aubin (and John
Frederic Wright, our executors or administrators, by an instrument in
writing under our or their hands and seals, or under the hand and
seal of one of us or them, should particularly describe and ascertain
the nature of the said Invention, and in what manner the same was
to be performed, and cause the same to be filed in the Great Seal
Patent Office within six calendar months next and immediately after
the date of the said Letters Patent.
NOW KNOW YE, that we, the said Charles Aubin and John Frederic

page_text: 1
De particularly described
and ascertained in and by the following statement thereof, that is to
say:-
Our Invention consists of the improvements herein-after described in
locks and latches, by which improvements greater security is obtained
than in locks and latches of the ordinary kind.
In constructing according to our Invention combined locks and
latches for prisons and places where it is wished to prevent tampering
with the bolt or latch by the introduction of something into the staple,
we construct and arrange the parts as follows:-
The latch bolt is shot forward by a mainspring in the usual way, the
said latch bolt being retained in its withdrawn position by a spring or
spring arm, a shoulder on which engages against a shoulder on the bolt.
The end of the said spring or spring arm is turned at right angles and
projects from the lock case. When the door is closed the projecting
end of the spring or spring arm is pressed inwards. The latch bolt is
thereby disengaged from the retaining spring or spring arm when it is
urged forward by the mainspring and bolts the door. The lower edge
of the plate of the bolt is provided with a series of depressions, the last
only of which is of sufficient depth to allow a latch bolt in the secondary
or warders' lock to advance sufficiently to permit the locking of the said
warders' lock, the said latch bolt when in a partly shot position limiting
the motion of the small locking bolt. When however the latch bolt is
fully shot the deep depression in its rear end being opposite the end of
the bolt of the warders' lock the last-named bolt can be shot, and
engaging behind a projection on the said latch bolt prevents its return.
Hence, when any obstruction is placed in the staple the principal bolt
cannot on the shutting of the door enter the staple sufficiently far to
enable the warder to turn the key of the warders' lock, and he thereby
discovers that some obstruction has been placed in the staple. He is
further informed of the obstruction by the position of the handle of the
1

page_text: Figure 1 represents in plan, the top plate being removed, a combined
lock and latch for prison doors and other doors constructed according to
our Invention, the latch bolt being represented in its withdrawn
position; Figure 2 represents the same with the latch_bolt in its shot
position, and the bolt of the warders' lock shot for preventing the
return of the said latch bolt; and Figure 3 represents a longitudinal
section of the lock and latch taken on the line A, B, of Figure 1.

page_text: so arranged with respect to the keyhole
of the warder's lock i that
the said keyhole n may at the will of the governor be covered or
uncovered by the said governor's lock.
When the parts of the combined lock and latch are in the respective
positions represented in Figure 1, the head of the spring latch of the
warder's lock is engaged with one of the notches or depressions / in the
main latch bolt a³, but the bolt m of the said warder's lock cannot be
shot to fasten the main latch bolt a² in consequence of the said spring
latch being itself unable to advance sufficiently far by its engagement
with one of the shallow notches or depressions h, a shoulder & on the
latch bolt coming against a shoulder m³ an the bolt m.
A like con-
dition of the parts of the lock obtains when the spring latch is
opposite any one of the other shallow notches or depressions h. When,
however, the main latch bolt a, a³, is fully shot (by releasing the
retaining arm d) into the position represented in Figure 2, the spring
latch is brought opposite the deep notch or depression hª in the said
latch bolt a, a. The spring latch 7, by now engaging with the deep
notch or depression ³, has advanced to such a distance as will permit
the bolt m of the warder's lock to advance sufficiently to lock the
main latch bolt a, a. When the bolt m of the warder's lock is shot by
the action of the key it engages behind the projection q on the under
side of the shot main latch bolt a and prevents its return (see Figure 2).
As the latch bolt a, a³, is shot its notches & act upon the curved nose of
the spring latch and press back the said latch.
By the foregoing description, reference being had to the accom-
panying Drawing, it will be understood that when any obstruction is
placed in the staple of the lock the main latch bolt a, a², cannot on the
shutting of the door enter the said staple sufficiently far to enable the
warder to turn the key of his lock, for it is not until the latch bolt a, a,
has been fully shot that the head of the spring latch is brought
opposite the deep depression or notch and enters the said depression
or notch and the shooting of the bolt m by the warder permitted. The
said warder thereby discovers that some obstruction has been placed in
the staple. The position of the handler on the follower of the latch
bolt a, a, by which the latch bolt may be withdrawn, also indicates the
position of the said main latch bolt a, a².
We do not limit ourselves to the position of the notches or de-
pressions 1, 2, as the said notches may be situated on the opposite edge

page_text: of the bolt to that represented. In this case the spring latch is situated
on the opposite side of the lock; and instead of using an independent
latch bolt the warder's bolt may carry a curved stud to engage with the
notched side of the latch bolt.
Our Invention consists further of the following improvements in
locks. In order to present a passage to the key through a solid block
or mass of metal to isolate the keyhole from the locking parts of the
lock, and thereby frustrate the attempts sometimes made to injure the
interior of the lock by means of acids or by mechanical means we adopt
the following arrangement:-We make the keyhole in a solid block or
curtain of metal, which is turned by the turning of the key. A pin on
the back of this curtain passes through a curved slot in a fixed metal
plate, which isolates the other parts of the lock from the curtain. The
said pin engages in a slot in a tumbler at the back of the isolating plate
described, the slot in the tumbler crossing that in the isolating plate.
On turning the key through a certain angle the tumbler described is
raised until a keyhole in it is raised so as to coincide with a keyhole in
the isolating plate, this compound keyhole making a considerable angle
with the keyhole in the lock case. By now pushing the key it can be
made to pass through the compound keyhole described and operate upon
the look in the usual
107

page_text: solid block or curtain of metal g (shown separately in Figure 8), in
which a keyhole / is made. In the top plate of the lock case is a key-
hole, which coincides with that in the curtain g when the latter is in
its normal position. This curtain or block g is capable of a partial
rotation on the plate e by the key. On the said curtain is a pin k
which works in a curved slot 1 (see Figures 6 and 7) in the fixed
isolating plate e, and on the under side of the said plate e is a tumbler m
turning on the centre m², and provided with a keyhole n. This tumbler
is conneeted by the pink to the curtain g so as to partake of the motion
of the said curtain. A spring p acting on the tumbler m causes the
said tumbler and the curtain g to which it is connected to take their
normal positions when at liberty to move; that is to say, when the parts
of the keyhole mechanism occupy the positions represented in Figures 6
and 7 the keyhole in the curtain is opposite the keyhole in the top
plate of the case, but the said keyholes h, i, make a considerable angle
with the keyhole f in the isolating plate e, and also with the keyhole c
of the lock mechanism. To lock or unlock the bolt the key is passed
through the keyhole and made to take into the keyhole in the
curtain g. By turning the key through the required angle the curtain g
is also turned or raised, and with it the tumbler m, and the keyholes h, n,
in the said curtain and tumbler respectively are made to coincide with
the keyhole fin the isolating plate. The three keyholes h, n, f, are thus
situated in the same line as the keyhole c of the lock, and by pushing
down the key it passes through the compound keyhole h, n, f, to the
keyhole c to operate upon the levers and bolt a in the usual way. On
withdrawing the key from the curtain g after the bolt has been shot or
withdrawn the said curtain takes its normal position by the action of
the spring of the tumbler m, and the keyhole f in the isolating
plate e is closed, and access to the lock mechanism through the keyhole
thus cut off.
Our Invention consists further of the following improvements in
locks In order to increase the safety of locks in which the bolts
engage in a slot in a plate or in a staple, we so construct the bolt that when
it is partly shot its ends open out and engage in the slot or staple by a
hooking action. By this means the separation of the bolts from the
plate or staple by the insertion of a wedge or other like instrument
between them is prevented, as it is only on the withdrawal of the bolt

page_text: bolt collapses sufficiently to allow its withdrawal. To effect this the bolt
is made of two similar flat plates with hooked ends. These plates are
placed on one another in a reversed position, and turn upon a pin at
their rear ends. When closed they constitute virtually a bolt of the
ordinary shape, that is, with a square end. On the lock plate is a pin
which engages in a slot in each of the bolt plates; these slots run along
the middle of the plates for the greater part of their length, but their
inner ends are inclined one on one side and the other on the other side.
When the bolt is so far shot that the inclined parts of the slots are
brought to the pin on the lock plate, the hooked ends of the plates open
out and act in the manner described.
A lock constructed according to this part of our Invention is re-
presented in elevation with the bolt withdrawn in Figure 9, and with
the bolt shot in Figure 10; Figure 11 represents the two parts of the
bolt detached. a, b, are the two nearly similar plates constituting the
bolt, the said plates having hooked ends turned in opposite directions.
The rear ends of the plates a, b, are jointed together at c, and they are
guided in their rectilinear motion by the pins or studs d, e, on the lock
case, the pin d working in a slot in the bottom plate a of the bolt,
and the pine working in a slot a², b², in each of the plates a, b. Each
of the said slots a², b², is partly straight and partly inclined, the inner
inclined parts of the said slots having the positions with respect to one
another represented in Figure 11. When the two plates a, b, are closed
as represented in Figure 9, they virtually constitute a single bolt of the
ordinary shape, but when the bolt is shot forward by the key acting on
the lower plate thereof, and the inclined parts of the slots a², b², are
brought to the pin e on the lock case, the further motion of the bolt
causes the hooked ends of the plates a, b, to open out and engage with
the slot in the staple plate has represented in Figure 10. By this
hooking of the bolt to the staple plate the pushing back of the bolt by
the insertion of a wedge between the parts of the bolt is prevented. On
withdrawing the bolt from the staple plate the first motion of the said
bolt causes the pin e and inclined parts of the slots a², b³, to collapse the
expanded hooked ends of the plates a, b, of the bolt to permit of their
withdrawal from the staple plate 7, and on the further motion of the bolt
thic two plates move together as one bolt as seen in Figure 9. In
Figure 10 the lever or levers of the lock are omitted in order the better
to exhibit the expanding action of the two parts or plates of the bolt.

page_text: as indicated in dotted lines in Figure 13. The fork c of the knob
spindle acting through the pin on the spring arm lifts the said spring
arm and withdraws its pin e from the lock case and releases the bolt, and
the further action of the hand withdraws the said bolt. On removing
the hand from the knob c the mainspring i shoots the bolt a, the
spring & bringing the spring arm into its normal or locking position,
and the several parts resume the respective positions represented in the
Drawing.
Having now described the nature of our Invention and the manner
in which the same is to be performed, we wish it to be understood that
we do not limit ourselves to the precise details herein described and
illustrated, as the same may be varied without departing from the
nature of our Invention; but we claim as our Invention of improve-
ments in locks and latches,-
First. The improvements in combined locks and latches herein-before
described and illustrated in Figures 1, 2, and 3 of the accompanying
Drawings, that is to say, the construction and combination of the parts
of mechanism described and illustrated for preventing the shooting of
the warder's lock until the main latch bolt has been fully shot into its
staple and indicating when the said main latch bolt has been tampered
with by the introduction of something into the staple of the latch
bolt.
Second. The combination with locks of the mechanism herein-before
described and represented in Figures 4, 5, 6, and 7 of the accompanying
Drawings for isolating the lock mechanism from the keyhole.
Thirdly. The construction and combination of the parts of lock bolts
herein before described and illustrated in Figures 9, 10, and 11 of the
accompanying Drawings, that is to say, making the lock bolt of two
plates jointed together, and having hooked ends and causing the said
hooked ends on the shooting of the bolt to open out and engage with
the staple or staple plate, substantially as described and illustrated.
Lastly. The improvements in spring latches herein-before described
and illustrated in Figures 12 and 13 of the accompanying Drawings,
that is to say, the addition to the latch of a spring or spring arm and
parts connected therewith, substantially as described and illustrated, for

page_text: In witness whereof, we, the said Charles Aubin and John Frederic
Wright, have hereunto set our hands and seals, this Twenty-
fifth day of January, in the year of our Lord One thousand eight
hundred and seventy-six.
Witness,
GEORGE SHAW.
CHARLES AUBIN.
(L.S.)
JOHN FREDERIC WRIGHT. (L.S.)