Improvements in Locks and Latches.
Year: 1893

page_text: Date of Application, 15th Sept., 1893
Complete Specification Left, 12th June, 1894-Accepted, 4th Aug., 1894
PROVISIONAL SPECIFICATION.
Improvements in Locks and Latches.
I HUNTER HENRY MURDOCH of Hastings in the Provincial District of
Hawke's Bay in the Colony of New Zealand Patent Agent do hereby declare the
nature of this invention to be as follows:-
My invention relates to door-locks and latches and to box desk and drawer locks
its objects being to simplify the construction of such locks and latches and to
render them less liable to get out of order.
In locks and latches of the ordinary construction the bolt is actuated by a spring
which is apt to break and thus render the lock useless. Now the main principle
of my invention consists in doing away with this spring and so constructing the
lock that the bolt or latch shall he actuated by gravity.
In constructing mortise and other door locks and latches according to my
invention I do away with the locking bolt and the spring by which it is actuated
and I so arrange the snap-bolt or latch as to render it capable of being locked as
required by means of the devices hereinafter described and I actuate the said bolt
by means of a bell-crank lever turning on a pin or fulerum preferably in the lower
rear corner of the lock-case the horizontal arm of which lever constitutes a counter-
balance the vertical arm engaging with the bolt so as to push it forward its
withdrawal being effected by the usual handle spindle and lever or "follower."
At the fore end of the counterbalance aforesaid and at the underside thereof is a
recess in which are two horizontal projections or catches one or other of which
engages with corresponding T shaped projections or catches formed on sliding
plates (hereinafter termed "locking-plates") a space or "gating" being formed
between the catches on the counterbalance to admit the catches on the said
locking-plates.
The said locking-plates (which are prevented from rising by cross-pins or bars)
are pushed backward and forward by means of a key having bits or steps like those
of the key of a lever lock which bits on the turning of the said key act upon
vertical projections or horns two of which are formed upon each plate and at
such distances apart that on the key which works between them being turned
a quarter of a revolution forward the slides shall be pushed forward so that their
catches shall engage with the fore-catch on the counterbalance and that when the
said key is turned a quarter of a revolution backward the said catches shall be
disengaged and stand in a line above the "gating" between the catches on the
counterbalance so as to allow the latter to rise and fall. The horns aforesaid
are at different distances from the axis of the key and the steps or bits of the key
are cut accordingly so that if a false key not having bits exactly corresponding
with the said horns were introduced it would either fail to draw back the locking-
plates sufficiently far to disengage their catches from the fore-catch on the
counterbalance or it would draw the said plates too far so that their catches
(or some one or more of them) would engage with the rear catch on the said
counterbalance.
A flat spring or a packing-strip of india-rubber or leather is or may be
interposed between one of the sides of the lock-case and the adjacent locking-
plate so as to cause sufficient friction to retain the locking plates in their
required positions.
From this description it will be seen that the locking mechanism is somewhat
similar in principle and action to that of a lover or tumbler lock sliding

page_text: locking-plates being substituted for levers or tumblers. A suitable recess is
formed in the underside of the counterbalance to afford space for the locking-
plates.
Instead of actuating the locking-plates by means of an ordinary key they may
be so constructed as to he actuated by means of a key consisting of a flat plate of
metal having suitable steps or bits cut thereon the shank of the key being at right
angles to the said plate and sliding in a vertical slot which with horizontal slots
above and below it forms the key-hole. In this case the horns of the locking-
plates have suitable inclines formed on them against which the bits of the key press
as it is slidden up or down so as to cause the said plates to slide backward or
forward as required.
the same.
The foregoing arrangement may be modified in various ways the principle being
Thus according to one modification I substitute for the sliding snap-
bolt or latch an oscillating snap-bolt or latch made in one piece with the bell-crank
lever aforesaid and at the lower end of the vertical arm thereof the fulcrum or pin
on which this lever turns being in the upper fore corner of the lock-case and
locking mechanism of any of the kinds herein described being applied to the
horizontal arm of the said lever.
According to another modification I substitute for the sliding locking-plates
oscillating levers having on their upper ends double catches which engage with
corresponding catches on the under side of the counterbalance of the bell-crank
lever (which may be of either of the kinds described) or (in the case of a false key
being introduced) with other catches formed on the said lever. These levers turn
on two pins in the lower part of the lock-case one or more levers being mounted
on cach pin according to the degree of security required and are pressed forward
by springs their motion being limited by stops. Suitable inclines are formed upon
the opposed sides of the said levers which being acted upon by the bits of the key
which is a flat one sliding in a vertical slot as herein-before described the double
catches on the levers are brought opposite the "gatings" between the catches on
the counterbalance so as to allow it to rise.
When it is wished to retain the oscillating catches in this position so as to admit
of the bell-crank lever being worked merely by the "follower" on the spindle a
wedge is inserted in the vertical slot of the key-hole and under the key so as to
hold it in its raised position. Otherwise on the descent of the counterbalance its
catches would engage with the catches on the oscillating levers the acting parts of
the said catches being bevelled for this purpose.
According to another modification of my invention I substitute for the sliding
or the oscillating snap-bolt herein-before described a latch or bolt turuing on a
pin at its rear end like the latch of a rim lock or a Norfolk latch its fore end being
bevelled so as to ride over the incline of the hasp on the door jamb and its under-
side having the aforesaid catches which engage with locking mechanism of any of
the kinds described.
In constructing desk and box locks according to my invention I form on the
hasp which is screwed to the lid of the desk or box suitable catches which when
the said lid is shut down snap into or are otherwise caused to engage with the
catches on the locking-plates or on the levers herein-before described.
In constructing drawer-locks according to my invention I mount in the lower
part of the lock-case oscillating levers of the kind herein-before described the
upper ends of which levers (which are without catches) when pressed by their
springs into an inclined position bear against the under part of the bolt so as to
support it in its raised or locked position and I make in the said under part
corresponding vertical slots which when the said levers are by the action of the
key brought into a vertical position so as to coincide with the said slots allow the
said bolt to descend.
With this lock I prefer to use a key having at one end a flat plate which can
he slidden upward in the vertical slot of the key-hole so as to act upon the
underside of the bolt and thereby raise it. On the other end of the key is a flat

page_text: plate which is at right angles to the first-named plate and has steps formed upon
it which upon the key being slidden upward act upon the inclines on the levers and
thereby bring them into a line with the slots in the bolt.
Locks and latches constructed according to my invention are cheap are not
5 easily picked and are not liable to get out of order.
Dated this Seventh day of August 1893.
Improvements in Locks and Latches.
1, HUNTER HENRY MURDOCH of Hastings in the Provincial District of
Hawke's Bay in the Colony of New Zealand, Patent Agent do hereby declare the
nature of this invention and in what manner the same is to be performed to be
particularly described and ascertained in and by the following statement :-
My invention relates to door locks and latches and to box, desk and drawer
locks its objects being to simplify the construction of such locks and latches and to
render them less liable to get out of order.
In locks and latches of the ordinary construction the bolt is actuated by a spring
which is apt to break and thus render the lock useless. Now my invention consists
in doing away with this spring and so constructing the lock that the bolt or latch
shall be actuated by gravity the said bolt or latch being combined with locking
mechanism as herein-after described.
In constructing mortise and other locks and latches according to my invention
I do away with the locking-bolt and the spring by which it is actuated and I so
arrange the snap-bolt or latch as to render it capable of being locked as required
by means of a bell-crank lever mounted upon the spindle of the lock the horizontal
arm of which lever constitutes a counterbalance the vertical arm engaging with
the said bolt so as to push it forward its withdrawal being effected by turning the
knob or handle affixed upon the said spindle. At the fore end of the counter-
balance aforesaid and at the underside thereof is a recess in which are two
horizontal projections or catches one or other of which engages with corresponding
T-shaped projections or catches formed on sliding plates (herein-after termed
locking-plates) a space or "gating" being formed between the catches on the
counterbalance to admit the catches on the said locking-plates. A flat spring or a
packing-strip of india-rubber or leather is or may be interposed between the cap-
plate of the lock-case and the adjacent locking-plate so as to cause sufficient
friction to retain the locking-plates in their required positions. The said locking-
plates, which are prevented from rising by cross-pins or bars, are pushed backward
and forward by means of a key having bits or steps like those of the key of a lever
lock, which bits on the turning of the said key act upon vertical projections or
horn two of which are formed on each plate and at such distances apart that on
the key which works them being turned forward the slides shall be pushed forward
so that their catches shall engage with the fore-catch on the counterbalance and
that when the said key is turned backward the said catches shall be disengaged
and stand in a line above the "gating" between the catches on the counterbalance
so as to allow the latter to rise and fall. The horns aforesaid are at different
distances from the axis of the key and the steps or bits of the key are cut
accordingly so that if a false key not having bits exactly corresponding with the
said horns were introduced it would either fail to draw back the locking-plates
sufficiently far to disengage their catches from the fore-catch on the counterbalance
or it would draw the said plates too far so that their catches (or some one or more
of them) would engage with the rear catch on the said counterbalance.
From this description it will be seen that the locking mechanism is somewhat

page_text: similar in principle and action to that of a lever or tumbler lock sliding locking-
plates being substituted for levers or tumblers. A suitable recess is formed in the
underside of the counterbalance to afford space for the locking-plates.
The foregoing arrangement may be modified in various ways, the principle being
the same.
Thus according to one modification I substitute for the sliding snap-bolt
or latch an oscillating snap-bolt or latch made in one piece with the bell-crank
lever aforesaid and at the lower end of the vertical arm thereof the fulcrum or
pin on which the lever turus being in the upper fore-corner of the lock-case
and locking mechanism of any of the kinds herein described being applied to the
horizontal arm of the said lever.
According to another modification I substitute for the sliding locking-plates
oscillating levers having on their upper ends double catches which engage with
corresponding catches on the underside of the counterbalance of the bell-crank
lever (which may be of either of the kinds described) or (in the case of a false
key being introduced) with other catches formed on the said counterbalance.
These levers turn on two pins on the lower part of the lock case one or more
levers being mounted on each pin according to the degree of security required and
are pressed forward by springs their motion being limited by stops. Suitable
inclines are formed upon the opposed sides of the said levers which being acted
upon by the bits of the key (which is a flat one sliding in a vertical slot) the double
catches on the levers are brought opposite the gatings between the catches on the
counterbalance so as to allow it to rise. When it is wished to retain the oscillating
catches in this position so as to admit of the bell-crank lever being worked merely
by the spindle a wedge is inserted in the vertical slot of the key-hole and under
the key so as to hold it in its raised position. Otherwise on the descent of the
counter-balance its catches would engage with the catches on the oscillating levers
the acting parts of the said levers being bevelled for this purpose.
According to another modification of my invention I substitute for the sliding or
the oscillating snap-bolt herein-before described a latch or bolt turning on a pin at
its rear-end like the latch of a rim-lock or a Norfolk latch its fore-end being
bevelled so as to ride over the incline of the hasp on the door-jamb and its
underside having the aforesaid catches which engage with locking mechanism of
either of the kinds described.
In constructing desk and box locks according to my invention I form on the hasp
which is screwed to the lid of the desk or box suitable catches which when the lid
is shut down snap into or are otherwise caused to engage with the catches on the
locking plates or on the levers herein-before described.
In constructing drawer locks according to my invention I mount in the lower
part of the lock case oscillating levers of the kind herein-before described the upper
ends of which levers (which are without catches) when pressed by their springs
into an inclined position bear against the under part of the bolt so as to support it
in its raised or locked position and I make in the said under part corresponding
vertical slots which when the said levers are by the action of the key brought
into a vertical position so as as to coincide with the said slots allow the said bolt.
to descend.
With this lock I prefer to use a key having a flat shank and at one end thereof
a flat plate which can be slidden upward in the vertical slot of the key-hole so as to
act upon the under-side of the bolt and thereby raise it. On the other end of the
key is a flat plate which is at right angles to the first-named plate and has steps
formed upon it which upon the key being slidden upward act upon the inclines
upon the levers and thereby bring them into a line with the slots in the bolt.
In applying the principle of sliding locking-plates and catches herein-before
described to the construction of locks for ledgers and other books I insert in the lock-
case sliding locking plates having at their upper parts the sliding catches described a
longitudinal notch being cut in the lower edge of each plate for the key to work in.
The said key consists of a flat plate of metal having steps or bits which on the key
being slidden horizontally in either direction push the locking-plates so as to cause

page_text: them to engage with or disengage from the the catches on the asp. Ine sapt
hasp and the bottom of the lock-case are formed with horizontal plates which are
respectively rivetted to the upper and lower covers of the ledger.
Locks and latches constructed according to my invention are cheap are not easily
picked and are not liable to get out of order.
Having thus described the nature of my invention I will proceed to describe the
manner in which the same is to be performed reference being hid to the accom-
panying drawings and to the letters and figures marked thereon. The same letters
and figures of reference indicate the same parts in all the figures.
Figure is a side elevation of a mortise lock constructed according to my
invention the cap-plate being removed.
Figure 2 is a sectional plan of the said lock the section being taken on the line X
Figure 1.
Figure 3 is a side elevation of the cap-plate.
Figure 4 is a sectional plan of the said plate the section being taken on the line Y
Figure 3.
Figure 5 is a sectional plan of the said lock illustrating a modification herein-after
described and
Figure 6 is a transverse section of the sliding locking-plate E'.
Figure 7 represents the key of the lock.
A is the lock-case and A2 is the cap-plate which is affixed by means of screws
screwing into holes aa a¹ in the usual manner. B is the snap-bolt the part of
which is made with the usual incline to ride over the hasp on the door jamb. C is
the bell-crauk lever the arm c' of which engages with the tail-end of the bolt the
arm c² constituting a counterbalance. is a boss which turns in holes a² in the
cap-plate and back plate. D is the spindle which carries knobs of the usual
kind. care the catches and is the recess in which work the horns e e² of the
locking-plates E E E³. The locking plate E2 has its horns at a greater or less
distance apart than the horns on the locking-plates El E³ and the bits f³ of
the key Fare cut to correspond. By turning the key to the left its bits are
brought to bear against the horns e e¹ and the catches ³ ³ are thus caused to
engage with the catch e and thus lock the counterbalance and by turning the key
to the right into the position represented in Figure 1 the catches ³ ³ are
brought into line opposite the gating c' and the counterbalance is free to rise and
fall. Should a false key having bits which do not correspond with the horns el e
be introduced into the lock it will either fail to withdraw the catches e³ ³ from the
catch or it will over-shoot the locking-plates (or one or more of them) and thus
cause the catches (or one or more of them) to engage with the catch and
thus lock the counterbalance. The locking-plates are prevented from rising by the
bar and the heel of the counterbalance. a is a hole in the cap-plate to admit a
stop-pin (indicated by the dotted circle a³) when it is wished to prevent the
counterbalance from rising without locking it with the key a coincident hole being
bored in the door on the inner side to admit the said pin. When the counter-
balance is unlocked the snap-bolt as it rides over the bevelled edge of the hasp on
the door-jamb raises the said counterbalance as indicated in dotted lines in Figure 1
and when the said bolt has cleared the said edge the said counterbalance forces the
said bolt forward into the said hasp.
In order to prevent the locking plates E E E³ from being shaken out of position
by the slamming of the door a metal spring or packing-strip of india-rubber or
leather or other elastic material may be applied to them. A convenient way of
doing this is by piercing the cap-plate A at a so as to form tongues which being
bent as represented in Figure 4 constitute springs which when the said cap-plate is
screwed on to the lock bears against the locking-plate E with sufficient friction to
retain the said plates in the position to which they have been brought by the action
of the key.
According to another arrangement instead of forming springs on the cap-plate as
described a separate spring & may be interposed between the said plate and the

page_text: locking-plate E' as represented in Figure 5 in which case the said locking-plate is
recessed at to make room for the said spring.
Figure 8 represents in side elevation the simplified arrangement herein-before
described in which the snap-bolt & is made in one piece with the counterbalance (
which turns on a pin c8 and is raised as required by means of a lever h formed on
a boss H in which the lock-spindle is fixed which lever engages with the tongue.
'The boss H like the boss c Figure 1 turns in holes in the cap-plate and back-
plate.
"
Figure 9 represents in side elevation a rim-lock constructed according to my
invention. The latch I is formed with a boss in which the spindle D is mounted
which boss turns in holes in the cap-plate and back-plate. The part is bevelled
like ordinary rim-lock latches and rides over the incline of a hasp of the ordinary
kind. The said latch is recessed at to pass two of the screws by which the
cap-plate is secured to the back plate and the lock is secured to the door. The
mechanism by which the latch or bolt in this and the preceding arrangement is
locked is the same as that described with reference to Figures 1, 2 and 3. The
locking-plates E' E' E' are prevented from rising by pins a a'.
Figure 10 represents in side elevation part of a door lock constructed according
to the modification in which oscillating catch-levers are substituted for the sliding
locking-plates.
Figure 11 is a plan of the said levers (represented in section on the line Z
Figure 10) and of the key K by which they are actuated.
Figure 12 is a side elevation of the said key.
Figure 13 represents on an enlarged scale a detail herein-after described.
All the other figures are drawn actual size.
JJJ are the catch levers.
are their catches. ³ ³ are the pins on
which they turn.
10 are catches formed on the counterbalance C. are
split springs which press the levers forward into an inclined position so that the
inclines on the catches shall be in the path of the inclines on the catches c' co
and that on the descent of the counterbalance the two sets of catches shall engage
and thereby lock the said counterbalance. are inclines formed on the
levers JJJ which inclines on being acted upon by the key K push the said
levers back into a vertical position so that their catches shall coincide with the
gatings ee when the counterbalance will be free to rise. In order to lock the
said counterbalance it is only necessary to depress the key in the vertical slot of
the key-hole a when the respective catches will engage as before.
Notches are
cut in the inclines as represented on a larger scale in Figure 13 in which
notches the angular edges of the key engage. The said key is thus prevented
from descending and keeps the catches from engaging with the catches e
and as long as the key is left in this position the counterbalance will be free to
rise. The bits enter the lock by the horizontal slot of the key-hole.
Should a false key having bits which do not correspond with the inclines be
introduced into the lock it will either fail to withdraw the catches from the
-catches or it will press the levers J1 J2 J3 (or some of them) too far outwards
and cause the catches (or some of them) to engage with the catches ee and
thus lock the counterbalance.
Figure 14 is a side elevation of a desk lock in which the hasp L is formed with
catches 12. The construction and action of this lock will be understood from
the foregoing description of the lock Figure 10. In Figure 14 the levers J¹ J¹ J2 J
are represented with their actuating springs formed thereon. The said levers may
however be actuated by separate springs as represented in Figure 10.
Figure 15 represents in side elevation with the cap-plate M removed a drawer
lock constructed according to my invention.
Figure 16 is the said cap-plate.
Figure 17 is a plan of the underside of the bolt.
Figures 18 and 19 are views (taken at right angles to each other) of a convenient
form of key for locking and unlocking this lock.

page_text: The drop-bolt N has two slots n'n' formed therein which when the oscillating
levers J' J¹ J' ] are brought into a vertical position admit them and allow
the bolt to drop. The key P has two operating parts pl p². In order to
shoot the bolt the part pl is introduced into the vertical slot of the key-hole
and slidden upward therein so as to lift the bolt till its lower edge is clear of
the levers JJJJ2 when they will be forced by the split-spring g into an inclined
position in which their upper ends will come under the part 2 of the bult and
prevent it from falling. In order to unlock the lock the end p² of the key is
inserted in the key-hole and slidden upward therein into the position represented
in Figure 15 when the bits acting upon the inclines force the levers JJ
into a vertical position when the bolt is free to fall. I prefer to hinge the
parts p p together by means of a "thimble" p³ inserted in the rings of the
said parts the upper flange of the said "thimble" being turned over upon.
the ring and closed thereon by pressure. This arrangement adimits of the said
parts being folded one upon the other.
Figure 20 represents in side elevation with the cap-plate removed a desk lock
constructed according to another modification of my invention. The hasp R has
catches with which the catches s² on the sliding locking plates S S engage
as herein-before described with reference to the catches in Figure 1 the said
locking-plates being actuated by means of a key similar to the key F except that
it turns upon a pin a. ³ ³ ss are the horns of the locking-plates.
Figure 21 represents in side elevation with the cap-plate removed a ledger lock
constructed according to my invention.
Figure 22 is a sectional plan of the said lock the said section being taken on the
line U Figure 21 and Figure 23 is a section taken on the line W Figure 21.
Figure 24 is a side elevation of one of the sliding locking-plates and
Figure 25 is a side elevation of the cap-plate.
TT T3 are the locking-plates. ( are the horns thereof which are made
short as represented as they are acted upon by a key U consisting of a thin
plate of metal having suitable steps or bits formed thereon.
are the
catches. V is the hasp and are the catches thereof. The said hasp is.
carried by a plate which is rivetted to the upper cover tol of the ledger W
and the bottom plate of the lock case X is rivetted to the lower cover w..
X2 is the cap-plate and 2 is the slot through which the key is introduced
and withdrawn. Y is a packing-strip of india-rubber or leather which may
be cemented or otherwise affixed either to the locking-plate T as represented in
Figure 21 or to the back of the cap-plate as indicated in dotted lines in Figure 25..
In order to lock the ledger the key U is inserted through the slot as represented
in Figure 22 and slidden to the left till its neck comes against the end of the sa
slot when the catches will engage with the catch when the key may be
slidden back till its bits are clear of the locking-plates and then be withdrawn. In
order to unlock the ledger the key is inserted with its bits to the right and slidden.
to the right till its neck comes against that end of the slot when the catches will
be clear of one another and the hasp can be raised.
The principle of actuating the sliding locking plates by means of a key sliding
horizontally as above described with reference to Figures 21, 22, 23 and 24 may
be applied to the locks herein-before described with reference to Figures 1,,.
9 and 20.
For this purpose the sliding locking-plates of such locks are modified
as represented in side elevation in Figure 26 in which it will be seen that the
horns ee² of the said plates are formed upon the underside thereof instead of
upon the upper side and the key U Figure 22 and the key-slot a Figure 25 are
substituted for the key F and the key-hole in which it works. Owing to the
narrowness of the said key-slot this arrangement affords great security against
the introduction into the lock of pick-locks or of devices for ascertaining the
form and position of the locking plates.
I wish it to be understood that I make no claim to the principle of actuating
the bolts or latches of locks by gravity nor to the principle of combining

page_text: gravitating bolts or latches with locking mechanism otherwise than essentially as
herein described and claimed. But I do not limit myself to the precise details
herein-before described as they may be modified without departing from the
nature of my invention.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is
Firstly. The improvements in door locks herein-before described and illustrated
in Figures 1, 2, 3, 4, 5 and 6 of the accompanying drawings that is to say
combining a bell-crank lever or counterbalance formed with catches and a fulcrum
in which the spindle is affixed with a sliding snap-bolt or latch and with sliding
"locking-plates" furnished with catches and "horns" the several parts being
constructed and arranged and operating essentially as and for the purpose herein-
before described.
Secondly. The improvements in door-locks herein-before described and illustrated
in Figure 8 of the accompanying drawings that is to say making the snap-bolt or
Intch in one piece with a bell-crank lever or counterbalance having a fulcrum at its
upper inner corner and catches on its free end and combining such counterbalance
with sliding locking-plates" and with an actuating lever mounted on the lock-
spindle the several parts being constructed and arranged and operating essentially
as and for the purpose described.
66
Thirdly. The improvements in door locks or latches herein-before described and
illustrated in Figure 9 of the accompanying drawings that is to say mounting on
the lock-spindle a bevelled latch having catches on its underside and combining
such latch with locking plates" the several parts being constructed and arranged
and operating essentially as and for the purpose described.
Fourthly. The improvements in door locks herein-before described and illustrated
in Figures 10, 11 and 13 of the accompanying drawings that is to say forming in a
recess in the bell-crank lever or counterbalance which actuates the sliding bolt
catches which engage with catches on oscillating "locking-levers" having inclines
which being acted upon by a sliding key of the kind described unlock the said
counterbalance as required the several parts being constructed and arranged and
operating essentially as described.
Fifthly. Constructing desk locks with oscillating "locking-levers" the catches
of which engage with catches on the hasp of the lock essentially as herein-before
described and illustrated in Figure 14 of the accompanying drawings.
Sixthly. The improvements in drawer-locks herein-before described and
illustrated in Figures 15, 16, and 17 of the accompanying drawings that is to
say forming the bolt of the lock with vertical slots in its under-side and mounting
in the lock-case oscillating locking-levers" which on the said bolt being raised
by the key represented in Figures 18 and 19 are forced by springs into an inclined
position so as to support the said bolt and on being acted upon by the said key are
forced into a vertical position so as to coincide with the said slots and thus allow
the said bolt to drop.
66
Seventhly. The improvements in desk-locks herein-before described and
illustrated in Figure 20 of the accompanying drawings that is to say fitting in
the lock-case sliding locking-plates" which on being acted upon by a key of the
kind represented in Figure 7 cause the catches on the said plates to engage with
or disengage from catches on the hasp essentially as described.
Eighthly. The improvements in ledger locks herein-before described and
illustrated in Figures 21, 22, 23, 24, and 25 of the accompanying drawings that
is to say forming the hasp and the bottom of the lock with suitable plates for
àttachment to the upper and lower covers of the ledger and fitting in the lock-
case sliding "locking-plates" which on being acted upon by the key sliding in a
horizontal slot in the cap-plate cause their catches to engage with or to disengage
from the catches on the hasp essentially as described.

page_text: Ninthly. The application of the locking device referred to in my eighth claim
to the locks herein-before described with reference to Figures 1, 8, 9 and 20 of the
accompanying drawings.
Dad this Fighteouth dor of April 1891
H. H. MURDOCH.