Improvements in Combination Locks.
Year: 1893

page_text: Date of Application, 11th Apr., 1893
Complete Specification Left, 24th July, 1893-Accepted, 30th Sept., 1893
Improvements in Combination Locks.
We, EDWIN MCCUMBER SKINNER, of Fort Wadsworth, in the County of
Richmond and State of New York Machinist and OLIVER MOREHOUSE FARRAND,
of No. 2135 Seventh Avenue, in the City County and State of New York, Jeweller,
both in the United States of America, do hereby declare the nature of this invention
to be as follows:-
This lock is especially adapted to the doors of buildings, but it may be used
upon the doors of safes, vaults, etc.
The knob spindle can be turned, and it is also fitted to move longitudinally of its
axis, and it is made in two parts that are connected, but one part can be turned
independently of the other in order that the latch bolt may be retracted from
inside the door by simply turning the inside knob and its portion of the spindle.
The parts of the locks are briefly described as follows:-
A latch bolt having a bevelled outer end; a dog pivotted to said latch-bolt;
two pawl carriers; a pawl pivotted to each carrier; a permutation bar having two
rows of teeth, one for each pawl to take into; pins placed in said rows of teeth
with the top surfaces of said pins slightly below the tops of the teeth; a safety-bar
fitted to slide in the permutation bar, said safety-bar having a deep notch and two
teeth; a lifter plate having a tooth passing into the deep notch in the safety bar;
a projection to take against the dog on the latch-bolt, a projection for the pawls to
rest upon, and a projection to pass into a notch in said bolt; a ring concentric with
the knob spindle and having an arm to lift the lifter plate, and springs to return
the parts to their normal position.
The lock is operated as follows:-
:-
To unlock the lock from the outside, the knob spindle must be moved
longitudinally of its axis so as to bring an arm on the spindle of the outer knob into
contact with the proper pawl carrier, and the knob is partly turned the proper
number of times and said spindle is then moved end wise and partially rotated one
or more times, and these movements are alternated so that said arm is in contact
with said pawl carriers and each time a pawl carrier is actuated the permutation
bar is moved forward a tooth by one of the pawls.
If the knob spindle has been manipulated properly, the permutation bar will be
moved to such a position that a deep notch in the permutation bar will be in line
with the deep notch in the safety-bar, at which time the finger upon the lifter-
plate that is in the deep notch in the safety-bar drops still further in said notch
and also into the notch in the permutation bar, and said lifter in dropping allows
the dog on the latch bolt to drop into the path of the arm on the knob spindle and
by turning said spindle in the reverse direction to that for acting upon the pawl
carriers, said arm takes against the dog and moves back the latch bolt.
If the knob spindle has not been manipulated properly, that is, if a pawl should
Obe brought into a tooth notch in which there is no pin, the absence of the pin will
allow the pawl to drop so far that said pawl will pass behind a tooth on the safety-
bar and when the permutation bar is moved forward one tooth the safety bar is
moved forward one tooth and the projection on the lifter plate is lifted out of its
notch in the safety bar and rides over the tooth on said bar, thereby the lifter
5 plate cannot drop even if the deep notches of the two bars are brought into line.
It is to be understood that the toothed end of each pawl is wide enough to take
into its own row of teeth and also to overhang part of the safety-bar, and that the top
surfaces of the pins in the rows of teeth keep the ends of the pawls from contact
with the safety-bar, and it is also to be understood that the pins in the permutation

page_text: bar are removable and that the combination upon which the lock is locked is
governed by the position of said pins.
To return the parts to their normal position, the ring mentioned aforesaid as
being concentric with the knob spindle and turning upon a hub on the lock-case, is
to be turned by the arm on the knob spindle, and said ring by an arm lifts the
lifter plate which latter lifts the pawls so that the pawls are free of the teeth of
the two bars; then the springs return the parts to their normal position.
There is a pin in the permutation bar to take against the safety bar and ensure
the safety bar being returned to its proper position when the parts are returned to
their normal position, and this pin can be placed in one of several holes in the
permutation bar so as to vary the number of times that the knob spindle must be
moved in operating the lock. We provide a device to hold down the lifter plate
so that, when desired, the lock cannot be operated from outside.
To retract the latch-bolt from inside the door, we provide an arm on the part of
the spindle connected to the inside knob, and by turning said knob said arm acts
upon the dog and retracts the bolt.
When our lock is used upon a safe door, only one spindle and its arm are used,
and the projection on the lifter plate is always in the notch of the bolt when the
lock is locked, hence the the bolt can not be retracted by any instrument inserted
between the door and its casing.
COMPLETE SPECIFICATION.
Improvements in Combination Locks.
We, EDWIN MCCUMBER SKINNER, of Fort Wadsworth in the County of
Richmond and State of New York, United States of America, Machinist, and
OLIVER MOREHOUSE FARRAND, of No. 2135 Seventh Avenue in the City of
New York, in said State of New York, Jeweller, 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:-
This lock is especially adapted to the doors of buildings but it may be used upon
the doors of safes, vaults, etc. The knob spindle can be turned and it is also fitted
to move longitudinally of its axis and it is made in two parts that are connected,
but one part can be turned independently of the other in order that the latch bolt
may be retracted from inside the door by simply turning the inside knob and its
portion of the spindle.
The parts of the lock are briefly described as follows:
A latch belt having a bevelled outer end; a dog pivoted to said latch bolt; two
pawl carriers; a pawl pivoted to each carrier; a permutation bar having two rows
of teeth one for each pawl to take into; pins placed in holes in said rows of teeth
with the top surfaces of said pins slightly below the tops of the teeth; a safety bar
fitted to slide in the permutation bar, said safety bar having a deep notch and two
teeth; a lifter plate having a tooth passing into the deep notch in the safety bar;
a projection to take against the dog on the latch bolt or projection for the pawls to
rest upon, and a projection to pass into a notch in said bolt; a ring concentric with
the knob spindle and having an arm to lift the lifter plate, and springs to return
the parts to their normal position.
The lock is operated as follows:
To unlock the door from the outside, the knob spindle must be moved
longitudinally of its axis so as to bring an arm on the spindle of the outer knob

page_text: into contact with the proper pawl carrier and the knob is partly turned the proper
number of times and said spindle is then moved endwise and partially rotated one
or more times and these movements are alternated so that said arm is in contact
with the pawl carriers and each time a pawl carrier is actuated the permutation
bar.is moved forward a tooth by one of the pawls.
If the knob spindle has been manipulated properly the permutation bar will be
moved to such a position that a deep notch in the permutation bar will be in line
with the deep notch in the safety bar, at which time the finger upon the lifter plate
that is in the deep notch in the safety bar drops still further in said notch and also
into the notch in the permutation bar, and said lifter in dropping allows the dog on
the latch bolt to drop into the path of the arm on the knob spindle and by turning
said spindle in the reverse direction to that for acting upon the pawl carriers, said
arm takes against the dog and moves back the latch bolt.
also
If the knob spindle has not been manipulated properly, that is, if a pawl should
be brought into a tooth notch in which there is no pin, the absence of the pin will
allow the pawl to drop so far that said pawl will pass behind a tooth on the safety
bar and when the permutation.bar is moved forward one tooth the safety bar
moved forward one tooth and the projection on the lifter plate is lifted out of its
notch in the safety bar and rides over the tooth on said bar, thereby the lifter
plate cannot drop even if the deep notches of the two bars are brought into line.
It is to be understood that the toothed end of each pawl is wide enough to take
into its own row of teeth and also to overhang part of the safety bar, and that the
top surfaces of the pins in the rows of teeth keep the ends of the pawls from contact
with the safety bar; and it is also to be understood that the pins in the permutation
bar are removable and that the combination upon which the lock is locked is
governed by the position of said pins.
To return the parts to their normal position the ring mentioned aforesaid as
being concentric with the knob spindle and turning upon a hub on the lock case, is
to be turned by the arm on the knob spindle, and said ring by an arm lifts the
lifter plate which latter lifts the pawls so that the pawls are free of the teeth of the
two bars; then the springs return the parts to their normal position.
There is a pin in the permutation bar to take against the safety bar and ensure
the safety bar being returned to its proper position when the parts are returned to
their normal position, and this pin can be placed in one of several holes in the
permutation bar so as to vary the number of times that the knob spindle must be
moved in operating the lock.
We provide a device to hold down the lifter plate so than when desired the
lock cannot be operated from the outside. To retract the latch bolt from inside
the door, we provide an arm on the part of the spindle connected to the inside
knob, and by turning said knob said arm acts upon the dog and retracts the bolt.
When our lock is used upon a safe door, only one spindle and its arm is used and
the projection on the lifter plate is always in the notch of the bolt when the lock
is locked, hence the bolt cannot be retracted by any instrument inserted between
the door and its casing.
In the drawings,
Fig. 1 is an elevation of the lock with the cap plate removed and with the knob
spindle and permutation toothed bar in section.
Fig. 2 is a transverse section of the lock at the line of Fig. 1, a portion of the
door being shown in section.
Fig. 3 is a view similar to Fig. 1 but with the parts in the position they assume
when the knob spindle has been operated correctly.
Fig. 4 is an elevation of a portion of the lock, showing the position of the safety
bar with respect to the permutation bar when the knob spindle has not been
operated correctly.
Fig. 5 is a plan of the permutation bar and safety bar detached.
Figs. 6, 7 and 8 are sections at the lines yy, zz and ww respectively of Fig. 1.
This is a cross section of the knob spindle, and

page_text: ig. 10 is an elevation of the ring for actuating the lifter plate, and
Fig. 11 is a section at 2, Fig. 1, with the bolt in position for operating as
a latch.
a is the lock case, the cap plate, and c the front plate of usual character. d is
the latch bolt guided by the lock case and by the stud e in a slot in said latch bolt.
ff are arms forming pawl carriers, having the stud e for their pivot, and to
the lower ends of said pawl carriers are pivoted the pawls h h respectively. The
pawls hh are provided with springs that tend to keep the toothed ends of the
pawls in contact with the teeth of the permutation bar and also to draw back
said pawls and carriers ƒƒ³.
is a stop to limit the backward movement of the pawl carriers and pawls. is
a lifter plate pivoted at land said plate has a downwardly projecting tooth 2, a
projection 3 for the fingers 4 4 of the pawls h h' to rest upon, a projection at 5, to
enter a notch at 6 in the latch bolt d, an incline at 7 and an arm at 8 upon which
latter bears the stud 9 of a dog m, pivoted at 18 to the latch bolt d.
n is a spring that acts upon said dog m to keep the stud 9 in contact with the
arm 8, and said spring also acts to throw the latch bolt forward.
is the permutation bar guided by the lock case and rod p' and retracted by the
spring p, and said bar has two rows of teeth, one row 10 being for the pawl h, and
the other row 11 for the pawl ¹; the teeth in said bar are inclined, and in the
row 10 there is a deep notch at 13. The permutation bar p is recessed between
the two rows of teeth 10 and 11 for the safety bar which has a deep notch at 12,
and teeth 14 and 15, and there is a cross pin at 23 in said safety bar.
There are
holes in the permutation bar in the rows of teeth 10 and 11 as shown most clearly
in Fig. 5, and into some of these holes pius q' are to be placed and the location of
these pins determines the combination of the lock. The holes in the permutation
bar for the pins 7' preferably extend entirely through the said bar and are
countersunk at the under side of said bar for the heads upon said pins, hence as
the said bar rests upon the rim of the lock said pins cannot become displaced.
The combination in Fig. 5 is 4-2-3-1-1-, there being four pins in the
row 10, then two in the row 11, then three in the row 10, then one in the row 11,
and finally one in the row 10. The top surfaces of the pins are below the top
of the teeth 10 and 11, for a purpose hereinafter explained. The knob spindle is
made in two parts rr, so that one can be turned independently of the other, and
the knob ² is upon the inside of the door and the knob is upon the outside of the
door. The spindler can be moved longitudinally of its axis, and the amount of
movement is determined by the inner end of the shank of either knob coming
against the portion 15 of the socket of the rose q³, in which the shank moves and
turns. Upon the portion of the knob spindle there is a collar 26, having an
arm 19, and in one position of the knob spindle said arm 19 is in the same plane as
the pawl carrier fas in Fig. 2, and when the spindle is moved to the left, said arm
will be in the same plane as the pawl carrier f
The operation of the lock thus far described is as follows:
Starting with the parts in the locked position shown in Figs. 1, 2, 5, 6, 7 and 8,
when the spindle is turned in the direction of the arrow 16, Fig. 1, the arm 19
comes against the pawl carrier f and moves the same and the pawlh, and the letter
taking into the row of teeth 10 moves the permutation bar p forward one tooth;
the pressure of the hand upon the knob spindle must now be released when the
spring returns the pawl carrier f and pawl h to its first position. In order to open
the lock upon the combination 4-2-3-1-1- before referred to, three successive
partial turnings and releasings must be given to the spindle r', by which the
pawl will have moved forward the permutation bar three teeth or four in all.
The knob spindler is now moved to the left, Fig. 2, so as to bring the arm 19
in the plane of the pawl carrier", and by two successive turns and releasings of
the spindle the permutation har p is moved forward two teeth by the pawl
The spindler is now moved back to the position of Fig. 2 so as to bring the
arm 19 in the path of the pawl carrier f, and then by three successive turns and
5

page_text: releasings of the spindle the permutation bar p is moved forward three teeth by
the pawl; in like manner the spindle is moved to the left and then to the right,
but only one turn and releasing is given to the spindle each time, so that the permu-
tation bar will be moved forward one tooth by the pawl and one by the pawl h, and
the parts will then be in the position shown in Fig. 3, in which the deep notch 13
of the permutation bar p will be in line with the deep notch 12 of the safety bar 9,
with the tooth 2 of the lifter / in said notches, and with the dog m in the path of
the arm 19, so that by turning said arm by the spindle in the direction of the
arrow 17, Fig. 3, the arm 19 will act against said dog m and move said dog and
the latch bolt d back and unlock the door. It is to be understood that in unlocking
the lock as aforesaid, the portion of the spindle is operated by turning the knob,
which latter is outside the door.
In order to return the parts from the position of Fig. 3 to that of Fig. 1, the
knob spindle must be moved to the left Fig. 2, so that the arm 19 is beyond the
dog m; then the knob spindle and arm 19 must be turned in the direction of
the arrow 17 until the arm 19 comes in contact with the pin 21 upon a ring 20
that is loose on a circular flange on the lock case, and the further movement must
be continued until the stop portion 36 of the ring 20 strikes the stud k. Upon
the ring 20 is a finger 22, and as said ring is turned the finger acts upon the
incline 7 of the lifter plate and lifts said plate so that the tooth 2 is out of the
notches 13 and 12 of the permutation and safety bar, and by the projection 3
acting upon the fingers 4 of the pawls lifts said pawls so that the spring p²
returns the permutation bar p to the position shown in Fig. 1.
We will now explain the use of the safety bar 7. The top surfaces of the
pins of the permutation bar p are sufficiently below the top of the teeth of said
bar so that the pawls hh can act upon said teeth to move said permutation bar,
and the surface of the tooth 15 of the safety bar is slightly below the tops of the
pins q', and it is to be understood that the toothed ends of the pawls are
sufficiently wide so that a portion of the toothed end of each pawl is over the
safety bar, as shown in Figs. 2 and 6; hence when the pawl or rests upon a
pin q', said pawl cannot strike said tooth 15 when the pawl is moved forward, but
if the person operating the lock should turn the spindle when the pawl or h¹ is
between two teeth of the permutation bar p, where there is no pin, the pawl would
then drop into the recess in the safety bar in front of the tooth 15, and as said
pawl is moved forward it will move the safety bar as well as the permutation bar
forward one tooth, and in so doing the tooth 2 upon the lifter plate will be lifted
out of the deep notch at 12, and over and behind the tooth 14 of said safety bar to
the position shown in Fig. 4, hence the further turning of the spindle will merely
move the permutation bar p forward, and if the permutation bar should be stopped
with the notch 13 of said bar in line with the tooth 2 of the lifter plate 1, said
tooth 2 cannot pass into the notch 13 because said tooth 2 rests upon the safety
bar 9 and the lifter plate cannot be moved downwardly by the spring n, when the
parts are in this position. We provide a pin at 23 in the safety bar g, which is
acted upon by the rear end of the permutation bar when the latter is retracted
and insures the safety bar being moved to the correct position when the parts
are returned from the position of Fig. 4 to that of Fig. 1, by simply turning the
ring 20 by the arm 19 so as to lift the plate and pawls, as before described.
In Fig. 3 we have shown holes at 24 in the safety bar q; by placing the pin 23
in the first hole nearest the tooth 15, the permutation bar p will only have to be
moved one tooth to bring the notch 13 of the permutation bar in line with the
notch 12 of the safety bar to open the lock; if in the second hole, two teeth, and so
on, thereby the number of times that the knob spindle will have to be moved to
open the lock can be varied to suit the person using the lock.
As before mentioned, the knob spindle is made in two parts rr, so that either
part may be turned independently of the other, there being a cylindrical portion
on entering a correspondingly shaped recess in r, the two parts being connected
together by a pin in that passes into a groove in the cylindrical portion of r',

page_text: see Fig. 9. The object of making the knob spindle in two parts is that the lock
may be unlocked from inside the door by simply turning the knob upon the inside
of the door. Upon the spindle there is a sleeve or collar t that turns with r, and
upon said collar t is an arm t' shown by dotted lines in Fig. 1, and full lines in
Figs. 28 and 9, and on the dog m is a stud 25, hence when the spindle r, is turned
in the direction of the arrow 17, Fig. 1, the arm t comes against the stud 25,
and the dog m and latch bolt are retracted so that the door may be opened.
The collars 26 and t are kept from moving upon the spindler by means of the
cylindrical sleeves that are in turn kept in place by the shanks of the
knobs
In order to prevent the lock being operated from outside the door, we provide an
arm that has the rod p' for its pivot, and said arm has a pin v' projecting through
a hole in the front plate e of the lock, see dotted lines Figs. 1, 7 and 11. It is
preferable to have the lug bevelled as shown in Fig. 11 so that the latch bolt
may be moved back by the arme when said arm is moved. Said arm is to be
moved by the finger applied to the pin el when the door is open, and when said arm
is moved it comes between the front plate e and the lug of the bolt d as shown in
Fig. 11. In this position of the bolt, if the lock is in the locked position of Fig. 1,
the lock cannot be operated from the outside because the projection 5 of the plate /
will then be against the under side of the bolt d, and the plate I cannot be moved if
the arm 19 is brought against for f in the effort to turn the knob spindle, it being
understood that when the parts are in the locked position as in Fig. 1 if the spindle
is turned and the permutation bar p moved forward the lifter plate is lifted
successively by the teeth of the bar pacting upon the tooth 2 of said lifter plate 1,
and each time that said plate is raised the projection 5 passes into the notch 6
in the latch bolt, hence when said latch bolt is held back by the arm e, the notch 6
is no longer in line with the projection 5, and said lifter plate cannot be moved
nor the lock operated from outside the door as before explained. The arm w
instead of passing between the lug and front plate, might have a finger o
projecting from the same as shown by dotted lines in Fig. 1 and full lines in Fig. 7,
so that when said arm is moved into the position shown by dotted lines in Fig. 7,
said finger will be over the lifter plate and prevent said plate being lifted
and the door being unlocked from the outside. The spring p² that retracts the
permutation bar p also acts against the arm v, and presses said arm tightly
against the front plate c and holds said arm in the position to which it may be
moved.
When the lock is to be used as a latch, the parts are brought to the unlocked
position Fig. 3, as before described, then by moving the arme so that it comes
between the front plate e of the lock case and the lug v² of the latch bolt, the latch
bolt can be retracted from either side of the door by simply turning either knob
or which knob by its spindle or will, by the arm 19 or t' act upon the dog m
and move the latch bolt.
With the parts in the unlocked position and operating as a latch as just
described, the parts cannot be returned to the position of Fig. I as
arm vis between the lug v² and the front plate c, because if the spindle is turned
long as the
and the lifter plate / raised by the arm 19 and ring 20, said plate will not be raised
sufficiently high to lift the tooth 2 out of the notches 12 and 13 of the safety and
permutation bars, because the projection 5 of said lifter plate will come in contact
with the under side of the latch bolt d and stop said lifter plate in its upward
moveinent.
Our lock may be used upon either the right or left hand edge of the door without
taking out and changing or reversing the latch bolt, as our lock merely requires to
be placed so as to have the incline of the latch bolt face in the proper direction, as
said lock works equally well whether the lock is placed so that the bolt is at the top
or at the bottom of the lock.
It will be evident that the portion of the lock spindle might be dispensed with
and the lock operated only by the spindler, the spindle being fitted with a suitable

page_text: collar or projection so that said spindle cannot be drawn out of the lock. In this
form the lock is adapted to safes, and when so used the projection
of the lifter
plate should be made sufficiently long so as to be always in the notch 6 of the bolt
when the lock is locked and thereby prevent the bolt being forced back by any
instrument inserted between the door of the safe and its frame.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is:
First. The combination in a lock with a knob spindle fitted to move longitudinally
of its axis and having an arm for actuating the lock, of the pawl carriers and pawls,
a toothed permutation bar for the pawls to take against and having holes between
the teeth, pins arranged in said holes to form the combination of the lock, a safety
bar having a notch and teeth and a lifter plate having a tooth to enter a notch in
the permutation bar and safety bar, substantially as specified.
Second. The combination in a lock with a knob spindle fitted to move longi-
tudinally of its axis, and having an arm for actuating the lock, of a toothed
permutation bar having holes between the teeth, pins arranged in said holes to
form the combination of the lock, a spring to retract the toothed bar, a safety
bar having a notch and teeth and mechanism substantially as set forth between
the knob spindle and toothed bar for operating the latter, substantially as set
forth.
Third. The combination in a lock with a lock spindle fitted to move longi-
tudinally of its axis, and having an arm for operating the lock, of the permutation
bar having two rows of teeth with holes between the teeth, pins arranged in the
holes to form the combination of the lock, a safety bar fitted to slide between the
two rows of teeth of the permutation bar, and springs for the permutation bar and
pawl carriers and pawls, each pawl having a toothed end that is over its row of
teeth of the permutation bar and over part of the safety bar, substantially as and
for the purposes specified.
Fourth. The combination in a lock with a knob spindle fitted to move longi-
tudinally of its axis, an arm on said lock spindle for operating the lock, of the
permutation bar having a deep notch at 13, and holes between the teeth of said bar,
pins arranged in said holes to form the combination of the lock, the safety bar
having a deep notch at 12, and teeth 14 and 15, and the lifted plate having a
tooth 2, and the pawl carrier and pawls for actuating said permutation bar and
safety bar, substantially as specified.
Fifth. The combination in a lock with a knob spindle fitted to move longi-
tudinally of its axis and an arm on said spindle for actuating the lock, of the
permutation bar having a deep notch and holes between the teeth, pins arranged in
said holes to form the combination of the lock, the safety bar having a deep
notch and teeth, the pawl carriers and pawls and the lifter plate having a
tooth at 2, and a projection 3 for the pawls to rest upon, substantially as
specified.
Sixth. The combination in a lock with a knob spindle fitted to slide longi-
tudinally of its axis, and an arm on said lock spindle for operating the lock, of the
pawl carrier and pawls, springs for said pawls, the permutation bar and safety bar,
a spring to retract the permutation bar, the lifter plate, the latch bolt and its dog,
and the loose ring 20 having a finger to take against the lifter plate substantially
as and for the purposes specified.
Seventh. The combination in a lock with a lock spindle fitted to move longi-
tudinally of its axis, an arm secured to said spindle, the permutation bar and safety
bar, the pawl carriers and pawls, and the notched latch bolt having a lug ², of the
lifter plate having a tooth at 5, and a pivoted arm & fitted to pass between the lug ²,
and the case to prevent the lifter plate being raised, substantially as and for the
purposes set forth.
Eighth. The combination in a lock with a knob spindle fitted to move

page_text: Tongitudinally of its axis, of a toothed permutation bar having holes between the
teeth and pins in said holes to form the combination of the lock, and mechanism
substantially as set forth for actuating said permutation bar, substantially as
specified.
Ninth. The combination with the latch bolt of a two part spindle and separate
knobs capable of being turned independently, the collar and arm on one part of the
spindle by which the latch can be withdrawn by one knob at any time, and the
collar and arm on the other part of the spindle and two sets of appliances intervening
between the spindle and the bolt that are acted upon alternately after an end
movement is given to the spindle, substantially as specified.
Teuth. The combination in a lock with the knob spindle and its arm for operating
the lock of the safety bar and permutation bar, said safety bar having holes therein,
and a pin in one of said holes for the permutation bar to take against when said
retracted bar is retracted, and mechanism substantially as specified for operating
said permutation bar, as set forth.
Eleventh. The combination in a lock with a knob spindle fitted to move longi-
tudinally of its axis, an arm upon said spindle for operating the lock, and the bolt
having a notch at 6 and the dog m upon said latch bolt, of the pawl carriers and
pawls, the permutation and safety bars and the lifter plate having a projection to
enter the notch in the bolt, substantially as and for the purposes specified.
Dated this out ,
P
o uty
1000,
ERNEST DE PASS,
Chartered Patent Agent,
78, Fleet Street, London, and 6, Victoria Street, Nottingham,
Agent for the Applicants.