AN IMPROVED CONSTRUCTION OF LOCKS AND LATCHES
Year: 1870

page_text: LETTERS PATENT to Charles Denton Abel, of No. 20, Southampton
Buildings, Chancery Lane, in the County of Middlesex, Patent
Agent, for the Invention of "AN IMPROVED CONSTRUCTION OF LOCKS
AND LATCHES." -A communication from abroad by Theodore Kromer,
of Neustadt, in the Grand Duchy of Baden.
Scaled the 9th May 1871, and dated the 28th November 1870.
PROVISIONAL SPECIFICATION left by the said Charles Denton Abel
at the Office of the Commissioners of Patents, with his Petition, on
the 28th November 1870.
I, CHARLES DENTON ABEL, of No. 20, Southampton Buildings, Chancery
Lane, in the County of Middlesex, Patent Agent, do hereby declare
the nature of the said Invention for " AN IMPROVED CONSTRUCTION OF LOCKS
AND LATCHES," to be as follows:-
This Invention consists of an improved construction of locks or
latches, wherein a row of sliding pins contained in recesses in a casing
and having each a number of grooves or notches are respectively
brought into such positions by the action of a corresponding number of
studs or pins upon a key that certain of the grooves which are deeper

page_text: than the rest, and are situated at different distances from the ends of the
pins, are all brought into a line so as to allow a hinged bolt or latch
to fall into them, the latch when in such position being unlocked,
whereas if any one or more of the pins are not brought into such
position the latch is prevented from falling into the deep grooves and
is thus locked.
The arrangement which it is preferred to employ is shown on the
accompanying Drawing, in which Figure 1 shows a front view of the
lock; Figure 2 shows a sido view, partly in section; Figure 3 shows
a section on line X, X, Figure 1; Figure 4 shows a plan, and Figure 5:
shows the key to the lock.
The lock consists of the rectangular (or otherwise shaped) casing P
with a cylindrical projection P', in which are formed five, or any other
desired number, of cylindrical recesses 1, 2, 3, 4, 5, arranged in a line
with each other. At the front end these recesses are reduced in size, :
as shown, while at the back end they are closed by a plate S secured
by screws S, S, to the casing P. In the recesses are fitted sliding
pins C¹, Ơ³, C³, C', C³, inserted from the back end and having each a
series of annular grooves as shown, one groove of each being of greater
depth than the others, which deep grooves are situated at different
distances from the ends of the pins. Behind the pins are inserted spiral
springs F, F, which when the pins are not acted upon by the key press
the pins outwards against the front ends of the recesses where they are
· retained by the shoulders formed by the reduced apertures. The key L,
Figure 5, has a row of pins 1, 2, 3, 4, 5, corresponding in number to
that of the apertures in the lock, while the length of each pin corresponds
with the distance of the deep groove from the inner end of the respective
sliding pin upon which it acts, so that by the introduction of the key
into the lock the sliding pins are all depressed in their recesses in such
a manner that all the deep grooves are brought in a line, as shown in ;
Figure 3. When in this position the bolt or latch G turning upon a
pin Z and fitting into a longitudinal groove in the casing can fall with
its thin lower edge h, i, into the before-mentioned deep grooves or
notches, so as to assume the position shown in full lines in Figure 1, in
which position the lock or latch is open. If the latch G be raised
slightly out of the deep grooves of the pins C (the key having been
removed) these are pushed forward by the springs F, whereupon the
latch cannot fall beyond the dotted position G', in which case it is locked;

page_text: i
at the same time it catches into the shallow notches of the pins O.. If
it be desired to unlock the latch again it must first be raised into. tlie
position G³, so as to be clear of the shallow notches of the pins, after
which the key is introduced, as before, and the latch allowed to fall
into the lowest position. The picking of this lock may be effectually
prevented by occasionally changing the relative positions of the sliding
pins.Ċ (which may be readily effected by removing the plate S) and
also changing the position of the pins of the key in a corresponding
manner. This lock may either be used as a fastening by itself or it
may be employed in conjunction with a sliding bolt. Such sliding bolt
is so formed with a projection that when shot forward when the lock is
locked (in which case the latch G is in the lower dotted position at
Figure 1), and it is endeavoured to push the sliding bolt back, the
projection thereof strikes against the surface a', b¹, of the latch, and
the backward motion of the sliding bolt is thus provented. The sliding
back of the bolt being only possible when the latch is in its lowest or
unlocked position. To admit of its being brought into such position
by the action of the key the projection of the sliding bolt is caused in
striking against the inclined surface a, b, as stated, to raise the latch
to such an extent that it is quite free of the sliding pins O, where-
upon the key can be made to act upon the pins, as before described.
When this has been done the bolt is again slid forward so as to free
the latch and allow it to fall into its lowest position. The bolt is now
free to slide back, as before stated, but before it has completed its
motion the before-mentioned, projection strikes against the inclined
surface d, h, of the latch in such manner as to raise the latter free of
the pins C, whereupon these will again be pushed forward by the
springs, so that on the shooting forward of the bolt the latch will again
assume the locked position.
30 SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Charles Denton Abel in the Great Seal Patent
Office on the 25th May 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
DENTON ABEL, of No. 20, Southampton Buildings, Chancery Lane
35 in the County of Middlesex, Patent Agent, send greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date tho Twenty-eighth day of November, in the
year of our Lord One thousand eight hundred and seventy, in the thirty-
fourth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Charles Denton Abel, Her special licenco
that I, the said Charles Denton Abel, my exccutors, administrators,
and assigns, or such others as I, the said Charles Denton Abel, my
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 "AN IMPROVED
CONSTRUCTION OF LOCKS AND LATCHES," (a communication to me from abroad
by Theodore Kromer, of Neustadt, in the Grand Duchy of Baden,) upon
the condition (amongst others) that I, the said Charles Denton Abel, my ':
executors or administrators, by an instrument in writing under my,
or their, or one of their hands and seals, 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 imme- !
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, tho said Charles Denton Abel, do hereby
declare the nature of the said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained in
and by the following statement thercof, reference being had to the a
accompanying Sheet of Drawings and to the figures and letters marked
thereon, that is to say :-
"
This Invention consists of an improved construction of locks or latches
wherein a row of sliding pins contained in recesses in a casing, and
having each a number of grooves or notches, are respectively brought a
into such positions by the action of a corresponding number of studs or
pins upon a key that certain of the grooves which are deeper than the
rest, and are situated at different distances from the ends of the pins, aro
all brought into a line so as to allow a hinged bolt or latch to fall into
them, the latch when in such position being unlocked, whereas if any a
one or more of the pins are not brought into such position the latch is
prevented from falling into the deep grooves and is thus locked.

page_text: The arrangement which it is preferred to employ is shown at Figures 1
' to 5 on the accompanying Drawing, in which Fig. 1 shows a front
view of the lock; Figure 2 shows a side view; Figure 3 shows a section
on line x, x, Figure 1; Figure 4 shows a plan, and Figure 5 shews à
5 plan and end view of the key to the lock.
'
.
The-lock consists of the rectangular (or otherwise shaped) casing P,
with a cylindrical projection P¹, in which are formed five or any other
desired number of cylindrical recesses 1, 2, 3, 4, 5, arranged in a line
with each other. At the front end these recesses are reduced in size,
) as shown, while at the back end they are closed by a plate S secured
by screws 8, 8, to the casing P. In the recesses are fitted sliding
pins C, 0, 0, C, C³, inserted from the back end, and having each a
series of annular grooves, as shown, one groove c², c³, c³, c', c³, of cach
being of greater depth than the others, which deep grooves are situated
5 at different distances from the ends of the pins. The front ends of the
pins are by preference reduced in size, as shewn, so as to pass into the
reduced part of the recesses. Behind the pins are inserted spiral
springs F, F, which when the pins are not acted upon by the key press
the pins outwards against the front ends of the recesses, where they are
-retained by the shoulders on the pins bearing against the projections
formed by the reduced part of the recesses. The key L, Figure 5, has
a row of pins A, P, P, P, P, corresponding in number with that of the
apertures in the lock, while the length of each pin corresponds with the
distance of the deep groove from the inner end of the respective sliding
5 pin upon which it acts, so that by the introduction of the key into the
lock the sliding pins are all depressed in their recesses in such a manner
that all the deep grooves are brought in a line, as shown in Figure 3.
When in this position the bolt or latch G turning upon a pin ≈, and
fitting into a longitudinal groove in the casing, can fall with its thin
), lower edge g into the before-mentioned deep grooves or notches so as to
assume the position shewn in full lines in Figure 1, in which: position:
the lock or latch is open.
:
:
If the latch G be raised slightly out of the deep grooves of the pins. C
(the key having been removed), these are pushed forward by the springs F,
5 whereupon the latch cannot fall beyond the dotted position G', in which
case it is locked; at the same time it catches into the shallow notches of‘
the pins O. If it be desired to unlock the latch again it must first be
raised into sucli a position (G) as to be clear of the shallow notches of
'

page_text: .
:
the pins, after which the key is introduced as before, so as to bring the
notches c in a line, and the latch is allowed to fall into the lowest
position. The picking of this lock may be effectually prevented by
occasionally changing the relative positions of the sliding pins C (which
may be readily effected by removing the plate S), and also changing tho
position of the pins of the key in a corresponding manner. This latter
may be effected by fitting the pins (shewn detached at Figure 6) loosely
into holes in the body of the key, and forming them with notches, as
shewn, so that when in place in the body a sliding plate (shewn
detached at Figure 7), fitting in a groove in , is slid so as to take into
the notches 'and thus hold the pins. For removing the pins the plate
is slid so as to bring the recesses in a line with the holes in the body ľº.
The pins are by preference formed with a number of notches, as shewn,
in order that the extent to which they project from 1 may be altered in
case a scutcheon or covering plate is fixed over the face of the pro-
jection P¹ of the lock. I do not claim this special construction of tho
key as part of the present Invention.
เ
In order to prevent any tampering with the lock by boring out the
reduced front portion of the recesses 1, 2, 3, 4, 5, to such an extent as
to allow of the sliding pins C being drawn out entirely, it is preferred
to introduce a steel pin at Y (Figure 3), as indicated in dotted lines,
passing transversely through the recesses. This pin after having been
bored out at the points where it passes through the recess is removed.
and hardened, and is then re-introduced in position, so that should the
front end of P' (which is also by preference of hardened steel) be heated:
so as to soften it sufficiently to allow of the front ends of the recesses
being bored out, yet on the boring instrument arriving at the steel pin
any further action of the same will be prevented.
As a means of readily detecting any attempt that may have been made
to pick the lock a pin p (Fig. 3) may be inserted through a hole in
the plato S so as to rest against the end of the sliding pin C³, and to
project slightly beyond the plate, so that if in trying to find the deep
groove of the sliding pin this has been pushed back beyond the position
indicated at Figure 2, the pin p will be made to project out beyond the
extent shown, and will thus indicato at once that the lock has been
tampered with.
I do not claim as part of this Invention the two above-described
davines LAS MEAWAuting and detration
.

page_text: It will be evident that the form and arrangement of the sliding pins O
and latch G may be variously modified; thus, instead of forming the
pins O cylindrical, with circular notches or grooves as shown, they may
be rectangular, flat, or otherwise shaped, with notches or projections
only on the upper sides thereof, and in some cases it may be expedient
to make the false notches of varying depths, so as to place still greater
difficulties in the way of any one attempting to pick the lock by trying
for the real notches. Also the latch G instead of turning upon a pin at
one end might be made to slide freely up and down in the groove of tho
casing.
.
The above-described improved lock may either be used as a fastening
by itself or to act in conjunction with a sliding bolt. In the former caso
the latch G is made to catch into a hasp, and a lever or equivalent con-
trivance actuated by a handle outside the door is combined with tho
lock for raising the latch G out of the grooved pins when it is desired to
lock the lock, the unlocking being effected by causing the latch to drop,
below the hasp by the action of the key. In this case the lock may.
be arranged to act as an ordinary latch to be opened with the before-
mentioned handle and without the use of the key during the day time,.
and to act as a lock at night, or at such times when it is desired to.
secure the fastening. This is effected by forming the hasp of the lock.
as shewn in plan and elevation at Figures 8 and 9. When the fastening
is used as an ordinary latch the latch G'on closing the door in the.
direction of the arrow slides up the inclined top surface of the pro-
jection 6, as shewn in dotted lines at G³, and drops into the hasp, as
shewn in full lines, the opening of the door being effected by raising the
latch by means of the before-mentioned handle and lever. When the
fastening is to be used as a lock a pin is inserted at the back of the lock
over the latch G' in such a position as to allow it to be raised sufficiently.
to clear the notched sliding pins, but not sufficiently to be raised entirely
out of the hasp by the handle; then by the insertion of the key the
latch will drop into the dotted position G, and in opening or closing the
door it will pass along the under surface of the projection b, as indicated.
The latch is then raised into the hasp by the handle so as to free the
sliding pins, and these in sliding forward hold the latch in the raised
locked position G. For unlocking the above operation is effected in
the reverse manner. By preference, however, the lock is used in com-
bination with a sliding bolt, the latch G when in the locked position.
•
i
-
n

page_text: acting as an obstruction to the sliding back of the sliding bolt, while
when it is in the unlocked position the bolt is free to slide back over the
top of the latch.
Figures 10 to 13 shew one arrangement by which this may be effected.
G is the latch of the before-described lock, and A is the sliding bolt, both i
of which are supposed to be fixed against a door to be fastened by the
sliding forward of the bolt A. This bolt is so arranged that its outer
face can just slide behind the inner face of the latch G as indicated, it is
provided with a triangular projection or stud B projecting somewhat
over the latch. When the bolt is shot forward and the lock is locked, ]
as shewn at Figure 10 (the position of the latch corresponding with
that G'at Fig. 1), and it is endeavoured to push the bolt back the
stud B strikes against the surface d, e, of the notch in the latch and
raises the latter slightly until the stud arrives at the bottom of the
notch when any further backward motion of the bolt is impossible. 1
.When it is desired to unlock the lock and withdraw the bolt, this is first
slid back as just described thereby raising the latch sufficiently to clear
all the notches of the sliding pins O (Fig. 3), whereupon these pins
are moved by the action of the key, so as to bring the deep grooves c in
a line with the latch, as before described. The bolt A is now again 2
slid forward so as to allow the latch G to fall into its lowest or unlocked
position, as shewn at Figure 11 (corresponding with the position G at.
Figure 1), whereupon the bolt A with its stud B will be free to slide
back along the upper edge of the latch until the bolt arrives in the
position shewn at Fig. 11. Here the stud B comes in contact with 2
the projecting inclined surface f, g, of the latch, so that by sliding the
bolt still further back it raises the latch by causing the inclined
surface f, g, h, thereof to slide along the stud as indicated in Figure 12,
the latch being grooved as shewn more clearly in plan at Figure 10° to
allow of this motion. By thus raising the latch the pins C are again 3
free to be moved forward out of the unlocked position by the springs F,
so that when the bolt is again shot forward for locking the door (during
which motion the stud B slides underneath) the latch, as shewn at
Fig. 18) the latch after the stud B has moved from under it will again.
fall into the locked position at Figure 10.
Figures 14 to 16 shew a modification of the just-described arrange-
ment of the sliding bolt and latch. Here the latch G has a dovetail
projection g, which when the latch is in the locked position, shewn in
:
.3
.

page_text: full lines at Figure 14, is situated in the notch a of the sliding bolt A,
so that in endeavouring to slide back the bolt the front edge of its
notch comes in contact with the end of the projection g which thus
prevents the sliding back of the bolt. For opening the lock the bolt A
5 is first slid in the direction of the arrow, Fig. 14, whereby the back
edge of its notch effects the raising of the latch into the dotted position
in which it is free of the sliding pins of the lock, so as to allow these to
be acted upon by the introduction of the key. On now sliding back
the bolt A the latch will drop out of the notch a into the unlocked
▸ position at Figure 15 when the lower edge of the bolt can slide back
over the top of the latch as at Figure 16. For locking the lock
again the bolt A is slid forward whereby the back edge of the notch a
(which it will be seen projects downwards somewhat lower than the
front edge) is made to catch the projection g of the latch and to draw it
up
into the notch into the dotted position, Figure 14, when the sliding
pins of the lock being free to shoot forward again the latch will be held
in the locked position.
Figure 17 shews another modification of the combined latch and
sliding bolt in which the lock may be made to act either as an ordinary
) latch lock, to open without the use of a key or as a lock. In this case
for opening the bolt A it is turned by means of a spindle B (actuated by
a handle) from the position shown in black to the position shewn in
blue. The bolt has a tail a, which when the lock is to act as an ordinary
latch comes in contact with the inclined end surface of the latch G on
5 the turning back of the bolt, and thus raises the latch sufficiently to
allow of the motion of the bolt. The forward motion of the bolt on
freeing the handle is effected by the spring D acting on the finger a³,
of the bolt. When the bolt is to be locked in its forward position a
pin E is inserted at the back of the lock over the latch G in such a
O position that the latch can only be raised sufficiently to lift it clear of
the sliding pins of the lock. Thus it will be seen that in endeavouring
to turn back the bolt A, the tail a thereof will come in contact with the
end surface of the latch, which will prevent its backward motion as soon
as the latch has been raised up to the pin E.
5
For unlocking the lock the latch is first raised into this position by
the action of the bolt, the key is then inserted, whereby the latch is
caused to drop into the unlocked position shewn in red lines, (the bolt
having been first turned into the red position) whereupon the bolt A
J

page_text: ཁཨ་སརྨ་
will be free to be turned back into the blue position with its tail passing
over the top of the latch. On releasing the handle of the bolt it will
be caused to spring forward by the action of the spring D and the
finger a¹ thereof will then raise the latch G so as to bring it into the
locked position again.
I do not claim as part of this Invention the special contrivances
herein-before described with reference to Figures 8, 9, and 14 to 17,
except in so far as they comprise the general construction of the
improved lock first herein-before described and the method generally of
arranging a sliding bolt to act in combination with the latch of the 1
lock.
Having thus described the nature of this Invention and in what
manner the same is to be performed as communicated to me by my
foreign correspondent, I wish it to be understood that I do not limit
myself to the precise details of the improved lock as herein-before ]
described and shown on the accompanying Drawing, as these may be
variously modified without departing from the essential features of the
Invention, (thus it will be evident that the number, form, and position of
the sliding pins C, and their notches may be varied as before-mentioned, .
as may also the arrangement and configuration of the latch G, and tho 2
manner in which it is mado to act in combination with a sliding bolt,)
but what I claim is,—
First. Constructing locks or latches with a series of sliding pins or
their equivalents having false notches and real notches, which latter are
arranged at varying distances from the ends of the pins, such sliding 2
pins being so arranged to act in combination with a latch bolt or
cquivalent device that the latter is held in a locked position by catching
into the falso notches of the pins, and is unlocked by bringing all the
real notches of the pin into such relative positions that the latch or
bolt can pass into them, substantially as herein-before set forth.
3
Second. The series of sliding pins C with false and real notches
contained in separate recesses in the casing P, and acted upon by
springs F, arranged and operating substantially as and for the purposes
herein-before set forth.
Third. The latch or bolt G with feather edge 9 fitting in a groove in 3
the casing P, arranged and operating in combination with the grooved
pins C, substantially as and for the purposes herein-before set forth.

page_text: Fourth. Arranging the latch G or its equivalent to act in combination
with a sliding bolt in such manner that when the latch is situated in
the false notches of the sliding pins it acts as an obstruction to the
sliding back of the bolt, but when it is situated in the real notches
of the sliding pins it allows of the backward motion of the sliding bolt,
substantially as herein-before set forth.
In witness whereof, I, the said Charles Denton Abel, have hereunto
set my hand and seal, this Seventeenth day of May, in the year
of our Lord One thousand eight hundred and seventy-one.