CERTAIN IMPROVEMENTS IN LOCKS FOR DOORS AND OTHER PURPOSES
Year: 1832

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
PARSONS (lately the younger), of Furnival's Inn, London, Gentleman, send
greeting.
WHEREAS His present most Excellent Majesty King William the Fourth,
by His Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Twentieth day of December, in the third year of His reign,
did, for Himself, His heirs and successors, give and grant unto me, the said
Thomas Parsons, His especial licence that I, the said Thomas Parsons, my
exors, admors, and assigns, or such others as I, the said Thomas Parsons, my
exors, admors, or assigns, should at any time agree with, and no others, from
time to time and at all times during the term of years therein expressed,
should and lawfully might make, use, exercise, and vend, within England,
Wales, and the Town of Berwick-upon-Tweed, my Invention of "CERTAIN
IMPROVEMENTS IN LOCKS FOR DOORS AND OTHER PURPOSES;" in which said Letters
Patent is contained a proviso obliging me, the said Thomas Parsons, by an
instrument in writing under my hand and seal, particularly to describe and
ascertain the nature of my said Invention, and in what manner the same is
to be performed, and to cause the same to be inrolled in His said Majesty's
High Court of Chancery within six calendar months next and immediately
after the date of the said in part recited Letters Patent, as in and by the
same, reference being thereunto had, will more fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Thomas Parsons, do hereby declare the nature of my said Invention to
consist,-
First (as regards door locks) in an arrangement of lever tumblers carrying
with them loose tumblers in such manner that both the lever tumblers act in
retaining the bolt as well in its locked as in its unlocked position, as also an
arrangement of lever tumblers without loose tumblers, such lever tumblers
acting in notches on the bolt, as herein-after explained. In both which cases
my said arrangement and form of tumblers and the springs is such as to
allow of the tumblers being made of very thin metal, so that I may have
several of them in one lock without increasing its size to an inconvenient
thickness.
And, secondly (as regard box locks), in having two or more thin bolts to
shoot at the same time with the same key without any tumblers, but so
arranged that the bolts do not require to be adjusted by the steps or risers
of the key before they can be thrown into the catch or keep when locking, but
do require to be so adjusted before they can be withdrawn from the catch or
keep when it is to be relieved from them. And in further compliance with
the said proviso, I, the said Thomas Parsons, do hereby describe the manner
in which my said Invention is to be performed, by the following statement
thereof, reference being had to the Drawing annexed, and to the figures
and letters marked thereon (that is to say):-
DESCRIPTION OF THE DRAWINGS.
Figures 1 and 2 represent a door lock with the front plate taken off to shew
the internal parts; and it may be as well here to observe that similar letters
are used to denote similar parts in all the Figures. A, A, A, A, A, colored
grey, is the bolt, on each side of which are formed two grooves or recesses in
the form of ares of circles, as shewn in the edge view of the bolt at Figure 6;
in these grooves the tumblers work, as herein-after explained. B, B, & C, C,
colored yellow, are 2 guides one on each side of the bolt, and each being
made of 5 pieces, as shewn by the edge view of the guides at Figure 7, so as
to form a groove or recess on each side similar to and corresponding with the
grooves in the bolt; these pieces are intended as guides for the tumblers and
not to guide the bolt, there being a clip D to guide the bolt, this clip D is
fastened or held by four strong screws which pass through the back plate of
the lock into the door to hold the lock to its place. For the sake of clearness
I have only shewn two lever tumblers in this Figure, one on each side of the
bolt, but it will be evident that any convenient number may be applied equally

page_text: well. The parts marked E, E, and. colored brown, are 2 loose pieces of
metal, which I call loose tumblers, one fitting and lying loosely in one of the
grooves of the bolt, and the other partly in the groove of the bolt and partly
in the groove in the guide C; and these are two similar pieces not seen in this
Figure in the grooves at the under side of the bolt, so that for each lever
tumbler there are two loose tumblers, and these latter are carried to and; fro
with the bolt when the bolt is put in action. The part, colored pink and
marked F (shewn separately at Figure 3), is one of my lever tumblers centered
upon a fulcrum at G; this fulcrum or axis passes into both the front and back
plates of the lock, and carries both the lever tumblers one on each side of the
bolt, as shown at Figure 2, where the second tumbler is marked H and
colored green. By this arrangement both the lever tumblers, it will be seen, act
from the same axis or centre. e, e, e, e, four screw holes to receive the screws
which pass through and fasten the front pipe to the lock.. f, the keyhole.
K, the key, the pipe of which receives the key pin fixed into the correspond-
ing part of the front plate, but not seen here by reason of the front plate
being removed to shew the inside of the lock. It will be necessary here to
observe that in Figures 1 and 2 I have represented a lock requiring a pipe
key to open it, in consequence of which, when required to unlock from either
side of the door, it is necessary to have two key pins one in each lock plate,
and, consequently, two keyholes. In each of these Figures, therefore, only
one keyhole f, and one key pin J, will be seen on the lever tumbler F. At L
and at M are cut two curves for the key to act upon, one suited for the key
to act upon through each key hole. Figure 4 is the second or, as shewn in this
Figure, the under tumbler, and is colored green and marked H; and by com-
paring the two lever tumblers with each other it will be seen that the space
to be occupied by the loose tumbler E, colored brown in each Figure, is cut at
a different part of the arc which forms the end of each tumbler.
Figure 5 is a plan of the bolt with the fulcrum or axis of the lever tumblers
shewn passing through a slot cut in the bolt precisely of the length required
for the proper action of the bolt; the axis has a square formed on it to fit the
slot of equal thickness with the bolt, and serves to steady that end of the
bolt. The guide pieces B and C should be made in five parts, as shewn at
Figure 7, if the bolt be placed in the middle between the two tumblers, as
in the Drawing, in order to afford the requisite facility for seeing the lower
tumblers, here colored green, while the manufacturer is adapting each to be
correctly raised by the key; and they may be afterwards attached together by
rivets or by screws, as shewn in this Figure, which screws also attach them
to the back plate.

page_text: Figure 8 is. the key. Now it will be observed that each of the lever
tumblers has a space for the loose tumblers cut from a different part of the
arc o, so that when the lever tumblers are pressed upon in the direction of
their line of motion by the action of their respective springs at S, they will
assume the position shewn in Figure 1, wherein they intercept the motion
of the bolt which is unlocked, and thus it is evident each lever tumbler must
be raised to a height differing from the other, and each step in the bit of the
key must be so proportioned to the lever tumbler on which it is to act as to
raise the loose tumbler E entirely within the recess in the bolt, or otherwise
the bolt cannot be moved by the key.
Figure 2 is a plan of the lock with the bolt thrown out by the key or locked,
the lever tumblers being so raised by it as to place the loose tumblers wholly
within the recess in the bolt, which is consequently not impeded in its motion
by the tumblers,, but on the continued motion of the key the springs will again
depress the lever tumblers, and the loose tumblers which they act upon will
abe carried into the position shewn in Figure 1, and thus the bolt will be
securely held by the tumblers and prevented from being moved except by
the right key; S is the case holding the springs which act upon the lever
tumblers F and H. These springs are formed by a small shouldered bolt
, acting against a spiral spring in a box or block pierced with as many holes
as there are bolts; one only can be seen in this view, but as there are two
.tumblers there must, of course, be two small bolts and springs, for as in this
arrangement the tumblers each rise different heights, each must have a
-separate spring acting upon it. For the sake of not confusing the Drawing,
and to render it more clear and simple, I have shewn only two tumblers, but
a competent locksmith will be aware that by reason of the peculiar support
the tumblers receive from the guides B, B, and C, C, on each side of the bolt
more tumblers than have been heretofore may be introduced into any given
thickness of a lock, and the number probably will be only dependent upon
the practicability of constructing springs. enough in the given space to act
upon them. The workman will know how to add a spring bolt and its
: appendages if desired, as also to adapt. this like other tumbler locks to the
several uses to which such locks are usually applied; this lock is more readily
. made with one keyhole and two keys, as in the lock shewn at Figures 9, 10,
11, 12, 13, and 14; herein-after described, for to construct it. with one key only,
unless one half of the tumblers be duplicated of or formed like each other
and arranged as is usual in Barron's locks, I believe it is requisite that the
¡back plate of the lock should be removeable so that the workman may work
from each side of the lock successively.

page_text: Having now described the various parts of the lock, I will proceed to
explain its action. The lock being at the unlocking position and the various
parts at rest, as shewn at Figure 1, the key must be introduced, and being
turned in the proper direction, the short step of the key will raise the pink
lever tumbler F until the loose tumbler E is lifted into the forward recess on
the front side of the bolt, while the long step of the key will raise the green
lever tumbler H until its loose tumbler is lifted into the corresponding recess
on the back side of the bolt at the moment the key will come in contact with
the talon of the bolt marked x, and throw it forwards, carrying with it the
two loose tumblers which have just been raised by the back and front lever
tumblers, and bringing the two loose tumblers, which have been lying inert
in the two hinder recesses, forward in order to be acted upon by the lever
tumblers when the key is turned completely from under the lever tumblers,
and they resume the position shewn in Figure 1, though the bolt will be
in the position shewn at Figure 2, where the lever tumblers are: shewn
raised by the key to the position required to let the bolt pass forward, and
it will be seen by examining this Figure that when the key is turned quite
from under the lever tumblers in order to remove it, the pink lever tumbler
will force down the loose tumbler E nearly out of the recess it is in, while
the green lever tumbler will force its loose tumbler down also a little
way, but not quite so far down as the pink one, the difference depending
entirely on the different situations: of the spaces cut in the front arcs of the
lever tumblers.
Figure 23 is a plan of the outside of the front plate of the lock. z is a
raised part to form a recess inside and lie over the clip D, which necessarily
projects to the extent of its thickness above the general surface of the upper
lever tumbler, as shewn in the section Figure 26.
Figures. 9, 10, 11 represent another door lock of a more simple form, and
without a loose tumbler, the back plate is removed to shew the inside. A, the
bolt, colored grey, having four curved notches cut in its edge at b, g, and c, d,
to admit the curved ends which I call the teeth of the tumblers, and a
recess B, Figures 9 and 10, cut out of it to admit the. locking plate, shewn
separately at Figure 12. r, r, r, r, r, colored yellow, five pieces of metal
screwed to the front plate of the lock in part to steady one end of the bolt,
but especially designed to support the tumblers, which are colored pink and
green; F in Figures 9, 10, and 11, is the upper tumbler having an arc
of a circle projecting from each end which I call a tooth, and H is part
of another tumbler colored green, and may be seen lying immediately under
F;.G, in Figures 9, 10, 11, is the fulcrum.of the lever.. tumblers fixed into

page_text: the front plate of the lock; S, Figures 9, 10, 11, colored spring for each
tumbler, similar to that described in Figures 1 and 2, with two screws to
fix it to the front plate of the lock; these springs keep the ends or teeth of the
tumblers into the notches in the edge of the bolt; f, Figure 9, is the keyhole
for the two pin keys; and K, Figure 10, colored gray, is an end view of the
bit of the key; Figure 9 is a plan of the lock, with the bolt drawn in or
unlocked, and the lock plate removed to shew the tumblers, each of which is
shewn by the two colors pink and green, and a dotted line to have its arc
or tooth differing in length from the other, and one end pressed by the springs
into the bolt at d. Figure 10 is a plan of the lock, with the bolt thrown
out and the tumblers withdrawn from the bolt by the key. Figure 11 is a
plan, shewing the locking plate attached by two screws to the bolt, and fitting
the recess B, shewn in Figures 9 and 10; the key is shewn as having raised
the tumblers parallel with the edge of and thrown out the bolt, and at the
point where its farther motion will allow the springs to force the arcs or
teeth of the tumblers into the notch of the bolt, when the bolt will be pre-
vented being moved back again, excepting by the right key, as a key not
fitted to each tumbler will either not release all the arcs or teeth at one end
of the tumblers from the bolt, or force one or more of those at the other end
into the corresponding notch of the bolt, which would equally prevent the
withdrawing of the bolt; Figure 13 is the key for the outside, and Figure 14
that for the inside of the lock; and a short pin is fixed on each side
of the keyhole on the front plate of the lock, as shewn in Figures 9, 10,
and 11, to prevent the passage of the wrong key. Any capable lock-
smith knows how to add a spring bolt and its appendages, and to adapt this
Invention to any other kind of lock, as also how to add as many tumblers
as he may find it practicable to construct springs to act upon, making the
arc or tooth of each to differ in length from all the others, that no two may
have to be raised alike for the bolt to pass.
Having now described the various parts of this lock which has no loose
tumblers, I will proceed to explain its action. Figure 9 shows the lock at
its unlocked position, the tooth V of the pink tumbler being in the curved
notch cut in the bolt at d, and thus holding the bolt fast while the correspond-
ing tooth of the green tumbler is only as far in the notch as shewn by the
dotted line. When the key is turned to throw the bolt forward to the locking
position, it first acts upon the lever tumblers, raising the tooth r of the pink
tumbler high enough to throw the tooth V out of the notch d, and the tooth
H of the green tumbler high enough to clear its tooth under V in the sauc
. manner, and this will bring the tumblers to the position shewn at Figure 10,

page_text: when all the teeth being clear of the notches the bolt will pass forward by
the action of the key; but it is obvious from this arrangement that if a
wrong key be used, even though the teeth at the foremost end of the levers.
were to be depressed sufficiently low to clear the notches, yet if this was done
in a degree the least too. much, the teeth at the other end of the tumblers
would at once rise into the notches 6 or g, and effectually prevent any action
of the bolt.
Figures 15 and 16 represent a box lock without tumbler, with the back'
removed. A, A, is a bolt under which there are two others, one colored pink
and one green. There is a groove in each of the bolts cut from the middle
part towards each end, with the usual opening upwards to receive the keep
or catch; W, W; the talons for the key to act upon, and formed upon each
bolt; at X are three springs fixed under the upper part of the rim of the
lock, and pressing against the bolts, which are all level on the top, to prevent
the right key from over shooting them as it might do within the springs.
Figure 15 shews the lock in its locked state, one limb of each bolt having
been moved by the key into the catch or keep of the lock; Figure 16 shows
the lock unlocked, all the bolts being withdrawn from the catch or keep of
the lock, which is removed, as shown; and the dotted lines in these two
Figures show the chief variations in the bolt next beneath the upper bolt,
while the third or undermost bolt must be varied a little from both; Figures
20, 21, and 22, are separate views of these bolts.
Figure 17 is the key, with its step adapted precisely to lock and unlock
each bolt, the talons of each being varied from the others in such manner
that the right key will throw the bolts, so that when unlocked the ends of all
their limbs shall correspond with the opening in the upper rim of the lock.
Figure 18 shows a section of the lock, with the key pressing against the
bolts, the upper bolt is colored yellow, the next under it pink, and the under-
most green. And the ends of their limbs are seen within the catch, which is
colored grey. Figure 19 is a back view of the lock, with the back plate on;
and Figure 20, a front view. Now, an examination of Figures 15 and 16
will show that there is not any impediment to prevent any of the bolts from
being pushed too far by any key, so that if an attempt be made to unlock
the lock with a wrong key, it will either not push all the bolts far enough to
unlock or too far, in which case it will be relocked by the passing of the
other limb within the catch or keep, thus answering the purpose of a tumbler
lock in a more simple and less costly form. And these bolts are equally
applicable to a padlock, or any other which allows of the use of the same
kind of catch or keep, two bolts may answer perhaps for some locks, and to

page_text: others more than three may be applied if required at the discretion of the
locksmith; Figure 24 is a section of Figure 9; and Figure 25, a section of
Figure 1.
Now whereas I claim as my Invention the form and arrangement of the
several lever and loose tumblers and guide pieces here shown, such being
applicable to door and other locks; and also the herein-before described
combination of several bolts, as likewise their peculiar shape with reference
to the part marked P in Figures 20, 21, and 22, acting together with the
same turn of the key, and here shown applied to box locks, but equally
applicable to padlocks. And such my Invention being, to the best of my
knowledge and belief, entirely new, and never before used within that part of
His said Majesty's United Kingdom of Great Britain and Ireland called
England, His said Dominion of Wales, or Town of Berwick-upon-Tweed, I
do hereby declare this to be my Specification of the same, and that I do
verily believe this my said Specification doth comply in all respects, fully and
without reserve or disguise, with the proviso in the said herein-before in part
recited Letters Patent contained. Wherefore I do hereby claim to maintain
exclusive right and privilege to my said Invention.
In witness whereof, I, the said Thomas Parsons have hereunto set my
hand and seal, this Thirtieth day of June, in the year of our Lord
One thousand eight hundred and thirty-three.