Year: 1897

page_text: I, HENRY SEXTON, Clerk of Works, Berks County Asylum, Moulsford, near
Wallingford, Berks, do hereby declare the nature of this invention to be as
follows:-
By this invention a mortise dead lock is single locked by means of an oval knob
on one side only operating on the bolt by means of a follower the bolt being further
shot to double lock by means of the key. The key will also also single lock instead
of using the knob and can be used on either side of the lock. An arrangement
is also introduced to prevent the lock being picked by a piece of wire or any thing
of that description.
The follower is made with an arm or lever at an angle of 45° a slot being
formed in the arm which engages with a stud or pin on the bolt so that when the
knob is turned the arm forces the bolt along to single lock the door the slot in the
arm of the follower being of sufficient length to allow the pin or stud of the bolt
to move along in the slot when the lock is double locked by the key. The key
operating direct upon the bolt allows it to be used on either side and to single lock.
A solid disc is introduced to revolve round the bush of the key hole when the
key is being used the disc taking up all the space between the side plates of the
lock and engaging with the tumbler when the key is removed so that the disc may
remain in position ready for the key to be again inserted. On each side of the
key hole a tumbler is arranged with a stud or pin in each reaching up to the side
plate of the lock these tumblers are operated by the key in the usual way and pre-
vent the lock being picked by wire.
I, HENRY SEXTON, of Berks County Asylum, Moulsford, Wallingford, in the
County of Berks, Clerk of Works, do hereby declare the nature of this invention
[Price 8d.]

page_text: and in what manner the same is to be performed, to be particularly described, and
ascertained in and by the following statement:―
The present invention relates to improvements in mortise dead locks for
asylums. The main object of it is to render such locks proof against being picked
as well as against dust or small articles clogging up the keyhole and thence getting
into the working mechanism.
This improved construction of lock will be found of especial service in lunatic
and other asylums where from sheer mischief. the locks are frequently tampered
with by the inmates. All the tampering they could do would be ineffectual.
I will now describe my invention in detail, reference being had to the accom-
panying drawings illustrating the same as applied to a mortise lock, and in
which:-
Figure 1 is a plan of the lock with the top plate removed. The key and spindle
being inserted, are in section.
Figure 2 is a vertical section of the lock.shewn fitted in a door, the section being
taken on the line 2-2 of Figure 1.
... **
Figure 3 is a section taken on the line 3-3 of Figure 1.
Figures 4 and 5 shew the front and sectional elevation respectively of the
revoluble disc or keyhole block.
"
Like reference letters denote different views of the same parts throughout these
drawings: a is the case, b is the bolt, c are the tumbler levers, d is the spindle,
e is the handle or knob thereof, f is the pinion or follower which moves the bolt b,
is the lower sur-
g is the stud or stump, h is one corner of the slot in the lever
face or edge of the slot in the lever c, j is an opening or longitudinal slot in the
lever c, is an opening or transverse slot in the lever c, is the top end of the
slot . is the circular disc or block revolubly mounted upon the bush of the koy-
hole; m and m' are the two pivoted guards, n, n' are the cover-plates of the
case, o, o¹ are the pivots of the guards m, m', p is the fixed stop against which the
front free end of the guards m, m¹ abuts, q and q' are the guard springs, r, r¹ are
the side openings in the guards m, m¹, s is the curved front surface of the said
guards, t is the top extremity of the said surfaces, is the key.
The lock consists of the usual case a containing a bolt 6 of the rack-and-pinion
type and the tumbler-levers c, arranged so that the lock may be either singly or
doubly locked; the single locking being effected by a part turn of the knob or
handle or by a complete turn of the key, and the double locking by a part turn of
the handle followed by a complete turn of the key, and the unlocking by either a
part turn of the key and a part turn of the handle, or by two complete turns of the
key in the same direction.
In practice it is found most convenient to employ an oval or elongated knob
or handle in place of the ordinary round one, chiefly because the direction of the
major axis of such elongated form indicates at a glance the exact position of the
bolt, that is to say, whether unlocked, single locked or double locked.
The operation in detail of the mechanism is as follows:-The turning of the
spindled by means of the knob e rotates the follower, or its equivalent, the
pinion f, which as the case may be engages or comes in contact with and operates
the bolt either forwards or backwards according to the direction in which the
knob is turned, and, assuming the spindle to have been turned in the forward or
locking position, simultaneously the stud or stump g, which is a rigid projection
fixed to the bolt plate, moves from its position shewn in Figure 1 to the opposite
corner of the slot in the lever c, and the lock would then be what is called single
locked. To finish the locking, the key is now given a complete turn in the same
direction and during this latter turn the lever c is raised and the surface of the
said lever is brought up to or underneath the stump or stud g, this stud being
now opposite the opening the continuation of the movement carries it forwards
into the opening k, the lever c then sinks again to its horizontal or normal
position, the stump or projection y riding to the top of the slot k, when the
movement is complete and the lock double locked.

page_text: "
The key may be used in either side of the lock, but the knob is usually fitted
to the outside of the door only.
..
I am aware that the above described movement is not novel and do not wish to
lay any claim to it alone, but only, in combination with the means hereinafter
described, for preventing mortise or other locks from being picked and also the
means for preventing the stopping up of the keyhole with dust or small objects
such as beads, splints, paper, &c., which should they penetrate to the mechanism,
are found so obstructive to the proper working of the same.
'
The means above, referred to comprise the circular disc or block shewn detached
in Figures 4 and 5 and the two tumblers or guards m and m¹ introduced around
the keyhole. The said disc is a circular block revolubly mounted in the lock
just behind the ordinary keyhole in the cover plate, or in other words, it is a
circular solid disc or block of the thickness of the inside of the lock between the
two cover plates and mounted revolubly upon the bush of the keyhole and turning
with the key. This disc or block has also a keyhole cut in. it which normally coin-
cides with the ordinary keyholes in the coverplates n, n¹ thus making a through
passage or clear keyhole from one side to the other of the lock.
The guards m, m² may be solid and drop into position by their own weight, but
they are preferably made hollow and possess side openings, r, 1 for reasons here-
after explained.
They are pivoted at o, o' and normally pressed against the stop p by the action
of springs q, q. Instead of being pivoted they may be slidably mounted in guides.
Should any dust or small objects such as beads, splints, paper &c. be put into the
keyhole they will be thrust out at the opposite side by the key when it is inserted.
On turning the key, the circular disc or block is carried or turned round with it,
and one of the tumblers or guards m, m¹ is thrust back by the "bit" of the key
which then follows with rubbing contact the curved fronts of the guard and after
passing the point t becomes again free of the guard and the latter again rests against
the stop while the key passes on to and operates the levers c.
The keyhole is open at the sides, such openings being closed by the disc and free
end of the guards when the latter are at rest, thus any dust or small objects which
might have been put into the keyhole are prevented from gaining access to the
lock mechanism. Should a piece of wire or the like be inserted for the purpose
of "picking" the lock, it could only penetrate through either of the openings r, r
in the guards, into their hollow interior when it could go no further and so could
not possibly get at the bolt or other mechanism. These guards when hollow thus
act as a trap to hold bend or divert a wire or other picker away from the lock
mechanism.
It will be obvious that the revoluble keyhole and movable keyhole guards as
above described are applicable to many other kinds of locks than mortise or rim
locks and that the only variations in them would be in the shape which would
depend upon the other fittings or surroundings.
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:-
1. The pivoted or slidable keyhole guards constructed, operated and working,
substantially as described and set forth.
2. The combination with a mortise or other lock, of the pivoted or slidable key-
hole guards, constructed, operated and working, substantially as described and set
forth.
3. The combination of the pivoted or slidable keyhole guards, with the solid
disc or block having a keyhole formed in it and revolubly mounted, between the
two cover plates, on the bush in the ordinary keyhole and adapted to be carried
round with the key, substantially as described and set forth.
4. The combination with a mortise or other lock, of the pivoted or slidable key-
hole guards and the solid disc or block revolubly mounted on the bush in the

page_text: ordinary keyhole and adapted to turn with the key, substantially as described and
illustrated in the accompanying drawings.
Dated this 13th day of May 1898.
PHILLIPS & LEIGH,
No. 22, Southampton Buildings, Chancery Lane, London, W.C.,
Agents for the Applicant.