Improvements in Locks and Keys.
Year: 1894

page_text: Date of Application, 22nd Feb., 1894-Accepted, 14th Apr., 1894
Improvements in Locks and Keys.
We, FREDERICK MANN of 154 Elthorne Road, Hornsey Rise, in the County of
Middlesex, Cabinet Manufacturer, and HENRY HERBERT AKERS of 53 Elthorne
Road, Hornsey Rise, in the County of Middlesex, Gentleman, 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 invention relates to improvements in locks and keys and will be best
understood by reference to the accompanying drawings, in which
Figure 1 is an elevation of the lock in its unlocked condition, the cover-plate
being removed.
Figure 2 is a similar view of the lock with the key, shown in section, locked
therein.
Figure 3 is an elevation showing the lock in its locked condition and with the
key removed.
Figure 4 is a section on the line 4-4 of Figure 2.
Figure 5 is a perspective view showing the underside of the bolt, and
Figure 6 a perspective view showing the upper side of the cam-plate.
The cover-plate of the lock is shown in Figure 4, represented in dotted lines in
Figure 1, and is altogether omitted from Figures 2 and 3.
Like letters indicate like parts throughout the drawings.
A is the lock-casing which may be of any desired construction and provided with
a cover-plate A¹ (Figure 4) secured to the casing A in any convenient manner.
The casing A is provided with one or more studs or projections A2 for guiding the
bolt B, the locking end of which in the ordinary manner is adapted to slide in and
out through an opening in one of the plates or walls of the casing A as shown for
example in Figure 3. The bolt B is provided with slots or recesses B' B' the
former for working on the stud A³, and the latter for accommodating the pivot
pin A, and with a recess B³ for enabling it to be shot backwards and forwards as
hereinafter described. The bolt B is moreover provided with a projection B in
conjunction with which the tumbler levers operate as hereinafter described.
Between the bolt B and wall A³ of lock casing A the cam-plate C is so arranged
that it can be freely rotated, said cam-plate for this purpose being conveniently
provided with a boss C', Figure 4, (also shown in dotted lines in Figures 1, 2
and 3) which is received in a circular hole in the plate A³, and may be secured
therein in any suitable manner; or would necessarily remain there if, as shown in
Figure 4, the cam-plate, bolt and tumblers filled the whole space between the
plates A A³ of the case.
The cam-plate C is provided with cam surfaces C³ C and with a projection C
which latter fulfils the function of the bit of an ordinary key; the cam-plate C is
moreover provided with an oblong, square, triangular, or equivalent non-circular
recess C into which the operative end of the key is adapted to fit as shown in
Figure 4, and with a curved slot C8 which serves for limiting the rotation of C
which is effected by the ends of CB abutting against the pin A secured in the lock-
plate A as indicated in Figures 1 and 3; other means may however be employed
for limiting the motion of the cam-plate C.
E E are the tumbler levers, two in number, but of which there may be any
lesired number. These tumbler levers are both pivotted on the before referred to
pin A secured in the plate A³ and, when the bolt is in its unlocked position, this
pin passes through the recess B2 of the bolt B. Each of the tumbler levers is
provided with a tail spring E, in the manner common to such tumbler levers,

page_text: '
which springs bear against a fixed pin A' secured in the lock-casing, each of the
tumbler levers being provided with a recess E and gate E' for engaging with or
releasing the stud or projection B of bolt B. Each tumbler lever is provided with
an opening E in which is located a pin or projection F mounted rigidly in or
forming part of a lever F pivotted at F2 to the plate A³. The lever F is acted
upon by a spring F³ in such manner as to tend always to move its operative end,
that is to say the upper end shown in Figures 1, 2 and 3 inwards towards the key.
The heel or projection F of lever F is always pressed by the spring F3 against
the outer surface of the cam-plate C, the canr surfaces C³ C of which serve for
moving the lever F outwards, and through it and its pin F', the tumbler
levers E E. The tumbler lever E may be provided at its underside with pins or
projections which, by bearing upon the lever F, would serve to retain said
tumbler lever, as also E', in their proper working position.
G is the key which may be provided with the usual bow G¹ or other handle by
means of which it may be turned and is provided with a projection G2 of shape
corresponding with that of the before-mentioned recess C in the cam-plate C. The
stem of the key is formed with one or more annular recesses G₁ and one or
more annular ribs G' with which the tumbler levers E' E engage.
In the key
illustrated in Figure 4, there is represented one annular recess G with which the
tumbler lever E is adapted to engage, and one annular rib G in conjunction with
which the tumbler lever E is adapted to operate. The rib G and reduced portion
at G are of such diameter that when the tumbler levers E' E are pressed by the
springs E3 into their innermost positions, that is to say, when the recesses Es of
these levers bear against the appropriate reduced portion or rib of the key, the
gates E of the tumbler levers EE will coincide with each other and the stud B*
of the bolt B is free to pass through the gates E³.
The cover-plate A is preferably provided with a cylindrical projection A
which forms an extended bearing for the key.
8
The operation of the before described lock is as follows;-The key is passed
through the projection AⓇ and pressed inwards until its non-circular projection G²
engages with the corresponding recess of the cam-plate C and the key is turned
in the usual manner in the direction necessary for shooting forward the bolt
supposing the bolt to occupy its unlocked position before the operation commenced.
Before the key is thus turned the lever F is supported by the cam-plate C in its
outermost position so that by the pin F1 engaging with the outer sides of the
openings E the tumbler levers E E are held in their outermost position, as shown
in Fig. 1, but when the cam-plate C is turned the smaller radius or diameter of the
cam-plate C is presented to the heel of the lever F which is thereby allowed to
move inwards under the influence of its spring F³ and in so doing releases the
tumbler levers E E so that under the influence of their springs E³ they are
similarly pressed inwards, their inward motion being limited by the surrounding
edges of the recesses E3 bearing against the ribbed or recessed portions of the
key G at which time the gates E all coincide. At this part of the operation the
bit C has come against the edge B³ of recess B3 and moves the bolt forward
towards the position shown in Figures 2 and 3. Upon the further rotation of the
key and through it of the cam-plate C when the bolt has nearly arrived at the
limit of its locking stroke the larger diameter of the cam-plate C is brought into
operation upon the lever F and causes said lever F to be pressed outwards from the
key and through its pin F to draw the tumbler levers É E' outwards so that the
gates E are thrown out of coincidence and withdrawn from the back of the stud B
of bolt B which thereby is locked in its shot-forward position as shown in
Figure 3.
The unlocking of the bolt is effected in substantially the reverse of the manner
before described with regard to the locking or shooting forward of the bolt, that
is to say, the key is inserted and turned in the proper direction so as to allow the
tumbler levers E E' to be moved towards or approach the key and thereby bring
the gates E' into proper coincidence, at which time the bit C by bearing against

page_text: the side B of bolt recess B³ moves the bolt into its unlocked position, after which,
through the lever F, the tumbler levers E E' are moved outwards so that the
gates E are again thrown out of coincidence and withdrawn from the back of the
Stud B' thereby locked in its inoperative position.
The before mentioned key projection G2 is of preferably oblong section slightly
tapering towards the end as indicated in Figure 4 so as to facilitate its insertion
into the cam-plate aperture C which is of corresponding oblong form. Between the
projection G and the annular rib G the key is of reduced diameter so as to form
a neck G. The thickness of G may be varied in relation to the thickness of the
other parts of the key, but it is essential that it (G) should have a radius less
than that extending from the axis of the key stem to the outer edge of at least
one of the wings of the projection G²; as long as this essential particular is
adhered to, the key or the projection G' thereof may be of any suitable shape for
instance the diameter of the neck or part G may be the same as the general
diameter of the key stem, the grooved part or parts G in such an arrangement.
being of smaller than said general diameter and the projection A of cover-plate A¹
being preferably grooved to accommodate the projection G2 when the key is being
inserted into or withdrawn from the lock.
The bolt B as shown particularly in Figure 5 has either formed in one with it
as indicated, or secured to it, a plate B in which is formed a hole B of peculiar
shape consisting of two transverse openings bb connected centrally by a longitudinal
opening 62. When the bolt B is in its unlocked position the opening b is immediately
opposite the cam-plate aperture C and passage through A", and when said bolt is
in its locked position the opening is immediately opposite C and passage
through Aº.
The key projection G² may be passed through the opening, when the bolt B is
in its unlocked condition, so as to fit into the cam-plate aperture C and when in
proper position therein, which is determined by the end of the key abutting against
the surface A Figure 4, of lock plate A³ the neck or part G is located in the
opening b. When now the key is turned for operating the bolt the projection G²
is moved out of coincidence with band cannot be withdrawn. At an intermediate
part of the motion of the bolt B the position of the projection G² coincides with
that of the longitudinal opening 2 connecting band but the key cannot then be
withdrawn because at that stage the tumbler lever E' is in engagement with its
annular key-groove G* as before described. The result of this therefore is that
whenever the position of the key-projection G2 coincides with that of the
openings which it can only do when the lock is in either its completely
unlocked or locked condition the key can be removed, for, as soon as the key is
turned from either of these positions, though, at the first and last parts of its
rotation, the bolt partakes of no motion the projection G extends diagonally
across or as shown in dotted lines in Figure 2.
It will be seen that unless the ribs and reduced portions of the key are of
proper size the tumbler levers E E' will either be allowed to move too far or not
sufficiently inwards so that the gates E' will not be brought into proper coincidence
to allow of the passage of the bolt stud B, so that a lock constructed according to
this invention will present very considerable difficulty should an attempt be made
to open it with any key but one specially provided for it.
An important feature which by itself would distinguish the before-described
lock from ordinary lever locks is that whereas in locking or unlocking an ordinary
lever lock the release of the bolt is effected by the movement outwards from the
key of the tumbler levers by the direct action thereon of the key and the locking
of the bolt is effected by the movement inwards towards the key of the tumbler
levers under the influence of their springs, the release of the bolt in the present
invention is effected by the movement inwards towards the key of the tumbler
levers under the influence of their springs and not by the direct operation thereon
of the key and the locking of the bolt is effected by the movement outwards from
the key of the tumbler levers also without the direct action of the key thereon.

page_text: Various modifications may be made in the before described lock without
departing from the essential features of the invention, for example we may form
the key-locking slot of the bolt B of other than the H-shape shown and if desired
we may fit upon the bolt-plate B7 other plates having slots or wards therein so as
to further complicate the lock and render it more difficult to be picked or opened
by any but the proper key.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed we declare that what we
claim is;-
1. Locking the key in a lock until the locking or unlocking operation is com-
pleted by means of the bolt or one or more plates attached to or formed in part
with it substantially as described.
2. In a lock a bolt having an H-shaped slot such as BB substantially as and for
the purpose described and illustrated in the accompanying drawings.
3. The combination with a lock adapted by means of its bolt to lock the key
therein of a key having two parts such as G G having radii of different lengths
from the axis of rotation of the key substantially as described and illustrated in
the accompanying drawings.
4. The combination with a lock whose bolt is provided with an H-shaped slot
such as bb63 of a key having a projection such as G2 and neck such as G'
substantially as described and illustrated in the accompanying drawings.
5. The combination and arrangement of parts constituting the complete lock
substantially as described and illustrated in the accompanying drawings.
Dated His 21st day of NPOTIBIFY TAYA
F. MANN.
H. H. AKERS.
W. P. Thompson & Boult,
Agents for the Applicants.