Improvements in Locks and Latches.
Year: 1899

page_text: Date of Application, 13th May, 1899-Accepted, 8th July, 1899
COMPLETE SPECIFICATION.
Improvements in Locks and Latches.
We, GODFREY WOOLLEY ALLEN, Managing Director of the Patent Lock Works
Limited, of 27, Chapman Road, Small Heath, in the City of Birmingham, and
JOHN GREEN, Locksmith, of 36, Camp Hill, City aforesaid, 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 pertains to locks and latches generally, and consists of an
improved means for holding latch-bolts and bolts-proper of locks and latches
in their shot and drawn back positions against being operated, or put into or
out of operation, from the outside by any other than a master key; that is to
say, the said means cannot be controlled from outside by an ordinary key,
although the latch or bolt as ordinarily (without the holding means) can be.
This invention is particularly applicable to simple latches as a means for locking
the latch-bolt in its shot position, so that its unlocking can only be controlled
from without by the master key and from within by hand, although
thesaid, invention can be, applied as a secondary security to
where a.
lock
latch-bolt is
ordinary locking of a
also applied, or even to the latch-bolt in such a lock so that both it and the bolt
proper can form locking means for a door or the like. The means according to
this. invention. also allows of a latch-bolt being fixed back or in its drawn-in
position, but in this instance the said fixing back and subsequent releasing is
done by hand from the inside, the master key having no effect.
bolt-proper in a
the
The holding means according to this invention is characterised by an external
lever-catch operated by hand from the inside of a door, an internal under-lever
operated by a key from the outside of a door and from the inside by the lever catch
as aforesaid, a post or stud carried either upon the said catch or the lever
and which engages either with parts of the casing of the lock or latch or the
latch-bolt or bolt proper in two positions, and a spring which retains the under-
lever and lever-catch in their different positions until its resistance is overcome.
In the accompanying sheet of drawings a night-latch fitted with improve-
ments according to this invention is shown in front-side elevation in Fig. 1, in
back-side elevation with its cover plate and tumbler mechanism removed
in Fig. 2, and in transverse section, also with the tumbler mechanism removed, in
Fig. 3. Figs. 4 and 5 are similar elevations of the night-latch to Fig. 2 but
the parts of the holding means according to this invention are in different
positions; for example, in Fig. 2 the latch-bolt is in its normal position, viz.,
shot, but the holding means is out of action, in Fig. 4 the said means is in action
to secure the latch-bolt in its shot position, whilst in Fig. 5 the holding means
retains the latch-bolt drawn back..
In these figs. c is a lever-catch fulcrumed loosely to the operating knob c
of the latch-bolt and working upon the front side a² of the latch a, the said
latch-bolt and operating knob having a sliding action within the casing, and
the lever-catch having a small knob or projection for moving it. This lever-
catch is shown as a Hat plate strung on the shank of the knob to turn and

page_text: carrying a post or stud co on its inner face, which said post works within and
projects through a cut-away part 4, in the front side of the casing, to the interior
of the latch, the said cut-away part having notches d², ds, formed in opposite
cross directions at its extremities. The stud can therefore, by moving the
lever-catch downwardly when the latch-bolt is normal, engage the notch d
as shown in Fig. 4, and when the latch-bolt is drawn back engage the notch d
as in Fig. 5, and can also freely move back and forth within the said cut-away
part on the latch-bolt sliding when the said lever-catch is in the position shown
in Figs. I and 2.
The latch-bolt is fitted with a suitable lever spring e in a manner well
known, and the tumbler mechanism (not shown) is fitted to it in a manner
common to the art.. The projecting part of the stud within the interior of the
latch couples to the lever-catch e, as aforesaid, an under-lever g, which is
fulcrumed at g2 so that parts or branches 3, g, of it are adjacent to a. ward
scating, m, for the key and within the path of the said keys bit, the said coupling
being made through a slot go formed within the said under-lever. This, last
named is a pivotted plate of suitable shape working flat against the inside of
the outer face of the latch's casing a². underneath the latch-bolt, and it can only
be directly operated by a key, although it is moved indirectly by the lever-catch
when the stud is made to engage the notch. The slot at its one end has
an extension 6, to admit of the passage of the stud, into the notch d² when the
latch-bolt is in the position shown in Fig. 5. When the lever-catch is in the
position in Figs. 1 and 2 drawing back the latch-bolt would only cause. the stud
to work idly within the cut-away part d of the casing and the slot g of the
under lever. A lever spring s works over the inclined surfaces of a horn g7,
for retaining the under-lever and lever-catch and parts carried by them in either
of the two positions Figs. 2 and 4, the lever-catch being stiff enough in its move-
ment to keep its position Fig. 5.
It will be obvious how the holding means is controlled by hand through the
lever-catch from the inside, but from outside a master key is formed whose bit
is so fashioned and shaped as to either act upon the branch g of the under-lever
when in the position Fig. 2 to secure the latch-bolt, or act upon the branch g³
when the under-lever is in the position Fig. 4 to free the said latch-bolt. Other
keys provided with a latch have their bits so fashioned as not to act upon the
branches of the under lever at any time.
The under lever shown separate by Fig. 6 of the drawings differs only in it
having its horn g in a different position, which in some instances would
accommodate a particular design of lock.
Instead of notches being formed within the casing for the engagement of the
stud, they, or their equivalents, may be formed upon the edges of the latch-
bolt, in which case the said cut-away part d would be purely a clearance one.
An additional stud could be formed upon the under-lever to engage notches or
projections upon the latch-bolt, in which case the stud e, now shown, would be
simply one passing through the casing for coupling the lever-catch and the
under-lever.
This invention is equally applicable to a latch-bolt operated by a turning
knob. In this case the lever catch would be loosely mounted upon the end of
the follower, or independently pivotted upon the side of the casing, but the
action and working of the parts would be identical with those of a night-latch.
The improvements can also be applied as a secondary security to a bolt proper
shot by 22 key, their application differing in no essential respect to what is shown
in connection with the night-latch.
We wish it to be understood that the holding means is operated by the key.
slightly in advance of the tumblers.
By fitting the improvements herein described to a night-latch the door can
be secured from within and without against an ordinary latch-key, the master
key being the only one which has the holding means under control. If the

page_text: holding means is brought into action from the inside the lever catch is operated
by hand, but if from the outside the bit of the key acts upon either of the
branches g, g, the latter branch to secure the latch-bolt, and the former branch
to free it.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is:-
First. In locks and latches, the combination of an external lever-catch working
upon the front side of the casing, an under-lever disposed within the lock casing
and coupled to the lever-catch and which is directly operated by a key, a post
or stud carried upon said catch or lever so as to engage parts of the lock casing
or the latch-bolt or bolt proper, and a retaining spring, all operating for the
purpose substantially as described.
Second. In locks and latches, the combination with the casing a having. a
notched cut-away part d within it, of a lever-catch c moved with the latch-bolt
and carrying a stud for engaging said cut-away part, an under-lever g coupled
to the lever-catch by the stud and which is directly operated from without
by a key so as to secure or release the latch bolt, and a retaining means such as s
and g for the under-lever and lever-catch, substantially as described.
Third. In locks and latches, holding means for a bolt proper or a latch-bolt
comprising a lever-catch and an under-lever, coupling stud, notches, and spring
retaining means, substantially as set forth in Figs. 1 to 5.
Fourth. In a night-latch or similar fastening, the specific construction and
arrangement of holding means described and set forth in Figs. 1 to 5.
του.
W. P. THOMPSON & Co.,
11, Burlington Chambers, New Street, Birmingham,
Also of Liverpool, London and Manchester,
Patent Agents for the Applicants.