Year: 1885

page_text: We, Sir GEORGE HAYTER CHUBB, Knight, of 128 Queen Victoria Street in the
City of London and GEORGE GASKELL EXTON of Thurlestone Road West Norwood
in the County of Surrey Engineer 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 that class of spring latch locks in which the latch or
bolt is disengaged from the catch plate either by pulling the knob or handle on
the side towards which the door opens or by pushing the knob or handle on the
other side.
The improvements are shown in the drawing annexed as applied to a mortice
lock but they are equally applicable to rim locks.
Figure 1 is a face view of the lock with the cover plate removed-Figure 2 is
an edge view of the lock with the cover plate shewn in section-a pair of push and
pull knobs or handles are also shown in connection with the lock.
As shewn in theso drawings we form the bolt A of the lock as a segment of a
circle and mount it on a pivot at the centre from which it is struck.
To save space and allow of a bolt of a radius greater than the width of the lock
case being used we make a slot B' in the back plate B of the lock case for the bolt
to turn back into and along the two opposite sides of this slot we form ribs B²
which stand out from the back of the plate-through holes formed in these ribs
is passed the pin A¹ which forms the pivot upon which the bolt turns-this pin is
In this end plate
as shown situated just in rear of the end plate of the lock case.
there is also a slot for the front part of the bolt to protrude through in the ordinary
manner.
In rim locks and in some cases in mortice locks the slot B¹ would not be left
open but the plate would be made at this point of such a form as to provide a recess
for the tail end of the bolt to turn back into.
In the rear end of the bolt is a slot A* into which passes the end of a lever C
and also slots A³ A³ into which are received the ends of pins which project from the
end of the lever arm at right angles to it.
Or in place of connecting the lever to the bolt in the above way the end of the
lever might be formed as shown at Figures 3 with a slot C2 in it of a width equal
to the depth of the bolt so that the tail end of the bolt can play to and fro within
the slot and form a single slot A³ in the bolt for the narrow bar or pin at the
extremity of the slot C to enter.
The lever turns on an axis at C¹ as shown and its tail end has a hole formed
through it through which passes the spindle D of the knobs.-E is a spring formed
of wire coiled a few times around a fixed pin F and one end made to bear against
the back plate of the case and the other against the lever. The pin F passes across
between the two stumps G which support the axis of the lever C. The spring
tends always to turn the lever into the position shewn in Figure 2 and so to make

page_text: the bolt protrude from the end of the lock case. The face of the bolt which strikes
against the striking plate whenever the door is pushed to we make as shown at
Figure 2 of a hollow curved form in place of making it straight as heretofore in
order that when it strikes against the striking plate it may be pressed inwards
more gradually and the blow against the striking plate be thereby relieved. We
also as heretofore provide the striking plate with a roller at the edge which the
face of the bolt strikes against and also provide means for adjusting the position of
this roller on the striking plate.
When the spindle D is drawn end wise in the direction of the arrow Figure 2
either by pulling on the one knob or pushing against the other a pin D¹ projecting
out from the spindle comes against the tail end of the lever Cand by turning this
lever withdraws the bolt A within the lock case and allows the door to which the
lock is affixed to be opened.
When the door has been opened and the pull or push upon the knobs released
we preferably cause the knobs to be brought back to their original position by a
coiled spring H as shown at Figure 2 and as is described in the provisional
specification lodged by us with an application for a Patent No 1777 in the present.
year:
Also according to our invention we use in combination with the knobs or
handles of push and pull latch locks a small locking bolt the end of which can be
made to enter between the inner end of the push knob and the rose plate whenever
it is desired to lock the latch and prevent it from being opened.
One way in which this can be effected is shown at Figure 2. In this case the
rose plate is made with a sideway extension by which a short locking bolt I like
an ordinary door bolt can be shot end wise so as either to bring its end into position
to prevent the knobs from being moved endwise or withdrawn so as to permit the.
knobs being moved freely endwise.
Various other ways of forming the locking bolt might be adopted. For example
a segment or portion of the outer rim of the rose might be made capable of turning
inwards on a pivot so that it might be brought between the flat plate of the rose
and the inner end of the knob. Or it might be a pin carried by an arm free to turn
on a pin outside of the rim of the rose.
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
1-Forming the arc bolt for a push and pull latch with a hollow curved face
substantially as described.
2. Coupling the end of the lever D to the tail of the bolt substantially in the
manner described with reference to Figures 1 and 2 and also with reference to
Figures 3.
3.-Forming the tail end of the lever with an eye or hole through it for the knob
spindle to pass through substantially as described.
4. The employment of a coiled wire spring for acting on the lever C substantially
as described.
5. The combination with the knobs or handles of push and pull latch locks of a
locking bolt to prevent the latch from being opened substantially as described.
6. The construction of latch locks substantially as hereinbefore described and
illustrated in the drawing annexed.
Dated this 6th day of October 1885.