Improvements in the Latch Mechanism of Front Door Locks.
Year: 1896

page_text: Date of Application, 10th Dec., 1896
PROVISIONAL SPECIFICATION.
Improvements in the Latch Mechanism of Front Door Locks.
I, EDMUND VAUGHAN, of Somerford, Willenhall, in the County of Stafford, Lock
Manufacturer's Clerk, do hereby declare the nature of this invention to be as
follows:-
In a front door lock, as ordinarily constructed, the latching bolt is moved back,
for unlatching, from the inside of the door, by drawing back a knob or handle.
This is an inconvenient operation, however, more especially owing to the fact that
the knob has to be held back while the door is pulled open; and, if the operation
of unlatching the door and pulling it open is attempted to be performed with one
hand only, there is a liability that in pulling the door open there may be some
relaxation of the force exerted in holding back the knob, and the door consequently
become latched again before it has been pulled open.
Now, this invention has for its object to avoid the inconvenience above
described, by providing mechanism for use in moving back the latching bolt,
from the inside of the door, which may be manipulated with much greater ease
than mechanism usually employed for the purpose, and by the use of which a
door may be readily unlatched and opened with one hand."
Mechanism, according to this invention, for the purpose of moving back the
latching bolt of a front door lock, comprises a two-armed or bell-crank lever
which is fulcrummed within the case. The outer end of one of the arms is
pivotally connected with the latching bolt tail, and the outer end of the other arm
is pressed, by means of a spring, in the direction to cause the latching of the bolt
and is provided with a stud which passes through a slot in the outer plate of the
case and has a knob affixed thereto. The latching bolt is drawn back
simply by, in effect, lifting the knob against the pressure of the spring aforesaid,
which is a much easier operation than drawing back a knob horizontally; but the
operator is not necessarily conscious of performing this distinct operation, he
will probably usually, owing to the appearance which the lock presents, operate
the knob to turn it, and in doing so will experience a sensation as if he were
actually turning the knob which to some extent he does, but the force
exerted to turn the knob has the effect of raising it and thus drawing back the
latch. The knob is very easily held up while the door is pulled open, as the pull
in opening the door is exerted in a sufficiently upward direction to keep the
latching lolt held back.
The latching bolt may be prevented from moving too far outwards, by one of the
arms of the two-armed lever, aforesaid, coming against a stud which is fixed
within the case.
The spring against the force of which the latching bolt is moved back may be
conveniently used for the double purpose of pressing forwards the latching bolt
and of operating the tumbler of the lock mechanism, and for this purpose may be
formed as a feather spring, of which the middle is formed to be passed over a
stud fixed within the case, its two ends being made to press, respectively, against

page_text: the arm which carries the knob and against a prolongation of the hinder end of the
tumbler.
It is preferred to form the inner end of the neck of the knob with a flange,
collar or rosc, of sufficiently large diameter to cover the slot through the outer
plate of the case, in whatever position the knob may be in.
Dated this 9th day of December 1896.
STEPHEN WATKINS,
Wolverhampton, Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in the Latch Mechanism of Front Door Locks.
I. EDMUND VAUGHAN, of Somerford, Willenhall in the County of Stafford, Lock
Manufacturer's Clerk, 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:-
In a front door lock, as ordinarily constructed, the latching bolt is moved back,
for unlatching, from the inside of the door, by drawing back a knob or handle.
This is an inconvenient operation, however, more especially owing to the fact that
the knob has to be held back while the door is pulled open; and, if the operation
of unlatching the door and pulling it open is attempted to be performed with one
hand only, there is a liability that in pulling the door open there may be some
relaxation of the force exerted in holding back the knob, and the door consequently
become latched again before it has been pulled open.
Now, this invention has for its object to avoid the inconvenience above
described, by providing mechanism for use in moving back the latching bolt,
from the inside of a door, which may be manipulated with much greater ease
than mechanism usually employed for the purpose, and by the use of which a
door may be readily unlatched and opened with one hand."
Mechanism, according to this invention, for the purpose of moving back the
latching bolt of a front door lock, comprises a two-armed or bell-crank lever
which is fulcrummed within the case. The outer end of one of the arms is
pivotally connected with the latching bolt tail, and the outer end of the other arm
is pressed, by means of a spring, in the direction to cause the latching of the bolt
and is provided with a stud which passes through a slot in the outer plate of the
case and has a knob or handle affixed thereto. The latching bolt is drawn back
simply by, in effect, lifting the knob against une pressure of the spring aforesaid,
which is a much easier operation than drawing back a knob horizontally; but the
operator is not necessarily conscious of performing this distinct operation, he
will probably usually, owing to the appearance which the lock presents, operate
the knob to turn it, and in doing so will experience a sensation as if he were
actually turning the knob which to some slight extent he does, but the force
exerted to turn the knob has the effect of raising it and thus drawing back the
latch. The knob is very easily held up while the door is pulled open, as the pull
in opening the door is exerted in a sufficiently upward direction to keep the
latching bolt held back.
In order that the invention may be clearly understood, I will proceed to describe
a practical application of the same by reference to the accompanying drawings,
of which Figure 1 is an elevation of a lock to which the invention is applied, the
cap plate being removed to expose the interior mechanism, and Figure 2 is a
section through the lock taken on line of Figure 1.
A is the two-armed or bell-crank lever, which is pivoted within the case by

page_text: The
means of a fulcrum pin a which is fixed to the front plate B of the case. The
arm b extends in a downward direction from the fulcrum pin a anu is pivotally
connected by means of a stud c, with the latching bolt C. The arm d extends in
a backward direction as shewn, and is pressed in a downward direction by a
spring D. The outer end of the arm d'is formed with a stud e which passes
through a curved slot E formed through the front plate B of the case.
curved centre line of the slot is struck from the centre of the fulcrum pin a.
The knob F is screwed onto the stud e and is tightened up against a shoulder at the
base of the screwed portion of the stud, as shewn. It will thus be seen that in order
to draw back the latching bolt the knob F has simply to be raised against the
pressure of the spring D.
The latching bolt is prevented from moving too far outwards by the stud e
coming upon the bottom of the slot E, and the knob may be prevented from being
raised unnecessarily high by the stud e coming against the top of the slot E.
The spring D against the force of which the latching bolt is moved back may be
conveniently used, as shewn, for the double purpose of pressing forward the latch-
ing bolt and of operating the tumbler G of the lock mechanism, and for this
purpose may be formed as a feather spring, as shewn, the hinder or loop portion
being passed over a stud f fixed within the case and the upper end being made
tress against a prolongation g of the hinder end of the tumbler.
It is preferred to form the inner end of the neck of the knob F with a flange,
collar, or rose, h, of sufficiently large diameter, as shewn, to cover the slot E through
the outer plate of the case in whatever position the knob may be.
The two-armed or bell-crank lever has been described and shewn as pressed by
means of a spring in a direction to move the latch bolt outwards and such arrange-
ment is preferred; but a weight may of course be substituted for the spring, as will
be obvious.
Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed, I declare that what I
claim is:
1. A front door lock provided with a two-armed or bell-crank lever pivoted
within the case and having the outer end of one of the arms engaged with the
latch bolt and the outer end of the other arm connected by means of a part which
passes through a slot in the outer plate of the case with a knob or handle, in com-
bination with a spring or equivalent means against the pressure or force of which
the latch bolt is drawn back when the knob or handle is raised, substantially
as described.
2. The means whereby the latch bolt of a front door lock is drawn back by
raising the knob or handle, substantially as described and shewn by the drawings
herewith.
STEPHEN WATKINS,
Wolverhampton, Agent for the Applicant.