Improvements in Latches.
Year: 1889

page_text: Date of Application, 14th Nov., 1689-Accepted, 4th Jan., 1890
COMPLETE SPECIFICATION.
[Communicated from abroad by CLEMENT FELTON, of No. 164, King Street West,
in the City of Toronto, in the Province of Ontario, Canada, Locksmith.]
Improvements in Latches.
I, FREDERICK JOHN CHEESBROUGH, of 15, Water Street, Liverpool, in the County
of Lancaster, Patent Agent, do hereby declare the nature of this invention and in
what inanner the same is to be performed, to be particularly described and ascertained
in and by the following statement :-
The object of the invention is to design a latch-lock which will instantly and
automatically lock itself upon being brought in contact with its catch, and which,
when locked will be practically impossible to open until pressure is exerted against
the door knob; and it consists essentially, of a bolt having a friction roller journaled on
its end and arranged in connection with simple mechanism contained in the lock-case,
which mechanism is designed to cause the bolt to project out of its case the instant
the door is closed and the lock comes in contact with the catch, which has a bevelled
recess formed on its face to receive the projecting end of the holt, which at this time
is hold so that it cannot be pushed back until the door knob is pressed upon.
Figure 1) is a view of my improved lock, with one of the sides of the case removed
to expose the interior construction of the mechanism.
Figure 2) is a perspective detail of the catch used in connection with my lock.
In the drawing, A, represents the bolt which has a friction roller, B, journale on
its end, as indicated. A curved finger, C, is fixed to and projects from the bolt A,
and a curved finger D, is pivoted immediately below the bolt A, and is provided with
a spring E, applied to it in such a manner as to hold the end of the curved finger D),
against the curved finger C. The heel of the curved finger D projects bohind the
block, F, which is movably held in the lock-case, and has a pin, G, connected to it
which projects through the face of the lock slightly on one side of the point where the
bolt, A, projects through. H, is a quadrant, pivoted at a, in the lock-case, and
The said quadrant is
actuated by a spring, I, in the direction indicated by arrow.
also connected by a pin and slotted hole to the bolt A. Ratchet-teeth, b, are formed
on the quadrant, H, and a ratchet-pawl J, pivoted in the lock-case, is arranged to
engage with the ratchet-teeth b. A pivoted bell-crank lever K, is located as indicated
one of its arms projecting behind the tail of the ratchet pawl J, whilo its other arm
projects over a spring plate, L, the tension of which is designed to hold the lever K.
clear of the tail of the ratchet-pawl J. A spindle, M, passes through and is shouldered
upon the arm of the lever, K, which rest on the spring plate L, through which the
said spindle also passes. On other end of the spindle M, an ordinary door-knob is
fixed.
Having now described the mechanism involved in my invention, I shall proceed to
explain its operation, and to do this must first draw attention to the catch-plate N,
which is secured to the face of the door-jamb, so that the wedge shaped recess, d, made
in it shall be opposite to the end of the bolt A, and the wedge-shaped recess e, opposite
to the pin G, when the door is closed.
In the normal position of the lock the friction roller, B, on the end of the bolt is
substantially flush with the face of the lock while the pin G, projects beyond the said
face. When the door is closed, the pin G, comes in contact with the wedge-shaped
recess e, as it ascends the said wedge is forced back, and acting against the heel of the
curved finger, D, raises the end of the said finger clear of the finger C, whon by the
action of the spring 1, the bolt A, is immediately shot out, being simultaneously
opposite to the wedge-shaped recess d, which it will be observed, is slanted in the
opposite direction to the wedge-shaped recess d. The ratchet pawl, J, drops into the
ratchet-teeth b, formed in the quadrant H, and effectually locks the said quadrant, so

page_text: that the bolt A, cannot be pushed in until the pawl J, is raised clear of the ratchet-
teeth; consequently, so long as the pawl remains in contact with the ratchet-teeth b
the door cannot be pushed open, as the end of the bolt, A, cannot ascend the incline of
the wedge d.
From this description it will be seen that the moment the door closes it is instantly
and automatically locked. In order to open the door pressure is directed on the
end of the spindle, M, so as to compress the spring plate I. The bell-crank
lever K, being simultaneously pushed down, its arm which is behind the tail of
the ratchet-pawl, J. presses the said ratchet-pawl, causing it to tilt on its pivot
and raise it out of contact with the ratchet-teeth b, thus releasing the bolt and
permitting it to be pushed back to clear itself of the catch-plate N. and resutting
the mechanism in the lock-case ready for the next operation.
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) A bolt A, arranged longitudinally movable in a lock-case and having a curved
finger C, connected to it, in combination with the curved finger D, block F, and
pin G, arranged substantially as and for the purpose specified.
2) A bolt A, arranged longitudinally movable in a lock-case, and connected to the
pivoted quadrant H, having ratchet-teeth b, formed on it, in combination with the
ratchet-pawl J, bell-crank lever K, and spring-plate L, substantially as and for
the purpose specified.
3) A bolt A with a friction roller, B, journaled on its end, and arranged longi-
tudinally movable in a lock-case, and connected to the pivoted quadrant H, having
ratchet-teeth b, formed on it in combination with the ratchet-pawl, J, bell crank
lever, K, spring plate L, and longitudinally-movable spindle M, substantially as
and for the purpose specified.
4) A bolt A, with a friction roller B, journaled on its end, and arranged longi-
tudinally movable in a lock-case, and having a curved finger C, connected to it
and arranged to operate in conjunction with the curved finger D, block F, pin G,
and spring E, in combination with the pivoted quadrant H, connected to the
bolt A, and actuated by the spring I, the ratchet-pawl J, engaging with the ratchet-
teeth b, the bell-crank lever K, spring-plate L, and spindle M, arranged sub-
stantially as and for the purpose specified.
5) A bolt A, arranged longitudinally movable in a lock-case, and having a curved
finger C, connected to it, in combination with the curved finger D, block F,
pin G, and wedge-shaped recesses d, and e, formed in the catch-plate N, sub-
stantially as and for the purpose specified.
6) A latch-lock constructed substantially as herein shown and described.
Dated this 13th day of November 1889.