IMPROVEMENTS IN COM- BINING DOOR CHAINS WITH LOCKS, LATCHES, AND BOLTS
Year: 1881

page_text: PROVISIONAL SPECIFICATION left by Henry Skerrett at the Office of the
Commissioners of Patents on the 19th October 1881.
HENRY SKERRETT, of the Great Western Buildings, 6, Livery Street, Birmingham,
in the County of Warwick, Mechanical Engineer. "IMPROVEMENTS IN COM-
BINING DOOR CHAINS WITH LOCKS, LATCHES, AND BOLTS."
My Invention consists in combining door chains with door locks, latches, and
bolts and their staples, in the manner hereinafter described, whereby the separate
case and staple required for the ordinary door chain are dispensed with.
In carrying my Invention into effect I construct and modify certain parts of the
locks, latches, and bolts, and the door chains to be used with them, in the following
manner:-
I will first describe my improved combined door chain and door lock.
The bolt of the lock has near its outer end and preferably on its upper edge a
hook like recess or cavity.
The door chain is connected at one end to the staple box of the lock, and the
free or unconnected end of the said chain has a hooked connector corresponding in
form to the cavity described in the end of the lock bolt.
When the chain of the combined chain and lock is required to be used for
fastening the door in an open position, the bolt of the lock is shot or made to
protrude from out of its case; the hooked end of the door chain is then placed in
the cavity of the shot bolt and made to lie flush with the upper edge of the said
bolt, the shank of the hooked end of the chain passing out of the open end or face
of the bolt. The parts having been thus arranged the withdrawal of the bolt into
the lock case by a key carries the hooked end of the chain described with the bolt
into the said lock case.
A locked down chain is thereby produced, and the connector end of the chain
cannot be disconnected from the lock until the bolt has been shot from out of its
case by the key.
When the bolt of the lock has been shot out of its case and the hooked end of
the chain taken from out of the cavity in the bolt the lock can be used as an
ordinary lock.

page_text: Or the free end of the chain described may be made in the form of a link or loop
which takes upon a hook formed out of the end of the bolt.
In latch locks the free end of the door chain is connected to the lock by a cut
away sliding plate on the lock face, which said sliding plate covers and uncovers
the terminal end of the chain by the shooting and withdrawing of the bolt by
the key.
My improvements consist further in forming combined door chains and locks by
extending the front plate of the lock case a short distance below the said lock case.
In this prolonged or extended part of the front plate a longitudinal slot or opening
of the kind used with ordinary door chain cases is made for the terminal end or
stud on the free end of the door chain to slide in.
The fixed end of the chain is connected as before described to the staple plate or
box of the lock.
When it is required to connect the door to the chain end, it is only necessary to
close the door and pass the stud or knob on the free end of the chain through the
enlargement at the end of the longitudinal slot or opening in the prolonged part of
the lock plate, when the door is fastened to the chain and is capable of opening
only to the length of the longitudinal slot, as before described.
In combining door chains with door latches, according to my Invention, I
construct the latch with a longitudinal slot with which the terminal end of the
door chain is engaged, the door chain being connected to an eye made in the staple
of the latch; and in combining door chains with door bolts, according to my
Invention, I construct the bolt case with a similar slot for the terminal end of the
door chain to engage with, the chain being connected to an eye in the staple of the
bolt. That part of the latch and that part of the bolt case in which the long slot
is formed is raised slightly out of the plane of the other part of the latch or bolt
case to permit of the ready motion of the terminal end of the chain in the
said slot.