A DOOR FASTENING, APPLICABLE INSTEAD OF A DOOR CHAIN to be as follows:
Year: 1885

page_text: I, JOHN OSMOND of. Clifton, Blackheath Park in the county of Kent Engineer,
do hereby declare the nature of my invention for "A DOOR FASTENING, APPLICABLE
INSTEAD OF A DOOR CHAIN to be as follows:-
"
My invention relates to a door fastening applicable instead of a door chain, that
is to say, to allow a door to be partly opened whilst it prevents it from being fully
opened. For this purpose, I provide on the door a horizontal bolt which is fitted
to slide along a guide until its hinder end reaches a stop at the front of the guide,
in which position the bolt is free to turn partly round in a horizontal plane. On
the door jamb I provide a catch to receive the front end of the bolt which can
be freely slid into or on to the catch, but this catch is so formed that when the
bolt is turned partly round in a horizontal plane, the bolt cannot be disengaged
from the catch. Assuming the door to be shut, but that it is desired to open it
only partly, the bolt is advanced a little so as to engage with the catch on the
jamb and then, on partly opening the door, the bolt is caused to slide forwards
and to turn to an attitude inclined to the plane of the door, allowing the door to
open to an extent determined by the length of the bolt, but no more.
The bolt then cannot be disengaged from the catch until by again closing the
door the bolt is brought back to its original position, when it can be withdrawn
from the catch. The catch may be formed so that when the bolt is slid to a less
or to a greater extent than is required to allow of the action above described, it
secures the door in the closed condition.

page_text: A Door Fastening, Applicable Instead of a Door Chain.
.
I, JOHN OSMOND of Clifton, Blackheath Park, in the County of Kent, 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 :-
My invention relates to a door fastening applicable instead of a door chain,
that is to say, it allows a door to be opened a certain distance whilst it prevents it
from being fully opened, and not being flexible as a chain is, it holds the door
partly open.
The accompanying drawings represent a fastening according to my
invention. Fig. 1 is a plan of part of the door and its jamb with the fastening in
position when the door is closed, the dotted lines' Fig. 1 shewing the position of
the parts when the door is, partly opened. Fig. 2 is a front view of the guide A
that is fixed on the door and of the catch B that is fixed on the jamb; Figs. 3
and 4 are end views of the guide A and of the catch B respectively, Fig. 5 is a
front view and Fig. 6 an end view of the bolt C. Fig. 7 is a plan shewing a
moditied form of the fastening, the dotted lines Fig. 7 shewing the position of the
parts when the door is being opened. Fig. 8 is a front view and Fig. 9 is a plan
shewing another modification in the form of the fastening. In all the figures
corresponding parts are marked as far as possible with similar reference letters.
Referring first to Figs. 1 to 6 inclusive the guide A, which is fixed on the door D
has through its front a long slot a a through which can freely pass the body of
the bolt C, and this slot is widened at a¹ a¹ for free passage of the one T end c c
of the bolt C. The catch B which is fixed on the door jamb J has also through
its front face a slot b and behind its front plate it is wide enough to take the other
T end cc of the bolt C. There is also at the back of this space at the front edge
of the catch a cross rib b¹ for strengthening the catch and fixing it to the jaib as
well as for preventing withdrawal of the bolt when it is angled. The door being
closed, the bolt C can by means of a knob c be drawn back out of the catch B,
and then the door can be opened. widely. But when the bolt C is pushed into the
catch B until its T end c¹ meets a stop 6, then on opening the door a certain
distance, the bolt C takes the attitude shewn in Fig. 1, its one T end c overlapping
the slot a of the guide A and its other T end c¹ being held behind the slot b of the
catch B, so that the door cannot be opened farther, but may be closed. I find it
convenient to make in the lower edge of the bolt C at its hinder T end c a small
notch c³ which, when the bolt is in the attitude shewn in Fig. 1a' engages on the
lip a of the slot a, and so keeps the door from being closed by the pressure of
wind or otherwise. When it is desired to close the door, the bolt is slightly lifted
so as to clear the notch from the lip a², and then the door can be closed, the
bolt C returning to the position shewn in Fig. 1. The door being closed, the bolt C
can be drawn a little back but not entirely out of the catch B, and in that condition
it acts as a simple bolt preventing the door from being opened.
As shewn in Figs. 7 and 7a the bolt C instead of being enclosed in a long guide
such as A Fig. 1, has its one end c¹ received in a socket E and slides through a
guide F which is attached to the door by a binge G. On pushing the bolt C
.

page_text: forward so as to engage its T end c¹ in the catch B releasing its end ct from the
socket E the door can be opened as far as the collar c³ on C will permit the guide F
coming to butt against this collar.
As shewn in Figs. 8 and 9 the bolt C is made with a long slot fitting on the
fixed central guide A which has T ends a' and a³ overlapping the sides of the
Blot of the bolt C. This slot is widened at c to allow the T end a to pass
through. The catch B is made with a projecting hook 63. On pushing the bolt C
forwards by applying the fingers to its rib c³, so that the front end of the bolt
engages in the catch B behind the hook b³, the widened part c³ of its slot then
coinciding with the T end a' of the fixed guide A, the door can be partly opened
as above described, this construction being substantially the saines that shewn
by Figs. 1 to 6 inclusive, except that according to the one construction, the bolt C
slides in the slot of the guide A, and according to the other, the slot of the bolt C
slides along the guide A.
Obviously the shapes and proportions of the parts may be farther variously
modified without departing from the nature of the invention, so long as there is
substituted for the ordinary flexible door chain, a rigid bolt which, when not in
use remains held in or on a guide against the door, but which can be slid forward
so as to engage in a catch fixed on the door jamb, and when it is fully slid can
swivel in the catch and can slide and swivel in the guide as the door is opened to
the extent which the length of the bolt permits.
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 :-
The construction of door fastening applicable instead of a door chain, substantially
as herein described and illustrated by the accompanying drawings.