IMPROVEMENTS IN SAFETY LATCHES
Year: 1877

page_text: LETTERS PATENT to Phinehas Edward Ayton, of Birmingham, in the County
of Warwick, Accountant Clerk, for the Invention of "IMPROVEMENTS IN
SAFETY LATCHES." A communication from abroad by George Charles Setchell,
of Greeneville, Connecticut, in the United States of America.
PROVISIONAL SPECIFICATION left by the said Phinehas Edward Ayton
at the Office of the Commissioners of Patents on the 9th January 1877.
PHINEHAS EDWARD AYTON, of Birmingham, in the County of Warwick,
Accountant Clerk. "IMPROVEMENTS IN SAFETY LATCHES." A communication from
abroad by George Charles Setchell, of Greeneville, Connecticut, in the United States
of America.
The said Invention consists of the arrangement herein-after described of a door
latch and parts connected therewith, whereby the door with which it is used is
capable of being opened to a limited extent for ventilation and other purposes, but
cannot be opened beyond the limited extent referred to by any one outside the
door.
The said Invention is especially suited for use on the doors of bedrooms, and as
herein-after explained, by day time or at any time when it is thought desirable it
may be readily thrown out of use.
The said Invention consists essentially of three parts, namely, a latch, a latch
plate to which the latch is jointed, and a staple behind which the end of the latch
engages, the said staple being fixed on the door frame and the lock plate on the
door. The end of the latch is connected to the staple by a strong chain. The
latch plate has a guide by which the motion of the latch is kept parallel to the
latch plate: The latch is not permanently jointed to the lock plate but is capable
of being detached therefrom.
The connection is effected as follows:-On the rear end of the lock plate is a pin
or axis, and on the rear end of the latch is a hole somewhat larger than the said
pin, but the hole of the latch can only be engaged with and disengaged from the
axis when the latch is turned into a position in which it is in a line with the lock
plate. This is effected by a feather on the axis and a slot opening into the hole in
the rear end of the latch. The end of the latch can only be engaged with or dis-
engaged from the axis on the back plate when the said feather and slot coincide;
that is, when the latch is in a line with the lock plate.

page_text: The action of the safety latch is as follows:-When the latch is connected with
the latch plate and turned into the position in which it engages behind the staple on
the door frame, it constitutes a latch by which the opening of the door is prevented by
any one outside the room, the latch having no connection with the outside of the door.
The person occupying the room can however lift the.latch and open the door to the
extent permitted by the chain. As the latch can only be detached from the latch
plate as already explained when in a line with the latch plate, this can only be
effected when the door is shut, as. the chain..will not permit the latch to take the
required position unless the door is shut. While therefore the latch can easily be
detached from the latch plate by a person inside the room and the latch thereby be 1
thrown out of action, this cannot be effected by a person outside of the room.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Phinehas Edward Ayton in the Great Seal Patent Office on the
16th June 1877.
16
PHINEHAS EDWARD AYTON, of Birmingham, in the County of Warwick,
Accountant Clerk. IMPROVEMENTS IN SAFETY LATCHES." A communication
from abroad by George Charles Setchell, of Greeneville, Connecticut, in the United
States of America.
The said Invention consists of the arrangement herein-after described of a door
latch and parts connected therewith, whereby the door with which it is to be used
is capable of being opened to a limited extent for ventilation and other purposes,
but cannot be opened beyond the limited extent referred to by any one outside the
door.
The said Invention is especially suited for use on the doors of bedrooms, and as
herein-after explained, by day time or at any time when it is thought desirable it
may be readily thrown out of use.
The said Invention consists essentially of three parts, namely, a latch, a latch
plate to which the latch is jointed, and a staple behind which the end of the latch
engages, the said staple being fixed on the door frame and the latch plate on the
door. The end of the latch is connected to the staple by a strong chain. The latch
plate has a guide by which the motion of the latch is kept parallel to the latch
plate. The latch is not permanently jointed to the latch plate, but is capable of
being detached therefrom.
The connection is effected as follows:-On the rear end of the latch plate is a pin
or axis, and on the rear end of the latch is a hole somewhat larger than the said
pin, but the hole of the latch can only be engaged with and disengaged from the
axis when the latch is turned into a position in which it is in a line with the latch
plate. This is effected by a feather on the axis and a slot opening into the hole in
the rear end of the latch. The end of the latch can only be engaged with or dis-
engaged from the axis on the latcli plate when the said feather and slot coincide;
that is, when the latch is in a line with the latch plate.
The action of the safety latch is as follows:-When the latch is connected with
the latch plate and turned into the position in which it engages behind the staple
on the door frame, it constitutes a latch by which the opening of the door is pre-
vented by any one outside the room, the latch having no connection with the out-
side of the door. The person occupying the room can however lift the latch and
open the door to the extent permitted by the chain. As the latch can only be
detached from the latch plate as already explained when in a line with the latch
plate, this can only be effected when the door is shut, as the chain will not perimit
the latch to take the required position unless the door is shut. While therefore the
latch can easily be detached from the latch plate by a person inside the room, and
the latch thereby be thrown out of action, this cannot be effected by a person out-
side the room.

page_text: I will now proceed to describe with reference to the accompanying Drawings the
manner in which the Invention may be performed.
Figure 1 represents in front elevation, and Figure 2 in edge view partly in
horizontal section a safety latch constructed according to this Invention, applied to
the inside of a-door in position for use; Figure 3 represents the lateli arranged in
position to be removed from its plate for throwing the latch out of use.
The same letters of referénce indicate the same parts in Figures 1; 2, and 3.
a is the latch capable of turning on the pin or axis b, and of being completely
detached from the said pin or axis as herein-after explained: The said pin or axis b
is carried by the latch plate c fixed by screws to the inner side of the door d. On
the said latch plate c is a guide c2 by which the motion of the latch a is kept
parallel to the latch plate c; e, is the staple behind which the latch a engages; the
said staple being fixed to the inside of the door frame f. The end of the latch a is
connected to the staple e by a strong chain g; eyes on the said latch and staple
receiving the end links respectively of the said chain as represented.
The latch a is capable of being connected with and disconnected from the latch
plate c, fixed on the inside of the door in the following manner. At the rear of the
pin or axis b on which the latch a turns is a feather 62, and in the rear end of the
latch a is a slot a² opening into the hole in which the pin or axis b works. When
the parts of the latch are in position for use, as illustrated in Figures 1 and 2, the
latch a is situated parallel to the latch plate c, and the slot a² in the latch is turned
from the feather 62 on the pin or axis 6, the said feather being situated in front of
an uncut-away part of the latch, and although the latch is capable when lifted of
turning on the pin or axis b; yet the said latch cannot be disconnected from the
latch plate c in consequence of the said feather 62, excepting as herein-after
explained.
.V
In order to disconnect the latch a from the latch plate c when it is wished to
throw the latch out of use, the said latch a is turned on its pin or axis b into the
position represented in Figure 3; that is to say; the said latch is turned from off the
latch plate and brought into a line with the said latch plate. When the latch is in
the position, Figure 3, the feather 62 on the pin or axis b coincides with the slot a³
in the latch a, when the latch may be withdrawn from off the latch plate c and the
latch thrown out of use. By an examination of the Drawing it will thus be seen
that the latch a can only be engaged with or disengaged from the pin or axis b on
which it turns by bringing the latch into the position in which it is in a line with
the latch plate c. The chain g by which the latch a is connected to the staple e is
of such a length as will only permit the latch to take the position represented in.
Figure 3, when the door to which the latch is applied is closed.
u
The safety latch is used in the following manner :-When the parts are in the
positions represented in Figures 1 and 2, the person occupying the room can lift the
latch after the manner of an ordinary latch, and open the door to the extent
permitted by the chain g for ventilating the room or for other purposes, but the
said door cannot be opened beyond this extent either by the person inside the room
or by any one outside the room, and as there is no connection between the latch a
on the inside of the door and the outside of the room the said latch cannot be lifted
by any one outside the room. When it is wished to open the door beyond the
extent permitted by the chain g, it is necessary to completely detach the latch a
from the latch plate c. This is effected by closing the door d and placing the latch a
in the position, Figure 3, and withdrawing it from off the pin b and feather b².
The latch is thus detached from the latch plate on the door and thrown out of use,
but the said latch is connected by the chain g to the staple e. The detachment of
the latch a from the latch plate c can only be effected when the door is shut, as the
length of the chain g will not permit the latch to take the position, Figure 3, unless
the door is shut; it therefore follows that while the latch may be readily detached
in the manner described from the latch plate by the person inside the room and the
latch be thereby thrown out of use, the said detachment of the latch cannot be
effected by a person outside the room.

page_text: Figure 4 represents the safety latch with the latch a shortened, and the latch
plate c and staple e arranged vertically on the door and door frame instead of
horizontally as in Figures 1, 2, and. 3:
For fitting the safety latch to a door in which the door frame has a beading or
other, obstruction, the acting end of the latch may be cranked to escape the said.
beading or obstruction, as represented in front elevation in Figure 5, and edge view.
in Figure 6, where the cranked part of the latch is marked a³. Or both the latch
and the staple may be cranked, as illustrated in front elevation in Figure 7 and
edge view in Figure 8 for the same purpose. In this arrangement the guide on
the latch plate in which the latch works is situated near the jointed end of the
latch.
..
Figure 9 represents a safety latch for a heavy door, the staple of which latch is
constructed somewhat differently from that represented in Figures 1 and 2.
f. In Figures 4, 5, 6, 7, 8, and 9 the parts. are marked with the same letters of
reference as corresponding parts in Figures 1, 2, and 3, and the several latches are
used in the same manner as previously described with respect to the latch
represented in Figures 1, 2, and 3.
Having now described the nature of the said Invention and the manner in which
the same is to be performed, I wish it to be understood that I claim as the said
Invention, the improvements in safety latches herein-before described and illustrated
in the accompanying Drawings, that is to say, a safety latch for a door consisting
essentially of a staple, a latch plate, and a latch, the latch being connected by a
chain to the staple and to the latch plate by a pin or connection constructed sub-
stantially as described and illustrated, whereby the said latch may be readily con-
nected with the latch plate for use, or disconnected therefrom for throwing the latch
out of use, which disconnection or throwing out of use of the latch can only be
effected by a person inside the room to the door of which the latch is attached, as
described and illustrated.
In witness whereof, I, the said Phinehas Edward Ayton, have hereunto set my
hand and seal, this Sixth day of June, in the year of our Lord One thousand
eight hundred and seventy-seven
Witness,
RICHARD SKERRETT,
Clerk to George Shaw,
Birmingham.
PHINEHAS EDWARD AYTON. (L.S.)