Year: 1888

page_text: Date of Application, 14th July, 1888
Specification Accepted, 17th Aug., 1888
I HERMANN MAUL, of 16 Gerbergasse, Dresden, in the Kingdom of Saxony,
Engineer, do hereby declare the nature of my said invention and in what manner
the same is to be performed, to be particularly described and ascertained in and by the
following statement :-
The object of my invention is to provide and fit safety door chains with improved
disengaging apparatus, whereby the chains may be disengaged from a distance.
And in order that my said invention may be particularly described and ascertained,
reference is hereby made to the accompanying drawings, in which similar letters of
reference indicate corresponding parts.
Fig. 1 is a sectional elevation of my invention.
a back view. Fig. 4 is a section on the line ca.
Fig. 2 is a front elevation. Fig. 3
Fig. 5 is a section on the line yy,
and Fig. 6 is a plan view, showing the application of my invention to a bed-room
door.
a is the chain. is the staple and plate secured to the door d. e is the ordinary
knob at the end of the chain."
Instead of the ordinary slotted sheath for receiving the knob c, I fit to the door
jamb or frame d¹ the metallic box e shown in the drawings. At the lower end of this
box a pin is fitted. A vertical lever plate y is pivotted to this pin, and a spring his
fitted as shown, which presses the plate y forward. is a horizontal bracket, rivetted
to the plate g, and projecting, through a suitable opening, into the slotted sheath k.
This sheath is open at the bottom. When the knob c is placed in the sheath k, the
knob is supported by the horizontal bracket i. m is an india rubber bag or ball,
placed between the vibrating plate y and the front plate of the case e.
This bag m is shown flattened or collapsed in Figs. 1 and 5. The bag m is connected
by flexible or other convenient tubing n n, with the india rubber ball o. This ball o
is self-expanding and filled with air.
When fitted in a bed room as shown in Fig. 6, the tube n may be carried round
to the side of the bed p, the ball being conveniently placed for the occupant.
In using my invention the knob c, at the end of the chain a is passed upwards into
the slotte sheath k, the bracket i being caused to recede while so doing. The

page_text: bracket then springs forward and sustains the knob c in position, thus securing the
door. When it is desired to release the chain, the air ball o is pressed, the air is
thereby driven through the tube n to the bag m, which is thereby caused to expand.
This expansion of the bag m drives the plate g backwards, whereby the bracket i is
withdrawn from under the knob c, which immediately falls out of the slotted sheath k
and releases the chain.
By means of obvious modifications in the method of fitting my invention, it may
be adapted to various situations, and to folding and other doors.
Having now particularly described and ascertained the nature of my said inven-
tion, and in. what manner the same is to be performed, I declare that what 1
claim is :-
1. The method of securing one end of the safety door chain, by means of the
bracket attached to the movable lever.g, supporting the knob c; the movements of
the bracket c being controlled by the spring hand elastic air bag g, severally operated
by the air ballo and communicating tube n, substantially as herein before described
and illustrated by the drawings.
2. The general construction, arrangement and combination of the several and
respective appliances, together constituting my improvements in safety door-chain
appliances, substantially as herein before described and illustrated by the drawings.
Datod Tu 14th 1000
GEO. DOWNING,
Agent for Applicant.