AN IMPROVED DOOR CHAIN
Year: 1878

page_text: LETTERS PATENT to Charles Borzecki Welin, Civil Engineer, of 34, Dean
Street, Oxford Street, in the County of Middlesex, for the Invention of "AN
IMPROVED DOOR CHAIN."
Sealed the 1st April 1879, and dated the 3rd October 1878.
PROVISIONAL SPECIFICATION left by the said Charles Borzecki Welin at
the Office of the Commissioners of Patents on the 3rd October 1878.
CHARLES BORZECKI WELIN, Civil Engineer, of 34, Dean Street, Oxford Street,
in the County of Middlesex. "AN IMPROVED DOOR CHAIN,"
This Invention consists,-
10. In an ordinary chain, of which the centre link is flat and made of solid metal,
with an eye at each end to receive the corresponding links; the thickness of the
said flat link is such that it can just pass through the aperture of the stop next
described. The ordinary links of the chain are too large to pass through the said
aperture; the terminal link of the chain is larger than the ordinary links, so that
it cannot be drawn through the arch of the stop.
2°. In the stop, which is shaped like an arch rising from a flat plate, by means of
which it is screwed to the door. This stop has an aperture in the arched portion,
through which can pass the flat link of the chain.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles Borzecki Welin in the Great Seal Patent Office on the 3rd
April 1879.
CHARLES BORZECKI WELIN, Civil Engineer, of 34, Dean Street, Soho, in the
County of Middlesex. "AN IMPROVED DOOR CHAIN."
This Invention relates to certain improvements in door chains, and consists,-
1°. Of an ordinary chain, of which the centre link is flat and made of solid metal,
with an eye at each end to receive the corresponding links; the thickness of the
said flat link is such that it can just pass through the aperture of the stop next
described. The ordinary links of the chain are too thick to pass through the said
aperture; the terminal link of the chain is larger than the ordinary links, so that
it cannot be drawn through the arch of the stop.
2nd. Of the stop, which is shaped like an arch rising from a flat plate, by means
of which it is screwed to the door. The stop has an aperture in the arched portion,
in order that only the flat link can pass through.
In the accompanying Drawing is represented a door chain constructed according
to this Invention. F, F, is the staple, which will be secured to the door, and E, E,
are the jaws, which are arched and separated so as to allow of the flat link A beeing
entered therein, and through and under which arched jaws the whole chain may run
until stopped by the terminating ring B. In this way the door may be opened for
a short distance, as in the case of the ordinary door chains, and the expense of the
long barrel as ordinarily employed will be avoided, and the whole device is handier
and more secure than those hitherto used. H, H, is the staple which will be secured
to the door post and to which the chain is attached.
I claim in a door chain the flat link A, the large stop ring B, and the arched-jawed
stop piece E, E, constructed and operating substantially as herein set forth and
shown in the Drawing.
In witness whereof, I, the said Charles Borzecki Welin, have hereunto set my
hand and seal, this Second day of April, in the year of our Lord 1879.