An Improved Non-return Air Valve.
Year: 1889

page_text: Date of Application, 8th Mar., 1889
Complete Specification Left, 29th Nov., 1839-Accepted, 1st Feb. 1890
PROVISIONAL SPECIFICATION.
An Improved Non-return Air Valve.
I, JOHN BOYD DUNLOP, of No. 50 Gloucester Street, Belfast, Ireland, Veterinary
Surgeon do hereby declare the nature of this invention to be as follows:-
My invention is devised with the object of facilitating the filling of foot-balls, air
tyres of wheels, life belts, collapsible boats, air beds, and other expansible articles,
with air under compression, as also to prevent the escape of the compressed air.
The device according to my invention consists of a short tube of caoutchouc or
other elastic material, one end of which is inserted, and projects a short distance
into the interior of the expansible article to be filled with compressed air. Within
the inner end of said tube is adapted a plug, rod or equivalent (slightly larger than
the diameter of the tube) of any suitable material, such for instance as hard rubber,
vulcanite and the like, which serving as a valve may be partially secured to the interior
of the tube by cement or equivalent means, or, if desired said plug may be retained
within the tube by a band or web of any suitable material passing over the open end
of said tube and secured to the sides thereof.
The action of the device is as follows:-
When air under pressure is forced into the article to be inflated, the elastic tube
aforesaid is caused to expand, thus allowing the air to pass around the plug or valve
into the air chamber. When the pressure ceases, the elastic tube immediately
contracts and tightly embraces the plug or valve, such contraction being assisted by
the pressure of the compressed air within the air chamber upon the tube and valve
above described, thus effectually preventing the escape of the compressed air.
Date this Savanth day of Mauch 1880
JAMES
STEVENSON,
Gray's Inn Chambers, 20, High Holborn, London, W.C., Agent for Applicant.
COMPLETE SPECIFICATION.
An Improved Non-return Air Valve.
I, JOHN BOYD DUNLOP of No. 50 Gloucester Street Belfast, Ireland, Veterinary
Surgeon 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 an improved non-return valve designed to facilitate the
inflation of foot-balls, air tyres of wheels (such as those referred to in the specifica-
tion of my former Letters Patent No. 1060789) life-belts, collapsible boats, air-beds
and other expansible articles, or the filling of the same with air under compression,
and also to prevent the escape of the compressed air.
In the accompanying explanatory sheet of drawings, Figure 1 illustrates my
improved valve in position for filling or inflating an expansible article with air or gas
under pressure. Figures 2 and 3 represent respectively an elevation and a sectional
elevation, both drawn to an enlarged scale, showing my improved valve detached
from the said article.
My improved device comprises a short tube A of caoutchouc or other elastic
material, one end of which is inserted, and projects a short distance into the interior
of the expansible article to be filled with compressed air, as shown in Figure 1.
Within this end of the said tube is arranged a plug or rod B which should be slightly
larger in diameter than the interior of the tube and is formed of any suitable
material, such for instance as hard india-rubber, vulcanite and the like. This plug

page_text: or rod serves as the valve and may be secured throughout a portion of its circum-
ference to the interior of the tube by cement or other suitable means, or, if desired
the said plug B may be retained within the tube A by a band or web b of any suitable
material, such as canvas, extending over the open inner end of said tube and secured
to the sides thereof. The plug of vulcanite or hard india-rubber aforesaid may be
formed with one or more circumferential grooves a.
The action of the device is as follows:-
When air under pressure is forced through the elastic tube A, the said tube is
caused to expand and thus allows the air to pass between it and the plug or valve B
into the air-chamber or article to be inflated. When the pressure ceases, the elastic
tube A immediately contracts and tightly embraces the plug or valve B, such
contraction being assisted by the pressure of the compressed air within the air-
chamber acting upon the exterior of the said tube, thus effectually preventing the
escape of the compressed air.
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
I claim is :-
The improved non-return air-valve herein before described and for the purposes
specified
Dated this 27th day of November 1889.
JAMES STEVENSON,
Gray's Inn Chambers, 20, High Holborn, London, W.C., Agent for Applicant.