Improvements in Air-valves for Pneumatic Tyres.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improvements in Air-valves for Pneumatic Tyres.
I, JOHANNES MATTHIAS DUMSTREY, of No. 27, Markgrafen Street, Berlin, in
the Empire of Germany, Manufacturer, do hereby declare the nature of this
invention to be as follows:-
My invention relates to improvements in air-valves for pneumatic tyres, the
object of the invention being to provide improved means for enabling ready
access to the valve proper which is a back-pressure valve of any well-known
or suitable construction, for the purposes of cleaning or repairing the latter or
replacing it by a new-one when worn out or damaged.
This object, according to the present invention, is attained by constructing
the complete valve of two separate and distinct parts, the one part of which,
that is to say the part which is affixed to the rim and air bag in the usual and
well-known manner, I shall hereinafter term the "lower part," whilst the other
part connecting with the air-pump also in the well-known manner, will be
hereinafter termed the upper part."
"
The said lower part consisting of a hollow stem externally threaded as usual,
is provided near its free or upper end with a ring tightly screwed thereon, pre-
ferably by means of left-hand thread, and serves for retaining upon the said
stem a sleeve provided with female thread but arranged to slide freely on the said
stem in its longitudinal direction until it will abut against the said fixed ring
and thus be retained. The part of the stem projecting beyond the fixed ring
is provided with a suitable packing, preferably india-rubber.
The hollow upper part is threaded at its free or upper end in the usual and
well-known manner for allowing the air-pump to be screwed thereto when
required, whilst its lower portion provided with external thread correspond-
ing exactly with the female thread of the said sliding sleeve on the said lower
part, contains the back-pressure valve proper consisting of a rubber plug or
other similar or suitable and well-known body.
The end of the lower portion of the said upper part below the back-pressure
valve therein enclosed, is excavated so that it will fit snugly upon the said
rubber or other tube-like packing applied to the upper end of the said lower
part, and it may also be cut away outside so as to form a flat surface bearing
against a flat projection extending upwardly from the said fixed ring on the
lower part, to prevent it from turning on the said packing,
The hollow end of the upper part being held against the packing on the
lower part and the sliding sleeve on the latter being moved upwards so as to
engage with the male thread on the lower portion of the upper part, turning
of the said sleeve or of the upper part, will draw the said two parts tightly
together and complete the valve for use, the said fixed ring on the lower part

page_text: serving as an abutment for the said sleeve and preventing the same from
coming off.
Dated this 13th day of February 1899.
HASELTINE, LAKE & Co.
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.
Improvements in Air-valves for Pneumatic Tyres.
I, JOHANNES MATTHIAS DUMSTREY, of No. 27, Markgrafen Street, Berlin, in
the Empire of Germany, Manufacturer, 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 improvements in air-valves for pneumatic tyres, the
object of the invention being to provide improved means for permitting ready
access to the valve proper, which is a back-pressure valve of any well-known
or suitable construction, for the purposes of cleaning or repairing the said
valve or replacing it by a new one when worn out or damaged.
In the accompanying drawing wherein similar letters designate correspond-
ing parts,
Figure 1 is an elevation, partly in section, of an air-valve embodying my
invention, and
Figure 2 is a horizontal section of the valve on the line A-B of Figure 1.
Figure 3 is an elevation, partly in section, of a modified form of the valve,
and
Figures 4 and 5 are horizontal sections of the valve on the lines E-F and
C-D, of Figure 3 respectively, Figure 4 being inverted.
Referring to Figures 1 and 2, a is the lower part, or that part of the valve
which is affixed to the rim and air-tube, and b is the upper part provided on
the top thereof with a closing cap of usual and well-known construction.
The threaded stem of the lower part is provided, near its free upper end, with
a fixed collar or ring d for retaining on said stem the connecting sleeve e.
f designates the rubber packing surrounding the fixed or auxiliary head g of
the stem a, said head being provided with a pair of tongues h for holding the
rectangularly shaped stem of the back-pressure valve in its proper position
when the cap e is being screwed off, or onto, the screw-threaded tail of the
back-pressure valve.
The upper part of the valve is externally recessed at the lower end of the
valve chamber so as to form a flat surface at one side thereof, thus allowing
the nose m of the ring d to project into the recess in order to prevent the upper
part of the air valve from turning, when the sleeve e is being screwed thereto.
The operation of the valve above specified is as follows:-For the purpose
of inflating the tyre, the cap is screwed off the upper part of the air valve,
and the air-pump is screwed thereto in the usual manner. During the opera-
tion of the pump, the valve body is lifted from its seat o, so as to allow the
air to enter into the tyre by way of the axial bore of the lower part of the
air-valve. Said bore has but a very small diameter, yet, although, the lower
end of the slender stem of the back-pressure valve i extends therein, it forners
a free passage for the air owing to its cylindrical form and to the rectangular
cross section of the stem n, said stem being prevented from turning, as already
mentioned above by the holding tongues, when the cap c is being screwed
off or onto the tail of the back pressure-valve.

page_text: In the modified form of valve shown in Figures 3, 4 and 5, the ring or
collar d is fixed to the upper part of the air-valve, and consequently the sleeve e
is likewise arranged on this part to slide freely thereon in its longitudinal
direction, so that when the two parts of the air-valve are screwed together by
means of the sleeve e, the female thread of the latter will grip the external
thread of the stem of the lower part a. Moreover in this modification the stem
has been cut away at two opposite sides so as to afford a hold for either of the
noses m provided on the ring d of the upper part of the air-valve.
The advantages attained by the described air-valve, consist especially in the
ready accessiblity to both the back pressure valve proper, and further, to all
the other interior parts of the device. Furthermore the described arrangement
of the air-valve consisting of two separate parts having a comparatively small
axial bore, and forming the compound valve when joined together by means of
the sleeve e, allows of using a stem or lower part of a rather slender shape as
compared with the similar valves heretofore known. In all the valves of this
type hitherto used, the stem, or part which is affixed to the rim and air-tube,
consists of a tube-like body which practically has nothing to do with the valve
proper, hence valves of the kind are in fact, in no way two-parts-valves," as
the present valve actually is. In the valves heretofore known the tube-like
stem necessarily has a large internal, and consequently, external diameter, so
that owing to the correspondingly wide hole to be cut into the rim of the
cycle wheel for inserting said tubular stem, the strength of the rim is consider-
ably diminished at the point where the valve is affixed to the rim. The incon-
veniences arising therefrom are effectually avoided by the novel air-valve
hereinbefore set forth.
"
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:
1. An air-valve for pneumatic tyres comprising a lower part and an upper
part joined together by an internally flanged sleeve, an abutment for the sleeve
flange provided either on the lower or on the upper part, a back pressure valve
in the upper part, a fixed valvular head on top of the lower part and means
at the lower part for holding the stem of the back pressure valve substantially
as set forth.
2. An air-valve for pneumatic tyres comprising a lower part and an upper
part joined together by an internally flanged sleeve, an abutment for the sleeve
flange provided either on the lower or on the upper part, a back pressure valve
in the upper part, a fixed valvular head on the top of the lower part provided
with an axial bore of a small diameter so as to allow the stem of the back
pressure valve to slide therein without jamming, substantially as set forth.
3. An air-valve for pneumatic tyres comprising a lower part and an upper
part joined together by an internally flanged sleeve, an abutment for the sleeve
flange provided either on the lower or on the upper part, a back pressure valve
in the upper part, a fixed valvular head on top of the lower part provided
with an axial bore of a small diameter so as to allow the stem of the back
pressure valve to slide therein without jamming, and a pair of tongues extend-
ing upwardly from the valvular head so as to prevent the stem from turning in
the bore, substantially as set forth.
Dated this 10th day of Vovom hun 1000
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.