Improvements relating to Pneumatic Tyre Inflators for Indicating or Registering the Pressure of Air Delivered.
Year: 1892

page_text: Date of Application, 27th Sept., 1892
Complete Specification Left, 27th Oct., 1892-Accepted, 3rd Dec., 1892
PROVISIONAL SPECIFICATION.
Improvements relating to Pneumatic Tyre Inflators for Indicating or
Registering the Pressure of Air Delivered.
I, JOHN MILBROWE SMITH 382 High Street West Bromwich Staffordshire
Cycle Manufacturer do hereby declare the nature of this invention to be as
follows:-
:-
My invention relates to improvements in pneumatic tyre inflators, and is designed
to indicate in a simple and compact manner, automatically while inflating the proper
pressure of air required.
The apparatus consists of a tubular pressure cylinder, made to attach to existing
inflators, and also for compactness fitted inside and combined with an inflator, one
end of pressure cylinder is closed and fitted with an inlet valve, the air when forced
through this valve into the cylinder comes in contact with an airtight piston,
causing it to slide along the cylinder, a variable amount of resistance is provided
for by a spiral spring pressing against the piston and top of cylinder, a small tube
is attached to the piston, passes inside the spring and through the top of cylinder,
and conveys the air to the tyre, attached to this tube is a numbered scale indicating
the pressure.
The compressed air actuating the piston, overcomes the spring and causes the
small tube to slide out at the top of the cylinder, and brings to view the number
representing the pressure then in the tyre.
I believe the apparatus will prove useful to cyclists as a means of ascertaining in
a simple and portable way, the proper quantity of air to inflate their pneumatic
tyres with.
It is obvious that the details of my invention, may be altered without departing
from the nature thereof.
Date this 26th day of Sentember 1800
COMPLETE SPECIFICATION.
Improvements relating to Pneumatic Tyre Inflators for Indicating or
Registering the Pressure of Air Delivered.
JOHN MILBROWE SMITH 382 High Street West Bromwich Staffordshire
Cycle 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 pneumatic tyre or football inflators, and
is designed to indicate while inflating the proper pressure of air required.
In order to elucidate the nature of my said invention, and the manner of per-
forming the same I have annexed a sheet of drawings, and to the figures and letters
of reference I now refer.
Fig. 1 is a perspective view of the apparatus showing inflator tube, pressure tube
and indicating scale, all extended.
Fig. 2 is a sectional view of pressure register.
Fig. 3 is a bracket tyre rest.
The apparatus consists of a tubular pressure chamber B constructed of metal or
vulcanite, sliding within the inflator tube A I utilise the bottom of pressure tube B
to form the piston of the inflator A, the inlet valve D, screwed into the piston C,
[Price 8d1

page_text: secures the leather piston washer and projects into the pressure tube B the inlet air
holes, to prevent return being covered by a flexable material.
To remove the great strain from the fingers, experienced when inflating a tyre
to a high pressure. I have designed a bracket tyre rest N shown at Fig. 3. it is
formed by a broad piece of metal, projecting from one side of the cap F and
screwed on the top of pressure tube B and shaped to a proper curve to bear upon
the tyre, it may be covered with rubber or felt.
I now refer to the registering apparatus shown partly in section at Fig. 4 and
Fig. 2. To indicate or register the pressure of air delivered, to make airtight a
soft cup shaped washer G preferably of leather, is fixed to the piston H by a
being perforated for the air to pass through, mounted upon the piston H
is the continuation tube J carrying the graduated numbered scale K, the male
screw L connects the pressure register with the tyre valve, by means of the usual
flexable rubber tube.
screw
To provide the proper amount of resistance to the piston H I use a spiral
spring M working in the vacant space between the outside of tube J and the inside
of pressure tube B but pressing upon the piston H at one end, and against the
inside of the cap F at the other end.
I now describe the action of the pressure register, supposing for an example, the
piston H has a surface equivalent to one square inch the spring M should be
capable of a variable pressure from nothing ranging to 40 lbs. when half closed, and
so on up to 80 lbs. when fully closed. The air having been forced through the
non return valve D into the pressure tube B and then through the continuation
tube J into the tyre, all being under an equal pressure of 40 lbs. per square inch,
when tested by a standard pressure gauge. It is now plain that there will be a
force of 40 lbs. exerted against the bottom of the piston H, this will cause it to slide
along the pressure tube B closing the spring M until the spring exercises an
equal force of 40 lbs. in opposition to the air pressure being 40 lbs. per square
inch, the piston H automatically finds this exact possition and rests.
I now arrange that 40 on the numbered scale K shall appear at the outside of
the cap F the pressure of 40 pounds per square inch, or either a higher or a lower
pressure will thus be registered in this manner.
By using the nozzle O shown at Fig. 5 instead of the piston C I can adapt the
pressure register for use with existing inflators.
The registering apparatus might be greatly varied instead of the spring M
working by compression I may use one working by expansion as shown in P Fig. 6,
or rubber to act as a substitute for a spring.
Also might use a pointer instead of the moving numbered scale. In fact the
details of my invention are capable of great variation, without departing from the
principle.
I believe the apparatus will prove useful, as a means of measuring the proper
quantity of air to deliver.
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
Firstly Apparatus for registering the pressure of air delivered during the
inflation of pneumatic tyres or footballs, consisting of a pressure tube enclosing a
variable spring capable of an equal resistance to the air pressure acting upon a
piston, connected to a numbered scale, to indicate that pressure.
Secondly The bracket rest to form a firm base upon the tyre.
Thirdly The combination of the aforesaid pressure register and tyre rest, with
or without an inflator tube, and the general arrangement and construction for as
and for the purposes hereinbefore described.
Dated this 24th day of October 1892.