Improvements in Valves for Pneumatic Tyres.
Year: 1893

page_text: Date of Application, 11th July, 1893
Complete Specification Left, 11th Apr., 1894-Accepted, 30th June, 1894
PROVISIONAL SPECIFICATION.
Improvements in Valves for Pneumatic Tyres.
ROBERT ABRAM LEE 203 Shaftesbury Avenue London W.C. Engineer do
hereby declare the nature of this invention to be as follows:-
My invention is an improved air valve for pneumatic tyres and consists of three
parts, the body and seating of the valve is a tee piece screwed on its lower end to
fit a bushing or socket which is joined to the air tube or bladder of a pneumatic
tyre the branch piece of the tee is screwed to suit the delivery end of an air pump
and the opposite end to the seating is screwed internally, the centre hole right
thro', communicates with a hole in the branch piece.
The valve & spindle is made in one, the valve being of conical form and the
stem or spindle at the end nearest the valve is reduced in diameter to allow the
air to pass it, the top end is screwed to suit the internal thread in the tee piece,
the seating is formed by the edge of the hole at the lower end of the tee, and the
outer edge, of this end of the tee is bevelled off to the hole, leaving a knife edge
which forms the seating, the conical valve screws up against this edge and is
absolutely air tight without grinding in. The top end of the spindle is fitted with
a millhead, fixed to the spindle, to open and close the valve.
Dated this 10th day of July 1893.
ROBERT ABRAM LEE.
COMPLETE SPECIFICATION.
Improvements in Valves for Pneumatic Tyres.
ROBERT ABRAM LEE 203 Shaftesbury Avenue London W.C. Engineer 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 is an improved air valve for pneumatic tyres, it consists of three
parts; the body & seating of the valve is a tee piece screwed on its lower end to
fit a bushing or socket which is joined to the air tube or bladder of a pneumatic
tyre, the branch piece of the tee is screwed to suit the delivery end of an air pump
and the opposite end to the seating is screwed internally, the centre hole right
through communicates with a hole in the branch piece. The valve and spindle are
made in one, the valve being of conical form and the stem or spindle at the end
nearest the valve is reduced in diameter to allow the air to pass it, the top end is
screwed to suit the internal thread in the tee piece, the seating is formed by the
edge of the hole at the lower end of the tee and the outer edge of this end of the tee
is bevelled off to the hole, leaving a knife edge which forms the seating, the conical
valve screws up against this edge and is absolutely air tight without any grinding
in. The top of the spindle is fitted with a millhead fixed to the spindle to open or
close the valve.
In carrying out my invention in order to make the internal screw thread and the
spindle thread fit air tight, to avoid loss of air in pumping up I find that the valve
spindle requires to fit well & tightly into the internal thread and when so made
however carefully the threads may be cut the tendency of the valve is to touch on
one side of the seating first this would wear the seating unequally and cause the
valve to leak; to overcome this difficulty 1 reduce the spindle in diameter-below

page_text: the screwed part-so that it is flexible and this flexibility causes the valve to
readily find its seat, in fact on this flexibility of the spindle depends the success of
the valve.
No back pressure arrangement is required for the valve itself is closed up before
the pump is removed and owing to the position of the valve at the bottom of the
tee piece the air pressure in the tyre tends to keep it closed.
This valve in addition to being used for pneumatic tyres may be applied to any
of the purposes that stop valves are used for, such as retaining gases & liquids in
vessels...
To open or close the valve I fix a millhead nut on the end of the valve spindle.l
In another arrangement to still further simplify the valve & make it consist of two
pieces only I extend the spindle about half an inch beyond its screwed part and
after passing the spindle thro' the body and screwing the valve up into its place
I bend this extension piece over at right angles to the stem (like a stop cock
handle) and this handle takes the place of the millhead nut for opening or closing
the valve.
Referring to the drawings the body of the valve is shown in section and the
valve & millhead is shown in full. The part marked B is the seating and A. is
the conical head of the valve which closes against B. C shows a bushing piece to
fix in the air tube, and the valve screws into this, the joint being made air tight by
luting. The part marked D is the branch to attach the pump to.
I am aware that the principle of a valve-for retaining pressures of steam
gases &c. with a fine line seating is not new & I make no claim to this
principle but
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
1st. A valve body formed as a tee piece with the seating at its lower extremity
and the top end screwed internally and a valve & spindle formed in one piece
the upper part of the spindle being screwed to suit the internal thread in
the body.
2nd. The flexible spindle conical valve substantially as described and shown in
the drawings.
3rd. The flexible spindle conical valve in combination with a tee shaped body
having a knife edge seating at its lower extremity substantially as described &
shown.
Dated the 11th C A_1 1004
ROBERT ABRAM LEE.