Improvement in Air Pumps for Effecting and Maintaining the Inflation of Pneumatic Tires of Vehicle Wheels.
Year: 1895

page_text: Date of Application, 4th Oct., 1895-Accepted, 9th Nov., 1895
COMPLETE SPECIFICATION.
Improvement in Air Pumps for Effecting and Maintaining the
Inflation of Pneumatic Tires of Vehicle Wheels.
I. BENJAMIN FRANKLYN SPARR, of 49, New Street in the City of Newark in
the County of Essex and State of New Jersey, United States of America,
Engineer, do hereby declare the nature of this invention and in what manner the
saine is to be performed to be particularly described and ascertained in and by the
following statement :--
The object of this invention is partly to provide a simple and effective means for
inflating the pneumatic tires of vehicle wheels and for maintaining a constant
pressure therein, and partly to provide a construction for protecting such device
from the penetration of dust and grit and from exposure to derangement by
external means.
The invention consists partly in the enclosure of the actuating crank or eccentric
for the air pump wholly within the hub of the wheel, partly in forming the pump
cylinder as an integral part of such hub, partly in special means for retaining an
actuating eccentric and its strap in their normal relations, and partly in seating the
inlet valve directly upon a safety valve introduced into the inlet valve chamber
and formed with a suitable seat therefor.
In the annexed drawing,
Fig. 1 is a vertical transverse section of a bicycle axle and hub of ordinary form
adapted for and provided with my improvement; Fig. 2 is a longitudinal vertical
section of the same;
Fig. 3 is an elevation of the cap of the pump cylinder showing the inlet valve
chamber in end view and with its plug removed to expose the enclosed valves, and
Fig. 4 a sectional elevation of the same similar to Fig. 2;
Fig. 5 is a side elevation of a portion of a pneumatic bicycle wheel with its hub
in transverse section to expose the enclosed actuating crank and connecting rod.
and Fig. 6 a transverse sectional elevation of the same showing a portion of the
hub broken away.
Figs. 3 and 4 are upon a much larger scale and Figs. 5 and 6 upon a smaller
scale then Figs. 1 and 2.
That form of the improvement illustrated in Figs. 1 and 2 is designed for
application to existing wheels not originally constructed with the improvement,
the reciprocating motion for the pump being derived from the rotation of an
eccentric secured upon the ordinary straight shaft or axle; while that illustrated
in Figs. 5 and 6 slows the shaft formed with a crank, the plain cylindrical hub
surrounding the same having the pump cylinder formed integral therewith, such
form being obviously preferable for cases wherein the hub and shaft may be
specially designed to receive my improvement. It will however be observed that,
the eccentric being a species of crank in mode of operation, such members are
readily interchangeable for the purposes of the present invention; and that the
term "crank "
in the appended claims is used generically to cover either form of
such actuating member for converting a rotary into a reciprocating motion.
Referring now to Figs. 1 to 4 inclusive, the shaft a is shown provided with an
eccentric 6 fixed thereon by means of the set screw c in a threaded hole c¹ into
which is introduced a second set- or jam-screw c for locking the primary screw c
from withdrawal. The wheel hub h is shown with its central portion cut out to
admit the eccentric b, and the portions of such hub thus separated are united
'

page_text: together by means of an encircling sleeve d formed internally with a transverse
eccentric chamber with cheeks adjacent to and parallel with the sides of the
eccentric and with a lateral internally threaded boss d² for the reception of the
pump cylinder e. An opening is made in one side of the eccentric chamber for
the introduction of the eccentric in its application to the shaft, which opening is
closed by means of the segmental cap d³.
The piston within the pump cylinder is connected to the eccentric by the rod f
formed at its outer end with a plain cylindrical eccentric strap 2 encircling the
eccentric and retained thereon from lateral displacement by the flat guiding cheeks
of the eccentric chamber.
The head or cap g of the pump cylinder is formed in the top with an outlet
valve chamber m with aperture m' leading thereto from the interior of the cylinder
and with a tube t leading therefrom to the tire T of the wheel and with a lateral inlet
valve chamber n with passage ' leading therefrom to the interior of the cylinder.
The outlet valve chamber is formed upon the bottom with a flat valve seat
between which and the disk valve v is interposed a perforated rubber washer w, a
spiral spring being interposed between the valve and the top of its chamber to
retain the valve normally upon its seat.
The inner end of the inlet valve chamber is similarly provided with a perforated
rubber washer w upon which is seated the safety valve u, shown comprising a flat disk
with its central portion struck up to form a cylindrical chamber u² for the inlet
valves and retained normally upon its seat by the spring u' interposed between the
same and an adjustable perforated screw plug p inserted in the outer end of the
chamber n to regulate the tension of the spring.
The inlet valve is seated upon the perforated rubber washer w upon the inner
side of the chamber u² with a spring s interposed between the same and the inner
end of the chamber n to retain it normally upon its seat.
The operation of the inflator, as thus described, is as follows:-The plug p
having first been set to permit the safety valve to blow off at the desired pressure,
the wheel is turned upon its axle and the piston thus reciprocated to draw in the
air through the aperture p', past the valve s to the pump cylinder, whence it is
forced the valve through the tube t into the tire T. As the tire reaches the
required degree of inflation, the continuous rotation of the wheel and its simul-
taneous actuation of the pump causes the safety valve u to lift in order to relieve
the excess of pressure produced by the pump, while still permitting the pump to
supply any loss sustained by the tire from leakage.
While I have illustrated in Figs. 5 and 6 a pump cylinder cast integral with a
plain cylindrical hub for the reception of the more compact crank mechanism
shown in connection therewith, it is obvious that such hub may be as readily cast
with the eccentric chamber illustrated in Figs. and 2; so that all other features
of the present improvement illustrated in the prereling figures and recited in the
claims appended hereto are cqually adapted to a hub with integral pump cylinder
as shown in the said Firs. 5 and 6.
It is obviously immaterial whether the recess or chamber for the inlet valve and
its spring be formed upon the under side of the safety valve and the adjacent
end of the chamber n left fat, or such recess be made in the inner end of the inlet
valve chamber, in which latter case the inlet valve would be seated upon the inner
face of the valve which would be similarly formed as a flat disk.
It will be observed that each of the valves illustrated herein is provided with a
series of radial wings for centering them in their respective chambers, which feature
forms no part of the present invention.
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. The combination, with a vehicle shaft provided with a suitable crank or
eccentric, of a pneumatic wheel hub mounted upon the same enclosing the said

page_text: crank or eccentric and having a laterally projecting pump cylinder in line there-
with, a piston within the said cylinder connected to the said crank or eccentric by
suitable rod, inlet, outlet and safety valves for the said cylinder, and a tube for
connecting the pump cylinder with the pneumatic tire of the wheel, as and for the
purpose set forth.
2. The combination, with a vehicle shaft provided with a suitable crank or
eccentric, of a pneumatic wheel hub mounted upon the same enclosing the said
crank or eccentric and formed with an integral lateral pump cylinder in line
therewith, a piston within the said cylinder connected to the said crank or
eccentric by a suitable rod, inlet, outlet and safety valves for the said cylinder,
and a tube for connecting the pump cylinder with the pneumatic tire of the wheel,
as and for the purpose set forth.
3. The combination, with a vehicle shaft provided with an eccentric, of a
pneumatic wheel hub mounted upon the same formed internally with transverse
cheeks to provide a closed eccentric chamber and with a laterally projecting pump
cylinder in line with the said eccentric, a piston within the said cylinder with a rod
terminating in a plain cylindrical strap encircling the eccentric and held thereon
from lateral displacement by the cheeks of the eccentric chamber, inlet and outlet
valves for the pump cylinder, and a tube for connecting the pump cylinder with the
pneumatic tire of the wheel, as and for the purpose set forth.
4. The combination, with a vehicle shaft and a pneumatic wheel hub mounted
thereon and carrying a lateral pump connected with the pneumatic tire of the
wheel, of an eccentric mounted upon the said shaft in line with the said pump and
provided with a radial screw hole, a set screw inserted within the said hole to
secure the eccentric from turning upon its supporting shaft and a jam screw
introduced within the said hole upon the head of the set screw to lock the
same in place, and a connecting rod provided at one end with an eccentric
strap for connecting the pump piston with the eccentric, as herein shown and
described.
5. In a bicycle pump, the combination, with the pump cylinder formed with
inlet and outlet valve chambers connected thereto, respectively, by induction and
eduction ports, the piston, and means for actuating the same, of a safety valve
formed with an inlet aperture and seated within the inlet valve chamber to close
the induction port, an inlet valve seated upon the inner face of the said safety
valve to close its inlet aperture, and an outlet valve in its respective chamber, as
and for the purpose set forth.
6. In a bicycle pump, the combination, with the pump cylinder formed with
inlet and outlet valve chambers connected thereto, respectively, by induction and
eduction ports, the piston, and means for actuating the same, of a safety valve
formed with an inlet aperture and seated within the inlet valve chamber to close
the induction port, an inlet valve seated upon the inner face of the said safety
valve to close its inlet aperture, an outlet valve within its respective chamber, a
plug secured adjustably within the mouth of the inlet valve chamber, and a spiral
spring interposed between the said plug and the said safety valve, as and for the
purpose set forth.
1
1
1005
ROBERT E. PHILLIPS, Assoc. M. Inst. C.E., M.I. Mech. E.,
Consulting Engineer and Patent Agent,
70, Chancery Lane, London, W.C., Associate Agent.