Improvements in Pneumatic Devices for Supporting the Bodies of Vehicles for Road or Rail..
Year: 1896

page_text: Date of Application, 28th Dec.; 1896
Complete Specification Left, 28th-Sept., 1897-Accepted, 20th Nov., 1897 -
PROVISIONAL SPECIF
TION:
Improvements in Pneumatic Devices for Supporting the Bodies of
Vehicles for Road or Rail..
I, HENRY WALLACE DOVETON DUNLOP of Viewmount Lucan in the County of
Dublin, Ireland, Civil Engineer, do hereby declare the nature of this invention
to be as follows:-
My invention has for its object to prevent the vibration produced in cars,
carriages, and vehicles of all descriptions when passing over rough roads or other
tracks. To do this, I divide each vehicle into two distinct parts as described in
the Specification of my British Patent No. 14,449 (93) riz: the upper part or
carriage" which directly bears the load and the lower part or truck which, by
means of wheels or runners moves on the roadway or track, and I interpose between
the said parts longitudinally or transverselv, a tube or tubes of india-rubber or
other suitable material inflated with air or other gas.
In order to reproduce completely, as I desire to do, the action of the pneumatic
tyre, although without its aid, its liability to puncture, and its great expense, I
place the "carriage" on the inflated tubes which lie on the truck and retain it
thereon by means of forks or other equivalent devices so as to allow the tube, as
in the case of the pneumatic tyre, to expand uniformly at every point of its length
not directly pressed thus securing (as I have determined by experiment) absolute
obviation of the vibration of the "truck."
In order that my invention may be clearly understood, I have illustrated its
application in the accompanying drawings in which Figs. 1, 1, & 1" show a form
of its application to two wheeled vehicles. Figs. 2 & 2 showing another form of
such application & Figs. 3 & 4 another form as applied to four-wheeled vehioles
such as Railway or Tramway Carriages.
In these drawings C is the inflated tube, A the Truck-frame, D & D the forks
directly supporting the body B and resting on the tubes C. P is a pin in the
frame A which can travel in a slot S in the fork D thus securing the latter
against being thrown off the tube and I is a pad or cushion of indiarubber between
the forks and the sides of the frame to prevent the transmission of lateral vibration.
As shown in Figs. 2 & 24, the shaft or other part of the truck-frame is embraced
by the tube which is laced along its line of closure a, a, a & D is, as before, the
fork which, in this case, completely embraces the tube, being closed below by a
scrow nut & bolt and hinged at H to enable the tube to be removed or shifted.
In Figure 3 the inflated' tubes are laid transversely to the length of the vehicle
over the fore and hinder axles the forks behind are placed at the ends of the iron
aims by means of which the body rests on the hinder springs of (say) a cab-the
ends of the hinder springs being linked to the body of the vehicle at L to prevent
back draught and the forks in front are located over the turn-table.
Dated this 19th day of December 1896.

page_text: Improvements in Pneumatic Devices for Supporting the Bodies of
Vehioles for Road or Rail.
I, HENRY WALLACE DOVETON DUNLOP, of Viewmount, Lucan, in the County of
Dublin, Ireland, Civil 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:--
J
My invention has for its object to prevent the vibration produced in cars,
carriages, or vehicles when passing over rough roads or other tracks, being trans-
mitted to the bodies of such vehicles.
An important feature of my invention is that the weight of the body of the
vehicle, which is borne by inflated elastic tubes, is only applied to the said tubes
at intervals along the same, so that these tubes between the points which are
subject to the weight, are free to expand under the air pressure in them as far as
their construction will allow, this action being similar to that which occurs in an
ordinary pneumatic tyre, the actual pressure being only applied to a comparatively
small portion thereof, and all the remainder of the tyre being free to expand to its
full extent.
A further important feature of the said invention consists in providing means
whoreby the body of the vehicle is positively secured in position on the under-
frame, so that there is no danger of its bodily displacement, but in such a manner
that the slight movements due to the yielding of the tubes are not interfered with,
the transmission of vibrations from the under frame to the body of the vehicle
being prevented, owing to the fact that there is no rigid contact at the points of
attachment.
-
According to my said invention I interpose between. the body and the under-
frame of the vehicle, (which may for example be constructed as in my former
British Patent No. 14,449 of 1893) my improved pneumatic devices which com-
prise a tube or tubes of india rubber or other suitable material inflated with air
or other gas, in combination with bifurcated supports or forks secured to the body
of the vehicle, and which forks rest upon said tubes at intervals along the same.
These forks form also the means for securing the body of the vehicle in position
as hereinafter more fully described for which purpose they may be connected' with
the frame by a bolt and slot connection or be so arranged as to embrace the bubes
and' frame.
In order that my invention may be clearly understood and readily carried' into
effect I will proceed to describe the same fully with reference to the accompanying
drawings, in which
Figure 1 is a side view illustrating the application of one construction of
pneumatic device according to this inveution, to a wheeled vehicle, only so much
of the latter being shown as is necessary to make the arrangement clear.
Figures 2 and 3 are detail views showing to a larger scale the fork of the said
pneumatic device.
Figures 4 and 5 show the application of the said device respectively to an
ordinary four wheeled carriage, and to a railway carriage..
-
Figures 6, 7 and 8 show respectively a side elevation, a transverse section, and an
end view of another construction of pneumatic device according to my invention.
Figure 9 is an end view showing a" slightly different construction to that in
the preceding figures. I
Referring more particularly to Figures 1 to 3, a is part of the under frame of

page_text: the vehicle, and b'is part of the body thereof, whilst e care the inflated tubes.ind
dd are the forks of the pneumatic device.
The tubes c are secured in grooves a' in the under frame by means of cement
or otherwise, and the forks d are provided with vertical stems d' which carry
brackets or plates for attachment to the body of the vehicle.
For the purpose of keeping the body in place on the under frame,
each fork has one of its arms extended downward as at d and pro-
vided with a slot through which passes a bolt screwed into the-
said under frame. The bolt works loosely in the slot, the amount of
play being such that whilst any material displacement of the body of the vehicle,
due say to a sudden jolt or jerk, is prevented, the slight movements due to the
yielding of the inflated tubes are not interfered with.
In some cases I may interpose a thickness or pad of india-rubber or other
analogous material, either solid, hollow or inflated, between the portion d³ of
the fork and the under frame of the vehicle to prevent or deaden lateral vibra-
tions, and a protective covering of india rubber or other suitable material may
also be introduced between the fork and the inflated tubes to prevent wear of the
latter.
In applying the above described arrangement to a four-wheeled carriage for
example, as illustrated in Figure 4, I may suitably modify the construction of
the forks, especially, as regards the portions thereof. Thus it will be seen
that in the forks at the front of the carriage, the stom is entirely suppressed
and the brackets d are formed directly on the forks, while in the forks at the rear
of the carriage, the stem d is strengthened considerably and extends horizontally
from the body of the carriage.
In the case of a railway carriage as shown in Figure 5, the tubes c of the
pneumatic device may extend along the entire length of the carriage, and the
forks d may be arranged approximately at equal distances apart.
In the construction of device shown in Figures 6, 7 and 8; two inflated tubes.c
are arranged the one above and the other below a member of the under-frame a or
it may be above or below the axle of the vehicle. The said tubes are connected by
a narrow communication tube c' (preferably composed of pliable or extensible
material) to equalize the pressure in them, and to admit of both tubes being
inflated through a single valve c The tubes c are in the example shown, retained
in place partly by side plates a secured to the under frame, and partly by a ring
or strap a², and are firmly held at their ends by flanged end-pieces a", these latter
being formed in two parts hinged at at and provided with lugs a through which
pass bolts a for securing the parts together when closed.
Obviously however instead of using end pieces of this construction, the said end
pieces may be formed say of india rubber enlargements on the tubes themselves,
and if desired the communication tube c may be otherwise disposed or be
altogether dispensed with. In the latter case each of the tubes e is provided with
a valve in order that it may be separately inflated.
With this construction of device the slot and bolt arrangement das for keeping
the vehicle body in place, is dispensed with and the forks d are caused to com-
pletely embrace the tubes c. For permitting the removal of the body of the
vehicle from the under frame, however, the forks are provided with hinges do
and suitable fastening devices such as lugs d and bolts so that they may be
opened when desired.
I find it advantageous with this construction to interpose between each of the
forks d and the tubes c, a thick ring or band of india rubber or other suitable
material for the purpose of protecting the tubes c from friction.
Moreover the said tubes c, or the above mentioned ring or band, or both, may if
desired be provided with a suitable recess or depression for the reception of the
said fork 'd.
The arrangement shown in Figure 9 is substantially similar to that shown in

page_text: Figures 6, 7 and 8 with the exception that two additional pneumatic tubes are
disposed on opposite sides of the member of the frame a as shown.
In some cases I may construct my pneumatic device with an endless inflated
tube surrounding the edges of an elongated wooden block, the lower half or portion
of which tube rests on the under frame, while the upper half or portion serves for
the forks to rest upon. The horizontal or lateral movement of the body of the
vehicle may be restrained by bands of india-rubber or other suitable material, or
-by springs connected to the said elongated block and the bottom of the carriage
body.
The means for keeping the body of the carriage in place, may in this and other
cases consist simply of a slotted plate or arm projecting downward and from the
vehicle body such slot serving to receive a bolt secured either to the aforesaid
elongated block or to the frame. The inflated tube may be secured to the edges
of the elongated block by what is known as the "clincher" arrangement.
By the employment of my improved pneumatic device for supporting the bodies
of vehicles of the kind referred to I am enabled to secure practically the samo
freedom from vibration as is afforded by the use of pneumatic tyres without their
unreliability and heavy cost, besides which my improved devices are equally as
applicable to railway as to other wheeled vehicles.
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:
1. Supporting the body of a vehicle on inflated tubes, so that the weight is
enly applied at intervals along the said tubes, substantially as and for the purposes
specified;
2. The combination with a vehicle body and inflated tubes arranged as set forth
in the preceding claiming clause, of means for attaching the body of the vehicle
to the under frame, so as to prevent displacement of the said body without trans-
mitting vibration thereto, substantially as described.
3. A pneumatic device for preventing vibration, consisting of an inflated tube
or tubes in combination with a fork or forks, substantially as described.
4. A pneumatic device constructed and arranged for supporting the body of
the vehicle substantially as described with reference to Figures 1 to 5, to Figures 6;
7 and 8, or to Figure 9 of the accompanying drawings.
d this 28th day of September 1897.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.