IMPROVEMENTS IN GRAVITY SWITCH BACK RAILWAYS
Year: 1885

page_text: I, LA MARCUS ADNA THOMPSON, of the City and County of Philadelphia, in the
State of Pennsylvania, United States of America, Manufacturer do hereby declare
the nature of my invention for "IMPROVEMENTS IN GRAVITY SWITCH BACK
RAILWAYS," 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 gravity switch back railways having two or more double
tracks and intended to be used as a means or source of pleasure and amusement for
transporting passengers at seaside resorts, fair grounds, and other places, and consists
of certain new and novel features in the construction and arrangement of the same
to be hereinafter fully explained, whereby passengers may be carried from a certain
starting point at any convenient or suitable elevation in a vehicle or car over
a series of descending and ascending longitudinal planes by the gravity momentum
acquired by the car in its passage over the planes to the opposite end of the course,
and thence to the terminal point located within a pavilion or other suitable structure,
with the terminal point at either the same or a lower elevation than that of the
starting point, and thereby obviating all necessity in the latter instance for changing
cars on the round trip, lessening the time required for making the trip, ensuring
greater safety to passengers riding thereupon, and entirely obviating many serious
and annoying features existing in structures or railways of this character as have
heretofore been constructed.
A further feature of my invention consists of a novel construction of vehicle or
car for use in this connection, and provided with mechanism, as will be hereinafter
fully described, for controlling the speed and for stopping the car ad libitum at any
point in its excursion, and also embracing as a further feature of my invention
mechanism operating automatically for preventing the car from running backward
down the descending planes of the course.
My invention further embraces mechanism operated by suitable motive power
for elevating the cars from the terminal point to the starting point when the
respective points are at different altitudes.
In the accompanying drawings fully illustrating my invention
:
Figure 1 is a side elevation of my improved switch back-railway showing-the
Beries of descending and ascending planes and the starting and terminal points at
the same altitude within a pavilion,
..
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page_text: Fig. 2 is a side elevation of a switch back railway showing also the series of
descending and ascending planes, the tunnel, the starting and terminal points at
different altitudes, and means for elevating the car to the starting point.
Fig. 3 is a plan or top view of Figs. 1 and 2.
Figs. 4 and 5 are respectively, top or plan views showing the automatic and
Bliding switches and sections of rails at the respective ends of the course or
railway.
Fig. 6 is a transverse section of Figs. 1 and 2.
Fig. 7 is a side elevation of a car in position, showing the brake shoes operated
by a lever, and such a vehicle as has been found well adapted for such purposes.
Fig. 8 is a cross section of the car showing the peculiar construction of brake and
with mechanism for operating the same.
Figs. 9 and 10 are respectively, side elevations showing the brake in both its
normal and operative positions.
Fig. 11 is a side elevation of the locking dog for holding the car when not in use
or while shifting it on the switches; and
Fig. 12 is a sectional side elevation of a car showing the automatic device for
preventing the car from running backward down the descending planes.
Similar letters of reference indicate corresponding parts in all the figures.
Referring to the drawings, A represents the ground or foundation upon which
the trestle work B, preferably constructed of wood, but if deemed best for the
purpose may be constructed of iron; and in form irregular or undulating or con-
sisting of a series of descending and ascending longitudinal planes. Upon the top
of this trestle work forming the road bed are stringers c, c¹, c' and c³, for the
reception of the rails d, d¹, d² and d³, upon which the cars travel. Rigidly secured
to the road bed of the trestle work B, and just inside of each pair of rail stringers,
and in juxtaposition thereto, are the guard stringers e, e¹, e³ and e³, made of any
suitable material, but slightly higher than the rail stringers with narrow interstices
or spaces f, f, between the respective stringers for the reception of the inside
flange of the car wheels. These guard stringers prevent the car wheels in their
passage over the series of descending and ascending planes from jumping the tracks.
Immediately inside of the guard stringers e, e¹ and e, e, and contiguous thereto, are
the brake stringers g, g¹, g' and g³, made preferably of wood for the car brake
shoes E and E¹, to slide upon and engage with, thereby enabling the attendant in
charge of the lever operating the brake shoes to stop the car at any point or part
of the course or railway.
F is a pavilion, either enclosed or open, of any suitable construction, and of such
height or elevation as may be desired. Access to the elevated starting point I,
therein being had by a staircase I, from the ground A.
The passengers having reached the elevated starting point I, within the pavilion F,
(as shown in Figure 2) are seated in the car D. The car. is then started down
a slight descending plane j, to the summit k, passing over the same to the point 7,
and collecting in its passage sufficient velocity or gravity momentum to carry it to
and over the summit m, to descend with increased velocity over the plane n, and
thence mounting the ascending plane o, through the automatically working switch P,
to the end of the course, and when the car is released from the locking dog, such as
is shown in Fig. 11, secured to the platform in any suitable manner at this end of
the course, the car starts on its return trip passing down over the tracks d and d³,
of the descending and ascending planes through a structure representing a tunnel K,
to the terminal point p, within the pavilion, but at a lower elevation than that of
the starting point (as shown in Fig. 2,) discharging the passengers opposite to or
aside of the staircase p³, leading to the ground A, or the passengers may be
discharged in the structure having the starting and terminal points at the same
altitude, as shown in Fig. 1, at the point p, and by the staircase I¹, they are enabled
to reach the ground A.
Recurring now to Figure 2, the car after discharging its passengers is carried in
any convenient manner up the short ascending planer, where it is held at the

page_text: summit, by a locking dog r³, rigidly secured to the bed of the trestle work B,
while shifting the car on the sliding switch R, (as shown in Fig. 5,) to the tracks
leading to the starting point I, within the pavilion F. The car being released
from the locking dog ³, it passes rapidly down the plane r, far enough for the
secondary cross-arm u, upon the underside of the car D, to engage with a belt
or chain u¹, carrying thereupon a series of hooks t, which chain or belt passes
over a series of pulleys v, having motion imparted to them by gearing located
in any convenient part of the pavilion and propelled by suitable motive power X,
located either inside or outside of the structure.
The car being elevated to the starting point I, from the point 8, by means of the
belt or chain u¹, is released by the attendant in charge of the brake lever and it is
at once in position ready for the reception of passengers for the next trip.
The car D, such as shown in Fig. 7 of the drawings, is constructed of strong
or stout material, preferably wood, with a series of seats D¹, which may be either
reversible or rigid ones, having standards or sides D³, made of similar material,
with openings D³, between the respective standards for the reception of the
passengers. Upon the tops of the standards D³, are hand gripa D', securely
fastened thereto. The front and back ends of the car are preferably provided with
dashboards G and G³, projecting outwardly therefrom. Immediately above the
dashboard G, of the car, is a seat G³, for the attendant in charge of the lever G³,
actuating the brake shoes E and E¹, and having a supporting arm h, projecting
downwards and rigidly secured to the floor of the car D.
Beneath the car D, beyond the back wheels, is a shaft x, held in bearings y; y¹,
which are rigidly attached to the underside of the car. This shaft, has
projecting from each side thereof the brake shoes E and E¹, which brake shoes are
loosely secured to this shaft x, by collars w and w¹.. To the interior sides of these
brakes is rivetted a cross-arm u. By means of collars or sleeves z, z¹, upon the
shaft a, and cross-arm u, the lever G³, is held snugly in position for actuating the
brake shoes E and E. This lever G³, passes upward through an oblong slot or
opening in the floor of the car D, and thence through guides and 23, secured in
any suitable manner to the underside of the attendant's seat and the seat of the
car nearest thereto, for ensuring the free movement of the lever actuating the
brake shoes and for effecting the stoppage of the car at any point in its excursion,
or if at any time occasion should arise for decreasing the speed or gravity
momentum acquired by the car in its passage over the series of descending and
ascending planes of the railway.
very
In railways constructed substantially as shown in Fig. 1, with the starting and
terminal points at the same altitude or in the same horizontal plane, it
essential to provide means for preventing the cars from taking a retrograde
movement or running back ward down the planes, and with a view of accomplishing
this end I have provided an automatic device such as is shown in Fig. 12 of the
drawings, and preferably consisting of a pawl or dog M, pivoted to the standard D³,
of the car.
This pawl or dog engages in one of the guard stringers when the
power accumulated by the car in its passage over the course has been entirely
expended, firmly holding it in position, and preventing any retrograde movement.
of the same.
This pawl or dog M, is prevented from reversing or flying backward by a pin M¹,
preferably inserted in the standard D³, a short distance above its normal position
which permits it to move freely and perform its specific function with entire
satisfaction.
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. As an improvement in gravity switch back railways, consisting of trestle
work so constructed and arranged as to form a series of descending and ascending
planes, and having the starting and terminal points at the same altitude, in

page_text: combination with a car, and means for preventing the same from running
backward down the planes, substantially as and for the purposes described.
2. As an improvement in gravity switch back railways, having the starting and
terminal points at different altitudes, the combination with the trackways or
stringers and rails thereon, of the guardways or stringers for preventing the car
from jumping the tracks in its passage over the course, and of the brake
slidingways or stringers, substantially as and for the purposes described.
3. As an improvement in gravity switch back railways, having the starting and
terminal points at different elevations, whereby passengers are carried from said
.starting point to the terminal point without change of cars, and means sub-
stantially as described for elevating the car to the starting point, substantially as
and for the purposes set forth.
4. In a gravity switch back railway, a car constructed substantially as described,
with brake shoes actuated by a hand lever for stopping the car at any point in its
excursion, substantially as and for the purposes described.
5. In a gravity switch back railway, the combination with the undulating
trestle work, having thereon the longitudinal trackways and rails, of the guard and
brake slide stringers contiguous thereto, of a car having brake shoes which engage
with said brake stringers through the operation of a lever, substantially as and for
the purposes set forth.
6. In a gravity switch back railway, the combination with the undulating
trestle work, of the automatic and sliding switches, of dogs for holding the cars,
and mechanism substantially as described for elevating the car from the plane r,
to the starting point, substantially as and for the purposes set forth.
In witness whereof, I, the said La Marcus Adna Thompson, have hereunto set
my hand and seal, this 20th day of October, in the year of our Lord one
thousand eight hundred and eighty-five.
Witnesses:
JOHN WALTER DOUGLASS.
LOUIS HERMAN KNEBLER.
LA MARCUS ADNA THOMPSON. (L.S.)
Carpmael & Co.,
Agents for the Applicant.