Improvements in See-saws for Recreation and Observation.
Year: 1897

page_text: Date of Application, 2nd Feb., 1897
Complete Specification Left, 23rd Apr., 1897-4ccepted, 12th June, 1897
PROVISIONAL SPECIFICATION.
Improvements in See-saws for Recreation and Observation.
I, ALFRED MAY DAVIS Mineral Waters Manufacturer Esher Street Westminster,
S.W. residing at 108 Upper Tulse Hill, S.W. do hereby declare the nature of this
invention to be as follows:-
These improvements relate to a gigantic see-saw of novel construction the beam or
oscillating portion of which hereafter called the girder is deflected towards the ends
thereby lowering the centre of gravity so that loads are carried above the floor of the
girder without raising the centre of gravity which would occur if the girder were
straight.
The girder may be of any desired length & breadth. It is carried on one or two, I
prefer two, specially constructed piers & is built in position, on the cantilever method.
These improvements also concern novel methods of loading the girder and actuating
and controlling it.
The piers & girders for combined strength and lightness are by preference built of
steel, the girders as lattice girders.
The girder may be loaded in the ways suitable for small or toy see-saws but for
the purpose of this invention I prefer loading the girder when in a horizontal position
immediately above the axis by means of lifts for the passage of which special provision
is made in, or attached to, the sustaining piers. A lift on one pier may be used for
ascending and on the other for descending.
To carry out this invention a rise and fall of the ends of the girder of one hundred
and fifty to two hundred and fifty feet with provision for carrying fifty to two hundred
and fifty persons at each end, is given as the mean.
The girder rests on a rocker or rockers brought to a suitable edge, or on a shaft in
ball, roller or antifriction metal bearings or the like.
From the landing stage on or above the girder passengers will be distributed in
equal numbers to both ends of the girder. At the ends of the girder pendulous
saloons or chairs are carried on struts, and oscillating or self-levelling platforms may be
erected.
The piers and lifts are continued upwards to a point approximating the height of the
end of the girder when at its greatest elevation. Here a saloon is built for observing the
motion of the girder as well as for observation generally. The saloon may be carried
on roller or ball bearings & be caused to revolve either by the action of the girder or
by power brought up from below or carried in the saloon.
Safety on the girder may be provided for by enclosing it in strong wire netting.
For spectacular & illuminating purposes the electric cable is landed immediately
above the axis of the girder.
A continuous cable tramway may be constructed to convey passengers to the ends
of the girder the cars being gripped on the cable at convenient intervals and the
cable worked by an electric motor. Or an electric railway with overhead contact
may be employed. The floor of the girder may be wood planks corrugated steel or
other suitable material, and where necessary steps are made.
To actuate the girder different methods may be employed, a bean steam engine or a
hydraulic ram may be connected with the girder in suitable positions, or a steel wire
cable may be attached to the ends of the girder & then be passed under pulleys fixed
in the ground and conducted under or above ground to any place where the power
required is most conveniently available. I prefer the latter method.

page_text: Each cable will be passed round large druins, grooved and in part cone shaped, up
which the cable will run and by gaining on the period of motion of the girder give the
necessary impulse. Or a single continuous cable attached to each end of the girder
may be passed round a suitably constructed drum to which reciprocal movement is
imparted. Hydraulic power may be employed for giving the first motion to the
girder and for continuing the motion if more convenient.
A large break drum is attached to the shaft to assist in overcoming the motion of
the girder and bringing it to rest.
It is not intended that the girder should make contact when in motion but in case
of its doing so provision is made for receiving it on a part of the girder specially
constructed for the purpose. This part will come in contact with a number of spring
buffers of graduated strengths fixed in the ground, sufficient play being given to the
buffers to allow for the arc of impact.
To prevent sudden jar to the girder and undue strain to the cable, the latter is
attached to a framework of spiral springs, which is itself attached to the girder. Or
other forms of springs and connections with them may be used for this purpose.
I, ALFRED MAY DAVIS, of Esher Street, Westminster, S.W., residing at 108, Uppor
Tulse Hill, S.W., Mineral Waters 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:-
This invention relates to gigantic seesaws for recreation and observation and will
be clearly understood by referring to the accompanying drawings wherein :-
Fig. 1 is a side elevation of a gigantic seesaw constructed according to my
invention.
Fig. 2 is an end view of Figure 1.
Fig. 3 is a side elevation of a modified form of seesaw, the supporting structure
being omitted, and,
Figure 4 is a detail.
Similar letters refer to corresponding parts in all the figures.
Referring to Figures 1 and 2, the seesaw consists of a girder A of lattice or other
suitable construction mounted on pivots or trunnions a which work in roller, ball or
other suitable bearings carried by the supporting piers B, or in lieu of trunnions
I may employ knife edges or rockers on the girder resting on suitable bearing blocks
carried by the piers or towers. The girder A may suitably be from 800 to 400 feet
long and may be built in position upon the cantilever principle. For strength and
lightness it would preferably be constructed of steel. At each end of the girder
saloons or cages are suspended pendulum fashion from pivots o so as to be self
levelling during the oscillations of the girder.
These saloons will be fitted with chairs, seats or lounges and may each accommodate
say 100 or more people; they would proferably be constructed of steel and may be
glazed or merely surrounded by a railing or otherwise constructed as preferred. By
deflecting the girder A downwards towards either end, as shewn in Figure 1, I am
enabled to carry the load above the floor thereof without raising the centre of gravity
as would be the case with a straight girder. A suitable floor or roadway 6 extends
from end to end of the girder and upon this floor or roadway I may lay rails for
electric or cable cars & to run upon by which passengers may be conveyed from the
centre of the girder to the saloons at the ends thereof. The piers B would preferably

page_text: be of steel or iron and may be of any suitable.construction; and at or about the level
of the girder, covered platforms or waiting rooms D are built to which access is
gained by the lifts E or staircases F. Other saloons or structures G may also be
built on the piers at different elevations and may be fitted up as refreshment bars,.
dining rooms, smoking rooms, drawing rooms and the like. The piers or towers B.
and their lifts or staircases are continued up past the level of the girder to a height.
approximating to the greatest elevation of the ends of the girder Å when in action.
Here a saloon or observatory H is built for watching the motion of the girder and for-
observation generally. The saloon or observatory H may be mounted on rollers (or
balls) running on circular rails or tracks 1 (Figure 4) and may be slowly revolved
by suitable gearing I, actuated by any convenient motor, or connected with the girder-
so as to be operated by the oscillatious thereof through the medium of a ratchet and.
pawl or equivalent mechanical device.
The oscillation of the girder may be effected by any suitable and convenient.
machinery or apparatus actuated by steam, hydraulic, electric or other motive power..
In Figure 1, is a wire rope, which, taking one or more turns round a drum L,
passes under guide pulleys M fixed to the ground and is secured to each end of the
girder through the medium of spring connections 1 whereby sudden jars or shooks
in starting or stopping are avoided. The drum L is intended to be rotated from a
convenient motor N by clutch or equivalent gear whereby it can be instantly thrown:
into and out of gear with the motor as desired. The drum being placed in gear with.
the motor by the clutch an impulse in one direction will be imparted to the girder by
the rope k, the drum is then thrown out of gear with the motor, so as to be free to- .
revolve independently thereof, and the girder permitted to swing in the reverse.
direction by its own momentum. These operations are repeated until the girder is in.
full swing, the duration of the impulses depending upon the judgment of the engineer.
When the girder is oscillating to its full extent further impulses may be imparted
thereto at intervals as found necessary. I prefer to construct the drum of double
conical form as represented with a spiral groove for the reception of the rope running
from end to end thereof, this construction enabling me to give to the girder a pull
having its greatest power at the start, when the rope encircles the least diameter of
the drum, and gradually increasing in speed until the girder reaches the centre of its.
arc of movement when the rope surrounds the greatest diameter of the drum; then as.
the rope descends from the centre of the other end of the drum its speed decreases
with the lessening momentum of the girder. In Figure 3 which shews a modified
form of girder the rope k in lieu of being connected with the ends of the girder is
attached by spring connections to the end of a dependent lever O of suitable construc-.
tion built on or secured to the girder. A large brake drum should be mounted on
the drum L to overcome the motion of the girder and assist in bringing it to rest.
If desired, saloons or cages C may be suspended beneath as well as above the floor-
of the girder, as shown in Figure 3, access to the lower saloons being gained by
suitable stairs dependent from the girder, and not illustrated in the drawings.
It is not intended that the girder should make contact at any time when in motion,.
but in order to avoid serious consequences should this accidentally occur, I provide
buffers P beneath each end of the girder adapte:l to engage with hydraulic or spring
buffers P 1 fixed in the ground.
If desired, in substitution for, or as an addition to, the cages or saloons C, I may
employ self levelling platforms, or a number of pendulous chairs or seats suspended
above the floor of the girder near the ends from suitable supports.
Safety on the girder muy be ensured by enclosing the same with strong wire-
netting.
Electric lights for spectacular and illuminating purposes may be placed at suitable
points on the girder and piers or towers and the electric main for these and for the
electric cars (when employed) may be landed close to the axis of the girder.
In conclusion I would observe that I do not confine or restrict myself to the
particular construction shown which merely illustrates a suitable method of carrying.
my invention into effect.
'

page_text: It will be obvious that in my invention it is not necessary to entirely stop the
oscillations in order that a passenger should reach either end of the beam or girder,
inasmuch as the point where the passenger steps on the beam is the centre of
oscillation or near it, and consequently the movement there is a minimum.
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. An improved seesaw or oscillating appliance in which the passage to either end
of the beam or girder is made from or near its contro of oscillation, the said beam or
girder consisting of a trussed lattice work or other similar construction and having a
path or floor along its length communicating with self levelling saloons, cages or
platforms at or near the ends of the said beam or girder.
2. A seosaw as claimed wherein the beam or girder is deflected at its ends so as to
permit of the self levelling saloons, cages or platforms being carried above the floor or
path thereof without raising the centre of gravity substantially as described and
illustrated.
8. The combination with seesaws of a revolving observatory or tower built upon
the piers supporting the beam or girder and actuated either by the oscillating beam
or girder or by independent means, substantially as described and illustrated.
4. An improved seesaw adapted to be loaded from near its centre of oscillation and
having a cable or electric railway extending along the length of the oscillating beam
or girder for communicating with self levelling saloons, cages or platforms at or near
the ends of the latter, substantially as described.
5. In seesaws, actuating the beam or girder by means of a rope attached to each end
of-the said beam or girder, and passing under pulleys and round a drum of double
cone shape, the said drum being made to revolve by any suitable motive power through
the medium of clutch or equivalent gearing and being controlled by a brake,
substantially as described and illustrated in the accompanying drawings.
6. A seesaw or oscillating appliance, constructed and arranged, substantially as
described and illustrated in the accompanying drawings.
Dated this Zord day of Apru 1897.
E. P. ALEXANDER & SON,
Chartered Patent Agents,
19, Southampton Buildings, Chancery Lane, London, W.C., Agents.