Improvements in Apparatus for Utilising the Power of Sea Waves.
Year: 1895

page_text: Date of Application, 13th Dec., 1895
Complete Specification Left, 14th Aug., 1896--Accepted, 10th Oct., 1896
Improvements in Apparatus for Utilising the Power of Sea Waves.
I, BERNARD MORLEY FLETCHER of 7 Victoria Street Westminster in the
County of Middlesex Civil Engineer do hereby declare the nature of my said
invention to be as follows:-
The object of this invention is to obtain useful energy from the sea waves by
means of a floating apparatus capable of being moored or anchored in a desirable
position.
In carrying out this invention I employ firstly-apparatus consisting of one or
more submerged platforms to which are fixed one or more tubular or other masts
constructed of suitable material and in such manner that the whole will float with
the mast or masts uppermost in the water and with their upper ends projecting
a convenient length above the water.
The platforms are so constructed and proportioned (and by reason of the length
of the masts are submerged to a sufficient depth beneath the troubled surface of.
the water) as to offer a resistance to each tendency to rise or fall on the changes
of level of the water.
Upon the vertical masts fixed to the submerged platforms may be gauged the
height of the waves from crest to trough as they rise and fall.
The masts may be circular or elliptical in section or of other convenient form.
The platforms may be of any convenient size and may be cut into square or
round or other suitable shape and they may be provided along or around their
edges or surfaces with strips or cheeks placed so as to increase the resistance to
movement in the water.
Secondly employ a floating buoy or buoys so constructed and loaded as to
rise and fall with the changes of the water level and placed around or alongside the
mast or masts which are comparatively stationary as regards the up and down
movement owing to the resistance offered by the submerged platform or
platforms.
The buoys may be of any convenient form and may be connected by means of
suitable friction or ratchet or other gearing to the mast or masts in such manner
that the wave power which raises and lowers the floating buoys may by means of
the gearing aforementioned be used to turn a wheel or drive a dynamo or pump or
other machinery or may be otherwise caused to perform useful work. Or the
floating buoys may be connected to the inasts or other portions of the said
stationary apparatus through the direct medium of pumps in such manner that
water may be delivered on each rise or fall of the floating buoys and being
conveyed through suitable connecting pipes may be used to drive a hydraulic
engine or turbine or other apparatus or it may be raised to a height or caused to
perform other useful work.
A deflection or guide blade or blades may be placed in such manner as to
obviate tilting of the apparatus when placed in a swift current.
Dated this Thirteenth day of December One thousand eight hundred and
ninet-five

page_text: Improvements in Apparatus for Utilising the Power of Sea Waves..
I, BERNARD MORLEY FLETCHER, of 7 Victoria Street, Westminster, in the
County of Middlesex, 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 :-
The object of this invention is to obtain useful energy from the sea waves by
means of a floating apparatus capable of being moored or anchored in a desirable
position.
In carrying out the invention I employ, firstly, apparatus consisting of one or
more submerged platforms to which are fixed one or more tubular or other masts
constructed of suitable material and in such manner that the whole will float with
the mast or masts uppermost in the water and with their upper ends projecting
a convenient length above the water.
.
The platforms are so constructed and proportioned (and by reason of the length
of the masts are submerged to a sufficient depth beneath the troubled surface of
the water) as to offer a resistance to each tendency to rise or fall on the changes of
level of the water.
Upon the vertical masts fixed to the submerged platforms may be gauged the
height of the waves from crest to trough as they rise and fall.
The masts may be circular or elliptical in section or of other convenient form.
The platforms may be of any convenient size and may be cut into square or
round or other suitable shape and they may be provided along or around their
edges or surfaces with strips or cheeks placed so as to increase the resistance to
movement in the water.
Secondly I employ a floating buoy or buoys so constructed and loaded as to rise
and fall with the changes of the water level and placed around or alongside the
mast or masts, which are comparatively stationary as regards the up and down
movement owing to the resistance offered by the submerged platform or
platforms.
The buoys may be of any convenient form, and may be connected by means of
suitable friction or ratchet or other gearing to the mast or masts in such manner
that the wave power which raises and lowers the floating buoys may by means of
the gearing aforementioned be used to turn a wheel or drive a dynamo or pump
or other machinery or may be otherwise caused to perform useful work. Or the
floating buoys may be connected to the masts or other portions of the said
stationary apparatus through the direct medium of pumps in such manner that
water may be delivered on each rise or fall of the floating buoys and being
conveyed through suitable connecting pipes may be usel to drive a hydraulic
engine or turbine or other apparatus or it may be raised to a height or caused to
perform other useful work.
A deflection or guide blade or blades may be placed in such a manner as to
obviate tilting of the apparatus when placed in a swift current.
I
Various attempts have been made from time to time to obtain useful energy
from the vertical oscillation of a buoy caused by the motion of sea waves but none
of these have hitherto met with conspicuous success. The chief reason for the
failure of the previous attempts lay in the difficulty which was experienced in
obtaining a fixed point' relatively to which the floating buoy was to oscillate
vertically, but which should nevertheless always remain a constant distance from
the middle point of the vertical travel of the buoy, that is to say from the
undisturbed level of the sea. A point fixed relatively to the bottom of the sea
clearly does not satisfy this condition as the rise and fall of the general level of the

page_text: sea due to the tides alters the distance of the undisturbed level of the sea from
the bottom.
By my invention I am enabled to overcome this difficulty and provide a point
capable of offering any desired resistance to upward and downward forces, and yet
which shall always remain a constant or almost constant distance below the
undisturbed level of the sea, that is below a horizontal plane intermediate between
the crests and troughs of the waves.
In order that my invention may be clearly understood, I proceed to describe
the same with reference to the accompanying drawings, which represent
elevations of one form of my apparatus in which the energy developed by the
oscillation of the buoy is transformed by pumps into a flow of water under
pressure.
A represents a mast which may be made of any suitable material, but preferably
is a hollow tubular metal structure, loaded with adjustable weights E at its lower
end, and carrying a platform B of any suitable size or shape. The platform B
may be rigidly connected to the mast and may be secured in a plane perpendicular
to the mast by stays B₁ or other suitable means or it may be attached to the mast
by a ball and socket or other suitable joint, and in this case may if desired, be
constrained by springs S tending to keep it in the plane perpendicular to the
mast.
The mast and platform are so weighted that the mast shall float in a vertical
position with the platform B immersed to a considerable depth leaving a
convenient length of the mast projecting above the surface of the water.
The
further the platform is immersed below the undisturbed level of the water the less
will be the motion imparted to it by the waves, because the amplitude of the wave
disturbance diminishes very rapidly at even small depths.
It will be found that such a platform will offer a very large resistance indeed to
à vertically displacing force, and such resistance can be further increased by
forming its upper and lower surfaces into cells by the affixing of strips or cheeks..
It is evident that rods ending in buoys may be used instead of masts and if it is
sufficient to render useful only a part of the stroke of the waves buoys attached to
the platform by chains may even be used.
I may employ any convenient number of platforms on the mast and they can be
of any convenient size and shape, provided the total resisting power is sufficient
and I may use any convenient number of masts to connect the platforms and to
serve as guides to the buoy or buoys hereafter to be described.
F represents a buoy or other suitable float of convenient size and shape and as
shown consists of a cylindrical air-tight vessel provided with an axial cylindrical
aperture F¹ through which the mast passes. This buoy is designed to rise and fall
with the waves while the mast owing to the resisting power of the platform B
remains comparatively stationary, and it is from this relative motion of the buoy
and mast that the requisite useful energy is obtained by means of suitable
gearing or intermediate mechanism.
Any suitable construction of buoy may be adopted and I may employ two or
more buoys suitably connected together.
For the conversion of the relative motion of the buoy and mast into energy
which can be transmitted to a convenient distance I prefer to employ double
acting pumps directly actuated by the said mast and vertically reciprocating buoy
to deliver water under pressure to any convenient position for the utilisation of the
energy so obtained. In the drawings two such pumps are shown adapted to take
in water through the inlets G' at both the up and down stroke and to deliver it.
under pressure into a common delivery pipe H which may be flexible and of
sufficient length to reach the place where the energy is required. The barrels G G
are carried by the buoy F and the bucket rods H by a cross-head A¹ secured. on
the mast A, but these arrangements may be varied to suit the requirements of each.
particular case.
I consider that in most cases pumps are the best means of converting the relative-

page_text: motion of the mast and buoy into available energy, but cases may clearly arise
where a purely mechanical device would be more suitable, and I wish it to be
understood that I do not in any way limit myself to the use of pumps for such
purpose, but may use any well-known mechanical device suitable for the
conversion of such reciprocating motion of the buoy relative to the mast into
rotary or other motion.
I may employ any suitable method of mooring my apparatus, and when necessary
may attach the cable or chain to any convenient part.
When moored by the mast there may be some tendency to tilt in a tide-way, and
I may counteract this tendency in two or more ways. I may mount the platform
eccentrically on the mast, in which case that portion of the platform which is
furthest from the mast will act as a vane and will lie down tide, and on the
platform tilting under the action of the tide on the buoy, the pressure due to the
current on the eccentric surface of the platform will tend to restore the horizontal
position of the platform, and to assist in this action I may affix a deflection or
guide blade. Also I may produce the mast downwards below the point of
attachment of the chain, and fix a body offering a surface of proper area to the
action of the current, whereby the pressure on the buoy may be balanced and
tilting avoided. A convenient way of making this surface is to use two plates
intersecting at right angles on the axis of the mast.
A flotilla of units such as I have described may be made to discharge into
a common delivery pipe whereby greater uniformity of flow is obtained. If desired
my apparatus may be used for pumping water to a distance and more especially
the sea water in which the apparatus floats.
The flow of water under pressure as obtained from my apparatus may be used to
drive an hydraulic motor or to perform other useful work.
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. In apparatus for utilizing the power of waves the employment of a platform
or submerged resistance which offers resistance to vertical movement yet maintains
an approximately constant distance from a plane equidistant between the average
elevations of the crests and troughs of the waves.
2. In apparatus for utilizing the power of sea waves the use of a mast or masts
a platform or platforms carried by the mast or masts the whole being so loaded
that it will float with the platforms horizontal and submerged and the masts
vertical and projecting a convenient distance above the water and capable of
offering considerable resistance to vertical displacement.
3. In apparatus for utilizing the power of sea waves the use of a mast or masts
a platform or platforms carried by the mast or masts the whole being so loaded
that it will float with the platforms horizontal and submerged and the masts
vertical and projecting a convenient distance above the water and capable of
offering considerable resistance to vertical displacement in combination with a
buoy or buoys or other floating structure capable of being reciprocated vertically
by the action of the waves as a means of producing motion of the buoy or buoys
or other floating structure relatively to the mast or masts substantially as
described.
4. In apparatus for utilizing the power of sea waves the combination of a
vertical mast or masts a horizontal submerged platform or platforms attached to
the mast or masts a buoy or buoys capable of vertical reciprocation relative to the
mast or masts and mechanism for utilizing the energy of this relative motion
substantially as described.
5. Apparatus for utilizing the power of waves comprising a buoy or movable
part and an approximately stationary part and means such as for example a pump
operated by or from the buoy for transmitting the power substantially as
described.

page_text: 6. The modifications of the devices above claimed which consist in substituting
buoys with rods or chains for masts.
7. The apparatus for utilizing the power of sea waves substantially as herein-
before described and illustrated in the accompanying drawings.
Dated this 12th day of August 1896,
B. MORLEY FLETCHER.
Boult & Wade,
Agents for the Applicant..