IMPROVEMENTS IN APPARATUS FOR PROPELLING SHIPS OR VESSELS, ALSO APPLICABLE TO THE RAISING AND PROPELLING OF WATER AND OTHER FLUIDS." PROVISIONAL SPECIFICATION
Year: 1864

page_text: LETTERS PATENT to Patrick St. George Græme, of No. 9, Waterloo
Place, Pall Mall, in the County of Middlesex, Captain, R.A., and Hugh
Forbes, of No. 6, Aberdeen Place, Maida Hill, in the County of Middle-
sex, for the Invention of "IMPROVEMENTS IN APPARATUS FOR PROPELLING
SHIPS OR VESSELS, ALSO APPLICABLE TO THE RAISING AND PROPELLING OF
WATER AND OTHER FLUIDS."
PROVISIONAL SPECIFICATION left by the said Patrick St. George Græme
and Hugh Forbes at the Office of the Commissioners of Patents, with
their Petition, on the 18th January 1864.
We, PATRICK ST. GEORGE GRÆME, of No. 9, Waterloo Place, Pall Mall, in
the County of Middlesex, Captain, R.A., and HUGH FORBES, of No. 6,
Aberdeen Place, Maida Hill, in the County of Middlesex, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN APPARATUS FOR PRO-
PELLING SHIPS OR VESSELS, ALSO APPLICABLE TO THE RAISING AND PROPELLING OF
WATER AND OTHER FLUIDS," to be as follows:-
Our Invention relates more particularly to an Invention for "An improved
Method of Propelling and Steering Ships" for which Letters Patent have been
granted to Edward Myers, of 2, Millbank Row, County of Middlesex, Civil
Engineer, and Hugh Forbes, of 6, Aberdeen Place, Maida Hill, County of
Middlesex, and bearing date the Eighth day of July 1863 (No. 1691).

page_text: In the Specification to the said Letters Patent was described an apparatus
consisting of two drums with teeth or cogs formed upon their surface, gearing
into each other in a similar manner to ordinary cog wheels. These drums
were contained in a closed casing and revolved upon axes carried by the latter.
The casing surrounded a portion of each drum as closely as possible on the
opposite sides to those were they were in gear, and communicated at the other
opposite sides with pipes or tubes leading to the exterior of the vessel; as the
drums were made to revolve the water passing from the outside of the
vessel through the one tube was received in the spaces between the cogs
of each drum, and was conveyed round in them, being prevented from escaping
by the closely fitting casing, and was discharged into and propelled along the
opposite tube to the exterior of the vessel, which by this action was propelled
through the water. In order to prevent any water from being carried back by
the drums on the sides where they were in gear the cogs and spaces were
each made of a semicircular form, so that when in the line of centres the
cogs filled. the spaces exactly or nearly so. Although the teeth so formed
fulfilled the above condition, it is evident that such a form of tooth or cog
would not work correctly, and that consequently if moving at a high velocity
a great deal of friction and consequent abrasion and deterioration of the cogs
would ensue.
Now one part of our present Invention consists in fixing outside the casing
upon the axes of the drums, having cogs of the before described or of any other
suitable form, cog wheels, the teeth of which have, as nearly as practicable,
precisely the same form and position as those of the cogs of the drums, and we
fix such cog wheels either on one end of the axes only or on both ends; by
this means the pressure will be greatly taken off the cogs of the drums and
put upon the external gearing, and consequently a great diminution in the wear
of the internal cogs will ensue, and when the outside gearing becomes worn
to any extent, this will be replaced by new gearing at a much less cost and
with much greater facility than would be the case if the drums themselves had
to be renewed.
It is a main feature of our Invention that the cogs of the outside gearing
should, as before stated, correspond as exactly as possible, as regards form
and position, with the cogs of the drums, as were they formed differently the
internal and external cogs would not at the same time be acting in the same
manner upon each other, and little or no advantage would be gained from the
outside gearing.
Another part of our Invention has for its object to relieve the cogs of the
internal drums entirely from a pressing contact by means of the before

page_text: mentioned outside gearing, and consists in forming the cogs to one or both of
the drums to the least possible extent smaller or the spaces to a slight extent
larger than those of the outside gearing (maintaining however the same pitch),
whereby the least possible space would always intervene between the cogs of
the drums that were in gear, and consequently no wear at all of such cogs
would take place. Or we form the cogs of one or both of the drums to a slight
extent smaller or the spaces to a slight extent larger than those of the outside
gearing as before mentioned, and then coat the former to such an extent with
india-rubber, Spence's sheathing composition, or other suitable material, that
such coating of two cogs that are in gear shall just be in contact, all pressure
being however, as completely as practicable, still taken by the cogs of the outside
gearing. When these latter are worn away through friction to such an extent
as in the first case to cause the cogs of the drums to come in contact, or in the
second case to cause undue pressure to take place between the coatings of the
cogs of the drums, we remove such worn outside gearing and replace the same
by new gearing, and in order that this outside gearing should wear away as
little as possible, we prefer to make the same of cast steel, or if we make them
of cast iron, we casebarden the working surfaces of the cogs.
In some cases it may be found that the advantage gained by the prevention
of any water being carried back to the inlet tube by the adoption of the form
of the cogs as described in the Specification to the before-mentioned Letters
Patent is considerably overbalanced by the loss of power from friction con-
sequent on the incorrectness of that form with respect to the maintenance of
constant velocity ratio in all positions of the cogs, as also the substitution as
much as possible of rolling contact for frictional contact. In such cases we
prefer to make the cogs or teeth both of the drums and the outside gearing
of such known forms as will best fulfil these latter conditions, such as the
epicycloidal, hypocycloidal, and the involute curves, modifying the forms of
the spaces on the drums, however, to such an extent as without material
prejudice to the perfect action of the cogs to attain as nearly as practicable to
the property of the semicircular form of cog and space, namely, the filling out
more or less completely of the space by the cog.
By the adoption of these forms also the further advantage would be gained
of affording larger spaces between the teeth or cogs, and consequently increasing
the volume of water discharged at each revolution of the drums, whereby of
course the useful effect of the apparatus would be augmented. In order to
fulfil this latter condition as completely as possible, we in some cases assume any
arbitrary length and pitch for the cogs of the drums, greater than those of the
outside gearing, thus reducing the number of cogs and increasing the spaces

page_text: of the drums from those of the outside gearing, but still maintaining such a
relative action between the two, and so forming the faces and flanks of the
cogs of the drums, that when these are caused to revolve by the outside
gearing, one tooth or cog of one of the drums shall in every position, whilst in
gear, be in contact with or move closely along the flank and face of the corre-
sponding tooth or cog on the other drum, whilst no locking of the teeth is
possible.
Although in the foregoing we have described our improvements as applied
to apparatus for propelling ships or vessels, yet it is evident that they are equally
applicable to the same apparatus when applied to the raising and propelling of
water and other fluids, such application being already well known.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Patrick St. George Græme and Hugh Forbes in the Great
Seal Patent Office on the 18th July 1864.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, PATRICK
ST. GEORGE GREME, of No. 9, Waterloo Place, Pall Mall, in the County of
Middlesex, Captain, R.A., and HUGH FORBES, of No. 6, Aberdeen Place,
Maida Hill, in the County of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighteenth day of January, in the year of our Lord
One thousand eight hundred and sixty-four, in the twenty-seventh year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto us,
the said Patrick St. George Græme and Hugh Forbes, Her special licence that
we, the said Patrick St. George Græme and Hugh Forbes, our executors,
administrators, and assigns, or such others as we, the said Patrick St. George
Græme and Hugh Forbes, our executors, administrators, and assigns, should
at any time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for "IMPROVE-
MENTS IN APPARATUS FOR PROPELLING SHIPS OR VESSELS, ALSO APPLICABLE TO
THE RAISING AND PROPELLING OF WATER AND OTHER FLUIDS," upon the condition
(amongst others) that we, the said Patrick St. George Græme and Hugh
Forbes, our executors or administrators, by an instrument in writing under
our or their hands and seals, or under the hand and seal of one of us or them,
should particularly describe and ascertain the nature of the said Invention, and

page_text: in what manner the same was to be performed, and cause the same to be
filed in the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that we, the said Patrick St. George Græme and Hugh
Forbes, do hereby declare the nature of the said Invention, and in what.
manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement thereof, reference being had to the
accompanying Drawing, and to the figures and letters marked thereon, that
is to say:-
Our Invention relates more particularly to an Invention for "An Improved
Method of Propelling and Steering Ships," for which Letters Patent have
been granted to Edward Myers, of 2, Millbank Row, County of Middlesex,
Civil Engineer, and Hugh Forbes, of 6, Aberdeen Place, Maida Hill,
County of Middlesex, and bearing date the Eighth day of July 1863
(No. 1691).
In the Specification to the said Letters Patent was described an apparatus
consisting of two drums with teeth or cogs formed upon their surface, gearing
into each other in a similar manner to ordinary cog wheels. These drums
were contained in a closed casing and revolved upon axes carried by the latter.
The casing surrounded a portion of each drum as closely as possible on the
opposite sides to those where they were in gear, and communicated at the
other opposite sides with pipes or tubes leading to the exterior of the vessel.
As the drums were made to revolve, the water passing from the outside of the
vessel through the one tube was received in the spaces between the cogs of
each drum and was conveyed round in them, being prevented from escaping
by the closely fitting casing, and was discharged into and propelled along the
opposite tube to the exterior of the vessel, which by this action was propelled
through the water. In order to prevent any water from being carried back
by the drums on the sides where they were in gear, the cogs and spaces were
each made of a semicircular form, so that when in the line of centres, the
cogs filled the spaces exactly or nearly so. Although the teeth so formed
fulfilled the above condition, it is evident that such a form of tooth or cog
would not work correctly, and that consequently, if moving at a high velocity,
a great deal of friction and consequent abrasion and deterioration of the cogs
would ensue.
Now one part of our present Invention consists in fixing outside the casing,
upon the axes of the drums having cogs of the before-described or of any
other suitable form, cog wheels, the teeth of which have, as nearly as
practicable, precisely the same forni and position as those of the cogs of the

page_text: drums, and we fix such cog wheels either on one end of the axis only or on
both ends; by this means the pressure will be greatly taken off the cogs of
the drums and put upon the external gearing, and consequently a great
diminution in the wear of the internal cogs will ensue, and when the outside
gearing becomes worn to any extent this will be replaced by new gearing at a
much less cost and with much greater facility than would be the case if the
drums themselves had to be renewed.
It is a main feature of this part of our Invention that the cogs of the
outside gearing should as before stated correspond as exactly as possible as
regards form and position with the cogs of the drums, as were they formed
differently the internal and external cogs would not at the same time be
acting in the same manner upon each other, and little or no advantage would
be gained from the outside gearing.
Figures 1, 2, and 3 on the accompanying Drawing shew an arrangement
of the apparatus constructed according to this part of our Invention. Figure 1
shows an end elevation of the same with the driving drum removed; Figure 2
shows a sectional plan of the same; and Figure 3 shows an elevation with the
end of the casing removed in order to shew the toothed drums. Similar
letters of reference indicate similar parts in each of the Figures.
A, A', are the toothed drums havings cogs and spaces of a semicircular form
in gear with each other, as shown in Figure 3, the rotation of which drums
inside the casing B, in the direction of the arrows, causes the water or other
fluid to be conveyed in the spaces between the cogs from the inlet pipe C to
the outlet pipe D. Upon the same spindles E, E', with the toothed drums
A, A¹, but outside the casing B, are the toothed wheels F, F1, the cogs and
spaces of which are formed as nearly as practicable precisely the same as
regards form and position as the cogs and spaces of the drums, so that when
rotary motion is imparted to the drum A by means of the driving pulley G,
then instead of the rotation of the drum A¹ being effected solely by the
motion imparted to the drum A, as was heretofore the case, such rotation of
the drum A¹ is also effected by the wheel F driving the wheel F¹ in precisely
the same manner as the drum A drives the drum A¹. By this means the
pressing contact between the drums and the consequent wearing of their cogs
is greatly diminished, and this would be still more the case if other cog wheels
similar to F, F¹, were placed upon the other ends of the spindles E, E',
outside the casing.
Another part of our Invention has for its object to relieve the cogs of the
internal drums entirely from a pressing contact by means of the before-men-
tioned outside gearing, and consists in forming the cogs to one or both of the

page_text: drums to the least possible extent smaller or the spaces to a slight extent
larger than those of the outside gearing (maintaining, however, the same
pitch), whereby the least possible space would always intervene between the
cogs of the drums that were in gear, and consequently no wear at all of such
cogs would take place; or we form the cogs of one or both of the drums to
a slight extent smaller or the spaces to a slight extent larger than those of
the outside gearing, as before mentioned, and then coat the former to such an
extent with india-rubber, Spence's sheathing composition, or other suitable
material, that such coating of two cogs that are in gear shall just be in
contact, all pressure being however, as completely as practicable, still taken
by the cogs of the outside gearing. When these latter are worn away through
friction to such an extent as, in the first case, to cause the cogs of the drums
to come in contact, or, in the second case, to cause undue pressure to take
place between the coatings of the cogs of the drums, we remove such worn
outside gearing and replace the same by new gearing; and in order that this
outside gearing should wear away as little as possible, we prefer to make
the same of cast steel, or if we make them of cast iron we caseharden
the working surfaces of the cogs. In some cases it may be found that the
advantage gained by the prevention of any water being carried back to the
inlet tube by the adoption of the form of the cogs as described in the Speci-
fication to the before-mentioned Letters Patent is considerably overbalanced
by the loss of power from friction consequent on the incorrectness of that form
with respect to the maintenance of constant velocity ratio in all positions of
the cogs, as also the substitution as much as possible of rolling contact for fric-
tional contact. In such cases we prefer to make the cogs or teeth both of the
drums and of the outside gearing of such known forms as will best fulfil these
latter conditions, such as the epicycloidal, hypocycloidal, and the involute
curves, modifying the forms of the spaces on the drums, however, to such an
extent as, without material prejudice to the perfect action of the cogs, to attain
as nearly as practicable to the property of the semicircular form of cog and
space, namely, the filling out more or less completely of the space by the cog.
Thus Figure 4 on the accompanying Drawing shews a section of a pair of
drums, and of the corresponding outside gearing in which the cogs are formed
with the involute curve, the width of the spaces and of the cogs being made
equal if measured on the pitch line P, P, in order to make the cogs fill in the
spaces as closely as possible, so as to prevent any water from being carried
back to the inlet pipe. For the same reason, instead of leaving the tops of
the cogs with square edges, and making the bottom of the spaces of a cor-
responding form for the teeth to work in, as is the case with ordinary cog

page_text: wheels of this form, the tops of the cogs are rounded off, as shewn, and the
spaces are filled in in a corresponding manner. By the adoption of the above-
mentioned forms also, the further advantage would be gained of affording
larger spaces between the teeth or cogs, and consequently increasing the
volume of water discharged at each revolution of the drums, whereby of
course the useful effect of the apparatus would be augmented. In order to
fulfil this latter condition as completely as possible, we in some cases assume
any arbitrary length and pitch for the cogs of the drums greater than those
of the outside gearing, thus reducing the number of cogs and increasing the
spaces of the drums from those of the outside gearing, but still maintaining
such a relative action between the two, and so forming the faces and flanks
of the cogs of the drums, that when these are caused to revolve by the
outside gearing one tooth or cog of one of the drums shall in every position
whilst in gear be in contact with or move closely along the flank and face
of the corresponding tooth or cog on the other drum, whilst no locking of the
teeth is possible.
Figure 5 shows a section of two drums A, A¹, and outside gearing F, F',
(shewn in dotted lines) constructed according to this part of our Invention.
F, F, are a pair of toothed wheels of any ordinary form and pitch; the cogs of
the drum A are of any assumed form, being in this case only five in number,
whilst the cog wheels have twelve cogs. The form of the cogs of the drum
A¹ is obtained by marking upon a disc of paper or wood fixed to the wheel F¹
the various positions of the cogs of A as they pass over it while both the
drum A and the disc are being made to revolve by turning the wheels F, F.
The inner boundary line, formed by marking all the positions of the cogs of the
drum A, as described, will give the outline of the cogs to the drum A¹, which,
it is evident from the manner in which their form is obtained, must always
work in contact with the cogs of the drum A so long as they are in gear, and
will also more or less completely prevent any water being carried back to the
inlet pipe.
Although the form and number of the cogs of the one drum are quite
árbitrary so long as by their rotation over a disc revolving with the same
velocity as above described, they are capable of producing a form for the cogs
of the other drum that will whilst in gear always be in contact with them, and
that will at every part of a revolution form such a contact, yet it will be
evident that there are some forms that will fulfil those conditions better than
others; such are the epicycloidal and in particular the involute forms, which
latter is the form of the portion X of the cogs shown at Figure 5. And if in
employing these the curve for the cogs of the drum A be generated upon the

page_text: same pitch circle P as that of the outside gearing F, and the thickness of the
cog on the pitch circle be made just equal to half the pitch, the form obtained
for the cogs of the drum A' will be identical with that of the cogs of the drum A.
The semicircular form of cogs and spaces may also be employed on this principle
for the cogs of the drum A, but it will be found that the cogs of the drum A¹
will in that case not be quite identical with them if produced in the above
described manner, for if they were identical, then, as the velocity ratio of the
pitch circles of the drums would be variable, and the velocity ratio of the
wheels F, F, driving the same, would be constant, it is evident either that a
locking would take place, or that a grinding and consequently a deteriorating
action between the cogs would ensue.
By employing drums and outside gearing constructed on the above described
principle, the advantage is gained of being able to employ drums with a less
number of cogs, and having therefore greater spaces than would be possible if
outside gearing were not employed, as without the latter drums having so
small a number of cogs would not work properly together, and would not fulfil
the required conditions.
It will be evident that the cogs of the drums constructed on this principle
may be reduced in size to a very slight extent so as not actually to be in
contact, and may also in that case be coated with any suitable material, such
as india-rubber or Spence's sheathing composition, as described with reference
to another part of our Invention.
Although in the foregoing we have described our improvements as applied
to apparatus for propelling ships or vessels, yet it is evident that they are
equally applicable to the same apparatus when employed for the raising and
propelling of water and other fluids.
Having now described the nature of our Invention, and the best means we
are acquainted with of performing the same, we wish it to be understood that
we do not claim generally the application of outside gearing to the apparatus
herein-before described, as we are aware that such application has already
been mentioned in the Specification to a Patent granted to Francis Noble
Knipe, and bearing date the 7th July 1791 (No. 1817), although the
arrangement there shown would not be practically applicable; but what we
claim in respect of the above described apparatus for propelling vessels and for
raising and propelling fluids is,-
First, combining with the toothed drums having cogs and spaces of a semi-
circular or other suitable form, external cog wheels, the cogs and spaces of
which have the same form and pitch as those of the drums, such outside

page_text: wheels being fixed on the same spindles with the drums, either on one side or
on both sides of the same.
Second, making the cogs of the drums to the slightest extent smaller or the
spaces to the slightest extent larger than those of the outside gearing, main-
taining, however, the same pitch and similarity of configuration, so as to
relieve the drums entirely from contact with each other, and yet to make them
work correctly together.
Third, making the cogs of the drums somewhat smaller or the spaces some-
what larger than those of the outside gearing, maintaining, however, the same
pitch and similarity of configuration, and coating the cogs or spaces, or both
the cogs and spaces of the drums, either entirely or partially to such an extent
with any suitable material, such as india-rubber or Spence's sheathing com-
position, as to make them come in contact, but not to press upon each other
when caused to revolve by the outside gearing.
Fourth, making the cogs of the one drum of any arbitrary size and pitch
different from those of the outside gearing, and so forming the cogs of the
other drum that they shall in all positions whilst in gear be in contact with or
move closely along the cogs of the other drum, whilst the velocity ratio of the
pitch circles of the two drums due to the form of their cogs is always the
same as that of the pitch circles of the outside gearing; also, either relieving
such cogs of all actual contact or reducing them somewhat in size, and coating
them with suitable materials, as herein-before explained.
In witness whereof, we, the said Patrick St. George Græme and Hugh
Forbes, have hereunto set our hands and seals, this Eighteenth day of
July, in the year of our Lord One thousand eight hundred and
sixty-four.
PAT. ST. G. GRÆME. (L.S.)
HUGH FORBES.
(L.S.)
PAT. ST. G. GRÆME. (L.S.)
HUGH FORBES.
(L.S.)