Improvements in Propellers for Ships.
Year: 1896

page_text: Date of Application, 4th Aug., 1896-Accepted, 26th Sept., 1896
COMPLETE SPECIFICATION.
Improvements in Propellers for Ships.
I, JOHN DAVID MARK, of 204 Dearborn Street, Chicago, Cook County,
Illinois, United States of America, 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 my invention is to provide a simple, economical and efficient
mechanism for propelling ships through the water; and the invention consists in
the features and combinations hereinafter described and claimed.
In the accompanying drawings,
Figure 1 represents a side elevation of a ship with my improvement attached
thereto;
Fig. 2 a transverse vertical section taken on line 2 of Fig. 1;
Fig. 3 an enlarged detail of one of the propelling blades or paddles in its open
position; and Fig. 4 an enlarged view of the same, showing the blade in its closed
position.
This invention relates particularly to the mechanism for propelling ships, and
is especially adapted for the propulsion of ships and boats through canals or inland
streams. In the navigation of canals, it is well known that the use of ordinary
propellers and side wheels are prohibited, owing to the fact that the splash from
the paddle wheels or the waves following the boat in the ordinary stern propeller
wash the banks in such way as to rapidly destroy the walls of the same.
principal object of my invention, therefore, is to overcome these objections by
providing simple and efficient mechanism for propelling the boat without dis-
turbing the water to any appreciable extent, or to such an extent as will raise
waves and "wash" to destroy the banks of an inland canal or stream.
The
In describing my improvement, I will describe the mechanism only, and not
enter into any detailed description of any particular kind of a boat, as it will
be readily seen that the mechanism is adapted to be applied to any kind of a
boat by slight modifications, such as may be used by the ordinary skilled
mechanic.
In constructing my improvement, I provide two pairs of sprocket wheels, A, A,
which are mounted upon shafts, a, a. Either one of these shafts may be con-
nected with any suitable source of motive power or energy, so as to drive the
connecting mechanism and thereby propel a boat as hereinafter described. The
mechanism in Figs. 1 and 2 is shown as applied to a boat, B, of which as above
stated no detailed description will be given. Each side of the boat is supplied
with propelling mechanism; but it is only necessary to describe one side, as such
description will answer for both.
The sprocket wheels and their supporting shafts are placed-as shown in the
drawings-one pair at each end of the boat, and around these sprocket wheels is
passed an endless driving chain, C, which supports and operates the paddles or
buckets, as hereinafter described. For the purpose of propelling the boats along
as the chains are moved, a number of buckets, D and D', are provided alternately,
and pivoted to the chain as at d. The buckets, D, are so pivoted that when the
chain is in operation they operate to drive the boat forward, while each alternate
set of buckets, D', is pivoted, so that during the reverse movement of the chain
they will operate to drive the boat backwards. In all other respects the construction

page_text: of the buckets or paddles is substantially the same, so that the description of one
will be a description of all.
In order to hold the buckets open in their operative position, as shown in the
lower portion of the chain in Fig. 1, connecting rods, , are provided, which are
pivoted to the outer free ends of the buckets at d, and to the chain at d³. The se
connecting rods are preferably made in two pieces and provided with heads, d,
between which is inserted a helical coiled spring,d, so that when the buckets are
in their operative position-as shown in Fig. 2-the water impact in the concave
portion of the buckets draw the bucket into its vertica! position and the connecting
rods to their outer position against the tension of the helically coiled spring, as
shown in Figs. 2 and 3. During the continued movement of the chain, the buckets
are drawn from the prow to the stern of the boat, and the boat propelled according
to the amount of energy used.
In order to overcome any resistance of the air, it is advisable that the buckets
be folded in their returning position, which is accomplished as follows: When the
bucket is moved out of the water the upper end contacts a loose wheel, A³, located
between the sprocket wheels-as shown in Fig. 2. By this action the bucket is
tilted in line with the chain and the helically coiled spring, d, allowed to expand
to its greatest length, thus shortening the connecting rod aud acting to bring the
buckets into their folding position, as shown in Fig. 4, so that no resistance
whatever of the air or water is encountered-at least not to any appreciable
extent.
It will thus be seen that the buckets assume their operative position very easily,
and without making any appreciable splash. The chain and buckets being
propelled gently and at a uniform speed, no wash is made, and the water as it is
displaced is thrown to the stern of the boat,, leaving a very small, narrow wake.
The waves ordinarily caused by the prow of the boat, due to the displacement of
the water, are met by the propelling mechanism and flattened down or minimized.
to such an extent that very little of it reaches the banks of the stream.
Shields or guards, E E, are provided and attached to the sides of the boat for
the purpose of covering the propelling mechanism and protecting it against articles
that might accidentally fall overboard, or be thrown overboard, and also from
articles floating in the water, as well as offering a safeguard for life and limb, in
that they prevent the people on boats from ordinarily contacting the propelling
mechanism.
I have not described any particular motor for driving my mechanism; but it is
understood that either steam or vapor engines, electric motors or other prime
movers may be used and connected to my improved mechanism; and while I have
entered into a more or less detailed description of my improvements and as being
embodied in certain precise forms, I do not desire to be limited thereto unduly, any
more than is pointed out in the claims. On the contrary, I contemplate all proper
changes in form, construction and arrangement, the omission of immaterial parts
and substitution of equivalents, as circumstances may suggest or render expedient.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be perforined, I declare that what I
claim is :
1. In a ship propeller, the combination of an endless driving belt, means for
supporting and driving the belt adjacent to and along the side of the vessel, and
buckets or paddles attached to such belt and adapted to contact the water
during the movements of the belt and propel the vessel along, substantially as
described.
2. In a ship propeller, the combination of an endless driving belt, means for
supporting and driving the belt adjacent to and along the side of the vessel,
buckets or paddles attached to such belt and adapted to contact the water during
the movements of the belt and propel the vessel along, and mechanism for holding
the buckets in their operative position on one side of the belt and in an inoperative

page_text: position on the opposite side of the belt during the movements of the chain through
the water, substantially as described.
3. In a ship propeller, the combination of an endless driving chain, sprocket
wheels upon which such chain is mounted for the purpose of supporting and
driving the belt adjacent to and along the side of a vessel, buckets or paddles
pivoted at one end to such chain and adapted to contact the water and propel the
vessel along during the movements of the chain, adjustable connecting rods pivoted
to the free ends of the buckets or paddles and to the chain for the purpose of
holding the buckets in their operative positions, and spring mechanism on such
connecting rods to permit the expansion of the rods during the operation of
the mechanism and close the same when out of contact with the water for the
purpose of throwing the buckets into their operative position, substantially as
described.
4. In a ship propeller, the combination of an endless driving chain, sprocket
wheels upon which such chain is mounted for the purpose of supporting and driving
the belt adjacent to and along the side of a vessel, buckets or paddles pivoted at
one end to such chain and adapted to contact the water and propel the vessel
along during the movements of the chain, adjustable connecting rods pivoted to
the free ends of the buckets or paddles and to the chain for the purpose of holding
the buckets in their inoperative positions, spring mechanism on such connecting
rods to permit the expansion of the rods during the operation of the mechanism
and close the same when out of contact with the water for the purpose of throwing
the buckets into their operative position, and protecting guards for the operating
mechanism, substantially as described.
Dated this 4th day of Aust 1806
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.