or other Motive Power.
Year: 1886

page_text: or other Motive Power.
I, PHILIP MIDDLETON JUSTICE of 55 and 56 Chancery Lane in the County of
Middlesex Fellow of the Institute of Patent Agents do hereby declare the nature
of this invention (a communication to me from abroad by Robert H. Isbell of the
City County and State of New York, United States of America) and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement :—
This invention consists of a series (two or more) of jointed arms, playing within
a shallow cylinder, and dividing the cylinder into separate variable chambers; the
arms being pivoted together at one end eccentrically as to the centre of the engine
shaft, and at the other end pivoted at different points upon the sides of the cylinder.
Motion around the centre of the shaft is produced by the chambers alternately
enlarging and contracting through the force of the power applied against the
movable arms.
The central pivot may be one attached to the shaft, the other ends
of the arms being pivoted at stationary points upon the circumference of the
cylinder, or the central pivot may be stationary and the outer ends revolve, in
which latter case the outer ends would be attached to the circumference of an
inuer cylinder itself attached to the shaft-in each case the principle would be
the same.
My invention is entirely distinct from that class of rotary engines which consist
of a smaller cylinder placed eccentrically within a larger one, and made to rotate
by means of pistons sliding in and out of the smaller one.
I know also, that prior to my invention, rotary engines have been made with
several cylinders arranged upon the circumference of a rotating cycle, and with
their pistons all attached to a point fixed eccentrically as to the shaft, that point
being stationary and the cylinders themselves rotating. But I know of no
application prior to mine, of the principle of jointed arms, to divide the cylinder
or engine in which the power acts into variable chambers. There are various ways
in which it may le applied.

page_text: The objects of my invention are various, comprising simplicity of construction,
reduction of friction, a proportional increase of surface for the power to act upon,
are more steady application of the power, less oscillation of the machine and
greater speed.
The accompanying drawings are made with special reference to a small engine
operated by steam, but the same principles and description are applicable in the
main, to an engine of any size or power, and also to water motors.
Fig. 1 is a side elevation of an entire machine.
Fig. 2 is a plan of the jointed arms, which play the part of pistons.
Fig. 3 is a perspective of the shaft, and attached to it the inner cylinder
containing the arms.
Fig. 4 is a side section of the outer cylinder on line x Fig. 1, and shows how
the steam enters.
Fig. 5 is a perspective of the outer cylinder, in which the other revolves, showing
the entrance and exit for the steam.
Fig. 6 is a plan showing a variation of the outer cylinder, suited to a case where
the entrance of further steam is to be cut off before the end of the stroke.
Fig. 7 is a perspective of the cap to close the outer cylinder, showing the pivot
upon which the jointed arms turn.
Figs. 8 and 9 are plans, respectively, of the inner cylinder with its jointed arms,
and of the outer cylinder in which it turns, suited to the case where two arms are
to be used instead of three.
Fig. 10 is a plan of a smaller machine.
Fig. 11 is a section on the line y of Fig. 2, of the inner ends of the jointed arms,
pivoted together.
All of the figures from 1 to 9 inclusive, are adapted to the case where the inner
ends of the jointed arms are stationary and the outer ends revolve, while Fig. 10
is a plan of the arms in a machine where the outer ends are stationary and the
inner ends revolve. Figs. 2, 5, 6, 7, 8, 9 are upon the same scale. Figs. 1, 3 and 4
are upon a reduced scale, but the same scale as each other. Fig. 11 is upon an
enlarged scale.
A, Fig. 1 is the frame upon which the machine rests, having bearings for the
shaft F at a, a.
B, (Figs. 1 and 5) is the outer cylinder solidly affixed to the
frame. C, (Figs. 1 and 7) is a cap fitting upon I of the outer cylinder B and closing
it, and having a bar n affixed to it at right angles on the inside. D, is a pulley by
which to take the power from the machine. E, (Figs. 2 and 3) is a shallow
cylinder, solidly affixed to the shaft F and forming part of it. This cylinder E fits
into the cavity E¹ of the outer cylinder B, and revolves in it.
The operating part of the mechanism lies within the cylinder E. It is a hollow
cylinder, with one end open toward the cap C, but closed by the said cap when in
operation, and with the other end, i,e, the inner end, attached at its centre to the
shaft F, and with that end closed, except for the ports or, openings e The jointed
arms G, G, G³, G¹ and G¹¹ G" are all of the same depth as the cylinder E, so that
when in position they form with the side of the cylinder E and the cap C, three
separate compartments, which are in all positions steam-tight, except for the
openings e. They are pivotted together like a hinge, at their inner ends around
the hole m, are joined at the points g, g', gl respectively, and are pivoted at the
points h, h¹, h, respectively, upon pivots affixed to the circumference of the circle,
equi-distant from each other. All the joints of the arms are made steam-tight.
When the parts are in position the hole m. receives the bar n, which is affixed to C
at a point one side of its centre. J, (Fig. 5) is the steam-chest, being a cavity
in the cylinder B, underlying the cylinder E and admitting steam through the
hole b. J is a like cavity, to serve as the exhaust through the hole c. The
partitions and r between them are upon a level with the rings o and p, and upon
them the inner. disc of the cylinder E revolves steam tight. The sides of the
cylinder E need not be steam tight against the sides of the cavity E¹. The inner
ends (at m Fig. 2) of the jointed arms, I provide with annular elevations or riba

page_text: which set into corresponding depressions or grooves, the rib of one arm just fitting
in the groove of another. This is shown in Fig. 11, which is a vertical section of
the circular ends of the arms hinged together, showing a part of one arm and only
the circular ends of the other two. The arm G¹ encloses G and G" encloses both.
Even when the bar n is removed they reniain locked together. The object of these
ribs and grooves is to render the motion smoother and also keep the joint steam-
tight. Two of the three arms must be made in parts. A similar construction
may be used at the joints g, g¹³, g, or even at the pivots h, h, h, when made
advantageous by the size of the machine.
In small machines no packing of the moving parts will be necessary. But in
larger machines, if necessary, the jointed arms may have appropriate packing
inserted upon their upper and under surfaces. Packing may be used at other
points when necessary.
The operation of the 3-armed machine is as follows:-
The steam enters at b. When one of the ports or openings e passes the
partition, steam enters the chamber with which that port communicates. The
pressure of the steam acting upon the jointed arms revolves the cylinder E in the
direction of the arrow (shown in Fig. 2) and that chamber begins to enlarge
through the movements of the jointed arms, and continues to enlarge until the port
passes the partition r, at which point the chamber has reached its largest possible
position. In the meantime, a second chamber has been filled by steam, by its port
passing the partition r¹. Each chamber discharges its steam into J as soon as its
port has passed the partition r. So that during the time it is contracting there
is no pressure of steam within it to resist the enlargement of the other two
chambers.
As the points h, h¹, h¹¹, are distant one-third of the circumference from each
other, the partitions r and r³ must be at a corresponding distance from each other.
Thus the steam acts in each chamber for two-thirds of the distance around, and is
at every moment acting in two chambers. There is, thus, no dead point. When
the machine is first started, the steam must enter one or both of the chambers
where pressure will turn it in the direction of the arrow. The force exerted is at
all times the same, or nearly so, being greatest in any chamber when it reaches,
about the position of G G, G¹ G, as shown in Fig. 2.
Each chamber is smallest when the outer ends of its enclosing arms (h¹ and h
for instance) are upon opposite sides of and equi-distant from the partition r³, or
nearly so, and in that position the outer end of the other arm (h) is directly
opposite. Consequently the ports e are arranged directly opposite the outer
ends of the arms and they must be put in such position that the arms will not
cover them in movement, at least enough to obstruct the passage of the steam.
The inner pivotal point m of the jointed arms I place inside the circle running
through the pivotal points of their outer ends (h, h¹, h¹¹) and distant from the
circumference of that circle one-third of its diameter. This determines the position
of the bar n upon the cap C.
I have discovered that this proportion (2 to 1) produces better results than any
other. The inner pivotal point, that is, the bar n, can, however, be placed at other
distances from the centre of the cylinder, and motion will result. The distance may
be varied for the same purposes for which the length of a crank is varied in other
engines, and upon the same principles.
The bar n in the drawings is represented as being directly over the partition r¹,
and the partition as in a line perpendicular to the centre. Neither of such
positions is essential. Nor is the position of the port e in its chamber exactly as
represented, essential. But it is essential that the ports e and the partition 21
shall be so placed with reference to each other, that steam shall not begin to enter
any chamber until such chamber is at its smallest capacity, and that the partition r
shall be so placed that the steam shall begin to exhaust as soon as it reaches its
Jargest capacity. These positions may be calculated exactly.

page_text: -
The spaces H lying between the dotted lines and the sides of the cylinder E
(Fig. 2) represent those parts of the cylinder which the jointed arms in their
movements never occupy or touch. These spaces may be entirely filled or manu-
factured solid with the side and rear plate of the cylinder E. When steam is used
as the motive power, they should be so filled, so as to make as small as possible the
chambers which the steam enters, and thereby prevent waste of force. But the
filling must be so arranged around the ports as not to obstruct the entrance or
exit of the steam.
The two legs into which the jointed arms are divided, I make equal to each
other. I have discovered that that arrangement produces better results than any
other. The machine will, however, work with the two legs unequal, The arms
are so arranged as to length, that they will be slightly bent when extended the
furthest, and thus will be always bent in the direction of the arrow, which is the
direction of the application of the power. The object of this arrangement is to
avoid all possibility of an arm catching upon the centre of its joint when fully
extended and becoming jammed, as might happen if it were straightened out fully
The object should be to bring the arm as nearly straight as possible when extended,
and yet avoid that danger.
Besides the use of jointed arms as described, another important feature of my
invention lies in the relative positions of the steam-chest J, and the cylinder E.
I place the steam-chest behind the revolving disc of the inner cylinder E.
In other engines, whether reciprocating, rotary or otherwise, oscillation is
produced, especially when run at high speed, on account of unbalanced pressure
against non moving parts. In this invention, the greater part of the force which
is not used in rotating the machine, is, as it were, divided in two, and one half
balanced against the other. Thus the steam-chest J should be made of such a size
that the rear surface of the inner disc of the cylinder E exposed to the pressure of
the steam in the steam-chest J', shall be nearly equal to the opposite surface of the
same disc exposed to the steam in the chambers, as it can be without relieving the
disc of sufficient pressure to keep it steam tight upon its bearing surfaces o, p, r,
and r¹. The rear surface of the disc exposed to the steam should be about three-
fourths of the inner surface so exposed in the chambers.
Some pressure will be exerted against the bar n but it will be continuous and in
one direction, and may thus be easily resisted, without oscillation of the machine.
In Fig. 6 which is a plan of the outer cylinder varied, the parts are all exactly
the same with the addition of a third partition 711, also made steam-tight with the
inner disc of the revolving cylinder. This operates as a cut-off, preventing the
further entrance of steam into the successive chambers, after their ports e have
passed the partition 11, and thus utilizing the expansive force of the steam already
in the chamber, while the port is passing from 11 to r. The chamber J¹ has no
outlet. The partition 711 may be arranged at any point between 7 and r¹ so as to
cut off the steam in any desired proportion.
Figs. 8 and 9 show the application of the same principles to a machine with two
arms instead of three, operating in the same way, and having analogous parts.
The inner cylinder revolves within the outer one in the same way, the outer ends
of the jointed arms K K, K¹ K', being pivoted at its rim at points opposite each
other and going around with it, and the inner ends being pivoted at upon the
bar n of the cap C. The ports t t allow steam to enter the two chambers
: successively so they pass the partition which is exhausted as they pass the
partition. If it is desired to cut off the steam before the ports reach 11
another partition 7 must be put in. The chambers P P (Fig. 8) should also be
filled up where-ever the arms do not extend, where steam is the motive power.
The action of a two armed machine is in general the same as that of the other,
except that the steam acts in each chamber during one half instead of two thirds of
a revolution, and there are, consequently, two dead points in the circle, to overcome
which difficulty a flywheel must be used,
'

page_text: Fig. 10 shows an application of the jointed arm principle to a machine, where
the inner ends of the arms revolve and the outer ends are stationary. In such a
machine there is only one cylinder, and it is stationary. R represents its side M M,
M¹ M are two arms jointed at m m³, with their outer ends pivoted at v, to opposite
sides of the cylinder, and pivoted together at their inner ends upon a pivot n which
is affixed eccentrically to the shaft N and serves as a crank. W is an ordinary
steam-chest with steam and exhaust ports, and a valve, to alternately supply steam
to and exhaust it from the two chambers formed by the arms. w w² are the
openings into the cylinder for that purpose, so arranged as to be out of the way of
the arms.
The arms move steam-tight, as before, against the inner end of the
cylinder, and the inner surface of a cap to be placed over the other end, such cap
not being shown in the drawing. In this machine, too, a fly-wheel is necessary to
carry the shaft and arms past the dead points.
•
Any number of arms may be used in that kind of machine where the outer ends
revolve (see Figs. 2 and 8) without altering the main principle; and I do not
confine myself to two or three or any particular number, but the best made in
which I have contemplated applying the principle of the jointed arms, is that of
the three arms illustrated in Fig. 2, being a decided improvement over other
methods.
Reversing, I would accomplish in a jointed arm engine, in the following way ;-
when the outer ends of the jointed arms are stationary, (Fig. 10) it is done in the
usual way, by reversing the current of steam. In a machine where the inner ends
of the arms are stationary, (Figs. 2 and 8) it may be done by leading the steam in
at e and out at 6 (Figs. 5 and 9). About two-thirds of the power will be obtained
in the reverse direction, unless the arms are made to come straight, which is not
feasible for the reason before stated.
For use as an engine or motor to be driven by the pressure of water, the only
change necessary in the construction shown in Figs. 2 and 8 would be an enlarge-
ment of the ports e and t, to a size a little larger than the pipe admitting the
water to the machine. In Fig. 10 all the places of entrance and exit for the
water would have to be enlarged in the same ratio. With water, there would
probably be little, if any, advantage in closing the spaces which the arms did not
reach (see H. Fig. 2), as the water would escape only as fast as it was supplied.
The advantage of the use of a machine upon this principle over the ordinary
water motor, is that it utilizes all the power of the water, since not a drop escapes
through the machine, and yet the friction of the parts is less than in any other
machine of which I know.
Having thus particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, as communicated to
me by my foreign correspondent, I declare that what I claim is :-
1. A rotary engine or motor, consisting of a series (two or more) of jointed,
arms within a closed cylinder or chamber, pivotted together at one end, at a point
within the cylinder, and eccentrically as to the centre of the engine shaft, and at
the other end pivoted at different points upon the sides of the cylinder, one end of
each arm being pivoted to some stationary part, and the other end pivoted directly
or indirectly to the shaft, in combination with appropriate devices to supply steam
or other motive power, successively to the different variable chambers thus formed
by the jointed arms and the sides of the cylinder.
2. A rotary engine or motor consisting of a series (two or more) of jointed arms,
contained within a closed cylinder, and dividing such cylinder into variable
chambers, pivoted together at their inner ends upon a stationary pivot, which is
affixed to the machine eccentrically as to the shaft, and at the outer ends pivoted
at different points upon the sides of the cylinder, such cylinder being affixed to
the shaft and turning with it, substantially as described, in combination with
appropriate devices to supply steam or other motive power successively to the

page_text: .
I
different variable chambers formed by the jointed arms and the sides of the
cylinder.
3. A rotary engine or motor consisting of two jointed arms contained within a
closed cylinder or chamber, and dividing such cylinder into variable chambers,
pivoted together at their inner ends upon a pivot attached eccentrically to the
shaft, and at their outer ends pivoted at stationary pivots placed at different points
upon the sides of the cylinder, in combination with appropriate devices to supply
steam or other motive power successively to the different variable chambers formed
by the jointed arms.
4. The three-armed machine shown in the drawings, consisting of the com-
bination of the inner cylinder E, the outer cylinder B, and the cap C, the inner
cylinder having 3 jointed arms pivoted at their outer ends at different points upon
the sides of the cylinder, and at their inner ends pivoted together upon a stationary
bar n affixed to the cap C, and having openings & into the chambers formed by the
arms; the outer cylinder having cavities ; and and partitions and to supply
and exhaust the steam or other motive power, substantially as described.
5. In a rotary engine or motor consisting of one cylinder rotating within another
by means of the pressure of steam or other power exerted within the inner
cylinder, the combination of the inner cylinder with its ports to admit the steam
or other power, and the outer cylinder with a chamber or steam-chest, lying
_behind the disc of the inner cylinder, substantially as and for the purpose
described.
6. In a rotary steam engine having an inner revolving cylinder and an outer
cylinder with steam-chest 71, as described, the partition r arranged between the
partitions and 1 substantially as and for the purpose described.
7. A rotary engine or motor operated by jointed arms, as described, so arranged
that the pivotal point of the inner ends of the arms is one third of the way across
the circle which runs through the pivotal points of their outer ends upon its
diameter, substantially as and for the purpose described.
8. In a rotary engine or motor operated by jointed arms as described, a jointed
arm which is just a little longer than the distance between its two ends when
furthest extended, cubstantially as and for the purpose described.
9. In a rotary engine or motor operated by jointed arms as described, a jointed
arm consisting of two equal legs or parts, substantially as and for the purpose
described.
10. In a rotary engine or motor, as described, the jointed arms provided at one
or more of their pivotal points with corresponding ribs and grooves, substantially
as and for the purpose described.
11. In a rotary steam engine operated by jointed arms as described, the cylinder
or chamber which contains the arms, with the spaces in it which are not touched
by the arms fille up, substantially as and for the purpose described.
Dated this 14th day of August 1886.
PHILIP M. JUSTICE.