A. NEW LEVER FOR CHANGING ALTERNATE. ROTARY MOTION INTO. CON- TINUOUS. ROTARY MOTION, AND. VICE VERSA
Year: 1870

page_text: LETTERS PATENT to Henry Woodcroft Hammond, of the City of..
Manchester, in the County of Lancaster, Engineer, for the Invention..
of "A. NEW LEVER FOR CHANGING ALTERNATE. ROTARY MOTION INTO. CON-
TINUOUS. ROTARY MOTION, AND. VICE VERSA."-A. communiction from.
abroad by Joseph Julien Chenal, of Genissiat (Ain), in. the Empire:
of France..
PROVISIONAL SPECIFICATION left, by the said Henry Woodcroft.
Hammond at the Office of the. Commissioners of Patents, with
his Petition, on the 18th January 1870..
"
I, HENRY WOODCROFT HAMMOND, of the City of Manchester, in the
5 County of Lancaster, Engineer, do hereby declare the nature of the
said Invention for "A NEW LEVER FOR CHANGING ALTERNATE ROTARY MOTION
INTO CONTINUOUS ROTARY MOTION, AND VICE VERSA," a communication from

page_text: This Invention relates to an arrangement by which a rocking lever
oscillating about a point transmits its alternate motion to an axis, which
thereby is made to revolve continuously. In order to obtain this result
a lever of the first kind may be used, which at the point where resistance
is applied widens out into a sectorial slot or frame of suitable width and
length having the fulcrum of the lever as a common centre. The inner
sides of the sectorial slot, cage, or frame are fitted with toothed segments
of suitable length, thus forming two racks, the first of which-I call the
interior convex one as being nearest to the fulcrum, and the other the
exterior concave or annular one being farthest from the same fulcrum:
Through the slot or open part of the frame a shaft is made to
pass which carries two discs toothed on part of their periphery, and so
arranged or cast together that their toothed portion shall be placed
symmetrically on the same side of their common axis or shaft.
This shaft receives its continuous rotary motion by the action of the
lever, and its position in the inside of the sectorial frame is such that
the distance of its axis from the interior rack shall be equal to the
radius of the pitch line of one of the toothed discs, which in this instance
shall be the smaller of the two, whilst the distance of its axis from
the exterior rack shall be equal to the pitch radius of the other or large
toothed disc or sectorial pinion. Moreover the number of teeth in each
disc is such that as soon as one ceases to be in gear with its rack the
other sectorial wheel will at once mash with its rack without interruption
or dead points. Thus it will be easily understood that by applying any
power to the long arm of the lever so as to cause it to oscillate about
its fulcrum, the toothed slot on the short arm will receive a reciprocating
rotary motion, and one of the racks gearing into its own toothed disc
during one-half oscillation of the lever will impart rotary motion to
the said disc and hence to the carrying shaft; then they get out of
gear and the other rack and pinion get to mash by the effect of the
return stroke or second half oscillation of the lever taking place.
A fly
wheel may be fitted on the shaft so as to regulate the motion, which
may then be communicated to machinery by any of the known means.
Thus the shaft receives a continuous rotary motion, and the action of
the two racks gearing alternately as the lever oscillates into the partly

page_text: toothed sectors (or sectorial pinions) may be compared to the working
of a pinion toothed all round, into which two sectors gear alternately,
each on its own side and moving in opposite directions.
It is evident that instead of a simple arm the motive lever may have
another arm attached to the other side of the slotted rack frame, thus
affording the means of applying additional power, and this second arm
will act as a lever of the second kind.
Also, in case two arms are used each of them may have its own
slotted double concentric rack frame communicating motion to two
separate shafts, or the motion of these two shafts may be jointly
imparted to one single main shaft. In this case each of the arms of
the levers acts both as a lever of the first and second kind. Conversely
by deriving motion from the shaft the continuous rotary motion of the
said shaft will communicate an alternate or rocking motion to the
lever.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Henry Woodcroft Hammond in the Great Scal
Patent Office on the 16th July 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
WOODCROFT HAMMOND, of the City of Manchester, in the County of
Lancaster, Engineer, 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 seventy, in the thirty-third
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said Henry Woodcroft Hammond, Her special licence
that I, the said Henry Woodcroft Hammond, my executors, adminis-
trators, and assigns, or such others as I, the said Henry Woodcroft
Hammond, my 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 "A NEW LEVER CALLED CONTINUAL LEVER FOR CHANGING ALTERNATE ROTARY
MOTION INTO CONTINUOUS ROTARY MOTION, AND VICE VERSA," a communication
**

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my
instrument in writing under my, or their, or one of their hands and
seals, should particularly describe and ascertain the nature of the said
Invention, and 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 I, the said Henry Woodcroft Hammond, do
hereby declare the nature of the said Invention, and in what manner
the same is to be performed, to be particularly described and ascertained
in and by the following statement thereof, that is to say:-
This Invention relates to an arrangement by which a rocking lever
oscillating about a point transmits its alternate motion to an axis,
which thereby is made to revolve continuously. In order to obtain
this result a lever of the first kind may be used, which at the point
where resistance is applied widens out into a sectorial slot or frame of
suitable width and length, having the fulcrum of the lever as a common
centre. The inner sides of the sectorial slot, cage, or frame are fitted
with toothed segments of suitable length, thus forming two racks, the
first of which I call the interior (convexe) one as being nearest to the
fulcrum, and the other the exterior (concave or annular) being furthest
from the same fulcrum. Through the slot or open part of the frame
a shaft is made to pass which carries two discs toothed on part of their
periphery, and so arranged or cast together that their toothed portion
shall be placed symmetrically on the same side of their common axis or
shaft. This shaft receives its continuous rotary motion by the action
of the lever, and its position in the inside of the sectorial frame is such
that the distance of its axis from the interior rack shall be equal to the
radius of the pitch line of one of the toothed discs, which in this instance
shall be the smaller of the two, whilst the distance of its axis from
the exterior rack shall be equal to the pitch radius of the other or
large toothed disc or sectorial pinion. Moreover the number of teeth
in each disc is such that as soon one ceases to be in gear with its
rack the other sectorial pinion will at once mash with its rack without
interruption or dead point. Thus it will easily be understood that by
applying any power to the long arm of the lever so as to cause it to

page_text: oscillate about its fulcrum the toothed slot on the short arm will
receive a reciprocating rotary motion, and one of the racks gearing
into its own toothed disc during one-half oscillation of the lever will.
impart rotary motion to the said disc and hence to the carrying shaft
Then they get out of gear and the other rack and pinion get to mash
by the effect of the return stroke or second half oscillation of the lever
taking place. A fly wheel may be fitted on the shaft so as to regulate
the motion which may then be communicated to machinery by any of.
the known means. Thus the shaft receives a continuous rotary motion,
and the action of the two racks gearing alternately as the lever oscillates
into the partly toothed sectors (or sectorial pinions) may be compared to
the working of a pinion toothed all round into which two sectors.gear
alternately each on its own side and moving in opposite directions.
.It is evident that instead of a single arm the motive lever may have
another arm attached to the other side of the slotted rack frame, thus
affording the means of applying additional power, and this second arm
will act as a lever of the second kind.
Also, in case two arms are used each of them may have its own.
slotted double concentric rack frame communicating motion to two
separate shafts; or the motion of these two shafts may be jointly
imparted to one single main shaft. In this case each of the arms of the
·levers acts both as a lever of the first and second kind. Conversely by
deriving motion from the shaft the continuous rotary motion of the
said shaft will communicate an alternate or rocking motion to the
lever.
:
In order to more fully explain the nature of my Invention and the
various ways in which it may be carried into practical effect, I have
represented the lever motion on the annexed Sheet of Drawings, on
which Fig. 1 is an elevation of a lever of the first kind having its sole
arm constructed according to this principle.
Figures 1 and 1b show different positions of the lever in motion;
Fig. 2 is the plan of the same. Fig. 3 is an elevation of the double arm
lever acting on one shaft. Fig. 4 is an elevation of a double arm lever
acting on two shafts. The dotted lines show the way in which the joint
dynamical effect produced on these two shafts is communicated to one
central shaft. The same letters of reference denote the like parts in all
the Figures.

page_text: A, lever arm, which is set in motion at its extremity B by hand or
any other motive power and oscillates about the fixed point or pivot C;
D, the framed slot carrying two toothed sectors or bent racks E, E;
whose centre of curvature coincides with the centre of the fixed point C;
G, disc, partly toothed, gearing into the rack E; H, similar disc gearing
into the rack F; J, shaft on which the discs G, H, are keyed, and
which takes up the continuous rotary motion. The discs G, H, instead
of being made of two pieces may also be cast together. The shaft I
propagates its motion to any distance, it also carries at same point
a regulating fly wheel which is balanced to suit the mode of driving
used.
Since Figures 3 and 4 only refer to modifications of the motive lever
system, the principle remaining unaltered, I will only describe the
mode of action of the arrangement shewn, Figs. 1, 1ª, 1, and 2, the
others being worked precisely alike.
Let us suppose the lever A. to be at rest when in the position shown,
Fig. 1, if any power is applied to the point B in the direction of the
arrow X the lever A is depressed and the frame D raises in the opposite
direction, thus describing circular arcs about the fulcrum C; during this
half revolution the rack E gearing into the toothed portion of the
disc G causes the same to revolve with the shaft in the direction of
the arrow Y, and the apparatus takes the position shown at Fig. 1ª.
If the power by which the lever A is made to oscillate is then applied in
the opposite direction (see the arrow Z) the lever A raises again and the
slotted frame D descends. It will be seen by Fig. 1ª that the number
of teeth of the discs and racks is such that when the oscillation of the
lever is completed in one direction and just about to begin in the other
the last tooth of the disc G leaves the rack E and the first tooth of the
disc H is seized by the rack F. For this purpose the first and the last
tooth of cach rack are made a little longer than the others so as to allow
for the transition or passage of the discs from one rack to the other. The
rack F being lowered by the action exerted along the arrow Z will thus
in its turn become a driver, and by communicating with the disc H
completes the revolution of the shaft I as commenced by the rack E in
the direction of the arrow Y. At the end of the oscillation effected
in the direction Z the mechanism will be in the position illustrated by
Fig. 1. The power ceasing to act on the lever A in the direction Z,
and the contrary action in the direction X taking place the rack E again

page_text: becomes a driver by acting on the disc G, and so forth. In case, as
stated above, it be required to change a continuous rotation into an
alternate circular motion the discs G, H, will receive a rotary motion
by any motive power so as to alternately gear into and drive the
racks E, E, thus imparting to the lever A an oscillating motion about
its fulcrum C.
In Fig. 3, A' is a lever or lever arm projecting from the slotted
frame D opposite to the lever A; this arm is acted upon at D'. In this
arrangement the lever A belongs to the first kind and the lever A' to
the second kind.
In Fig. 4 each of the levers A, A'; is provided with a slotted
frame D, D', which are both constructed in the same manner and act
on separate shafts I, I'. If it is desired to couple the effects thus
obtained each of these shafts is made to carry a wheel by which rotary
motion is jointly given to as single shaft J. In this case each of the
arms A, A', acts both as a lever of the first and second kind.
Having thus described the nature of this Invention and various means
by which it is or may be carried into effect, I wish it to be distinctly
understood that what I claim is, the above described lever system
allowing to change directly alternate circular motion into continuous
circular motion, or vice versa, and I do not confine myself therein to
the forms, dimensions, or constructive details above set forth for the
better understanding of the Invention.
And I also claim the use and application thereof to all instances where
it may be usefully employed.
In witness whereof, I, the said Henry Woodcroft. Hammond, have
hereunto set my hand and seal, this Twelfth day of July, in the
year of our Lord One thousand eight hundred and seventy.
HENRY WOODCROFT HAMMOND. (L.S.)