IMPROVEMENTS IN MECHANISM FOR CONVERTING ROTARY MOTION INTO RECIPROCATING MOTION
Year: 1866

page_text: LETTERS PATENT to Henry Willis, of Worcester, Shoe Manufacturer,
and George Rice, of Worcester, Tailor and Draper, for the Invention
of "IMPROVEMENTS IN MECHANISM FOR CONVERTING ROTARY MOTION INTO
RECIPROCATING MOTION."
Sealed the 14th August 1866, and dated the 17th February 1866.
PROVISIONAL SPECIFICATION left by the said Henry Willis and George
Rice at the Office of the Commissioners of Patents, with their Petition,
on the 17th February 1866.
We, HENRY WILLIS, of Worcester, Shoe Manufacturer, and GEORGE
RICE, of Worcester, Tailor and Draper, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN MECHANISM FOR CONVERTING ROTARY
MOTION INTO RECIPROCATING MOTION," to be as follows:-
Our Invention consists of the mechanism herein-after described, whereby
rotary motion is so converted into reciprocating motion that if the rotary
motion be uniform the reciprocating motion into which it is converted is also
uniform or nearly uniform. The said mechanism consists essentially of two
wheels mounted on parallel axes and gearing with one another. One of the

page_text: said wheels, namely, that the rotary motion of which is to be converted into
a reciprocating motion, is of a nearly elliptical figure, its longest diameter
being about twice its shortest diameter. The other of the said wheels has
an hour-glass figure, or nearly the shape of the numeral 8. The said wheels
are geared together in such a way that the part of the elliptical wheel of
longest diameter engages in the part of the hour-glass wheel of shortest
diameter. To the axis of the hour-glass wheel or to the wheel itself a
crank is attached, the said crank being in the direction of the longest
diameter of the said wheel. A connecting rod jointed at one end to the
crank may be jointed at its other end to a slide capable of only rectilinear
motion. On giving a uniform rotary motion to the elliptical wheel a uniform
or nearly uniform reciprocating motion is communicated by the connecting
rod to the slide. The two wheels are best geared together by being made
toothed-wheels, each of the wheels having the same number of teeth; or the
elliptical wheel may be an ordinary toothed wheel, and the hour-glass wheel
may have pins or teeth on its face in a position resembling the teeth of a
crown wheel, and the teeth of the elliptical wheel be made to engage with
the said pins or teeth. We do not, however, limit ourselves to any particular
method of gearing the said wheels together.
Our Invention is applicable to a great variety of purposes where a uniform
or nearly uniform reciprocating motion is required.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Henry Willis and George Rice in the Great Seal Patent
Office on the 14th August 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, HENRY
WILLIS, of Worcester, Shoe Manufacturer, and. GEORGE RICE, of Worcester,
Tailor and Draper, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Seventeenth day of February, in the year of our
Lord One thousand eight hundred and sixty-six, in the twenty-ninth year
of Her reign, did, for Herself, Her heirs and successors, give and grant
unto us, the said Henry Willis and George Rice, Her special licence that
we, the said Henry Willis and George Rice, our executors, administrators,
and assigns, or such others as we, the said Henry Willis and George Rice,
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

page_text: 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 "IMPROVEMENTS IN
MECHANISM POR CONVERTING ROTARY MOTION INTO RECIPROCATING MOTION," uppl
the condition (amongst others) that we, the said Henry Willis aud George
Rice, our executors or administrators, by an instrument in writing under
our, or their, or one of 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 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 George Rice, on behalf of myself and
the said Henry Willis, 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:-
Our Invention consists of the mechanism herein-after described, whereby
rotary motion is so converted into reciprocating motion that if the rotary
motion be uniform the reciprocating motion into which it is converted is also
uniform or nearly uniform. The said mechanism consists essentially of two
wheels mounted on parallel axes, and gearing with one another. One of the
said wheels, namely, that the rotary motion of which is to be converted into a
reciprocating motion, is of a nearly elliptical figure, its longest diameter being
about twice its shortest diameter; the other of the said wheels has an hour-
glass figure, or nearly the shape of the numeral 8. The said wheels are
geared together in such a way that the part of the elliptical wheel of longest
diameter engages in the part of the hour-glass wheel of shortest diameter.
To the axis of the hour-glass wheel or to the wheel itself a crank is attached,
the said crank being in the direction of the longest diameter of the said
wheel. A connecting rod jointed at one end to the crank may be jointed at
its other end to a slide capable of only rectilinear motion. On giving a
uniform rotary motion to the elliptical wheel a uniform or nearly uniform
reciprocating motion is communicated by the connecting rod to the slide.
The two wheels are best geared together by being made toothed wheels, each
of the wheels having the same number of teeth; or the elliptical wheel may
be an ordinary toothed wheel, and the hour-glass wheel may have pins or
teeth on its face in a position resembling the teeth of a crown wheel, and the
teeth of the elliptical wheel be made to engage with the said pins or teeth.
We do not, however, limit ourselves to any particular method of gearing the
said wheels. together. Our Invention is applicable to a great variety of

page_text: purposes where a uniform or nearly uniform reciprocating motion is
required.
Having explained the nature of our Invention we will proceed to describe,
with reference to the accompanying Drawing, the manner in which the same
is to be performed.
Figures 1, 2, and 3 represent mechanism constructed according to our
Invention for converting rotary motion into a uniform or nearly uniform
reciprocating motion applied to the tension plate of a winder for a sewing
machine, Figure 1 representing the position of the parts when the tension
plate has made its advance stroke, Figure 2 when it is in the middle of its
stroke, and Figure 3 when it is at the end of its return stroke; Figure 4 is a
plan of Figure 1, and Figure 5 is a plan of Figure 2.
The said mechanism consists of two toothed wheels a and b mounted upon
parallel axes, and gearing with one another. The toothed wheel a is of a
nearly elliptical figure, its longest diameter being about twice its shortest
diameter; the other wheel 6 has an hour-glass figure, or nearly the shape of
the numeral 8. The said wheels a, b, have the same number of teeth, and
are geared together in such a way that the part of the eliptical wheel a of
longest diameter engages in the part of the hour-glass wheel b of shortest
diameter, as illustrated in the Drawing. The rotary motion to be converted
into a reciprocating motion is transmitted to the axis of the eliptical wheel a
by any convenient gearing. To the hour-glass shaped wheel b (or the axis
thereof) a crank c is attached, the said crank being situated in the direction
of the longest diameter of the said wheel to the said crank c; the bar or
slide d of the tension plate e is connected by the crank pin engaging in the
slotted arm d in the manner represented. The said bar or slide d is capable
only of a rectilinear motion. By giving a uniform rotary motion to the
elliptical wheel a a uniform or nearly uniform reciprocating motion is
transmitted to the bar or slide d through the hour-glass wheel b and crank c.
We prefer to gear the two wheels a, b, together by means of teeth on their
periphery, as represented, but we do not limit ourselves thereto, as the
elliptical wheel a may be an ordinary toothed wheel, and the hour-glass
wheel b may have pins or teeth on its face in a position resembling the teeth
of a crown wheel, and the teeth of the said elliptical wheel be made to engage
with the said pins or teeth.
The manner of describing the Figures of the wheels a and b is illustrated
by the Diagrams Figures 6 and 7, Figure 6 illustrating the manner of
describing the wheel a, and Figure 7 that of describing the wheel b. The
line, Figure 6, represents the extreme length of the wheel a. From the

page_text: middle of the line ƒ the circle g is struck, and a diameter h, i, is drawn at
right angles to the diameter f. From the middle of the radius h the circle k
is struck, and from the middle of the radius i the circle is struck. The
space enclosed between the intersections of the circles k and 1, that is, the
space marked by the thick or strong lines, is the outline of the wheel a. The
teeth are cut in the wheel in the direction of radii from the centre.
The Diagram, Figure 7, for describing the wheel 6 is constructed in the
same manner as the diagram, Figure 6, excepting that the radii of its several
circles are of one-half the length of the radii of the corresponding circles in
Figure 6. The extreme outline of Figure 7, that is, the part marked by the
thick or strong lines, is the outline of the wheel b, within which the teeth of
the said wheel are formed in the manner illustrated in Figures 1, 2, and 3.
Having now described the nature of our Invention, and the manner in
which the same is to be performed, we wish it to be understood that we do
not limit ourselves to the precise details herein described and illustrated in
the Drawing, as the same may be varied without departing from the nature
of our Invention; but we claim as our Invention the improvements in
mechanism for converting rotary motion into reciprocating motion herein-
before described and illustrated in the accompanying Drawing, that is to say,
by means of two wheels, one having nearly an elliptical figure, and the other
nearly an hour-glass figure, the said wheels being geared together and
made to act upon a sliding bar, substantially in the manner described and
illustrated.
In witness whereof, I, the said George Rice, have hereunto set my
hand and seal, this Thirteenth day of August, in the year of our Lord
One thousand eight hundred and sixty-six.
Witness,
GEORGE SHAW.
GEORGE RICE. (LS.)