IMPROVEMENTS IN TRANSMITTING MOTION."
Year: 1873

page_text: LETTERS PATENT to the Right Honorable James Earl of Caithness,
of Barrogill Castle, in the County of Caithness, North Britain,
for the Invention of " IMPROVEMENTS IN TRANSMITTING MOTION."

page_text: rotated, and to form in the cross head of the piston rod or other recipro-
cating part corresponding spiral grooves, projections, or flat surfaces, the
two forming male and female parts. As the female part moves along
one set of spirals on the male part it imparts a rotatory motion thereto
in a direction dependent upon the direction of the spirals, and when the
female part returns or moves in the reverse direction along the reverse
set of spirals it continues the rotatory motion of the shaft or male part
in the same direction as before, thus producing a complete revolution.
The two sets of spirals may be distinct and marked at each single
stroke by its own driver, the two drivers or female parts being mounted
ratchet fashion so that they will each operate when moving in one
direction only, the two being made to come into action alternately. If
the two sets of spirals cross each other on the male part, then a single
driver only need be employed, such driver being made to shunt from
one set of spirals to the other at cach end of its stroke.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said James Earl of Caithness, in the Great Seal Patent
Office on the 22nd April 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, the Right
Honorable JAMES Earl of CAITNESS, of Barrogill Castle, in the County
of Caithness, North Britain, send greeting.
WHEREAS Her niost Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-second day of October, in the year
of our Lord One thousand eight hundred and seventy-three, in the 37th
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said James Earl of Caithness, Her special license
that I, the said Jaimes Earl of Caithness, my executors, administrators,
and assigns, or such others as I, the said James Earl of Caithness,
my executors, administrators, or 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
"IMPROVEMENTS IN TRANSMITTING MOTION," upon the condition (amongst
•

page_text: 44441
munness, my executors or
administrators, by an instrument in writing under my hand and seal,
should particularly describe and ascertain the nature of the said Inven-
tion, 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 James Earl of Caithness, do hereby
declare the nature of my said Invention, and in what manner. the
same is to be performed, to be particularly described and ascertained in
and by the following statement, reference being had to the accom
panying Drawings and to the letters and figures marked thereon, that is
to say:
This Invention relates to a simple and effective arrangement for con-
verting a rectilinear reciprocating motion into a continuous rotatory
motion, and is more particularly applicable as a substitute for the crank :
in steam engines or other machines.
According to my Invention I propose to form right and left spiral
grooves, projections, or flat surfaces upon the shaft to be rotated, and to
form in the cross head of the piston rod or other reciprocating part
corresponding spiral grooves, projections, or flat surfaces, the two
forming male and female parts. As the female part moves along one
set of spirals on the male part, it imparts a rotatory motion thereto in a
direction dependent upon the direction of the spirals, and when the
female part returns or moves in the reverse direction along the reverse
set of spirals, it continues the rotatory motion of the shaft or male part in"
the same direction as before, thus producing a complete revolution.
>
And in order that my said Invention may be fully understood I shall
now proceed more particularly to describe the same, and for that
purpose shall refer to the several Figures on the annexed Sheet of
Drawings, the same letters of reference indicating corresponding parts:
in all the Figures.
A represents the shaft or male part, to which a continuous rotatory
motion is to be imparted, and which is mounted in bearings 1, 2; x, y,
are right and left handed grooves (projections or flat surfaces) cut or
formed spirally on and partially round the shaft or male part A, each 1
groove extending (between its two extreme points) over half the circum-"
ference of the latter; B and C are cones sliding longitudinally over the

page_text: shaft or male part A, and formed on their internal or female surfaces
with studs or projections a and b corresponding to and working freely in
the spiral grooves x and y respectively. The cones B and C gear alter-
nately with the corresponding internal cones B¹ and C¹, forming
respectively the centre portions of the cross heads or bars D and E for
the purpose hereafter described. The latter are supported and guided
by the side brackets or frames F, F, (in which they have a rectilinear
reciprocating motion) and are connected at their ends by rods G, G,-to-
the piston rod or other reciprocating part of the engine or machine;
c, c, are plates or rings attached to the largest side of the internal cones
B and C, and forming inner flanges round the same for checking. the
cones B and C, or preventing them from moving too far out of gear with
the internal cones B¹ and C¹.
Supposing the apparatus to be in the position shown on the Drawing
and that a rectilinear reciprocating motion is communicated to the cross
heads or bars D and E in the direction of the arrow shewn in black, the
internal cone B¹ presses against or comes in frictional contact with the
corresponding cone B, by which the latter is prevented from turning,
and is carried along the shaft or male part A; in so doing the stud or
projection a on its internal or female surface presses in a direct line
against one side of the groove x, and being constrained to remain in the
same, consequently causes the shaft or male part A to revolve in. the
direction indicated by the curved arrows. At the same time the internal
cone C of the cross head E leaves or moves out of gear with the cone C,
which is therefore free and at liberty to revolve with the shaft or male
part A on the arrival of the cross heads or bars D and E at the termina-
tion of the stroke in the direction described, when the shaft or male
part A will have performed half a revolution, and on commencing the
return stroke as indicated by the arrow in red the internal cone C³ of
the cross head E then presses against or comes in frictional contact with
the cone C, whilst the internal cone B¹ of the cross head D leaves or
moves out of gear with the cone B, and the stud or projection b on the
internal or female surface of the cone C pressing in a direct line against
the side of the groove y (the same sides of the grooves x or y relatively
to the advancing studs a or 6 being acted upon during either stroke),
causes the shaft or male part A to revolve in the same direction as before
until the arrival of the cross heads D and E at the other end of the
stroke, when the shaft or male part A will have performed a comple

page_text: revolution, and the operation being repeated a continuons rotatory motion
is thereby given to the same.
The two sets of spiral grooves, projections, or flat surfaces may be
formed so as to cross each other on the same portion of the shaft or
male part A in which case a single cross head or driver only need be
employed, the same being shunted from one set of spirals to the other
by springs or other mechanical contrivance at the termination of the
stroke in either direction.
Having now described and particularly ascertained the nature of my
said Invention, and the manner in which the same is or may be used or
carried into effect, I would observe in conclusion that what I consider to
be novel and original, and therefore claim as the Invention secured to
me by the herein-before in part recited Letters Patent is, the application
and use of spiral grooves, projections, or flat surfaces formed on and
partly round a shaft in combination with corresponding grooves, pro-
jections or flat surfaces formed on the interior of a frictional or other
driver connected with some rectilinear reciprocating part of a steam
engine or other machine for the purpose of imparting a continuous
rotatory motion to the said shaft, substantially as herein-before described
and illustrated by my Drawings.
In witness whereof, I, the said James Earl of Caithness, have to
this my Specification set my hand and seal, the Twenty-second
CAITHNESS. (L.S.)