A NEW OR IMPROVED RIGHT AND LEFT HAND MECHANICAL MOVEMENT APPLICABLE FOR STEERING APPARATUS FOR SHIPS AND OTHER VESSELs, and for oTHER PURPOSES.
Year: 1873

page_text: LETTERS PATENT to Henry Jarman, of Poplar, in the County of
Middlesex, Pattern Maker, for the Invention of "A NEW OR IMPROVED
RIGHT AND LEFT HAND MECHANICAL MOVEMENT APPLICABLE FOR STEERING
APPARATUS FOR SHIPS AND OTHER VESSELs, and for oTHER PURPOSES.
PROVISIONAL SPECIFICATION left by the said Henry Jarman at the
Office of the Commissioners of Patents, with his Petition, on the
15th January 1873.
I, HENRY JARMAN, of Poplar, in the County of Middlesex, Pattern
Maker, do hereby declare the nature of the said Invention for "A
NEW OR IMPROVED RIGHT AND LEFT HAND MECHANICAL Movement appLICABLE FOR
Steering ApparaTUS FOR SHIPS AND OTHER VESSELS, AND FOR OTHER PURPOSES,"
to be as follows
The object of this Invention is the construction of a simple and
efficient right and left hand mechanical movement by the employment
of a nut with the so-called diamond thread, which consists of a right
and a left hand thread cut on or in the same surface of a round article,

page_text: thus leaving diamond-shaped pieces of thread standing up on the said
surface. For this purpose I employ a round bar made in two halves,
which can slide on their inner or flat surfaces, one against the other.
One half bar has right-hand thread cut in its outer half round surface;
the other half has left-hand thread cut in its outer half round surface.
A nut with right and left hand diamond thread corresponding thereto
fits and works on the said bar. On turning the nut one way or the
other while being kept from shifting longitudinally the two half bars
move in opposite directions on each other. This movement may be
applied to many purposes where a to-and-fro or right-and-left hand
movement is desired for two moving mechanical parts.
I have more particularly found it advantageously applicable for con-
structing steering apparatus for ships and other vessels. One mode of
applying it to such steering apparatus is as follows:-I fix to the rudder
head an ordinary cross head of wrought iron or other suitable material;
the same has two projecting pins or gudgeons, one on each side, on each
of which pins one end of two connecting rods or arms are fitted; the
other two ends of the said connecting rods are connected to lugs formed
on two guide bars, the said guide bars forming two half screws, one of
which has a right-hand thread, and the other a left-hand thread. The
said screw or guide bars are worked in opposite directions by a nut which
has right and left hand thread cut in it which forms a diamond thread.
The said nut forms the boss of the steering wheel; it revolves in a bearing
on a standard, and gives the required motion to the rudder. A bearing
fitted on the rudder head and the revolving nut form the two sliding
bearings for the guide bars or screw. The guide bars are by preference
square where they pass through and slide in the correspondingly shaped
rudder head guide.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fifteenth day of January, in the year
of our Lord One thousand eight hundred and seventy-three, in the
thirty-sixth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Henry Jarman, Her special licence
that I, the said Henry Jarman, my executors, administrators, and
assigns, or such others as I, the said Henry Jarman, 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 OR IMPROVED RIGHT AND
LEFT HAND MECHANICAL MOVEMENT APPLICABLE FOR STEERING APPARATUS FOR SHIP3
AND OTHER VESSELS, AND FOR OTHER PURPOSES," upon the condition (amongst
others) that I, the said Henry Jarman, my executors or administrators,
by an 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 sanie 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 Jarman, do hereby declaro
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 accompanying Drawings,
and to the letters of reference marked thereon, that is to say:
-
The object of this Invention is the construction of a simple and
efficient right and left hand mechanical movement by the employment
of a nut with the so-called diamond thread, which consists of a right
and a left hand thread cut on or in the same surface of a round article,
thus leaving diamond-shaped pieces of thread standing up on the said
surface. For this purpose I employ a round bar made in two halves,
which can slide on their inner or flat surfaces, one against the other.
One half bar has right-hand thread cut in its outer half round surface;
the other half has left-hand thread cut in its outer half round surface.
A nut with right and left hand diamond thread corresponding thereto
fits and works on the said bar. On turning the nut one way or the
other while being kept from shifting longitudinally the two half bars

page_text: move in opposite directions on each other. Or the construction may be
reversed, that is, the nut in two halves, and the bar made to turn. This
movement may be applied to many purposes where a to-and-fro or right.
and left hand movement is desired for two moving mechanical parts.
I have more particularly found it advantageously applicable for
constructing steering apparatus for ships and other vessels.
The accompanying Drawings illustrate one mode of applying it.
Figure 1 is an end view; Figure 2 is a side clevation; and Figure 3 is a
plan of apparatus constructed according to my Invention as applied to
steering gear; Figure 4 is an end view of the standard frame; and
Figures 5 and 6 are section and end view respectively of the nut having
right and left hand screw threads cut thereon. Similar letters of
reference refer to like parts in all the Figures.
b
.
I fix to the rudder head an ordinary cross head a of wrought iron or
other suitable material. This cross head has on each side a projecting 1
pin or gudgeon b; on each pin 6 one end of two connecting rods or
arms c, c, are fitted; the other two ends of the said connecting rods c, c,
are connected to lugs d, d, formed on two guide bars e, e, the said guide
bars forming two half screws, one of which has a right-hand thread, and
the other a left-hand thread, as clearly shewn at Figure 3. The said 2
screw or guide bars are worked in opposite directions by a nut f, which
also has right and left hand thread cut in it, which forms a diamond
thread. The nut f forms the spindle or shaft, on which the steering.
wheel g is fitted; it revolves in a bearing on a standard h, and gives the
required motion to the rudder. A swivel bearing fitted on the rudder 2
head and the revolving nut form the two sliding bearings for the guide
bars or screw. The guide bars are by preference square where they
pass through and slide, in the correspondingly shaped rudder head
guide.
Having now described the nature of my said Invention, and in what
manner the same is to be performed, I declare that I do not limit myself
to the precise arrangement described for carrying my Invention into
effect, neither do I limit its application to steering gear alone, because it
is applicable as a mechanical movement where a right and left hand
motion is required; but I claim,—
First. The construction, employment, and method of action of a
mechanical movement consisting of a bar in two pieces with a right-

page_text: hand thread on one piece and a left-hand thread on the other piece, and
of a nut having corresponding threads cut thereon (or vice versa, viz.,
the nut in two pieces and the bar in one piece), so that by moving the
nut a motion in contrary directions is given to the two component parts
of the bar (or vice versa), substantially as described and illustrated in
HENRY JARMAN. (L.S.)