CERTAIN IMPROVEMENTS IN MECHANISM OR APPARATUS FOR INDICATING THE SPEED OF REVOLVING SHAFTS
Year: 1874

page_text: LETTERS PATENT to Sir David Lionel Salomons, Baronet, of Broom
Hill, Tunbridge Wells, in the County of Kent, for the Invention
of "CERTAIN IMPROVEMENTS IN MECHANISM OR APPARATUS FOR INDICATING
THE SPEED OF REVOLVING SHAFTS."
Sealed the 14th August 1874, and dated the 16th February 1874.
PROVISIONAL SPECIFICATION left by the said Sir David Lionel
Salomons at the Office of the Commissioners of Patents, with his
Petition, on the 16th February 1874.
I, Sir DAVID LIONEL SALOMONS, Baronet, of Broom Hill, Tunbridge
Wells, in the County of Kent, do hereby declare the nature of my said
Invention for "CERTAIN IMPROVEMENTS IN MECHANISM OR APPARATUS FOR
INDICATING THE SPEED OF REVOLVING SHAFTS," to be as follows:-
The Invention is designed for the purpose of enabling the speed or
revolution of driving or other shafts to be indicated with accuracy and

page_text: facility in such a manner as to admit of the indications being read off on
a dial or tablet at a distance from such revolving shaft, for instance,
the variable or uniform speed of a shaft in a factory or other works
through the medium of this Invention can be told off and indicated
with accuracy in the offices or other places adjacent to the works, or on
floors situated above or below the said shaft.
The arrangement, application, and working of the Invention may
be thus described:-In a convenient position near to the shaft or shafts
(the speed of which is or are to be indicated) I place a centrifugal two-
ball governor or other analogous regulator, which is driven by such
shaft or shafts; but for the purpose of this description I will as an
example take a two-ball centrifugal governor of the ordinary class. The
sleeve of this governor is connected with and actuates a forked lever or
levers in a manner similar to the lever transmitting motion to the
"throttle valve of a steam engine, or in other convenient manner. This
forked lever or levers through the medium of a connecting rod or rods
and lever communicates with the finger of a dial or tablet, and is
arranged so as to move either in a segmental, circular, or rectilinear
direction.
The dial or tablet is so numbered that when the shaft (the speed of
which is to be indicated) is at rest the indicating finger of such dial or
tablet will stand opposite the cypher placed below or above, or on the
right or left of the indicating numbers, such starting point being
marked zero, or by any other convenient sign. Thus it will be evident
that when the shaft is revolving and imparting motion to the governor
the centrifugal force of the balls will in accordance with their speed
increase or diminish their distance apart, and so give a rise or fall to the
sleeve on the central spindle of the governor to which they are con-
nected; this rise and fall is communicated to the indicating finger of
the dial or tablet, or other indicating medium, by means of the forked
lever and connecting rod or rods and levers before mentioned, in such
a manner as to cause such finger or other indicator to move along the
numbers of the dial or tablet in accordance with the speed of the
revolving shaft, thus enabling the number of revolutions such shaft is
making at any one time to be readily ascertained, and any irregularity,
increase, or diminution of speed noticed and checked. Or for actuating
the indicating finger a centrifugal blower or air pump may be sub-

page_text: stituted in lieu of the foregoing arrangement, the adaptation of which to
the revolving shaft would be as follows:-
The centrifugal blower or air pump is conveniently placed near to or
at a distance from the shaft (the speed of which is to be indicated) and
is driven by positive or frictional gearing direct from and by such shaft
The air passing through the blower or pump is received into or com-
municates with a tube or reservoir connected with (direct or by means
of suitable mechanism) the line of figures on the numbered dial or
tablet. A short terminal length of this tube or cylinder is prepared to
receive an easily fitting piston and an helical spring, which forms the
support for the piston in the tube, or a chamber and index hand, with
or without the foregoing arrangement of piston and spring, may be
employed. From this piston or chamber the indicating finger of the
dial or tablet projects and is actuated so as to rise or fall, according to
the increased or diminished pressure of air in the tube or chamber, such
action being transmitted direct, as before mentioned, or by lever or
levers and spring.
The sensitiveness of the above-mentioned mechanism communicating
motion to the indicator through the medium of the atmospheric pressure
in the tube or chamber enables such indicator to tell off the speed of the
revolving shaft with accuracy and precision.
When applying the improved indicator to ships' or other locomotive
machinery two or more governors may be employed supported on
gimbols, in which case the motion from the governors to the indicator
will be communicated through suitable connections having flexible or
universal joints, a weighted pendulum being employed for the purpose
of maintaining the apparatus in the required position, and an arc may
be added to indicate the motion.
In conclusion it will be evident that in lieu of springs cylinders with
compressed or exhausted air working in unison or against each other
may be emnloved.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Sir David Lionel Salomons in the Great Seal
Patent Office on the 15th August 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, Sir DAVID
LIONEL SALOMONS, Baronet, of Broom Hill, Tunbridge Wells, in the
County of Kent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixteenth day of February, in the year
of our Lord One thousand eight hundred and seventy-four, in the thirty-
seventh year of Her reign, did, for Herself, Her heirs and successors
give and grant unto me, the said Sir David Lionel Salomons, Her
special licence that I, the said Sir David Lionel Salomons, my executors,
administrators, and assigns, or such others as I, the said Sir David
Lionel Salomons, 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, usc, exercise, and vend, within the United Kingdom of
Great Britain and Ireland, the Channel Islands, and Isle of Man, an
Invention for "CERTAIN IMPROVEMENTS IN MECHANISM OR APPARATUS FOR
INDICATING THE SPEED OF REVOLVING SHAFTS," upon the condition (amongst
others) that I, the said Sir David Lionel Salomons, 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 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 Sir David Lionel Salomons, 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 and accompanying Drawings, that is
to say:
The Invention is designed for the purpose of enabling the speed or
revolution of driving or other shafts to be indicated with accuracy and
facility in a manner which will admit of the indications being read off
on a dial or tablet at a distance from such revolving shaft, for instance,

page_text: the variable or uniform speed of a shaft in a factory or other works
through the medium of this Invention can be told off and indicated with
accuracy in the offices or other places adjacent to the works, or on floors
situated above or below the said shaft.
According to these improvements the speed or number of revolutions
of the shaft to be indicated is obtained through the rise and fall or other
movement of a finger or pointer on a numbered tablet or dial obtained
through the agency of centrifugal velocity acting upon mechanism in
connection with an ordinary two ball governor, or through the increased
or diminished pressure of air acting upon an indicating finger through
the medium of a balanced piston or other equivalent placed in a
cylindrical tube, or by the depression or elevation of fluids.
In order that the Invention may be well understood, and explained in
detail, I have hereunto annexed a Sheet of Drawings illustrating as
examples three different applications and arrangements of my Invention,"
the first being that whereby indications are told off upon a table through
the agency of a two-ball centrifugal governor, and which is represented
in elevation at Figure 1, the indications telling off the number of rcvo-
lutions, as shewn at Figure 2, are obtained through the means of air,
the pressure of which is increased or diminished by the action of a
centrifugal air pump on a rising and falling piston carrying the indicating
finger.
Figure 3 represents an arrangement of terminal air pressure tube which
will give a radial movement to the indicating finger.
And Figure 4 represents in elevation an arrangement of chamber con-
taining mercury, the annular velocity of which will cause the mercury
to rise and fall in a central tube; the varying elevation obtained will
indicate the speed of the shaft on a suitably prepared tablet.
In Figure 1 a is the sleeve of the governor, which is connected with
and actuates the forked bell-crank lever b in a manner similar to the lever
transmitting motion to the throttle valve of a steam engine; this lever b
communicates through the medium of the rod c with the train of
gearing d; the action of this gearing through the rack e gives a rise and
fall to the indicating finger fin proportion to the speed or velocity of
the shaft to be indicated. The numbers upon the dial are so arranged
that when thic shaft (the revolutions or speed of which is to be indicated)

page_text: is at rest the indicating fingerf will stand opposite the cypher or zero
on the tablet i; thus it will be evident that when the shaft is revolving
and imparting motion to the governor the centrifugal force of the balls
will in accordance with their speed increase or diminish their distance
apart, and so give a rise or fall to the sleeve a on the central spindle a¹;
this rise or fall is communicated to the indicating finger of the tablet i
by means of the forked bell-crank lever b, connecting rod c, train of
gearing d, and rack e. The indications thus obtained enable the speed
or number of revolutions the shaft is making to be ascertained at any
one time, and any irregularity in the increase or diminution of the speed
of the same will be readily noticed and checked.
In Figure 2 an arrangement of centrifugal blower or air pump is shown
as the motor for actuating the indicating finger, in this arrangement
the blower a is driven by the shaft, the speed of which is to be indicated;
the exhaust pipe a¹ of the blower communicates direct with the tube or
pipe b, which may extend to any portion of the building desired; the
terminal length of this tube is provided with the cylinder c, in which is
placed the easily fitting piston d, from which projects the indicating
fingerf; this piston has a slight pressure exerted upon it by the spring e,
which in conjunction with the pressure of air on its under surface,
transmitted thereto by the blower a, governs the movement of the
indicating finger, so that in accordance with the speed of such centri-
fugal blower a a proportionate rise and fall will be given to the piston,
which through the medium of its indicating finger and tablet i enables
the speed of the shaft driving the blower to be ascertained with accuracy
at any one time.
In lieu of the piston and indicator, as shewn at Figure 2, an arrangement
of flattened spring tube may be employed, as shewn at Figure 3, in this
arrangement the exhaust tube b' is flattened for a portion of its terminal
length, and takes the form of a spring bow or curve; the extreme end
of this tube is closed in and connected by means of the lever c¹ with the
end of the radial indicating finger d', the pointer of which moves over a
numbered dial. When in action the pressure of air in the flattened
spring tube has a tendency to straighten its curved formation, and con-
sequently moves its closed-in end, connected with the indicating
finger, a distance proportionate to the pressure exerted. The move-
ment outward of the flattened tube as the pressure of air within it
increases indicates the highest number of revolutions the shaft driving

page_text: the blower can make, and any diminution in the pressure caused by a
reduction of speed of the driving shaft at once allows the flattened tube
by reason of its collapsing spring to move towards its normal position
at zero.
The counteracting forces thus brought to bear upon the
indicating finger enable its radial movement to accurately determine at
any time the speed of the shaft driving the blower.
At Figure 4, a, a, are two cylindrical chambers containing mercury,
accurately balanced, and capable of being connected with a shaft by
means of straps or other equivalent for the purpose of giving them an
annular motion round their central supporting pin b, the termination of
each chamber is provided with an outlet c, c, communicating direct with
the vertical glass tube d, placed directly over the centre of motion of
the two cylindrical chambers. A tablet i provided with numbers is
placed immediately behind the vertical tube d; thus it will be seen that
the speed of revolution at which the mercurial vessels a, a, is driven will
cause the mercury contained therein to rush through the outlets c, c,
into the vertical glass tube d, where during the revolution of the vessels
it will form a column, which will rise and fall in proportion to the speed
of the same, the varying elevations of the mercury in the central tube d
will enable the speed of the shaft driving the annular mercurial vessels
to be indicated on the tablet with accuracy and precision.
When applying the improved indicator to ships' or other locomotive
machinery two or more governors may be employed supported on
gimbols, in which case the motion from the governors to the indicator
will be communicated through suitable connections having flexible or
universal joints, a weighted pendulum being employed for the purpose
of maintaining the apparatus in the required position, and an arc may
be added to indicate the motion.
Having now described the nature of my said Invention, together with
the method of carrying the same into practical effect, I wish it to be
distinctly understood in conclusion that although I have shewn and
described several arrangements of the application of centrifugal velocities
for the purpose of carrying out my Invention I do not wish to confine
myself to the precise details hercin described so long as the essential
features of the Invention are retained, therefore what I claim, is the
application of centrifugal velocity acting upon an indicating finger
through the medium of solids, fluids, or air, in the manner and for the

page_text: purpose as herein substantially described, set forth, and fully illustrated
in the Drawings annexed.
In witness whereof, I have hereunto set my hand and seal, the
Fourteenth day of August, in the year of our Lord One thousand
eight hundred and seventy-four.
Witness,
ALFRED APPS,
433, Strand,
London.
DAVID L. SALOMONS. (L.s.)