Improvements in Speed Indicators.
Year: 1889

page_text: Date of Application, 18th June, 1889
Complete Specification Left, 18th Mar., 1890-Accepted, 19th Apr., 1890
PROVISIONAL SPECIFICATION.
Improvements in Speed Indicators.
1, ALBERT READ SHERMAN, of Pawtucket, Providence County, State of Rhode
Island, United States of America, Inventor, do hereby declare the nature of this
invention to be as follows:-
The object of my invention is to provide a speed indicator for shewing the degree
of speed as compared with a clock, that the engine may be running at, as a basis
for increasing its speed when it is running too slow or diminishing it when running
too fast. Indicators for this purpose have heretofore been provided in which a time
clock was combined with gearing which was actuated by an impulse from each
revolution of the engine shaft which gearing rotated an index hand which when com-
pared with the hands of the clock would shew the relative pace at which the engine
was moving. My invention is founded upon this general principle; and consists
in the combination with a clock, of a graduated travelling dial or scale of annular
shape which rotates around the clock dial and is actuated by the impulses of
revolution from the engine and also in the combination with said clock and annular
dial of the particular means for transmitting the impulses of revolution from the
engine to the annular dial, as hereinafter fully described.
In carrying out the invention, a notched disc or wheel, whose periphery is divided
into sixty teeth, is mounted to rotate concentrically with the hand arbor. This dise
carries a cylinder enclosing the clock works and extending forward as far as the
clock dial. Upon the edge of this cylinder is detachably fitted, by friction lugs, an
annular dial. This dial rests near the plane of the clock dial and slightly overlaps
the same so that the minute hand points to the sub-divisions on the said annular dial.
This annular or ring-shaped dial is graduated into equal sub-divisions which are
numbered from the zero point in both directions. The number of the graduations
on one side of the zero point are marked " power gain" and those on the opposite
side are marked "power loss." This annular dial has its zero point set opposite the
minute hand of the clock and when the engine is travelling at its normal speed the
annular dial moves at the same rate as the minute hand, although not actuated by
the clock. This annular dial moves with the cylinder and is actuated by the toothed
disc into whose teeth there meshes a snail wheel or worm on whose shaft is keyed
a ratchet wheel which is intermittently rotated by a pawl jointed to an arm hung
upon the snail or worm shaft, a detent being provided to prevent any back motion
of the ratchet wheel. The oscillation of the arm serves to give an intermittent
revolution to the ratchet wheel and this gradually turns the worm plate or snail,
the toothed disc and cylinder and the annular dial. For oscillating the arm it is
provided with a segment of a grooved pulley, over which there passes a cord to one
end of which is attached a weight while its other end passes over a pulley and extends
to a crank rock shaft or other oscillating or revolving part of the engine. At each
revolution or rocking motion of this part of the engine, this cord and weight are
alternately drawn up and let down and as the cord moves, its frictional contact
against the segment causes the lever to oscillate and thus actuate the pawl for giving
an intermittent motion to the ratchet wheel. Instead of using this weighted cord
and the segment for oscillating the lever and pawl, 1 may provide a pulley to be
continuously rotated by a belt from the engine and attach to the hub of the pulley a
cam adapted to bear against the pawl lever to oscillate it.
The operation of my speed indicator is as follows; The annular dial, which is
made removable from, and adjustable to any position on, the rotary cylindrical
flange of the toothed disc, is fitted on to the edge of the said flange with the zero
point opposite the minute hand. The gearing is now connected to the engine and

page_text: adjusted by the length of the stroke of the pawl to rotate the toothed disc bearing
the flange, once in an hour, each of the sixty teeth of the disc representing one
minute. It will, therefore, be seen that when the engine is running at normal speed,
say sixty revolutions à minute, it will turn the annular dial just as fast as the clock
turns its minute hand and the zero point of the dial will travel with the minute hand.
If, however, the engine runs too slow, the zero point of the dial will drop behind
the minute hand and mark the indication "loss." On the other hand, if the engine
runs faster than the normal speed, the zero point of the dial will advance faster
and go beyond the minute hand and mark the indication "gain" "and by this means
the running of the engine may be corrected from time to time, to preserve a uniform
pace. To limit the stroke of the pawl in rating the normal speed of the engine, an
eccentric stop is provided, by adjusting which the stroke of the pawl lever is
regulated and its pawl is made to take the required number of teeth of the ratchet
wheel, according to the speed of the engine.
This speed indicator is of very simple and inexpensive construction since it does
not involve any complication in the clock mechanism but uses the ordinary clock to
which other gearing is applied without alteration of the clock mechanism and while
being simple and inexpensive it is at the same time an accurate and reliable indicator
and is unaffected by vibration and jar.
In making use of my invention, it is not necessary that the dial should be a
complete circle but it may be only a segment of a circle and instead of being mounted
upon an enclosing flange or cylinder it might be carried by an arm. may also
modify the construction of gearing for imparting rotary motion to the annular dial;
thus instead of using the snail or worm above described, I may use a train of
wheels and pinions meshing with a crown wheel on the back of the annular dial.
Dated this 18th day of June 1980
A. R. SHERMAN.
By A. M. & Wm. Clark,
53, Chancery Lane, London, Patent Agents.
COMPLETE SPECIFICATION.
Improvements in Speed Indicators.
1, ALBERT HEAD SHERMAN of Pawtucket, Providence County, State of Rhode
Island, United States of America, Inventor, do hereby declare the nature of this
invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
The object of my invention is to provide a speed indicator for shewing the degree
of speed, as compared with a clock, that the engine may be running at, as a basis for
increasing its speed when it is running too slow or diminishing it when running too
fast. Indicators for this purpose have heretofore been provided, in which a time
clock was combined with gearing, which was actuated by an impulse from each
revolution of the engine shaft, which gearing rotated an index hand which, when
compared with the hands of the clock, would show the relative pace at which the
engine was moving.
My invention is founded upon this general principle, and consists in the combina-
tion with a clock, of a graduated travelling dial or scale of annular shape, which
rotates around the clock dial, and is actuated by the impulses of revolution from the
engine, and also in the combination with said clock and annular dial of the particular
means for transmitting the impulses of revolution from the engine to the annular
dial, as hereinafter fully described.
Reference is to be had to the accompanying drawing, forming a part of this speci-
fication, in which similar letters of reference indicate corresponding parts in all the
figures.
Figure 1 is a front view of the speed indicator ;

page_text: Figure 2 is a detail in similar section showing a modification;
Figure 3 is a side elevation ;:
Figure 4 is a face view of the worm plate; and
Figure 5 is a perspective view in detail of a further modification of my invention.
In the drawing, A represents any good time clock which, as shown belongs to
the class of marine clocks, or clocks which are actuated by a spring instead of a
weight.
The clock may, however, be operated by a weight and pendulum, if desired. The
clock is contained within a suitable enclosing case B, having a hinged front door and
a glass face. To the back of the case the clock frame is securely fastened by a
central bolt C, (Figure 2) whose threaded end passes into a screw-threaded hole in
the clock frame A, or into a nut attached thereto. Around the bolt is disposed a
flanged sleeve D, and between the end of this sleeve and the back plate of the clock
is disposed a washer E. On this sleeve and between its flange and the washer E
there turns loosely a notched disk or wheel F, whose periphery is divided into sixty
teeth.
Projecting laterally from this disk and enclosing the clock works, there is a flange
or cuff G, which extends forward as far as the clock dial. Upon the edge of this
flange or cuff is detachably fitted by friction lugs a, an annular dial H. This dial
rests near the plane of the clock dial and slightly overlaps the same, so that the
minute hand points to the subdivisions on the said annular dial.
This annular, or ring-shaped, dial graduated into equal subdivisions which are
numbered from the zero point Z, in both directions. The number of the graduations
on one side of the zero point are marked "power gain" and those on the opposite
side are marked "power loss." This annular dial has its zero point set opposite the
minute hand of the clock, and when the engine is travelling at its normal speed the
annular dial moves at the same rate as the minute hand, although not actuated by
the clock. This annular dial moves with the flange or cuff G, and is actuated by the
toothed disk F, into whose teeth there meshes a worm b, (Figures 2 and 4) constructed
on the face of a disk or plate I, fixed rigidly to a short shaft J, journaled in and
extending through the side of the case. On the outer end of this shaft is keyed a
ratchet wheel K, (Figures 2 and 3) which is intermittently rotated by a pawl L,
jointed to an arm M, hung upon the shaft J.
N, is a detent to prevent any back motion of the ratchet wheel. The oscillation of
the arm M serves to give an intermittent revolution to the ratchet wheel, and this
gradually turns the worm plate, the toothed disk with cuff G, and the annular dial.
For oscillating the arm M its end M2, is provided with a segment M¹, of a grooved
pulley. Over this grooved pulley segment there passes a cord N', which at its lower
end is attached to a weight O, while its other end passes over a pulley P, and extends
to a crank rock shaft, or other oscillating or revolving part of the engine. At each
revolution or rocking motion of this part of the engine, this cord and weight are
alternately drawn up and let down, and as the cord moves, its frictional contact
against the segment M³ causes this segment and the lever M to oscillate, and thus
actuate the pawl for giving an intermittent motion to the ratchet wheel.
I
Instead of using this weighted cord and the segment M' for oscillating the lever M,
may provide a pulley Q, to be continuously rotated by a belt from the engine, and
attach to the hub of the pulley a cam R, adapted to bear against the lever M to
oscillate it.
The operation of my speed indicator is as follows--
The annular dial, which is made removable from and adjustable to any position on
the rotary cuff or flange of the toothed disk, is fitted on to the edge of the said cuff
with the zero point opposite the minute hand. The gearing is now connected to the
engine and adjusted by the length of the stroke of the pawl to rotate the toothed
disk bearing the cuff once in an hour, each of the sixty teeth of the disk representing
one minute. It will, therefore, be seen that when the engine is running at normal
speed, say sixty revolutions a minute-it will turn the annular dial just as fast as the
clock turns its minute hand, and the zero point of the dial will travel with the minute

page_text: "
hand. If, however, the engine runs too slow, the zero point of the dial will drop
behind the minute hand and mark the indication "loss." On the other hand, if
the engine runs faster than the normal speed, the zero point of the dial will
advance faster and go beyond the minute hand and mark the indication "gain,"
and by this means the running of the engine may be corrected from time to time to
preserve a uniform pace. To limit the stroke of the pawl in rating the normal speed of
the engine, a stop s, (Figure 3) is affixed to a plate on the side of the case, and is
constructed in the form of an eccentric boss secured by a set screw. By turning the
projecting part of this boss to or from the lever M, the lever strikes the stop sooner
or later in its stroke, and the play of the latter is regulated, and its pawl is made to
take the required number of teeth of the ratchet wheel according to the speed of
the engine.
This speed indicator is of very simple and inexpensive construction, since it does
not involve any complication in the clock mechanism, but uses the ordinary clock, to
which other gearing is applied without alteration of the clock mechanism, and while
being simple and inexpensive, it is at the same time an accurate and reliable indicator,
and is unaffected by vibration and jar.
In making use of my invention, it is not necessary that the dial H should be a
complete circle, but it may be only a segment of a circle, and instead of being
mounted upon the cuff or flange it might be carried by an additional hand P, as in
Figure 5.I may also modify the construction of gearing for imparting the rotary
motion of shaft J to the annular dial H, thus instead of using the construction shown
in Figure 2, I may (see Figure 2) use a train of gears 61, 62, 63, 64, meshing with a
crown wheel F¹, on the back of annular dial H.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is―
1. A speed indicator, consisting of the combination, with a time clock having the
usual graduated face and moving index hands, of an additional or supplemental dial
or scale having circular graduations marked thereon, and arranged to travel around
the clock dial, and gearing for rotating it by the engine, said gearing being arranged
outside the clock mechanism, substantially as described.
2. A speed indicator, consisting of the combination, with a time clock, of an annular
dial surrounding the clock dial, and graduated as described, and gearing for connecting
the annular dial to the engine, substantially as described.
3. The combination, with a time clock, of an annular dial surrounding the clock
dial, a toothed disc or wheel arranged behind the clock, and having a cuff or flange
extending around the clock and adjustably connected to the annular dial, and a
gearing connecting the toothed disk to the engine, substantially as described.
4. The combination, with the gears of a speed indicator, of a ratchet wheel, an
oscillating arm hung upon the axis of said wheel and provided with a segment M¹,
and a pawl; a detent for the ratchet wheel, and a weight with a cord passing over the
said segment and over a pulley, substantially as and for the purpose described.
5. The combination, with the clock frame and the case, of a bolt C, a flanged
sleeve D, surrounding the bolt, the washer E, arranged between the clock frame and
the sleeve, and the disk or toothed wheel F, arranged to rotate between the flange of
the sleeve and the washer, substantially as described.
Dated his fou day of March
A. R. SHERMAN.
By A. M. & Wm. Clark,
53, Chancery Lane, London, Patent Agents.