Year: 1886

page_text: I, HENRY HERDEN of Wellsboro' in the County of Tisga and State of
Pennsylvania United States of America Civil Engineer, 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:-
..
My Invention relates to the class of speed indicators in which the indicating
mechanism is actuated by the centrifugal action of weights receiving motion from
the machinery whose speed is to be indicated.
My Invention consists in a slotted shaft, and a two armed lever pivoted therein
and provided with weights on the ends thereof, and in combination therewith of an
index and a spring for opposing the centrifugal action of the weights of the lever.
It also consists in means for preventing the vibration of the weighted lever when
the indicator is running at a low speed.
Reference is to be had to the accompanying drawings forming part of this
Specification; wherein; Figure 1 is a front elevation showing the enclosing case
in section, and the dial and index in dotted lines. Figure 2 is a side elevation
with the side of the casing removed. Similar letters of reference indicate corre-
sponding parts in both the Figures.
The casing A, in which all of the parts of the speed indicator are contained, is
provided with a transverse partition B, and in the partition B and end of the
casing A is journaled a shaft C, which projects through the end of the casing and
is provided with a pulley D. The portion of the shaft C between the partition B
and the end of the casing A is preferably made rectangular in cross-section, and is
slotted to, receive the lever E which is pivoted on the pin F passing transversely.
through the shaft C. The arms e el of the weighted lever E upon opposite sides
of. the shaft C are of equal length and are provided with weights G. G. The
journal a of the shaft C which is received in the partition B is made hollow, and a
rod b extending through the journal a is connected with a cord c which passes
under a pulley & hung in the slot of the shaft C and which extends into the slot of
the shaft, the end of the cord being attached to the arme of the lever E. The

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opposite end of the rod b is attached by a swivel-joint to a slide f.which moves
along a guide rod g secured in the casing A parallel with the axis of the shaft C.
The slide is attached to one end of a cord h which is wound once around and
secured to the drum i on the spindle j of the indicator. A flat spring H secured
at one end to the partition B is connected at the opposite end with a cord k
attached to the smaller part of a snail 7 secured to the spindle ; so that, as the
cord is wound upon the snail it is received on a continually increasing diameter.
A spring m projecting from the partition B at right-angles to the spring H bears
against the side of the spring H with sufficient friction to modify the movements
of the spring and the weighted lever carried by the shaft C when the indicator is
used for indicating low speeds; but the length of the spring m is less than the
distance through which the spring H.moves, so that the spring H during the latter
part of its outward excursion leaves "the spring m. The free extremity of the
spring m is bent backward away from the spring H so that when the spring H
retracts it may readily pass the end of the spring m.
Upon the outside of the casing A is formed a dial I as indicated in dotted
lines in Figure 1. The spindle j extends through the side of the casing, and is
provided with an index n which turns in front of the dial I. The shaft C is
provided with a transverse screw o for limiting the movement of the lever E. The
speed indicator receives its motion through a belt p from the machinery whose
speed is to be indicated. As the shaft C revolves, the centrifugal action of the
weights G G¹ tend to bring the lever E into position at right angles with the
shaft C. The centrifugal action of the weights G G¹ is opposed by the spring H,
through its connection with the spindle j. and the connection of the drum i with
the arme of the lever E in the manner already described.
An increase in the speed of the shaft C by increasing the centrifugal action of
the weights GG tends to put the spring H under greater tension, and by unwinding
the cord h on the drum i and winding the cord upon the snail the spring secures
a greater advantage over the action of the weights G. G. When the indicator is
employed to indicate low speeds, the tendency of the weighted lever to vibrate
under a light pull of the spring H is opposed by the bearing of the spring m against
the side of the spring H.
By employing a single lever E with equal arms e e¹ and the weights G G¹
arranged in the manner described, the weighted lever is affected only by centrifugal
action. Any lateral or longitudinal movement of the indicator will produce
opposite effects upon the weights G G' which would neutralize each other. For
this reason my improved speed indicator is especially adapted for use on railway
trains and steam vessels where it is liable to be subjected to shocks from various
directions. The indicator is adapted to the machine in connection with which it is
to be used by applying a pulley D of the required diameter, or by adapting the
graduations of the dial I to the speed to be indicated.
Having now particularly described, and, ascertained the nature of the said
Invention, and in what manner the same is to be performed; I declare that what
I claim is ;
1st In an indicator, the combination with a shaft carrying a weighted lever, of
the spring opposing the movements of said lever and connected to a spindle, said
spindle also being connected to said lever and carrying an index, substantially as
set forth.
2nd In a speed indicator the combination of the slotted shaft C, the two armed
lever E and weights G G' attached thereto, the spindle į means for connecting the
spindle with the weighted lever, a spring H connected with the spindle, and an
index n, carried by the end of the spindle, substantially as herein specified:
3rd In a speed indicator the combination of the shaft C, the two armed weighted
lever E, the cord c, rod. b, slide f, cord h drum i spindlo j, snail l, cord k and
spring H substantially as herein specified.

page_text: 4th In a speed indicator, the combination with a weighted lever E and a
spring H opposing the centrifugal action of the weighted lever of a spring m
arranged to bear against the side of the spring H substantially as herein specified.
5th In a speed indicator the combination with the shaft C and the weighted
lever E of the screw o for limiting the motion of the lever E as herein specified.
6th In a speed indicator the combination of the shaft C, weighted lever E, cord c
guiding-pulley d, rod b, slide f, guiding rod g, cord h, drum i, spindle j, snail 1,
cord, spring H, and spring m, substantially as herein described.
1 1000