Improvements in Steam Engine Indicators.
Year: 1897

page_text: Date of Application, 25th May, 1897-Accepted, 7th Aug., 1897
COMPLETE SPECIFICATION.
Improvements in Steam Engine Indicators.
I, PETER E. APGAR, of 120 Gebhardt Street, in the City and County of Phila-
delphia, State of Pennsylvania, United States of America, 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 Improvements in Steam Engine Indicators, and consists
more particularly of mechanism employed to regulate the travel of the drum to
which the card adapted to receive the diagram is attached, so that, regardless of
the stroke or travel of the piston the travel of the card drum and length of the
diagram will always be the same.
I further provide means by which the card drum may be thrown in or out of
action without interfering with the working of any of the parts of the device.
Referring to the accompanying drawings:
Fig. 1 represents a side elevation of a portion of a steam engine with the device
embodying my improvements attached thereto.
Fig. 2 is a side elevation of my device detached from the engine and on a
somewhat larger scale than that shown in Fig. ¡l.
Fig. is a plan view.
Fig. 4 is a partial sectional elevation taken on the line 2-2 of Fig. 3.
Fig. 5 is an enlarged sectional elevation taken on the line 3-3 of Fig. 3, and
Fig. is a diagrammatic view illustrating the manner of attaching or detaching
the cord which operates the card drum.
A represents the cylinder of the engine, and a, the threaded opening by means
of which my device is secured.
The pressure cylinder, B, of the indicator is of the ordinary type containing a
piston, B, and a rod b', together with a spring, S, properly adjusted to resist the
variable pressure acting upon the piston, B.
The lever, 62, is connected to the piston rod, 61, by a link, 63, and to the cylinder, B,
through the medium of a link, 64. The lever, 62, is also provided at one end with
a socket to receive a lead pencil by which the diagram upon the card is traced.
All these parts, together with the drum, C, which is spring actuated, are old and
well known and in common practice; a cord is secured at one end to said drum,
the other being connected to the cross-head or other moving parts, the movement
of the latter imparting motion to the drum upon which a card to receive the
diagram is placed. In carrying out my invention, I provide in addition to the
construction above set forth, a frame I), which is secured by a screw, d, to the
arm, 65 which connects the cylinder, B, with the drum, C; at the end of this
frame is a pulley, D¹, provided with an annular casing, D², the cord, E, which is
attached to the spring actuated drum, C, passes through holes in the annular
casing, D2, and around the pulley, D', the end of said cord being provided with a
hook, e, adapted to engage a ring, f, on the cord F. The cord, G, is secured to a
lever, a', which is bolted to the cross-head, A', said cord passing between the

page_text: small pulleys, and d', mounted upon a hanger, d³, which is adjustable, secured
to the stem, by means of a set screw,, d', the stem, d³, is adjustably secured to
the arm, D, by means of a set screw, thereby imparting to the rollers a
universal movement so as to enable the cord, G, to lead off in any direction.
The arm, D, is pivotally secured to the frame, D, by a thumb nut, D4, which 5
holds the arm firmly in position' after the same has been properly adjusted.
Formed upon the frame, D, is a drum or casing, H, which encloses the spring, S',
and upon a central sleeve, h2, is mounted a wheel, I, to which one end of the
spring, S, is secured, the other end being secured at a point, to the drum, H.
A sleeve, ², fastened to and forming the hub of the wheel, I, carries the cord, F, 1
and a thumb screw, ; is, adapted to hold the wheel; I, in position upon the
fulcrum pin, i.
Upon the cord, F, is formed a loop, F', to which is attached the ring, f, and
mounted upon an upright projection, D³, is a spring actuated pulley, K, mounted
upon a stem, k, which is adapted to a slot in the projection, D5, and held in position 1
by a thumb screw, k', a washer, 2, being interposed between the pulley, K, and
thumb screw, k', and adapted to a square shoulder, 3, formed upon the stem, k
The cord, E, which as can be seen in Fig. 6, is capable of being readily hooked
or unhooked when the working parts of my device are in motion, passes around the
pulley, D', which is mounted upon a block, L, said block being capable of lateral 2
adjustment in the slot, , by means of a stem, 11, secured to said block and a thumb
screw,, adapted to said stem.
"
A block, M, is secured to the frame, D, and adjustable in respect thereto, the
same being held in position by a thumb screw, m. Upon said block are pro-
jections, m¹, and m2, provided with holes through which the cord, E, passes and
an eccentric, M³, provided with a handle, m³, having a spring, S, arranged to
hold said eccentric in and out of engagement with the cord, E, which passes
between the same and a segmental block, M2, the arrangement being such that the
eccentric after having been thrown into engagement with the cord, E, will allow..
the same to travel in the direction of the arrow shown in Fig. 3, to the full extent 3
of its movement, but when the movement is reversed the eccentric will tightly bind
the cord, E, against the block, M2, and thus check the movement of the card
cylinder, C, whilst the other parts of the device may still continue in motion.
In order to increase or decrease the travel of the card drum the hub, h³, of the
wheel, I, can be provided with collars of greater or less diameter as shown in dotted 3
lines in Fig. 3, and by removing the thumb screw, h³, which holds said collars
in position a collar of greater or less diameter may be adjusted and a change of
travel quickly made without deranging any of the working parts.
A further reduction in the travel of the cross-head may be made by employing
an additional set of pulleys, N and N¹, as shown by dotted lines in Figs. 2 and 3, 40
in which case the cord will be secured to the pulley, N, and a cord, N³, will
connect the pulley, N', with the spring actuated pulley, K; but as cases are rare
.in which such a reduction is required, it is not thought necessary to enter into
further details regarding this particular portion of the device.
Having now particularly described and ascertained the nature of my said 4
"invention and in what manner the same is to be performed, I declare that what I
claim is:
1
First: An Indicator for Steam Engines, comprising in combination with the
*pressure cylinder lever operated therefrom and the card cylinder, a frame provided
at one end with a wheel acted upon by a spring, and having a grooved pulley, a 50
cord adapted to the grooved periphery of said wheel, an adjustable arm secured
to said frame and provided with pulleys for guiding the cord. A second cord
secured at one end to the hub of said wheel, a spring actuated pulley to which the
-opposite end of said cord is secured the same being adjustably secured to said
frame. A third cord detachably secured at one end to the latter cord and guided 5
by an adjustable pulley mounted upon the end of the frame, the said cord being

page_text: secured at the other end to the spring actuated card cylinder, substantially as
specified.
Second: An indicator for steam engines, comprising in combination with the
pressure cylinder and card cylinder, a frame provided with an adjustable arm, a
cord guided thereby leading to the cross-head or other working parts of the
engine, a spring actuated wheel pivoted to said frame, and having a grooved
periphery for taking up the slack of said cord, a hub upon said wheel, a collar
upon said hub, a cord secured to the same, a spring actuated pulley, adjustably
secured to the frame for taking up the slack of the last mentioned cord, a loop in
said cord, a ring hung to said loop, a cord leading from the card cylinder and
provided with a hook to engage the said ring, a pulley mounted upon the end of
the frame and guiding the last mentioned cord, stop mechanism mounted upon
the frame for locking the latter cord after it has travelled to the full extent of its
movement in one direction, said stop mechanism being interposed between the card
cylinder and pulley mounted upon the end of the frame, substantially as specified.
Third: An indicator for steam engines comprising in combination with the
pressure cylinder and card cylinder, a frame detachably secured to the card cylinder
and provided at one end with an adjustable arm having pulleys universally
adjustable in the end thereof, a cord adapted thereto, a wheel acted upon by a
spring, mounted in a drum or casing in the frame, said wheel having a grooved
periphery receiving said cord, the drum or casing secured to or forming part of
the frame, a hub projecting out from said wheel, a cord adapted to said hub, a
spring actuated pulley adjustably secured to the frame near the opposite end
thereof, receiving the last mentioned cord, a pulley mounted upon a sliding block
guided in the end of the frame, a thumb screw mounted upon the stem in said
block and capable of adjusting the position of said pulley and a cord carried by
said pulley, substantially as specified.
Fourth A reducing gear for steam engine indicators, comprising an operating
cord, a spring actuated wheel acting upon the same, an intermediate cord adapted
to a reduced portion of said wheel, a spring actuated pulley, adapted to the latter
cord, an indicator cord adapted to the last named pulley and to a loop in the
intermediate cord, and acting upon the card cylinder, substantially as specified..
Fifth A reducing gear for steam engine indicators, comprising an operating
cord, a wheel rotatable in one direction by said cord, spring means for operating
the said wheel in the opposite direction, an intermediate cord secured to the hub
of said wheel, a pulley acted upon in one direction by said intermediate cord,
spring means for operating said pulley in the opposite direction, an indicator
cord secured to the intermediate cord and operating the card drum and mechanism
for acting upon the indicator cord after the same has travelled to the full extent
of its motion in one direction, substantially as specified.
Sixth A stop motion for steam engine indicators, comprising an eccentric or
cam and a block arranged upon opposite sides of the cord and a spring acting upon
said eccentric or cam and adapted to lock said cord.
Dated this 25th day of You 1807
HASELTINE, LAKE & Co.,
45 Southampton Buildings, W.C., Agents for the Applicant.