Year: 1888

page_text: Date of Application, 31st Jan., 1888
Specification Accepted, 16th Mar., 1888
I, JOHN PATERSON, residing at John Street, Victoria, British Columbia, Mechanical
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 instruments used upon steam-engines to gauge
or test their several parts or their operation; and my invention has for its object the
placing in the hands of engineers, engine-builders, and others having valuable steam-
engines in charge, a correct and speedy method of testing the fairness and adjusting
the crank-shafts of steam-engines.
My invention consists in a pointer supported by and movable upon a rod or bar
which is secured by a frame to the piston-rod of the engine and held parallel therewith
in the same horizontal plane, said pointer being adapted to be centered on the crank-
shaft; and a second pointer adapted to be centered on the crank-pin, and to be moved
about the first pointer as a center, whereby the crank-throw may be tested at all
points, and the fairness of the shaft determined.
My invention further consists in details of construction and adjustment, all of
which I shall hereinafter fully describe by reference to the accompanying drawings,
in which :-
Figure 1 is a plan of the instrument, showing it in position.
Figure 2 is a cross-section through sliding-head H, and connected parts.
A is the piston-rod of the engine, B is the connecting rod, C is the crank-shaft,
D is the crank, and E is the crank-pin.
F is a frame, preferably of brass, and connected at fwith the working part of the
piston-rod A.
G is a rod, bar, or tube, preferably the latter for the sake of lightness, which is
fitted in the other end of frame F, in sockets therein, so that it may be adjusted
lengthwise, it being fixed in the position to which it is adjusted by the set-screws g.
The rod G lies in the same horizontal plane as the piston-rod, and extends a fow
inches beyond the center of the crank-shaft, forming, practically, a perfectly parallel
extension of the piston-rod A.

page_text: On the end of rod G, next the shaft, is carried the sliding adjustable head H,
adapted to be set in position by a screw h, and fitted on the top side with a small
level I.
In the end of head H, and next to the shaft, is fitted and adapted to rotate the
hub j, in which is fitted the radial arm or tube ), which is adjustable lengthwise, and
is set by a screw j¹.
The outer end of this arm carries a sliding-head K, adapted to be set by a screw k,
and having fitted to it, adjustably, a pointer L, set by a screw l. A pointer M is fitted
in the end of the hub of arm J, and is adapted to move endways therein; said last-
named pointer being for the purpose of setting the instrument in order that the
pointer L may revolve concentric with the path of the crank-pin.
If the outside of the crank-pin is flat, or has been bruised, it will be necessary to
drill a small hole in the center and put in a pin, represented here by e, allowing it to
project about one-eighth of an inch.
To use the instrument, first disconnect the connecting rod from the crank-pin,
leaving the cross-head about one inch from its extreme outward travel.
After setting the head H, perfectly level by means of the level in its top, center
pointer. M on the crank-shaft C.
Then turn the crank-shaft around, and adjust the pointer L to the center of its
crank-pin. Then gauge said pin at the outward and inward centers of the crank-
throw, by the pointer L.
It will thus be readily perceived whether the shaft is rectangular with the line of
the cylinder. Then turn the crank-pin to the top, and then to the bottom, following
with the pointer L, which will show at once whether the shaft is level or not.
The application of this instrument will show the slightest variation of the shaft from
the rectangular path of the piston's travel, and at the same time point out the slightest
variation of the shaft from a true level..
This it will accomplish in a few minutes, without the labor and great loss of time
required to take out the piston, center the cylinder, apply a line and a lovel as is
usually done, involving a heavy loss, as for example, in the case of large engines used
in driving the machinery of factories and mines.
The advantages resulting from the use of this instrument are the absence of hot
bearings; saving of brasses and oil; increase of power; as well as reducing, to a
minimum the risk of breaking. shafts and crank-pins, with the accompanying.wreckage
resulting therefrom. In situations where a number of steam-engines are under one
ownership or control, only one instrument will be required. Being made for the
largest engine, it is only necessary to have bushings bored and in halves to fit the
various sizes of piston-rods, and turned outside to fit the frame, while any convenient
length of tube may be used as well as a number of pointers of various lengths.
In order to test the instrument at any time, it is only necessary to turn the radial
arm around against a plumb line to test the level, and against the largest tube to test
the other two points.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I déclare that what I
claim is,
1. An instrument for testing the fairness of crank-shafts of steam engines, consisting,
essentially; of the following parts; to wit:a frame to be secured to the piston-rod of
the engine, a pointer carried by the frame, and adapted to center on the crank-shaft,
and a second pointer, also carried by the frame and movable about the first pointer as
a center, said second pointer being adapted to center on the crank-pin, substantially.
as described.
2. An instrument for testing the fairness of crank-shafts of steam-engines,
consisting of a frame to be secured to the piston-rod, a pointer carried by the frame,
for centering on the crank-shaft, a second pointer carried by said frame and movable
about the first pointer as a center, for centering on the crank-pin, and a level
carried by the frame for adjusting it, substantially as described,

page_text: 3. An instrument for testing the fairness of crank-shafts for steam-engines,.
consisting of a frame to be secured to the piston-rod of the engine, and composed of
adjustable parts for properly setting it, a pointer for centering on the crank-shaft,
said pointer being mounted upon the frame so as to be adjustable to position, a
second pointer for centering on the crank-pin, said pointer being movable about the
first pointer as a center, and so mounted as to be adjustable to position, and a level on
the frame for leveling it, substantially as decribed.