Improvements in Friction Testing Machines.
Year: 1895

page_text: Date of Application, 22nd Nov., 1895
Complete Specification Loft 11th Aug
1898-Accepted. 12th Sept., 1896
PROVISIONAL SPECIFICATION.
Improvements in Friction Testing Machines.
I JOHN GOODMAN Professor of Engineering at the Yorkshire College of the
Victoria University Leeds in the County of York do hereby declare the nature of
this invention to be as follows:-
This invention refers to that class of testing machine used for testing the friction
between axles or journals and their bearings and for analogous purposes, and more
particularly, to means for applying the load to or on the bearing in such a manner,
that the bearing is free to tilt or rotate through a small angle caused by the
friction of the bearing without altering the central direction of the pull or load.
In a machine to which my invention is applied, the bearing to be tested is fitted
within a stirrup shaped casting, hereinafter referred to as the stirrup; and which
is fitted with a long floating steelyard. The journal or axle passes of course also
through the stirrup, and is usually carried on friction rollers or rather wheels.
A pair of connecting links of equal length are suspended from two knife edges, one
to or on each side of the stirrup; and the lower ends of these links carry in their
turn by knife edges a cross bracket or crosshead. From this crosshead a single
central connecting link, also suspended on a knife edge, passes downwards to a
compound lever arrangement.
It will be evident, that this arrangement of a pair of connecting links, stirrup
and crosshead, constitutes a parallel motion device; whereby the stirrup, and
consequently the bearing to be tested, is free to tilt or rotate through a small
angle without altering the central direction of the pull or load.
My invention farther comprises means for adjusting the pair of knife edges in
the stirrup, so that the resultant line of the pull or load through the aforesaid
connecting links is perfectly true with the centie line of the axle or journal; in
other words, the vertical line through the centre of the shaft. should exactly bisect
the line joining the two knife edges. Should this not be the case, I effect the
necessary adjustment by moving one of the knife edges nearer to or farther from
the bearing, by tilting the same in the following manner. The said knife edge is
prolonged beyond one of the sides of the stirrup sufficiently far to enable a lever
to be fitted and keyed or otherwise secured thereto. The other, lower end of the
lever, supposing the lever to hang vertically, is held in position by means of two
nuts fitting on a screwed rod, one on each side of the lever; which latter is
provided with a hole through which the screwed rod passes. One end of the
screwed rod is hinged to a pin fixed to the side of the stirrup.
It will be evident, that by screwing the nuts along the screwed rod, that the
lever will be moved, rotating the knife edge fulcrum so that the top or bearing
edge of the same is tilted to one side or the other, i.e. towards or away from the
bearing.
Dated this 20th day of November 1895
J. CLARK JEFFERSON,
30 Park Row, Leeds, Agent for Applicant.

page_text: Improvements in Friction Testing Machines.
I JOHN GOODMAN Professor of Engineering at the Yorkshire College of the
Victoria University Leeds in the County of York 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 :-
This invention refers to that class of testing machines used for testing the friction
between axles or journals or the like and their bearings and for analogous purposes,
and more particularly to means for applying the load to or on the bearing in such
a manner, that the bearing is free to tilt or rotate through a small angle caused by
the friction of the bearing without altering the central direction of the pull or
load.
In a machine to which my invention is applied, the bearing to be tested is fitted
within a stirrup shaped casting, hereinafter referred to as the stirrup, and which is
fitted with a long floating steelyard. The journal or axle passes of course also
through the stirrup, and is usually carried on antifriction rollers or rather wheels.
A pair of connecting links of equal length are suspended from two knife edges,
one on each side of the stirrup; and the lower ends of these links carry in their
turn by knife edges a cross bracket or crosshead. From this crosshead a single
central connecting link, also suspended on a knife edge, passes downward to any
suitable lever arrangement.
It will be evident that this arrangement of a pair of connecting links, stirrup, and
crosshead, constitutes a parallel motion device; whereby the stirrup, and conse-
quently the bearing to be tested, is free to tilt or rotate through a small angle
without altering the central direction of the pull or load.
The
My invention farther comprises means for adjusting the pair of knife edges in
the stirrup, so that the resultant line of the pull or load through the aforesaid
connecting links is perfectly true with the central line of the axle or journal, in
other words the vertical line through the centre of the shaft should exactly bisect
the line joining the two knife edges. Should this not be the case, I effect the
necessary adjustment by moving one of the bearing knife edges farther from or
nearer to the bearing or axle by tilting the same in the following manner.
said knife edge is prolonged beyond one of the sides of the stirrup sufficiently far
to enable a lever to be fitted and keyed or otherwise secured thereto. The other
lower end of the lever, supposing the lever to hang vertically, is held in position
by means of two nuts fitting on a screwed rod, one on each side of the lever;
which latter is provided with a hole through which the screwed rod passes.
One
end of the screwed rod is hinged to a pin fixed to the side of the stirrup.
It will be evident that by screwing the nuts along the screwed rod, the lever
will be moved, rotating the knife edge fulcrum, so that the top or bearing edge of
the same is tilted to one side or the other, i.e. towards or away from the axle, or
bearing to be tested.
And in order that my invention and the manner in which the same is to be
performed may be more readily and clearly understood, I have annexed hereto the
accompanying drawing, which is a longitudinal section of a machine constructed
in accordance with my invention; one side of the before mentioned stirrup being
however shewn in side elevation, in order to shew the means for adjusting the
stirrup knife edges at equal distances from the centre line of the axle or bearing
to be tested.
a indicates the bearing to be tested, and 6 the axle on which it rests.
c is the before mentioned stirrup, to which the bearing a is fitted; so that the
latter is attached temporarily but securely to the former. The stirrup c is provided
with a floating steelvard d

page_text: e and are a pair of connecting links of equal length, suspended from the
stirrup e by means of the knife edges g and h respectively; which are fitted in the
sides of the stirrup c. The lower ends of the links e and f, carry suspended from
them by means of knife edges i and j, the cross bar k. Midway between the knife
edges i and j, the cross bar k is provided with a knife edge fulcrum 1, from which
is suspended the central connecting link m. The lower end of the link m is
connected by a knife edge n with the lever o of a compound or other lever
arrangement.
It will be evident that owing to the parallel motion device formed by the
stirrup c, crosshead or cross bar k, and links e and f, the pull of the link m is
transmitted through the centre of the axle 6 parallel to the links e, f, and m,
whether the floating steelyard d is in a horizontal position or is tilted through a
small angle by the friction between the bearing and axle.
The knife edge his prolonged at on side, so as to be fitted with a lever p. The
outer end of the lever p is provided with a hole, through which passes the screwed
rod g; the rod q being hinged at r to the stirrup c. Two nuts, one on each side of
the lever p, fitted on the rod q, hold the lever p firmly in position. If the bearing
edge of the knife edge h is not at exactly the same distance from the centre of the
axle or bearing d as the knife edge g, then by slackening one of the said nuts
and tightening up the other, the knife edge his tilted in one direction or the other,
so as to move the bearing edge of the same nearer to or farther away from the
centre of the axle b or bearing a as may be required to make the said distances
exactly equal.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. In friction testing machines of the class herein referred to, the use of a
parallel motion device substantially as aud for the purpose herein set forth.
2. In friction testing machines of the class herein referred to, the combination
of the stirrup c cross bar k and links e and ƒ substantially as and for the purpose
herein set forth.
3. In friction testing machines of the class herein referred to, the means for
adjusting the position of the stirrup knife edges with respect to the centre of the
axle substantially as and for the purpose herein set forth.
4. My improved friction testing machine constructed and arranged substantially
as herein set forth and illustrated.
Dated this 10th day of August 1896.
J. CLARK JEFFERSON,
30 Park Row, Leeds, Agent for Applicant.