Apparatus for Indicating the Rate of Speed or Movement of Engines, Machines, and the like.
Year: 1894

page_text: Date of Application, 20th Oct., 1894
Complete Specification Left, 17th July, 1895-Accepted, 5th Oct., 1895
PROVISIONAL SPECIFICATION.
Apparatus for Indicating the Rate of Speed or Movement of
Engines, Machines, and the like.
I, WILLIAM CHADBURN, of 11 Waterloo Road, Liverpool, in the County of
Lancaster, Engineer, do hereby declare the nature of this invention to be as
follows:-
This invention has reference to apparatus for indicating the rate of speed or
movement of revolving or reciprocating parts of engines or machines, and the like,
wherein the pointer or other indicating part shews at any instant the rate of speed
at which the engine or machine is moving or running; and it has special reference
to that class of apparatus of this kind, wherein the means, employed to effect the
indication comprises a fluid resistance device, as a flyer or fan revolving in a fluid,
as the air, and adapted to move or swing about a point, and accordingly as the
apparatus is driven faster, the fluid resistance device is moved from or about said
point, which movement is transmitted to the indicating pointer, and that move-
ment takes place against another and separate resistance which becomes greater,
and, vice versa, less as the return action takes place; and is thus a varying
resistance.
Prior to this invention in this class of apparatus the varying resistance referred
to has been mostly effected by a cam or equivalent device connected with the
moving part supporting the fluid resistance device, and with a spring, the cam
being adapted to throw or move the leverage at which the spring acts on the parts,
at a greater or less distance from the axis about which it moves as it is turned or
moved more or less, and in one direction or the other. The adjustment of this
cam mechanism, and its formation, are somewhat difficult, and when in the hands
of those who are not familiar with the constructing and fitting of these instruments
or parts, they (the instruments) are liable to become deranged, and the apparatus
incorrect in its action.
Now, according to this invention, the liability of derangement etcetera, above
referred to, are obviated, and the apparatus is rendered more simple. This is
effected by, in lieu of the employment of a cam in connection with a spring as a
means of obtaining the varying or variable resistance, of employing two or more
springs, but without a cam, which come into action or go out of action one after
the other accordingly as the moving part carrying the fluid resisting device is
moved more or less. Thus, when in an increase of rate of speed taking place as
this moving part moves one spring is extended or compressed, the resistance
increased, and then a further increase of resistance takes place as a further
movement takes place by causing the moved parts to bring another spring into
action, and thus two or more springs alone are, by their being acted upon and put
in tension or compression, adapted to provide the variable resistance and power
required.
In one arrangement by which this may be effected, the frame or part on which
the fan or other fluid resisting device is mounted and works is connected by tooth
gearing to a rack, in connection with which the springs work, and, in action as the
said fluid resistance device support is moved about its axis, the toothed gearing is
put in motion, and the rack is actuated, bringing, in the case of an increase of rate
of speed being transmitted to the apparatus, second, or second and third, springs

page_text: into play, which, conversely, as the rate of speed decreases, go out of action.
Thus, the variable resistance referied to is effected. These springs in the return
stroke of the fluid resistance support or frame, when the rate of speed becomes less,
effect the returu action thereof.
Dated this 19th day of October 1894.
CHEESBROUGH & ROYSTON,
Fels. Chart. Inst. P.A.,
15 Water Street, Liverpool, Applicant's Patent Agents
Apparatus for Indicating the Rate of Speed or Movement of
Engines, Machines, and the like.
I, WILLIAM CHADBURN, of 11 Waterloo Road, Liverpool, in the County of
Lancaster, 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 :-
This invention has reference to apparatus for indicating the rate of speed or
movement of revolving or reciprocating parts of engines or machines, and the like,
wherein the pointer or other indicating part shews at any instant the rate of speed
at which the engine or machine is moving or running; and it has special reference
to that class of apparatus of this kind, wherein the means, employed to effect the
indication, comprises a fluid resistance device, as a flyer or fan revolving in a fluid,
as the air, and adapted to move or swing about a point; and accordingly as the
apparatus is driven faster, the fluid resistance device is moved from or about
said point, which movement is transmitted to the indicating pointer; and that
movement takes place against another and separate resistance which becomes
greater as the movement becomes greater, and, vice versa, less as the return action
takes place; and is thus a varying resistance.
Prior to this invention, in this class of apparatus, the varying resistance referred
to has been mostly effected by a cam or equivalent device connected with the
moving part supporting the fluid resistance device, and with a spring, the cam
being adapted to throw or move the leverage at which the spring acts on the parts,
at a greater or less distance from the axis about which it moves as it is turned or
moved more or less, and in one direction or the other. The adjustment of this
cam mechanism, and its formation, are somewhat difficult, and when in the hand of
those who are not familiar with the constructing and fitting of these instruments or
parts, they (the instruments) are liable to become deranged, and the apparatus
incorrect in its action.
Now, according to this invention, the liability of derangement, difficulties,
etcetera, above referred to, are obviated, and the apparatus is rendered more
simple. This is effected by, in lieu of the employment of a cam in connection
with a spring as a means of obtaining the varying or variable resistance, of
employing two or more springs, but without a cam, which come into action, or go
out of action, one after the other accordingly as the moving part carrying the
fluid resisting device is moved more or less. Thus, when an increase of rate of
speed takes place, as this moving part moves, one spring is extended or compressed,
and the resistance increased; and then a further increase of resistance takes place,
as a further movement takes place, by causing the moved parts to bring another
spring into action, and thus two or more springs alone are, by their being acted
upon and put in tension or compression, adapted to provide the variable resistance
and power required.
In one arrangement by which this may be effected, the frame or part on which
the fan or other fluid resisting device is mounted and works is connected by tooth

page_text: gearing to a rack, in connection with which the springs work; and, in action, as
the said fluid resistance device support is moved about its axis, the toothed gearing
is put in motion, and the rack is actuated, bringing, in the case of an increase of :
rate of speed being transmitted to the apparatus, a second spring, or second and :
third springs, into play, which, conversely, as the rate of speed decreases, go out-of
action. Thus, the variable resistance referred to is effected. These springs in
the return stroke of the fluid resistance support or frame, when the rate of speed
becomes less, effect the return action thereof.
Drawings illustrative of the invention are hereto annexed. In these,
Figure 1 is an elevation partly in section, and Figure 2 a plan of same.
Figure 3 shews a modified arrangement of the flyer or fluid resistance device.
In the drawings, a is a frame to which the different parts of the mechanism are
mounted and connected; b is the shaft through which motion is transmitted to the
instrument from the engine or other thing, the rate or velocity of which-as the
rate of revolution of a revolving part thereof is to be indicated. is a spur
wheel on b; and d is a spur wheel mounted in the movable frame e, said frame being
The wheel dis
hinged on the spindle h, and having radial movement about same.
kept normally in gear with c by the spring el. The frame e is adapted to be moved, ›
by a cam or the like, fixed in the casing in any suitable way, and adapted to be
worked from outside, and to act on and raise or lower the frame e through the
projection e. is the frame which carries the fan j, the frame being loosely
mounted on the spindle h. kis a rack supported and adapted to move up and down.
on the frame a'; aud it is connected and geared with the frame i by the quadrantal
racks laud m, (which are supported by a pin n), and the toothed wheel o forming
part of or connected with the frame i. p and q are two springs connected with and
operating upon the rack k, the spring p being the primary one, and spring the
secondary one; these being the springs above referred to, which act upon the frame i,
and by which the variable resistance to the movement of that frame is produced.
The fan is driven from the shaft h, by the spur wheel which is fixed on the
shaft ; pinions, supported by the frame i and meshing with r; the spur wheel s
mounted and fixed on the same shaft with s; and a pinion t driven by s and mounted
on the spindle carried by the frame i on which the fan j is fixed. u is the pointer
of the instrument, it being mounted on an extension, which is in the form of a
spindle, on the frame i, and works over a dial supported in the case in the usual
manner.
r
26
9
The operation of the instrument is as follows:-Rotary motion is transmitted to
it through the wheels c, d, and f, and the shaft h is thereby revolved; and the
wheel of the fan device being fixed on this shaft, and being geared with the fan j
through the wheels », s', and t, the tendency is for the frame i to be revolved with
the shaft h, owing to the resistance offered by the air to the rotation of the fan j,
and to the friction of the gearing. To obtain the necessary resistance to this
swinging action, to give the required movement to the pointer u, the springs p and
(acting in connection with the frame i through the rack k and quadrants I, m) are
employed, and by these such a varying resistance to the rotation of the frame i is
provided as will give a suitable increment of movement of the pointer, for every
increment of rate of speed transmitted to the instrument from the engine or machine
which it is being used in connection with. When only relatively low velocities are
being transmitted to the instrument, the spring p by its own natural increase of
resistance in stretching, alone provides the required resistance, but as the rate of
speed increases, the tendency of the increase on the frame i is to make the rate
of increase of the movement of the frame greater; and when this takes place, the
increase of resistance is afforded by the spring q. For instance, when the frane i
has revolved, a portion of its movement, say about half of its total movement, it is
found that the spring p aloue is not sufficient to give the requisite resistance to the
further movement of the frame to give a suitable and the required movement of
the pointer, and corresponding graduated scale on the dial; but by the second
spring y coming into action at this point, the required additional resistance in a
E

page_text: simple, reliable, and satisfactory. manner is provided. The spring p works in
tension, and the spring 9. in compression. The lower spring is adapted to be
adjusted-by having its lower end attached to a sliding part pl of the frame a', its
adjustment being made by, a screw and key, in the common well known way;
while the spring q is adjustable through the hollow screw plug. q', which is adapted
to be screwed a greater or less amount through the part of the frame, and through
which the spindle k' of the rack k passes.
In the modification shewn in Figure 3, the fan is arranged with its spindle in
the same axial line with the spindle h; aud motion is transmitted to it from the
wheel on the spindle through the intermediate gearing shewn.
Having now particularly described and ascertained the nature of this inven-
tion and in what 'manner the same is to be performed; I declare that what I
claim is :-
1. In apparatus for or used in indicating the rate of speed of engines, machines,
or mechanisms wherein a pointer or indicator is, through a movable device such
as herein specified, and a resistance device acting against the tendency of motion
of the former, operated and controlled, the employment in connection with said
resistance device of two (or more) springs which are brought into action one after
the other in the performance of the stroke of the said resistance device, and as the
tendency of the increase of movement of the said movable device takes place ;
operating substantially as and for the purposes described.
2. In apparatus for or used in indicating the rate of speed of engines, machines,
or mechanisms wherein a pointer or indicator is, through a movable device such as
herein specified, and a resistance device acting, against the tendency of motion of
the former, operated and controlled, the combination of the movable frame i
having the fan j and driving, gearing, springa p and q, toothed rack k, and inter-
mediate gearing between said rack and the frame i; as set forth with reference to
and shewn in the drawings.
Dodiks 16th dox of Tule 1895
CHEESBROUGH & ROYSTON,
15 Water Street, Liverpool, Applicant's Patent Agents.