IMPROVEMENTS IN CENTRIFUGAL MACHINES
Year: 1885

page_text: "
I, WILLIAM ROBERT LAKE, of the firm of Haseltine, Lake & Co, Patent Agents,
Southampton Buildings, in the County of Middlesex, do hereby declare the nature
of my invention for IMPROVEMENTS IN CENTRIFUGAL MACHINES' (a communi-
cation from William H. Tolhurst, of Troy, New York, United States of America,
Manufacturer of Machinery,) 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 centrifugal machines, and has for its
object to provide means for reducing the strain and friction upon the bearings of a
basket-supporting shaft in a centrifugal machine due to the unequal distribution of
the load in the basket.
The said invention consists
Firstly in providing a fixed support for the shaft-supporting step, the upper
surface of which is so formed that when the step is centrally located thereon it
will occupy a horizontal position, and any movement of the step changing its
location upon said surface will change its angular position relative to the line of
direction of the shaft. Secondly in providing a step for a basket-supporting shaft
that is free to revolvo by a rotary sliding movement upon the surface of its
supporting base; and, Thirdly in providing a step for a basket-supporting shaft
that is adjustable angularly to the line of direction of said shaft.
In the accompanying drawing.
Figure 1 is a plan view of my improved centrifugal machine with part omitted
to show the driving pulley.
Figure 2 is a plan view of the step and supporting base with the basket and
supporting shaft removed.
Figure 3 is a vertical central section of the machine on the dotted line x y
Figure 1 showing the shaft vertical and the step centrally located upon its
support.
Figure 4 is a similar section showing the shaft inclined to the limit of its
oscillation and the step upon one side of its support.
Figure 5 is a plan view of the step in different positions upon its supporting
base.

page_text: A is the bed plate of the machine to which is bolted the stationary basket
inclosing curb, B, from which project upwardly three arms C supporting at their
upper ends the bearings of the upper end of shaft D and connected therewith by a.
universal joint. The said universal joint consists of the ball F in which the shaft
rotates and the socket J in which the ball turns to any desired angle, the shaft
being free to slide vertically through its bearing in the ball F, the bearings being
located within the driving pulley E fixed to the shaft.
The lower end of the shaft rotates in a ball d which is free to turn or tip in any
direction in the step a. The step is supported by the bed-plate or base A and is
free to travel about the concave surface b of the base anywhere within the raised
annulus g.
In Figures 3 and 4 I have shown the contact surfaces of the base and step
curved to the arc of a circle the centre of the circle being located at ; in Figure 3.
The position of this arc relative to an arc of a circle having the universal joint
at the upper end of the shaft as a centre is shown by the dotted lines i and h
respectively.
The operation of a centrifugal machine used as a hydro-extractor is as follows;
the wet goods to be dried are placed within the basket G, the walls of which are
pierced by numerous perforations, as shown by the dots in Figure 3 and the
basket is rotated at a high rate of speed. The centrifugal force expels the water
from the goods through the perforations into the curb, from which it flows by
gravity through suitable apertures therein, as H which are shown covered in
Figure 3. In loading the basket with goods to be thus dried they are seldom or
never evenly distributed therein, from which it follows that one side will be
heavier than the others, and when the basket is rotated at a high rate of speed a
very great strain, friction, and wear will be thrown upon the bearings of the
basket supporting shaft if they are secured rigidly to their supporting frame, and
upon the frame itself.
Many expedients have been heretofore resorted to for the purpose of overcoming
this difficulty. The bearings have been loosely confined by springs which soon
break or wear out without entirely relieving the bearings of the friction due to
excessive vibration of the various parts.
A convex shaft supporting step resting upon a concave supporting base has also
been employed, but the movements of the step were controlled by springs in
various ways and necessarily so for the reason that only those convex surfaces
could be employed whose convexity or concavity was measured by the arc of a
circle, the centre of which was the universal joint connecting the upper end of the
shaft with its supporting frame, and the gyroscopical movement of the basket and
shaft would at once force the step from its support the tendency of the shaft being
to assume a horizontal position.
By connecting step a with shaft 1 by means of the ball d adapted to turn or
tip in any direction in a corresponding socket in the step an universal joint is
formed which permits of an universal angular adjustment of the step a relative to
the shaft D, and this universal adjustment in connection with the freedom of the
shaft to slide vertically in its bearings located at or near its end, opposite the end
supported by the step, permits of the use of a supporting base having a convex
surface or walls with inclined surfaces ascending as they extend from the centre
outward, the incline being considerably steeper than the inclination of a concave
surface formed upon the arc of a circle whose centre is the universal joint within
the driving pulley E.
I am thus able by means of gravity without the use of restraining springs to
overcome the gyrascopical, or other force which tends to drive the supporting step
from the centre of its supporting base. When the shaft oscilates to one side of
a vertical line as from the position shown in Figure 3, to that shown in Figure 4,
the step a is carried to one side of its supporting base, travelling up its inclined
surface and thereby lifting the travelling parts and the load of the basket; the

page_text: upper end of the shaft sliding up through its bearings and the step tipping
relatively to the shaft as shown in Figure 4.
The position of the step is shown by the dotted circle in Figure 2. If the parts
are, for the sake of experiment suddenly forced to their extreme limit, to the
position shewn in Figure 4, while the shaft and basket are rapidly rotated to the
right or in the direction taken by the hands of a watch, the shaft will slowly
return to an approximately vertical position, the step a revolving by a rotary
sliding motion to the left around the centre of its supporting surface, carrying the
end of the shaft with it, and gradually approaching the centre as it revolves until
the unequal distribution of the load is balanced, when the revolution continues in
a circle which is constant for a given variation in the distribution of the load.
Under these circumstances the load would ordinarily be of such even distribution
that the diameter of the circle described by the centre of the revolving step would
not exceed about one half of an inch.
In order to understand and fully appreciate the importance of the angular
adjustability of the step relative to the shaft, and of the formation of the step
supporting surface to develop such adjustability, it is necessary to examine into
the causes of the retrogressive revolutions of the step and shaft.
By inspection of Figure 4, it will be seen that the shaft has oscillated to one
side so as to depart considerably from the vertical position shewn in Figure 3 but
the step in travelling from the centre of its supporting surface has departed much
farther from the horizontal position shewn in Figure 3, so that the side of the
step farthest from the centre of its support is much nearer the upper end of the
shaft than is the opposite side of the step.
It is also apparent that the lower side of the step sustains a larger share of the
weight of the supported parts including the loaded basket.
Now as the shaft and basket rotate and the heavier side of the basket reaches a
point in line with the shaft and the centre of the supporting surface (see Figure 5)
farthest from said centre, the pull in the direction of arrow N° 1 upon the shaft
and step, due to the centrifugal force of the extra weight pulling in the direction
of the arrow,
will tend to relieve the lower side of the step of its extra pressure and
transfer it to the opposite and upper side of the step, so that the weight or
frictional pressure between the surfaces of the step and its support will be about
evenly distributed throughout the surface of the step, and as it cannot travel
farther in the direction of the pulling force without travelling up the steep incline
and considerably elevating the whole load, it remains stationary until the line of
direction of the pulling force changes.
If the effect of a quarter of a revolution or rotation of the basket to arrow No 2
is considered it will be found that there is no apparent result, as the rapidity of
movement has not afforded sufficient time to retransfer the weight to the lower
side of the step and overcome the inertia of the step. As the pulling force passes
another quarter to arrow No 3 there is restored to the lower side of the step not
only the weight it would support with the parts at rest, but, by reason of the pull,
almost the entire weight is transferred to the lower side, so that the frictional
contact of the upper or opposite side is very slight, and the pulling force in passing
on to the next quarter, arrow No 4 causes the step to slide, by a partially rotary
motion to a position approximating that shewn by the broken lines K, the lower
side of the step acting in the nature of a pivot upon which the step has turned
back, by reason of its tendency to descend the inclined surface, toward the centre
of the supporting base.
The next rotation of the shaft and its load would act in a similar manner upon
the step and cause it to assume a position approximating that shewn by the
broken line m. Many turns of the shaft are required to cause the step to revolve
once around the centre of its supporting base, and several revolutions are required
to bring the step into its final orbit of revolution.
From the foregoing explanation it will be seen that no restraint or control
whatever except the inclined supporting surfaces and gravity is put upon the

page_text: movements of the shaft supporting step which is permitted to travel about by easy
stages to accommodate itself to the unequal distribution of the load in the basket,
which arrangement wholly prevents any binding friction upon the bearings and
reduces all vibrations upon the moving or stationary parts to a minimum.
Thus the angular adjustment of the supporting step, to the line of direction of
the shaft permits of such a distribution of the weight upon the step, as to cause the
same to revolve by a rotary sliding movement until it finds the proper orbit of
revolution to maintain the equilibrium of the pulling force, which is constantly
changing in direction during a period of rotation of the shaft.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed as communicated
to me by my foreign correspondent, I declare that what I claim is
First. In a centrifugal machine, an oscillating basket shaft, provided with a
supporting step free to travel upon a fixed supporting surface, said step being
angularly adjustable to the line of direction of said shaft, and said shaft being
vertically adjustable to the conformation of said supporting surface, substantially as
described.
Second. In a centrifugal machine, a vertically adjustable basket supporting shaft,
connected by an universal joint at or near its upper end, with a supporting frame,
and adapted to rotate in a supporting step which is free to revolve by a sliding
rotary movement about the surface of a fixed support, substantially as described,
in combination with said movable step, and fixed support, for the purposes
specified.
Third. In a centrifugal machine, having a vertically adjustable basket, sup-
porting shaft connected by an universal joint at or near one end with a supporting
frame, and at its other end with a movable supporting step in which it rotates, a
step supporting base provided with an upper concave surface, adapted to support
the step in a central horizontal position when the said shaft is vertical, and to
change the angular position of the step relatively to the shaft when the stepped
end of the shaft oscillates to one side of a vertical line, the angle formed between
the step and shaft constantly increasing on one side, and diminishing on the
opposite side as the step travels from the central part of the supporting surface
outward, substantially as described, and for the purposes set forth.
Dated this 21st day of July 1885,
HASELTINE, LAKE & Co.,
For the Applicant.