Year: 1896

page_text: Date of Application, 6th June, 1895
Complete Specification Left, 5th Mar., 1897-Accepted, 15th May, 1897
We ALFRED HERBERT RANDOLPH of 6 Hertford Street, Mayfair in the
County of London Major and GILBERT GILKES AND CO. LTD. of Canal Iron
Works Kendal Engineers do hereby declare the nature of this invention to be as
follows:-
Our invention relates to an improved butter churn as hereinafter described.
According to our invention the churn consists of two bowls placed one inside the
other and arranged to revolve independently about a common vertical axis. The
inner and steeper bowl has an opening at its apex or bottom for a purpose
hereinafter indicated.
We prefer that the bowls should have the form of paraboloids of revolution but
we do not confine ourselves to this specific form as portions of other conics or
suitably curved surfaces may be employed. The depths and diameters of the
bowls may be arranged to suit the required capacity of the churn.
The operation of our improved churn is very simple and is somewhat as follows,
that is to say :-The inner bowl which is open at the top is driven at such a speed
that the cream is caused to rise along its inner surface and to be discharged at the
top edge into the outer bowl against the interior surface of the latter. The outer
bowl which may be open or covered during this part of the operation is stationary
or driven at a lower speed than its discharging speed so that the cream discharged
thereinto from the top of the inner bowl falls to the bottom and is drawn again into
the inner bowl through the opening in the apex thereof. This continuous
circulation causes the butter to be formed and to remain in the grain. As soon as
the operation is completed the outer bowl is revolved at its discharging speed to
extract the butter-milk which is caught in an annular vessel suitably placed to
receive it.
בד
3000
W. P. THOMPSON & Co.,
322, High Holborn, London, W.C., Patent Agents for the Applicants.
We, ALFRED HERBERT RANDOLPH of 6, Hertford Street, Mayfair, in the
County of London, Major, and GILBERT GILKES & Co., LTD., of Canal
Iron Works, Kendal, in the County of Westmoreland, Engineers, 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 :-
Our invention relates to an improved churn as hereinafter described.
According to our invention the churn consists of two bowls placed one inside the

page_text: other with means for revolving the same independently about a common axis. The
hbowls are preferably in the form of paraboloids of revolution, but other conics or
suitably curved surfaces may be employed.
In order that our invention may be clearly understood we will now proceed to
describe the same with reference to the accompanying drawings, in which
Figure 1 is an elevation partly sectional of a churn constructed in accordance
with our invention.
Figure 2 is a plan view of the same.
A is the frame adapted to support the axles of the bowls, and the driving
mechanism which consists in the example illustrated of a wheel B mounted on an
axle B' fixed to the frame A and adapted to be rotated by the handle B². C is
the inner bowl, D the outer bowl, and E an annular vessel for receiving the butter
milk. Said vessel E is secured to a hollow shaft E, rotating in bearings A, A²
in the frame A, and provided with a suitable pulley E which is driven by a.
belt E from the hand wheel B. E is a guide pulley round which the belt passes.
The inner bowl C is supported by arms C froin a hollow spindle C, and the top
of said spindle is also provided with arms C which are received in slots in the
upper rim of the vessel E. The outer bowl D is provided with a boss D' to which
is secured a spindle D which passes into the hollow shaft E being supported on a
bearing at or near the bottom of said shaft. Orifices D' and Es are provided in
the spindle and shaft through which the pin D may be passed when it is required
that the spindle should rotate with the shaft. In order to prevent the outer bowl
from rotating when desired we provide what we will call a stop rod consisting of a
rod F, the lower extremity of which is squared to fit in a square recess in the
boss D'. Said red is provided with an arm F by which it may be secured to the
frame A. The outer box! D is preferably provided with an external rim D* which
extends over the inner wall of the vessel E for a purpose hereinafter indicated.
Said vessel E has a tap at the bottom by which the butter milk may be drawn off,
and to facilitate this the bottom of said vessel may be inclined as shewn. When
the rod F and arm F¹ are removed the inner bowl can be lifted by the arms C³ C¹
and withdrawn from the apparatus. Said inner bowl has a portion of its apex
removed so that a circular orifice exists at the bottom. In the case of bowls
formed by parabolic curves the apex of the inner bowl is cut off at the plane formed
by the revolution of the latus rectum, in other cases the size of the orifice would
have to be determined by experiment. The distance between the orifice of the
inner bowl and the apex of the outer bowl is as small as possible consistent with
the prevention of choking by the accumulation of butter grains in the bottom. For
example in one churn constructed according to this invention wherein the outer
bowl is about 12 inches in diameter at the top, the distance hereinabove mentioned
is about one inch. The inner bowl is preferably of such a depth that its rim is
about the same distance below the rim of the outer bowl. A suitable cover for
the churn may be provided if desired, but we do not consider this advisable.
The operation of our improved churn is as follows:
The outer bowl is preferably filled to about half its depth with cream, and then
the inner bowl is inserted. The pin D is removed. and the outer bowl fixed by
the stop rod F F¹ to the frame A.. The shaft E is then driven so as to rotate the
vessel E und bowl C at the correct speed of discharge for the said bowl. The
speed of discharge will be hereinafter indicated. The cream rises in a film on
the inner surface of the bowl C and discharges over its top with more or less
velocity against the outer bowl. It would at first sight appear that the formation
of the butter is due to the impact of the cream against the outer bowl, but
experiment seems to shew that so far from this being the case it is important to
reduce the force of impact as much as possible in order to get the butter to come
satisfactorily. The action appears to be due primarily to the drawing of the
liquid into a film continuously. The churning is continued until the butter "comes
in the grain," when work is ceased the stop rod F' F may be removed, and the
inner bowl lifted out. The orifices D' E' in the spindle D3 and shaft E' are now

page_text: will therefore enable us to design a bowl of a inches focal length 16 a inches in
height of a capacity suitable for producing L pounds of butter. The design of an
inner bowl to suit the outer one previously designed is by no means a simple
matter. Naturally in order to facilitate the driving arrangements it would be
very convenient to make it of less steepness, that is to say, of greater focal length
than the corresponding outer bowl. The diagram Figure 3 in which R and Q are
parabolas of the same focal length placed one within the other shews at once that
if the inner bowl is to perform its function properly it is absolutely necessary that
it should be designed to a steeper curve. We have found that if the focal length
of the curve for the inner bowl be taken as about three quarters that of the outer
bowl a satisfactory result is attained. As we have abovementioned the apex of the
inner bowl is cut off at the latus rectum.
The speed of rotation of the bowls for discharging the liquid can be calculated

page_text: In churuing a cold draught must clearly be avoided when using open bowls such
as we have described, as previously stated we may provide a cover for the
apparatus, but such cover impedes aeration and inspection, and we do not consi ler
its use desirable.
The advantages obtainable by the use of our improved churn may be summarised
as follows-The parts are revolved at constant speed, and it is never necessary t
reverse the direction of rotation, free ventilation is secured throughout the churn,
which is also continuously open to inspection. Furthermore, cream may even with
advantage be churned at a high temperature, and if the cream is too thick the
churning action stops until water or milk is added, also during the process of
churning the cream cannot possibly "go to sleep." The action is slow but
thorough, and consequently we obtain a high yield of batter which is produced in
perfect grain and maintained so in subsequent operations. The butter milk and
wash water are extricated and the butter grains left behind intact without any
manipulation, and they may be further dried by revolving the churu. The butter
whilst in the churn being always in grain has no tendency to stick to the bowls
which may therefore be of metal, copper tinned or nickel plated, and aluminium
are found to be suitable materials of which to make the said bowls, the use of the
last named being however limited by difficulties at present existing as to soldering.
The churn is exceptionally easy to clean, and every part can be very readily
inspected.
We have described the bowls as being formed to parabolic curves and believe
that the best results can only be obtained with such curves, but we wish it
understood that we do not restrict ourselves in this respect. Furthermore, it is
not necessary that the outer annular vessel should be rotated with the inner bowl
although mechanical difficulties are obviated by this arrangement as shewn, any
suitable arrangement of driving gear may be employed and we may also vary the
other details of construction without departing from our invention..
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. A butter churn consisting essentially of two bowls which are adapted to be
independently rotated about a common vertical axis, one of said bowls having an
opening in its bottom and being located within the other bowl, and operating as
specified.
2. A churn constructed and operating substantially as described with reference
to Figures 1 and 2 of the accompanying drawings.
Dated this 5th der of March 1907
W. P. THOMPSON & Co.,
Of London, Liverpool, Manchester, and Birmingham,
Patent Agents for the Applicants.