IMPROVEMENTS IN CHURNS
Year: 1881

page_text: LETTERS PATENT to Norman Stewart, of Hazel Grove Park, Hayward's
Heath, in the County of Sussex, for an Invention of "IMPROVEMENTS IN
CHURNS." A communication from abroad by Archibald Stewart, of Ottawa,
Canada
PROVISIONAL SPECIFICATION left by the said Norman Stewart at the
Office of the Commissioners of Patents on the 6th August 1881.
NORMAN STEWART, of Hazel Grove Park, Hayward's Heath, in the County of
Sussex, "IMPROVEMENTS IN CHURNS." A communication from abroad by Archibald
Stewart, of Ottawa, Canada.
This Invention is recommended by the simplicity of its construction, and by the
"dashes," no internal
economy it effects in both time and power; it has no
apparatus whatever, and yet its productive quality far surpasses that of the most
elaborate churn.
I effect these improvements mainly by the character of the movement which I
give to the cream or other matter in the churn, a movement which needs no costly
machinery to effect. The external form of the churn is optional. It is to the
peculiar configuration of the interior to which is chiefly due the effective direction
imparted to the particles composing the liquid to be operated upon. A longitudinal
section of the churn would afford in the lines immediately representing the section
of the internal surface curvatures very similar to those presented by the figure
in the position shown, the centre of the figure being removed. To the
body of the churn I give a rocking or an oscillating movement. The material to be
operated upon being admitted into the churn, and a movement imparted to it as
aforesaid, it will be obvious that this rocking or oscillating action given to the
matter will tend to force it to pass in quick successive motion from end to end of
the interior; it is now that the importance of the special shape given to the internal
surface of the churn is perceived. Instead of dashing forward in a direction more
or less horizontally inclined, the matter is deflected from such a course by the
peculiar curviture which is given to the interior surface of the churn. Necessarily
rapid in its movement the matter is compelled to take a certain course, the central

page_text: line of which literally represents the figure eight, and the stream of fluid is made
to intersect at the centre of the churn. It is to the peculiar nature of this con-
cussion and intermingling of the component particles of the matter operated upon
that is to be attributed the superiority of the products of my Invention.
. Another great improvement resulting from the form I give to my apparatus is
that any amount of air can be admitted into the churn without the slightest
difficulty. As, during its course, the cream or other matter approaches the top of
the churn it takes a downward direction, and not a particle comes in contact with
the central part of the upper surface of the machine; thus, apertures may be made
in that surface through which air can enter, but no grain of internal matter can
make an exit.
The means which I adopt to impart that peculiar oscillation to the churn which
will best aid in directing the matter in the churn to follow the course already
described consists in supporting the churn on its underside by movably jointing it
to the upper end of a vertically oscillating lever pivoted to the churn frame. The
movements and oscillations are produced by a crank in such a way that when the
churn is directly over the lever, and the crank is on its upper centre, the end of
the churn opposite to the crank pivot is lower than the end attached to the crank;
and when the crank, during its revolution, reaches its lower centre, then a reverse
position of the churn is effected, and so on alternately.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent and,
of an Order of the Lord Chancellor filed by the said Norman Stewart in the
Great Seal Patent Office on the 3rd March 1882.
NORMAN STEWART, of Hazel Grove Park, Hayward's Heath, in the County of
Sussex. "IMPROVEMENTS IN CHURNS." A communication from abroad by Archibald
Stewart, of Ottawa, Canada.
The churn which is the object of this Invention is recommended by the
simplicity of its construction and by the economy it effects in both time and
power. It has no "dashers," no internal apparatus whatever, and yet its
productive quality far surpasses that of the most elaborate of its competitors.
I effect these improvements mainly by the character of the movement which I
give to the cream or other matter in the churn. The external form of the churn is
optional. It is to the peculiar configuration of the interior to which is chiefly due
the effective direction imparted to the particles composing the liquid to be operated.
upon. A longitudinal section of the churn would afford, in the lines representing
the section of the internal surface, curvatures very similar to those presented by
the figure ∞ in the position shown, the centre of the figure being removed.
To the body of the churn I give a rocking or an oscillating movement by means
herein-after described. The material to be aperated upon being admitted into
the churn, and an oscillating movement imparted to it, there will obviously result
from this oscillation a quick successive motion of the matter from end to end of
the churn. It is now that the importance of the special shape given to the
internal surface of the churn is perceived. Instead of dashing forward in a
direction more or less horizontally inclined, the matter is deflected from such a
course by the peculiar curvature which is given to the internal surface of the
churn. Necessarily rapid in its movement, the matter is compelled to take a
certain course, the central line of which literally represents the figure 8, and
the stream of fluid passes through the centre of the churn. It is to the peculiar
nature of this intermingling of the component particles of the matter operated
upon that is to be attributed the superiority of the products of my Invention.
Another great improvement resulting from the form I give to my apparatus is,
that any amount of air can be admitted into the churn without the slightest
difficulty. As during its course the cream or other matter approaches the top of
the churn it is forced by the peculiar form of the surface which it encounters to
take a downward direction, so that not a single particle comes in contact with the
central part of the upper surface of the machine. Thus apertures may be made
in that surface through which air can enter, but no grain of internal matter can
make an exit.
The means which I adopt to impart that peculiar oscillation to the churn which
will best aid in directing the matter in it to follow the course already described
consists chiefly in supporting the churn on its under side by moveably jointing it to
the upper end of an oscillating lever pivoted to the churn frame.
That my Invention may be more fully understood, I will now, with the aid of
the illustrations shown on the Sheet hereunto annexed, proceed to give a minute
detail of its various parts and movements.
Figure 1 is an elevation of the churn with its sustaining frame and the various
parts of the mechanical appliances by which I give to it the necessary oscillating.
movement. Figure 2 is a longitudinal section of the churn, and Figure 3 a cross
section through the line Y, Z, showing the peculiar form of its interior surface.
The object for which this form was finally given to the churn will be fully shown
hereafter. In the mean time I will describe the parts which are necessary
additions to the churn. In Figure 1, A is a rod or lever jointed or articulated at
its lower end to the frame B, which supports the churn H. To that frame it is
united by means of a pivot.. The upper end of the rod is articulated and united

page_text: in a similar manner to the body of the churn. Thus it is shown on the Figure,
but the rod and its pivots may be variously associated with the churn. To
complete the mechanical means of giving a rocking or an oscillating motion to the
churn thus suspended by the said rod and its pivots, I make use of a crank C, as
shown, or of an eccentric. The degree of inclination to which this crank is
designed to tilt the churn is not rigidly determined; but the easy and uncon-
strained action of the body of the churn should be kept in view; all violent or
unnecessary strain either upon the crank or the pivots should be avoided. The
crank works freely within a bearing D, which in the example given is fixed to the
body of the churn, but both the crank and its bearing may be placed in positions
apart from the body of the churn. The ends of the crank shaft rest on bearings
fixed to the churn-frame B. To one end of this shaft a hand-wheel E is fitted, so
proportioned as to afford a reasonably easy leverage for the working of the churn.
If necessary, steam power may be communicated to the shaft.
Some latitude may be permitted to the form which the churn should assume. I
prefer to give it an oblong shape, proportioned somewhat as shown in the Figures.
No doubt it is indispensable that the internal ends of the churn should be curved,
but whether semicircular, or more or less elliptical, is optional. It is also indis-
pensable to my churn, for it forms a part of my Invention, that the upper surface
of the inside of the churn should be slightly curved, as shown in the section, Fig. 2.
A curved bottom to the churn also forms part of my Invention, but this is not so
important; the churn may have a level bottom. The important objects which
this curvature is intended to effect will be seen in the following description of the
action and working of the churn.
Suppose the churn, which is made of any suitable material, choice in this case
has a very wide latitude, to be in the horizontal position represented on the
Drawing, it will follow that the crank C will be in the same position. Give
motion to the wheel E and the crank being then forced to turn will in its course
present itself at the point where it is shown by dotted lines, that is to say, at right
angles to a horizontal line, and therefore at its greatest elevation. That end of the
churn to which the crank is articulated as aforesaid being constrained to follow
the movement of the crank, will also have achieved its most elevated position, a
position which is shown on the Drawing by dotted lines. At this point commences
the reactive or reciprocating motion of the churn. Continuing the action of the
crank the churn will still move onwards but towards the resumption of a hori-
zontal position, to which it arrives when the crank is in a similar state. Following
its prescribed course the crank will now begin to raise the opposite end of the
churn until, in its downward course, it again reaches a vertical position, thereby
raising the said end of the churn to its highest point, and where it would present
a similar inclination to that already represented by dotted lines, but in a strictly
reversed position. Pursuing its course the crank will at length complete a single
revolution, raising at the same time the depressed end of the churn and resume the
position which it is seen to hold on the Drawing.
I have described special mechanical means for producing the oscillating
movement of my churn; but without changing the distinctive method employed,
the arrangement of the details of which it is composed may in various ways be
modified.
Let the churn be now set really to work, and the perfectly satisfactory effects
resulting from the movement first described upon the matter destined for conversion
into butter will be seen.
The degree of activity to be given to the movement of the churn is a point
which must be regulated in great measure by the judgment of the dairyman.
Assuming about a medium action the matter to be operated upon will, more or less
rapidly, pass with a continuous successive motion from end to end of the churn-
chamber. In order that this alternating movement of the matter should be so
regulated that it shall have the greatest productive effect in converting the said
matter into butter of the highest possible quality, I give a slightly curved form to

page_text: the central part of the top of the interior of the chamber. In like manner the
bottom surface instead of being straight may also be curved. This peculiarity of
form is shown in Figure 2. It might indeed be produced by two curves meeting,
leaving an edge at their junction. The degree of inclination to be given to this
curvature is to be regulated by the amount of deflection necessary to guide or
force the moving matter in the churn to take a prescribed course. For this
purpose the curves are so designed that the matter to be operated upon is con-
strained to flow in a continuous rapid course from end to end of the chamber in
such a manner that after it has made one complete forward and backward
movement it continues to represent whilst in motion a form similar to the figure ∞,
as shewn by the arrows in Fig. 2. This peculiar movement tends to realise the
best results of which churning is capable.
The facility and freedom moreover with which air is admitted into my churn
aid materially towards the perfection of such results. Air is an element absolutely
necessary for the due conversion of cream into butter. The difficulty of conveying
air into the churn-chamber which has resulted in a frequent insufficient supply of
that element has hitherto caused much perplexity in the dairy and the appearance
of very inferior butter in the market. The peculiar course taken by the matter in
my churn simply and entirely obviates this difficulty. By glancing at Figure 2 it
will be observed that at no point during its alternate backward and forward course
does the matter, or can the matter, in the churn come in contact with the centre
of the chamber, or with any point within a certain distance of the centre. In the
area thus left free at the upper part of the churn I make an opening of ample
dimensions and fit it with a cover marked G, Figure 2. In this cover abundant
perforations may be made for a fully adequate supply of air. A novel method of
admitting air into the chamber is by means of two air funnels a fixed in the
cover G, one for the admission, the other for the emission of air in accordance with
the oscillation of the churn. Thus the peculiar course and action which my im-
provements impose upon the matter in the churn not only produce a thorough and
effective commingling of the particles of the matter but leave part of the upper
surface of the churn untouched by the cream or other material operated upon, and
so the greatest facility is given for a due supply of air.
Having thus described the Invention communicated to me, I conclude by
observing that no restriction. is intended to the precise forms and details
herein-before set forth, but what I claim as new and desire to secure by Letters
Patent is,
First. The construction of churns having the transverse middle part of the upper
and lower surfaces of their interior curved convexly, substantially as herein-before
described.
Secondly. The construction of churns having the transverse middle part of
their upper internal surface curved convexly, their lower internal surface
being flat.
Thirdly. The combination and application of certain mechanical appliances
for giving a rocking or an oscillating movement to churns, substantially as herein-
before described.
Fourthly. The application and use of air funnels adapted to churns as described.
In witness whereof, I, the said Norman Stewart, have hereunto set my
hand and seal, this First day of March, in the year of our Lord One
thousand eight hundred and eighty two.