IMPROVEMENTS IN MACHINERY FOR MIXING AND KNEADING
Year: 1881

page_text: LETTERS PATENT to John "Melvin, of Glasgow, in the County of Lanark,
North Britain, Engineer, for an Invention of "IMPROVEMENTS IN MACHINERY
FOR MIXING AND KNEADING,"
PROVISIONAL SPECIFICATION left by the said John Melvin at the Office
of the Commissioners of Patents on the 25th October 1881.
JOHN MELVIN, of Glasgow, in the County of Lanark, North Britain, Engineer.
"IMPROVEMENTS IN MACHINERY FOR MIXING AND KNEADING."
This Invention has for its object to improve and simplify the construction and to
improve the action of machinery for mixing and kneading, and which is suitable
for making dough and for other similar purposes.
The vessel or box into which the materials to be mixed or kneaded are put is
The
made with vertical ends, and with a curved bottom having vertical sides.
vessel is formed with trunnions by which it is supported in bearings in frame
standards, and it can be turned on these trunnions about a horizontal axis for the
purpose of emptying it. Three rotating mixers are fitted to work inside of the
vessel, their axes of rotation being horizontal with the middle one a little lower
than the lateral ones; and the bottom is curved to suit the sweeps of the mixers so
that these may in turning pass almost in contact with it. The middle mixer is
fixed on short shafts which pass through the trunnions and which have spurwheels
fixed on them externally and gearing with pinions on a first-motion or driving
shaft. The lateral mixers are also fixed on short shafts, and these shafts pass
through bosses on the ends of the vessel and have small spur wheels fixed on them
externally to gear with similar spurwheels fixed on the shafts of the middle mixer.
The frame standards are shaped so that the bosses for the shafts of the lateral
mixers, which bosses project over the frames, act against them as stops for the two
positions in which the vessel has to be placed. The two lateral mixers are alike,
each consisting of three longitudinal bars held by curved or straight arms at the
ends. Of the three bars of each lateral mixer the two outer ones are diametrically

page_text: opposite and the other one is placed so as to allow of the action of the middle
mixer. The middle mixer is made with one or two longitudinal bars, and it carries
these bars through parts of the spaces passed through by the lateral mixers. The
outer bar of the middle mixer passes over or beyond the axial or central part of
each of the lateral mixers in turn, and the outer bars of the lateral mixers, each in
its turn, passes over or beyond the axial or central part of the middle mixer. The
end arms of the several mixers are curved or shaped so as to clear each other and
to admit of the overlapping movements taking place. The overlapping movements
considerably improve the mixing and kneading action and the several longitudinal
bars coming frequently almost in contact with each other keep each other clear
and exert an efficient dividing action on the materials. The longitudinal bars are
by preference formed with a slight helical curvature or twist in order that when
they approach each other the action may not be simultaneous along the entire bars
but gradual.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Melvin in the Great Seal Patent Office on the 22nd April
1882.
JOHN MELVIN, of Glasgow, in the County of Lanark, North Britain, Engineer.
"IMPROVEMENTS IN MACHINERY FOR MIXING AND KNEADING."
My said Invention has for its object to improve and simplify the construction
and to improve the action of machinery for mixing and kneading, and which is
suitable for making dough and for other similar purposes.
The vessel or box into which the materials to be mixed or kneaded are put is
formed with trunnions, by which it is supported in bearings in frame standards,
and it can be turned on these trunnions about a horizontal axis for the purpose of
emptying it. Three rotating mixers are fitted to work inside of the vessel, their
axes of rotation being horizontal, and the bottom is curved to suit the sweeps of
the mixers so that these may pass almost in contact with it. The two lateral
mixers are alike, each consisting of three longitudinal bars held by arms at the
ends. The middle mixer is made with one longitudinal bar and it carries its bar
through parts of the spaces passed through by the lateral mixers. The bar of the
middle mixer passes over or beyond the axial or central part of each of the lateral
mixers in turn, and the outer bars of the lateral mixers each in its turn passes over
the central part of the middle mixer. The overlapping movements considerably
improve the mixing and kneading action, and the several longitudinal bars coming
frequently almost in contact with each other keep each other clean and exert an
efficient dividing action on the materials.
And in order that my said Invention and the manner of performing the same
may be properly understood, I hereunto append a Sheet of explanatory Drawings
to be hereinafter referred to, and representing a mixing and kneading machine as
made with my improvements.
Figures 1 and 2 on the accompanying Sheet of Drawings are side and end
elevations of the machine, the latter being partly in section; Figure 3 is a plan
partly in horizontal section; and Figure 4 is a transverse vertical section. In these
Drawings, the same reference numerals are used to mark the same or like parts
wherever they are repeated.
The vessel or box 5 in which the mixing or kneading is effected is made with
vertical ends 6, and with a curved bottom 7, the longitudinal sides 8, 9, being one
vertical and the other slightly inclined. Trunnions 10 are fixed on the ends 6 and
rest in bearings in frame standards 11, and the vessel 5 can be turned on these
trunnions for the purpose of emptying it. Three rotating mixers 12, 18, 14, are
fitted to work inside of the vessel 6, their axes of rotation being horizontal and at
the same level, or nearly so, and the bottom 7 is curved to suit the sweeps of the
mixers, so that these in turning may pass almost in contact with it. The middle
mixer 13 is fixed on short shafts 15 which pass through the trunnions 10 and
which have spur wheels 16 fixed on them externally and gearing with pinions 17
on a first-motion driving shaft 18, having on it fast and loose pulleys 19 for a
driving belt. The lateral mixers 12, 14, are also fixed on short shafts 20, and these
shafts pass through bosses on the ends 6 of the vessel, and have small spur-
wheels 21 fixed on them externally to gear with similar spurwheels 22 fixed on the
shafts 15 of the middle mixer 13, and which may, as shown, be made in the same
pieces with the large spurwheels 16.
The frame standards 11 are shaped so that the bosses for the shafts 20 of the
lateral mixers 12, 14, which bosses project over the frames, act against them as
stops for the two positions in which the vessel has to placed. The vessel is
turned down for emptying by means of a worm 23, the spindle of which is made

page_text: with a square end to receive a key or handle, and the worm 28 gears with a toothed
aro 24 fixed on one end of the vessel. When the vessel is turned up it is locked
in position by two bolts 25 which enter sockets at the ends 6, these bolts 25 being
connected to levers 26 on a shaft 27, on one end of which there is a hand lever 28.
These bolts 25 prevent the vessel from being turned over by the action of the
mixers, and by acting on both ends of the vessel they keep it steady and take
strain off the toothed are 24 and wormwheel 23.
The two lateral mixers 12, 14, are alike, each consisting principally of two
longitudinal bars which are diametrically opposite and equally distant from the
centre. There is in each case a third longitudinal bar 29 close to the centre, but
this bar having no appreciable mixing action on the materials serves principally
for cleaning the bar of the central or middle mixer 13. The outer bars of the
lateral mixers 12, 14, move almost in contact with lateral parts of the bottom 7 of
the vessel, whilst the single bar of the middle mixer 13 moves almost in contact
with the middle part of the bottom which is not reached by the lateral mixera.
In this way the three mixers are continually removing the materials from the
surface of the bottom, whilst at other parts of their courses they have a very
effective dividing and mixing action on the main body of the materials.
longitudinal bars of the mixers 12, 13, 14, are by preference formed with a very
slight inclination or helical twist in order that when they approach each other the
action may not be simultaneous along the entire bars, but gradual.
The
The vessel is provided with a cover, which is not shown in the Drawings, bat
which is by preference of wood and hinged to the top of the highest side 9,
and made with a part at right angles to the top to extend down to the top of the
other side 8.
Having thus particularly described my said Invention, and the manner of
performing the same, I have to state that I do not restrict myself to the
precise details herein described or delineated, but that what I believe to be
novel and original and claim as the Invention secured to me by and in terms of the
hereinbefore in part recited Letters Patent is,-
1. The arranging or combining together of the parts of machines for mixing and
kneading, substantially in the improved manner hereinbefore described.
2. The combination of the three mixers placed with their axes at about the
same level, the two lateral or outer mixers having three longitudinal bars, two of
which are diametrically opposite and equally distant from the centre, the third
being in or close to the centre, whilst the middle mixer has a single bar, which, in
rotating, comes nearly in contact with the central bars of the lateral mixers, the
parts being arranged and operating substantially as hereinbefore described.
In witness whereof, I, the said John Melvin, have hereunto set my hand and
seal, this Twenty-first day of April, in the year of our Lord One thousand
eight hundred and eighty-two
Witness,
EDMUND HUNT,
Patent Agent,
Glasgow.
JOHN MELVIN. (LS)