being Applicable for Mixing Ground Substances with Liquid Substances Generally.
Year: 1887

page_text: - Date of Application, 19th May, 1887
Complete Left, 17th Mar., 1888
Complete Accepted, 27th Apr., 1888
being Applicable for Mixing Ground Substances with Liquid
Substances Generally.
I DAVID ESPLIN THOMSON of Gillespie Street Works, Edinburgh, in the County
of Midlothian, North Britain, Engineer do hereby declare the nature of this invention
to be as follows:-
This Invention, which relates to a new or improved machine for mixing dough for
bread making is also applicable for the mixing of ground or pulverized substances
with a liquid or liquids so as to form a pasty or plastic mass.
The machine consists of a box which is wholly or partly circular and mounted on
trunions. The box is provided with a lid at the top to enable the substances to be
mixed to be charged into the said box and to be discharged therefrom when required.
Within the box there are arranged a pair of cranks having helical stirrers or blades
carried thereon. One of these cranks is attached to a shaft which passes through a
sleeve attached to the other crank these again also passing through the trunions of the
aforesaid box.
The gearing for driving the cranks with the aforesaid helical blades thereon is
arranged so that the two cranks may revolve in the same direction within the box or
by applying reversing gear they may be driven in opposite directions. The arrange-
ment is such that by the action of the helical blades the substances to be mixed into a
plastic mass are, when the cranks are driven in the same direction, caused by the
action of the helical blades thereon to be worked towards the centre; and when the
cranks are driven in opposite directions whilst the one set of blades draws the material
to be mixed towards the centre the helical blades on the other crank tend to work the
substances being mixed from the centre towards the end. When it is required that
the substances being mixed shall be drawn wholly from the centre to the ends then

page_text: the two cranks with the helical blades thereon are both revolved in the direction
opposite to that herein before first stated which would draw the said mixed substances
towards the centre.
The machine is provided with the necessary clutches for throwing the different parts
into or out of gear when required and for the purpose of preventing or diminishing
the noise due to spur gearing, friction gearing is employed. When the substances
are thoroughly commingled and are ready for being removed from the box wherein
the commingling has taken place the box is turned over on its trunions to a sufficient
angle to allow the contents being discharged and this may be conveniently effected
by a pinion or a tangent screw gearing into a toothed rack fixed upon the said box.
Dated this 18th day of May 1887
J. H. JOHNSON, DAY & JOHNSON,
115, St. Vincent Street, Glasgow,
Petitioner's Agents.

page_text: A New or Improved Machine for Mixing Dough, the said Machine
being Applicable for Mixing Ground Substances with Liquid
Substances Generally.
I, DAVID ESPLIN THOMSON of Gillespie Street Works, Edinburgh, in the County
of Midlothian, North Britain, 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 :-
My Invention, which relates to a new or improved machine, for mixing dough for
bread-making is also applicable for the mixing of ground or pulverized substances
with a liquid or liquids so as to form a pasty or plastic mass.
The machine consists of a box which is wholly or partly circular and mounted on
trunnions. The box is provided with a lid at the top to enable the substances to be
mixed, to be charged into the said box and to be discharged therefrom when required.
Within the box there are arranged a pair of cranks having stirrers or blades carried
thereon. The inner of these cranks is attached to a shaft which passes through a
sleeve attached to the outer crank, these again also passing through the trunnions of
the aforesaid box.
The gearing for driving the cranks with the aforesaid stirrers or blades thereon is
arranged so that the two cranks may revolve in the same direction within the box, or,
by applying reversing gear they may be driven in opposite directions while the
relative speed of the blades to each other may be the same or differential. The
arrangement is such that by the action of the stirrers or blades the substances to be mixed
into a plastic mass are, when the cranks are driven in the same direction, caused by the
action of the stirrers or blades thereon to be worked towards the centre and when the
cranks are driven in opposite directions, whilst the one set of stirrers or blades draws
the material to be mixed towards the centre; the stirrers or blades on the other crank
tend to work the substances being mixed from the centre towards the ends. When
it is required that the substances being mixed shall be drawn wholly from the centre
to the ends, then the two cranks with the said stirrers or blades thereon are both
revolved in the direction opposite to that hereinbefore first stated which would
draw the said mixed substances towards the centre.
The machine is provided with the necessary clutches for throwing the different
parts into or out of gear when required and for the purpose of preventing or
diminishing the noise due to spur gearing, friction gearing may be employed.
When the substances are thoroughly commingled and are ready for being removed
from the box wherein the commingling has taken place, the box is turned
over on its trunnions to a sufficient angle to allow of the contents being discharged
and this may be conveniently effected by a pinion or a tangent screw gearing into a
toothed rack fixed upon the said box.
In order that my Invention may be properly understood and readily carried into
effect, I have hereunto appended 9 sheets of drawings shewing three modifications
under which my Invention may be carried into practice and in the several Figures of
which corresponding parts are marked with the same letters of reference. Of these
drawings Figure 1, is a front elevation partly in section and Figure 1*, a detail
hereinafter explained.
Figure 2, is a plan and Figure 3, an end elevation looking at that end of the
machine marked Z, in Figures 1 and 2, illustrating the first modification of my

page_text: Invention. In these Figures the general framing of the machine is marked A. In
this framing there is carried the mixing box B, which is supported in hollow journals
or trunnions B¹, carried in bearings in the frame A, as shewn more particularly at
Figures 1 and 2, and on which it is capable of being rotated through a sufficient angle
for discharging the dough when required, and of being moved back again into its
normal position for receiving a fresh charge of dough-mixing materials. Within
the box B, there are carried the two cranks C, and D, on each of which there are
fixed the helically situated stirrers or blades C', and D¹. The outer or larger crank C,
is fitted with hollow or trunnion bearings a, as shewn more particularly in section at
the right hand side of Figure 1, and on the outer parts or ends of these bearings the
large spur wheels C³, are fixed for rotating the said crank C, with its stirrers C¹, as
hereinafter described. Within the trunnions a, of the large or outer crank C, the
journals b, of the inner or smaller crank D, are carried, these journals 6, extending
sufficiently far beyond the outer ends of the hollow journals or trunnions a, to receive
and to carry the spur wheels D', by which the inner crank D, and its stirrers D¹, are
driven as hereinafter described. The upper part of the box B, is formed with a lid B₁,
connected by a hinge across the centre of the top of the box and which may be fastened
when shut down by any suitable contrivance for retaining it closed. The purpose of this
door B', is to enable the dough when ready to be taken out of the mixing machine to
be easily discharged from the said box B, through the opening covered by the door B¹,
this opening extending the whole width of the box and being of sufficient size to
enable the entire contents of the box in the condition of dough to be discharged in one
piece or lump; the said piece or lump of dough falling out of the box B, by its own
weight when the said box is turned over through a sufficient angle to bring the mouth
of the box B, downwards, that is to say in its lowest position, in place of in its
uppermost position, namely the position shewn in Figures 1, 2, and 3, of the annexed
drawings. The upper part of the box B, is also provided at the side farthest from the
door B, with charging spouts B', by which the flour and other material for mixing
into dough are charged into the machine from a flour loft above. These spouts are
preferably provided with doors to exclude dust or extraneous matter from getting into
and becoming admixed with the dough mixing materials. The charging spouts B², are
also preferably inclined from each other, that is to say, towards the ends of the dough-
mixing box B, for the purpose of the better distribution of the dough-mixing
materials within the box B, at the time of charging the said materials thereinto.
At one end of the machine the driving pulleys E, F, and G, are situated, these
being carried upon the driving shaft H, which is mainly supported in bearings attached
to the frame A, and whose, outer end is carried in the outer bearing H₁, Figures 1,
and 2. From this shaft H, the several motions used in driving the machine are
obtained. At either end of the shaft H, a spur pinion H', is carried. These spur
pinions H, each respectively gear with large spur wheels C, and through them rotate
the large or outer crank C, and its attached helical or straight stirrers C¹, within the
dough mixing box B. On the shaft H, there are carried two pinions H³, and H.
The pinion H, gears into another pinion H³, directly, causing it to rotate on the
shaft H', in one direction. The pinion H, gears into an intermediary pinion H',
Figure 2, rotating loosely on the stay shaft H, Figure 2. This intermediary
pinion H, in turn gears into the pinion H, seen more particularly in Figures 2 and 3.
Both clutch pinions H and H, rotate on the shaft H', and give motion to it in either
direction by means of the engaging clutch W, actuated by the lever L. On the ends
of the shaft H, are other toothed pinions H8, which gear into the large spur
wheels D, for driving the inner and smaller crank D, with its helical stirrers D'.
When the driving belt is running upon the outer pulley G, it rotates the shaft H, at
the same speed as the pulley revolves, but when it is on the driving pulley E, which
is carried loosely upon the shaft H, and with which is connected the spur pinion I,
motion is given to the shaft J, by the pinion I, gearing into the spur wheel J, on the
said shaft. The shaft J, also carries upon it the spur pinion J³, which in turn gears
with the spur wheel J, and this causes the shaft H, to revolve at a slower speed and
correspondingly greater power,

page_text: When the pulley G, revolves with the driving belt and carries the shaft at the same
speed the pulleys E, and F, together with the gearing 1, J, J', and J', remain at rest.
When the belt is shifted to the pulley E, motion is given to the spur wheel I, and
thence to the spur wheel J¹, and J, causing the spur wheel J, to rotate at a slower
speed than the pulley E. The wheel J³, engages with the shaft H, automatically by
means of the sliding cotter J, as shown in detail at Figure 1, passing through the
shaft H, and working in the boss of the wheel J', which as shewn is formed with
three recesses a, a', and a², one edge or face of each of which is flat and against
which one end of the sliding cotter engages, being forced against the said face by the
curved face of the opposite recess pressing against the opposite end of the cotter by
the action of rotation of the wheel J. The sliding cotter it is here explained engages
with any one of the flat faces of the recesses a, a', or a', with which it first comes
into contact. The sliding cotter Jª, disengages itself when motion is again given to
the pulley G.
When it is desired to run the machine at the fast speed in the initial stage of the
process of making dough, this is done by shifting the belt to the pulley G, and when
the more powerful speed is desired this is attained by shifting the belt to the pulley E.
The belt prongs O¹, and O' are actuated by a lever M.
When the dough constituting material is thoroughly mixed and the dough is in a
finished state ready to be removed from the mixing box B, the driving belt is stopped
and all the parts of the machine brought to a state of rest. The mixing box B, is then
turned over on its trunnions in the direction of the large arrow at the upper right
hand side of Figure 3, of the annexed drawings. This turning over of the box B, is
effected by means of the tangent screw K, shewn in dotted lines at Figure 3, gearing
into the worm-wheel segment L', attached to one side of the mixing box B. The
tangent screw K, is carried upon the shaft K1, Figures 1 and 3, which is formed with
a square end as shewn at Figure 3, for the purpose of receiving the handle for
rotating it. It will be obvious that by means of the tangent screw K, acting upon
the worm-wheel segment L', that the mixing box B, can be moved by rotation in
either direction into any required position.
The machine is provided with a handle or lever M, pivoted at its lower end and
connected to the sliding bar N, on which the prongs 01, and O', constituting the belt-
forks are carried and by means of this the driving belt is shifted to or from any one
of the driving pulleys E, F, or G, as required.
Figure 4, is a side elevation partly in section shewing my new or improved dough-
mixing machine with the second modification of gearing for driving it.
Figure 5, is a plan of the same.
Figure 6, an end elevation thereof looking in the direction of the end marked X,
in Figures 4, and 5.
Under this second modification one driving pulley E, only is used. This pulley E,
is formed with a large boss at the centre which fits over a clutch P, preferably formed
of steel. The clutch is made in two pieces and recessed as shown. Between the
pieces is placed a gun metal or other bush P¹. The clutch P, rotates upon the shaft H,
and is held in position longitudinally by the bolt P2, and cotter passing through
longitudinal slots in the shaft H, and fixed in the bolt P³.
When it is desired to give motion to the shaft H, the lever q, shewn in plan at
Figure 5, is pushed outwards. This draws the bolt P', in the centre of the shaft H,
in the same direction and causes the bush P1, to be also moved longitudinally outwards.
The bush P¹, carrying the clutch P, is thus caused to engage with the clutch P³,
which is fixed upon the shaft H, and thus the pulley E, becomes engaged with the
said shaft H, and drives it. The clutches P, P, P, and P, are formed with teeth
which engage with each other as is well understood and as shewn at Figure 4.
To work the machine with a slow or "purchase" speed, the lever q, is pushed
inwards thus moving the pulley E, longitudinally on the shaft H, in that direction and
causing the teeth of the clutch P, to become engaged with the clutch P. The
clutch P, is fixed upon the spur wheel I, which runs loosely upon the shaft H, and
motion is given to the shaft H, by the wheel I, gearing into the wheel J', upon the

page_text: shaft J, thus actuating the pinion J', which gears into the spur wheel Jo, fixed upon
the said shaft H. Upon the pulley O, Figure 4, is a strap working in the flanged
pulley R. Attached to the pulley R, is the pinion S, Figure 6, this runs on a stud and
gives motion to the pinion S₁. The position of the shaft T, is such that the centre
of it, the centre of the pinions S, and S¹, and the centre of the pulley O, are in a
direct line when the pinion T¹, is not in gear with the pinion S¹. By moving the
lever R², downwards the pinion S1, is thrown into gear with the pinion T', which in
turn causes the shaft U, to rotate by means of bevil pinions secured on the shafts T³,
and U. This gives motion to the worm shaft K¹, with its worm screw K, by means
of a pitched chain k, running on the sprocket wheels K', and causing the box B, to
rotate forward on its trunnions to the necessary angle for discharging its
contents.
By moving the lever R², in the opposite direction the pinion S, engages with the
small spur wheel T¹, and gives a reverse motion to the shaft T. This actuating of the
shafts U, and T³, in the reverse direction causes the shaft K', and worm screw K,
thereon to move the box back to its proper or normal position for working a fresh
charge of material.
This description of apparatus for mechanically tilting the box B, is suitable for all
sizes of my said machine but is specially adapted for larger machines only and it also
applies to the other modification shewn at sheets 7, 8 and 9.
I do not expressly confine myself to this method of self tilting but may carry it into
effect by means of working it from shafts H, or H', and likewise by either friction
gearing or cone friction clutches.
Figure 7, of the annexed drawings is a front elevation partly in section of a third
modification of gearing for driving my improved dough mixing machine.
Figure 8, is a plan corresponding to Figure 7, and Figure 9, an end elevation of
the same.
In this arrangement a single driving pulley E, also is used and it is formed on one
half of a conical clutch.
On the boss of the pulley E, Figure 7, is placed a friction wheel E¹, and a grooved
or belt wheel O. Between the friction wheel E, and the belt wheel O, is a space in
which a bush P¹, is fitted which gives motion to the pulley E, longitudinally, the said
bush being actuated by the bolt P, situated in a central hole in the shaft H, and
communicating with the bush Pl, by means of a cotter passing through the bush P',
shaft H, and fixed to the bolt P³, as shewn. The bolt is pushed in by means of the
hand wheel Q, screwed on the shaft H, Figure 7, which as it is turned in one direction
causes the pulley E, to engage with the cone E³, This cone E³, being fixed to the
shaft H, it is obvious motion is thus communicated to it at the same speed as that at
which the pulley E, revolves.
When it is desired to work the machine at a slow or "purchase" speed, the machine
is stopped by holding the hand wheel Q until motion ceases, to be communicated to
the cone E, that is to say until the action of the screw upon the end of the shaft H,
has drawn the conical surfaces of the pulley,E, and clutch E2, out of frictional contact,
when the wheel E', and pulley E, revolve loosely on the shaft H.
By moving the hand wheel V, it rotates a worm V, working in the wheel V¹, thus
causing the eccentric shaft V2, to revolve sufficiently to engage the friction wheels E¹,
and E, and as the wheel E, carries with it the pinion J³, gearing with the spur
wheel J, this gives motion to the spur wheel J³, and through it drives the shaft H, at
the slow or "purchase" speed.
The motion to the shaft K, for tilting the box B, B, for discharging the contents
may be given by hand as shewn in Figures 1, 2, and 3 or by a mechanical tilt as
shewn on the sheets 4, 5 and 6, and sheets 7, 8 and 9 and the description of this part
relating to sheets 4, 5 and 6 equally applies to this modification.
It is to be understood that although I have described and on the annexed drawings
have shewn my dough mixing machine as having the dough mixing box B, mounted
upon trunnions yet in place of so mounting it the box B, may be a fixture in which
case it is constructed with a discharging door at the lower part thereof. The cranks

page_text: C, and D, with their blades C, and D¹, are preferably made as steel castings but they
may be made of cast iron rendered malleable by the well-known process of making
what is known as "
malleable cast iron," and in place of forming the said blades C,
and D', in one piece with the cranks C, and D, they may be formed separately and
bolted or otherwise attached thereto.
Having now particularly described and ascertained the nature of my, said Inven
tion, I desire to observe in conclusion that although I have set forth and shewn upon
the annexed sheets of drawings three systems or modifications of gearing which are
at the present time the best known to me for producing the requisite variations in the
movements of the inner and outer cranks C, and D, with their helical straight and
oblique blades C¹, and D¹, yet I do not wish it to be understood that my Invention is
limited to the actuating of the cranks and blades C, C¹, and D, D¹, by the said
systems of gearing only, as other systems of gearing may be used for producing the
aforesaid variations of motion of the aforesaid cranks and blades, but what I
claim is :-
1. A dough mixing machine wherein a pair of concentric cranks provided with
straight and oblique stirrers or blades are rotated within the dough mixing box and
extending across the entire width of the box, the said cranks and blades being
caused to rotate either in the same direction, at the same speed or at different speeds
or in opposite directions at equal or different speeds and operating upon the dough
mixing materials substantially as herein before described and shewn on the annexed
sheets of drawings.
2. In a dough mixing machine, the dough mixing box within which the cranks and
mixing blades rotate, the said box being mounted on trunnions coaxial with the axes
of the cranks and capable of being rotated upon the said trunnions for the purpose of
discharging the dough and for being returned to its normal position; the said box
being also provided with a discharging door and otherwise constructed and fitted
substantially as hereinbefore described and shewn upon the annexed drawings.
3. The system of gearing for driving the cranks C, and D, with their stirrers C¹,
and D¹, in the same direction and at the same speed or in the same direction at
different speeds or in opposite directions at equal or different speeds as hereinbefore
described and shewn at Figures 1, 2 and 3, of the annexed drawings.
4. The system of gearing for driving the cranks C, and D, with their stirrers C₁,
and D', in the same direction and at the same speed or in the same direction at
different speeds or in opposite directions at equal or different speeds together with the
sprocket wheels and chains and relative gearing for operating the mixing box B,
as hereinbefore described and shewn at Figures 4, 5 and 6 of the annexed
drawings.
5. The system of gearing for driving the cranks C, and D, with their stirrers C¹,
and D', in the same direction and at the same speed or in the same direction at
different speeds or in opposite directions at equal or different speeds together with the
sprocket wheels and chains and relative gearing for operating the mixing box D, as
hereinbefore described and shewn at Figures 7, 8 and 9.
Dated this 16th day of March 1888.
ST. JOHN V. DAY,
115, St. Vincent Street, Glasgow,
Applicant's Agent.