IMPROVEMENTS IN MACHINERY OR APPARATUS FOR ROASTING, GRINDING,
Year: 1881

page_text: LETTERS PATENT to John Parnall, of Narrow Wine Street, in the City and
County of Bristol, Scale and Weighing Machine Maker, for an Invention of
"IMPROVEMENTS IN MACHINERY OR APPARATUS FOR ROASTING, GRINDING,
PROVISIONAL SPECIFICATION left by the said John Parnall at the Office
of the Commissioners of Patents on the 22nd October 1881.
JOHN PARNALL, of Narrow Wine Street, in the City and County of Bristol, Scale
and Weighing Machine Maker. "IMPROVEMENTS IN MACHINERY OR APPARATUS
FOR ROASTING, GRINDING, AND MIXING COFFEE, CHICORY, AND OTHER LIKE
SUBSTANCES."
My Invention relates to improved machinery or apparatus for roasting, grinding,
and mixing coffee, chicory, and other like substances, whereby these operations or
any one of the same is or are more economically and more rapidly effected, and the
aroma or flavour of the said substances is more effectually preserved than in the
apparatus hitherto used.
In carrying the said Invention into practice I provide a cylinder or drum into
which I insert a series of tubes for the purpose of conveying heat to the interior,
and also for the purpose of carrying off the vapours which arise during the process
of roasting. An outer casing which surrounds the said drum is provided with
suitable outlets leading to a ventilating chamber for carrying off the products of
combustion and vapour.
The necessary heat for roasting is obtained by the combustion of a mixture of
gas and air conveyed through suitable burners.
To ensure uniform results and prevent overheating, the supply of gas is regulated
by an indexed gas tap controller or governor of improved construction, that is to
say, I provide a toothed rack mounted on a metal plate, and held in position by
guide plates. This rack is actuated by a metal worm formed on the front of a disc
Dains art

page_text: or circular plate, and also provided with a spindle which passes through the frame
or case containing the various parts. The said rack is fitted with a small arrow at
its upper end, and at the lower end is connected by wire or cord to the tap which
supplies the gas to the roaster.
For grinding the substances after they have been roasted I provide a mill
constructed with a movable side plate connected by pivoted set screws; this
arrangement readily admits of access to the interior of the mill for purposes of
cleaning or examination. The hopper or receiver of the said mill is provided with
a loose metal casing in the centre of which a cone is fixed. Surrounding this cone
and embedded in the casing are a number of magnets, which effectually prevent
the passage of nails or small particles of iron into the interior of the mill."
For mixing the substances I provide a cylinder or drum mounted on suitable
standards, and entirely surrounded with an iron casing except at the bottom, where
a drawer or hopper is provided to receive the contents of the cylinder after being
mixed. The said casing is provided with a hinged door to afford access to the
interior of the cylinder, which is formed with a slide or door for the purpose of
filling or emptying. The interior of the cylinder is provided at each end with a
steel spiral worm, the said spiral worms being nearly of equal diameter to that of
the cylinders at the ends, but gradually decreasing in diameter towards the centre,
where they intersect each other. This method of construction causes the substances
that are being mixed to continually gravitate towards the centre of the cylinder
by sliding over a series of smooth surfaces, whereby they are effectually and rapidly
mixed without being subjected to the friction or concussion which takes place in
other methods of mixing. The outer casing surrounding the cylinder effectually
prevents the dust or aroma from escaping when the contents of the cylinder are
being discharged into the drawer or other suitable receptacles.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John Parnall in the Great Seal Patent Office on the 22nd April
1882.
JOHN PARNALL, of Narrow Wine Street, in the City and County of Bristol, Scale
and Weighing Machine Maker. "IMPROVEMENTS IN MACHINERY OR APPARATUS
FOR ROASTING, GRINDING, AND MIXING COFFEE, CHICORY, AND OTHER like
SUBSTANCES."
My Invention relates to improved machinery or apparatus for roasting, grinding,
and mixing coffee, chicory, and other like substances, and is designed to afford
means whereby such operations may be performed more economically and rapidly,
and the aroma or flavour of the coffee or other substance more effectually preserved
than with the apparatus hitherto used for these purposes.
In practising my Invention I construct a machine with a roasting cylinder or
drum, into which I insert a series of perforated tubes for conveying heat to its
interior, and also for carrying off the vapours which arise during the process of
roasting.
The outer casing which surrounds the drum is provided with suitable outlets
leading to a ventilating chamber for carrying off the products of combustion and
vapour.
The necessary heat for roasting is obtained by the combustion of a mixture of
gas and air conveyed through suitable burners.
To ensure uniform results and prevent overheating the supply of gas is regulated
by an indexed gas-tap controller or governor.
I also provide a mill for grinding the coffee or other substances after they have
been roasted, and a machine for mixing granular substances.
My said Invention is illustrated in the accompanying Drawing, in which,—
Figure 1 is a side elevation.
Figure 2, an end elevation with portions removed; and
Figure 3, a plan or top view of an improved roasting cylinder constructed
according to the first part of my Invention.
a is the drum or cylinder to receive the substance to be roasted; a¹, a¹, are
perforated tubes which pass through the said drum and are supported at each end
by metal rings with holes formed therein; b is a ventilating chamber fixed on the
outer casing of the said cylinder provided with an outlet b', and communicating
with other outlets 6s formed in the casing for the purpose of carrying off the waste
heat and vapour; 6 is an inlet formed in the ventilating chamber, and provided
with a sliding cover for conveying the substance to be roasted into the drum or
cylinder; c, c, are bulb-shaped burners for consuming a mixture of gas and air
which is ignited at the extremities of the said burners.
The perforated tubes a rapidly conduct away the vapour which arises from the
substance being roasted, whilst the ventilating chamber b checks the escape of the
heat by causing it to travel around the said cylinder to the outlets 62, and then
around the casing to the outlet 61; the consumption of gas is thus greatly
economized. Ordinary gas roasters are made with only one outlet, the heat
being allowed to escape before it is properly utilized.
Figure 4 is a front elevation.
Figure 5, a side elevation, and
Figure 6, a plan of the indexed controller for regulating the supply of gas to the
fauoraid now

page_text: between these plates is inserted a toothed rack d³ carrying at its upper end an
arrow d; d is a spindle formed with a double worm projecting from a disc d³;
this double worm gears into and actuates the toothed rack d³, the position of the
arrow being shown on an index plate de fixed in front of the rack.
The lower end of the said rack is provided with a chain, preferably of copper,
which passes over grooved pulleys to the lever of the main gas tap, which is
provided with a weighted lever. This arrangement enables the attendant by
means of the double worm and rack to so control the supply of gas to the roasting
cylinder as to ensure uniform results in the roasting, and prevent overheating of
the substance being roasted.
Figure 7 is a front elevation.
Figure 8, a side elevation, and
Figure 9, a plan or top view showing a grinding mill constructed according to
my improvements.
In these Figures e is a pedestal provided with bearings e¹ for supporting a shaft e
carrying fly-wheels e³ at its ends. In the centre of the shaft e a taper or conical
piece with a toothed surface is formed and arranged to work inside a conical
shell, which is toothed on its inner surface; this shell is provided with pivoted
set-screws e³ for securing in place thereon a slotted side plate e, which maintains
the proper relative position of the piece e* and its lining, and keeps the cutting
surfaces in contact.
When it is desired to remove any obstruction or clean out the interior of the
mill, the pivoted set-screws eo are thrown back, thus releasing the side plate e and
allowing ready access to the interior of the shell. The hopper fis fitted with a
loose casing f¹ formed of zinc or other non-magnetic metal, a taper or conical
piece being fixed in the centre. Inside the casing f' magnets f³ are embedded,
and adjacent to these magnets I arrange wire pins for collecting and carrying to
the magnets any nails or particles of iron which may enter the hopper; these nails
or iron particles are attracted and held by the magnets whilst the substances to be
ground pass freely into the mill.
Figure 10 is a front elevation.
Figure 11 an end elevation, and
Figure 12, a plan or top view of my improved mixing machine.
In these Figures g, g, are standards of iron or other suitable material forming
the back and front supports, whereon is mounted in suitable bearings a spindle or
shaft g carrying a cylinder g². Spiral steel worms with wired edges are fitted
inside this cylinder, and are secured to the circular ends thereof, and to the shaft g¹;
g' is a sliding door covering the aperture through which the cylinder is filled and
emptied. A casing 95, preferably of iron, is secured to the standards g, and is
formed with a hinged cover 96 which permits access to the slide g, which may be
withdrawn through an aperture covered by a hinged door g' formed in the front
standard. A drawer 98 is provided for receiving the mixed substances from the
cylinder.
At each revolution of the cylinder the spiral worms g³ cause the substances to be
mixed to be carried upwards, and also to slide towards the centre of the cylinder,
where they are rapidly mixed without the friction or concussion which arises in
other methods of mixing. When the contents of the cylinder are being discharged
into the drawer, the outer casing g effectually prevents the aroma or dust from
escaping into the atmosphere.
Having thus fully described my said Invention and the manner of performing
the same, I wish it understood that I claim,―
The improvements above specified consisting of the following novel features,
either separately or combined in any manner necessary or desirable for the purposes
above specified, that is to say:-
First. The roasting cylinder provided with perforated tubes and a ventilating
chamber, substantially as described with reference to Figures 1 to 3 of the Drawing
and for the purpose specified.

page_text: Second. The indexed gas controller, substantially as described with reference to
Figures 4 to 6 of the Drawing and for the purpose specified.
Third. The improved grinding mill with provision for permitting ready access to
the interior, and for separating nails or particles of iron from the substance
introduced into the hopper to be ground, substantially as described with reference
to Figures 7 to 9 of the Drawing.
Fourth. The improved apparatus for mixing granular substances, substantially as
described with reference to Figures 10 to 12 of the Drawing.
In witness whereof, I, the said John Parnall, have hereunto set my hand and
seal, this Twentieth day of April, in the year of our Lord One thousand
eight hundred and eighty two.
JOHN PARNALL. (L.S.)