IN THE CONSTRUCTION OF GRINDING MILLS
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by the said Charles Duckering at the
Office of the Commissioners of Patents on the 26th July 1883.
CHARLES DUCKERING of Waterside Works Lincoln Engineer
IN THE CONSTRUCTION OF GRINDING MILLS"
"IMPROVEMENTS
The object of iny said invention is to effect improvements in the construction of
mills for grinding barley, beans, maize oats, wheat, and other substances.
Instead of the ordinary horizontal mill stones, I use a vertical mill wheel of hard
chilled cast iron and formed or approximating to the form of a prolate spheroid,
mounted upon a horizontal axle. In close proximity to this mill-wheel I place
another casting of similar material, which is concave to the mill wheel and
surrounding a portion of its circumference and curved periphery. This concave is
mounted upon a horizontal axle or equivalent centres parallel to that of the mill
wheel, and is placed sufficiently near to the mill wheel to grind the substances fed
in between the mill wheel and the concave casting
The convex surface of the periphery of the mill wheel has rows of teeth formed
thereupon, and the concave has also rows of teeth, but the latter are larger and
coarser at the upper end and gradually lessened in size down to the lower
extremity; and the distance of the upper part of the concave from the mill-wheel
is greater than the lower part, in order to graduate the operation of grinding.
The distance of the concave from the mill wheel is regulated by carefully
balancing the same on its axle and by suitable adjustable gear, and such regulation
is also assisted by arrangements for automatic action, such as springs or weights,
to keep the concave to its work and yet allow the same to yield in case of an
obstruction arising.
The faces of the teeth upon the mill wheel and concave rospectively are formed
in opposite directions to each other.
The mill wheel is driven, or caused to revolve, by any suitable motive power.
The whole of the mill wheel and concave are (by preference) enclosed in a
suitable cast iron casing

page_text: •
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Charles Duckering in the Patent Office on the 26th January
1884.
CHARLES DUCKERING of Waterside Works, Lincoln Engineer IMPROVEMENTS
IN THE CONSTRUCTION OF GRINDING MILLS"
The object of my said invention is to effect improvements in the construction
of mills for grinding barley, beans, maize oats, wheat, and other substances.
Instead of the ordinary horizontal mill stones I use a vertical mill wheel of hard
chilled cast iron and formed or approximating to the form of a prolate spheroid,
mounted upon a horizontal axle
In close proximity to this mill-wheel I place another casting of similar material
which is concave to the mill-wheel and surrounding a portion of its circumference
and curved periphery This concavo is mounted upon a horizontal axle or equi-
valent centres parallel to that of the mill-wheel, and is placed sufficiently near to
the mill-wheel to grind the substances fed in between the mill-wheel and the
concave casting
The convex surface of the periphery of the mill-wheel has rows of teeth formed
thereupon and the concave has also rows of teeth but the latter aro larger and
coarser at the upper end and gradually lessened in size down to the lower
extremity and the distance of the upper part of the concave from the mill-wheel is
greater than the lower part, in order to graduate the operation of grinding.
The distance of the concave from the mill-wheel is regulated by carefully
balancing the same on its axle and by suitable adjustable gear and such regulation
is also assisted by arrangements for automatic action such as "springs or weights-to-
keep the concave to its work and yet allow the same to yield in case of an
obstruction arising.
The faces of the teeth upon the mill wheel and concave respectively are formed
in opposite directions to each other.
The mill-wheel is driven, or caused to revolve, by any suitable motive power.
The whole of the mill-wheel and concave are (by preference) enclosed in a
suitablo iron casing.
And in order that my said invention may be clearly understood reference is
hereby made to the accompanying drawings in which similar letters of reference
indicate corresponding parts in the several figures.
a is the
Fig. 1 is an elevation of my invention-Fig. 2 is an elevation of the mill-wheel,
cam-wheel, and shoe Fig. 3 is a section to show the form of the mill-wheel Fig. 4
is a side elevation of the concave and Fig. 5 is a front view of the same.
outer casing, to which standards b. b are fitted (shewn in dotted lines) The mill-
wheel c is fitted to the axle d which works in brasses e. e The axle is fitted with
an ordinary crank handle for manual power or with a driving pulley for other
power or with both such appliances
The form of the teeth is shewn in Figs. 2 and 3, but I do not confine myself to
the precise form shewn in Fig. 2. as that form may be varied and the serrations
otherwise made but the curved form of the teeth (shewn at f in Fig 3) forms an
essential feature of my invention
The cam-wheel g. shewn in Fig. 2 revolves with the mill wheel c
The cams
upon this wheel g impart an intermittent motion to the shoc h This shoe is so
placed as to receive the grain to be ground and the intermittent motion imparted
by the cams assists the feed to the mill
The concave 2 is held in position by the bolt i which passes through the casing

page_text: and the concave But the concave is also held to its work and regulated by the
link and screw and spring l. m is a hand wheel for regulating the distance of
the lower end of the concave from the mill-wheel and the fly-nut n acts as a set
screw
Two lugs o one on each side of the casing are provided for sustaining a shoot or
delivery trough for the meal.
The general mode of forming the teeth in the concave is shewn in Fig; 5, but the
form and size of the teeth are varied to suit the various substances required to be
ground
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I claim:
1 In grinding mills for the purposes described the use of mill wheels having curved
teeth, and an adjustable concave in combination therewith, constructed, mounted
and actuated substantially as herein before, described and shewn on the drawings
2 In grinding mills for the purposes described, the use of the cam wheel g in
combination with the shoe h mounted and operating as described, or any mere
modification thereof..
3 The general combination and arrangement of the several and respective parts
together forming my improvements in the construction of grinding mills substan-
tially as hereinbefore described and shewn on the drawings.
In witness whereof I the said Charles Duckering have hereunto set my.
hand and seal this twenty fifth day of January in the year of our Lord One
thousand eight hundred and eighty four