IMPROVEMENTS IN COFFEE MILLS
Year: 1886

page_text: I GEORGE AMBROSE WILKINS of N° 90° Gloucester Road in the County of
Middlesex Gentleman do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN COFFEE MILLS" to be as follows:-
This invention relates to mills of the kind in which the runner or rotating
serrated part works in a vertical plane and consists of the improvements herein
after described by which the construction of the said mills is simplified their
efficiency increased and adjustment of the acting parts facilitated and a more
accurate adjustment produced.
The case or body of the mill consists of a shell formed in two halves the junction
of the said halves being in a vertical plane. The upper part of the said shell
constitutes the hopper in which the coffee to be ground is placed and the lower
part constitutes the chamber in which the coffee is ground. The inner faces of the
two halves of that part of the shell which constitutes the said chamber are of
concave form and have serrations formed on them. The rotating acting part or
runner is mounted on a spindle which passes through the centre of the said
chamber and to one of the projecting ends of the said spindle the crank or handle
by which the mill is worked is secured. The said rotating acting part or runner
has serrations formed on each of its faces and is of a form corresponding to that
of the interior of the said chamber. Bosses are formed at the periphery of the
runner which bosses project beyond the periphery and beyond the faces of
the runner and a boss is formed on each side of the runner near its axis which
bosses are opposed to plain or unserrated parts of the shell and prevent contact
of the serrations formed on the runner with those formed within the grinding
chamber. The bosses at the periphery of the runner also assist in discharging the
ground coffee from the mill. The two parts of the case or body of the mill are
bound together by a bar or strap connected to opposite edges of one of the halves
by means of a hinge or other suitable joint at one end and a screw at its other end
or by means of a screw at each end which bar or strap has an eye formed in it nt
its middle which eye surrounds one of the projecting ends of the spindle of the
runner and bears against the other of the halves of the case or body of the mill
near its centre. A spring is placed between the two parts of the case below the
grinding chamber for the purpose hereinafter described. The adjustment of the

page_text: parts is effected by turning the aforesaid screw or screws in one or other direction.
When turned in one direction the distance between the two parts of the shell and
the runner is decreased and the spring is compressed between the said two parts
of the shell and when turned in the other direction the said spring expands an
increases the distance between the said parts the extent of separation thereof being
governed by the extent to which the said screw or screws is or are turned.
Passages are formed in the shell through which the coffee berries placed in the
hopper descend into the grinding chamber. The mill is supported on a base
plate by legs or standards formed on or secured to one of the halves of the
case. The hopper is provided with a separable cover which when the mill is in
use serves as the receptacle for receiving the ground coffee passing from the mill.
Dated this twenty seventh day of January 1886.

page_text: I GEORGE AMBROSE WILKINS of N° 90° Gloucester Road in the County of
Middlesex Gentleman 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:-
This invention relates to mills of the kind in which the runner or rotating
serrated part works in a vertical plane and consists of the improvements herein-
after described by which the construction of the said mills is simplified their
efficiency increased and adjustment of the acting parts facilitated and a more
accurate adjustment produced.
The case or body of the mill consists of a shell formed in two halves the junction
of the said halves being in a vertical plane. The upper part of the said shell
constitutes the hopper in which the coffee to be ground is placed and the part
below the said hopper constitutes the chamber in which the coffee is ground. The
inner faces of the two halves of that part of the shell which constitutes the said
chamber are of concave form and have serrations formed on them. The rotating
acting part or runner has trunnions formed on it which pass through and work in
holes in the said shell at the centre of the said chamber and to one of the said
trunnions the crank or handle by which the mill is. worked is secured. The said
rotating acting part or runner has serrations formed on each of its faces and is of
a form corresponding with that of the interior of the said chamber. Bosses .or
teeth are formed at the periphery of the runner which bosses or teeth project
beyond the periphery and beyond the faces of the runner and a shoulder is formed;
on each side of the runner around the said trunnions which bosses or teeth and
shoulders are opposed to plain or unserrated parts of the shell and prevent contact
of the serrations formed on the runner with those formed within the grinding
chamber. The bosses at the periphery of the runner also assist in discharging the
ground coffee from the mill. The two parts of the case or body of the mill are
bound together by a bar or strap connected to opposite edges of one of the halves
by means of a hinge or other suitable joint at one end and a screw at its other end
or by means of a screw at each end which bar or strap has an eye formed in it at
its middle which eye surrounds one of the projecting trunnions of the runner and
bears against the other of the halves of the case or body of the mill near its centre.
The adjustment of the parts is effected by turning the aforesaid screw or screws in
one or other direction. When turned in one direction the distance between the two
parts of the shell and the runner is decreased and when turned in the other direction.
the said two parts of the shell are free to separate to some extent the extent of
separation being governed by the extent to which the said screw or screws is or
are turned. Passages are formed in the shell through which the coffee berries
placed in the hopper descend into the grinding chamber. The mill is supported
on a base plate by legs or standards formed on or secured to one of the halves of
the case.
The hopper is provided with a separable cover which when the mill
is in use serves as the receptacle for receiving the ground coffee passing from
the mill.

page_text: Having thus described the nature of this invention I will proceed to describe
the manner in which it is to be or may be performed reference being had to the
accompanying drawings and to the letters and figures marked thereon. The same
letters and figures of reference indicate the same parts in each of the Figures of
the Drawings.
Figure 1 of the said Drawings is an elevation of the mill Figures 2 and 3 are
sections thereof taken respectively on the lines A and B Figure 1 and Figure 4 is
an elevation of the mill with part of the case removed in order to show the
interior thereof. The other Figures of the Drawings represent parts of the mill
hereinafter referred to.
a, b are the two halves of the shell constituting the case or body of the mill the
interior of the half a being shown separately in elevation in Figure 5 and in section
in Figure 6. The parts of the said two halves a, b which constitute the grinding
chamber are of circular form and concave, as shown in the drawings. The teeth
or serrations formed on the inner face of that part of the said half shell which
constitutes one side of the grinding chamber are marked c, c in Figures 5 and 6
the said teeth being coarse at and near the centre of the grinding chamber and
finer towards and at the outer part thereof. The interior of the corresponding
part of the half b of the said shell has like teeth or serrations formed on it. The
rotating acting part or runner which is of a form corresponding with that of the
interior of the grinding chamber is shown in edge view separately from the other
parts of the mill in Figure 7. Referring to the said Figure d', d are the trunnions
formed on the runner which trunnions pass through and work in holes in the
centres of those parts of the halves a and b of the shell which constitute the
grinding chamber d¹ being the trunnion to which the handle is connected which
handle is marked & in Figures 1, 2 and 3 and is secured to a wheelf affixed to the
said trunnion d' as shown in the said Figures 2 and 3. The teeth formed on
the faces of the said runner which are opposed to the toothed inner faces of
the shell a, b are marked g, h in Figures and 7 and the said teeth like the
teeth formed on the interior of the said shell are coarsest near the centre and
finer towards the periphery. The projecting bosses or teeth at the periphery
of the said runner are marked i, i and the unserrated parts of the shell to
which the said bosses or teeth are opposed are marked j. j. The faces h¹, h' of
those parts of the said runner on which the teeth h, h are formed constitute
the shoulders around the trunnions and k, k are the unserrated parts of the
shell α, b to which the said shoulders are opposed as shown in Figures 2
and 3 is the bar or strap by which the two parts a, b of the shell are bound
together.
The said bar or strap is connected to the part b at its ends one of the said ends
having hooks, formed on it which engage with lugs m, m on the said part b
and the other end being secured by means of a screw bolt n¹ and nut n which
screw bolt n¹ is engaged with a lug o on the said part 6 The two halves a, b of
the shell are in contact only at the upper part marked b¹ in Figure 2 the half a
being free to approach towards and recede from the half b at the lower part and
the adjustment of the parts of the mill in order to make it grind fine or coarse is
effected by regulating the distance of the said half a from the half 6 by turning
the screw nut n³ in one or other direction the pressure of the bar on the said
half a being increased or decreased according to the direction in which the said
screw is turned. In order that the adjustment of the parts may not be impeded
by particles of ground coffee accumulating between the halves a and b of the shell
the circular part of the half a which part constitutes one side of the grinding
chamber is made of the same diameter as the runner the action of the teeth i, i
on which prevent accumulation or packing of the ground particles between the
unserrated margins of the faces of the circular parts of the two halves a, b of the
case.
In order to prevent escape of ground particles from the sides of the case
or shell projecting rims are formed on the said part 6 between which rims the
part a is confined as shown in Figure 3 in which Figure and in Figure 2 the said

page_text: projecting rims are marked 63, 6' The separation of the half a of the shell from
the half b when the screw nut n¹ is relaxed is produced by the pressure of the
ground coffee between the runner and the sides of the grinding chamber which
pressure being equal on both sides of the runner causes it to work in the centre of
the grinding chamber whatever may be the distance between the sides thereof.
However closely the two halves a, b of the shell may be drawn together the teeth
formed on the runner and those within the grinding chamber cannot come in
contact in consequence of the bearing of the projecting teeth i, i and the faces h¹, h¹
of the shoulders on the former against the unserrated parts j, j and k, k on the
latter when the said halves a, b are at the minimum distance from each other
The passages in the shell or case a, b through which the coffee berries pass into
the grinding chamber are marked a, b in Figure 2. p, p are the legs and q is
the base plate by which the mill is supported is the exit spout by which the
ground coffee passes from the mill and 8 is the separable cover of the mill which.
cover is shown in Figure 4 in the position in which it is placed to receive the
ground coffee passing from the mill.
I do not confine myself to the means herein before described for adjusting the
parts of the mill as the adjustment may be effected by means of a screw engaging
in one side of the hopper and passing through and bearing against the other side
or any other arrangement may be used which will admit of the distance between
the two sides of the grinding chamber being readily increased or decreased.
The several parts of the mill may be made of cast iron the grinding surfaces
being hardened by being cast in chill moulds. The parts which are subject to
most wear may however be made of cast steel.
In using the mill the coffee berries are placed in the upper part of the shell or
case a b (which constitutes the hopper) whence they descend into the grinding
chamber on both sides of the runner and on the runner being rotated the coarser
of the teeth thereon and on the inner sides of the grinding chamber first act on the
said berries and crack or break them. The broken portions of the berries then
pass between the finer of the teeth on the runner and sides of the grinding
chamber and are acted on by the said teeth until they are sufficiently reduced to
pass from the grinding chamber by the exit r at the lower part of the body of
the mill.
Mills constructed as hereinbefore described although especially suitable for use
in grinding coffee may be used for grinding matters of any kind which are not of
such a nature as to be liable to clog the grinding teeth or to injure them.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be or may be performed I wish it
to be understood that I do not limit myself to the precise details herein before
described and illustrated in the accompanying Drawings as the same may be
varied without departing from the nature of my invention but I declare that
I claim as my said invention
First. The general combination and arrangement of parts constituting the mill
hereinbefore described and illustrated in the accompanying Drawinga.
Secondly. A mill consisting essentially of a toothed or serrated runner formed
substantially as hereinbefore described and capable of rotatory motion in a vertical
plane and mounted within a shell or case the faces of the interior of which are
toothed or serrated at the parts opposed to the toothed or serrated faces of the
runner the said shell or case being formed in two parts and provided with means
for increasing or decreasing the space between them in order to the adjustment of
the relative positions of the acting parts of the mill.
Thirdly. The combination in a coffee mill of a runner capable of rotation in a
vertical plane and having two acting faces with two stationary or non rotating
toothed or serrated acting parts each of the acting faces of the said parts being
opposed to one of the acting faces of the said runner.

page_text: Fourthly Forming the whole of the body or case of an upright mill in two
parts as hereinbefore described the line of junction of the said parts being at or
near the centre of the said body or case and in a vertical plane.
Fifthly. Effecting the adjustment of the acting parts of an upright mill
constructed as hereinbefore described by drawing together or separating the
two parts of the case.
Sixthly. The means herein before described for securing together the two parts
of the case of a mill constructed as herein before described and for adjusting the
distance between the acting parts thereof the said means consisting of a bar bearing
near its middle on one of the halves of the case and connected or secured at its
ends to the other of the said halves in such a way as, to admit of the distance
between the said bar and the half of the case to which it is secured or connected
being varied as required.
Seventhly. The combination in a mill of a runner formed substantially as
*hereinbefore described with a non rotating toothed or serrated part or plate of
circular form and of the same diameter as the runner and capable of adjustment
within a part of the case of the mill extending beyond or partly surrounding or
enclosing the periphery of the runner.