Improvements in Grinding Mills.
Year: 1892

page_text: Date of Application, 24th Mar., 1892-Accepted, 30th Apr., 1892
COMPLETE SPECIFICATION.
Improvements in Grinding Mills.
We ALEXANDER MCGREGOR of Albion Iron Works, Leigh, in the County of
Lancaster, Engineer, and HENRY BURCH of the same place, Draughtsman, 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 has for its object improvements in that class of grinding mills
for which Letters Patent were granted to us dated 28th day of September 1891,
and No. 16396.
The nature of the present invention and the manner in which the same is to be
performed or carried into practical effect will be readily understood on reference to
the three sheets of drawings, marked with figures and letters of reference corre-
sponding with those in the following explanation thereof.
In the Specification of the Patent above referred to we describe the adoption by
us of a part or piece (which we therein designate a swan neck case") as
surrounding the feeding spout and formed or secured to the bottom part of the
hopper.
According to this present arrangement, instead of supporting the cast iron saddle
or seat which carries the hopper by means of two or more standards, stays or legs,
as is usually done in grinding mills of this description, we make use of an arched
bracket or bridge piece b (Figs. 1, 2, 3, and 8) and bolt, or otherwise firmly secure
the feet or abutments of the same to the top of the main frame a, one on either
side thereof; and concentric, or nearly so with the main shaft x. The top of this
bridge piece forms a firm and strong seat or support for the upper end of the swan
neck case c which rests thereon and is firmly bolted or otherwise secured to the
same. The lower end of this swan neck case e rests upon the main frame,
immediately behind the plate a¹ to which it is firmly bolted or otherwise secured.
This lower end of the swan neck case c is constructed in such manner as to form
the inlet spout or shute for conducting the grain or other material to be operated
upon to the grinding chamber. It will be readily seen that this arrangement of
bridge piece secured at each side of the main frame, together with the manner in
which the swan neck case c is supported by the bridge piece band bolted to the
same, and supported by the frame and bolted to the plate a', adds considerably to
the stiffness and strength of the whole of the machine framework and at the same
time forms a very firm support for the hopper d which is carried by the saddle or
seat cast to the upper end of the swan neck case c.
In order to form a more durable and secure swinging joint or supporting connec-
tion for the vibrating feed spout e so that it may not only operate noiselessly and
without jar, but at the same time admit of its easy removal and replacement as
required; the plate or part e¹ forming the upper end of the vibrating feed spout e
is formed with a long pin g firmly rivetted, cast or otherwise secured to the same.
This pin is carried down through a vertical hole or bearing formed in the swan
neck case e and is continued down through a similar hole or bearing formed in the
bridge piece b. When the joint pin g drops into the hole or bearing the feed spout
is in proper position for work, and to remove it, it simply requires lifting out.
this arrangement this vibrating feed spout e is entirely and effectually carried and
supported by the joint pin g; the upright lever f imparting the vibrating motion
only, which it does by gearing into the inverted cup e² formed in the underside of
the plate e of the feed spout e. This plate or part el having both the joint pin and
the inverted cup formed in the one piece is much stronger than when attached
separately, and takes all the strain from the other parts of the feed spout which we
prefer to make of wood (as being lighter).
By

page_text: In order to cause the grain or other material which is being operated upon to
distribute itself more uniformly over the sieve or grating h, Fig. 3, and pass more
readily through the same, instead of forming the sieve of one straight inclined
surface, we form the same in the manner shown, having two inclined surfaces (or
it may be one inclined and one level surface) the steeper incline being only con-
tinued for about one half the length of the sieve, so that the bulk of the grain may
be brought to that part which has a greater vibratory movement than the part
which is close to the opening in the hopper; but at the same time without being
carried entirely over the sieve as would be the case if the steep incline were
continued the whole length.
Although we have described and shown the sieve or grating as formed in one
piece, it may be jointed, or formed in two parts, so that the inclination of one or
the other of the parts may be adjusted as desired.
According to a modification of the arrangement for carrying the feed spout, and
with the object of allowing it to have a longitudinal or backward and forward
vibratory movement, the junction of the bridge and swan neck case is formed with
a bearing for a crank shaft 1, Fig. 7, the crank being jointed to the underside of
the feed spout at m and the upright lever n being actuated by an eccentric face
plate or other suitable means so as to give it the backward and forward movement.
In order to arrest the motion of the feed spout the forward part of the same is
suspended by means of a chain m' (or a rod) attached to the arm of a lever m² or
by any other adjustable arrangement, so that by actuating the same the forward
part of the feed spout may be raised or lowered and the socket e' which engages
the upright lever n lifted out of gear or brought into gear with the same, or the
socket may be formed on the end of the lever n and the pin on the plate e¹.
This arrangement of raising the feed spout for the purpose of bringing it out of
gear with the upright lever may also be applied to those grinding mills in which
the feed spout is made to vibrate sideways. In this case the pin g instead of being
rivetted to the upper part of the feed spout is jointed to the same.
In the Specification of the before mentioned Letters Patent the upright lever
for actuating the feed spout is described as having two pieces of steel or other
suitable material, one on either side of it, so that it may be actuated by the
eccentric without backlash and with as little friction as possible. With the same
object in view according to this part of the present invention, the upright lever is
provided with a single piece of steel or other suitable material i Figs. 1 and 4,
which is bent around the boss of the lever and rivetted or otherwise secured to the
same; and in order that the two ends of the steel may give the necessary pressure
on the eccentric for allowing the same to revolve freely but without any looseness,
we make use of the screw bolt k or other suitable arrangement which can be adjusted
as desired.
The next part of the invention relates to the manner of guarding the fly wheel
in machines constructed in the manner shown and described in the before mentioned
Patent in which the fly wheel, being placed within the frame is necessarily nearer
the hopper of the machine and more likely to injure the attendant and consists in
forming a cover O, Figs. 1 and 6 of a shape to correspond with that part of the
frame which surrounds the fly wheel w and secured to the frame in the position
shown.
With the same object in view, the arch plates u (Fig. 1) which connect the front
and back pairs of legs, are formed with pockets (Figs. 1 and 6) which conform
to the shape of the frame and add to its stability, at the same time securely
guarding that part of the fly wheel w underneath the frame which would otherwise
be exposed.
The last part of the invention relates to the manner of securing the adjustable
nut p (Figs. 1, 5, and 9) which gives the necessary compression to the spiral
spring 9 which according to the before mentioned Patent is placed around the
telescope screw box.
In order to prevent the nut from shaking loose when the machine is at work we

page_text: form the nut p with a serrated or toothed flanger and a latch or catch s which
engages with the same; this latch or catch is formed of sufficient length to retain
its hold of the toothed flauge r when the nut is forced away from the face t¹ of the
tubular bearing t on the accidental passage of any hard substance through the mill.
The latch or catch may be kept in position by means of a spring s' as shown in
Fig. 5 or a set screw s² as shown in Fig. 9 or by any other suitable arrangement so
as to admit of its being readily moved out of gear with the flange of the nut when
it is desired to turn the latter for adjusting the pressure of the spiral spring g
The latchs can be hinged to the tubular bearing t or otherwise attached but in
order to simplify this casting the ears to which the latch or catch is hinged are
formed in one with the oil cup or box z. this latter being a separate casting and
secured to the tubular bearing hy screws as shown in Fig. 9, or other suitable
means.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. The combination of the main frame, swan neck, and arched bridge piece
supporting the hopper substantially as hereinbefore described and illustrated by the
drawings.
2. The combination of the bridge piece and swan neck case, either or both being
provided with a bearing or bearings for the hinge pin or shaft of the vibrating
feed spout substantially as hereinbefore described and illustrated by the annexed
drawings.
3. The plate el having a joint pin or shaft g firmly secured or cast to the same,
together with the inverted cup or socket e² formed in one with the plate, the said
plate el forming the foundation or superstructure on which the parts forming the
complete feed spout are constructed.
4. The combination of a rocking lever gearing into a cup or socket under the
vibrating feed spout with a chain and lever, or other equivalent device for raising
the said spout out of gear with the said rocking lever substantially as described and
illustrated by the annexed drawings.
5. The formation of the sieve of the vibrating feed spout, the incline at the end
where the vibration is greatest being reduced as and for the purposes herein before
described and illustrated by the annexed drawings.
6. The combination of the lever and spring piece with the adjusting bolt k
or its equivalent substantially as hereinbefore described and illustrated by the
drawings.
7. In a grinding mill formed with the fly wheel within the frame, the manner of
covering or guarding the same, as described in reference to Figs. 1 and 6.
8. In a grinding mill formed with the fly wheel within the frame, the arrange-
ment of the arch plates having the pockets vas described in reference to Figs. 1
and 6.
9. The combination of the sliding screw box, adjusting nut provided with
serrated or toothed flange, and a latch or catch so formed as to retain its hold on
the toothed flange when the nut is forced away from the face of the tubular
bearing t in the manner shewn and described.
10. The combination with the tubular bearing in which the screw box slides of
a separate oil cup fastened thereto substantially as described and illustrated and
provided with lugs or ears to which is hinged or otherwise attached the latch or
catch for retaining the serrated or toothed flange of the nut.
Dated this 23rd day of March 1892.
GEO. DAVIES & SON,
4, St. Ann's Square, Manchester, Agents for the Applicants.