Improvements in Crushing Mills.
Year: 1896

page_text: PROVISIONAL SPECIFICATION.
Improvements in Crushing Mills.
We, ROBERT ABBOT HADFIELD, of The Grove, Endcliffe Vale Road, Sheffield,
in the County of York, Steel Manufacturer, and ALEXANDER GEORGE MACKENZIE
JACK, of Fir Vale House, Sheffield, do hereby declare the nature of this invention
to be as follows:-
This invention has reference to crushing mills of the kind in which the travelling
crusher head or pestle (hereinafter called the head) has a gyratory motion as well
as one of rotation about its own axis. In such mills the head has sometimes been
made in the form of a frustum of a cone or of pestle shape, and integral with its
shaft thus rendering it necessary when the head has become worn to substitute
a new head and shaft.
Now the object of the present invention is to obviate this disadvantage, for which
purpose the head is made as a compound head whose outer portion is in the form
of a removable mantle or sleeve (hereinafter called the mantle) which constitutes
the acting surface and which when it has become worn can be removed and a new
one substituted instead of a new head or head and shaft having to be provided.
This mantle is comparatively thin and of the requisite external form and dimen-
sions and is adapted to fit and is fixed over a suitably shaped supporting head (it
may be a frustum of a cone) which forms part of the shaft or may be separable
therefrom. The form of the mantle will depend on circumstances. We some-
times make it thicker at its lower edge, that is, where its diameter is greatest, and
where it is subjected to the greater wear, the top or portion where the diameter
is smallest being made relatively thinner as the crushing work is not so severe at
that part. Means are provided to prevent the mantle from moving round on the
supporting cone which constitutes the head body. In one arrangement the said
body is cast with a projecting longitudinal key or rib (or with more than one)
adapted to fit into a corresponding recess or recesses in the head body but some-
times the external surface of the mantle is grooved or corrugated longitudinally,
the inner surface is made approximately of the same form so that transversely the
section of the mantle is of equal thickness and the head body is grooved or
corrugated to receive the mantle which is thereby prevented from working round.
Means are also provided to prevent the mantle from fifting. For this purpose
one plan is to provide nuts screwed on the upper part of the shaft, the face of the
lower nut bearing on the upper surface of mantle; any adjustment that may be
necessary owing to the mantle settling down on its supporting cone may be made
by means of these nuts.
In a small machine the head body may be forged or cast integral with the shaft,
but in a machine of larger or heavy type where a shaft if so made would be
expensive and difficult to produce the head body over which the mantle is fixed
may be cast or forged separately and be shrunk keyed or otherwise securely fastened
on the shaft.
In order to produce an apparatus of durable kind we make the mantle as

page_text: described of the steel known as Hadfield's Manganese steel; but the mantle may
be of any suitable grade of steel or other metal or alloy.
The mantle can be removed from the head body by lifting off the hopper,
unscrewing the nuts from the shaft and then raising the mantle by hooks from the
lower edge; and a new mantle can be fixed in position without in any way
removing or disturbing the upright shaft.
Improvements in Crushing Mills.
We, ROBERT ABBOT HADFIELD, of The Grove, Endcliffe Vale Road, Sheffield,
in the County of York, Steel Manufacturer, and ALEXANDER GEORGE MACKENZIE
JACK, of Fir Vale House, Sheffield, 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 reference to crushing mills of the kind in which the travelling
crusher head or pestle (hereinafter called the head) has a gyratory motion as well
as one of rotation about its own axis. In such mills the crushing head is made in
one form of a frustum of a cone, or other suitable form, and is secured upon its
driving shaft, and when it has become worn to the extent of only a small percentage
of its total weight it has been necessary to substitute therefor a new head. Now
the object of the present invention is to obviate this disadvantage, for which
purpose the head is made as a compound head whose outer portion is in the form
of a removable mantle or sleeve (hereinafter called the mantle) which constitutes
the acting surface and which when it has become worn can be removed and a new
one substituted instead of a new head or head and shaft having to be provided.
This mantle is comparatively thin and of the requisite external form and dimen-
sions and is adapted to fit and is fixed over a suitably shaped supporting head (it
may be a frustum of a cone) which forms part of the shaft or may be separable
therefrom. The form of the mantle will depend on circumstances. We some-
times make it thicker at its lower edge, that is, where its diameter is greatest, and
where it is subjected to the greater wear, the top or portion where the diameter is
smallest being made relatively thinner as the crushing work is not so severe at that
part. The outer surface may be plain or corrugated as required. Means are
provided to prevent the mantle from moving round on the supporting cone which
constitutes the head body.
In the accompanying drawings,
Fig. 1 shows in vertical sectional elevation a shaft with head body integral
therewith and mantle in position on the head body;
Fig. 2 shows a cross section on line A B of Fig. 1.
Figs. 3 and 4 are similar views illustrating a modification wherein the head
body is made separate from the shaft.
In both examples, 1 is the shaft, 2 the head body, 3 the mantle, which is
represented as being made thicker at its lower edge, that is, where its diameter is
greatest and where it is subjected to the greater wear, the top or portion where the
diameter is smallest, being made relatively thinner because the crushing work is
not so severe at that part. The mantle 3 is shown cast with projecting longitudinal

page_text: keys or ribs 5 (or there might be only one) adapted to fit into corresponding recesses
in the head body 2. The external surface of the mantle is shown plain, but
sometimes this surface is grooved or corrugated longitudinally.
In order to produce an apparatus of durable kind, we make the mantle, as
described, of the steel known as "Hadfield's Manganese steel"; but the mantle
may be of any suitable grade of steel; or of other metal or alloy.
4, 4, are nuts to prevent the mantle from lifting. As will be seen, the face of the
lower nut bears on the upper surface of the mantle; any adjustment that may be
necessary, owing to the mantle settling down on its supporting cone, may be made
by means of these nuts. In a small machine the construction represented in Figs. 1
and 2 may be adopted, the head body 2 being forged or cast integral with the
shaft 1; but in a machine of larger or heavy type, where a shaft 1 if so made
would be expensive and difficult to produce, it is preferable to adopt the construc-
tion represented in Figs. 3 and 4, the head body 2 over which the mantle is fixed
being, in this case, cast or forged separately, and shrunk, keyed, or otherwiso
securely fastened on the shaft 1.
In either construction, the mantle 3 can be removed from the head body 2 by
lifting off the hopper and spider of the machine (not shewn in the drawings),
unscrewing the nuts 4 from the shaft 1, and then raising the mantle 3 by hooks
from the lower edge; and a new mantle can be fixed in position without in any
way removing or disturbing the shaft 1.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed we declare that what we
claim is:-
1. A crushing mill in which the gyratory crusher head or pestle comprises a
head body integral with or fixed upon the shaft, and a mantle or sleeve which fits
upon and is fixed to the said head body and constitutes an acting surface which
(when worn) can be readily removed and replaced by another, substantially as
described.
2. In a crushing mill of the kind referred to in Claim 1, the construction and
arrangement of the parts as described with reference to, and shewn in Figs. 1
and 2, the head body 2 being integral with the shaft 1, and being formed with
longitudinal recesses which receive and hold corresponding keys or ribs 5 formed
on the inner surface of the mantle or sleeve 3, which is prevented from lifting by
nuts 4 screwed onto the shaft 1.
3. The modified construction of crusher head shown in Figs. 3 and 4 of the
uccompanying drawings.
Dated this 3rd day of Jul 1807
For the Applicants,"
W. LLOYD WISE,
46 Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.