IMPROVEMENTS IN MACHINERY FOR BREAKING OR CRUSHING STONE, BONES, AND OTHER HARD SUBSTANCES
Year: 1884

page_text: I THOMAS ARCHER, junior, of Dunston Engine Works, Gateshead, Engineer
do hereby declare the nature of my Invention for IMPROVEMENTS IN MACHINERY
FOR BREAKING OR CRUSHING STONE, BONES, AND OTHER HARD SUBSTANCES, and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
My Invention consists in certain improvements in machines for crushing stone,
bones or other hard substances such improvements being chiefly applicable to
machines in other respects constructed in accordance with Specification. of a
Patent granted to me, dated 14th May 1878 N° 1928.-As described in the said
recited Specification of Patent I employ a slowly revolving roller in combination
with a squeezer; the movement of the roller being such as to advance the material
being operated upon, in the direction of the delivery of the machine the differences
and improvements forming the subject of my present Invention being those which
I now proceed to describe by the aid of the Drawings hereto attached.-These
improvements are also applicable to stone breaking machines without revolving
rollers but I prefer to use the roller.
In the machine already referred to, I described a safety arrangement of spring
which enabled the machinery to give way (rather than to break, or to be brought
to a stand) if any material were supplied to it too large to pass through, and too
hard to be broken by the machine, but I find that with that arrangement there is
a defect arising from the fact that the tension of the spring must be very consider-
able to begin with so as to make the machine at all efficient, and that the tension
very rapidly increases as the releasing movement proceeds. If on the other
hand weights be applied through a system of levers there is a defect arising from
the fact that the momentum of the weight when once put in motion tends to carry
the releasing action further than might be necessary, and therefore to impair the
efficiency of the machine. I meet these defects by combination of weight, and
spring as shewn in the Drawing whereby the momentum of the weight tends to
counteract the increased tension of the spring, and consequently to give more
uniform and efficient release than either weight or spring alone.
A. is the lever taking the thrust of the squeezer; this lever is capable of moving
on the centre B. C is the spring arranged above and below the end of the lever A,
and D is the weight accompanying it--both spring and weight tend as set to keep

page_text: the squeezer pressed towards the revolving roller. Another part of my improve-
ment consists in a very simple form of adjustment whereby to regulate the desired
proximity of the squeezer, and the roller, and thus the more or less fineness of
crushing effected by the machine. This adjustment consists of a set screw E.
working in the frame of the machine and raising, or allowing to descend the
lever A, whereby as will be seen from the Drawing that part of the lever A which
takes the thrust in crushing is allowed to advance towards, or is withdrawn from
the revolving roller.-Another part of my improvement consists in the form of
knuckle joint and thrust piece which allows without excessive friction the vertical
movement of the squeezer.-I construct this piece as shewn in the Drawing at F,
so as that it turns, to the extent of the movement required by the vertical move-
ment of the squeezer upon a point which is the centre of the curve forming the
bearing against the lever A, the opposite end of the piece F. being a curve with
the same centre, but I may vary the movement of the squeezer so as to give
increasing nip at certain parts of its movement by variation of either of these
curves by preference of course the larger curve, or by variation in the contour of
that part of the squeezer against which the part F (with circular contour) bears
that is to say, I may so arrange the shape of the curved large end of the thrust
piece F, or its line of bearing on the squeezer as that at the moment at which
from the position of the eccentric G, the driving power is most effectively applied,
there shall be the greatest nip, and that as the power is less efficiently applied there
shall be less nip. The variation in the form of this curve is indicated by dotted
lines H. H. It is possible of course to make the thrust piece in the form of a
roller instead of a segment but I do not think it is advantageous. In other respects
the construction of the framework and the material of the machine are of the
ordinary character, or like my patented machine before referred to and so well
known as to need no description.
:
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed I declare that what
I claim is =
1st The use of combined weight and spring for releasing arrangement.
2nd The method of adjustment, and
3rd The form of knuckle joint and thrust piece all as and for the purpose
substantially as described and whether used together or separately and whether
with the exact form of machine shewn in the Drawing or any other form of
machine.
Dated this Seventh day of August 1884.