Stone-grinding Wheels.
Year: 1890

page_text: Stone-grinding Wheels.
I, GEORGE BARNEY ECKHARDT, of No. 909 E. Bancroft Street, Toledo,
Ohio, United States of America, Manufacturer, 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 stone grinding wheels. Heretofore, grinding wheels
have been generally constructed of a series of concentric rings secured to a suitable
backing provided with an opening through which the material used to grind down
the stone is fed. It has been found in practice, that the best cutting result of the
material cannot be obtained for the reason, that it would not be changed between
the rings so as to present a fresh surface to the stone as the wheel was operated, as
that part nearest the centre would be slightly agitated or changed, thereby leaving
the work to be done by the material confined between the rings farthest removed
from the centre.
It is the object of the invention to overcome these obstacles by producing a
grinding wheel which shall be so arranged, that the cutting material will be drawn
towards and away from the centre, whereby, the said cutting material is caused to
be brought into contact with every part of the grinding wheel, thereby increasing
the utility of the wheel and the rapidity of grinding down the stone.
With these objects in view, the invention consists broadly of a grinding wheel
constructed with a series of fingers arranged in such a manner as to exert a
centripetal action upon the grinding material, whereby, when the wheel is in opera-
tion there will be a constant circulation of a grinding material to the centre; the
invention further consists in the various novel details of construction as will be
hereinafter fully described in the Specification, illustrated in the drawings, and more
particularly pointed out in the claims.
In the accompanying drawings forming part of this Specification and in which
like numerals of reference indicate corresponding parts, I have illustrated one form
of device embodying the essential features of my invention, although the same may
be carried into effect in other ways without in the least departing from the spirit
thereof, and in these drawings,
Figure 1, is a top plan view of my improved grinding wheel, showing its peculiar
construction.
Figure 2, is a similar view, showing the cover in place upon the wheel.
Figure 3, is a vertical sectional view, showing more particularly the relation
between the cover and wheel and also the clutch.
Figure 4, is a similar view taken on the line y-y of Figure 1, showing the
manner of holding the point in position upon the fingers, and also the cover, and,
Figure 5, is a perspective detail view of a removable point used on this wheel.
Referring to the drawings, 1, designates the wheel which may be constructed of any
metal, but preferably in this instance of iron, consisting of two outer fingers 2, and
two inner fingers 3. The peripheries of the fingers 2, are involute, or more properly
speaking eccentric, with regard to the pivotal point about which the wheel revolves,
while the inner sides are of a like configuration only in a less degree, and terminate
The inner
at 4, forming points, the function of which will be described further on.
fingers are also eccentrically arranged. The fingers are connected and braced by
means of a plate 5, which is of sufficient thickness to give rigidity to the said
fingers. It has been found in practice that when the wheel is made of cast iron,
that the points of the outer fingers crumble when in use, from the fact that being
thinner than the remaining portion of the fingers they become chilled sooner when
taken from the mould, and are consequently brittle and apt to break, and cannot be
sharpened when they have become dulled. In order to overcome these obstacles I
го

page_text: provide the wheel with a removable point 6, provided with an angular recess 7,
adapted to engage an angular point 8, on the fingers. Upon one end of each of the
points 6, is cast a plate 9, which bears upon the inner end of the fingers 2, as shown,
and is held in place thereon, by-means of a threaded stud 10, and nut 11, secured
thereon. The plates 9, also carry lugs or projections 12, which bear against the
fingers 2, and serve to brace the points against lateral play. The cover 13, is con-
structed preferably of a circular piece of metal 14, and is provided with recesses 15,
adapted to engage with the plates 9, to hold the said cover from moving.
.1.
The coupling or clutch 16, for communicating with the motion imparting
mechanism, consists of a base 17, provided with an aperture adapted to receive a
bolt. 18, which extends through an opening, 19, in the wheel, n'nut 20, serving to
clamp the clutch and wheel securely together. At each end the coupling is pro-
vided with an upward extending flange 21, through which extends a bolt 22, for
clamping 'the lower end of the shaft '23, 'in place, which shaft communicates with a
motion imparting mechanism.
I'
'
In operation, the wheel is revolved in the ordinary manner and the cutting
material, which may be chilled 'shot, sand, or emery, is fed to the interior of the
wheel by the fingers '2. As the wheel revolves the cutting material will work t
its way under the lower part of the wheel until it strikes recesses 24, when they
will act to drive the material under the 'wheel, and passes it along until the
recesses in the next point actuates it'in a similar manner. As the utility of this.
device depends largely upon the rapidity with which it can grind away stone, it
follows that the greater the amount of material that can work its way between the
grinding faces and stone, the more rapid will be the operation. In order to give as
large feed as possible, I provide the recesses 24, to which reference has been made,
on the inner faces of each of the fingers, so that as the wheel revolves, and the
material strikes the said recesses, it will pass under the wheel more rapidly than
were a straight wall presented as with wheels of ordinary construction.
The cover to which reference 'has been made, is designed more particularly to
compensate for the wear of the wheel, and may not be used at first, but after the
wheel has been reduced to say one-third of its original heft, the cover is then added
which brings the wheel to its original weight, and also prevents the cutting
material spilling out over the top of the wheel when the same has worn thin
from' use.
די
By arranging the fingers eccentrically as described, at every half turn of the
wheel all the space between the two points is covered, and as the motion is directly
against the cutting material, it is forced under the wheel, none of it being carried
to, or left idle in the centre thereof; by this construction every part of the bottom
of the wheel works directly on the cutting material, so that no point of the said
wheel comes in direct contact with the stone.
Having now, particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is ;.
1. A grinding wheel consisting of a series of connected, eccentrically disposed
fingers.
2. A grinding wheel provided with eccentrically disposed fingers, and a plate
connecting said fingers.
3. A. grinding wheel constructed with a series of eccentrically arranged fingers,
and removable points carried by the outer series of fingers."**
4. A grinding wheel provided with eccentrically disposed fingers, said fingers
being arranged in concentric series.
5. A. grinding wheel constructed with a series of fingers arranged substantially
eccentric to their pivotal point.
6. A grinding wheel constructed of a series of eccentrically arranged fingers, the
onter of the said series being provided with removable points, a cover adapted to
fit on said wheel, and means for holding the cover in position.
1
1

page_text: 7. A grinding wheel constructed of a series of fingers, arranged substantially
eccentric to their pivotal points, the inner faces being provided with recesses. I
Dated this Second day of October 1890.
ORGE BARNY ECKHARDT.
Abel & Imray,
Agents for the Applicant.