Year: 1889

page_text: I, William HerbERT TAGGART, of Freeport, County of Stephenson, State of Illinois
United States of America, dentist, 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:-
In this invention the wheels are formed directly upon their shafts.
illustrated in the accompanying drawings, in which:
Fig. 1 shows a side view of the entire apparatus.
Fig. 2 is a view in the direction of the arrow of Fig. 1.
Fig. 3 is an enlarged section on the line -y, Fig. 1.
2:
Fig. 4 is a section on the line ey, Fig. 2.
It is fully
Fig. 5 is a section similar to those in figures 3, 4, illustrating a slight modification
in construction, for purposes hereinafter set forth.
In these drawings A-A are handles, and D-D' are corresponding jaws pivoted
The jaws are
together at C, and thrown open by a spring B in the usual manner.
perforated, and in them are placed, respectively, a steel matrix H and a steel
pressure-block G. Both matrix and block are provided with shoulders resting
upon the faces of the jaws respectively, and with integrally formed shafts J, K, fitting
the perforations in the jaws.
The inner surface of the block is plane, and at right angles to the axis of the
in line with the axis of the
shaft K which, when the forceps are closed as shown,
matrix H and its shaft J. The inner end of the matrix bead H is provided with a
recess of the form desired for the emery wheel, and is beveled from the outside
toward this recess to form a sharp cutting edge, all whose points may meet the face
of the block G when the forceps are closed --- the construction of the jaws being
such that in this position their inner faces are at a distance from each other just equal
to the combined lengths of the block G and matrix H, exclusive of their shafts. The
shaft. J is centrally perforated in the direction of its length, and in this perforation
is placed a shaft I, whose roughened end portion P projects to any desired distance
into the depression Lin the matrix head H. A set-screw working in the jaw D,
passes through a suitable opening in the shaft J and secures the shaft. I in any
desired position, and a set-screw E in like manner fastens the shaft K.
If now a piece of an emery or corrundum wheel, or of any similar substance, be
warmed until it reaches a plastic state, and be then placed in the matrix, closing the

page_text: forceps will force it into every part of the recess, including the slight depressions in
the surface of the shaft I, and the surplus material, if there be any, will be neatly and
clearly separated from the portion within the matrix by the cutting edge as the latter
meets the surface of the block G. The mass being then cooled is afterward removed
from the matrix as a perfect disc, perfectly mounted upon the shaft I and ready for
use in the dental engine. It is plain that matrices of any desired form may replace
the frusto-conical matrix shown, and that the face of the block G may be provided
with a projection or depression of such form that the outer face of the completed
wheel may be re-entrant or projecting, and further, that a great variety of matrices
may be used without substituting another block for the plane-faced block & shown in
the drawings, the size of the wheel to be formed being limited only by the size of
the plane pressure-surface.
For some purposes it is necessary that portions of the shaft I near the wheel
mounted upon it be smaller than it is practicable to make the body of the shaft, it
being desirable that the entire series of wheels may be used in the same shaft holder.
Two difficulties are then presented: The shaft is too small to afford secure attachment
for the wheel; and the material of which the wheel is formed is forced into the space
surrounding the small portion of the shaft and must be removed after the wheel is
completed. The shaft is therefore provided with an end disc 0, Fig. 5, at least equal
in diameter to the diameter of the main portion of the shaft, and this, whatever the
form of the matrix, always covers or fills the perforation in the bottom thereof, and
prevents the plastic substance from passing into the space about the small portion of
the shaft. It may be remarked that this space is necessary in order that the same
matrix may be used with either shaft, and that the shaft may be removed, longi-
tudinally, when the disc has been formed upon its extremity. Making the jaw D'in
two parts attains one of these objects, but not the other.
I have forced the matrix and pressure blocks together by various other devices,
e.g., by a screw and by a cami, moving either one in the line of its axis, but
I prefer the method illustrated as essentially the same, but more convenient and rapid
in operation.
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. In a device for forming abrading wheels upon their shafts, the combination with
two co-acting jaws, of a pressure block attached to one of said jaws, a matrix
attached to the other jaw and having a cutting edge, adapted to bear upon said
pressure block, and an axial bore adapted to receive a shaft and means substantially
as shown and described for securing a shaft in the hore of said matrix during the
formation of an abrading wheel, substantially as and for the purpose set forth.
2. In an apparatus for forming abrading wheels directly upon their shafts, the
combination with two suitably bored co-acting jaws, of a pressure block having a
shank removably seated in the bore of one of said jaws, an axially bored matrix
having a shank removably seated in the other of said jaws, and formed with a trans-
verse opening and a transverse set-screw seated in said last named jaw and adapted
to pass through the transverse opening in the shank of the matrix to secure a shaft
in said shank, and at the same time to secure the shank in the jaw in which it is
seated, substantially as and for the purpose set forth.
Dated this 7.1
1*
1000