tal Tools.
Year: 1890

page_text: Date of Application, 30th Dec., 1890
Complete Specification Left, 30th Sept., 1891-Accepted, 12th Dec., 1891
PROVISIONAL SPECIFICATION.
Dental Tools.
A communication from abroad by GEORGE H. PEIRCE, of 178, West Springfield
Street, Boston, State of Massachusetts, United States of America, Physician.
I, JOHN CORRY FELL, of the firm of Fell & Wilding of 1, Queen Victoria
Street, in the City of London, Patent Agents, do hereby declare the nature of this
invention to be as follows:-
My invention relates to that class of dental tools commonly known as a disc
carrier or holder and it is the object of my invention to provide a simple form of
holding mandrel adapted to receive the discs, with means for clamping the discs
securely when in use, the construction being such as to allow the ready removal
of the worn disc and the substitution of another.
My invention consists in a mandrel having a face plate upon its end provided
with spurs, a central opening in the end of the mandrel, the head having a screw
threaded stem adapted to the central opening and a split portion below the face
plate forming a part of the circumference of the mandrel but not a part of the
face plate. This split portion has a series of teeth or a single tooth adapted to
engage with the threads of the stem when the said split portion is forced inward
by a sliding collar. By this construction I hold the head positively against dis-
placement at the same time allowing it to be easily removed and as easily inserted.
The shank of the mandrel as shown is adapted for connection with any suitable
holder and power may be transmitted to rotate the mandrel in any suitable
manner. The forward end is provided with a face plate having a series of spurs
projecting over its surface, these spurs being adapted to penetrate the material of
the disc which is placed upon them. A central opening passes through the face
plate extending into the body of the mandrel, this opening being perfectly plain
and it is adapted to receive the screw threaded stem of the head, the opening
being of a diameter equal to or slightly exceeding that of the stem so that the said
stem will slip into the opening easily and be capable of an easy removal. The
disc is clamped between the under face of the head and the face plate, the spurs
preventing independent rotation of the disc. In order to hold the stem of the
head in position I provide the mandrel in rear of the face plate with a split portion
this being preferably of spring metal so as to stand normally outside the line of
the circumference of the shank of the mandrel. I prefer to have this split portion
made integral at its rear end with the material of the mandrel though it may be
made of a separate piece and held in place by a pivot or otherwise. The inner
face of the split portion is provided with a single spur, or a series of teeth which
when the split portion is pressed inward engage the threads of the stem and
thus prevents the removal of the head so long as the split part is pressed inward.
In
I do not limit myself to the threaded stem for the head as it may be provided
with a series of notches or a series of parallel depressions though it is desirable to
have the ordinary spiral as more perfect adjustment can thus be secured.
order to press the split portion inward I arrange a sliding collar or sleeve which
encircles the shank of the mandrel and as this sleeve is moved outward toward
the end the split portion is pressed inward until its spur or teeth engage with the
threaded stem of the head. To remove the head it is only necessary to slide
back the sleeve which will allow the split portion to spring outward, and the head
will then be free to be removed.

page_text: COMPLETE SPECIFICATION.
Dental Tools.
A communication from abroad by GEORGE H. PEIRCE, of 178, West Springfield
Street, Boston, Massachusetts, United States of America, Doctor of
Medicine.
I, JOHN CORRY FELL, of the firm of Fell and Wilding, of 1, Queen Victoria
Street, in the City of London, Patent Agent, 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 :-
My invention relates to that class of dental tools commonly known as a "disk
carrier or holder;" and it is the object of my invention to provide a simple form
of holding mandrel adapted to receive the disks with means for clamping the disks
securely when in use, the construction being such as to allow the ready removal
of the worn disks and the substitution of others.
My invention consists in a mandrel having a face-plate upon its end provided
with spurs, a central opening in the end of the mandrel, a head having a screw-
threaded stem adapted to the central opening, and a split portion below the face-
plate forming a part of the circumference of the mandrel, but not a part of the
face-plate. This split portion has a series of teeth or a single tooth adapted to
engage with the threads of the stem when the said split portion is forced inward
by a sliding collar. By this construction I hold the head positively against
displacement, at the same time allowing it to be easily removed and as easily
inserted.
In the accompanying drawings I have represented the mandrel in side elevation
in Figure 1, and in Fig. 2 I have shown a central section longitudinally of the end
thereof.
The shank of the mandrel, as shown at a, is adapted for connection with any
suitable holder, and power may be transmitted to rotate the mandrel in any suit-
⚫able manner. This forward end is provided with a face-plate b, having a series
of spurs projecting from its surface, these spurs being adapted to penetrate the
material of the disk which is placed upon them. A central opening passes through
the face-plate extending into the body of the mandrel, this opening being perfectly
plain, and it is adapted to receive the screw-threaded stem c of the head d the
opening being of a diameter equal to or slightly exceeding that of the stem, so
that the said stem will slip into the opening easily and be capable of as easy
removal. The disk is clamped between the under face of the head and the face-
plate, the spurs preventing independent rotation of the disk.
In order to hold the stem of the head in position I provide the mandrel in the
rear of the face-plate with a split portion, as at e, this being, preferably, of spring
metal, so as to stand normally outside the line of the circumference of the shank
of the mandrel. I prefer to have this split portion made integral at its rear end
I with the material of the mandrel, though it may be made of a separate piece and
held in place by a pivot or otherwise. The inner face of the split portion is
provided with a single spur or a series of teeth, which when the split portion is
pressed inward engages the tbreads of the stem, and thus prevents the removal of
the head so long as the split part, is pressed inward.
I do not limit myself to a threaded stem for the head, as it may be provided
with a series of notches or a series of parallel depressions, though it is desirable
to have the ordinary spiral thread, as more perfect adjustment can thus be secured.
In order to press the split portion inward I arrange a sliding. collar or sleeve,
which encircles the shank of the mandrel, as shown at f and as this sleeve is moved
outward toward the end, the split portion is pressed inward until its spur or teeth
engage with the threaded stem of the head. To remove the head it is only
necessary to slide back the sleeve, which will allow the split portion to spring
outward, and the head will then be free to be removed.

page_text: Having now particularly described and ascertained the nature of my inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is
1. The described dental tool, consisting of a shank or mandrel, a face-plate
carried thereby, a central opening passing through the face-plate and into the
shank, a head having a stem adapted to enter said opening, and a part, as e, having
a spur or teeth for engaging said stem and means for operating said part e,
substantially as described.
2. In combination with the mandrel having a face-plate with spurs, a split
portion in rear of said face-plate, a head having a screw-threaded stem adapted
to enter an opening in the face-plate and mandrel, said split portion having teeth
or a spur for engagement with the threaded stem, substantially as described.
Dated this 30th day of September 1891.
FELL & WILDING,
1, Queen Victoria Street, London, E.C., Agents for the Applicant.