Improvements in Dental Engines.
Year: 1893

page_text: Date of Application, 21st Mar., 1893
Complete Specification Left, 15th June, 1893-Accepted, 15th July, 1893
PROVISIONAL SPECIFICATION,
[Communicated from abroad by WILLIAM PERRY HORTON, Junior, of 106, Euclid
Avenue, Dentist, and ANSEL. B. JONES, of 757, Scovill Avenue, Electrician,
both in Cleveland, Ohio, United States of America.]
Improvements in Dental Engines.
I, HENRY HARRIS LAKE, of the Firm of Haseltine Lake & Co. Patent Agents,
45 Southampton Buildings, in the County of Middlesex, do hereby declare the
nature of this invention to be as follows:-
This invention relates to dental engines, and its principal object is to provide a
dental engine, in which the burr and burr-operating shaft revolves, with means
whereby a current of electricity may be passed through said shaft and burr thereby
deadening the nerve and counteracting the pain incident to boring into a tooth.
To this end the invention consists in certain peculiarities in the construction,
arrangement and combination of the several parts substantially as hereinafter
described.
The improved dental engine comprises the usual standard, the burr actuating
shaft, and the burr on the end of said shaft. The burr actuating shaft is divided
transversely and its sections connected by a flexible piece or shaft whereby the
burr may have its necessary freedom of movement in every direction, but it is
obvious that the shaft may be otherwise constructed for this purpose.
The rear end of the shaft has its bearing in an arm which has a sleeve at its
lower end fitted upon and rigidly secured to the upper end of the standard or
support. A pulley mounted upon the rear end of shaft adapts said shaft for con-
nection with a suitable means for operating it, a suitable source of electricity is
provided, one pole of which communicates by a wire with the dental engine in the
manner hereinafter described, and the other pole by another wire with a suitable
electrode, the latter being intended for application to the external part of the jaw,
or to the head or body of the patient.
As will be seen, the apparatus for producing the electricity, consists of an electric
battery of the ordinary type, but I contemplate using, in practice, one in which the
strength of current applied to the engine can be regulated to suit the demands and
exigencies of special cases. In practice I preferably connect the positive pole of
the apparatus with the dental engine and the negative pole with the electrode; the
latter should preferably be placed in juxtaposition to the nerve or tooth to be
operated upon.
It is not broadly new with me to pass a current of electricity through a dental
tool so as to deaden the nerve of the patient in advance of the operation of the tool,
but heretofore this principle has been employed only in connection with tools
which do not rotate, and the wire extending from a pole of the battery has been
secured directly to the excavator. This would obviously be impracticable in dental
engines in which the tool rotates, and I have therefore devised the construction now
to be fully set forth which makes the principle above mentioned applicable for use
with any of the modern dental engines with but slight changes in the construction
thereof.
As above stated the actuating shaft is supported at its rear end by an arm which
in turn is supported by the standard or support said arm having a horizontal
opening through which said shaft extends and within which it is journalled.
Secured to the standard or to the afore mentioned sleeve by any suitable means
as for example (another sleeve) fitted closely thereto aud projecting upwards
opposite the arm above mentioned, is a second arm which is in contact with the

page_text: rear end or extremity of the driving shaft. This arm is connected by a wire with
the positive pole of the battery, and it forms a contact with the rear end of said
shaft, so that when the current is applied or completed by the placing of the
electrode into contact with the face or other part of the person of the patient, and
the burr against the tooth to be operated upon, the current will pass from the
positive pole of the battery through the second arm thence into and through the
shaft and burr from whence it issues to the nerve and deadens the latter. The rear
end of the shaft forming the contact with the said arm is preferably reduced and
said arm where it is engaged by said reduced end of the shaft is preferably
thickened so as to prevent its rapid wearing away by the friction incident to the
rotation of the shaft. It will of course be understood that said arm does not rotate
with the shaft.
The driving shaft is inclosed within a tube or sleeve which is suitably constructed
RO as to not interfere with the flexibility of the lower end of the shaft, and should
be made of a suitable insulating material to prevent the current escaping from the
shaft other than through the burr.
The lower end of the shaft is preferably made of flexible non-conducting material,
but I do not limit myself to this specific construction. At its lower end it is
provided with a hand-piece which should be made of non-conducting material.
The arms should be insulated in order to prevent the passage of the current from
them into the standard or the sleeve surrounding same.
Dated this 21st day of March 1893.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Dental.Engines.
I, HENRY HARRIS LAKE, of the Firm of Haseltine, Lake & Co., Patent
Agents, 45 Southampton Buildings, in the County of Middlesex 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 dental engines, and its principal object is to provide a
dental engine, in which the burr and burr-operating shaft revolves, with means
whereby a current of electricity may be passed through said shaft and burr thereby
deadening the nerve and counteracting the pain incident to boring into a tooth.
To this end the invention consists in certain peculiarities in the construction,
arrangement and combination of the several parts substantially as hereinafter
described.
In the accompanying drawing illustrating my invention:-
Figure 1 is a side view of part of a dental engine showing the same adapted to
my improvement.
Figure 2 is a section on the line 2-2 of Figure 1, and
Figure 3 is a section on the line 3-3 of Figure 1.
A represents the upper part of the standard of a dental engine, B the burr
actuating shaft, and C, the burr on the end of said shaft. The shaft B is shown
divided transversely and its sections connected by a flexible shaft B' whereby the
burr C may have its necessary freedom of movement in every direction, but it is
obvious that the shaft may be otherwise constructed for this purpose.
The rear end of the shaft B has its bearing in an arm D, which has a sleeve E
at its lower end fitted upon and rigidly secured to the upper end of said standard A.
A pulley F mounted upon the rear end of shaft B adapts said shaft for connection
with a suitable means for operating it. G designates a source of electricity, one
pole of which by the wire I' communicates with the dental engine in the manner

page_text: hereinafter described, and the other pole by the wire H' with a suitable electrode H,
the latter being intended for application to the external part of the jaw, or to the
head or body of the patient.
As will be seen, the apparatus for producing the electricity shown in the drawing
consists of an electric battery of the ordinary type but I contemplate using, in
practice, one in which the strength of current applied to the engine can be regulated
to suit the demands and exigencies of special cases. In practice I preferably
connect the positive pole of the apparatus with the dental engine and the negative
pole with the electrode; the latter should preferably be placed in juxtaposition to
the nerve or tooth to be operated upon.
It is not broadly new with ine to pass a current of electricity through a dental
tool so as to deaden the nerve of the patient in advance of the operation of the
tool, but heretofore this principle has been employed only in connection with tools
which do not rotate, and the wire extending from a pole of the battery has been
secured directly to the excavator. This would obviously be impracticable in dental
engines in which the tool rotates, and I have therefore devised the construction now
to be fully set forth which makes the principle above mentioned applicable for use
with any of the modern dental engines with but slight changes in the construction
As above stated, the shaft B is supported at its rear end by an arm D, which in
turn is supported by the standard A, said arm having a horizontal opening through
which said shaft extends and within which it is journalled.
thereof.
Secured to the standard A, or to the sleeve E, by any suitable means (as for
example a closely fitting sleeve i), and projecting upwards opposite the arm D, is
another arm I, which is in contact with the rear end or extremity of said shaft B.
This arm is connected by the wire I' with the positive pole of the battery, and it
forms a contact with the rear end of said shaft, so that when the current is applied
or completed by the placing of the electrode into contact with the face or other
part of the person of the patient, and the burr against the tooth to be operated
upon, the current will pass from the positive pole of the battery through said arm I,
thence into and through the shaft and burr from whence it issues to the nerve and
deadens the latter. The rear end of the shaft B forming the contact with the said
arm I is preferably reduced, as shown at band said arm where it is engaged by
said reduced end of the shaft is preferably thickened so as to prevent its rapid
wearing away by the friction incident to the rotation of the shaft.
It will of course
be understood that said arm I does not rotate with the shaft.
The shaft B is enclosed within a tube or sleeve J, which is suitably constructed
so as not to interfere with the flexibility of the lower end of the shaft, and should
be made of a suitable insulating material to prevent the current escaping from the
shaft other than through the burr C.
In the drawings I have shown it as made of flexible non-conducting material, but
do not limit myself to this specific construction. At its lower end it is provided
with a hand-piece which should be made of non-conducting material. The arm I
should be insulated as shown at K to prevent the passage of the current from it
into the standard A or sleeve E.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, as communicated to me by
my foreign correspondents, I declare that what I claim is
1. The combination with the standard or support, and rotatable shaft and burr of
a dental engine, of an arm within which said shaft is journalled, a rotatable contact
point on the end of said shaft, a non-rotatable arm serving as the other contact
point, an electricity producing apparatus, one pole of which is connected with said
non-rotatable arm, and an electrode connected with the other pole of said battery
all substantially as shown and described.
2. The combination with the standard of a dental engine, an arın D secured
thereto and projecting upwards therefrom, said arm having an opening through its

page_text: upper end, an insulating tube or sleeve passing at one end into said opening and
having a hand piece at its opposite end, a rotatable shaft passing through said tube
or sleeve, and having a burr at one end and a pulley at its opposite end, said shaft
being divided transversely and having its sections flexibly connected together, of a
rotatable contact point on the rear end of said shaft, non-rotatable arm I extending
upwards from said standard opposite to said arm D, and baving its upper end in
contact with said rotatable contact point, an apparatus, for producing electricity
one pole of which is connected to said non-rotatable arm, and an electrode connected
with the other pole of said battery, substantially as shown and described.
Dated this 15th day of June 1893.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.