Improvements in Electrical Apparatus for use in Dental Surgery and other Electro-surgical Treatments.
Year: 1897

page_text: Date of Application, 5th Oct., 1897--Accepted, 20th Nov., 1897
COMPLETE SPECIFICATION.
Improvements in Electrical Apparatus for use in Dental Surgery and
other Electro-surgical Treatments.
I WILLARD ELBRIDGE DOW, Treasurer, of Middle Street, Braintree, County of
Norfolk, State of Massachusetts, United States of America, 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:―
The rapid development within a comparatively recent period of cataphoresis as
applied in dental surgery, has necessitated the use of instruments capable of
delicate manipulation and adjustment for the administration of anaesthetics by the
electric current, and existing means having been found unsuited to the exigencies
of the new methods of treatment, it is the object of my present invention to
present in a compact form, electrical apparatus specially constructed and arranged
to meet the requirements of dental surgery in particular, but also of allied electro-
surgical treatment in general wherever unusual nicety of construction and adjust-
ment is demanded.
The various features of my invention will be fully described and illustrated in
the accompanying drawings and specification, and set forth in the claims.
Fig. 1 shows in perspective the various instrumentalities of my improved
apparatus in their preferred form, assembled in a convenient case;
Fig. 2 is a view in side elevation, partly in section, of a rheostat constructed in
accordance with my invention, including a diagram of the preferred form of
connections;
Figs. 3, 4, 5 and 6 showing respectively in elevation, partly in section, the
various instrumentalities composing my novel apparatus; while
Fig. 7 is a view in section of a universal socket, illustrated to aid in the under-
standing of the manner of operating certain of the instrumentalities.
In the embodiment of my invention selected for description and illustrated in
the drawings, the various instrumentalities are contained within a suitable case A,
in the bottom of which is enclosed a suitable source of electricity, shown as three
cells of dry battery, indicated in dotted lines in Fig. 1, and lettered respec-
tively a, b, a³, their poles being respectively connected by wires (not shown) to
suitable terminals mounted on a base a, preferably in accordance with the diagram
of connections shown in Fig. 2 and to be described later.
An important feature of my invention is the means to permit the administration
of the electric current in constantly increasing volume, but with such minute
graduations of intensity as to avoid the slightest possibility of shock, even in
treating the nerve of a tooth, at its best the most sensitive organism of the human
ly and almost invariably rendered hypersensitive when diseased.
The ordinary rheostat is not sufficiently delicate in adjustment for the purpes,
inasmuch as its resistance is usually cut into or out of the circuit coil by coil,
while rheostats in which provision is made for longitudinal insertion or withdrawal
of resistance are, so far as I am aware, of such complicated construction as to
preclude their use in apparatus of the class under description,
1

page_text: My improved rheostat, the preferred form of which B is best illustrated in
Fig. 2 consists essentially of a resistance medium b, mounted upon the periphery
of a support b, of suitable contour, preferably cylindrical in form and of hard
rubber or other insulating material in substance, although any suitable means
may be used if the resistance medium be properly insulated, and as I have
selected for illustration as a convenient medium, a helix of wire wound in con-
tinuous transverse coils upon the cylinder, the insulation may be accomplished
merely by leaving sufficient space between the convolutions of the spiral.
This body portion of the rheostat with its resistance coil is, in accordance with
my invention, arranged to be carried bodily past, and in electrical engagement
with, one contact piece to bring into contact different points in the length of the
resistance wire composing the coil, while one end may be maintained constantly
in engagement with another contact piece, thus permitting a greater or less length
of the wire to be included in the circuit, as desired, with consequent regulation
in the resistance of the circuit and the strength of the current.
That the introduction or withdrawal of resistance may be gradual, to secure
the advantages to which reference has already been made, the rheostat is rotated
while moving longitudinally, and any suitable means may be adopted to effect
this, but as a convenient and simple mode of causing such concurrent double
motion by a single actuating movement, the cylinder is shown as having a
longitudinal bore 62, the walls whereof are threaded to receive and engage
operatively a threaded rod 63 preferably of substantial equality in length with the
cylinder and suitably supported at its outer end as in a binding post 64.
The rod is thus adapted to serve as supporting means for the body or support
proper of the resistance medium, and may also be utilized as a conductor or contact
piece in providin for constant connection with one end of the resistance, and to
accomplish this a suitable bushing of electro-conductive material is in this
instance inserted in the end of the bore 62, and the end 6 of the resistance wire
brought into fixed electrical contact with it.
This bushing is preferably of metal and threaded internally in order that it
may take the chief wear of the engagement with the rod b³, which, in the instance
illustrated, is fixed in the binding post 64 by the binding screw 67, movement of
the body of the rheostat being effected by manual rotation of the same, to facilitate
which a milled head may be provided.
The contact piece past which the body is to be moved may be of any suitable
construction and arrangement, but I prefer to make it in the form of a fixed
spring clip, substantially as shown at 69, split at its top, as indicated in Fig. 1,
and embracing the body of the rheostat intermediate the ends, affording a wide
bearing or region of contact with the bare resistance medium, thus ensuring
electrical contact, and also serving as a brace or bearing physically for the rheostat
body to relieve the rod or its equivalent of undue lateral strain by accident or
otherwise.
Suitable attaching means, as the screws 610, 611, may be provided to secure the
binding post and clip in about the relative position shown, on a suitable base, and
the wires of the circuit may also be brought into electrical contact with these,
and secured by them. I prefer to connect the rheostat in the circuit in series, and
will now proceed to describe the preferred manner of connecting up the various
contacts, etcetera, shown in perspective in Fig. 1 and diagrammatically in Fig. 2.
C is a switch lever, pivoted at c, and adapted to swing over and contact with
points c¹, 2, 3, 4, while D is a similar switch pivoted at d and adapted to co-
operate with points d¹, da, d³, dr.
E, E are respectively the negative and positive main terminals of the apparatus,
and F, F, the conductors of a flexible double conducting cord connected at one
end to E, E, and at its other end either directly to any desired electrodes, as those
shown at M, P, N, or to a universal socket H preferably of the form shown in
Fig. 7, in section, h being the metallic head to which one of the conductors is
connected. and h¹ a conducting piece within the head from which it is insulated in

page_text: suitable manner, as by the bushing h², and connected with the other conductor
of the cord.
Interchangeable electrodes may be fitted in the socket H, as desired, and thus
included in the circuit, and different conductors, may similarly, be joined to the
terminals.
The terminal E, see Fig. 2, is connected at f' to the negative pole of the battery
cell a¹ and the positive pole of the latter is connected to the switch point c', while
the cell a² is connected in between the points c¹, 2, and the cell a between the
points c, c, a length of resistance r being connected in between the points c³, c.
From the switch--lever c a connection e runs to the rheostat clip 69 and the
binding post 4, is wired at c, c, to the terminal E.
The switch-board lever pivot d is connected at to the switch point c' and thus
to the positive pole of the battery, while between the switch points d¹, dª³¸¸№³, d²,
respectively, are connected-in resistance units 1, 2, 3, and the point dis con-
nected to the conductor c, leading to the terminal E.
To illustrate the operation of these connections in a typical instance, the
electrode M, which is an ordinary sponge electrode of a well-known type applied
to the surface of the patients' body at a convenient region, and one cell a¹ of the
battery cut in by placing the switch lever C on the point c¹.
The other electrode, as that shown at N, is then applied to the organ to be
electrically treated, as for example a tooth, in a cavity of which it is desired to
introduce an anaesthetic by cataphoresis.
The electrode N and its handle I have been specially devised by me for this
purpose and the latter comprises an elongated support p of insulating material (sce
Fig. 5) provided at each end with a contact socket pl, the two being electrically
connected and adapted respectively to receive interchangeably any one of a series
of electrodes of suitable shape, as the electrode N or S, each of which preferably
has a stem-like contact piece or shank n, s, respectively, adapted to enter either of
the sockets p¹.
In its simplest and most desirable form the handle P is composed simply of a
plurality of co-axially arranged tubes, the outer 2 of insulating material and the
inner of electro-conductive material with open ends exposed, as illustrated, to
constitute the sockets described.
The handle P is preferably used in connection with a flexible conductor F
having at its end a contact terminal piece or pin of the very common type shown
at f*, which serves equally well to enter the hole of a binding post, or one of the
contact sockets p', opposite which it is shown in Fig. 5 ready for assemblage.
The electrode N consists essentially of a split member or portion ¹, preferably
composed of a bundle of fine wires united to the shank in suitable manner and
adapted to receive and embrace a pellet or flock of cotton or other suitable
vehicle n² for the anaesthetic.
By a sliding ring ³, or its equivalent, preferably a glass bead or beads, the
degree of separation of the wires may be regulated to permit the insertion of the
electrode in cavities or other recesses of different sizes.
The electrode S, Fig. 5, consists simply of a shank or stem s having an enlarged
head s¹, to cover a wider surface than the electrode just described and its face may
Le flat, or recessed, as indicated by dotted lines.
The electrode N having been inserted in the cavity or otherwise applied, the
circuit is thereby completed through it, the conductor to the terminal E, thenee
Ly the conductor f¹ to the negative pole of the battery a¹, through the point c',
lever C, pivot c, and conductor c* to the rheostat clip 69, resistance b' and binding
post b', from which it is led by the conductors c, c, to the terminal E and back to
the body of the patient through the flexible conductor F and sponge electrode M.
Should the strength of current when all the resistance of the rheostat is in
circuit be insufficient, the head 78 is grasped and rotated, to the left in the instance
illustrated, and the cylinder is forced, by screwing it on the rod, hodil out through
the clip, the convolutions of the resistance medium 61 gradually passing into

page_text: the clip, not coil by coil, but longitudinally of the spiral so that the decrease of
resistance and increase of current strength at the point of application is without
'shock to the patient.
If one battery, without resistance, proves insufficient, after returning the
cylinder to normal innermost position, another battery may be introduced by
throwing the switch-lever Conto the point, and the rheostat cylinder again
screwed out gradually.
As the strength of three batteries is usually excessive for ordinary cases, I insert
between the points and c a length of resistance r so that when the switch
lever C is moved to point 3, the resistance is thrown in, as well as the three
cells, but when the lever is moved to point
on without resistance r.
the entire strength of the battery is
For use when a lamp is connected up between the terminals E, E, and in
analogous instances, I have provided the extra resistance units 1, 2, 3, connected
between the points d', d², d³, d, and the operation of this circuit will be readily
understood from the diagram in Fig. 2 by those skilled in the art.
Where this circuit is used, by throwing the switch C on one of its points the
rheostat B will be included in the circuit of the switch 1) as a shunt and its opera-
tion will affect the resistance thereof accordingly.
In Fig. 3 I have shown a cautery, for the operation of which the circuit of the
switch 1) is peculiarly suited, and which is specially adapted for use in connection
with the socket H to which reference has been made.
The body T of this instrument is preferably formed of an elongated rod or
support of insulating material having a central longitudinal boret through which
is extended a conductor of suitable material and form, while the rod is encased
in a bi-part electro-conductive sheath, the members 2, 3, whereof are slightly
separated and so insulated, while the insulating gap is bridged by a spring
contact arm suitably placed to enable the operator to depress it when grasping
the handle for operation.
Between the outer end of the conductor t and sheath member 2 a loop * of
platinum or other electro-conductive material of high resistance is extended
outwardly, a convenient manner of attachment being to wedge the ends of the
loop, as at to into a recess in the extended end, integral or otherwise, of the con-
ductor t, and similarly at t into an arm 18 soldered or otherwise connected to tha
sheath t³.
The sheath member is preferably externally threaded and the end of the
conductor slightly extended to engage respectively the metallic head h and
contact piece when the instrument is secured into the universal socket H.
A cap T may be provided to cover the cautery loop when not in use.
The instrument 0, shown in Fig. 4 in section partly in elevation, is especially
designed for magnetic exploration of shallow but confined portions of the body,
particularly the eye, from which it is adapted to withdraw magnetic bodies.
It consists of an elongated core o of magnetizable material upon which is wound
a helix of insulated wire o¹, surrounded in turn by a metallic protecting sheath of
adapted to serve as a handle and substantially co-extensive with the helix of but
beyond which is extended a reduced, conical continuation o³ of the core o, in
position to be readily presented to the foreign substance in the eye or like part of
the body where such a "magnetic electrode" would be of utility.
The ends of the sheath are preferably closed by bushings o of insulating
material, thus permitting one end of the helix to be connected to the sheath, and
the other to the core, which is headed at 0, the diameter of this end of the
electrode," and its external construction, being suitable to permit its connection
with the universal socket H, in the same manner as that described with reference
to the cautery.
A spring clasp 5 serves to receive the socket H when not in use, and to prevent
it from swinging around in the case,

page_text: 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:-
The improvements in electrical apparatus for use in dental surgery and other
electro-surgical treatments; that is to say:-
1. In a rheostat, a resistance coil or helix; a contact piece in constant electrical
engagement with the convolutions thereof; and means, acting upon rotation of
said coil, to cause axial movement of the latter, substantially as described.
2. In a rheostat, a rotatable body or support; a helix of resistance wire mounted
thereon; a contact piece in constant electrical engagement with one or more of
the coils of said helix; and means engaging said body and acting upon rotation
of the same to cause axial movement thereof, substantially as described.
3. In a rheostat, a rotatable cylindrical body of insulating material having a
longitudinal bore; resistance wire wound on said body in the form of a helix with
separated coils; a contact piece in constant electrical engagement with said helix;
a rod entering the bore of said cylinder, and means intermediate said rod and
cylinder, acting upon rotation of the latter to cause axial movement thereof,
substantially as described.
4. In a rheostat, a rotatable tubular body of insulating material, provided with
a peripherally mounted resistance helix, and threaded interiorly; a threaded
member entering and in operative engagement with said tubular body, and
electrically connected with one end of said helix; a clip or contact piece embracing
said body and in electrical contact with said helix; means to rotate said body;
a support for said threaded member; and a base upon which said clips and support
may be fixed in adjusted relative position, substantially as described.
a support for said threaded member; and a base upon which said clip and support
of insulating material provided at its ends with similar contact sockets electrically
connected with one another and adapted to receive interchangeably any of a series
of electrodes having similar contact pieces or shanks, substantially as described.
6. A universal electrode-support or handle composed of a plurality of co-axially
arranged tubes, the outer of said tubes being formed of insulating material, and
the inner of conductive material arranged to present open ends respectively adapted
to receive any of a series of interchangeable electrodes, substantially as described.
7. An electrode of the class described, comprising a contact shank adapted to
enter a suitable contact socket and having a split portion or member adapted to
receive a pellet of fibrous material or other suitable vehicle for an anaesthetic,
substantially as described.
8. An electrode of the class described, comprising a shank or contact piece; a
bundle of wires secured thereto; and a ring or the like to regulate the degree of
separation of the wires in said bundle, substantially as described.
9. An electrode consisting of a contact piece or shank, adapted to enter and be
supported by a suitable contact socket, said shank being provided with a head, or
laterally extended member, substantially as described.
10. An electrode, or cautery, of the class described, comprising an elongated
tubular support of insulating material; a conductor arranged longitudinally
within said support; a bipart sheath of conductive material mounted externally
on the support, the members of the sheath being insulated from each other; à
cautery loop between and electrically connecting said conductor and sheath at
one end; means to connect the members of said sheath electrically at will; said
electrode having its parts arranged at its end distant from the cautery loop to
enter a suitable contact socket, substantially as described.
11. A magnet or magnetic electrode, comprising an elongated core of magnet-
izable material, an insulated helix of wire surrounding the same and a metallic
sheath for said helix and core; said electrode presenting at one end a reduced
continuation of the core, beyond said helix and sheath, and means to connect said
helix in circuit with a suitable source of electricity, substantially as described.
12. An electrode of the class described, comprising a nail -like core of magnet-

page_text: izable material; an exciting helix therefor and having one end of its wire
connected thereto; a metallic protecting sheath for the intermediate portion of
the core,
and electrically connected to the other end of the helix wire; said core
extending at its point beyond said sheath and helix, and arranged at its head to
enter and engage with one contact member of a suitable contact socket, while the
portion of the sheath adjacent the head of the core is adapted to engage with the
other contact member of said socket, substantially as described.
13. An electrode of the class described, comprising a shank or contact piece; a
split portion or member adapted to receive a pellet of fibrous material or other
suitable vehicle for an anaesthetic; and a bead or beads of insulating material to
regulate the diameter of said split portion, substantially as described.
Dated the 4th day of October 1897.
WM. BROOKES & SON,
55 and 56 Chancery Lane, London, Agents for the Applicant.