Improvements in Drilling Machines for Dentists."
Year: 1898

page_text: Date of Application, 22nd June, 1898-Accepted, 4th Feb., 1899
COMPLETE SPECIFICATION.
Improvements in Drilling Machines for Dentists."
I, PAUL VOLLAND, of 87, Prinzenstrasse, Berlin, S. in the Empire of Germany,
Manufacturer, do hereby declare the nature of this invention and in what manner
the saine is to be performed, to be particularly described and ascertained in and by
the following statement :-
The present invention has for object certain new and useful improvements in
drilling and shaping machines, such as are used by dentists, and it more especially
consists in the peculiar construction and combination of the various component parts
of the machine. The motor, switches, commutator, and current regulator are disposed
in a box which forms the base or plinth of the stand, and the apparatus is adapted to
be turned to all sides as may be required.
In order to render the present invention more readily understood, reference is had
to the accompanying sheets of drawings, in which
Fig. 1 shows a side elevation of the ball-shaped motor, with supporting rings and
protecting box in section;
Fig. 2 shows the telescopic stand which encloses the parts serving to connect the
flexible drill-shaft with the motor-axle, said parts being shown in detail in Figs. 3, 4, 5
and 6, partly in side view and partly in section.
The motor is ball-shaped and of suitable and known construction, the ball-form
requiring least space and therefore being best adapted for the present purpose. The
electric current is conducted to the motor from the floor of the room in any con-
venient manner, and the switches, and regulating appliances are adapted to be worked
by the foot of the operator by means of suitably arranged levers or the like according
to requirement.
In order to admit of the motor a being moved and turned in any desired direction,
it is supported by a correspondingly shaped ring b, which is lined on its inner
periphery with a strip of leather, rubber, or other similar material, said lining being
marked c in the drawings, for the purpose of preventing friction of iron against iron
and wearing of ring and motor-casing resulting therefrom. A second ring d, also
provided with suitable lining, is made to surround the upper portion of the motor-
casing in order to firmly hold the latter. The ring d is adapted to slide on upright
pillars f, which are screwed or otherwise fastened with their lower ends into the body
of ring b, which, in its turn, is firmly secured to the base-plate by screw-bolts b' or
し
in similar fashion. The upper parts of pillars are screw-threaded and partly sur-
rounded by helical springs g, which rest upon the upper ring d and press the latter
against the motor-casing when nuts f¹ are screwed down, g₁ are metal washers or
plates, placed between springs g and nuts in order to maintain springs and nuts in
proper position. According to the degree of compression of springs g, the ring d is
pressed more or less firmly against the motor-casing, in such manner as to allow the
motor to be moved to any required position with more or less freedom. The upper
extremities of the screw-threaded portions of pillars f pass through suitable
apertures in cover-plate k and are adapted to receive nuts e, by means of which the
said cover-plate k, mantle i, and base-plate are firmly held together.
l

page_text: Underneath the base-plate l, and at convenient distance therefrom, a metal or
other plate 6, held in position by studs and screws 5, is provided for the purpose of
forming a protective casing for the switches, commutator and current regulator,
which are of known construction, and also for the terminals of the conducting
wires.
The revolving shaft m of motor a is made to slightly protrude from the ball-
shaped casing of the latter, and is adapted to receive shaft n forming part of
the stand. The stand proper (Fig. 2) is telescopically extensible and encloses
the also extensible driving-shaft for the drilling or shaping tool. It is constructed
as follows:
The shaft n (Fig. 3), having at its upper extremity a horizontally projecting
stud o, is to be attached to the motor axle m by means of a ferrule boss p provided
at its lower end, and is secured by screw p¹. Into a tube r (Fig. 5) of larger diameter
and closed at one end by means of a screw-plug 8, having a bore through its centre,
the hollow shaft t (Fig. 4) is introduced after the aforesaid screw-plug has
been removed. The hollow shaft t has a longitudinal groove t¹ intended to receive
and guide stud o of shaft n, thus admitting of the latter being displaced in an upward
or downward direction within shaft t. Rings or bands h on shaft t, as shown in Fig. 4,
are provided for the purpose of holding and guiding the said hollow shaft within the
tube r, the lowermost of said rings or bands resting upon the centrally-pierced base-
plate of tube r, so as to prevent shaft t from dropping out of the latter. The
upper portion of shaft is thickened or swelled and projects with its extremity u into
the bore of screw-plug 8. The lower end of flexible shaft and drilling-device w
(Fig. 2) is introduced into aforesaid extremity u of shaft t and there fixed by means
of screw u (Fig. 4), which is made to project through groove into the interior of
the hollow shaft t. Through the intermediary of stud o on shaft n the rotary motion
of motor spindle m is communicated to shaft t, and thence to flexible shaft v and
drilling or shaping device w.
In order to firmly connect the herein before described component parts, the upper
portion of screw-plug 8 is provided with an external screw-thread, upon which the
ferrule-like lower portion y of the flexible shaft and drilling device v, w is secured.
All the aforesaid parts forming the extensible stand are contained in and displaceable
within the widest tube (Fig. 6) which is adapted to be screwed, by means of head 3,
into the neck a¹ of motor casing a. Tuber, displaceable in tube z, can be fixed
in position by clamp 2, and a convenient handle for manipulating the stand (marked 1
in the drawings) is provided at convenient distance above the base or plinth of the
apparatus.
The component parts of the described device thus form a compact whole, which
admits of easy mobility of the working parts, whilst being in direct connection with
the motive power and possessing sufficient stability for admitting of the performance
of the various classes of work required by dentists.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1) A new or improved electrical drilling and shaping machine, in which the
motor is moveably placed in suitable supports, after the manner of a ball-and-socket-
joint, substantially as set forth and illustrated.
2) In machines as claimed under 1), a special method of construction, consisting in
the ball-shaped motor being placed in and held by two supporting rings 6 and d,
whereby the said motor is rendered moveable in all directions, the screws connecting
the said supporting rings serving also for securing in their relative positions the
component parts of the protective casing, substantially as herein before described and
illustrated in the accompanying drawings.
3) In electrical drilling and shaping machines, forming the subject of claim 1), for
the purpose of avoiding cord- or belt-transmission, the employment of a telescopically

page_text: extensible driving shaft, consisting of a hollow shaft or tube t longitudinally
displaceable on spindle n, substantially as and for the purpose herein before described
and illustrated in the accompanying drawings.
CAMBIE & WINCKELSETT,
Warwick Buildings, 40, High Holborn, London, W.C.,
For the Applicant.