Improvements in Dental Engine Hand Pieces.
Year: 1898

page_text: Date of Application, 22nd June, 1898--Accepted, 13th Aug., 1898
COMPLETE SPECIFICATION.
Improvements in Dental Engine Hand Pieces.
I, ARTHUR WILLIAM BROWNE, of Prince's Bay, in the County of Richmond,
and State of New York, United States of America, Manufacturer, 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 hand-pieces for dental engines, and consists of certain
improvements, hereinafter claimed, applicable to that class of hand-pieces in which
the tools carried thereby may be operated at various angles relatively to the handle
or body of the hand-piece.
The object of my invention is to provide a hand-piece of this class, of simple
and comparatively durable construction, and in which the tools carried by it may
be quickly and easily adjusted to any angle, within certain limits, relatively to
the handle portion, the tool firmly locked in any position to which it may be
adjusted, or yieldingly held in any position of angular adjustment, and possessing
other advantages, all of which will hereinafter be more fully explained.
In the accompanying drawings Figure 1 is a view in side elevation of a hand-
piece made in accordance with my invention. Fig. 2 is a sectional longitudinal
central view of the front portion of said hand-piece, on an enlarged scale. Fig. 3
is a view in elevation of the front portion of the hand-piece shown in Figure 2
and turned at a right angle thereto. Fig. 4 is a cross sectional view of the hand-
piece on the line 4-4 of Fig. 3.
The head or tool-holding portion of the hand-piece consists of a tubular elbow A
composed of two members A1 and A2 arranged preferably at a right angle relatively
to each other. Fitted in the bore of the member A¹ of the head and having bearing
therein is a rotary socket or tool-holder B, provided with a gear B¹, which rotates
with the tool-holder in an enlarged portion a of the bore of the member A¹ of
the head. A perforated nose-piece C having screw-threaded connection with
the member A¹, serves to hold the socket or tool-holder in place in the head.
Suitable operating tools, such as the bur D. are adapted to be fitted in the tool
holder by way of the shank D₁ which is inserted in the socket of the tool-holder,
and a flattened portion on the inner end of the shank engaging a corresponding
flattened projection b in the inner end of the socket of the tool-holder serves to
cause the operating tool to rotate with the tool-holder. In the end of the tool
shank is an annular groove d' adapted to be engaged by a notched swing-slide E
pivoted by a screw e within a slot in the head A. The outer end of the swing
slide is rounded and milled and projects slightly beyond the front of the head A
in order that it may be readily swung by the thumb or finger into operative
position to cause its notch to engage the groove of the operating tool and securely
hold the same in position in the tool-holder without interfering with its rotary
motion, or be swung out of engagement with said operating tool to permit the
same to be withdrawn from the holder. Fitted in the bore of the member A³
of the head is a gear F. a socket bearing f in the front end of which fits and
rotates upon a journal a projecting from the partition between the bores of the
respective members of the head. The front end of the gear F engages the gear
of the tool-holder B, which projects through an opening in said partition, as will
be seen by reference to Figure 2, whereby when the gear F is rotated, as will

page_text: later on be explained, rotary motion is imparted to the tool-holder and the tool
carried thereby.
:
For the purpose of making suitable supporting connection between the above
described head or tool-holding portion of the hand-piece and the handle-portion
or body, further on to be described, in such a way that it may be adjusted to
any angle, within certain limits, relatively to said-handle-portion and at the
same time provide a suitable driving connection between the gear F of the head
and the driving spindle of the hand-piece, which driving connection will be freely
operative in whatever position of angular adjustment the head may occupy
relatively to the handle-portion, I have provided mechanism as follows:--
On the exposed end of the member A2 of the hand-piece head is a rounded or
ball-like projection G constituting one member of a universal or ball-and-socket
supporting connection between the head and handle-portions of the hand-piece,
the other member of this connection being formed by a spring-jawed socket H
split at and provided with a tubular exteriorly threaded extension H¹ which
screws into the front interiorly threaded end of a tubular metallic handle section I
of the handle-portion. The connection between the socket extension H' and the
handle section I is preferably by means of left-handed screw threads, and the
socket member H may be securely held in the handle section I by means of a
set screw i passing through an opening in said handle section and into an indenta-
tion on the extension H¹ of the socket member. The ball member of the sup-
porting connection fits in the socket member, and may be freely moved about
therein in any direction, and consequently the hand-piece head may be moved
or adjusted to any angular position relatively to the handle-portion, the extent of
this universal movement of the head being limited by the head coming in contact
with the outer end of the socket member H. Surrounding the spring-jawed socket
member H is a clamp sleeve J having a cone-shaped socket corresponding with
the exterior cone shape of the socket member H. The inner end of this sleeve.
which is reduced in diameter, surrounds and freely turns upon one end of a long
nut K screwing upon the threaded socket extension H¹, and a flange or annular
shoulder k on the forward end of said long nut and bearing against a shoulder on
the interior of the clamp sleeve, and a collar L secured to the long nut by means
of a set screw l, serve to hold the clamp sleeve upon the long nut and cause said
sleeve to move endwise with the nut, whilst leaving said nut free to be turned
without turning said sleeve. The collar L is preferably roughened or serrated
upon its outer surface, and provides ready means for turning the long nut in
opposite directions. Turning of the nut in one direction by means of its serrated
collar moves the clamp sleeve forward to cause the spring jaws of the socket H
to grip and hold the ball member G with more or less tightness according to the
amount of pressure brought to bear by the clamp sleeve, while turning of the nut
in the opposite direction releases the ball member from pressure of the socket
member, and leaves it free to be moved in all directions.
The front section M of a rotary driving spindle has bearing in the tubular exten-
sion H¹ of the socket member H of the said universal supporting connection, and
is connected at its rear end with the main section M¹ of said driving spindle,
which is mounted in bearings in the handle portion of the hand-piece. Near
the front end of the spindle M is an annular flange m³ which abuts against a
shoulder h¹ on the inside of the socket member H, and serves to prevent inward
movement of the driving spindle, outward movement of this spindle being prevented
by the end of the main section M¹ of the spindle abutting against the inner end
of the socket member extension H¹.
The universal driving connection between the gear F of the hand-piece head
and the driving spindle M is shown as consisting of four lateral projections m on
the end of the driving spindle M and which are adapted to engage with as many
longitudinal slots or notches f¹ in the end of the gear F opposite to the end thereof
provided with the gear teeth. The extremity of the driving shaft at the centre
or junction of the lateral projections, is formed with a slightly rounded projec-

page_text: tion m' adapted to fit in a corresponding concaved seat in the bottom of a socket
in the gear F into which socket the slots or notches f¹ open. It will be seen that
the gear F may be freely rocked in all directions about the projection m¹ as a
centre, without interfering with the driving connection between said gear F and
driving spindle, even while the parts are being operated. It will further be seen
that the projection m¹ about which the universal driving connection turns is also
the centre of the universal or ball-and-socket supporting connection, and that
when the hand-piece head is rocked in any direction about said universal sup-
porting connection, the said universal driving connection permits of the gear F
moving correspondingly.
A hard rubber handle section N, preferably flat-sided or triangular in cross
section, may be fitted upon the metal handle section I, and prevented from turning
thereon in suitable way. A metal ferrule 0 screwed upon the rear end of the
handle section I, and a dog, not shown, on the rear end of the driving spindle M¹,
form part of a slip-joint" connection of well known construction, for making a
readily detachable connection with a flexible driving shaft and sheath of a dental
engine.
<<
The operation of my improved hand-piece is as follows:-With the hand-piece
suitably connected to a dental engine and an instrument or operating tool of the
desired size and shape, as the bur D, locked in the tool-holder B, rotary motion
may be imparted to the driving spindle M by the operation of the engine, and
this rotary motion communicated to the tool-holder and tool carried thereby by
means of the universal driving connection between said driving shaft and the
gear F, and the angle gearing between the gear F and the gear B¹ of the tool-
holder B. By relieving the ball member G of the universal supporting connection
between the head and handle portions of the hand-piece from pressure of the
spring jawed socket member H, by turning of the collar L, the head may be
moved in any direction whatever to vary the angular position of the operating
tool relatively to the longitudinal axis of the hand-piece, the universal driving
connection moving with and accommodating itself to the movement of the universal
supporting connection. After the head and tool have been adjusted to the proper
position, they may be firmly clamped and retained in such position by turning
of the collar L in the proper direction, or any desired degree of frictional tension
may be brought to bear upon the head by means of the collar.
In a hand-piece constructed according to my invention, the operating tool, it
will be seen, is susceptible of a very wide range of adjustment in all directions.
It can be moved in the arc of a circle in the plane of the longitudinal axis of the
hand-piece from its extreme obtuse angle of say 115°, to its extreme acute angle
of say 630, these extreme positions being indicated by dotted lines, Fig. 2. When
in either of these extreme positions, or in any intermediate position between them,
the operating tool may be moved in a complete circle about the longitudinal axis
of the hand-piece. It will further be seen that the hand-piece head may be moved
laterally to adjust the longitudinal axis of the operating tool to one side or the
other of the longitudinal axis of the handle-portion, such positions being indicated
by dotted lines Fig. 3. When in either of these positions the operating-tool may
be adjusted to various angles relatively to the hand-piece, approximately the same
as when the longitudinal axis of the operating-tool and the hand-piece lie in
the same plane. In fact the operating tool owing to the universal connections
may be adjusted, within certain limits, in any direction to occupy any angular
position with reference to the hand-piece. The construction is such that the
operating tool may be locked in any position whatever to which it may he
adjusted. which is not true of adjustable angle hand-pieces as heretofore con-
structed, and in which detent devices are emploved to lock the operating tool in
certain determined positions. The clamping device for the universal or ball-
and-socket supporting connection between the hand-piece head and handle portions
be readily actuated to firmly lock the head in any position to which it may
he adjusted so that the position of the operating-tool cannot be altered without
may

page_text: first releasing the clamping device; or said clamping device may be adjusted
or set to apply just so much pressure upon the supporting connection as is necessary
to hold the operating-tool against ordinary working pressure applied to it in
operation, while leaving it free to be readily adjusted to any position by the thumb
or finger without the necessity of actuating the clamping device; or just so much
pressure may be applied to the supporting connection by the clamping device, as
will permit the operating tool to yield under excessive working pressure in operation,
while holding it with sufficient force to prevent its yielding to ordinary or light
pressure in operation, this latter adjustment being particularly advantageous
when the instrument is being operated upon frail teeth in the human mouth, a
function unique in this class of devices. One advantage of the capability of the
operating tool being turned in a circle about the longitudinal axis of the hand-
piece, is that when, as shown, the finger-grasping portion of the hand-piece, as N,
is flattened or tri-angular in cross-section, the dentist may turn the operating
tool about the hand-piece without changing the position of the same in his hand.
By this means, the operating-tool may be readily adjusted so that it may be
operated when downward, upward or sidewise pressure is applied to it, without
turning the hand-piece to accommodate the changed direction in which the
operating tool is to be operated.
It should be observed that my present invention consists of a compound universal
connection; that is to say, a universal or ball-and-socket supporting connection
between the hand-piece head and the handle-portion, and a universal driving con-
nection between the tool-holder of said head and the driving spindle of the handle-
portion, together with the means for clamping the same. As to this compound
universal connection and its clamping device, it is obvious that the detailed con-
struction herein shown and described may be varied or modified, whilst keeping
within the spirit and scope of my invention, and I therefore do not wish to confine
myself to said detail construction. As to the other features of the hand-piece
herein shown and described, I desire it to be understood that I do not claim them
herein as of my present invention, and also that my present improvements may
be applied to adjustable angle hand-pieces differing in construction from the one
shown and described. For example, the handpiece head and the tool-holder, the
handle-portion, and the ferrule of the slip-joint connection may be of any well
known or suitable construction. Instead of applying my improvements to a hand-
piece of the "slip-joint" variety, it is obvious that they may be used with any
other style of adjustable angle hand-pieces, such as the ordinary "angle attach-
ment" which is adapted to be fitted upon a hand-piece, or with a hand-piece that
is connected directly to an engine arm or flexible shaft. Nor is it necessary that
the handle-portion of the hand-piece should be flattened or triangular in cross
section. It will also be obvious that that part of my improvements which provides
for yieldingly or frictionally clamping the adjustable hand-piece head is not con-
fined to a hand-piece in which the head may be universally adjusted, for I believe
myself to be the first to provide means fe yieldingly holding the heads of adjust-
able angle dental engine hand-pieces.
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
claim is
1. The combination, in a dental engine adjustable angle hand-piece, of the
handle-portion, the head, a ball-and-socket supporting connection between said
handle portion and said head, a driving spindle mounted in said handle-portion,
a tool-holder mounted in said head at an angle to said handle-portion, and a
universal driving connection between said driving spindle and said tool-holder,
the said universal supporting and driving connections having a common centre,
substantially as and for the purposes hereinbefore described.
2. The combination, in a dental engine adjustable angle hand-piece, of the
handle-portion, the head, a ball-and-socket supporting connection between said

page_text: handle-portion and said head, a driving spindle mounted in said handle-portion,
tool-holder mounted in said head, a universal driving connection between said
driving spindle and said tool-holder, and an adjustable clamping device for fric-
tionally clamping said ball-and-socket supporting connection between the handle-
portion and the head, whereby any desired degree of frictional tension may be
applied to said supporting connection, substantially as and for the purposes here--
in before described.
3. The combination, in a dental engine adjustable angle hand-piece, of the
handle-portion, a head having ball-and-socket supporting connection therewith,
a tool-holder mounted in said head at an angle to said handle-portion, and provided
with gear-teeth, a gear mounted in said head at an angle to said tool holder and
meshing with the gear teeth thereof, and a rotary driving spindle mounted in said
handle-portion and having universal driving connection with said gear, substan-
tially as and for the purposes hereinbefore described.
4. The combination, in a dental engine adjustable angle hand-piece, of the
handle-portion provided with a split socket, a head provided with a ball fitted
in said split socket, an endwise movable sleeve surrounding said split socket
for causing the same to frictionally clamp the ball on said head, means for adjusting
said sleeve, a tool-holder mounted in said head, a driving spindle mounted in said
handle-portion, and a universal driving connection between said tool holder and
said driving spindle, substantially as and for the purposes herein before described.
5. The combination, in a dental engine adjustable angle hand-piece, of the
handle-portion, a head having ball-and-socket supporting connection therewith,
a tool-holder mounted in said head at an angle to said handle-portion and provided
with gear teeth, a gear mounted in said head at an angle to said tool-holder and
meshing with the gear teeth thereof, said gear being provided with a socket, and
a concave seat in the bottom of said socket, and also with slots in the side of said
gear and which open into said socket, a rotary driving spindle mounted in the
handle-portion and provided with a rounded extremity having bearing in the seat
in said gear and also with lateral projections which engage the slots in said gear,
substantially as and for the purposes herein before described.
6. The combination, in a dental engine adjustable angle hand-piece, of the
handle-portion, a spring jawed socket provided with a tubular externally threaded
extension connected to said handle portion, a clamp sleeve surrounding said spring
jawed socket, a nut screwing upon the threaded extension of said socket and
having swivelling connection with said sleeve, a collar secured to said nut, a driving
spindle having bearing in said handle portion and passing through said tubular
Bocket extension and projecting into said socket, a head provided with a ball seated
in said socket, a tool holder mounted in said head at an angle to said handle portion
and provided with gear teeth, a gear also mounted in said head at an angle to said
tool holder and meshing with the gear teeth thereof, and a universal driving con-
nection between said gear and the driving spindle of the handle portion, substan-
tially as and for the purposes hereinbefore described.
7. The combination, in an adjustable angle hand-piece for dental engines, of
the handle portion, the driving spindle mounted therein, the head provided with
a tool holder arranged at an angle relatively to said handle portion, said head and
tool holder being adjustably connected to said handle portion and said driving
spindle, respectively, and an adjustable clamping device for frictionally clamping
said head, whereby it may be either firmly held in any position whatever to which
it may be adjusted or yieldingly held against working pressure while in operation,
but free to be angularly adjusted without operating the clamping mechanism,
substantially as described.
1000