Improvements in Backing and Crowns for Artificial Teeth.
Year: 1899

page_text: Date of Application, 25th Apr., 1899-Accepted, 15th July, 1899
COMPLETE SPECIFICATION.
Improvements in Backing and Crowns for Artificial Teeth.
I, CEPHAS WHITNEY, Dentist, of 39, Duke Street, Kingston, Jamaica, British
West Indies, do hereby declare the nature of my invention, and in what manner
the same is to be performed, to be particularly described and ascertained in and
by the following statement:-
-
The object of my invention is to provide a backing and crown for artificial
teeth, so constructed, that the facing or porcelain, if fractured or damaged, may
he quickly and easily removed from the backing and another porcelain or facing
as conveniently substituted.
A further object of my invention is to provide a crown or cap for the facing
which will serve materially to hold the facing in proper position and will,
furthermore, act to prevent the facing from chipping or fracturing at its cutting
edge. Another object of my invention is to provide a backing for artificial teeth
which will enable a tooth to be applied to crown or bridge work in the customary
manner, if so desired.
The invention consists of novel features of construction which will be herein-
after described and pointed out in the claims.
Reference is to be had to the accompanying drawings forming a part of this
specification, in which similar characters of reference indicate corresponding parts
in all the views.
Figure 1 is a front elevation of an artificial tooth to which the improvement
has been applied;
Figure 2 is a side elevation of the same;
Figure 3 is a sectional elevation through the complete tooth;
Figure 4 is a cross section of the tooth;
Figure 5 is a perspective showing the facing from the inner side;
Figure 6 is a perspective showing the backing from the outer side;
Figure 7 shows the locking pin;
Figure 8 is a side elevation of a tooth showing a slightly modified construction;
Figure 9 is an elevation of the same from the inner side of the tooth;
Figure 10 is a sectional elevation of a tooth showing a slightly modified con-
struction, the principle being the same;
Figure 11 is a cross section of the form shown in Figure 10;
Figure 12 is a cross section showing another slightly modified construction;
and
Figure 13 shows a stud which may be inserted in an ordinary facing so as to
adapt it for use with my invention.
The facing A is such as is ordinarily employed in the construction of artificial
teeth, being composed of porcelain or any suitable material. The inner or rear
surface of the facing is provided, as shown in Figure 5, with one or more
eyes 11, which may be secured to the facing in any suitable or approved manner,
or formed as a part thereof. A single eye is illustrated in Figure 5, which is
attached to a plate 12, the said plate being counter-sunk in the back of the facing
and held therein by dove-tailing, cement or other suitable means. In Figure 13
[Price Sd1

page_text: a stud is shown which is designed to screw into the facing and thus to form an
eye similar in effect to the eye 11, shown in Figure 5.
In Figure 6 I have illustrated the backing B, combined with a crown C. The
backing B. is preferably of metal which may be of any kind found suitable to the
purpose. The backing is usually made tapering, its front face 13 being flat so
as to fit snugly against the rear face of the facing A, the outer face 14 of the
backing being inclined, but if desired, the backing may be of uniform thickness
from top to bottom.
The backing is provided with one or more recesses or openings 15, opening at
the flat side thereof and corresponding with the eyes 11 employed in connection
with the facing. Each recess 15 in the backing, is adapted to receive an eye 11
and the backing is furthermore provided with a bore or longitudinal aperture 16.
adapted to receive the locking pin 19 which also passes through the eye 11 and
locks two parts together. In the forms shown in Figures 1 to 6 inclusive, this
bore and pin extend from the top to the bottom, while in Figures 8 to 11
inclusive, they extend only a part of the way, and in Figures 10 and 11 they are
curved. It is evident that the construction described may be reversed by placing
the lug upon the backing and in the recess in the facing, although the other
construction is preferred. At one end of the backing B is located the crown C
when a crown is used. This is preferably a part of the back and extends beyond
its inner face, the under surface of said crown being more or less under-cut, as
illustrated at 17 in Figure 6. In practice, if it is desired, the backing may be
reinforced by a rib 18 which extends along its outer face at its centre and from
top to bottom, the recess or recesses 15 being in such case located within the said
rih. In practice the backing is placed against the rear face of the facing, the
eves or lugs 11 of the facing being made to enter the recesses 15 in the back.
When the backing is so placed on the facing, the crown C will extend over and
neatly receive the biting or cutting edge of the facing, as is illustrated in
Figures 1, 2 and 3. The backing is firmly secured to the facing by passing a
pin or key 19, the lower end of which is ordinarily tapering, through the bore
or aperture 16 in the backing, and through the eye or eyes 11, attached to the
facing and occupying the recess 15 in the back. When a facing becomes frac-
tured or otherwise damaged, it may be readily removed by abstracting the lock-
ing pin or key 19 whereupon it may be expeditiously and conveniently replaced
by a new facing.
In the form shown in Figures 10 and 11, a recess is formed in the rear face of
the facing A within which is secured the piece 12 having a bore therein, the
bore in this case being curved instead of straight. The piece 12 in this case has
a recess receiving a lug b upon the backing B. This lug, as well as the backing,
at proper points, have holes which will register with the bore in the piece 12
when in place. The pin 19 is curved and fits the bore, securing the parts in
place. In Figure 12 is shown a modification in which the lug not provided
with a perforation, but with side notches which receive the locking pin or pins
19. Two locking pins are shown, but it is evident that one only may be used,
or the lug be made in the form of a hook and a single locking pin used. The
facing provided with my improved backing and crown may be attached to crown
and bridge work in the customary of in any desired manner, and if at any time
it is injured, it may be quickly and cheaply replaced.
As shown in Figures 8 and 9, the crown C may be omitted and the backing B
may be provided with an off-set 20 caused by striking out the material of the said
backing in producing therein the opening or recess 15 herein before referred to
and shown in the other figures.
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;-
-
1. A tooth composed of a facing and a backing, one of which has a recess and

page_text: a bore leading thereto, while the other has a lug fitting the recess, and a locking
pin passing through the bore and locking the lug, substantially as described.
2. In a tooth constructed after the manner defined under head 1, the crown
projecting from a backing B over the end of the facing, substantially as
described.
3. A curved locking pin 19, passing through curved bores in the facing A
and lug b, substantially as described.
Dotal this 25th dow of i 1900
A. M. & WM. CLARK.
Chartered Patent Agents, 53, Chancery Lane, London.