Improvements in Dental Matrices and Matrix Retainers.
Year: 1895

page_text: Date of Application, 27th Aug., 1895
Complete Specification Left, 1st May, 1896-Accepted, 4th July, 1896
PROVISIONAL SPECIFICATION.
Improvements in Dental Matrices and Matrix Retainers.
I, JOSEPH MILTON STROUT, of 457 Congress Street, Portland, in the County
of Cumberland, and State of Maine, United States of America, Dentist, do
hereby declare the nature of this invention to be as follows :--
The object of my invention is to provide a matrix retainer that may be easily
and expeditiously adjusted and used upon either the upper palatal or the lower
teeth or the buccal, lingual, or palatal surfaces and cross ways of the teeth, with the
points between or on approximate surfaces. A further object of the invention is
to so construct the matrix retainer that it can be set up by the fingers in like
manner as a wrench and whereby, furthermore, the retainer can be placed in
position with the under side of the back portion of its barrel turned up or under
at a right angle, in which position it will act as a napkin holder and cheek
distender, or whereby it may be turned down close to the gum. The matrix
retainer may likewise be placed on the inside or lingual surface of the lower teeth
with the matrix encircling the outside or buccal surface of the molars and
bicuspids, and be at the same time out of the way of the operator, assisting also
Another object of the
to hold the napkin down and the tongue out of the way.
invention is to provide a matrix which will be simple, durable, and economic in its
construction, and made of sections united at one point in their length in a manner
to be readily disengaged when they are to be withdrawn, obtaining the result of a
band matrix yet possessing all the advantages of a two-piece matrix.
The matrix retainer consists of a pair of opposing jaws adapted to engage the
matrix, the one jaw being formed on a barrel and the other jaw on a screw threaded
shank which engages an interiorly screw threaded sleeve held to turn within the
barrel, the sleeve being provided with a nut whereby the jaws may be moved
towards and away from one another. The sleeve is held in position by a collar
which screws on the end of the barrel and engages a rib on the sleeve. The jaw
on the shank is curved in the direction of the jaw on the band and both preferably
terminate in a spur. The matrix is preferably made of light spring metal and is
in the form of a band. It may be made in oue piece, the ends being disconnected,
or in two sections the sections being connected at the back by overlapping the ends
at that point and securing them together by a fastening device. Near each end of
what may be termed the front of the matrix there are apertures or openings to
receive the spurs of the jaws of the retainer. The opposite end of each section
is provided with one or more openings and the fastening device which preferably
consists of a plate having pins corresponding in number and relation to each other
to the openings in the matrix sections. A button is pivoted on the said plate,
having a handle and recesses in one of its side edges to receive the pins of the
plate. When the sections of the matrix are to be connected its ends are placed
upon the plate and the pins passed through the openings in both of the sections.
The plate will then be upon the inner face of the band thus formed and by carrying
the button upward over the overlapping edges of the sections until its recesses
receive the projecting ends of the pius, a firm and locking connection will be
obtained between the sections of the retainer.
The matrix having been placed around a tooth, the one jaw is brought to an
engagement with one indented or apertured portion of the band matrix, and the

page_text: nut or head is then turned until the barrel has traveled sufficiently upon the shank
of the other jaw to engage its spur with the opposite side of the matrix band and
by continuing to turn the head the band will be made to bug tightly to the tooth
and will be held in firm position thereon. When the matrix is to be removed, the
fastening device is disconnected from the sections of the matrix and the sections
may be removed either by drawing either out separately from between the teeth,
or the two sections may be drawn out simultaneously, still in engagement with the
retainer.
The retainer may be applied to a matrix which is made in two substantially
triangular sections, and it' evident that the retainer will act as effectively in this
form of matrix as in the band form.
Dated this 27th day of August 1895.
A. M. & WM. CLARK,
53, Chancery Lane, London, Chartered Patent Agents.
Improvements in Dental Matrices and Matrix Retainers.
I, JOSEPH MILTON STROUT, of 457 Congress Street, Portland, in the County
of Cumberland and State of Maine, United States of America, Dentist 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 object of my invention is to provide a matrix retainer that may be easily
and expeditiously adjusted and used upon either the upper or the lower teeth, or
the buccal, lingual or palatal surfaces and cross ways of the teeth, with the points
between or on approximate surfaces. A further object of the invention is to so
construct the matrix retainer that it can be set up by the fingers in like manner as
a wrench, and whereby furthermore, the retainer can be placed in position with
the under side of the back portion of its barrel turned up or under at a right angle,
in which position it will act as a napkin holder and cheek distender, or whereby it
may be turned down close to the gum. The matrix retainer may likewise be placed
on the inside or lingual surface of the lower teeth with the matrix encircling the
outside or buccal surface of the molars and bicuspids, and be at the same time out
of the way of the operator, assisting also to hold the napkin down and the tongue
out of the way.
Another object of the invention is to provide a matrix which
will be simple, durable and economie in its construction, and made of sections
united at one point in their length in a manner to be readily disengaged when they
are to be withdrawn, obtaining the result of a band matrix yet possessing all the
advantages of a two-piece matrix.
The invention consists in the novel construction and combination of the several
parts, as will be hereinafter fully set forth and pointed out in the claims.
Reference is to be had to the accompanying drawings forming a part of this
specification, in which similar figures and letters of reference indicate corresponding
parts in all the views.
Figure is a plan view of a portion of a set of teeth, illustrating the application
of the retainer to a matrix placed upon one of the teeth, the retainer being shown
in plan view;
Figure 2 is a side elevation of the retainer and that portion of the matrix
engaged thereby ;
Figure 3 is a longitudinal section through the retainer;
Figure 4 is a transverse section taken on the line 4-4 of Figure 3;
Figure 5 is a side elevation of the matrix retainer, illustrating its application to
a matrix made in two disconnected parts;

page_text: Figure 6 is a plan view of one of the sections of the matrix shown in Figure 5 ;:
Figure 7 is a rear elevation of the improved matrix ;
Figure 8 is a section through the improved matrix, taken on the line 8-8 of
Figure 7; and
Figure 9 is a view of the improved matrix from the rear, illustrating the latch
disengaged from the sections of the matrix.
The matrix retainer which is best shown in Figure 3, consists of a barrel 10.
having near one of its ends upon one side a fork 11 terminating in a spur 12. The
interior of the barrel may be made in one diameter, or in two diameters as
illustrated, and the bore is plain. At or near what may be termed the outer or
handle end of the barrel, an exterior thread 13 is produced. Within the enlarged
portion of the bore of the barrel a sleeve 14 is entered and turns loosely, the
interior of the sleeve being provided with a thread, and terminated at its outer end'
in a thumb nut or head 15. The sleeve is further preferably provided near the
thumb nut with an annular exterior rib 16.
The sleeve is held in position in the barrel but prevented from leaving the same,
by means of a collar 17, which is screwed upon the threaded surface of the barrel
and is provided with a flange at its outer end whereby the rib on the sleeve will
be received loosely between said flange and the heel or outer end of the barrel.
The fork 11 may be termed a jaw, and opposite this jaw a second jaw 18 of like
character is located, provided with a shank 19, which is exteriorly threaded and is
introduced into the threaded portion of the sleeve 14. The jaw 18 is curved from.
the shank in direction of the fork or jaw 11 of the barrel and is likewise preferably
made to terminate in a spur 20.
The matrix A is preferably made of light spring metal and is in the form of a
band.
It may be made in one piece, the ends being disconnected as shown in
Figure 2, but preferably the matrix is made in two sections a and a¹, connected at.
back by overlapping the ends at that point and securing them together by a
fastening device B.
At the
Near each end of what may be termed the front of the matrix, apertures or
openings 21 are formed to receive the spurs of the jaws of the retainer.
opposite or inner end of each section, one or more (preferably two) openings 22
are produced, as shown in Figure 9, and the fastening device B, which is to fasten
together the inner ends of the matrix is preferably made, as shown also in Figure 9,
of a plate 23 provided with pins 24 corresponding in number and relation to each
other to the openings 22 in the matrix sections. A button 25, is pivoted on the
said plate 23, having a handle 26 and recesses 27 in one of its side edges to receive.
the pins 24 of the plate. When the sections of the matrix are to be connected
the end of the section provided with the openings 22 is placed upon the plate 23,.
and the pins 24 passed through the openings in both of the sections. The plate 23
will then be upon the inner face of the band thus formed, and by carrying the
button 25 upward over the overlapping edges of the sections until the recesses 27
shall receive the projecting ends of the pins 24, as shown in Figure 7, a firm and
locking connection will be obtained between the sections of the retainer. It is.
evident that the sections may be readily disconnected by simply removing the
button from locking engagement and separating the plate from the sections.
The matrix having been placed around a tooth, as shown in Figure 1, the jaw 18,
which may be termed the stationary jaw of the retainer, is brought to an
engagement with one indented or apertured portion of the band matrix, and the
nut or head 15 is then turned until the barrel has travelled sufficiently upon the
shank of the fixed jaw to engage its spur 11 with the opposite side of the matrix
band, and by continuing to turn the head the band will be made to hug tightly to
the tooth, and will be held in firin position thereon.
When the matrix is to be removed the fastening device is disconnected from the
sections of the matrix, and the sections may be removed either by drawing either
out separately from between the teeth, or the two sections may be drawn out
simultaneously, still in engagement with the retainer.

page_text: In Figure 5 I have illustrated the application of a retainer to a matrix 28, which
is made in two substantially triangular sections, one of which is shown in detail in
Figure 6, and it is evident that the retainer will act as effectively in this form of
matrix as in the band form.
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 I
claim is,
1. A matrix retainer, consisting of opposing jaws constructed to engage the
matrix, a nut, and a screw device connecting the nut with one of the jaws, whereby
one jaw may be moved to or from the other by the manipulation of a single nut,
as specified.
0
2. A matrix retainer, consisting of a barrel, having a jaw formed thereon, a
second jaw opposed to the barrel jaw and provided with a shank entering the said
barrel, each jaw having a spur to engage the matrix, and a sleeve held to turn in
the barrel and having threaded connection with the shank of the second jaw,
whereby the barrel may be made to travel to and from the jaw with the shank, as
and for the purpose specified.
3. A matrix, the same consisting of a band constructed in sections, the said
sections being provided with openings at their ends, and a fastening device
comprising a body having pins therein, adapted to enter the openings in the
sections of the matrix, and a pivoted locking arm or button adapted to be carried
over the overlapping ends of the band and to an engagement with the pins on the
body of the said fastening device, as and for the purpose set forth.
4. A matrix, comprising two sections detachably connected at one end and a
clamping device adapted to be connected to the opposite ends of the said sections
whereby the same are secured together, substantially as set forth.
5. A matrix, comprising two sections detachably connected at one end and
having their opposite ends perforated, in combination with a clamping device
having spurs adapted to engage said perforations, substantially as set forth.
Dated this 29th day of April 1896.
A. M. & WM. CLARK,
53 Chancery Lane, London, Chartered Patent Agents.