Improvements in Dental Matrix Retainers.
Year: 1896

page_text: Date of Application, 30th Dec., 1896-Accepted, 20th Feb., 1897
Improvements in Dental Matrix Retainers.
I, JOSEPH MILTON STROUT, of 457 Congress Street,. Portland, in the
County of Cumberland and State of Maine, United States of America, Gentleman,
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 :-
This invention relates to matrix carriers and retainers for dental purposes. An
essential feature of the invention is a device of the character and for the purpose
aforesaid which will protect the operating parts and reduce the discomfort and
annoyance to the patient to a minimum, the exterior surface and exposed parts
being smooth and of such formation as to cause no unpleasantness by contact of
the tongue therewith when the device is in use.
The improvement consists of a barrel open at one end for the introduction and
removal therefrom of the operating mechanism, and closed at the opposite end
and formed with a lateral extension to bear against the teeth to be treated, and to
which one end of the matrix is secured, the other end portion of the matrix passing
loosely through an opening or slot therein and having attachment with the
tightening mechanism the latter consisting of a feed screw journaled within the
barrel, a nut mounted upon the feed screw and having the movable end of
the matrix connected therewith, a cap closing the open end of the barrel and
forming a bearing for the outer end of the feed screw, and a crown attached to the
projecting end of the feed sorew for turning the latter to draw or tighten the
matrix about the tooth to be treated.
For a full understanding of the merits and advantages of the invention reference
is to be had to the accompanying drawings and the following description.
The improvement is susceptible of various changes in the form, proportion and
the minor details of construction without departing from the principle or sacrificing
any of the advantages thereof, and to a full disclosure of the invention an adaptation
thereof is shown in the accompanying drawings, in which :-
Fig. 1 is a side elevation of a matrix retainer for effecting the ends of this
invention.
Fig. 2 is a longitudinal section thereof.
:
Fig. 3 is a view similar to Fig. 2 showing a different arrangement of the
parts.
Fig. 4 is a detail view showing the device applied.
Corresponding and like parts are referred to in the following desoription and
indicated in the several views of the drawing by the same reference characters..
The barrel 1, forming the body of the device is closed at one end and provided
with a lateral extension 2, and is open at the opposite end which is closed by a
cap 3, having screw-thread connection with the barrel and centrally apertured to
provide for the passage therethrough of the outer end of the feed screw 4 which
is journaled within the barrel. A crown 5 milled or corrugated to enable the
fingers to secure a firm grip thereon, is attached to the projecting end of the feed
scrow 4 and provides a means for turning the latter when it is required to adjust
the matrix 6 to the size of the tooth to be treated. The inner end of the feed
screw, 4 is made conical and obtains a bearing in a similarly formed recess in the
inner wall at the closed end of the barrel, and a shoulder 7 is provided near the

page_text: outer end of the feed screw to engage with the inner end of the cap 3 to prevent
outward displacement or longitudinal movement of the feed screw when the parts
are assembled and the cap 3 is screwed home. If from any cause it be required to
gain access to the interior of the barrel and the operating parts, the cap 3 is
removed from the barrel and the enclosed parts removed through the open end
thereof.
A. slot or opening 8 extends through, the bearing face of the lateral extension 2
and communicates with the interior of the barrel, and provides a passage for the
movable or adjustable end portion of the matrix 6. A retaining slot 9 is formed
in the lateral extension 2 contiguous to the opening 8 and extends parallel with the
latter, and is adapted to receive the outer end of the matrix 6 which is secured
therein in any convenient and substantial' way so as to admit of the matrix being
readily removed to be substituted by a new one or for any required purpose.
A nut 10 is located within the barrel and mounted upon the feed screw 4 and
the movable end of the matrix is connected therewith, the outer portion of the
matrix forming a loop to encircle the tooth to be treated, as clearly indicated in
Fig. 4. By turning the feed screw, which is effected by means of the orown 5,
the nut 10 is caused to move within the barrel so as to tighten or loosen the
matrix according to the direction in which the feed screw is turned thereby making
provision for adapting the size of the matrix to the dimension of the tooth to be
treated.
The construction illustrated in Fig. 3 is in-all essential particulars substantially
the same as that shown in the other figures, with the exception that the terminal
portion of the matrix makes connection with the nut 10-exterior to the barrel and
passes through an opening 11 formed at the juncture of the lateral extension 2
with the barrel, and the nut is formed with a projection 12 which operates in a
longitudinal slot 13 formed in the inner side of the barrel. This construction
admits of the matrix being detached from or secured to the nut 10 without
necessitating the removal of these parts from the barrel. Hence, the matrix can
be removed or substituted by a new one in less time than required to make a
similar change where it is required to remove the operating parts from the barrel.
This form of matrix retainer operates in precisely the same manner as that
illustrated in the other views.
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
oclaim is
1. A matrix retainer comprising a barrel having a lateral extension formed with
an opening and a retaining slot, a feed screw journaled within the barrel a crown
at one end of the barrel and having connection with the feed screw for rotating
the latter, a nut looated within the barrel and mounted upon the feed sorew, and
a matrix having one end secured in the aforesaid retaining slot and having its
other end passing loosely through the opening in the lateral extension of the barrel
and connected with the nut, substantially as set forth.
2. A matrix retainer comprising a barrel open at one ond and having its opposite
end closed and provided with a lateral extension formed with an opening, a cap for
closing the open end of the barrel, a feed screw journaled within the barrel and
having an end portion projecting through and beyond the cap and held against
longitudinal movement, a crown secured to the projecting free end of the feed
screw, a nut located within the barrel and mounted upon the feed screw and a
matrix having one end secured to the lateral extension and having its opposite end
passing loosely through the opening in the lateral extension and attached to the
aforesaid nut, substantially as and for the purpose specified.
3. A matrix retainer comprising a barrel having a lateral extension formed with
an opening 8 in its bearing face and an opening 11 at the juncture of the lateral
extension with the barrel, a feed screw journaled within the barrel and provided
with means for rotating it, a nut mounted upon the feed screw and baving a

page_text: projection operating in a longitudinal slot in the inner side of the barrel, and a
matrix having one end secured to the aforesaid lateral extension and having its
other end passing through the opening 8 in the bearing face of the lateral extension
and out through the opening 11 at the juncture of the said extension with the
barrel, and secured to the projection of the nut, substantially as and for the
purpose described.
Dated this 30th day of December 1896.
F. WISE HOWORTH,
46 Lincoln's Inn Fields, London, W.C., Agent for the Applicant.