US364070A - Artificial tooth - Google Patents

Description

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(No Model.) 4 D. D. WEISELL.

- ARTIFICIAL TOOTH. I

No. 364,070. Patented May 31, 1887.

7V" sea I 74007423024 UNITE STATES PATENT OFFICE.

DAVID D. WEISELL, OF FORT WAYNE, INDIANA.

" ARTIFICIAL TOOTH.

SPECIFICATION forming part of Letters Patent No. 364,070, dated May 31, 1887.

Application filed March 4, 1886. Serial No. 194,063. (No model.)

To alZ whom it may concern:

Be it known that I, DAVID D. WEIsELL, a citizen of the United States, residing at Fort Wayne,in the county of Allen and State of Indiana, have invented new and useful Improvements in Artificial Teeth, of which the following is a specification.

My invention relates to certain improvements in the manufacture of artificial teeth, and the purpose thereof is to provide means wherebya secure and permanent attachment of the teeth to the supporting-plates may be afforded.

The invention consists in the several novel features of construction and combinations of parts,hereinafter fully set forth, and definitely pointed out in the claims annexed to this specification.

In the accompanying drawings, Figures '1, 2, and 3 are perspective views of blocks-of artificial teeth, showing one method of applying.

my invention. Fig. 2 is a vertical section of the central tooth in Fig. 1. Fig. 4 is a vertical section of a tooth, showing a modified construction. Fig. 5 is a perspective view showing a modified form of the fastening device.

In the said drawings the reference-numeral 1 designates a block of artificial teeth of the usual constructiomhaving the artificial mounting 2, upon whichthe plateis attached. These teeth are usually prepared either singly or in blocks of two or more.

In connecting the blocks with the plate by which they are supported some difficulty has been experiencedin providing a strong, simple, and permanent fastcning device, and for this purpose a vertical staple, a wire bent at both ends, and pins having one or both extremities headed have been employed,-as well as other devices. These devices,however, have heretofore usually been inserted in the inner sides of the teeth coincident with a line at .a right angle with the axial line of the tooth..

It will readily be seen that the space required for their adj ustmentin this position seriousl y weakens the tooth, while the direction of their insertion is least calculated to resist the strain brought to bear upon them during mastication. These serious defects frequently result in the chipping and breaking of the teeth, loosening of their attachments, or their entire displacement from the plate. 011 the other hand, staples, when employed, have been upon the inner side of the gum part of the tooth, which renders the adjustment of the teeth on the plate impracticable, and at the same time weakens the gum part unless the same is made so thick as to render the'dentures heavy and clumsy. To avoid these objections, I place the staples 3 in the bottom of a groove, 4, formed in the base of the teeth, where they do not interfere with the adjustment of the teeth relatively to the plate, and where they impart additional strength to theteeth. These staples may be provided with heads 4, which are inserted in the base and body of the tooth invert the staple, placing the loop thereof in the body of the tooth and allowing the headed ends to project.

Instead of staples 3, I may employ pins 5,

having headed ends 6, which are set in the base and body of the tooth during manufacture,

lying in a line substantially coincident with the axis of the tooth. For the front teeth I prefer that the end of the pin buried in the body of the tooth shall-be conical, as shown in Fig. 2", whereby'the cavity receiving it approximates the shape of the tooth,and the latter is not unduly weakened at any one point.

In manufacturing the teeth agroove or channel, 4., Fig. 2, is formed in the base of the tooth, and the pin 5 is inserted at the bottom of said groove, being allowed to project far enough so that they will not come in contact with the model while adjusting them upon the model base-plate, sufficient space being also allowed for the rubber, celluloid, or other material of which the plate is formed to flow around the exposed ends of said pinsand secure the teeth to the plate.

In the employment of staples as attaching devices the headed ends are insert-ed at the bottoms of the grooves 4, theloops of the staples being exposed in a mannersimilar to that already described. Thismauner of inserting the pins, staples, or other intermediate fastening for uniting the teeth to the plate is applicable to all classes of artificial teeth. It gives an attachment more in accordance with nature, admits of a natural shape and finish to the teeth, allows a greater length and body of porcelain on'the inner side, and is in all respects a strong, practical,and substantial mode of attachment.

I have shown in Fig. 4 a modified construction by which I am able to avoid the use of metallic fastenings, and at the same time to provide for the shrinkage and contraction of the rubber.

I form in the base of each tooth a cavity, 8, extending into the body of the tooth substantially in its axial line, and of such size and form as to contain a proper quantity of the material of the plate, or of an intermediate attachment to secure the teeth thereto. The shape of the cavity is cylindrical above, terminating below with a cavity shaped like a frustum of a cone. In order to compensate for the shrinkage, the proportions of these cavities must correspond with the following geometrical proportions:

Dividing the cavity 8, into nine equal parts vertically, five of these divisions will measure the depth of the cylindrical portion, having its opening in the base of the tooth. Three of said divisionswill measure the depth of the frustum-shaped portion, and the remaining division the depth of a shallow cylindrical chamber, 9, below the frustum. The diameter of the opening in the base of the tooth is two thirds the depth of the cavity, and the angle of divergence of the frnstum-shaped portion is thirty-four degrees. The shrinkage of vulcanized rubber and most other materials during the manufacture of the plate or intermediate attachment renders this mode of attachment impractical, save when the cavities are formed in, accordance with the proportions specified above. This form of attachment enables me to secure the same advantages with regard to natural shape, beauty, finish, length and body of porcelain on the inner sides, and strength of tooth and attachment already specified in connection with the pin or staple attachment. All of these modes of attachment are especially adapted to the use of gold or platinum plates with rubber, celluloid, or other intermediate attachment.

I prefer to form the cavities in the teeth which receive-the ends of the attaching-pins in the following manner: From some easilydestructible material-such wood, fusible metal, or alloys-*1. constrt a core having one end shaped in exact conformity with the shape and size of the cavity to be formed. The other end of said core is made plain for insertion in holes in the tooth-mold, a suitable number of said cores being inserted in the molds in such manner as to correspond with the depth of the cavities, their position in the bodies of the teeth, and the number of teeth to be molded. The teeth are then formed in the usual manner, and by the use of heat,

either before or during the baking, the cores are fused or destroyed, leaving the cavities in the exact position and shape required.

The method hereinbefore described of forming the cavities in the teeth, which method consists in .the molding of said teeth upon a destructible core by which the cavityis formed, forms no part of my present invention, as the same 'method has heretofore been used for various purposes, the core being made of any suitable destrnctible material by which the desired form of cavity might be given and the core afterward burned out.

Having thus described my invention, what I claim is-- 1. Artificial plate teeth formed singly or in blocks, each tooth being provided with the usual mounting, and having a groove or channel formed in the base of each tooth and following the line of attachment to the rubber, each tooth being also provided with one or -more pins entering the tooth axially at the bottom of said groove, and having a conoidal head buried in the body of the tooth, and a headed end projecting into and wholly'coutained in the groove, substantially as described.

2. An artificial tooth having a body, 1, and mounting 2, and provided with a groove, 4, in combination with one or more pins, 5, provided with an inverted conoidal head, said pins entering the tooth axially, and having their projecting ends lying within the groove 4, substantially as described.

In testimony whereof I afiix my signature in presence of two witnesses.

DAVID D. \VEISELL.

. Vitnesses:

THOMAS M. BIDDLE, W. B. KNAPP.

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