Method of and means for producing dental plates.

Application filed February 3, 1912.

To all whom it may concern:

. Be it known that I, Henry J. Smith, a citizen of the United States, residing in the city and county of Philadelphia, State of 5 Pennsylvania, have invented a new and useful Method of and Means for Producing Dental Plates, of which the following is a specification.

My invention relates to the production of 10 dental plates and suction disks for the same, and it consists of a novel method of forming a plate to properly retain a suction disk in cup-shape.

It further consists of improved means for 15 molding such plate.

It further consists of other novel features of construction, all as will be hereinafter fully set forth.

The annexed drawings and the following 20 description set forth in detail, one mechanical form embodying the invention and one way of carrying out the method, which, however, may be varied within the scope of the claims.

In said annexed drawings—Figure 1 represents a section of the plaster-cast or impression taken of the mouth. Fig. 2 represents a section of a mold in which the intaglio matrix is made. Fig. 3 represents a 30 section of a mold having the wax pattern in it and having the relief matrix poured into it. Fig. 4 represents a section of the intaglio matrix with the retainer - forming mold in position. Fig. 5 represents a sec35 tion of the complete mold with the rubber in place. Fig. 6 represents an enlarged detail view of the rubber plate, the retainer-mold and the intaglio matrix. ‘Fig. 7 represents a plan view of the retainer-mold. Fig. 8 40 represents a plan view of said mold with the central covering-disk removed. Fig. 9 represents a plan view of said mold with said covering-disk removed and the retainershell in position. Fig. .10 represents a plan view of the reverse side of the retainermold. Fig. 11 represents a plan view of the opened retainer-mold. Fig. 12 represents a. perspective view of the central coveringdisk. Fig. 13 represents a perspective view of the suction-disk. Fig. 14 represents a perspective detail view of the retainer-shell.

Patented Apr. 23,1912. Serial No. 675,166.

Fig. 15 represents a sectional detail view of as much of a plate as is sufficient to illustrate the finished article. Fig. 16 represents a similar view illustrating the suction-disk 55 m position.

Similar numerals, of reference indicate corresponding parts in the figures.

Referring; to. the drawings, the reference numeral 1 indicates the plaster-cast or im- 60 pression taken of the roof of the mouth and of the gums. In carrying out my method, this cast is. covered with a coating, 2, of varnish or similar substance to which plaster will not adhere while in liquid form. This 65 cast, is now placed into the drag, 3, of an ordinary dentist’s flask, and an intaglio matrix, 4, is formed by pouring plaster into the cope, 5, of the flask. A retainer-forming mold, 6, is formed by a disk, 7, having a 70 central, circular opening, 8, and a central, circular recess, 9, formed with an annular groove, 10, at the periphery of its bottom. A circular cover, 11, fits into the recess and has an annular flange, 12, which fits into the 75 annular groove.

The mold-disk has equidistant radial slits, two, 13, of which extend from the central opening to the periphery of the recess, and one, 14, extends through the periphery of 80 the disk. This mold-disk is made from tin or similar soft metal, so that it may be opened at the longer slit, 14 and then bent outward at the short slits, as illustrated in Fig. 11. The mold-disk has perforations, 85 15, through it, near its periphery. The mold-disk has, on the side opposite the one having the recess, a circular boss, 25, surrounding the central opening.

In now carrying further my improved 90 method, I pass a flanged thimble or retainershell, .16, of gold or other non-corroding metal in the retainer-mold, with the neck of the shell extending through the central opening. in the mold and the flange resting 95 against the bottom of the recess, which is then covered by the cover. The retainermold is now placed upon the most level portion of the part of the matrix 4, and gently pressed against the same, so as to make the 100 mold adapt itself to the shape of the matrix, whereupon the mold is secured to the matrix

1,024,152 by tacks, 17, driven through the perforations in the mold. A wax pattern, 18, of the finished plate is now formed in the matrix, which is thereupon placed in the drag, 19, 5 of a dentist’s flask, whereupon liquid plaster is poured into the cope of the same, forming a relief matrix, 20. When the plaster is set, the wax is boiled out. of the plaster mold, whereupon said mold is packed with 10 rubber, care being taken that the retainershell or thimble be well packed. The plaster-mold is now placed in a vulcanizing oven. When the rubber-plate is vulcanized, the intaglio matrix is removed and the cover 15 for the retainer-mold is removed. If upon inspection, it is found that an insufficient quantity of rubber has been packed to completely fill the retainer-shell, rubber is added, until it is full, and the plate is again 20 subjected to vulcanization. If removable flat retainer-shell is sufficiently filled, the retainer-mold is pried open at the through slit 14- and then bent open at the shorter slits so as to withdraw the mold from under 25 the flange of the retainer - stud, 21, thus formed in the center of a circular depression, 22, formed by the circular boss, 25, upon the retainer-mold, in the circular recess, 23, produced in the roof of the plate 24. 30 In the finished denture, a disk,. 26, of soft rubber, having a central opening, 27, is slipped over the retainer-stud and, on account of the depression at the center of the recess in the plate, said disk forms a suc85 tion-cup which aids in retaining the finished denture in place, causing the same,, on account of the vacuum produced within such suction-cup, to adhere to the roof of the mouth. The rubber disk may be readily *o replaced, as soon as it loses its resiliency, by merely slipping the worn-out disk off from the retaining-stud and replacing another.

I am aware that dentures with studs, 45 principally screwed or riveted into the plate, have been made and used for many years, and I am also aware that dentures have been made with the stud integral with the plate and with certain inclined or sloping surfaces 50 which were intended to give the required cup-shape to the suction disk, and I am also aware that temporary molds have been employed for the purpose of forming such retaining - studs formed from soft metal 55 which would adapt themselves to the contour of the part of the mouth, but I am not aware of any mold or method, whereby such mold could be spread open to remove the mold from the stud without cutting of the 60 same. Neither am I aware of any mold or method whereby it is possible to add rubber to the stud after vulcanization to correct error in the first packing, nor of any mode or method of making dental plates wherein 65 the suction-disks may be depressed in their centers without the employment of dished or otherwise oblique or inclined fastening members.

I am aware of the Patents, No. 801,911, granted October 17th, 1905, ' and No. 70 821,192, granted May 22nd, 1906, the latter of which is for a suction cavity having a bottom ascending angle which I do not employ, while the former relates to a process and a product, which process I do not em- 75 ploy. My present invention is therefore differentiated from said prior art by the employment of the tapering retainer having the tapering flanged shell thereon, and to none of the devices of the prior art do I 80 herein make my claim.

Other modes of applying the principle of my invention may be employed for the mode herein explained. Changes may therefore be made in the method and the device for 85 performing the same without departing from the essential steps and mechanisms set forth in the following claims.