US1950872A - Mold for artificial teeth - Google Patents

Description

March 13, 1934. G. H. WHITELEY 1,950,872

rMOLD FOR ARTIFICIAL TEETH Filed June 2l. 1932 iol Patented Mar. 13, i934 ATENT ii M @LD FR AEJTIFICEAL TEETH of New York Application .lune 21, 1932, Serial No. 618,535

6 Claims.

My invention relates to an iinproved mold for molding articial teeth of a character adapted to be employed as facings in bridge work and capable of replacement in case of breed-rage.

More particularly, the object of my invention is to provide a mold adapted to ici-in the porcelain facing with a slot upon its lingual said slot having an enlargement along the axial length of the tooth to provide engagement anchoring means formed at the back of said tooth and constituting an anchorage of the facing upon the bridge.

With these and other objects in View, the nature of which will be more fully understood from the following specication, the invention consists in the novel features of const 1ucticn hereinafter more fully described and defined in the claires.

Referring to the drawing: Fig. a plan view of my improved mold with one half of the upper mold part broken away; Fig. 2 is a transverse section taken online 2--2 of Fig. l.; Fig. 3 is a trans verse section taken on line 3-3 of Fig. l; Fig. is an enlarged sectional view of the rigt hand por-- tion of 3; 5 is a perspective view of one cf the core pin structures; 5 is a perspective view of the porcelain facings as by the inold parts shown; Fig. *I is a transverse sectional View taken on line '7-'7 of Fig. (i and Fig. 8 is a sectional view oi a modification.

2 and 3 are respectively the bottom and top mold portions and provided with the usual positioning pins fi. These rnold portions 2 and 3 are respectively provided with recessed portions 5 and 6 to form the mold space A into which the porcelain material in a pasty condition is inserted and molded to form the facing indicated in Figs. 5 and '1. From these iigures, it will be seen that the labial portion A ina-y follow the ordinary natural frontal or labial conguration of an incisor while the lingual or back portion. of the tooth meets the labial portion A adjacent to the incisal edge F. The upper part of the tooth is curved upward and forward from the lingual face E to form the cervical end C. Aside from the general structure of the facing just referred the tooth is furthe molded with a vertical anchor receiving groove D having an enlargement its inner part adjacent to the axial length of the tooth, indicated at E.

Referring again to the mold, the lower mold portion 2 is provided with a longitudinal groove space 2o intermediate of the two rows of tooth mold recesses. Arranged wit .in this groove is a horizontal bar '7 from which proiect a series of core pins 8 having downwardly extending web portions 9 of less thickness than the diameter of the core pins. Each of the core pin structures is guided through an aperture 3o having a cross secn tion corresponding to that of the core pin and its web. The length of the pins is such that they extend through the wall 8b and well toward the inoisal end 10 of the tooth spaces; furthermore, the shank 9a of web 9 is guided through a slotted portion 8d of the aperture in wall 8b and web 9 may extend along the bottom surface or floor of the tooth recess 5 as indicated at 9d. The engagement of the web 9 through the aperture 9c. of wall 8b and along the surface of the tooth recess 5 insures the molding of a slotted opening B in the lingual wall of the tooth body as shown in Fig. 43. Furthermore, the webs 9o ci' the core pins insure accurate guiding of the pins and prevent them rotating upon their supporting 1^ar '7, and enable the bar with its siii core pins to be moved longitudinally of the tooth spaces and insure a definite corresponding movement of all ci the pins simultaneously and Without danger oi? the pins being unsupported and liable to being bent. To enable the roost perfect action, the pins and their webs should be of substantially the same size throughout their length where they extend into the tooth molding space. .if desired, the webs 9 of the pins 8 may be made somewhat deeper and be guided in longitudinal shallow grooves 8c in the floor 5 of the tooth spaces, as shown in Fig. 8.

Each side of the mold has the molding recesses and each is provided with a core bar '7 and core pins 8 as above described; and, moreover, there is interposed between the two core hars '7, '7, a lockM ing bar 13 which is slightly tapered throughout its length as more fully shown in Fig. 1. The taper of the locking bar 13 is the counter part of the taper in the core bars '7, as can be more readily seen in Fig. 1. Furthermore, the core bars '7 are preferably tapering in a downward direction so that the contacting faces between the locking bar 13 and the core bar '7 is an inclined surface which has the eifect of holding the locking bar 13 in locked relation to the core bars '7 and the latter, in turn, are held against upward movement by reason of the core pins 8 guided through the apertures 8o. In this manner, it is possible to remove the upper mold part 3 without any dis engagement of the remaining parts connection with the lower rnold portion 2, since they are all interengaged in one manner or the other, which hold thein in locked engagement until the locking bar 13 has been removed to release the core bars '7.

As it is most desirable that no material strain shall be put upon the core pins 8, especially when driving in the locking bar 13, I form the core bars 7 with holes 'la near each end and these engage pins 7b, said pins extending through the sides of the mold portion 2 and projecting into the space 2a. In this manner, the pins 7b receive the longitudinal strain on the core bars by the locking bar 13 and practically no strain comes upon the core pins 8 themselves.

In operation, the lower mold part 2 is tted with the core bars 7 and their core pins 8 and locked in that position by the locking bar 13. The tooth spaces about the cores 8 and 9 of the mold portion 2 as at 12 are then partly filled with the body enamel to near the incisal end 10. The upper mold portion 3 is then lled with the lighter enamel extending to the incisal edge and may be backed with some of the body enamel and pressed over the core pins when the two mold parts 2 and 3 are pressed together. The application of the particular shade of material is only incidental to my improvements in the mold structure, and while I am, therefore, illustrating and describing the nature of the article to be made by my improved mold, I do not limit myself to any particular color or shading of the tooth. j

It will now be apparent that I have devised a novel and useful construction which embodies the features of advantage enumerated as desirable, and while I have in the present instance shown and described the preferred embodiment thereof which has been found in practice to give satisfactory and reliable results, it is to be understood that I do not restrict myself to the details stated as the same are susceptible of modification in various particulars, without departing from the spirit or scope of the invention.

I claim:

1. A mold for making artificial teeth, comprising upper and lower mold portions each provided with a tooth recess cooperating to form a fully walled tooth shaped space, in combination with a core pin slidably movable in the direction of the axis of the tooth space and having a longitudinal web portion xedly extending from the core pin and guided along the ooror" the tooth space and terminating at a distance from the incisal end of the same, and clamping means for clamping the core pin and its web when adjusted in the tooth space.

2. The invention according to claim 1, wherein the core pin and its web are guided through a wall in one of the mold portions adjacent to the cervical end oi the tooth space, and wherein further a bar is provided to which the core pin and web are secured, and a wedge shaped clamping bar is arranged for locking the core pin and its bar in molding position.

3. The invention according to claim l, wherein the web of the core pin is guided in a longitudinal groove along the face of the mold space.

4. The invention according to claim l, wherein further, the core pin is of greater thickness than the web and the web is guided in a groove formed in the wall of the tooth space.

5. In a mold for molding artificial teeth, two mold parts each of which contain a plurality of completely walled tooth shaped recesses arranged in parallel rows, in combination with a pair of core bars each provided with a plurality of integral molding core pins and web portions, said core pins and web portions adjustable relatively to and through the walls of the tooth spaces, and means interposed between the core bars for simultaneously forcing them apart and thereby locking the core pins in molding position within the tooth recesses.

6. In a mold for molding articial teeth, two mold portions detachably connected and each provided with a recessed portion which when the two mold parts are associated one upon the other forms a complete tooth space with closed cervical end, combined with a core bar movable toward and from and independent of the cervical end of the tooth space, a core pin and associated web integral therewith projecting transversely from said core bar through the cervical wall of the tooth spaces, said pin and web adjustable into and out of the tooth space and the edge of the web beveled to make a close and strong clearing fit upon the cervical portion of the tooth space, and locking means for retaining the core bar in position for simultaneously holding the core bar and core pin in molding position within the tooth space.

GEORGE H. WHITELEY.

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