US 1270943 A
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Description (OCR text may contain errors)
G. W. GRHVIM.
APPLICATION FILED DEC. 3!. 19%?- Patented July 2, 1918.
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GEORGE W. GRIMM, OF WEST I-IOBOKEN, NEW JERSEY.
Specification of Letters l atent.
Patented July 2, Tfill'd.
Application filed December 3 1, 1917. Serial No. 209,680.
proved porcelain crown tooth with an ad justable attachment for use on vulcanite plate work or other dentures. j Special objects are to facilitate the attachment of an anchoring device to the crown and insure the firm retention of said anchoring device whether it is baked in the crown or afterward attached thereto.
Uther objects are to provide an improved means of attachment of l the teeth to the plate which permits said plate 'to be made lighter in weight and less. bulky, to give greater comfort to the wearer, to afford more room for the tongue, to promote clearer enunciation by wearers of artificial teeth, to dispense with the use of vulcanite or other backing behind the porcelain crown, thereby improving the color or appearance of the tooth and making it more nearly like a natural tooth, and to permit the ,tooth to be ground away at the neck portion to fit the gum and conform to the alveolar ridge without weakening the attachment of thetooth to the plate or other denture.
A further important object isto make the attachment in separate parts so that the grinding and fitting of the crown to the alveolar ridge may be done before the final attachment is made. Other objects will ap-,
pear as the description proceeds.
The invention will be first hereinafter described in connection with the accompany ing drawings, which constitute part of this specification, and then more specifically defined in the claims at the end of the description.
In the accompanying drawings, wherein similar reference characters are used to designate corresponding parts throughout the several views Figure 1 is a central. vertical section through a tooth or crown constructed and attached to a plate or denture substantially in accordance with this invention.
Fig. 2is a section on the line IIII of Fig. 1.
Fig. 3 is a detailed view of the complete, anchoring device with its parts detached from each other.
. Fig. 4; is a detailed view of a modified form of the top member of the anchoring device anchoring member.
Figs. 5 and 6 are detailed views of modified forms of the bottom anchoring member, and y 1 1 V.
Fig. 7 is a central vertical section of. a
porcelain crown showing the bottom niemi her of the anchoring device as it is secured therein. after baking. I Y I The porcelain crown or body POI'tlOlLOf the artificial tooth l is formed witha cavity 2 in its end for connection with the .vulcanite plate orrother denture 3, as illustrated in Fig. 1. In order to strengthen this connection, the socket or cavity 2 is formed with an inwardly protruding ridge 4t intermediate its base and upper edge, and the walls of the cavity above and below said ridge arecon cave, as at 5 and 6. The diameter at the innermost edge of the ridge 4 is less than the greatest diameter of the concave portion 5 below said ridge. The connection between the crown and plate is strengthened or rein forced by a metal anchoring device com} prising a bottom member 7, a top member 8 and a connecting member; or pin 9; The crown 1 is bored at the bottom of the cavity 2 to receive the bottom member 7 which may be baked therein, as illustrated in Fig. .1, or secured therein after baking, as illustrated in Fig. 7. Said member 7 is formedwith a screw threaded socket 10 to receive the lower screw-threaded end 11 of the pin 9. The upper end of said pin is also threaded at 12 preferably in the opposite direction, to engage a threaded passage 13 in the member 8. The member 7 is fixed at the base of the bore 14: in the crown, while the member 8, when in position as shown in Fig. 1, seats upon the upper edge of said bore at the bottom of the cavity 2, being retained in that position by the pin 9 having its screw threaded ends 11 and 12 engaging the socket 10 in the member 7 and the passage 13 of the member 8, respectively.
The bottom member 7 of the anchoring device is preferably formed with a conical nection.
lower end 15 and an annular groove 16, as shown in Figs. 1 and 2, in order to strengthen the joint between it and the crown. Other forms of the bottom anchoring member, may, however, be used as, for instance, with the straight sides illustrated at 17, Fig. 5, or with bulged sides 18, Fig. 6. The top member and pin may: also be ,-made in one piece, if desired, as illustrated at 19, Fig. 4. The top member 8 of the anchoring device preferably has its lower face rounded or inclined, as at 20, to'permit'the vulcanite to flow in around said head and thus strengthen. the con- Said member 8 is further provided with notches 21 to receive a spanner wrench for adjusting the same andjalso for preventing said member from becoming unscrewed'or loose after the vulcanite has set around it.
*VV-hen the anchoring device is to be. at-
tached to' the crown after the latter has been baked, the. walls of the bore 14;,are preferably made divergent near-the bottom ofsaid bore, as'illustrated at 22 in'Fig; 7, so that the-cement or other filling material 23 used for securing the member 7 fills this enlarged bottom portion of tliebore in the crown as' well'as the groove '16 in the member 7 ,ther'eby making a very strong joint. The mp, of the member 8 is, arranged below the ridge 4 .in the cavity 2, sothat the plastic material or vulcanite which fillsthe portion of, the cavity below said ridge is held firmly around said member.
The-bottom, member 7 of the anchoring device,if attached to thecrown before baking, will not interfere with said .crown being ground to fit the gum and uneven surfaces of the alveolar ridge, whereas, if the entire anchoring device were made in one piece with its-top end projecting from the bore 14, it would beilrthe way of the grindingdisk ortoolgenerally flused for grinding down and fitting'crowns. If necessary, the upper portion of the crown may be ground down as far as the broken lines Having thus described my invention,
,what I claim as new and desire to secure by Letters Patent of the United States is 2-- 1. 1m an artificial tooth, the combination .with a crown having a cavity therein, of
an, anchoring device comprising a bottom member secured in said cavity and having a screw-threaded socket in its upper end, a top member adapted to be embedded in the plastic material to which the crown is to be attached, said top member having a screw threaded passage, and a connecting pin having threads on its ends to engage the threaded socket in the bottom member and the passage in the top member, respectively.
2. In an artificial tooth, the combination with a crown having aca-vity therein, of an anchoring device comprising a bottom member secured in said cavity and having a screw threaded socket in its upper end, a top member adapted to be embedded in the plastic material to which the crown is to be attached, said top member having a screw threaded passage, and a connecting pin having oppositely inclined threads on its ends to engage the threaded soeketin the bottom member and the passage in the top member, respectively.
.3. In an artificial teeth, the combination with a crown having a bore therein with diverging walls, of an anchoring device comprising a bottom member arranged be tween the diverging walls of? the bore, and a headed member connected to said bottom member and adapted to be embedded in plastic material to which the crown is to be attached, and a plastic filling around said bottom member within the diver 'in walls of the bore for. securing said bottom memberin place said bottom member having an annular; groove also occupied by said plastic filling.
In testimony whereof I have signed my name to this specification.
GEORGE; TV. GRIMM.
Copies of this patent may be obtained for five cents each, by addressing the fGommissioner of Patents,
' *Washington, 110.