US1299364A - Fastening for removable dental bridges and bridge-plates. - Google Patents

Description

C. W. LOKEY.

FASTENING FOR REMOVABLE DENIAL BRIDGES AND BRIDGE PLATES.

- APPLICATION FILED JULY 16. 1911.

1,299,364, I Patented Apr. 1 1919.-

s "UITE CHARLES W. LOKEY, 0F BIRMINGHAM, ALABAMA.

FASTENING FOR REMOVABLE DENTAL BRIDGES AND BRIDGE-PLATES.

Specification of Letters Patent.

seamed Apr. 1, 1919.

Application filed July 16, 1917. Serial No. 180,702.

To all whom it may concern." V

\ Be it known that I, CHARLES W. LOKEY, a citizen of the United States of America, residing at Birmingham, in the county of Jefferson and State of Alabama, have invented certain new and useful Improvements in Fastenings for Removable Dental Bridges and Bridge-Plates, of which the following is a specification.

My invention relates to fastenings for removable dental bridges and bridge plates which will permit the abutment tooth to which the bridge or plate is fastened, to have a free normal movement during mastication without straining or breaking the joint between the fastening elements or their respective connections to the abutment and bridge or bridge plate.

My present invention is more especially intended as an improvement on the type of dental fastening described in Letters Patent of the United States No. 1,193,034, issued to me on the 16th day of August, 1916, and which comprises a keeper, formed of hard metal shaped to provide side grooves and preferably a top groove alining with the side grooves, and an anchor attachment for the removable bridge or bridge plate, which is formed of bent wire (preferably drawn wire of hard metal such as iridio platinum) that is shaped to fit snugly into the grooves of the keeper and to interlock firmly therewith so that the fastening resists with much strength any relative movement between the keeper and anchor except in the direction in which the bridge or bridge plate is moved to detach it from. the abutment.

According to my present invention the web of the keeper and the sides of the anchor which engage it are so shaped as to permit a limited rocking play to take care of the normal -movement between keeper and an chor in a transverse plane through the joint. Provision for this play can be made by mak ing the web of the keeper in transverse cross-section elliptic or wider at its center than at its ends, and leaving the sides of the anchor that engage the keeper straight, or the same play may be obtained where the sides of the web are straight and provision for the rocking play is made in the shape of thei) parts of the anchor which engage the We 1' v a My present invention further contemplates contracting the anchor by slightly drawing or bending in either or both sides thereof near the neck so that it will snap over the thicker central portionof'an elliptic keeper web and'securely prevent accidental disconnection of the fastening elements without, however, interfering with the limited play that makes provision for normal movements of the bridge or the abutment tooth.

A further objectof my invention is to improve the construction of the keeper proper by tapering its end next to the gum so that it is inclined away from the gum. This arrangement will prevent food collecting between the keeper and gum and make it easier to keep the parts clean.

'My invention further comprises the novel details of construction and arrangements of parts which in their preferred embodi ments only are illustrated in the accompanying drawings which form a part of this specification, and in which Figure 1 is a plan view illustrating the lower jaw with a bridge plate attached by my improved fastening and partly broken away.

Fig. 2 is a perspective view of the anchor.

and keeper detached, the keeper being shown attached to a tooth or abutment.

Fig. 3 is an enlarged sectional view through the abutment showing the assembled anchor and keeper in side elevation.

Fig. 4 is a view showing the anchor in front elevation mounted in a bridge orbridge plate.

Fig. 5- is an enlarged vertical sectional view taken on the line 5-5 of Fig. 3, with the anchor shown in elevation.

Fig. 6 is a view similar to Fig. 5 of a modification of my invention in which the sides of the web are straight and the anchor loop enlarged to provide for the rocking play desired.

Similar reference numerals refer to similar parts throughout the drawings.

In the embodiment of my invention illustrated, a detachable bridge plate is adapted to be attached to abutments 1 which may be of any suitable construction and attached to any desired, natural teeth as may be best suited for each individual case. To each abutment I- solder or otherwise attach an elliptic shape.

a keeper which is formed of a block of hard metal having a flat front face 2 which is connected by an integral shankor' web 3 with a back face 4 which is preferably thinner than the front face and adapted to be sol dered to the abutment. The web, which is formed by the side grooves in the keeper, is preferably cut away below the top or outer endcdge ofthe keeper so as to form a top groove or seat for the anchor. The web, as shown in Figs. 1 to 5, is made thicker at or slightly below its center (see Fig. 5) and it istapered or made thinner toward its top and bottom ends so as to give it in vertical cross section what may be termed generally The inner end of the keeper adjacent to the gum is beveled away from the abutment and gum as indicated by the outwardly sloping face 5.

The bridge plate 6 has firmly embedded therein an anchor, preferably formed of drawn wire or hard metal. It comprises ends 7 which are rigidly embedded in the rubber saddle of the bridge plate or they may be rigidly attached in any other suitable manner to a metal saddle or to the bridge or bridge plate. The wire is bent upwardly to form a loop portion 8, the bases of the sides of which .are bent outwardly and horizontally at 9 to join the ends 7 which lie in a plane at right angles to that of the loop. The sides of the loop, as shown in Fig. 2, are straight and correspond to the construction shown in Fig. 8 of my Letters Patent hereinbefore referred to, as such form can be used with my improved keeper, but I prefer to contract the neck of the anchor loop by drawing in its sides as at 10 (Figs. l and Itis preferable that both sides of the loop be thus drawn in but not essential as a snap lock could be obtained by contracting the neck of the loop in any manner.

From a consideration of Fig. 5 it will be apparent that when the keeper and anchor loop are interlocked, the keeper is free' to rock in the anchor within predetermined limits in either direction, as indicated by the. arrow, and thus allow for the normal play or movement of the abutment tooth during masticatlon, and it is conversely true that the bridge plate itself can have a like keeper and the anchor would prove an unsat1sfactory fastening fora bridge or bridge plate. By contracting the neck of the loop it will snap into place about the keeper web and can only be disengaged by a strong pull upwardly or downwardly according to whetherthe bridge is carried by the upper or lower jaw. In Fig. 6 I show the keeper web 11 formed with parallel sides and the top 12 of the anchor loop is struck onan arc from the center of the web and made as wide as :is necessary to provide for the rocking play desired. The sides of the loop are bent in at 1 3 to engagethesides ofvthe web and are then bent out away from'the sides thus forming side bearings which will permit the keeper and anchor to rock relatively.

The essential feature of my invention :is that the keeper and anchor be designed :to permit only sufiicient relative rocking movements to avoid undue strains on the fastenings or abutments that would .otherwiseire salt from normal toot-h movements during mastication.

Having thus described'my invention, what I claim as new and desire to secureby Letters Patent, is:-

1. In a dental fastening, in combination, a keeper having a head and a vertically elongated shank which tapers in width toward one end, and an anchor having sides which straddle the shank behind the head and clamp between them the widest portion thereof, clearance being left between *the sides and narrow end of the shank to permit only a limited rocking movement of the shank in the anchor and of the anchor on the shank.

2. In a dental fastening, in combination, a keeper having side grooves, and an anchor adapted to straddle the keeper and :engage it to preventboth downward and lateral play .in the joint, there being a clearance provided above and below the points of contact between the sidesof the keeper and the anchor to permit only a predetermined relative rocking movement in the joint between the anchor and keeper, as and for-the purposes described.

3. In a dental fastening, in combination, a keeper having opposite side grooves .which leave between them a substantially elliptical shaped web disposed with its long axis vertical, and an anchor formed of bent wire having closely spaced side members aclapted tobe received in said grooves and in normal position to yieldingly engage the said web only opposite its'short axis.

4-. In a dental fastening, a keeper formed of an elongated body of hard metal having in its opposite side faces longitudinal grooves which shape the body into front and back wallsconnected by a longitudinal and relatively narrow central web which tapers toward both end edges of the keeper.

5. In a dental fastening, an anchor ment With a keeper, one of the sides of said formed of hard metal Wire having a portlon eye being bent to contract its end adjacent thereof adapted for attachment to the bridge to the bridge or bridge plate. 10 or bridge plate, and having portions thereof In testimony whereof I affix my signature. 5 spaced from said attachment portion and CHARLES W. LOKEY.

bent at an angle thereto into closely spaced Witness: parallelism to form a clasp eye for engage- NoMIE WELSH.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. 0.

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