US1110379A - Dental instrument. - Google Patents

Description

THOMAS DAY CRAIG, F ALBIA, IOWA.

DENTAL INSTRUMENT.

Specification of Letters Patent.

Patented se t.15, 1914.

Application filed January 17, 1914. Serial No. 812,791.

To all whomct may concern: p i v I Be it known that I, THoMAsDAr CRAIG, a citizen of the United States of America, residing at Albia, in thecounty of Monroe and State'of Iowa, have invented certain new and useful Improvements in Dental Instruments, of which the following" is a specification. 1

The present invention relates to improvements in dental instruments, and is designed especially for use in the removal ofcrowns, bridges, bands, and all; artificial surfaces 7 affixed to teeth.

forth and claimed hereinafter;

vice.

In the accompanying drawings Iv have illustrated one complete example of the physical embodiment of my inventionv constructed according to the best mode I have so far devisedfor, the practical application of the principles ofmyinvention.

While I have herein illustrated the instrument as adaptedfor removinga crown from a tooth, and shall describe only this one feature of the device, it will of course be un derstood that the device is capable of use in 40 many other ways in dentistry which need notbe described at this time. s i a s Figure 1 is a side elevation of an instrument constructed according to my invention.

Fig. 2 is a plan viewof Fig.1. a Fig. 3 is what mightbe termed a front end elevation .of the instrumentshowing its application to a tooth crownbeforeremoval of the crown. F ig. 4a is a underside plan view of the actuating lever for withdrawing the crown from the tooth. Fig. 5 is a perspective view of ,oneofthemovablejclampingjaws of the dei Fig. *6" is an enlarged view of the swwiwhkh f r s t pivot f r that-W0 movements of the clamping jaws, showing n'addit-ion a retaining screw for the actuat lnglever. Fig, 7 is a perspective view of one of the heads of the device.

i In the preferred embodiment of my invention as exemplified in the drawings I have utilized the principles of the common type of pliers orscissors in the pivoted handles 1 and 2 of whlchthe screw or threaded pin 3 forms thecouplingmember. In Fig. 6 it will be seen that the pin 3 is formed with an annular disk etadapted to be seated in a recess inthe lever arm 2, and is further pro vided with a spherical head or ball 5 with a kerf G'thereinL and an annular groove 7 'between the head and disk as will be described.

The two levers 1 and 2 in addition tobeing .operableby hand, are provided with'a power operating device comprising the piv otedscrew bar 8"which is swiveled at 9 in the lever arm 1 and is passed throughan en-, larged opening in the lever arm 2 and provided with a'thumb nut' lO adapted to bear upon the outer face of the lever arm 2 when drawing the two arms together.

. The short arms of thelevers 1 and i2 are provided with duplicate heads 11 and12, an

gularly disposed and depending from the leversv at a spaced distancein order to pro,- vide an opening 13 of considerable size for convenience of the operator. Each of the heads -is providedwith a dovetail groovel l extending from endsto end of the'head and open at top and bottom, and these grooves tionof thedevice. I I

, As seenclearly in Fig. 5 the movable jaws orclutches are metal barsT-shape in cross section crowned witha spherical head or. ball 16 and' formed with outwardly'curved lower fingers 17 between which thetooth crown is to be 1 clutched and then removed. I

., Thejaws 15 are slidable in the mortises of the heads of the lever arms and they are (I moved by means of the springpressed actuating leverv 18 whichis fulcrumed by means of the socket 19 in the arm over the ball or head 5 of the pivot screw 3. A set or retaining screw 20 (Fig. 6) is threaded into an opening in the lever 18 and engages in the annular groove 7 of the pinto lock the lever 18 against displacement from its fulcrum 5, but permits free leverage movement of the lever. The lever 18 is connected to the heads 1 of the jaws 15 through the medium of the separated grooves 21 formed in the forks 22 of the lever 18, and in Fig. 1 it will be seen that these grooves are on a circumference struck from the socket 99 as a center, and that, when required, the lever 18 may be swung laterally upon the ball 5 as a pivot, as when attaching or detaching the lever 18 from the device.

The actuating lever 18 is operated or moved on its pivot 5 by means of a thumb nut 23 on the swiveled stem 24: which is passed through an opening 25 in the end of the lever, and it will be seen in Figs. 1 and 2 that this stem is provided with a tubular T-head or "sleeve 26, slipped over the screw bar 8 and through which the screw bar 8 is free to move. In this manner the actuating lever is anchored on the screw bar of the lever arms,'but the parts may be easily detached from each other when desired.

' From the above descriptiontaken in connection with the drawings it is evident that the instrument is capable of two distinct movements i. e. the clamping of the grasping jaws on the tooth and then the pulling or sliding movement of the engaged clutch fingers 17 to withdraw the crown from the tooth. The former of these movements is accomplished by drawing the two lever arms 1 and 2' together by means of the nut wing, into the position of Fig. 8 to grip the tooth as in a vise and form an anchor or support for the further movements ofthe operative parts of the device. The slidable jaws or clutches are shown in just the proper position to dislodge the crown, and this dis lodgment is accomplished by means of the actuating lever 18, which, through turning its wing nut is moved on its fulcrum and causes the slidable jaws to be moved and guided through the slotted .heads of the levers 1 and 2, and the fingers or claws of the slidable jaws engaging under the crown draw the crown from engagementwith the tooth. The vise or clamping jaws may then beloosened and the instrument withdrawn from the mouth carrying the dislodged crown with it as will be readily understood. I do not wish to be understood as limiting myself to the precise constructions illustrated, as changes may be made within the scope of my claims without departing from the spirit of myfinvention. As for instance the shape of the slidable jaws and their clutching time ma be changed, or other additional jaws ma be providedto constiftutea set adapted for interchangeable use. The shape and size of the mortise and tenon construction may also be varied if desired, and other colorable change and modifications'are contemplated in the physical embodiment of my invention.

Special attention is directed to the ball and socket fulcrum of the actuating lever by means of which the lever is permitted to have a freedom of movement onits fulcrum to adjust itself when operating to pull the crown from the tooth, and the feature involving the spherical heads on the slidable jaws having their connection with the actu ating lever through the round grooves in the lever head or forks is especially meritorious for facilitating attachment and removal of the actuating lever in addition to coupling the jaws with the lever ends.

The grooves 21 are shaped to fit the round heads 16 so that the heads are not likely to pull out and can be taken out only at either side of the head.

Having thus fully described my invention, what I claim is 1. The combination in a dental instrument havingpivoted lever arms and spaced angular depending heads thereon, of movable clutching jaws in said heads, and means for moving said jaws, for the purpose described.

2. The combination with a pair of pivoted arms having spaced angular depending heads, of clutching jaws movable in said heads, and a lever mechanism for moving said jaws as described.

p 8. The combination with a pair of lever arms formed'with heads approximately at right angles thereto, slidable clutching jaws in said heads, a pivot for said arms, and a lever to actuate said jaws having its fulcrum on said pivot.

d. The combination with a pair of lever arms formed with heads at approximately right angles thereto, slidable jaws in' said heads, a pivot for said arms having a fulcrum head, and an actuating lever for said jaws having asocket and interlocked with said fulcrum head.

5. The combination with a pair of lever arms formed with slotted heads at approximately right angles thereto, slidable jaws in said heads, and a pivot for said arms having a fulcrum head and annular groove, of an actuating lever having a socket over said fulcrum head, and a retaining pin engaging said groove. I

6. In a dental instriunent, the combination with clutching jaws movable with relation to the instrument, an actuating lever for said jaws, and a ball and socket fulcrum connection between said lever and instrument.

7. In a'dent'a-l instrument, the combination with. pivoted lever arms having heads at approximately right angles thereto, clutching jaws movable in said heads, and coupling heads on said jaws, of an actuating lever having a slotted head operatively engaging said coupling heads.

8. In a dental instrument, the combination with pivoted lever arms having mortised' heads at approximately right angles thereto, clutching jaws slidable therein and having tenons, and spherical coupling heads on said jaws, of a fulcrumed, actuating lever having a forked end and the forks having separated slots embracing said heads as described. a

9. The combination in a dental instrument having pivoted lever arms and spaced heads at approximately right angles thereto thereon, a screw bar hinged to one arm and passed through an opening in the other arm and a wing nut on said screw bar, slidable clutching jaws in said head, a spring pressed perforated actuating arm for moving said 20 clutching jaws, a screw bar attached to the first mentioned screw bar and passed through said actuating arm, and a thumb nutthereon bearing against said arm.

In testimony whereof I afiix my signature 25 Copies of this patent may be obtained for five cents each, by addressing the Commissioner of .Patents,

Washington, D. G.

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