US1170523A - Right-angle nerve-extractor. - Google Patents

Description

A. FERNALD.

RIGHT ANGLE NERVE EXTRACTOR.

APPLICATION FILED JuLY 9.1915.

Patented Feb. 8, 1916.

gvwen/foz H. Tienen THB COLUMBIA PLANOGRAPH co., WASHINGTON. D. C.

llNlTFDf STATE@ PATENT FFllUlE.

ADELBEBT '.EERNALD, 0F BOSTON, MASSACHUSETTS.

rIEtIGri-I'.-AGELE NERVE--EXTRACTOR To all 'whom t may concern Be it known that l, ADELBERT FERNALD, a citizen of the United States, residing at Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful improvements in Right-Angle Nerve-Extractors, of which the following is a specification. i i

The present invention relates to the art of dentistry and more particularly to a tool which can be used as a nerve extractor, root canal reamer or driller, andvwhich embodies novel features of construction whereby the operator can work upon the back teeth without the necessity of bending and flexing the tool, and can effectively operate the tool by manual means.

Further objects of the invention are to provide a tcol of this character which is comparatively simple and inexpensive in its construction, which admits of the various styles of tools being readily placed in position or removed therefrom, which is light and compact in its construction so that it can be easily handled and manipulated, and which can be readily assembled and taken apart.

l/Vith these and other objects in view, the invention consists in certain novel combinations and arrangements of the parts as will more fully appear as the description proceeds, the novel features thereof being pointed out in the appended claim. y

For a full understanding of the invention reference is to be had to the following de scription and accompanying drawing, in which Figure 1 is a side elevation of a dental tool constructed in accordance with the invention, showing a nerve extractor point as fitted within the chuck. Fig. 2 is an enlarged vertical sectional view through the head of the tool. Fig. 3 is a similar view showing the manner of applying the linger piece to the main shaft. Fig. 4: is a horizontal sectional view taken on the line fl-l of Fig. 2. Fig. 5 is an enlarged detail sectional view of the chuck, portions being broken away.

Corresponding and like parts are referred to in the following description and indicated in all the views of the drawings by the same reference characters.

Specifically describing the present embodiment of the invention, the numeral l Specification of Letters Eatent.

Patented Feb. 8, 1916.

Application filed July 9, 1915. Serial No. 33,994.

designates a tubular stock which has one end thereof exteriorly threaded at la, while the opposite end thereof projects into a looped handle 3 which is secured to the sides of the stock. Extending through the tubir lar stock 1 and journaled therein is a main drive shaft L1, one end of the shaft having a small bevel gear 5 applied thereto, while the opposite end thereof projects beyond the stock 1 and has a cylindrical finger piece or sleeve 6 rigidly applied thereto. The exterior surface of the cylindrical linger piece or sleeve 6 is preferably milled or roughened so that it can be readily grasped by the lingers and the small set screw 7 is shown as provided for securing the finger piece to the shaft. This linger piece is positioned within the looped handle 3, and one end thereof is preferably reamed out at 6 so as to fit over the end of the stock 1 and obtain a bearing thereon.

A sleeve 8 is fitted upon the threaded end 1a of the stock 1, the diameter of the small bevel gear 5 being substantially the same as the exterior diameter cf the stock 1 so that the bevel gear 5 can be inserted through the bore of the sleeve 8. At the outer end of the sleeve 8 is a tubular head 9 which has the axis thereof arranged at right angles to the axis of the sleeve. A short tubular shaft 10 is journaled within the head 9, and the upper end of the bore of the head is rea-med out or enlarged at 9a to provide a chamber for a bevel gear 11 which is rigid with the tubular shaft 10 and normally meshes with the before mentioned bevel gear 5 at the end of the main shaft 4. A cap piece 12 is threaded within the mouth of the enlarged upper end 9a of the bore of the tubular head 9, said cap or plug being formed with a central opening 12a to receive the upper end of the tubular shaft 1), and being also provided with a kerf 12b so that it can be readily engaged by a screw driver or like tool when being placed in position or removed therefrom.

A chuck 13 extends through the tubular shaft 10 and is formed with an axial opening 14 adapted to receive the shank of a nerve extractor A or any similar tool. The lower end of the` chuck 13 terminates in a conical enlargement 15 and is longitudinally slotted at 16, while the upper end thereof is threaded for engagement with a milled thumb nut 17. The bore of the tubular shaft 10 has the lower end thereof fiared at 10Ll for coperation with the inclined walls of' the conical enlargement 15 at the end of the chuck 13 to force the jaws formed by the slot 16 into a gripping engagement with the nerve extractor or like tool A when the chuck is drawn upwardly into the tubular shaft.

By loosening the thumb nut 17 the jaws of the chuck 13 will be permitted to spring apart a sufficient amount to admit of the shank of any form of tool A such as a nerve extractor, root canal reamer, or driller being inserted into the bore of thev tubular shaft or Withdrawn therefrom. After the shank of the desired form of tool A has been inserted into the bore of the chuck 13 the thumb nut 17 is tightened so as to draw the chuck upwardly into the tubular shaft and cause the jaws thereof to be forced into a gripping engagement with the point by the cam action between the flared mouth of the tubular shaft 10 and the conical enlargement 15 at the slotted end of the chuck. When tightening the thumb nut 17 the cylindrical finger piece G is grasped between the fin-l gers so as to prevent rotation of the tubular shaft 10 and chuck 13 with the thumb nut.

After the desired style of tool A has been inserted in the chuck, the desired rotary movement can be imparted thereto by rolling the cylindrical finger piece 6 between the fingers of the hand. The looped handle 3 provides a convenient means for holding the tool in proper position while manipulat ing the same, and the working tool A is disposed at right angles to the stock and handle so that the operator can work upon the back teeth without the necessity of fiere ing the tool in the usual manner. This is a great advantage, since a tool often has to be bent at substantially right angles to the handle when being used upon the back teeth and Copies of this patent may be obtained for` ve cents each, by addressing the Gommssioner of Fatents,

under` these conditions the tool not infrequently breaks when rotated.

An important feature yof the hand operated right angle nerveextractor, root canal reamer and driller is that the chuck is so constructed that it will hold any make, any size, and any length required ofbroaches, reamers, and drills. vVhen'using the drills and breaches" the tools may be cut offI at suitable lengths before inserting them into the chuck. When the instrument is thus constructed, finebroaches, drills, and reamers can more readily follow the irregular nerve canal, without being broken, and this is very important, since, otherwise there would be danger of drilling throiigh the sides of the root.

Having thus described the inventiomwhat I claim as new Aand desire to secure by Letters Patent, is:#-

A dental drill of the including a tubular stock, a flat looped han dle projecting longitudinally from one end of the tubular stock, a head upon the opposite end of the tubular. stock, a main shaftV extending longitudinally through the tubular stock and Journaled therein, one end of the main shaft-projecting into the interior of the looped handle, a finger operated sleeve rigidly applied to the said end* of the main shaft and arranged within the confines of the flat looped handle so as to be readily engaged by the fingers of the hand grasping the handle, and a chuck mounted within the head and geared tothe opposite end of' the main shaft.

In testimony whereof I affix my signature in the presence of two witnesses.

ADELBERT FERNALD. Witnesses Sanna V. GILLIS, W. E. BOARDMAN.

Washington, D. C.

character described7`

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