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Publication numberUS988939 A
Publication typeGrant
Publication dateApr 4, 1911
Filing dateNov 30, 1909
Priority dateNov 30, 1909
Publication numberUS 988939 A, US 988939A, US-A-988939, US988939 A, US988939A
InventorsWilliam H Hudson
Original AssigneeWilliam H Hudson
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Surgical forceps.
US 988939 A
Abstract  available in
Previous page
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Claims  available in
Description  (OCR text may contain errors)




988,939; y Patented Apr.4, 1911.

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To all whom it may concern:

Be it known that I, WILLIAM I'I. HUDSON, a citizen of the United States, residing at Montgomery, in the county of Montgomery and State of Alabama, have invented certain new and useful Improvements in Surgical Forceps, of which the following is a Specification.

My invention relates to improvements in surgical forceps, and relates particularly to instruments of this type for use in head surgery.

In performing the trephining operation, and more particularly in forming the osteoplastic flap or trap-door, the best practice is to first form a plurality of openings in the skull, and then connect the openings by means of narrow channels or canals, these channels and openings forming the outlines of the flap. The openings are formed by a suitable trephining instrument or instruments, and extend through the skull but do not penetrate the membrane (the dura mater) forming the covering of the brain, and inasmuch ,as it is essential that this covering vbe not penetrated or affected in any material degree, the instrument for forming the connecting channels must be so arranged as to operate from the inner side of the skull and move outwardly, being so formed as to provide a minimum liability of affecting the membrane during the operation.

The present invention relates more particularly to the instrument for forming the connecting channels.

Instruments for this purpose heretofore provided and which are formed with three members have been arranged in such form as to provide a movement of the inner cutter in a straight vertical line, the opposing cutter being carried by one member acts also in a vertical line. The movements of the two opposing cutters are in parallel lines, thereby providing an operative movement, similar to that of a punch.

In use, instruments having the straight line movements have been found unsatisfactory eXcepting possibly in the thinnest portions of the skull, where the pressure required in causing the inner cutter to pass through the skull may be provided by the operator using simply the ordinary handles; where the thicker portions of the skull are encountered, the pressure required in closing the handles is so great as to make it im- Specification of Letters Patent.

Application filed November 30, 1909.

Patented Apr. 4.-, 1911.

Serial No. 530,650.

possible to be applied by a hand grip, and where the skull is of maximum thlckness is restricted to practically a shaving, the cutter acting more in the manner of a scraper than as a cutter'. This results in the requirement of the expenditure I,of a large amount of time in making the channel, the channel cutting, under the most favorable circumstances, requiring from ten to eighteen separate operations to the inch, this number increasing as the thickness of the skull increases.

The present invention, while having the same general object in view as prior instru. ments referred to, viz., the forming of the connecting channels, provides this result with a greatly increased rapidity, and at the same time, provides all possible restrictions against affecting the brain membrane heretofore referred to, each cutting operation removing a bite of skull material of considerable size, thereby requiring a less number of cutting operations than with any of the instruments heretofore produced for this purpose. In actual practice, I have found that where the instruments heretofore provided have removed but small bites or shavings of the material, the instrument forming the subject matter of this invention uniformly removed bites of a length ranging from one-fifth to one-sixteenth of an inch with each operation, depending upon the thickness of the skull, the relative number of operations required to produce the same length of channel being from four to ten to one in favor of the instrument herein set forth. To produce this result the principle of operation of the forceps is modified from that of having the inner cutter moving in a straight line to that of having the path of movement of this inner cutter eX- tending in a curved line of .greater radius than the radius of the line corresponding with the path of movement of the outer cutter, thereby providing two cutters having relatively curved paths of movement, these paths extending on lines having different radii and intersecting one another. By this particular form of relative movement, the inner cutter tends constantly to move forward in the direction of cutting and thereby provides a substantially curved wall when the bite has been removed, the blades having a reverse shear action.

Another object is to provide an instrument of this type with means for adjustcutter.

ably controlling the length of the distance between the cutters in open position, thereby preventing liability of penetrating the skull to a greater depth than is absolutely required to permit of forming the bite.

A further object is to provide a cutting blade of maximum strength and capable of resharpening when desired, but formed in such manner as to be readily reinserted into the channel after the bite has been removed.

A further object is to provide means for deadening theshock produced by contact of the handles as the bite is completed.

To these and other ends, the nature of which will be readily understood as the invention is hereinafter disclosed, said invention consists in the improved construction and combination of parts hereinafter fully described, illustrated in the accompanying` drawings, and particularly pointed out in the appended claims.

In theaccompanying drawings, in which similar reference characters indicate similar parts in each of the views, Figure 1 is a side elevation of an instrument embodying my invention, parts being shown in section, the cutters being shown in open position, said view also showing the arcs indicating the lines of relative paths of movements of the respective cutters. Fig. 2 is a similar view showing the cutters in closed position. Fig. 3 is a top plan view of the forward end of the instrument. Fig. 4 is a sectional view taken through the shank of the movable Fig. 5 is a sectional view taken on the line 5 5 of Fig. 4.

The instrument herein shown is a forceps of the type having three members, and embodies two pivotally connected members, one of which is formed with one of the cutting members, the other pivotal member carrying the complemental cutter, the connection between the latter cutter and its carrying member being a pivotal one.

10 and 11 designate the two members pivotally connected together by means of a suitable connection 12 forming a fixed pivot point for the two members. Each of said members has its rearwardly extending portion in the form of a handle of any preferred type, the rewar portion being preferably roughened,'as at 13, each handle having outwardly extending portions 14 that serve as engaging members for the hand of the operator in manipulating the instrument in a forward direction. The handles are normally retained separated by means of a spring 15, while one of the handles is provided with a plate 16, of suitable metal, and which serves to deaden the shock produced by the closing of the handles in use, any suitable material which will produce this result, being employed, as for instance, copper. This plate is shown as secured to the handle 10by suitable screws 17 it will be readily understood however, that it may be carried by the handle 11 instead, or each handle may be provided with a plate for this purpose.

The forward end of the member 10 is formed substantially as sho-wn in Fig. 1, being inclined downwardly to a more or less degree, and having an opening 18 extending therethrough, in a substantially vertical direction, said opening having continuous walls formed by the side portions 19, the frontportion 20 and rear portion 21.V The front portion 2O is of less height than the general height of the forward end of this member, the upper portion being cutaway as indicated; the lower face of the portion 20, however, extends in a plane corresponding with the lower plane of the forward end of the member, said lower face being in the form of a cutting edge 22, said edge following a contour similar to that of the movable cutter, .presently described, but being of a size sufficiently larger than the side of the movable cutter to provide a space between the cutters when the latter are in closed position. The portion 2O is curved in horizontal section to permit of the use of a movable cutting blade having its forward end rounded as indicated in Fig. 4. rlhe length of the cuttingface 22, is suflicient to provide a coperating face with the entire cutting portion of the movable cutter.

As it is desirable in some cases, that the bite be provided by a severance no-t wholly due to the passage of the movable cutter through the skull, I form the portion 20 with a rounded face 23 leading to the cutting edge 22, this construction permitting a lifting movement of the instrument with the cutting edge 22 as a fulcrum, and thereby permit the bite to be made not simply by a closing of the handles', but also by a relative pivotal movement of the instrument, with the cutting edge as the pivot point, the particular shape indicated, permitting such pivotal or rocking movement without-a tendency of the instrument to slip during the movement.

The rear wall 21 of the opening is curved in the direction of its vertical length, as shown in Fig. 1, and forms a riding face for the shank of the movable cutter 24,7said cutter being pivotally mounted as at 25 within the forward end of the member 11, said cutter also havingits rear face curved in' the direction of its length to permit itto have an extended contact with the wall 21 during the movement of the cutter. To retain the cutter 24 in contact with -saidfwall 21, l provide a pin 26 which extends' from one side wall to the other at a sufficient distance from the front of the wall 21 to provide a passagewayv for the shank 27 of the cutter 24.

The movable cutter 24 is formed of the shank portion 27 and cutting portion 28, the latter being in the form of a hook continuation of the shank, the inner face of the hook providing the cutting edges, the portion 28 being preferably of the cross-sectional configuration indicated in Fig. 5, the lateral Width of said portion being slightly in excess of the width of the shank portion 27, as indicated in Fig. 4.

To control the length of movement of the movable cutter, I provide one of the members, preferably the member 11, with an adjusting screw 29, one end of which is adapted to contact with the opposite `member when the handles are in their open position, said screws serving to adjustably limit the opening movement of the members, this adjustment being used for the purpose of accommodating the instrument to different thicknesses of skull, it being understood that the opposite eXtreme of relative movement of the cutters is the same regardless of the length of movements of the cutters.

As shown in Fig. l (wherein the line w represents the arc that would be traversed during a pivotal movement of the cutting edge 22, and g/ the arc traversed by the movable cutter), the arcs corresponding with the respective paths of movement of the cutters have different radii, that of the movable cutter being greater than that for the relatively stationary cutter 22, the two arcs intersecting each other. Obviously the movement of the movable cutter will be such as tend to carry the front end of the cutter forwardly as it continues its course through the skull with the result that the bite so formed will have an approximately straight wall through the skull, this tendency to eat forwardly into the bone as the handles are closed, eliminating the gradually rounding eHect produced by the instrument heretofore used for this purpose.

The particular cross-sectional forms of the movable cutter shown in Figs. 4 and 5, are of special value in operation. In use, the completion of a bite carries the movable cutter out of the channel and therefore to reinsert it the movable cutter is passed throughthe trephined opening and moved along the channel portion previously cut, the lesser width of the shank permitting of a free movement of the cutter through the channel to proper position. The particular curvature of the outer face of the cutting portion 28 both laterally and in the direction of length of the cutter, provides a special advantage in the use of the instrument due to the fact that there is practically no liability of the membrane, which lies beneath the skull, being damaged during the forward movement of the movable cutter to a position which will rovide for a new bite, the rounded forward portion serving to gradually pre this membrane away from the skull and ermit the cutting edge to pass into operative position.

Having thus described my invention what I claim as new is 1. In an instrument of the class described, two pivotally connected members, one of said members having an opening formed with a rear wall curved in the direction of its length, the opposing wall terminating in a cutting face, and a movable cutter carried by the other member and adapted to coact with said cutting face during pivotal movements of said members, said cutter having a sliding contact with said rear wall during the cutting movements, and means carried by the cutting member adapted to retain the cutter in contact with said curved wall, whereby the movement of the cutter will be limited to movements extending in a line corresponding with the arc of a circle.

2. In an instrument of the class described, two pivotally connected members each carrying cutting faces, means to limit the opening movement of the members to control the space between the cutting faces for the reception of the material to be cut, and a shock-deadening plate carried by one of said members and adapted to limit the closing movement of the members.

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




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

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4201213 *Jan 30, 1978May 6, 1980Codman & Shurtleff, Inc.Surgical tool
US4722338 *Dec 12, 1983Feb 2, 1988Daniel FarleyMedical instrument for removing bone
Cooperative ClassificationA61B17/1611