US2092929A - Penetrative implement - Google Patents

Description

Sept. 14, 1937. E'. J. OVINGTON 2,092,929

PENETRATIVE IMPLEMENT Filed May 29, 1954 -II IIIIIIIIIQ I IIIIIIIII,

I 7411627507 152 10602 0 r1 001323 52211 W Q/ZZO 7 776;?

Patented Sept. 14, 1937 U N IT E E PA ENT"- PENETRATIVE IMPLEMENT Edward J., Ovington, Auburndale, Mass. Application. May 29, 1934, Serial.No.. 728,103

the arcuate cut; andthen displacing'the tip of This invention relates to improvements in penetrative implements.

More especially it relatesto sharp pointed-im plements, such as needles and awls, for making 5" small holes in material, either for the introduction of a thread,.or-the like, or for some other purpose; and it-is especially applicable where the implement is to bewithdrawn, and the hole which it has made is thereafter to be filled or otherwise closed.

As the invention relates to that part of the implement which functions in the making of the hole, the invention is useful both where that is the whole function of the implement, as in the case of an awl, and also where the implement serves some further function as the introducing of a thread, as in the case of a needle.

Thus the invention has utility in a considerable number of aspects. Fields of primary importance are for the sewing of leather and of living tissue. As the sewing of leather is illustrative of the manner in which the invention l functions when applied to other materials, and

of its construction for attaining the results which are .to be described, the characteristics ofthe invention will be herein described with reference to needles for the sewing of leather, and also with some reference to surgery; but it will be understood that the utility and the advantages are-:notslimited to. the materialsnamed, or the particular uses described.

l 'I'heimplement of the. invention has an improved construction which as applied to the sewing :of leather is. adapted to 1 make-the requisite holeothrough the leatherlby an improved cutting and bending method of. formation; In: addition, the-hole itself is; what. may be called an improved hole, that is, .the-walls surrounding. the hole-:stand in a condition .and in :rnutualrelations which: have special advantages believed to be new; and the completed sewn article is an improvement overarticles sewn. with -.thread as heretofore known; so far. asI am aware.

Objects of theinvention are that .the implement; as it penetrates, shall cut a. tongueof the material and then bend or press that tongue away-y meantimegraduazlly'and cleanly extendinglthe cut, with the-cutting in'advance of the: bending, and without tearing the tissue. The initial-cutting of-the'material is on a curved line, as on an arc of 2a circle; and the hole thus started :is'enlargedby "the double operation of graduallyextendingthe cut' in arcuate form: at eaohrend iof'ithe. initial-arc, thus imaking a flap of: the-materialewhich. is; on:.thev concave .side of,

that flapby. smooth, pressure. If,, ;the mate. rial be leather.,;.thedisplacingtakes thegformi of a bending of the flap out of :itsloriginal position .in. the: plane; of: thecmaterialy and then the surrounding .walls. of. the ultimate holeeare in .part.

a; surface cleanly cut. by theneedle, :and are ini part aniinbent surface which'was. initiallyan ex.- terior surface ofthe material. If. the material be livingtissuethe, displacing-takes the: form of a compressing and lateralfiow; of surrounding tissue. In both cases.,;rag.ged.;edges;-and.'torn. tissues are avoided ,;-.which'. is amatter. of human. consequence if=.;use of theaneedlerhappento:be; surgicaL-as 1we1l:as;one whichzin any caseafiects. the strength and durability of the sewing. In'

thev case ofsthe sewing; of leather this iS-{Df particular importance; Leather-,is-inherently resil-' ient; and the little-q bent :flap .upon: being displaced ;from its normal .:place in; the sheet of leather; presses back; against the thread whichoccupies ithehole'lg If it-happensthat the flap;

has been put back into the hole',..which can be done byztheszpresser. footand the draft of thread in a sewing; machine, the fiap presses :tightly against the intrudedthread and holds the-sew.- ing more firmly than if there were merely-a punchedrroundhole' of:the;-size;;of thread. In the .acase of? patent leather the invention avoidsr thepstriae of;;cracks and incipent rentswhich surround stitching holes punched by ordinaryneedles.

As. applied in surgeryptheuU -shaped character-' istic of the arcuate line of cut stops accidental traumas. When the arc is extended through .so many degrees F of: curvature that-the end portions approach parallelism; any'accidentallpresss ing -of ,the hand of the. surgeon towardleither side .does not extendthe cut sidewise and make the-holeunnecessarily large. This shape of ricedle-hole also makes the wound-of suchformzas to have a best chance of healing quickly andof leaving the least scar, cave side of thepneedle is; under compression parallel to the surface-in all-directions from the concave-face of the needle.v Thetissuewis by natureresilient; and this compression extends. to that part :of --thetissue which is, about; to. be cut. The presence of a stateof compression there, asucontrasted with-the presence of a state of tension and stretch; tends tolprevent tearing The tissue on the conof the-tissue-at the points which are about to t sistance, because all of the rupturing necessary to be done is done by cutting; and this is done only gradually and with a drawing out by the blades, as the penetration proceeds. Also, it is done with a thinner wedge of blade than with prior needles.

In the construction and maintenance of the needle, the cutting edges can be brought up to sharpness with but little or none of the hand operation which is known as the finish pointing. Moreover, the invention makes the cutting part of the needle so that its sharp edges can easily be re-sharpened.

Other advantages result from or are found in the construction and mode of operation hereinafter described. The particular embodiments of the invention herein described are illustrative, and the invention may be applied in otherways without departing from the spirit and scope of the invention. It is intended that the patent shall cover, by suitable expression in the appended claims, whatever features of patentable novelty exist in the invention disclosed.

In the drawing:

Figure l, which may be considered to be a pla shows a needle embodying the invention, having a shank of the straight round type, laid with its concave face upward, the edges of the concave face being the cutting edges of the needle;

Figure 2 is a side elevation of the same;

Figures 3, 4, 5 and 6 are cross sections of the same at the places indicated, being end elevations, but in Figure 6 there is added a representation of a bit of sheet material as penetrated by'the needle at this cross section thereof, showing the face of that material;

Figure 7 is a side elevation of the same needle in the act of penetrating two sheets of material;

Figure 8 is a plan of a fragment of the material of Figure 7 from which the needle has been withdrawn and in which the flap has returned to its initial position, showingthe effect of the needle upon the material;

Figure 9 is a section in side elevation through two sheets of material and a hole therein made by the needle, showing a loop of thread therein;

Figure 10 is a-similar section in side elevation showing two loops of thread in such a hole, looped together, the material thus constituting a sewn article;

Figure 11 is a side elevation of another form of the needle, being a curved needle, embodying the invention;

Figures 12, 13 and 14 show some other forms of cross-section which either of the needles of the invention may have;

Figure 15 is a representation of a body of living tissue being penetrated by a needle of the invention, in which the stippling indicates compression eifected by the needle which is seen in cross-sec tion; and' Figure 16 represents in edge elevation a grinding wheel for sharpening the needle of the invention, this needle being seen in cross-section.

In the implement of the invention, whether it have an eye or be merely an awl, and whether it be straight or curved, the shank tapers to a point for penetrating the material; this tapering portion of the implement has at least two cutting edges; and the surface connecting these edges is concave, and is herein referred to generically as being of U-form. The concavity is preferably of the general style of a crescent, as indicated in Figures 3, 4, 5 and 12. At all stages ofsize of the crescent, the curvature preferably reaches to a considerable extent of angular measure. The concavity and the crescent formation may vary somewhat, especially in different needles, illustrations of which are found in Figures 12, 13 and 14; but it will be noted that in each of these cases it has been preferred to extend the curvature to so large a fraction of a circle that a shape approaching a U is formed, and that consequently a pressure of the needle toward the right or left, for example in Figures 3, 4, 5, 12 or 14, would not be favorable for cutting material on that side of the needle. This safeguards the material against the cutting of an unnecessarily large hole by side pressure of the operators hand.

In the construction represented in the drawing, the needle of Figure 1 is represented with a shank l0 having an eye l2 and a tapering portion l4 leading to an extreme point portion I5. The eye is shown'at the dull end, but it might be at the middle or near the point; or means other than an eye might be provided for drawing thread; or all devices of the sort might be omitted, as in the case of an awl. The tapering portion has cross sections, as seen in Figures 3, 4 and 5, whose shapes may be described in general terms as being crescent, although the two faces are not necessarily circular curves. The edges where those two curved sides intersect are sharp. cutting edges marked a, b. The taper preferably is long, and these cutting edges depart so little from parallelism that the passing of the tapered part through material, as leather, or live tissue, presents the thin wedge blade to the material with such a slow enlargement of dimension between the two cutting edges of the blade that the cutting is done with a drawing of the blade edge along the material, to which there is very little resistance. When this implement is thrust endwise through a sheet of leather or other dead material, as represented at 20 in Figure '7, the material ultimately becomes cut on a curved line as represented at 22 in Figure 8; and the flap consisting of the tongue thus formed becomes bent out of the plane of the sheet 20 as the needle progresses, as seen in Figure '7, until finally, when the full body of the shank is passing through, having the cross section seen in Figure 6, the flap 24 is so far bent downward thereby that the hole is cut and spread open as there shown, ready to receive whatever thread may be drawn through by the eye l2, or be otherwise inserted.

Figure 9 represents a thread as thrust through the holeand left thereby a needle. shows how the flap 24 of the material tends by resilience to press the thread, as the flap tends to return to its position illustrated in Figure 8. The thread is thus more tightly gripped than if there were a mere round hole made by the needle. And when that flap has been pulled back, as it may be by friction and thread tension upon withdrawal of the needle, to the position represented in Figure 10, the pressure of the flap upon the thread in the plane of the material is manifest.

A material such as the live tissue of man, or animals, is resiliently mobile in high degree. Around an incision into which needle and thread have been introduced it can undergo compression; and the tissue transmits pressure in all directions somewhat as a fluid does. Therefore the tissue at both sides of each cutting edge a and b in Figure 15 is in a state of compression from the gradual thickening of the intrudedconcave-con- This figurevex body of the implement represented in Figure 15; and by its native resiliency it can then tend strongly to return to its former position upon the withdrawal of the needle; and it will then remain in compression owing to the presence of the thread which remains as an intruded body. In entering, the concavity of the one face diminishes the stretching or spreading effect which the implement is imposing on the tissue at the region of the blade edge, as compared with a blade whose wedge-form is plane on one or both sides or is convex on both sides. Unlike a needle which merely makes a straight out and at the same time bulges it, or one which radially enlarges a small hole made by the very point of the needle, both of which tear the tissue more or less in the making of the hole, this needle makes the hole by first curring a flap and then pressing aside the flap. Thus the walls surrounding the hole are cleanly cut and hence relatively smooth, regular and firm, and automatically tend to close together, both in the case of leather and of living tissue. Therefore the thread is more firmly held than it is in ordinary sewing; the article thus sewn has its material in a state of resilient compression against intruded thread; and the frictional holding is secure and very strong, the part which is compressed within the thickness of the material continuing to hold the thread.

When the needles cut through the material is clean, as represented in Figure 8, and the ends of the cut approach a parallelism of direction, as there indicated, the walls of each hole are in condition to resist strongly a seam tension without tendency of the holes to become enlarged by extension of incipient radial rents, such as might have been already started if a needle of some other type had been used.

In the needles of the invention, it is desirable that the curves of the crescent as seen in cross section should bear approximately the same rela tion to each other at all sections of the taper, as is seen by comparing Figures 3, 4 and 5.

In manufacturing the needle of the invention the concave tapering portion can be made by a stamping process which deforms a round pointed blank of the material into the desired concave crescent shape. In such a blank there will already have been an accurate round pointing of the round needle wire according to the contour of a predetermined curve. This contour is preferably convex from point to shank, but the degree or curve of convexity depends upon the rate at which the various dimensions of the crescent cross-section are desired to increase. Then, when the blank is by a press operation struck into a crescent cross-section, the edges will come up into shape in fairly sharp cutting condition with little or no extra metal appearing as a flash around the actual edge. Even when finish pointing is necessary, it can be done much more easily with this type of needle than with flat sided needles of former-type. When the needle shape has been made by stamping, the edges a and b can be made sharp by the simple procedure of holding the needle on the surface of a V-shaped recess in a grinding wheel, as indicated in Figure 16.

The terms concave and convex are herein used as being comprehensive of surface forms which are variously re-entrant or variously salient respectively, several of which are seen in the drawing.

I claim as my invention:

1. A penetrative implement of the class described, having a portion which tapers to a sharp point and in the taper has sharp cutting edges precisely two in number; said tapering portion having a forward side and a rear side, of which the forward side has a channel contour throughout said taper, and the rear side has a salient contour throughout said taper; the two said contours merging into the two said cutting edges, which extend along opposite borders of said channel to the extremity of the said oint, each cutting edge being the edge of a sloping surface. of the channel contour.

2. A penetrative implement as in claim 1, further characterized in that the tapering portion is of approximately crescent shape in cross-section throughout the taper to the extremity of the point, with the two cutting edges extending along the two horns of the crescent, the grinding of each edge, for sharpness, being on the said salient side thereof.

EDWARD J. OVINGTON.

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