Патент USA US2404427код для вставки
‘July 23, 1946-\ s. BLOOMFIELD 4 2,404,427 EXPANSIBLE ‘ll-AWv SCREW DRIVER Filed Feb. ' 23, 1944 % 5, INVEN TOR. Patented July 23, 11946‘ 2,404,427 UNITED, STATES ‘ PATENT OFFICE Samuel Bloom?eld, Wichita,’ Kans. Application February 23, 1944, Serial No. 523,519 3 Claims. (Cl. 145-—50) 1 v This invention relates to hand tools of the type employed in moving to and from position, conventional‘kerfed screws, bolts, machine screws and the like, the primary object being the pro vision of such an instrumenthaving as a part thereof, simple, rugged, inexpensive,‘ unique and e?icient means for gripping the longitudinal side walls of the kerf _to preclude accidental disen-' gagement. ' ' One of the importantraims of the present in vention is the provision of a hand tool of the 2 ’ ~ able period of time and much effort has been expended in solving this aim. ’ ' ‘The e'xpansible jaw vscrew driver illustrated herewith and about to be described, has been found to be e?icient, inexpensive to construct, andeasy to manipulate. ' a ' ' The conventional screw driver about which parts. of'the tool embodying the invention may be assembled, comprises the well-known han 10 dle ill, from which extends a shank l2. In this aforementioned character that is in the nature instance, the shank is attenuated, cylindrical member, ‘uniform in diameter throughout its of a screw driver having as a part thereof, re length and with planar inclined, diametrically silient jaws, movable to engagement with the opposite faces l4 forming the blade portion of the tool. An annular groove l6 formed in shank edges of a screw kerf as torque is applied to the screw driver shank in either direction about its longitudinal axis. Another object of this invention is. to provide I2 is spaced inwardly from faces M, as illustrated in Figs.'3 and 4. _ ’ The plurality of jaws that are loosely ?tted an inexpensive hand tool for manipulating screws, upon shank I2, is, in this instance, a pair of‘ that embodies an assembly of interrelated parts 20 semi-cylindrical jaws l 8 each having an internal contour conforming to that of the blade portion at the blade end of the tool, which assembly is of shank I2 against which they are assembled. A shifted to and from a normal position through head ZQis formed within ‘each jaw [8 to enter the interaction of the manual manipulation of the tool and the means for yieldably engaging the said parts. Other objects of theinvention include the speci?c manner of constructing the screw driver , groove [6.5 7' When beads 20 of the two jaws H? are in the aforementioned ‘relation with respect to‘ gifOove IS; the ‘end of the blade formed by the conver shank, the jaws associatedv therewith, and the gence of'faces l4, rests immediately. above in means for yieldably holding the jaws in a nor , ternal shoulders 22 formed on the jaws. When mal position, all of which will appear duringvthe course of the following speci?cation, referring to ‘jaws l8 are so, positioned with respect to each other and the blade of shank’! 2, the specially formed split collar 24 is positioned as illustrated in Fig. 1." This split collar is aresilient annulus having at least two slits 26 provided therein the accompanying drawing wherein: \ Fig. .1. is a condensed side elevational view of an expansible jaw screw driver, made to embody 35 that extend inwardly from that edge of collar the features of the present invention. ,24 adjacent to the free end of shank l2. Fig. 2 is a fragmentary side elevational view The slits are designed as illustrated in Fig. 4 of a portion of the tool showing the jaws there and when in the normal position, these slits pro of in an expanded condition.v Fig. 3 is a fragmentary vertical sectional View 40 gressively, increase in width as their inner end is approached. These‘slits terminate in an en through that portion of the tool shown in Fig; 2 largement 28, all to the end that" the split collar but taken on line III--III of Fig. 1. 24 may yieldably yet effectively hold the jaws l8 Fig. 4 is an enlarged stretch-out perspective in a normal position but allow the expansion of view of the component parts of the screw driver. the jaws, as hereinafter set down. Fig. 5 is an enlarged cross sectional view taken 45 The outer edge of. jaws I8 formed by the meet-.4 on line V-—V of Fig. 1; and ing of theouter side surfaces thereof and the Fig. 6 is a similar cross sectional view taken edge surface at their upper ends, is beveled as ‘on line VI—VI of Fig. 2. at 3!] to facilitate the placement of split collar One of the greatest problems experienced by 24 when the latter is moved downwardly over jaws users of screw drivers or similar tools that are 50 l8. The frictional engagement between split col employed in manipulating kerfed structural hard lar 24 and jaws l8'will maintain these elements ware, is the tendency of .the screw driver blade in a desirable working relation and against rel to slip from the Vkerf as force is exerted,v about ative displacement. Well-known means may be the longitudinal axis of the shank of the tool. ‘utilized to secure collar 24 against longitudinal This problem has'been prevalent for a consider 55 movement, if desired. 2,404,427 '3 ‘claimed’ as new and desired to be secured by Let Each jaw I8 is specially formed at itskerf en A relatively short planar- and knurled area 32 is ground, cast or otherwise formed to insure a positive grip between the opposed faces 34 of the kerf of screw‘ 36. These ters Patent is: 1. A screw driver of the character described ' gaging edge. comprising, in combination, a handled shank having a blade; a plurality of jaws loosely ?tted onto the blade and extending longitudinally therealong; means on each jaw respectively, to areas 32 are in parallelism with faces 34 of the’ screw kerf and when the tool is manipulated in prevent accidental longitudinal displacement of a normal fashion, these knurled areas 32 will be forcedagainst faces 34. e 7 ' ' the jaws; and resilient means engaging the jaws ' ‘ to allow radial movement of the jaws The operation of the ‘hand tool is obvious from 10 adapted as torque is applied to the blade, said jaws each the foregoing speci?cation but it should be having a shoulder engageable by the end of the stressed that, advantages arise from the inter- ' blade as longitudinal force in one direction is ap engagement between internal shoulders 22 and‘ the end of shank I2 formed by the meeting of ' faces l4. When a torque is applied to. causenthe, plied to rthe'shank during use of the screw driver. 1,5. ‘ shank to move about its longitudinal axis, sur_ ' faces l4will act in a manner graphicallyv illus- , 2. A_ screw driver of the character described 7 comprising, in combination, a handled shank having ‘a blade at one end thereof and an annu trated in Fig. 6, i. e; jaws l8 will be forced from _ lar groove formed therein adjacent to the blade; a plurality of jaws loosely ?tted; onto the blade thernormal position shown in Fig. 5 to the condi- - ~ tion shown in Fig. 6, where knurled areas 32 are 20 and extending longitudinally therealong over the said groove; an internal bead on each jawrespec- _ snugly and ?rmly pressed against the faces ‘340i 7 tively, ?ttedTinto the groove to'preventlongitu the kerf, Increasing the force of thetorque will dinal displacement of the jaws; ‘and resilient amplify the" outward pressure exerted between means engaging the jaws adapted toallow radial-v jaws I8 and they will be more'rigidly directedv against the opposed surfaces‘ 34 to positively‘pre 25 movement ofthe'jaws as torque is applied to the .blade, each vof said .3‘ aws having a'shoulder formed. clude accidental displacement.‘ /The, application on the inner; face thereof engageable by the end of such torque is sufficient to‘, overcome the ten of vthe'blade when longitudinalfforce in one direc sion :of split collar 24 'andiwhen the tool is in tion is exerted on the screw driver during-use. operation the condition of jaws ‘l8 and split col la'r 24.is asillustrated in, Fig. 2.. Release of the 30; _ 3. A screw driver of the character described torque applying forcerwill permit collar“ to re-‘ comprising, in combination, a >handle,d,~i'attenu turn jaws l8 to the normal position and the tool ated, ‘cylindrical shank having a pair of planar may be removed'from engagement with the screw diametrically opposed, inclined faces r'forme'd '7 kerfthe same as‘thollgh the gripping jaws were thereon at one end'thereof; an annular groove formed in the shank spaced inwardly from the f-The use of theunique expandible jaws does not" thereof, not present.- ' - ' ' r i - 1 I - ; . .7 _ . - “ said inclined faces; a pair of opposed jaws each add to the bulk of the tool to such an extent as having. a cavity formed-thereincontoured to to render its, use objectionable, and since the ' snugly ?t a length ofthe shank on each side of. overall thickness of the screw engaging ends of "jaws 18 need not be greater than that of conven 40" the groove; a bead on each jaw ?tted into the groove; a shoulder on each jaw to engage the end ' tional screw drivers,v the tool is usable ‘:wherever of the shank at the said inclined faces; and re a-standard screw driver could be employed. silient means circumscribing the jaws to‘ hold the ' Any tendency'of the operator to exert down same in place on the shank, the side edges of the ward pressure on shank l2 will not establish a; 'maladjustmentzbetween the parts. The end‘ of 45; planar faces on the shank serving to spread the shank; [2 will always rest upon shoulders 22 whether, ‘the jaws are in. the normal position‘ or spread in work.‘ ' » ‘ jaws as torque is applied thereto during operation - of the screw driver, the end of said shank and theshoulders on the innerfaces of the jaws being in engagement to ‘cooperate with the inter-?tted The preferred embodiment of the invention has been‘ illustrated and such modi?cations and ‘al 50? groove and beads to prevent relative longitudinal movement of theshank and the jaws when longi teration in speci?c structure as "are within the tudinal force in one direction 'is exertedg’on the ' spirit of the invention may be made without de partingfrom the scope of the‘ appended claims. - Having-thus described the invention, what is ‘ shank. seMvEL BLOC-Mime: .