US2796099A - Screw holding screw driver - Google Patents

Description

INVENTOR. .BIER/52,

u Arroz/VEV- June 18, 1957 H. E. DIERKR SCREW HOLDING SCREW DRIVER ,Filed June 15, 1954 w ii 9 7 j nited States Patent O 'i SCREW HOLDING SCREW DRIVER Hugh E. Dierker, Encino,`Caiif.

Application June 15, 1954, Serial No. 436,861

Claims. (Cl. 145-52) My invention relates to screw holding screw drivers and like tools designed to drive in, or withdraw, threaded securing elements having a head provided with a slot, kerf, recess 'or groove to be engaged by the bit or blade of the tool which is rotated to cause the securing elements to move into, or out of, a body or hole therein.

The handling of such securing elements is often awkward as, for instance, when there is insuicient room to get a persons hand to the point at which the securing elements are to be located to steady such elements during the initial securing operation. Also since considerable force must be exerted against the screw or other securing element while turning it, and the groove or recess in the head may be quite shallow, it is very easy for the bit or blade to slip out of the head owing to the user failing to keep it squarely engaged in such recess in the head.

Efforts to improve tools used for the purpose of manipulating securing elements of the kind described have long been made, and numerous attempts to provide improved tools and means for securely holding such elements have also been proposed. Although some success has been achieved, many of such tools have drawbacks, such as lack of adaptability, unnecessary complexity with consequent high cost `of manufacture, and liability of failure in use, and the like.

lt is the general object of my invention to provide a novel, simple, strong and inexpensive tool for the purpose described.

An object of my invention is to provide a novel tool which will iirrnly grip a headed and threaded securing element until such element is substantially fully driven home and which tool may be thereafter easily and quickly released from the head of the element and again applied thereto, whereby the tool will be centered and held in centered position on the head of such element while the element is being driven home.

Another object of my invention is to provide a minimum of parts which may be readily applied to standard forms of screw drivers, and the like, with a minimum amount of modification of the latter.

A further object of my invention is to provide a novel screw driver or like tool incorporating a standard form of tool with special parts, the standard tool being usable at times in its usual manner and without impairment of its effectiveness that may otherwise be caused by such special parts during a particular portion of a driving operation of the securing element.

A still further object is to provide a screw driver with novel holding means, whereby a securing element is rigidly held by a slidable cam actuated means, and in which spring elements for holding the securing element in contact with the bit of the screw driver are entirely eliminated.

The invention resides in the parts and combination and arrangement of the parts as more fully hereinafter described in detail in the accompanying specification and defined in the claims.

Other objects, advantages and features of invention ice may appear from the accompanying drawings, the subjoined detail description, and the appended claims.

The accompanying drawing illustrates the invention in a form I at presentdeem preferable.

Figure 1 is a side elevational view showing the screw holding screw `driver of my invention in position engaging a screw about to be driven into the work which is shown in section.

Fig. 2 is a cross-sectional view on enlarged scale taken on line 2-2, Fig. 1. A portion of the handle is broken away to contract the view.

Fig. 3 is a cross-sectional view analogous to Fig. 2, but showing the screw removed and the parts moved to normal or inoperative position.

Fig. 4 is a fragmentary view in cross-section on the same scale as, and analogous to, Fig. 2, but showing the driving end of the tool in use in the final steps of driving home a screw.

Fig. 5 is a cross-sectional view taken on line 5--5, Fig. 4.

Fig. 6 is a shortened view similar to Figs. 2 and 3, but looking from the left to the right in Fig. 3 and showing the screw driver with its bit in retracted position. Dot and dash lines indicate a projected position of the screw driver blade or bit.

Fig. 7 is a fragmentary detail perspective view showing the cam arrangement for moving the screw holding means longitudinally relative to the screw driver blade.

Fig. 8 is a fragmentary cross-sectional view showing the screw driver in the iinal stages of driving home a screw into a body or hole therein, and which screw has been almost completely embedded in the body or Work piece.

Referring to Fig. 2 `of the drawing, the number 10 indicates the handle of the screw driver in which the shank 11 is rigidly embedded and held as, for instance, by longitudinal ridges 12 on the butt of the shank which is molded into the handle (see Fig. 3). The handle 10 is provided with a recess 13 at its upper end around shank 11 and a helical compression spring 14 surrounding shank 11 is positioned therein.

A tubular member or sleeve generally indicated at 15 has an upper portion 16 of a diameter slightly greater than that of the shank 11 but of a greater diameter at its lower portion to accommodate a tubular interior cam member 17 which is secured to the sleeve 15 in any suitable manner, as by brazing. The lower end of sleeve 15 and the lower end of cam member 17 are co-terminous, and enter the upper end of recess 13 and provide a seat for the sleeve 15 on the upper end of sprin-g 14.

The shape of cam 17 is clearly shown in Fig. l7 from which it will be noted that the cam has an upper surface progressing helically from a low point 18, at which a depression 19 is formed, to a high point 20 lying directly over the low point. A vertical face 21 joins the high point of the cam with one side of depression 19. The sleeve 15 has a sliding and rotary movement relative to shank 11, and the rotary movement is limited in one direction by a pin 22 driven into a transverse hole 9 drilled in shank 11. A projecting portion of the pin rides on the helical face 8 of cam 17 when the sleeve 15 is held stationary, and the handle 10 is turned, or the shank 11 is held stationary by the handle and the sleeve 15 turned. Sleeve 15 is knurled at 23 to facilitate holding it against rotation or rotating it when required, or when longitudinal movement on the shank is desired against the resistance of spring 14, during which time the pin 22 is free to move vertically with respect` to the cam 17. However, if the handle 10 is turned with the sleeve 15 free to rotate, pin 22 will engage with the vertical face 21 of the cam 17 and effect rotation of the sleeve 15 together with the'shank 11.

It should be noted that outward movement of the sleeve 3 15 on the shank 11 under the eort of spring 14 is limited by the engagement of the piu 22 in the depression 19 at the low point 18 of the cam member 17, while upward movement' of the shank r11 against; they resistanceV of the spring 14 is. limited by the spring 14 becoming fully-compressed with the turns .of the spring in contact with one another and against the bottom of recess13. in handle 10. The extreme positions ofthe pin, 22with1respect to the cam 17 :are shown in Fig. 6 in which the pin isshown in full lines at .the low point ofthe cam and in depression 19, and in dotted lines at its upper limit of axial movement of shank 11- relative to sleeve 15.

The lower portion `ofsleeve 15 is provided with, diametrically opposite holes 24 and25 (Fig. 3), which er1- able pin 22 .to be driven into position in hole 9 drilled in shank {11.ftov1eceive it. In orderctoenter the pin 22 in the hole 9 for the correct distance, thek hole 9 is made a drivey it fort-.the pin 22 part way through shank 11 and is preferably carried through fromits inner end as. a hole 27 of smaller diameter `than that of hole 9, thus providing both a locating seat for the inner end of pin 22vand make provision. to enable the pin 22 to be driven out of the shank (if required) by means of any suitable tool with anend entering the small diameter hole 27 through the hole 25.

The. outer'end of sleeve 15 adjacent .the bit 6 of shank 11 is tted with a screw holding chuck, generally indicated at 28, and best shown in detail in Figs. 2, 4 and 8 in association with screw holding and drivingy operations, and in Figs; 3 and 6 when not in use, or when a screw has been removed therefrom. Chuck 23 is formed with a short tubular skirt 29 secured, as by brazing, to the outer end of sleeve 16. Beyond the end of the sleeve 16, the chuck is slotted diametrically as shown at 3i) and is provided with an inwardly projecting flange 31 having a T-shaped slot 32 therethrough symmetrical with the axis of the sleeve.Y Slot 30 is provided to enable the head of a screw 35 to be slippedy sideways into the chuck while the stem or shank .of the screw is received in slot 32, which is provided with a semi-circular end 7 co-axial with the axis of the chuck and sleeve 16. A slot 33, Figs. 5 and 6, extends outwardly from the semi-circular end 7 of slot 32 to enable the end of the screw driver bit 6 which provides a driving surface or face to pass therethrough. Preferably thelower edge of slot 32 is chamfered as at 5 to the angle of the head of a wood screw. received in the chuck, thereby'affording good seated co-action between the screw and :the underside of flange 31.

The circumferential outer wall of the chuck is continued outwardly beyond the inwardly projecting flange 31 for a short distance to provide retaining walls 4 around a screw head retaining seat 34, the slot 33 obviously cutting through the side of this retaining seat 34.

It will be understood that when driving a screw, such as 35, into any member, indicated at 36, the screw driver ory tool of my invention will be used as shown in Fig..1 and the user will rotate the tool until the chuck 23 engages (or closely approaches). with the work whereupon the shank 11 and sleeve 15 will be oscillated to release engagement of the driving face or surface of bit 6 from the kerf in the head of screw 35 and the chuck will be slipped oi sideways from the head tt of screw 35; and the screw head retaining seat 34 is then pushed axially against the head of the screw and the driving face or surface of bit 6 of the screw driver again inserted in the slot in the screw head (see Fig. 4). The final turns required .to -fully embed thehead of the screw can then be given with a full thrust and torque applied to the driver shank 11, since the sleeve 16 is free to be pushed backwardly on the shank of the screw driver against the resistance of spring 14 while the chuck 23 remains firmly centered on the screw head during all times the latter .projects 4above the surface ofthe body', because the re- :taining walls, 4r will vencircle .the periphery of the screw 4 head and maintain it centered on seat 34 and in alignment with the bit 6.

It will be noted that the inclination of the upper suryface of cam 17, from the top of depression 19 to the high point 20, is quite gradual so that pin 22 in contact therewith will not be moved therealong by action of the spring 14 (which is only of suicient strength to maintain the sleeve 15 and shank 11 separated to the limit of pin 22 when in depression 1,9) and to cause the screw head retaining seat 34 to be urged against the screw head and thereby position the retaining walls 4 around the head a of screw 35. Thus it will be seen that when a screw is positioned in chuck 28 and piu 22 moved along the upper surface of cam 17 that the sleeve 15 will be locked in screw holding position by frictional engagement of the pin 22 on the cam surface which imparts a wedging action between the pin 22 and the cam.

In operation, the head a of a screw 35 may be slipped sideways into the shuck 28, the shank b of screw 35 eX- tending through slot 33, and with the sleeve 16 being held from turning, the handle 10 of the screw driver is pushed toward the screw and the bit 6 seated in the slot or kerf inthe screw head and the handle 1@ and shank 11 are then turned in the same direction as when driving the screw home. In this operation, about a quarter turn of the handle 10 will bring the driving surface or face of bit or blade 6 ofthe shank 11 tightly against the screw head and will rigidly lock and rmly hold the screw in the chuck.` During this screw securement operation, the pin 22 will be engaged by the helical face 8 of the cam 17 to force the shank 11 and its bit 6 outwardly of the sleeve 16 and into tight engagement with the screw, to thereby force the underside of the screw head into the chamfered portion 5 on the underside of flange 31.

Alternatively, the screw head may be inserted with the groove across the head aligned with the bit of the screw driver and the handle pushed longitudinally while holding the ksleeve against movement. The bit will at once enter the groove and can be held in engagement'by the partial turn described. It will be understood that the turning movement may equally well be given, but in the opposite direction, to the sleeve instead of the handle which will then be held stationary.

The screw 35 thus tightly secured in the chuck 28 may then be secured to the work in the usual way, the screw driver being turned until the chuck engages against the work which it will do before the screw is fully driven. The handle or sleeve is then given a short counter-rotation and pressure on the handle released, this enabling the bit to be withdrawn into the sleeve either manually or automatically by action of the spring 14. The chuck is then slipped off the head of the screw and the screw head retaining seat or cup 34 of the chuck is positioned to er1- circle the head a of the screw and the handle 11B pushed toward the screw head causing the bit to pass through the openings or slots 32, 33 in the inwardly extending flange 31 in the chuck and engage in the groove or kerf in the screw head (see Fig. 4), and the screw may then be fully driven home by rotating the screw driver in the usual manner. The pin 22 bearing against vertical face 21 of cam 17 will guide the bit 6 into the slots 32, 33, as shown in the dotted line position in Fig. 6.

It is to be noted that full pressure can be exerted against the head of a screw when spring 14 is compressed, since the latter is completely enclosed by supporting walls, and the application of pressure is direct from the handle 10 to the bit 6; the spring 14 being only of sucient strength to provide a firm co-action of the parts and to force the seat or cup 34 against the screw head a and the work 36, thereby enabling the retaining walls 4 to embrace the screw head and hold or center the screw head and bit 6 in operative engagement. However, the `spring 14 is not of sufficient strength to force the cup-shaped screw head retaining seat walls 4 against the work (Fig. 8) so as to Vmar or deface they surface thereof.

It will be understood that a screw driver for Phillips head screws may be easily provided by suitable adaptation of a chuck and bit therefor without departing from the spirit of my invention.

While I have described and illustrated a presently preferred embodiment of my invention, it is obvious that various changes may be made therein by those skilled in the art without departing from the scope of the invention as defined by the appended claims.

I claim: v

1. In a tool of the class described, a shank having a handle at one end and a driving member at its other end adapted to engage the head of a securing element provided wth a stem; a sleeve member receiving said shank; a retaining chuck at the outer end of said sleeve member and having a side opening adapted to receive the head of a securing element therein, and having a slot adapted to receive said stem; an inwardly projecting flange member in said chuck above said side opening; co-acting cam means respectively ixedly connected to said shank and sleeve, and including a cam member and a projecting member; and `spring means arranged to normally urge said sleeve outwardly on said shank; said cam member having a spirally inclined cam surface having a high point approximately directly above the low point, said points being connected by a vertical operating face, and said projecting member and vertical operating face being so positioned and arranged on said shank and sleeve and relative to said driving member whereby said driving member is alined with ysaid slot when said projecting member rides on said vertical operating face; and said cacting cam means being effective upon movement of said projecting member on said cam surface in one direction to advance said driving member into engagement with a securing element positioned in said chuck to securely hold said element against said ange until released by a reverse movement of said projecting member on said cam surface.

2. A tool as set forth in claim l, and in which an open* ing is provided in said inwardly projecting flange for the passage therethrough of an edge of said driving member.

3. A tool as set forth in claim 1, and in which retaining walls extend outwardly from said inwardly projecting ange member to encircle the head of a securing element.

4. A tool as set forth in claim l, and in which an opening is provided in said inwardly projecting ange for the passage therethrough of an edge of said driving member; and retaining walls extending outwardly from said inwardly projecting flange member to encircle the head of a securing element.

5. A tool as set forth in claim 1, and in which said cam is provided at its low point with a depression to receive said projecting member.

References Cited in the tile of this patent UNITED STATES PATENTS 950,318 Dunning Feb. 22, 1910 2,248,054 Becker July 8, 1941 2,273,861 Green Feb. 24, 1942 2,312,869 Boyer Mar. 2, 1943

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