US2774401A - Screw-holding drivers - Google Patents

Description

Dec. 18, 1956 V A. B. HALLAM SCREW-HOLDING DRIVERS Filed Jul 20, 1953 United States Patent SCREW-HOLDING DRIVERS Arthur Blakey Hallam, Leeds, England, assignor to Chas.

F. Thackray Limited, Leeds, England, a British com- P y Application July 20, 1953, Serial No. 369,179

Claims priority, application Great Britain July 28, 1952 7 Claims. (Cl. 14552) This invention relates to screw drivers of the type incorporating screw-holding means which grip the screw and hold it in the required position whilst it is driven wholly or partly into position.

Various devices have been constructed and incorporated into screw drivers for holding the screwduring the operation of screwing into position. In some cases spring claws or slotted tips are furnished at the end of the screw driver with a driver tip located behind them and relative movement is provided between the two parts. In one known construction a screw driver has a rod axially mounted within a sleeve carrying the tool handle and a slotted hollow tip into which the screw can readily be inserted for its head to lie within the tip in line with the driver tip. The latter is in the form of a spring-loaded plunger in the end of the rod and the latter is moved axially by means of a screw head which requires to be rotated clockwise or anticlockwise into the handle to cause the rod to project or withdraw. Such rod approaches the screw, the driver tip enters the screw head slot and then continued movement of the rod causes the latter to slide over the driver tip until its end bears against the screw head and holds it firmly in the screw-holding tip. The disadvantage with this arrangement is that the action of screwing the rod into or out of position is rather lengthy, and is a two-handed operation and in many cases quick action is desirable.

According to the present invention there is provided a screw driver incorporating a screw-holding device and a screw head pressure applicator mounted to allow relative axial movement between the two parts, a driver tip to rotate a held screw when the tool handle is turned and a pivoted lever for causing the relative axial move ment between the two parts for applying pressure on the head of the screw. The construction may be such that a screw is held in a hollow of a holding tip on the screw driver sleeve with a rod in the sleeve carrying a rod whereby said pivot can pass over the dead centre between the fulcrum and link pivot on the rod. The arrangement may be such that adjustment can be allowed between the lever fulcrum and the pressure applying end of the driver tip carrying rod. The screw-holding tip may be cupped or recessed on its outer face or otherwise shaped and positioned to enable said tip to be located on the head of a partly driven-in screw and the driver tip then to be projected through the holding tip "ice to drive a round or flat headed screw fully home into position.

Referring now to the accompanying drawing in which several embodiments of the invention are shown:

Fig. 1 is a sectional side elevation of one form of improved screw-holding driver;

Fig. 2 is a front elevation of a modified form of screwholding driver;

Fig. 3 is a sectional side view of the operating end of a screw-holding driver;

Fig. 4 is a sectional sideelevation of a further modifled form of screw-holding driver; and t Fig. 5 is a sectional side elevation of the operating end of a screw-holding driver with a lever catch.

In a particular embodiment of this invention shown in Fig. 1 there is provided a screw driver incorporating a screw-holding device and means for applying pressure on the screw head. The screw driver includes a sleeve 2 to which the tool handle 3 is secured at one end and a screw-holding tip 4 is furnished at the other end. The latter is hollow with an opening 5 in one side and a slot 6 which enables the head and stem or neck of the screw to be inserted and held axially in relation to the screw driver sleeve. In the latter is mounted a pressure-applying rod 7 carrying a driver tip 8 projecting from its outer end and spring loaded at 9 in the end of the rod. When the rod is in position the driver tip projects into the hollow screw-holding tip and is clear of the head of a screw. The rod is prevented from rotating by having fins or other projections 10 which slide in slots 11 in the tool sleeve, although the rod may be of square or other section in a complementary bore. To give axial movement to the rod a lever 12 is mounted in the handle 3 by means of a fulcrum pin or screw 13 passing through the handle and the lever is enlarged at 14, substantially in U-shaped formation, i. e. the lever end is flattened with'a transverse hole 15 through it and a slit 16 leading thereinto so that there is resilience between the two legs of a U. The fulcrum is on one side of this slit and a pivot pin 17 passes through the other part and on this pivot is a link 18 which ispivoted at 19 at its other end to the end of the rod. Thus as the lever is forced inwardly towards the handle the link pivot swings about the fulcrum and as it approaches dead centre the U-shaped part of the lever closes slightly and then beyond the dead centre eases outwardly slightly thus retaining the rod rigidly in its position against rearward movement. This operating movement of the rod forces its end face 20 towards the screw head and during this movement the driver tip enters the screw head and the rod moves over the tip and against the screw head due to the spring loading. As it is desirable to allow for adjustment in the distance between the lever fulcrum and the pressure end of the rod the link is attached to a screwed part 21 inserted into the end of the rod and furnished with a lock nut 22.

In a modification shown in Figs. 2 and 3, the adjustment for the pressure applying rod carrying the driver tip is provided between the lever fulcrum and the tool handle. A mounting pin 23 is carried by the fulcrum 13 of the lever which does not engage the tool handle. The end of this pin 23 enters a screw-threaded plug 24 fitted axially into the end of the tool handle. The plug can rotate about the pin and the two are engaged, say by a circlip 25 in the plug engaging an annular groove in the pin, so that withdrawal of the plug lengthens the distance between the fulcrum and the pressure tip 20 of the rod and as the plug is moved inwardly, the distance willbe shortened. This adjustment enables the rod to be set in relation to a screw head according to the size of the latter.

sleeve is screw-threaded externally to receive an adv justing cap 26 in.v. .hich isirotatahly;v anchoredv the. lever mounting pinll Thusas thecapis screwed ontonor off the sleevegthe aforesaid adjustmentis-again-achieved. A slot 27 is formed in the driversleeve to;aceomrnodate the U-shaped part; 14 f the.l ever-,and allow'movernent of the link 18. Furthermore, a projecting pin 2? on the driver rod'slides ingth oS slot toprevent rotation of the 7 V v V 7 means providing resilience of thejoperatinglever'adjacent 7 rod. This slot in the sleeve registerswiththe. slot tam handle -29: which 'rnayhe moulded onto .the sleeve, or; a

preformed handl e isse cnred thereonin. any convenient rnanner. V V g a r f In the aforesaid. constructions the pivo connecting.

thexlink of the U shapedz part of :the lever is adapted .to move: beyond-dead centre: when the;l ever is closed down, thus molding. the screw-driver in -its. operative position.

In some cases lt1mlyfbB desirable to have a lever which 7 can be retained in itsclosed position and, havea guick- A suitable arrangementis shown in;

release action; Fig 5-vvherein when the leveris closed down thesaid pivotal. connection-17 has. not reached the centre. and

thus the lever w ouldswing back if not held. To hold the:lever-in position a spring-loaded pivoted .catch 3.0 is' fujnishedwith its head 3lz engaging over the tip-of the lever. to hold the latter downin position. To release the lever thepersongrippingthe screw-driver can simplypush-theleverheadin the-.direction of the arrow against the. spring loading whereupon the lever. will spring up. 1

to its: open position. Onreleasing the catch it will return to its normal position'and. whenthe. lever is pressed downoagain itwilliorce theicatchback slightly am ne.

" catch, head will spring "back to hold thelever down;

Itwill readily be understoodthe screw-holding driver.

a simplegrippinghandle, whichcan he fluted or otherwise shaped to. facilitate, the grip, the. screw-holding driverrnay ;be partof; an ordinaryfbrace handlesimilar.

practice. V V V g Wh'at'I claim is: V

1 A: screwdriver incorporating a. shank, means for.

rotatingthe shank; ascrew holding-v tip on thea'end jof.

"may' be modified to suitrequirements, e. g., instead of ed in said shank for its outer end to engage and clamp the screwhead in the shank tip, an axially displaceable spring loaded driverv tip in said clamping end of the rod to engage the screw head' andfrotate with the rod, a

pivoted lever connected by 'a. linkto the rod to give it axial movement and apply pressure ,on the screw head, saidillevei. being; connected: ithrouglr its. fulcrum: to: a; mounting el'ement;..an adjustable thru st memberengag ing the said element to make the pressure applicator-"rod initially. adjustable 'in relation to a screw head, and

its fulcrumabetween the-latter and the pi'vot- Off its link connection to the rodto. ensure a, firm*grip. ona screw head and allow for slight variations in screw-heads.

- 2; A screwdriver according toclaim 1, characterised f in that'lthe lever resilience: andmountingis .such thatits pivotal .connectioncfto thev can'passmver the deadr centre; between: the: leven fulcrum. .and link. pivot on; the rod to maintain pressurenonsascrew head throughthe;rod..

3i A" screw. driver according to 'clairn.:1:,i characterised;

in that :the lever: is (substantially. .U,-shaped at'its fulcrum;

end toprovidelesilience between; its fulcrum and .its;.

connection. toxthe; pressure. applicator rod;

4. A;screw driveriac'cording to. claim, 1.," Whereinjthe thrust: memberiisi carried: by :a. handle on the tool shanle.

.5. Ascrew :driveraccording to. claim 1., wherein the; thrustzmernber; is carrieiby thetool shank.

- 6..A screw driver accordin'g'toclaim' 1,;chaiacterised! inwthat said. pivoted lever is: mountedland viconne'cted to.

the pressure applicator rodsofas: to. spring back: from;

its-zclosed position;.and a releasable.;catch-' for retaining:

the lever closeda. j 7

'7. screw' driver; according to, claim 1, characterised: in that said .pivoted' lever .is. mounted ,and connected to:

the pressureapplicator. [OdI'SO as' to spring back. from; its closeds position, and aqspring loaded. quick release:

catchlfor'retainingihe lever closed; 7

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