Screw-driver.

Application filed September 28, 1907.

To all whom it may concern:

Be it known that I, Albert N. Bender, residing in Racine, in the county of Racine and State of Wisconsin, have invented, new 5 and useful Improvements in Screw-Drivers, of which the following is a description, reference being had to the accompanying drawings, which are a part of this specification.

This invention relates to improvements in 10 screw drivers.

One of the objects of the invention is to provide a screw driver which will firmly clamp and hold a screw during the operation of driving it.

A further object of the invention is to provide means for securely locking the screw driver to the screw after it has been clamped thereto and thereby remove any possibility of accidental disengagement.

A still further object is to provide a screw driver which may be used for boring holes for countersinking purposes.

With the above, and other incidental, objects in view, the invention consists of the 25 parts, and combination of parts, and all equivalents thereof.

In the accompanying drawings, in which similar characters of reference indicate like parts: Figure 1 represents a side view of my 30 improved screw driver engaging a screw, parts being broken away to show interior construction; Fig. 2 is a view thereof taken at right angles to Fig. 1; Fig. 3 is a view of the clamping end of the screw driver; Fig. 35 4 is a view of the head of a screw adapted for use with this improved screw driver; Fig. 5 is a view of a fragment of a round headed screw partly in section, also adapted for use with this improved screw driver;

and Fig. 6 is a view of a fragment of a modified form of screw driver provided with means for locking the screw clamping jaws to the screws.

Referring to the drawings, the numeral 8 45 indicates the shank of the screw driver, the upper squared end of which may be connected to a suitable handle, or to any suitable turning device. The lower end of the shank is provided with an enlargement 10 50 round in cross section and forming the head of the screw driver. The head is provided at diametrically opposite portions thereof with recesses 11, 11 extending longitudinally thereof, and in the recesses are 55 disposed fulcrumed clamping levers 12, 12,

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The undercut portions of the head provide means for engagement with the wedge shaped clamping jaws of the engaging levers to draw the screw wedgingly against 5 the lower end of the head of the driver and to prevent its accidentally becoming disengaged therefrom. A round headed screw may also be provided with these wedge shaped recesses to adapt it for use with the 1C driver as clearly shown in Fig. 5 of the drawings, and the lower end of the driver head is provided with a concave recess to accommodate the rounded portion of the screw head. In operation the finger porta tions of the engaging levers are pressed together. .This movement will open the wedge shaped jaws and permit them to engage the wedge shaped recesses in the head of the screw. By removing the pressure from the 20 finger portions the coiled spring will force them apart and cause the jaws to close and draw the screw head tightly against the end of the head of the driver and will securely hold the screw in this position dur25 ing the entire operation of driving it home into the material desired.

. If it desired to lock the screw to the driver it is only necessary to turn the locking nut „ f ^owllwardly until the tapered end engages the engaging levers. The nut being m the path of movement of the levers will prevent their being accidentally pressed together, and the screw will be securely held between ,.. the jaws. It is obvious that the screw ^oc driver may also engage a screw which is already in engagement for withdrawal. The wedge shaped jaws are so shaped that tiiev may be conveniently used for boring a tapered hole when it is desired to countersink the head of a screw. ₄₀