Screw Holding Driver

Abstract

An insulated screw holding driver has a tubular plastic handle which encases the working elements of the screw holder including twin expanding bits and their control housing, rod and cam pin pre-assembled as an insert into the handle which holds this assembly and its components in place. The handle has an outer polygonal contour and an inner circular contour.

Description

DESCRIPTION OF THE INVENTION

The present invention relates to screw holding drivers of the type disclosed in U.S. Pat. No. 3,150,699 dated Sept. 29, 1964 and is concerned more particularly with such a driver having an insulated handle construction and also having a particularly advantageous method of assembly and for holding of the various elements in place.

It is a general object of the invention to provide an improved screw holding driver.

A further object of the invention is to provide a screw holding driver wherein the tubular plastic handle encases the operating parts of the blade or bit holding tube, and the blades or bits and their expanding pin are carried by the tube and held in place by the handle.

Other objects and advantages of the invention will be apparent from the following description of a preferred embodiment thereof, taken in connection with the accompanying drawings, in which:

FIG. 1 is a side elevational view of the screw holding driver;

FIG. 2 is a composite schematic perspective view illustrating the various elements of the screw holding driver and their method of assembly;

FIG. 3 is a cross sectional view taken in the plane indicated by the line 3--3 in FIG. 1; and

FIG. 4 is a cross sectional view taken in the plane indicated by the line 4--4 in FIG. 1.

Referring to the drawings, the screw holding driver of the instant invention comprises a tubular extruded plastic handle 10 which is formed preferably with an outer hexagonal shape and an inner round or cylindrical shape. At its front end the hollow handle 10 has a reamed recess 11 terminating in a radially disposed shoulder 11a. Received within the reamed recess 11 and abutting the shoulder 11a is a metallic tube 12 which may have its outer surface knurled at 13 substantially throughout its length and which carries and surrounds the two opposite bits or points 14. These bits or points are of the constructions shown in the above identified patent to which reference is made for more particular description. These bits 14 are received on opposite sides of a rod 16 of the character shown and described in the above patent. To spread the bits 14 apart as they recede into the hollow handle 10, there is a transverse cam pin 17 received in respective apertures 18 in the opposite sidewalls of the tube insert 12 and dispersed between the respective conventional cam surfaces of the bits. It is noted that certain components of the tool including the bits 14, the rod 16, the tube 12 and the pin 17 are pre-assembled by placing the two bits 14 onto the rod 16 with their retaining ears 14a received into the groove 16a of the rod, and then inserting the pin 17 through the two apertures 18. The two bits 14 and the rod 16 are moved with respect to tube 12 until they contact and engage the pin 17 which is freely held in the apertures 18 to prevent its loss. With the parts thus pre-assembled, this pre-assembled unit is pressed into the handle 10 until the tube 12 engages the shoulder 11a, and the knurl 13 seats inside of the reamed recess 11 with a light press fit. If the knurl is omitted, then a suitable glue or adhesive may be employed to hold the tube insert 12 within th handle 10. Epoxy may be employed. As seen in FIG. 3, for example, the ends of the pin 17 are adjacent and may contact the wall of the hollow handle 10 within the reamed recess 11 and the pin 17 is retained in position by the handle 10.

As explained in the above identified patent, in operation a screw to be held is placed with the slot embracing the points 14 and when the bit structure is caused to recede within the handle 10 the pin 17 forces the bits 14 apart to engage and hold the walls of the screw slot.

While I have shown and described a preferred form of the invention, it is obvious that the invention is capable of variation and modification from the forms shown so that the scope should be limited only by the scope of the claims appended hereto.

Claims

I claim:

1. In a screw holding driver the combination comprising a tubular plastic handle, a tubular member, a bit assembly having a pair of opposing bits and a rod engaged with said bits, a camming pin positioned in the forward part of said tubular member, said tubular member having said bit assembly positioned therein with said opposing bits having gradually sloping cam surfaces engaging opposite sides of said camming pin, said tubular member having means to hold the bits in locking engagement with said rod, said tubular member extending over a substantial part of said bits to hold said bits and said rod assembled with said bit assembly, the inside of one end portion of said plastic handle having a reamed recess for receiving said tubular member with said bit assembly therein, said tubular member being press fitted into said plastic handle.