US2604912A

US2604912A - Screw driver

Info

Publication number: US2604912A
Application number: US74567A
Authority: US
Inventors: Wallace A Walker
Original assignee: Western Electric Co Inc
Current assignee: AT&T Corp
Priority date: 1949-02-04
Filing date: 1949-02-04
Publication date: 1952-07-29
Anticipated expiration: 1969-07-29

Description

y 29, 1952 w. A. WALKER 2,604,912

SCREW DRIVER Filed Feb. 4, 1949 FIG. .2

INVENTIOR M. A. WALKER 3y ATTORNEY Patented July 29, 1952 SCREW DRIVER Wallace A. Walker, Baltimore, Md., assignor to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Application February 4,1949, Serial No. 74,567

2 Claims. (01. 144-32) This invention relates to screwdrivers, and more particularly to screwdrivers for use in connection with small screws.

The manufacture and assembly of small parts require the use of small screws, which in many instances are too small to be started into a tapped hole by hand. To facilitate the handling of such screws it has been suggested that a small pilot be formed integrally on the end of the screwdriver bit, and that a complementary hole be provided in the head of the screw so that the screw may be positioned on the bit and held in position as the bit is turned to thread the screw into a tapped hole. The pilot formed on the end of the bit also enables an operator of the tool to pick up small screws merely by dipping or pushing the end of such a screwdriver bit through a mass of the screws contained in a suitable receptacle. While this type of screwdriver bit greatly facilitated the handling of small screws, the pilot formed integrally thereon tends to break off after being used only a short period of time due to the fact that the pilot has a very small diameter and formerly was made of a relaitvely brittle grade of steel. When the pilot of bits of this design broke off it was necessary to discard the entire bit.

An object of the invention is to provide new and improved screwdrivers.

Another object of the invention is to provide a screwdriver with means for readily picking up and holding small screws, and for centering and guiding such screws into tapped holes.

An apparatus embodying certain features of the invention, comprises a screwdriver bit provided with a central bore along its longitudinal axis and a length of resilient wire positioned in the bore so that one end thereof extends beyond the blade of the bit to form a pilot.

A clear understanding of the invention will be had from the following detailed description of a specific embodiment thereof, when read in conjunction with the appended drawing, in which:

Fig. 1 is an enlarged view of a screwdriver bit embodying certain features of the invention;

Fig. 2 is an enlarged, perspective view of a screw which the improved screwdriver bit shown in Fig. l is designed to engage, and

Fig. 3 illustrates one type of screwdriver with which the bit shown in Fig. 1 may be used.

Referring now to the drawing, and more particularly to Fig. 1, there is shown a screwdriver bit indicated generally by the numeral [0, which is of the type that may be inserted in a power tool or other su table means by which the b t ay be rotated when desired. The bit l0, comprises a body I I having a blade portion l2 provided on one end thereof, which is adapted to engage the slot provided in the head of a screw to be operated by the bit 10.

The body I I is provided with a central bore l5, which extends from the blade 12 and communicates with a notch 16 provided in the body. The notch I6 is of such depth that the bottom thereof is aligned with the central axis of the bore 15. A pilot 20 made of a highly resilient wire, such as, music wire, is positioned in the bore l5. The inner end of the pilot 20 is tapered at 21 so that it may be wedged between the side of the bore I5 and the bottom of the notch 16.

The pilot 2|] is of such length that, when the tapered end 2| is wedged against the bottom of the notch l6 so that the pilot will not fall out of the bore [5, the other end thereof extends beyond the end of the blade I2 a distance required to support a screw to be used with the bit l0, such as a screw 23 shown in Fig. 2. The screw 23 has an externally threaded shank 24, a central bore 25 to receive the outer end of the pilot 20, and a transverse slot 26 provided in a head 21 thereof to receive the end of the blade I2.

The bit in is of the type intended to be used with a suitable driving tool, such as a manually operated tool or a small power tool equipped with a chuck adapted to receive small bits. The bit I0 may be used in a special tool 30, such as is shown in Fig. 3, which is essentially a chuck arranged to be selectively engaged by a suitable driving means, so that the operator thereof is not required to hold a bulky or heavy power tool while assembling small screws, like the screw 23, in parts to be secured together.

The tool 30 consists of a head 3|, which is secured to a shaft 32 rotatably mounted in a body 33. A socket 35 is secured to the opposite end of the shaft 32, in which the bit I0 is rigidly held by a set screw 36. The head 3| is provided with a friction ring 31, which may be placed in contact with a revolving surface to turn the head 3|, which in turn, rotates the socket 35 and the bit l0 secured therein. The operation of the tool 30, as well as a suitable means for driving the head 3|, are fully disclosed and claimed in C. J. Hackbarth et al. Patent 2,331,468, granted October 12, 1943. Therefore, a more detailed description of the tool 30 is unnecessary.

Operation In using the bit l0, let it be assumed that it is secured in the socket 35 of the tool 30. A screw,

like the screw 23, is positioned on the pilot 20 by hand or the tool may be manipulated so as to pass the pilot 20 through a mass of screws, like the screw 23, in order to pick up a screw on the pilot so that it enters the central bore 25 thereof with the head of the screw positioned adjacent to the blade. I2 of thebit (Fig. 3). The tool 30 then-is manipulated so as to positionthe end of the threaded portion 24 of the screw in a tapped hole provided in a part into which it is to be threaded. The tool and the part then are moved together so that the friction ring 3'1, on"

the head of the tool 30, may be engaged by a suitable driving means, suchas thedrivingm'eans described in the aforementioned Patentz2g3'3lA'fi8;-

As the head of the tool is rotated to drive the bit 10, the blade l2 engages the slot-26 of the screw, whereby the screw is rotated and threaded into.

the tapped hole adapted to receive the screw. When the screw is fully secured in the tapped hole,.the partiha'vingthe'holetherein is moved-to disengage the pilot 20 from the-screw, and the toolis' moved to di'sengagethe ring?! from the driving -means.

The above operations are repeated many times in the manufactureof small parts on a massproductioni basis. The pilot 20; being made ofa highly resilient wire, such as music wire, is sufficiently'resilient to withstand the shock. encountered in operations of this" type, even though it has. a very small. diameter. Should the pilot-20 break off, it is a relatively simple matter to pry the tapered end of the pilot loose from the bottom of the notch 16* so that it may be removed from the bore 15, and to" insert another pilot in the bore This type of screwdriver bit is a substantial improvement over bits having the pilot formed integrally therewith, because the entire bit is not rendered useless when the pilot breaksofi- What i's'cla'imed is:

1. A screwdriverbitdesigned to operate small screws having a central bore therein communieating? with a slot provided in the head of the screw, which comprises a steel body having a thin blade formed on one end thereof for engaging the slot' in the'head. of such screws, said body having a notch cut therein intermediate the ends thereof and a central bore extending from the blade to the'no'tch, and a highly resilient'wire positioned in the central bore so that one end extends beyond the blade to form a pilot adapted to engage the central bore of a screw to be operated by the blade, said notch being designed to communicate with a substantial portion of the central bore so that a portion of the opposite end of thewire extends into, the notch and is wedged between the bottom of the:v notch and the bore, whereby the end' of the wire may be pried loose from the bottom of the notch when it is desired to remove the wire from the central bore in the body.

2. A screwdriver bit designed to operate small screwsh-aving: a central bore therein communicatingwiththe slot provided in the head of the screw, which comprises a steel body having a thin bladetformedon one end thereof for engagingthe. slot in the head of such screws, said body having'a' notch cut therein intermediate the ends thereof and a central bore extending from the blade end of the body to. the notch,.said notch being of such depththat; the bottom. thereoiis aligned with the longitudinal axisof the bore, a wire having a resiliency substantially greater than that of the bodyposit-ioned insaid bore, said wire having itsend adjacent to the notch tapered to-permit a portion-of theend of the wire to pass into the notch and. wedge'thewire between the bore and the bottomof the notch, said wire being of such length that. a portion thereof extendsbeyond the blade todorm a pilot adapted to engage thecentral' bore provided in screws to be operated by the-blade.

WALLACE A.. WALKER.

REFERENGES. CITED The following references areof record in the his of this" patent:-

UNITED. STATES: PATENTS Number Name. Date 847,774 Hoffman Mar. 19, 1907 1,300,275 Johnson Apr; 15, 1919 1,314,012 Mowers Aug. 26, 1919 1,410,088 White Mar. 21, 1922 1,501,222 Lamp July 15, 1924 1,797,390 Wood Mar. 24,1931 2,329,398 Duffy Sept. 14, 1943 2,522,165 Clough, Sept. 12, 1950