US3812894A

US3812894A - Screw-driver

Info

Publication number: US3812894A
Application number: US00363636A
Authority: US
Inventors: J Bradbury
Original assignee: Individual
Current assignee: Individual
Priority date: 1973-05-24
Filing date: 1973-05-24
Publication date: 1974-05-28
Anticipated expiration: 1991-05-28

Abstract

A screw-driver designed for operation to exert maximum force on the screw being turned, by providing a gripping member on the shank for engagement by the fingers of the hand of the operator to forcibly press the bit of the tool into engagement with the head of the screw. This force, in an axial direction, supplements the force exerted by the other hand in the same direction, as the tool handle is held by the latter for rotating the screw-driver.

Description

United States Patent [191 Bradbury SCREW-DRIVER [76] Inventor: James J. Bradbury, 413 University Bl d-.2 qleb2 9tlill99lsw [22] Filed: May 24, 1973 [21] Appl. No.: 363,636

[52] US. Cl 145/50 R [51] Int. Cl B25b 15/00 [58] Field of Search 145/50 R [56] References Cited UNITED STATES PATENTS 1,816,359 7/1931 Carlin 145/50 R 2,734,413 2/1956 Dunkelberger 145/50 R 2,884,972 5/1959 Harris 145/50 R FOREIGN PATENTS OR APPLICATIONS Great Britain 145/50 R m1 3,812,894 [451 May28, 1974 Primary ExaminerAl Lawrence Smith Assistant Examiner-J. T. Zatarga Attorney, Agent, or FirmSamuel Lebowitz 5 7 ABSTRACT A screw-driver designed for operation to exert maximum force on the screw being turned, by providing a gripping member on the shank for engagement by the fingers of the hand of the operator to forcibly press the bit of the tool into engagement with the head of the screw. This force, in an axial direction, supplements the force exerted by the other hand in the same direction, as the tool handle is held by the latter for rotating the screw-driver.

1 Claim, 3 Drawing Figures SCREW-DRIVER This invention relates to a screw-driving tool and more particularly to a screw-driver designed for operation with both hands in order to exert maximum force between the tool and a screw to be rotated thereby.

It is the object of the present invention to provide a rugged and improved screw-driver which is capable of performing its functions rapidly and reliably.

The improved screw-driver is provided with a thumb and finger grip on the shank of the tool which permits the fingers of one hand to guide the tool and press the same against the head of the screw being turned, in supplement to the force exerted by the other hand applied to the handle of the tool in a conventional manner to rotate the screw-driver and force it against the screwhead.

Other objects and purposes will appear from the detailed description of the invention following hereinafter, taken in conjunction with the accompanying drawing, wherein FIG. 1 is a front elevation of the tool in accordance with the invention;

FIG. 2 is a vertical sectional view along line 2-2 of FIG. 1; and

FIG. 3 is a perspective view of the tool in the course of its engagement with a screw when the parts are in the position shown in solid lines in FIG. 1.

The screw-driver in accordance with the invention is comprised of a cylindrical shank 1 having an enlarged handle 2 at one end thereof, and a tool bit 3 at the opposite end thereof. The enlarged handle 2 may be formed of any material such as wood, plastic or the like, and is preferably fluted in order to provide a secure grip for the hand H in engagement therewith, which serves to press the bit within the nick of a screw S which is adapted to be rotated by the screw driver.

The shank 1 is provided with a gripping member for grasping by the thumb and fingers of the other hand H. A limit stop 4 is affixed to the shank in order to transmit the pressing forces exerted by the hand H to the bit 3 of the tool. The gripping member 5 may assume the form of a wing-nut provided with laterally disposed arms or wings 6, 6' on the opposite sides of a diametral bore which is reciprocably movable on the cylindrical shank of the screw-driver. A disc washer 7, integral with the base of the wing-nut, abuts against the annular ring 4 which projects radially from the shank to provide the limit stop against movement of the gripping member, in the direction indicated by the arrow shown in FIG. I. The gripping member may assume any desired configuration for engagement by the thumb and fingers, and may be molded or cast of metal, plastic or any other suitable material.

- The screw-driver may be operated as a conventional screw-driver to engage the wedge-shaped bit 3 within the pick of a screw S to rotate the screw in either an advancing or withdrawing direction. When increased force in the driving of the screw is desirable, the other hand is used to engage the wings 6, 6' of the gripping member, in order to provide additional force against the head of the screw to enhance the engagement of the bit 3 within the nick, so that the screw-driver may be turned while the bit is securely within the nick. This secure engagement eliminates the shearing of the screwhead and improves the guidance of the screw as it is advanced by the screw-driver.

The limit stop 4 on the shank of the screw driver may be formed in many different ways, such as by peening, or by soldering, welding or swaging a split annular ring within a peripheral recess or groove in the shank of the tool.

While the illustrated embodiment shows the gripping member reciprocable along the shank of the tool, as indicated in the alternate position thereof shown in dotted lines in FIG. 1, the gripping member may be mounted at a fixed position on the shank, between the handle and bit, for rotary movement relative thereto.

While the shank is shown of cylindrical contour, the same may be polygonal or of any other cross-section as long as the gripping member is capable of relative rotary movement thereon.

While the tool bit3 is shown of conventional wedgeshaped construction, the improved feature of the invention may be applied as well to screw-drivers having bits of different contours for cooperation with corresponding contours of screw-heads, such as the Phillips Screw, or hexagonal terminals or sockets.

I claim:

1. A screw-driver comprising a. an elongated substantially cylindrical shank having a handle at one end thereof for facilitating the application of rotary movement to said shank as well as pressure in the axial direction of the latter, by one hand of the operator,

b. a bit at the opposite end of said shank for engaging the head of a screw,

c. a protuberance extending radially from said shank adjacent to the end thereof remote from said handle and beyond said bit, and

d. a wing nut mounted on said shank between said protuberance and handle for free rotary and reciprocating movement on said shank, with the wing members of said wing nut providing comfortable and balanced grip thereon between the thumb and finger of the other hand of the operator to exert additional pressure in an axial direction against said protuberance to enhance the force of engagement between said screw-driver and screw.

Claims

1. A screw-driver comprising a. an elongated substantially cylindrical shank having a handle at one end thereof for facilitating the application of rotary movement to said shank as well as pressure in the axial direction of the latter, by one hand of the operator, b. a bit at the opposite end of said shank for engaging the head of a screw, c. a protuberance extending radially from said shank adjacent to the end thereof remote from said handle and beyond said bit, and d. a wing nut mounted on said shank between said protuberance and handle for free rotary and reciprocating movement on said shank, with the wing members of said wing nut providing comfortable and balanced grip thereon between the thumb and finger of the other hand of the operator to exert additional pressure in an axial direction against said protuberance to enhance the force of engagement between said screw-driver and screw.