US3455355A - Reversible bit handtool - Google Patents

Description

July 15, 1969 R, E, MCLOGAN ET AL 3,455,355

REVERSIBLE BIT HANDTOOL Filed Nov. 13, 1967 1521/6 m@ 7:5' Raz/sse @ET/fc @ga/w, fg/Zaadz? afvens'eng @n Z/few 61.556,42 gy m 7M United States Patent O U.S. Cl. 145-50 1 Claim ABSTRACT OF THE DISCLOSURE A reversible bit handtool in the form of a screwdriver is disclosed as comprising a handle -body of molded thermoplastic material having an axial passage of circular transverse section, a metal insert of square transverse sectional outline having corner to corner dimensions corresponding to the passage diameter and `disposed in force t relation in the mouth of the passage to embed the corners of the insert in the handle body, the insert having U- shaped side wall openings to dene a pair of opposing, laterally inwardly angled cantilever spring llinger portions that converge in a direction leading axially inwardly along the passage, and a double-ended one-piece bit substantially longer than the passage to bottom therein and project therefrom, the bit having an intermediate shank portion of a length to occupy the full length of the socket for either direction of insertion of the bit, the intermediate shank portion being square in transverse section and complementing the insert in transverse size to establish frictionally retained force fit engagement with the lingers of the insert.

BACKGROUND OF THE INVENTION This invention relates to handtools of the type wherein a double-ended bit is reversibly mountable in a handle body which is to apply torque to the bit. More particularly, the invention is concerned with a reversible type pocket-size screwdriver wherein the shank is frictionally held against accidental escape but is readily removable to be reversed or replaced as desired.

In the past with tools of this type, it has been found necessary to provide specially machined formations on the tool shank to be engaged by a spring or lever type retainers device mounted within the handle body. In other arrangements, a spring or lever type retainer device is i. mounted intermediately on the shank to engage a socket structure within the handle body.

These arrangements involve excessive cost and require unduly large and bulky handle bodies so that there remains a need for an inexpensive and reliable pocket-size reversible screwdriver.

SUMMARY OF THE INVENTION In accordance with the present invention, a doubleended shank of square bar stock or of other noncircular configuration is reversibly mounted in a handle body and is frictionally retained therein by an insert bushing provided within the mouth of the handle body. The shank has an intermediate length portion of uniform transverse sectional size and shape and of a length to engage the bushing for either mounting position ofthe shank in the handle body. The bushing denes a socket having a transverse sectional outline that corresponds in size and shape to the intermediate length portion of the shank, the bushing carrying opposing integral spring ngers that frictionally clamp against the shank. In the disclosed embodiment, the insert bushing is a one-piece split metal sleeve of formed -sheet stock to define the socket with a square transverse outline that mates with the square shank. The split sleeve presents opposing side wall por- Patented July l5, 1969 tions that are provided with U-shaped wall openings to define cantilever spring lingers inclined laterally inwardly along the handle body passage and converging in a direction leading axially into the passage.

The handle body passage is circular in section and receives the square sleeve in force t relation. The corner to corner dimension across the lats of the insert sleeve is approximately the same as the diameter dimension of the handle passage so that the corners of the insert sleeve embed into the material of the handle body and lock the insert against rotation.

Other features and advantages of the invention will be apparent from the following description and claim, and 4are illustrated in the accompanying drawings which show structure embodying features of the present invention and the principles thereof.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings forming a part of the specification, and in which like numerals are employed to designate like parts throughout the same,

FIG. 1 is a side elevational view of a pocket-size screwdriver constructed in accordance with the present invention;

FIG. 2 is an enlarged end elevation of the screwdriver shown in FIG. 1;

FIG. 3 is a side elevational view of the bushing that is incorporated in the screwdriver of FIG. 1; and

FIG. 4 is a lengthwise section through the bushing of FIG. 3 and is taken 4as indicated on the line 4-4 of FIG. 3.

DESCRIPTION OF PREFERRED EMBODIMENT Referring now to the drawings, a particular embodiment incorporating the invention is shown herein as a reversible bit pocket-size screwdriver designated generally at 10 in FIG. 1. The screwdriver has a handle body 11 provided with an insert bushing 12 that frictionally retains a double-ended shank 13 which serves as a reversible bit having the usual driver blade tip 13D at one end and a Phillips type tip 13P at the other end. The bit tips may be of any desired form as the particular forms illustrated here are merely for purposes of` disclosure.

The handle body for the pocket-size screwdriver illustrated herein is molded of any suitable thermoplastic material such as cellulose acetate and has a conventional fluted exterior contour having a body diameter, peak to peak, of about 5/8 inch and -having a body length of about 2% inches. A spring steel clip 14 is; shown aixed -alongside the handle body. An axial passage 11A opens through one end of the handle body, the passage being dead-ended therein. In the particular form illustrated herein, the passage 11A is provided by drilling with a No. 16 bit to provide the handle with a circular passage that is about 0.177 inch in diameter and about 1.80 inches long.

The insert bushing 12 is disposed in the mouth region at the open end of the handle passage to define a socket that is noncircular in transverse section and that is complementary in size and shape to mate with the shank. In the form illustrated herein, the insert bushing 12 is of metal and is oversized in relation to the handle passage and is press lit in place to embed in the material of the handle body and preclude relative rotation of the insert and handle body.

The particular bushing 12 disclosed herein is a onepiece split metal sleeve of square-shaped transverse sectional outline and is formed of sheet stock such as No. 28 gauge sheet brass (0.0149 inch) so that the inside distance across the at of the sleeve-shaped bushing is about .128 inch and so that the outside distance across the at side is about 0.160 inch to approximate the I.D. of the handle passage. For the disclosed handle passage, the

3 LD. is 0.177inchaV sleeve about 0.125 'in'ch wide or less across the fiat would fit without embedment in the handle body material. Thus, the sleeve width of 0.160 inch provides substantial embedment of the corner regions of the sleeve in the handle body material to preclude turning of the sleeve within the handle.

In a typical pocket-size screwdriver, the shank 13 is 3% inches long and is formed from 1A inch square bar stock so that the intermediate shank portion 13S is uniform in transverse section and is of a length to occupy the bushing socket for either position of the bit in the handle passage. The shank may be formed of heat treated AISI No. 6150 nickel-plated steel with no machine or forming operations required on the bar stock except for the shaping of the tips 13D and 13P.

The formed metal sleeve that serves as the bushing 12 has a central base wall portion 15, parallel side wall portions 16, 16 leading integrally from opposite corner extremities of the base wall and half-size edge wall portions 18 leading from corresponding corner extremities of the side walls and terminating in edge to edge adjacency in a plane parallel to the base wall 16. Each side wall has a generally U-shaped Wall opening 16U that borders and denes a spring linger portion 19 leading generally lengthwise of the handle passage in laterally inwardly angled relation to act as a cantilever spring in exerting clamping action against the shank. The Wall openings 16U have leg regions anking each spring nger of sufficient width t insure permanent clearance for the spring ngers thus preventing binding and insuring free swinging. The pair of cantilever spring fingers 19 are about 0.170 inch long and are positioned in confronting opposing relation to exert a simultaneous pinching against opposite at faces of the shank portion.

For the particular insert shown, the inside distance across the at, corner to corner, is about 0.130 inch to allow for variations in the sizing of the l/a inch square bar stock and the normal tip to tip spacing of the cantilever spring lingers is about 0.108 inch so that each spring iinger undergoes a deection of between about 0.007 inch and about 0.010 inch as it resiliently flexes to accommodate insertion of the shank. These relationships in the simplifed structure shown herein establish a proper pinching or clamping action secure enough for reliably holding the shank in place against accidental escape and yet accommodating easy withdrawal and replacement.

The construction shown herein is particularly suited to pocket-size hand tools such as Screwdrivers where the body diameter is restricted and complex shank enlargements or wide-throw spring mounted retainers increase both cost and size factors.

Thus, while preferred construction features of the invention are embodied in the structure illustrated herein,

it is to be understood that changes and variations may be made by those skilled in the art without departing from the spirit and scopeof the appended claim.

What is claimed is:

1. A reversible bit handtool comprising a molded thermoplastic handle body having an axial passage deadended therein, said passage being circular in transverse section and including a mouth region opening through one end of said handle body, said handle body having a onepiece metal bushingrneans force-lit in said passage at said one end anddeiining a socket at the mouth region of said passage, said bushing means being comprised of formed sheet stock of square transverse sectional outline to provide a base wall portion, parallel side wall portions leading integrally from opposite corner extremities of the base wall portion and edge wall portions leading from corresponding extremities of the side wall portions and terminating in edge to edge adjacency in a plane parallel to said base wall portion, each of said side Wall portions having a generally U-shaped wall opening to border and define a corresponding laterally inwardly angled freeswinging cantilever spring linger portion leading generally lengthwise of said passage and being disposed in laterally spaced confronting relationship and converging in a direction leading axially into said passage, said bushing means having corner to corner dimensions exceeding the diameter of said circular passage whereby each corner of said bushing means projects into said body for forceat engagement within said passage, a double-ended one-piece bit substantially longer than said handle passage to bottom in said handle passage and project therefrom, said bit having an intermediate shank portion of a length to register with said socket for either position of said bit in said handle, said intermediate shank portion being of uniform noncircular transverse section complementary to said socket in transverse size and shape for frictionally retained force-lit engagement with said bushing means.

References Cited UNITED STATES PATENTS 772,593 10/1904 Wagner 145-50.2 1,961,246 6/1934 Powers 279--102 2,158,728 5/1939 Peters 14S-50.2 X 2,596,594 5/1952 Petre 14S-50.2 X

ROBERT C. RIORDON, Primary Examiner R. V. PARKER, JR., Assistant Examiner U.S. Cl. X.R. 279-79, 102

P01050 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PatenfNo. 3,155,355 Dated July 15, 1969 Inventor-(s) Russell E. MCLOgaIl et al. i

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

r-Column l, line 46, "retainers" should be retainer column- 2, line LM, "pocket-size" should be pocket type column il, line l?, corner should follow "corresponding".

SIGNED AND SEALED Nov 181959 (SEAL) Attest:

Edward M.F1ewher,1r WILLIAM E 5m JR Attesting Officer Cmmissioner of Pate-nts

Images