US3752202A

US3752202A - Hand fastener driving tool

Info

Publication number: US3752202A
Application number: US00227880A
Authority: US
Inventors: H Condon
Original assignee: Vaco Products Co
Current assignee: Vaco Products Co; Klein Tools Inc
Priority date: 1972-02-22
Filing date: 1972-02-22
Publication date: 1973-08-14
Anticipated expiration: 1990-08-14

Abstract

A hand driving tool, such as a screwdriver, comprising a torque magnifying handle and a headed bit. The handle defines a longitudinal bore to recieve the head of the headed bit. The bore is specially configured to minimize mechanical binding forces and to eliminate suctional resistance to bit removal without requiring the perforation of the head end of the handle.

Description

finite States Patent [191 Condon Aug. 14, 1973 HAND FASTENER DRIVING TOOL [75] Inventor: Harry F. Condon, Hillsdale, Mich.

[73] Assignee: Vaco Products Company, Chicago,

[22] Filed: Feb. 22, 1972 [21] App]. No.: 227,880

Related US. Application Data [63] Continuation-impart of Ser. No. 20,295, March 17,

1970, abandoned.

[52] US. Cl. 145/61 L, 81/177 G [51] Int. Cl. B25g 3/02 [58] Field of Search 81/177 A, 177 G,

81/177 N, 121 R; 145/50 R, 50 C, 61 R, 61 E, 61 L, 61 J; 279/9, 102; 287/53 H; 292/347 [56] References Cited UNITED STATES PATENTS 1,632,227 6/1927 Halsey 145/61 1,035,427 8/1912 Donoghue 145/61 R 2,063,419 12/1936 Zongaro 279/102 X 2,725,086 11/1955 Keyes 145/61 L Primary Examiner-James L. Jones, Jr. m e?! aerM rkr B s. ,7 Attorney-Max Dressler, Marshall W. Sutker et a1.

[57] ABSTRACT A hand driving tool, such as a screwdriver, comprising a torque magnifying handle and a headed bit. The handle defines a longitudinal bore to recieve the head of the headed bit. The bore is specially configured to minimize mechanical binding forces and to eliminate-suctional resistance to bit removal without requiring the perforation of the head end of the handle.

14 Claims, 9 Drawing Figures Patented Aug. 14, 1973 3,752,202

FIG,

FZGC? 164 55 F IG. 9 I

A WWW/III,

This application is a continuation-in-part of my copending U.S. Pat. application Ser. No. 20,295 which was filed on Mar. 17, I970 and now abandoned.

This invention relates to a hand fastener driving tool, and in particular to one comprising a handle adaptable interchangeably to receive and removably retain a series of headed bits.

There are many interchangeable bit hand driving tools known to the hand driver art. In many such tools, metallic bits having specially configured ends remote from the bit ends are received in specially configured sockets in handles. Such bits are usually single purpose bits, however they may be double headed bits reversibly insertable in a specially configured handle. In that case the metallic bit itself is usually configured to be keyed within the handle. A typical example of the latter type of tool is illustrated in U.S. Pat. No. 3,455,355.

Another type of interchangeable bit hand driving tool which has recently come into vogue is one in which a.

longitudinally bored handle is provided,.the bore being adapted to receive a series of headed bits, such as metallic bits. The end of the bit is embedded in a plastic head larger than the bit, which head is somewhat smaller than the usual driver handle. In such tools both the enlarged bore defining handle and the head of the headed bits are made of suitable plastic materials.

Difficulties is using such tools and in removing the plastic head of the headed bit from the plastic head receiving bore are frequently encountered. One attempt which has been made to reduce the difficulty encountered in removing the head from the bore has been to bore or mold a passageway through the head end ofthe handle, which passageway terminates in communication with the inner end of the bore in the handle. Thishas not been entirely satisfactory and has presented the distinct disadvantage of positioning an opening in the head end of the handle which, when the palm of a user's hand is pressed thereagainst, tends to abrade the skin in use, and to cause blistering.

In accordance with this invention, a hand fastener driving tool incorporating a handle defining a specially configured bore for receiving the head end of a headed bit is provided. This tool provides means for assuring easy removal of the head of the headed bit from the bore, without creating resistant suction forces and without the necessity of providing an opening through the head end of the handle.

More particularly, the hand driving tool of this invention comprises an enlarged torque magnifying handle defining an elongate bore at one end and defining a smooth opposite end for engagement by a users hand. The bore is configured complementarily to receive the head portion of a headed bit, the headed bit comprising also a fastener engaging metallic bit member projecting from the head. The inner surface of the bore and the outer surface of the head provide complementary surface portions which are of generally the same size and which are proportioned and shaped to prevent relative rotation therebetween. The outer surface of the head and the inner surface of the bore define between. them a slight space which provides an air passage or air channel from the exterior of the handle to the inner-most end portion of the bore. In one embodiment of this invention, an opposed pair of head engaging pad means are provided intermediate the ends of the handle bore,

the pad means being spaced apart sufficiently to frictionally engage opposed surfaces of the head thereby to frictionally retain the head of the headed bit within the bore, hence within the torque magnifying handle.

The handle may also desirably define a plurality of small stop members which limit the distance which the head may be inserted into the bore and which prevent full seating of the rounded end of the bit head against the confronting concave surface in the bore. When these stop members are provided, the contact between the head and the confronting surfaces of the bore, is-

minimized. This prevents sweating and the like, which, particularly in hot and humid weather, tends to freeze portions of the head and the handle to each other, resulting in resistance to removal of the headed bit from the handle. Further, to minimize the possibility of suction forces resisting removal of the head, the inner end portion of the bore functions as a suction relief chamber. This provides an enlarged volume air space, which, if sealing should accidentally occur between the head and.the bore surfaces, provides a substantial volume of air against which suction forces would be applied, rather than a very small volume, thereby minimizing the possibility of substantial suction forces resisting removal of the headed bit.

It has been determined that the oppositely acting friction padmeans may be one, two, three or more in number and.that the friction pad means and stop members may desirably be integrally formed to provide their respective functions in concert.-

These and other features and advantages of this invention. will become apparent from the following description and appended drawings of which:

7 FIG. 1 is an exploded side elevational view of a hand fastener driving tool of this invention;

FIG. 2 is a view, partially in section, of the assembled tool of FIG. 1;

FIG. 3 is a cross-sectional view of the torque magnifying handle. of FIG. 1;

FIG. 4 is a viewtaken substantially along the line 4-4 of FIG. 3, showing, in dotted line, the general position of an assembled headed bit;

FIG. 5 is a view similar to FIG. 3, but rotated about its longitudinal axis;

FIG. 6 is a cross-sectional view taken substantially along the line 6-6 of FIG. 5;

FIG. 7 is a longitudinal cross-sectional view of a further torque magnifying handle of this invention;

FIG. 8 is a view taken substantially along the line 8-8 of FIG. 7; and

FIG. 9 is a view similar to FIG. 2 showing an assembled hand fastener driving tool incorporating the handle of FIG. 7.

Referring now to the drawings, a torque magnifying fastener; driving tool 10 of this invention comprises a torque magnifying handle 20 and an interchangeable and removable. headed bit 30. Headed bit 30 comprises a head 32 molded from a suitable plastic material, such as any butyrate commonly used for screwdriver heads and the like, and a metal bit 34.

The bit 34 comprises an elongate shank portion 36 and a fastener engaging portion 38. In the embodiment specifically illustrated in FIG. 1, the bit is illustrated as a screwdriver blade, although other bits, such as nut driver bits, cross head screwdriver bits, and bits of other well known types may be similarly embedded, in a conventional manner, in plastic heads 32. The portion of the bit shank 36 embedded in the plastic head 32 may be configured in any well known manner to key it against relative rotation within the head.

At the end remote from bit 34, head 32 provides a smooth and rounded head end 40. Intermediate the head end 40 and the opposite end of the head, a plurality of flats 42 are provided. In the embodiment illustrated, the flats 42 extend along a major portion of the longitudinal extent of the head 32, and are six in number to define, in transverse cross-section, an equilateral hexagon, a regular polygon. The hexagonal configuration of the head provides a convenient means for keying the headed bits to the torque magnifying handle in the manner to be described, thereby to prevent relative rotation between them.

The torque magnifying handle 20 may conveniently define an outer fluted longitudinal surface which provides a plurality of flutes 50. Handle 20 defines a longitudinally oriented aperture or bore 52 opening at one end of the handle, and provides a smooth nonperforated convex end 54 at the other end. Under some circumstances the end 54 engages the palm of a user. Its smooth configuration minimizes abrasion of the users palm.

As best seen in FIGS. 4 and 6, at one end a portion of the bore 52 is generally hexagonal in shape, each of the equilateral sides of the hexagon, for convenience, being designated as lands 56. Preferably, the lands are each equal in transverse dimension. Pairs of opposed lands 56 are preferably spaced from each other a distance of not more than ten thousandths of an inch more than the spacing between confronting parallel flats 42 on the headed bit 30. Also, the lands 56 preferably incline very slightly inwardly from their'outermostedges at one end ofthe bore 52 to their innermost edges intermediate the ends of bore 52. It will be apparent, therefore, that the lands and the flats are of substantially the same size, but with the head defining a slightly smaller hexagon. Therefore, upon insertion of the head into the bore, there is provided a very slight space between the lands and the flats which defines an air passage means 57 extending from the outermost end of the bore 52 to the innermost end of the bore 52, and between the handle and the head.

Intermediate the ends of the .bore a pair of projecting head engaging means are provided. These opposed gripper pads 58 project inwardly from a pair of opposed lands and are spaced apart a distance substantially equal to the space between an opposed pair of flats. When the headed bit is inserted into the aperture, gripper pads 58 snugly and frictionally grip the confronting pair of flats 42 thereby to retain the head, hence the headed bit, in removably assembled engagement with the torque magnifying handle. Except in the vicinity of the gripper pads, the very slight spacing providing the air passage means 57 between the head and the interior wall surface of the handle will be maintained, thereby to eliminate the suction effect normally encountered in tools of this character wherein headed bits frequently sealingly engage the walls of the bore in the handle.

To assure easy removal of the headed bit from the handle, in the event that the head and handle should accidentally become sealingly engaged, an inner bore portion or suction relief chamber 60 is provided. Suction relief chamber 60 is of a relatively large volume, as compared to the volume of the space which would be provided if the bore 52 terminated in a shape complementary to the rounded head end 40 as is a known practice. The larger volume, of course means that a lesser suction force will be encountered when the head is removed, than if the chamber was not there and the bore simply ended in a shape generally complementary to the head end 40 of the'headecl bit 30.

To maintain communication between chamber 60 and the other end of the bore 52, a plurality of stops or spacers 62 are provided. These spacers which are generally dimple-like in configuration project from the rounded or concave intermediate portion 64 of bore 52. Spacers 62 prevent the seating of head end 40 against concave inner portion 64, thereby making it impossible for them to sealingly engage. This also provides constant communication, to the extent that it may be necessary, between suction relief chamber 60 and theother end of bore 52. Spacers 62, by eliminating such sealing engagement, also eliminate the possibility of sweating or freezing of the plastic head end 40 to the handle at the concave end portion 64. Spacers 62 and gripper pads 58 cooperate to locate the headed bit relative to the bore.

Referring now to the embodiment illustrated in FIGS. 7 to 9, a further torque magnifying driving tool of this invention comprises a torque magnifying handle 120. which is adapted to receive interchangeable and removable headed bits, such as bits 30.

The outer end surface of the torque magnifying handle may define a plurality of flutes 150. Handle 120 defines a longitudinally oriented bore 152 opening at one end of the handle and provides a smooth nonperforated convex end 154 at its other end. The smooth ended configuration minimizes the potential of abrading a users hand.

One end of the bore 152 is generally hexagonal in shape, each of the equilateral sides of the hexagon being designated as lands 156. Pairs of opposed lands 156 are preferably spaced from each other a distance of not more than about ten thousandths of an inch more than the spacing between the confronting parallel flats 42 of the headed bit 30. Lands 156 preferably incline slightly in the manner described in connection with the inclination of lands 56. Because the dimensions of the bit head define a slightly smaller hexagon than those of the space defined by the lands 156, upon insertion of the head into the handle bore, a very slight space is provided between the lands andthe flats to define an air passage 157 extending from the outer end of the bore 152 to its innermost end, and between the handle and the head.

Intermediate the ends of the bore, means are provided between lands 156 and flats 42 for providing gripping engagement between the handle and the head. These means comprise three narrow gripper pads or elements 158, each of which projects inwardly from a land toward a confronting flat 42. The gripper elements 158 serve to provide oppositely acting components of force and to snugly and frictionally grip the confronting flats 42, thereby to retain the head, hence the headed bit is removably assembled engagement with handle 120. The narrow gripper elements enhance both gripping of the headed bit 30and its separation because of the more limited area of contacL'Except in the vicinity of the gripper elements, the very slight spacing between the handle and head will be maintained, thereby to eliminate the suction force frequently encountered in tially less than the full circumferential extent of the inner surface of the handle.

To assure easy removal of the headed bit from the handle in the event that they become sealingly engaged accidentally, a portion of the bore designated as suction relief chamber 160 is provided. Suction relief chamber 160 is similar to chamber 60, and functions in the manner described in connection with the embodiment of FIGS. 1-6.

To maintain communication between chamber 160 and the remote end of the bore 152, abutment means are provided. The abutment means comprises three narrow stop means or spacer elements 162 which, in the embodiment of FIGS. 7 to 9 are integrally formed with gripper pads 158 as continuations thereof. Spacer elements 162 project sufficiently inwardly from the concave intermediate portion 164 of bore 152 to prevent the seating of head end 30 against portion 164. That provides constant communication, to the extent that it may be necessary, between the outside of the handle and the suction relief chamber 160. The abutment means also serves to locate the headed bit 30 axially of the aperture or bore 152.

The minimal engagement of the handles and heads also markedly reduces mechanical binding forces encountered in known tools of this general character which result from imperfections in molding techniques. In such cases high and low spots on the parts, when they are mated, cause binding, making it difficult and occasionally almost impossible to retract headed bits from handles.

It is thus apparent, that this invention provides highly desirable and highly effective torque magnifying fastener driving tools in which a large variety of headed bits may be removably attached to a torque magnifying handle.

The foregoing specification and drawings will suggest still other variations within the scope and purview of the invention to those skilled in the art. Accordingly the invention is to be limited only in accordance with the claims.

What is claimed is:

1. A hand fastener driving tool comprising a headed bit comprising a metallic bit member projecting from a separate but integrated enlarged plastic head, an enlarged torque magnifying plastic handle defining a head receiving aperture at one end and defining a smooth non-apertured surface at the other end, the inner surface of the handle defining said aperture and the external surface of said'head being generally complementary in configuration and being proportioned and shaped to prevent relative rotation the'rebetween, and to provide an air passage therebetween which extends from the exterior of said handle at said one end to the inner end of said aperture, the inner surface of said handle providing opposite acting projecting head means extending less than the full circumferential extent of the inner surface of the handle for frictionally engaging circumferentially spaced confronting surfaces of said head for retaining said head in said aperture, whereby upon removal of said head from said aperture no suction force is created.

2. In the hand fastener driving too] of claim 1 in which said external surface of said head and said inner surface of said aperture define regular polygonal elongate surfaces spaced slightly apart, and in which said head engaging means project inwardly from opposed polygonal surfaces of said handle into engagement with said head.

3. In the hand fastener driving tool of claim 1 in which the inner end of said aperture terminatesin a suction relief chamber defined by said handle in communication with the inner end of said aperture.

4. In the hand fastener driving tool of claim 1 in which the inner end of said aperture is generally complementary in configuration to the end of said head, the inner end of said aperture defining a plurality of projecting spacers engaging said head thereby to prevent sealing contact between said inner end of said aperture and the adjacent end of said head.

5. A torque magnifying plastic handle adapted to interchangeably receive a plurality of headed bits, said bits each comprising a metallic bit member projecting from a separate but integrated enlarged plastic head, said handle defining a head receiving aperture at one end and a smooth non-perforated opposite end, said aperture being defined by at least four elongated lands defining in transverse cross-section a regular polygonal configuration, gripper pads projecting slightly inwardly from at least two, but less than all, of said lands and being positioned to act oppositely to frictionally engage the circumferentially spaced enlarged head of a headed bit and to retain the head within said aperture.

6. In the torque magnifying handle of claim 5, wherein at the inner end of said aperture a plurality of projecting spacers are provided for engagement with the innermost end of the head of a headed bit to space said innermost end from said inner end.

7. In the torque magnifying handle of claim 5 in which said handle defines an enlarged suction relief chamber in communication with said aperture.

8. In the torque magnifying handle of claim 7 wherein at the inner end of said aperture a plurality of projecting spacers are provided for engagement with the innermost end of a headed bit to space said inner most end from said inner end.

9. A hand fastener driving tool comprising an enlarged torque magnifying plastic handle defining a head receiving aperture at one end and defining a smooth nonapertured surface at the other end, said handle having an internal surface defining a bore in communication with said aperture, stop means on the inner surface of the handle intermediate the ends of said bore to provide an abutment against which a headed bit is seated, a headed bit inserted in said bore through said aperture, said headed bit comprising a metal bit member projecting from a separate but integrated enlarged plastic head, said head being seated against said stop means to locate said bit axially relative to said bore, cooperating means on the inner surface of the handle and the external surface of the head for preventing said bit from rotating relative to said handle, and means on the inner surface of said bore and the external surface of said head for providing gripping engagement between said inner surface and said head, said last named means extending less than vthe full circumferential extent of the inner surface of said handle thereby to provide communication between the portion of the bore inwardly of the stop means and the portion of the bore outwardly of the stop means when the head is seated against the stop means, whereby upon removal of said head from said bore no suction force is created.

10. A hand fastener driving tool in accordance with claim 9 wherein said means for providing gripping engagement comprises gripper elements projecting inwardly from the inner surface of the'handle.

11. A hand fastener driving tool in accordance with claim 10 wherein said gripper elements are at least two in number and act with components of force oppositely of each other to grippingly engage said head.

12. A hand fastener driving tool in accordance with claim 10 wherein said stop means and said gripper elements are formed integrally.

13. A hand fastener driving tool comprising an enlarged torque magnifying plastic handle defining a head receiving aperture at one end and defining a smooth nonapertured surface at the other end, said handle having an internal surface defining an elongate bore in communication with said aperture, stop means on the inner surface of the handle intermediate the ends of said bore to provide an abutment against which a headed bit is seated, a headed bit inserted in said bore through said aperture with one end of said headed bit being seated against said stop means to locate said bit axially relative to said bore and being spaced substantially away from the innermost end of said bore, said headed bit comprising an enlarged plastic head and a metal bit member projecting outwardly of said handle, the external surface of said head and the confronting inner surface of said handle being generally complementary in configuration, thereby to prevent relative rotation therebetween, the inner surface of said handle providing at least two friction members for frictionally engaging confronting surfaces of said head for retaining said head in said aperture, said friction members extending less than the full circumferential extent of the inner surface of said handle, to provide an air passage between confronting surfaces of said head and handle and to provide communication with the inner end of said bore so that, upon removal of said head from said bore, no suction forces are created.

14. A hand fastener driving tool in accordance with claim 13 wherein said friction members are narrow, are at least three in number and are integrally formed with said stop means.

UNITED STATES PATENT OFFICE. CERTIFICATE GI -CORRECTION Patent No. 3,752,202 Dzited August 1 .1973

Inventor(s) Harry F. Condon It 1e certified that error appears in the above identified patent and that seid Letters Patent are hereby corrected asv shown below:

In the Abstract, line 3 of text "recieve" should be receive --5 Column 5, line 61 (CLAIM 1), before "means" insert engaging Signed and sealed this 20th day of November 1973.

(SEAL) Attest:

EDWARD VLFLETCEERJR RENE D TEGTMEYER Attesting Officer Acting Commissioner of Patents

Claims

1. A hand fastener driving tool comprising a headed bit comprising a metallic bit member projecting from a separate but integrated enlarged plastic head, an enlarged torque magnifying plastic handle defining a head receiving aperture at one end and defining a smooth non-apertured surface at the other end, the inner surface of the handle defining said aperture and the external surface of said head being generally complementary in configuration and being proportioned and shaped to prevent relative rotation therebetween, and to provide an air passage therebetween which extends from the exterior of said handle at said one end to the inner end of said aperture, the inner surface of said handle providing opposite acting projecting head means extending less than the full circumferential extent of the inner surface of the handle for frictionally engaging circumferentially spaced confronting surfaces of said head for retaining said head in said aperture, whereby upon removal of said head from said aperture no suction force is created.

2. In the hand fastener driving tool of claim 1 in which said external surface of said head and said inner surface of said aperture define regular polygonal elongate surfaces spaced slightly apart, and in which said head engaging means project inwardly from opposed polygonal surfaces of said handle into engagement with said head.

3. In the hand fastener driving tool of claim 1 in which the inner end of said aperture terminates in a suction relief chamber defined by said handle in communication with the inner end of said aperture.

9. A hand fastener driving tool comprising an enlarged torque magnifying plastic handle defining a head receiving aperture at one end and defining a smooth nonapertured surface at the other end, said handle having an internal surface defining a bore in communication with said aperture, stop means on the inner surface of the handle intermediate the ends of said bore to provide an abutment against which a headed bit is seated, a headed bit inserted in said bore through said aperture, said headed bit comprising a metal bit member projecting from a separate but integrated enlarged plastic head, said head being seated against said stop means to locate said bit axially relative to said bore, cooperating means on the inner surface of the handle and the external surface of the head for preventing said bit from rotating relative to said handle, and means on the inner surface of said bore and the external surface of said head for providing gripping engagement between said inner surface and said head, said last named means extending less than the full circumferential extent of the inner surface of said handle thereby to provide communication between the portion of the bore inwardly of the stop means and the portion of the bore outwardly of the stop means when the head is seated against the stop means, whereby upon removal of said head from said bore no suction force is created.

10. A hand fastener driving tool in accordance with claim 9 wherein said means for providing gripping engagement comprises gripper elements projecting inwardly from the inner surface of the handle.