US3900058A

US3900058A - Multipurpose impact hand tool

Info

Publication number: US3900058A
Application number: US505468A
Authority: US
Inventors: Meade Mcardle
Original assignee: Individual
Current assignee: Individual
Priority date: 1974-09-12
Filing date: 1974-09-12
Publication date: 1975-08-19
Anticipated expiration: 1992-08-19

Abstract

An impact hand tool particularly adapted for driving a threaded fastener and for applying an axial impact to the fastener when needed to facilitate starting the fastener or to overcome binding thereof. The tool includes an elongate, tubular body portion having an elongate bit extending axially from one end thereof. The bit is mounted for axial sliding movement relative to the body portion and an impact hammer is provided interiorly of the body portion adapted for movement toward and away from the bit. A spring is provided for biasing the impact hammer toward and into engagement with the bit, and a pair of finger-engageable arms are provided extending from the impact hammer to facilitate moving the hammer against the force of the spring and to a cocked position. Upon subsequent release of the impact hammer from the cocked position, the hammer is thrust by the spring into engagement with the bit to force the bit outwardly from the hollow body portion and impart an impact to the fastener.

Description

United States Patent [191 McArdle 1 MULTIPURPOSE IMPACT HAND TOOL Meade McArdle, Rt. 2, Box 73A, Horse Shoe, NC. 28742 22 Filed: Sept. 12,1974

211 Appl.No.: 505,468

[76] Inventor:

Primary ExaminerAl Lawrence Smith Assistant ExuminerMarc R. Davidson Attorney, Agent, or Firm-Parrott, Bell, Seltzer, Park & Gibson Aug. 19, 1975 [5 7 ABSTRACT An impact hand tool particularly adapted for driving a threaded fastener and for applying an axial impact to the fastener when needed to facilitate starting the fastener or to overcome binding thereof. The tool includes an elongate, tubular body portion having an elongate bit extending axially from one end thereof. The bit is mounted for axial sliding movement relative to the body portion and an impact hammer is provided interiorly of the body portion adapted for movement toward and away from the bit. A spring is provided for biasing the impact hammer toward and into engagement with the bit, and a pair of finger-engageable arms are provided extending from the impact hammer to facilitate moving the hammer against the force of the spring and to a cocked position. Upon subsequent release of the impact hammer from the cocked position, the hammer is thrust by the spring into engagement with the bit to force the bit outwardly from the hollow body portion and impart an impact to the fastener.

10 Claims, 5 Drawing Figures MULTIPURPOS E IMPACT HAND TOOL This invention relates generally to a multi-purpose hand tool useful for driving threaded fasteners and for various other purposes.

When driving a threaded fastener such as a wood screw, it is often necessary, initially, to tap the fastener with a hammer to facilitate starting the same. Sometimes, during the course of driving the fastener, it also becomes necessary to tap the fastener with a hammer to overcome binding of the fastener. While the use of a conventional screwdriver and a hammer may be employed for this purpose in some applications, particular problems are presented when working in tight or rela tively inaccessible locations, or when using threaded fasteners to install large or bulky objects such as screens or storm windows where the use of one hand is required to hold the bulky object in place. In these instances it is difficult, if not impossible, to properly position the fastener and at the same time tap or strike the fastener with a hammer to facilitatestarting the same.

With the foregoing in mind, it is an object of this invention to provide a simple hand tool adapted for single-handled operation and particularly adapted for driving threaded fasteners such as wood screws and for applying an axial impact thereto when needed to facilitate starting the fastener or to overcome binding thereof.

It is a further object of this invention to provide a multi-purpose hand tool having a variety of different working bits and being adapted for single-handed use for imparting an impact by the bit to a workpiece where the use of a hammer and a separate tool would otherwise be required.

More particularly, it is a further object of this invention to provide a multipurpose hand tool having interchangeable bits in the form of a screwdriver, chisel, nail set, punch, or the like and wherein the body portion of the hand tool includes a mechanism whereby the bit may be forcibly driven outwardly from the body portion for imparting an axial impact to a workpiece.

In accordance with this invention, the hand tool has a hollow, elongate body portion and has an elongate bit extending axially from one end of the body portion and being mounted for axial sliding movement relative to the body portion. An impact hammer is provided in the interior of the hollow body portion and a spring is provided for biasing the impact hammer toward the bit. Finger-engageable means are provided extending from the body portion to facilitate moving the impact hammer against the force of the spring into a cocked position. Upon subsequent release of the impact hammer from the cocked position, the hammer is thrust by the spring toward the bit to force the bit outwardly from the hollow body portion and impart an axial impact to the workpiece.

In accordance with a more specific aspect of the invention, a latch mechanism may be provided to permit retaining the impact hammer in any one of several axially spaced cocked positions until an impact from the tool is needed, whereupon the hammer may be released.

Some of the objects and advantagesof the invention having been stated, others will appear when taken in connection with the accompanying drawings, in which FIG. 1 isan isometric vi'ew of an impact hand tool in accordance with the invention having a screwdriver bit installed therein, and illustrating various other types of bits which may be interchangeably employed in the hand tool;

FIG. 2 is an exploded isometric view of the hand tool illustrated in FIG. 1, with parts broken away for clarity;

FIG. 3 is a longitudinal sectional view of the hand tool shown with the impact hammer thereof in the released position;

FIG. 4 is a longitudinal sectional view similar to FIG. 3 showing the impact hammer in the cocked position;

and

FIG. 5 is a transverse sectional view of the hand tool taken substantially along the line 55 of FIG. 3.

Referring now more particularly to the drawings, the hand tool includes an elongate, tubular body portion, generally indicated at 10, having an elongate bit 20 projecting axially from one end thereof. Bit 20 has a working end 21 in the form of a screwdriver blade with the opposite inner end 22 of the bit being of noncircular cross section. As illustrated, the inner end 22 of the bit is formed of a square cross section for a short distance along the length thereof and an enlarged flange 23 is formed at the juncture of the non-circular crosssection end portion with the remainder of the shank of the bit.

As illustrated in FIG. 2, an insert 1 l, at one end of the hollow, tubular body portion 10, has a square restricted opening 12 therein defining a socket for receiving the square end portion 22 of bit 20 so as to prevent rotation of the bit relative to the body portion while allowing sliding movement of the bit in an axial direction relative to the body portion.

Bit 20 is removably retained in place on the body portion by means of a cap 13 adapted to slide over the shank of the bit 20 and to engage the flange 23 and restrict outward movement of the bit relative to the cap. As illustrated, the outer portion of insert 11 is externally threaded and is adapted to threadably engage with the internally threaded cap 13. Thus, as will be seen from FIGS. 3 and 4, when cap 13 is threaded onto the threaded outer portion of insert 11 with a bit 20 extending from the cap, flange 23 of the bit permits limited axial sliding movement of the bit for a short distance, preferably about one-eighth to one-fourth inch.

Located at the opposite end of body portion 10 from bit 20 is an enlarged cap 14 which is preferably of a smooth external contour to permit comfortably gripping the body portion and exerting axial and rotative driving forces thereto. The cap is hollow and is telescopically received on body portion 10 and is provided with fastener means such as a set screw 15 to permit adjustably securing the cap at different positions along the body portion 10 to thereby vary the overall length of the hand tool to fit the size of the hand of the user. As illustrated in FIG. 2, several axially spaced holes 16 are provided in the body portion 10 for receiving the set screw 15 therein.

A generally cylindrical impact hammer or plunger 30 is provided interiorly of the hollow body portion 10 and is adapted for axial sliding movement within the body portion toward and away from the bit 20. As illustrated, impact hammer 30 has a generally flat impact surface 31 at one end thereof. A reduced diameter generally cylindrical portion 32 extends axially from the opposite end of the impact hammer 30 for engaging and carrying one end of an elongate coil compression spring 33. The

opposite end of the coil compression spring 33 engages a spring centering hub 17 on the inside of cap 14. Thus, spring 33 biases the impact hammer toward and into engagement with the inner end 22 of bit 20. Spring 33 may be easily replaced by a spring of a different strength, and the force of the spring may be adjusted to some degree by adjustment of the position of cap 14.

As illustrated in FIG. 3, when the impact hammer 30 is in the released position, the impact surface 31 thereof engages the innermost end surface of the bit 20 extending through the opening 12 of insert 11, and pushes the bit outwardly from the body portion 10. To facilitate moving the impact hammer against the force of the spring and to a cocked position, fingerengageable means in the form of a pair of arms 34 extend outwardly from opposite sides of the impact hammer 30 and pass through opposing elongate longitudinally extending slots 19 provided in the side wall of the body portion 10.

The arms 34 are positioned so as to permit engaging and pulling the same with two fingers of the hand while holding the tool with the palm of the hand and the other fingers. The adjustable capability of cap 14 permits adjusting the axial distance along the length of the hand tool between the end of the cap and the fingerengageable arms so as to best fit the hand of the user.

The arms 34 may be pulled back manually and released one or more times, as needed, to provide an impactive force to the bit. However, preferably, the hand tool is provided with latch means for engaging the impact hammer 30 and retaining the same in the cocked position for being subsequently released when needed. As illustrated, the latch means is in the form of a lever arrangement carried by the tubular body portion 10.

The lever arrangement includes a latch member 40 pivotally carried by a support 41 and having a jaw 42 at one end thereof extending into the interior of the hollow body portion through an opening 18 in the wall thereof for engaging the impact hammer 30. Latch member 40 also has a trigger surface 43 on the opposite end thereof which may be depressed to release jaw 42 from the impact hammer. A spring 44 is provided for biasing the jaw 42 toward the inward position into engagement with the impact hammer 30.

In order to permit adjustably selecting the amount of impact to be imparted to the workpiece by the tool, the impact hammer preferably has a series of longitudinally spaced notches 35 provided in the side thereof. This permits positioning the impact hammer at any of several different axially spaced cocked positions and retaining the same in position with the jaw 42 of the trigger mechanism engaging one of the different notches. Thus, if a relatively small amount of impact is desired, the impact hammer may be moved against the force of the spring for a relatively short distance, and when a large impact is desired, the impact hammer may be moved axially beyond the latch so that the jaw 42 of the latch member engages the impact surface 31 of the impact hammer.

OPERATION The hand tool may be used in the manner of any conventional tool with the impact hammer either in the retool may be conveniently employed to impart an axial impact to the screw without removing the screwdriver blade from position in engagement with the screw. This may be accomplished merely by depressing the trigger surface 43. If successive impacts are required, the tool may be easily cocked with one hand while still in engagement with the screw by pulling the fingerengageable arms 34 back with two fingers while holding the tool with the palm of the hand and the remaining fingers.

As illustrated in FIG. 1, various other bits may be interchangeably employed in the hand tool of this invention. For example, the hand tool may be used with other types and sizes of screwdriver bits such as a Phillips screwdriver bit 52, or with bits intended for various other purposes such as a wood chisel bit 50 for gouging or chiseling wood by applying successive impacts to the bit. Also, the tool may also be used with nail set bit 51 to countersink nails without the need for a hammer to impart an impactive force to the bit. Any number of other types of bits, not illustrated, may also be employed. For example, a sharpened pointed bit may be employed as a punch for forming indentations in wood or metal surfaces to facilitate starting screws or drills.

It will be understood that in most instances, where the working end of the bit is no larger than the shank, the same cap 13 may be interchangeably employed with all bits. However, where the working end of the bit is larger than the shank as for example with the chisel bit 50 illustrated, a separate cap 13 is suitably provided on the shank of the bit.

In the drawings and specification there has been set forth a preferred embodiment of the invention, and although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation.

That which is claimed is:

I. An impact hand tool particularly adapted for applying an impact to a workpiece such as a threaded fastener, said hand tool comprising an elongate, hollow body portion having a pair of opposed elongate longitudinally extending slots in the side wall thereof, an elongate bit extending axially from one end of the body portion and being mounted for axial sliding movement relative thereto, an impact hammer mounted for axial sliding movement within the hollow body portion toward and away from the bit, means in the body portion cooperating with the impact hammer for biasing the same toward the bit, and a pair of finger-engageable arms carried by the impact hammer and extending exteriorly of the body portion through the elongate slots therein and serving to facilitate moving the impact hammer away from the bit against the biasing means and to a cocked position whereby upon subsequent release thereof the impact hammer is thrust by the biasing means toward the bit to force the bit outwardly from the body portion for imparting an impact to the workpiece.

2. An impact hand tool according to claim 1 wherein said means for biasing the impact hammer toward the bit comprises a spring positioned within the hollow body portion and cooperating therewith and with the impact hammer for biasing the hammer axially toward the bit.

3. An impact hand tool according to claim 1 wherein said elongate bit has means at the inner end thereof cooperating with the body portion to prevent rotative movement of the bit relative to the body portion.

4. An impact hand tool according to claim 1 additionally including latch means cooperating with the impact hammer for retaining the same in the cocked position and for permitting subsequently releasing the same.

5. An impact hand tool according to claim 4, wherein the impact hammer has a plurality of longitudinally spaced notches provided in the side thereof, and wherein the latch means includes means carried by the body portion and extending into the interior thereof to eng 3e a selected one of the notches in the impact hammer, said latch means being thereby adapted to retain the impact hammer at any of several different axially spaced cocked positions so as to permit adjustably selecting the amount of impact to be imparted to the workpiece by the tool.

6. An impact hand tool according to claim 1 additionally including an enlarged cap extending over the body portion in telescoping relation therewith at the opposite end of the body portion from the bit, the outer periphery of said cap being smoothly contoured for permitting comfortably gripping the hand tool while manually applying axial and rotative driving forces thereto, and wherein fastener means is provided cooperating with the cap and with the body portion to permit adjustably securing the cap to the body portion at a selected axial position along the length thereof to thereby permit adjusting the axial distance along the length of the hand tool between the end of the cap and the finger-engageable arms so as to fit the hand of the user.

7. An impact hand tool according to claim 1 additionally including a set of interchangeable bits, each bit having a different working end and each bit being adapted for being received in said body portion, and wherein said body portion includes means cooperating with the bit positioned in the body portion to permit removing and interchanging the same with any selected one of the set of bits.

8. An impact hand tool particularly adapted for driving a threaded fastener and for applying an impact thereto when needed to facilitate starting the fastener or to overcome binding thereof, said hand tool comprising an elongate, tubular body portion having an elongate slot opening through the side wall thereof extending longitudinally along a portion of the length of the body portion, an elongate bit extending axially from one end of the body portion and being mounted for axial sliding movement relative thereto, said bit having means at the inner end thereof cooperating with the body portion to prevent rotative movement of the bit relative to the body portion, an impact hammer mounted for axial sliding movement within the tubular body portion toward and away from the bit, a compression spring cooperating with the impact hammer and with the body portion for biasing the impact hammer toward the bit, finger-engageable means carried by the impact hammer and extending through the elongate slot opening in the body portion and being adapted to facilitate moving the impact hammer longitudinally away from the bit against the biasing force of the spring means and to a cooked position whereby upon subsequent release of the finger-engageable means, the impact hammer is thrust by the compression spring toward the bit to force the bit outwardly from the body portion for imparting an impact to the fastener.

9. An impact hand tool according to claim 8 wherein the working end of said bit is in the form of a screwdriver.

10. An impact hand tool particularly adapted for driving a threaded fastener and for applying an impact thereto when needed to facilitate starting the fastener or to overcome binding thereof, said hand tool comprising an elongate tubular body portion having a restricted noncircular opening at one end thereof and having a pair of opposed elongate slot openings through the side wall thereof extending longitudinally along a portion of the length of the body portion, an elongate bit extending axially from the restricted opening in the body portion and being mounted for axial sliding movement relative thereto, said bit having means at the inner end thereof cooperating with the restricted noncircular opening to prevent rotative movement of the bit relative to the body portion, an impact hammer mounted for axial sliding movement within the tubular body portion toward and away from the bit, spring means cooperating with the impact hammer and with the body portion for biasing the impact hammer toward and into engagement with the bit, a pair of finger-engageable arms carried by the impact hammer and extending through the elongate slot openings in the body portion and being adapted to facilitate moving the impact hammer longitudinally away from the bit against the biasing force of the spring means and to a cocked position, and latch means cooperating with the impact hammer for retaining the same in the cocked position and for permitting subsequent release of the impact hammer whereby the hammer is thrust by the spring means into engagement with the bit to force the bit outwardly from the body portion for imparting an impact to the fastener.

Claims

1. An impact hand tool particularly adapted for applying an impact to a workpiece such as a threaded fastener, said hand tool comprising an elongate, hollow body portion having a pair of opposed elongate longitudinally extending slots in the side wall thereof, an elongate bit extending axially from one end of the body portion and being mounted for axial sliding movement relative thereto, an impact hammer mounted for axial sliding movement within the hollow body portion toward and away from the bit, means in the body portion cooperating with the impact hammer for biasing the same toward the bit, and a pair of finger-engageable arms carried by the impact hammer and extending exteriorly of the body portion through the elongate slots therein and serving to facilitate moving the impact hammer away from the bit against the biasing means and to a cocked position whereby upon subsequent release thereof the impact hammer is thrust by the biasing means toward the bit to force the bit outwardly from the body portion for imparting an impact to the workpiece.

5. An impact hand tool according to claim 4, wherein the impact hammer has a plurality of longitudinally spaced notches provided in the side thereof, and wherein the latch means includes means carried by the body portion and extending into the interior thereof to engage a selected one of the notches in the impact hammer, said latch means being thereby adapted to retain the impact hammer at any of several different axially spaced cocked positions so as to permit adjustably selecting the amount of impact to be imparted to the workpiece by the tool.

8. An impact hand tool particularly adapted for driving a threaded fastener and for applying an impact thereto when needed to facilitate starting the fastener or to overcome binding thereof, said hand tool comprising an elongate, tubular body portion having an elongate slot opening through the side wall thereof extending longitudinally along a portion of the length of the body portion, an elongate bit extending axially from one end of the body portion and being mounted for axial sliding movement relative thereto, said bit having means at the inner end thereof cooperating with the body portion to prevent rotative movement of the bit relative to the body portion, an impact hammer mounted for axial sliding movement within the tubular body portion toward and away from the bit, a compression spring cooperating with the impact hammer and with the body portion for biasing the impact hammer toward the bit, finger-engageable means carried by the impact hammer and extending through the elongate slot opening in the body portion and being adapted to facilitate moving the impact hammer longitudinally away from the bit against the biasing force of the spring means and to a cocked position whereby upon subsequent release of the finger-engageable means, the impact hammer is thrust by the compression spring toward the bit to force the bit outwardly from the body portion for imparting an impact to the fastener.