Insulated Socket Tool Handle Assembly With Reversible Ratchet

Abstract

An electrically insulated spin-drive handle assembly with a reversing ratchet drive, adapted for use with various socket heads. Within the handle are internal ratchet teeth engagable by a double pawl element carried by a rotatably mounted pawl carrier. A socket stem is connected by a transverse pin to the pawl carrier and extended through and beyond the handle to receive various socket heads. The double pawl element is selectively urged to either forward-drive or reverse-drive engagement with the ratchet teeth using a selector cap recessed in the rearward end of the handle. The selector cap is formed of dielectric material so that a forward or reverse selection can be made for the ratchet mechanism manually without danger of electrical shock.

Description

BACKGROUND OF THE INVENTION

This invention relates to hand tools for turning threaded connectors, such as machine screws, bolts and nuts, and especially to a spin-drive-type hand tool with a socket for gripping a hexagonal bolt head or the like. More particularly the invention relates to a ratchet-drive-type handle assembly for various socket heads with special provision for insulating the tool operator from electrical shock.

Socket wrenches with reversing ratchet drive are well known in the art, mostly in connection with lever-type handles. The handles usually have a square male connector element that fits in a square female recess in the various sockets with which the wrench is to be used. Also spin-drive-type handles for socket heads are often used. The spin-drive handle assemblies normally have a drive stem with the square connector element at the forward end. The square connector is a universal male connection for the matching square female recess formed in all the various types of socket heads with which the spin drive handle is to be used.

The prior art, however, does not provide universal spin-drive-type handle assemblies for socket heads wherein a reversible ratchet mechanism is associated with the handle. While spin-drive-type handles with ratchet mechanisms are used with interchangeable screwdriver blades having integral stems, these types of devices have a special collet in the handles themselves which serves to grip the shank of the blade or other tool head. It will be apparent that such handles are not suitable for use with conventional interchangeable socket heads. Also, handle assemblies with reversible ratchet mechanisms for universal use with a variety of socket heads are not available.

The principal problem with the development of such a handle assembly is the matter of mounting, as an integral part of the handle assembly, a universal socket drive stem with a square end portion for connection to standard socket heads. The forces that are exerted on the stem during use would tend to quickly brake or damage a ratchet mechanism to which the stem must necessarily be connected.

Another problem associated with handle assemblies of the type discussed above is that of electrical insulation. In electrical applications it is extremely important that portions of hand tools to be gripped by a worker's hands be carefully insulated. While screwdriver handles and other spin-drive-type handles can readily be formed of dielectric material to provide the necessary insulation, where a ratchet mechanism is associated with the handle, an additional problem is presented. Most currently available reversible ratchet drive mechanisms have a metal selector part which is used to change the direction of drive of the ratchet mechanism from forward drive to reverse drive. If an operator using the handle assembly were to hold the handle in one hand while it engaged a bolt head or the like and then with the other hand attempt to move the selector to change the direction of drive he could easily be the victim of electrical shock when working on electrical installations.

Still another problem that could occur in connection with reversible ratchet-type spin-drive handles is that of inadvertent operation of the drive selector so that the turning of the handle might suddenly cease to drive the socket head in the desired direction.

The socket tool handle assembly of the present invention, however, incorporates a reversible ratchet mechanism and other associated features that resolve the difficulties indicated above and afford other features and advantages heretofore not obtainable.

SUMMARY OF THE INVENTION

It is among the objects of the invention to provide a spin-drive handle assembly with reversing ratchet drive adapted for use in association with various socket heads of conventional construction.

Another object of the invention is to provide a spin-drive handle assembly with associated reversing ratchet mechanism wherein the operator is insulated from electrical shock while spinning the handle and/or while operating the direction selector for the ratchet drive.

These and other objects and advantages are achieved by the unique construction of the spin-drive handle assembly of the invention as adapted for use with a variety of conventional socket heads. The assembly includes an elongated handle formed of dielectric material and adapted for manual twisting about the spin axis. The handle has an axial bore extending therethrough from a forward end to a rearward end and a counterbore at the rearward end. Within the counterbore is anchored an element defining internal ratchet teeth around the spin axis and located coaxial therewithin is a pawl carrier also adjacent to the rearward end of the handle and adapted for rotary movement about the spin axis.

A socket stem is located within the bore and has one end thereof received within the pawl carrier and connected thereto with a transverse pin.

A double pawl element is carried by the pawl carrier and adapted for movement between positions of forward drive and reverse drive engagement with the ratchet teeth. The pawl element is urged toward one or the other of its positions by means of a selector mechanism operatively connected to the pawl carrier and pivotal about the spin axis between positions urging the pawl element to one or the other of its drive positions. The selector mechanism has a selector cap formed of insulating material operatively connected thereto and protectively located within the counterbore. The selector cap is adapted to be manually turned to operate the selector mechanism for selecting the drive direction.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevational view of a spin-drive handle assembly embodying the invention;

FIG. 2 is a cross sectional view taken on the line 2--2 of FIG. 1;

FIG. 3 is a fragmentary cross sectional view on an enlarged scale taken on the line 3--3 of FIG. 2; and

FIG. 4 is a transverse sectional view drawn to the same scale as FIG. 3 taken on the line 4--4 of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring more particularly to the drawings there is shown a spin-drive handle assembly with reversing ratchet drive for universal use with a variety of socket heads (not shown) of conventional construction. The assembly comprises a handle 10 formed of dielectric material such as ABS plastic or other insulating material of suitable strength and durability, and a stem 11 with a square shank portion 12 at its outer end to provide a male connector adapted to be inserted in a matching square female recess in a standard type socket head. The inner end of the stem 11 is received in an axial bore 13 that extends through the handle 10. A bushing 14 with a knurled outer surface is tightly fitted in the forward end of the handle 10 and is adapted to receive and support the forward end of the stem 11.

Formed at the rearward end of the handle 10 are three counterbores of progressively larger diameter and including an inner counterbore 16, a serrated intermediate counterbore 17 and an outer counterbore 18. An annular housing 20 with a knurled outer surface is tightly fitted in the serrated intermediate counterbore 17, the forward portion of its inner surface being provided with ratchet teeth 21 and the rearward portion being of greater diameter and provided with a smooth machined interior cylindrical surface 22.

A pawl carrier 30 is mounted coaxially within the housing 20 and is adapted for rotary movement therein. The pawl carrier 30 has a rearward end 31 of larger diameter that fits against the interior cylindrical surface 22 of the annular housing 20, the carrier being retained relative to the housing 20 against axial movement by means of a shoulder 32 at the rearward end 31, that bears against the ends of the ratchet teeth 21 of the annular housing and by a lock ring 33 that seats in an annular groove 34 formed in the surface of the pawl carrier and which bears against the forward end of the housing 20.

The pawl carrier 30 has an axial bore 35 extending therethrough and a counterbore 36 at the forward end thereof. The counterbore 36 receives the inner end of the stem 11 which is secured therein by a transverse pin 37 which extends through and is tightly fitted in a transverse bore 38 in the stem 11. The outer ends of the transverse pin 37 are loosely received in opposite ends of a transverse bore 39 through the pawl carrier 30.

It will be noted that the diameter of the transverse bore 39 is somewhat larger than the diameter of the ends of the pin 37 so that the end of the stem is loosely connected to the pawl carrier 30. With this manner of connection, bending forces and other stresses applied to the stem are not directly transferred to the pawl carrier and it will be seen that some flexing of the inner end of the stem can be accommodated so as to minimize the danger of damage to or breaking of the pawl carrier or associated parts thereof.

The pawl carrier has a lateral slot 41 (FIGS. 3 and 4) cut therein perpendicular to the axis thereof and extending to the bore 35. Pivotally mounted within the slot 41 is a double pawl element 42 with its teeth at the opposite ends thereof adapted for selective driving engagement with the ratchet teeth 21 of the housing 20. The pawl element is pivotally connected to the pawl carrier 30 by a pivot pin 43 extending therethrough and having its opposite ends received in opposite ends of a bore 44 in the pawl carrier 30.

Referring to FIG. 4 it will be seen that the double pawl element 42 is capable of limited pivotal movement between a forward-drive position illustrated in FIG. 4 wherein the handle drives the stem when turned clockwise and ratchets when turned counterclockwise, and a reverse drive position (not shown).

A ratchet drive selector element 50 is used with its associated parts to control the position of the pawl element 42 to provide either forward or reverse ratchet drive. The element 50 has a central annular flange 51 that rests against the rearwardly extending face of the pawl carrier 30 and that has its circumferential edge slidably engaging the interior cylindrical surface portion 22 of the annular housing 20. Extending forwardly from the flange portion 51 is an inwardly projecting member 52 that seats within the bore 35. The member 52 has a transverse bore 53 that receives a plunger 54 and a helical spring 55. The helical spring 55 bears at one end against the wall of the bore 35 and at the other end against the plunger 54 to urge the plunger radially outward against the pawl element 42 (FIGS. 3 and 4).

Extending rearwardly from the annular flange 51 of the element 50 is a knurled knob portion 56 that extends partly into the outer counterbore 18. It will be seen that the selector element 50 may be turned within limits of about 30.degree.of pivotal movement between the position indicated in FIG. 4 wherein the plunger 54 urges the double pawl element 42 to its forward ratchet-drive position, to another limit position wherein the plunger 54 urges the double pawl element 42 into its reverse ratchet-drive position.

An insulated cap 60 formed of suitable dielectric material such as ABS plastic, is located within the counterbore 18 and has a serrated recess adapted to be tightly fitted over the knurled knob portion 56 of the selector element 50. The cap 60 is adapted to be manually twisted between two limit positions to select the desired drive direction for the ratchet mechanism. The necessary movement between positions requires about a 30.degree. turning of the cap 60 relative to the pawl carrier 30.

It will be noted that the cap 50 is recessed within the counterbore 18 so that it is protected against accidental or inadvertent turning movement that could disengage the ratchet drive. Also it will be noted that both the handle 10 and the cap 60 are formed of electrical insulating material so that a person using the tool would be protected against electrical shock both when spinning the tool and when changing the ratchet drive.

While the invention has been shown and described with respect to a specific embodiment thereof this is intended for the purpose of illustration rather than limitation and other variations and modifications of the specific device herein shown and described will be apparent to those skilled in the art all within the intended spirit and scope of the invention. Accordingly the patent is not to be limited to the specific embodiment herein shown and described nor in any other way that is inconsistent with the extent to which the progress in the art has been advanced by the invention.

Claims

I claim:

1. A spin-drive handle assembly with reversing ratchet drive for a socket head comprising:

an elongated handle of dielectric material adapted for manual twisting about the spin axis and having a forward end and rearward end, and an axial bore extending from end to end with at least one counterbore at the rearward end,

means anchored to said handle in said counterbore, defining internal ratchet teeth around said spin axis,

a pawl carrier mounted within said handle adjacent said rearward end for rotary movement about said spin axis,

a socket stem extending along said spin axis from within said pawl carrier, through said bore and beyond the forward end of said handle,

a pin extending perpendicular to said spin axis through said pawl carrier and said stem to connect said stem to said pawl carrier,

a double pawl element mounted in said pawl carrier for movement between positions of forward-drive and reverse-drive engagement with said ratchet teeth,

selector means operatively connected to said pawl carrier and pivotable about said spin axis between a position urging said pawl element to said forward-drive position, and a position urging said pawl element to said reverse-drive position, and

a selector cap formed of dielectric material, located within said counterbore, said cap being operatively connected to said selector means and adapted to be manually turned to operate said selector means.