U.S. patent number 3,824,881 [Application Number 05/398,653] was granted by the patent office on 1974-07-23 for insulated socket tool handle assembly with reversible ratchet.
This patent grant is currently assigned to Wright Tool and Forge Company. Invention is credited to Richard B. Wright.
United States Patent |
3,824,881 |
Wright |
July 23, 1974 |
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.
Inventors: |
Wright; Richard B. (Akron,
OH) |
Assignee: |
Wright Tool and Forge Company
(Barberton, OH)
|
Family
ID: |
23576242 |
Appl.
No.: |
05/398,653 |
Filed: |
September 19, 1973 |
Current U.S.
Class: |
81/63; 81/177.85;
81/32 |
Current CPC
Class: |
B25B
13/465 (20130101) |
Current International
Class: |
B25B
13/00 (20060101); B25B 13/46 (20060101); B25b
013/46 () |
Field of
Search: |
;81/62-63.2,177R,177G
;145/76,70,75 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Jones, Jr.; James L.
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.
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.
* * * * *