Locking assembly for maintaining a box wrench engaged with a bolthead

A locking assembly is placed in a web area of a box wrench and includes a ball that is resiliently biased outwardly of the plane of that web into a position to engage one surface of a bolthead. The engagement between the ball and the bolthead maintains the box wrench engaged with the bolthead. The ball can be forced back into the web area to permit the wrench to move past the bolthead. The ball is biased outwardly by a resilient pad. In another form of the invention, a resilient snap ring maintains the ball in the web area, with a ball seating surface being defined in that web area The ball is held in place by edges of either a housing or by edges positioned on the web area.

TECHNICAL FIELD OF THE INVENTION 
The present invention relates to the general field of hand tools, and to 
the particular field of wrenches, specifically box wrenches. 
BACKGROUND OF THE INVENTION 
A box wrench, also known as a socket wrench, has a head that fits 
completely around a bolthead for applying torque to that bolthead. The box 
wrench also has a handle attached to the head and a user manipulates the 
handle to move the bolthead. The box wrench has the advantage of totally 
surrounding the bolthead whereby torque application is maximized. Box 
wrenches have been used for a wide variety of applications for many years. 
While quite successful, box wrenches do have a drawback. A large box wrench 
may have a very long handle and/or be quite heavy. In either case, it may 
be difficult to keep the box head engaged around the bolthead as that box 
head may tend to slip off of that bolthead under the influence of gravity. 
In some situations, it may even be necessary to have two people operate a 
box wrench, in which one person's job is simply to hold the box wrench 
head on the bolthead. 
Accordingly, there is a need for a box wrench that can be maintained 
engaged with a bolthead by one user, even if the wrench is quite heavy or 
has a very long handle, yet which can be easily dropped past a bolthead 
when desired. 
OBJECTS OF THE INVENTION 
It is a main object of the present invention to provide a box wrench that 
will remain engaged with a bolthead, even if the box wrench is quite heavy 
and cumbersome. 
It is another object of the present invention to provide a box wrench that 
can be maintained engaged with a bolthead by one user. 
It is another object of the present invention to provide a box wrench that 
can be maintained engaged with a bolthead by one user, even when the box 
wrench is quite long and cumbersome to use. 
It is another object of the present invention to provide a box wrench that 
can remain engaged with a bolthead when desired, yet which can easily be 
dropped past the bolthead when desired. 
SUMMARY OF THE INVENTION 
These, and other, objects are achieved by a locking assembly that is 
mounted adjacent to a box head of a wrench. The locking assembly has an 
element that engages a bolthead to keep the box head engaged with the 
bolthead, yet which can be moved out of the way to permit the box head to 
move past the bolthead when desired. 
Specifically, the locking assembly includes a ball inside of a housing that 
is mounted in a web of a box head. The ball engages either a top surface 
or a bottom surface of a bolthead when the box head is in surrounding 
relationship with the bolthead. In this manner, the ball prevents the 
boxhead from moving off of the bolthead. However, the locking assembly 
further includes a resilient element in the housing that biases the ball 
into bolthead-engaging position. The ball can be forced out of the 
bolthead-engaging position against the bias of the resilient means whereby 
the box head can be moved past the bolthead when desired.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION 
Shown in FIG. 1 is a conventional wrench 10 having a handle 12 with an open 
end 14 on one end and a box end 16 on the other end. The open end 14 
includes two jaws 18 and a web area 20 for engaging a bolthead. The box 
end 16 includes a web area 22 surrounding a box area 24 on which a 
multiplicity of points 26 for engaging a bolthead. 
The present invention is embodied in a locking assembly for maintaining the 
box end engaged with a bolthead. The locking assembly 30 is shown in FIG. 
2 in flush box end 32 and in FIG. 3 in an offset box head 34. 
Referring to FIGS. 2 through 7, a housing slot 36 is defined in the web 
area 22 adjacent to the box area 24. The housing slot includes a front 
section 37 and a rear section 38. The front section includes two parallel 
side walls 40 and 42 extending along longitudinal centerline 44 of the 
handle from inner surface 46 of the web area towards the open end 14. The 
side walls are spaced apart by a slot width dimension 48. The rear section 
38 of the housing slot includes two wing-receiving slots 50 and 52 that 
define a width dimension 54 for the rear area that exceeds width dimension 
48. 
A housing element 60 is slidably mounted in the housing slot 36, and 
includes a rear portion 62 to which is connected a forward portion 64. The 
rear portion 62 includes two wings 66 and 68 that are sized and shaped to 
be slidably received in the wing-receiving slots 50 and 52. The forward 
portion 64 includes a top wall 68, a bottom wall 70 and two side walls 72 
and 74. The walls all terminate in forward ends 76, 78, 80 and 82 
respectively, with ends 76 and 78 being arcuate. As is best shown in FIG. 
9, wall forward ends 80 and 82 curve toward each other. This curvature is 
not seen in FIG. 4 because FIG. 4 is a perspective view. These forward 
ends 80 and 82 define a housing slot 84 therebetween, with this housing 
slot having a slot width. The housing has a rear width dimension 86 
defined between the outer-most tangential locations of wings 66 and 68 
that is essentially equal to the housing width dimension 54, but is 
slightly less than such dimension so the housing can slide into and out of 
the housing slot. The housing further has a forward width dimension 88 
defined between the two side walls 72 and 74 which is slightly less than 
the slot width dimension 48 so the housing can be slidably received in 
that slot. The housing has a depth dimension 90 that is defined between 
the rearmost surface of the rear portion and the plane containing the slot 
84 defined between forward ends 80 and 82, and a height dimension 91 that 
is measured between the inner surface of the top and bottom walls 68 and 
70. 
A resilient pad 92 of felt material, or the like, is mounted on inner 
surface 94 of the rear wall 96 of the housing. The depth dimension 90 is 
measured from the inner surface 94. The pad 92 has a front surface 98 and 
a rear surface 100, with a thickness measured between the front and rear 
surfaces 98 and 100 respectively. The thickness of the pad 92 reduces the 
depth dimension of the housing by the amount of the thickness. 
The locking element further includes a ball 102, such as a ball bearing or 
the like, located inside the housing. The ball is spherical and has an 
outer diameter that is selected to permit the ball to move freely within 
the housing in the vertical direction 104, but to be positioned to 
protrude out of the housing and to be held by the wall forward ends 80 and 
82 so it will not fall out of the housing. Therefore, the ball has an 
outer diameter that is less than the housing height dimension 91, less 
than the housing depth dimension 90 and greater than the width dimension 
of slot 84 and less than the housing width dimension 88. This dimension of 
the ball vis a vis the housing depth dimension causes the ball to protrude 
out of the housing via the slot 84 when the ball rests against the pad 
front surface 98. Pressing the ball against the pad causes the pad to give 
and causes the ball to move in direction 108 and into the housing. The 
thickness of the pad is selected so that such pressing the ball in 
direction 108 will cause the pad to compress sufficiently to permit the 
ball to move far enough into the housing to have the outermost tangential 
location of the ball flush with the plane containing the slot 84. That is, 
the ball protrudes out of the housing a distance as measured along the 
ball diameter that corresponds to the thickness of the pad. To ensure that 
the ball can be moved totally inside the housing, the housing contains a 
concave indentation 110 (see FIG. 6). The ball thus moves from the 
outwardly projecting position shown in FIG. 5 to an inward location shown 
in FIG. 6 in which the ball has compressed the pad. As shown in FIG. 8, 
the pad can include two spaced apart portions 92' and 92'' with a gap 112 
defined therebetween. 
Operation of the locking apparatus is illustrated in FIGS. 9 through 11B. 
Ball 102 engages top surface 114 of a bolthead 116 to prevent the wrench 
box end from slipping off of that bolthead as is best seen in FIG. 10B. 
The wrench is operated in the normal manner. However, if it is desirable 
to move the box end past the bolthead, the wrench is pressed forward in 
direction 118 to press the ball against the bolthead and force the ball 
against the pad in direction 108. This causes the pad to give and moves 
the ball into the housing from the FIG. 10B position into the FIG. 11B 
position. With the ball fully inside the housing, the wrench can be moved 
past the bolthead. The resilient pad thus biases the ball into the locking 
position, but such bias can be overcome to move the ball out of the 
locking position. The housing thus can be seen as having two depth 
dimensions, one being measured between the pad front surface 98 and the 
plane containing slot 84 and a second depth dimension measured between the 
pad rear surface 100 and the plane containing the slot 84. The diameter of 
the ball element is larger than the first depth dimension but is smaller 
than the second depth dimension so the ball will protrude when the pad 
element is not compressed. The pad element can be of different thicknesses 
so that it need not be completely compressed (i.e., will have some 
thickness remaining) when the ball element has moved into the housing far 
enough to permit the bolthead to clear the box wrench. 
The box wrench can include six or twelve points as is known to those 
skilled in the art. 
Additional forms of the invention are shown in FIGS. 12 through 21. While 
the basic concept associated with the above-discussed forms applies to the 
forms shown in FIGS. 12 through 21, these forms differ slightly from each 
other and from the above-discussed forms in structural elements. 
Therefore, the operation and use of these forms will not be presented as 
these forms operate in a manner that is similar to the above-discussed 
forms in permitting a wrench to be placed on a nut and held in place on 
that nut. Any variations between the operation of these forms of the 
invention and the forms disclosed in the above-discussed FIGS. will be 
apparent to one skilled in the art based on the teaching of this 
disclosure. 
A locking assembly 30a is shown in combination with a wrench 32a in FIG. 
12. The assembly 30a can slide into and out of a housing slot 36a defined 
in the web area of the wrench. The assembly has a rectangular shape and 
the slot in the wrench has a corresponding shape. The FIG. 12 assembly 
differs from the FIG. 2 assembly by deleting the wings. Assembly 30a can 
slide into and out of the wrench web section from either direction as 
indicated in FIG. 12. As discussed above, the wrench web section is 
machined to hold the ball in assembly. This is indicated in FIG. 12 where 
the wrench web includes two edges E1 and E2 that extend adjacent to the 
ball and are spaced from each other a distance that is selected to hold 
the ball in the assembly. For example, the spacing between edges E1 and E2 
is less than the diameter of the ball. The ball moves within the assembly 
up and down and rearwardly as discussed above so the wrench can be placed 
on a nut from above or below, yet the ball will engage a surface of the 
nut to hold the wrench in place on that nut. However, since the assembly 
includes a soft mesh M1 in the rear thereof, the ball can be forced back 
into the assembly into the mesh to allow a nut to by-pass the ball. As 
will be appreciated by those skilled in the art the housing of the 
assembly includes a top lip (see FIG. 15, however, all assembly housings 
will have similar structure) TL and a bottom lip BL that extend far enough 
outwardly beyond the ball to prevent that ball from moving out of the 
housing, while the above-discussed structure of the wrench itself prevents 
the ball from falling out of the housing. The sketches of FIG. 15 and 
corresponding figures appear to show the ball held in a housing in a 
manner that will permit the ball to fall out of the housing, but this 
showing is for convenience only, and the ball is held in the assembly by 
the lips and edges as above described extending beyond the end of the 
housing far enough to keep the ball in the housing while permitting that 
ball to move up and down as above described. 
FIGS. 16 and 17 show another form of the invention in which a planar plate 
200 is embedded in the resilient pad 92. The plate 200 has a lower end 202 
and an upper end 204. The plate controls movement of the ball from the 
full line position shown in FIGS. 16 and 17 to the dotted line position 
shown in those figures. The plate pivots about one end or the other 
depending on which end the ball is adjacent, between a dotted line 
position 200' when the ball is forced into the resilient pad to permit a 
nut to pass into or out of the wrench and a full line position 200'' when 
the ball is in a nut blocking position shown in full lines. 
Yet another form of the invention is shown in FIGS. 18-21 as assembly 30a. 
Assembly 30a includes a resilient snap ring 210 is fixedly mounted to the 
wrench in an opening 212. The snap ring holds ball 102' in the opening 
212. The ball 102' is positioned in the opening 212 to protrude therefrom 
far enough to prevent a nut from passing by that ball. The ball 102' does 
not move into or out of the opening as the balls discussed above which are 
mounted on a resilient pad. No such pad is present in assembly 30a, 
accordingly, a wrench including assembly 30a must be lifted onto and off 
of a nut. 
The opening 212 includes a ball seating surface 220 that causes the ball to 
move outwardly of the slot into a nut abutting position. In the position 
shown in FIG. 20, a nut will abut the ball, with the ball engaging the 
snap ring. This will cause the wrench to be fixed to the nut. The wrench 
is lifted off of the nut to free it from the nut. The ball can move to 
another position engaging the surface 220 and, again, be forced into a nut 
engaging position. 
In some instances, a resilient pad is not desired. Accordingly, another 
form of the invention, shown in FIGS. 22 and 23, includes an assembly 250 
that excludes any resilient pad. The assembly 250 thus has a solid housing 
252 against which the ball rests. As is the case in all forms of the 
invention, the housing 252 includes a projection 254 that engages a 
corresponding dimple in the wrench to hold the housing in position in the 
wrench. The projection co-operates with a slip fit established between the 
housing and the wrench slot to hold the housing in the wrench. That is, 
the housing and the slot are sized with respect to each other whereby the 
housing slides into the slot but will have a tight fit whereby friction 
holds the housing securely in place. 
It is understood that while certain forms of the present invention have 
been illustrated and described herein, it is not to be limited to the 
specific forms or arrangements of parts described and shown.