An improved open-end wrench which will retain an appropriately sized nut in the U-shaped recess at either end of the wrench, thus preventing loss of the nut and freeing one hand for other activities. Resilient insert means such as a spring wire clip or equivalent means is slidably positioned within the jaws forming the U-shaped recess so as to protrude slightly into the recess on at least one side. Sliding movement of the resilient insert means permits the nut to be frictionally engaged and held within the U-shaped recess, during threading or unthreading of the nut or like conventional use of the open-end wrench.

BACKGROUND OF THE INVENTION 
As is well known to industrial workers, particularly in the automotive and 
in aircraft trades, it is frequently necessary to start or remove nuts 
from studs and bolts which are located in relatively inaccessible 
positions. Common practice is for the worker to hold the wrench in one 
hand and to use the other hand to initially position the nut for 
threading, or to catch the nut after it is unthreaded. When working at an 
appreciable elevation, as with aircraft, the nut may be easily lost, 
particularly where the worker must use one hand for safety or balance. 
Also, the bolt or stud may be positioned between two closely adjacent 
parts so that it is difficult to place or remove the nut, under any 
circumstances. The annoyance of not being able to easily start a nut, or 
attending the accidental loss of a nut with the necessity of retrieval, is 
well known to even the casual user of tools of the type described. 
Numerous efforts have been made to develop tools which simplify the task of 
starting or removing nuts from threaded members, such as studs and bolts. 
One commercial variation of an open-end wrench, for example, is provided 
with a box wrench at one end which may be offset for hand clearance. 
However, use of a box wrench attachment of the type described does not 
solve the problem of loss of nuts, since the box wrench must necessarily 
have an opening of sufficient internal diameter to pass easily over the 
nut. Also, such arrangement negates the possibility of jaws of differing 
width at either end of the wrench, as is customary with the standard 
open-end wrench. 
More recently, nut holding attachments have been specifically devised for 
open-end wrenches, such devices being intended to hold the nut in place 
between the jaws of the wrench uring the starting of the nut. Such devices 
are disclosed for example in Malcolm U.S. Pat. No. 2,369,400 and Becker 
U.S. Pat. No. 2,557,628. However, such devices, which are placed 
externally of the wrench, have the disadvantage of being easily dislodged. 
They also present protrusions and projections which interfere with use of 
the wrench, and which cause the attachments to be discarded by the worker 
as generally useless for day to day operations. They also have the 
disadvantage of greatly increasing the cost of the wrench. A principal 
defect of such attachment means is their inability to effectively hold a 
nut within the jaws of a wrench so that the tool can be easily used for 
the intended purpose. 
SUMMARY OF THE INVENTION 
This invention relates generally to an improved open-end wrench, and more 
particularly to an open-end wrench having substantially integral means for 
holding a nut in place between the jaws of the wrench during starting (or 
removal) of nuts in positions of comparative inaccessibility. 
In general, it is an object of the present invention to provide an improved 
open-end wrench which can be quickly, easily and firmly engaged upon a 
nut, for purposes of normal use, and just as easily disengaged from the 
nut. 
It is a particular object of the invention to provide an improved open-end 
wrench wherein one or both ends of the wrench is provided with slidable 
resilient insert means for frictionally engaging a nut within the jaws of 
the wrench, whereby the position of the nut can be maintained and 
controlled throughout threading and unthreading operations of the nut 
carried out with only one hand. 
A further object of the invention is to provide an improved open-end wrench 
for such purpose which has no substantial protruding parts and which to 
all outward purposes resembles a conventional open-end wrench. 
A still further object of the invention is to provide an improved open-end 
wrench of such character which is relatively inexpensive and simple in 
construction, and which can be easily manufactured without any appreciable 
added expense. 
As a brief statement of the invention, a nut-holding improvement has been 
made in a conventional open-end wrench of the type wherein an elongate 
handle terminates at either end in jaws forming a U-shaped recess to 
receive a nut. The improvement consists in the insertion of resilient 
means within a U-shaped opening of the jaws so as to protrude a slight 
distance into the U-shaped recess on at least one side. Bearing in mind 
that the jaws have a fixed width of opening, the resilient insert 
functions to frictionally engage at least one of the parallel sides of a 
multisided nut (e.g., hex nut, square nut, etc.) and thereby hold the nut 
within the opening between the jaws during operations of threading or 
unthreading the nut. The degree of frictional resistance is such that the 
nut can be easily inserted into a retained position, and just as easily 
removed, by movement of the wrench or by the pressure of the fingers. Such 
frictional resistance is achieved by a resiliency and slide mounting of 
the insert within the U-shaped recess of the wrench, so that the insert 
can be spread apart to grasp the nut during use, but will return to its 
original position thereafter. In general, for advantageous use, the force 
of the frictional engagement should be sufficient that the full weight of 
the wrench can be supported on the nut. In any event, the frictional 
resistance should be sufficient to retain the nut within the U-shaped 
opening against the force of gravity, so that a positive action is 
required to place or to remove the nut from the wrench opening.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIGS. 1 to 4, reference numeral 10 generally represents a 
standard open-end wrench provided with nut receiving heads 12 and 14 at 
either end. Each of the heads is provided with opposed jaws 16 and 18 
which are dimensioned to provide a generally U-shaped opening of a fixed 
width, depending upon size and intended use of the wrench. Conventionally, 
the head at one end is of a size to accommodate one size of nut whereas 
the head at the other end will accommodate a nut of slightly larger or 
smaller size (e.g., 3/4 inch and 11/16 inch). In accordance with the 
present invention, the standard construction of the wrench is improved by 
the provision of resilient insert means at one or both ends of the wrench. 
As shown in FIG. 1, the resilient insert means is in the form of a 
generally U-shaped clip of spring wire 22. In one very satisfactory form 
of the invention, the insert 22 is formed as a substantially U-shaped 
length of spring steel (viz., music wire) wherein the side portions 24 and 
tip portions 26 are permanently deformed in an outward direction as 
respects the central portion 27 and the parallel sides 29 of the U-shaped 
opening 20. This construction permits the wire insert 22 to be 
frictionally engaged within a properly dimensioned groove 28 which is 
formed on the inside periphery of the opening 20, midway between the edges 
of the parallel sides or "jaws" of the wrench. The groove 28 is 
dimensioned so as to be sufficiently deep to receive the diameter of the 
spring wire 22 so that a portion of the wire will protrude a slight 
distance into the U-shaped opening or recess 20, on either side thereof 
(see FIG. 1, also FIG. 3), and to permit some vertical movement of the 
shank portions 24 of the wire in the groove (see lower portion 31 of 
groove 28 in FIG. 3, and enlarged detail of FIG. 7). Referring to FIGS. 1, 
1a and 4, the outer ends of the recess 28 may be slightly beveled, as at 
30, to receive the outwardly flaring tips 26 of the spring wire. This 
arrangement permits the wire to be inserted within the groove so that the 
tip portions 26 protrude slightly beyond the open end of the wrench, as 
indicated in FIG. 1. 
Upon frictionally engaging a nut 32 within an opening 20 of the wrench (see 
left portion of FIG. 1), the sides of the nut will engage the shank 
portions 24 of the insert 22, whereas a forward point 34 of the nut will 
engage the inner loop 27 of the insert wire. As illustrated, the effect is 
to slidingly move the wire 22 slightly inward with respect to the opening 
20 so that the shank portions 24 of the spring wire move inward to firmly 
engage and wedge the nut 32 between both the shank portions 24 and end 
portions 26. As particularly illustrated in FIG. 1a, the ends 26 become 
locked within the groove 28. At the same time, the shank portions 24 of 
the wire are pressed outward by the nut, into the space 31 provided in 
groove 28 for such outward or vertical movement. The net effect is that 
the nut 32 is firmly positioned and retained within the U-shaped opening 
20, by the resiliency of the insert 22, where it will remain during all 
the operations to thread or unthread the nut on a bolt or stud. When it is 
desired to remove the wrench from the nut, all that is required is a brief 
separating movement of these parts, that is, by grasping and pulling the 
nut with the fingers or by moving the wrench outward with respect to the 
nut (e.g., as held in position on a bolt). 
It will be appreciated that the spring wire 22 is easily and inexpensively 
fabricated and that existing open-end wrench constructions are likewise 
easily modified to receive the spring wire. By way of illustration, a 
rotary routing tool of desired dimension and hardness can be passed 
between the opposed jaws 16 and 18 to rout out the parallel side portions 
of the groove 28 and, at the end of the pass, the inner curved portion. 
Such operation is easily understood and well within the skills of the 
conventional tool maker. 
With reference to both the dimensions of the groove 28 and the insert 22, 
and the material of construction of the latter, the relationship should be 
such that the extending side portions of the insert can be resiliently 
spread apart by the entering nut, for example, into the spaces 31 provided 
within the groove, while retaining sufficient frictional engagement with 
the nut to firmly hold the nut within the U-shaped recess 20. Thus, 
assuming use of a wire of spring steel, having a diameter within the range 
of 0.02 to 0.07 inch (0.05 to 0.18 mm), the width of the router employed 
to form the groove 28 can be of substantially equivalent dimension to the 
diameter of the wire. This will insure a firm frictional fit of the 
resilient insert 22 within the groove 28. The depth of the groove 28 may 
be equal to or just slightly less than the diameter of the wire, say 0.018 
to 0.068 inch (0.045 to 0.17 mm), to thereby facilitate the outward 
movement of the wire into the space 31 at the bottom of the groove 28. On 
the other hand, the "spring" configuration of the wire can be such that 
only about 1/2 to 1/3 the diameter of the wire will normally be received 
within the groove and, conversely, about 1/2 to 1/3 of the diameter of the 
wire will protrude into the U-shaped recess 20. 
As indicated, this particular relationship can be achieved by preselection 
of the dimensions of the spring wire or like insert 22 with respect to the 
excess space or depth 31 of the groove 28. It can also be achieved by a 
configuration of the insert to provide a certain amount of vertical play 
within the groove, for example, as provided by the bends 25 between the 
portions 24 and 26 of the wire insert. 
From the foregoing, it will be evident that the present invention makes 
possible the modification of existing open-end wrenches to provide a very 
substantial improvement in the use of such tools. In particular, the 
improved open-end wrench of the present invention enables a worker to 
position a nut within the resilient insert means at the appropriate end of 
the wrench and to thereafter position the nut on the end of a bolt or 
stud, in a one-handed operation. Having thus started the nut, the wrench 
can be easily rotated in the most suitable fashion for the task at hand, 
and the worker will be assured throughout such operation that the nut will 
not fall from the wrench (or vice versa). When the nut has been tightened 
on the bolt, as desired, the wrench is easily disengaged by simple outward 
movement to disengage the wrench (i.e., to disengage the resilient insert 
means) from the nut. In like fashion, a nut can be easily removed from a 
bolt or stud in a reverse operation, with virtual elimination of 
accidental loss of the nut such as frequently occurs with conventional 
wrenches due to the necessary clearance provided between the jaws of the 
wrench and the nut. One-handed operations within relatively inaccessible 
spaces are thus facilitated, with no fear of accidental loss of the nut 
when it becomes free of the bolt. When the nut is loose from the bolt, it 
is easily removed from the wrench by simply pulling it out with the 
fingers. These and other advantages in the use of the wrench will be 
apparent to those skilled in this art, including, particularly, the 
freeing of one hand for balance or safety while the wrench is being 
employed in the other hand. 
It will additionally be apparent that the improved open-end wrench of the 
present invention can be easily fabricated on existing manufacturing 
lines, with only very minor and inexpensive alterations in the 
manufacturing procedure, thus facilitating manufacture at a very small 
increase in cost, while providing all of the described advantages.