[0001] Open-ended wrenchs are among the most important tools that the mechanic carries.
The wrenchs are used for securing nuts to bolts in many applications. The nuts may
be shaped square or hexagonal and the open-ended wrench is useful for securing either.
The nuts are measured between two parallel sides thereof by a line perpendicular to
both sides through the middle. The wrench open end has two parallel faces or jaws
adapted to fit easily over the nut. When the wrench is positioned it can be turned
in the appropriate direction to either secure the nut against a fixture or to loosen
the nut. In many applications, the wrench cannot be turned a full 360° because another
object is in the path of the handle. The wrench has to then be removed from the nut
and repositioned free from the interferring object.
[0002] Ratchet wrenchs are also well known in the art. However, these wrenchs are the box-type
which fits over the top of the nut. Typically, the ratchet wrench includes a ratcheting
handle and a nut driver which fits over the handle. This creates a unit of substantial
width compared with the typical open end wrench. In many instances, it is difficult
to get a ratchet wrench over the top of the nut because of lack of space and it is
necessary to use the open-ended wrench. In the past, each time it is desired to move
the wrench it has to be slipped off the nut and reapplied at a different angle and
then turned in appropriate amount. This must be repeated many times where a small
angular area exists in which the wrench can be turned.
[0003] It would be desirable if an open-ended wrench could be designed which could be moved
against the direction of turning to a new position without physically being removed
from the nut. Such as open-ended wrench would have all the ease of use of the traditional
ratchet-type wrench and the additional ability to fit in the small spaces.
[0004] In accordance with the one preferred embodiment of this invention, there is provided
an open-end wrench used to secure a nut comprising a main body and a lower jaw member.
The main body forms the first jaw and the back of the open end. The lower jaw member
is pivotably connected to the main body to pivot between first and second positions
respectively displacing said lower jaw from said upper jaw by first and second distances.
The first distance allows the wrench to rotate the nut as it is rotated and the second
distance allows the wrench to rotate around the nut as it is rotated.
[0005] One preferred embodiment of the subject invention is hereafter described with specific
reference being made to the following Figures in which:
Figure 1 shows the open-ended ratchet wrench viewed from the top;
Figure 2 shows a side view of the open end ratchet wrench taken along lines 2-2 shown
in Figure 1; and
Figure 3 shows a top view, partially in cutaway showing the various positions of the
movable parts of the open end ratchet wrench.
[0006] Referring now to Figure 1, the open end ratchet wrench 10 consists of three principle
parts, the main body 12, the lower jaw member 14, and the pawl 16. Lower jaw member
14 is connected to body 12 by a pin 18 and pawl 16 is connected to body 12 by a pin
20. Member 14 rotates around pin 18 and pawl 16 rotates around pin 20 in a manner
which will be describe hereafter.
[0007] When member 14 is connected to body 12, open-end 22 is formed. Open-end 22 consists
of upper jaw 24, a lower jaw 26 and a back 28. Open-end 22 is sized so that the distance
between upper jaw 24 and lower jaw 26 is slightly larger than the size of a nut 30
which may be inserted into open end 22. Back 28 is rounded so that the point 32 of
a hexagon nut 30 may fit near back 28.
[0008] As will be explained hereafter, when wrench 10 is forced against nut 20, pawl 16
rotates about pin 20, releasing lower jaw 14 so it can rotate around pin 18 in a downward
direction. When this occurs the distance between upper jaw 24 and lower jaw 26 increases
so that the open end 22 may slip around nut 30. The amount which lower jaw member
14 rotates is based on the direction from one point such as 32 of nut 30 to the diametrically
opposite point of nut 30.
[0009] Referring now to Figure 2, the manner in which lower jaw member 14 is coupled to
main body 12 is illustrated. Lower jaw member 14 has a cam extension 34 extending
therefrom. The thickness of the main part of member 14 forming lower jaw 26 is the
same thickness as is main body 12. Cam 34, however, is thinner than either lower jaw
member 14 or main body 12. A cut is made horizontally through body 12 in the area
adjacent to where lower jaw member 14 is to be placed. Cam 34 is placed within cut
36 and held there by pin 18. In this manner, cam 14 rotates around pin 18. Cut 36
should be made sufficiently large so that cam 34 can rotate as member 14 rotates.
While not shown in Figure 2, it should be noted that pawl 16 is also positioned substantially
within cut 36.
[0010] Referring now to Figure 3, a top cut-away view of wrench 10 is shown with the cut
area being shown so that the entire lower jaw member 14 and pawl 16 are shown. In
addition, Figure 3 shows the normal position of member 14 and pawl 16 in solid lines
and the rotated positions of member 14, referenced as 14a, and the rotated positions
of pawl 16, referenced as 16a, shown in dashed lines.
[0011] Cam extension 34 which extends within cut 36, has an area 38 adapted to receive a
spring 40, the other end of which is inserted into a hole 42 drilled into main body
12. In addition, cam 34 includes two teeth 44 and 46. The back end 48 of pawl 16 is
normally positioned against tooth 44 to hold lower jaw member 14 into position shown
by the solid line. When pressure is applied against front end 50 of pawl 16, pawl
16 rotates about pin 20 to the position shown by the dashed lines shown as 16a. In
this position, the back end 48 of pawl 16 is above tooth 44 allowing lower jaw member
14 to rotate downward above pin 18 to the position shown in the dashed lines as 14a.
In this instance, the back 48 of pawl 16 rests against the now raised tooth 46a preventing
lower jaw 14 from further rotation.
[0012] Pawl 16 has an area 52 adapted to receiving spring 54 the other end of which is inserted
into hole 56 drilled into main body 12. Spring 54 biases pawl 20 downward so that
it will normally attempt to be positioned against tooth 44 as long as lower jaw member
14 is in the normal position shown by the solid line. This usually is the case as
a result of the biasing effect of spring 40 on member 14. Pawl 16 should extend beyond
back 28 at a position below (towards lower jaw member 14) the position of point 32.
[0013] When it is desired to secure a nut in a direction by rotating the handle 58 downward,
lower jaw member 14 is in the solid line position and upper jaw 24 and lower jaw 26
are positioned around the opposite flat surfaces of nut 30. Upon reaching a barrier
pass which handle 58 cannot move, pressure is applied against nut 30 which forces
pawl 16 to rotate about pin 20. This frees cam 34 to rotate about pin 18. As the handle
58 is raised, a greater distance is furnished by nut 30 in open end 22 between jaws
24 and 26 and lower jaw member 14 rotates about pin 18. Tooth 46 should be positioned
to allow lower jaw member 14 to rotate a sufficient amount to allow the open end 22
to rotate about nut 30 in the reverse direction.
1. An open end wrench for securing a nut comprising: a main body integrally forming
an upper jaw and a back; a lower jaw pivotably connected to said main body to pivot
between first and second positions respectively displacing said lower jaw from said
upper jaw by first and second distances, said lower jaw including a cam having a tooth
therein; said first distance allowing said wrench to rotate said nut as it is rotated
and said second distance allowing said wrench to rotate around said nut as said wrench
is rotated; and release means for releasing said lower jaw to pivot from said first
position to said second position, said release means including a pawl extending from
said body to between said jaws, said pawl being pivotably connected to said body to
pivot between a first cam position engaging said tooth and a second cam position disengaged
from said tooth.
2. A wrench as claimed in claim 1 including spring means for biassing said cam and
pawl to position in which said pawl engages said tooth.
3. A wrench as claimed in claim 1 or 2 in which said upper jaw, lower jaw and back
form an open end, said pawl extending into said open end and is pivoted by resulting
force applied thereto by forcing said wrench against said nut.
4. A wrench as claimed in claim 3 including spring means for biasing said cam and
pawl to positions in which said pawl engages said tooth.
5. A wrench as claimed in claim 1 in which said upper jaw, lower jaw and back form
an open end, said release means extending into said open end and releases said lower
jaw by the resulting force applied thereto when said wrench is forced against said
nut.
6. A wrench as claimed in any of claims 1 to 3 including spring means for biasing
said lower jaw to said first position.
7. A open-end wrench having an open end expandable between first and second positions,
said wrench being adapted for turning a nut in one direction when said open end is
in said first position and adapted for rotating around said nut when said open end
is expanded to said second position, said wrench comprising:
integral means forming a first jaw and back of said open end, said means having a
cut therein from said back;
second jaw means having integral first and second portions, said first portion forming
a second jaw, said second portion forming a cam sized to fit within said cut, said
cam having a tooth along the edge thereof, said cam being pinned within said cut;
and
pawl means including pin means, said pawl means being at a location pinned by said
pin means within said cut so one end of said pawl means engages said tooth when said
pawl means is in a first position, said pawl means being rotatable about said pin
means to a second position disengaged from said tooth, said pawl means extending into
said open end through said back, and being rotatable by a force being applied thereto
at the end opposite to said one end.
8. A wrench as claimed in claim 7 including spring means for biasing said second jaw
means and said pawl means to positions in which said pawl means engages said tooth.
9. A wrench as claimed in claim 7 or 8 including first spring means compressibly positioned
between said means forming said first jaw and back and said second jaw means to normally
maintain said second jaw means in a position to allow said pawl means to engage said
tooth; and
second spring means compressibly positioned between said means forming said first
jaw and back and said pawl means to normally maintain said pawl means engaged with
said tooth.
10. An open-end wrench with first and second jaws adapted to having opposite sides
of a nut juxtapositioned therewith, said wrench having a body with a top surface and
a bottom surface to form a back connecting said first and second jaws, the improvement
comprising: an opening between said top and bottom surfaces; a second jaw member having
first and second portions, said first portion having top and bottom surfaces and a
surface connecting said top and bottom surfaces to form said second jaw, said second
portion having a top and bottom surface pinned in said opening to allow said second
jaw member to rotate, and a surface, including a tooth, connecting said top and bottom
surfaces of said second portion; and a pawl having first and seconds ends, said pawl
being pinned in said opening to rotate between a first position in which said first
end engages said tooth and a second position in which said first end is disengaged
from said tooth, said second end extending beyond said back so that when said second
end is forced against said nut, said pawl rotates from said first position to said
second position allowing said lower jaw member to rotate away from said upper jaw
as said wrench is moved around said nut.
11. A wrench as claimed in claim 10 including a spring for biasing said pawl towards
said first position.
12. A wrench as claimed in claim 11 including a further spring for biasing said second
jaw member to a position so that said first end of said pawl can engage said tooth.
13. A wrench as claimed in any of claim 10 to 12 in which said nut adapted to have
opposite sides thereof juxtapositioned with said wrench has opposite sides separated
by a given distance, said tooth being positioned so that when said pawl engages said
tooth said second jaw is said given distance away from said first jaw.
14. A wrench as claimed in any of claims 10 to 12 in which said nut adapted to have
opposite sides thereof juxtapositioned with said wrench has opposite junctions between
adjacent sides separated by a second given distance, in operation, rotating away from
said first jaw by an amount so that said first and second jaws are separated by said
second given distance.
15. A wrench as claimed in any of claims 1 to 6 in which said cam includes a second
tooth therein for engaging said release means to prevent further pivotal movement
of said lower jaw.
16. A wrench as claimed in any of claims 7 to 9 in which said cam includes a second
tooth therein for engaging said pawl means when said pawl means is rotated to said
second position, said second tooth being positioned on said cam to define the second
position to which said wrench expands.
17. A wrench as claimed in any of claims 10 to 14 in which said second portion of
said second jaw member includes a second tooth connecting said top and bottom surfaces;
said first end of said pawl engaging said second tooth to limit the amount said second
jaw member rotates when said pawl is rotated to said second position.