Support means for conduit

An attachment apparatus is provided for attaching an elongated shaft to a structural element, wherein the shaft defines a longitudinal axis, and the structural element includes an opening through the structural element which defines a central axis extending in a direction generally perpendicular to the axis of the shaft. The apparatus includes a helical coil of wire having a central coiled section and opposed end sections protruding from the coiled section, an inner space defined by the coiled section that is sized to grip the shaft and to prevent relative axial movement between the helical coil and the shaft when the coil is mounted on the shaft, and a fastening assembly for fastening the apparatus to the structural element when at least one end section is inserted into the opening. The apparatus is mounted on the elongated shaft by rotating the opposed end sections so that the coiled section unwinds, increasing the diameter of the inner space to a point where it is slightly larger than the cross-sectional diameter of the shaft. The elongated shaft is inserted through the inner space to a desired position relative to the apparatus, and the opposed end sections are rotated so that the coiled section rewinds, decreasing the diameter of the inner space until the shaft is firmly retained through the apparatus. In a preferred embodiment, the fastening assembly includes hook-shaped tips defined by the opposed end sections, and spaced-apart by a distance greater than the diameter of the opening.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates generally to fasteners, and, more 
particularly, to an attachment apparatus for attaching an elongated member 
alongside a structural element having an opening formed therein. 
2. Discussion of the Prior Art 
Presently, in the construction of a walk-behind lawn mower for trimming 
grass, a lawn mower deck is provided which supports a controllable engine, 
and at least one grass cutting blade. Such lawn mowers include a handle 
bar allowing an operator to position the lawn mower over the grass to be 
trimmed. Remote engine controls are commonly placed on the handle bar so 
that they may be reached quickly. The linkage between the engine control 
and the remote control is often a mechanical linkage, such as a cable. 
Since cables have a tendency to buckle when placed under relatively high 
longitudinal compressive forces, such as those necessary to manipulate the 
engine controls, the cables are often placed in a conduit, sheath, or 
other elongated hollow shaft, sufficiently rigid to prevent such buckling. 
A typical conduit is constructed of a synthetic resin material, such as 
Polyvinyl Chloride (PVC), which provides sufficient rigidity. 
A conduit provides the additional benefit of protecting the cable from 
corrosive environmental effects. However, due to the frictional forces 
exerted on the cable by the interior of the conduit, the conduit must be 
secured to the lawn mower so that the remote control may effectively push 
and pull the cable through the conduit. 
It is known to provide a metallic clamp-type device which may be fastened 
to a shroud extending around the engine, effectively clamping and securing 
the conduit to the shroud while allowing the cable to be pushed and pulled 
within the conduit. Clamp-type devices are commonly secured to the shroud 
by means of a self-tapping screw, requiring an opening defined in the 
structural element which has a sufficient depth, or side wall, that 
provides a surface for the screw to tap itself upon. Extruded holes, holes 
which have been stamped or punched through a relatively flat element, 
turning the edges of the element inward, provide an opening with 
sufficient depth for self-tapping screws. 
In assembly, clamp-type devices require that the conduit be positioned in 
the clamping area of the device, and retained, usually by hand, while the 
device is fastened to the structural element. If the conduit is positioned 
incorrectly, the remote engine control will not be allowed to move through 
its full range of motion, reducing its effectiveness in controlling the 
engine. Therefore, it is important to correctly position the conduit with 
respect to the engine. Because such clamp-type devices require that the 
assembler use one hand to position the conduit, and the other hand to 
secure the device, assembly becomes a difficult and time-consuming 
process, increasing production time, and labor costs associated with 
producing a lawn mower. 
It is also known to provide a strap fastener constructed of a flexible 
synthetic resin material which may be used to secure the conduit to the 
structural element. Plastic strap fasteners, which resemble those used 
with trash bags, are relatively inexpensive to produce, but are generally 
not reusable. In addition, they are limited to use with tubular or 
cylindrical structural elements, such as the handle bar on the lawn mower, 
and cannot be used to secure conduits and the like to relatively large 
flat surfaces, such as the engine shroud. Additionally, plastic strap 
fasteners cannot be used around heated areas because they may melt, or 
otherwise rapidly lose structural integrity. 
It is further known to provide a snap-on axial end fitting for a conduit 
which may be used to attach the end of the conduit perpendicular to the 
surface of the shroud. These fittings are commonly made of a synthetic 
resin material, and provide at least one flexible barb, allowing the 
fitting to be pushed into a receiving aperture, securing the fitting to 
the structural element once the barb has been pushed through the aperture. 
Such an end fitting allows the conduit to be quickly positioned and secured 
to the element. However, because such fittings must be placed on the axial 
end of the conduit, the distance between the shroud and the end of the 
cable protruding from the conduit must be relatively small so that 
buckling of the exposed portion of the cable does not occur. Additionally, 
these fittings require a special aperture in the shroud, one which has a 
relatively shallow depth and a specific shape so that the barb may be 
allowed to effectively retain the conduit on the shroud. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide an apparatus for 
attaching a sleeve, conduit or other elongated shaft alongside a 
structural element at an opening formed in the structural element so that 
the shaft is secured to the element. 
It is another object of the present invention to provide an attachment 
apparatus that permits an elongated hollow shaft to be attached to a 
structural element while protruding past the apparatus to protect the 
entire length of the cable supported within the shaft from buckling. 
It is a further object of the present invention to provide an apparatus for 
attaching an elongated shaft to a structural element having any shape of 
surfaces, such as relatively flat surfaces, or relatively curved surfaces. 
It is yet another object of the present invention to provide an apparatus 
which may be fastened to a structural element with relative quickness. Yet 
a further object of the present invention is to provide an apparatus which 
may be fastened to a structural element adapted for use with a prior art 
fastening device. 
In accordance with the present invention, an attachment apparatus is 
provided for attaching an elongated shaft to a structural element, wherein 
the shaft defines a longitudinal axis, and the structural element includes 
an opening through the structural element which defines a central axis 
extending in a direction generally perpendicular to the axis of the shaft. 
The apparatus includes a helical coil of wire having a central coiled 
section and opposed end sections protruding from the coiled section, an 
inner space defined by the coiled section that is sized to grip the shaft 
and to prevent relative axial movement between the helical coil and the 
shaft when the coil is mounted on the shaft, and a fastening assembly for 
fastening the apparatus to the structural element when at least one end 
section is inserted into the opening. 
The apparatus is mounted on the elongated shaft by rotating the opposed end 
sections so that the coiled section unwinds. Unwinding the coiled section 
causes the diameter of the inner space to increase. The diameter of the 
inner space is increased to a point where it is slightly larger than the 
cross-sectional diameter of the shaft. 
The elongated shaft is inserted through the inner space to a desired 
position relative to the apparatus. Once the desired position is achieved, 
the opposed end sections are rotated so that the coiled section rewinds, 
decreasing the diameter of the inner space. The coiled section is rewound 
until the diameter of the inner space is slightly smaller than the 
cross-sectional diameter of the shaft, causing the coiled section to 
create impressions on the surface of the shaft, and allowing the apparatus 
to be firmly seated upon the shaft. The opposed end sections are then 
rotated to a desired radial position with respect to the coiled section. 
In a preferred embodiment, the fastening assembly is adapted for use with a 
relatively circular opening. The assembly includes hook-shaped tips 
defined by the opposed end sections, and spaced-apart by a distance 
greater than the diameter of the opening. The tips extend in a direction 
tangential to the coiled section and intersect a plane defined by the 
longitudinal axis of the shaft and the central axis of the opening. As the 
apparatus is fastened to the structural element and the tips of the two 
end sections are pushed into the opening in the structural element, the 
tips are deflected toward one another and the coiled section is forced to 
partially unwind until the tips are pushed completely through the opening, 
allowing the coiled section to rewind.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Preferred embodiments of an attachment apparatus for attaching an elongated 
shaft to a structural element are illustrated in the drawing figures. As 
shown in FIG. 8, the elongated shaft 12 defines a longitudinal axis, and 
the structural element 14 includes an opening 16 defined therein, 
extending through the structural element 14 in a direction generally 
perpendicular to the surface of the element 14. 
The shaft 12 has a relatively tubular construction, such as a conduit, with 
an interior space adapted for carrying a control linkage, such as a cable, 
as shown in FIG. 7. The control linkage connects a remote engine control 
with an engine, such as a lawn mower engine, allowing an operator to 
control the condition of the engine by manipulating the remote control. 
The frictional forces which result from pushing and pulling the cable 
through the shaft 12 require that the shaft 12 be rigidly attached to the 
structural element 14. 
As shown in FIG. 8, the structural element 14 presents a relatively flat 
surface, such as that presented by an engine shroud commonly found on a 
lawn mower. Alternatively, the structural element may present a relatively 
rounded surface, so long as an opening is provided in the element within 
which the apparatus may be received. 
As shown, for example, in FIG. 5, the attachment apparatus is configured to 
attach the elongated shaft to the structural element 14 and includes a 
helical coil of wire 20 having a central coiled section 22 and opposed end 
sections 24, 26 protruding from the coiled section 22. An inner space 28 
is defined by the coiled section 22 and is sized to grip the elongated 
shaft 12 and to prevent relative axial movement between the helical coil 
20 and the shaft 12 when the coil 20 is mounted on the shaft 12. A 
fastening means is defined by at least one of the end sections for 
fastening the apparatus to the structural element 14. 
There exist several embodiments of the attachment apparatus 10. With 
reference to FIGS. 1-9, a first embodiment 30 is fastenable to the 
structural element 14 which has a relatively circular opening 32, and 
includes a fastening means 34 having the opposed end sections 24, 26 
presenting hook-shaped tips 36, 38 spaced apart by a distance greater than 
the diameter of the circular opening 32. The opposed end sections 24, 26 
of the coil 20 extend in a direction generally tangent to the coiled 
section 22. As shown in FIG. 6, when the first embodiment 30 is fastened 
to the structural element 14 having the circular opening 32, the tips 36, 
38 intersect a plane defined by the longitudinal axis of the shaft 12 and 
the axis of the opening 32 in the structural element 14. 
The first embodiment 30 is mounted on the elongated shaft 12 in a two step 
process. First, as depicted in FIG. 3, the opposed end sections 24, 26 are 
rotated in a first direction so that the coiled section 22 unwinds, 
thereby increasing the diameter of the inner space 28 to a point where the 
diameter of the inner space 28 is slightly larger than the cross-sectional 
diameter of the shaft 12. The elongated shaft 12 is then inserted through 
the inner space 28 to a desired position relative to the first embodiment 
30 of the apparatus 
The second step is depicted in FIG. 4. Once the shaft 12 is placed in the 
desired position, the opposed end sections 24, 26 are rotated in a second 
direction to predetermined positions relative to each other so that the 
coiled section 22 is rewound, decreasing the diameter of the inner space 
28. Rotating the opposed end sections 26 to the predetermined positions 
decreases the diameter of the inner space 28 so that it is slightly 
smaller than the cross-sectional diameter of the shaft 12. This causes the 
coiled section 22 to create impressions on the surface of the shaft 12, 
allowing the first embodiment 30 to be permanently and firmly seated upon 
the shaft 
Once the rotational force exerted on the opposed end sections 24, 26 is 
removed, they take desired radial positions with respect to the coiled 
section 22, as depicted in FIG. 5. The other embodiments of the attachment 
apparatus 10 are mounted on the shaft 12 in substantially the same manner, 
therefore, the method of mounting the attachment apparatus 10 will not be 
discussed further. 
The ability to firmly mount the attachment apparatus 10 on the shaft 12 in 
a desired relationship relative to each other allows the shaft 12 to be 
accurately positioned on the lawn mower more quickly than the prior art 
fasteners. The ability to mount the apparatus 10 on the shaft 12 while 
having the shaft 12 extend through the apparatus 10 yields an accurate 
quick-mounting apparatus that may be used where the distance between the 
structural element 14 and the lawn mower engine is relatively large, 
thereby, preventing undesired buckling of the control cable. 
Each turn of the coiled section 22 represents an active coil. The number of 
active coils in the coiled section 22 is directly proportional to the 
firmness and rigidity with which the attachment apparatus be may be 
mounted on the shaft 12. Increasing the number of active coils also 
increases the amount the end sections 24, 26 must be rotated to enlarge 
the diameter of the inner space 28 so that the shaft 12 may be inserted, 
thereby, increasing the difficulty of mounting the attachment apparatus 10 
on the shaft 12. 
A coiled section presenting between three and seven active coils provides a 
satisfactory balance of this need for firmness, and ease of mounting. Each 
of the embodiments of the attachment apparatus 10 use substantially the 
same number of active coils, therefore, the number of active coils will 
not be discussed further. 
The diameter and material of the wire of the helical coil 20 is also an 
important aspect of the preferred attachment apparatus 10. For instance, 
as the diameter of the wire is increased, the elasticity of the wire is 
decreased, and as the diameter of the wire is decreased, the strength of 
the wire is decreased. Due to the need for rotating the end sections 24, 
26 to mount the attachment apparatus 10 on the shaft 12, the wire must be 
able to withstand the rotating while being sufficiently strong to attach 
the shaft 12 to the structural element 14 and withstand the vibrational 
forces exerted by the engine and longitudinal forces exerted by pushing 
and pulling the cable through the shaft 12. 
Music or piano wire having a diameter of between approximately 0.762 mm 
(0.03 inches) and 1.27 mm (0.05 inches) is suitable in providing a 
sufficiently elastic and yet strong wire from which to make the helical 
coil 20. Each of the embodiments of the attachment apparatus 10 use wire 
having substantially the same diameter, therefore, the size of the wire 
diameter will not be discussed further. 
Since the attachment apparatus 10 will be exposed to nature's elements, the 
wire must also be corrosion resistant. Zinc plating the piano wire through 
hydrogen imbrittlement, or black chromate plating the wire provides a wire 
that is sufficiently corrosion resistant. These processes do not 
substantially affect the elasticity nor the strength of the wire. Each of 
the embodiments of the attachment apparatus 10 use wire which is corrosion 
resistant, therefore, the corrosion resistance of the wire will not be 
discussed further. 
The first embodiment 30 is fastened to the structural element 14 having the 
circular opening 32 by inserting the tips 36, 38 through the circular 
opening 32. The tips 36, 38 are oriented so that as they are pushed 
through the circular opening 32, they are deflected toward one another in 
a direction forcing the coiled section 22 to unwind. The coiled section 22 
rewinds once the tips 36, 38 are pushed fully through the circular opening 
Such an orientation of the tips 36, 38 is important. If they were oriented 
so that the tips 36, 38 were deflected in a direction causing the coiled 
section 22 to wind tighter around the elongated shaft 12, too much force 
would be required to push the tips 36, 38 into the opening 32. 
Additionally, the tips 36, 38 would not fully return to their previous 
position relative to each other. This would yield the undesired result of 
having an apparatus which could not be easily inserted into an opening, 
but could possibly be pulled out of the opening, thereby not effectively 
attaching the shaft 12 to the structural element 14. 
A second embodiment 40 of the attachment apparatus 10 is depicted in FIGS. 
10-13. The second embodiment 40 is also fastenable to the structural 
element 14 having the circular opening 32. However, the second embodiment 
40 includes a fastening means 42 having the end section 24 of coil 20 
presented as an inverted U-shaped snap-hook 44 with a bowed-edge 46 and a 
width that is greater than the diameter of the circular opening 32. The 
end section 24 of the coil 20 extends in a direction generally radial to 
the coiled section 22 within a plane defined by the longitudinal axis of 
the shaft 12 and the axis of the opening 32 in the structural element 14. 
The second embodiment 40 is fastened to the structural element 14 having 
the circular opening 32 by pushing the snap-hook 44 through the opening 
32. As the snap-hook 44 comes into contact with the side walls 18 of the 
opening 32, the bowed-edge 46 is deflected, thereby compressing the 
snap-hook 44. Once inside the opening the snap-hook 44 re-expands. The 
shape of the bowed-edge 46 preferably allows the snap-hook 44 to removably 
fasten the second embodiment 40 to the structural element 14. However, the 
snap-hook may be formed in a shape that prevents removal. 
A third embodiment 48 of the attachment apparatus 10 is depicted in FIGS. 
14-17 and includes a fastening means 50 having the opposed end sections 
24, 26 of the helical coil 20 presenting hook-shaped tips 52, 54. When the 
third embodiment 48 is mounted on the shaft 12, the tips 52, 54 extend in 
a direction generally radial to the coiled section 22 within a plane 
intersecting the longitudinal axis of the elongated shaft 12. The tips 52, 
54 are spaced apart from each other so that the third embodiment 48 may be 
fastened to the structural element having the circular opening 32, or, 
alternatively, it may be fastened to a structural element 55 having an 
elongated opening 56. 
FIGS. 16 and 17 depict the third embodiment 48 fastened to structural 
element 55 having the elongated opening 56. The third embodiment 48 is 
fastened to the structural element 55 by inserting the hook-shaped tips 
52, 54 into the elongated opening 56, so that as the tips 52, 54 are 
pushed through the elongated opening 56, they are deflected toward one 
another in a direction along the longitudinal axis of the elongated shaft 
FIGS. 18-19 depict a forth embodiment 58 of attachment apparatus 10 which 
is fastenable to the structural element 55 having the elongated opening 
56, and includes a fastening means 60 having the opposed end sections 24, 
26 of the helical coil 20 presenting hook-shaped tips 62, 64. When the 
forth embodiment 58 is mounted on the shaft 12, the tips 62, 64 extend in 
a direction generally radial to the coiled section 22 within a plane 
intersecting the longitudinal axis of the elongated shaft 12. The 
hook-shaped tips 62, 64 are spaced apart from one another by a distance 
greater than the length of the elongated opening 
The forth embodiment 58 of apparatus 10 is fastened to the structural 
element 55 having the elongated opening 56 by inserting the tips 62, 64 
into the opening 56. As the tips 62, 64 are pushed through the elongated 
opening 56, they are deflected toward one another in a direction along the 
longitudinal axis of the shaft 
Although the invention has been described in the above preferred embodiment 
with reference to the illustrated figures, it is understood that 
substitutions may be made and equivalents employed herein without 
departing from the scope of the invention as set forth in the claims.