An adjustable clamp

An adjustable wiring harness clamp (10) including a base portion (16), a loop portion (18), and a clamp mechanism (14). The base portion (16) includes an opening (20) for inserting a fastener (22) in order to secure the clamp to a structure, and an opening (32) for receiving clamp mechanism (14). Loop portion (18) includes an inner surface (24), an outer surface (25), and a tapered free end (28). Outer surface (25) includes a groove (26) for receiving a band (36) of clamp mechanism (14). Groove (26) is contiguous opening (32). Adjustment of clamp mechanism (14) contracts loop portion (18) and reduces its size to accommodate smaller size harnesses.

TECHNICAL FIELD 
This invention pertains to wiring harness clamps, and more particularly, to 
flexible, adjustable lobe-type clamps for securing bundles of wires, 
cables or the like. 
BACKGROUND OF THE INVENTION 
In the manufacture of commercial airplanes, a large number of wires are run 
throughout the airplanes connecting various pieces of electronic 
equipment. Typically, the wires are run together in bundles to form a 
wiring harness, and the wiring harness is secured to the structure of the 
airplane by means of clamps. Federal Aviation Administration (FAA) 
regulations require wiring harnesses to be securely fastened within the 
clamps so that the individual wires of the harness are held firmly in 
close engagement with each other. This helps prevent damage to the wires 
caused by abrasion between the wires and their supports. 
Clamps for securing wiring harnesses and bundles of wires are generally 
well known. One type of such clamp is known as a P-clamp, which comprises 
a mounting bracket having a loop portion and two extensions extending from 
the ends of the loop portion. The extensions align with one another and 
have aligned openings for receiving a fastener for securing the clamp to a 
structure. The loop portion of the P-clamp is not adjustable and because 
of this, P-clamps are made in a variety of sizes to accommodate wiring 
harnesses of different sizes. 
With the P-clamp, because the mounting fastener is used to close the bundle 
of wires, individual wires cannot be added or removed from the clamp while 
the clamp is fastened to a structural member. In order to add or remove an 
individual wire or wires, the P-clamp must be demounted from the 
structure. Likewise, while a wiring harness is being created, the harness 
cannot be supported on the structural member by a P-clamp. If wires are 
added to or removed from a bundle, resulting in a change in the bundle's 
size, the P-clamp must be exchanged for one of different size. 
Another type of clamp is known as an "alligator clamp." An alligator clamp 
includes a flexible C-shaped loop portion and a base portion extending 
from the back side of the loop portion. The base portion is mounted to a 
structural member to secure the clamp. The ends of the C-shaped loop are 
spaced from each other for the addition or removal of wires from the 
clamp. The ends of the C-shaped loop are closed by a nylon wire tie, or 
the like. Although an alligator clamp can be mounted to a structural 
member without being closed, the loop portion of the alligator clamp is 
open completely when the nylon wire tie is not fastened thereto. This 
arrangement allows individual wires to fall out of the clamp as the wiring 
harness is being created and, subsequently, when wires are added to or 
removed from the clamp. 
Other types of clamps are disclosed by U.S. Pat. No. 3,169,005, of I. D. 
Wallach, entitled, "Resilient Sheet Material Bracket to Support Wires", 
issued Feb. 9, 1965; and U.S. Pat. No. 4,153,228, of Delserro et al, 
entitled, "Self-Tightening Clamp", issued May 8, 1979. The Wallach patent 
discloses a split sleeve wire bracket having a looped portion and a leg 
portion formed integrally from a sheet of plastic or other suitable 
material. The looped portion forms a complete circle to close on itself 
for securing a plurality of wire strands or cables. The bracket disclosed 
by this patent is not adjustable to accommodate wire bundles of varying 
diameter. 
The Delserro patent discloses a self-tightening clamp having a first, 
counter-clockwise curved portion and a second, clockwise curved portion, 
with the second curved portion encircling the first curved portion. The 
second curved portion has an extension, and the clamp is provided with a 
base, wherein the end portion of the base is adapted to be secured to the 
end portion of the extension. Securing of the extension to the base causes 
the second curved portion to contract the first curved portion, thereby 
reducing its diameter. Like the P-clamps, the clamp disclosed in the 
Delserro patent must be demounted in order to allow for the addition or 
removal of an article from within the first curved portion. 
Accordingly, the present invention is directed toward a wiring harness 
clamp that is adjustable in size and which provides for the easy addition 
or removal of wires from the clamp without the necessity of demounting the 
clamp, and which is designed to hold the wires in its unclamped mounted 
position. While the present invention is particularly well suited for 
clamping wiring harnesses, it is believed to have general utility for 
holding a variety of articles. Accordingly, it is not intended that the 
scope of the present invention be limited to wiring harnesses. 
DISCLOSURE OF THE INVENTION 
Briefly described, the present invention is an adjustable clamp for 
securing a bundle of wires or the like in close engagement, wherein the 
clamp comprises a base portion adapted for mounting to a structure, and a 
loop portion, including an inner surface, an outer surface, and a free 
end, extending from the base portion. The free end is adapted to engage 
the inner surface. The loop portion has sufficient flexibility so that the 
free end can be moved progressively inwardly of the loop in engagement 
with the inner surface thereof in order to contract the size of the loop, 
and can be moved away from the inner surface of the loop to create a gap 
for the insertion and removal of wires. The clamp also includes a clamp 
mechanism for securing around the outer surface of the loop portion in 
order to contract the size of the loop. 
The clamp mechanism is adjustable in order to selectively contract the size 
of the loop. The clamp mechanism can be progressively, incrementally 
tightened to contract the loop for smaller bundles of wires. The clamp 
mechanism is secured releasably around the loop portion and can be cut and 
removed from the loop portion in order to separate the free end of the 
loop portion from the inner surface. The clamp mechanism preferably is a 
nylon wire tie, which is relatively inexpensive and can be discarded after 
use. 
Preferably, the free end of the loop portion is tapered. This provides a 
smooth inner surface between the free end and the initial section of the 
loop. 
According to an aspect of the invention, the base portion includes an 
opening through which the clamp mechanism is adapted to extend. The 
opening allows the clamp mechanism to extend around the loop portion past 
the base portion. 
Preferably, the clamp mechanism includes a band and an incrementally 
adjustable lock mechanism, and the outer surface of the loop portion 
includes a groove for receiving the band and restraining lateral movement 
of the band with respect to the loop portion. 
The free end of the loop portion can be moved away from the inner surface 
of the loop to create a gap with the base portion mounted to the 
structure. This allows for the addition or removal of wires from the loop 
portion without having to demount the clamp. 
According to an alternative embodiment of the invention, the outer surface 
portion adjacent the free end of the loop portion includes a ridge, and 
the inner surface portion adjacent the base portion includes a groove for 
receiving the ridge. The ridge and groove are adapted to restrain lateral 
movement of the free end with respect to the inner surface. 
These and other advantages and features will become apparent from the 
following detailed description of the best mode for carrying out the 
invention and the accompanying drawings, and the claims, which are 
incorporated herein as part of the disclosure of the invention.

BEST MODE FOR CARRYING OUT THE INVENTION 
Referring to FIG. 1, the adjustable clamp 10 of the present invention 
includes a mounting bracket 12 and a clamp mechanism 14. The mounting 
bracket 12 includes a base portion 16 and a loop portion 18. The base 
portion 16 is substantially flat along its length and includes an opening 
20 for receiving an eyelet 21 and a fastener 22. Eyelet 21 is held 
securely within opening 20. Fastener 22 secures mounting bracket 12 to a 
structural member such as, for example, a stringer forming part of the 
structural frame of the fuselage of an aircraft. 
The loop portion 18 of mounting bracket 12 is formed integral with base 
portion 16, and mounting bracket 12 is made of a single sheet of plastic 
or other suitable material that will retain its shape, as shown. The 
mounting bracket 12 is formed by any process suitable for the material 
chosen. For plastic, the mounting bracket 12 can be, for example, 
injection molded or heated and shaped in a mandrel, or stamped and 
subsequently coldworked. 
Loop portion 18 includes an inner surface 24 and an outer surface 25. Outer 
surface 25 includes a central groove 26 extending around its perimeter. 
Central groove 26 is sufficiently wide to accommodate clamp mechanism 14. 
The free end 28 of loop portion 18 tapers to a narrow leading edge 30. 
This provides a substantially smooth inner surface 24 between free end 28 
and the initial section 31 of loop portion 18. 
A rectangular opening 32 is formed in the base portion 16 adjacent the 
initial section 31 of loop portion 18. Opening 32 is contiguous with 
groove 26. Opening 32 provides a passage for clamp mechanism 14 around 
loop portion 18 past base portion 16. 
Clamp mechanism 14 can be any type of clamp mechanism adapted to engage 
loop portion 18 and contract the loop portion and thereby reduce its 
diameter or size. Preferably, clamp mechanism 14 is a nylon wire tie 
including a band 36 and a lock mechanism 38. Band 36 includes a series of 
incremental ridges (not shown), and lock mechanism 38 includes a pawl 
mechanism housed within an opening 39 through which band 36 extends. The 
pawl mechanism engages the ridges on the band 36 so as to lock the clamp 
mechanism in a closed position. Clamp mechanism 14 can be reduced in size 
by pulling band 36 through lock mechanism 38, but it cannot be expanded in 
size due to the pawl mechanism. 
FIG. 2 shows the adjustable clamp 10 assembled. Clamp mechanism 14 is 
secured around loop portion 18 with band 36 of clamp mechanism 14 received 
within groove 26 on the outer surface 25 of loop portion 18. Groove 26 
prevents band 36 from sliding laterally off of the outer surface 25 of 
loop portion 18. Band 36 also extends through opening 32 in base portion 
16. The free end 28 of loop portion 18 engages inner surface 24 of loop 
portion 18, thereby forming a closed loop. 
As shown in FIG. 3, adjustable clamp 10 is shown in a closed, clamped 
position with a wiring harness 40 securely held by loop portion 18 such 
that the individual wires of wiring harness 40 are held in close 
engagement with each other. The clamp 10 is secured to a structure 50 by 
means of fastener 22. Preferably, mounting bracket 12 is secured to 
structure 50 with base portion 16 in an upright position, as shown. This 
configures loop portion 18 so that it supports wires 40 when loop portion 
18 is opened, as discussed later. 
Should a wiring harness of smaller dimension be carried by adjustable clamp 
10, as shown in FIG. 4, clamp mechanism 14 can be tightened so that the 
free end 28 of loop portion 18 moves progressively inwardly of the loop 
portion in engagement with the inner surface 24, thereby contracting the 
size of loop portion 18. In this manner, a wiring harness 42 of smaller 
size than wiring harness 40 can be held securely within loop portion 18, 
as is the larger size wiring harness 40 of FIG. 3. This arrangement allows 
for the provision of a smaller inventory of clamp sizes to accommodate a 
range of wiring harness sizes. 
Preferably, the mounting bracket 12 is made of a material having sufficient 
flexibility and resiliency to allow the size of loop portion 18 to be 
adjustable within a range of sizes. For many types of material, the free 
end 28 of loop portion 18 will be able to extend inwardly of the loop to a 
point corresponding with point 46 upon full tightening of clamp mechanism 
14. This degree of contraction of loop portion 18 corresponds to 
approximately a 20% to 30% reduction in the diameter of the loop portion 
18. For some materials, a greater degree of contraction may be achievable. 
FIG. 5 shows the mounting bracket 12 secured to a structural member 50 by 
means of screw 22. The clamp mechanism 14 is shown being cut away from 
mounting bracket 12 by means of a cutting device 52. Removal of clamp 
mechanism 14 provides access to the wiring harness 40 held by loop portion 
18. Upon removal of clamp mechanism 14, application of a force to the free 
end 28 of loop portion 18, as indicated by arrow 56, moves the free end 28 
away from the inner surface 24 of loop portion 18 and creates a gap 
therebetween for insertion and removal of wires 58, as indicated by arrows 
60. Upon the removal or addition of wires, free end 28 is released, and 
its natural resiliency brings it back into engagement with inner surface 
24, thereby closing loop portion 18. To tighten loop portion 18, a new 
clamp mechanism is extended around loop portion 18, through opening 32, 
and into groove 26 extending around the perimeter of loop portion 18. The 
new clamp mechanism is tightened so that loop portion 18 contracts around 
the wiring harness 40 to the point where the wires are held in close 
engagement with each other. 
Accordingly, a wiring harness clamp is provided that does not have to be 
demounted in order to add or remove wires from the clamp. The 
easily-removable and disposable clamp mechanism provides access to the 
loop portion. In addition, when loop portion 18 is opened, as shown in 
FIG. 5, the wiring harness does not tend to fall out of the loop. The 
opening in loop 18 is created above the wires. 
FIGS. 6 and 7 illustrate an alternative embodiment of the present 
invention. In FIG. 6, a ridge 62 is provided along the outer surface 25 of 
loop portion 18 at the free end 28 of loop portion 18. Ridge 62 extends 
centrally along the free end 28 for a portion of its length and terminates 
at point 64. At point 64, ridge 62 tapers to become flush with surface 25. 
The inner surface 24 of loop portion 18 and a portion of base portion 16 
are provided with a corresponding groove 66, which extends centrally for a 
short length along loop portion 18. Ridge 62 and groove 66 are designed to 
engage in a tongue-and-groove arrangement, which prevents lateral movement 
of free end 28 with respect to inner surface 24. FIG. 7 illustrates the 
tongue-and-groove arrangement of ridge 62 and groove 66. The natural 
resiliency of loop portion 18 biases ridge 62 into groove 66 and maintains 
the tongue-and-groove arrangement therebetween. As can be seen in FIG. 7, 
ridge 62 is restrained from lateral movement, as indicated by arrow 68. 
The general resiliency of mounting bracket 12 should keep free end 28 from 
becoming displaced laterally out beyond the lateral side edges of loop 
portion 18 without the provision of ridge 62 and groove 66. However, for 
certain mounting bracket materials and certain applications, provision of 
ridge 62 and corresponding groove 68 may be advisable. 
Accordingly, it can be seen that a wiring harness clamp is now provided 
that is adjustable, provides for easy addition or removal of wires while 
the clamp is mounted to a structure, and supports the wires when the clamp 
is in an open position. 
It is to be understood that many variations in size, shape, and 
construction can be made to the illustrated and above-described embodiment 
without departing from the spirit and scope of the present invention. Some 
of the features of the preferred embodiment may be utilized without other 
features. Therefore, it is to be understood that the presently described 
and illustrated embodiment is non-limitive and is for illustration only. 
Instead, my patent is to be limited for this invention only by the 
following claim or claims interpreted according to accepted doctrines of 
claim interpretation, including the doctrine of equivalence and reversal 
of parts.