Cable protector

A cable protector for insertion into the open end of a duct or conduit for preventing a cable pulled therethrough from being damaged by the edges of the duct or conduit. The cable protector has a substantially C-shaped cross-section and includes a turned-over lip which encapsulates the end of the duct and prevents the cable protector from being pulled into the duct or conduit. A groove at the juncture of the lip and a curved transitional portion facilitates folding of the cable protector to allow insertion thereof into a variety of sizes of ducts or conduits. Ribs located on the external surface of the body of the cable protector ensures a substantially tubular configuration of the protector after its diameter has been reduced to fit into the intended duct or conduit. The inside surface of the cable protector may be textured to minimize friction.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to devices for protecting cable as it is pulled 
through a duct or conduit. 
2. Description of Related Art 
In those instances where cable or wires must be run through a concrete, 
plastic or metal duct, or a conduit or pipe, a device commonly referred to 
as a cable protector is often placed at the open end of the duct or 
conduit for the purpose of protecting the integrity of the cable as it is 
pulled into the duct or conduit. Indeed, the rough edge of a duct or 
conduit can often damage the cable, rendering it inoperative or useless. 
Generally, these cable protectors have comprised a rounded split piece of 
semi-rigid, semi-flexible material (such as plastic) of a uniform 
thickness which is folded over to form a tubular-like shape capable of 
fitting into the open end of the duct or conduit. These cable protectors 
are equipped with a smooth flanged end whose purpose is to protect the 
cable or wires from having contact with the end of the duct or conduit as 
the cable is pulled therethrough. A typical prior art cable protector of 
this type is known as the "Leaderguard" brand (types 345, 800, 225 and 
400) manufactured by Virginia Plastics Company, Inc. of Roanoke, Va. 
A major difficulty with the cable protectors which are presently in use is 
that, as the cable protector is folded over for placement into the duct or 
conduit, the flanged end of the protector turns inwardly and upwardly. 
That is, the more the cable protector is folded over to create a smaller 
tubular configuration, the more the flanged end turns inwardly and 
upwardly. If folded over enough, the flanged end would disappear 
completely. This creates the likely possibility of the cable protector 
being pulled into and lost inside of the duct or conduit as wires or cable 
are pulled therethrough. 
In addition, since the present cable protectors are designed to be of a 
uniform thickness throughout, a centerline is created as the cable 
protector is folded over for insertion into a duct or conduit. This 
centerline is naturally stressed more than the other areas of the cable 
protector on each side of the centerline. Thus, the cable protector may 
fracture along the centerline rendering the cable protector useless. The 
creation of the centerline fold also prevents the cable protector from 
having the substantially tubular configuration of the duct or conduit in 
which it is placed. Thus, the cable protector may encounter some 
difficulty in being inserted into the duct or conduit. 
Further problems encountered with the cable protectors currently in use is 
that the smooth polished outside surface of the cable protector may be 
scratched or cut due to a sharp edge or burr. This creates a potential 
point of fracture, particularly in cold or dry conditions. Also, current 
cable protectors are provided with a smooth polished inside surface. This 
smooth surface can create additional surface friction as cable is drawn 
therethrough, potentially causing damage to some insulations on the cable. 
OBJECTS AND SUMMARY OF THE INVENTION 
It is therefore a primary objective of the present invention to provide a 
cable protector which will not be entirely pulled into a conduit or pipe 
as cable or wire is pulled therethrough. 
Another object of the present invention is to provide a cable protector 
which has a more uniform circular fold or tubular configuration when 
inserted into a duct or conduit. 
A still further object of the present invention is to provide a cable 
protector in which the problem of fractures in the smooth polished surface 
are reduced. 
A still further objective of the present invention is to provide a cable 
protector which will decrease surface friction as cable or wire is fed or 
pulled across the cable protector. 
The foregoing and other objects are achieved in accordance with one aspect 
of the present invention by use of a cable protector for insertion into a 
duct or conduit having an open end comprising a body portion, a lip 
portion, and a transitional portion between the body portion and the lip 
portion. The cable protector also includes an inside surface, an outside 
surface, and means for preventing the cable protector from being pulled 
entirely into the duct or conduit. The body portion of the cable protector 
has a curved configuration. The transitional portion extends outwardly in 
an arch formation between the body portion and the lip portion. The lip 
portion of the cable protector extends outwardly and downwardly from the 
transitional portion. 
In accordance with another aspect of the present invention, the means for 
preventing the cable protector from being pulled into the duct or conduit 
comprises means for encapsulating the open end of the duct or conduit. The 
cable protector further comprises means for facilitating the flexing of 
the lip portion. The means for facilitating the flexing of the lip portion 
comprises groove means between the lip portion and the transitional 
portion on the outside surface of the cable protector. 
In accordance with another aspect of the present invention, the lip portion 
preferably folds downwardly and inwardly upon insertion of the cable 
protector into a duct or conduit. The means for encapsulating the open end 
of the duct or conduit comprises the folded lip portion together with the 
transitional portion. 
In accordance with still another aspect of the present invention, the cable 
protector may include an inside surface which is textured. 
In accordance with yet another aspect of the present invention, there is 
provided a cable protector for insertion into a duct or conduit having an 
open end which includes a body portion having a curved outside surface and 
a lip portion. The body portion preferably has means for ensuring a 
substantially tubular configuration when the cable protector is placed in 
the duct or conduit. 
In accordance with still another aspect of the present invention, the cable 
protector preferably further includes means for gripping tightly to the 
interior surface of the duct or conduit, which may be irregularly shaped. 
The means for ensuring a substantially tubular configuration preferably 
comprises rib means formed on the curved outside surface of the cable 
protector. The means for allowing the cable protector to grip tightly to 
the duct or conduit also may comprise the rib means formed on the curved 
outside surface of the cable protector. The rib means may comprise a 
plurality of elongated protrusions on the outside surface of the body 
portion. 
In accordance with other aspects of the present invention, the rib means 
may comprise alternating thick wall portions and thin wall portions formed 
on the curved outer surface of the body portion. The thick and thin wall 
portions may be oriented either vertically or horizontally on the curved 
outer surface with respect to the longitudinal axis of the body portion. 
In one embodiment, the rib means may be, for example, V-shaped. 
In yet another embodiment of the present invention, the rib means may 
comprise a plurality of bands of varying thickness positioned 
substantially horizontally on the curved outer surface. The bands may 
include a thickest band positioned closest to the lip portion and a 
thinnest band positioned farthest away from the lip portion. The bands are 
of preferably a progressively decreasing wall thickness from the thickest 
band to the thinnest band.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring now to the drawings, there is illustrated in FIG. 1 a perspective 
view of a cable protector 10 constructed in accordance with a preferred 
embodiment of the present invention. Cable protector 10 comprises a single 
piece of semi-rigid, semi-flexible material formed in a curved 
configuration, somewhat C-shaped in cross-section. The cable protector 
material may consist of a plastic such as polyamide, polypropylene, 
polyester, polyethylene, thermoplastic rubber, or even rubber. Cable 
protector 10 includes an inside surface 12 which is concave and an outside 
surface 14 which is convex. The outermost boundaries of cable protector 10 
are generally defined by an upper edge 16, a lower edge 17, and two 
opposed lateral edges 18 and 19. 
Generally, with reference to FIGS. 1 and 8 which illustrate the invention 
in repose, prior to use, cable protector 10 comprises a curved, 
semi-cylindrical body portion 20. At the upper end of body portion 20, 
extending outwardly, away from the longitudinal axis of body portion 20, 
is a curved, arch-like transitional portion 30. In accordance with one 
aspect of the present invention, a substantially planar lip portion 40 
extends outwardly and downwardly (as viewed in FIGS. 3 and 8) from 
transitional portion 30. A groove 42 is preferably formed between 
transitional portion 30 and lip portion 40 to facilitate flexing of the 
latter with respect to the former. 
In order to place cable protector 10 into a duct or conduit, the cable 
protector is folded or curled over so that lateral edges 18 and 19 are 
brought towards each other, as illustrated in FIG. 5. By curling over 
cable protector 10 in this manner, a substantially tubular configuration 
is formed. Lateral edge 18 need not precisely meet lateral edge 19 when 
protector 10 is curled over. Rather, lateral edge 18 may be curled over 
and past lateral edge 19 so as to form a tubular structure which is small 
enough in diameter to fit within the desired duct or conduit. 
Upon curling cable protector 10, lip portion 40 will fold downwardly and 
inwardly towards body portion 20 as shown in FIGS. 4 and 9, due to the 
placement of groove 42 between lip portion 40 and transitional portion 30. 
Generally, lip portion 40 will fold over to the greatest extent in the 
area of a midpath point 56 (see FIG. 5)of the protector. Also, at point 56 
transitional portion 30 will extend in an upwardly ad inwardly direction 
relative to its position before protector 10 is curled. The folding over 
of lip portion 40 becomes less and less pronounced towards the peripheral 
edges 58a and 58b of cable protector 10. 
As shown in FIGS. 6 and 7, upon insertion of cable protector 10 into a duct 
or conduit 52, folded lip portion 40 together with transitional portion 30 
encapsulates an open end 54 of a duct or conduit 52. This prevents cable 
protector 10 from being pulled entirely into duct or conduit 52 as wires 
or cable are fed through the duct or conduit. Groove 42 may also act to 
stop cable protector 10 from being pulled into duct or conduit 52 by 
abutting open end 54 of the duct or conduit as cable protector 10 is 
pulled therein. 
Referring once again to FIG. 1, outside surface 14 of body portion 20 may 
include a plurality of ribs 22 which preferably comprise alternating thick 
and thin wall portions extending from the area of lower edge 17 of 
protector 10 to transitional portion 30. Forming naturally between ribs 22 
on outside surface 14 are channels 24. Ribs 22 comprise the thick wall 
portions, while channels 24 comprise the thin wall portions. In an 
alternate embodiment seen in FIG. 2, ribs 22 may be extended on outside 
surface 14 to terminate at groove 42. 
The placement of ribs 22 on outside surface 14 of body portion 20 creates a 
more uniform circular or tubular configuration when cable protector 10 is 
curled to be inserted into duct or conduit 52. This not only allows cable 
protector 10 to fit more securely in duct or conduit 52, but also inhibits 
the creation of a stressed center line which could cause a fracture in the 
cable protector. 
Inside surface 12 of cable protector 10 may be finished with a textured or 
stippled surface. This decreases the friction which is created by the 
pulling of cable wires over the cable protector, causing less damage to 
both the wires and the cable protector. It also decreases the likelihood 
that the interior surface will be fractured due to a sharp edge or burr. 
Referring now to FIG. 10, there is illustrated an alternate embodiment of 
the present invention which comprises a cable protector without the inside 
surface texture or groove-lip features of the first embodiment described 
above. In the embodiment of FIG. 10, the upper edge 60 terminates 
transition portion 30 short of the area where a groove and lip would be 
formed. In this manner, the general shape of the cable protector of FIG. 
10 is similar to that of the prior art Leaderguard described in the 
related art section of this application. The cable protector of FIG. 10 
does, however, include ribs 22 and channels 24 which function as 
above-described to allow the product to flex more uniformly. 
Referring now to FIG. 11, there is illustrated yet another alternate 
embodiment of a cable protector which includes a groove 42 and fold-over 
lip portion 40, but does not have any rib-like structure on its outer 
surface 20. Inside surface 12 may be provided with texture 12 as desired. 
FIGS. 12 and 13 show another embodiment of the present invention which uses 
a plain inside surface 12, a groove 42 and fold-over lip portion 40. 
Outside surface 14 has located thereon alternating V-shaped ribs indicated 
generally by reference numeral 64. V-shaped ribs 64 comprise relatively 
thick wall portions 66 and relatively thin wall portions 68. This 
variation in wall thickness allows the cable protector to flex more 
uniformly (there is greater flexibility near lower end 17 than upper end 
16), and facilitates form-fitting of the protector to the interior of the 
piece of duct or conduit in which it is installed. The configuration of 
ribs 64 in this embodiment makes it clear than many different thick and 
thin rib configurations would suffice to perform the function of the 
present invention. 
Referring now to FIGS. 14 and 15, there is illustrated yet another 
embodiment of the present invention wherein the outer surface includes rib 
portion 70 that is substantially horizontal. Ribs 70 are shown upon a 
cable protector which has no lip or groove (like FIG. 10), but does 
include an optional texture on its inside surface 12. Ribs 70 comprise 
alternating thick wall portions 72 and thin wall portions 74. This 
embodiment also provides a more uniform curvature of the cable protector 
as a result of elimination of the tendency to bend along the thin wall 
portions of vertically oriented ribs. Although the thick and thin wall 
portions 72 and 74 are shown in an alternating configuration and having 
about the same width, clearly other configurations are possible. 
FIGS. 16 and 17 illustrate a still further embodiment of the present 
invention wherein the outside surface 14 of the cable protector is 
provided with a "stairstep" type of rib configuration which is indicated 
generally by reference numeral 80. Ribs 80 are oriented horizontally, and 
progressively decrease in thickness from the top rib 82 to the bottom rib 
84. In other words, top rib 82, which is closest to groove 42 and lip 40, 
has the thickest wall, while bottom rib 84, positioned farthest away from 
rib 82, has the thinnest wall. Thick wall rib 82 provides the strongest 
support for the groove-lip structure and is therefore closest to it. Thin 
wall rib 84, being farthest away from the groove-lip structure, can be 
much thinner. Of course, stairstep ribs 80 need not be of equal width, nor 
do they need extend strictly horizontally. Obviously, numerous 
modifications and variations of the present invention are possible in 
light of the above teachings. It is therefore to be understood that within 
the scope of the appended claims, the invention may be practiced otherwise 
than as specifically described herein.