UNDERCARPET CABLING FIXTURE

Abstract: A fixture (10) for elongated members (14, 16) of an undercarpet cable (12) comprises a web (26), elongated edge margins (34, 36) connected to the web (26), and channels (28, 30) in the web (26) for supporting the elongated members (14, 16) along an arcuate route for the undercarpet cable (12), the channels (28, 30) extend along a surface of the web (26) and are curvilinear along their lengths, and adjacent channels (28, 30) are spaced apart with varying distances therebetween.

Description: UNDERCARPET CABLING FIXTURE The invention relates to a fixture for signal transmission membeYs of an undercarpet cable, and specifically, a fixture which provides individual curvilinear channels that support and route the corresponding signal transmission members free from stress as the cable follows along a curved route. Undercarpet cable is a flat, signal transmission cable with a web containing one or more signal transmission members in the form of electrical conductors or optical fibers that convey power or communications signals. The cable may also contain strengthening members, also called stress-bearing members , extending parallel to the signal transmission members. The cable is laid along a prescribed route against a floor of a building . Carpet is laid on the floor to cover the floor and the cable. Thus , signal transmission cable which is suitable for routing against a floor to be covered by a carpet is called undercarpet cable. There is a requirement to avoid tension or compression stresses from being applied to the signal transmission members, thereby to avoid distortion or other damage. Such stresses are difficult to avoid , for example, when undercarpet cable follows along a curved route, since portions of the cable nearer an axis of curvature are placed in compression , and portions of the cable farther from the axis of curvature are placed in tension. U . S. Patent 4,419,538 discloses elongated stress-bearing members and a single electrical conductor within a jacket of an undercarpet cable. The stress-bearing members are free to move longitudinally with respect to the jacket to relieve stretching or compression stresses which might be transmitted to the electrical conductor. A disadvantage is that the stress-bearing members tend to emerge or retract with respect to an end of the jacket. A further disadvantage is that the stress-bearing members are subject to constraint by the cable to maintain constant parallel spacing from one another. If the cable follows along a curved route having a relatively small radius of curvature, the stress-bearing members are subjected to stretching or compression stresses due to their constraint by the cable or due to or due to the individual stress-bearing member being 'bent with an excessively short radius of curvature. British Published Specification Number 24,533 , November 14, 1908, discloses a fixture in which unsevered lengths of conductors are routed in arcuate channels. One of the conductors is in a zig-zag route from one side of a channel to the other side of the channel. The channel does not restrain the conductor from being subject to an excessively short radius of curvature along the zig-zag route. According to the invention , a fixture for signal transmission members of an undercarpet cable provides individual curvilinear channels that support and route corresponding signal transmission members free from stress as the cable follows along a curved route. The channels alternatively may support and route strengthening members of an undercarpet cable. Thus, signal transmission members and strengthening members of an undercarpet cable are collectively called elongated members. The elongated members, which first are separated from the confines of the cable, are supported along respective channels. The outer most channel farthest from the axis of curvature of a curved route of the cable is arcuate along its length . Each additional channel is sinuous along its length and may project toward or away from the adjacent channel. One advantage of the invention is that the elongated members are unsevered as the cable follows along a curved route. Another advantage is that none of the elongated members supported by the fixture are shortened in length or bent with an excessively short radius of curvature. Thus, the signal transmission members have equal transmission path lengths. Another advantage is that the . elongated members are not constrained to remain parallel to one another and are spaced apart by the channels with varying distances therebetween , thereby enabling the cable to follow along a curved route having a relatively small radius of curvature. A fixture, according to the invention , comprises , a web, elongated edge margins connected to the web, and channels in the web for supporting elongated members of an undercarpet cable along an arcuate route for the undercarpet cable, characterized in that; one of the channels is arcuate along its length and each additional channel is sinuous along its length. The invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is a perspective view of the subject fixture with a prepared undercarpet cable exploded therefrom; Figure 2 is a perspective view , similar to Figure 1 , with the cable in place in the subject fixture; Figure 3 is a top plan view of the subject fixture with the cable in place; and Figure 4 is a section through the subject fixture taken along line 4-4 of Figure 3. A fixture 10 is shown in the drawings in conjunction with an undercarpet cable 12 having two elongated members 14, 16 , which are optical fibers. The optical fibers 14, 16 are carried in a central web 32 with tapered marginal flanges 34, 36 to each side of the central web. Such cable is of well-known design and need not be discussed in further detail. The fixture 10 will receive the elongated members of the cable and provide both support and protection for the elongated members throughout the length of the turn. The fixture is a formed rigid member defining at least two tracks between an inlet and an outlet spaced apart in a plane and angularly offset with respect to each other. One of the tracks defines an arcuate path. Each subsequent track is radially inwardly spaced from the arcuate track and defines a curvilinear path of equal length to the length of the arcuate outer path. The fixture 10 can be utilized with undercarpet cables of various forms , for example, cables carrying electrical conductors of single strand , multiple strand or carrying coaxial configurations or carrying strengthening members. Further, the fixture 10 is not restricted to the number of fibers , conductors or strength members, which can be handled by the fixture. The fixture 10 is a rigid member, preferably of insulative plastic material , which can be molded or machined . The fixture 10 has a low, rather flat, transverse profile with an entry end 18 and an exit end 20 angled with respect to each other in the plane of the fixture to define a generally arcuate member. The fixture has an outer arcuate tapered shoulder 22 and an inner curvilinear tapered shoulder 24 on opposite sides of a profiled central web 26. The central web includes a curvilinear, arcuate outer track or channel 28 and at least one inner curvilinear track or channel 30. The overall curvilinear lengths of the channels 28 and 30 are equal or identical . The inner track or channel 30 preferably is formed by a plurality of connected curvilinear segments. The end-most segments curve inwardly in a direction to separate the tracks or channels 28, 30 transversely and to facilitate molding of the fixture 10. An arcuate intermediate segment is connected to the end-most segments. The inner channel or track configuration need not be truly a sinusoidal configuration but is sinuous and simulates a sinusoidal appearance. It should be noted that, if there are additional inner tracks or channels , each would be inwardly and transversely spaced from the track or channel 30 and would differ only by the radiuses and dimensions forming the various segments. Each such additional track or channel would still have the requirement of having a total linear length equaling the linear length of the outer channel 28. The present invention is utilized by first preparing a length of the cable 12 as shown in Figure 1 . The tapered marginal flanges 34, 36 are removed and much of the central web 32 is also removed to leave only portions 38 , 40 of the web 32 which carry the elongate members 14, 16. The portions 38 , 40 are then placed in respective tracks 28 , 30 of the fixture 10 , as shown in Figures 2 and 3 , and are preferably secured in place by the application of an adhesive tape 42. It will be noted from Figure 2 that it is not critical that the length of cable prepared be exactly the length of the fixture. A cable is prepared by stripping the tapered marginal flanges and central web of said cable to free the elongate members carried thereby. Then the fixture 10 is utilized by, placing the freed elongate members into individual tracks in the fixture 10 and by securing said cable at the ends of said fixture. The fixture 10 has an entry end and an exit end angularly offset with respect to each other and having respective profiles similar to the transverse profile of the cable 12. The first arcuate track 28 formed in said fixture extends from said entry end (18) to said exit end (20) . At least one second track 30 formed in the fixture radially inwardly of said arcuate track 28 has a curvilinear length between said entry and said exit ends (18 , 20) such that the overall length of each said second track 30 equals that of said arcuate track 28. The fixture 10 has tapered marginal portions 22 and 24 to each side of said fixture 10 whereby the transverse profile of the cable is approximated throughout the fixture. It should also be noted that the present example is shown making a 90 degree turn . The present invention is not restricted to any particular angle and could be more or less than 90 degrees as the situation determines. For example, the entry and exit ends of said fixture 10 may be angled 45 degrees with respect to each other. The subject fixture 10 may be provided with hold down means (not shown) or can be secured in place by means of adhesives (also not shown) .

Claims: CLA1 S: . 1 . A fixture for elongated members of an undercarpet cable 'comprises, a web , elongated edge margins connected to the web , and channels in the web for supporting the elongated members along an arcuate route for the undercarpet cable, characterized in that; the channels (28, 30) extend along a surface of the web (26) and are curvilinear along their lengths, the curvilinear length of each channel (28 , 30) is equal to the curvilinear length of a corresponding elongated member (14, 16) supported in the corresponding channel (28 , 30) , and adjacent channels (28 , 30) are spaced apart with varying distances therebetween . 2. A fixture for elongated members of an undercarpet cable as recited in claim 1 , wherein one of the channels (28 , 30) is arcuate along its length and each additional channel (30) is sinuous along its corresponding length. 3. A fixture for elongated members of an undercarpet cable as recited in either of claims 1 or 2, wherein the channels (28, 30) extend from a first end (18) of the fixture (10) to a second end (20) of the fixture (10) , and the second end (20) is angularly offset in the plane of the fixture (10) from the first end (18).. 4. A fixture for elongated members of an undercarpet cable as recited in either of claims 1 , 2 or 3 , wherein the curvilinear lengths of the channels (28, 30) are equal . 5. A fixture for elongated members of an undercarpet cable as recited in either of claims 1 , 2 , 3 or 4, wherein the transverse profile of the fixture (10) approximates that of the cable (12) . 6. A fixture for elongated members of an undercarpet cable as recited in either of claims 1 , 2 , 3 , 4 or 5 , wherein the elongated members ( 14, 16) are optical fibers.

Inventors: BOWEN PATRICK TERRY, BOWEN, PATRICK, TERRY
Applicants: AMP INC, AMP INCORPORATED
Application year: 1985
Main classification: H02G3
IPC codes: H02G3