SPECIFICATIONPad-type fiber optic splice organizerBackground of the inventionThis application relates to the art of assembly fixtures and, more particularly, to an assembly fixture for organizing cable splices. The invention finds particular use in conjunction with splicing fiber optic cables and will be described with particular reference thereto. It is to be appreciated, however, that the invention has broader applications, and that at least certain features thereof may be utilized with other types of cables, including metallic wires, flexible waveguides, and the like.
The extremely small diameter of optic fibers enables fiber optic cables to contain a large number of individual fibers. When fiber optic cables are spliced, the individual fibers are separated from each other and connected to corresponding fibers of another cable. Unlike metal wires, optic fibers do not hold a bent or deformed orientation, and it is, therefore, more difficult to organize the fibers for splicing. As individual fibers and groups of fibers are separated from the cable, some arrangement is commonly provided for holding these individual fibers and groups in the separated arrangement. After the splicing is completed, it is common to enclose the splice in a splice case for protection and for strain relief.It is desirable that the individual fibers be held firmly within the splice case to inhibit movement and vibration of the individual splices which would degrade transmission characteristics therethrough.
In accordance with the present invention, an organizer apparatus is advantageously provided for organizing optic fibers during splicing and for holding the completed splice against movement.
Brief description of the inventionIn general, the subject new organizer apparatus includes a generally planar base surface which supports a plurality of flexible leaves. A leaf mounting means mounts the flexible leaves to the base surface in a generally book-like arrangement.
This arrangement conveniently enables the leaves to be flexed upwardly from the mounting means to receive splice connections therebetween.
In accordance with the invention, the individual leaves are of a soft, resilient material constructed from a synthetic polymer. The leaves include opposed, cooperable strips of hook and loop fastening fabric. These hook and loop fabric strips enable the leaves to be selectively interconnected with the spliced optic fibers received therebetween. Leaf holddown means are provided for holding the leaves in a generally parallel relationship analogous to a closed book to, in turn, retain the splices in located position.
In accordance with another aspect of the invention, a fiber optic cable splice containing apparatus is provided which includes a splice case, a main frame assembly, and a splice enclosure assembly.
The splice case includes a pair of end plates which are each adapted to receive at least one cable which is to be spliced. A plurality of torque bars extend between the end plates to maintain them in a fixed, spaced relationship. The main frame assembly includes a mounting means for mounting the assembly on the torque bars and a cable receiving means for receiving ends of the cables to be spliced. The splice enclosure assembly is mounted on the main frame assembly to enclose the splices therein.
According to a more limited aspect of the invention, the main frame assembly is connected to the torque bars by means of retainer clips. An elongated socket strip and an elongated male strip are adapted to be fit together, and are mounted on the main frame assembly and on each retainer clip. In this manner, the retainer clips may be conveniently attached to the main frame assembly.
According to a more detailed aspect of the invention, the splice enclosure assembly includes a generally planar base surface having a pair of side walls upstanding from the opposed side edges thereof. The plurality of flexible leaves are located on the base surface between the side walls. A leaf mounting means comprised of a plurality of posts disposed at spaced intervals adjacent one of the side walls facilitates mounting the leaves to the base surface in a book-like arrangement. With this mounting, the leaves are adapted to be opened like a book about the mounting posts for receiving a plurality of fiber splices therebetween.
A principal benefit of the present invention is the provision of an improved organizer apparatus for splicing fiber optic cables and the like.
Another benefit resides in the provision of such an apparatus which is economical to manufacture and simple to use in the field.
A further benefit of the invention is the provision of an apparatus for organizing individual fibers and groups of fibers during a splice and for securely holding the spliced fibers against movement after the splice is completed.
Still further benefits and advantages of the invention will become apparent to those of ordinary skill in the art upon a reading and understanding the following detailed description of the preferred embodiment.
Brief description of the drawingsThe invention may take form in various parts and arrangement of parts, a preferred embodiment of which will be described in detail in the specification and illustrated in the accompanying drawings which form a part hereof and wherein:Figure 1 is an exploded perspective view of a splice organizing apparatus constructed in accordance with the present invention;Figure 2 is a cross-sectional view through the apparatus of Figure 1 in its assembled condition taken transversely of the longitudinal axis at the area generally designated by lines 2-2 in Figure 3;Figure 3 is a cross-sectional view of the main frame assembly and splice enclosure taken along lines 3-3 of Figure 2; and,Figure 4 is an exploded perspective view of the splice receiving leaves used in the apparatus of Figure 1.
Detailed description of the preferred embodimentReferring now to the drawings wherein the showings are for purposes of illustrating a preferred embodiment of the invention only and not for purposes of limiting same, Figure 1 shows a conventional splice case A in which an optic fiber organizer apparatus B is mounted. The splice case clamps the ends of the spliced cables to relieve the splice from cable tension and provides a hermetically sealed environment for protecting the splice.
The organizing apparatus B facilitates organization of optic fibers during the splicing operation and retains the spliced cables substantially vibration and motion free after the splice is completed. In this manner, a long-lived splice is provided which is substantially free of transmission interference.
The splice case A includes a pair of end plates or members 10 and 12 which are maintained in a fixed, spaced relationship by a pair of parallel spaced apart torque bars 14, 16. A pair of semi-cylindrical cover members 18, 20 are selectively connected in a hermetically sealed relationship with each other and with the end plates. As shown, each end plate defines or includes at least one aperture therethrough which receives one of the cables to be spliced. Each end plate on a conventional or typical splice case shown in Figure 1 includes a pair of resilient semi-circular members which are clamped in a hermetic seal with each other and with the surface of the associated cable.
The cable is clamped with a sufficiently high degree of mechanical engagement so that it is unable to be withdrawn under normal cable tensions.
Other conventional techniques for tightly engaging the cable and hermetically sealing the junction between the cable and the end plate may also be utilized satisfactorily.
With reference to both Figures 1 and 2, the organizer assembly B includes a channel-like main frame assembly 30 which is mounted between the torque bars 14, 16. The main frame assembly includes a pair of spaced apart side walls 32 and 34 whose exterior surfaces are spaced substantially the same distance apart as the torque bars such that the main frame assembly would fit snugly therebetween. The side walls include lateral support portions or ledges 36, 38 for supporting other portions of the organizer apparatus as will be described. The inside area of a lower or bottom wall 40 of the frame assembly is covered with a resilient padding layer 42. This padding layer wraps around the ends of the main frame bottom wall and extends along its length to protect received cables.Optionally, a cable mounting means may be provided at each end of the main frame assembly for securely connecting a received cable or cables thereto. Such a cable mounting means may include a bendable bonding strap which is connected to the bottom wall 40 by a threaded fastener ararrangement The bonding strap is wrapped securely around the received cable or cables.
The main frame assembly side walls 32, 34 include female socket strips 50, 52, respectively, extending longitudinally therealong. In the preferred embodiment, the main frame assembly comprises a plastic material with the female socket strips being integrally formed or molded therewith. Each female socket strip defines a generally circular recessed area which is surrounded with the plastic material over an angle of more than 1800 (Figure 2). Each female socket strip has a generally linear lower edge which rests on the associated, adjacent splice case torque bar.
Each of a plurality of identical retainer clips 54 includes a longitudinal male strip portion 56 (Figure 1) which is dimensioned to be fit into the female socket strips in the manner shown in Figure 2. Each retainer clip defines a torque bar receiving recess 58 and has a main frame assembly abutting projection 60 which abuts the lowermost surface of the associated torque bar and the main frame assembly side wall. In this ng apparatus to the torque bars.
With primary reference to Figure 1 and secondary reference to Figures 2 and 3, a splice enclosure 70 is received in the main frame assembly between the main frame assembly side walls 32, 34 and is supported by the main frame assembly support ledges 36, 38. A cable receiving passage is defined between the main frame assembly and the splice enclosure. The splice enclosure includes a bottom wall 72 on which a resilient liner 74 is mounted to protect optic fibers and received cables. The resilient liner wraps around the edges of the bottom wall (Figure 3) with a radius of curvature that provides a deterrent to sharp bends in the optic fibers.
A pair of spaced apart splice enclosure side walls 76, 78 is disposed normal to bottom wall 72, and extends parallel to the frame assembly side walls and the torque bars 16, 18. Each of these side walls includes a plurality of inwardly facing, longitudinally extending sawtooth projections 80. A plurality of posts 82, 84, and 86 are mounted vertically in the splice enclosure bottom wall in a linear array which is parallel to and closely adjacent the splice enclosure side wall 76. A greater or lesser number of such posts could also be advantageously employed.
Referring to Figures 1 and 4, several leaves 90 are disposed in the splice enclosure 70 generally parallel to the splice enclosure bottom wall. The leaves 90 are advantageously provided in pairs with one such pair comprised of leaves 90a, 90b which are shown in Figure 4. Grommets 92, 94, 96 fasten leaves 90a, 90b together and define apertures through which the posts 82, 84, 86, respectively, are received. Once positioned on the posts, the individual leaves and the pairs of leaves may be folded upward like pages in a book to provide access to the spaces therebetween. The leaves are constructed of a soft, resilient material, such as felt or other non-woven fabric. Preferably, the felt material is constructed of a synthetic polymer or the like whose physical properties do not change with age and which is not susceptible to rot or decay.
Two pairs of hook and loop fabric, eg., VELCRO, fastening strips 98, 100, and 102, 104 are adhesively or otherwise connected with the mating faces of leaves 90b, 90a, respectively, in order to secure the optic fibers and the splices. It is to be appreciated that a plurality of leaf pairs may be mounted or stacked on posts 82, 84, 86 as deemed necessary and/or appropriate to accommodate different numbers of splices properly.
A leaf holddown means 110 (Figure 1) is provided for selectively retaining the leaves in a parallel relationship with the splice enclosure bottom wall. In the preferred embodiment, the leaf holddown means is comprised of a plurality of resilient holddown members with two such members 112, 114 being shown. Members 112, 114 are dimensioned for receipt in oppositely disposed ones of sawtooth assists in camming the holddown members therepast. The undercut portion of each sawtooth inhibits the leaf holddown members from being removed. The leaf holddown members may be inserted after all the leaves are in place upon completion of a splice, after several pairs of leaves have been installed, or after each pair of leaves has been installed.
With particular reference to Figure 3, when performing a splicing operation, the ends of the cables to be spliced are received through the splice case end walls 10, 12 and clamped securely therein. The main frame assembly 30 is positioned between the torque bars 14, 16 and fastened in place with the retainer clips 54. A sufficient length of cable casing to reach from the end wall to splice enclosure bottom wall 72 is retained. The remaining casing is removed. The unsheathed fibers are laid across the bottom wall of the main frame draping off the opposite ends.
The splice enclosure 70 is mounted on the main frame assembly ledges 36, 38, and a first pair of leaves 90 is disposed in the splice enclosure on posts 82, 84, 86. The upper leaf 90a of the pair is flexed upward and folded over the side wall 32.
First groups of the fibers from each cable to be interconnected are cut to the appropriate length and folded over the liner pad 74 at the ends of the splice enclosure bottom wall 70. The corresponding fibers from each cable are spliced at splices 120. After splicing the first fiber groups, the fibers and splices are effectively secured to the lower leaf 90b by the cooperative relationship of the hook and loop strips 98, 100 and 102, 104 as the upper leaf 90a is folded over the splices. Subsequent pairs of leaves are inserted and the splicing operation performed analogously with additional groups of fibers. The splice retaining members 112, 114 are inserted to hold the leaves and the splices stationary.
The invention has been described with reference to the preferred embodiment. Obviously, modifications and alterations will occur to others upon a reading and understanding of this specification. It is intended to include all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.