The present invention relates generally to a stripping device having one or more alignment maintaining features. More particularly, the present invention relates to a device for readily stripping protective material from electrical wiring and/or fiber optic strands where alignment is maintained so as to allow for stripping longer lengths of material more accurately and reliably.
Fiber optic strands generally have various outer layers around their optical fibers, such as coating or buffering layers or outer jackets. Electrical wires also generally have some sort of outer insulation or jacket. When such strands or wires are connected, it is common to strip the outer layers as part of the termination process.
Various devices have been proposed for use in stripping of protective outer materials from fiber optic strands and electrical wires (collectively referred to as “transmission carriers” below). For example, U.S. Pat. No. 4,271,729 discloses such a device in which two grip members are pivotably attached to an end block. Movable blade members are mounted in the end block. The wire to be stripped is slid through an opening in the end block, and then the grip members are squeezed together, thereby bringing the blade members together to cut into the protective material to be stripped. The wire is then pulled through the device and out of the end block, sliding the wire's metal carrier out of the protective coating “downstream” of the blade members, thereby stripping the inserted wire. U.S. Pat. No. 4,850,108 discloses a related stripping device suitable for stripping an array of fiber optic strands. MICRO-STRIP® tools from Micro Electronics, Inc. are further examples of available stripping tools.
While currently available devices work well in many applications, in particular in stripping relatively shorter lengths of material on the order of a few centimeters, further improvement is possible. For example, if longer lengths of material are to be stripped, the protective material on the loose downstream end may bind, bend, and/or buckle, resulting in an inaccurate or incomplete stripping. Also, with currently available tools, technicians may have to strip longer lengths in several steps (i.e., 5 centimeters at a time in three steps to strip 15 centimeters). Along with being time consuming, such repeated stripping and resultant handling of an optical fiber transmission carrier increases the possibility of inadvertent damage. Even for relatively shorter lengths, available devices do not positively maintain fiber alignment or securely hold the protective material during stripping, which can lead to imperfect results at times. These issues are magnified when attempting to strip relatively long lengths and/or small diameter optical fibers. Therefore, gripping and/or alignment of the transmission carrier to be stripped could be improved, particularly for longer strip lengths and/or smaller diameter transmission carriers, thereby providing a more effective and reliable tool.
A device is disclosed for stripping an outer material from a transmission carrier, the device includes an end block defining a passageway therethrough, the transmission carrier being placeable in the passageway. A pair of grip members is pivotally attached to the end block and movable between an open position and a scoring or cutting position. In one embodiment, an alignment mechanism is attached to at least one of the grip members for holding the transmission carrier at a distal point spaced from the end block with a predetermined clamping force. A scoring or cutting mechanism is attached to the end block proximate the passageway and actuated by pivoting of the grip members to the cutting position to cut into the outer material of the transmission carrier. The transmission carrier can be removed from the passageway while the alignment mechanism holds the end portion of the outer material of the transmission carrier at the distal point, thereby allowing a stripping off the end portion while inhibiting bending, binding and/or buckling over a length of the end portion. Various options and modifications of the concepts of the present invention are possible.
For example, the device may further include a spring member attached to at least one of the grip members for biasing the grip members to an open position. The alignment mechanism may include a resilient clamping member for providing the predetermined clamping force at a distal point from the end block or generally along or at a distance from the end block. The predetermined clamping force should not provide a crushing force that can damage the transmission carrier. However, the alignment mechanism should apply a sufficient pulling force for removing the end portion of the outer material being stripped. In another embodiment, the alignment mechanism can provide a pulling force, thereby initiating a separation of the covering being removed.
Further, the grip members may include heel portions and toe portions extending from the heel portions, the grip members being pivotally attached to the end block via the heel portions, and the alignment mechanism may include at least one resilient clamping member being attached to the toe portions. If so, the toe portions may contact each other, and the at least one resilient clamping member may be compressed when the grip members are in the cutting position. The grip members may include heel portions and toe portions extending from the heel portions, and the alignment mechanism may include a notch disposed in a surface of at least one of the toe portions, thereby inhibiting the formation of a crushing zone between the grip members. Also, the grip members may include heel portions and toe portions extending from the heel portions, and the alignment mechanism may include a first alignment mechanism disposed on at least one of the toe portions, and further including a second alignment mechanism disposed between the cutting mechanism and the first alignment mechanism. If so, the first alignment mechanism may include one or more of at least one flexible member and a notch disposed in at least one of the toe portions.
The cutting mechanism may include two reciprocating cutting blades, and the two reciprocating cutting blades may be held in the end block such that they are removable and replaceable. Likewise, the end block may further include a removable and replaceable transmission carrier insert guide for positioning and inserting the transmission carrier relative to the cutting mechanism.
In further variations, a relief passage is disposed in at least one of the grip member toe portions sized for receiving the end portion of the outer material when the grip members are in the cutting position. As above, various options and modifications are possible.
Preferably, a resilient means is provided for holding a portion of the outer material at a distal point spaced from the cutting mechanism with a force sufficient to allow the end portion of the outer material to be stripped from the transmission carrier, thereby inhibiting buckling over a portion of the outer material being stripped. As above, various options and modifications are possible.
a-10c depict different blade configurations that can be used with the concepts of the stripping device.
Detailed reference will now be made to the drawings in which examples embodying the present invention are shown. The detailed description uses numerical and letter designations to refer to features in the drawings. Like or similar designations in the drawings and description have been used to refer to like or similar parts of the invention.
The drawings and detailed description provide a full and written description of the invention, and of the manner and process of making and using it, so as to enable one skilled in the pertinent art to make and use it, as well as the best mode of carrying out the invention. However, the examples set forth in the drawings and detailed description are provided by way of explanation of the invention and are not meant as limitations of the invention. The present invention thus includes any modifications and variations of the following examples as come within the scope of the appended claims and their equivalents.
Described below are multiple embodiments and modifications to designs of stripping devices useful for stripping relatively long lengths of protective material from transmission carriers such as fiber optic strands and electrical wires. The concepts of the present invention generally inhibit bending, binding, and/or buckling (hereinafter buckling) of the portion of the transmission carrier being stripped, thereby allowing improved performance. The disclosed devices can be modified for use with other transmission carriers and/or varying sizes of transmission carriers. For example, fiber optic strands may have outer coating with outer diameters in the range of 200 microns or less, and may range up to 900 microns or more that require stripping for termination. The individual optical fibers disposed within the coatings have smaller diameters. Further, the concepts of the invention may be used with coated fibers having polymeric or UV curable coatings or outer jackets with varying dimensions. The disclosed designs also have applicability to stripping electrical wire of varying sizes. Accordingly, it should be understood that the disclosed designs may be used with many different types of transmission carriers, and the specific examples disclosed herein should not be considered limiting.
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A transmission carrier insert guide 58 may be attached to end block 16 to guide the transmission carrier through the end block and past cutting mechanism 18. Transmission carrier insert guide 58 may be a removable and replaceable part sized for a particular diameter, shape, and/or size of the transmission carrier. Accordingly, a family of such transmission carrier insert guides may be provided for a given stripping device so that various sizes of transmission carriers may be accurately stripped using stripping device 10. Likewise, blades 42 and 44 can be removed and accordingly sized for a particular transmission carrier geometry. Transmission carrier insert guide 58 may include a body portion 60, an outer flange 62, and a neck section 64 sized to receive the particular transmission carrier to be stripped. A removable guide lock 66 may be used to hold the selected transmission carrier insert guide 58 in place within end block 16.
As mentioned above, various forms of an alignment mechanism may be employed to ensure transmission carrier 20 is held and may be stripped without buckling. For example, as shown in
Resilient clamping members 70 and 72 should be sized and/or selected of a material such that the resilient clamping members may hold the coated transmission carrier 20 with a clamping force suitable to hold the transmission carrier and allow the fiber or wire to be stripped without damaging the fiber or wire. However, the coated transmission carrier 20 should not be gripped so tightly that the inner transmission carrier portion 20a is damaged. Rather, the clamping force should suitably hold the transmission carrier and to allow stripping of the end portion of outer material while inhibiting buckling during the stripping of the outer material.
Alternatively, or in addition to resilient clamping members 70 and 72, an alignment mechanism may include a relief passage 74 disposed in at least one grip member toe portion 25. As shown, mating relief passages 74 and 76 may be provided opposite each other in toe portions 25 and 27. Relief passages 74 and 76 should be sized and/or shaped large enough so as to allow for clamping and stripping, as described above. Preferably, the relief passages are made larger than the outer material 20b of the transmission carrier, thereby allowing resilient clamping members 70 and 72 to perform the clamping. Alternately, appropriate relief passages 74 and 76 could be used alone, without resilient clamping members 70 and 72. In such case, the relief passages would have a predetermined size suitable for the outer diameter and/or shape of transmission carrier being stripped. In other embodiments, relief passages 74 and 76 could also be omitted entirely, if desired performance was achieved.
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Various options and modifications are possible for the device of
a-10c depict different blade configurations that can be used with the stripping device concepts of the present invention.
Many modifications and other embodiments of the present invention, within the scope of the appended claims, will become apparent to a skilled artisan. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed herein and that modifications and other embodiments may be made within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.