Patent Application
20070143990
The present invention relates to handling tools for fiber optic jumper, strand and cable connectors. In particular, the present invention relates to tweezers type handling tools for fiber optic cable connectors.
Ever increasing miniaturization of data cable connectors in general and optical fiber cable connectors in particular makes insertion, removal and handling of cable connectors more difficult to accomplish. Fiber optic cable connectors in particular need to be handled with care to avoid contaminating contact with the connector's optical front end. Moreover, optical cable connectors ends need to be cleaned on a recurring basis.
In industrial applications, cable connectors are often densely arrayed on panels such that the high volume of connected cables may shield off ambient illumination to a large degree. Additional illumination is therefore desirable at the attachment location of the handled cable connector.
Also, despite the cable connectors small size, considerable forces may be required to insert and remove the cable connector. This in combination with fiber optic cables or shielded coaxial cables increased bending stiffness poses additional challenges for a precise, efficient and reliable insertion and removal of cable connectors. There exist also standards for minimum cable bending radii which may be inadvertently exceeded in cases where the cable extending from the clamped connector is not supported in the handling tool. Therefore, there exists a need for a connector handling tool that keeps the cable in substantial alignment with the connector immediately adjacent the clamped connector. The present invention addresses this need.
A number of prior art connector handling tools attempt to address the particular challenges of handling modern cable connectors. There exist tools having an angled grip portion on the opposite end of the grasping claws. Such tools provide ergonomic transfer of manual push and pull forces on the expense of cable connector fine control and risk affecting adjacent connectors due to their size and clumsy functionality.
There are other tools similarly configured like tweezers for increased positioning control of the cable connector on the expense of reduced manual push and/or pull force transfer. Such tools also require the manual connector grasping force being simultaneously applied with push/pull forces, which degrade handling flexibility. Therefore, there exists a need for a cable handling tool that provides maximum positioning control of the cable connector and at the same time maximum manual push and pull force transfer, preferably with manual connector grasping force being separately applicable. The present invention addresses this need.
Simultaneous illumination of the connector insertion location has been addressed in prior art connector handling tools by attaching a flash light peripherally or centrally on the handling tool. Central flashlight attachment provides only very limited illumination of the insertion side, since most of the beam cone is obstructed the tool's front portion and the connector and its cable held in the tool. Peripheral attachment on the other hand provides satisfactory illumination but requires an extended tool length since the tool has to be held in hand behind the attached flash light. Therefore, there exists a need for an illumination solution that provides unobstructed illumination while the connector handling tool may be hand held at an approximately equal gripping end offset as the flash light. The present invention addresses also this need.
Tweezers type handling tools commonly feature two members joint at a pivoting end opposite a gripping end and are hand held in between. The long distance between gripping end and pivoting end introduces increased instability of the grasping faces at the gripping end and frequently causes an offset condition which could induce trouble to adjacent connectors when the tweezer lever slips off the connector being held. A deviation torque induced by unbalanced contact pressure in the grasping faces and/or unbalanced manual clamping force may induce excessive angular deflection of the grasping faces such that the connector may eventually laterally eject from its position between the two opposing grasping faces. Unbalanced grasping face contact pressure is a particular problem with connectors having a large ratio of clamping height to clamping width. Therefore, there exists a need for tweezers type handling tool having features opposing effects of deviation torque. The present invention addresses this need.
Unbalanced grasping face contact pressure occurs also in cases of connectors being combined with cables of increased stiffness such as fiber optic cables. Where the cable handling tool holds only the connector itself, the cable commonly laterally emerges from in between the handling tool. Depending on the cables stiffness a certain momentum is thereby induced on the connector. Therefore, there exists a need for a connector handling tool that provides for an insulation of cable torque from the grasped connector by additionally holding both the connector and the immediately adjacent cable portion in alignment within the handling tool. The present invention addresses also this need.
A tweezers type cable connector handling tool features two levers extending between a connector gripping end and an opposite pivoting end. Each lever has a grasping face at the gripping end for holding the cable connector. Each lever also features one of two guiding faces in guiding interaction with each other such that a deviation torque eventually resulting from unbalanced grasping face contact pressures and/or unbalanced hand clamping forces is communicated between the two levers. Angular deformation of the grasping faces is kept consequently to a minimum. The handling tool provides also for a connector cable receiving channel positioned in between the two levers and in between the gripping end and the pivoting end. The receiving channel is longitudinally aligned with the two grasping faces such that a cable extends substantially straight from a corresponding connector clamped between the grasping faces. Keeping the cable straight immediately behind the clamped connector assists in keeping grasping face contact pressures balanced and deviation torque within predictable limits. It further assists in isolating cable forces from the clamped connector.
The levers feature also first/second tapers on their outside faces such that a tool grasping force between the two grasping faces is amplified while the handling tool is pushed/pulled towards/away from the gripping end. The boundary contours of first/second tapers increase thereby towards the center of the manual clamping forces externally applied on the handle levers. A bending stress distribution in the handle levers is consequently balanced between pivoting end and gripping end. This contributes to an ergonomic and lightweight configuration of the handling tool.
Guiding faces may be provided by a post extending from a first inner face of one of the two levers into a cavity embedded in a second inner face of one other of the two levers. The receiving channel may be provided by two adjacent posts arrayed with a cable channel spacing substantially in direction of the handling tool's pivoting axis.
The handling tool may further alternately feature a ratchet closure, a latching pin lock or a lever rotation lock for locking the tool grasping force and thereby securing the cable connector without need to further apply the manual clamping force. The cable connector is consequently easily held and manipulated without need to simultaneously and continuously apply the manual clamping force.
The handling tool also features an integrated flash light approximately tangentially pointing towards the gripping end. The flash light's housing is a continuation of the outside contour of the lever in which the light source is integrated. The flash light's housing is integrated in a bending stress communicating fashion in the respective lever.
The grasping faces are provided either by removable attached rubber layers or by a grasping boot that may be snapped on a corresponding boot receiving nose at the gripping end of a respective handle lever. The grasping boots may be interchanged to adopt the handling tool to various types of cable connectors.
Fig. A-A is a cross section indicated in
Fig. B-B is a cross section indicated in
A tweezers type cable connector handling tool 1 in the following called tool 1 is shown in
The tool grasping force FG is applied within the grasping plane PG geometrically defined as a normal plane to the pivot axis AJ. Manual clamping force FC is most likely out of plane with grasping plane PG due to the naturally non symmetric hand squeeze as may be well appreciated by anyone skilled in the art. Also, the grasping face contact pressures may be off balance due to imperfect fit of connector C1 with grasping faces 71 (see
The clamped connector C1 is inserted at its respective assembly location via tool 1 by a hand applied push force FP. The clamped connector C1 is removed from its respective assembly location via tool 1 by a hand applied pull force FL. Push and pull forces FP, FL may also be out of grasping plane PG and additionally contribute to undesirable deviation torque TD.
The tool 1 may feature an integrated flash light 6 with its illumination axis AB extending approximately tangential away from the outside contour of the respective lever 4 and in plane with the grasping plane PG. The illumination axis AB exits between the clamping force FC center and the gripping end 2 providing illumination unimpeded by the operator's hand, the connector C1 or the connector cable C2. At the same time, the tool 1 may be hand held in close proximity to the gripping end 2 warranting maximum control and external force transmission efficiency between the operator's hand and the clamped connector C1.
Referring also to the remained of the Figures, the tool 1 features first and second levers 4, 5 extending between the tool's 1 gripping end 2 and pivoting end 3. Each of the levers 4, 5 have respective grasping faces 71 facing each other. The two levers 4, 5 are rotatably connected at a joint 9. The two levers 4, 5 pivot around pivot axis AJ. A biasing spring 94 may push the levers 4, 5 away from each other. Angular movement may be limited by well known rotation stops in the joint 9.
In the preferred case of the tool 1 being fabricated from plastic material, limited material stiffness of the levers 4, 5 requires communication of the deviation torque TD between the two levers 4, 5 to keep angular deflections of the grasping faces out of the grasping plane PG to a minimum. In that context and in reference to
The tool further features a connector cable receiving channel 47 positioned in between the two levers 4, 5 and in between the gripping end 2 and the pivoting end 3. The receiving channel 47 is longitudinally aligned with the grasping faces 71. Consequently, a cable C2 extending immediately adjacent from a connector C1 clamped in between the grasping faces 71 is substantially aligned with the clamped connector C1.
Referring to
The first taper T1 and/or the second taper T2 may be in plane with the grasping plane PG or may be two dimensional tapers. The tapers T1, T2 are preferably symmetrical with respect to the deviation axis AD for a balanced communication of pulling forces FL and/or pushing forces FP as may be clear to anyone skilled in the art.
Referring to
Referring to
Two of the disengaging features 453 may be oppositely placed on opposing outside side faces 412 of the first lever 4 such that the respective ratcheting forces are externally overcome by opposing and neutralizing external disengaging forces FD. At the same time, the two posts 451 of the two respective disengaging features 453 may be arrayed with the channel spacing CS substantially in direction axially with respect to the pivoting axis AJ thereby defining the connector cable receiving channel 47. The cable channel spacing CS may be sufficiently larger than a maximum diameter of cable C2 to warrant the disengaging of the two pairs of respective ratchet faces 452, 551 irrespective the cable C2 being present in the receiving channel 47.
Referring to
Referring to
The grasping boot 7 may have a cavity fit snugly fitting the receiving nose 44. The grasping boot 7 may snap in via snap its perforation 72 on a corresponding snap hook 42, 52.
Referring to
In the preferred case of the tool 1 being made of plastic material, the levers 4, 5 are fabricated with an internal rib configuration including keels 49, 59 that extend centrally between pivot end 3 and gripping end 2 symmetrically with respect to the grasping plane PG. The keel width may be selected in conjunction with the cable channel spacing CS such that the keel 59 may propagate past the cavities 55, 56 with continuous width. In case of lever 4 featuring the flash light 63, the keel 49 is interrupted between stress communicating interfaces 406, 416. The housing 63 acts similar to a wedge between the stress communication interfaces 406, 416 and bridges bending stresses across the gap of the keel 49. The overall stiffness of the lever 4 remains consequently similar to the stiffness of lever 5 irrespective the material removed from lever 4 to provide space for the flash light 6. The outside shape of the housing 63 is a continuation of the lever's 4 outside shape such that the operator's hand may conveniently hold the tool 1 in close proximity to the gripping end 2.
The tool 1 may also include a latching pin lock 8 in between the levers 4, 5. The latching pin lock 8 may have a latching pin 81 extending substantially parallel with respect to the pivot axis AJ. Both latching pin ends 811, 812 may be externally accessible for moving the latching pin 81 along a latching cam 82 of the lever 4 for interlocking with a closure hook 83 of the lever 5 while the levers 4, 5 are in a connector grasping position with respect to each other as illustrated in
The tool 1 may further include a joint lever 91 attached to the joint 9 via a joint axle preferably made of a nut 93 and a screw 92. The nut 93 may be screwed on the screw 92. One of the nut 93 and the screw 92 may be rotationally and axially secured in the joint 9 and one other of the screw 92 and the nut 93 may be rotationally and axially rigid connected with the joint lever 91, which in turn is rotationally free held in the joint 9. Joint lever 91 and joint 9 define together a rotational snap guide 915 such that the joint lever 91 may be snap rotated at least between a joint 9 lock position and a joint 9 release position. In the lock position the nut 92 and the screw 93 are tightened with respect to each other such that the joint 9 is rotationally fixed. In the release position the joint 9 is rotational free. The joint lever 91 may be a well known pocket clip. The joint lock mechanism described in this paragraph may be alternately employed with the ratchet closure 45 or the latching pin lock 8.
Levers 4, 5 may feature a grip 43 along their respective top and bottom outside faces 413, 513. The grip 43 may be of soft rubber comolded with the structural portions of the levers 4, 5. Lever 5 may also feature a strap ring 57 at the pivoting end 3. Functions and features described in conjunction with levers 4, 5 may be employed vice versa as may be well appreciated by anyone skilled in the art.
The tool 1 is operated by hand holding it approximately where the levers 4, 5 have their boundary contours at a maximum. A connector C1 may be inserted with its immediately adjacently extending cable C2 in the open receiving channels 47 followed by grasping the connector C1 between the grasping faces 71. The connector C1 is then clamped by applying the manual clamping forces FC. The two levers 4, 5 may be fixed in its clamping position to each other automatically by the ratchet closure 45 or manually via latching pin lock 8 or above described joint lock. Following the clamping step, the connector C1 may be conveniently inserted, removed and/or otherwise securely handled without need to continuously apply the clamping forces FC and without particular influence of the cable's C2 bending stiffness. The flash light 6 may be employed at any time by actuating the light switch 62. The connector C1 may be released from the tool 1 by applying the external disengaging force(s) FD in case of an employed ratchet closure 45 or alternately by unlocking the latching pin lock 8 or the joint lock.
Also depicted in
Accordingly, the scope of the invention described in the Figures and in the above is set forth by the following claims and their legal equivalent:
