Overhead Line Clamp

Abstract

Overhead Line Clamp An overhead line clamp (100) securable to an overhead line (2), the overhead line clamp (100) comprising a pincer member (102), a hinge (104) enabling the pincer member (102) to be actuated between an open position and a closed position, where in the closed position the pincer member (102) is configured to secure the overhead line (2), and a manual latch (108) configured to actuate the pincer member (102) between the open and closed positions.

Description

[Technical field]

[0001] Embodiments of the present invention relate to overhead line clamps, in particular, but not exclusively, they relate to overhead contact line clamps for electrified overhead line systems. [Background technology]

[0002] Electrified overhead line systems for transportation, also called overhead catenary systems, comprise electric cables configured to transmit electrical energy to vehicles such as electric locomotives, trolleybuses, trams or even heavy road vehicles.

[0003] The vehicle is equipped with overhead line equipment such as a pantograph, bow collector, or trolley pole to collect electrical energy from the overhead line system.

[0004] A typical overhead line system includes an upper wire, a lower wire (contact wire), and periodically spaced droppers which suspend the lower wire from the upper wire.

[0005] The top end of each dropper is connected to an upper wire by a clamp. The bottom end of each dropper is connected to a lower wire by a clamp. Each clamp forms a tight mechanical and electrical connection.

[0006] Existing clamp designs are time consuming to tighten, especially when the clamp must be loosened and slightly repositioned multiple times to set the correct vertical height of the contact line.

[0007] BRIEF DESCRIPTION OF THE DRAWINGS According to one aspect of the present invention, there is provided an overhead contact wire clamp configured to secure a dropper to an overhead contact wire, a dropper connector for fastening the clamp to the dropper; a pincer member, each shaped to fit within a corresponding groove of the imaginary contact line when the pincer member is in a closed position; a hinge that allows the pincer member to move between an open position and a closed position; and a manual latch configured to actuate the pincer member between the open and closed positions.

[0008] The manual latch provides the advantage of allowing quick fixation of the dropper to the overhead contact line and allowing quick adjustment of the clamp position to correct the verticality of the dropper, since the manual latch eliminates the need for tools.

[0009] The manual latch may include a manual lever having a stroke length configured such that when the manual lever is at one end of its stroke, the pincer members are in an open position spaced far enough apart to receive a groove of the imaginary contact line therebetween, and when the manual lever is at a second end of its stroke, the pincer members are in a closed position clamping against the groove.

[0010] The advantage is that it further increases the speed at which the dropper can be secured to the aerial contact line.

[0011] The manual lever may have a mechanical advantage of, for example, greater than two. However, a mechanical advantage of greater than three or greater than four manual levers may further reduce the effort required for a single stroke operation as described above while allowing the use of a durable rigid hinge (e.g., a metal living hinge as described below). The length of the manual lever may be at least as long as or greater than the length of the pincer member.

[0012] The manual latch may be a bi-stable latch mechanism. For example, the manual latch may be an over-center latch that may include a manual lever configured to rotate a cam to actuate a pincer member.

[0013] An advantage is that toggle-like feedback is provided to the user indicating that the pincer members are in the closed position, eliminating the need for a torque specification for the user to manually check and adhere to.

[0014] The latch may include a stud interconnecting the pincer members, one end of the stud secured to the latch configured to press against a first of the pincer members and the other end of the stud secured to a second of the pincer members opposite the first pincer member.

[0015] Alternatively, the manual latch may be of a different type than an over-center latch.

[0016] The manual latch may further comprise a catch engageable when the pincer members are actuated in the closed position to prevent movement of the pincer members away from the closed position.

[0017] An advantage is that the latch is resistant to being loosely actuated, for example as a result of noise, vibration and harshness of passing vehicles or wind induced vibration of the line, among others.

[0018] The clamp may include a conductive material for forming an electrical connection between the dropper connector and the pincer member. The conductive material may be copper, silver, tin, aluminum, or alloys thereof.

[0019] The hinge may be a living hinge. The hinge may comprise a conductive material. The hinge may be integral with the pincer member.

[0020] An advantage is that a single compact of conductive material can be used.

[0021] The hinge may include a dropper connector. The dropper connector may include a socket for receiving a dropper.

[0022] The socket may be disposed on a hinge so that when the pincer members are moved to the closed position, deformation of the hinge compresses the socket to secure the clamp to the dropper. An advantage is that the same user's hand actuation secures the clamp to both the virtual contact wire and the dropper. A further advantage is that electrical conductivity is maintained in use during vibration through the clamp.

[0023] According to a further aspect of the present invention, there is provided a system including an overhead contact wire clamp, an overhead contact wire, and a dropper.

[0024] According to a further aspect of the present invention there is provided an overhead line clamp securable to an overhead line, A pincer member; a hinge that allows the pincer member to move between an open position and a closed position, where in the closed position the pincer member is configured to secure the overhead line; and a manual latch configured to actuate the pincer member between the open and closed positions.

[0025] For a better understanding of various examples of embodiments of the present invention, reference will now be made, by way of example only, to the accompanying drawings, in which: [Brief description of the drawings]

[0026] [Figure 1] FIG. 1 illustrates an example of an overhead line system. [Diagram 2] FIG. 2 illustrates an example of an imaginary contact line. [Diagram 3] FIG. 3 illustrates an example of an overhead contact wire clamp. [Figure 4] FIG. 4 illustrates the imaginary contact line clamp with the cam lever in the open position. [Diagram 5] FIG. 5 illustrates the imaginary contact line clamp with the cam lever in the closed position. Description of the Preferred Embodiments

[0027] An exemplary electrified overhead line system for transportation is illustrated in Figure 1. The overhead line system 1 comprises an upper catenary wire 3, a lower contact wire 2, and periodically spaced droppers 4 that suspend the contact wire 2 from the catenary wire 3.

[0028] The contact wire 2 is a conductive wire configured to contact and form an electrical connection with overhead equipment of the vehicle. The contact wire 2 is suspended at a substantially constant vertical height above the rail / roadway to maintain constant contact with the overhead equipment of the vehicle, such as a pantograph, bow collector, or trolley pole.

[0029] The catenary wires 3 are conductive wires attached at intervals to a supporting structure such as a mast or building. The catenary wires 3 run parallel to and above the contact wires 2. The catenary wire 3 hangs down at each intermediate span under its own weight and the weight of the hanging droppers 4 and contact wires 2.

[0030] The droppers 4 are upright conductive lines, such as generally vertical wires, for suspending the contact wire 2 from the catenary wire 3. The droppers 4 connected to the mid-span of the catenary wire 3 are typically shorter than the droppers connected towards the end spans of the catenary wire 3 to compensate for the sagging of the catenary wire 3 and ensure that the contact wire 2 is at a constant height.

[0031] The illustrated exemplary system 1 is suitable for implementation on a permanent way, heavy rail. However, the clamp of the present invention can also be used on other types of overhead line systems, e.g. electrified overhead line systems for light rail / tram. The latter systems may have spaced support wires perpendicular to the contact wire 2, which connect to the contact wire 2 directly or via short droppers 4.

[0032] 2 illustrates an example of a cross-section of a contact wire 2. Without limitation, the contact wire 2 may be a single-core wire, such as a cold-drawn solid wire made from copper, silver, tin, or alloys thereof.

[0033] The contact line 2 has a non-circular cross section. The contact line 2 has grooves 20 on both its left and right sides. The grooves 20 provide a clamping surface for the clamp, allowing for an interference clamp fit in which a pincer member enters the grooves 20 and laterally compresses the contact line 2. The exact dimensions of the contact line 2 may be standardized, but may vary overall depending on the railroad standards applicable to the region.

[0034] 3 illustrates an exemplary implementation of a virtual contact line clamp 100, according to various embodiments of the present invention. The clamp 100 is configured to clamp onto a contact line 2 of a geometry defined by a relevant standard, such as the contact line 2 shown diagrammatically in FIG.

[0035] The clamp 100 comprises pincer members 102 each shaped to fit within a corresponding groove in the imaginary contact wire 2 when the pincer members 102 are in the closed position.

[0036] In the closed position, the tips of the pincer members 102 may be spaced apart by a value selected from the range of at least 5.5 millimeters to less than 8 millimeters, such as about 6 millimeters, so that the pincer members 102 can fit into the grooves 20 with an interference that prevents at least the European style contact wire 2 from falling out.

[0037] In the open position, the tips of the pincer members 102 may be spaced apart from one another by more than 8 millimeters, which is wide enough to accommodate at least the upper portion of the contact line 2.

[0038] The clamp 100 includes a dropper connector 106 for securing the clamp 100 to the dropper 4. The illustrated dropper connector 106 includes a socket for receiving the dropper 4. The socket is shown as a through hole through which an end of the dropper 4 (e.g., a crimped end) can be inserted and then clamped by deformation of the socket to secure the end of the dropper 4 to the clamp 100.

[0039] It will be appreciated that in other embodiments, other types of dropper connectors 106 may be used.

[0040] The clamp 100 may comprise a unitary body of conductive material. The body may integrally combine the pincer member 102 and the dropper connector 106.

[0041] The conductive material forms an electrical connection between the dropper connector 106 and the pincer member 102. This allows power to be transferred from the dropper 4 to the contact wire 2.

[0042] The clamp 100 further comprises a hinge 104 that allows the pincer member 102 to be actuated between an open position shown in Figure 4 and a closed position shown in Figure 5. The hinge axis of the hinge 104 is substantially parallel to the axis of the contact line 2.

[0043] In the illustrated example, the hinge 104 is a living hinge made of the same conductive material as described above. The inherent flexibility of copper means that the living hinge 104 does not necessarily have to be weaker / geometrically less stiff than the pincer member 102.

[0044] The dropper connector 106 may be located at the hinge 104 between the pincer members 102 . The dropper connector 106 may be vertically oriented and perpendicular to the hinge axis of the hinge 104. The dropper connector 106 may be a hole in a conductive material. The dropper connector 106 may be sized for a given dropper cross section. For example, the dropper connector 106 may have a hole diameter greater than about 5 millimeters. By positioning the dropper connector 106 on the hinge 104, the act of actuating the pincer member 102 to the closed position deforms the hinge 104 sufficiently that the dropper connector 106 compresses and presses against the side of the end (e.g., the crimped end) of the dropper 4.

[0045] 3-5 further illustrate a manual over-center latch 108 in the form of a cam lever comprising a cam 110 and a manual lever 112. The term "cam" is understood to cover both lobed cam mechanisms and eccentric mechanisms.

[0046] The latch 108 has a latched open position in which the pincer member 102 is in an open position, as shown in Figure 4. The latch 108 has a latched closed position in which the pincer member 102 is in a closed position, as shown in Figure 5. The latch 108 is bi-stable, switching between stable positions when moved "over-center" of the cam 110.

[0047] The lever 112 is manually operable with a mechanical advantage of greater than two, greater than three, or greater than four to allow an adult hand to elastically deform the hinge 104 (e.g., a copper living hinge) via the cam lever 112 until the cam 110 reaches an over-center position (maximum lift).

[0048] The lever 112 is allowed to pass through an over-center position (maximum lift of the cam 110) at least a short distance in order to settle into a stable latched closed position.

[0049] The latch 108 includes a stud 114 that interconnects the pincer members 102. One end of the stud 114 is fixed to the latch 108. The cam 110 is configured to press against a first one of the pincer members 102A. The stud 114 extends through the first pincer member. The other end of the stud 114 is fixed to a second pincer member 102B opposite the first pincer member 102A.

[0050] The stroke length of the lever 112 is such that when the lever 112 is at one end of its stroke (FIG. 4), the pincer members 102 are in an open position spaced far enough apart to receive between them the grooves 20 of the imaginary contact wire 2. When the lever 112 is at a second end of its stroke (FIG. 5), the pincer members 102 are in a closed position to clamp against the grooves 20 of the imaginary contact wire 2. The stroke of the lever 112 may be greater than 60 degrees, or greater than 100 degrees, such as about 120 degrees.

[0051] The illustrated lever 112 is long enough that the tip of the lever 112 projects above the top of the hinge 104 when at the second end of its stroke (FIG. 5) corresponding to the latched closed position. The lever 112 may be at least as long as the length of the pincer member 102, or slightly longer. In FIG. 5, the lever 112 may be substantially parallel to the first pincer member 102A at the second end of its stroke.

[0052] FIG. 3 illustrates generally an exemplary catch 116A that is engageable when the pincer members are actuated in the closed position to prevent movement of the pincer members away from the closed position.

[0053] The illustrated catch 116A includes teeth on the cam 110 configured to engage with a tooth receiving surface formation 116B (e.g., a stud hole) on the side of the first pincer member 102A when the cam 110 is rotated over-center toward the latched closed position of the lever 112. The teeth and tooth receiving surface structure may be shaped to create a ratcheting force that prevents backward rotation of the lever 112 .

[0054] Thus, as shown, the catch 116A may be configured to automatically engage when the lever 112 reaches the latched closed position. Additionally, the catch 116A is configured such that it requires more force to move the lever 112 from the latched closed position to the latched open position than it does to move the lever 112 from the latched open position to the latched closed position.

[0055] It will be appreciated that the catch 116A is not limited to the particular example shown. For example, an alternative (or additional) type of catch could include a side slot towards the distal end of the lever 112. When the lever 112 reaches the latched closed position, the side slot of the lever 112 could be coaxially aligned above the dropper connector 106. Thus, the dropper 4 can be slid into the side slot at the end of the lever 112. This means that the lever 112 cannot be moved from the latched closed position without first sliding the dropper 4 laterally out of the side slot.

[0056] In other examples, the manual latch 108 may be of a different type than an over-center latch. Examples include: a manually operable crank such as a threaded screw having a manually operable crank lever at one end; - Rotating button clamps, such as quarter turn clamps, half turn clamps, or full turn clamps; -Including but not limited to scissor mechanism clamps or other push-pull clamps.

[0057] Some exemplary embodiments involving cranking may include a torque limiter to automatically prevent over-torque. The torque limiter may be a clutch-based torque limiter or another type of torque limiter. The clutch-based torque limiter may include a pawl clutch or a ball detent clutch, or another suitable type of clutch. Such a clutch may be further adapted to prevent reverse movement of the manual latch, for example, by shallowing the ball detent surface in the reverse direction to reduce the torque at which the ball pops out of the detent.

[0058] Although embodiments of the present invention have been described in the above paragraphs with reference to various examples, it should be understood that modifications to the given examples can be made without departing from the scope of the invention as defined in the claims. For example, a clamp can be used at the top of the dropper to connect to the catenary line.

[0059] The features set out in the above description may be used in combinations other than those expressly set out.

[0060] Although functions are described with reference to particular features, those functions may be performed by other features, whether or not described.

[0061] Although features have been described with reference to particular embodiments, those features may be present in other embodiments whether or not they are described.

[0062] Although the foregoing specification has attempted to draw attention to those features of the invention which are believed to be particularly important, it is to be understood that the applicant claims protection for any patentable feature or combination of features referred to in this specification and / or shown in the drawings, whether or not specifically emphasized.

Claims

1. An overhead contact wire clamp that can be fixed to an overhead contact wire, a pincer member; 1. An overhead contact wire clamp comprising: a hinge that allows the pincer member to actuate between an open position and a closed position, wherein the pincer member is configured to secure the overhead contact wire in the closed position; and a manual latch configured to actuate the pincer member between the open position and the closed position.

2. The overhead contact wire clamp of claim 1 , wherein the manual latch comprises a manual lever.

3. 2. The overhead contact wire clamp of claim 1, wherein the manual latch is a bistable latch mechanism.

4. 2. The overhead contact wire clamp of claim 1, wherein the manual latch comprises a stud interconnecting the pincer members, one end of the stud being secured to the manual latch and configured to compress against a first one of the pincer members, and the other end of the stud being secured to a second one of the pincer members opposite the first pincer member.

5. 2. The overhead contact wire clamp of claim 1, wherein the manual latch further comprises a catch engageable when the pincer member is actuated in the closed position to prevent movement of the pincer member away from the closed position.

6. 2. The overhead contact wire clamp of claim 1, further comprising a conductive material for forming an electrical connection between a socket of the overhead contact wire clamp and the pincer member.

7. In the form of an overhead contact wire clamp configured to secure a dropper to an overhead contact wire in the form of an overhead contact wire with a gutter, the overhead contact wire clamp comprising: a dropper connector for securing the overhead contact wire clamp to the dropper; the pincer member and the pincer member are each shaped to fit within the groove of a corresponding one of the imaginary contact lines when the pincer member is in a closed position; the hinge enabling the pincer member to move between the open and closed positions; 2. The overhead contact wire clamp of claim 1, further comprising: said manual latch configured to actuate said pincer member between said open position and said closed position.

8. An overhead contact wire clamp as described in claim 7, wherein the manual latch comprises a manual lever, the stroke length of the manual lever being configured such that when the manual lever is at one end of its stroke, the pincer members are in the open position spaced far enough apart to receive the groove of the overhead contact wire therebetween, and when the manual lever is at a second end of its stroke, the pincer members are in the closed position clamping against the groove.

9. 9. The overhead contact wire clamp of claim 8, wherein the manual lever has a mechanical advantage of greater than two.

10. An overhead contact wire clamp as described in claim 7, wherein the manual latch is a bistable latch mechanism and the manual latch is an over-center latch.

11. An overhead contact wire clamp as described in claim 10 dependent on claim 8, wherein the manual latch comprises a manual lever, and the over-center latch comprises a manual lever configured to rotate a cam to actuate the pincer member.

12. 12. The overhead contact wire clamp of claim 11, wherein the manual lever is configured to rotate the cam to actuate the pincer member and provide toggle feedback to a user indicating that the pincer member is in the closed position.

13. An overhead contact wire clamp as described in claim 7, wherein the manual latch further comprises a catch engageable when the pincer member is actuated in the closed position to prevent the pincer member from moving away from the closed position, the catch comprising a slot toward the distal end of the manual lever, the slot in the manual lever being coaxially aligned above the dropper connector when the manual lever reaches the latched closed position.

14. 8. The overhead contact wire clamp of claim 7, wherein the hinge is a living hinge.

15. 8. The overhead contact wire clamp of claim 7, wherein the hinge comprises the dropper connector.

16. 8. The overhead contact wire clamp of claim 7, wherein the dropper connector comprises a socket for receiving the dropper.

17. 17. The overhead contact wire clamp of claim 16, wherein the socket is disposed on the hinge such that when the pincer member moves to the closed position, deformation of the hinge compresses the socket to secure the overhead contact wire clamp to the dropper.

18. An aerial contact wire clamp as described in claim 17, comprising a conductive material for forming an electrical connection between the dropper connector and the pincer member, and the hinge comprising the conductive material.

19. 20. The overhead contact wire clamp of claim 18, wherein the hinge is integral with the pincer member.

20. 20. A system comprising the overhead contact wire clamp of any one of claims 7 to 19, the overhead contact wire, and the dropper.

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