GB2348892A - Swivel connector for ropes - Google Patents

Abstract

A swivelling rope connector has sockets 4, 5 for rope ends 6, 7. Split swivel nuts 8, 9 are assembled about dumbbell-shaped joining piece 10. The nuts are screwed into threaded ends of respective sockets 4, 5 and secured thereto by grub screws 11 - 14 whose heads may be welded over or each secured by a lead pellet. The connector has grease nipples 15 - 18. The plain bearing surfaces provided between nuts 8, 9 and piece 10 are said to withstand high and shock loads better than ball- or roller-bearings.

Description

Improvements in or Relating to Ropes This invention relates to improvements in or relating to ropes and is more particularly concerned with the connection of rope lengths together.

In various industries, long lengths of ropes have to be used and there can be a problem with the build-up of torque in the rope more particularly where long lengths of rope are involved at high load, such as for example in the open-cast mining industry with the drag lines that are used and also in deep water mooring systems used in the oil industry. Such ropes may have to carry loads from 150 tonnes to 700 tonnes. It is known to connect lengths of rope together by a swivelling mechanism connector which uses ball and roller bearings but, in general, the Applicant believes that such previous proposals tend not to be suitable in many applications due to the general inability to withstand high load or shock load. Additionally, such swivelling mechanisms may possibly involve protruding parts which could fail or snag and may have other disadvantages in shape and/or ease of use or maintenance.

It is an object of the present invention to alleviate at least one of the aforementioned problems, or other problem, associated with rope connectors.

According to the present invention there is provided a rope connector comprising two sockets, each socket being for receiving a respective rope end, the sockets being relatively rotatably connectable together by plain thrust bearing means or journal bearing means of the connector.

Further according to the present invention there is provided a rope assembly comprising two lengths of rope connected together by means of a rope connector in accordance with the immediately preceding paragraph.

In one embodiment of the present invention the rope connector has two generally similar swivel nuts each of which locates in a respective open end of the associated socket, said swivel nuts embracing the mid section of a dumbbell shaped joining piece.

Thus, in practice, in said embodiment, the main bearing surfaces of the rope connector will be annular axial surfaces of the swivel nuts in contact with inner annular axial surfaces of respective dumbbell ends of the dumbbell shaped piece.

Preferably, the rope connector is provided with grease nipple means (for example four grease nipples) in order that the bearing surfaces may be lubricated with grease.

Also, preferably, the swivel nuts and dumbbell piece are made from low-friction materials.

Where the rope connector includes swivel nuts, preferably, the swivel nuts are locked in place to their associated socket by fastening means in the form of one or more (grub) screws, the heads of which may be welded over for permanent fixing or the sockets may be provided with a chamber for a lead pellet to be positioned over the top of the screw head, for a system that may require regular dismantling.

Preferably, the rope connector is of a stream lined shape.

Many advantageous features of the rope connector will be apparent from the following description and drawings.

An embodiment of a rope connector in accordance with the present invention, will now be described, by way of example only, with reference to the simplifie diagrammatic FIGURES of the accompanying drawings in which: FIGURE 1 shows a part sectional view through a rope connector in accordance with the present invention joining two ropes relatively rotatably together, and FIGURE 2 shows a modified detail of the rope connector in FIGURE 1.

Referring to the FIGURES of the drawings a rope connector 1 connects two lengths of the rope 2 and 3 together in such a manner that relative rotation of the rope lengths can take place in order to relieve torque build-up.

The rope connector 1 consists of a tapered socket 4 arranged to rotate relative to a similar tapered socket 5; socket 4 being attached to the end of rope 2 and socket 5 being attached to the end of rope 3. Each end of the rope 2,3 is attached to its associated socket 4,5 in a known manner for example using a molten zinc or resin compound 6,7.

The rope connector 1 further includes two similar split swivel nuts 8 and 9 closely embracing the midsection lOa of a dumbbell shaped joining piece 10.

Each of the swivel nuts 8 and 9 is split in order to allow introduction onto the midsection or shaft of the dumbbell portion 10 and each swivel nut 8,9 is screwed into the respective open threaded end 4a, 5a of the sockets 4,5. As shown in FIGURE 1 each swivel nut 8,9 has flange portion 8a, 9a (which is circular in shape to match the diameter of the socket end 4a, 5a) and each swivel nut is screwed up tightly on the socket end 4a, 5a so that the flange 8a, 9a fits tightly and snugly on the axial annular surface of the socket end 4a, 5a. Each swivel nut 8a, 9a is locked or fixed to the respective socket end 8a, 9a by two diametrically opposed grub screws 11,12,13 and 14 in order to prevent accidental release. If the two ropes lengths 2,3 are to be permanently connected together the heads of the grub screws 11, 12,13,14 may be recessed and welded over, for permanent fixing. If the connection of the ropes 2 and 3 is to be temporary then the heads of the grub screws 11,12,13 and 14 need not be welded over.

FIGURE 2 shows a detailed view of a grub screw (for example 11) with a chamber X provided for a lead pellet to be inserted over the head of the grub screw in order to allow for regular dismantling of the rope connector in a manner which should be evident from the drawings.

Four grease nipples 15,16,17 and 18 are provided to allow the central chamber C defined by the two sockets 4 and 5 to be filled with grease, to grease the contact surfaces between the dumbbell and the swivel nuts and to allow future top-up of grease to the chamber C.

Previous rope connectors (not shown) have used ball and roller bearings but such arrangements may not be suitable for withstanding high loads or shock loads that might be incurred with ropes used in mining or mooring systems (more particularly for the oil industry).

Advantageously, the overall shape of the rope connector 1 is streamlined with no protruding parts that could snag or foul on any surrounding structure.

Thus, rope 2 is able to rotate or swivel about its axis relative to rope 3 in order to alleviate or prevent massive torque buildup that may otherwise occur in particular installations and which would otherwise be a serious problem.

As rope can only be made in limited lengths, joining is necessary by one or more rope connectors. Advantageously, the rope connector 1 can be installed in situ at any location and may be employed in a permanent mode (in which the heads of the grub screws are welded over) or in a temporary or reusable mode (as in FIGURE 2) where such welding need not be employed.

Advantageously, attachment of the rope connector 1 to two rope lengths 2,3 can be achieved in a normal engineering environment without special skills or training and the rope connector can, advantageously, be utilised to connect the rope lengths of the same or different diameter together.

Additionally, the rope connector is designed to have a higher breaking load than the rope 2,3 itself for safety reasons.

It is to be noted from the configuration of the rope connector 1, that axial thrust bearing surfaces Y and Z are provided on the swivel nuts and dumbbell respectively and said bearing surfaces are of a very low friction material with grease between them in order to give a better swivel or rotation than a ball and roller bearing.

Normal connection of two rope lengths together would be provided five items (or without swivel capability three items) ie socket end, shackle, swivel, shackle, socket end. However the arrangement as aforedescribed in FIGURE 1 effectively does the same job of said five items. Furthermore, the length of rope-to-rope is reduced.

It is believed that the relative dimensions of the rope connector parts and rope connector and rope are advantageous more particularly from a strength point of view.

It is to be understood that the scope of the present invention is not to be unduly limited by the particular choice of terminology and that a specific term may be replaced by any equivalent or generic term. For example, the term"bearing"could be replaced by"bearing means"."Connector"could be replaced by"joint"or "swivel joint"."Nut"or"dumbbell"may be replaced by"member"."Screw"or "grub screw"may be replaced by"fastener means". The term"rope"is to be interpreted in a broad sense and could comprise a length of material including for example metal and/or carbon fibre and/or may be of any suitable construction.

Further it is to be understood that individual features, method or functions related to the rope connector or bearing means might be individually patentably inventive.

The singular may include the plural or vice versa.

Therefore, still further according to the present invention there is provided a rope connector for connecting two lengths of rope together generally in alignment, said rope connector comprising one or more of the following features: a) Two sockets including bearing means which is a non-ball and/or non-roller bearing; b) Plain thrust bearing means; c) Double plain thrust bearing means; d) Plain journal bearing means; e) Axial annular surfaces on a joining piece which extends into each socket; f) Axial bearing surfaces provided on means (for example swivel nuts) mounted on socket; g) Said rope connector being streamlined; h) A dumbbell shaped joining piece extending between two sockets, and i) Any feature or combination of features derivable from this description and/or FIGURES of the drawings.

Claims (14)

1. Claims 1. A rope connector comprising two sockets, each socket being for receiving a respective rope end, the sockets being relatively rotatably connectable together by plain thrust bearing means or journal bearing means of the connector.
2. 2. A rope connector according to claim 1, wherein the rope connector has two generally similar swivel nuts each of which locates in a respective open end of the associated socket, said swivel nuts embracing the mid section of a dumbbell shaped joining piece.
3. 3. A rope connector according to any preceding claim, wherein the rope connector is provided with grease nipple means in order that the bearing surfaces are lubricated with grease.
4. 4. A rope connector according to claim 3, wherein the grease nipple means comprises four grease nipples.
5. 5. A rope connector according to any of claims 2-4, wherein the swivel nuts and dumbbell piece are made from low-friction materials.
6. 6. A rope connector according to any of claims 2-5, wherein the swivel nuts are locked in place to their associated socket by fastening means.
7. 7. A rope connector according to claim 6, wherein the fastening means takes the form of one or more screws.
8. 8. A rope connector according to claim 7, wherein the or each screw is a grub screw.
9. 9. A rope connector according to claim 7 or 8, wherein the heads of which are welded over for permanent fixing.
10. 10. A rope connector according to claim 7 or 8, wherein the sockets are provided with a chamber for a lead pellet to be positioned over the top of the screw head, for a system that may require regular dismantling.
11. 11. A rope connector according to any preceding claim, wherein the rope connector is of a stream lined shape.
12. 12. A rope assembly comprising two lengths of rope connected together by means of a rope connector in accordance with any of claims 1 to 11.
13. 13. A rope assembly substantially as described herein with reference to figure 1 of the drawings.
14. 14. A rope connector substantially as described herein with reference to figure 2 of the drawings.