CA1190030A

CA1190030A - Device for splicing cable ends

Info

Publication number: CA1190030A
Application number: CA000399100A
Authority: CA
Inventors: Gustaaf Stipdonk
Original assignee: HEY MAJESTY QUEEN IN RIGHT OF PROVINCE OF ALBERTA ALBERTA OIL SANDS EQUITY; Petro Canada Exploration Inc; Esso Resources Canada Ltd; Pancanadian Petroleum Ltd; Alberta Energy Co Ltd; Hudsons Bay Oil and Gas Co Ltd; Gulf Canada Ltd; Canada Cities Service Ltd; Petrofina Canada Inc
Current assignee: HEY MAJESTY QUEEN IN RIGHT OF PROVINCE OF ALBERTA ALBERTA OIL SANDS EQUITY; Petro Canada Exploration Inc; Hudsons Bay Oil and Gas Co Ltd; Gulf Canada Ltd; Canada Cities Service Ltd; Imperial Oil Resources Ltd; Petro Canada Enterprises Inc; Ovintiv Canada ULC
Priority date: 1982-03-23
Filing date: 1982-03-23
Publication date: 1985-07-09
Also published as: DE3310224C2; JPS58203213A; DE3310224A1; GB2118583B; AU545939B2; GB8308001D0; GB2118583A; AU1264083A

Abstract

"DEVICE FOR SPLICING CABLE ENDS" A steel connector for joining the steel cable ends of a conveyor belt is provided. The connector comprises a pair of tubular sleeves - one of which is slipped onto each cable end. Each sleeve has a bore having an inner section of reduced diameter relative to the outer section. The cable end is expanded radially, by driving a cone into its end, and then the expanded end is wedged tightly into the inner section of the sleeve to fix them together. Bridging means are threaded into the outer sections of the two sleeves to hold them together in lineal alignment. The bridging means is operative to permit the sleeves to flex relative to each other.

Description

3~

l FIELD OF T~IE INVENTION

2 This 1nvention relates to a connector for joining two

3 steel cable ends. The connector finds particular application for

4 splicing cable ends ~n a conveyor belt.

RACKGROUND OF THE INVENTION
__ _ 6 The invention has been developed in connection with -the 7 very large conveyor belts used in Alberta to transport tar sand from a 8 mine to a bitumen recovery plant. Therefore the invention and the 9 problems which it seeks to alleviate are described below with respect to this particular application; however~ it is to be understood that ll the invention is not limited to said application.
12 The tar sand conveyor belts are larye and operate in 13 demanding conditions. They commonly have a width of 60 inches and 14 may stretch in length over a distance of several hundred feet or several miles, depending on their role in the system. In use, a 16 stream of tar sand is continuously dropped onto the endless belt at 17 the loading point, to form a furrow about 55 inches in width and 18 12 inches in height. The stream usually includes large boulders l9 and,in winter, chunks of frozen tar sand. Some of these pieces weigh hundreds or thousands of pounds and, in some cases~ they are 21 dropped onto the belt from a height of several feet. As a result, 22 the belts frequently e~perience deep cuts and impact stress. In 23 addition, the hydrocarbons present in the tar sand tend to permeate 24 the material of the belt and cause deterioration.
In structure, each belt comprises a bottom layer of rubber, 26 a series of steel cables laid lengthwise in parallel, closely spaced 27 arrangement on top of the bottom layer, and a top layer of rubber laid 28 over the cables. The three components are bonded together by a middle 29 layer of vulcanized tie-gum rubber.

1 Each conveyor is Formed of one or more supported lengths 2 of belt. In the case of a conveyor made using only a single length 3 of belt, the ends of the length are joined to form an endless belt 4 running on idlers and around two end rolls. In the case of a longer conveyor, the ends of several lengths are joined in sequence in end 6 to end relation to form the endless belt. Furthermore, when a belt 7 fails, it is usual to cut out a short length at the failure point 8 and splice in a substitute length of new material. So each belt in-g cludes one or more joins or splices along its length.
As prevlously mentioned, the belts are subjected to 11 stress and chemical attack thus they periodically fail. These 12 failures commonly occur at the splices.
13 Heretofore the conventional practice for joining the 14 belt ends involved the following: the top layer of rubber would be cut away at the splice zone to expose the cable ends. These ends would be 16 scrupulously cleaned. An end portion of the bottom layer would be cut 17 away. Then the bottom rubber layer ends would be brought into abutment 18 and the cable ends laid in side-by-side overlapping relation. Tie-gum 19 would then be applied to cover the splice zone, a section of top rubber would be laid on, and the whole would be vulcanized.
21 It will be perceived from the foregoing that the connection 22 means between the steel cable ends in a joint of this kind is only the 23 tie-gum rubber, supported by the top and bottom layers o-f rubber As 24 mentioned, this is where f~ilure occurs.
The cost is high for repairing such a failure. The failure 26 point is frequently high off the ground. The weather is often cold.
27 Thus it is frequently necessary to first build a heated shelter high 28 off the ground over the splice area. The splicing procedure itself is 29 slow going and labor intensive. But most important, the belt is out of operation for 2 or 3 days. In the case of a 125,000 BOPD synthetic 3~

1 crude plant, the shutdown oF a belt can reduce the volume of feed to 2 the plant by 25%, which translates into a loss of many thousands of 3 dollars per day.
4 One solution to this problem would be to develop a mechanical connector to join the cable ends. Such a connector pre-6 ferably should have the following characteristics:
7 (1) a high order of strength;
8 (2) compactness, as the closely spaced cables each will g include such a connector at the splice and they must all fit without problem within a limited area, 11 (3) a limited degree of flexibility, to enable the con-12 nector to negotiate the passage over the end rolls 13 without serious problems; and 14 (4) lengthwise adjustability to permit the cables to be pre-tensioned to about the same extent.

17 In accordance with the invention, a steel mechanical 18 connector is provided, to join two steel cable ends.
19 The connector comprises a pair of tubular sleeves~ one for each cable end. Each sleeve forms a longitudinal bore therethrough 21 consisting of two sections - an outer bore section and an inner bore 22 section of reduced cross-sectional area relative to the outer section.
23 The sleeve bore is Gf sufficient cross-sectional area so that the 24 sleeve may easily slip over the cable end.

3~9 l With the sleeve in place on a cable end, a wedge member, 2 such as a metal cone, is embedded in the cable end to enlarge it. The 3 enlarged end is of a size sufficient to pass through the outer bore 4 section but not through the inner bore sec-tion~ The cable end is then pulled tightly into the inner bore section to wedge it therein and 6 provide a friction interlock between cable and sleeve.
7 At this stage, each of the sleeves is affixed to a cable 8 end and extends beyond the latter.
9 A bridging component is then interconnected with each sleeve so as to hold -them together in aligned lineal relation while preferably per-ll mitting of limited universal movement of one sleeve relative to the other.
12 One specific bridging component with these capabilities is described below.
3 Broadly stated, the invention is a connector for joining two 4 cable ends in a conveyor belt, comprising: a pair of sleeves, each such sleeve forming a lontiduinal bore extending therethrough, said bore having an 16 inner section of reduced cross-sectional area relative to the remainder of 17 the bore, said bore being of sufficient cross-sectional area so that each 18 sleeve can slip onto one of the cable ends to be joinedi a pair of wedge 19 elements, each adapted to be embedded in one cable end, once the sleeve has been slipped onto the cable end, to expand said cable end sufficiently so that 21 the expanded end is small enough to enter the bore's outer section but is too 22 large to pass through the bore's inner section, whereby each sleeve may be 23 securely attached to one cable end, and briding means for interconnecting 24 the sleeves, said bridging means comprising rigid elongated first means ex-tending between the sleeves, second means for connecting one end of -the first 26 means with one sleeve and enabling said first means to pivot relative to the 27 longitudinal axis of said sleeve, and third means for connecting the other 28 end of the first means with the other sleeve and enabling said first means to 29 pivot relative to the longitudinal axis of said sleeve, whereby the bridging means is operative to hold the sleeves together in substantially aligned 31 lineal relation while permitting the connector to flex, to a limited extent, 32 when passing around a conveyor roll.

,~ 'b , 5 3~

1 In ano-ther aspect, the invention encompasses a method for 2 connecting two ends of steel cable. The method comprises slipping a 3 tubular sleeve over each cable end, said sleeve having a bore which ~ has an inner section of reduced cross-sectional area relative to its outer section, expanding the cross-sectional area of each such cable 6 end; drawing each sleeve outwardly on its associated cable end, to 7 tightly wedge the expanded cable end into the inner section of the 8 sleeve, and joining the sleeves with bridging means for holding the 9 sleeves together in substantially linear alignment.
The lnvention is exemplified by the preferred embodiment 11 set forth in the drawings and described below.

13 Figures la, lb and lc are top plan views showing the two 14 ends of a conveyor belt with the top rubber layer removed and the bottom rubber layer not shown - the pairs of cable ends to be spliced are 16 shown : in staggered spaced-apart arrangement in Figure lag with the 17 sleeves in place in Figure lb, and with the bridging means in place in 18 Figure lci 19 Figure 2 is a perspective exploded view showing the connector; and 21 Figure 3 is a side sectional view showing a connector 22 joining two cable ends.

__ 24 A connector 1 is shown in the Figures connecting a pair of cable ends 2, which form part of a conveyor belt 3.

~ 6 --3~D

1 The connector 1 comprises a pair of tubular sleeves 4, 2 each sleeve 4 being associated with one oF the cable ends 2. Each 3 such sleeve 4 has a longitudinal bore 5 extending therethrough. The 4 bore 5 consists of an inner section 5a and an outer section 5b. lhe inner section 5a is of reduced cross-sectional area relative to the 6 outer section 5b. More particularly, the inner section 5a is tapered 7 in configuration, while the non-reduced outer section 5b is cyl;ndrical.8 The diameter of the inner section 5a is oF sufficient size so that the 9 sleeve 4 slips easily onto the cable end 2.
A wedge member, specifically a cone 6, is embedded in each 11 cable end 2 to expand it, so that said expanded cable end is too large 12 to pass through the tapered inner section 5a of the bore 5 but is 13 still capable of passing through the non-reduced outer section 5b.
14 The cable end 2 is drawn into its associated sleeve 4 to wedge the expanded cable end 2 tightly into the tapered inner section 5a 16 of the bore 5. Each sleeve 4 is thus fixed on its cable end 2.
17 The outer end 7 of each sleeve 4 is internally threaded.
18 An externally threaded lock screw 8 is screwed deep into the outer 19 section 5b of the bore 5 to abut the cone 6 and prevent it being ex-truded from the cable end 2.
21 A sleeve interconnecting or bridging assembly 9 is provided 22 to ioin the two sleeves 4. The assembly 9 includes a shaft 10 threaded 23 at its ends. Rings 11 are threaded onto the shaft ends to provlde 24 enlarged heads. The rear shoulder 12 of each shaft ring 11 is arcuately formed, as shown. The shaft 10 extends into each of the outer sections 26 5b of the sleeve bores 5. An externally threaded sleeve lock ring 13 is 27 screwed into each bore outer section 5b to trap the relevant shaft head 28 11. The inner shoulder 14 of each sleeve lock ring 13 is arcuately 29 shaped, so as to mate with the shoulder 12 of the head 11. Since the outside diameter of the shaft 10 is slightly less than the internal 3q~

1 diameter of the sleeve lock ring 13, the sleeves 4 may move universally 2 relative to each other. The degree of movement is limited, but is 3 suFficient to ensure that the connector 1 may flex when passing around 4 the conveyor drums.
The invention is characterized by several advantages.
6 Firstly, a steel bond between cable ends now replaces the prior art 7 rubber bond, with consequent improvement with respect to strength 8 and resistance to chemical attack. Secondly, the connector takes up 9 little space, so that a multiplicity of side~by-side pairs of cable ends can be connected within the spatial confines of the belt. Thirdly~
11 the connector has a degree of flexibility in it which allows it to 12 pass around the conveyor drums without cutting into the rubber of the 13 belt. And finally, the connector comprises means for drawlng its 14 associated cable ends together to a sufFicient extent to enable the cables to be pulled tc approximately the same tension.
16 While one specific embodiment of the invention has been 17 shown in the Figures and described above, the scope of the invention 18 is defined by the following claims.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A connector for joining two cable ends in a conveyor belt, comprising:
a pair of sleeves, each such sleeve forming a longitudinal bore extending therethrough, said bore having an inner section of reduced cross-sectional area relative to the remainder of the bore, said bore being of sufficient cross-sectional area so that each sleeve can slip onto one of the cable ends to be joined;
a pair of wedge elements, each adapted to be embedded in one cable end, once the sleeve has been slipped onto the cable end, to expand said cable end sufficiently so that the expanded end is small enough to enter the bore's outer section but is too large to pass through the bore's inner section, whereby each sleeve may be securely attached to one cable end; and bridging means for interconnecting the sleeves, said bridging means comprising rigid elongated first means extending between the sleeves, second means for connecting one end of the first means with one sleeve and enabling said first means to pivot relative to the longi-tudinal axis of said sleeve, and third means for connecting the other end of the first means with the other sleeve and enabling said first means to pivot relative to the longitudinal axis of said sleeve, whereby the bridging means is operative to hold the sleeves together in substantially aligned lineal relation while permitting the connector to flex, to a limited extent, when passing around a conveyor roll.

2. The connector as set forth in claim 1 comprising:
fourth means, associated with said second means, for moving the sleeve, attached to said second means, along the first means; and fifth means, associated with said third means, for moving the sleeve, attached to said third means, along the first means;

whereby the sleeves may be drawn together as required to tension the cable ends.

3. A connector for joining two cable ends in a conveyor belt, comprising:
a pair of sleeves, each such sleeve forming a longitudinal bore extending therethrough, said bore having an internally threaded outer section and an inner section of reduced cross-sectional area relative to that of the outer section, the bore being of sufficient cross sectional area so that each sleeve can slip onto one of the cable ends to be joined;
a pair of wedge members, each adapted to be embedded in one cable end, once the sleeve has been slipped onto the cable end, to expand said cable end sufficiently so that the expanded end is small enough to enter the bore's outer section but it too large to pass through the bore's inner section, whereby each sleeve may be securely attached to one cable end; and bridging means for interconnecting the sleeves, said bridging means being operative to hold the sleeves together in substantially aligned lineal relation while permitting of limited tilting movement of each sleeve relative to the longitudinal axis of the connector , whereby said connector may flex , to a limited extent, when passing around a conveyor roll, said bridging means comprising a shaft, having a removable enlarged head at each end, for extending into each of the bore outer sections, a pair of externally threaded rings adapted to be mounted on the shaft between the heads and to thread into the outer sections of the sleeves, each said ring having a longitudinal bore extending therethrough which is sized to loosely accommodate the shaft but is sufficiently small so that the ring may not pass over the enlarged head, said rings being adapted to connect the sleeves with the shaft, to restrain the contained heads within the sleeves while permitting of some tilting of the shaft, and to be screwed inwardly or outwardly in the sleeves to adjust the spacing between the cable ends, each shaft head and associated ring having rounded mating shoulders which permit of limited flexing of the connector.

4. The connector as set forth in claim 1, further comprising:
a pair of externally threaded screws, each adapted to be screwed into one of the sleeves, before the shaft is inserted, to restrain the wedge member from displacement out of the cable end.

5. A method for connecting two ends of steel cable in an endless conveyor belt having a plurality of such cable end pairs, comprising:
slipping a tubular sleeve over each cable end, said sleeve having a bore which has an inner section of reduced cross-sectional area relative to its outer section;
expanding the cross-sectional area of each such cable end by embedding a wedge in said cable end;
drawing each sleeve outwardly on its associated cable end, to tightly wedge the expanded cable end into the inner section of the sleeve;
joining the sleeves with a bridging means operative to hold the sleeves together in substantially linear alignment, said means being capable of being adjusted to pull the sleeves closer to-gether; and adjusting said bridging means to pull the sleeves together to obtain a tension generally the same as that obtained in the other cable end pairs.