MXPA98009235A - Conveyor for use in the insertion of an extraction line within uncondu - Google Patents

Abstract

An air-flow activated conveyor (I) for pulling an extraction line (6) through a length of a conduit (2) having an inlet and outlet end, said conveyor comprises an arrow (3) having one end guide (4) for pulling a rear end (5), means (7) on said rear end receiving and retaining a guide end of said extraction line, at least one element of air flow mitigation (9, 10) coupled said arrow that at least partially interrupts a flow of air introduced at the inlet end of said conduit from an air source for said conveyor from the rear end driven said conveyor along said tube driving said extraction line along of it and through said exit

Description

CONVEYOR FOR USE IN THE INSERTION OF AN EXTRACTION LINE INSIDE A CONDUIT BACKGROUND OF THE INVENTION The present invention relates to an apparatus for use in the insertion of an extraction line into a conduit and more particularly to an air-flow activated conveyor for use in effecting that insertion.

PREVIOUS TECHNIQUE The telecommunication cables lie mostly underground these days in specially constructed trenches. To protect the cables from potential damage from water, debris and bugs, communication cables are typically placed inside plastic conduits (usually polyvinylchloride (PVC)). There are many thousands of kilometers of such cables already deposited in underground conduits, but due to the rapid increase in telecommunications and thus the need for more cables, presumably, hundreds of thousands of kilometers of cable will be required in the future.

There are generally three catees of conduits installed, those that are left empty in reserve waiting to receive new cables, those that are already partially full and those that are completely occupied with cables. These are the first and second catees mentioned above with which the invention is mainly related. The process of inserting cables into conduits is time-consuming, requires intensive labor and thus is costly. The existing methods for inserting extraction lines in the ducts are slow, laborious and inefficient.

To feed a cable through a conduit it is necessary to insert an extraction line into the conduit that is then anchored to the front end of the cable so that it can be pulled through the end of the length of the conduit. The extraction lines can be inserted and simply left to rest inside a conduit waiting for the subsequent insertion of a cable. The above is useful for the cable installer since in this case the extraction line is already placed in the conduit before the installation of the cable which allows the extraction line to be easily coupled to the front end of the cable that is pulled then through the extraction line. An existing method for inserting an extraction line into a conduit includes the use of a crude parachute to which an extraction line is connected. The parachute is inserted via an inlet end into the conduit. Pressurized air is then supplied to the parachute which causes it to inflate after which it leaves the tube taking the extraction line with it. To maintain the required positive air pressure, the inlet end of the duct must seal to prevent air escaping. The above is currently carried out in a crude manner by inserting at the entrance end of the duct rags and the like which must be manually held in position while the positive pressure is supplied to the interior of the tube. Positive pressure is introduced into the duct via a copper tube that is connected to a source of pressurized air. Rags and other similar packaging surround the copper tube. The line of attraction must be free enough to travel through or around the package resulting in a compromise to seal integrity resulting in loss of pressure in the conduit via the inlet end. Sealing the duct with pulp has presented a major problem for operators and has a particular problem when the duct is full of water and debris due to the hangover. When a conduit is under pressure and is sealed ineffectively, pressurization can push water and debris out through the inlet end of the conduit. The sealing of the conduit has been particularly difficult in the case where a conduit is partially filled with cables. Another problem that arises from the use of the previous method is that of the collapse or puckering of the parachute. The parachute used in the present invention essentially comprises a sheet of textile material or the like to which it connects at points located peripherally one end of each of multiple lengths of thread each of which ends at its other end in a joint that also receives the extreme guide of the line of attraction.

The parachute is prone to collapse within the conduit particularly if the air is collected asymmetrically in the parachute allowing more air to pass around an edge compared to the symmetrical by the passage and the proper balance of the parachute in normal operation. This imbalance can cause the parachute to turn, entangling the connecting wires in which case the thread can capture the air that collects the parachute fabric. The above means that the entangled parachute has to be "fished" out of the conduit and the process must restart by increasing the time and labor involved in the insertion of the extraction line. In practice this problem can occur repeatedly before reaching the insertion successfully.

An additional problem may occur where the cables inside a partially filled conduit cross to form a V that then captures the parachute in the throat of the V shape. When this occurs the extraction line (thread) continues to be driven by air beyond the parachute capture point giving the operating personnel the impression that the parachute is still pulling the extraction line through the conduit when in fact it is stuck. The parachute must be released from the capture point by pulling the extraction line through the conduit followed by repeated attempts of insertion until the parachute travels successfully through the tube. The above is inefficient, intense in work and time consuming.

There are other problems with the use of the arrangements of the prior art: for example, the wire of the extraction line comes into contact with the hands of the user during the feeding being a risk of "burn with cable" and the copper tube is It must hold in position by an operator along with the package of rags and sponges to prevent explosions. In addition, two men are usually required in the duct well, one to feed the extraction line and the other to hold the copper air line and the rags in position.

In another method of the prior art, poles can be inserted from either end of a conduit until they are in the middle after which the conduit is cut and joined creating another undesirable union and thus another site through which water can enter. Unwanted. Push poles can be inserted from one end of a conduit to 100 meters. This method is laborious and can lead to damage to the wiring within the conduit particularly where a thrust post comes into contact with a formation V described above.

SUMMARY OF THE INVENTION The present invention provides an apparatus that allows the free insertion of problems of extraction lines into conduits adapted to carry cables such as, but not limited to, telecommunication cables. The present invention is used in conjunction with an apparatus that has become the subject of a co-pending application of the present inventor which overcomes the problems of the aforementioned prior art methodology. In accordance with the present invention there is provided an air-assisted self-sufficient conveyor for pulling an extraction line through a length of conduit.

In its broadest form, the present invention comprises: an air-activated conveyor for pulling an extraction line through a length of conduit having inlet and outlet ends, said conveyor comprising: an arrow having a guide end and an end later; means at said rear end receiving and retaining a guide end of said extraction line; at least one air flow mitigation element coupled to said arrow that at least partially interrupts a flow of air introduced at the inlet end of said conduit from an air source for said conveyor from the rear end and thereby urging said conveyor to along said tube driving said extraction line along said tube and through said outlet.

Preferably, the means for delaying the air flow comprise at least one air manifold between the ends of the arrow and arranged radially around said arrow and widened in the direction of the rear end. Each carrier preferably comprises at least one radial array of air collecting cells or at least one flexible skirt.

According to an alternative example the air collectors can be defined as a flexible skirt where the skirt of each collector captures the air and moves radially of said arrow in response to positive air pressure thus creating a low friction coupling between one end widening of each of the skirts and the inner wall of the duct. The leading edge of the arrow ends in a nose cone and the leading end of each of the remaining pickers includes a small opening that allows positive air pressure to flow out in the direction of the guide picker to ensure that the guide picker does not lack air.

The skirt of each of the collectors ends at or near said nose cone and allows the positive air pressure in each of the collectors to exit via said nose cone thus reversing the direction of the air leaving each collector. The collectors can be fixed independently of the arrow.

In an alternative example, the air collector may comprise a structure similar to an umbrella connected to the arrow. The configuration, material and texture can vary according to the circumstances, such as the internal state of the duct in which the extraction line is inserted.

According to an alternative example, the conveyor can include means at the guide end and the trailing end to allow the coupling of a conveyor to multiple conveyors where required. Said means may comprise detachable couplings. The coupling can be effected by means of parts with male / female profile at the end of the adjacent arrow elements.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will now be described in greater detail in accordance with a preferred non-limiting example and with reference to the accompanying drawings in which: Figure 1 shows an isometric view of a conveyor having a pair of air collectors and inserted in a conduit according to a copy of the invention; Figure 2 shows an enlarged view of the conveyor comprising two arrow elements; Figure 3 shows the conveyor of Figure 2 with arrow elements coupled together; Figure 4 shows a conveyor with an air collector comprising an array of collecting cells; Figure 5 shows a tandem conveyor with guide and posterior collectors where the rear collector has gaps.

DETAILED DESCRIPTION OF THE PREDILLE EXAMPLE With reference to Figure 1 there is illustrated a conveyor 1 conforming to an exemplary adapted to travel along the interior of a conduit 2 under the assistance of positive air pressure from an air source (not shown) applied at one end of the tube entrance. It will be recognized that the exemplary conveyor illustrated in Figure 1 is only one example of a wide variety of conveyor configurations. For example, a conveyor may comprise an arrow element with one or more collectors that may be of the type of a flexible skirt or of the type of an air collection cell. Thus, in the case where multiple collectors are used in an arrow element, the collectors must be of the same type or a combination of the skirt variety and the variety of air collection cells. The conveyor 1 comprises a generally elongated shaft 3 having a guide end 4 and a rear end 5. In use, the conveyor 1 pulls an extraction line 6 from an inlet end of the tube to an end of the tube. departure. The rear end 5 of the arrow 3 includes connecting means 7 receiving a simple knot to which said guide end 6a of the extraction line 6 is attached. The rear end 4 of the arrow 3 has itself mounted a nose cone 8 which provides an aerodynamic guide tip profile and contributes to the balance and operation of the conveyor. Between the ends of the arrow there are two longitudinally separated air collectors 9 and 10. The collectors 9 and 10 illustrated are formed from a radial array of air collection cells arranged radially around the arrow 3. According to an alternative example you can use an arrangement only, with a minimum of two air collectors arranged diametrically. ideally the air collectors are symmetrically arranged around the axis of the arrow 3 to prevent the out-of-balance forces generated by the air pressure, which tend to twist or entangle the conveyor making directional stability. Ideally, the conveyor is of sufficient strength to prevent the possibility of turning inside the conduit in which case the conveyor would get stuck as in the prior art arrangements previously described.

Each of the harvesters 9 and 10 comprises a plurality of air collecting skirts 11 arranged radially each of which comprises a flexible material.

Each of said collectors is at least partially fixed to the arrow 3. Each collecting skirt 11 is angled from its guide edge to its trailing edge.

Once the extraction line 6 is connected to the connecting means 7 which can comprise an elastic cycle through which the line 6 can be placed and the tube end sealed, the conveyor 1 is ready for use. Once the inlet end of the conduit 2 is sealed, the air from a pressurized air source is introduced into the region 13 of the conduit 2 after which the collecting skirts 11 of the conveyor 1 are displaced radially as they collect the pressurized air . The foregoing causes the conveyor to travel along the conduit 2 at an extremely rapid rate until it exits the conduit pulling the extraction line 6 together with it. Once the extraction line 6 is through the tube, the conveyor 1 is uncoupled from the extraction line 6 to be reused.

Where a single air collector is used, it is preferable that the skirt (where the skirt variety is used) or the envelopes (where the variety of harvesting cells is used) displaced radially to a point that enlarges the collection of air. Thus, it is ideal that the displacement is such that the air collection of the entire transverse area of the tube is achieved. The above will result in the skirt or cells engaging the inner wall of the conduit 2 as the skirt or cell envelopes move radially. Where multiple collectors are used, subsequent collectors will include an opening for the guide end to allow air to pass to ensure that the guide end of the collector does not lack pressurized air. Also the later collectors will allow passage around the periphery of the skirt or the air collection cells.

Figure 2 shows an enlarged view of a double conveyor similar to the example of the invention illustrated in Figure 1.

Each conveyor can be connected by rope to an adjacent conveyor so that uncoupling a conveyor from an adjacent conveyor is a relatively simple matter. Similarly, the extraction line 6 can be uncoupled and coupled as an alternative by means of a rope connection at the rear end 5 of the arrow 3.

Figure 2 shows mutually separated arrow elements 20 and 21. The arrow element 20 includes the flexible skirt collector 22 and the arrow element 21 comprises the skirt collector 23. The arrow elements 20 and 21 are engageable by means of a female male interconnection with rope. The element 20 comprises the part of male profile with rope 24 and the element 21 the part with female profile 25. This arrangement allows convenient adjustment to the length of the conveyor according to the requirements.

Figure 3 shows the skirt pickers 22 and 23 as they appear when the arrow (hidden) elements of the conveyor of Figure 2 are coupled together.

Figure 4 shows a single arrow element 30 with a collector 31 comprising air collection cells 32 according to an alternative example of the invention.

Figure 5 shows a tandem conveyor 40 comprising arrow elements 41 and 42 including in them respectively the pickers 43 and 44. The collector 43 includes in each of the air collection cells 45 an opening or openings 46 that provide an opportunity for the passage of air which prevents the guide collector 44 from lacking pressurized air.

It will be recognized by those skilled in the art that numerous variations and modifications can be made to the invention so widely described herein without departing from the spirit and scope of the invention.

Claims (18)

1. CLAIMS: 1. An air-activated conveyor for pulling an extraction line through a length of conduit having an inlet end and an outlet end, said conveyor comprising: an arrow having a guiding end and a trailing end; means at said rear end receiving and retaining a guide end of said extraction line; at least one air flow mitigation element coupled to said arrow that at least partially interrupts a flow of air introduced at the inlet end of said conduit from an air source for said conveyor from the rear end and thereby urging said conveyor to along said tube driving said extraction line along said tube and through said outlet.
2. 2. A conveyor according to Claim 1 wherein said mitigation elements comprise a collector or air collectors that receive air to drive said conveyor through said tube.
3. 3. A conveyor according to Claim 2 wherein at least one collector comprises an array of separate air collecting cells adjacent to each and disposed radially around said arrow.
4. 4. A conveyor according to claim 3 wherein each of said cells is formed by a flexible envelope that is inflated after the entry of air into it.
5. 5. A conveyor according to Claim 2 wherein at least one of said pickers comprises a flexible membrane in the shape of a skirt having an end fixed to said arrow and a free opposite end moving radially of said arrow when the air is collected. by said flexible membrane.
6. 6. A conveyor according to Claim 5 wherein, when multiple air collectors are attached to said arrow, a guide air collector, upon entry of the air, expands to a point where the flexible envelope can be attached to the interior wall of the air. tube so that minimum, if any, air passes to said collector and one or more subsequent collectors allow the passage of air to prevent the air collector guide lacks air.
7. 7. A conveyor according to Claim 6 wherein at least one collector comprises a flexible skirt and at least one other collector comprises said air collecting cells.
8. 8. A conveyor according to Claim 7 wherein a guide collector comprises said cells and at least one subsequent collector comprises said flexible skirt.
9. 9. A conveyor according to Claim 7 wherein a guide collector comprises said flexible skirt and at least one subsequent collector comprises said collector cells.
10. 10. A conveyor according to Claim 8 or 9 wherein the guiding end of a guide collector includes a nose cone.
11. 11. A conveyor according to Claim 10 wherein each collector '5 has a nose cone.
12. 12. A conveyor according to Claim 11 wherein the arrow comprises interconnected arrow elements detachable from an adjacent arrow element.
13. 13. A conveyor according to claim 12 wherein each of the arrow elements includes at least one air collector mounted thereon.
14. 14. A conveyor according to Claim 6 wherein the material of the flexible cells or the flexible skirt is a fabric.
15. 15. A conveyor according to Claim 14 wherein when multiple collectors are on said arrow are arranged in an axial alignment.
16. 16. A conveyor according to Claim 15 wherein an arrow element engages as a screw to an adjacent element.
17. 17. A conveyor according to Claim 16 wherein said arrow includes a plurality of collectors, each subsequent collector has openings for the air passage 25 to reduce or prevent the lack of air to the guide collector.
18. 18. A conveyor according to Claim 16 wherein the flexible skirt is reinforced with wires. EXTRACT OF THE INVENTION An air flow activated conveyor (1) for pulling an extraction line (6) through a length of a duct (2) having an inlet and outlet end, said conveyor comprises an arrow (3) having a guide end (4) for pulling a rear end (5); means (7) at said rear end receiving and retaining a guide end of said extraction line; at least one air flow mitigation element (9, 10) coupled to said arrow which at least partially interrupts a flow of air introduced at the inlet end of said duct from an air source for said conveyor from the rear end driving thus said conveyor along said tube driving said extraction line along said tube and through said outlet.