Abstract: A cable straightener removes mini-bends from cable as it is unwound from a reel for installation in an underground duct, providing improved blowing performance for any cable with non-negligible stiffness and that exhibits reel-set or shape memory recovery, for example cables enclosed within small diameter tubular steel jackets, cables enclosed within aluminum laminated polymer sheets, and cables enclosed within hard polymer tubing. Residual stresses induced in such cables are reduced by first and second sets of straightener rollers prior to pushing/blowing installation.

Abstract: Method and device for installing cables in ducts using a pressurized fluid, a fluid being applied which, under the operational pressure and operational temperature applied during the installation, is in a liquid state and which, under the ambient pressure and ambient temperature prevailing at the location of the installation, is in gaseous state. By applying such a fluid, the advantages of installing a cable using a liquid flow and using a gas flow may be combined, while the drawbacks respectively associated therewith are obviated.

Abstract: A method for installing a ducting system with branches, wherein at the point of a branch in an existing duct of the system a splittable Y-branch connector with an inlet opening, an outlet opening and at least one branch opening is installed by cutting a duct portion from the existing duct at the point of the branch, opening the splittable branch connector and arranging it around a bundle of guide tubes extending between the cut end portions of the duct, and closing and securing the Y-branch connector with splittable coupling collars in such a manner that the inlet opening and the outlet opening engage in sealing manner over the respective cut ends of the existing duct, and the branch opening is secured by engagement of a branch stub around a branch duct through which a branch guide tube is laid.

Abstract: Guide tubes are arranged in a loose bundle and are fed into an existing tubular conduit or protective duct by a powered tractor and are pulled through the duct by the volumetric flow of compressed air which is introduced into the inlet end of the duct. The guide tubes are pressurized and closed at their leading end and trailing end. The existing duct is open at both ends. When the filling degree of the guide tube bundle (sum of guide tube cross-sectional areas compared to that of channelization duct) is provided in the range of from about 30% to about 60%, blowing/pushing installation of the guide tube bundle is substantially trouble free, and the bundle of guide tubes can be installed in a flexible and efficient manner over relatively greater distances.

Abstract: A method and apparatus for installing a cable in a tube is provided wherein the cable is installed by the combination of a pushing force and a pressurized fluid drag force. In particular, the pressurized fluid drag force is applied by alternately passing a first pressurized fluid having first hydrodynamic properties and a second pressurized fluid having second (different) hydrodynamic properties into the tube at substantially a same location.

Abstract: The invention pertains to a method of installing cables (2) in cable ducts (6a, 6b, 6c) using installation devices (1) propelling the cables (2) into the ducts (6a, 6b, 6c). In accordance with the invention, the installation devices (1) are powered by means of pressurized fluid (f), such as air, transported through the ducts (6a, 6b, 6c). This results in a smaller number of compressors (4) and operators being necessary. The duct in which a cable is installed and/or parallel ducts may be used for transporting the pressurized fluid (f). The feed direction of the cable (=>) may coincide with, or be opposed to, the transport direction of the fluid (->). The invention further provides an installation device (1) for use in the method. Method and device for installing cables.

Abstract: With the object of removing moisture from a system of N.gtoreq.2 elongated hollow guiding members (20) for cable-like elements (27), in the system a gas flow (G) is maintained. The gas flow is supplied to the system by way of a gas-supply opening (29) of a coupling-in number (23) coupled to first ends (21) of a number of K hollow guiding members (20) and discharged from the system by way of a gas-discharge opening (30) of a coupling-out member (23) coupled to first ends (21) of the L=N-K remaining hollow guiding members. A coupling-through member (26) coupled to second ends (24) of the N hollow guiding members (20) provides a gastight coupling-through between the second ends (24) of the K hollow guiding members and the L second ends of the L remaining hollow guiding members. Preferably K=N-1, and the N-1 hollow guiding members are located within the Nth hollow guiding member.

Abstract: For removing cables from tubes, the invention provides a method wherein a cable is sucked from a tube, by connecting an evacuating pump to a cable lead-through apparatus one end of which is connected to the tube and the other end of which is provided with a lead-out opening for the free end of the cable. In one embodiment, the final portion of the cable is removed from the tube by connecting a compressor to the same cable lead-through apparatus. The invention also provides an apparatus for removing cables through suction force, wherein, in one embodiment, the same apparatus can also be used for installing cables in a tube through blowing.

Abstract: A pulling element is provided for use in installing, by means of compressed area, cables in a ducting system including ducts having different inner diameters. The pulling element includes a first part having a first end which is connectable to a cable and a second end which includes a coupling member, wherein first flexible members are provided around a body of the first part for sealing engagement with an inner wall of a first duct having a first inner diameter. The pulling element also includes a second part having a central longitudinal opening and a coupling element capable of cooperating with the coupling member of the first part so as to actively couple the first and second parts when the first part is proximal to the second part, wherein second flexible members are provided around a body of the second part for engagement with an inner wall of a second duct having a second inner diameter greater than the first inner diameter.

Abstract: A tube connector comprising an elongate hollow body with an opening at both ends for receiving the end of a tube of a pair of tubes to be coupled to each other, which tube connector comprises means for providing, upon completion of the connection between the connector and the tubes to be connected, a passage for air from the interior of at least one of the tubes to the surroundings.The use of such connectors in installing glass fiber cables or bundles in a tube line consisting of more than one tube by means of a blowing technique has as an advantage that the course of the pressure gradient along the tube line is more linear than in the case where the connectors couple the successive tubes completely hermetically.

Abstract: A cable (5) is inserted in a tube (2) wound on a tube reel (1). The cable is fed from a cable reel (6) through a cable-advancing unit (4) into a free inlet end (2.1) of the tube (2). Compressed air is applied to an air inlet (8) of the advancing unit (4), and led through the tube along the cable already inserted in the tube. The tube reel is put on a support 7, which is driven to a periodic movement in the vertical direction between to extreme positions (amplitude A, period P). During part of each period the movement is a free fall, or at least approximates a free fall. The movement may be sinusoidal with period P=2.pi.?A/g!.sup.1/2 (g is gravitational constant). In this case, the support (7) may be part of a rotatably supported lever, or may be part of a seesaw. In addition, the movement may be the vertical component of a maintained swinging movement. In this case the support (7) may be the swinging part of a Chinese swing.

Abstract: A cable (5) is inserted, by way of a free end (2.1), into a tube (2) wound around a tube reel (1) which is fixed, with its winding axis (y) vertical, onto a carrier (7). The carrier with the tube reel is subjected to a periodical movement having a vertical component and a longitudinal component. The vertical component is a vertical oscillation having a period (P) and an amplitude (A.sub.v =gP.sup.2 /32) for an, at any rate approximately, "free-fall" movement during part of each period, preferably during half a period. The longitudinal component is an oscillating rotation around the vertical winding axis of the tube reel having the same period (P) and an amplitude (A.sub.L). The "free-fall" movement is preferably commenced when the rotational direction of the oscillating rotation is reversed and becomes backward, as opposed to the insertion direction of the cable.

Abstract: The invention pertains to a method of installing cables (2) in cable ducts (6a, 6b, 6c) using installation devices (1) propelling the cables (2) into the ducts (6a, 6b, 6c). In accordance with the invention, the installation devices (1) are powered by means of pressurized fluid (f), such as air, transported through the ducts (6a, 6b, 6c). This results in a smaller number of compressors (4) and operators being necessary. The duct in which a cable is installed and/or parallel ducts may be used for transporting the pressurized fluid (f). The feed direction of the cable () may coincide with, or be opposed to, the transport direction of the fluid (.fwdarw.). The invention further provides an installation device (1) for use in the method.

Abstract: A method for installing a tube or a bundle of tubes in an existing tubular conduit. The tube or tubes are passed into the existing tube by means of a fluid under pressure which is introduced into the existing tube at the inlet end. The tube or tubes can be open or closed at their forward end and are connected to a guide device and/or a pulling device. The existing tube can be open or closed at the end. With the method according to the invention, tubes can installed in an existing tube in a flexible and efficient manner, which tubes can be used for various purposes, for instance as an envelope of telecommunication cables.

Abstract: A method for installing a tubular cable-duct around a cable buried in the ground includes steps of freeing a portion of the buried cable from the ground in a forward longitudinal direction of the cable, starting from a free end of the buried cable, and advancing a foremost end of the cable-duct and subsequent portions of the cable-duct in the forward longitudinal direction of the cable over the portion of the cable freed from ground, starting from the free end of the cable. The advancing step includes the sub-steps of exerting pulling forces on the cable with a pulling device engaging the free end of the buried cable in a direction which is substantially opposed to the forward longitudinal direction of the cable, and exerting pushing forces with a pushing device engaging the cable-duct in a direction which is substantially opposed to the direction in which the pulling forces are exerted.

Abstract: A partially leaky pulling plug (10) coupled to the foremost end (8) of a cable (4) which is to be pulled through a tubular cable conduit (6) with the aid of drag forces of a flowing medium, is provided with a suitably dimensioned flow opening (12) for allowing the flow-through of the flowing medium in a manner not reducing the drag forces considerably, however with a certain pressure difference (Px-Px') across the plug (10). This pressure difference imparts thrust to the plug. The thrust of the plug exerts additional tensile forces on the foremost end (8) of the cable. Preferably the plug has a circumferential suction seal with the inside wall (11) of the conduit (6), and the flow opening is dimensioned such that during installation the flow velocity in the flow opening is essentially equal to that of sound in the flowing medium. The flow opening (12) may be fixedly chosen or may vary in a pressure-dependent manner.

Abstract: The invention relates to a method, a device and a method for installing a cable in a tubular cable duct. In the method, the foremost end (3) of the cable (1) in the duct (10) and subsequent portions of the cable are first accelerated in a short time with continuous supply of further portions of cable from a torsion-free store. Then, from the instant a certain speed v is reached, the cable is maintained at a tension such that, at said speed and tension, centrifugal forces in bends and inwardly pulling components of tensioning forces in the cable compensate for one another at the position of said bends, the further portions of the cable being supplied at a supply speed such that the part of the cable already fed into the duct can continue to slide on the basis of its mass moment of inertia.

Abstract: The invention relates to a method, a device and a method for installing a cable in a tubular cable duct. In the method, the foremost end (3) of the cable (1) in the duct (10) and subsequent portions of the cable are first accelerated in a short time with continuous supply of further portions of cable from a torsion-free store. Then, from the instant a certain speed v is reached, the cable is maintained at a tension such that, at said speed and tension, centrifugal forces in bends and inwardly pulling components of tensioning forces in the cable compensate for one another at the position of said bends, the further portions of the cable being supplied at a supply speed such that the part of the cable already fed into the duct can continue to slide on the basis of its mass moment of inertia.

Abstract: An improved method for installing a cable (4) in a tubular cable conduit (6) with the aid of the drag forces of a flowing medium by applying additional tensile forces by a partially leaky pulling plug (10) coupled to the foremost end (8) of the cable and a partially leaky pulling plug for carrying out the improved method. The plug is provided with a suitably dimensioned flow opening (12) for allowing the flow through of the flowing medium in a manner not reducing the drag forces considerably, however with a certain pressure difference (Px--Px') across the plug (10). This pressure difference imparts thrust to the plug. The thrust of the plug exerts additional tensile forces on the foremost end (8) of the cable. Preferably the plug has a circumferential suction seal with the inside wall (11) of the conduit (6), and the flow opening is dimensioned such that during installation the flow velocity in the flow opening is essentially equal to that of sound in the flowing medium.

Abstract: A method and device for installing a cable, more in particular a glass fiber cable, into a duct of a channelization system, the consideration which has led to this being based on the fact that the dragging working, considered from the cable inlet end, as caused by a flow of compressed gas effected in a relevant duct portion will increase according to a non-constant function and, dependent on the geometry and the length of the duct portion, can be insufficient over the initial part of it to compensate the friction forces exerted on the cable locally. According to the invention it has now been suggested to fulfill such a compensation function by exerting on the cable a pushing force working extending to the point where the dragging working will be sufficient to compensate the friction forces.