Accessory to assist in the installation of a conduit in a duct, known as a conduit puller.
The cable puller's innovative design with a threaded rod and pivoting arms provides simple torque control and reduced bulk, facilitating duct installation across various diameters.
Patent Information
- Application Number
- FR2024000764
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2024-01-26
- Publication Date
- 2025-12-26
- Estimated Expiration
- 2044-01-26
AI Technical Summary
Existing cable pullers for installing ducts are bulky and complex, making them impractical for small diameters, and lack simple control over tightening torque.
A cable puller design featuring a threaded rod with pivoting arms and a drive piece that allows controlled movement of the arms, ensuring a linear function of pivot axis distance based on rod rotations, enabling precise torque control and reduced bulk.
The design enables easy control of clamping torque and reduces bulk, allowing installation of ducts with precise force application across varying diameters.
Smart Images
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Abstract
Description
Title of the invention: Accessory to aid in the installation of a duct in a conduit known as a duct puller
[0001] The present invention relates to an accessory to assist in the installation of a duct in a conduit, hereafter called a duct puller, this duct puller being intended to be inserted into a duct and coupled to a lifting equipment, such as a winch or a cable, to assist in the installation of the duct inside a conduit in particular by hoisting.
[0002] It relates in particular to a cable puller intended to be inserted into a duct and coupled to lifting equipment, such as a winch, to assist in the installation of the duct inside a conduit, in particular by hoisting, said cable puller comprising: - a threaded rod provided at one of its ends, called the upper end, with a hooking element, - arms, - an arm support mounted on the rod, and within which the rod can rotate, each arm being at one of its ends, called the first end, coupled to the support by a pivoting joint around an axis orthogonal to the rod for a movement of said arm between a position close to the rod and a position away from the rod, each arm being equipped at the other of its ends, called the second end, with a pad intended to bear against the inside of the duct to be installed and coupled to the arm by pivoting around a pivot axis parallel to the axis of the pivoting joint of the arm to the support,Each arm whose pivot axis connecting the skate to the arm is parallel to the pivot axis connecting the skate to the arm of another arm, forming with this other arm a pair of arms.
[0003] A cable puller that assists in installing a liner inside a conduit, such as a chimney flue, is known. Typically, such a cable puller is inserted into the liner to be installed. The cable puller is held inside the liner by the pressure of its pads against the inner wall of the liner. The cable puller is also connected, via its attachment mechanism, to a lifting device, such as the cable of a winch positioned at the top of the flue. Once the cable puller is secured to the liner and connected to the lifting device, the lifting device is simply activated to raise the liner inside the flue to the top of the flue. The cable puller can then be detached from the liner and the lifting device. However, cable pullers currently on the market are bulky, making their use for small liner diameters impossible.Furthermore, the design of these cable pullers is complex and makes it difficult to control the tightening torque applied to ensure that the cable puller is properly held inside the sheath by the pressure of the cable puller's pads inside the sheath.
[0004] One object of the invention is to provide a cable puller whose design allows for simple control of the tightening torque.
[0005] Another object of the invention is to propose a cable puller whose design can limit the bulk of the cable puller.
[0006] To this end, the invention relates to a cable puller intended to be inserted into a duct and coupled to a lifting device to assist in the installation of the duct inside a conduit, said cable puller comprising a threaded rod provided at one of its ends, called the upper end, with a hooking element, arms, an arm support mounted on the rod, and inside which the rod can rotate, each arm being at one of its ends, called the first end, coupled to the support by a pivoting joint around an axis orthogonal to the rod for a movement of said arm between a position close to the rod and a position away from the rod, each arm being equipped at the other of its ends, called the second end, with a pad intended to bear against the inside of the duct to be installed and coupled to the arm by pivoting around a pivot axis parallel to the axis of the pivoting joint of the arm to the support,each arm whose pivot axis connecting the pad to the arm is parallel to the pivot axis connecting the pad to the arm of another arm, forming with this other arm a pair of arms, characterized in that the cable puller comprises, carried by the rod, a drive piece for moving the arms to move said arms from one position to another, in that said piece, capable of being immobilized in rotation around the rod, is a threaded piece mounted axially mobile along the rod by cooperation of the thread of the piece with the thread of the rod in the state immobilized in rotation of the piece around the rod and driven in rotation of the rod on itself, in that said piece, in the state driven axially along the rod in the direction of approaching the support, is active by sliding contact on the arms for moving the arms from the approach position to the spread position,and in that the arms of the arm or each pair of arms are configured such that the distance between the pivot axes connecting the skate to the arms of said pair of arms is a linear function of the number of rotational turns of the threaded rod from a reference position corresponding to the position of maximum proximity of the arms of the pair of arms.
[0007] Because the distance between the pivot axes connecting the pad to the arms of said pair of arms is a linear function of the number of rotations of the threaded rod from a reference position corresponding to the position of maximum proximity of the arms of the pair of arms, within manufacturing errors, i.e., within plus or minus two percent, the clamping torque exerted by the pads on the sleeve is more easily controlled by the operator. In other words, when the part is stationary rotating around the rod and the rod is rotated one revolution, the variation in the distance between the pivot axes connecting the pad to the arm the length of the arms of said pair of arms is substantially constant, that is to say, constant to within two percent, regardless of the position of the part along the rod.
[0008] According to one embodiment of the invention, the distance between the pivot axes connecting the skate to the arm of the arms of a pair of arms, which is a linear function of the number of rotation turns of the threaded rod, is equal to ax + b, with x corresponding to the number of rotation turns of the threaded rod from the reference position, a being a constant for the variation of the distance between the pivot axes connecting the skate to the arm of the arms of said pair of arms over one rotation turn of the rod, and b being a constant for the distance between the pivot axes connecting the skate to the arm of the arms of said pair of arms in the position of maximum proximity of the arms of said pair of arms.
[0009] According to one embodiment of the invention, the arms are curved arms with a concave curved surface facing outwards from the cable puller and an opposite convex curved surface. This design makes it possible to cover a wide range of cable diameters.
[0010] According to one embodiment of the invention, each curved arm has a radius of curvature whose center follows an arc of a circle in the driven state of the arm between its extended position and its position close to the rod, this arc of a circle having a center located on the axis of the pivoting connection of the arm to the support.
[0011] According to one embodiment of the invention, the axes of the pivoting links of the arms of a pair of arms to the support are parallel to each other and extend in two parallel planes arranged on either side of a first plane passing through the rod and on either side of a second plane passing through the rod and orthogonal to the first plane.
[0012] According to one embodiment of the invention, the support is a washer provided with a hole through which the rod passes, said rod being free to rotate inside said hole.
[0013] According to one embodiment of the invention, the pivoting connection of each arm to the support comprises a shaft section mounted inside a bearing of the support, said bearing being formed by an opening in said support, this shaft section passing through a through orifice of the arm disposed at the first end of the arm.
[0014] According to one embodiment of the invention, the arm movement drive piece is a plate through which the arms pass to allow a fixed mounting in rotation of said piece around the rod in the immobilized state in rotation of the support around the rod.
[0015] According to one embodiment of the invention, the arm movement drive part comprises, at each location of the part traversed by an arm, a light with an edge adapted to come into contact with the concave curved surface of the arm and an opposite edge adapted to come into contact with the opposite convex curved surface of the arm.
[0016] According to one embodiment of the invention, the number of arms is equal to four. Brief description of the drawings
[0017] The invention will be better understood upon reading the following description of exemplary embodiments, with reference to the accompanying drawings in which:
[0018] [Fig-1] represents a perspective view of a cable puller in the rap position maximum proximity of the arms;
[0019] [Fig.2] represents a partial front view of a cable puller in an intermediate position of approaching the arms between the maximum approach position and the maximum spread position;
[0020] [Fig.3] represents a perspective view of a cable puller in the position of maximum arm spread;
[0021] [Fig.4] represents a principle view of the displacement of the center of the radius of curvature of a curved arm;
[0022] [Fig.5] represents a top view of a cable puller in a position with the arms away from each other;
[0023] [Fig.6] represents a schematic view of a cable puller in position in a duct and ready to be hoisted into a partially depicted conduit;
[0024] [Fig.7] represents a curve with the number of rotation turns of the rod on the abscissa and the distance between the pivot axes of the arms of a pair of arms of the cable puller on the ordinate;
[0025] [Fig.8] represents a front view of an arm.
[0026] As illustrated in [Fig.6], the cable puller 1, the object of the invention, is intended to be inserted into a sheath 20 which is itself to be introduced into a conduit 22, such as a chimney flue, to ensure a lining of said conduit 22.
[0027] This operation requires a lifting equipment 21, such as a winch, positioned at the top of the conduit 22 and whose cable is intended to be hooked to the cable puller 1 initially positioned at the base of the conduit 22 in order to be able to hoist it in the coupled state to the conduit 20 up to the top of the conduit where the cable puller 1 is uncoupled from the lifting equipment 21 and detached from the conduit 20.
[0028] This cable puller 1 comprises a rod 2 having a thread shown in Figures 3. This threaded rod 2 is equipped at one of its ends, called the upper end and shown in Figures 4, with a hooking element 5 for attaching to the lifting equipment 21. This hooking element 5 is in the form of a lifting ring to which a part of the lifting equipment, such as the winch cable, can be attached. The opposite end of the threaded rod 2 is free.
[0029] The cable puller 1 further comprises arms 6, an example of which is shown in [Fig. 8], and an arm support 7 mounted on the rod 2. The rod 2 can rotate inside this arm support 7, which, in the figures, has the shape of a washer. This washer is equipped with a hole 71 through which rod 2 passes. Rod 2 is free to rotate inside this hole 71.
[0030] Each arm 6 is, at one of its ends, called the first end and represented in 8 in the figures, coupled to the support 7 by a pivoting link 9 about an axis XX' orthogonal to the longitudinal axis of the rod 2 for a displacement of the arm 6 between a position close to the rod 2 and a position away from the rod 2.
[0031] In the example illustrated in the figures, the pivoting connection 9 of each arm 6 to the support 7 comprises a shaft section 91 mounted inside a bearing 92 of the support 7. The bearing 92 is formed by an opening in the support 7. The shaft section 91 passes through a through hole 61 of the arm 6 located at the first end 8 of the arm 6. This section 91 is then fitted into the bearing 92 of the support 7. Thus, coupling each arm 6 to the arm-carrying support 7 is easy.
[0032] In the examples shown, the number of arms 6 is four. Each arm 6 is also equipped at its second end 10, opposite the first end 8, with a pad 11 intended to bear against the inside of the sheath 20 to be installed. This pad 11 is coupled to the arm 6, which pivots about a pivot axis YY' parallel to the axis XX' of the pivot joint 9 connecting the arm 6 to the support 7.
[0033] Each arm 6, whose pivot axis YY' connecting the skate 11 to the arm 6 is parallel to the pivot axis YY' connecting the skate 11 to the arm 6 of another arm, forms with this other arm 6 a pair of arms 6. Thus, when the number of arms is equal to four, there are two pairs of arms.
[0034] As illustrated in [Fig.5], the axes of the pivoting links 9 of the arms 6 of a pair of arms to the support 7 are parallel to each other and extend in two parallel planes arranged on either side of a first plane PI passing through the rod 2 and on either side of a second plane P2 passing through the rod 2 and orthogonal to the first plane PL. This arrangement prevents the arms from interfering with each other in a close position.
[0035] To allow the arms 6 to move from a close position to a spread position, or vice versa, the cable puller 1 includes, carried by the rod 2, a drive piece 12 for moving the arms 6. This piece 12 is adapted to be immobilized against rotation around the rod 2 and is provided with a thread shown in 13. This piece 12 is mounted fixed against rotation in the immobilized state of the support 7 around the rod 2. This immobilization against rotation of the support 7 around the rod 2, that is to say the fixed holding against rotation of the support 7 in the driven state of the rod 2, is carried out by the operator who, with one hand, holds the rod 2, generally by its hooking member 5 to drive the rod 2 in rotation, while with his other hand, he immobilizes the arm support 7 against rotation.
[0036] As the moving drive part 12 of the arm 6 is traversed by the arms 6, the part 12 is also mounted fixed in rotation in the rotationally immobilized state of the support 7 around the rod 2. It is the arms 6 which prevent such rotation of the part 12.
[0037] In the example illustrated in the figures, the part 12 for driving the arms 6 is a plate through which the arms 6 pass to allow a fixed mounting in rotation of the part 12 around the rod in the immobilized state in rotation of the support 7 around the rod 2.
[0038] To this end, the part 12 comprises slots 16, each through which an arm 6 passes. In the rotationally immobilized state of the part 12 around the rod 2, via, for example, a rotational immobilization of the arm support 7, and in the rotationally driven state of the rod 2 about itself, the part 12 is axially movable along the rod 2 by cooperation of the tapped hole 13 of the part 12 with the thread 3 of the rod 2. This cooperation allows, in the rotationally driven state of the rod 2 in a first direction of rotation, the passage of the part 12 from the position of maximum proximity of the arms 6, shown in [Fig. 1], in which the part 12 is away from the arm support 7, to the position of maximum separation of the arms 6 illustrated in [Fig. 3], in which the part 12 is closer to the arm support 7, passing through intermediate positions. such as those shown in [Fig.2].
[0039] Obviously, rotating the rod 2 in the opposite direction allows the reverse movement.
[0040] The part 12 is, in the axially driven state along the rod 2 in the direction of a rapprochement of the support 7, activated by sliding support contact on the arms 6 for the passage of the arms 6 from the approached position to the spread-out position.
[0041] In practice, the arm movement drive part 12 comprises, at each location of the part 12 traversed by an arm 6, a light 16 with an edge 161 suitable for making contact with a surface of the arm 6 and an opposite edge 162 suitable for making contact with an opposite surface of the arm 6.
[0042] The arms 6 of each pair of arms 6 are configured, i.e. shaped and dimensioned, so that the distance between the pivot axes YY' connecting the skate 11 to the arm 6 of the arms of the pair of arms is a linear function of the number of rotation turns of the threaded rod 2 from a reference position corresponding to the position of maximum approach of the arms 6 of the pair of arms.
[0043] In particular, and as illustrated in [Fig. 7], the distance between the pivot axes YY' connecting the skate 11 to the arm 6 of the arms 6 of a pair of arms, which is a linear function of the number of rotational turns of the threaded rod 2, is equal to: ax + b with x corresponding to the number of rotations of the threaded rod 2 from the reference position a, which is a constant to the variation of the spacing distance of the pivot axes YY' connecting the skate 11 to the arm 6 of the arms of said pair of arms on one rotation of the rod and b which is a constant at the distance of separation of the pivot axes YY' connecting the skate 11 to the arm 6 of the arms 6 of said pair of arms in the position of maximum approach of arm 6 of said pair of arms.
[0044] In the example shown in [Fig.7], the line drawn, with the number of turns on the abscissa and the distance between the pivot axes YY' connecting the skate 11 to the arm 6 of the arms 6 of a pair of arms on the ordinate, is an affine function with a equal to 2.4 millimeters and b equal to 150 millimeters.
[0045] As illustrated in [Fig. 4], the arms 6 can be curved arms with a concave curved surface shown in 14 of the figures and an opposite convex surface shown in 15 of the figures. The concave curved surface faces outwards from the cable puller 1.
[0046] Each curved arm 6 has a radius of curvature whose center C follows an arc of a circle in the driven state of the arm 6 between its extended position and its position close to the rod 2, this arc of a circle having a center Cl disposed on the axis of the pivoting link 9 of the arm to the support 7.
[0047] The three centers C, represented in [Fig.4], illustrate the evolution of the positioning of the center of the radius of curvature of the arm 6 on the arc of the circle of center Cl in the state driven in displacement of the arm 6.
[0048] To enable such movement of the arm and the other arms, the arm 6 drive part 12 comprises, at each location of the part 12 traversed by an arm 6, a light 16 with an edge 161 suitable to come into contact with the concave curved surface 14 of the arm 6 and an opposite edge 162 suitable to come into contact by support with the opposite convex curved surface 15 of the arm 6.
[0049] The convex surface 15 is subjected to stress during the movement of the arm 6 from the close to the extended position. The slots 16 thus act as guide slots. During the movement of the arms 6 from the extended to the close position, the guidance can again occur at the level of the convex surface of the arm 6 or at the level of the concave surface of the arm 6.
[0050] The installation of a cable puller 1 is similar to the installation of a cable puller in the prior art. It is therefore sufficient to position the cable puller in the duct 20 in a position close to the arms 6, as illustrated in [Fig. 1], to rotate the rod 2 while keeping the support 7 fixed in rotation until the pads 11 come into contact with the inside of the duct 20, and then to attach the lifting equipment 21 to the attachment member 5 of the cable puller 1.
[0051] The fact that the variation in the distance between the pivot axes connecting the skate 11 to the arm 6 of the arms 6 of a pair of arms 6 is constant to within ±2% for one revolution of the rod 2, regardless of the position of the part 12 along the rod 2, allows for to perfectly control the pressure force of the pads 11 on the inside of the sheath 20.
[0052] The dismantling of the sheath puller 1 is carried out as in the prior art.
Claims
Demands
1. Cable puller (1) intended to be inserted into a duct (20) and coupled to a lifting device (21) to assist in the installation of the duct (20) inside a conduit (22), said cable puller (1) comprising a threaded rod (2) (3) having at one of its ends, called the upper end (4), a hooking member (5), arms (6), an arm support (7) mounted on the rod (2), and within which the rod (2) can rotate, each arm (6) being at one of its ends, called the first end (8), coupled to the support (7) by a pivoting joint (9) about an axis (XX') orthogonal to the rod (2) for a displacement of said arm (6) between a position close to the rod (2) and a position away from the rod (2),each arm (6) being equipped at its other end, called second end (10), with a pad (11) intended to bear against the inside of the sheath (20) to be installed and coupled to the arm (6) pivoting around a pivot axis (YY') parallel to the axis (XX') of the pivoting connection (9) of the arm (6) to the support (7), each arm (6) whose pivot axis (YY') connecting the pad (11) to the arm (6) is parallel to the pivot axis (YY') connecting the pad (11) to the arm (6) of another arm (6) forming with this other arm (6) a pair of arms (6), characterized in that the sheath puller (1) comprises, carried by the rod (2), a drive piece (12) for moving the arms (6) to move said arms (6) from one position to another,in that said part (12) capable of being immobilized against rotation about the rod (2) is a part (12) with a thread (13) mounted axially mobile along the rod (2) by cooperation of the thread (13) of the part (12) with the thread (3) of the rod (2) in the state immobilized against rotation of the part (12) about the rod (2) and driven in rotation of the rod (2) about itself, in that said part (12) is, in the state driven axially along the rod (2) in the direction of an approach to the support (7), active by sliding contact on the arms (6) for the passage of the arms (6) from the approach position to the spread position,and in that the arms (6) of the or each pair of arms (6) are configured such that the distance between the pivot axes (YY') connecting the skate (11) to the arm (6) of the arms (6) of said pair of arms is a linear function of the number of rotational turns of the threaded rod (2) from a reference position corresponding to the position of maximum proximity of the arms (6) of the pair of arms.
2. Cable puller (1) according to claim 1, characterized in that the distance between the pivot axes (YY') connecting the skate (11) to the arm (6) of the arms (6) of a pair of arms (6) which is a linear function of the number of rotation turns of the threaded rod (2) is equal to ax + b with x corresponding to the number of rotation turns of the threaded rod (2) from the reference position, a which is a constant to the variation of the spacing distance of the pivot axes (YY') connecting the skate (11) to the arm (6) of the arms (6) of said pair of arms on one rotation turn of the rod (2) and b which is a constant to the spacing distance of the pivot axes (YY') connecting the skate (11) to the arm (6) of the arms (6) of said pair of arms (6) in the position of maximum approach of the arms (6) of said pair of arms (6).
3. Cable puller (1) according to any one of claims 1 or 2, characterized in that the arms (6) are curved arms with a concave curved surface (14) facing outwards from the cable puller (1) and an opposite convex curved surface (15).
4. Cable puller (1) according to claim 3, characterized in that each curved arm (6) has a radius of curvature whose center (C) follows an arc of a circle in the driven state of the arm (6) between its extended position and its position close to the rod (2), this arc of a circle having a center (Cl) disposed on the axis of the pivoting link (9) of the arm to the support (7).
5. Cable puller (1) according to any one of claims 1 to 4, characterized in that the axes (XX') of the pivoting links (9) of the arms (6) of a pair of arms (6) to the support (7) are parallel to each other and extend in two parallel planes arranged on either side of a first plane (PI) passing through the rod (2) and on either side of a second plane (P2) passing through the rod (2) and orthogonal to the first plane (PI).
6. Cable puller (1) according to any one of claims 1 to 5, characterized in that the support (7) is a washer having a hole (71) through which the rod (2) passes, said rod (2) being free to rotate inside said hole (71).
7. Cable puller (1) according to any one of claims 1 to 6, characterized in that the pivoting connection (9) of each arm (6) to the support (7) comprises a shaft section (91) mounted inside a bearing (92) of the support (7), said bearing (92) being formed by an opening in said support (7), this shaft section (91) passing through an orifice (61) through the arm (6) disposed at the first end (8) of the arm (6).
8. Sheath puller (1) according to any one of claims 1 to 7, characterized in that the part (12) of the drive in movement of the arms (6) is a plate through which the arms (6) pass to allow a fixed mounting in rotation of said part (12) around the rod (2) in the immobilized state in rotation of the support (7) around the rod (2).
9. Puller (1) according to claim 8 taken in combination with claim 3, characterized in that the drive part (12) for moving the arms (6) comprises, at each location of the part (12) through which an arm (6) passes, a slot (16) with an edge (161) adapted to come into contact with the concave curved surface of the arm (6) and an opposite edge (162) adapted to come into contact with the opposite convex curved surface of the arm.
10. Cable puller (1) according to any one of claims 1 to 9, characterized in that the number of arms (6) is equal to four.