Accessory to help install a sheath in a conduit called a sheath puller
The sheath puller design with a threaded rod and pivoting arms facilitates precise torque control and size reduction, addressing bulkiness and usability issues of existing models.
Patent Information
- Application Number
- FR2024000764
- Authority / Receiving Office
- FR · FR
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-01-26
- Publication Date
- 2025-08-01
- Estimated Expiration
- 2044-01-26
AI Technical Summary
Existing sheath pullers are bulky and complex, making them difficult to use for reduced sheath diameters and challenging to control the tightening torque effectively.
A sheath puller design with a threaded rod, pivoting arms, and a driving part that allows controlled movement of the arms based on the number of rod rotations, ensuring a linear function of pivot axis distance for precise torque application.
Enables easy control of tightening torque and reduces the size of the sheath puller, accommodating a wide range of sheath diameters with improved usability.
Smart Images
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Abstract
Description
Title of the invention: Accessory to assist in the installation of a sheath in a conduit known as a sheath puller
[0001] The present invention relates to an accessory for assisting in the installation of a sheath in a conduit, hereinafter called a sheath puller, this sheath puller being intended to be inserted into a sheath and coupled to lifting equipment, such as a winch or a cable, to assist in the installation of the sheath inside a conduit, in particular by hoisting.
[0002] It relates in particular to a sheath puller intended to be inserted into a sheath and coupled to lifting equipment, such as a winch, to assist in the installation of the sheath inside a conduit, in particular by hoisting, said sheath puller comprising: - a threaded rod provided at one of its ends, called the upper end, with a hooking member, - arms, - an arm-carrying 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 connection about an axis orthogonal to the rod for movement of said arm between a position close to the rod and a position separated from the rod, each arm being equipped at the other of its ends, called the second end, with a pad intended to bear inside the sheath to be installed and coupled to the arm pivoting about a pivot axis parallel to the axis of the pivoting connection of the arm at 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] Such a sheath puller which assists in the installation of a sheath inside a conduit, such as a chimney flue, is known. Conventionally, such a sheath puller is introduced into a sheath to be installed. This sheath puller is held inside the sheath by the support of the sheath puller pads on the inner wall of the sheath. The sheath puller is, moreover, by its hooking member coupled to lifting equipment, such as the cable, of a winch placed at the top of the conduit. Once the sheath puller is held to the sheath and coupled to the lifting equipment, it is sufficient to operate the lifting equipment to hoist the sheath inside the conduit to the top of said conduit. The sheath puller can then be detached from the sheath and the lifting equipment. However, the sheath pullers currently on the market are bulky, making their use for reduced sheath diameters impossible.Furthermore, the design of these sheath pullers is complex and makes it difficult to control the tightening torque applied to ensure that the sheath puller is properly held inside the sheath by pressing the sheath puller pads inside the sheath.
[0004] An aim of the invention is to propose a sheath puller whose design makes it possible to easily control the tightening torque.
[0005] Another object of the invention is to propose a sheath puller whose design can make it possible to limit the size of the sheath puller.
[0006] For this purpose, the invention relates to a sheath puller intended to be inserted into a sheath and coupled to lifting equipment to assist in the installation of the sheath inside a conduit, said sheath puller comprising a threaded rod provided at one of its ends, called the upper end, with a hooking member, arms, an arm-carrying 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 connection about an axis orthogonal to the rod for movement of said arm between a position close to the rod and a position separated from the rod, each arm being equipped at the other of its ends, called the second end, with a pad intended to bear inside the sheath to be installed and coupled to the arm pivoting about a pivot axis parallel to the axis of the pivoting connection 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 sheath puller comprises, carried by the rod, a part for driving the arms to move them from one position to another, in that said part capable of being immobilized in rotation around the rod is a threaded part mounted axially movable along the rod by cooperation of the threading of the part with the thread of the rod in the state in which the part is immobilized in rotation around the rod and driven in rotation of the rod on itself, in that said part is, in the state driven axially along the rod in the direction of bringing the support closer, activated by sliding contact on the arms for the arms to move from the close position to the separated position,and in that the arms of the or each pair of arms are configured so that the distance between the pivot axes connecting the pad to the arm of 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 approach of the arms of the pair of arms.
[0007] Thanks to the fact that the distance between the pivot axes connecting the pad to the arm of the arms of said pair of arms is a linear function of the number of rotational revolutions of the threaded rod from a reference position corresponding to the position of maximum approach of the arms of the pair of arms, to within construction errors, that is to say to within plus or minus two percent, the tightening torque exerted by the pads on the sheath is more easily controllable by the operator. In other words, in the state of the part being immobilized in rotation around the rod and driven in rotation of the rod on one revolution, the variation of the distance between the pivot axes connecting the pad to the arm of the arms of said pair of arms is substantially constant, that is to say constant to within plus or minus two percent, whatever the position of the part along the rod.
[0008] According to one embodiment of the invention, the distance between the pivot axes connecting the pad to the arm of the arms of a pair of arms which is a linear function of the number of rotational revolutions of the threaded rod is equal to ax + b with x corresponding to the number of rotational revolutions of the threaded rod from the reference position, a which is a constant to the variation of the distance of separation of the pivot axes connecting the pad to the arm of the arms of said pair of arms over one rotational revolution of the rod and b which is a constant to the distance of separation of the pivot axes connecting the pad to the arm of the arms of said pair of arms in the position of maximum approach 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 outward from the sheath puller and an opposite convex curved surface. This design makes it possible to cover a wide range of sheath 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 position separated from and its position close to the rod, this arc of a circle having a center arranged 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 connections 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 bore through which the rod passes, said rod being free to rotate inside said bore.
[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 arranged at the first end of the arm.
[0014] According to one embodiment of the invention, the part for driving the arms in movement is a plate through which the arms pass to allow said part to be mounted fixed in rotation around the rod in the state in which the support is immobilized in rotation around the rod.
[0015] According to one embodiment of the invention, the part for driving the movement of the arms comprises, at each location of the part crossed by an arm, a light with an edge capable of coming into bearing contact with the concave curved surface of the arm and an opposite edge capable of coming into bearing 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 on reading the following description of exemplary embodiments, with reference to the appended drawings in which:
[0018] [Fig-1] represents a perspective view of a sheath puller in the rap position maximum proximity of the arms;
[0019] [Fig.2] represents a partial front view of a sheath puller in the intermediate approach position of the arms between the maximum approach position and the maximum separation position;
[0020] [Fig.3] represents a perspective view of a sheath puller in the position of maximum arm spacing;
[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 sheath puller in the position separated from the arms;
[0023] [Fig.6] represents a schematic view of a sheath puller in position in a sheath and ready to be hoisted into a partially represented conduit;
[0024] [Fig.7] represents a curve with the number of rotations of the rod on the abscissa and the spacing between the pivot axes of the arms of a pair of arms of the sheath puller on the ordinate;
[0025] [Fig.8] represents a front view of an arm.
[0026] As illustrated in [Fig.6], the sheath puller 1, object of the invention, is intended to be inserted into a sheath 20 which must itself be introduced into a conduit 22, such as a chimney flue, to ensure lining of said conduit 22.
[0027] This operation requires 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 sheath puller 1 initially positioned at the base of the conduit 22 to be able to hoist it in the state coupled to the sheath 20 to the top of the conduit where the sheath puller 1 is uncoupled from the lifting equipment 21 and detached from the sheath 20.
[0028] This sheath puller 1 comprises a rod 2 having a thread shown at 3 in the figures. This threaded rod 2 is equipped at one of its ends, called the upper end and shown at 4 in the figures, with a member 5 for attachment to the lifting equipment 21. This attachment member 5 is in the form of a lifting ring to which 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 sheath puller 1 also comprises arms 6, an example of which is shown in [Fig.8] and an arm-carrying support 7 mounted on the rod 2. The rod 2 can rotate inside this arm-carrying support 7 which, in the figures, has the shape of a washer. This washer is provided with a hole 71 crossed by the rod 2. The 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 shown at 8 in the figures, coupled to the support 7 by a connection 9 pivoting around an axis XX' orthogonal to the longitudinal axis of the rod 2 for a movement of the arm 6 between a position close to the rod 2 and a position separated 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 orifice 61 of the arm 6 arranged at the first end 8 of the arm 6. This section 91 is then housed in a nested manner in the bearing 92 of the support 7. Thus, the coupling of each arm 6 to the arm-carrying support 7 is easy.
[0032] In the examples shown, the number of arms 6 is equal to four. Each arm 6 is, moreover, equipped at its second end 10, opposite the first end 8, with a pad 11 intended to bear inside the sheath 20 to be installed. This pad 11 is coupled to the arm 6 to pivot about a pivot axis YY' parallel to the axis XX' of the pivoting connection 9 of the arm 6 to the support 7.
[0033] 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, 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 connections 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 makes it possible to prevent the arms from interfering with each other in the close position.
[0035] To allow the arms 6 to move from a close position to a spaced position, or vice versa, the sheath puller 1 comprises, carried by the rod 2, a part 12 for driving the arms 6 to move. This part 12 is capable of being immobilized in rotation around the rod 2 and provided with a thread shown at 13. This part 12 is mounted fixed in rotation in the state in which the support 7 is immobilized in rotation around the rod 2. This immobilization in rotation of the support 7 around the rod 2, that is to say the fixed maintenance in 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 in rotation the arm-carrying support 7.
[0036] As the part 12 for driving the arm 6 in movement is crossed by the arms 6, the part 12 is also mounted fixed in rotation in the state immobilized in rotation 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 in movement is a plate through which the arms 6 pass to allow the part 12 to be mounted fixed in rotation around the rod in the state in which the support 7 is immobilized in rotation around the rod 2.
[0038] For this purpose, the part 12 comprises slots 16 each crossed by an arm 6. In the state immobilized in rotation of the part 12 around the rod 2 via, for example, an immobilization in rotation of the arm-carrying support 7 and, in the state driven in rotation of the rod 2 on itself, the part 12 is mounted axially movable along the rod 2 by cooperation of the tapping 13 of the part 12 with the thread 3 of the rod 2. This cooperation allows, in the state driven in rotation of the rod 2 in a first direction of rotation, the passage of the part 12 from the position of maximum approach of the arms 6, shown in [Fig.l], in which the part 12 is spaced from the arm-carrying support 7 to the position of maximum spacing of the arms 6 illustrated in [Fig.3] in which the part 12 is brought closer to the arm-carrying support 7 by passing through intermediate positions such as those shown in [Fig.2].
[0039] Obviously, driving the rod 2 in rotation in an opposite direction allows the reverse movement.
[0040] The part 12 is, in the state driven axially along the rod 2 in the direction of a move towards the support 7, activated by sliding support contact on the arms 6 for the passage of the arms 6 from the close position to the spaced position.
[0041] In practice, the part 12 for driving the arms to move comprises, at each location of the part 12 crossed by an arm 6, a slot 16 with an edge 161 capable of coming into bearing contact with a surface of the arm 6 and an opposite edge 162 capable of coming into bearing contact with an opposite surface of the arm 6.
[0042] The arms 6 of each pair of arms 6 are configured, that is to say shaped and dimensioned, so that the distance between the pivot axes YY' connecting the pad 11 to the arm 6 of the arms of the pair of a 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 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 pad 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 with the variation of the distance of separation of the pivot axes YY' connecting the pad 11 to the arm 6 of the arms of said pair of arms over one rotation of the rod and b which is a constant at the distance of separation of the pivot axes YY' connecting the pad 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 straight line drawn, with the number of turns on the abscissa and the distance between the pivot axes YY' connecting the pad 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 may be curved arms with a concave curved surface shown at 14 in the figures and an opposite convex surface shown at 15 in the figures. The concave curved surface faces outwards from the sheath 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 spaced position and its position close to the rod 2, this arc of a circle having a center Cl arranged on the axis of the pivoting connection 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 a circle with center Cl in the state when the arm 6 is driven in displacement.
[0048] To allow such movement of the arm and the other arms, the part 12 for driving the movement of the arms 6 comprises, at each location of the part 12 crossed by an arm 6, a light 16 with an edge 161 capable of coming into contact with the concave curved surface 14 of the arm 6 and an opposite edge 162 capable of coming into bearing contact with the opposite convex curved surface 15 of the arm 6.
[0049] The convex surface 15 is stressed when the arm 6 moves from the close position to the separated position of the arms. The Lights 16 therefore form guide lights. When the arms 6 move from the separated position to the close position, the guidance can take place again 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 sheath puller 1 is similar to the installation of a sheath puller of the state of the art. It is therefore sufficient to position the sheath puller in the sheath 20 in a position close to the arms 6, as illustrated in [Fig.l], to turn the rod 2 while keeping the support 7 fixed in rotation until the pads 11 come to bear on the inside of the sheath 20, then to hook the lifting equipment 21 to the hooking member 5 of the sheath puller 1.
[0051] The fact that the variation in the distance between the pivot axes connecting the pad 11 to the arm 6 of the arms 6 of a pair of arms 6 is constant to within plus or minus 2% for one revolution of the rod 2, whatever the position of the part 12 along the rod 2, makes it possible to perfectly control the bearing 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 state of the art.
Claims
Claims
1. Duct puller (1) intended to be inserted into a duct (20) and coupled to lifting equipment (21) to assist in the installation of the duct (20) inside a conduit (22), said duct puller (1) comprising a threaded (3) rod (2) provided at one of its ends called the upper end (4) with a hooking member (5), arms (6), an arm-carrying support (7) mounted on the rod (2), and inside 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 connection (9) about an axis (XX') orthogonal to the rod (2) for a movement of said arm (6) between a position close to the rod (2) and a position separated from the rod (2),each arm (6) being equipped at the other of its ends called second end (10) with a pad (11) intended to bear inside 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) of which the 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 part (12) for driving the movement of the arms (6) for the passage of said arms (6) from one position to another,in that said part (12) capable of being immobilized in rotation around the rod (2) is a part (12) threaded (13) mounted axially movable 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 in rotation of the part (12) around the rod (2) and driven in rotation of the rod (2) on itself, in that said part (12) is, in the state driven axially along the rod (2) in the direction of a move towards the support (7), active by sliding support contact on the arms (6) for the passage of the arms (6) from the close position to the separated position,and in that the arms (6) of the or each pair of arms (6) are configured so that the distance between the pivot axes (YY') connecting the pad (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 approach of the arms (6) of the pair of arms.,
2. Sheath puller (1) according to claim 1, characterized in that the distance between the pivot axes (YY') connecting the pad (11) to the arm (6) of the arms (6) of a pair of arms (6) which is a linear function of the number of rotational revolutions of the threaded rod (2) is equal to ax + b with x corresponding to the number of rotational revolutions 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 pad (11) to the arm (6) of the arms (6) of said pair of arms over one rotational revolution of the rod (2) and b which is a constant to the spacing distance of the pivot axes (YY') connecting the pad (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. Sheath puller (1) according to one of claims 1 or 2, characterized in that the arms (6) are curved arms with a concave curved surface (14) facing the outside of the sheath puller (1) and an opposite convex curved surface (15).
4. Sheath 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 spaced position and its position close to the rod (2), this arc of a circle having a center (Cl) arranged on the axis of the pivoting connection (9) of the arm to the support (7).
5. Sheath puller (1) according to one of claims 1 to 4, characterized in that the axes (XX') of the pivoting connections (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. Sheath puller (1) according to one of claims 1 to 5, characterized in that the support (7) is a washer provided with a bore (71) crossed by the rod (2), said rod (2) being free to rotate inside said bore (71).
7. Sheath puller (1) according to 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) passing through the arm (6) arranged at the first end (8) of the arm (6).
8. Sheath puller (1) according to one of claims 1 to 7, characterized in that the part (12) for driving the arms (6) in movement is a plate crossed by the arms (6) to allow a fixed mounting in rotation of said part (12) around the rod (2) in the state immobilized in rotation of the support (7) around the rod (2).
9. Sheath puller (1) according to claim 8 taken in combination with claim 3, characterized in that the part (12) for driving the movement of the arms (6) comprises, at each location of the part (12) crossed by an arm (6), a light (16) with an edge (161) capable of coming into bearing contact with the concave curved surface of the arm (6) and an opposite edge (162) capable of coming into bearing contact with the opposite convex curved surface of the arm.
10. Sheath puller (1) according to one of claims 1 to 9, characterized in that the number of arms (6) is equal to four.
Citation Information
Patent Citations
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