FR2931716A1 - APPARATUS FOR THE INSTALLATION OF A CRYING MEMBER - Google Patents

Abstract

An apparatus for fitting a crimping nut comprises a housing (10) in which a pull rod (13) has a threaded end (15) projecting from an anvil (12) integral with the housing (10) for moving a cooperating portion of the crimp nut, and an opposite end with a head (14). An actuating mechanism in translation of the tie rod in the axial direction and a drive mechanism in rotation of the tie rod around the axial direction are also provided. The translational actuating mechanism comprises an axially displaceable piston (16) carrying a reversible self-return clamping system (17) to a clamped position for radial clamping of the rod (13) in a region axially adjacent to the head (14). The head (14) is held axially in the tight position of the clamping system (17) and released in the spaced position to be able to move axially on either side of the clamping system (17). The apparatus comprises a release sleeve (21) slidably mounted coaxially on the rod (13) in such a way that axial movement of the sleeve (21) towards the head (14) controls the passage of the clamping (17) to the discarded position.

Description

Apparatus for the application of a crimping element 10 Technical Field of the Invention

The invention relates to an apparatus for installing a crimping nut, comprising a casing enclosing: a tie rod mounted in a sliding pivot connection in an axial direction, and constituted by a pull rod having a protruding threaded end an anvil secured to the housing for moving a cooperating portion of the crimping nut, and an opposite end having a head, a mechanism for actuating the puller in translation in the axial direction between an extended position and a retracted position of the threaded end 20, a mechanism for rotating the tie rod around the axial direction.

State of the art Such a setting apparatus is used on crimping nut crimping units. An apparatus conventionally comprises a tie rod adapted to pull, screw and unscrew a cooperating part of the crimping nut, and an anvil for the support of another part of the crimping nut. An axial movement between the pulling rod and the anvil causes an equivalent movement between the corresponding parts of the crimp nut, generating a crimping bead. The

screwing movement of the pulling allows the establishment of the nut on the tie rod before crimping, while its unscrewing movement allows the separation of the tie rod and the nut after crimping.

Conventionally, the tie rod is in the form of a pull rod having at least one threaded end protruding from the anvil, and an opposite end with a head. The threaded portion of the rod ensures the transmission of axial pulling forces to the cooperating portion of the crimping nut, and the head allows the transmission of axial pulling forces of the actuating mechanism in translation towards the pull rod. Such a pull rod is conventionally constituted by a specific component or by a commercial screw.

Whatever the variant of the pull rod, the tie rod is a wear part which has a high replacement frequency. Replacing the tie rod involves removing the used rod and installing a new rod. Generally these operations are long and require specific tools. In the case of the use of a pull rod constituted by a commercial screw, its implantation within the casing requires additional mechanical parts which reduce the flexibility of use.

OBJECT OF THE INVENTION The object of the invention is to provide an apparatus for installing a crimping nut which allows rapid replacement of the tie rod without requiring tools, and which improves the flexibility of use by allowing the indifferent implementation of specific traction rods or constituted by commercial screws without requiring additional mechanical parts in one or the other of the cases.

The apparatus according to the invention is remarkable in that the mechanism for actuating in translation comprises a piston displaceable in the axial direction, and carrying a radial clamping system of the rod, which can occupy a tight position to retain the head axially and a spaced apart position for releasing the head, said clamping system comprising: - an automatic return device to the clamped position, and a release bushing slidably mounted coaxially on the rod to control the passage of the clamping system to the discarded position when axial movement of the sleeve towards the head.

Such a clamping system allows a setting and removal of the pulling particularly simple and effective, as well as its holding in position after installation. The tight position is used, without specific action by means of any suitable automatic return device, for maintaining the position of the tie after its introduction. The separated position is controlled during the operations of setting up and withdrawing the tie rod. The control towards the spaced position is achieved by the unclamping sleeve at the time of the withdrawal operation, and by the head of the rod at the time of the introduction of the tie rod. Such a release sleeve, housed permanently in the volume delimited internally by the casing and the anvil, thus allows the removal of the rod without tools. The establishment of the rod does not require tools either because the passage to the remote position is controlled by the axial movement of the head and its return to the tight position results from the presence of the automatic return device.

This operation applies regardless of the pull rod, specific or constituted by a commercial screw.

According to a preferred embodiment, the clamping system comprises at least two jaws movable radially in respective directions 30 arranged in a concurrent manner, each jaw being able to comprise

advantageously an inner face equipped with a chamfer inclined towards the body of the rod approaching the head.

Other technical features may be used alone or in combination: the head of the pull rod comprises a coupling member to the rotary drive mechanism, the end of the release sleeve on the side of the threaded end of the rod comprises axial support means co-operating with complementary retention means carried by the anvil.

Brief description of the drawings

Other advantages and features will emerge more clearly from the following description of a particular embodiment of the invention given by way of non-limiting example and shown in the accompanying drawings, in which: FIG. the part concerned by the invention of an apparatus according to the invention, FIGS. 2 to 6 represent the successive phases for the withdrawal of a used tie rod; FIGS. 7 and 8 represent the successive phases for the installation of 'a pulling.

Description of a preferred embodiment of the invention

Figures 1 to 8 illustrate a part of an apparatus for the installation of a crimp nut (not shown) according to the invention. The apparatus comprises a housing 10 internally defining a cylindrical chamber 11 open on one side outwards by means of an opening. On the side of this opening, a removable anvil 12 is secured to the housing 10 by any fastening means

adapted. More specifically, the anvil 12 is disposed at the periphery of the opening of the casing 10 and delimits itself a passage to the outside.

A tie is mounted in the housing 10 in a sliding pivot connection directed in an axial direction. As shown, the tie rod is constituted by a pull rod 13, indifferently formed by a specific piece or by a commercial screw. The rod 13 is composed of a generally cylindrical elongated body, equipped at one end with a thread, and at the opposite end of a head 14. The axial direction coincides with the axis of revolution of the stem body 13. The threaded end 15 of the rod 13 is disposed protruding from the anvil 12 to be able to screw and pull, and then unscrew, with a cooperating portion of the crimping nut, to create an axial displacement of this nut part. The head 14 of the rod 13 is provided to protrude radially from the cylindrical body of the rod 13. The junction between the rod body and the head 14 delimits a shoulder axially facing the threaded end 15, and more generally towards the outside of the housing 10.

The apparatus further comprises a mechanism for actuating the pull rod in translation in the axial direction (partially shown). The mechanism 20 for actuating in translation ensures a controlled axial movement of the threaded end 15 between a retracted position and an extended position. During the movement of the extended position to the retracted position, the tie rod is capable of transmitting axial forces to the part of the nut to be fixed on the threaded end 15. These efforts are intended to create a permanent deformation of the nut, forming a crimping bead, between said integral portion of the threaded end 15 and another portion of the nut abutting against the anvil 12 during the movement of the tie rod.

The translational actuating mechanism is provided with a piston 16 mounted to translate inside the cylindrical chamber 11 in the axial direction, and movable in this direction in a back-and-forth motion.

controlled by a pneumatic or hydraulic or electric system for example. On the side of the opening of the housing 10, the piston 16 defines a housing receiving a radial clamping system 17 of the body of the rod 13. The clamping system 17 described below is advantageously reversible to be able to occupy a tight position and a discarded position. It is also equipped with an automatic return device to the tight position when no external mechanical action is applied to it.

The notion of radial direction corresponds to the set of directions included in any plane perpendicular to the axial direction.

The zone of the rod 13 in which the clamping system 17 is intended to transmit centrifugal radial forces is axially adjacent to the head 14, at the level of the shoulder between the body of the rod 13 and the head 14. tightening 17 consists of an outer ring gear 18 fitted into the walls of the housing of the piston 16 and a plurality of jaws 19 movable radially. The number of jaws 19 is greater than or equal to two. Their respective directions of movement are arranged concurrently. The mobility of each of the jaws 19 is contained in a predetermined radial stroke. Each jaw 19 thus varies radially between a state remote from the ring 18 and a state close to the ring 18. Associated with each of the jaws 19, a return spring 20 permanently forces the jaw 19 associated with its state away from the crown 18.

The radial mobility of all the jaws 19 gives the clamping system 17 its ability to vary between a tight position and a remote position. The return springs 20 constitute a device for automatically returning the clamping system 17 to its tight position. The spaced position is controlled by external mechanical actions applied to the jaws 19 tending to spread radially towards their state close to the ring 18. On the contrary, the tight position is controlled

automatically by the springs 20 when no external mechanical action is applied to the jaws 19 outside those of the springs 20, tending to bring them radially towards their state away from the ring 18. When the rod 13 is depressed so that the body of the rod 13 extends axially between the jaws 19 and that the head 14 is facing the bottom of the housing 16 of the pison, the automatic return to the clamped position has the effect of creating the radial clamping of the rod 13 in the zone axially adjacent to the head 14. In this configuration, the jaws 19 constitute axial stops for the head 14, in order to retain it axially inside the housing of the piston 16. As a result, the tight automatic position of the system clamping device 17 ensures the mechanical coupling of the tie rod and the piston 16 as long as there is no external action to move the jaws 19 away radially. When passing towards the separated position, the radial stroke of the jaws 19 is sufficient to allow that in the spaced position of the clamping system 17, the head 14 is released in the axial direction to allow it to pass axially on either side of the clamping system 17.

As illustrated in Figures 1 to 8, each jaw 19 has an inner face intended to come to apply the radial forces on the rod 13, which is equipped with a chamfer inclined towards the body of the rod 13 by approaching the head 14 when it is retained by the clamping system 17. The chamfers are intended to receive the external mechanical actions applied to the jaws 19 for the passage to the remote position. To transmit such external mechanical actions when the rod 13 is in a configuration where the head 14 is retained by the clamping system 17, the latter comprises a substantially cylindrical unclamping sleeve 21 slidably mounted coaxially on the pull rod 13. The length of the sleeve 21, its axial position and its thickness at the end of the side of the head 14 of the rod 13 are chosen so that a sufficient axial movement of the sleeve 21 towards the head controls the passage of the clamping system 17 to the discarded position by transformation of an effort

axial applied to the sleeve 21 in a radial force transmitted by the end of the sleeve 21 to each of the jaws 19 at the chamfer of its inner face. The transformation of an axial force into a radial force is performed, for each jaw 19, by the inclination of the chamfer carried by said jaw 19. The radial forces transmitted to the jaws 19 must be sufficient to separate them to the discarded position tightening system 17.

The end of the unclamping sleeve 21 opposite to the head 14, that is to say on the side of the threaded end 15 of the pull rod 13, comprises means of support in the axial direction cooperating with complementary retaining means carried by the anvil 12. The bearing means are constituted by a radial flange 22 intended to bear axially against a shoulder of the anvil 12 facing inwards, on the side of the chamber 11 These additional means have the effect of ensuring that the unclamping sleeve 21 remains confined in the volume delimited internally by the casing 10 and the anvil 12 as the anvil 12 is fixed on the casing 10, making the sleeve 21 captive without disassembly of the anvil 12.

The sliding pivot connection between the casing 10 and the tie rod is formed on the threaded end 15 side by an axial cylindrical bearing arranged on the periphery of the passage defined by the anvil 12, and on the side of the head 14, by mounting the piston 16 in the chamber 11.

To perform the operations of screwing and unscrewing the crimp nut on the threaded end 15, the apparatus comprises a rotation drive mechanism (not shown) of the tie rod around its axial direction. By way of example, such a drive mechanism may be formed by an electric motor. For the mechanical connection between the tie rod and the rotary drive mechanism, the head 14 comprises a coupling member to the rotary drive mechanism. In the figures, the organ

coupling is constituted by an axial orifice 24 having a polygonal section in which is engaged a complementary shaped pin carried by a rotating part 23 of the rotary drive mechanism. The rotating part 23 is mounted in the piston 16 in a pivot connection axial direction, able to suppress the degree of freedom in translation in the axial direction between these two parts.

The use of the apparatus described above is as follows: in the normal operating configuration (FIG. 1), the clamping system 17 is in a clamped position and ensures the axial retention of the head 14, and therefore of the assembly of the pull rod 1: 3. The movement of the piston 16 of the translation actuating mechanism is directly transmitted to the active part of the tie rod, that is to say the threaded end 15 projecting from the outside of the anvil 12. The axial displacement of the Piston 16 provides for the variation of the threaded end 15 between a retracted position and an extended position to create a crimping bead in a deformable area of the crimp nut. The unclamping sleeve 21 is confined inside the casing 10, retained axially by the internal shoulder of the anvil 12. When the tie has a wear requiring its replacement, the advantageously removable anvil 12 is removed from the casing 10 to give access to the unclamping sleeve 21 (Figure 2). In this state, an axial thrust force F1 (FIG. F3) applied to the bushing 21 causes an axial displacement of the bushing 21 in the direction of the head 14. The end of the bushing 21 on the side of the head 14 coming to bear against the chamfers carried by the jaws 19, the axial force F1 then causes the transmission of radial forces by the sleeve 21 to the jaws 19. These radial forces are opposed to the permanent forces in opposite directions applied by the return springs 20 the jaws 19, so as to cause a displacement Dl of the latter to their state close to the outer ring 18. The simultaneous movements D1 of the jaws 19 result in the passage of the clamping system 17 to its spaced apart position. In this position of the clamping system 17, the head 14 is

released in the axial direction so that it can pass axially on the other side of the clamping system (Figure 4) by simply applying an axial pulling force F2 on the rod 13, to come outside the housing of the piston 16. The pull rod 13 and the unclamping sleeve 21 move axially together, the sleeve 21 being carried by the rod 13 pulled along F2. Referring to Figure 5, the force F2 is prolonged until the complete removal of the rod 13 and the sleeve 21 outside the housing 10 (Figure 6). The removal of the tie rod is complete and it is sufficient to separate the sleeve 21 and the rod 13 used, for later use of the sleeve 21.

The introduction of a new traction rod 13 is then carried out by axially introducing the new rod 13 inside the casing 10, starting with its head 14, until rnont contact the head 14 against the chamfers of the jaws 19 (Figure 7). In this configuration, the application of an axial thrust force F3 applied to the new rod 13 causes the transmission of radial forces by the head 14 to the jaws 19. In the same way as at the time of application of the F1 force on the unclamping sleeve 21, the radial forces induce a simultaneous displacement D2 jaws 19 resulting in the passage of the clamping system 17 to its spaced apart position. In this position of the clamping system 17, the head 14 is released in the axial direction so that it can pass axially from the other side of the clamping system 17 until it comes against the rotating part 23, making sure to engage its tenon in the coupling member 24 carried by the head 14. The tightening system 17 automatically returns to its tightened position by action of the return springs 20. The jaws 19 ensure the holding in position of the new traction rod 13 ( Figure 8). The introduction of the new traction rod 13 ends after the assembly of the unclamping sleeve 21 coaxially on the new rod 13 and after the fixing of the anvil 12 on the housing 10. The device is then again in the state shown in Figure 1.

From the foregoing, it is understood that the withdrawal and implementation of the tie rod are particularly simple, fast, and require no tools. On the other hand, the combination of the reversible clamping system 17 with automatic return to the tight position and the unclamping sleeve 21 improves the flexibility of use: these two complementary elements allow the indifferent implementation of specific pull rod 13 or constituted by commercial screws, without requiring additional mechanical parts in one or the other of the cases.

Claims (5)

Revendications1. Apparatus for fitting a crimping nut, comprising a housing (10) enclosing: a tie rod mounted in pivotal connection sliding in an axial direction, and constituted by a pull rod (13) having a threaded end (15) made of protrusion of an anvil (12) integral with the housing (10) for moving a cooperating part of the crimping nut, and an opposite end with a head (14), a mechanism for actuating the puller in translation in the axial direction between an extended position and a retracted position of the threaded end (15), a mechanism for rotating the tie rod around the axial direction, characterized in that the translational actuating mechanism comprises a piston (16). ) displaceable in the axial direction, and carrying a radial clamping system (17) of the rod (13), able to occupy a tight position to retain the head (14) axially and a spaced apart position to release the head (14), said system of ser rage (17) comprising: an automatic return device to the clamped position; and a release socket (21) slideably coaxially mounted on the rod (13) to control the passage of the clamping system (17) to the retracted position when axial movement of the sleeve (21) towards the head (14). 2. Apparatus according to claim 1, characterized in that the head (14) of the pull rod (13) comprises a coupling member (24) to the rotary drive mechanism. 12 5 3. Apparatus according to one of claims 1 and 2, characterized in that the end of the unclamping sleeve (21) on the side of the threaded end (15) of the rod (13) comprises support means axial (22) cooperating with complementary retaining means carried by the anvil (12). 4. Apparatus according to one of claims 1 to 3, characterized in that the clamping system (17) comprises at least two jaws (19) radially movable in respective directions arranged concurrently. 10 5. Apparatus according to claim 4, characterized in that each jaw (19) has an inner face equipped with a chamfer inclined towards the body of the rod 13) approaching the head (14) when the head ( 14) is in a position retained by the clamping system (17). 15