MXPA96003040A - Rizad tool - Google Patents

Abstract

A tool for crimping a compression sleeve on a tube includes support arms (50) that rotate about fixed pivots (68), and each carrying a slidably mounted curling jaw (52) that is supported by the associated arm ( 50) for a rotary movement of the jaw around the longitudinal axis thereof, the movement of the respective jaws (52) being guided by the ramp cams (58) and the cam surfaces (60) operating to maintain the faces the end of the jaws in true parallelism with each other, despite the movement of the jaws (52) around an arcuate path, and the rotation of those jaws (52) in relation to the support arms (50), the movement of the jaws under the influence of the sliding surface contact of the cam members in the absence of the linear contact, while at the same time providing a sliding greater area between the respective jaws and their bridges. associated support beads, thus improving the durability of the curly tool

Description

ROLLING TOOL FIELD OF THE INVENTION The present invention relates to a curling tool for use in the assembly of tubular compression couplings on tube sections. A compression coupling comprises a tubular sleeve containing O-rings, which is compressed in the radial directions in order to couple the compression coupling with the respective ends of the tubes, and in doing so, form a leak-resistant joint. between the ends of the tube, the joint itself having considerable mechanical strength, and supporting itself in the absence of auxiliary support members.

BACKGROUND OF THE INVENTION In order to form a successful compression joint using a compression sleeve, one of the main considerations is that the crimping tool does not scratch, cut, scrape, or bite the compression sleeve during the crimping operation. In addition, it is essential that the curling jaws approximate each other in extreme to extreme parallelism. If the jaws do not engage with one another in extreme-to-extreme parallelism, then there is a likelihood of pricking and cutting the compression sleeve in a tube around its circumference, while other points on the circumference of the compression sleeve they do not compress completely. This can result in a failed union, where an explosion and leakage may occur in the damaged portion of the compression sleeve when the tube line is subjected to pressure, and in the alternative, axial leakage of the tube may occur in the insufficiently compressed portions of the compression sleeve. For this reason, curling tools for use in the compression coupling assembly are required to include curling jaws that can move radially with respect to the longitudinal axis of the compression sleeve. However, a simple clamp type link can not perform this movement successfully, in which the jaws of the clamps move each one on an arched path. The result is that considerably more force is exerted on the compression sleeve, on its radius closer to the pivot of the clamps, with the danger of cutting the compression sleeve at that radius, while at the same time, a lesser comprehensive force is exerted. and possibly insufficient in the radius diametrically opposite. For this reason, it was proposed in German Patent Number 3,423,283 published on January 2, 1986, to provide a curling tool wherein the opposing jaws of the crimper move in parallel with one another as they progress from the open position of the tool crimper to the closed curling position thereof. In order to perform that movement, this prior teaching requires that the curling jaws be stopped in their position by rollers attached to the respective jaws, and that they move along cam tracks on a support plate during their movement between the jaws. open and closed positions of the jaws. In addition, the jaws are required to travel over ramp cams, which act additionally to guide the jaws in parallel with each other during a closing movement of the jaws. Curling tools of this type find extremely high working pressures when in use. This in turn results in rapid wear of the rollers and their associated supports, and in turn, results in rapid wear of the ramp cams, and in turn in turn results in the jaws being left free to approach one another. to the other in a different way than in true parallelism, due to the play in the mechanism. These problems are further exaggerated due to the fact that the rollers are coupled with their cam tracks in a linear coupling only, and also, the jaws engage with their ramp cams in a linear coupling only. In case there is a game in the mechanism, and that the curling jaws approach the compression sleeve other than in parallel with each other, then it will result in a scraping and scratching and a possible cut of the compression sleeve, and also, the compression sleeve will it can compress out of the center with respect to its longitudinal axis, resulting in an over-compression of the 0-rings in a radius of the compression sleeve, and the possible destruction of the 0-ring in that location, and insufficient compression diametrically opposite of the 0-ring that results in an axial leakage of the tube at that location. In order to eliminate these drawbacks of the prior art crimper tool of German Patent Number 3,423,283, it is proposed, in the United States Patent Number 5,148,698 issued September 22, 1992, to provide a crimper tool having three curling jaws, one of which is fixed in relation to the frame of the crimper tool, and the other two of which can slide into the jaw support arm, to thereby produce a curling force approaching a truly radial compression on the compression sleeve. The United States of America patent discloses that the three dice move in a radial fashion when they ripple a connection. In practice, for that to happen, a multitude of factors have to be taken into consideration, at least one of those factors being beyond the control of the manufacturer of the jaws. In order to produce a truly radial movement of the jaws, the friction between the dice and the connection must be within a very narrow range. If it is not within that range, the previously loaded springs that are used to initially place the two dice in motion will not be at the correct preload pressure to compensate for the friction loads. In practice, the friction imposed on the jaws can vary to a large degree, the result being that in practice the dice do not always meet in a truly radial trajectory, resulting in a non-uniform crimping. When this happens, the tubes that are joining with connections do not always remain in axial alignment with the connections. This is due to the angular deviation between the tube and the connections, caused by a non-uniform crimping geometry because the dice move in a non-uniform manner. The lack of uniformity of the crimp can result in a severe bite of the connection at the corners of the die, and a failure of the dice to close completely. Additionally, dirt accumulates between the respective die segments, which requires the cleaning of the dice as an event of each day. If there is dirt present between the dice as they come together, the dirt prevents a complete closing of the dice, resulting in an incomplete ripple. This problem is increased according to the teachings of U.S. Patent No. 5,148,698, in which the dirt easily accumulates on the juxtaposed faces of the fixed die and the movable dies, making the placement of the juxtaposed faces the crack. between the juxtaposed faces it is difficult to access and difficult to clean. In addition, the three-jaw design of the prior art severely limits how far the jaws can be opened, this in turn requiring the crimper to fit over the pipe, and then slide axially of the pipe and over the connection before it is can perform a curling operation. The use of a fixed compression jaw and two movable jaws results in three points around the circumference of the compression ring that can be subject to possible pitting and scraping of the compression sleeve at those points. In addition, the compression tool itself is of a complex construction and is expensive to manufacture. further, although it is expected that the durability of the tool will be greater than that described in German Patent Number 3,423,283, it is subject to wear on the sliding faces of the two movable jaws, which, due to the requirement of a fixed jaw and two sliders, must have a reduced sliding contact area with your support arm.

OBJECT OF THE INVENTION It is an object of the present invention to provide a crimping tool that removes the cam rollers and their associated cam tracks, and that also eliminates the ram cam which engages the jaws in a linear coupling. It is also an object of the present invention to provide a crimping tool having only two jaws, to thereby reduce the number of points at which the compression sleeve is punctured, while at the same time providing better supporting surface area between the jaws. compression jaws and their support arms, and in turn, a lower wear index of the sliding surfaces of the jaws in relation to their support arms. The other object of the present invention is to provide a curling tool having curling jaws that are smaller in overall size than those previously proposed, thus allowing the jaws to be lighter in weight. This provides two benefits to the user, since the curling tool is smaller than previously proposed, it can reach even tighter spaces, and being lighter, it is easier for a worker to handle. In addition, the crimper tool of the present invention has fewer components in motion, and eliminates numerous contact surfaces of concentrated load bearing, thereby extending the life of the crimper tool.

SUMMARY OF THE INVENTION In accordance with the present invention, the crimper tool is comprised of two compression jaws, each rotating in relation to its associated support arm, about an axis extending substantially parallel to the longitudinal axis of the tubular sleeve . Each of the jaws includes a cam surface which, when the jaws are closed, is respectively coupled with a ramp cam positioned on a stationary member of the "curling tool in a sliding surface area coupling therewith. the ramp cams and the cam surfaces of the jaws increase progressively in their area as the jaws move from the open position to the closed position thereof, mounting the respective jaws to rotate within their support arms respective about the longitudinal axis of the compression sleeve The geometry of the pivots for the support arms is arranged in such a way that on an opening or closing movement of the jaws, the cam surfaces of the jaws run over the cams of ramp in a continuous confronted coupling with them, moving the jaws one in relation to the other truth in parallelism with one another.

DESCRIPTION OF THE DRAWINGS The invention will now be described with reference to the accompanying drawings, which illustrate a preferred embodiment of the present invention, and in which: Figure 1 is an illustration of a curling tool of the prior art when in the open position Figure 2 is a view corresponding to Figure 1, showing the curling tool of the prior art when it is in a fully closed position. Figure 3 illustrates a curling tool in accordance with the present invention, when in a fully open position. Figure 4 illustrates the crimper tool of the present invention when it is in a partially closed position, ready to perform a crimping operation. Figure 5 is a view corresponding to Figure 4, but, showing one of the curling jaws when in the fully advanced crimping position, the other jaw being shown, for comparison purposes, when it is in a condition ready to effect the curling operation. Figure 6 is a view corresponding to Figure 4, showing the curling jaws when in a fully closed position.

DESCRIPTION OF THE PREVIOUS TECHNIQUE Referring now to Figures 1 and 2, where the same reference numerals have been used to denote the corresponding parts of the crimper, a crimper tool of the type described in German Patent Number 3,423,283 is shown. Figure 1 shows the curling tool of the prior art when it is in a fully open position, and in a condition where it can receive or be placed on a tube 10 surrounded by a compression sleeve 12, with the compression sleeve being any known form. The crimper tool itself includes a pair of relatively massive side plates 14, each of which is provided with cam grooves 16 on their mutually presented faces, the side plates 14 being stopped in a spaced apart relationship by a central spacer block 20. The plates laterally configured laterals 14, only one of which is shown in Figure 1, have sandwiches between them, the supporting arms 22 which are mounted for a pivotal movement between the side plates 14 by the pivots 24, the support arms pivoting on 26 with a curling jaw 28, carrying the curling jaws 28 each, a roller 30 running inside the cam grooves 16 in the respective side plates, in order to guide the curling jaws 28 in parallel with each other in the moment the curling tool moves to the closed position, as illustrated in Figure 2. As you can see immediately, when moving e from the open position shown in Figure 1, to the closed position shown in Figure 2, the curling jaws 28 have been brought into engagement with the ramp cams 32 and 34 provided on the upper surface of the central spacer block 20, being The ramp cams 32 and 34 are necessary in order to keep the curling jaws 28 in parallel with one another. This is because the respective pivots 26 are moving on arcuate trajectories, and consequently, they are rising at the moment when the end faces of the respective curling jaws 28 approach each other. In the absence of the ramp cams 32 and 34, the curling jaws 28 could be moved to a position where their end faces are angled relative to one another, a condition that must be specifically avoided if one is to obtain a successful ripple. in a curling shirt. The ramp cams 32 and 34 are required in addition to the rollers 30 and the cam slots 16, in which any wear of the rollers and their supporting arrows, or wear of the cam surfaces of the slots 16, as will occur by normal use of the tool, it will be amplified on the end faces of the curling jaws 28 by reason of the link used to move the jaws 28. Furthermore, wear on the pivots 24 and 26 can further exaggerate the problem. Starting with the tool in the position shown in Figure 1, the tool is placed on the crimper shirt 12 assembled on the tube 10, or the assembled tube 10 and the crimper shirt 12 are inserted between the curling jaws 28. Then, as shown in FIG. shown in Figure 2, and by means of a hydraulic roller connected to the central separator block 20, whose piston 36 carries rollers against friction 38, the support arms 22 are oppositely forced away from each other to the position shown in Figure 2. This, in turn, causes the rollers 30 to pass through the cam grooves 16 to orient the end faces of the curling jaws parallel to each other, and also, to cause the lower edges of the curling jaws 28 to engage with the respective ramp cams 32 and 34. During the final closing portion of the movement, the ramp cams 32 and 34 cause the end faces of the respective curling jaws to rise in unison, the curling jaws themselves being raised at that moment due to the fact that the pivots 26 are each moving on an arcuate path comprised of a radius from the associated pivot 24. It will be noted that the rollers 30 engage the cam grooves. 16 in a linear coupling. Also, it will be noted that the curling jaws 28 engage the respective ramp cams 32 and 34, also in a linear coupling. The extensive use of the curling tool will cause the wear of the cam grooves 16 of the rollers 30, and the supporting arrows for the rollers and will also cause wear on the ramp cams 32 and 34, and the points at which the jaws 28 are coupled with the respective ramp cams 32 and 34 in a linear coupling. The extensive use of the tool will result in wear at different points, and eventually, the curling jaws 28 will not move in true parallelism with each other, but instead will assume random angled positions of their end faces. one in relation to the other. If the curling jaws 28 approach the compression sleeve 12 in a manner other than in true parallelism, then the crimping effected on the compression sleeve will be uneven with the problems of scratching, scraping, and possibly cutting the sleeve of compression on an end face of one of the jaws, with possible destruction of the contained ring-0, while the opposite end face of that jaw, the compression sleeve 12 can be compressed improperly, allowing this to leak through 1 ring-0 in an axial direction of the contained tube. These conditions can not be tolerated in the assembly of a pipe system, in that once the compression sleeve has curled in a failed manner, then, it must be cut from the tubes, removed from the tubes, and then placed Replacement compression sleeve on the adjacent ends of the tubes, and then, the ripple operation has to be repeated. More importantly, the failure may not be noticed about the initial assembly of the pipe, which can be proved by sufficiency. At a later date and after the entire pipeline system has been assembled, and in operation for several months, the failed compression coupling may possibly fail, with disastrous consequences, and very considerable expense to effect repairs. In order to release the support arms 22 from the closed position, the hydraulic roller 36 carrying the rollers 38 retracts, thereby allowing the support arms 22 to move from the position shown in Figure 2, back to the position shown in FIG. Figure 1, under the influence of the springs indicated diagrammatically at 40.

DESCRIPTION OF THE PREFERRED MODALITY A preferred embodiment of the invention will now be described with reference to Figures 3 to 6, of which, Figure 3 shows the crimper tool when in a fully open position, ready to receive an assembled compression sleeve on the ends of the tube; Figure 6 shows the curling tool when it is in a fully closed position, and Figures 4 and 5 show the curling tool when it is in intermediate positions to the completely open and completely closed positions of the curling tool. Referring now to Figure 3, the crimper tool includes two pivoted support arms 50, each of which bears a jaw 52, which is slidably mounted on the associated support arm by "sliding" tracks 54, for a rotational movement of the respective jaws about the longitudinal axis of these jaws, each of the jaws 52 is provided with a cam member 56 that includes a ram cam 58, to cooperate with the cam surfaces 60 on an anvil 72. The respective jaws 52 each is forced to a starting position where the respective cam members 56 are in engagement with the respective support arms 50. For this purpose, a spring 62 is provided on each of the arms 50, the spring 62 reacts against a push rod 64, and stopping under compression by a pressure screw 66. The respective support arms 50 are pivoted each at 68 between the separated side plates 70, between which the support arms 50 are walled.

The anvil 72 can be fixedly mounted between the side plates 70, or it can be pivotally mounted thereon at 74. In use, the tubes and the compression sleeve (not shown) are inserted between the jaws 52, and then, the support arms 50 are rotated around the respective pivots 68, in order to place the jaws 52 in the position shown in Figure 4. In Figure 4, the jaws 52 are shown in a position where the ramp cams 58 have made an initial engagement with the cam surfaces 60, and prior to the rotational movement of the jaws 52 relative to their respective support arms 50. As will be seen in Figure 4, the respective support arms 50 have been moved angularly around their pivots to an angular position Rs, ie, they have each moved precisely around the respective pivots 68. In doing so, the ramp cams 58 or the respective cam members 56, have been placed in a surface coupling with the cam surfaces 60, ready for a subsequent sliding movement of the ramp cams 58 on their associated cam surfaces 60 in a mating engagement with the cam surfaces 60. The facing engagement of the ramp cams 58 with the cam surfaces 60 is important because a relatively large area of contact is provided in true face-to-face contact, which operates to reduce wear on the ramp cams 58 and cam surfaces 60, which slide relative to each other. the others in a contact facing opposite to a linear contact. As indicated in Figure 4, the movement of the support arms 50 from the initial position shown to its finished complete curling position will result in the respective support arms 50 moving from the initial position Rs to the final position. Rf. This in turn results in the respective jaws moving downwards towards the cam surfaces 60 by the distance R, the geometry of the ramp cams 58 and the cam surfaces 60 being such that the ramp cams 58 and the cam surfaces 60 are substantially maintained in a continuous sliding engagement during the closing of the support arms 50, which, as previously reported, will result in the jaws 58 moving downward by the distance R. In the event that the jaws 52 are rigidly mounted on their respective support arms 50, the end faces of the jaws 52 would approach each other, in a different way than in parallelism. The parallelism of the end faces of the jaws 52 is realized by the use of the cam members 56 and the cam surfaces 60 of the anvil 72. As the jaws 50 move toward each other, the respective jaws 52 rotate within its support arms against the force of the spring 62, this rotation being caused by the engagement of the ramp cams of the cam members 56 with the associated cam surfaces 60. Optionally, the anvil 72 is free to rotate about a pivot 74 carried by the side plates 70, to thereby provide a fully self-adjusting configuration, further ensuring that the jaws 52 approximate each other in true parallelism. Referring now to Figure 5, which shows the effect of moving only one of the support arms 50a, it will be seen that the free end of the jaw 52, which initially extends a distance A beyond its associated support arm 50, has been retracted to a distance B, while at the same time, the cam member 58 has descended down the cam surface 60 by a distance C. The anvil 70, in the event that it pivots, is incapable of moving on the coupling of the other cam surface 60 with the opposite cam member 56, ie, without considering which of the jaws 52 is moving at any particular time, the entire system is maintained in symmetry with the end faces of the jaws 52 kept in parallel with each other. In the event that a compression sleeve is not present between the jaws, then, the springs 62 and the push rods 64 maintain the cam members 56 and their ramp cams 58 in an appropriate surface engagement with the cam surface. associated 60. Figure 6 illustrates the crimper tool when it is in a fully closed condition, the end faces of the respective jaws 52 having engaged with each other, this position being the completion of a full crimping operation on the sleeve of understanding. As is known, the respective support arms 50 can be rotated by rollers 30 carried by a hydraulic roller 36, which is forced upwards between the downwardly extending arm 76 of the respective support arms 50. During the movement in Reversing the jaws 52 from the closed position illustrated in Figure 6 to the open position illustrated in Figure 3, first, the cam members 56 will traverse the cam surfaces 60 upwardly, with the respective jaws 52 turning in at that time. their sliders 54 by the force imposed by the springs 62 and the push rods 64, the ramp cams 58 and the cam surfaces 60 remaining in a surface engagement during this movement, until such time as the cam members 56 become to engage with the support arms 50, as illustrated in Figures 3 and 4. Once the cam members 56 have engaged with their associated support arm 50, then, another rotation of the jaws 52 is prevented within the support arms 50 under the influence of the springs 62. The continuous opening movement of the support arms 50 will then lift the ramp cams 58 from the cam surfaces. associated 60, this allows the jaws to move to a fully open position, as illustrated in Figure 3. It is of significance for the present invention that only two jaws are employed, this in turn providing a sliding surface area greater between the jaw 52 and the receptive support arms 50. Also, the cam action of the ramp cams 58 and their associated cam surfaces 60, proceeds in a face-to-face surface coupling after the initial linear coupling, thereby providing a maximized support surface area that has no linear contact. Additionally, since only the side plates 70 are required to provide a pivotal support for the respective support arms 50, and optionally the anvil 72, the side plates 70 may be of a lighter weight than in the previous proposed constructions of curling tools , which tend to be problematic, heavy, and difficult to place, particularly in the larger sizes of these curling tools. Since only the springs 62 are required to return the jaws 52 to their initial position where the cam members 56 engage the support arm 50, these springs may be of relatively light weight. As will be apparent to those skilled in the art, any other convenient elements may be provided to force the jaws. The respective members of the curling tool can conveniently be manufactured by the known hot stamping forging process, or in the alternative, they can be manufactured by a casting operation, using a non-crystalline malleable steel which is machined as necessary subsequently to the emptying operation.

Claims (5)

1. A tool for crimping a compression sleeve used in a compression coupling, which includes: a support; two pivoted support arms for arcuate movement around the support; a curling jaw slidably mounted on the support arm for a sliding movement rotatable about a longitudinal axis of the respective curling jaws; a cam member on the curling jaw; elements forcing the respective curling jaws to rotate in relation to the associated support arm to a determined position in relation to the support arm; and a ramp cam on each cam member that can be engaged in a facing engagement with a cam surface carried by the support, the ramp cam operating to rotate the associated ripple jaw relative to the associated support arm, to maintain the end faces of the respective curling jaws in parallelism with one another during a curling operation. The tool of claim 1, wherein the cam members on the respective curling jaws are engageable with the associated support arm, and the elements for forcing the respective curling jaws operate to force the cam members into a direction for coupling the cam members with the associated support arm. The tool of claim 1, wherein the support is provided by parallel spaced side plates between which the respective support arms are placed for a pivotal arcuate movement about the arrows carried by the side plates. The tool of claim 1, wherein the forcing elements are provided by springs carried by the respective support arms, and which react on the curling jaws to force the curling jaws to the determined position. The tool of claim 1, wherein the respective cam surfaces are each provided on an anvil carried by the support.