MXPA06015053A - Reusable fitting for tubing - Google Patents

Abstract

A fitting for use with corrugated tubing, the fitting comprising:a nut having a passage therethrough for receiving the tubing, the tubing being corrugated tubing having a series of peaks and valleys;a plurality of retainers positioned forward of the nut, the retainers having a sealing surface for placement in a valley of the corrugated tubing;a body having an annular pocket formed circumferentially around the retainers, the body having a body sealing surface, wherein upon sealing, the tubing is compressed between the sealing surface and the body sealing surface;a spring positioned within a cavity in the retainers, the spring driving the retainers into the pocket when the fitting is not sealed.

Description

REUSABLE PIPE ACCESSORIES DESCRIPTION OF THE INVENTION The flexible gas pipeline (FGP) system, also referred to as corrugated stainless steel pipe (CSST) and formerly Interior Gas Pipe (IGP) was developed in Japan and was first introduced into that market. by Osaka Gas and Tokyo Gas Companies during the early 1980s. The system uses stainless steel corrugated tubing supplied in roll or reel with fittings that can be fixed in the field to distribute gas from such a central supply point. as a meter or regulator to several devices inside a house or building. The technology, which compares the process of placing gas pipe in a house to the wiring of a house for electricity, substantially reduces the installation time and therefore the associated higher labor cost. The technology was brought to the United States of America by the Gas Research Institute, which considered it as a means to make gas installations more competitive; with this increasing the percentage of new construction with gas plumbing and increasing the total natural gas consumption nationwide. The technology was recommended and enthusiastically supported by the main gas suppliers who had seen the significantly higher cost of installed pipeline as their only major obstacle to selling more gas. Acquiring the acceptance code required more time and effort, but the product is now recognized by all national model codes and ANSI, the National Fire Protection Association / National Fuel Gas Code and is tested and recognized by the American Gas Association . This product will eventually supply the black iron pipe that accounts for approximately 80% of all fuel gas piping today, as well as copper piping which, while enjoying many of the same advantages of the FGP, is being prohibited from its application at an increased speed. There have been multiple types of accessories placed in the field. An accessory introduced into the field used a fiber seal to make the seal and no special tools were needed to assemble this accessory. This accessory had a higher leakage incidence than those of flared metal-to-metal seal used by another manufacturer. Another accessory introduced in the campp used a first specialized tool to flatten the seizures at the end of the CSST tube where the fitting had to be fixed and then a second tool was used to make a single flare at the end of the tube. This product today is out of the market due to pipe failures caused by the hardening of stainless steel work in the flattening and flapping process. Another type of accessory was introduced into the field without using special tools to make a metal-metal seal by bending the convolutions of the tube on itself creating a double flare. After a limited time in the field it was noted that this accessory design was inconsistent in making a leak tight seal. The remedy to the problem was to design an insert-type flare tool; This was used for approximately three years. A second redesign was carried out, improving the insert tool to a latching tool. Other accessories have been introduced by the owner of the present invention and are described in US Patents 6,276,728, 6,079,749, 5,799,989, the contents of which are hereby incorporated by reference in their entirety. While these accessories are well suited for their intended purposes, improvements can be made in certain aspects of these accessories. The embodiments of the invention include an accessory that is used with corrugated pipe, the accessory comprises: a nut having a passage through it to receive the pipe, the pipe is corrugated pipe that has a series of peaks and valleys; a plurality of retainers that are placed forward of the nut, the retainers have a sealing surface to be placed in a valley of the corrugated pipe; a body having an annular recess formed circumferentially around the retainers, the body having a body sealing surface, wherein upon sealing, the compressed tube between the sealing surface and the body sealing surface; A spring placed inside a cavity in the retainers, the spring pushes the retainers into the recess when the accessory is not sealed. BRIEF DESCRIPTION OF THE DRAWINGS Referring now to the drawings in which similar elements have similar numbers in the different Figures: Figure 1 is a cross-sectional view of an exemplary accessory in its assembled unsealed state; Figure 2 is a cross-sectional view of an exemplary nut; Figure 3 is a perspective view of an exemplary retainer; Figure 4 is a cross-sectional view of an exemplary body; Figure 5 is a plan view of an exemplary spring; and Figure 6 is a cross-sectional view of an exemplary accessory in its assembled sealed state. FIGURE 1 is a cross-sectional view of an accessory 10 in an embodiment of the invention. The fitting 10 includes a nut 100, a body 200, retainers 300 and a spring 400. Figure 1 shows the accessory 10 in a partially assembled open position. The nut 100, and the body 200 can be made of metal (for example, brass) and can be machined or cast. The pipe 500 can be corrugated stainless steel pipe (CSST) or any other corrugated pipe. In Figure 1, the accessory is assembled, but not sealed. The tube 500 is shown placed in the nut 100 and the body 200. The tube 500 is an annular corrugated tube having an outer surface having peaks and valleys. The nut 100 includes a slot 102 and seal 104 (e.g., o-ring) at a first backward end for sealing against a sleeve 502 in the pipe 500 as described in US Patent 6,695,353, the total content of which is incorporated in the present for reference. The O-ring 104 resists the entry of foreign material into the fitting. The nut 100 includes external threads 106 which engage the internal thread 202 in the body 200. As will be described in detail herein, the nut 100 includes a nut surface 108 at a forward forward second end on which the surface 308 is mounted. of the retainer when the body 200 and the nut 100 are tightened. Similarly, the body 200 includes a body surface 204 at a second forward end on which the retainers 300 are mounted when the body 200 and the nut 100 are tightened. The retainers 300 include a cavity 302 positioned on the front face of the retainer 300 to contain the spring 400. The retainers 300 include a seal surface 304 behind the cavity 302. As will be described herein in detail below, the Corrugated pipe is compressed between the sealing surface 304 and the body sealing surface 206. A retaining rear cavity 306 at a first rearward end of the retainer 300 receives a spout from the tube 500 when the fitting is tightened. When disassembled or in its partially assembled state, the spring 400 pushes the retainers 300 into a recess 210 formed in the body 200 circumferentially around the retainers 300. This moves the retainers 300 and the spring 400 out of the outer diameter of the retainer 300. 500 tube to allow its assembly and disassembly. The tube 500 can be freely inserted into or removed from the nut when the retainers 300 are in the recess 210. In this way, the accessory 10 can be reused. In the partially assembled state shown in Figure 1, the body 200 engages the nut 100 but the threads 106 and 202 are not fully engaged. The retainers 300 are pushed into the recess 210 by the spring 400. The tube 500 is inserted into the fitting until it makes contact with the body sealing surface 206 at the second forward end of the body 200. Figure 2 is a view in cross section of the nut 100. As noted above, the nut 100 includes the nut surface 108 at a second forward end of the nut 100. The nut surface 108 is angled at an oblique angle less than 90 degrees relative to a longitudinal central axis of the accessory 10. This angle is mirror reflects on the surface 308 of the retainer at the first backward end of the retainer 300. Figure 3 is a perspective view of a retainer 300. The accessory includes a plurality of retainers and may have three or more retainers.1 The spring 400 is received in the cavity 302 to be positioned outside the outer diameter of the tube 500 when the accessory is not sealed. In exemplary embodiments, three retainers are used, each extending to 120 degrees of the tube. When the fitting is sealed, the three retainers are spliced at their ends, to form a continuous retaining ring. The sealing surface 304 compresses one or more convolutions of the tube 500 against the body sealing surface 206 to form a metal-to-metal seal. Figure 4 is a cross-sectional view of the body 200. The body 200 includes an annular notch 212 that extends toward a first rearward end of the body 200. The notch 212 receives an anterior portion of the retainers 300 when the fitting is assembled . The body 200 includes a tapered surface 214 which serves as a pilot to align the body 200 with the tube 500. The tapered surface 214 is at an oblique angle with reference to the centerline of the fitting. The tapered surface 204 is also angled relative to the body sealing surface 206, which is shown as perpendicular to the center line of the body 200. Figure 5 depicts the spring 400. The spring 400 is a wound wire spring yet; rest state having a diameter greater than the outside diameter of the tube 500. Tabs 402 at the ends of the spring are bent inwardly to prevent the spring 400 from jamming on the surface of the retainers 300 .; When the accessory 10 is disassembled or partially assembled 1 as shown in Figure 1, the spring 400 | forces the retainers outward in a radial direction to place the retainers 300 within the recess 210. The retainers 300 will remain in place within of the holes; 210 in the open position even if the accessory is dropped or shaken. As the body 200 is tightened on the nut 100, the retainers 300 move inward in a radial direction compressing the spring 400. The inward movement of the retainers 300 is driven by the angled nut surface 108 and the surface 204 of angled body, which form an oblique angle with reference to the center line of the accessory 10. Figure 6 depicts the accessory 10 in its sealed state, as the body 200 is tightened on the nut 100, the retainers 300 are pushed radially inward through interaction with the surfaces 108 and 204 as the nut 100 moves towards the body 200. This causes the sealing surface 304 to be placed in a valley behind one or more corrugated tube peaks 500. . As the nut 100 and the body 200 are tightened even further, the retainers 300 enter the notch 212. As the nut 100 enters the body 200, the first convolution of the tube 500 is compressed between the sealing surface 304 and the body sealing surface 206. This forms a metal-to-metal seal between the body 200 and the tube 500 and between the retainers 300 and the tube 500. The seal is such that the outside diameter of the seal is equal to or is not substantially greater than the outside diameter of the tube 500 This allows the tube to be removed from the nut 100 when the nut 100 and the body 200 are loosened.

The sealing surface 304 is dimensioned and closely matches the corrugation geometry of the tube 500 and requires less force to splice. The resulting seal of sealing surface 304 is not a horn and does not extend beyond the outer diameter of the tube. The sealing surface 304 reduces the tension applied to the tube 500 compared to conventional speakers. The body sealing surface 206 is a line seal for greater reliability. If the nut 100 is loosened from the body 200, the spring 400 pushes the retainers 300 radially outwardly until the sealing surface 304 is released from the outside diameter of the tube 500. The tube 500 can then be removed. This allows the accessory 10 to be reused. An accessory accng to the exemplary embodiments of the invention provides several advantages. The thrust design (that is, the accessory can be pushed onto the tube 500) does not require disassembly and is reusable. The accessory 10 is joined by forcing the edges to prevent disassembly and can be made of a wide variety of materials. Although the preferred embodiments have been described and shown, various modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accngly, it should be understood that the present invention has been described by way of illustration and not limitation.

Claims (11)

1. CLAIMS 1. An accessory that is used with corrugated tube, the accessory is characterized because it comprises: a nut that has a passage through it to receive the tube, the tube is corrugated tube that has a series of peaks and valleys; a plurality of retainers placed on the front of the nut, the retainers have a sealing surface for placing them in a valley of the corrugated pipe; a body having an annular recess formed circumferentially around the retainers, the body having a body sealing surface, wherein upon sealing, the tube is compressed between the sealing surface and the body sealing surface; A spring placed inside a cavity in the retainers, the spring pushes the retainers into the recess when the accessory is not sealed. The accessory according to claim 1, characterized in that: the nut includes a nut surface at a front end of the nut, the nut surface engages a retainer surface in the retainer to direct the nut toward a center line of the nut. accessory when coupling the nut and the body. The accessory according to claim 2, characterized in that: the body includes a body surface at a front end of the body, the body surface engages the retainer to direct the retainer toward a center line of the fitting when coupling the nut and the body. The accessory according to claim 2, characterized in that: the nut surface has an oblique angle less than 90 degrees with respect to the center line of the accessory. The accessory according to claim 4, characterized in that: the oblique angle is mirrored on the surface of the retainer. The accessory according to claim 1, characterized in that: the retainer includes a retention cavity rear opposite the sealing surface, the rear retainer cavity receives a peak of the corrugated tube. 7. The compliance accessory, with claim 1, characterized in that: when the accessory is not sealed, the spring and the retainers have an internal diameter greater than the outer diameter of the tube. The accessory according to claim 1, characterized in that: the body sealing surface is substantially perpendicular to the center line of the accessory. The accessory according to claim 1, characterized in that: the body includes a tapered surface at a front end of the body, the tapered surface provides a pilot surface for aligning the tube with the body. The accessory according to claim 1, characterized in that: the nut includes external threads that couple the threads formed inside the body. 11. An accessory that is used with corrugated tube, the accessory is characterized in that it comprises: a nut having a passage through it to receive the tube, the tube is corrugated tube that has a series of peaks and valleys; a plurality of retainers placed on the front of the nut, the retainers have a sealing surface that is placed in a valley of the corrugated pipe; a body having an annular recess formed circumferentially around the retainers, the body having a body sealing surface, wherein upon sealing, the tubing is compressed between the sealing surface and the body sealing surface; a spring placed inside a cavity in the retainers, the spring pushes the retainers to the recess when the accessory is not sealed; wherein the nut includes a nut surface at a first front end of the nut, the nut surface engages a retainer surface in the retainer to direct the retainer toward a centerline of the fitting when coupling the nut and body; wherein the nut surface has an oblique angle of less than 90 degrees with respect to the center line of the fitting; the oblique angle is mirrored on the surface of the retainer; wherein the retainers include a rear retainer cavity opposite the sealing surface, the rear retainer cavity receives a peak from the corrugated tube; When the accessory is not sealed, the spring and retainers have an internal diameter greater than the external diameter of the tube; wherein the body includes a tapered surface at an anterior end of the body, the tapering surface provides a pilot surface for aligning the tube with the body.