HK40009407B - Fitting for medical piping system - Google Patents

Description

Accessories for medical tubing systems

Background Art

Embodiments generally relate to fittings for use with pipes, and more particularly, to fittings suitable for use with medical tubing in healthcare facilities. Medical tubing within healthcare facilities has traditionally been rigid copper tubing that meets the NPFA 99 specification for healthcare facilities. Healthcare facilities include a wide variety of facilities, including hospitals, mobile healthcare centers and clinics, medical and dental offices, nursing homes, limited healthcare facilities, and the like. Traditionally, healthcare facilities have used brazed copper tubing that is supplied in short lengths and joined together by brazing; any change in direction requires an additional brazed joint. The installation of rigid copper tubing is labor intensive and requires that each length of copper tubing be contained within a sealed drain area so that the brazing process does not introduce contaminants into the surrounding area. The installation and removal of the sealed drain area is time consuming and increases installation time.

DE 103 22 972 A1 relates to a connecting element for a corrugated pipe comprising a tubular coupling, an expansion ring and an annular seal to be coupled together such that a tight joint is produced by compressing the annular seal between the inner surface of the tubular coupling and the outer surface of the pipe.

Summary of the Invention

According to one embodiment, a fitting for use with a metal bellows having peaks and valleys includes a nut configured to receive the tube; a seal for placement in the valley of the tube, the seal including a sealing surface; and an adapter configured to be press-fit into the nut, the adapter including an adapter sealing surface; wherein, when assembled, the adapter is press-fit into the nut and the tube is compressed between the adapter sealing surface and the sealing surface.

In addition to, or alternatively to, one or more of the features described above, further embodiments may include wherein the adapter sealing surface is arcuate.

In addition to or as an alternative to one or more of the features described above, further embodiments may include wherein the adapter sealing surface is spherical or toroidal.

In addition to, or as an alternative to, one or more of the features described above, further embodiments may include wherein the sealing surface is flat.

In addition to, or alternatively to, one or more of the features described above, further embodiments may include wherein the sealing surface is frusto-conical.

In addition to or alternatively to one or more of the above features, further embodiments may include: wherein the nut includes a first cavity configured to receive an adapter; the adapter includes a sealing ridge formed thereon, the outer diameter of the sealing ridge being greater than the inner diameter of the first cavity.

In addition to or alternatively to one or more of the above features, further embodiments may include: wherein the nut includes a first cavity configured to receive an adapter; the adapter includes a locking ridge formed thereon, the locking ridge having an outer diameter greater than an inner diameter of the first cavity.

In addition to or instead of one or more of the features described above, further embodiments may include wherein the locking ridge comprises an edge that mechanically secures the nut to the adapter.

In addition to or instead of one or more of the features described above, further embodiments may include wherein the adapter includes a locking ridge formed thereon and spaced apart from the sealing ridge, the locking ridge having an outer diameter greater than an outer diameter of the sealing ridge.

In addition to or instead of one or more of the features described above, further embodiments may include wherein the locking ridge comprises an edge that mechanically secures the nut to the adapter.

In addition to or instead of one or more of the features described above, further embodiments may include wherein the adapter includes an engagement surface between the sealing ridge and the locking ridge, the engagement surface having an outer diameter greater than an inner diameter of the first lumen.

In addition to or instead of one or more of the above features, further embodiments may include: wherein the nut includes a second cavity; and the tube includes a sleeve; the accessory further includes: a sleeve locking ring, the sleeve locking ring configured to be placed in the second cavity, the sleeve locking ring including an outer surface and an inner surface, the outer surface including a tapered bevel, the inner surface including at least one ridge configured to engage the sleeve; a swage sleeve, the swage sleeve configured to be placed in the second cavity, the swage sleeve including a tapered surface, the tapered surface facing the bevel on the sleeve locking ring.

In addition to or instead of one or more of the features described above, further embodiments may include wherein, upon assembly, the swage sleeve is press fit into the second cavity and the tapered surface of the swage sleeve engages the ramp of the guard locking ring to drive the guard locking ring toward the guard.

In another embodiment, a fitting for use with a metal bellows having peaks and valleys encased in a jacket comprises: a nut including a first cavity and a second cavity and a shoulder extending radially inwardly between the first cavity and the second cavity, configured to receive the tube through the second cavity; a seal configured to be placed in the valley of the tube, the seal including a sealing surface and a circumferential recess configured to abut and receive the shoulder to limit movement of the seal; and an adapter configured to be press-fitted into the nut, the adapter including an adapter sealing surface, the adapter including a sealing ridge formed thereon, the sealing ridge having an outer diameter greater than that of the first cavity. an inner diameter; a sheath locking ring configured to be placed in the second cavity, the sheath locking ring comprising an outer surface and an inner surface, the outer surface comprising a tapered bevel, the inner surface comprising at least one ridge configured to engage the sheath; a swage sleeve configured to be placed in the second cavity, the swage sleeve comprising a tapered surface facing the bevel on the sheath locking ring; wherein, upon assembly, the adapter is press-fit into the first cavity and the swage sleeve is press-fit into the second cavity, the tube is compressed between the adapter sealing surface and the sealing surface, and the tapered surface of the swage sleeve engages the bevel of the sheath locking ring to drive the sheath locking ring toward the sheath.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded cross-sectional view of a fitting and a pipe in an exemplary embodiment.

FIG. 2 is a cross-sectional view of the adapter of FIG. 1 .

FIG3 is a cross-sectional view of the nut of FIG1 .

FIG. 4 is a cross-sectional view of the seal of FIG. 1 .

5 is an end view of the boot locking ring of FIG. 1 .

6 is a partial cross-sectional view of the shield locking ring of FIG. 1 .

FIG. 7 is an exploded view of the boot locking ring of FIG. 6 .

FIG8 is a cross-sectional view of the swaging sleeve of FIG1.

9 is a cross-sectional view of the assembled fitting and conduit in an exemplary embodiment.

DETAILED DESCRIPTION

FIG1 is an exploded cross-sectional view of the fittings and flexible conduit in an exemplary embodiment. The conduit 10 comprises a flexible annular corrugated metal tube 12 (e.g., copper alloy, stainless steel, etc.) and a sheath 14 having a smooth exterior. The sheath 14 can be a co-extruded non-metallic sheath that fills the spaces between the corrugations (e.g., peaks and valleys) to mechanically attach the sheath 14 to the corrugated metal tube 12. In one embodiment, the sheath 14 is a polymer sheath, such as low-density polyethylene. Other materials that provide sufficient tensile strength to resist the movement of the corrugations under pressure can be used. The sheath 14 can include one or more flame retardant additives. The sheath 14 can meet ASTM E84, with a maximum flame spread index of 25 and a maximum smoke density index of 50. The conduit 10 can be implemented using metal conduits for medical applications.

The fitting includes an adapter 100, a seal 200, a nut 300, a boot locking ring 400, and a swage sleeve 500. Each of these elements is described herein along with the fitting assembly shown in Figure 9. The adapter 100, seal 200, nut 300, boot locking ring 400, and swage sleeve 500 may be made of metal (e.g., brass or stainless steel).

FIG2 is a cross-sectional view of the adapter 100. The first end of the adapter 100 includes a cylindrical recess 102 for receiving a metal (e.g., copper) tube. The metal tube can be brazed to the adapter 100. The recess 102 can have various inner diameters to accommodate metal tubes of different sizes. A flow conduit 104 is formed in the adapter 100 centered about the centerline of the adapter 100. At a terminal end 106 of the adapter 100, a guide diameter 108 is provided. The guide diameter 108 is a cylindrical lip that is slightly smaller than the inner diameter (at the valley) of the metal tube 12. The guide diameter 108 helps to center the metal tube 12 with the adapter 100 to promote a better seal between the adapter 100 and the metal tube 12.

Adapter sealing surface 110 is located adjacent to pilot diameter 108. As described in further detail herein, adapter sealing surface 110 interacts with a sealing surface on seal 200 to compress metal tube 12 and form a metal-to-metal seal. In an embodiment, adapter sealing surface 110 is curved or arcuate. In an exemplary embodiment, adapter sealing surface 110 is a portion of a spherical surface or a torus. The sealing surface on seal 200 can be linear, planar, or frusto-conical. The interaction between the curved adapter sealing surface 110 and the planar sealing surface on seal 200 creates a line seal, thereby reducing the axial compressive load required to create a seal when the fitting is installed.

The adapter centering surface 112 is adjacent to the adapter sealing surface 110. The outer diameter of the adapter centering surface 112 is slightly smaller than the inner diameter of the first cavity 306 ( FIG. 3 ) of the nut 300 to center the nut 300 on the adapter 100. The front edge of the adapter centering surface 112 may be chamfered to facilitate insertion of the adapter 100 into the nut 300.

Adapter centering surface 112 abuts sealing ridge 114. The outer diameter of sealing ridge 114 is larger than the outer diameter of adapter centering surface 112. The outer diameter of sealing ridge 114 is larger than the inner diameter of first cavity 306 of nut 300. Sealing ridge 114 can be curved and include a portion of a spherical surface or a torus. Because the outer diameter of sealing ridge 114 is larger than the inner diameter of cavity 306 of nut 300, adapter 100 is press-fitted into nut 300 and forms a fluid-tight seal between adapter 100 and nut 300.

Engaging surface 116 is located behind sealing ridge 114. The outer diameter of engaging surface 116 is slightly smaller than the major diameter of sealing ridge 114 and slightly larger than the outer diameter of adapter centering surface 112. The outer diameter of engaging surface 116 is slightly larger than the inner diameter of cavity 306 of nut 300. Engaging surface 116 helps center adapter 100 to nut 300 when adapter 100 is press-fitted into nut 300 and a slip fit is created between adapter 100 and nut 300.

The locking ridge 118 is located behind the engagement surface 116. The major diameter of the locking ridge 118 is slightly larger than the major diameter of the sealing ridge 114 and larger than the inner diameter of the cavity 306 of the nut 300. The locking ridge 118 can be triangular in cross-section, providing an edge that mechanically secures the nut 300 to the adapter 100.

FIG3 is a cross-sectional view of the nut 300 of FIG1 . A flow conduit 304 is formed in the nut 300 centered about the centerline of the nut 300. The nut 300 receives the adapter 100 in a first cavity 306 and receives the pipe 10 through a second cavity 308. The first cavity 306 has an angled opening 310 to facilitate insertion of the adapter 100 into the first cavity 306. A shoulder 312 extends radially inward between the first cavity 306 and the second cavity 308 and serves as a stop to limit the travel of the seal 200.

FIG4 is a cross-sectional view of seal 200 of FIG1 . The seal may be implemented using a pair of split rings, collets, C-rings, or the like. In FIG4 , seal 200 is a split ring. The front end of seal 200 (the end facing adapter 100) includes a sealing surface 202. In the example of FIG4 , the sealing surface is linear in cross-section and may be frusto-conical. In the exemplary embodiment, sealing surface 202 is angled 55 degrees relative to the central axis of adapter 100. It will be appreciated that sealing surface 202 may have a different shape. The rear end of seal 200 (the end facing pipe 10) includes a cavity 204 having an arcuate shape to receive the apex of metal pipe 12. A circumferential flange 206 extends rearwardly and defines a circumferential notch 208 around the perimeter of seal 200. The outer diameter of flange 206 is smaller than the inner diameter of shoulder 312 of nut 300. When the fitting is assembled, the shoulder 312 is received in the recess 208 to limit the travel of the seal 200 , and therefore the travel of the pipe 10 .

The seal 200 includes a radially inwardly facing circumferential lip 212. The inner diameter of the lip 212 is sized to be slightly larger than the outer diameter of the valley on the metal tube 12. The lip 212 is received in the valley on the metal tube 12 to position the seal 200 on the pipe 10.

FIG5 is an end view of the jacket locking ring 400 of FIG1 . The jacket locking ring 400 in FIG5 is a C-shaped ring that is compressed by a swage sleeve 500 to mechanically engage the jacket 14 of the pipe 10. As shown in FIG6 , the jacket locking ring 400 has a thickness x at the front end (facing the adapter 100). The thickness of the jacket locking ring 400 is gradually reduced to a thickness y by means of a bevel 402. In one embodiment, x is 0.15 inches and y is 0.007 inches. The inner surface of the jacket locking ring 400 includes one or more ridges 404 shaped to engage the jacket 14 of the pipe 10. The ridges 404 can be radially arranged on the inner surface of the jacket locking ring 400. The ridges in FIG7 have a triangular cross-section that provides an edge for engaging the jacket 14. It should be understood that other cross-sections of the ridges 404 can be used. The outer diameter of the jacket locking ring 400 is slightly smaller than the inner diameter of the second cavity 308 in the nut 300.

FIG8 is a cross-sectional view of the swage sleeve 500 of FIG1 . The swage sleeve 500 is generally cylindrical in shape. The front edge (facing the adapter 100) is angled (e.g., 20 degrees relative to the centerline of the fitting) to define a tapered surface 502. The tapered surface 502 cooperates with the beveled surface 402 on the boot locking ring 400 to compress the boot locking ring 400 inwardly toward the centerline of the fitting. This drives the ridges 402 into the boot 14 to mechanically secure the fitting to the pipe 10. The outer diameter of the swage sleeve 500 is slightly smaller than the inner diameter of the second cavity 308 in the nut 300, so that the swage sleeve 500 is press-fit into the nut 300 to mechanically secure the swage sleeve 500 to the nut 300.

FIG9 is a cross-sectional view of the assembled fitting and pipe 10 in an exemplary embodiment. To assemble the fitting onto the pipe 10, the jacket 14 is removed to expose at least two complete peaks and at least a portion of the valley beyond the second peak. The pipe is cut in the valley at the distal end of the metal tube 12.

The pipe 10 is passed through the swage sleeve 500, the boot locking ring 400, and the nut 300. The sealing device 200 is secured to the exposed metal pipe 12 so that the sealing surface 202 is positioned directly behind the first peak of the metal pipe 12, with the lip 220 in the valley of the metal pipe 12. The pipe 10 can then be pulled back until the sealing device 200 contacts the shoulder 312 on the nut 300. At this point, the boot locking ring 400 and swage sleeve 500 can be positioned, to the extent manually possible, in the second cavity 308 of the nut 300. The adapter 100 is positioned, to the extent manually possible, in the first cavity 306 of the nut 300.

Once the fitting is manually assembled, a compression tool is used to simultaneously drive the adapter 100 into the nut 300 and the swage sleeve 500 into the nut 300. Driving the adapter 100 into the first cavity 306 causes several actions to occur. A seal is formed between the adapter sealing surface 110, the metal tube 12, and the sealing surface 202. This seal is the primary seal and includes the double-flared metal tube 12 compressed between the adapter sealing surface 110 and the sealing surface 202. In embodiments where the adapter sealing surface 110 is arcuate, a wire seal is formed on the metal tube 12.

The sealing ridge 114 engages the inner diameter of the cavity 306 of the nut 300 to create a fluid-impermeable seal between the adapter 100 and the nut 300. The locking ridge 118 engages the inner surface of the cavity 306 of the nut 300 to mechanically secure the nut 300 to the adapter 100. The swage sleeve 500 is driven into the second cavity 308 of the nut 300. The tapered surface 502 cooperates with the beveled surface 402 on the boot locking ring 400 to compress the boot locking ring 400 inward toward the centerline of the fitting. This drives the ridge 402 into the boot 14 to mechanically secure the fitting to the pipe 10, preventing any expansion under pressure. The interference between the outer diameter of the swage sleeve 500 and the inner diameter of the cavity 308 secures the swage sleeve 500 to the nut 300.

In embodiments, the pipe can be installed in much longer lengths than rigid copper pipe. This significantly reduces installation time by eliminating the need to set and seal the installation area for drainage troubleshooting. Additionally, the use of press-fit connections eliminates the need to braze fittings onto the pipe.

While preferred embodiments have been shown and described, various modifications and substitutions can be made thereto without departing from the spirit and scope of the invention. It is to be understood, therefore, that the present invention has been described by way of illustration and not limitation.

Claims (14)

1. An accessory for use with a metal bellows (12) having peaks and valleys, said accessory comprising: Nut (300), configured to receive the tube (12); A metal seal (200) for placement in the valley of the tube (12), the seal (200) including a sealing surface (202); and An adapter (100) is configured to be press-fitted into the nut (300), the adapter (100) including an adapter sealing surface (110); The feature is that, during assembly, the adapter (100) is press-fitted into the nut (300), and the tube (12) is pressed between the adapter sealing surface (110) and the sealing surface (202) and is in a flared shape. 2. The accessory according to claim 1, wherein the adapter sealing surface (110) is arc-shaped. 3. The accessory according to claim 2, wherein the adapter sealing surface (110) is spherical or annular. 4. The accessory according to claim 2, wherein the sealing surface (202) is flat. 5. The accessory according to claim 2, wherein the sealing surface (202) is truncated conical. 6. The accessory according to claim 1, wherein the nut (300) includes a first cavity (306) configured to receive the adapter (100); The adapter (100) includes a sealing ridge (114) formed thereon, the outer diameter of which is larger than the inner diameter of the first cavity (306). 7. The accessory according to claim 1, wherein the nut (300) includes a first cavity (306) configured to receive the adapter; The adapter (100) includes a locking ridge (118) formed thereon, the outer diameter of which is larger than the inner diameter of the first cavity (306). 8. The accessory according to claim 7, wherein the locking ridge (118) includes an edge that mechanically secures the nut (300) to the adapter (100). 9. The accessory according to claim 6, wherein: The adapter includes a locking ridge (118) formed thereon and spaced apart from the sealing ridge (114), the outer diameter of the locking ridge (118) being larger than the outer diameter of the sealing ridge (114). 10. The accessory according to claim 9, wherein the locking ridge (118) includes an edge that mechanically secures the nut (300) to the adapter (100). 11. The accessory according to claim 9, wherein the adapter (100) includes a mating surface (116) located between the sealing ridge (114) and the locking ridge (118), the outer diameter of the mating surface (116) being larger than the inner diameter of the first cavity (306). 12. The fitting according to claim 1, wherein the tube (12) is inserted into the sheath (14), wherein: The nut (300) includes a second cavity (308); and The accessories further include: A sheath locking ring (400) configured for placement in the second cavity (308) includes an outer surface and an inner surface, the outer surface including a tapered bevel (402) and the inner surface including at least one ridge configured to engage the sheath (14); A forged sleeve (500) is configured to be placed in the second cavity (308), the forged sleeve (500) including a tapered surface (502) facing the ramp (402) on the sheath locking ring (400). 13. The accessory according to claim 12, wherein: During assembly, the forged sleeve (500) is press-fitted into the second cavity (308), and the tapered surface (502) of the forged sleeve (500) engages the inclined surface (402) of the sheath locking ring (400) to drive the sheath locking ring (400) toward the sheath (14). 14. The fitting according to claim 1, wherein the tube (12) is inserted into the sheath (14), wherein: The nut (300) includes a first cavity (306) and a second cavity (308) and a shoulder (312) extending radially inward between the first cavity (306) and the second cavity (308), the shoulder being configured to receive the tube (12) through the second cavity (308); A seal (200) is provided for placement in the valley of the tube, the seal (200) including a circumferential recess (208) configured to abut against and receive the shoulder (312) to restrict movement of the seal (200); The adapter (100) includes a sealing ridge (114) formed thereon, the outer diameter of which is larger than the inner diameter of the first cavity (306); The accessories further include: A sheath locking ring (400) configured to be placed in the second cavity (308), the sheath locking ring (400) including an outer surface and an inner surface, the outer surface including a tapered bevel (402), and the inner surface including at least one ridge configured to engage the sheath; A forged sleeve (500) configured for placement in the second cavity (308), the forged sleeve (500) including a tapered surface (502) facing the inclined surface (402) on the sheath locking ring (400); During assembly, the adapter (100) is press-fitted into the first cavity (306), and the forged sleeve (500) is press-fitted into the second cavity (308). The tapered surface (502) of the forged sleeve (500) engages the inclined surface (402) of the sheath locking ring (400) to drive the sheath locking ring (400) toward the sheath (14).