Patent Application
20160123507
Fire sprinkler systems are increasingly recognized as necessary safety features in the construction of new buildings and in the upgrading of existing buildings. There is a problem, however, in the installation of fire sprinkler systems.
Many styles of fire sprinkler heads have built-in deflectors that require rotational orientation of the sprinkler head to correctly position the deflector to produce the desired spray pattern when the head operates. All prior art fire sprinkler heads are attached to the piping mains by tapered pipe threads designed to produce a water tight seal using the interference of the tapered threads, plus either or both of a thread tape or thread paste. Thus, it can be appreciated that proper orientation of prior art sprinkler heads can usually only be accomplished by under-tightening the sprinkler heads or over-tightening the sprinkler heads. Overtightening of the tapered pipe threads produces interference between the mating threads, resulting in distortion of the mating parts. Under-tightening over the tapered pipe threads can produce leaks.
U.S. Pat. No. 8,474,472 discloses a pipe fitting useable in the installation of a sprinkler head comprising (a) a body having an open upstream end and an open downstream end, the downstream end having internal threads capable of accepting a threaded male fitting, the body defining an gasket retention area located upstream of the internal threads; and (b) an elongated gasket disposed within the gasket retention area. In the invention, the gasket retention area and the gasket are chosen so that a threaded male fitting threadedly disposed within the downstream end of the body can be rotated within the downstream end of the body 360.degrees while remaining liquid tight for pressures in excess of 300 psig. However, the internal threads of the disclosed pipe fitting are typically made from a thermal plastic, and, so, are vulnerable to assembly stresses and can be damaged on installation of mating part by misaligning threads “cross threading”. Cross threading occurs when two threaded parts are assembled and the threads are not aligned with each other allowing one thread to cut into the other. Cross threaded assemblies are most common when at least one of the mating threads are soft (plastic) and are most common with two tapered threads where initial assembly has substantial thread clearance.
Accordingly, there is a need for a fire sprinkler fitting which avoids the aforementioned in the prior art.
According to one aspect of the present invention, there is provided a pipe connector fitting comprising a) a body comprising a longitudinal axis, a throat, opposed side walls, an upstream end and a downstream end; b) a bore defined by the body; c) a plurality of metal threads disposed within the body; d) an elongate gasket comprising a non-round cross-section; and e) a gasket retention area defined by the body and sized and dimensioned to accept and retain the elongate gasket both when the elongate gasket is non-compressed and fully compressed, such that the elongate gasket is never allowed to escape the gasket retention area into the throat of the body, the gasket retention area comprising a flat gasket retention surface disposed perpendicular to the longitudinal axis of the body, the elongate gasket being disposed within the gasket retention area; wherein, when a threaded male fitting is threadedly disposed within the body, the threaded male fitting can be rotated within the downstream end of the body 360 degrees while remaining continuously fluid tight for pressures in excess of 300 psig.
According to another aspect of the present invention, there is provided a method of using a pipe connector fitting, wherein the method comprises the steps of: a) disposing the elongate gasket within the gasket retention area; b) disposing a fire sprinkler head comprising an upstream end within the downstream end of the body; c) threadedly disposing the fire sprinkler head into the downstream end of the body until the upstream end of the fire sprinkler head contacts the elongate gasket and sufficiently presses against the elongate gasket to elect a liquid tight seal with the gasket; and d) rotating the sprinkler head for up to 360 degrees until it is in proper orientation.
Features, aspects and advantages of the present invention will become better understood with reference to the following description, appended claims, and accompanying drawings where:
The following discussion describes in detail one embodiment of the invention and several variations of that embodiment. This discussion should not be construed, however, as limiting the invention to those particular embodiments. Practitioners skilled in the art will recognize numerous other embodiments as well.
As used herein, the following terms and variations thereof have the meanings given below, unless a different meaning is clearly intended by the context in which such term is used.
The terms “a,” “an,” and “the” and similar referents used herein are to be construed to cover both the singular and the plural unless their usage in context indicates otherwise.
As used in this disclosure, the term “comprise” and variations of the term, such as “comprising” and “comprises,” are not intended to exclude other additives, components, integers, ingredients or steps.
In one aspect, the invention is a pipe connector fitting 110 comprising a body 112, a bore 114, a plurality of metal threads 116, an elongate gasket 118 and a gasket retention area 120.
The body 112 can be any size and dimension, and made from any material, but the body 112 is typically made from a thermoplastic, although in some applications it can be made from cast iron, steel, copper or brass.
The bore 114 is defined by the body 112 and comprises an internal surface 132 and a bore opening 134. The bore 114 can be any size and dimension, but preferably is sized and dimensioned to accept and rigidly retain an end of a pipe section (not shown) for which the pipe connector fitting 110 is to be used.
The plurality of metal threads 116 are disposed along the internal surface 124 of the body 112. Preferably, the body 112 is made of thermoplastic and the plurality of metal threads 116 are molded into the body 112. The metal threads 116 are disposed either within the bore 114 or immediately outside of the bore 114. When disposed within the bore 114, the metal threads 116 are typically molded into the opposed side walls 126 of the body 112. Other attachment means, however, can be used. When the metal threads 116 are disposed immediately outside of the bore 114, the metal threads 116 are attached to the body 112 by any suitable connection means. The metal threads 116 can be attached to the body 112 by being molded to the body 112. The metal threads 116 can be attached to the body 112 by adhesives, by welding or by mechanical connection means, such as clamps, clips, metal threads or press-fit.
Typically, such metal threads 116 are a ½-14 NPT can conform to ASTM standard F1498, with the exception that the pitch diameter is at the end to oversize. Tolerance for fit with a threaded plug gauge is +/−1½ turns these metal threads 116 are made to approximately 2 turns larger than the maximum size for a tapered pipe thread.
The elongate gasket 118 can be any size and dimension and made from any material, including but not limited to plastic, polyvinyl chloride, rubber, metal or an elastomeric material. Typically, the elongate gasket 118 is made from an elastomeric material. Many known elastomeric materials can be used in the elongate gasket 118 such as EPDM, neoprene, silicone, buna-N, Hypalon, (Hypalon is a trademark for chlorosulfonated polyethylene (CSPE) synthetic rubber (CSM)) polyurethane, Santoprene, (Santoprene is a trademark for Thermoplastic Elastomer (TPE) Thermoplastic Vulcanate (TPV) vinyl and Viton (Viton is a trademark for FKM).
The body 112 defines a gasket retention area 120 located upstream of the metal threads 116. The gasket retention area 120 is provided by a circumferential notch defined in the opposed side walls 126 of the body 112, and comprises a flat gasket retention surface 138 disposed perpendicular to the longitudinal axis of the body 112. The gasket retention area 120 is sized and dimensioned to accept and retain the elongate gasket 118 both when the elongate gasket 118 is non-compressed and when the elongate gasket 118 is fully compressed. The gasket retention area 120 is thus sized and dimensioned such that the elongate gasket 118 is never allowed to escape from the gasket retention area 120 into the throat 122 of the body 112.
As best illustrated in
In one typical embodiment, the elongate gasket 118 has an inside diameter of about 0.61 inches, a length L1 of about 0.27 inches and a width L2 of about 0.139 inches. It is typical in all embodiments that the ratio L2/L1 is typically between about 0.4 and about 0.6.
As illustrated in
Both the elongate gasket 118 and the gasket retention area 120 are chosen so that a threaded male fitting 136 threadedly disposed within the downstream end 130 of the body 112 can be rotated within the downstream end 130 of the body 112 360 degrees (one complete rotation) while remaining continuously fluid tight for pressures in excess for 300 psig, preferably in excess of 600 psig, more preferably in excess of 850 psig and most preferably in excess of 875 psig.
Next, as illustrated in
Lastly, as illustrated in
The invention provides pipe fitting useable in the installation of a sprinkler head which can be rotated within the downstream end of the body 360.degrees while remaining liquid tight for pressures in excess of 300 psig. Because the internal threads are metal rather than thermoplastic, the internal threads are not vulnerable to assembly stresses. The metal threads carry all of the assembly stress, leaving the plastic and gasket to do the sealing.
Having thus described the invention, it should be apparent that numerous structural modifications and adaptations may be resorted to without departing from the scope and fair meaning of the instant invention as set forth herein above and described herein below by the claims.
This application claims priority from U.S. Patent Application Ser. No. 62/075,660 entitled “Pipe Connector Fitting with Elongate Gasket and Metal Threads,” filed Nov. 5, 2014, the entirety of which is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 62075660 | Nov 2014 | US |
