Connectors for plumbing lines

The present invention comprises couplings which require no adhesives or cold welding or similar techniques for joining lengths of pipe of any known composition. The couplings, in their various shapes, are molded from Ultra High Molecular Weight Polyethylene (UHMWP). Within each end of each coupling form there are a plurality of spaced apart inwardly extending flexible rings, each ring terminating in an angular tip portion which is deformed in the direction of the inserted pipe end and forms a plurality of locking annular seals around the inserted pipe end portion. UHMWP has an inherent self-lubricity which facilitates the insertion of the pipe end portion. UHMWP is chemically inert.

FIELD OF INVENTION 
The present invention is in the general field of plumbing. More 
specifically, the invention presents couplings of the various 
configurations required by alignment and joinings with improved sealing 
and ease of installation. 
BACKGROUND OF THE INVENTION 
Plumbing lines are used generally to encompass the supply of necessary 
liquids to buildings for various purposes and the removal of liquids from 
buildings and from surrounding areas. Such lines include water supply and 
the removal of wastes from the buildings as well as waste water from 
surface run-off. For example, water for building sites is generally 
supplied by cast iron mains, each section having a familiar "bell shape" 
on one end into which is inserted the cylindrical end of the adjacent pipe 
length. This juncture is usually sealed with the use of oakum pounded into 
the joint which is otherwise unsecured. In time, the pressure of water 
passing through the line can lead to leaks which, in turn, requires 
excavation at the leaking joint and repair. Water is supplied to 
individual structures from the main line by insertion of a T-connector 
emplaced in the line, the connector usually being of cast iron sealed 
within the line by usual systems of oakum. The outlet from the T-connector 
is obviously of a smaller diameter, commensurate in size to provide the 
required volume of water to the structure. At this point current practice 
is to use PVC pipe to the structure. Current practice is to use PVC 
couplings to adhesively connect the pipe lengths to bring the water to the 
structure. From this point on, piping for delivery of water within the 
structure may depend upon the size of the structure. Within houses use of 
copper lines and fittings is most common. In commercial buildings PVC or 
copper is used depending upon the volume of water involved, i.e., greater 
volume in high rise buildings dictating PVC because copper piping is 
generally restricted to diameters of one inch or less and is used in 
houses, the copper piping is accordingly appropriately coupled by the well 
known "cold welding" techniques. 
Disposal of wastes from structures presents a different problem in the 
selection of material for the waste lines due to the more corrosive nature 
of the waste liquids. Such waste liquids usually contain solids which 
dictates the use of pipes of 3-4 inch diameter and upwards. Because of 
weight and lack of resistance to corrosion cast iron disposal lines are no 
longer used. Other than for large diameter major disposal lines concrete 
supply pipes are rejected because of weight and difficulty in making 
sufficiently sealed joints. PVC pipe in diameters up to at least 8 inches 
are now available together with appropriate couplings. At the present 
time, pipes and couplings are joined by use of adhesives. In large 
diameter pipes application of adequate amounts of adhesives is time 
consuming and labor intensive. The corrosive character of waste liquids 
has been known to react with the adhesives over a period of time which can 
result in loss of seal integrity. 
SUMMARY OF THE PRESENT INVENTION 
The present invention comprises couplings which require no adhesives or 
cold welding or similar techniques for joining lengths of pipe of any 
known composition. The couplings, in their various shapes, are molded from 
Ultra High Molecular Weight Polyethylene (UHMWP). Within each end of each 
coupling form there are a plurality of spaced apart inwardly extending 
flexible rings, each ring terminating in an angular tip portion which is 
deformed in the direction of the inserted pipe end and forms a plurality 
of locking annular seals around the inserted pipe end portion. UHMWP has 
an inherent self-lubricity which facilitates the insertion of the pipe end 
portion. UHMWP is chemically inert. Prior use of UHMWP is disclosed in my 
co-pending application Ser. No. 07/301,893.

DETAILED DESCRIPTION OF THE INVENTION 
FIG. 1 discloses the conventional members used to join lengths of plumbing 
pipe, i.e., a union coupling, a Y-coupling, an elbow coupling and a 
T-coupling, all being cylindrical, particularly in the ends where pipes 
are inserted. 
FIG. 2 is a cross-sectional view of the union coupling seen in FIG. 1. The 
union coupling was selected because it is the most simplistic coupling to 
illustrate the present invention. The coupling consists of the outer 
surface 1, an inner surface 2 and an interior circular inwardly extending 
rib 3 which forms a limit to the extent to which opposing ends of pipes 
may be inserted. The remaining couplings shown in FIG. 1 do not have such 
a rib because the angular form inherently limits the insertion of a pipe 
beyond a evident juncture. 
In FIG. 3, each end of the coupling has an inner surface 4 carrying a 
plurality of annular grooves 5 and a plurality of annular inwardly and 
upwardly extending flexible ridges or rings 6, each ridge or ring 
terminating in a flexible tip 7. It is to be noted that the upper surface 
6a of each ridge or ring 6 is of the same length as the lower surface 6b 
resulting in the flexible tip 7 being inwardly and upwardly inclined at a 
45.degree. angle relative to lower surface 6b. It is to be further noted 
that surfaces 6a and 6b are parallel. The inner diameter of the ridges or 
rings 6 is less than the outer diameter of the pipe to be inserted. This 
increases the flexibility of ridges or rings so that they are curved 
upwardly when a pipe is inserted into the coupling. Any attempt to 
displace a pipe from within a coupling causes the rings and flexible tips 
to bear more strongly against the outer surface of pipe P thus increasing 
the sealing and securing of the pipe P within the coupling. 
The couplings of the present invention eliminate any use of gaskets or 
adhesives with pipes of any composition thus providing not only quicker 
installation but less expense in labor and material costs as well as an 
improved sealing by the plurality of rings.