Pipeline connector

A bell-lock mechanical pipeline connector is provided wherein a seal of soft material is wedged into a sealing mode by collet wedge lock fingers which in turn are actuated by a wedging means which is functional upon shearing of a pin.

BACKGROUND OF THE INVENTION 
In both offshore and onshore pipeline construction, the manually welded 
joint has become the standard by which other forms of pipeline joining are 
evaluated. Pipe joining, by whatever means, is more costly offshore where 
weather conditions can severely hinder pipeline construction operations. 
In recent years, considerable improvements have been made in conventional 
pipelaying systems, and more specifically in pipe joining processes. 
Semi-automatic and then fully automatic welding systems have been 
developed, proven in the field, and now accepted offshore. However, the 
art remains deficient in the provision of mechanical connectors for 
diverless, subsea tie-ins of large-diameter pipe in deep water. 
Accordingly, the present invention is directed to overcoming this 
deficiency of the art. 
REFERENCE TO RELATED APPLICATIONS 
The invention of the present application is related to the inventions of 
application Ser. No. 264,317 filed May 18, 1981; application Ser. No. 
335,913 filed Dec. 30, 1981; application Ser. No. 342,536, filed Jan. 25, 
1982; and application Ser. No. 443,367 filed Nov. 22, 1982. 
SUMMARY OF THE INVENTION 
The present invention pertains to a connector for joining a bell-end pipe 
to a straight-end pipe, which connector includes among its parts, collet 
wedge fingers encircling the straight-end pipe and insertable into the 
bell-end pipe, deformable sealing material at the lateral extremity of the 
collet wedge fingers, driving means for pressing the collet wedge fingers 
and deformable sealing material into sealing engagement with the bell-end 
pipe, and locking means attached to the bell-end pipe for maintaining the 
sealing engagement. Preferably, the driving means includes colleted lock 
washers enclosed by a drive ring, and the drive ring is releasably 
attached to the collet wedge fingers by shear pins. Also preferably, the 
locking means are collet spring fingers which lock the driving means in 
position.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
The bell-lock mechanical pipeline connector of the present invention is 
shown in an unlocked mode in FIG. 1. Pipe end 10 extends inwardly of 
bell-shaped pipe end 11, and collet wedge lock fingers 12 encircle pipe 
end 10 and extend inwardly of bell-shaped pipe end 11. Drive ring 13 is 
attached to collet wedge lock fingers 12 by shear pin 14. Enclosed between 
lock fingers 12 and drive ring 13 are colleted lock washers 15. Wedge lock 
stop 16 is attached to bell-shaped end 11 and functionable to limit the 
inward movement of lock fingers 12 into pipe end 11. Collet hold lock 
fingers 17 are attached to the exterior of bell-shaped pipe end 11. The 
colleted lock washers 15 of the present invention are somewhat thicker and 
radially shorter than the well known Belville washer. Lock washers 15 
provide superior gripping properties due to the large change in outside 
and inside diameter during actuation and the unique load-displacement 
relationship which is achieved as the washers are flattened under 
compression. The load-deflection characteristics of the washers are 
non-linear as a result of the changing shape of the washers during 
flattening. Within limits, the initial shape of the washers may be chosen 
to achieve a desirable flattening, or actuation load. 
Since a single lock washer does not develop a sufficient shear load 
transfer area, it is preferable to use multiple washers. Such washers may 
be spaced apart so that the gripped pipe will not be subjected to 
excessive pressure. Also, the washers are properly designed to avoid 
interference with each other when rotated, i.e., compressed. Proper washer 
spacing may be achieved, in accordance with one embodiment, by the use of 
smaller diameter "dummy" washers. The "dummy" washers simply function to 
separate the gripping washers. 
The connector of FIG. 1 is actuated or locked into place by shoving drive 
ring 13 toward the shoulder of collet wedge lock fingers 12 so that 
colleted lock washers 15 are compressed into a vertical position. As each 
washer flattens, its effective radial thickness increases, thereby putting 
radial pressure against pipe end 10. As shown in FIG. 2, with the 
connector in a locked position, shear pin 14 is severed into 14(a) and 
14(b). Wedge lock stop 16 prevents further forward movement of the lock 
fingers 12 after soft seal material 18 is jammed into the intersection of 
pipe end 10 and pipe bell-end 11. Once this occurs, collet lock fingers 17 
fall into position behind the shoulder of drive ring 13, thereby 
effectively locking the connection together and sealing the joint with 
soft seal material 18. Suitable soft seal materials are, for instance, 
copper, zinc, lead and combinations thereof. 
Instead of the collet lock fingers 17, it is also feasible to use a 
threaded outer ring 20 which functions by screwing onto drive ring 13. 
The foregoing description of the invention is merely intended to be 
explanatory thereof. Various changes in the details of the described 
apparatus may be made within the scope of the appended claims without 
departing from the spirit of the invention.