1. A connector comprising two mutually engageable connector housings and a detecting unit for detecting incomplete engagement of said housings, said detecting unit being a separate component for selective attachment to one of said housings, and having a spring acted on by the other of said housings and adapted to accumulate a resilient force during engagement of said housings, said force tending to move said housings in the direction of separation.
2. A connector according to claim 1 wherein the other of said housings ceases to act on said spring on complete engagement of said housings, thereby releasing spring force accumulated during engagement of said housings.
3. A connector according to claim 2 wherein said detecting unit comprises a body, a compression spring housed in said body, and a slider movable in said body to compress said spring, said slider having an abutment engageable by the other of said housings during engagement of said housings, and means to disengage said abutment from the other of said housings on complete engagement of said housings.
4. A connector according to claim 3 wherein said slider includes a resilient cantilever arm, said abutment is provided on said arm, and said body includes a ramp adapted to bend said arm during engagement of said housings, to permit disengagement of said abutment from the other of said housings on full engagement thereof.
5. A connector according to claim 3 wherein said abutment comprises a protrusion having a front face perpendicular to the attachment direction of said housings, and for engagement by the other of said housings during engagement of said housings, and a back face angled with respect to said attachment direction.
6. A connector according to claim 4 wherein said abutment comprises a protrusion having a front face perpendicular to the attachment direction of said housings, and for engagement by the other of said housings during engagement of said housings, and a back face angled with respect to said attachment direction.
7. A connector according to claim 1 wherein said one of said housings has an external attachment rail having a T section and extending in the attachment direction of said housings, and said detecting unit has an elongate T section socket open at one end to receive said rail, the other end of said socket having an abutment engageable with said rail, wherein said rail and socket have a resilient latch engageable to maintain said rail against said abutment.
8. A connector according to claim 7 wherein said resilient latch includes a projection of said detecting unit and slidable in a groove of said rail, said projection being engageable with an obstruction of said groove.
9. A connector according to claim 1 and being elongate in a direction perpendicular to the attachment direction of said housings, a detecting unit being provided at each end of said one of said housings.
10. A connector according to claim 1 wherein said detecting unit latches the other of said housings on complete engagement of said housings.
11. A connector according to claim 10 and having a lever on one of said housings, said lever being engageable with the other of said housings and pivotable to draw said housings into complete engagement, said detecting unit being disengaged from the other of said housings on application of a force to said lever in a disengaging direction, said force exceeding a predetermined limit.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An extended settable composition comprising:
cement;
cement kiln dust;
a set retarding additive; and
water, wherein the extended settable composition is capable of remaining in a pumpable fluid state for at least about 1 day.
2. The extended settable composition of claim 1 wherein the extended settable composition is capable of remaining in a pumpable fluid state for at least about 5 days.
3. The extended settable composition of claim 1 wherein the density of the extended settable composition is in the range of from about 8 pounds per gallon to about 16 pounds per gallon.
4. The extended settable composition of claim 1 wherein the water comprises water selected from the group consisting of freshwater, saltwater, brine, seawater, and combinations thereof.
5. The extended settable composition of claim 1 wherein the water is present in the extended settable composition in an amount in the range of from about 40% to about 150% by weight of the composition.
6. The extended settable composition of claim 1 wherein the cement comprises a hydraulic cement selected from the group consisting of Portland cement, pozzolana cement, gypsum cement, high alumina content cement, slag cement, silica cement, and combination thereof.
7. The method of claim 1 wherein the hydraulic cement is present in the extended settable composition in an amount of about 25% to about 75% by weight, and wherein the cement kiln dust is present in the extended settable composition an amount of about 25% to about 75% by weight.
8. The extended settable composition of claim 1 wherein the set retarding additive comprises a set retarding additive selected from the group consisting of an organic acid, a lignosulfonate, a synthetic retarder, and combinations thereof.
9. The extended settable composition of claim 1 wherein the set retarding additive comprises tartaric acid.
10. The extended settable composition of claim 1 wherein the set retarding additive comprises a sulfomethylated lignin.
11. The extended settable composition of claim 1 wherein the set retarding additive is present in the extended settable composition in an amount in the range of from about 0.1% to about 5% by weight of the composition.
12. The extended settable composition of claim 1 wherein the extended settable composition comprises at least one additive selected from the group consisting of fly ash, slag cement, shale, zeolite, and metakaolin.
13. An extended settable composition comprising:
hydraulic cement in an amount of about 25% to about 75% by weight;
cement kiln dust in an amount of about 25% to about 75% by weight;
a set retarding additive comprising tartaric acid; and
water, wherein the extended settable composition is capable of remaining in a pumpable fluid state for at least about 5 days.
14. The extended settable composition of claim 13 wherein the density of the composition is in the range of from about 8 pounds per gallon to about 16 pounds per gallon.
15. The extended settable composition of claim 31 wherein the water comprises water selected from the group consisting of freshwater, saltwater, brine, seawater, and combinations thereof.
16. The extended settable composition of claim 13 wherein the water is present in the composition in an amount in the range of from about 40% to about 150% by weight of the composition.
17. The extended settable composition of claim 13 wherein the hydraulic cement comprises a hydraulic cement selected from the group consisting of Portland cement, pozzolana cement, gypsum cement, high alumina content cement, slag cement, silica cement, and combination thereof.
18. The extended settable composition of claim 13 wherein the set retarding additive is present in the composition in an amount in the range of from about 0.1% to about 5% by weight of the composition.
19. The extended settable composition of claim 13 wherein the extended settable composition comprises at least one additive selected from the group consisting of fly ash, slag cement, shale, zeolite, and metakaolin.
20. A method comprising: preparing an extended settable composition comprising cement, cement kiln dust, a set retarding additive, and water, wherein the extended settable composition is capable of remaining in a pumpable fluid state for at least about 1 day.