Cryogenic fluid coupling

1. A coupling for transferring a cryogenic fluid comprising:

a. a nozzle including:

i) a nozzle bayonet including a nozzle inner tube and a nozzle outer tube with a bayonet insulation space defined therebetween;

ii) a warm seal positioned at a distal end of the nozzle bayonet, said warm seal having a warm seal engagement surface facing radially inwards;

iii) a nose seal positioned at a proximal end of the nozzle inner tube so that a distal passage within the inner tube is defined between the warm seal and the nose seal, said nose seal having a nose seal engagement surface facing radially inwards;

iv) a nozzle poppet valve having a nozzle poppet with a nozzle poppet spring urging the nozzle poppet towards a closed position at an outlet of the nozzle poppet valve and an inlet configured to receive the cryogenic fluid;

v) a proximal passage positioned between the outlet of the nozzle poppet valve and the nose seal;

vi) a purge line and a vent line in fluid communication with the distal passage;

vii) said nozzle bayonet extending downstream of the outlet of the nozzle poppet valve in a direction of fluid flow through the outlet of the nozzle poppet valve when the nozzle poppet is in an open position, said nose seal positioned between the outlet of the nozzle poppet valve and the warm seal;

b. a receptacle including:

i) a receptacle inner tube and a receptacle outer tube with a receptacle insulation space defined therebetween;

ii) an outer casing surrounding and annularly spaced from at least a portion of the receptacle outer tube to that a coupling space is defined therebetween,

iii) a receptacle poppet valve having a receptacle poppet with a receptacle poppet spring urging the receptacle poppet towards a closed position at an inlet of the receptacle poppet valve and an outlet in fluid communication with the receptacle inner tube;

c. said receptacle coupling space sized to receive the nozzle bayonet and configured so that the receptacle sequentially engages the warm seal of the nozzle with an outer surface of the outer casing and then the nose seal of the nozzle with an outer surface of the receptacle outer tube during insertion of the nozzle bayonet into the receptacle coupling space with the nozzle poppet engaging the receptacle poppet to open the nozzle poppet valve and the receptacle poppet valve when the nozzle bayonet is fully inserted into the receptacle coupling space so that the nozzle and receptacle are in a coupled condition.

2. The coupling of claim 1 further comprising a latching mechanism configured to latch the nozzle and receptacle in the coupled condition.

3. The coupling of claim 2 wherein the latching mechanism includes a latching pin positioned on the casing of the receptacle and a latching collar rotatably connected to the nozzle bayonet, said latching collar including a latching groove configured to receive the latching pin after the nozzle bayonet has been at least partially inserted into the receptacle coupling space, said latching groove configured to latch the nozzle and receptacle in the coupled condition when the latching collar is rotated.

4. The coupling of claim 3 wherein further comprising a turning handle connected to the latching collar.

5. The coupling of claim 3 further comprising a venting detent formed within the latching groove and configured so that the nozzle and receptacle are secured in a venting condition when the latching pin of the receptacle is positioned within the venting detent, wherein said nozzle poppet valve and said receptacle poppet valve are closed and said receptacle is disengaged from the nose seal when the nozzle and the receptacle are in the venting condition.

6. The coupling of claim 1 wherein the bayonet insulation space and the receptacle insulation space are both vacuum or near-vacuum insulated.

7. A nozzle for a cryogenic fluid coupling comprising:

a. a nozzle bayonet including a nozzle inner tube and a nozzle outer tube with a bayonet insulation space defined therebetween;

b. a warm seal positioned at a distal end of the nozzle bayonet, said warm seal having a warm seal engagement surface facing radially inwards;

c. a nose seal positioned at a proximal end of the nozzle inner tube so that a distal passage within the inner tube is defined between the warm seal and the nose seal, said nose seal having a nose seal engagement surface facing radially inwards;

d. a nozzle poppet valve having a nozzle poppet with a nozzle poppet spring urging the nozzle poppet towards a closed position at an outlet of the nozzle poppet valve and an inlet configured to receive the cryogenic fluid;

e. a proximal passage positioned between the outlet of the nozzle poppet valve and the nose seal; and

f. a purge line and a vent line in fluid communication with the distal passage;

g. said nozzle bayonet extending downstream of the outlet of the nozzle poppet valve in a direction of fluid flow through the outlet of the nozzle poppet valve when the nozzle poppet is in an open position, said nose seal positioned between the outlet of the nozzle poppet valve and the warm seal.

8. The nozzle of claim 7 wherein the bayonet insulation space is vacuum or near-vacuum insulated.

9. The nozzle of claim 7 further comprising a latching collar rotatably connected to the nozzle bayonet, said latching collar including a latching groove.

10. The nozzle of claim 9 further comprising a turning handle connected to the latching collar.

11. The nozzle of claim 10 further comprising a venting detent formed within the latching groove.