assembly 600 includes a fourth disc spring 620 a fifth disc spring 640 and a sixth disc spring 660 the three of which are stacked in parallel with one another fourth disc spring 620 has a first radial inner portion 622 a first radial outer portion 626 and a first intermediate portion 625 between first radial inner portion 622 and first radial outer portion 626 which deflects under axial load first radial inner portion 622 defines a first central opening therethrough and includes an upwardly extending portion 624 first radial outer portion 626 includes a downwardly depending portion 628 fifth disc spring 640 has a second radial inner portion 642 a second radial outer portion 646 and a second intermediate portion 645 between second radial inner portion 642 and second radial outer portion 646 which deflects under axial load second radial inner portion 642 defines a second central opening therethrough and includes an upwardly extending portion 644 second radial outer portion 646 includes a downwardly depending portion 648 sixth disc spring 660 has a third radial inner portion 662 a third radial outer portion 666 and a third intermediate portion 665 between third radial inner portion 662 and third radial outer portion 666 which deflects under axial load third radial inner portion 662 defines a third central opening therethrough and includes an upwardly extending portion 664 third radial outer portion 666 includes a downwardly depending portion 668 third assembly 700.