plate 302 from base edge 354 to inner edge 307 tab 350 is bent at base edge 354 ninety degrees from plate 302 toward plate 304 and includes a base portion 358 an extension 360 and a distal end 362 extension 360 has a width which is approximately half the width of base portion 358 and further extension 360 extends from one side of base portion 358 thereby making hook tab 350 l shaped tab 350 further includes a hook 364 on distal end 362 which is opened toward inner edge 307 tab 352 is lanced from an inner portion of plate 304 such that there is a gap in ring 304 from base edge 356 to edge 309 tab 352 is bent at base edge 356 ninety degrees from plate 304 toward plate 302 and is essentially c shaped having outer side edges 366 368 which extend from plate 304 towards distal end 370 of tab 352 side edge 368 includes a notch 372 having parallel notch edges 374 376 that are joined by vertical notch edge 378 the length of notch edges 374 376 corresponds with the width of hook 364 with particular reference to fig1 by utilizing l shaped hook tab 350 and c shaped notch tab 352 assembly 320 can fit within spring cavity 32 and can be assembled without forcing hook 364 to deform in order to pass over its engagement point on notch tab 352 in this respect while within cavity 32 hook 364 can be manipulated to pass next to edge 368 and then to be positioned within notch 372 as hook 364 is being manipulated into notch 372 spring 30.