Appeal No. 2004-1395 Page 5
Application No. 09/407,053
Carlston's side bearing unit 30 is shown in Figures 2, 4, 5 and 6. The side
bearing unit 30 includes a round top cap 32, a housing 34 and first and second
thermoplastic elastomeric springs 36 and 38. The generally round top cap 32 includes
a top surface 40, a downwardly depending integrally formed side wall 46 and a bottom
surface 48 having a centrally located integrally formed depending secondary solid stop
50 and a primary stop surface 52. A housing 34 includes a base portion 56, an
integrally formed upwardly extending side wall 60 which includes a primary stop portion
62 and an integrally formed upwardly extending secondary stop 66 that cooperates
with the depending secondary stop 50. The housing 34 fits within the round top cap 32
creating an internal void 68.
Carlston's first and second thermoplastic elastomeric springs 36 and 38 are
situated within internal void 68 in a piggyback position. Both thermoplastic elastomeric
springs are identical and by placing them in series, the available travel of the side
bearing can be doubled and the spring rate cut in half. The two elastomeric springs are
separated by a plate 75 and both are mechanically locked to the plate by pins 77, thus
forming an elastomer spring assembly. Referring to Figure 7, it is apparent that the
elastomeric spring is an open-ended hollow tube. The thermoplastic elastomer spring
36 is designed to fold and flex as it is subjected to a work cycle. Carlston teaches
(column 4, lines 15-22) that
Page: Previous 1 2 3 4 5 6 7 8 9 10 Next
Last modified: November 3, 2007