Inclusive p, d and 3He cross sections have been obtained using experimental data on p4He collisions over an incident proton energy range of 46-400 GeV. Considering the slopes of spectra, the effective nuclear temperature has been found to be T o = 11 MeV, which is in good agreement with experimental results for lower energies and heavier targets. The shape of the 3He inclusive spectrum suggests the existence of two different 3He production mechanisms. The experimental 3He cross section is compared with theoretical predictions assuming fragment formation as a result of the spectator and cluster knockout mechanisms. The 4He ~ 3He + n vertex constant has been found to be G2 = 10.9+0.2 fro.