That is the emblem for the "Elinox" line of knives. As a nickle-silver inlay it was used from about 1957 until about 1973. There are some instances of the Elinox style shield being used as a stainless-steel inlay in the mid 1970s, but these are not common and typically only appear on certain knives (the Outdoorsman being the most common). 1974+ this style logo is mainly seen as a "hot stamped" foil logo at first for the Elinox line (until 1978) and then for the "Economy" line (Elinox is dropped) until around 1994 when it's dropped altogether. Post 1994 the Economy models get a hot-stamped version of the traditional Victorinox shield.