Colt Trademark Emblem

Greetings,I was wondering if anyone knew why on some Colt pistols there is one spear with the colt and on others there are two spears. I have an older Colt 22 LR revolver and my dad has an old Colt .25 autoloader and on his pistol there's only one spear and on my revolver there's two.Take Care,Zack Jones