Today I would like to introduce to you the Robert Adams Pattern no 177 Spring Hinge which I am sure you will agree is almost identical to Smith's design, hinting at possible collusion between Adams and by the time this model was introduced the company of Smith, Major, Stevens.
The picture below was taken from the Engineers Compendium of 1915, 6 years after Smith, Major, Stevens became a private limited company. The Robert Adams 177 is on the bottom right of the page.