Robert;
If Lefever had a patent on this bolting system I have not found it. The 1878 patent mentioned did not patent the Doll's Head itself, this had already been patented, but patented the square shoulders for same. Early Lefevers had both an underbolt & a sliding bolt locking into the rib extension. By about 1882 the underbolt had been done away with & the top bolt had assumed a vertical position which rocked back & forward to open or lock. Configuration of this bolt went through several changes, was first operated by a thumb push lever & eventually by the side pivot top lever. The 1890 patent introduced the Two-Hook cocking system which at first retained the side-pivot top lever but by about 1892 had given way to the side swinging bolt as an extension of the top lever (Though a seperately attached part). Earlier bolts had all entered the notch, whether under bolt or top bolt from the rear, this new top bolt entered from the left side & acording to Lefever literature was cut on a 15° angle making it self compensating for wear with the top lever coming around to the left as wear occured. This bolting system would remain until the end of production.
An 1889 LAC catalog pictures & describes what is essentially the final form of the vertical bolt with side-pivot lever & having the compensating screw in upper tang. A reprint of this catalog is available from Cornell's.
