Nitro Special Single Trigger

US1889049A Single-trigger mechanism for double-barrelled firearms
   Invented by Harry E. Howland

NOTE: It appears part numbers are more complicated than they appear.

  The single trigger is non-selectable. It fires right barrel first, then the left barrel. If you only fire the right barrel, then break the action, the single trigger is re-set. If you look at Figures 5 and 6, you will see #31 Tongue. The tongue is actuated by the right hammer.

Single Trigger, Left, Fired  

Single Trigger, Left, Cocked  

Single Trigger, Right, Fired  


Single Trigger, Right, Cocked 

Tensioned Slide  



Tensioned Slide, Side 

NOTE: If you look at the upper right, the solid line shows the right hammer [16] and Tongue [31] in the fired condition, while the dashed line shows the right hammer and tongue in the cocked position.

16 Right Hammer
23
25
30 Lug
31 Tongue
32 Decending Arm
33 Forwardly Projecting Lug
34 Forwardly Directed Lug
35 Tensioned Slide Spring
36 Tensioned Slide Spring Anchor Screw
37 Tensioned Slide Spring Front Mount

Tensioned Slide, Top 

NOTE: It seems like there was a difference between the patent drawing and the actual implementation. In this drawing, the right sear appears to be "bobbed" and the "Lateral Finger" removed and replaced by a pin.

Sears from Single Trigger 

  The sears are upside-down, the "Lateral Fingers" should point INWARD

13a Spindle
13b Enlarged Head (of Top Lever)
16 Right Hammer
17 Right Sear
18 Left Hammer
19 Left Sear
20 Lateral Finger
25 Pin (Fixed to Right Sear)
27 Longitudinally Slidable Arm
28 Plate Portion
29 Open Ended Slot
31 Tongue

13 Top Lever
13a Spindle
13b Enlarged Head (of Top Lever)
14 Lower Tang
15 Upper Tang
16 Right Hammer
17 Right Sear
18 Left Hammer
19 Left Sear
35 Tensioned Slide Spring
36 Tensioned Slide Spring Anchor Screw
39 Safety Lever
40 Safety Slide (Button)
41 Inertia Piece
42 Inertia Piece Spring