I took some shots of the pencils I have on hand.
I identified 7 different types of barrel twist mechanisms. The first picture illustrates those types. The arrows in the picture point to slight shoulders in the tubes.
The second and third pictures are the pencils I have. Below the pictures, I have a description of each. You can click the pictures for a higher resolution version. IF there are any you want to see in greater detail, please let me know and I will try to accomodate.
1. Stubby? Vacuum Filler, Undated. Nose drive of some sort. 1.1mm
2. Vacuum Filler, undated. Nose drive. Same nose drive mechanism as #1, even though #1 pencil is shorter. 1.1mm
3. Ripley, 1939. Big cone, barrel drive Type 1. Cone not as big as #2. No bands on bottom half of barrel. 1.1mm
4. Slender, Q3 1935. Barrel drive Type 2. one band on bottom half. 1.1mm
5. Standard, Q1 1936. Barrel drive Type 2. No bands on bottom half. 1.1mm
6. Junior, Q1 1937. Barrel drive Type 2. One band on bottom half. 1.1mm
7. Junior, Q2 1937. Barrel drive Type 2. No bands on bottom half. Slightly longer pencil than #6. 1.1mm
8. Standard, Q2 1937. Barrel drive Type 2. No bands on bottom half. 1.1mm
9. Senior Maxima, Q4 1937. Barrel drive Type 3. 1.1mm
10. Senior Maxima, Q4 1937. Barrel drive Type 3. 1.1mm
11. Major, Q3 1938. Barrel drive Type 3. 1.1mm
12. Debutante, 1939. Injector Type. 1.1mm
13. Debutante, Q2 1940. Barrel drive Type 4. 0.9mm
14. Debutante, Q2 1940. Barrel drive Type 4. 0.9mm
15. Major, Q2 1940. Barrel drive Type 5. 0.9mm
16. Dunno what size, Q4 1940. Barrel drive Type 4. 0.9mm
17. Junior, Q4 1941. Barrel drive type 3. 0.9mm
18. Dunno what size. Same size as #16. Barrel drive Type 6. 0.9mm (I think this may be a duofold)
19. Debutante, Q1 1941. Barrel drive Type 7. 0.9mm
20. Major, 1942. Vacumatic in Duofold plastic. Barrel drive Type 6. 0.9mm
21. Debutante, Q1 1943. Barrel drive Type 6. 0.9mm
22. Major, 1946. Barrel drive Type 6. 0.9mm
23. Major, 1946. Barrel drive Type 6. 0.9mm
24. Major, 1946. Barrel drive Type 6. 0.9mm
25. Junior, 1947. Barrel drive Type 6. 0.9mm
Also note that pencils 20 and 21 do not have the little knurled part on the nose cone. They are completely smooth.
Edited by BrianMcQueen, 18 April 2014 - 12:44 PM.