Number

Axis

Comments

1

Result

This
is the main result axis. The rod is undriven and all elements are free
to rotate on it. Each cage contains a digit wheel.

2

Intermediate

Split
into segments vertically. Each segment carries two fixed 57t gear
wheels to connect the digit wheel on
the result axis to the corresponding readout cage on the first
difference axis. Each segment also carries a fixed detent wheel. All 4
cages similar.

3

First
Difference

The
first difference axis. Driven at the rate of one revolution per turn of
the crank. Readout cages fixed
on the rod. Each cage
contains a digit wheel and a readout assembly. The 1½" sprocket in the drive
mechanism bolted to the 2½" gear provides the drive to the carry
axes.

4

Intermediate

Split
into segments vertically. Each segment in cages 1, 2, and 3
carries two fixed 57t gear wheels to connect the digit wheel on the first
difference axis to the corresponding readout cage on the second
difference axis. Each
segment
also carries a fixed detent wheel. Since there is no digit in cage 4
of the second difference axis, the upper segment carries only a single
57t
gear and a detent wheel. The 57t gear in the drive
mechanism
is free to turn on the upper segment and acts as an idler between the
two
driving 2½" gears.

5

Second
Difference

The
second difference axis.
Driven at the rate of one revolution per turn of the crank. Each of cages 1, 2, and 3 contains
a digit wheel and a readout assembly. Cage 4 is empty. 
6

Intermediate

Split
into segments vertically. Each segment in cages 1 and 2
carries two fixed 57t gear wheels to connect the digit wheel on the second difference axis to
the corresponding readout cage on the third difference axis. In cage 3
the segment has just a single 57t gear and a detent wheel. The fourth
cage is empty.
The 57t gear in the drive mechanism is fixed on the upper segment of
the rod. It acts as an idler between the two driving 2½" gears.

7

Third
Difference

The
third difference axis.
Driven at the rate of one revolution per turn of the crank. Each of cages 1 and 2 contains a
digit wheel and a readout assembly. Cages 3 and 4 are
empty. The 2" sprocket
in
the drive mechanism bolted to the 2½" gear receives the drive
from
the main crank.

unmarked

Intermediate

Split
into segments vertically. In cages 1 and 2 each segment
carries a single 57t gear and a detent wheel. Cages 3 and 4 are
completely empty, so this axis is not visible in the picture above, but
it occupies a similar position relative to the third difference axis as
axis #6 does to the second difference axis.

8

Detent

Undriven,
this rod carries the bell
cranks providing the detents for the digit wheels on the result axis. All four cages similar.

9

Detent

Undriven,
this rod carries the bell
cranks providing the detents for the digit wheels on the first
difference
axis. All four cages similar.

10

Detent

Undriven,
this rod carries the bell
cranks providing the detents for the digit wheels on the second
difference
axis. Only cages 1, 2, and 3 have this
assembly. Cage 4 is empty.

11

Detent

Undriven,
this rod carries the bell
cranks providing the detents for the digit wheels on the third
difference
axis. Only cages 1, and 2 have this assembly. Cages 3 and 4 are empty.

12

Carry
Intermediate

Undriven,
this rod holds the face plate and gear assemblies of the carry
mechanism in cages 2, 3, and 4. All elements are free to turn on the
rod. Cage 1 is empty since there is no carry into the units digit.

13

Carry
Trip

Split
into segments vertically. Each segment carries two pawls and the double
arm crank assembly. Provides
the carry trip linkage from one digit to the next higher digit. These
assemblies span two cages since this is the path to communicate the
carry
information from one digit to the next higher. Thus there are three
segments,
between cages 1 and 2, cages 2 and 3, and cages 3 and 4. The lower pawl
is in the lower of the two connected cages. The upper pawl and crank
assembly
are in the upper of the two connected cages.

14

Bolting

First
difference bolting axis. Driven at the rate of one revolution per four
turns of the crank. The bolting
assemblies are fixed on this rod in all four cages. The face plate and
gear assemblies of the carry mechanism in cages 2, 3, and 4 are also
mounted
on this rod, but free to turn. Cage 1 has no face plate and gear
assemblies
since there is no carry into the units digit.

15

Carry
Trip

Split
into segments vertically. Each segment carries two pawls and the double
arm crank assembly. Provides
the carry trip linkage from one digit to the next higher digit. These assemblies span two cages
since this is the path to communicate the carry information from one
digit to
the next higher. Thus there are three segments, between cages 1
and
2, cages 2 and 3, and cages 3 and 4. The lower pawl is in the lower of
the
two connected cages. The upper pawl and crank assembly are in the upper
of
the two connected cages.
The 2½" gear in the drive mechanism is free to turn on the rod.
It
acts as an idler between the two driving 57t gears.

16

Bolting

Second
difference
bolting axis. Driven at the rate of one revolution per four turns of
the crank. The bolting assemblies are fixed on this rod in cages 1, 2,
and 3. Cage 4 is empty. The
face plate and gear assemblies of the carry mechanism in cages 2 and 3
are also mounted on this rod, but free to turn. Cages 1 and 4 have no
face
plate and gear assemblies since there is no carry into the units digit
and
no digit wheel in cage 4. The 3" sprocket in the drive mechanism is
bolted to a 57t gear below and receives the drive from the carry axes.

17

Carry
Trip

Split
into segments vertically. Each segment carries two pawls and the double
arm crank assembly. Provides the carry trip linkage from one digit to
the next higher digit. These
assemblies span two cages since this is the path to communicate the
carry information from one digit to
the next higher. There are two segments, between cages 1 and 2,
and
cages 2 and 3. The lower pawl is in the lower of the two connected
cages.
The upper pawl and crank assembly are in the upper of the two connected
cages. The 2½"
gear
in the drive mechanism is fixed on the upper segment of the rod as there is no carry
trip on the top two segments of the second difference axis. It acts as an idler between the
two driving 57t gears.

18

Bolting

Third
difference
bolting axis. Driven at the rate of one revolution per four turns of
the crank. The bolting assemblies are fixed on this rod in cages 1 and
2. Cages 3 and 4 are empty. There
are no carry mechanism components on this rod, the third difference
being
a constant.

19

Carry
Stop

Nothing
is mounted on this rod. It provides a stop for the 1½" narrow
strip on the face plate of the carry mechanism.

20

Carry
Stop

Nothing
is mounted on this rod. It provides a stop for the 1½" narrow
strip on the face plate of the carry mechanism.

21

Carry
Stop

Nothing
is mounted on this rod. It provides a stop for the 1½" narrow
strip on the face plate of the carry mechanism.

22

Carry

Result
carry axis. Driven at the rate of one revolution per two turns of the
crank. Carry reset arms are fixed to the rod in cages 2, 3, and 4. Cage
1 is empty since there is no carry
into the units digit. This
rod also provides the anchor for the tension springs on the carry
mechanism faceplates.

23

Intermediate

This
rod carries a 57t gear which acts as an idler between the two driving
2½" gears. The rod extends
the full height of the machine and provides the anchor for the
carry
trip tension springs.

24

Carry

First
difference carry axis.
Driven at the rate of one revolution per two turns of the crank. Carry reset arms are fixed to the
rod in cages 2, 3, and 4. Cage 1 is empty since there is no carry into
the units digit. The
3" sprocket
in the drive mechanism is bolted to a 2½" gear below and brings
the drive from the first difference axis. This rod also provides the anchor
for the tension springs on the carry mechanism faceplates. 
25

Intermediate

This
rod carries a 57t gear which acts as an idler between the two driving
2½" gears. The rod extends the full height of the machine and
provides the anchor for the carry
trip tension springs.

26

Carry

Second
difference carry axis.
Driven at the rate of one revolution per two turns of the crank. Carry reset arms are fixed to the
rod in cages 2, and 3. Cages 1 and 4 are empty since there is no carry
into
the units digit and no digit wheel in cage 4. The 1½" sprocket in the
drive mechanism is bolted to the 2½" gear below and provides the
drive
to the bolting axes. This rod also provides the anchor
for the tension springs on the carry mechanism faceplates. 
27

Intermediate

Undriven,
this rod extends the
full height of the machine and provides the anchor for the carry
trip tension springs.
