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Marchant Figurematic - The Carriage

The Figurematic carriage is built in two sections. The upper section contains the supporting framework and the counter register, while the lower section contains the main accumulator register.

The present machine has a 20-digit accumulator (the "main register" or "middle dial"), a 10-digit counter register (the "upper dial"), and a simple tabulator mechanism.

This page describes the layout and construction of the carriage. The registers and auxilliary mechanisms are described in the sections following.

CarriageComplete.jpg (25kb) Overview.

This view shows the completed carriage with the cover removed.

The assembly is about 15" long, 4" deep, 3-1/2"high, and weighs about 5 pounds. The main register alone contains well over one thousand manufactured parts.

CarriageUpper.jpg (27kb) The carriage upper section.

The top plate which forms the "backbone" of the carriage frame is a reinforced pressing of 0.045" steel. The heavy end plates which support the carriage mounting shafts are of 0.125" (1/8") steel.

The register mechanism is supported by a series of intermediate plates of 0.030" steel, which are held firmly in position by the top plate and the slotted locating strips and locking wires.

The locking wires and the mechanism pivot shafts are secured by two screwed retainer plates on the inside of each of the end plates. The mechanism can be disassembled without removing the top plate or the end plates.

CarriageLower.jpg (28kb) The carriage lower section.

The lower section of the carriage is built from a similar set of intermediate plates attached to a rigid U-shaped channel at the rear. Additional stiffness is provided by slotted strips and the sensing finger guards at the front.

The register consists of 20 identical mechanisms in the central region, and two abbreviated mechanisms at either end.

CarriageLHInnerAnnotated.jpg (27kb) The sections assembled.

In this view, the carriage has been assembled without the left-hand end plate so as to show the internal arrangements.

The upper and lower sections of the carriage are joined by a 1/16" rod A at the lower front of the frame plates. The lower section can swing downwards about the pivot A to engage the register with the actuator unit below.

B and C are the slotted strips which reinforce the upper section, while strips D and E are for the lower. (Strip D actually passes through the oval clearance slots in the upper plates. Rod F also passes through both sections to operate part of the lower register mechanism). G and H are the clearing shafts for the upper and lower registers.

The five fingers extending to the rear of the carriage are part of a basic tabulator mechanism for the Clear/Return function. Rotating the thumbwheel (top right) extends one or other of the fingers, which operates the shift terminating mechanism at the corresponding position as the carriage returns to the right.

CarriageRear.jpg (27kb) Carriage rear view.

The upper section of the carriage is supported on a pair of 1/4" steel shafts through the holes in the upper and lower corners of the end plates. The lower section is normally held upwards and clear of the actuator by the springs at either end of the clearing shaft.

At the rear of the upper section are the drive gears and idlers for the counter register, and below these is the sawtooth rack for the carriage positioning mechanism. The fingers for the tabulator mechanism are visible at the far end.

The carriage shift and clearing operations are described further in the sections following.

CarriageOpen.jpg (30kb) The carriage opened.

Although the carriage appears totally impenetrable when fully assembled, it can quite readily be opened to give full access for routine lubrication or maintenance.

Original text and images Copyright © John Wolff 2005.
Page created: 26 February 2005.

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