Challenges with adjustment of the space mechanism

SPACE MECHANISM ADJUSTMENT FAILURE

Whether requested by pushing a button on the front of the typewriter or by activating a solenoid, the typewriter does trigger a single cycle of the left operational clutch. It moves a lever under the bail that is moved down by the movement of the operational clutch, turning the rotation of the clutch into a single downward pull and release of the lever. 

The lever in turn is connected by a few linked levers to the trigger for escapement, so that it should trip the escapement torque bar just as the print escapement does. The movement was not large enough to twist the bar and release the escapement pawl. 

I worked with the adjustments and even tried substituting a longer screw for one of the adjusters, but even that wasn't satisfactory. I realized that I had to change the print escapement setup if I was going to be able to get the space mechanism working. 

HOW THE TWO SPACING MECHANISMS WORK AND INTERACT

The common core of the two mechanisms is a claw which pulls down on a tab on the escapement torque bar, slipping off the tab to ensure a short activation of the escapement pawl to give a single column movement. This claw is pulled down by the rotation of a bar shaped lever. 

Bar lever

Claw atop tab on escapement torque bar

claw pulls off the tab

Remember that the escapement torque bar runs across the back of the machine just behind the carrier. When it rotates the bottom edge pulls the escapement pawl out of the escapement rack teeth. Since the claw pulls down but immediately pops off the tab, the pawl is only pulled out for a very brief period. It is long enough that the mainspring begins pulling the carrier to the right since the pawl is no longer holding in the rack. 

Because the torque bar flips back into its idle position rapidly, the pawl is released and slides into the next tooth of the escapement rack, halting the movement to exactly one column. Thus, we need the bar lever to move enough to pull the claw down off the torque bar but twisting the escapement torque bar in the process. 

There are two ways that the bar lever is rotated to pull down on that claw. One is a pull rod coming from near the front of the machine, the other is a complex set of levers that move when the operational clutch powers a space request.

The print escapement rod will be pulled, rotating the bar lever, at the proper time during a print cycle. A filter shaft turns during a print cycle and on it is a cam with a roller that drives the pull rod for print escapement. The cam is shaped so it yanks on the pull rod when the type ball has already struck the page and is returning to its rest position. The carrier can now move without smearing the typed character. 

If a solenoid activation or the front 'space' pushbutton triggers the operational clutch for space, the motor power spins the clutch through 180 degrees. A roller on the clutch surface moves a bail in a down then up cycle through that rotation. The space request pushes a space activation lever lip under the bail so that the space activation lever is pulled down and then released upwards as part of the clutch cycle. 

The space activation lever connects to the bar lever, with two adjustable screws that should cause the bar lever to yank the claw of the common escapement mechanism I described above. It is a complicated set of pivoting parts designed to push down on the bar lever when a space request is made but not stop its movement by the pull rod during print cycles. 

space activation lever pulled down by bail

The partial plate shown on the right of the diagram above is the plate that houses the mainspring and drums. 

mainspring plate holds adjustment screws

one adjuster shown, second pushes on top tab in front of the one shown

As the 1053 is adjusted now, the bar lever ("escapement trigger lever") is already partly rotated while the pull rod is in its idle position, so that the print cycle turns it a final amount to operate the claw ("trigger"). Because of that, the adjustment screw from the spacebar latch lever doesn't adjust far enough down to impart enough rotation of the bar lever to trigger a space. 

Because of the interaction between the two mechanisms, I couldn't get space working. I had to go back and completely reset the print escapement settings. What was necessary was for the bar lever to be nearly completely unrotated while the pull rod is idle, but therefore its relatively small rotation as the rod is pulled has to be enough to move the claw to trigger the escapement torque bar. 

STARTING OVER AND CHECKING EVERYTHING

This took more time that it would seem, in part because there is an interaction with some carrier return adjustments that are, as usual, totally unmentioned in the adjustment manual but really important. All in all, I put in about four hours work on this. It included a disassembly of the donor machine to see how all the parts work and several comparisons to my working 1053. 

I changed a CR setting to let the escapement torque bar sit more upright at rest, then tried different settings of the trigger eccentric screw before I got to a state where, with the escapement trigger lever (bar lever) basically flat and unrotated, the trigger (claw) was just over the tab on the torque bar. 

I then adjusted the filter shaft cam so that it was positioned properly. The objective is for the roller to have just reached the low point on the cam at the rest position of a print cycle. The cam was not right and I had to loosen its setscrew and move it to the desired spot.

The setscrew is in a very inconvenient location where tools can't reach it at its proper position. I had to work out a method that involved releasing the pressure from the roller, after loosening the setscrew in mid print cycle. I could then rotate the cam by hand while the machine was at the print cycle rest position, getting it at the ideal spot. 

While working on this method I discovered that a spring was missing, that should twist the lever with the roller so that it follows the cam. I grabbed a suitable spring from the donor machine and attached it so that the escapement roller will work as intended.

Removing the pressure on the roller let me hand cycle a print cycle until the cam with its loose setscrew had moved out to a spot with reasonable access, then I tightened it down. I verified that it was correct, if you back up from the rest position the roller immediately moves upwards, so we are at the beginning of the low zone. This gives maximum time for the type ball to print a character before we release the escapement pawl to move forward. 

I ran out of time in the shop at this point. I expect that I just have to adjust the length of the pull rod so that a print cycle will always trip the escapement torque bar. The adjustment screws for the space mechanism are in much better position with lots of range available. Once the print cycle escapement is verified I can adjust the space mechanism and hopefully finish the job. Perhaps another hour or three of fun ahead.