Handling decks properly was an art, involving a 'riffling' somewhat akin to shuffling a deck of playing cards which would loosen the cards that might be sticking together, dislodge any foreign matter (e.g. dust). Even with proper handling of cards that were continuously kept in a controlled environment, jams would occur. These were a daily or at best weekly occurrence. When you factor in aged card decks and the passage of many years since the last proper adjustment of the reader, your experiences are not surprising.

The mechanical process to allow one and only one card to move through the mechanism is the primary culprit in these jams, since allowing two cards to feed at the same time is going to lead to a jam further into the card path. However, other spots in the path might be out of adjustment enough to let a card skew a bit, allowing a moving card corner to strike some fixed part of the machine. Do the jams all seem to begin at the same point in the card path? Does it appear that you have two cards together at that point triggering the pileup? Those might give you a hint as to what is the root cause of the jams.

Carl

IBM punched card manufacturing

IBM's Fred M. Carroll[24] developed a series of rotary type presses that were used to produce the well-known standard tabulating cards, including a 1921 model that operated at 400 cards per minute (cpm). Later, he developed completely different press capable of operating at speeds in excess of 800 cpm, and it was introduced in 1936.[5][25] Carroll's high-speed press, containing a printing cylinder, revolutionized the manufacture of punched tabulating cards.[26] It is estimated that between 1930 and 1950, the Carroll press accounted for as much as 25 per cent of the company's profits[27]

A punched card printing plate.

Discarded printing plates from these card presses, each printing plate the size of an IBM card and formed into a cylinder, often found use as desk pen/pencil holders, and even today are collectable IBM artifacts (every card layout[28] had its own printing plate).

IBM initially required that its customers use only IBM manufactured cards with IBM machines, which were leased, not sold. IBM viewed its business as providing a service and that the cards were part of the machine. In 1932 the government took IBM to court on this issue, IBM fought all the way to the Supreme Court and lost; the court ruling that IBM could only set card specifications. In another case, heard in 1955, IBM signed a consent decree requiring, amongst other things, that IBM would by 1962 have no more than one-half of the punched card manufacturing capacity in the United States. Tom Watson Jr.'s decision to sign this decree, where IBM saw the punched card provisions as the most significant point, completed the transfer of power to him from Thomas Watson, Sr.[27]

Unfortunately Stan can't remember where he got the above :-((

Timecardsales.com is successor company in Memphis. Six Carroll Presses were sent to Memphis the week before we found out about the sale. The new owner was reluctant to sell to us so as to keep the presses out of the hands of a competitor. (?)

At the time, the trade association was still active. Will check on today's status.