Modern.....what do you mean?

an automatic punching machine for cardboard books from 1908

Hans van Oost

Many inventions are older then we might think. Nowadays most book music is punched by automatic punching machines; about three of these machines are known to me, but by now there surely will be more inexistance. It turns out, however, that in the past efforts were already made in the past to automate the time-consuming hand-punching.

On pictures taken in the Limonaire factory (view HP 1979, p.18) we can see rows of ordinary punching machines, operated by charming ladies. These ladies, of course, had to be paid and is is no wonder that Limonaire looked for a way to save this labour. In the European Patent Office in Rijswijk I found a French patent for an automatic punching machine from Limonaire. It was applied for at Jan. 4th 1908 and granted under number 385.948 on April 2nd of the same year. A summary of the text, translated from the French, follows below. It has been adapted here and there  for the sake of readability:

This invention concerns a machine for perforating cardboard and paper music media, intended for mechanical musical instruments like pianos, organs etcetera.

This machine contains a number of punches that are uncoupled in rest and can be coupled, by means of electromagnets, to a pushing device that goes up and down. The punches thus coupled make perforations in the cardboard, that is being moved on in small steps. In the meantime a cardboard master book is lead over an electric keyboard, whereof the seperate keys each open and shut the contact of the current circuit of an electromagnet, every time when a key falls through a hole of the master book.

A machine can punch more books or rolls at one time by means of one master book, with a multiple switch that makes it possible for one scanning key to work more electromagnets at the time.

A model of this machine is depicted on the accompanying drawings. Figure 1 is a cross section and figure 2 is an upper view that shows several layers in cutouts. 1 represents a frame in which a number of sliding vertical rods 2 are suspended. To these rods the punches 3 are fitted in such a way that they can be changed easily. The rods are supplied with the compression springs 4 and can be pushed down. By these means the punches go through the cardboard or paper 5 that is moved on over table 6. In these table as many die holes 7 as there are punches are screwed in.

The hinged interposer rods 8 are attached to the top of the sliding rods 2.  These interposer rods are are attached to the armature plates 12 of the electromagnets 13 via the interposer pull-rods 9, the rotating links 10 and the armature pull-rods 11. The compression springs 14 take care of the proper return of the handles 8 to their original oblique position when the electromagnets are not working.

Over the handles 8 the punch hammer 15 is moving. The punch hammer is moved up and down by two crank eccentrics with connecting rods 16. In the lower surface of the clearance grooves 17 have been made, corresponding with the handles 8 in their oblique position, with as result that the punch hammer will push down only those rods 2 that have been pulled to vertical by the electromagnets, as can be seen on the figure 1.

The paper or cardboard strip to be punched is lead between the transport roller 18 and the pressure roller 19, while the master book 20 is moving in the opposite direction between the same roller 18 and the pressure roller 21. At each turn of the eccentrics 16 the roller is transported over a small distance by a cam projection 22 attached to the wheel of the eccentric, a push rod 23, a pawl 24 and a ratchet 25. The master book and the strip to be punched are thus both moved equally, every time that the punch hammer is around its highest position.

Underneath the master book 20 and the supporting surface 26 a series of feeler keys 27 is attached. The points 28 of these keys can fall upwards through the holes in the master book. The points 29 are then submerged in the small mercury basins 30, by which movement the current circuit for the electromagnets 13 is closed. As a result the electromagnets become magnetic and pull the plates 12. The matching interposer rod 8 is pulled to a vertical position by way of 11, 10 and 9. the matching sliding rod with punch is then pushed down by the punch hammer with its next stroke.

In order to keep all parts of the machine within a limited space, the parts are placed in staggered positions, for instance in the way depicted in the design. Moreover, the positioning of the electromagnets 13 on top of the apparatus makes them  easier accessable.

In some cases the cardboard is narrow and has only a limited number of tracks. In that case is is of advantage to feed more cardboard strips side by sitde through the machine. In that case the mercury basins 30 are each connected to more magnets 13 by means of a multiple switch. Each perforation in the master book thus causes holes to be punched in the cardboard strips in corresponding places.

It is clear that place and form of the parts described above can be changed or replaced by other parts or constructions with the same action without deviation of the patent. For instance, the scanning levers can be replaced by electric contacts operated by pneumatics with high or low pressure and a keyless frame like in pianistas. The command or coupling mechanisms may have other forms too.

Conclusion

The machine presented here to perforate cardboard or paper strips is characterized by the electromagnetic drive of the punches with hinged rods and a mechanic pushing device with grooves in it to keep it clear from the non-functioning punches, and the current for the electromagnets is being opened and shut via a master book that is moved forward with the same speed as the product to punch, and a key frame with electric contacts linked to these electromagnets.

For the Société Limonaire Frères, E. Blétry.

So much for the patent. Although the design of modern automatic punching machines has changed the principle is still the same: the cardboard is fed through the machine in small steps, the punches are operated mechanically, and the coupling between the punches and the mechanism is made by electricity. In the Limonaire machine both the punches and the scanners have been staggered in eight steps, as can be seen on fig. 2.

The latest punching machines do not use a master book anymore. By means of an interface the cardboard books are punched directly from a MIDI-file on a diskette. Modern punches are round for easier sharpening. Cardboard music punched by these machines can be recognised because they have rounded holes instead of the familiar rectangles.

It is a shame that no Limonaire punching machine seems to have survived today. It would have been a monument for industrial archaeology.

With thanks to Robbie Rhodes, USA, for his valuable comments