Finishing a piano scale design on his kitchen table in 1860, this drawing is often thought to be the one that launched his career in the piano building business. By 1866 enough capital had been raised for Theodore Heintzman to open his own factory.
By 1879 more than 1,000 instruments had been manufactured, and this factory passed the 2,000 mark in 1884 some five years later.
In 1896 Theodore Heintzman completed a drawing of a particular plate design that would catapult the Heintzman Piano Co to the top of the Canadian piano market, where this company would remain for more than 100 years.
This plate design incorporated what is called the Patented Agraffe Bridge. This bridge takes the place of the pressure bar assembly usually found in upright pianos. In the grand piano, this bridge takes the place of the v-bar design which the strings pass under.
The bridge has holes drilled at 7-10 degrees angle for bearing purposes. Each piece of treble piano wire must pass through one of the holes and then be attached at both the hitch pin and the tuning pin.
This particular piano plate design causes the Canadian Heintzman piano to be one of the most difficult pianos to re-string. In the upright version, one can tilt the piano over onto a tilting piano truck which will help to find the hole for each piece of wire. Another way to accomplish restringing of an upright with this bridge is to have a mirror placed underneath the working area and a lamp on top to shine light into the holes.
In the grand version of this piano the flange with the holes cannot be seen at all from either the tuning pin side or the sounding board side of the plate. Also, because the grand piano pin block must be supported from underneath when driving the pins in, usually a small mirror is used or the job is done by feel only.
One of the benefits of having this type of design is to keep each piano string of the unison equal distance away from each other for quality sound and for equal hammer wear over the entire surface of the hammer strike point.
Another benefit of this type of design is to prevent bridge roll. Bridge roll syndrome is when the treble bridge attached to the piano sounding board is slowly dragged, in a lengthwise rolling motion, towards the player over years being under tremendous tension. This is often one of the contributing factors in the sounding board deterioration of pianos.
Here are some photos of the Heintzman & Co Patented Agraffe Bridge. Both the upright version and the grand version of this design are shown here.