A press brake is a machine tool used to bend, shape or punch sheet or thicker metal or other materials. All types of press brake have, generally, a particularly tough outer frame, a flat bed, a lower die into which the work is pressed, an upper ram, and a "back gauge". The material to be bent is placed on the bed, and the ram lowered to press the material into the lower die which forms it into the desired shape  - be this means a simple 90° bend, a V, a U or whatever the shape of the tooling employed can be obtained. By further manipulations of the material, further bends can be made to form box or other complex shapes. Some press brakes work on an upstroke principle, this being preferred for certain class of job.
Press brakes range from small manual machines for one-off jobs to large computer-controlled models capable of handling repetitive production tasks. Several press brakes can be put in a line and long jobs - well beyond the capacity of even the largest individual machine available - successfully completed.
Both mechanical and hydraulically operated models are made, though the letter is now far more common being more sensitive in operation and so easier to use and both more powerful and accurate in operation.
Press brakes are commonly used in metal-fabrication, sheet-metal shops - and experimental workshops where prototype parts can be quickly made and modified.
Operating a conventional, manually-controlled press brake does requires a degree of skill and experience - the work involving precision measurements and careful control of the bending forces and angles employed. As powerful machines, open at the front, the very high pressures and forces involved require that safety of the operator is parmount.
The Promecam Company was based first at 63 Rue de Strasbourg, Saint-Denis in the heart of Paris and then at a new factor in Chateau-Du-Loir. Production begin in 1955 with the company expanded rapidly, enjoying great success and finally being taken over in 1986 by the AMADA Group. Today, production continues of a range of advanced machines suited many different kinds of press brake application.
The details on this page from a catalogue from the early 1960s and show models made from the mid-1950s until the late 1960s. The number associated with each model is the pressure in tons that it can exert. Later catalogues start here..
"I had several Promecam press brakes in my subcontract engineering company. They were super efficient when tooled up properly and extremely versatile, especially later ones with CNC controls. The only slight problem we had was the automatic balancing valve which tripped out .We cheated by putting a suitable load - a compression spring - at the other end.".