In cutting brads that have heads, the general arrangements are somewhat different as explained in the diagram fig. 967, in which as before, the rectangular aperture in the bottom tool is bounded by the strong black line, the tail of the punch is shaded, the stop s, is situated as far beyond the aperture in the bed, as the vertical height of the head, and it is so made that the small part which extends to the right, overhangs the slip of iron that is being cut, after the manner of a puller-off; but the overhanging part only comes into action when the slip is tilted up, either by accident, or from being so short as to give an insufficient purchase for the hand. It is also to be observed that the width of the point of the brad, is just equal to the projection of its head.
On the end of the strip of iron being first applied, a wedge-farm piece is cut off, exactly equal to the difference between the tail of the punch and the bed, and a little projection is left near s, and which projection, after the iron is turned over, rests against the tail of the punch, as shown in the figure, so that the succeeding cut removes the one brad and forms the head of the following: the tail of the punch being inclined to the precise angle drawn from the point to the head of the brad, as denoted in the diagram.
When, 'as it is more usual, brads are cut out by steam power, the cutters are not worked in a fly press, but the moving cutter is commonly fixed at the end of a long arm which is moved rapidly up and down by a crank; the strip of metal is held in a spring clamp, terminating in an iron rod, which rests in a Y or fork, so that the boy who attends the machine, can turn the metal over very rapidly between every alternation of the machine; these particulars are shown in fig. 954, page 937.
The machine fig. 954, may be used for brads either with or without heads, it is, however, always necessary to turn the iron over between every cut; but in the toggle press fig. 953 on the same page, and which acts much more quickly, it is not requisite to reverse the metal, as the entire press is moved on its pivots e e, by the rod g, so as to incline the press alternately to the right and left, to the angle of such nails as are simply wedge-form, or have no heads, as in fig. 966, page 947.
In some machines resembling fig. 954, the nail as soon as cut off is grasped in a pair of forceps or dies, whilst a hammer, also moved by the machine, strikes a blow that upsets the metal, and constitutes the flat head in the kinds known as cut nails, and tacks.41
* The first patent for making nails that the author has met with, was granted to John Clifford, 17th July, 1790 (see Repertory of Patent Inventions, 1st Series, Vol. vii, p. 217). The mode preferred by the patentee, was to employ two rollers of iron faced with steel, in which were sunk impressions of the nails, half in each roller. The indentations were arranged circumferentially with the heads and tails in contact, so as to extend the grooves around the roller, and roll the whole rod of iron into a string of nails, which required to be separated from each other with shears, nippers, or other usual means. Sometimes many grooves were cut around the rollers, and a sheet of iron was then converted into several strings of nails that required to be separated nearly as before.
The same inventor took outs second patent, about six months later, for a method of making nails by punching. The plates of metal were forged or rolled taper to the angle of the nails, and were then cut up by a punch and bed, each made taper and also to the angle of the nail. Nails that required heads were afterwards put into a heading tool or bed, having a taper hole of corresponding form, that left a small piece of the thick end projecting; and the head was upset with a punch or die, just after the manner now practised in making solid headed pins. This second patent was sealed on the 4th of Dec, 1790. and is described in the 377th page of the volume before referred to.
Subsequently to this period not less than thirty to forty patents have been granted for making brads and nails, and some three or four of them have been very successfully worked.