384 



NAILS, MANUFACTURE OF 



of two parts : tho first is a mode of forming nails, and the shafts of screws, by pinching 

 or pressing ignited rods of iron between indented rollers ; the second produces the 

 threads on the shafts of the screws previously pressed. The metallic rods, by being 

 passed between a pair of rollers, are rudely shaped, and then cut asunder between a 

 pair of shears ; after which they are pointed and headed, or otherwise brought to their 

 finished forms, by the agency of dies placed in a revolving cylinder. Tho several 

 parts of the mechanism are worked by toothed wheels, cams, and levers. The second 

 part of Dr. Church's invention consists of a mechanism for cutting the threads of 

 screws to any degree of obliquity or form. 



3Ir. Edward Hancorne, of Skinner Street, London, nail-manufacturer, obtained a 

 patent in October 1828, for a nail-making machine, of which a brief description may 

 give a conception of this kind of manufacture. Its principles are similar to those of 

 Dr. Church's more elaborate apparatus. 



The rods or bars having been prepared in the usual way, either by rolling or ham- 

 mering, or by cutting from sheets or plates of iron, called slitting, are then to be made 

 red-hot, and in that state passed through the following machine, whereby they are at 

 once cut into suitable lengths, pressed into wedge forms for pointing at the one end, 

 and stamped at the other end to produce the head. A longitudinal view of the 

 machine is shown in fig. 1544. A strong iron frame-work, of which one side is 

 shown at a a, supports the whole of the mechanism, b is a table capable of sliding to 

 and fro horizontally. Upon this table are the clamps, which lay hold of the sides of 

 the rod as it advances ; as also the shears which cu"t the rod into nail-lengths. 



These clamps or holders consist of a fixed piece and a moveable piece ; the latter 

 being brought into action by a lever. The rod or bar of iron shown at c, having been 

 made red-hot, is introduced into the machine by sliding it forward upon the table b, 

 when tho table is in its most advanced position ; rotatory motion is then given to the 

 crank-shaft d, by means of a band passing round the rigger pulley e, which causes the 

 table b to be drawn back by the crank-rod/; and as the table recedes, the horizontal 

 lever is acted upon, which closes the clamps. By these means the clamps take fast 

 hold of the sides of the heated rod, and draw it forward, when the moveable chap of 

 the shears, also acted upon by a lever, slides laterally, and cuts off the end of tho rod 

 held by the clamps : the piece thus separated is destined to form one nail. 



1544 



Suppose that the nail placed at g, having been thus brought into the machine and 

 cut off, is held between clamps, which press it sideways (these clamps are not visible 

 in this view) ; in this state it is ready to bo headed and pointed. 



The header is a steel die h, which is to be pressed up against the end of the nail by 

 a cam, i, upon the crank-shaft ; which cam at this period of the operation acts against 

 the end of a rod k, forming a continuation of the die h, and forces up the die, thus 

 compressing the metal into the shape of a nail-head. 



Tho pointing is performed by two rolling snail-pieces or spirals I, I. These pieces 

 are somewhat broader than tho breadth of the nail ; they turn upon axles in tho side 

 frames. As the table b advances, tho racks m, on the edge of this table, take into the 

 toothed segments n, n, upon the axles of the spirals, and cause them to turn round. 



These spirals pinch the nail at first closo under its head with very little force ; but 

 as they turn round, the longer radius of the spiral comes into operation upon tho 



