TAMBOURING. 



517 



the end of the upper jaw V, by forcing it to shut 

 and press against the lower jaw. 



3d. Above, and towards its centre, are two small 

 rounded ears, each pierced through, and separated 

 the one from the other, by a space equal to the 

 thickness of the upper jaw, and intended to receive 

 the corresponding ear v of that jaw. 



4th. A little to the right of the ears, is a very 

 small vertical nob t 1 ', for stopping the needle, if at 

 any time it tended to catch the cloth too far for- 

 ward. 



5th. Directly to the right, a thin plate T', having 

 a cone-shaped hole, larger without than within ; a 

 front view of this plate is given in fig. 11. 



The upper jaw V, is represented in the same fig. 

 8 ; it is put out of its place, that, by raising it a 

 little upwards, we might better show its shape. 



The lower jaw being set in its place, it is enough 

 to arrange the upper jaw, and put a peg through it 

 crossing the three ears, that the pincer might be 

 fully mounted. We see at the same time that, of 

 course, it is shut by the action of the spring t', and 

 that we cannot open it but by using on the end of 

 the upper jaw V a pressure from above, capable of 

 overcoming the elasticity of the spring t'. 



Fig. 9. represents an upper view of the pincer ; 

 in which we see the breadth of the jaw and the 

 spring. 



Fig. 10. represents a pincer seen at the extremity 

 of a side of the plate T'. 



Fig. 12. represents a needle V of its natural 

 size ; the hole is in the centre, the thread passes 

 through it as in a common needle, but it is not 

 doubled ; it is enough to mix the thread-ends at the 

 small end with those at the larger, near the needle, 

 and afterwards roll them together, by passing them 

 between the finger and thumb, that they may hold 

 the better, and pass through the cloth with ease. 



When a pincer is open, and only half of the 

 needle is thrust through the opening of the plate 

 T , it is lodged in an angular grove, having less depth 

 than the needle's thickness ; and when the pincer 

 closes, the upper jaw presses it in the groove ; thus, 

 the needle is held secure, provided that it be not 

 prevented by the three edges of its triangular 

 shape. 



All the pincers being arranged and adjusted at a 

 proper distance, on the prismatic rod S, to form the 

 upper row of the right hand carriage, as seen in 

 fig. 1. we shall now endeavour to explain how 

 the workman is enabled to open all the pincers of 

 that row at once, when the needles are to be given 

 to the pincers of the opposite carriage, after having 

 fixed them in the cloth. 



To gain that object, there is an axis of iron U, 

 broader than thick in form, turning on itself, and 

 extending from one end to the other of the carriage 

 (fig. 1.) ; a section of it is seen in U, (fig. 13.) This 

 axis is supported by two kinds of forks u (fig. 6.) 

 which are bolted to the extremity of the branches 

 Q ; and it is kept in proper play by a nob u' ; those 

 parts of the axis by which it rests on the forks, are 

 round, and the latter are of such a height, that 

 when its flat portion is turned upwards, it only 

 touches the extremities of all the upper jaws, V, 

 without pressing them, so that the pincers remain 

 secure ; but, when we turn it a little on itself, it 

 leans on the extremities of these pincers, and opens 

 them by acting on the elasticity of the spring t, 



The workman must now be enabled to turn the 

 axis IT, whether it be to open the pincers, or shut 

 them, for they may shut of themselves, by means of 



the springs t, as soon as the axis U is brought up- 

 wards. 



M. Heilmann, with that intention, adapts to the 

 two extremities of the axis U, two toothed sectors 

 xx, a front view of which is seen in fig. 2. ; each of 

 these sectors regularly catches with a vertical rod 

 X (fig. 1. and 2.) impinging against the branch Q, 

 on which it is kept by props, and the rod X itself 

 in its lower part is furnished with a horizontal 

 peg x' (fig. 1.) perpendicular to its surface; by 

 means of these pegs, motion is given to the rod 

 X, to the sector x, and consequently to the axis 

 u for opening and shutting the pincers. But 

 to see how the workman performs this opera- 

 tion with his feet, let us return and consider the 

 pedals P (figs. 1. and 2.). We have already shown 

 that the frame P", which is set in motion by these 

 pedals, bears on its right extremity (fig. I.) a piece 

 P'', intended to put the lever n o in play. A front 

 view of this piece is given above its place (fig. 2.), 

 and to the left under No. 3. It is observed that 

 it has teeth throughout two thirds of its circum- 

 ference, and that it is used as a pinion ; by its 

 toothed part it catches with a sector r, mounted 

 on the extremity of the shaft R, which can turn on 

 itself, and it is supported by props r'r', fixed in the 

 centre of the horizontal and lower cross beams of 

 the frame. The axis R bears also two branches 

 Z Z (fig. 2.), set crosswise on itself, and terminated 

 by the forks z and z'. They are intended to receive 

 the pins x' of the rods X; their manner of working 

 can be easily understood. In fine, by reverting to fig. 

 2. let us suppose that the workman, by turning the 

 handle N in the direction of the arrow, draws back 

 the right hand carriage; the carriage then returns; 

 he fixes the pegs x' in the forks z ', into the cloth ; 

 he plants the projecting half of the needles that it 

 bears, and these halves penetrate into the pincers 

 of the left hand carriage, which are open to receive 

 them ; it is now necessary to shut the left hand 

 pincers, that they may take up the needles, and 

 open those on the right hand that they may lay 

 them down. That is the whole process which the 

 workman performs with his foot, at a single stroke ; 

 he presses on the pedal that is raised for the purpose 

 of drawing the cords which bears it; then the rota- 

 tory motion resulting from it in the corresponding 

 pulley, communicates itself to the shaft P , to the 

 pinion p", to the sector r, to the shaft R, and 

 simultaneously to the two branches Z Z ; the ex- 

 tremities z z of these branches (fig. 1. and 2.), rise 

 up, and bear the pins x, in their ascending move- 

 ment. Consequently the rods X remount by gliding 

 in their grooves, and set in motion the sector x and 

 the shaft U, which last, in turning, presses on the 

 end of all the upper jaws V, and at once opens all 

 the pincers : by the same motion of the branches Z Z, 

 the forks z"z', terminating on the left, descend, 

 drawing along with them the pins of the rods X of 

 the left hand carriage, and turn round the cor- 

 responding sectors and the shaft on which they are 

 mounted, that it may strike with its flat side on the 

 ends of the upper jaws V, and thus the whole pin- 

 cers of that side are shut by the springs t'. 



By this method the workman shuts the left hand 

 pincers and opens those on the right, which last 

 will remain open till they have received the needles 

 after the return of the left hand carriage. The 

 same motion of the pedal which produces this 

 double effect, changes also the position of the lever 

 n o (fig. 2.), and leads the wheel O' on the wheel 

 M', so that the workman has only to turn the 



