Patent GB-255081-A (GB)
Title: Improvements in or relating to the manufacture of toothed combs
IPC: B29D21/04
Filed: 1926-07-08
Abstract: 255,081. Gueutin, A. P., July 8, 1925, [Convention date]. Combs, toilet and like. - In making toothed combs the blanks are operated upon by milling- cutters to form grooves which are subsequently sawn into tooth spaces or the milling-cutters may form the finished spaces in one operation. Alternatively the outer extremities of the spaces may be finished bv the cutters and the remainder grooved and sawn. A machine for operating according to the first method comprises a workholder 1, Fig. 14, carrying a comb 2, a pair of milling-cutters 6 and a saw 9. The comb is fed transversely for producing each tooth by a number of cams 4 and is longitudinally indexed to space the teeth by a screw 15 engaging a longitudinal slide 14. The cutters are rotated by belts 40 maintained at a uniform tension and are reciprocated to and from each other by cams 7 and springs 8. The saw is carried by an arm 11 which is oscillated against its own weight by cams 12 and rods 36 - - 38, an arcuate slot 39 serving to guide the saw and the drive being through belts 41. To produce teeth of different length the work-holder is given a supplementary transverse movement by means of a slide 18 having inclined or curved slots 21 which engage pins 22 secured to the holder. In operation the cutters 6 are brought together and the comb is fed between them by the cams 4 to produce a groove on each side. The cutters are then separated and the saw 9 is oscillated to cut a slot between the teeth. The comb then returns and the feed-screw 15 is given a partial rotation by means of a ratchet 28 and pawl 30, Fig. 15, actuated against spring pressure by a cam on the shaft carrying the cams 4. A second ratchet and pawl of opposite hand are provided for moving the slide in the reverse direction, only one ratchet being in action at a time. A gear-wheel 25 on the screw 15 meshes with a gear-nut 24 engaging a screw 19 having an eye-end 26 which is slidably connected to a rod 27 on the slide so that each time the comb is indexed it is also fed transversely to vary the length of the next tooth. The stroke of the pawls 30 is adjustable to vary the pitch of the teeth. In a modified machine the cutters 42, Fig. 18, have their teeth formed so as to overlap without touching and act on the comb 80 so as to form the teeth completely at one operation for the whole of their length or for part of their length, as shown, the remaining part being subsequently removed by a saw. The comb is held in a clamp 81, Figs. 19 and 20, carried by a slide 83 which is longitudinally indexable on a carriage 84 vertically movable in guides 91 by means of a cam 78 acting against the weight of the carriage. The slide 83 is indexed by a screw 85 and a ratchet .88 engaged at each vertical movement of the carriage by a pawl 89 pivoted to the machine framing. The slide carries an adjustable template 96 which governs the length of each tooth formed. The cutters 42 are mounted on shafts 43 rotatable in bearings on brackets 46 pivoted on axes 48 which pass through the pitch line of a pair of intermeshing gears 50 on the shafts, whereby on one shaft being rotated by a belt 54 both cutters will always be rotated in synchronism. Each cutter-spindle carries a plain roller 51, the rollers being normally maintained in contact by a spring. In operation, as the carriage 84 is fed downwards to form a tooth space the comb passes between the rollers 51 and forces the cutters apart according to its external shape, as shown in Fig. 18. When the correct depth of tooth has been reached the template 96, Figs. 19 and 20, engages a lever 97, 99, pivoted at 98 so as to force a wedge 100 between the rollers and separate the cutters completely. The comb then descends on a saw 58 which finishes the tooth-space, the length being determined by the template engaging a fixed stop 102. The saw-shaft 59 is mounted in links 63 carried by shackles 64 which allow the saw to be given a rapid oscillation by means of a cam 79 and lever 103 when the comb is in its lowermost position to produce the radius r, Fig. 18. The saw is driven by belts 69, 61, the latter being tensioned by a weighted jockey-pulley 65, Fig. 19.