Patent GB-1520662-A (GB)
Title: Displacement device for the brush carrier of a brush-making apparatus
IPC: A46D3/08
Filed: 1975-10-06
Abstract: 1520662 Brush making apparatus GOTTLIEB EBSER MASCHINENFABRIK KG 6 Oct 1975 [4 Oct 1974] 40762/75 Heading A4K [Also in Divisions Fl and F2] Continuous rotation of an input shaft 20 is converted to intermittent rotary movement of an output shaft 2 through a ratchet gear of which the transmission ratio is varied by programme-controlled pneumatic cylinders 26, 27, 28, 29, 30 which vary the position on an oscillating member 19 of a connection 23 between that member and a connecting rod 18. The mechanism forms part of a brush making machine in which holes to receive bristles are bored at adjustably spaced intervals in a brush body, and to this end the output shaft 2 is connected by means (not shown) comprising a rack and pinion and a lever with a brush holder to control longitudinal movements of the latter. Two further mechanisms of similar type are provided to control transverse movements of the brush holder and to govern the depth of drilling of the bores. The member 19 is oscillated about a fixed pivot 24 by an eccentric 21 and connecting rod 22 causing the rod 18 to reciprocate a rack bar 16 when the connection 23 is displaced from coincidence with the pivot 24. Pawls 3, 4 at the ends of arms 12, 13 secured to toothed sectors 14, 15 meshed by the rack bar and freely rotatable on the shaft 2 are thereby oscillated between extreme positions indicated by full and dashed lines and their engagement with a toothed wheel 1 fixed to the shaft 2 is controlled by a member 5 mounted on an arm 6 pivotally mounted at 7 and controlled by a pneumatic cylinder 46 and by a cam 44 driven by the shaft 20. The cam has a thickened portion so that during one half of a revolution the arm 6 is immobilized in a position in which the member 5 holds both pawls clear of the wheel 1. During the other half of a revolution the cam permits an upward or downward movement of the arm 6 by the cylinder 46 whereby the member 5 is positioned to allow either pawl 3 or 4 to engage the wheel 1 and thereby advance the latter in either direction. The wheel is held after each displacement by a member 51 actuated by the cam 44 and linkage 50, and a spring-loaded friction brake 63 prevents overshooting of the wheel. The degree of advancement imparted to the wheel for each stroke of a pawl 3 or 4 is adjustable in one-tooth increments from zero to 24 teeth by the arrangement of cylinders 26 ... 30, each of which is of double-acting type with a fluid connection 66, Fig. 3a, at each end, the two connections of each cylinder being connected to a respective valve 31, controlled by a perforated strip 37 driven intermittently from the shaft 20 through mechanism 40, 41. The cylinder 46 is also controlled by the strip 37. Each valve 31 comprises two plungers 38, 39 coupled together and depressible by a push rod 33 coupled through a lever 32 with an eccentric on the shaft 20. When the shaft is positioned such that the push rods are withdrawn leftwardly a lever 42 also actuated by the shaft 20 is operative to raise needles 35 out of the perforations in the strip 37 and thereby reset all of the push rods in their upper positions, shown in dashed lines. Thereafter the push rods are allowed to descend as determined by the perforations so that each push rod is positioned opposite one or other of the plungers 38, 39 to determine the next pattern of valve actuation by the push rods.