Patent GB-1467572-A (GB)
Title: Feeder for headed objects
IPC: A47G19/00
Filed: 1975-02-17
Abstract: 1467572 Fluidic circuits A J SMITH 17 Feb 1975 [13 March 1974] 6630/75 Heading F1P [Also in Divisions B8 and F2] Heated objects such as nails are fed to a feeder device in bulk and are discharged therefrom in ordered alignment, the feeder device comprising a bowl 10 which is supported for vibration relative to a base and which initially receives the nails in bulk, and an inclined discharge shoot 12 spaced from the bowl 10 which receives the nails from the bowl 10 and from which shoot 12 they are discharged to a further device, the bowl 10 being associated with a delivery path 14 which comprises a ramp 94 leading from the bottom of the bowl 10 up to a circular path 96 which circumscribes the mouth of the bowl 10, the nails being caused to travel up the ramp 94 and along the path 96 under the action of a pneumatic hammer 40, Fig. 15, which imparts vibration to the bowl 10 and path 14, the path 96 having an annular skirt 104 extending downwardly therefrom, part of which is cut away at 108 adjacent the upper receiving end of the shoot 12 to permit the nails to drop in turn into the shoot 12. As the nails travel along the skirt 104 of path 96 they are retained thereon by a nail retaining device 98 which is supported by the base against vibration relative thereto and which has a lip 100  which engages the heads of the nails, the lip 100 being relieved at 118 adjacent the cut away 108 to permit the head of each nail to perform an upward arcuate movement as it drops into the shoot 12. The pneumatic hammer 40 is suspended from a pair of pedestals (42) secured to the bottom of the bowl 10, Fig. 2 (not shown), the latter being supported on a frame (18), which forms the said base, by means of four leaf springs 28 which each  extend from an anchor lug by (30) on the frame (18) to a support lug 32 located on the lowermost surface of the bowl 10.  The shoot 12, Fig. 11, comprises a pair of rightangled rails 110 which define a slot 111 for the nails therebetween, the nails being supported in single file by their heads therein. A gate 134 in the form of a bifurcated dog 136 is pivotally mounted at 138 on one of the rails and a tension spring 146 urges the dog 136 to a position in which a retainer lip 140 thereon blocks the slot 111 to prevent passage of nails therefrom. When a nail receiving magazine M is inserted into a slot 152 it abuts the dog 136 to cause anti-clockwise rotation thereof, thereby permitting the nails to enter the magazine M. When a certain number of nails have been discharged from the shoot 12, such that a nailsensing device 160 is not obstructed by the presence of nails, the device 160 causes operation of the pneumatic hammer 40 through the control circuit of Fig. 15 thereby causing vibration of the bowl 10 and trackway 14 to feed further nails to the shoot 12 The pneumatic hammer 40, Fig. 17 comprises a housing 44 in which a mass 48 is reciprocable, the hammer 40 having a fluid inlet port 52 in communication via a branch conduit 56 with a main conduit 58, Fig. 15, the latter being in communication with a pneumatic fluid source (not shown), the hammer 40 also having a fluid outlet port 60. Two sub-chambers A, B are defined by the mass 48 and housing 44, the chamber B having an exhaust port 72. In the position of the mass 48 as shown in Fig. 17 fluid flows through the conduits 58 and 56 and inlet port 52 and through an annular groove 74 and the fluid passageway 49 defined between the mass 48 and housing 44 to both the chambers A, B but is exhausted from the chamber A through the outlet port 60 such that pressure builds up in the chamber B to cause rightward movement in Fig. 17 of the mass 48 to a position in which the latter blocks off the port 60, opens the port 72 and aligns the inlet port 52 with a bore 78, 76 in the mass 48 such that fluid is now fed to the chamber A to cause leftward movement of the mass 48, and thus receprocatory movement of the mass 48 takes place, which means that vibration is being imparted to the bowl 10 and path 14, provided that fluid can be exhausted from the chamber A through the fluid outlet 60. When it is no longer possible to exhaust fluid through the outlet 60 a back pressure builds up in the chamber A and thus reciprocatory movement of the mass 48 is prevented. The control circuit of Fig. 15 includes means for permitting  and preventing such exhaust through the outlet 60 of hammer 40 under the control of the nail-sensing device 160. As shown in Fig. 15 the device 160 comprises a fluid-jet orifice 166 in communication with the main fluid conduit 58, fluid being blown across the slot 111 in the shoot 12 from the orifice 166 to a fluid acceptance port 170 when there are no nails present in that part of the shoot 12 adjacent the sensing device 160, such that the fluid is passed through a conduit 174 to a valve actuator 90 and pressurizes a plenum chamber 172 thereof to cause a diaphragm 176 to be extended and thus to block a port 186, so that fluid passing through the main conduit 58 and a branch conduit 92 to the actuator 90 is unable to enter the latter and thus passes through a conduit 88 to a flow control valve 70 causing a shuttle 84 therein to move against the action of a compression spring 86 to a position in which a bore 85 in the shuttle 84 aligns with a  conduit 64 leading from the outlet port 62 of the hammer 40 and a port to atmosphere 82 in the valve 70 whereby fluid is permitted to exhaust from the chamber A of the hammer 40 and reciprocatory movement of the mass 48 is now possible, and due to the resultant vibration of the bowl 10 and path 14 nails are fed to the shoot 12, and when the path between the jet orifice 166 and acceptance port 170 is blocked by the presence of nails, the diaphragm 176 is returned to its position shown in Fig. 15 under the action of a spring 184 so that fluid supplied through the conduit 58 is exhausted at 180 from the valve actuator 90 and thus the shuttle 84 returns to its position shown in Fig. 15  under the action of the spring 86, causing a back pressure to build up in the chamber A of the hammer 40 and thus the cessation of the operation of the hammer 40 and consequently the feed of nails from the bowl to the shoot 12.