Patent GB-726724-A (GB)
Title: Improvements in and relating to mount and bulb loading machines for making electric devices such as incandescent lamps
IPC: B23Q7/04
Filed: 1953-04-22
Abstract: 726,724. Delivering articles. BRITISH THOMSON-HOUSTON CO., Ltd. April 22, 1953 [April 23, 1952], No. 11082/53. Class 78 (1). [Also in Groups XI and XXXVII] In apparatus for making electrical devices, more particularly miniature electric lamps (see Group XI), a turret machine for making the filament mounts is associated with a system of shoots, and conveyers for associating the mounts with bulbs at an assembly station from which they are transferred to a sealing machine. The mounts each comprise a filament 5, Fig. 2, with its ends connected to leading-in wires 3 which have a part fused within a glass bead 4 and end portions 6 bent outwardly, completed mounts being released in succession from the turret on to a shoot B1 down which they slide with the end portions 6 of the wires extending over the side rails B8 of the shoot. The release of the mounts on to a reciprocating rack conveyer is controlled by a solenoidoperated escapement device comprising an upper stop or finger B37, Figs. 3 and 5, and a lower stop B137. The upper stop B37 is fast on one end of a hollow horizontal shaft B38 the other end of which is attached to a crank actuated by the armature of a solenoid B40 controlled by a signal from the mount making machine, whilst the lower stop B137, secured on a shaft B138 passing through the hollow shaft B38, is actuated by the armature of a solenoid B140 controlled by signals from the sealing machine. The functions of the two controls are such that the upper stop B37 holds the mount until a predetermined instant of the mount making machine cycle in order to equalize the variations in time of the different mounts in sliding down the rails B8, whilst the lower stop B137 is timed to release the mount in synchronism with the sealing machine and at the instant when the rack conveyer B3 is positioned to receive it. Bulb-loading mechanism. A quantity of bulbs is loaded in bulk into a hopper D1, Fig. 9, and gravity fed through a bottom opening D10 and flexible rake D3 into a vibrating trough D2. The trough, which is supported on inclined cantilever springs D5, D6 secured on a base D7, is vibrated by a conventional electromagnetic vibrator D8 having a frequency of 3,600 cycles per minute. The bulbs are progressed towards and along a longitudinal slot into which they are aligned neck downwardly by a longitudinal guide bar D11 located above them. A tipping-plate D12 at the outer end of the trough causes the bulbs to pivot so that they fall, neck-upward, into an escapement tube D13, their movement being assisted by an air jet. A control device which de-energizes the vibrator and arrests the flow of bulbs when they reach beyond a predetermined height in the escapement tube, is provided by a switch D16 connected in the vibrator circuit and comprising a spring blade D 18 provided with a lightweight extension or vane D17. A jet of air blown from a tube D21 through a slot in the escapement tube strikes the vane when the level of the tubes is below that point, and maintains the circuit closed. When, however, the air passage is obstructed by a bulb, the vane D17 swings forward and allows the switch to open. Jamming of the bulbs within the tube is prevented by vibrating the hopper once per loading cycle by the closure of an auxiliary switch D61 connected in parallel with switch D16 and closed by a bracket D62 on the reciprocating plate D23. The actual loading of the bulbs into the clips of a chain conveyer is achieved by a mechanism comprising a horizontal plate D23 which is reciprocated vertically by a link D31 and connecting-rod C31 and carries a pair of oppositely directed upper plungers D24 and a similar lower pair D25 with conical ends extending through apertures at the lower portion of the tube D17. The plungers are spring-biased inwardly and withdrawn intermittently by vertical cams D27 as a result of the reciprocation of plate D23. The timing is such that as the plate D23 is moved downwardly the upper plungers move in and contact a bulb above its widest portion, forcing it down until the plungers rest against its neck and its lower end is pressed into a clip C6 of the chain conveyer, the bulb being thus retained during the upward return movement of the plate D23. In the event of a bulb not being loaded on to the conveyer, a vertical detector plunger D35 mounted on the vertically reciprocating plate D23 and positioned subsequent to the bulb loading station operates a, mount ejector to remove the mount intended for attachment to the missing bulb. In a modified device for feeding tubular bulbs into the apparatus to receive a mount, the bulbs slide at random down a shoot, Fig. 11 (not shown), towards the upper end of a vertical guide tube at which the hooked end of a hair-spring is located, so that tubes which have their open end foremost are engaged by the hook and tilted around so that they enter the vertical guide tube by their closed rounded end. An escapement or metering device provided at the lower end of the guide tube comprises a sleeve which is reciprocated over the lower portion of the guide tube and has a lower portion of reduced internal diameter corresponding to that of the guide, so that it forms a continuation of the latter. A pair of levers pivoted at different heights on opposite sides of the exterior of the inner tube are spring-biased so that their lower ends tend to project through apertures in the wall of the tube and obstruct the passage of a bulb therethrough, the wall of the sleeve being slotted to receive the upper ends of the pivoted levers. In its reciprocation the sleeve exercises a cam action on the levers and moves their inner ends intermittently to permit the escape of a succession of bulbs. Conveyers. The rack-conveyer B3, Fig. 3, comprises, a parallel pair of stationary outer guide rails B44 of wedge-shaped section, spaced apart to receive between them a pair of reciprocable inner guide rails B45 consisting of a generally U-shaped metal strip. Both the inner and outer rails have equidistant notches B48 along their upper edges to receive the transverse portions of the leading-in wires of the mounts, and the inner rails are supported within the outer rails by front and rear supporting links B49, B50 the lower ends of which are connected to the horizontal arms of bellcranks B51, B52 respectively. The depending arms of the bell-cranks are linked to a common connecting rod B55 which produces slight intermittent vertical movements of the inner guide rails, whilst intermittent horizontal movements are imparted by a rocker arm B56 which is pivoted on the machine frame and connected to the rails through a pin-and-slot connection B58 at its upper end, its lower end being connected to a connecting-rod C14. The mounts are thus progressed from notch to notch along the outer rails in a succession of jumps. On reaching the end of the reciprocating rack the mount is lifted by the inner guide rails and deposited on a rocking-slide B61 which is rocked forwardly so that the mount slides down to a pair of hinged gates arranged to be separated by upward movement of a wedge-shaped cam at the upper end of a vertically reciprocable rod B72, allowing a mount to drop into the open end of a bulb, as shown in Fig. 2.