GB2172271A - Feeding printed circuit boards - Google Patents

Abstract

Rigid or flexible plates, especially printed-circuit boards, unpierced at least at one edge are continuously fed from file P by a movable gripping member 18, applied to the edge of the uppermost plate P1, lifting means 26 to lift and separate it from the next plate, and feed-rollers 28, 30, to cause the plate P1 to tip up when it is released by said gripping member in order to bring it into an approximately horizontal position. The plate P1 may then be transferred to a conveyor (not shown) of the machine to be fed, without it rubbing against the other plates in the pile P. <IMAGE>

Description

SPECIFICATION Device for the continuous feed of products in plate form, especially printed-circuit boards The present invention relates to the automatic and continuous feeding of products in plate form, and more particularly of printed-circuit boards, arranged in a pile, these plates being removed one by one from said pile in order to be delivered to a conveyor, for example a roller- or belt-conveyor.

There is known (French Patent No. 79 02 709 published under No. 2 447 882) a continuous plate-feed device comprising gripping means designed so as to grip at least one plate by its edge and to bring it into a slanting position, the opposite edge continuing to rest on the pile in question, and a conveyor to receive the plate delivered by the gripping means and to carry it to a continuous process machine.

In the known machines the gripping means grasp the surface of the plates, this manner of gripping only being possible if this plate has several unpierced parts, a fact which limits the applications of such machines. Furthermoe, these known machines require complex adjustment for each different type of plate, which necessitates the intervention of qualified personnel and causes considerable interruption in production. Moreover, in the case of handling printed-circuit boards, in which interference with the treated surface must be avoided, it is necessary to avoid contact with suction gripping means.

The present invention seeks to provide a device which does not exhibit the above disadvantages.

According to the invention there is provided a device for the continuous and automatic feeding of a continuous process machine with rigid or flexible plates, which plates are unpierced at least at one edge and arranged in one or more piles, said device comprising a movable gripping member, designed so as to apply itself to an edge of that plate situated on the top of the pile, and lifting means associated with said gripping member, said lifting means being operable to lift the plate held by the gripping member in order to separate it from the next plate, then to carry the plate between two feed-rollers, these being arranged so as to cause the plate to tip up when it is released by said gripping member in order to bring the plate into an approximately horizontal position, from which it may be carried to a conveyor for feeding to the continuous process machine without the plate rubbing against the remaining plates in the pile.

According to one embodiment of the invention, the movable gripping member consists of a series of suckers fixed to a support beam and in parallel with the edge of the plate to be gripped, this support beam being actuated by a system of jacks in order to take hold of the edge of the plate with the help of said suckers, to lift it and then to carry it to the feed-rollers.

Preferably, the sets of feed-rollers comprise one or more lower, drive rollers and one or more upper rollers designed so as to allow the gripping member suckers to pass when they are delivering the plates.

Preferably also, the plates to be handled one by one are positioned on a lifting table which forms a magazine and is driven automatically in such a way as to hold the plate in the gripping position at a permanently constant level, this level being detected by a photoelectric cell to which are connected the lifting table's driving means.

In order that the invention may be better understood, an embodiment thereof will now be decribed by way of example only and with reference to the accompanying drawings in which: Figure 1 is a perspective view of an embodiment of the device according to the invention; Figures 2 and 3 are detailed, enlarged views showing the method of operation of the device which is the subject of the invention; and Figure 4 is a plan view of the device shown in Figs. 2 and 3.

Fig. 1 shows the whole of the device according to the invention. This device essentially comprises a lifting table 10, which receives the pile of plates P, and a gripping and handling system, which is designated as a whole by the reference numeral 12 and is designed so as to grasp the plate situated on the top of the pile P by its edge and then to lift it and carry it to a conveyor system (not shown) while causing it to tip up slightly so that it does not rub against the other plates.

These means, which are peculiar to the invention, will be described in detail below, with reference to Figs. 2 and 3.

Figs. 2 and 3 are detailed, cross-sectional views of Fig. 1.

In Figs. 2 and 3 there may be seen the pile P of plates to be handled, supported by the lifting table 10 which will be described in detail below, these plates abutting a vertical positioning plate 14.

According to the invention, a member is provided to grip the plate P1 situated on the top of the pile P by its edge. This gripping member comprises a beam 16 along which are fixed suckers such as 18. The beam 16 is mounted on the main frame of the device, by means of a joint 20, and is in one piece with a lifting and tipping mechanism consisting of a shaft 22 which is firmly connected to the beam and which can move in slots such as 24 under the control of a jack 26, as will be seen below. Associated with this suction gripping member 18 is a feed-roller system consisting of one or more lower, drive rollers 28, driven rotationally by a variable speed geared motor, and one or more upper rollers 30 each mounted on a frame 32 linked at 33 to the main frame of the device, the upper rollers being able to tip, as will be seen below, through the action of a jacking system 34.The design of the upper rollers 30 is such that, when they are moved, the suckers 18 are able to occupy a position (Fig. 3) located behind the shaft of the rollers 30.

We shall now describe the method of operation of the device according to the invention.

The aim of the machine is, therefore, to lift continuously and successively the plate P1 situated on the top of the pile P in order to deliver it to the conveyor of a machine. To this end, the bank of suckers 18 (Fig. 2) applies itself to the edge of the plate Pt, under the control of the jack 26, the jack 26 then being actuated so that the suckers lift the plate P1 by its edge and carry it between the sets of rollers 28, 30, these being controlled by the jack 34. The frame 32 tips when the suckers release the plate P, and in this way the plate is gripped between the two sets of rollers 28-30 (Fig. 3). Taking into account the staggered relative positions of the axes of the rollers 28, 30, the plate P1 is tipped up so as to assume an approximately horizontal position, as shown in Fig. 3.It is then driven along by the roller 28 in order to be arranged on the machine to be fed (not shown). A detector 36 is provided at the exit from the rollers to initiate a fresh cycle.

In Figs. 3 and 4 the position occupied by the suckers 18 when the plate P1 is being driven along is shown at 18'. The position of the plate Pt, which may be seen in Fig. 3, shows that the invention enables rubbing of plates against each other to be avoided.

The plates forming the pipe P are positioned on a lifting table which forms a magazine 10 and is positioned between the uprights of the main frame of the device, the plates abutting a vertical plate 14. The lifting table 10 is actuated by a motor driving a winch, or any other equivalent means (not shown), in such a way that it rises steadily as the plates are delivered, positioning the top plate P1 always at the same level. This level is governed and controlled by a photoelectric cell from which information is delivered to the drive motor actuating system for the table 10. When the magazine 10 is completely empty, a button is actuated which causes the table to descend for reloading.

In this embodiment, the lifting table 10 comprises arms 38 allowing the introduction of a carrier (not shown) pre-loaded with fresh plates. This system enables the setting-up between different machines of a shuttle service effected by carriers loaded with piles, the procedures taking place between the operations of unloading and loading such machines thereby being simplified.

The device according to the invention allows the plates to be gripped at one edge, which prevents them from being damaged in any way. Furthermore, it is possible to move several piles of plates at the same time, which permits use of the whole width of the machine to be fed, these machines thereby being subject to even wear and production thereby being maximized. This is particularly advantageous in the case of use with printed circuits.

Finally, it is possible, without previous adjustment and using pre-loaded carriers, to load the magazine with plates of varying shapes and thicknesses, according to manufacturing requirements, a fact which virtually obviates the need for any intervention by qualified staff and for breaks in production.

Claims (7)

1. A device for the continuous and automatic feeding of a continuous process machine with rigid or flexible plates, which plates are unpierced at least at one edge and arranged in one or more piles, said device comprising a movable gripping member, designed so as to apply itself to an edge of that plate situated on the top of the pile, and lifting means associated with said gripping member, said lifting means being operable to lift the plate held by the gripping member in order to separate it from the next plate, then to carry the plate between two feed-rollers, these being arranged so as to cause the plate to tip up when it is released by said gripping member in order to bring the plate into an approximately horizontal position, from which it may be carried to a conveyor for feeding to the continuous process machine without the plate rubbing against the remaining plates in the pile.

2. A device according to claim 1 wherein said movable gripping member consists of a series of suckers fixed along a support beam in parallel with the edge of the plate to be gripped, said support beam being actuated by a jacking system in order to take hold of the edge of the plate with the aid of said suckers, to lift it and finally to carry it to said feedrollers.

3. A device according to either one of claims 1 or 2 wherein the feed-rollers comprise one or more lower, drive rollers, driven rotationally at variable speed, and one or more upper rollers designed so as to iet the gripping member suckers pass when said member is delivering the plates.

4. A device according to claim 3 wherein the upper rollers are mounted on a frame linked to a main frame, a jacking system allowing said rollers to tilt in order to grip a plate with the aid of the lower rollers, the respective axes of the lower and upper rollers then being staggered so as to cause the gripped plate to be lifted to a horizontal position.

5. A device according to any one of the preceding claims wherein the piles of plates are positioned on a lifting table which forms a magazine and is driven automatically in order to hold the upper plate at a permanently constant level, this level being detected by a photoelectric cell which controls the driving means of said lifting table.

6. A device according to claim 5 wherein said lifting table is equipped with arms allowing the positioning of a carrier pre-loaded with plates to be handled.

7. A device for the continuous and automatic feeding of a continuous process machine substantially as hereinbefore described with reference to the accompanying drawings.