GB2174932A - Automated manipulator for electrical components - Google Patents

Abstract

The manipulator for mounting components on a printed circuit board has a table (11) for supporting the board, a gripper (10) for placing components at different, prearranged positions on the board and a bending device (13) engageable with component lead wires protruding from the underside of the board to bend the wires over towards the underside to retain the components in their respective positions. The table moves with respect to the bending device to effect bending. The bending device can be reconfigured and has a number of wire engaging pins mounted detachably on a support in accordance with a selected one of a number of different wiring patterns. <IMAGE>

Description

SPECIFICATION Improvements relating to an automated manipulator This invention relates to an automated manipulator and it relates particularly to an automated manipulator suitable for performing an assembly task particularly the assembly of printed circuit boards.

The assembly of a printed circuit board involves placing electrical components at selected positions on the board so that the lead wires protrude from the underside of the board. It is necessary that the components be retained in position prior to soldering and commonly this is achieved by bending the wires over towards the underside using some form of clench mechanism.

According to one aspect of the present invention there is provided an automated manipulator suitable for mounting electrical components on a printed circuit board, the manipulator including a table for supporting a printed circuit board, a gripper arranged to place components on the board at preselected positions thereon so that the lead wires of the components protrude from the underside of the board and means engageable with the protruding wires to bend the wires over towards said underside to retain the components in position on the board, the table supporting the printed circuit board being displaceable with respect to the bending means thereby to effect said bending.

An arrangement of this kind wherein the table is displaceable with respect to the bending means has the advantage that a bending means of relatively simple construction can be employed and, in particular, the bending means does not necessarily require a separate drive mechanism.

In accordance with another aspect of the invention a reconfigurable bending means is used. This may comprise a body member, for example a plate, mounting detachably a plurality of wire engaging elements at different selectable positions thereon in accordance with a desired pattern. With this arrangementthe bending means may be reconfigured readily to be compatible with different layouts of printed circuit board. In one example, the body member comprises a plate formed with a matrix of holes. The wire engaging elements may be in the form of pins which are mounted detachably in selected ones of the holes in accordance with the desired pattern.

In one form, the plate may comprise a first part slideable with respect to a second part thereby to hold the pins securely in their respective holes.

In order that the invention may be carried readily into effect examples only thereof are now described by reference to the accompanying drawings of which, Figure 1 shows a perspective view of an automated manipulator useful for assembling printed circuit boards, and Figures 2a and 2b show sectional views through a device for bending lead wires.

Referring initially to Figure 1 an automated manipulator comprises a gripper 10 arranged to move relative to a table 11 which supports a printed circuit board 12 for assembly. The gripper is conditioned to place components at different, prearranged positions on the board in accordance with a desired circuit layout. The component lead wires protrude from the underside of the board and a mechanism, hereinafter referred to as clench mechanism, shown generally at 13 below the board, is arranged to bend over the protruding lead wires towards the underside thereby to retain the components in position prior to soldering.

The inventors have found that a convenient and cost effective arrangement is produced if the table is capable of displacement relative to the clench mechanism which remains in a fixed position.

In this example the table can be displaced in the x and y axis directions so that every part of the printed circuit board can pass above the mechanism 13. This arrangement has the dual advantage that the clench mechanism 13 need not necessarily have a separate drive and that the number of degrees of freedom (and so drives) associated with the gripper arm itself may be reduced. In the shown example, the gripper arm can undergo a translation in they axis direction on a carriage 14 and both a translation on, and rotation about, the z axis direction.

A clench mechanism commonly used hitherto consists of a flat metal plate carrying a number of porjections which engage with protruding lead wires, causing them to bend, when the plate moves about relative to the printed circuit board.

The inventors have now devised a clench mechanism which can be reconfigured readily to be compatible with the different patterns of lead wire which arise with different circuit board layouts. A reconfigurable clench mechanism is found to be particularly well suited to an automated assembly system wherein the gripper arm may be pre-programmed to assemble a number of differently configured circuits.

In one arrangement the clench mechanism has a modular construction consisting of a flat base plate having a matrix of locating features for mounting detachably individual wire engaging elements. The locating features may typically been provided with a suitable quick-release locking devices to facilitate a rapid reconfiguration of the mechanism, the wire engaging elements being located in selected ones of the features in accordance with a desired pattern, corresponding to a respective circuit layout.

Typically the mechanism would be reconfigured between different batches of circuit board. The wire engaging elements may be stacked in a suitable store positioned close to the manipulator workstation or alternatively placed by the gripper arm on a pallet which can be transported to and from the workstation on the same conveyor, shown at 15 in Figure 1, as is used to transport the printed circuit boards.

In another arrangement the base of the clench mechanism is provided with a matrix of holes and pins may be positioned in selected ones of the holes in accordance with a desired pattern. As shown in Figure 2 the base plate 20 of the mechanism is in three parts 21, 22, 23 of which the central part 22 can slide with respect to the two outer parts 21, 23 as indicated by the arrow S.

One of the holes is shown at 24 and a pin 25 is held securely in position by displacing the central part 22 sideways as shown in Figure 2b thereby to press the pin hard against the wall portions of the hole formed in the outer parts 21, 23. Clearly this system could be used to mount different forms of wire engaging element. It will be appreciated that the gripper itself can be used to load the wire engaging elements rapidly onto the base plate; moreover the arrangement provides a quick-release system for securing all the wire engaging elements simultaneously.

Claims (11)

1. A automated manipulator suitable for mounting electrical components on a printed circuit board, the manipulator including a table for supporting a printed circuit board, a gripper arranged to place components on the board at preselected positions thereon so that the lead wires of the components protrude from the underside of the board and a bending device engageable with the protruding lead wires to bend the wires over towards said underside of the board to retain the components in position on the board, the table supporting the printed circuit board being displaceable with respect to the bending means to effect said bending.

2. A manipulator according to Claim 1 wherein said bending device comprises a number of wireengaging elements mounted detachably on a support in accordance with a desired wiring pattern.

3. A manipulator according to Claim 2 wherein said wire-engaging elements are mounted detachably on the support in accordance with a selected one of a number of different wiring patterns.

4. A manipulator according to Claim 2 or Claim 3 wherein said bending device comprises an assembly of substantially parallel plates, holes are provided in the assembly to locate said wire engaging elements in respective positions in the assembly and one of the plates is displaceable slidably with respect to the other plates to retain the wire engaging elements firmly, but releasably, in their respective positions.

5. A manipulator according to Claim 4 wherein said assembly comprises a first plate, a second plate and a third plate which is positioned between, and displaceable slidably with respect to, the first and second plates; the first and second plates have respective, coaxially aligned holes and recesses and the third plate is provided with further holes which can be aligned, by displacement of the third plate, with the holes and recesses in the first and second plates to allow wire engaging elements to be mounted in, or removed from, the assembly.

6. In an automated manipulator suitable for mounting electrical components on a printed circuit board a bending device engagable with component lead wires, protruding from the underside of the board, to bend the wires over towards said underside to retain the components in position on the board, wherein the bending device has a number of wire-engaging elements mounted detachably on a support in accordance with a desired wiring pattern.

7. A bending device according to Claim 6 wherein said wire-engaging elements are mounted detach- ably on the support in accordance with a selected one of a number of different wiring patterns.

8. A bending device according to Claim 6 or Claim 7 comprising an assembly of substantially parallel plates, holes being provided in the assembly to locate said wire-engaging elements in respective positions in the assembly and one of the plates being displaceable slidably with respect to the other plates to retain the wire-engaging elements firmly, but releasably, in their respective positions.

9. A bending device according to Claim 6 wherein said assembly comprises a first plate, a second plate and a third plate which is positioned between, and displaceable slidablywith respect to, the first and second plates; the first and second plates have respective coaxially aligned holes and recesses and the third plate is provided with further holes which can be aligned, by displacement of the third plate, with the holes and recesses in the first and second plates to allow wire engaging elements to be mounted in, or removed from, the assembly.

10. An automated manipulator suitable for mounting electrical components on a printed circuit board substantially as herein described by reference to the accompanying drawings.

11. A bending device substantially as herein described by reference to the accompanying drawings.