IES970498A2 - Improvements in and relating to transport of electronic circuits - Google Patents

Abstract

A container (1) for transport of electronic circuits has a frame with a base (2), top structure and back stops (4) extending between end frames (10). The opposed end frames (10) support a front clamp bar (11) and top clamp bar (12). Circuit boards are placed in grooved receivers mounted on the base (2) and top structure and are secured between a back stop (4) and the front clamp bar (11). A top of each circuit board is engaged by the top clamp bar which restricts vertical movement of the printed circuit board. <Fig. 1>

Description

Improvements in and relating to transport of electronic circuits The invention relates to the transport of electronic circuits .

At present, electronic circuits such as printed circuit 5 boards are stored and transported in a disposable static dissipative envelope. This is usually surrounded by a shock-absorbing casing such as static foam encased in one or more outer cases of cardboard or similar material.

Needless to say, this arrangement leads to a large degree 10 of handling of the circuits and use of a large amount of packaging material. This can cause a proportion of the circuits to be damaged, either physically or electrically by static charge build-up. Further, the materials required are expensive, as is the labour for materials 15 handling. Also the packing materials are typically discarded after use promoting wastage and disposal problems .

The invention is therefore directed towards providing a 20 method and apparatus for storage and transport of electronic circuits to overcome these problems.

Statements of Invention According to the invention, there is provided a method of transporting electronic circuits comprising the steps of :placing the circuits directly in containers having means for supporting the circuits, and - 2 IE 970498 said containers being mounted on or forming part of a trolley for storage or transport.

Preferably, the circuits are placed in the containers at the final stage of production. This minimises circuit handling. The container may be adjustable or fixed.

In one embodiment, the container comprises an outer frame which clamps the circuits in position.

In one embodiment, the containers are separated from each other and the walls of the trolley by a shock absorbing material, which is ideally static dissipative.

Preferably, the circuits are clamped by clamp arms which rotate about a pivot to accommodate different sized circuits for effective clamping. There may be more than one clamping arm, at least one for each degree of freedom. Preferably, the circuits are also secured in position on a base frame of the trolley, such as by use of apertures and engaging pegs. The circuits may be placed on racks which fit into the containers.

According to another aspect, the invention provides a container for transport of electronic circuits, the container comprising a frame, means for supporting one or more circuits on the frame, and means for releasably retaining each circuit in situ to prevent movement of the or each circuit on the frame. Preferably the retaining means is a clamping means for clamping each circuit on the frame.

In one embodiment, the framework comprises base members having apertures or other means for securing circuit trays or racks in place. Preferably, the clamping means IE 970498 - 3 comprises one or more clamping arms which rotate about an axis to engage the containers and press them down against the base. For example, there may be a front clamp bar and a top clamp bar which rotate to prevent sideward and upward movement of the circuits during transport.

Preferably, the surfaces of the container are coated with a shock absorbing material which is preferably static dissipative.

The invention also provides a circuit storage and transport assembly comprising containers as described above and a trolley which supports the containers.

Detailed Description of the Invention The invention will be more clearly understood from the following description of some embodiments thereof, given by way of example only, with reference to the accompanying drawings in which :Fig. 1 is a perspective view from above of a container of the invention; Figs. 2 and 3 are detail diagrammatic end elevational views illustrating the manner in which a clamp bar is used to clamp circuits on the container; Fig. 4 is a detail perspective view showing one end of the container; and Fig. 5 is a detail perspective view illustrating the clamping of a circuit on the container.

The invention provides a method and apparatus for storage and transport of electronic circuits. An important aspect IE 970498 - 4 is that the circuits are placed immediately after the final production stage into a container and from that point to their final destination, they are not handled individually. Circuits are placed into grooved receivers in a rack structure. This structure prevents movement of individual circuits by means of clamp mechanisms to restrain movements in the planes not covered by the grooved slots.

When the rack is filled, it is placed on a container such as that as shown in Fig. 1. The container 1 comprises a base 2 having a number of spaced-apart inverted channelshaped steel members which have perforations 3. In addition, the container 1 has longitudinal structural members forming back stops 4 extending parallel to the base members 2. A top structure 5 similar to the base 2 is also provided; this is omitted for clarity from Fig. 1 but can be seen in Figs. 4 and 5.

The container 1 also comprises generally rectangular end frames 10. The opposed end frames 10 support a front clamp bar 11 and a top clamp bar 12 (Figs. 4 and 5) each of which extends between and is pivotally carried on the end frames 10. Pivot arms 13 carry the front clamp bar 11 and are pivotally connected to the associated end frames 10 by pivot pins 17 and movement is controlled by a linkage 14 comprising a bottom link arm 15 and a top link arm 16. An outer end of each pivot arm 13 has a hook 20 for engagement with an eye 21 on a rotatable support 22 connected to each end frame 10 by pivot pin 23.

The top clamp bar 12 is carried on a pivot shaft 27 connected between top link arms 16 on the end frames 10.

The circuit boards 26 are placed in grooved receivers 24 (Fig. 5) mounted on the base members 2 and top 5 and are IE 970498 - 5 secured between a back stop 4 and the front clamp bar 11. A top of each circuit 26 is engaged by the top clamp bar 12 which causes an upper grooved receiver 24 to depress and restrict the vertical movement of the printed circuit board 26.

Once in place, the racks are secured in position by rotating the two pivot arms 13 downwardly so that the top clamp bars and the front and rear clamp bars move into position to press against the circuits 26 and hold them in position. Each of the pivot arms 13 is connected through the linkage 14 with the top clamp bar 12.

All parts of the container 1 which contact the circuits 26 are lined or coated with a shock absorbing material such as foam which is static dissipative. The manner in which the clamp bars are moved into position is shown in Figs. 2 and 3 whereby the pivot arm 13 moves from an upper inoperative position held in place by a clip 25 to a lower operative position at which the clamp bars press against the cages. The pivot arm 13 is pulled downwardly by a chain connecting the hook 20 to the eye 21. The eye 21 is pulled downwardly by the toggle movement of the arm 22 pivoting about the pivot pin 23.

Once a suitable number of containers have been filled on a trolley (not shown) such a trolley may be easily moved onto a truck. The invention therefore finds particularly beneficial application for transport of circuits from a circuit manufacturer to an end user such as a computer manufacturer. There would be greatly reduced material costs because packaging is not needed. This latter feature also results in a much reduced labour requirement for materials handling, in turn resulting in a lower circuit defect rate.

IE 970498 - 6 The invention is not limited to the embodiments described. For example, the container may be of any suitable configuration whereby it securely holds circuits in place without them moving relative to each other or relative to the trolley. For example, the clamp bars may be individually pivoted.

It will be noted that each of the back stops 4 is slibably adjustable on the end frames 10 to allow adjustment for accommodation of circuit boards of different size.

It will be appreciated that the invention provides a method and apparatus for storing and transporting printed circuit boards which are sensitive to mechanical shock and static charges without the use of packaging material. The invention provides for the secure clamping of printed circuited boards without distortion of the printed circuit boards to facilitate safe transport. Essentially a number of the circuit boards are clamped in a cage arrangement for transport. A number of the cages which may be single or double sided can be contained within an enclosure which ideally has sealed doors. The cages may be positioned horizontally or vertically within the enclosure. The cages are separated from each other and the walls of the enclosure by a shock absorbing material which is ideally static dissipative. All faces of the cages and interior of the enclosure are surface treated or lined to ensure a static dissipative surface.

In the embodiment described the printed circuit boards are held in static dissipative slides or receivers which are mounted on perforated steel sections, the slides or receivers having spigots which engage the perforations in the steel section. Alternatively the channels could be machined in a static dissipative material or any other material which is surface treated to achieve a static IE 970498 dissipative effect. It will be appreciated that the boards are restrained at the back by a stop bar with a static dissipative foam or similar material. This stops rear movement without damage to the board. Alternatively, the circuit boards could be restrained by individual stop mechanisms .

Forward movement of the board is stopped by the front clamp bar which in this case is pivoted. Alternatively the front clamp bar could be a removable device as long as it functions to prevent the forward movement. The clamp bar is lined with a static dissipative foam or similar surface treated material.

Vertical movement of the board is restrained by the cam like movement of the top clamp bar which is causes the top board guide to depress by a distance sufficient to eliminate clearance. In this case the movement of the top bar is caused by a linkage connected to the front clamp mechanism. Alternatively, the top clamping mechanism could be operated independently. Further protection to the circuit boards may be achieved by installing shock monitoring devices such as impactometers and\or static monitoring devices.

Claims (6)

1. IE 970498 CLAIMS

1. A method of transporting electronic circuits comprising the steps of :placing the circuits directly in containers having means for supporting the circuits, and said containers being mounted on or forming part of a trolley for storage or transport.

2. A method as claimed in claim 1, wherein the container comprises an outer frame which clamps the circuits in position, and preferably the containers are separated from each other and the walls of the trolley by a shock absorbing material, which is ideally static dissipative, preferably the circuits are clamped by clamp arms which rotate about a pivot to accommodate different sized circuits for effective clamping, preferably the circuits are also secured in position on a base frame of the trolley, such as by use of apertures and engaging pegs.

3. A method of transporting electronic circuits substantially as hereinbefore described with reference to the accompanying drawings.

4. A container for transport of electronic circuits, the container comprising a frame, means for supporting one or more circuits on the frame, and means for releasably retaining each circuit in situ to prevent movement of the or each circuit on the frame.

5. A container for transport of electronic circuits substantially as hereinbefore described with reference to the accompanying drawings. IE 970498 - 9 ABSTRACT Improvements in and relating to transport of electronic circuits (Fig. n 5 A container (1) for transport of electronic circuits has a frame with a base (2), top structure and back stops (4) extending between end frames (10). The opposed end frames (10) support a front clamp bar (11) and top clamp bar (12). Circuit boards are placed in grooved receivers

6. 10 mounted on the base (2) and top structure and are secured between a back stop (4) and the front clamp bar (11). A top of each circuit board is engaged by the top clamp bar which restricts vertical movement of the printed circuit board .