GB2055322A

GB2055322A - Improvements in or relating to tools for removing circuit elements

Info

Publication number: GB2055322A
Application number: GB7925670A
Authority: GB
Original assignee: Fujitsu Services Ltd
Current assignee: Fujitsu Services Ltd
Priority date: 1979-07-24
Filing date: 1979-07-24
Publication date: 1981-03-04
Also published as: DE8016702U1; GB2055322B

Abstract

A tool for removing circuit elements particularly DILICS, from a support, comprising a first U- shaped member (1) having a pair of substantially parallel legs (2) connected together at their upper ends. The lower ends of the legs (2) form abutments to engage the support (12) and a second U-shaped member (3), also having a pair of parallel legs (4) is slidable within the first member and has facing projections (9) at the free ends of its legs, to engage the ends of the DILIC. Thus when the upper ends of the members are squeezed together against the force of spring (6), the DILIC is pulled out of the support. <IMAGE>

Description

SPECIFICATION Improvements in or relating to tools for removing circuit elements INTRODUCTION This invention relates to tools for removing circuit elements from supports on which they are mounted. The invention is particularly, but not exclusively, concerned with removing dual-in-line integrated circuit packages (DIL ICS) from printed circuit boards.

The object of the invention is to provide such a tool which is simple in construction and easy to operate.

SUMMARY OF THE INVENTION According to the invention there is provided a tool for removing circuit elements from a support, comprising a first member having two substantially parallel legs connected together at their upper ends, a second member also having two substantially parallel legs connected together at their upper ends and arranged to slide up and down within the first member, the tool being such that, in use, it can be positioned over the circuit element to be removed with the legs of the first member abutting the support and with projections at the lower ends of the legs of the second member engaging opposite ends of the element, whereupon a force can be applied between the members so as to pull the second member upwards away from the support while keeping the first member in abutment with the support, thereby applying an upward force to the element for removing it from the support.

It will be appreciated that the words "up per", "lower" and so on, as used in this specification, are not intended to simply any fixed orientation for the tool, but are merely intended as relative terms. The tool can, of course, equally well be used for withdrawing circuit elements horizontally or vertically downwards, depending on the position of the support on which they are mounted.

Preferably, each of the members is formed from a strip of metal bent into a general Ushape.

BRIEF DESCRIPTION OF DRAWINGS One tool in accordance with the invention will now be described by way of example with reference to the accompanying drawings of which Figs. 1 and 2 are respectively front and side elevations of the tool.

DESCRIPTION OF THE EMBODIMENT Referring to Figs. 1 and 2, the tool comprises a first generally U-shaped member 1 having parallel legs 2, and a second generally U-shaped member 3 having parallel legs 4.

Each member is preferably formed by bending a suitably pre-shaped strip of metal. The second member 3 can slide up and down within the first member, and is retained in position by tabs 5, integral with the legs 4, these tabs being bent around the legs 2.

The second member 3 is biassed downwards with respect to the first member by means of a spring 6 located between the upper ends of the two members. The first member 1 has a pair of elongated slots 7 in its legs 2, and the second member 3 carries a pair of stops 8 positioned within the slots, these stops serving to limit the downward travel of the second member. The stops 8 also contribute to the mechanical stability of the member 3 sliding within member 1. The bottom end of each leg 4 is bent over to form a projection 9 and a further pair of projections 16.

In Fig. 1, the tool is shown in position for extracting a DILIC 10 from a socket 11 which is in turn mounted on a printed circuit board 12. The socket 11 has a pair of recesses 13, one at either end, which allows the projections 9 on the second member 3 to engage the underside of the DILIC 10. The position of the stop 8 is chosen so that the projections 9 are aligned with these recesses when the ends of the legs 2 of the first member are abutting the printed circuit board. Also, in this position, the further projections 16 engage the upper surface of the DILIC 10.

The DILIC can be extracted from the socket 11 by squeezing the upper ends of the two members 1, 3 together between fingers and thumb. This causes the second member 3 to be pulled upwards, against the spring pressure, while keeping the ends of the legs 2 firmly in abutment with the printed circuit board. Because the ends of the legs 2 remain in abutment, and because the projections 9 move simultaneously, the extracting force is always substantially perpendicular to the surface of the circuit board. Moreover, the further projections 16 restrain the DILIC from tilting. This prevents the pins of the DILIC from being bent as it is extracted from the socket.

It will be appreciated that to place the tool in the position shown in Fig. 1, the ends of the legs 2, 4 must be splayed apart slightly to allow the projections 9 to be hooked over the ends of the DILIC 10. It can be seen that only a very small clearance is necessary between the DILIC 10 and any adjacent component.

For example, Fig. 1 shows another DILIC 14 positioned on the printed circuit board 12 and separated from the first DILIC 10 by a small gap, which is nevertheless wide enough to allow the tool to be correctly positioned.

The tool can also be used for removing DILIC's which are mounted directly on printed circuit boards, without any socket. In this case the stop 8 is removed and positioned instead in a hole 15 in the leg 4, above its original position. This allows the second member 3 to travel further downwards before it is arrested by the stop, to a position in which the projections 9 touch the surface of the circuit board and can therefore hook under the DILIC.

In a modification of the tool described above, the stops 8 may be fixed permanently in the holes 15. In this case, adjustment of the travel of the member 3 is achieved by means of a pair of bent wire stops (not shown) mounted on the outside of the legs 2.

When the tool is to be used for removing socket-mounted DILICs, these bent wire stops are hooked over the stops 8 so as to limit the downward travel of the member 3 to the position shown in the drawing. When the tool is to be used for removing DlLICs mounted directly on the printed circuit board, these bent wire stops are swung aside so as to allow the stops 8 to travel down to the lower ends of the slots 7.

Claims

1. A tool for removing circuit elements from a support comprising a first member having a pair of substantially parallel legs whose free ends form abutments to engage the support, and a second member which is slidably guided with respect to the first member in a direction parallel to the legs and also has a pair of substantially parallel legs whose free ends have facing projections to engage the circuit element.

2. A tool according to claim 1 in which the free ends of the legs of the second member are turned inwardly to form the projections.

3. A tool according to claim 1 or claim 2 in which each member comprises a flat strip formed into a U-shape.

4. A tool according to claim 3 in which the said strips are of substantially equal width and are held in alignment by means of tabs extending from the edges of each leg of one member and engaging the edges of the corresponding leg of the other member.

5. A tool according to any preceding claim in which the second member is resiliently biassed towards the free ends of the legs of the first member by means of a spring engaged between the members.

6. A tool according to claim 4 or claim 5 further comprising a guide pin which protrudes from the surface of each leg of one member and cooperates with an elongate slot in the corresponding leg of the other member.

7. A tool according to any of claims 2 to 6 further comprising an additional inward projection on each leg of the second member, which projection is spaced from the free end and cooperates with the first said projection in engaging the circuit element.

8. A tool substantially as herein described with reference to the accompanying drawings.