GB2188195A - Mounting means for an electrical assembly - Google Patents

Abstract

The mounting means includes a housing (10) into which an assembly (30) may be inserted in a first direction (31). The housing (10) carries an electric connector (14) which is arranged to engage with a connector (33) carried by the assembly (30) when the assembly is moved in a direction perpendicular to the first direction. Guide means (18) carried by the housing (10) are arranged to engage the assembly (30) and actuating means (16, 17, 19) are provided to provide the necessary movement of the assembly to effect engagement between the two connectors (14, 33). <IMAGE>

Description

SPECIFICATION Mounting means for electrical assembly Electrical assemblies, which may include printed circuit boards or other forms of component-carrying structure, are commonly made so asto be contained in a housing, generally containing a number of such assemblies, but readily removable therefrom. This requires the provision of electric connectors having two mating parts, one being carried on the assembly and the other on the housing. It is common for such connectors to have multiple separate electrical contacts, numbers upto several hundred being common. Oneformofelectricconnectorcommonly used istheso-called edge connector, in which contacts are arranged in two parallel rows, though other forms of connector may be used.A problem which has been known for a considerable time is that considerable mechanical force is necessaryto engage or disengage the mating parts of such connectors. Byway of example, an insertion force of 100gums or more per contact is necessary with a conventional edge connector, giving a total insertion force of, say, 30kg ms for a 300-contact connector.

This problem has been overcome by using what have been called "zero insertion force" connectors.

In these the contacts in one part of the connector are moved before the other part is inserted so that the contacts do not provide any resistance to the insertion. When the two parts of the contact are mated then the contacts are released to effect the electrical connection. Such an arrangement has a number of disadvantages. One is the essentially complex construction necessary to produce the movement of the contacts. Another is that it prevents one ofthe essential actions of an edge connector, that of contact wiping during mating to clean the contact surfaces.

It is also known, as an alternative, simply to use some means which force the two mating parts of the connector together. British Patent No. 1,093,491 illustrates one technique of doing this, involving a number of levers. Other common arrangements use screws or threaded rods which produce the engagement and also secure the assembly into the housing. Such arrangements require the assembly to be inserted into the housing in the direction of engagement ofthe two parts ofthe connector. Whilst this is a common situation for rack-mounted equipment it meansthatthe assembly hasto be inserted in to the housing in the direction of engagement of the connector. This means that, in the majority of cases the connectors are fitted to a shorter side of the assembly, thus limiting the number of connections possible.

According to the present invention there is provided mounting means for an electrical assembly having a first multiple-contact electric connector carried on one edge thereof; the mounting means including a housing into which the assembly may be inserted in a first direction, a second electrical connectorcarried by the housing and arranged for engagement with the first electric connector carried in said assembly by relative movement between the housing and the assembly in a direction substantially perpendicularto said first direction, guide means carried by the housing and arranged to engage the assembly on the insertion of the assembly into the housing, and actuating means operable when the assembly is correctly inserted into the housing to effect said relative movement so asto produce engagement between said first and second electric connectors.

The invention will now be described with reference to the accompanying drawings, in which: Figure 1 is a schematic side view of mounting means according to a first embodiment ofthe invention; Figure2 is a sectional front view of part of Figure 1 along the line Il-Il; Figure 3 is a similarviewto Figure 1 showing an electrical assembly inserted into the housing; Figure 4 is a sectional front view of the mounting means and assembly of Figure 3 along the line IV-IV; Figure 5 is a sectional front view with the assembly in its operating position; Figure 6 is a view of part of a second embodiment; Figure 7illustrates a method of ensuring correct insertion of an assembly into the housing; Figure 8 illustrates a third embodiment of the invention; and Figures 9 and 10 illustrate alternative forms of actuating means.

Referring nowto Figure 1,thisshowsasectional side view of a housing 10 having an upper part 11 containing the actuating means and a base 12 from which extend short upwardly-directed ribs 13, as shown more clearly in Figure 2. Securedtothe bottom ofthe upper part 1 is first connector 1A which projects into the chamber 15 between the upper part 11 and base 12.

A recess in the upper part 11 contains the actuating meanswhich includes an actuating shaft 16 supported for rotation in the upper part 11 and carrying two cams 17. Each cam carries a guide member 18 extending into the cham ber 15 and having at its lower end a pair of inwardly-directed guide lugs 19. Rotation oftheshaft 16 and cams 17 from the position shown will raisethetwoguide members 18. A pivoted handle 19 is provided on the outer end ofshaft 16 as shown in Figure 1.

Figures 3 and 4 show similarviews ofthe mounting means but with an electrical assembly 30 in position in the housing. The assembly is a package of a size and shape which can be inserted into the chamber 1 5 from the front in the direction of the arrow 31 in Figure 3 between the two ribs 13. Aslot 32 is formed in each side of the assembly 30 nearthe top in such a positionthatthetwo inwardly-directed guide lugs 19 enter into the slots as the assembly is inserted into the chamber. The assembly 30 carries an electric connector 33 of a form which will engage the connector 14 carried by the housing when the assembly is correctly inserted into the chamber.

To engage the two connectors 14 and 33 the shaft 1 6 is rotated through 180" by the handle 19. This causes the guide members 18 to liftthe assembly 30 into the position shown in Figure 5 where the connectors are engaged. Disengagement of the two connectors is effected by a further 180 rotation of the shaft 16 such that the guide members 18 press the assembly 30 downwards. The assembly may then beremovedfromthechamberthroughthefront ofthe housing.

An alternative to forming the slots 32 in the assembly is to provide two pairs of pins projecting from each side of the assembly in positions which would enable them to be lifted by the guide members when the assembly is correctly positioned.

Figure 6 shows part only of such an arrangement, with pins 60 positioned so asto engagetheguide lugs 19. The latter could be formed so as to provide a seating for the pins 60. It will then be necessary to provide an additional pair of lugs 61 on the guide members 18 to disengage the connectors. An advantage of such an arrangement would be that the assembly cannot be lifted to matethetwo connectors unless it is fully inserted into the chamber. To ensure that the wrong module cannot be inserted into a particular position in the housing a system of keying pegs and holes could be provided.

Figure 7 shows part of such an arrangement in which a keying peg 70 carried on the rear ofthe housing and projecting into the chamber 15 is accepted into a hole 71 only when the assembly 30 has been inserted into its allocated position in the housing. Different assemblies could have the holes 71 in different positions to accept the keying pegs mounted on the housing in the appropriate positions. Other keying arrangements may also be used. The positions ofthe pegs 70 and apertures 71 may be reversed.

Another possible variation in the means of engagement between the actuating mechanism and the assembly is illustrated in Figure 8. Instead of the inwardly-directed guide lugs 19 of Figure 1 to 5, each guide member 18 now carries a peg 80 directed towards the front of the housing. The rearmost guide member 18 extends further into the chamber 15 than does the front guide member so that the assembly 30 can be inserted into the chamber. The assembly carries two apertures 81 arranged to receive the pegs 80 when the assembly has been fully inserted. As an alternative the pegs 80 may be carried on the assembly so as to engage with the guide members 18.

There will clearly be other ways of providing satisfactory engagement between the guide members and the assembly.

It is equally possible to use a range of actuating mechanisms in place of the rotating cam arrangement shown in Figures 1 to 5. One alternative, shown in Figure 9, uses a sliding actuating member having inclined faces to raise the guide members 18. Referring to Figure Sthe actuating member 90 is carried in the top 11 of the housing 10 and is able to slide backwards and forwards. Each ofthe guide members 18 has a pin 93 provided at its upper end which passes through an inclined slot 92 in the actuating member 90. Forward movementoftheactuating member 90, say by means of a pivoted handle 91, causes the pins 90 to rise in the slots 91, raising the two actuating members 18 and the assembly 30so that the two connectors engage.Disengagement is effected by moving the actuating member90towardstherearof the housing by raising the handle 93 from the position shown in broken outline.

Another actuating mechanism is shown in Figure 10. In this the actuating mechanism uses a th readed rod 100, rotatable by a handwheel 101. Two threaded portions on the rod 100 carry threaded nuts 102 which actuate pivoted bell-crank levers 103. These in turn actuatethe guide members 104. Rotation ofthe handwheel in one direction raises the guide members, whilst rotation in the opposite direction lowers them.

Any suitable combination of actuating mechanism arrangements may be used, with or without appropriate keying arrangements. As already stated, the advantage of the invention is that a large number of electrical contacts may be accommodated on the assembly and sufficient force may be exerted to effect satisfactory connection. More than two guide members may be used if necessary.

twill be apparent that the direction of engagement of the connectors need not be absolutely perpendicular to the direction of insertion of a module into the housing. Itwould be possible, forexample,totaperthetopsurfaceofthemodule sothatit istalleratthefrontthan atthe rear. Since the direction of engagement of the connectors must be essentially the direction in which the module is moved this latter direction would therefore not be perpendicularto the direction of insertion. Such an arrangement is, however, considered to be with in the scope ofthe invention.

The assembly may be a simple printed circuit board carrying components, or it may be a module of far more complex form. The module may comprise of more than one separate assembly. For example two printed circuit boards could be placed face-to-face, with components mounted on the outer faces, and inserted together as one into the housing.

Each board would have its own separate connector on the housing.

Arrangements may be provided to ensure that damage does not occur if contacts in the connector become bent, by limiting the force which the actuating mechanism may apply, such as by the provision of a slipping clutch 105 in the embodiment of Figure 10.

Aswith any housing containing a numberof electircal assemblies cooling air may be circulated between the assemblies to remove excess heat.

Figure 8 shows the provision of a fan 82 forthat purpose, circulating air in the direction of the arrow 83.

Claims (12)

1. Mounting means for an electrical assembly having a first multiple-contact electric connector carried on one edge thereof, the mounting means including a housing into which the assembly may be inserted in a first direction, a second electrical connectorcarried bythehousingandarrangedfor engagement with the first electric connector carried by said assembly by relative movement between the housing and the assembly in a direction substantially perpendicularto said first direction, guide means carried by the housing and arranged to engage the assembly on the insertion ofthe assembly into the housing, and actuating means operable when the assembly is correctly inserted into the housing to effect said relative movement so as to produce engagement between said first and second electric connector.

2. Mounting means as claimed in Claim 1 in which the guide means include pairs of inwardly-directed lugs arranged to engage in slots formed in the two sides of the electrical assembly.

3. Mounting means as claimed in Claim 1 in which the guide means include pairs of inwardly-directed lugs arranged to engage pegs projecting from the sides of the electrical assembly.

4. Mounting means as claimed in Claim 1 in which the guide means include pegs projecting in a direction opposite to the direction of insertion of the electrical assembly into the housing and arranged to engage in cooperating apertures in the electrical assembly.

5. Mounting means as claimed in any one of Claims 1 to 4 in which the actuating means includes at least one cam in engagementwiththeguide means and carried on a shaft rotatable to cause movement ofthe guide means in said perpendicular direction.

6. Mounting means as claimed in any one of Claims 1 to 4 in which the actuating means includes an actuating member movable in said first direction and having included surface which engage with said guide means.

7. Mounting means as claimed in any one of Claims 1 to 4 in which the actuating means comprise a rotatable rod having at least one threshold portion, a nut movable on the or each threaded portion, and a pivoted lever movable with said nut and engaging with the guide means, whereby rotation of the rod causes movement of the guide means in said perpendicular direction.

8. Mounting means as claimed in anyone of Claims 1 to 7 which includes keying means arranged to ensure correct insertion of an assembly into said housing.

9. Mounting means as claimed in any one of Claims 1 to 8 in which the actuating means includes meansforlimiting theforce applied to said first and second connectors in said perpendicular direction.

10. Mounting means as claimed in anyoneofthe preceding claims in which the electrical assembly comprises a printed circuit board.

11. Mounting means as claimed in anyone of Claims 1 to 10 which includes means for circulating cooling airthrough or around the or each electrical assembly carried in the housing.

12. Mounting means for an electrical assembly substantially as herein described with reference to the accompanying drawings.