GB2118370A

GB2118370A - Housing for cooling electrical equipment

Info

Publication number: GB2118370A
Application number: GB08232816A
Authority: GB
Inventors: Thomas Victor Mcdonald; Paul Francis Lannin; Graham John Baldwin
Original assignee: Smiths Group PLC
Current assignee: Smiths Group PLC
Priority date: 1982-03-31
Filing date: 1982-11-17
Publication date: 1983-10-26
Also published as: GB2118370B

Abstract

A housing for electrical equipment has its upper and lower faces 20 and 30 formed by two box-shape sections 100 and 200. Each section is made from two parallel metal plates 21 and 106, and 31 and 201 separated by metal extrusions 104, 105, 109 and 110, and 202, 203, 204 and 205 to which the plates are rivetted at their edges. The plates have venting apertures 22, 111, 206 and 31 that allow cooling air to flow through the sections 100 and 200, and through the housing. Side plates 51 and 61 are joined at their edges to the extrusions of respective box-like sections. The housing has two compartments which are screened from one another by a dividing wall 3. One compartment has rails by which electric circuit cards are mounted vertically in the compartment such that they can be readily removed through a front aperture 12 that is closed by a removable cover plate 13. <IMAGE>

Description

SPECIFICATION Electrical equipment housings and methods of manufacture This invention relates to housings for electrical equipment and to methods of manufacture of such housings.

The invention is more especially, but not exclusively, concerned with equipment housings for use in aircraft.

The primary function of electrical equipment housings is to provide environmental protection for the electronic components contained within it, the housing being as light and small as possible.

To ensure that electrical equipment made by different manufacturers can be interchanged, and that the aircraft can be designed and built without reference to the manufacturers of the electrical equipment, several standards exist to govern the size and interfaces of the equipment. An example of one such standard is ARINC 600. This standard details criteria such as modular increment in size (width) of housings, their length, height, hold down location, and position and type of electrical connections.

The standard also sets out the location and nature of the ventilation apertures, located on the top and bottom surfaces of the housings, by which cooling air passes through the enclosure. The provision of efficient cooling is often complicated by the fact that the heat-generating components may not be located directly in the flow path of the cooling medium.

Previous equipment housings have been expensive to make with the required degree of accuracy and mechanical strength. This is because, either the component parts have been different to make accurately or they have been expensive to assemble, requiring dedicated tools and jigs.

It is an object of the present invention to provide a housing and a method of manufacture of a housing that can be used substantially to alleviate the above-mentioned problems.

According to one aspect of the present invention, there is provided a housing for electrical equipment having a plurality of opposite faces forming the exterior of said housing, wherein at least two opposite faces of said housing are provided by box-like sections comprising: first and second plate members having venting apertures therein, and one or more spacer members extending intermediate said first and second plate members arranged to separate said plate members in a parallel relationship to one another, thereby to enable flow of cooling gas through said box-like sections and through said housing via said apertures.

The spacer members may be rod-shape extrusions of metal, and may be of U-shape in cross section.

The plate members may be rivetted to the spacer members, each box-like section including at least two spacer members arranged to extend along opposite edges of the plate members. Further faces may be provided by further plate members secured at opposite edges to said spacer members, to extend between said box-like sections. The housing may be arranged to contain a plurality of electrical circuit board members, opposed plate members of the box-like sections being provided with means mounting opposite edges of the electrical circuit board members with respective plate members such that cooling gas can flow between said electrical circuit board members.The housing may have an opening at one end thereof, and a removable cover member arranged to cover said opening, said housing including means slidably mounting electrical circuit board members at substantially right angles with the opening, such as to enable the board members to be inserted into and removed from the housing through the opening. The housing may include first and second compartments electrically screened from one another.

According to another aspect of the present invention there is provided a method of manufacture of a housing for electrical equipment comprising the steps of: forming two box-like sections by securing first and second parallel plate members to rod-shape members such that said rod-shape members extend intermediate and parallel to said plate members, positioning said box-like sections opposite and spaced from one another, securing edges of further plate members to edges of said box-like sections such that said further plate members extend between said box-like sections substantially at right angles thereto such as to support said box-like sections and form additional faces of said housing.

A housing and a method of manufacture of a housing according to the present invention, will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of the housing; Figure 2 is a view of the rear of the housing; Figure 3 is a view from below of the housing; Figure 4 is an exploded view showing the construction of the housing; Figures 5A to 5Cshow, in section, components from which the housing is made; Figure 6 is a sectional side elevation along the line VI of Figure 2; Figure 7 is a sectional front elevation along the line VII of Figure 6; and Figure 8 is a sectional plan view of the housing along the line VIII of Figure 7.

The general configuration of the housing will be described first with reference to Figures 1 to 4. The housing complies with ARINC 600-1 and, in this respect, has a height h of 7.64 inches and a depth d of 12.52 inches. The width w of the housing may take any one of the values laid down in the specification.

The housing has two compartments 1 and 2 that are separated from one another by a dividing wall 3 of sheet aluminium. The main compartment 1 is situated on the left hand side of the housing and is for mounting a number of electronic circuit cards 4. The side compartment 2 is for containing a power supply unit (not shown) that is electrically screened from the main compartment 1 by the wall 3.

The front face 10 of the housing is of rectangular shape and has an aperture 12 on its left side enabling access to the card compartment 1. The aperture 12 is substantially the same size as the compartment 1 so as to enable the cards 4 to be readily removed or replaced. The aperture 12 is normally closed by a cover plate 13 (Figure 4) that is screwed to the front face 10. To the rightofthe aperture 12,there is provided a handle 14 for use in carrying and removal of the housing from an equipment rack (not shown).

Two mounting fixtures 15 and 16 are located at the bottom edge of the front face 10 of the housing for locking it into a rack (not shown).

The top face 20 and under face 30 of the housing are similar, being provided by flat plates 21 and 31 respectively of aluminium alloy. The top and under faces 20 and 30 are both provided with a number of small circular holes 22 and 32 that are for venting purposes and that are arranged to match with the venting provided in the rack in which the housing is to be mounted. In this respect, the venting apertures 22 on the top face 20 are arranged in two rectangular areas 23 and 24 that extend substantially along the entire length (depth) of the housing, whereas the venting apertures 32 on the under face 30 are arranged in an area 33 of almost semicircular shape at the rear end of the housing.

The rear face 40 of the housing is shown in Figure 2 and has a rectangular aperture 41 of the same shape as the aperture 12 in the front face 10. The rear aperture 41 enables access to the rear of the card compartment 1 and is normally covered by a rear cover plate 42 that is screwed to the housing. The rear plate 42 itself has a narrow rectangular aperture 43 arranged vertically. The aperture 43 is shaped to retain a standard electrical connector 44 by which electrical connection of the cards 4 and power supply is made.

The left, side face 50 of the housing is formed by an uninterrupted plate 51 of aluminium alloy that is rivetted in position. The right, side face 60 has a similar cover plate 61 that is held to the housing by screws so as to enable ready access to the underlying power supply compartment 2.

The internal construction of the housing will now be described in detail with reference to Figures 4 to 8. The major part of the housing is constructed from flat sheet aluminium alloy and from extruded struts or rod-like members. The struts are of three different sections A, B and C as shown in Figures 5A, 5B and 5C. Strut A being of L-shape section with arms of equal length; Strut B being of U-shape section; and Strut C being similar to Strut B but with a bevelled lip C' extending along the length of one outer edge, the purpose of which will become evident later.

Referring more particularly now to Figures 4,6 and 7, the housing has two box sections 100 and 200 which provide respectively the top face 20 and under face 30 of the housing. The construction of the two box sections is similar. The upper section 100 includes the flat top plate 21 that is rivetted along its edges 102 and 103 to the upper arm of respective horizontal struts 104 and 105 of the U-shape construction shown in Figure 5C, the lip C' on the strut providing a rounded edge along the top of the section. The upper section 100 also has a parallel lower plate 106 that is rivetted along its edges 107 and 108 to the lower arms of the same struts 104 and 105. The front and rear edges of both plates 21 and 106 are similarly rivetted to front and rear struts 109 and 110 of U-shape section, such as shown in Figure 5B. This forms an enclosed box section of rigid construction.The lower plate 106 is provided with venting apertures 111 arranged to enable air to flow through the box-like section 100. The venting apertures 111 in the lower plate 106 can be located anywhere over the surface and preferably are positioned close to the region of the card compartment 1 where maximum cooling is required.

The lower box section 200 is of similar construction to the upper box section 100, comprising an upper plate 201 and the under plate 31 separated from one another by struts 202 to 203 extending horizontally between the two plates at their edges.

The side struts 202 and 203 are of the kind shown in Figure 5C and are arranged such that the lip C' runs along the lower edges of the box section to provide a rounded edge to the housing and assist location of the left and right side plates 51 and 61. The strut 204 at the front edge is of the U-shape shown in Figure 5B, whilst the strut 205 at the back edge is of the kind shown in Figure 5C, being arranged with its lip C' extending along the bottom edge.The under plate 31, as mentioned above, is provided with the venting apertures 32 towards its rear end whereas the upper plate 201 has apertures 206 located towards the forward end of the section 200, in the region of the cards The upper and lower sections 100 and 200 both carry two horizontal mounting struts 100 and 121, and 220 and 221 respectively which serve for mounting two members vertically within the housing. The struts 120 and 220, which are of L-shape section shown in Figure 5A, extend along the length of the lower surface of the upper section 100 and the upper surface of the lower section 200 respectively.

The struts 120 and 220 are both spaced inwardly from the right hand edge of the housing by about one third of its width, the wall 3 of the power supply compartment 2 being rivetted at its top and bottom edges to these two struts. This also serves to support two vertical struts 37 and 38, of L-shape section that are rivetted to the front and rear edges of the wall 3.

The other struts 121 and 221 are also of L-shape section and extend across the width of the housing from the power supply compartment wall 3 to the left hand edge of the housing. These two lateral struts 121 and 221 serve to support a vertical array of electrical sockets (not shown) with which the cards 4 make electrical contact.

The left face of the housing is formed by a panel 25 comprising the plate 51 to which are rivetted two vertical struts 52 and 53 of L-shape section (as shown in Figure 5A) at the front and rear edges. The left side panel 25 is itself rivetted along its top and bottom edges respectively to the left strut 104 of the top box section 100 and the left strut 202 of the bottom box section 200.

The right edges of the upper and lower box sections 100 and 200 are rivetted to the upper and lower edges of a right side member 400. The member 400 is in the form of a cut-away plate 401 to which are rivetted two upright struts 402 and 403 of L-shape cross section. The plate 401 has a large central aperture 404, rectangular in shape which enables access to the power supply compartment 2.

In use this plate 401 is closed by the right side cover plate 61 that is held with the housing by scrows 406.

The rear face 40 of the housing is formed by a rear frame panel 45 which extends across the rear of the housing. The frame panel 45 is rivetted along its upper edge to the strut 110 of the upper box section 100, along its lower edge to the strut 205 of the lower box section 200, along its vertical edges to the struts 403 and 53 respectively, and also to the rear yertical strut 38 mounted with the wall 3. The frame panel 45 defines the rear aperture 41 through which access to the rear of the card compartment 1 is made. The rear cover plate 42 is secured to the frame panel 45 by screws the frame panel 45 also serving to support a rear fascia panel 47 of rectangular shape that i,s rivetted to the frame panel 45 to the left of the removable cover plate 42.

The front face 10 of the housing is of similar construction to the rear face 40. In this respect it has a front frame panel 70 of rectangular shape defining the front aperture 12. The front frame panel 70 is rivetted along its edges, to the horizontal struts 109 and 204, and the vertical struts 52 and 402. The panel 60 is also rivetted along a vertical line, to the right of the aperture 12, to the front vertical strut 37 secured to the power supply compartment wall 3. The front cover plate 13 is secured over the aperture 12, to the frame panel 70 by screws so that it can readily be removed. A rectangular fascia panel 71 is rivetted to the frame panel 70, to the right of the cover plate 13, the handle 14 extending through the fascia panel and frame panel and being bolted to the housing, within the power supply compartment 2.

Internally, the housing is arranged in accordance with the particular application to which it is to be put.

In the arrangement illustrated, the card compartment 1 is arranged for mounting the electronic circuit cards 4 vertically and to receive the cards from the front of the housing. For this purpose, longitudinal spring rails 80 are secured to the plates 201 and 106 respectively forming the floor and roof of the housing, the cards 4 being slid into the rails from the front, The assembly of the housing is carried out by first constructing the upper and lower box sections 100 and 200 by rivetting the plates 21, 106# 201 and 31 about their edges to the appropriate struts.The internal struts 120, 121, 220 and 221 are then rivetted to the autsides of the box sections 100 and 200, and the sections placed on a suitable jig that is arranged to space and align them correctly with respect to one another, The power supply compartment wall 3 is rivetted to the struts 120 and 220, following which the Outer left side panel 25 and the right side member 400 are rivetted to the edges of the two box sections 100 and 200.

After this, the rear frame panel 45 and the front frame panel 70 are rivetted in position to the upper and lower sections 100 and 200, and to the vertical struts 37,36, 52, 53, 402 and 403. The fascia panels 47 and 71 are then secured to the rear and front panels 45 and 70. The front, rear and side pover plates 13,42 and 61 can then be screwed into position.

It can be seen that the body of the housing is made entirely from flat sheet metal and straight extruded sections which are suitably cut to size. By avoiding the need for a cast frame or for any bending operations, the cost of producing a housing of accurate dimensions is significantly reduced. Housings of different sizes can be readily made from the same basic components simply by cutting them to different sizes.

Mounting the cards 4 vertically and longitudinally in the housing enables them to be readily replaced from the front, thereby avoiding the need to remove the housing from its mounting rack. Since cooling air is supplied to the top and bottom of the housing, the vertical orientation of the cards promotes flow of air through the housing.

The box-like sections 100 and 200 providing the top and bottom faces of the housing also aid efficient dissipation of heat from components within the housing. This is because the interior of the sections 100 and 200 can be used as ducts to direct cooling air from the exterior of the housing to those internal regions having the greatest dissipation of heat. This is accomplished simply by providing venting apertures on the internal surfaces in the desired locations. The sections 100 and 200 also have a further advantage in that any bolt, screw or rivet head, or other fixture used for mounting equipment within the housing can be contained on the inside of the box section, without the need for any projections on the outer surface of the housing.

Claims

1. A housing for electrical equipment having a plurality of opposite faces forming the exterior of said housing, wherein at least two opposite faces of said housing are provided by box-like sections comprising: first and second plate members having venting apertures therein, and one or more spacer members extending intermediate said first and second plate members arranged to separate said plate members in a parallel relationship to one another, thereby to enable flow of cooling gas through said box-like sections and through said housing via said apertures.

2. A housing according to Claim 1, wherein said spacer members are rod-shape extrusions of metal.

3. A housing according to Claim 1 or 2, wherein said spacer members are of U-shape in cross section.

4. A housing according to any one of the preceding claims, wherein said plate members are rivetted to said spacer members.

5. A housing according to any one of the preceding claims, wherein each said box-like section includes at least two spacer members arranged to extend along opposite edges of said plate members.

6. A housing according to Claim 5, wherein further faces are provided by further plate members secured at opposite edges to said spacer members, to extend between said box-like sections.

7, A housing according to any one of the preced ing claims, wherein said housing is arranged to contain a plurality of electrical circuit board members, and wherein opposed plate members of said box-like sections are provided with means mounting opposite edges of said electrical circuit board members with respective plate members such that coo Iing gas can flow between said electrical circuit board members.

8. A housing according to any one of the preceding claims, wherein said housing has an opening at one end thereof, and a removable cover member arranged to cover said opening and wherein said housing includes means slidably mounting electrical circuit board members at substantially right angles with said opening, such as to enable said board members to be inserted into and removed from said housing through said opening.

9. A housing according to any one of the preceding claims, including first and second compartments electrically screened from one another.

10. A housing for electrical equipment having a plurality of orthogonal faces some at least of which have venting apertures therein, wherein at least two opposite faces of said housing are provided by respective box-like sections comprising: first and second rectangular plate members having venting apertures therein, first and second rod-shape spacer members extending and secured intermediate said plate members along opposite edges of said plate members, wherein further faces of said housing are provided by rectangular plate members secured along opposite edges to said spacer members, to extend at right angles to said box-like sections, and wherein said housing includes means mounting electr c;; circuit board members with plate members of said box-like sections to extend between said box-like sections so as to be exposed to flow of cooling gas through said venting apertures.

11. A housing substantially as hereinbefore der scribed with reference to the accompanying drawings.

12. A method of manufacture of a housing for electrical equipment comprising the steps of: fonn- ing two box-like sections by securing first and second parallel plate members to rod-shape members such that said rod-shape members extend intermediate and parallel to said plate members, positioning said box-like sections opposite and spaced from one another, securing edges of further plate members to edges of said box-like sections such that said further plate members extend between said box-like sections substantially at right angles thereto such as to support said box-like sections and form additional faces of said housing.

13. A method substantially as hereinbefore described with reference to the accompanying drawings.