GB1567567A

GB1567567A - Electrical connecting means

Info

Publication number: GB1567567A
Application number: GB360877A
Authority: GB
Original assignee: Danfoss AS
Current assignee: Danfoss AS
Priority date: 1976-02-07
Filing date: 1977-01-28
Publication date: 1980-05-14
Also published as: DE2604764B2; DK143774B; FR2340635A1; DE2604764A1; DK47477A; DE2604764C3; DK143774C

Description

(54) IMPROVEMENTS IN AND RELATING TO AN ELECTRICAL CONNECTING MEANS (71) We, DANFOSS A/S., A Danish Company, DK-6430 Nordborg, Denmark, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be pardallarly described in and by rhe following statement: The invention relates to an electric connecting means for a motor compressor unit.

The present invention provides an electrical connecting means for a casing of a motor compressor unit, the casing having an electrical connector secured to it for providing electrical connection to its interior, wherein the comectg means comprises a support for securing to the casing adjacent to the connector, an electrical terminal carrier having a sheet metal member provided with an earth teRal, an electrical connector for electrical connection to the carrier and for pin and socket electrical connection to the connector on the casing and a screw for securing the carrier to the support so that an electrically conductive connection is provided between the support and the sheet metal member.

With this construction, it is not necessary to provide a special earth terminal on the support nor is it necessary to provide an electric lead between this terminal and the earth terntal on the carrier. Instead, the earth tenninal of the carrier is electrically conductively connected to the support by way of the sheet metal member of the carrier.

With the aid of the fixing screw, a secure electric contact can be established, for example by way of a screwthread cut in the support.

It has proved pay & uiarly favourable for the support to comprise an outwardly directted lug for receiving the fixing screw. When the surface of the sheet metal member is damped against the surface of the lug, adequate stability is obtained to enable the entire carrier to be applied with only one fixing screw.

In this connection it is recommended that the lug or the sheet metal member is provided with a screw-theaded hole for receiving the end of the screw, and the sheet metal member or the lug respectively is provided with an open-ended slot for receiving, laterally, the shank of the screw. The fixing screw can then be screwed into the support or the sheet metal member right from the start and pushed into rhe slot during final assembly. This permits rapid securing of the carrier.

It is a special advantage for that one of the lug or the sheet metal member provided with the slot to be obliquely flanged towards the screw head at the open end of the slot and the screw head partially to cover the flange when the sheet metal member is secured to the lug.

The result of this is that the screw head receives a three-point support, namely at one point of its periphery on rhe unslotted portion and at two adjacent points on its periphery at the edges of the slot in the flanged portion. This results in an extraordinarily secure clamping connection and other securing means to prevent loosening of the screw, e.g.

spring rings, can be omitted. In addition, the material of the edges bounding the slot press into the peripheral edges of the screw head at the said adjacent points so that a secure electric connection is obtained between the lug and the sheet metal member.

Preferably, the screw-threaded hole is provided in the sheet metal member. In this case, the mounting requires no subsequent mechanical treatment whatsoever. It may also be completely lacquered. This is because when tightening the screw rhe lacquer layer is positively broken at the point of contact between the screw head and the edges of the slot.

Farther, the support may have an abutment face adjoining the lug and the slot has a length permitting an edge portion of the carrier to lie against that face. A defined position for the carrier is obtained in this way.

Further, the support may be provided with a wall lying substantially parallel to the lug, the carrier being supported, in use, between rhe lug and rhe wall. This wall provides a reliable guide for the carrier and/or prevents deflection of the carrier upon excessive loading.

It has proved desirable for the earth terminal to be formed by a sheet metal attachment riveted to the sheet metal member. This riveting produces a secure electrically conductive connection between the earth terminal and the sheet metal member.

A particularly simple arrangement is obtained if the sheet metal attachment comprises a base portion having a screwthread for receiving a clamping screw and riveting tabs extending from the base portion, the sheet metal member being arranged to receive the base portion in face to face relation and having a hole for forming an extension of the screwthread in the base portion and slots for receiving the tabs. Further, another two tabs extend from the base portion in a sense opposite to the aforesaid tabs, one of the said other tabs being longer than the other and having two terminal spades extending from it which lie substantially parallel to the aforesaid tabs. At the sheet metal attachment, one lead can therefore be damped to the base surface and two leads can be clamped onto the terminal spade.

As a further development, the carrier com prises an insulating member secured to the sheet metal member, the insulating member carrying power terminals. The power terminals are therefore insulated from one another and from the earth terminal.

In particular, the sheet metal member may comprise an end section which receives the earth terminal, which is isertable between two guides provided on a frame-like extension of the insulating member, which has flanges which are engageable with a cross-member of the frame extension and which has a lug which, after insertion between the guides, can be bent to engage another coss-member of the frame extension, the lug and flanges serving to lock the sheet metal member to the insulating member. The sheet metal member and insulating member are therefore simply pushed into one another and securely joined by bending over the lug.

With particular advantage, the power terminals are arranged in one row with the earth terminal and comprise sheet metal attachments which are constructed in the same way as the earth terminal attachment and are riveted to the insulating member.

For reasons of strength of material, that part of the insulating member to which the power terminals are attached, and to allow the same sheet metal attachments to be used, the riveting tabs of each sheet metal attachment is stepped so that it can be riveted either to the sheet metal member or to the insulating member. In the case of the earth terminal, riveting can then be effected at the stepped part.

It is favourable if the terminal spades are parallel to one another and are arranged, in use, to lie at an angle to the axis of the sheet metal member which is in the form of a strip.

This simplifies the plugging operation. With cables led out from the top, the connecting leads then already possess an upwardly directed component.

Further, the said other tabs are parallel to each other and lie substantially at right angles to rhe terminal spades. This simplifies placement of the connecting leads to be clamped to the base surface.

Next, each terminal spade is bent near its root to reduce the 6pacing between it and the other terminal spade of the respective attachment. Terminal spades of different ,polarity in this way obtain a larger mutual spacing so that the danger of contact is minimised.

The sheet metal member may also carry at least one cable clamp. In this case, the or each cable clamp is so arranged that the said screw is between it and rhe earth terminal.

This results in a compact construction which still provides adequate spacing between the earth terminal and the cable damp for the connecting leads.

Preferably, a cable clamp is provided at one end of the sheet metal member, said one end being provided with a stay which is substantially at right angles to rhe sheet metal mem- ber, a further cable clamp being provided on the stay. In particular, the first-mentiened cable damp is intended for rhe mains supply cable and the second cable clamp is intended for a cable having connecting leads for components outside the compressor units. Both cable clamps are conveniently accessible with a screwdriver.

It is also favourable if the or each cable clamp comprises two insulating parts. The damping screw(s) then simultaneously serve to fix the clamps to the sheet metal member.

In this case the clamping screw can be a friction fit in a throughhole of one of the said parts. The two parts are then already provisionally interconnected before attachment to the sheet metal member. Nevertheless, the frictional contact does not prevent tightening of the damping screw.

With advantage, part of the or each cable clamp is provided by a cover which is securable to the sheet metal member and forms part of a housing of rhe assembly. Such a cover can therefore also be carried by the sheet metal member.

The present invention also provides a motor compressor unit casing having attached thereto a connecting means according to the invention.

If the connector on the casing comprises plug pins extending from the casing, it is of advantage if the support is so arranged on the casing that the sheet metal member is disposed to one side of the pins.

In practice, it suffices for the sheet metal member to be disposed on one side, preferably the right-hand side, of the plug pins. This results in the most convenient possibility of assembly for a right-handed mechanic. The fixing screw and the clamping screws are also conveniently accessible.

An electrical connecting means constructed in accordance with the invention will now be described, by way of example only, with reference to the accompanying drawings in wich:- Fig. 1 is a perspective exploded view of the connecting means; Fig. 2 is a plan view of the carrier of the means shown in Fig. 1; Fig. 3 is a view from below of the carrier shown in Fig. 1; Fig. 4 is a section on the line 4--4 in Fig.

2; Fig. 5 is a section on the line 5-5 in Fig. 2; Fig. 6 is a section on the line 6--6 in Fig. 2; Fig. 7 is a longitudinal section through a support lug with rhe carrier secured thereto; Fig. 8 is a section on the line 8-8 in Fig. 2, and Fig. 9 is a section similar to Fig. 8 through a modified embodiment.

Referring to the accompanying drawings, Fig. 1 illustrates a section of a casing 1 of a rrnetilly sealed refrigerant motor com pressor unit which can be attached to a support (not shown) by a foot 2. A plug 3 with three pins 4 serves to connect the main winding and auxiliary winding of an electric motor of the unit. A support 5 in rhe form of a sheet metal member is welded to the casing 1. On ene side of the pins 4, rhe support 5 com prises an upwardly extending wall 6 with a counterbearing surface 7 and on the other side a supporting wall 8, a lug 9 spaced from the wall 8, and an arm 10 with a bent tongue 11. The lug has a slot 12 and flanged end portions 13.

A terminal carrier indicated generally at 14 comprises a sheet metal member 15 and an insulating member 16 that is connectible thereto. The carrier 14 may be disposed between the support 5 and the lug 9 and damped by tightening a fixing screw 17 which engages in a screwthreaded hole in the sheet metal member 15 (as shown in Fig. 7).

Three connecting terminals are provided, namely an earth terminal 18 (Fig. 2) on the sheet metal member 15 and a first insulated connecting terminal 19 and a second insulated connecting terminal 20 on the insulating member 16. All terminals consist of sheet metal attachments 21 riveted to the associated parts (Figs. 5 and 6). Further, two cable damps 22 and 23 are provided on the sheet metal member 15 (Fig. 8). The entire arrangement is covered by a cap 24 which is retained by means of a resilient strap 24a when one end of the strap is engaged behind the counterbearing 7 and the other end of the strap engaged behind the tongue 11.

To enable the sheet metal member 15 and insulating member 16 to be interconnected, the insulating member comprises a frame-like extension 25 with two transverse stays 26 and 26a. One end section 27 of the sheet metal member 15, which is later to receive the earth terminal 18, is pushed over the frame-like extension 25, and thereby guided by the underside of a wall portion 28 as well as by the top of projections 29. Two hooks 30 bent out of the sheet metal member 15 engage under the transverse stay 26. In this position a lug 31 is bent downwardly so that it can be supported against the transverse stay 26.

The sheet metal member 15 and insulating member 16 are now securely interconnected (Fig. 4).

Three (or perhaps even more) sheet metal attachments 21 are welded in one row to the unit thus formed. Each sheet metal attachment 21 consists of a base surface 32 from which two riveting stays 33 and 34 are bent downwardly. In addition, it comprises a screwthread for a clamping screw 35. The two other sides of the base surface 32 comprise a short upwardly projecting stay 36 and a longer upwardly projecting stay 37. Two plug-in spades 38 and 39 are bent out of the latter, the spacing between the spades being reduced by kinks 40. The latter also serve to increase the spacing between the plug-in spades of two adjacent connecting terminals. The sheet metal attachments are mounted in the illustrated oblique position, the riveting stays engaging through complementary apertures 41 in the insulating member 16 or 42 in the sheet metal member 15. Between these apertures, a hole 43 or 44 is in each case provided as an extension of the clamping screw 35. Riveting stays 33, 34 have a step 45 (see Fig. 5) on which the riveting tool engages when riveting is performed in the rhinner sheet metal member 15. However, in the thicker insulating member 16 the riveting tool engages the projecting portion 46 of the riveting stay (see Fig. 6), it being necessary for the aperture 41 to possess a corresponding step. Ribs on the insulating member 16 increase the creepage path.

The carrier 14 is mounted on the support 5 by clamping the sheet metal member 15 to the lug 9 (Fig. 7). For this purpose the fixing screw 17 is screwed into the sheet metal member 15 before final assembly, this resulting in a spacing between the screw head 47 and the sheet metal member 15. If, now, the carrier is offered so that the shank of the screw is introduced in the slot 12, the position illustrated in Fig. 7 will necessarily be obtained when tightening the screw. This is because the screw head is guided on the oblique surface of the flanged end portion 13 and the sheet metal member 15 is thereby pressed downwardly until it abuts an abutment surface 48 of the support 5. When no further displacement is possible, the screw 17 slightly deforms, this being shown to an exaggerated extent in Fig. 7, whereby it is supported at one point below the shank and at two points, namely the edges of the slot 13, above the shank. At the two upper points, an edge on the screw head intersects two bounding edges. This leads to high surface pressure for pressing away any lacquer which may be present at this location and a secure electrical connection between rhe screw and lug is obtained. Loosening of the screw is also unlikely.

To secure the cable clamps 22 and 23, to the sheet metal member 15, the latter is provided on that side of the fixing screw 17 remote from the earth terminal 18 with an extension 49 and an adjoining transverse stay 50 (see Fig.

8). The cable clamp 22 consists of a lower portion 51 and an upper portion 52, and the cable clamp 23 consists of a lower portion 53 and an upper portion 54. These portions consist of insulating plastics. The extension 49 possesses three holes 55 in which projections 56 of the lower portion 51 engage, and two tapped holes 57 in which damping screws 58 engage. The transverse stay 50 possesses an aperture 59, in which a projection 60 of the lower portion 53 engages, and a tapped hole 61 in which a clamping screw 62 is screwed.

The throughholes in the lower portions 51 and 53 are dimensioned so that the clamping screws 58 or 62 are held therein under friction, e.g. by providing this region with a cast seam which engages in the screwthread. In this way the parts of the cable clamps can be assembled together and then mounted on the sheet metal member 5 as a unit. Upon tightening of the clamping screws 58 or 62, cables can be clamped tight in apertures 63 or 64.

In the construction illustrated in Fig. 9, the cable clamps 22' and 23' have been slightly modified in that a cover 65 which covers the end of the cap 24 is made in one piece with the lower portions 51' and 53'.

One can use the same sheet metal member 15 as in the preceding figures but the apertures 55 and 59 can be omitted. For provisional connection of the cover 65 there are two pins 66. If still further abutments are formed thereon, one can ensure that, after connection, the tapped holes 57 and 61 are accurately aligned with the pre-mounted clamping screws 58 or 62.

The connecting assembly can be attached to the casing 1 as follows. The sheet metal member 15 is fastened to the insulating member 16 as described above. The connecting terminals 18, 19 and 20 are then riveted on. A mains cable (net shown) is thereafter passed through the cable clamp 22 and the ends of the individual conductor leads are clamped to the connecting terminals 18, 19 and 20 by means of the damping screws 35.

The ends of the leads maintain their direction during this procedure. The cable clamp 22 can then be screwed tight, simultaneously clamping the cable in position to the sheet metal member 15.

In a similar manner, a connecting cable for internal leads (to be connected to parts of the refrigerator outside the compressor unit) is passed through the cable clamp 23 and the ends of the individual leads, provided with clamping surfaces, are pushed onto the plug-in spades 39. After securing the cable clamp 23 to the member 15 and simultaneously clamping the connecting cable in position, the direction of the ends of the leads need only be slightly changed. Finally, short connecting leads are placed on the plug pins 38. The pre-assembled unit thus formed in then clamped to the lug 9 in the manner described above. It is only necessary then to connect free ends of the short connecting leads to the connecting terminals of a socket connector (not shown) which has previously been inserted on the plug pins 4. Finally, the cap 24 is placed thereover and retained by the spring strap 24a.

If repairs become necessary, the connecting terminals as well as the cable clamps can be readily reached by the mechanic.

WHAT WE CLAIM IS;- 1. An electrical connecting means for a casing of a motorwompressor unit, the casing having an electrical connector secured to it for providing electrical connection to its interior, wherein the connecting means comprises a support for securing to the casing adjacent to the connector, an electrical terminal carrier having a sheet metal member provided with an earth terminal, an electrical connector for electrical connection to the carrier and for pin and socket electrical con nection to the connector on the casing and a screw for securing the carrier to the support so that an electrically conductive connection is provided between the support and the sheet metal member.

2. Connecting means as claimed in claim 1, in which the support comprises a lug for receiving the said screw.

3. Connecting means as claimed in claim 2, in which the lug or the sheet metal member is provided with a screw-threaded hole for receiving the end of the screw, and the sheet metal member or the lug respectively is provided with an open-ended slot for receiving, laterally, the shank of the screw.

4. Connecting means as claimed in claim 3, in which that one of the lug or the sheet metal member provided with the slot is obliquely flanged towards the screw head at the open

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

because the screw head is guided on the oblique surface of the flanged end portion 13 and the sheet metal member 15 is thereby pressed downwardly until it abuts an abutment surface 48 of the support 5. When no further displacement is possible, the screw 17 slightly deforms, this being shown to an exaggerated extent in Fig. 7, whereby it is supported at one point below the shank and at two points, namely the edges of the slot 13, above the shank. At the two upper points, an edge on the screw head intersects two bounding edges. This leads to high surface pressure for pressing away any lacquer which may be present at this location and a secure electrical connection between rhe screw and lug is obtained. Loosening of the screw is also unlikely.

To secure the cable clamps 22 and 23, to the sheet metal member 15, the latter is provided on that side of the fixing screw 17 remote from the earth terminal 18 with an extension 49 and an adjoining transverse stay 50 (see Fig.

8). The cable clamp 22 consists of a lower portion 51 and an upper portion 52, and the cable clamp 23 consists of a lower portion 53 and an upper portion 54. These portions consist of insulating plastics. The extension 49 possesses three holes 55 in which projections 56 of the lower portion 51 engage, and two tapped holes 57 in which damping screws 58 engage. The transverse stay 50 possesses an aperture 59, in which a projection 60 of the lower portion 53 engages, and a tapped hole 61 in which a clamping screw 62 is screwed.

The throughholes in the lower portions 51 and 53 are dimensioned so that the clamping screws 58 or 62 are held therein under friction, e.g. by providing this region with a cast seam which engages in the screwthread. In this way the parts of the cable clamps can be assembled together and then mounted on the sheet metal member 5 as a unit. Upon tightening of the clamping screws 58 or 62, cables can be clamped tight in apertures 63 or 64.

In the construction illustrated in Fig. 9, the cable clamps 22' and 23' have been slightly modified in that a cover 65 which covers the end of the cap 24 is made in one piece with the lower portions 51' and 53'.

One can use the same sheet metal member 15 as in the preceding figures but the apertures 55 and 59 can be omitted. For provisional connection of the cover 65 there are two pins 66. If still further abutments are formed thereon, one can ensure that, after connection, the tapped holes 57 and 61 are accurately aligned with the pre-mounted clamping screws 58 or 62.

The connecting assembly can be attached to the casing 1 as follows. The sheet metal member 15 is fastened to the insulating member 16 as described above. The connecting terminals 18, 19 and 20 are then riveted on. A mains cable (net shown) is thereafter passed through the cable clamp 22 and the ends of the individual conductor leads are clamped to the connecting terminals 18, 19 and 20 by means of the damping screws 35.

The ends of the leads maintain their direction during this procedure. The cable clamp 22 can then be screwed tight, simultaneously clamping the cable in position to the sheet metal member 15.

In a similar manner, a connecting cable for internal leads (to be connected to parts of the refrigerator outside the compressor unit) is passed through the cable clamp 23 and the ends of the individual leads, provided with clamping surfaces, are pushed onto the plug-in spades 39. After securing the cable clamp 23 to the member 15 and simultaneously clamping the connecting cable in position, the direction of the ends of the leads need only be slightly changed. Finally, short connecting leads are placed on the plug pins 38. The pre-assembled unit thus formed in then clamped to the lug 9 in the manner described above. It is only necessary then to connect free ends of the short connecting leads to the connecting terminals of a socket connector (not shown) which has previously been inserted on the plug pins 4. Finally, the cap 24 is placed thereover and retained by the spring strap 24a.

If repairs become necessary, the connecting terminals as well as the cable clamps can be readily reached by the mechanic.

WHAT WE CLAIM IS;- 1. An electrical connecting means for a casing of a motorwompressor unit, the casing having an electrical connector secured to it for providing electrical connection to its interior, wherein the connecting means comprises a support for securing to the casing adjacent to the connector, an electrical terminal carrier having a sheet metal member provided with an earth terminal, an electrical connector for electrical connection to the carrier and for pin and socket electrical con nection to the connector on the casing and a screw for securing the carrier to the support so that an electrically conductive connection is provided between the support and the sheet metal member.
2. Connecting means as claimed in claim 1, in which the support comprises a lug for receiving the said screw.
3. Connecting means as claimed in claim 2, in which the lug or the sheet metal member is provided with a screw-threaded hole for receiving the end of the screw, and the sheet metal member or the lug respectively is provided with an open-ended slot for receiving, laterally, the shank of the screw.
4. Connecting means as claimed in claim 3, in which that one of the lug or the sheet metal member provided with the slot is obliquely flanged towards the screw head at the open

end of the slot and the screw head partially covers the flange when the sheet metal member is secured to the lug.
5. Connecting means as claimed in claim 3 or claim 4, in which the screw-threaded hole is provided in the sheet metal member.
6. Connecting means as claimed in claim 5, in which the support has an abutment face adjoining the lug and the slot has a length permitting an edge portion of the carrier to e against that face.
7. Connecting means as claimed in any one of claims 4 to 6, in which the support is provided with a wall lying substantially parallel to the lug, rhe carrier being supported, in use, between the lug and rhe wall.
8. Connecting means as claimed in any one of claims 1 to 7, in which the earth terminal is formed by a sheet metal attachment riveted to the sheet metal member.
9. Connecting means as claimed in claim 8, in which the sheet metal attachment comprises a base portion having a sorewiread for receiving a clamping screw and riveting tabs extending from the base portion, the sheet metal member being arranged to receive the base portion in face to face relation and having a hole for forming an extension of the screwthread in the 'baste portion and slots for receiving the tabs.
10. Connecting means as claimed in claim 8 or claim 9, in which another two tabs extend from the base portion in a sense opposite to the aforesaid tabs, one of the said other tabs being longer rhan the other and having two terminal spades extending from it which lie substantially parallel to the aforesaid tabs.
11. Connecting means as claimed in any one of claims 1 to 10, in which the carrier com prises an insulating member secured to rhe sheet metal member, rhe insulating member carrying power terminals.
12. Connecting means as claimed in claim 11, in which the sheet metal member comprises an end section which receives rhe earth terminal, which is insertable between two gussies provided on a framelike extension of the insulating member, which has flanges which are engageable with a cross-member of the frame extension and which has a lug which, after insertion between the guides, can be bent to engage another cross < nember of the frame extension, the lug and flanges serving to lock the sheet metal member to the insulating member.
13. Connecting means as claimed in claim 11 or claim 12, in which the power terminals are arranged in one row with the earth terminal and comprise sheet metal attachments which are constructed in the same way as the earth terminal attachment and are riveted to the insulating member.
14. Connecting means as claimed in claim 13, in which thac part of the insulating member to which the power terminals are attached is thicker than that part of the sheet metal member to which rhe earth terminal is attached, the riveting tabs of each sheet metal attachment being stepped so that it can be riveted either to the sheet metal member or to the insulating member.
15. Connecting means as claimed in claim 10 or any one of claims 11 to 14 when appendant to claim 10, in which the terminal spades are parallel to one another and are arranged, in use, to lie at an angle to the axis of the sheet metal member which is in the form of a strip.
16. Connecting means as claimed in claim 15, in which the said other tabs are parallel to each other and lie substantially at right angles to the terminal spades.
17. Connecting means as claimed in claim 10 or any one of claims 11 to 16, when appendant to claim 10, in which each terminal spade is bent near its root to reduce the spacing between it and the other terminal spade of the respective attachment.
18. Connecting means as claimed in any one of claims 1 to 17, in which the sheet metal member carries at least one cable clamp.
19. Connecting means as claimed in claim 18, in which the or each cable clamp is so arranged that the said screw is between it and the earth terminal.
20. Connecting means as claimed in claim 18 or claim 19, in which a cable clamp is provided at one end of the sheet metal member, said one end being provided with a stay which is substantially at right angles to the sheet metal member, a further cable clamp being provided on the stay.
21. Connecting means as claimed in any one of claims 18 to 20, in which the or each cable clamp comprises two insulating parts, one of which comprises projections for engaging in complementary holes or recesses in the sheet metal member, and at least one damping screw for passing through both parts and for engagement in a screwthread in the sheet metal member.
22. Connecting means as claimed in claim 21, in which the clamping screw is a friction fit in a throughhole of one of the said parts.
23. Connecting means as claimed in any one of claims 18 to 22, in which part of the or each cable clamp is provided by a cover which is securable to the sheet metal member and forms part of a housing of the assembly.
24. An electrical connecting means substantially las hereinbefore described with reference to, and as illustrated by, the accompanying drawings.
25. A motor compressor unit casing having attached thereto an assembly as claimed in any one of claims 1 to 24.
26. A casing as claimed in claim 25, in which the electrical connector on the casing comprises plug pins extending from the casing, the support being so arranged on the casing that the sheet metal member is disposed to one side of the pins.
27. A motor compressor unit casing as claimed in claim 25 or claim 26 and substan tially as hereinbefore described with reference to, and as illustrated by, the accompanying drawings.
28. A motor compressor unit having an assembly as claimed in any one of claims 1 to 24 and/or a casing as claimed in any one of claims 25 to 27.