Background of the invention

The invention relates to a bottom part of an enclosure for electrical in stallations. More specifically, the invention relates to a bottom part of an enclosure for electrical installations, which comprises a rectangular bottom as well as a first wall and, opposite to the first wall, a second wall which are leading upward from the bottom, a third wall and a fourth wall opposite to the third wall, whereby the first wall of the bottom part has a first locking member to fasten a cover to the bot tom part, whereby the second wall has a first locking member to fasten the cover to the bottom part.

Users of electrical enclosures, depending on the use of the electrical en closure, have most varying requirements as well as wishes concerning what the bottom part of the electrical enclosure and also the cover of the electrical enclosure should technically be, to make the electrical enclosure as suitable as possible for its application. These requirements by the users of electrical enclosures in practice complicate the production of electrical enclosures by their manufacturers. To allow the manufacturers of electrical enclosures to deliver, with a short delivery period, electrical enclosures meeting the required/desired technical characteristics to the users, enclosure manufacturers would have to have a large quantity of pre-manu- factured electrical enclosures in stock. This is very difficult and, practically-speak ing, even impossible, because typically there is not enough storage space, and even if space were available, the danger exists that such a large number of electrical en closures has been manufactured and stored that buyers cannot be found for all of them. Due to the above, buyers of electrical enclosures in practice have to wait for an electrical enclosure to be delivered, if the type of the electrical enclosure is such that one is not stocked.

Brief description of the invention

It is an object of the invention to provide a bottom part of an enclosure for electrical installations, the bottom part being very easily and fast greatly modi fiable to meet the users’ requirements and requests as concerns its technical char acteristics, whereby the invention at the same time eliminates the need to have a large stock of different bottom parts for electrical enclosures. To achieve the object of the invention, the invention is characterized by what is disclosed in the charac terising part of the attached claim 1. An essential feature of the invention is that the bottom part (which is typically large) comprises a set of detachable form-locking pieces (several times smaller than the bottom part) by means of which the enclosure cover in its first position may be fastened to the bottom part, or alternatively in its second position in which the cover is rotated by 180 degrees in relation to the first position, in other words the opening direction (“handing”) may be changed. Advantageously in this case, with the technical structure of the form-locking pieces, with the fastening method of the cover and the application of the electrical enclosure in mind, may additionally slightly differ from each other. The form-locking pieces do not impair the looks of the bottom part, because the form-locking pieces are adapted on re cesses formed in the walls of the bottom part so that their planar outer surface is in the same plane as the outer surface of the wall of the bottom part.

The form-locking piece advantageously comprises a hinge member which allows the cover to the attached by a hinge to the desired side of the bottom part, whereby the opposite side of the bottom part has a form-locking piece which comprises a recess to fasten the cover by a screw joint to the bottom part or a han dle to fasten the cover to the bottom part.

If the cover is not to be fastened with a hinge to the bottom part, the form-locking pieces of the bottom part comprise a recess to fasten the cover by a screw joint to the bottom part or a handle to fasten the cover to the bottom part.

If the opposite walls of the bottom part have more than one form-lock ing piece, which is advantageous as the bottom part is big, the form-locking pieces are adapted in recesses that are diametrically opposite on opposite walls of the bottom part. In such a case, the fastening means on the cover of the electrical en- closure are suitable for attaching to the desired side of the bottom part to corre spond with the opening direction of the cover.

To keep the form-locking piece in place on the wall of the bottom part so that it cannot detach from the recess in the wall to the direction that is away (outward) from the outer surface defined by the wall, the recess in the wall is ad- vantageously determined by a wall portion formed in the wall, which comprises a groove parallel to the plane defined by the wall and extends perpendicularly to the plane defined by the bottom of the bottom part, whereby the form-locking piece has a tongue which is adapted to lock the form-locking piece to the wall. Instead of a groove, the wall portion that defines the recess may advantageously have a tongue which is parallel to the plane defined by the wall and extends perpendicu larly to the plane defined by the bottom of the bottom part, whereby the form- locking piece has a groove that is adapted to lock the form-locking piece to the wall so that the form-locking piece cannot detach from the recess in the wall into a di rection away from the outer surface defined by the wall.

Preferred embodiments of the invention are disclosed in the attached dependent claims.

The greatest advantages of the inventive bottom part of an enclosure for electrical installations are that by utilising small-sized form-locking pieces it may easily and very fast be made suitable for receiving a cover in various ways depending on how the cover is to be fixed to the bottom part with, for example, the handing of the cover in relation to the bottom part in mind. The invention signifi cantly reduces the need to manufacture and store a large number of different, typ ically large, bottom parts that require a lot of storage space. Due to the invention, customers can very quickly be provided with the desired bottom part for an elec trical enclosure. Brief description of the drawings

The invention will now be described in closer detail with the help of ex emplary descriptions by referring to the attached drawings in which:

Figure 1 shows an electrical enclosure that comprises the inventive bot tom part, Figure 2 is an enlarged view of a corner of the electrical enclosure of

Figure 1,

Figure 3 shows a corner of the cover shown in Figure 2,

Figure 4 shows the bottom part shown in Figure 1 without form-locking pieces and as seen directly towards the inner bottom of the bottom part, Figure 5 is an enlarged, perspective view of the corner of the bottom part in Figure 4,

Figure 6 shows the corner according to Figure 4 with its form-locking pieces,

Figures 7a and 7b show a first implementation of the form-locking piece as a perspective view, and similarly directly from a side,

Figures 8a and 8b show a second implementation of the form-locking piece as a perspective view, and similarly directly from a side,

Figures 9a and 9b show a third embodiment of the form-locking piece as a perspective view, and similarly directly from a side, Figure 10 illustrates a second embodiment of the inventive bottom part,

Figure 11 illustrates a third embodiment of the inventive bottom part, Figures 12a to 12c illustrate different variations of the inventive bottom part, and

Figures 12d to 12f illustrate different implementations of the form-lock ing piece as seen from above.

Detailed description of the invention

Figure 1 shows an electrical enclosure comprising the inventive bottom part 1 and a cover 8 attached on it. The bottom of the bottom part 1 is rectangular, and leading upwards from it are walls 3 to 6 of the bottom part, of which walls 3 and 6, only, are seen in Figure 1. Figure 4 shows all the walls 3 to 6 of the bottom part 1, as seen towards the bottom 2 (inner bottom) of the bottom part.

The first wall 3 of the bottom part 1 has a first locking member 30al and a second locking member 30a2, by means of which the cover 8 is fixed with hinges to the bottom part, see Figure 1. The locking members 30al and 30a2 com- prise form-locking pieces 7b whose structure is shown in Figures 8a and 8b. The form-locking pieces 7b are loose parts and comprise a hinge part 70b which to gether with a hinge part 82 formed on the cover 8 form the hinging of the cover 8.

The second wall 4, opposite to the wall 3 of the bottom part 1, has a first locking member 40al and second locking member 40a2 to which the cover 8 is additionally fastened. The locking members 40al, 40a2 comprise form-locking pieces whose structural details differ from the structure of the form-locking pieces 7b of the locking members 30al, 30a2 of the wall 3. The structure of the form-lock ing pieces 7c on the second wall 4 is shown in Figures 9a and 9b: the form-locking pieces 7c comprise a handle 70c which attaches removably to a detent 81 on the cover 8, see Figure 2. When the handle 70c co-operates with the detent piece 81 on the cover 8, the handle attaches the cover to the bottom part 1. By turning a latch 700c of the form-locking piece 7c, the handle 70 rises upwards and detaches from the detent 81 of the cover 8, thereby opening the locking. The structure and oper ation of the locking corresponds with the structure of handle locking, which a per- son skilled in the art is very familiar with, so the detailed structure of handle lock ing is not described in this context.

The fourth wall 6 of the bottom part 1 has a first locking member 60al and a second locking member 60a2, see Figure 1. Additionally, the third wall of the bottom part 1, opposite to the fourth wall 6, similarly has two locking members but these are not shown in Figure 1. The locking members of the third wall and fourth wall 6 comprise form-locking pieces 7a whose structure is shown in Figures 7a and 7b. In the enclosure of Figure 1, the locking members of the third wall and fourth wall 6 do not act as locking members for the cover 8, because the cover is locked (fastened) to the bottom part 1 by means of the locking members 30al, 30a2 on the first wall 3 and the locking members 40al, 40a2 on the second wall. The pur- pose of the form-locking pieces 7a on the third and fourth wall 6 is to act as stiffen ers, only, improving the appearance of the bottom part, which will be explained below.

The locking members 30al, 30a2, 40al, 40a2 on the opposite walls 3 and 4 of the bottom part 1 are diametrically placed opposite each other so that the locking member 40al is diametrically located opposite to the locking member 30al and the locking member 40a2 is diametrically located opposite to the locking member 30a2. The same applies to the locking members on the walls 5 and 6, that is, the first locking member (not shown in Figure 1) of the wall 5 is diametrically positioned opposite to the first locking member 60al of the wall 6, and the second locking member (not shown in Figure 1) of the wall 5 is diametrically located op posite to the second locking member 60a2 of the wall 6.

By means of the locking members 30al, 30a2, 40al, 40a2, the fastening of the cover to the bottom part 1 may be implemented in a number of ways: The cover 8 may be alternatively hinged to the wall 3 (as in Figure 1) by means of the hinge parts 82 on the cover, or to the wall which is opposite to the wall 3. If the cover 8 is to be hinged to the bottom part 1 wall opposite to the wall 3, the form locking pieces 7c of Figures 9c and 9b are adapted on the wall 3 (or the form-lock ing pieces 7a of Figures 7a and 7b), and on the wall opposite to the wall 3, the form locking pieces 7b of Figures 8a and 8b are adapted. If the type of the cover 8 is such that it is to be screwed to the bottom part 1, the form-locking pieces 7a of Figures 7a and 7b are installed on the walls of the bottom part, cf. Figure 6 and Figure 11, in which the walls 4 and 6 of the bottom part have the form-locking pieces 7a of Figures 7a and 7b. In Figures 7a and 7b, the reference number 70a indicates a recess made in the form-locking piece 7a. The recess 70a receives a screw (see screw 87” in Figure 11) by means of which the cover 8 may be fastened to the bottom part 1. The screw threads fasten to the wall portion of the recess 70a. The recess 70a may also be a through-hole, through which the screw is led, in which case a nut may be connected to the screw.

Due to the fact that different kinds of locking members / form-locking pieces may be adapted on the walls of the bottom part 1, the cover 8 may, if so desired, be fastened to the bottom part 1 in numerous ways, such as with eight handles by means of using the form-locking piece 7c of Figures 9a and 9b.

Irrespective of how the cover 8 is connected to the bottom part 1 and what kind of fastening members the cover has, the walls 3 to 6 of the bottom part are even without disturbing recesses or protrusions due to the form-locking pieces 7a, 7b, 7c comprising a planar outer surface 72a, 72b, or 72c, which is in the same plane as the outer surface of the wall, to which wall the for-locking piece is adapted. To allow this, formed in the walls 3 to 6 of the bottom part 1 there are recesses 3al, 3a2, 4al, 4a2, 5al, 5a2, 6al and 6a2 to receive the form-locking pieces 7a, 7b, or 7c, see Figure 4 which shows the bottom part 1 without form-locking pieces thereby making the recesses visible.

The form-locking pieces 7a, 7b, or 7c thus make the outer walls 3 to 6 of the bottom part 1 appear smart and uniform. In the example of Figure 1, the form locking pieces 7a adapted on the third and fourth wall 6 do not have the function of locking the cover 8; their purpose is, as disclosed in the above, to provide the enclosure with a presentable appearance without the recesses 5al, 5a2, 6al, 6a2 (cf. Figures 4 and 5) in the bottom part 1 impairing the appearance of the bottom part. They additionally stiffen the wall 6, just like the other form-locking pieces of the enclosure, all of which stiffen and strengthen the walls of the bottom part. Figure 5, showing a corner of the bottom piece 1 without form-locking pieces, discloses the structure of the recesses 4a2 and 6al formed in the walls of the bottom part. The structure of the other recesses (3al, 3a2, 4al, 5al, 5a2, 6a2) in the bottom part 1 is similar. The recess 4a2 is defined by a wall portion formed in the wall 4 and comprising three main surfaces (bottom surface, two edge sur- faces, and end surface), the wall portion comprising oppositely adapted grooves 11 (the grooves 11 on the edge surfaces) which run in parallel with the plane defined by the wall 4 and extend perpendicularly to the plane defined by the bottom 2 of the bottom part. The form-locking pieces 7a, 7b, and 7c similarly have two oppo sitely adapted tongues 73a, 73b, 73c, cf. Figures 7a, 7b, 8a, 8b, 9a, 9b. Due to the grooves 11 and tongues 73a, 73b, 73c, the form-locking pieces 7a, 7b, and 7c can be made form-lock in the recesses 4a2, 6al, or any other recess in the bottom part 1 so that the form-locking pieces cannot detach from their corresponding walls in the direction which is away (outwards) from the outer surface defined by the walls. The form-locking described thus takes place for all the form-locking pieces of the bottom part 1. The form-locking implemented by a groove-tongue joint is preferably play-free, whereby the form-locking pieces effectively strengthen/stiffen the walls of the bottom part.

Figures 12a to 12c show three form-locks, differing in detail, for the form-locking pieces that allow the cover to be locked with screws. For this purpose, the form-locking pieces 7a’, 7a”, 7a” comprise a hole 70a’, 70”, 70”’ for a screw. Figures 12a to 12c use the same reference numbers as Figures 4, 7a, 8a and 9a for the corresponding parts. The form-locking pieces 7a’, 7a” and 7a’” are locked in a recess 3al’, 3al”, 3al’” formed in the wall 3’, 3”, 3’” of the bottom part. As illus trated in Figures 12a to 12c, the form of the tongues 73a’, 73a”, 73a’” of the form- locking pieces 7a’, 7a”, 7a’” may vary to a great extent. Figures 12a to 12c addition ally illustrate that the form-locking pieces 7a’, 7a”, 7a’” may, instead of tongues, have grooves 74a’, 74a” and 74a’” to lock the form-locking piece by form-locking into a tongue 12’, 12”, 12”’ in the wall 3’, 3”, 3”’ of the bottom part. As understood from Figures 12a to 12c, the form of the grooves 74a’, 74a” and 74a’” may greatly differ, and a number of non-illustrated forms are possible.

Differing from Figures 12a to 12c, the form-locking piece may comprise a groove on both of its opposite edges, which is illustrated by form-locking pieces 7a ^v and 7a ^VI shown in Figures 12e and 12f, in which case the recess made in the wall of the bottom part naturally has to have tongues to receive the grooves. The forms of the form-locking pieces 7a, ', 7a”, 7a’”, 7a ^IV , 7a ^v and 7a ^VI of

Figures 12a to 12f may equally be used for form-locking pieces having such a type that they provide a hinge locking instead of screw fastening, cf. Figures 8a and 8b, or handle locking, cf. Figures 9a, 9b.

In summary, with regard to the form-locking pieces and their form, it may generally be said that they are loose pieces, and to achieve form-locking there may be a tongue and groove on their opposite edges, and the recesses of the bottom part 1 may have a groove or tongue. To make the bottom part with its form-locking pieces practical to manufacture and to use, all the recesses of the bottom part are similar, and the forms of all the form-locking pieces are similar whereby any form- locking piece - regardless of whether it produces a screw, hinge, or handle fastening - may be adapted in any recess of the bottom part.

In Figures 4 and 5, the reference number 49a2 denotes a detent formed in the recess 4a formed in the wall 3. The other walls of the bottom part 1 have similar detents 39al, 39a2, 59al, 59a2, 69al, 69a2. These detents 39al, 39a2, 49al, 49a2, 59al, 59a2, 69al, 69a2 are collars formed of the through-holes 48a2, see Figure 5, formed in the recesses of the walls 3 to 6. The purpose of the detents 39al, 39a2, 49al, 49a’, 59al, 59a2, 69al, 69a2 is to prevent the non-desired mov ing of the form-locking pieces 7a to 7c in the direction of the planes defined by the walls 3 to 6 of the bottom part 1 away from the bottom of the bottom part and off the recesses 3al, 3a2, 4al, 4a2, 5al, 5a2, 6al, 6a2. For this purpose, there is stop- per member 71a, 71b, and 71c at the end of the form-locking pieces 7a to 7c, which abuts the bottom 2 of the bottom part, cf. Figures 7a, 7b, 8a, 8b, 9a, 9b, the stopper member locking into the detents 39al, 39a2, 49al, 49a2, 59al, 59a2, 69al, 69a2. The stopper member 7 la, 7 lb and 7 lc is formed by a flexible tab in which is formed a collar 710a, 710b, 710c, see Figures 7b, 8b, and 9b. When a form-locking piece, such as the form-locking piece 7c of Figure 9b, is inserted in a recess, such as the recess 49a2 of Figure 5, its stopper member 7 lc contacts the wall of the hole 48a in the recess, whereby the stopper member yields in the lateral direction; and when insertion continues, the collar 710c of the stopper member 71c sets against the col lar of the hole 48a2, locking the form-locking piece 7c in the recess 49a2. When the form-locking piece 7c is to be removed from the recess, lateral force is exerted on its stopper member 7 lc by means of a screwdriver, for example, whereby the stop per member yields so that its collar 710c is released from the collar of the hole 48a, and the form-locking piece 7c may be pulled out of the recess 49a2.

The purpose of Figure 10 is to show that the form-locking piece 7b’, by means of which the cover 8’ is locked with a hinge to the bottom part 11’, may be formed such that also its hinge part does not protrude from the plane defined by the outer surface of the enclosure side 3’. The hinge part 82’ on the cover 8’ is similarly formed such that it does not protrude from the enclosure.

The bottom part according to the invention is recommendably made of plastic. The plastic used may recommendably be ABS plastic (acrylonitrile butadi ene styrene) or PC plastic (polycarbonate). Alternatively, the bottom part may be made of metal. The form-locking pieces, too, are recommendably made of plastic. If a form-locking piece comprises a handle, it is of metal.

In the above, the invention is described by means of examples, where- fore it is noted that the details of the invention may be implemented in various ways within the scope of the attached claims. Therefore the number and form of the recesses and form-locking pieces in the bottom part may vary. At minimum, the bottom part 1 of the enclosure has two recesses which are formed in opposite walls of the bottom part and in which form-locking pieces are adapted. By forming at least one set of recesses and form-locking pieces in all the walls of the bottom part, the fastening of the cover to the bottom part of the enclosure is made possible in very varying ways either by hinging it on any wall of the bottom part or by fastening the cover to the bottom part by form-locking pieces to which the cover attaches with screws and/or form-locking pieces which comprise a handle for attaching the cover to the enclosure. It is conceivable that the form-locking of the form-locking pieces is established with one groove-and-tongue type joint, only, the position of which on the wall portion defined by the recess may vary. The detents (cf. e.g. de tent 49a2 in Figure 5) formed in the recesses of the bottom part, by means of which the moving of the form-locking parts is prevented away (upwards) from the bot tom of the bottom part so that it detaches from the bottom part, may be formed of the wall portion of the recess in the bottom part, against which the upper end of the form-locking piece, so the end having the recess, hinge part, or handle (cf. re cess 70a in Figure 7a, hinge part 70b in Figure 8a, or handle 70c in Figure 9a) stops and rests when the form-locking piece is being pushed away (upwards) from the bottom of the bottom part. In the solution last referred to, the form-locking piece is adapted in place in the recess of the bottom part from the side of the bottom of the bottom part, that is, in the opposite direction to the one in the above examples in which the form-locking piece is adapted in place in the recess of the bottom part by pushing it towards the bottom of the bottom part, that is, from above. As indicated by the exemplary description of the invention with its drawings, the external form of the form-locking pieces may vary to a large extent, but nevertheless establishing a form lock.