Abstract:
The invention relates to a maintenance device ( 1 ) in which the individual functional modules ( 3-6 ) are aligned in a vertical direction and the compressed air flows through them in a vertical direction.

Description:
BACKGROUND OF THE INVENTION 
     The invention concerns a maintenance device for compressed air systems, comprising at least two functional modules, such as a filter module, a shut-off module, a regulator module, a lubricator module or the like, having a connection for a line carrying the compressed air to be treated, a connection for a line carrying the treated compressed air and, optionally, a connection for electric lines. 
     EP 261 711 A1, DE 36 06 953 A1 and DE 295 09 073 disclose maintenance devices of the above-mentioned type. These maintenance devices comprise functional modules disposed next to one another and having a plurality of different functions for the compressed air to be treated. These functional modules filter, drain, or lubricate the compressed air to be treated. A certain pressure can also be set. Further functions are feasible. Each of these maintenance devices has the substantial advantage that it can be adjusted to the specific needs of a customer: i.e. it comprises only those functional modules which are required to treat the compressed air in accordance with the specific requirements. These modules are disposed next to one another, in a horizontal direction, and the compressed air to be treated flows through same from the right to the left or vice versa. 
     A disadvantage thereof is that the piping for the compressed air has to be guided such that the flow always approaches the maintenance device from a predetermined side, i.e. from the right or left. This may require considerable installation effort. 
     A further disadvantage consists in that these known maintenance devices are relatively wide in dependence on the number of individual functional modules and thus cannot be easily mounted at any location on the machine. 
     A further disadvantage is that, when the maintenance device is enlarged, i.e. through addition of further functional modules, the existing pressure lines have to be correspondingly shortened. When functional modules are removed, connection to the existing pressure lines is no longer possible since they are too short and spacers have to be installed. 
     It is therefore the underlying purpose of the invention to provide a maintenance device which is relatively small and can be easily increased or reduced in size. 
     SUMMARY OF THE INVENTION 
     This object is achieved in accordance with the present invention in that all functional modules are disposed vertically, one on top of the other, and are connected to one another. 
     Through the vertical arrangement, one on top of the other, the width of the maintenance unit is not determined by the number of functional modules but by the width of the functional modules. Modification of the maintenance device through addition of further functional modules or by removing individual functional modules does not change the connection configuration, position or installation plan of the compressed air lines since the compressed air lines are guided to the maintenance device in a horizontal direction. The lines do not have to be shortened or lengthened since the width of the inventive maintenance device, i.e. its horizontal size, is not changed rather the height, i.e. its vertical extent. The maintenance device in accordance with the invention is relatively narrow. It can therefore be easily mounted to machines, in particular, a machine support or the like, since supports or tables of this type are sufficiently wide to accommodate such a maintenance device. Clearly, the maintenance device can also be mounted to a wall. 
     In accordance with a preferred embodiment, the connection for the line carrying the compressed air to be treated and the connection for the line carrying the treated air are provided on a common functional module. This functional module is the connection piece to which all pneumatic and, optionally, electric lines are connected. Further functional modules are then connected to this functional module in a vertical and generally downward direction, with the exception of pneumatic and electric connections. 
     In one embodiment, the pneumatic connections may be opposite to one another or, in another embodiment, may be provided on the same side surface. The functional module preferably comprises one connection on each of the two opposite side surfaces for the line carrying the compressed air to be treated. Such maintenance devices can be universally used, since the compressed air lines can be introduced from either side and the compressed air lines (inlet and outlet air lines) must not be re-installed or adapted to the air guidance configuration of the maintenance device. The inlet air line and the outlet air line may be connected e.g. on the left side or both on the right side or the inlet air line may be connected on the left side and the outlet air line on the right side or the inlet air line may be connected on the right side and the outlet air line may be connected on the left side. The connections on the functional module which are not required are plugged closed. 
     In a further development, the rear side of the functional module is provided with at least one of the connections. This allows one or the other or both pressure lines to be introduced from the rear side. 
     In an embodiment, the functional modules comprise at least one coupling flange via which they can be connected to a further functional module, wherein the coupling flange comprises a transfer opening for the compressed air to be treated and a transfer opening for the completely or partially treated compressed air and, in particular, a portion of an electric plug connection. The compressed air is transferred from one functional module to another via the transfer openings, wherein the functional modules are, in turn, provided with a preferably vertically extending air line. This air line preferably terminates on the upper side and lower side of the functional module. Untreated compressed air can pass through the functional module or air can pass through the corresponding treatment station. The individual functional modules are thereby coupled to a bus system to considerably simplify the structure of individual maintenance devices and to reduce the electric wiring to a minimum. 
     One embodiment provides for a functional module, in particular a filter module, which is structured as a conversion module into which the compressed air to be treated flows vertically from the top, is deflected and exits at the top. This filter module can be operated with and without a filter, wherein with inserted filter, the compressed air has been filtered before flowing out. This functional element is generally the last element which terminates the maintenance device in the vertical direction and no further functional element is added to this functional element. Further functional elements can be installed before this functional element, i.e. between the connection organ and the filter module, such that the filter module once more constitutes the last element. 
     One variant provides that at least one functional module has a distributor connection. This distributor connection forms a branch such that compressed air can be branched off from the system. Therein, the distributor connection can be coupled to the air line within the functional module before or after the functional element such that either the treated or untreated air can be branched off. 
     In a preferred fashion, all functional elements comprise such a distributor connection such that, depending on the requirements, air can be branched off from any section of the maintenance device without great installation effort. 
     In one embodiment, the air line is configured and the functional modules are disposed such that the air is treated in a vertical direction from the bottom to the top. This means that when the compressed air to be treated has been inlet, it is first guided through all functional elements to the lowermost functional element and then, starting with the lowermost functional element, is then treated within the individual functional elements in rising sequence, wherein the completely treated compressed air exits the maintenance device at the uppermost functional element. 
     A preferred embodiment provides that an installation module, comprising the connections for the compressed air to be treated, for the treated compressed air, and the connection for the electric lines, constitutes a connection element whose lower side has a coupling flange and which has insertion elements and/or a display unit which, in particular, also accommodates the further functional elements. This installation module also serves for connecting all pneumatic and electric lines and is optionally also provided with fastening means such that the maintenance device can be mounted e.g. to a machine support or to a wall. The individual functional modules are coupled to this installation module from below, which does not impact on the pneumatic and electric connections. These further functional modules are adjusted using the installation module which, in turn, comprises insertion elements and/or a display unit, e.g. a LCD screen for this purpose. 
     In a preferred fashion, only this installation module is provided with fastening means such that the further functional modules can be easily removed from the maintenance device for revision, maintenance and/or repair without having to remove the maintenance device. 
     A preferred embodiment provides that the connection for the compressed air to be treated, the connection for the treated compressed air and optionally the connection for electric lines is provided on one of the functional modules. 
     Further advantages, features and details of the invention can be extracted from the dependent claims and the following description showing, in detail, a preferred embodiment. The features shown in the drawing and disclosed in the claims and the description may be essential for the invention either individually or collectively in any arbitrary combination. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a schematic side view of a first embodiment of a maintenance device; 
     FIG. 2 shows a front view of the maintenance device; 
     FIG. 3 shows a perspective view of another embodiment of a maintenance device; 
     FIG. 4 shows a perspective view of a lower section of the maintenance device in accordance with FIG. 3; and 
     FIG. 5 shows an exploded view of a functional module. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1 schematically illustrates a wall  1  to which a maintenance device, designated in its totality with  2 , is mounted, wherein the maintenance device  2  has a total of four functional modules  3 ,  4 ,  5  and  6 . The uppermost functional module  3 , formed as installation module  7 , is mounted to the wall  1  using e.g. screws (not shown). This installation module  7  has two connections  9  and  10  on the side wall  8  or side surface facing the observer. A line  25  (FIG. 3) guiding the compressed air to be treated is connected to the connection  9  and a line  26  (FIG. 3) carrying the treated compressed air is connected to the connection  10 . The compressed air thereby enters into and exits from the functional module  3  at the same side, i.e. the side wall  8 . 
     The side wall (not shown) opposite to the side wall  8  also comprises two connections such that the lines  25  and  26  guiding the compressed air can be alternatively connected to this side wall. It is also possible to connect one line  25  or  26  to the side wall  8  and the other line  26  or  25  to the opposite side wall. 
     A pulsed lubricator module  11  is located below the installation module  7  and an EP regulator module  12 , comprising a switch-on valve and soft start, is disposed below the pulsed lubricator module  11 . The lowermost functional module  12  is a filter module  13  comprising a pre-filter and superfine filter. Flow passes from the top to the bottom through the functional modules  3  to  6  via an air line  14  disposed in the rear area, wherein the compressed air in the filter module  13  is deflected to the top. The air thereby flows through a filter provided in the filter module  13 . Flow passes in the forwardly disposed air line  15  through the individual functional modules  3  through  5  from the bottom to the top, wherein the air is treated in each functional module. 
     FIG. 1 also shows that the functional modules  4  to  6  comprise distributor connections  16  on their side walls by means of which part of the compressed air can be branched off. The side walls are furthermore provided with coupling elements  17  via which the individual functional modules  3  to  6  can be interconnected. 
     FIG. 2 shows the front view of the maintenance device  2 , wherein the installation module  7  has an operation board  18  with a display unit  19 . The operation board and the display unit are located at an ergonomically favorable position on a surface  20  inclined towards the front (FIG.  1 ). The pulsed lubricator module  11  is located below this installation module  7  and comprises an operation display  21  and further display elements  22  and  23  e.g. for the operational condition and the oil supply. The EP regulator module  12  also has an operation display  21 . The set regulator pressure can be adjusted on the operation board  18  and can be displayed or read on the display element  19 . Low pressure compressed air can be branched off via the distributor connection  18 . 
     The filter module  13  also comprises an operation display  21  and display elements  22  and  23 . The lower side of the filter module  13  is provided with an outlet stopper  24  e.g. for water. 
     FIG. 3 shows a perspective view of the maintenance device  2 , wherein only the coupling elements  17  have an alternative shape. The two compressed air lines  25  and  26  are connected to the connections  9  and  10  at the same side wall. It is clearly shown that further functional modules can be easily coupled below the installation module  7  and above the functional module  6  or the filter module  13  without having to dismount the entire maintenance device  2  from the compressed air lines  25  and  26  or from the wall  1 . The installation or length of the compressed air lines  25  and  26  must not be modified. This also applies should one of the functional modules be removed. Since the compressed air lines  25  and  26  can be connected to the visible side wall  8  and also to the opposite side wall or also to the rear side of the installation module  7 , the maintenance device  2  can be universally used and the compressed air lines  25  and  26  can be connected as required. Existing installations must not be modified. 
     FIG. 4 shows the EP regulator module  12  and the filter module  13  which are connected to one another via the coupling element  17 . The upper side of the EP regulator module  12  is formed by a coupling flange  27  into which the two air lines  14  and  15  feed. Part of an electric plug connection  28  is also visible by means of which the electric lines of the individual functional modules can be connected to one another. 
     FIG. 5 shows the EP regulator module  12 . Visible are, in particular, the diaphragm  29 , via which the desired pressure is adjusted, and the electronics  30 . The two air lines  14  and  15  open into the coupling flange  27  at transfer openings  31  and  32 . Sealing is achieved via rubber seals (e.g. O-rings or the like, not shown). 
     One sees that the individual functional modules  3  to  6  are disposed one on top of the other in a vertical direction and the compressed air to be treated as well as the treated compressed air are guided in an essentially vertical direction within the functional modules  3  through  6 . When the maintenance device  2  is extended or if a functional module is removed, only the vertical size of the maintenance device changes. The width of the maintenance device  2  and in particular the connections  9  and  10  remain, in any event, unchanged.