Abstract:
An integrated unit for air treatment in pneumatic systems comprises a box-shaped body provided with an inlet for the air to be treated and at least one outlet for the treated air and holds devices for treatment and regulation of the air flow between the inlet and outlet. The devices consist of at least one filter device, one pressure regulator and one progressive-starting device.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to an integrated unit performing a plurality of functions related to air treatment in pneumatic systems. 
         [0003]    2. State of the Prior Art 
         [0004]    Practically all pneumatic systems using compressed air for actuation functions of every type start with a unit for treatment of the compressed air. In fact, the air before being admitted into the distributors and actuators is required to be regulated and filtered. Therefore, these units are applied to all working machines, such as assembling machines, machine tools, packaging machines, etc.; in the compressed-air distribution systems, in the car field, in particular in equipped lorries, in the industry field, etc. 
         [0005]    All known units consist of individual elements, each having a specific function, that are then assembled in series with each other. The most traditional combination of elements used in automation may comprise a manual on-off valve at the inlet, a filter, a pressure regulator, an electric on-off valve, a pressure switch, several intakes, etc. 
         [0006]    The elements can be someway of the modular type so as to have attachments and sizes compatible with each other in the same series, but in any case they are always elements that must be assembled one after the other. 
         [0007]    There are many limits and defects in the units made with known elements. It is to be mentioned the big sizes, in particular with a high extension in the formation direction of the series; the very bad ergonomics due to the fact that the functions of interest of the user or the maintenance man are distributed in an incoherent manner on the unit, some on the upper side (the pressure regulating hand grips, for example), some on the front (manometer, etc.), some on the lower side (filter cup), so that there are not only positioning difficulties but also a poor understanding of the functions performed by each element and of the point which must be acted upon for regulations; the difficulties for servicing interventions, such as replacement of the filter cartridge; the very bad overall aesthetic appearance that is no longer suitable for the modern machines for which the units are designed. 
         [0008]    In addition, some functional problems are still unresolved, so that the reliability of the system as a whole is impaired due to leakages, jamming, etc. 
         [0009]    For example, in known filter modules or elements the servicing interventions, such as replacement of the filter cartridge, are difficult and often uncomfortable, above all when the unit is positioned in regions of the machine utilizing it that are hardly accessible. In particular, in order to receive the condensate at the filter base, the cartridge is always disposed vertically in a cup under the air inlet, with the air flow that is radially directed from the cartridge outside to the inside. Such an arrangement creates problems in terms of vertical bulkiness that can be hardly resolved, so that uncomfortable operations are required even if the filter cup is only to be unscrewed. 
         [0010]    In addition, the automatic systems for condensate discharge are subjected to jamming in the presence of solid particles suspended in the air and therefore they are often refused by the user. 
         [0011]    It is a general aim of the present invention to obviate the above mentioned drawbacks by providing an innovative integrated unit enabling supply of the different facilities that are necessary at the inlet of pneumatic systems and, among other things, possessing features of small bulkiness, high reliability, practical and quick use and ready maintenance. 
         [0012]    It is a further aim of the present invention to provide said unit with a filtering device equipped with an efficient and easily accessible filter, above all for the operations concerning maintenance and replacement of the cartridge and that, if also equipped with a device for condensate discharge, does not suffer for jamming due to the presence of solid particles entrained into the device by the air flow. 
         [0013]    A still further aim of the present invention is to provide the unit with a regulation device for progressive starting that is of reduced bulkiness and is capable of offering a satisfactory progressive starting irrespective of the conditions of the circuit downstream thereof. 
       SUMMARY OF THE INVENTION 
       [0014]    In view of the above aims, in accordance with the invention, an integrated unit for air treatment in pneumatic systems has been devised, which comprises a box-shaped body provided with an inlet for the air to be treated and with at least one outlet for the treated air and containing devices for treatment and regulation of the air flow between the inlet and outlet, said devices comprising at least one filter device, one pressure regulator and one progressive-starting device. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    For better explaining the innovative principles of the present invention and the advantages it offers over the known art, a possible embodiment applying said principles will be described hereinafter by way of example, with the aid of the accompanying drawings. In the drawings: 
           [0016]      FIG. 1  is a diagrammatic front view of a unit in accordance with the invention; 
           [0017]      FIG. 2  is a diagrammatic view partly in section of part of the inside of the unit seen in  FIG. 1 ; 
           [0018]      FIG. 3  is a diagrammatic view of the unit taken along line III-III in  FIG. 2 ; 
           [0019]      FIG. 4  is a diagrammatic view in section of a detail of the unit where also part of the block diagram of the unit circuit is represented; 
           [0020]      FIG. 5  is a diagrammatic view of the unit taken along line V-V in  FIG. 2 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0021]    With reference to the drawings, shown in  FIG. 1  is an integrated unit generally denoted at  210 , implemented in accordance with the principles of the invention. Unit  210  has a generally parallelepiped or box-shaped conformation with a body  10  on the external surface of which connectors, commands, indicators, etc. appear. In particular, a main inlet connector  11  and an opposite main outlet connector  12  are present. Advantageously, also an auxiliary outlet  13  which is filtered but not regulated and two auxiliary outlets  14 ,  15  in parallel to the main outlet  12  but with a connector of different diameter (¼″, for example) can be present. All connectors are disposed on side faces. 
         [0022]    The indicators and commands are disposed on the front panel. As clarified in the following, they comprise, among other things, a regulator  224  for regulation of the progressive-starting function and a manual shutoff and air-discharge valve  228 . Advantageously, there may be also the presence of a pilot pressure regulator  227 , an outlet pressure switch  17 , a manometer  16  and LED signallers visually indicating the activation state of the pressure switch and the state of a possible inner solenoid valve (denoted at  229  in  FIG. 4 ). The connections of the manometer and pressure switch at the exit of the device are well visible in the section in  FIG. 5  as well. 
         [0023]    As further described in the following, unit  210  also comprises a filter device  114  whose plug  120  for access to the cartridge is disposed with a horizontal axis and appears on the front panel as well, and a condensate discharging device  115  with a lower outlet  127  for the water and projecting from the lower side of the unit. 
         [0024]    Also provided may be an electric side connector  18  reproducing the electric signals of the pressure switch and LED indicators and said connector  18  is powered and receives the activation signal from the solenoid valve. 
         [0025]    Shown in  FIG. 2  is part of the whole unit. In particular, clearly shown is the main inlet connector  11 , the device portion  110  concerning filtering and condensate discharge, with the filter unit  114  and the condensate collection and discharge assembly  115 , a piloted valve  212  for pressure regulation, a piloting unit with progressive starting  215 . 
         [0026]    Diagrammatically shown in  FIG. 3  is a section taken along line III-III in  FIG. 2  of the portion  110  of unit  210  carrying out air filtering and condensate discharge, in accordance with a preferred solution of the invention. 
         [0027]    With reference to  FIG. 3 , the filter and condensate discharge region comprises a body  111  (advantageously of one piece with the body of the remainder of the unit) provided with an inlet  112  for the air to be filtered coming from the main inlet connector  11 , and an outlet  113  for the filtered air which is directed to the remainder of the unit and towards the main outlet connector  12 . Housed in body  111  is the filter unit  114  and the condensate collection and discharge assembly  115 . 
         [0028]    The filter unit  114  is advantageously extended along a horizontal axis  116  while the condensate assembly  115  is disposed under the filter unit and is extended along a vertical axis  117 . The condensate assembly is disposed downstream of the filter unit and the air flow radially passes through the filter from the inside to the outside. 
         [0029]    In particular, the filter unit is provided with a suitable cylindrical filtering cartridge  118 , received in a suitable seat  119  sealingly closed by the threaded plug  120 , also of horizontal axis  116 . 
         [0030]    Advantageously, the air inlet  112  communicates with the inside of cartridge  118  through an on-off valve  121  the closure member  122  of which is pushed and closed against an abutment  123  by the action of a spring  124 . Axially present internally of the plug  120  is a rod  125  that, when the plug  120  is correctly screwed down in place, keeps the valve open against the action of spring  124 . 
         [0031]    The condensate assembly  115  comprises a cup  126  for collection of the condensate entrained through the filter. The cup has a lower exhaust outlet  127  that can be operated either manually (with a screw threaded plug or a valve, for example) or advantageously in an automatic manner by a known float valve  128  opening when the liquid level in the cup exceeds a predetermined threshold. 
         [0032]    Present on the cup  126  top is a system consisting of inclined lamellae  129  such disposed that they are licked by the air flow directed towards the outlet  113  so as to separate the condensate from the flow itself and cause dripping of the condensate into the underlying cup. 
         [0033]    The horizontal arrangement of the filter with front extraction makes the device both compact and of easy placement and quick maintenance. In addition, the air flow passing through the filter cartridge from the inside to the outside causes the intercepted dirt to remain internally of the cartridge when the latter is removed from its seat, which will facilitate replacement of the cartridge and make it quicker. Separation of the condensate after filtering also prevents particles of dirt from reaching the condensate assembly and stopping or clogging the exhaust outlet. This ensures a high reliability of the possible advantageous self-discharge device. 
         [0034]    Automatic closure of the inlet air flow when the filter plug is unscrewed avoids accidental air escape into the surrounding atmosphere and makes filter replacement more comfortable and quicker. Since separated flow cut-off cocks are not required, the device is cheaper and less bulky. 
         [0035]    Turning back to  FIG. 2 , the outlet  113  after discharge of the condensate directly leads to a regulation valve  212  provided with a closure member  240  that, urged by a spring  241 , closes passage to the outlet  12 . The closure member  240  is operated for opening by a control piston  242  which is acted upon, on the side towards the closure member, by the outlet pressure (through a passage  243 ) and, on the side opposite to the closure member, by a control pressure (through a passage  213 ). Thus a pressure regulating valve  212  of the differential type is obtained, i.e. a regulation member that is movable by means of the opposite thrusts produced by the pressure coming out of the regulator itself and by the pressure at the piloting inlet  213 . 
         [0036]    The piloting inlet is controlled by a piloting module or unit, generally denoted at  215 , to perform, among other things, the function of progressive starting. 
         [0037]    An advantageous embodiment of the piloting unit  215  is shown in  FIG. 4  (in an extended view for better understanding). This unit  215  comprises an inlet  230  that will be connected upstream of valve  212  (through a passage  214 , not shown in  FIG. 2 ), and an outlet  211  directed to the outlet connector  12 . 
         [0038]    As clearly shown in the circuit diagram drawn under module  215 , between the inlet and outlet there is the presence of the pressure regulator  212  being controlled by the piloting inlet  213 . 
         [0039]    Connected upstream of regulator  212  is the inlet of a secondary circuit  214  leading to a piloting unit  215  supplying the piloting command  213  to valve  212 . 
         [0040]    The piloting unit comprises a progressive starting device  216  fed from the inlet  214  and sending air from the outlet  226  to the piloting command  213 . 
         [0041]    In particular, device  216  comprises an inlet duct  217  connected to the inlet  214 , possibly through further control members to be described in the following. Duct  217  is divided into a main branch  218 , connected with the outlet  226  through an on-off valve or closure member  219  pushed for closure by a spring  220 , and a secondary branch  221  reaching the outlet  226  through a throttled passage  222 . Throttling  222  can be advantageously obtained in an adjustable manner by means of a pin  223  axially movable through an adjusting hand grip  224 . 
         [0042]    A distributor or slide valve  225  exerts pressure on the closure member  219  in the direction of the opening thereof, against the action of spring  220 , due to the pressure to which it is subjected that is created in the outlet duct  226 . In this manner, the flow rate established by the pin produces a gradual pressure increase in the outlet duct until the thrust present on the side downstream of the closure member  219  overcomes the thrust on the upstream side and the closure member opens the main duct  218  to the outlet. It is apparent that pressure variation on the outlet  226  is used to consequently control operation of valve  212  that will thus produce a corresponding pressure variation in the outlet line  211 . Obviously the variation on the outlet  211  takes place irrespective of what is connected therewith. 
         [0043]    Thus a perfect progressive starting is obtained under any load condition of the line. Reaching of the condition of full operation of the main circuit is also ensured irrespective of the presence of possible small pressure losses on the main circuit itself. 
         [0044]    In the advantageous embodiment described, the true progressive starter acts on piloting of a valve instead of being directly placed on the main line, which on the contrary happens in the known art. 
         [0045]    Such a structure also offers other advantages. The progressive starter  216  must be sized for the (very reduced) pilot flow rate necessary for regulator  212  and not for the much bigger flow rate of the main line  211 . This enables a progressive starting unit to be made which is of much more reduced bulkiness than in the solutions of the known art. The intrinsic sturdiness of the unit is also favored. 
         [0046]    The piloting circuit of valve  212  with which the progressive starter is connected can also advantageously be a pilot circuit for pressure regulation on the main line. In fact, if along line  214  a known pilot pressure regulator  227  is placed, pressure stabilization on the outlet line  211  occurs during normal operation after the progressive starting. In addition, also provided in series with the pilot regulator can be a manual valve  228  and/or an electric valve  229 , of the type 3/2. Advantageously, as shown in  FIG. 4 , valve  228  can be inserted in the body of the progressive starter. Valves  228 ,  229  enable opening and closure of valve  212  to be carried out in a controlled manner. Thus an efficient piloted regulator of reduced bulkiness and high sturdiness is obtained. 
         [0047]    At this point it is apparent that the intended purposes have been achieved by providing an integrated unit having many functions while being of reduced sizes, said unit also offering high efficiency, reliability and sturdiness. It is clear that an integrated unit manufactured in accordance with the invention can be easily positioned in reduced spaces while always maintaining high accessibility and ease of use and maintenance. It is also apparent that the manufacturing costs can be greatly reduced as compared with those of the known art according to which separated elements to be assembled are provided. In particular, use of a monobloc body between the inlet and outlet of the unit and enclosing most of the facilities required further reduces costs and bulkiness and prevents many possibilities of leakage. In the advantageous embodiment shown the whole unit is substantially formed of two bodies, the main one  20 , with the filter, the controlled valve  212  and all the ducts between the inlet and outlets, and a secondary body implementing the control module  215 . Due to the front arrangement of the displays and commands, the device can be easily mounted on a panel. 
         [0048]    Obviously, the above description of an embodiment applying the innovative principles of the present invention is given by way of example only and therefore must not be considered as a limitation of the scope of the patent rights herein claimed.