Patent Publication Number: US-2012036844-A1

Title: Pneumatic system with one or more piston-cylinder arrangements

Description:
RELATED APPLICATIONS 
     This application is a continuation-in-part of U.S. patent application Ser. No. 11/575,052 filed Mar. 9, 2007, which claims priority to International Patent Application No. PCT/SE2005/001423 filed Sep. 28, 2005 which claims the benefit of priority to Swedish Patent Application No. SE 0402334-7 filed Sep. 28, 2004 whose contents are incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present invention relates in general to a pneumatic system, the system comprising int. al. one or more piston-cylinder arrangements or other similar arrangements, generically designated “motors”, where a piston unit in a selected embodiment will be reciprocally moveable within a cylinder unit by a pneumatic pressure medium put under excess pressure by means of a control valve. More particularly, the present invention relates to such a pneumatic system with a pressure source adapted for generating a medium under pneumatic excess pressure, a control valve coordinated with the pressure source, across or via a first conduit, in any event one piston-cylinder arrangement or a “motor” whose operating or working chamber is coordinated with said control valve, across or via a second conduit, and whose low-pressure or return chamber is coordinated, across or via a third conduit, with one side of a coupling arrangement whose other side is coordinated with said pressure source, across or via a fourth conduit. 
     The present invention is principally intended to be able to offer a coupling arrangement which is physically discrete and separate from a utilized, standardized piston-cylinder arrangement and which not only offers energy savings but also increased speed of the reciprocal motion of the piston unit. 
     More particularly, the present disclosure relates to the utilization of a piston-cylinder arrangement where the piston unit is, by the intermediary of action from a control valve, by a system pressure acting within a working chamber, caused to move in a first direction and where a recuperation or return to a starting position on cessation of the above disclosed action, via the control valve, will take place automatically by an applied lower pressure acting in a low-pressure or return chamber. 
     Thus, the present invention will require access to a system for a pneumatic excess pressure, hereinafter referred as “system pressure” and access to a system for a pneumatic low-pressure, hereinafter referred to “low-pressure system”, where the system pressure will act within a working chamber during one stroke of the piston within the piston-cylinder arrangement, all while the pressure within the low-pressure system increases somewhat depending upon available volume of said low-pressure system, with a smaller increase in a larger volume and vice versa. 
     BACKGROUND ART 
     Numerous different embodiments of methods and arrangements of the above-disclosed nature are previously known in the art. 
     As a first example of the state of the art, and the technical field to which the present invention relates, mention might be made of a single piston-cylinder arrangement, shown and described in greater detail in  FIG. 1 , the arrangement being actuable by means of a single control valve, where the control valve is adapted, in a first adjustment position, to permit the supply of hydraulic or pneumatic system pressure to a working chamber and thereby positively displace a piston unit (to the right) while a medium or an air volume, enclosed in the return chamber, will depart from this chamber to an open low-pressure system, here illustrated as atmospheric pressure, according as the volume in the working chamber increases. 
     Via said single control valve, it is now possible to cause it, assuming a second adjustment position, to supply hydraulic or pneumatic pressure to a return chamber which will then serve the purpose corresponding to a working chamber and thereby positively displace the piston unit (to the left) while an air volume, enclosed in the working chamber and now serving as the return chamber, departs from the return chamber to the low-pressure system, here illustrated as atmospheric pressure, according as the volume in the working chamber increases. 
     A piston-cylinder arrangement, connected in this manner and utilizing a control valve constructed and connected in this manner, has proved to entail a control and operation under high losses and thereby displaying a low degree of efficiency. 
     As a second example of the state of the art, more focused on the technical field to which the present invention relates, mention might be made by referring to a piston-cylinder arrangement, shown in greater detail and described in  FIG. 2 , with a single control valve, where a return chamber of the piston-cylinder arrangement is inter-connected to a coupling arrangement. 
     This coupling arrangement will be pressurized by a control valve at the same time as pneumatic system pressure is supplied to the working chamber within the piston-cylinder arrangement and, as a result, a lower, but nevertheless increasing, pressure is built up in said return chamber, this pressure also being increased by the motion of the piston unit. 
     The coupling arrangement disclosed here displays, as a low-pressure system, a series connection of an accumulator tank, a low-pressure valve, a non-return valve and a throttle, all with the common purpose of permitting a damping control of the motion of the piston unit towards an end position for the stroke and, by the intermediary of an excess pressure supplied to the coupling arrangement within the low-pressure system, to return the piston unit to its starting position (shown in  FIG. 2 ). 
     Observing the technical considerations, which are to be related to the basic preconditions for the present invention, mention might also be made, as part of the prior art, with reference to a piston-cylinder arrangement which is schematically illustrated and described in  FIG. 3 . 
     This piston-cylinder arrangement displays an extremely complex structure for the cylinder part or unit, which, with the aid of ducts in association with the cylinder, may form an accumulator tank for its low-pressure system, and with an array of ducts within the end piece or section of the cylinder unit, to be able to create the preconditions for introduction of a low-pressure regulator, a high-pressure regulator and an expansion space. 
     The practical construction of such a specifically designed and constructed piston-cylinder arrangement is illustrated more closely and described in Swedish Patent Publication Number SE-C2-510 463. 
     Reference is also made to the contents of the International Patent Application PCT/SE01/00589 (International Publication Number WO 01/73299 A1), in which it is disclosed a method and an energy-saving cylinder device of a single-acting type. 
     More specifically, this publication does reveal a method of in an energy-saving way operating a single-acting cylinder device provided with a return function, which comprises a cylinder part ( 2 ) with an interior cylinder serving duct ( 50 ) and a piston ( 4 ) arranged in a movable manner in the duct ( 50 ), said piston defining a working chamber ( 5 ) and a return chamber ( 6 ) in the duct ( 50 ) and executing a working stroke and a return stroke in the same, the method comprising the steps of; 
     causing a first fluid to flow into the working chamber ( 5 ) from a pressure source ( 39 ), which has an output pressure, and thereby operating the working stroke of the piston ( 4 ), 
     closing the return chamber ( 6 ), so that a second fluid in the return chamber ( 6 ) is compressed during the working stroke of the piston ( 4 ), and 
     opening the working chamber ( 5 ) after the working stroke, so that the first fluid is permitted to flow out of the working chamber ( 5 ) into the atmosphere and so that the second fluid compressed in the return chamber ( 6 ) returns the piston ( 4 ) during the return stroke. 
     As significant steps, related to that publication, it is suggested the step of reducing the pressure of the second fluid in the return chamber ( 6 ), if this pressure exceeds an upper pressure value, which is the pressure reached first of either the output pressure of the pressure source ( 39 ) or a maximum pressure value, which corresponds to a maximum permissible pressure in the return chamber ( 6 ) during operation. 
     Consideration Related to the Present Invention Problem Structure 
     Considering the circumstance that the technical deliberations that must be made by a person skilled in the art to be able to offer a solution to one or more technical problems posed is, on the one hand, initially a necessary insight into the measures and/or sequence of measures to be adopted and, on the other hand, a necessary selection of the means required, the following technical problems are likely, in view hereof, to be relevant in the evolution of the subject matter of the present invention. 
     Considering the state of the art, as described above, it should therefore be seen as a technical problem to be able to realize the importance of, the advantages associated with and/or the technical measures and considerations which will be required in order to create a coupling arrangement which may offer the operational technical advantages which may be deemed to be related to the above-described construction but still be able to refrain from the constructional complexity of the piston-cylinder unit, according to the mentioned Swedish Patent Publication and/or according to the mentioned International Patent Publication, and where measures have been adopted which entail that this operational technical effect has been capable, in a simple manner, of being transferred to system constructions and couplings within a pneumatic system applicable to standardized single piston-cylinder arrangements, such as according to  FIG. 1 , utilizing single control valves, and thereby be able to offer a piston-cylinder arrangement or motor displaying a simple and automatic return motion. 
     There resides a technical problem in being able to realize the importance of, the advantages associated with and/or the technical measures and considerations which will be required in order to create such preconditions that already installed piston-cylinder arrangement or arrangements, with associated control valve or valves, may readily be retrofitted, according to the disclosures of the present invention, by a simple coupling-in of a special unit, enclosing a coupling arrangement according to the present invention, and a simple supplementary provision of conduits, as well as a simple modification of the control valve. 
     There resides a technical problem in being able to realize the importance of, the advantages associated with and/or the technical measures and considerations which will be required in a pneumatic system with a pressure source adapted for generating a medium or air, which is under excess pressure and is utilized as a system pressure, a control valve coordinated with the pressure source, across or via a first conduit (tube or hose), one or more piston-cylinder arrangements or one or more “motors” whose working chamber is coordinated, across or via a second conduit, with said control valve and whose low-pressure or return chamber is coordinated, across or via a third conduit, with one side of a unitary coupling arrangement whose other side is coordinated, across or via a fourth conduit, with said pressure source, and where said coupling arrangement is to be in the form of a unit, which is pneumatically coordinated with the piston-cylinder arrangement but discrete and separate or separable from said piston-cylinder arrangement, where there is, within said unit and extending between connections associated with the unit, in any event one coordinated coupling-in of a high-pressure regulator and a low-pressure regulator. 
     Moreover, there resides a technical problem in being able to realize the importance of, the advantages associated with and/or the technical measures and considerations which will be required in a pneumatic system, where, during the time elapsed for a stroke, the coupling arrangement will be adapted so as to be able to offer a controlled compression of the medium within the low pressure or return chamber by the observation of relevant static or dynamic conditions within the low-pressure system and its volume. 
     There resides a technical problem in being able to realize the importance of, the advantages associated with and/or the technical measures and considerations which will be required in a pneumatic system, where said piston-cylinder arrangement may each consist of a single standardized unit. 
     There resides a technical problem in being able to realize the importance of, the advantages associated with and/or the technical measures and considerations which will be required in a pneumatic system where a single standard safety valve is to be connected to a conduit, a fourth conduit, or the like. 
     There resides a technical problem in being able to realize the importance of, the advantages associated with and/or the technical measures and considerations which will be required in a pneumatic system, where said unit may display a compact coupling-in of a safety valve and a coupling-in of said high-pressure regulator and said low pressure regulator. 
     There resides a technical problem in being able to realize the importance of, the advantages associated with and/or the technical measures and considerations which will be required in a pneumatic system where in an accumulator tank associated with the low-pressure side or the low pressure system, may when necessary be directly or indirectly connected to a volume, serving as low-pressure or return chamber, for one or more piston-cylinder arrangements at rest or undergoing change. 
     There resides a technical problem in being able to realize the importance of, the advantages associated with and/or the technical measures and considerations which will be required in a pneumatic system where said high-pressure regulator may be adjustable to a maximum system-adapted low-pressure or return chamber related value, which is applicable at the end of a piston stroke. 
     There resides a technical problem in being able to realize the importance of, the advantages associated with and/or the technical measures and considerations which will be required in a pneumatic system, where said low-pressure regulator may be adjustable to a minimized, system-adapted value, which applies to a low-pressure or return chamber in conjunction with an initial piston stroke. 
     There resides a technical problem in being able to realize the importance of, the advantages associated with and/or the technical measures and considerations which will be required in a pneumatic system, where the high-pressure regulator may be adjustable manually and/or by the intermediary of a step motor. 
     There resides a technical problem in being able to realize the importance of, the advantages associated with and/or the technical measures and considerations which will be required in a pneumatic system, where the low-pressure regulator may be adjustable manually and/or by the intermediary of a step motor. 
     There resides a technical problem in being able to realize the importance of, the advantages associated with and/or the technical measures and considerations which will be required in a pneumatic system, where said coupling arrangement may be adapted to cause pressurization of said low-pressure or return chamber before a first stroke, this latter being actuable by the action of said control valve. 
     There resides a technical problem in being able to realize the importance of, the advantages associated with and/or the technical measures and considerations which will be required in a pneumatic system, where said safety valve may consist of a non-return valve adapted, in the event of an emergency stop, rapidly to bleed the system of air. 
     There resides a technical problem in being able to realize the importance of, the advantages associated with and/or the technical measures and considerations which will be required in a pneumatic system, where an accumulator tank, associated with a coupling arrangement, is to be incorporated in said unit, or alternatively coupled into said third conduit as a complement to the accumulator tank-like effect which the low-pressure or return chamber of the piston-cylinder arrangements gives to a utilized low-pressure system. 
     There resides a technical problem in being able to realize the importance of, the advantages associated with and/or the technical measures and considerations which will be required in a pneumatic system, where a selected number of separately controlled piston-cylinder arrangements may, as regards their low-pressure or return chamber, be coordinated with and connected to one and the same low-pressure system and one and the same coupling arrangement. 
     There resides a technical problem in being able to realize the importance of, the advantages associated with and/or the technical measures and considerations which will be required in a pneumatic system, where a selected number of first, separately controlled piston-cylinder arrangements may, as regards their low-pressure or return chamber, be coordinated with and connected to one and the same first coupling arrangement, dimensioned and adapted to each one of said utilized piston-cylinder arrangements and their mutual positions as well as relevant conditions prevailing within the low-pressure system. 
     There also resides a technical problem in being able to realize the importance of, the advantages associated with and/or the technical measures and considerations which will be required in a pneumatic system, where a selected number of other, separately controlled, piston-cylinder arrangements will be able, as regards their low-pressure or return chambers, to be coordinated with and connected to one and the same other coupling arrangements, dimensioned and adapted to said piston-cylinder arrangement and their mutual positions as well as relevant conditions prevailing within the low-pressure system. 
     There resides a technical problem in being able to realize the importance of, the advantages associated with and/or the technical measures and considerations which will be required in a pneumatic system where all piston-cylinder arrangements coordinated to one coupling arrangement should be dimensioned equally or in any event substantially equally. 
     Solution 
     The present invention thus takes as its point of development the state of the art, as disclosed by way of introduction in respect of a pneumatic system, with a pressure source adapted for generating a medium or air placed under pneumatic pressure, a control valve coordinated with said pressure source, across or via a first conduit, in any event one piston-cylinder arrangement or one “motor” whose working chamber is coordinated, across or via a second conduit, with said control valve and whose low pressure or return chamber is coordinated, across or via a third conduit, with one side of a coupling arrangement whose other side is coordinated with said pressure source, across or via a fourth conduit. 
     In order to be able to solve one or more of the above-outlined technical problems, the present invention in particular discloses that the prior art is to be supplemented by causing the coupling arrangement to be in the form of a unit, pneumatically coordinated with the piston-cylinder arrangement but nevertheless physically discrete and separate from said piston-cylinder arrangement, and that there is disposed, within said unit and extending between connections associated with said unit, in any event one direct or indirect coupling-in of a high-pressure regulator and a low-pressure regulator. 
     In addition the present invention suggests that, during the time elapsed for a stroke, the coupling arrangement will be adapted so as to be able to offer a controlled compression of the medium or air, within the low-pressure or return chamber by the observation of relevant static or dynamic conditions within said low-pressure system or a volume of a tank, designated as an accumulator tank. 
     As proposed embodiments, falling within the scope of the fundamental concept of the present invention, it is disclosed that said piston-cylinder arrangement may advantageously consist of a single, such as a standardized, piston-cylinder unit. 
     It is further disclosed that a safety valve be connected to a conduit, a fourth conduit, or the like. 
     Said unit should advantageously display a parallel coupling of a safety valve and a coordinated coupling-in of said high-pressure regulator and said low-pressure regulator. 
     It is further disclosed that an accumulator tank, related to the low-pressure system, may, when necessary, be directly or indirectly connected to one or more low-pressure or return chambers, disposed at one or more piston-cylinder arrangements. 
     Said high-pressure regulator should advantageously be adjustable to a value adapted to a low-pressure system, applying at the end of a piston stroke. 
     Said low-pressure regulator should be adjustable to a value adapted to a low-pressure system valid for the low-pressure or return chamber in conjunction with an initial piston stroke. 
     The high-pressure regulator should be adjustable to its allocated limit value manually and/or by the intermediary of a step motor. 
     The low-pressure regulator should be adjustable to its allocated limit value manually and/or by the intermediary of a step motor. 
     Said coupling arrangement is adapted to allow pressurization of the low-pressure system and thereby causing said low-pressure or return chamber, prior to a first piston stroke, to be activated by the intermediary of the action of said control valve. 
     During time intervals for a piston stroke, the coupling arrangement is adapted to be able to offer controlled compression of the medium or air within the low-pressure system and its low-pressure or return chamber. 
     Said high-pressure regulator is adapted to permit the presetting of a valid active maximized pressure for the low-pressure system and its low-pressure or return chamber, at the end of the piston stroke. 
     Said low-pressure regulator is adapted to allow the presetting of a valid active minimized pressure for the low-pressure system and its low-pressure or return chamber, at the beginning of the piston stroke. 
     Further, a coupled-in safety valve should consist of a non-return valve adapted, in the event of an emergency stop, to bleed the system of air. 
     An accumulator tank provided for the low-pressure system and related to the coupling arrangement may be incorporated in said unit or alternatively coupled in as a separate unit to a conduct, such as said third conduit. 
     A selected number of separate, controlled piston-cylinder arrangements are, in respect of their low-pressure or return chamber, provided for the low-pressure system, coordinated with one and the same coupling arrangement. 
     A selected number of first, separately controlled, piston-cylinder arrangements are, in respect of their low pressure or return chambers, provided for the low-pressure system, coordinated and connected to one and the same first coupling arrangement. 
     A selected number of second, separately controlled, piston-cylinder arrangements are, in respect of their low-pressure or return chambers, provided for the low pressure system, coordinated and connected to one and the same second coupling arrangement. 
     All piston-cylinder arrangements, coordinated to one and the same coupling arrangement, may advantageously be dimensioned identically or in any event substantially identically. 
     Advantages 
     The advantages which may principally be deemed to be associated with the present invention and the thereby disclosed specific significative characterizing features are that there have hereby been created preconditions for being able to render considerably more efficient the operation of one or more standardized piston-cylinder arrangements with a control valve coupled thereto by simple coupling-technical complements and the coupling-in of a separate unit, containing a coupling arrangement with access to a low-pressure regulator and a high-pressure regulator, as well as the utilization of a safety valve within a low-pressure or return conduit. 
    
    
     
       BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS 
       Prior art constructions and currently proposed embodiments, displaying the significant characterizing features, associated with the present invention, will now be described in greater detail herein below, for the purposes of exemplification and with reference to the accompanying Drawings. In the accompanying Drawings: 
         FIG. 1  shows the prior art fundamental construction of a standardized piston-cylinder arrangement with an associated control valve and where the one adjustment position of the control valve gives a displacement effective by a system pressure of the piston unit in a first direction (to the right) while the other adjustment position of the control valve gives a displacement, effective by the system pressure, of the piston unit in a second, opposing direction (to the left) while an air volume, enclosed in a return chamber, is allowed under throttle to pass out to atmospheric pressure; 
         FIG. 2  shows a prior art construction of a coupling arrangement related to a piston-cylinder arrangement with a series connection from a return chamber of an accumulator tank, a low-pressure valve, a non-return valve and a throttle, and where this coupling arrangement is supplied with a reduced system pressure to the return chamber at the same time as the working chamber is supplied with a system pressure by the intermediary of the action of one and the same control valve, and there have thereby been created the preconditions for, at the end of a piston stroke, via a selected excess pressure in the accumulator tank and the return chamber, to cause the piston unit to return to its starting position, in accordance with that described and illustrated in Patent Publication DE-32 33 739-A1; 
         FIG. 3  illustrates and describes as a prior art a simplified coupling arrangement integrated and coordinated with a specially constructed piston-cylinder arrangement and where a low-pressure regulator and a high-pressure regulator are integrated within a cylinder portion, in order to control the reciprocating movement of a piston unit, in accordance with that which is described and illustrated in Patent Publication SE-C2-510 465; 
         FIG. 4  illustrates and describes a standardized piston-cylinder arrangement which has been supplemented with a unit-related coupling arrangement, in accordance with the present invention; 
         FIG. 5  illustrates and describes a system with five piston-cylinder arrangements coordinated with a low-pressure system constructed with access to each return chambers and with a single coupling arrangement, in accordance with the present invention; 
         FIG. 6  illustrates and describes a system with three different sets of piston-cylinder arrangements, where each one of these is coordinated with its allocated coupling arrangement and where the low-pressure system utilizes the free volume accessible by the intermediary of the return chambers and a coupled-in accumulator tank; 
         FIG. 7  is a side elevation, partly in section, of a coupling arrangement coordinated to a unit, in accordance with the disclosures of the present invention; 
         FIG. 8  is a plan view of the unit shown in  FIG. 7 ; 
         FIG. 9  is a side elevation and cross section of the arrangement and construction for a high-pressure regulator, included in the unit, according to the present invention, but with the upper portion removed, given that its construction and function are apparent from  FIG. 10 ; 
         FIG. 10  is a side elevation and cross section of the arrangement and construction for a low-pressure regulator, included in the unit according to the present invention; 
         FIG. 11  illustrates in greater detail the coordination between the high-pressure regulator, the low-pressure regulator and a non-return valve serving as a safety valve; 
         FIG. 12  also shows the coordination of the high pressure regulator, the low-pressure regulator and the safety valve, according to  FIG. 11 ; and 
         FIG. 13  shows one preferred coupling-in of a valve serving as an emergency stop. 
     
    
    
     DESCRIPTION OF THE PRIOR ART, IN ACCORDANCE WITH FIGS.  1 ,  2  AND  3   
     As regards the prior art, illustrated in the appended Figures,  FIG. 1  illustrates the prior art fundamental construction of a standardized piston-cylinder arrangement  1  with associated control valve  2  and where the one adjustment position of the control valve gives a displacement of a piston unit or a piston member  1   a  in a first direction (to the right in  FIG. 1 ), while the second adjustment position of the control valve gives a displacement of the piston unit or the piston member  1   a  in a second, opposing direction (to the left in  FIG. 1 ), relating to a fixed cylinder unit or a cylinder member  1   b.    
     The inlet and outlet of the arrangement  1  are each provided with a throttle and one-way valve  1   c,    1   d  so that it will not be possible for the system pressure to act with full force on the piston member  1   a  within the working chamber  1   e  without an established pre-set counter pressure in the return chamber  1   f.    
     This circumstance is part of the prior art domain and will not, therefore, be described in detail. 
     The arrangement  1  is here of a construction, where the motion of the piston member  1   a  (to the right) requires pneumatic pressure in the working chamber le and where the return chamber  1   f  is in throttled cooperation with the atmosphere “a” and its pressure by the intermediary of the control valve  2 . 
       FIG. 2  illustrates and describes the construction of a coupling arrangement  3  related to a piston-cylinder arrangement, designated  3 : 1 . 
     The coupling arrangement  3  may here be considered as comprising, counting from the return chamber  3 : 10 , a series coupling of an accumulator tank  3 : 14 , a low-pressure valve  3 : 12 , a non-return valve  3 : 11  and a throttle  3 : 15  and, as a result, this coupling arrangement  3  will be progressively supplied with a reduced system pressure at the same time as the working chamber  3 : 8  is directly supplied with the system pressure  3 : 5  by the intermediary of the action of one and the same control valve  3 : 4 . 
     There have thereby been created the preconditions for, at the end of a piston stroke, via a selected excess pressure in the return chamber  3 : 10  and in the accumulator tank  3 : 14 , returning, under a pressure reduction, the piston unit  3 : 2  back to its starting position, in accordance with that which is illustrated and described in Patent Publication DE-32 33 739-A1. 
     More specifically, it may be ascertained that the coupled-in non-return valve  3 : 11  will not serve as a safety valve in accordance with the preconditions for the present invention, and that a “T” coupling  3 : 16  is utilized in order simultaneously to distribute the system pressure direct to the working chamber  3 : 8  and via the throttle  3 : 15  to the coupling arrangement  3 . 
     Referring to  FIG. 3 , this Figure illustrates and schematically describes an alternative coupling arrangement, coordinated with an extremely complicated and specially constructed piston-cylinder arrangement  1 , and where a low-pressure regulator  12  and a high-pressure regulator  11  are structured and integrated with a cylinder part or unit  1   b,  in order to control the reciprocating movement of a piston member or a piston unit  1   a  in accordance with that which is described and illustrated in greater detail in Patent Publication SE-C2-510 465. 
     More particularly, this relates to a method and an apparatus for being able to eliminate the occurrence of so-called “piston rod racing” at the first piston stroke in various types of pneumatically reciprocating piston members included in a piston-cylinder arrangement or “motor”, and where the working chamber and return chamber are usually at atmospheric pressure. 
     The utilization is here proposed of a pressure regulator, connected to a pressure medium source ( 4 ) which, via a shunt ( 29 ), is disposed to be able to be connected to the return chamber of the pneumatic “motor”. 
     This regulator is designed so that, on the application of compressed air ( 4 ), it allows the opening of the shunt ( 29 ) into the return chamber so that this is automatically pressurized at the same time as the working chamber is placed under fall working pressure. 
     The pressure regulator will now close ( 22 ) the above-mentioned shunt ( 29 ) as soon as a desired pressure has been reached in the return chamber. 
     Description of Currently Proposed Embodiment 
     It should be emphasized by way of introduction that, in the following description of currently proposed embodiments which display the significant characterizing features related to the present invention and which is clarified by means of the figures, shown in the accompanying Drawings, we have selected terms and special terminology with the intention principally of clarifying the inventive concept. 
     However, in this context it should be observed that the expressions selected here should not be considered as restrictive exclusively to the terms selected and utilized here but it should be understood that each thus selected term is to be interpreted so that, in addition, it encompasses all technical equivalents which function in the same or substantially the same mariner in order thereby to be able to attain the same or substantially the same intention and/or technical effect. 
     With reference to  FIG. 4 , this Figure thus schematically illustrates the fundamental preconditions for the present invention and where the significant properties associated with the present invention have been given general concrete form by one now proposed embodiment of the present invention described in greater detail herein below. 
     Thus,  FIG. 4  is intended to illustrate a utilized pneumatic system  6  with a pressure source  8  adapted for generating a medium or air under pneumatic pressure, in the form of a system air pressure “ST”, set at 7 bar, a control valve  2  coordinated with the pressure source  8 , across or via a first conduit “A”, a piston-cylinder arrangement or a “motor”  1 , whose working chamber  1   e  is coordinated with said control valve  2 , across or via a second conduit “B”, and whose return chamber  1   f  is coordinated, across or via a third conduit “C”, with a low-pressure system “LT”, coordinated with one side of a coupling arrangement  10 ′, whose other side is coordinated, across or via a fourth conduit “D”, with said pressure source  8  and said system pressure “ST”. 
     Said coupling arrangement  10 ′ is given the form of a unit  10  coordinated pneumatically with the piston-cylinder arrangement  1  but discrete and physically separated from the piston-cylinder arrangement. 
     Within said unit  10  and extending between connections  10   a,    10   b  associated with the unit there is disposed in any event one coupling-in of a high-pressure regulator  11  and a low-pressure regulator  12 , whose characteristics will be described in greater detail herein below with reference to  FIGS. 9 ,  10  and  12 . 
     However, it might be mentioned already at this stage that the utilized high-pressure regulator  11  (see  FIGS. 11 and 12 ) should be directly coupled-in to a conduit, designated “C”, and a low-pressure regulator  12  series connected to said conduit “C”, the regulator being coupled, by the intermediary of a conduit “D”, to the system pressure “ST” or source  8 . 
     Naturally, the coupling-in may also be put into effect by the intermediary of a separate conduit with a “T” junction, designated “T”. The low-pressure regulator  12  is to be connected direct to the pressure side “D” of the system and measure the pressure between the output of the low pressure generator  12  and the low-pressure chamber  1   f  of the system. 
     The high-pressure regulator  11  is connected after the low-pressure regulator  12  to its own duct which communicates the regulator with the low-pressure conduit “C”. 
     A non-return valve  13  may be placed before or after the high-pressure regulator  11 , but must be placed in the conduit between the outgoing pressure in the low-pressure regulator  12  and the low-pressure chamber if of the system. 
     Said piston-cylinder arrangement  1  may advantageously consist of a single standardized unit. 
     Once again, referring to  FIG. 4 , it will be apparent that a safety valve  13  is connected to said fourth conduit “D” or by corresponding means. 
     Said unit  10 , with its associated coupling arrangement  10 ′, displays more particularly a parallel coupling of a safety valve  13  with a series coupling of said low-pressure regulator  12  and said high-pressure regulator  11 , whose outlet may be opened to the atmosphere “a”. 
     An accumulator tank  14  ( FIG. 6 ) is directly or indirectly connected to the low-pressure system “LT” by the intermediary of one or more low-pressure or return chambers  1   f    
     Said high-pressure regulator  11  is adjustable to a low-pressure system-adapted value valid at the end of a piston stroke. 
     Said low-pressure regulator  12  is adjustable to a low-pressure system-adapted value, valid for the low-pressure or return chamber if in conjunction with a piston stroke. 
     The high-pressure regulator  11  is adjustable manually and/or by the intermediary of a step motor, and the low-pressure regulator  12  may also be adjustable manually and/or by the intermediary of another step motor. 
     Said coupling arrangement  10 ′ is adapted to be pressurized by the intermediary of the low-pressure or return chamber if before a first piston stroke, this latter being activated by the intermediary of the action of said control valve  2 . 
     During a time interval for one piston stroke, the coupling arrangement  10 ′ is adapted to be able to offer a controlled compression of the medium (the air) within the low-pressure system “LT” with associated accumulator tank  14 ,  14   a  and  14   b,  respectively, including one or more or coordinated with the volume related to one or more low pressure or return chambers  1   f    
     Said high-pressure regulator  11  is adapted to permit presetting of an actively maximized pressure valid for the low-pressure system, with one or more return chambers  1   f  at the end of the piston stroke. Occurring excess pressure is allowed to pass to the atmosphere “a”. 
     Said low-pressure regulator  12  is adapted to permit presetting of an actively minimized pressure valid for the low-pressure system, with one or more return chambers if at the beginning of the piston stroke. 
     Said safety valve  13  consists of a non-return valve adapted, on activation of an emergency stop, to permit a bleeding of the system of air via a valve  13   a  (see  FIG. 13 ). 
     Said accumulator tanks  14   a,    14   b  ( 10 A:  10 B) related to the unit  10  and the coupling arrangement  10 ′ are integrated in said unit  10  or alternatively coupled-in to said third conduit “C” and the low-pressure system “LT”. 
     A selected number (five) of separately controlled piston-cylinder arrangements  1  in  FIG. 5  are, as regards their allocated low-pressure system “LT” which is here limited to the free space for the low-pressure or return chambers  1   f  coordinated with one and the same unit  10  and one and the same coupling arrangement  10 ′. 
       FIG. 6  then illustrates that a selected number of a first set of separately controlled piston-cylinder arrangements  1 A are, as regards their low-pressure or return chamber  1   f  and accumulator tank  14   a,  coordinated and connected to one and the same first coupling arrangement  10 A within a first unit  10 A. 
     A selected number of a second set of separately controlled piston-cylinder arrangements IB are, as regards their low-pressure or return chamber  1   f  and accumulator tank  14   b,  coordinated and connected to one and the same second coupling arrangement  10 B′ within a second unit  10 B. 
     All piston-cylinder arrangements  1 A and  1 B, respectively, associated with a coupling arrangement and coordinated with associated units  10 A and  10 B, respectively, are dimensioned identically or in any event substantially identically. 
     Thus,  FIG. 4  illustrates and describes a single standardized piston-cylinder arrangement  1  (cf. the embodiment illustrated in  FIG. 1 ) which has been supplemented with a single unit-related coupling arrangement  10 ′, in accordance with the present invention. 
       FIG. 5  illustrates and describes a system with five identical piston-cylinder arrangements  1 , coordinated with a single coupling arrangement  10 ′, in accordance with the present invention. 
       FIG. 6  illustrates and describes a system with three different sets of mutually identical piston-cylinder arrangements  1 A,  1 B and  1 C, where each one of them is coordinated with its allocated coupling arrangement  10 A,  10 B′ and  10 C. 
       FIG. 7  shows in side elevation and partly in section a coupling arrangement  10 ′ coordinated to one unit  10 , in accordance with the disclosures of the present invention. 
       FIG. 8  shows the unit  10 , according to  FIG. 7 , in plan view, while  FIG. 9  shows, in side elevation and in section, a high-pressure regulator  11 , included in the unit  10  according to the invention, while  FIG. 10  shows in side elevation and in section a low-pressure regulator  12  included in the unit  10 , according to the invention. 
     The High-Pressure Regulator  11  ( FIG. 9 ) 
     This high-pressure regulator  11  displays an adjustment screw  11   a  (not shown) for presetting of a highest permitted pressure in the low-pressure system. 
     This adjustment may be put into effect manually and with a locking function with the aid of a locking nut  11   b  or by regulation by different types of motor power. 
     A sliding/guide washer  11   c  affords low friction against a spring lid on rotation of the adjustment screw  11   a.    
     The spring lid is adapted for a pressure regulation against a piston lie. 
     The piston lie is adapted for a fixing of the spring lid together with a QUAD-ring  11   f  as well as an edge seal ring  11   g.    
     The combination between the spring force in the spring lid and the pressure surface  11   h  in the piston lie entails that, when the current maximum low-pressure in the low-pressure chamber  1   f  or the low-pressure system “LT” exceeds the spring force lid, leakage will occur between the sealing surface in the edge seal ring  11   g  and the parallel surfaces of the block construction  11   o.    
     The edge seal ring  11   g  constitutes a sealing ring or gasket usable for creating as slight resilience as possible on bleeding of the system via a channel  11   i.    
     Said QUAD-sealing ring  11   f  is a gasket or sealing ring which is employed for centering the piston lie with the lowest possible friction and a sealing against a chamber surrounding the spring unit  11   d.    
     An air bleeder channel  11   j  to the atmosphere “a” of excess pressure in the high-pressure regulator  11  utilizes a channel  11   i,  which is located between the edge seal ring  11   g  and the QUAD-ring  11   f.    
     Reference numeral  11   k  illustrates a casing or a body for the regulator. 
     Bleeder holes  11   m  are adapted for a pressure increase/pressure reduction within the body  11   k    
     The pressure from the low-pressure system acts on the pressure surface  11   n  by the intermediary of a channel  11   n ′ and is affected by the pressure of the low-pressure chamber as well as the spring force in the spring  11   d.    
     The adjustment screw  11   a  is bottomed against an edge  11   p  on delivery, in which event the cylinder arrangements are run and adjustment screw  11   a  opened until an excess pressure occurs and bleeding of air to the atmosphere “a” takes place through the channel  11   i.  Thereafter, the locking nut  11   b  is locked and the system has been finely tuned. 
     High pressure regulator  11  may have mechanical stop surfaces  11   o  and  11   p  indicating the highest and lowest positions of piston  11   e.  Piston  11   e  may be of a hard and/or non-bendable material so as not to bend or stack at surface  11   q.  Piston  11   e  may stop against mechanical stop surface  11   o  until pressure is lowered such that the force of spring  11   d  will close the bleeding from the unit to mechanical stop surface  11   p.  When the system begins to run, pressure may further increase as the cylinders in the system begin to move. In this case, mechanical stop surface  11   p  will still hold piston  11   e  in the same position despite the increase in pressure from the preset pressure to the highest pressure in the machine under one cycle. 
     When the pressure increases to the highest level in the closed low pressure system by the set pressure from spring  11   d,  pressure will also increase on piston area  11   h  from the mechanical stop surface  11   p.  This may create a bleeding through the edge seal ring  11   g  until pressure is lowered and the force from the spring  11   d  may close the bleeding from the unit. The highest pressure top under the cycle may be set at different phases during the cycle depending on how the combinations of cylinders are moving during one stroke. 
     Leakage may only occur when a sealing in the piston-cylinder arrangement starts to wear creating higher pressure from one side of the cylinder to the other. High pressure regulator  11  may be adjusted so that small bleeding occurs from channel  11   j  to atmosphere “a” to stabilize the system while in operation, while indicating that a cylinder may be in need of replacement or repair. If the high pressure regulator  11  is not trimmed in from the beginning, internal leakage of the cylinders may not be possible due to a rise in pressure inside the high pressure regulator  11  without the ability to bleed. 
     Before the system is pressurized the piston  11   e  may rest against the mechanical stop surface  11   p  by the force of present spring  11   d.  When the pressure rises from the highest pressure during one cycle the piston  11   e  may start to lift up from mechanical stop surface  11   p  and toward mechanical stop surface  11   o.    
     When the system goes into an emergency stop, air will empty from channel  11   n ′ which may increase the pressure on spring  11   d.  This action may result in piston  11   e  moving down and resting on mechanical stop surface  11   p.    
     The Low-Pressure Regulator  12  ( FIG. 10 ) 
     With reference to  FIG. 10 , this Figure shows in section the construction of the low-pressure regulator  12 . 
     An adjustment screw  12   a  is shown here for setting of the lowest permitted pressure in the low-pressure system LT of the system. 
     Adjustment may be put into effect manually and with locking by means of a locking nut  12   b  or regulation by different types of motor power. 
     Reference numeral  12   c  discloses a sliding/guide washer with low friction against a spring  12   d  for an adapted pressure regulation on rotation of the adjustment screw  12   a.    
     A piston  12   e  is adapted for a fixing of a spring  12   d  and cooperates with a QUAD-ring  12   f  and supports against a high-pressure stub shaft  12   g.    
     The combination effect, between the spring force from the spring  12   d  and a recess  12   h  in the piston  12   e,  entails that, when the current lowest pressure is overcome by the spring force in the spring  12   d  in the low-pressure chamber  12   i  of the system, a sealing ring  12   j  opens against a pressure surface  12   j ′and system pressure is supplied to the low-pressure chamber until the force of the piston surface overcomes the spring force  12   d  and closes the supply of system pressure “ST” via a channel  120 . 
     The high-pressure stub shaft  12   g  holds the sealing ring  12   j  fixed in its valve seat  12   j′.    
     The sealing stub shaft  12   b  is guided by a centering  12   h  in the lower part of the piston  12   e  serving as a recess. 
     A lower part is guided with the aid of a bushing  12   k    
     The stub shaft  12   g  also has a number of bores  12   g ′ uppermost above the bushing  12   k  for maximizing the air flow. 
     As a result of this design, a very rapid aeration of the system is created. This also controls the balance in the regulator. This design of the low-pressure regulator  12  creates major possibilities for rapid air change in the low pressure chamber of the low-pressure system. 
     The QUAD-ring sealing gasket  12   f  is employed for centering of the piston  12   e  and also for affording the lowest possible friction. 
     A channel  121  offers a pressure boost to the low pressure system and its low-pressure chamber. 
     Reference numeral  12   m  is intended to illustrate a casing or a body for the regulator unit  12 . 
     One or more bleeder holes  12   n  are adapted for a pressure boost/pressure reduction of the pressure inside the body  12   m.    
     The system pressure “ST” acts, via an opening or channel  12   o  and in a closed regulator a system pressure is created against a surface  12   p  as well as the outer surface of the stub shaft below the sealing ring  12   j,  which keeps the regulator closed. When the pressure against the piston surface  12   p  is reduced, the spring force increases in the spring  12   d  and the valve opens. 
     The pressure surface  12   e ′ for the piston  12   e  is affected by the pressure of the low-pressure system “LT”, the spring force in the spring  12   d,  as well as the action of the system pressure through the surface  12   p  and the outside of the stub shaft. Piston  12   e  may have mechanical stop surfaces  12   s  and  12   t  indicating the highest and lowest position of the piston  12   e.  Mechanical stop surface  12   s  may be at the top of piston  12   e,  when the system is filled up and closed to prevent undesired motion. Mechanical stop surface  12   t  may be at the bottom of piston  12   e  when the system is pressurized to prevent undesired motion. Piston  12   e  may be of a hard and/or non-bendable material so as not to bend or stack at surface  12   u  and piston  12   e  may be stable to prevent undesired motion when under production. 
     Reference numeral  12   q  illustrates a block construction. 
     The adjustment screw  12   a  is unscrewed to a maximum position to an abutment against the edge  12   r  on delivery, the cylinder arrangement is run and the adjustment screw  12   a  closed until the load in the working equipment of the low-pressure chamber is homed, i.e. a cylinder with a suspended load is to lift a load to the home position. Thereafter, the lock nut  12   b  is locked and the system is finely tuned. 
     The design of the sealing gasket or ring  12   j  is as a square, but with the upper and lower outer sides rounded off. This rounding-off is so as to create an improved sealing configuration against the sealing surface  12   j′.    
     The task of the bushing  12   k  is to hold the high pressure stub shaft in a centered position. 
     The spring  12   t  serves the purpose of holding the upper rounded-off portion of the high-pressure stub shaft  12   g  against a depression  12   h  belonging to the piston. 
     The purpose of the chamber  12   i  is to guide the force of the piston  12   e  against the spring  12   d  so that the supply of an increased system pressure may take place to the low-pressure system “LT”. 
     The upper rounded-off comers of the sealing ring or gasket  12   j  create an abutment against a rounded-off sealing surface  12   j′.    
     The air speed may be increased or reduced by changing the angle of the walls of the air intake or the seat. 
     When the regulator opens, the system pressure “ST” flows through the channel  12   o  in order to create a more rapid air flow to the low-pressure system “LT”. 
     When the valve is closed, the system pressure “ST” lies against a surface  12   p  as well as the inner surface of the stub shaft below the sealing ring  12   
     The system pressure passes through a first channel, through a second channel outside the sealing ring  12   j  to the low-pressure chamber of the system. 
     Referring to  FIG. 11 , this Figure schematically illustrates the interconnection of the high-pressure regulator  11 , the low-pressure regulator  12  and the non-return valve  13  and also illustrates how an excess pressure in the high pressure regulator  11  is to be led to the atmosphere “a”. 
       FIG. 12  illustrates that the arrangement  10 ′ is pressurized via an open emergency stop valve  13   a  and a conduit “ST” and the low-pressure system is activated via conduit “LT”. 
     Bleeding of the system pressure “ST” through a change of the position in the valve  13   a.    
     In that the system pressure “ST” falls, the non-return valve  13  opens and bleeds the low-pressure system “LT”. 
     If an excess pressure occurs in the low-pressure chamber if which exceeds the system pressure “ST”, the non-return valve  13  opens and releases back the excess pressure through the system conduit “ST” back to a tank  14 . 
     Bleeding to the atmosphere “a” takes place to a limited degree through the high-pressure regulator  12  in the block  10 . 
     The bleeder conduit of the high-pressure regulator to the atmosphere “a” is extremely limited in diameter, to the remaining dimensions in block  10 . 
     The bleeder conduit  11  of the high-pressure regulator to the atmosphere “a” is extremely limited in diameter, in response to other dimensions. This is because the high pressure regulator  11  should only take care of leakage over the piston of the cylinder. 
     When the pressure reaches a maximum value against the force from spring  12   d,  this may separate the high pressure system from  12   o  through  12   j  against sealing surface  12   j ′. Such action may create a closed low pressure system separated from the high pressure system by closing sealing surface  12   j ′ with the sealing ring or gasket  12   j.    
     Increased pressure in the low pressure chamber may have no effect on the low pressure regulator  12 . When the pressure increases over the preset pressure (i.e. when cylinders start to move) in the low pressure chamber, no effect will be had on the low pressure regulator  12 . The system will run from the present pressure up to maximum value depending on the cylinder size, movement and size of tank volumes at each cycle. 
     The piston  12   e  may stop against mechanical stop surface  12   s  when the preset pressure is reached at which point pressure may expand without affecting the low pressure regulator  12 . When the cylinders start to move, pressure increases further while mechanical stop surface  12   s  still maintains piston  12   e  in the same position, thus keeping the high and low pressure system separated from each other. 
     The cylinders normally stand in a base position. Once the cylinders begin to move, the pressure will rise in the closed system. The highest pressure under the cycle may be at a different location during the cycle depending on how the combination of the cylinders in the machine is moving. 
     Before the system is pressurized, piston  12   e  may rest against mechanical stop surface  12   t.  When pressure goes from the high pressure side to the low pressure side, the piston  12   e  may start to lift from mechanical stop surface  12   t  toward mechanical stop surface  12   s.  This action may close the low pressure side from the high pressure side and create two separate systems. 
     The system may go into an emergency stop at which point compressed air from the cylinders may empty via channel  12   o  (ST). The force on spring  12   d  may be lowered which may open the low pressure side to the high pressure side to relieve compressed air to the atmosphere. At this point the piston  12   e  will go down and rest on mechanical stop surface  12   t.    
     Tank Volumes and Preset Pressures in the Present Invention 
     In a pneumatic machine, embodiments of the present invention may be combined with different tank volumes, placed in different locations in the machine or combined with different numbers of tanks. The tank volumes may affect the highest pressure at the low pressure side during one stroke, impacting the speed of the forward and return strokes. For example, in one exemplary embodiment, a small tank volume may create a higher pressure at the low pressure side of the closed system at the end of the stroke (small tank volume, low speed forward stroke, high speed return stroke). In another exemplary embodiment, a larger tank volume may create a lower pressure at the low pressure side of the closed system at the end of the stroke (large tank volume, higher speed forward stroke, lower speed return stroke.) 
     The pressure within the present invention may be preset in order so that the cylinders may have the correct speed and force to set at a home position. The preset pressure for the return stroke may depend on the size of the load required and/or the tank volume size. The combination of the preset pressure and the tank volume may set the speed for the forward and return strokes. The present invention may be combined with a flow meter, for example a flow meter at inlet port D in  FIG. 4 , to detect leakage at the cylinder front gable sealing, which may be the first part that normally fails. Service personnel may then be warned to repair or replace the failing parts. 
     Compression Ratio 
     The compression ratio of the present invention may vary depending on the installation of the present invention. For example, a large cylinder with a short stroke may have a high force for the return stroke due to the piston area while still requiring a small amount of air. In another embodiment, a small cylinder with a large stroke may have a low force for the return stroke due to the piston area while still requiring a large amount of air. In any one embodiment, all cylinders installed with the present invention may have the same pressure for each cylinder home position (i.e. the pressure need to keep each cylinder in the home position). The pressure ratio may be changed by installing tank volumes close to cylinders with a large tube diameter and by connecting a small tube diameter between a tank and head tube in the low pressure system. The small tube diameter may only be used for filling up the system and for observation of the pressure inside the system. 
     The features reflected in the characterizing section of the claims offer basic condition for group coordinate piston-cylinder arrangements, whereby said group is put under pressure before the system is activated, as illustrated above. 
     The consequences of this are that each piston-cylinder arrangement within a group may be under its own compression state, which is controllable via a variable tank volume and that groups of piston-cylinder arrangements may be coordinated with different tank volumes. 
     This coordination of piston-cylinder arrangements and the controlled compression rate offer the benefit that said arrangements may expose different compression rates during working stroke and return stroke. 
     This offers the benefit that each individual arrangement and its piston stroke may be controlled. 
     The invention may offer the possibility that three arrangements “expand”, is displaced, while one arrangement “compresses”, is returned, one arrangement “expands” while four “compress”. 
     The practical application of this coordination is that when all arrangements within a group “expand” simultaneously there is required a larger tank volume for causing one stroke, however, if said arrangements are controlled in a manner where only one arrangement shall “expand”, then the remaining arrangements within the group are part of the required tank volume. 
     The practical application, however, requires an adjustment of the force required, as the force within the compression must be adapted to the relevant and required force. 
     The present invention is naturally not restricted to the embodiment described above by way of example but may undergo modifications without departing from the inventive concept as defined in the appended claims. 
     In particular, it should be observed that each illustrated unit and/or circuit may be combined with every other illustrated unit and/or circuit within the framework of being able to attain the desired technical function.