Patent Publication Number: US-11644023-B2

Title: Air compressor

Description:
This application claims priority to Italian Patent Application 202019000004792 filed Dec. 31, 2019, the entirety of which is incorporated by reference herein. 
     This invention relates to an air compressor. 
     Air compressors are used in many different application sectors, both professionally and domestically. 
     Indeed, whilst professional use of air compressors has become established, it is also becoming increasingly widespread in a domestic setting, for example with reference to hobbies or even to more common activities such as washing/suction. 
     By way of example only, the compressor described is of the reciprocating type. Reciprocating compressors compress air by means of a piston which is movable with reciprocating motion inside a cylinder. 
     The air compressor comprises a pressure switch, that is to say, a device configured to keep the pressure inside the tank within the limits of use. In prior art compressors, the pressure switch is usually separate from the pumping unit body. The peripheral position of the pressure switch may result in one or more disadvantages, for example the pressure switch and its activating push-button are not properly protected, or an end user (above all in the case of a private, non-professional user) may become distracted during use of the compressor while searching for the activating push-button. 
     The aim of this invention is to provide a positive-displacement air compressor which is easy and practical to use. As well as having a lower number of exposed and damageable parts. 
     A further aim of this invention is to provide a positive-displacement air compressor which is effective, simple and convenient to use. 
     The technical features of this invention, in accordance with the above-mentioned aims, are clearly inferable from the content of the present disclosure. 
    
    
     
       Moreover, the advantages of this invention will become more apparent from the detailed description which follows, with reference to the accompanying drawings which illustrate an example, non-limiting embodiment, in which: 
         FIG.  1    is a schematic perspective view of an embodiment of an air compressor according to this invention; 
         FIG.  2    is a top view of a detail of an air compressor according to this invention illustrated in  FIG.  1   ; 
         FIG.  3    is a schematic perspective view of an embodiment of an air compressor according to this invention; 
         FIGS.  4 A and  4 B  are top views of a detail of the embodiment of an air compressor according to this invention illustrated in  FIG.  2   ; 
         FIGS.  5 A and  5 B  are schematic cross-sections of a detail of one or more embodiments of an air compressor according to this invention; and 
         FIGS.  6 A and  6 B  are schematic cross-sections of a detail of one or more embodiments of an air compressor according to this invention. 
     
    
    
     In particular with reference to  FIGS.  1  and  3   , the numeral  1  denotes as a whole an air compressor, for example transportable, according to this invention. The air compressor  1 , described and illustrated in more detail limited to the parts necessary for an understanding of this solution, comprises:
         at least one pumping unit, substantially known and not visible in the figures, comprising a cylinder inside which a piston moves with reciprocating motion,   an electric motor, also not illustrated, configured to drive the at least one pumping unit,   a pressure switch  5  comprising a body  5   a  and a push-button  50  for activating and deactivating or switching off, movable between a first position and a second position,   a housing  3 , configured to cover at least said at least one pumping unit, said electric motor and said pressure switch, and   a switch  4 , coupled to the housing  3  and movable between a first operating position and a second operating position.       

     The switch  4  is configured to move the activating and switching off push-button  50 , in such a way that, when the switch  4  is in the first operating position, the push-button  50  is in the respective first position and, when the switch  4  is in the second operating position, the push-button  50  is free to switch between the first and the second position. 
     The push-button  50  may for example switch between the first position and the second position. The first position of the push-button  50  may correspond to a deactivation of the pressure switch  5 , for example electric contacts inside the body  5   a  of the pressure switch are opened, that is to say, are not in contact, and the second position of the push-button  50  may correspond to an activation of the pressure switch  5 , for example the electric contacts are closed, that is to say, are in contact. For example, the first position of the push-button  50  may correspond to a pressed down position of the self-same push-button  50  and the second position of the push-button  50  may correspond to a raised position of the self-same push-button  50 . The first position of the push-button  50  may be an operating configuration and the second position of the push-button  50  may be a home position, and the push-button  50  may comprise inside it an elastic element, for example a spring, which keeps the push-button  50  in the home state in the second position. The movement between the first and the second position may bring the push-button  50  away from the body  5   a  of the pressure switch  5 , and vice versa. For example, when the push-button  50  is in the second position, the pressure switch  5  is configured to activate the pumping unit; when the push-button  50  is in the first position, the pressure switch  5  is configured to inhibit the movements of the pumping unit. 
     When the pressure switch  5  is operating, the push-button  50  may automatically switch between the first position and the second position. For example, automatic switching may occur as a function of reaching a predetermined pressure in a tank  2  fed by the pumping unit. 
     Alternatively, as described in more detail below, switching from the first position to the second position and/or vice versa may occur as a function of an intervention by a user who moves the push-button  50  by means of the switch  4 . 
     For example, the switch  4  is connected or constrained to the housing  3  and/or preferably switches between the first and the second operating positions. According to one aspect, in addition or alternatively to the housing  3 , the switch  4  may be connected or constrained to the pressure switch  5 . 
     The switch  4  is substantially placed at the push-button  50  and is configured to move the push-button  50  for activating and deactivating the pressure switch  5 . In this way, when the switch  4  is in the first operating position, the push-button  50  is pressed and brought into the first position; when the switch  4  is in the second operating position, the push-button  50  is free to switch between the first position and the second position. In other words, when the switch  4  is in the first operating position, the push-button  50  is kept in the first position and is prevented from switching between the first position and the second position. 
     For simplicity, hereinafter reference will be made to the non-limiting example in which the first operating position of the switch  4  corresponds to the first position of the push-button  50  of the pressure switch  5 . 
     In an alternative embodiment it is possible that the second operating position of the switch  4  corresponds to the first position of the push-button  50  which in turn causes inhibition of the pumping unit. 
     In one or more embodiments, the compressor  1  may be mounted on a tank  2 , illustrated for example in  FIG.  1   . As illustrated in  FIG.  1   , all of the components of the compressor  1  are in use covered by the housing  3  and therefore are not visible and/or accessible from the outside, unless the housing  3  is removed. 
     According to one aspect of the invention, the switch  4  may be constrained to the housing  3  at a surface  3 A of the housing  3 . Thanks to the fact that the push-button  50  of the pressure switch can be pressed by the switch  4  exposed by the housing  3 , it is possible to simultaneously protect the pressure switch  5  and its push-button  50 , and to operate the pressure switch  5 . 
     The switch  4  preferably comprises a grip element  40  for facilitating movement of the switch  4  by a user. The grip element  40  may be located at an exposed first surface  4 A of the switch  4 , that is to say, visible on the housing  3 . For example, the grip element  40  may be formed on the first surface  4 A of the switch  4 . The grip element  40  may project outside the housing  3 . 
     The switch  4  also comprises a jutting portion  42 , covered by the housing  3  and which projects towards the inside of the self-same housing  3 . The jutting portion  42  may be located at a second surface  4 B of the switch, opposite to the exposed surface  4 A. The jutting portion  42  may be part of the second surface  4 B. The jutting portion  42  is configured to move the push-button  50  of the pressure switch  5  as a function of the movement of the switch  4 . In this way, a movement of the switch  4  corresponds to a movement of the push-button  50  of the pressure switch  5 . As is described in more detail below, the jutting portion  42  has a predetermined shape which allows the movement of the push-button  50  away from or towards the body  5   a  of the pressure switch  5 . 
     According to one aspect, one part of the switch  4  is exposed by the housing  3  (for example, surface  4 A and grip element  40 ) and part of the switch  4  faces and projects towards the inside of the housing  3  (for example the jutting portion  42 ). 
     The switch  4 , the grip element  40  and the jutting portion  42  may be formed in a single body, or they may be assembled by means of fixing elements, for example screws. 
     According to one aspect, the housing  3  may comprise one or more end of stroke elements  32 , which are configured to guide the movement of the switch  4  and/or to stop the stroke of the switch  4  in a predetermined position, for example in the first operating position and in the second operating position. In addition or alternatively, the housing  3  may comprise one or more locking elements  34 , which are configured to engage with the switch  4  at least when the switch  4  is in the first position. For example, the one or more locking elements  34  may be configured to prevent the switch  4  from shifting from the first position, unless this is due to an intervention by an operator. 
     The end of stroke element  32  may be a rise, for example a step, in the surface  3 A of the housing  3  which is located at the switch  4 . The end of stroke element  32  is configured to allow the switch  4  to translate between the first and the second operating positions and to prevent a movement of the switch  4  beyond the first and the second positions. In other words, when the switch  4  reach either one or the other position, it is no longer able to continue the stroke any further. 
     In addition or alternatively, the locking element  34  may consist of a rise, for example a tooth, in the surface  3 A of the housing  3  which is located at the switch  4 . The rise may be configured to engage with the switch  4  when the switch  4  is in the first operating position. In other words, during the translation of the switch  4  between the second operating position and the first operating position, a part of the switch  4  passes over the locking element  34 , so as to remain in position. The locking element  34  and the switch  4  may stably engage with each other when the switch  4  reaches the first position, for example in a snap-on fashion. 
     Although illustrated in  FIGS.  6 A and  6 B , the end of stroke element  32  and/or the locking element  34  may be applied to what is illustrated in  FIGS.  5 A and  5 B . 
     That solution is advantageous, since the elastic element inside the push-button  50  of the pressure switch  5  can apply a force which is not negligible against the jutting portion  42  of the switch  4 . Without the presence of one or more locking elements  34 , the push-button  50  may be able to push the switch  4  out of the first operating position. Therefore, the locking element  34  may be configured to prevent the switch  4  from autonomously shifting from the first operating position. 
     According to one aspect of the invention, the end of stroke element  32  and/or the locking element  34  may be rigid and stable. Preferably, the one or more end of stroke elements  32  and/or the one or more locking elements  34  may be located at the first surface  3 A of the housing. Even more preferably, the one or more end of stroke elements  32  may be covered by the switch  4 . Even more preferably, the one or more locking elements  34  may be covered by the switch  4  when the switch  4  is in the first operating position. 
     According to one aspect, the housing  3  comprises an opening  30  into which the switch  4  can be inserted. At the opening  30 , there may be elements present which facilitate keeping the switch  4  in contact with the housing  3 . 
     As illustrated in  FIG.  1    and in  FIG.  2   , the switch  4  may be of the type rotatable about an axis of rotation X and may be configured to be in the first operating position and in the second operating position, which is rotated relative to the first position. The rotation may be, for example 180°. The grip element  40  is located at the first surface  4 A, which is circular in the example illustrated. The grip element  40  may be formed starting from the surface  4 A and may extend away from the housing  3 . 
     Alternatively, as illustrated in the embodiment of  FIG.  3    and in  FIGS.  4 A and  4 B , the switch  4  may comprise a switch translating along a longitudinal line Y. The switch  4  may be configured to switch between the first operating position (illustrated in  FIG.  5 A ) and the second operating position (illustrated in  FIG.  5 B ), translated relative to the first operating position. The grip element  40  of the switch  4  is located at the first surface  4 A, which is rectangular in the example illustrated. The grip element  40  may be formed starting from the surface  4 A and may extend away from the housing  3 . 
       FIGS.  5 A and  5 B  are side cross-section views of a detail of this invention, wherein the switch  4  is in the second position and in the first position respectively. In particular, in the cross-sections illustrated, the pressure switch  5  and the push-button  50  are visible, which in use are covered by the housing  3 . 
     According to one aspect, the switch  4  may be coupled to the body  5   a  of the pressure switch  5 . For example, the switch  4  may comprise a through hole  44  and the body  5   a  of the pressure switch  5  may comprise a receiving seat  52 ; a fixing element, for example a screw, is configured to be inserted into the through hole  44  and constrained to the seat  52 . 
     Alternatively, the switch  4  may be only constrained to and held in position by the housing  3 . 
     As illustrated in the figures, the axis of rotation X may be parallel to a line along which the push-button  50  moves. The push-button  50  is located a predetermined distance from the axis of rotation X of the switch  4 ; in other words, the movement of the push-button  50  occurs along an axis parallel to but not coinciding with the axis of rotation X. 
     The jutting portion  42  of the switch  4  may comprise a cam  42 A configured to convert the rotary movement of the switch  4  into a translating movement of the push-button  50  towards or away from the body  5   a  of the pressure switch  5 . In this way, by means of a rotation of the switch  4 , the push-button  50  passes from the first position to the second position and/or vice versa. 
       FIGS.  6 A and  6 B  are side cross-section views of details of this invention, illustrated in  FIGS.  4 A and  4 B  respectively, wherein the switch  4  is in the first and second position respectively. In particular, in the cross-sections illustrated, the pressure switch  5  and the push-button  50  are visible, which in use are suitably covered by the housing  3 . 
     As illustrated, the switch  4  may be constrained to and held in position by the housing  3 . The switch  4  may be composed of parts, one part comprising the jutting portion  42  and the other comprising the grip element  40 . 
     The parts of the switch  4  may for example be held together by a fixing element, not illustrated, for example a screw. Alternatively, the switch  4  may be formed in a single body. 
     The jutting portion  42  of the switch  4  may comprise a ramp  42 B configured to convert the longitudinal translating movement of the switch  4  along the line Y into a translating movement of the push-button  50  along a line perpendicular to the line Y (for example vertical) towards or away from the body  5   a  of the pressure switch  5 . In this way, when the switch  4  is made to translate, the push-button  50  passes from the first position to the second position and/or vice versa because the ramp  42 B makes contact with the push-button  50  and guides it towards one or the other position. The ramp  42 B extends along the longitudinal line Y and/or follows a geometric linear path. In other words, the thickness of the ramp  42 B varies along a line parallel to the movement of the push-button  50  of the pressure switch  5  and along the longitudinal line Y. 
     In the example illustrated, the ramp  42 B increases along the longitudinal line Y, in particular from right to left when observing  FIGS.  6 A and  6 B .