Valve assembly for pump

Abstract

The invention describes a valve assembly (35) for a pump, comprising: a first chamber (45); a second chamber (50) communicating with the first chamber (45) through a first valve seat (55); a first shutter body (60) housed in the second chamber (50) and movable between a closed position and an open position; a first resilient element (65) adapted to urge the first shutter body (60) towards the closed position counter to the pressure present in the first chamber (45); a coupling sleeve (70) adapted to provide the second chamber (50) in fluid communication with the outlet duct (B), the first resilient element (65) being compressed between the coupling sleeve (70) and the first shutter body (60); wherein the coupling sleeve (70) comprises at least one passage duct (105) passing through the annular sleeve in a transverse direction with respect to a central axis (C) of the annular sleeve and opening into the inner cavity (75), to provide the second chamber (50) in fluid communication with the outlet duct (B).

Description

Technical Field

[0001] The present invention relates to a valve assembly for a pump, such as a valve assembly for a piston or plunger positive displacement pump, which piston or plunger positive displacement pump can be mounted on a pressure washer or other machine for dispensing and / or distributing pressurized fluid, typically water. Background Art

[0002] As is well known, pumps, especially piston or plunger positive displacement pumps, are typically provided with an inlet manifold connected to a tank of the fluid to be pumped, and a delivery manifold adapted to be connected to a fluid dispensing device, typically in the form of a dispensing gun or lance.

[0003] Between the delivery manifold and the dispensing device, these pumps include a regulating valve assembly which is fluidly interposed between the delivery manifold and the dispensing device to regulate the delivery pressure.

[0004] Conventionally, the regulating valve assembly is fluidly connected to the delivery manifold through an inlet pipe and to the dispensing device through an outlet pipe.

[0005] As is well known, the control valve assembly includes a first chamber in communication with the inlet pipe and a second chamber in communication with the first chamber and the outlet pipe.

[0006] The valve assembly further includes a coupling sleeve provided with a central chamber, which coupling sleeve is interposed between the second chamber and the outlet pipe to provide fluid communication therebetween.

[0007] A first shutter body is received in the second chamber, which first shutter body is urged by a spring and is generally adapted to cooperate with a first valve seat to close the communication between the first chamber and the second chamber.

[0008] In particular, the spring itself is compressed between the coupling sleeve and the first shutter body.

[0009] As is well known, one or more passage pipes are formed in the first shutter body, which passage pipes can provide a path for fluid from the second chamber to the outlet pipe when the first shutter body is in the open position.

[0010] Thus, during the fluid dispensing step, when fluid flows from the first chamber to the outlet pipe with the first shutter body in the open position, the fluid first enters the second chamber and then suddenly makes a substantially right-angled turn to pass through one of the passage pipes formed in the first shutter body, further makes a substantially right-angled turn to reach and then pass through the seat for receiving the spring which is also in contact with the flowing fluid, then flows into the central chamber of the coupling sleeve, and then reaches the outlet pipe.

[0011] A well-known drawback in this field is that, due to the above-described configuration of the passageway and also due to the coils of the spring overlapping the fluid, there is an undesirable pressure drop and there occur many turbulences that adversely affect the distribution of the fluid.

[0012] In view of the foregoing, an object of the present invention is to overcome this drawback of the prior art.

[0013] Another object of the present invention is to achieve the above object within the scope of a simple, reasonable and affordable solution.

[0014] These and other objects are achieved by the features of the present invention set forth in the independent claims.

[0015] The dependent claims outline the preferred and / or particularly advantageous aspects of the present invention. Summary of the Invention

[0016] In particular, the present invention provides a valve assembly for a pump, comprising:

[0017] - a first chamber adapted to be arranged in fluid communication with an inlet pipe (e.g., in particular, adapted to receive fluid, such as a liquid, through a first chamber inlet pipe),

[0018] - a second chamber in communication with the first chamber through a first valve seat, the second chamber being adapted to be arranged in fluid communication with an outlet pipe (e.g., for distributing fluid, i.e., a liquid),

[0019] - a first shutter body received in the second chamber and movable between a closed position and an open position, in which closed position the first shutter body closes the first valve seat and in which open position the first shutter body opens the first valve seat,

[0020] - a first elastic element adapted to push the first shutter body towards the closed position (in particular, against the pressure present in the first chamber),

[0021] - a coupling sleeve provided with a sleeve that closes to itself in the form of a ring (i.e., annularly) around a central axis and defines an internal cavity extending along said central axis, wherein the coupling sleeve is adapted to provide fluid communication between the second chamber and the outlet pipe, and the first elastic element is compressed between the coupling sleeve and the first shutter body;

[0022] characterized in that the coupling sleeve includes at least one channel pipe that passes through the sleeve (annularly, i.e., in the form of a ring that closes to itself) in a transverse direction with respect to the central axis of the coupling sleeve and opens into the internal cavity (to provide communication between the second chamber and the internal cavity) to (or is adapted to, or so as to) provide fluid communication between the second chamber and the outlet pipe.

[0023] Due to this solution, the valve assembly can provide a path for fluid to flow from the second chamber to the outlet pipe, and the change in the direction from the second chamber to the outlet pipe is not abrupt, thus allowing for a reduction in pressure loss and generally allowing for an increase in the efficiency of the pump associated with the valve assembly.

[0024] Furthermore, the at least one channel pipe of the valve assembly can provide a path for fluid to flow from the second chamber towards the outlet pipe, and this path does not affect the first elastic element (such as a compression spring), that is, this path does not provide for fluid to flow in contact with the first elastic element, thereby avoiding the formation of turbulence.

[0025] For example, the internal cavity of the coupling sleeve can be adapted to be set in fluid communication with the outlet pipe, for example, direct fluid communication.

[0026] Another aspect of the present invention provides that the channel pipe or each channel pipe can flow into the second chamber at one end and into the internal cavity of the coupling sleeve at the opposite end.

[0027] In practice, according to the present invention, it can be provided that the channel pipe or each channel pipe can have an end opening on the second chamber and an opposite end opening on the internal cavity of the coupling sleeve.

[0028] Another aspect of the present invention provides that the coupling sleeve can include a plurality of channel pipes, and the plurality of channel pipes can be evenly distributed along the (annular) range forming a ring of the (i.e., annular) sleeve.

[0029] Yet another aspect of the present invention provides that the coupling sleeve can have at least three different channel pipes, and each channel pipe passes through the (annular, i.e., closed to itself in the form of a ring) sleeve in a transverse direction with respect to the central axis of the coupling sleeve and flows into the internal cavity.

[0030] Another aspect of the present invention provides that the valve assembly can include a valve body, a (at least) first chamber and a second chamber are defined within the valve body, and the coupling sleeve can be rigidly fixed to the valve body.

[0031] Another aspect of the present invention provides that the coupling sleeve can be rigidly fixed (e.g., screwed) to the valve body at the second chamber, and the coupling sleeve can have: a first part that extends within the second chamber; and a second part that (e.g., closes the second chamber and) (at least partially) protrudes outside the valve body, and the outlet pipe is adapted to be sealingly fluid-connected to this second part.

[0032] Due to this solution, the connection of the outlet pipe to the coupling sleeve is particularly easy.

[0033] Another aspect of the present invention provides that the first shutter body may not have a passage pipe adapted to provide fluid communication between the second chamber and the outlet pipe (i.e., there is no passage pipe directly leading into the second chamber).

[0034] Due to this solution, the fluid flowing from the second chamber to the outlet pipe does not pass through the shutter body, thus eliminating a sudden change in the direction of the fluid passing through the shutter body itself.

[0035] Another aspect of the present invention provides that the connection sleeve may have a plurality of passage pipes, each passage pipe being adapted to provide fluid communication between the second chamber and the outlet pipe (and thus in fluid communication with the internal cavity of the connection sleeve).

[0036] Due to this solution, the connection sleeve is particularly effective in connecting the second chamber and the outlet pipe for fluid distribution.

[0037] Another aspect of the present invention provides that the internal cavity of the connection sleeve may have along the central axis of the connection sleeve: a first section close to the second chamber, a first elastic element being partially inserted into the first section; a second section away from the second chamber (this second section may be adapted, for example, to be directly fluid-connected to the outlet pipe, for example); and an intermediate section between the first section and the second section, the intermediate section having a cross-sectional area smaller than that of the second section.

[0038] In particular, according to the present invention, it can be provided that each passage pipe may open into the internal cavity of the connection sleeve at the second section.

[0039] Due to this solution, the path of the fluid from the second chamber towards the outlet pipe is particularly smooth, i.e., the change in direction is particularly gentle, thus minimizing the pressure drop.

[0040] Furthermore, according to the present invention, the fluid to be distributed reaching the outlet pipe from the second chamber does not pass through the first elastic element (i.e., the spring), thus avoiding turbulence that would otherwise be caused by passing through the first elastic element.

[0041] Another aspect of the present invention provides that the cross-sectional area of the first section of the internal cavity of the connection sleeve (relative to a cross-sectional plane orthogonal to the central axis) may be smaller than the cross-sectional area of the second section (relative to a cross-sectional plane orthogonal to the central axis). For example, optionally, the cross-sectional area of the first section of the internal cavity of the connection sleeve may be 0.4 to 0.6 times the cross-sectional area of the second section. For example, optionally, the cross-sectional area of the first section of the internal cavity of the connection sleeve may be approximately half of the cross-sectional area of the second section.

[0042] Yet another aspect of the present invention provides that the connecting sleeve may have an axially narrowing portion that defines the middle section of the internal cavity and can provide a abutment surface for the first elastic element.

[0043] Due to this solution, the structure of the valve assembly is particularly reasonable.

[0044] Another aspect of the present invention provides that the channel pipe may have a central axis that is inclined at an angle of less than or equal to 45° with respect to the central axis of the connecting sleeve, for example, preferably inclined at an angle of less than 40° with respect to the central axis of the connecting sleeve, for example, preferably inclined at an angle that is substantially equal to 35° (or possibly smaller) with respect to the central axis of the connecting sleeve.

[0045] Due to this solution, the path of the fluid through the connecting sleeve from the second chamber towards the outlet pipe has no sharp turns, especially no 90° turns, but only provides a limited direction change that allows the pressure drop to be minimized.

[0046] Yet another aspect of the present invention provides that the first elastic element may be at least partially inserted into the internal cavity of the connecting sleeve.

[0047] Another aspect of the present invention provides that the cross-sectional area of the second section of the internal cavity of the connecting sleeve (relative to a plane orthogonal to the central axis) may be 5 to 10 times the cross-sectional area defined by the middle section (relative to a plane orthogonal to the central axis), for example, preferably 7 to 8 times the cross-sectional area of the middle section.

[0048] Due to this solution, the relationship between the cross-sectional areas of the middle section and the second section causes the closing of the first closing body to be slowed down when the distribution of the fluid suddenly terminates, for example, especially by closing the distribution device (usually a gun or a spray gun) connected to the outlet pipe, that is, preventing the sudden closing of the first closing body.

[0049] In other words, due to this solution, the so-called sector water hammer in technical terms caused by the closing of the distribution device (i.e., the spray gun or the gun) can be eliminated or at least reduced.

[0050] In addition, another aspect of the present invention provides that the cross-sectional area of the channel pipe (for example, each channel pipe) may be equal to 2 to 3 times the cross-sectional area of the middle section of the internal cavity of the connecting sleeve.

[0051] Another aspect of the present invention provides that the first closing body can be assembled onto the connecting sleeve (i.e., on the annular sleeve, that is, arranged to circumferentially surround the connecting sleeve) and can move along the connecting sleeve between an open position and a closed position.

[0052] Due to this solution, the movement of the first opening / closing body is guided by the coupling sleeve.

[0053] In this way, improper positioning of the first opening / closing body can be avoided, which may invalidate the valve assembly and impair the operation of the valve assembly.

[0054] Another aspect of the present invention provides that the valve assembly may further include:

[0055] - A discharge pipe, which communicates with the first chamber through the second valve seat,

[0056] - A third chamber, which is defined in the valve body, communicates with the second chamber, and is partially defined by a sliding plunger inserted into the valve body,

[0057] - A second opening / closing body, which is rigidly connected to the plunger and is accommodated in the first chamber, in the first chamber, the second opening / closing body can move between a closed position and an open position, in the closed position, the second opening / closing body closes the second valve seat, in the open position, the second opening / closing body opens the second valve seat, and

[0058] - A second elastic element, which is adapted to push the second opening / closing body towards the closed position contrary to the pressure present in the third chamber.

[0059] Due to this solution, as long as the pressure in the third chamber cannot overcome the force exerted on the plunger by the second elastic element, the second opening / closing body remains in the closed position.

[0060] However, if the flow rate of the pumped fluid increases and / or if the dispensing device is closed, the pressure in the second chamber and the third chamber increases, increasing the thrust exerted on the plunger contrary to the second elastic element.

[0061] When this pressure exceeds a critical value, which can be adjusted by adjusting the preload of the second elastic element, the second opening / closing body is moved away from the second valve seat, opening the direct communication between the first chamber and the discharge pipe.

[0062] In this way, all the fluid pumped by the pump, or at least the flow rate of the excess fluid, flows through the discharge pipe, for example, towards the inlet manifold, thereby ensuring that the fluid pressure at the outlet of the valve assembly never exceeds the critical value.

[0063] Another aspect of the present invention provides that a third chamber can be in fluid communication with the second chamber through a connecting pipe, and the cross-sectional area of the connecting pipe (with respect to a cross-sectional plane orthogonal to the central axis of the connecting pipe, the connecting pipe extends from the second chamber to the third chamber along this central axis) can be smaller than the cross-sectional area of the passage pipe (with respect to a cross-sectional plane orthogonal to the central axis of the passage pipe). For example, optionally, the cross-sectional area of the connecting pipe can be 0.4 to 0.6 times the cross-sectional area of the passage pipe. For example, optionally, the cross-sectional area of the connecting pipe can be approximately half of the cross-sectional area of the passage pipe of the coupling sleeve.

[0064] The present invention can also provide a pump, such as a positive displacement pump, which is provided with a valve assembly according to one or more (e.g., all) aspects described above.

[0065] Another aspect of the present invention provides that the pump can include:

[0066] - A pump body that defines one or more cylinders; and a head that is fixed to the pump body and is adapted to close one end of each cylinder; a reciprocating piston that is slidably received within each cylinder;

[0067] - An inlet manifold that is adapted to be connected to a fluid source to be pumped;

[0068] - A delivery manifold that is adapted to be connected to a fluid distribution device for the pumped fluid,

[0069] - A drive motor for the one or more reciprocating pistons,

[0070] - The valve assembly is connected (e.g., through the inlet pipe) to the delivery manifold to receive fluid (i.e., liquid) from the delivery manifold. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] After reading the following description provided by way of non-limiting examples, other features and advantages of the present invention will become more apparent with the aid of the pictures shown in the drawings.

[0072] Figure 1 is a view of a pump provided with a valve assembly according to the present invention.

[0073] Figure 2 is along Figure 1 a cross-sectional view of the valve assembly along the trace II-II, where the first shutter body is in the closed position.

[0074] Figure 3 is Figure 2 an enlarged view of a part of

[0075] Figure 4 is along Figure 1Cross-sectional view of the valve assembly along the trace II-II, where the first switch body is in the open position.

[0076] Figure 5 is Figure 2 An enlarged view of a part, where the fluid flow from the second chamber into the connection sleeve is schematically shown.

[0077] Figure 6 is a schematic view, where Figure 4 The cross-sectional area of the valve assembly is visible, where the outlet pipe and the distribution device are connected to the valve assembly. Detailed Description

[0078] With particular reference to these drawings, a pump, such as in particular a positive displacement piston pump 10 or a plunger pump, is generally designated by the reference numeral 10 and can be mounted, for example, on a pressure washer or on another machine or system for distributing or dispensing a pressurized fluid, typically water.

[0079] The pump 10 includes a pump body 15 defining one or more cylinders and a head 20 fixed to the pump body 15 and adapted to close one end of each cylinder.

[0080] Alternative pistons are slidably received within each cylinder and are adapted to cooperate with the corresponding cylinder and head 20 to define respective variable volume compression chambers.

[0081] The pistons are kinematically connected to a single drive shaft by respective motion mechanisms, such as a crank - rod motion mechanism, which is adapted to convert the rotational motion of the drive shaft into a reciprocating linear motion of the pistons.

[0082] The drive shaft can be rotated by a drive motor, such as by an electric motor or alternatively by an internal combustion engine.

[0083] The cylinders, pistons, compression chambers, drive shaft and drive motor are not shown or are not visible in the figures as they are known and conventional in themselves.

[0084] The pump 10 includes an inlet manifold 25 and a delivery manifold 30, both of which can be formed in the head 20.

[0085] For example, each compression chamber can be connected to the inlet manifold 25 by a respective inlet valve and to the delivery manifold 30 by a respective delivery valve.

[0086] The inlet valves and the delivery valves can be automatic valves and are conventional in themselves.

[0087] The inlet manifold 25 can be connected to a fluid source to be pumped, such as a tank containing fluid, or alternatively to a fluid supply network (such as a water network), while the delivery manifold 30 can be connected to a dispensing device G, such as a dispensing gun or spray gun.

[0088] The dispensing device G can be provided with a special valve member adapted to selectively open and close fluid dispensing after manual operation.

[0089] A valve assembly (generally designated by reference numeral 35) can be fluidly (e.g., hydraulically) interposed between the delivery manifold 30 and the dispensing device G.

[0090] The valve assembly 35 can first include a rigid (e.g., metallic) valve body 40 that defines a space for receiving and allowing fluid to flow from the delivery manifold 30.

[0091] The valve body 40 is generally an internally hollow tubular body in which the fluid received from the delivery manifold is received and flows.

[0092] For example, the valve body 40 can generally be defined by a tubular (multi-pass, e.g., four-pass) body (or fitting) having an internal cavity in which the fluid is received and flows in a manner that will become clearer hereinafter.

[0093] The valve assembly 35 has, for example, a first chamber 45 defined in the valve body 40 that is adapted to be placed in fluid communication with an inlet conduit A for receiving said fluid from the delivery manifold 30.

[0094] In particular, the first chamber 45 can be in continuous hydraulic communication with the delivery manifold 30 through the inlet conduit A, which is fluidly (sealingly) connected to the valve body 40 (e.g., directly connected to a corresponding one of the passages of the valve body 40).

[0095] Thus, the first chamber 45 is adapted to receive fluid from the delivery manifold of the pump.

[0096] In the illustrated embodiment, the inlet conduit A can coincide with an end section of the delivery manifold 30.

[0097] The valve assembly 35 also includes, for example, a second chamber 50 defined in the valve body 40 that is in fluid (e.g., hydraulic) communication with the first chamber 45 through a first valve seat 55.

[0098] It is to be noted that, within the scope of this specification, a valve seat generally refers to any passage, opening, or hole of any shape and size that is adapted to provide two separate volumes in hydraulic communication and is adapted to be blocked by a corresponding closure body to selectively prevent such communication.

[0099] The first opening / closing body 60 is received within the second chamber 50 and is movable between a closed position and an open position. In the closed position, the first opening / closing body 60 closes the first valve seat 55 to prevent communication between the first chamber 45 and the second chamber 50. In the open position, the first opening / closing body 60 opens the first valve seat 55 to allow communication between the first chamber 45 and the second chamber 50.

[0100] The first opening / closing body 60 can be continuously urged towards the closed position by a first elastic element 65 (e.g., by a spring), and the first elastic element 65 acts contrary to the pressure of the fluid in the first chamber 45.

[0101] The second chamber 50 is adapted to be set in fluid communication with an outlet pipe B, and the outlet pipe B is adapted to be connected (e.g., to a dispensing device G such as a dispensing gun or lance) to set the second chamber 50 in fluid communication with the dispensing device G for dispensing a fluid.

[0102] The valve assembly 35 further includes a coupling sleeve 70 (or delivery sleeve), and the coupling sleeve 70 is adapted to set the second chamber 50 in fluid communication with the outlet pipe B.

[0103] In particular, the coupling sleeve 70 is adapted to be interposed between the second chamber 50 and the outlet pipe to set them in fluid communication.

[0104] The coupling sleeve 70 has an annular sleeve, i.e., closed to itself in the form of a ring around a central axis C, and the annular sleeve defines an internal cavity 75 extending along the central axis C.

[0105] In practice, the sleeve (annular, i.e., closed to itself in the form of a ring) can generally define the tubular body of the coupling sleeve 70, or the tubular body of the coupling sleeve 70 can be provided.

[0106] As Figure 6 schematically shown, the internal cavity 75 can be adapted to be set in fluid communication with the outlet pipe B, e.g., direct fluid communication.

[0107] The coupling sleeve 70 closes the second chamber 50 at one end.

[0108] In particular, as can be better seen in Figure 3 the coupling sleeve 70 can be rigidly fixed (e.g., screwed) to the valve body 40 at the second chamber 50 (e.g., directly connected to one of its corresponding passages).

[0109] In particular, as in Figure 3More visibly, the coupling sleeve 70 may have a first part extending within the second chamber 50 and a second part (closing the second chamber 50 and) partially protruding outside the valve body 40, and the outlet pipe B (and thus the dispensing device G) is adapted to be fluidly connected to the second part in a sealed manner.

[0110] Specifically, the inner cavity 75 of the coupling sleeve 70 may have a first section 80 close to the first chamber 45, a second section 85 remote from the second chamber 50, and an intermediate section 90 between the first section 80 and the second section 85 along its extent relative to the central axis C.

[0111] In particular, the coupling sleeve 70 may have a shoulder 95 facing radially towards the central axis C, the shoulder 95 defining an axial narrowing of the inner cavity 75 and circumferentially bounding the intermediate section 90.

[0112] Thus, the cross-sectional area of the intermediate section 90 (relative to a plane having a cross-sectional area orthogonal to the central axis C) may be smaller than the cross-sectional area of the second section 85 (relative to a cross-sectional plane orthogonal to the central axis C).

[0113] In particular, the cross-sectional area of the second section 85 of the inner cavity 75 of the coupling sleeve 70 is 5 to 10 times, for example preferably 7 to 8 times, the cross-sectional area of the intermediate section 90.

[0114] Furthermore, the cross-sectional area of the intermediate section 90 (relative to the plane having a cross-sectional area orthogonal to the central axis C) may be smaller than the cross-sectional area of the first section 80 (relative to a cross-sectional plane orthogonal to the central axis C).

[0115] For example, the cross-sectional area of the first section 80 (relative to a plane having a cross-sectional area orthogonal to the central axis C) may be 3 to 5 times the cross-sectional area of the intermediate section 90 (relative to a plane having a cross-sectional area orthogonal to the central axis C).

[0116] Moreover, the cross-sectional area of the first section 80 (relative to a plane having a cross-sectional area orthogonal to the central axis C) may be smaller than that of the second section 85, for example approximately half of the cross-sectional area of the second section 85.

[0117] A first elastic element 65 may be included (i.e., interposed) and compressed between the coupling sleeve 70 and the first opening and closing body 60, for example partially received in the inner cavity 75 of the coupling sleeve 70.

[0118] In particular, as in Figure 3As better seen in the enlarged view, the first elastic element 65 (i.e., the spring) can be inserted into a first section 80 of an internal cavity 75 of a connection sleeve 70 and is arranged in abutting form on an abutment surface 100 provided by the axial narrowing of the connection sleeve 70 that defines an intermediate section 90 (i.e., provided by the shoulder 95 that faces radially towards the central axis C of the connection sleeve 70).

[0119] Furthermore, the first switch body 60 can be assembled onto the connection sleeve 70 and can move along the connection sleeve 70 between an open position and a closed position.

[0120] In particular, the first switch body 60 can be assembled onto the connection sleeve 70 so as to circumferentially surround the connection sleeve 70.

[0121] For example, as can be seen in Figure 3 the first switch body 60 is assembled onto the portion of the connection sleeve 70 that is inserted (in the valve body 40 and in particular) into the second chamber 50. The first switch body 60 is in particular assembled onto the portion of the connection sleeve 70 that defines the first section 80 of the internal cavity 75.

[0122] More specifically, the first switch body 60 can generally have the shape of a cup, the mouth of which is assembled onto the connection sleeve 70 and that makes sliding contact with the connection sleeve 70 during movement between the closed position and the open position.

[0123] Thus, the internal cavity defined by the cup-shaped body of the first switch body 60 is in fluid communication with the internal cavity 75 of the connection sleeve 75, in particular directly leading to the first section 80 of said internal cavity 75.

[0124] Thus, the first elastic element 65 (i.e., the spring) can be included in a receiving seat generally defined by the first section 80 of the internal cavity 75 of the connection sleeve 70 and the said internal cavity of the first switch body 60.

[0125] In each position assumed by the first switch body 60 from the open position to the closed position (including the open position and the closed position), the switch body is always at least partially assembled onto the connection sleeve 70.

[0126] In other words, the first section 80 of the internal cavity 75 of the connection sleeve 70 can never open directly onto the second chamber 50.

[0127] As can be seen in Figure 3 and Figure 5 a sealing gasket G can be associated with the first switch body 60. The sealing gasket G is assembled onto the (cup-shaped) body of the first switch body 60 and is preferably partially inserted into an annular groove formed in the first switch body 60.

[0128] The sealing gasket G is specifically designed to ensure a fluid seal when the first opening / closing body 60 is in the closed position.

[0129] As described above, the coupling sleeve 70 is adapted to place the second chamber 50 in fluid communication with the outlet pipe B.

[0130] Specifically, the coupling sleeve 70 includes at least one channel pipe 105, preferably a plurality of channel pipes (e.g., identical to each other in shape and size), each of which can provide a passage for fluid to flow from the second chamber 50 to the internal cavity 75 of the coupling sleeve 70 (towards the outlet pipe B and, for example, a distribution device G connected to the outlet pipe B).

[0131] Each channel pipe 105 passes through the annular sleeve in a lateral direction with respect to the central axis C of the coupling sleeve 70.

[0132] Specifically, each channel pipe 105 opens into the second chamber 50 at one end and into the internal cavity 75 of the coupling sleeve 70 at the opposite end.

[0133] In practice, each channel pipe 105 has an open end on the second chamber 50 and a relative open end on the internal cavity 75 of the coupling sleeve 70 (e.g., at the second section 85 of the coupling sleeve).

[0134] Each channel pipe 105 has a central axis D that is inclined at an angle of less than or equal to 45° with respect to the central axis C of the coupling sleeve 70, for example, preferably less than or equal to 40°, and, for example, substantially equal to 35°.

[0135] The plurality of channel pipes 105 are preferably equiangular with respect to each other.

[0136] The cross-sectional area of each channel pipe 105 (with respect to a plane having a cross-sectional area orthogonal to the central axis D of the channel pipe 105) is 2 to 3 times the cross-sectional area of the intermediate section 90 of the internal cavity 75 of the coupling sleeve 70 (with respect to a plane having a cross-sectional area orthogonal to the central axis C).

[0137] Preferably, the second chamber 50 is in fluid communication with the internal cavity 75 of the coupling sleeve 70 and is thus in fluid communication with the outlet pipe B only through the channel pipe 105 or the plurality of channel pipes 105.

[0138] Specifically, the first opening / closing body 60 does not have a channel pipe adapted to place (the internal cavity 75 of the coupling sleeve 70 and thus have) the second chamber 50 in fluid communication with the outlet pipe B.

[0139] In other words, the first opening and closing body 60 does not have a passage conduit that directly leads into the second chamber 50.

[0140] The valve assembly 35 further includes a discharge conduit 110 that is in fluid communication with the first chamber 45 through a second valve seat 115.

[0141] The discharge conduit 110 may be (at least partially) formed in the same body that forms the first chamber 45 (e.g., in the valve body 40).

[0142] Preferably, the discharge conduit 110 is adapted to provide communication between the first chamber 45 and the inlet manifold 25 of the pump 10 (e.g., through a respective one of the passages in the valve body 40 that is connected to the inlet manifold 25).

[0143] However, in other embodiments, it is not excluded that the discharge conduit 110 may provide communication between the first chamber 45 and other low-pressure volumes, such as a tank of the liquid to be pumped.

[0144] For example, as can be better seen in Figure 3 the second valve seat 115 may be made of a separate annular body 120 that is inserted into the first chamber 45, possibly with a specific sealing gasket and fixed within the valve body 40.

[0145] A second opening and closing body 125 is received within the first chamber 45 and is movable between a closed position and an open position. In the closed position, the second opening and closing body 125 closes the second valve seat 115, preventing communication between the first chamber 45 and the discharge conduit 110. In the open position, the second opening and closing body 125 opens the second valve seat 115, allowing such communication.

[0146] The valve assembly 35 further includes a third chamber 130 that is separated from the first chamber 45 but is continuously in fluid (i.e., hydraulic) communication with the second chamber 50.

[0147] For example, the third chamber 130 and the second chamber 50 may be connected by a connecting conduit 135 that may be provided within the valve body 40 itself.

[0148] Specifically, the connecting conduit 135 opens into the second chamber 50 at one end and into the third chamber 130 at the opposite end.

[0149] The cross-sectional area of the connecting conduit 135 (with respect to a plane having a cross-sectional area orthogonal to the central axis of the connecting conduit) may be approximately half of the cross-sectional area of each of the passage conduits 135 provided in the coupling sleeve 70 (with respect to a plane orthogonal to the central axis D).

[0150] The third chamber 130 is partly defined by a sliding plunger 140 which is rigidly fixed to the second shutter body 125 such that the pressure of the fluid in the third chamber 130 tends to turn the second shutter body 125 towards the open position of the discharge duct 110.

[0151] More specifically, the plunger 140 may be slidably received within a cylinder 145 which is inserted into and rigidly fixed to the valve body 40 (e.g. inserted into and fixed to a respective one of the passages in the valve body 40), the bottom wall of the cylinder 145 separating the first chamber 45 from the third chamber 130.

[0152] Thus, the third chamber 130 is in effect defined between the piston 140 and the cylinder 145.

[0153] In the example shown, the cylinder 145 is formed as a separate body relative to the body forming the first chamber 45, in this case relative to the valve body 40, and the cylinder 145 may be rigidly connected to the first chamber 45, for example by a threaded connection and insertion of a particular sealing gasket.

[0154] In particular, as Figure 2 or Figure 3 visible, the cylinder 145 may be made up of several parts 145A, 145B, 145C which are then arranged against each other (and possibly fixed) so that the cylinder 145 can be used as a whole.

[0155] However, it is not excluded that in other embodiments the cylinder 145 may be formed with the valve body 40 in a single body form, and that the cylinder 145 may be formed as a single integral body.

[0156] The second shutter body 125 may be rigidly connected to the plunger 140 which is slidably fitted into a through-hole obtained in the bottom wall of the cylinder 145, one or more gaskets being preferably associated with the plunger 140 and the gaskets being adapted to ensure that the first chamber 45 and the third chamber 130 remain hermetically separated.

[0157] In particular, the plunger 140 may be removably connected to the second shutter body 125, for example by a threaded connection.

[0158] The valve assembly 35 includes a second elastic element 155, such as a spring, which is adapted to push the second shutter body 125 towards the closed position of the second valve seat 115 and thus towards the closed position of the discharge duct 110.

[0159] In the illustrated example, the second elastic element 155 is positioned on the opposite side of the plunger 140 relative to the second opening / closing body 125 and is located outside the third chamber 130.

[0160] In particular, the second elastic element 155 can be partially received in the cylinder block 145 and is interposed between a first abutting element 160 and a second abutting element 165, the first abutting element 160 being associated with the plunger 140 and the second abutting element 165 being rigidly connected to the cylinder block 145.

[0161] The first abutting element 160 can be defined by a body that is coaxially inserted into the cylinder block 145 with the plunger 140 and is provided in abutting form on the plunger itself, for example, being coupled to the plunger 140 by form coupling.

[0162] The second abutting element 165 can be shaped as a pin (e.g., coaxial with the plunger 140), and the second abutting element 165 can be rigidly fixed to a connecting body 170, which in turn can be fixed to the cylinder block 145, for example, screwed onto the cylinder block 145.

[0163] Specifically, as better visible in Figure 2 the second elastic element 155 is located (i.e., provided in abutting form) on the second abutting element 65 through the interposition of a plate.

[0164] More specifically, the second abutting element 165 can be coupled to the connecting body 170 by a threaded connection such that by tightening or loosening the second abutting element 165 relative to the cover, an axial displacement of the second abutting element in the sliding direction of the plunger 140 can be caused, thereby changing the pre-compression of the second elastic element 155 and thus changing the force that pushes the second opening / closing body 125 towards the closed position.

[0165] The connecting body 170 can in turn be coupled to an external protective cover L, for example, by a coupling having a convex hexagon - concave hexagon shape, so as to become integral when tightened / loosened to the external protective cover L.

[0166] More specifically, the second opening / closing body 125 can generally have the shape of a cup, and the mouth of the cup is fixed (e.g., screwed) to the plunger 140.

[0167] The operation of the above valve assembly 35 will be described below starting from the case where the drive motor of the pump 10 is shut off and the pump 10 stops.

[0168] In this case, both the first opening / closing body 60 and the second opening / closing body 125 are in their respective closed positions.

[0169] When the drive motor is started, the piston of the pump 10 immediately at least begins to pump a small amount of fluid from the inlet manifold 25 to the delivery manifold 30.

[0170] As the speed of the motor increases, the flow rate of the fluid pumped into the first chamber 45 of the valve assembly 35 also increases.

[0171] At this time, contrary to the action of the first elastic element 65, the pumped fluid pushes the first opening and closing body 60 towards the open position, so that it flows into the second chamber 50 and from the second chamber 50 into the connecting sleeve 70 to reach the outlet pipe B, for example, flowing towards the distribution device G, and the fluid leaves from the distribution device G.

[0172] In particular, as Figure 5 schematically shown in, with reference to the cross-sectional channel pipe 105, the path of the fluid flowing from the second chamber 50 in the connecting sleeve 70 to the outlet pipe B is particularly smooth, that is, generally without sharp turns.

[0173] During the distribution of the fluid, a part of the fluid reaching the second chamber fills the third chamber 130 through the connecting pipe 135.

[0174] Preferably, the preload of the second elastic element 155 can be adjusted in such a way that during the distribution of the fluid (i.e., when the first opening and closing body is in the open position), since the area provided by the plunger 140 in the third chamber 130 is larger than the area provided by the plunger 140 in the first chamber 45, the pressure in the third chamber 130 can overcome the force exerted on the plunger 140 by the second elastic element 155 and the pressure in the first chamber 45, so as to at least slightly move the second opening and closing body 125 away from the second valve seat 115, allowing a smaller part of the fluid pumped by the pump 10 to reach the discharge pipe 110.

[0175] When the distribution of the fluid terminates, for example, when the distribution spray gun or gun is closed, since the fluid cannot flow towards the outlet pipe B, the fluid acts on the first opening and closing body 60 through the inner cavity 75 of the connecting sleeve 70 (with the help of the first elastic element, i.e., the spring), so that the first opening and closing body 60 enters the closed position.

[0176] The specific structure of the inner cavity 75 of the connecting sleeve 70, especially the narrowing part defined by the middle section 90, results in a pressure drop, allowing the first opening and closing body 60 to be gently closed, that is, allowing the elimination or at least significant weakening of the so-called water hammer.

[0177] In this case, that is, when the distribution of the fluid terminates (for example, when the distribution device G is closed), the pressure in the second chamber 50 and the third chamber 130 increases, increasing the thrust acting on the plunger 140 contrary to the second elastic element 155.

[0178] In view of this, the second opening / closing body 125 will move further away from the second valve seat 115 so that all the fluid pumped by the pump 10 flows through the discharge pipe 110, for example, towards the inlet manifold 25.

[0179] The present invention thus conceived is susceptible of numerous modifications and variations, all of which fall within the scope of the same inventive concept.

[0180] Moreover, all details may be replaced by other equivalent technical elements.

[0181] In fact, depending on the requirements, the materials used as well as the possible shapes and dimensions may be arbitrary, and thus do not depart from the scope of protection of the appended claims.

Claims

1. A valve assembly (35) for a pump (10), comprising: - a first chamber (45) adapted to be placed in fluid communication with the inlet duct (A), a second chamber (50) communicating with said first chamber (45) via a first valve seat (55), said second chamber (50) being adapted to be arranged in fluid communication with an outlet duct (B), a first shutter body (60) housed in the second chamber (50) and movable between a closed position, in which the first shutter body (60) closes the first valve seat (55), and an open position, in which the first shutter body (60) opens the first valve seat (55), - a first elastic element (65) adapted to push the first shutter body (60) towards the closed position, - a coupling sleeve (70) provided with a sleeve closed to itself in the form of a ring around a central axis (C) and defining an internal cavity (75) extending along said central axis (C), wherein said coupling sleeve (70) is suitable for placing said second chamber (50) in fluid communication with said outlet duct, said first elastic element (65) being compressed between said coupling sleeve (70) and said first shutter body (60); Characterized in that the coupling sleeve (70) comprises at least one channel pipe (105), which passes through the sleeve in a transverse direction relative to the central axis (C) of the coupling sleeve (70) and opens into the internal cavity (75) to set the second chamber (50) in fluid communication with the outlet pipe (B).

2. The valve assembly (35) according to claim 1, wherein: The first shutter body (60) is free of a passage conduit adapted to place the second chamber (50) in fluid communication with the outlet conduit (B).

3. The valve assembly (35) according to claim 1, wherein: The coupling sleeve (70) has a plurality of passage conduits (105), each passage conduit being adapted to place the second chamber (50) in fluid communication with the outlet conduit (B).

4. The valve assembly (35) according to claim 1, wherein: The internal cavity (75) of the coupling sleeve (70) has, along the central axis (C) of the coupling sleeve (70): a first section (80) close to the second chamber (50), in which the first elastic element (65) is partially inserted; a second section (85) away from the second chamber (50); and an intermediate section (90) between the first section (80) and the second section (85), wherein the intermediate section (90) has a cross-sectional area smaller than that of the second section (85).

5. A valve assembly (35) according to the preceding claim, wherein: The coupling sleeve (70) has an axial narrowing which delimits the middle section (90) of the inner cavity (75) and provides a bearing surface (100) for the first elastic element (65).

6. The valve assembly (35) according to claim 1 or 2, wherein: The passage duct (105) has a central axis which is inclined at an angle less than or equal to 45° relative to the central axis (C) of the coupling sleeve (70).

7. The valve assembly (35) according to claim 1, wherein: The first elastic element (65) is at least partially inserted into the inner cavity (75) of the coupling sleeve (70).

8. The valve assembly (35) according to claim 4, wherein: The cross-sectional area of ​​the second section (85) of the interior cavity (75) of the coupling sleeve (70) is 5 to 10 times the cross-sectional area defined by the intermediate section (90).

9. The valve assembly (35) according to claim 4, wherein: The cross-sectional area of ​​the passage pipe (105) is equal to 2 to 3 times the cross-sectional area of ​​the middle section (90) of the inner cavity (75) of the coupling sleeve (70).

10. The valve assembly (35) according to claim 1, wherein: The first shutter body (60) is assembled to the coupling sleeve (70) and is movable along the coupling sleeve (70) between the open position and the closed position.

11. The valve assembly (35) of claim 1, further comprising: - a discharge duct (110) communicating with said first chamber (45) via a second valve seat (115), a third chamber (130) defined in the valve body (40), communicating with the second chamber (50) and partly delimited by a sliding plunger (140) inserted in the valve body (40), a second shutter body (125) rigidly connected to the plunger (140) and housed in the first chamber (45), in which the second shutter body (125) is movable between a closed position, in which the second shutter body (125) closes the second valve seat (115), and an open position, in which the second shutter body (125) opens the second valve seat (115), and - a second elastic element (155) suitable for urging said second shutter body (125) towards said closed position, counter to the pressure prevailing in said third chamber (130).

Images