A spray gun with automatic locking mechanism and method for manufacturing a spray gun

Abstract

Spray gun (10) with an automatic locking mechanism comprising a spray gun main body comprising at least one channel body (34, 70) that provides a fluid channel (16, 18, 20) for the passage of fluid from a fluid inlet to a fluid outlet of the spray gun (10); a valve (22, 24) for selectively opening and closing the fluid channel (16, 18, 20); an actuator element (32) operably coupled to the valve (22, 24) in such way that the valve (22, 24) can be caused to open and close the fluid channel (16, 18, 20) by manual operation of the actuator element (32), wherein the actuator element (32) can be actuated into a first position in which the actuator element (32) causes the valve (22, 24) to be in a state in which the fluid channel (16, 18, 20) is open and wherein the actuator element (32) can be actuated from the first position to a second position in which the actuator element (32) causes the valve (22, 24) to be in a state in which the fluid channel (16, 18, 20) is closed; and a locking structure (38, 40, 42) for releasably locking the actuator element (32) in the first position.

Description

[0001] Description Spray gun with automatic locking mechanism The present invention relates to a spray gun with an automatic locking mechanism. Spray guns for irrigation with automatic locking mechanisms for locking the valve of the spray gun in an open or closed state are commonly known in the art. EP 3 271 079 B1 discloses a spray gun for irrigation purposes in which a locking device is provided for locking an actuation lever relative to a handle element in or- der to lock the valve of the spray gun in an open state. Spray guns with a variety of locking devices are also known from EP 2 368 640 B1, JP 5607328 B2, JP 5749661, JP 4482832, or JP 5583104. JP 5583104 B2 discloses a lock mechanism for maintaining the on-off valve in a water- passing state. The lock mechanism comprises a locking arm which is attached to the water passing pipe. The leading end of the spring portion comes into contact with the spring receiver of the locking arm, and the locking arm is supported at a predetermined height by the elastic force of the spring portion. However, JP 5583104 B2 does not disclose, amongst others, a biasing element that exerts a force on the locking element when the actuator element is actuated into the first position so that the locking element is urged to engage with the counterlocking element and that exerts a force on the locking element when the actuator element is actuated from the first position to the second position so that the locking element is urged to disengage with the counterlocking element. JP 2009-022848 A discloses a follower which is with its one end coupled to the open / close valve housing and with its opposite end guided within the guidance path of the cam. The end guided in the cam is at all times coupled and guided within the cam. However, JP 2009-022848 A B2 does not disclose, amongst others, a biasing element that exerts a force on the locking element when the actuator element is actuated into the first position so that the locking element is urged to engage with the counterlocking element and that exerts a force on the locking element when the actuator element is actuated from the first position to the second position so that the locking element is urged to disengage with the counterlocking element. Some of the solutions known from the prior art require an overstroke of a valve closing element when closing the valve by the actuation lever due to necessary manufacturing tolerances or due to the distance a cam element has to cover while running along a specific guiding structure. It is an object of the present invention to provide a spray gun that can be manufactured in a simple and cost-efficient way and in which the required overstroke is reduced. The object of the present invention is achieved by a spray gun with the features defined in claim 1. More specifically, the present invention provides a spray gun with an automatic locking mechanism comprising: a spray gun main body comprising at least one channel body that pro- vides a fluid channel for the passage of fluid from a fluid inlet to a flu- id outlet of the spray gun; a valve for selectively opening and closing the fluid channel; - an actuator element operably coupled to the valve in such way that the valve can be caused to open and close the fluid channel by manual operation of the actuator element, wherein the actuator element can be actuated into a first position in which the actuator element causes the valve to be in a state in which the fluid channel is open and wherein the actuator element can be actuated from the first position to a second position in which the actuator element causes the valve to be in a state in which the fluid channel is closed; - a locking structure for releasably locking the actuator element in the first position, wherein the locking structure comprises: • a locking element that is engaged with a counterlocking element to lock the actuator element in the first position and which is disengaged with the counterlocking element when the actuator element is in the second position; • a biasing element that exerts a force on the locking element when the actuator element is actuated into the first position so that the locking element is urged to engage with the counterlocking element and that exerts a force on the locking element when the actuator element is actuated from the first position to the second position so that the locking element is urged to disengage with the counterlocking element. A spray gun with such a locking structure can be manufactured in a simple and cost- efficient way. Engagement and disengagement of the locking element, i.e., locking the actuator element in the first (or: valve open) position and releasing the actuator element to move in the second (or: valve closed) position are driven by the biasing element exerting a biasing force on the actuator element on its way into the first position and from the first position into the second position. In between the actuator element is reliably locked in the first position. According to an exemplary embodiment of the present invention, the locking element further comprises at least one hinge pin which is configured to be hung or clipped into at least one corresponding hinge support hook which is integrally formed to the actuator element such that the locking element is pivotably movable about the at least one hinge pin, wherein, in a non-biased (neutral) position of the locking element, the locking element is preloaded by the biasing element and pushed into the at least one hinge support hook substantially without play. According to an exemplary embodiment of the invention, the valve comprises: - a valve body providing a valve section as a part of the fluid channel, - valve stem arranged at least partially within the valve section and configured to leave open the valve section in a first stem position and to close the valve section in a second stem position; and - a resilient element exerting a force on the valve stem to urge the valve stem out of a first stem position into the second stem position; in particular wherein the actuator element is operably coupled to the valve stem so that the valve stem is pushed against the force direction of the resilient element towards the first stem position when the actuator element is actuated into the first position and wherein the force of resilient element transferred by the valve stem acts on the actuator element such that the actuator element tends to be pushed from the first position into the second position and can be fixed in the first position by the locking element engaging with the counterlocking element. Thus, the actuator element, when actuated, directly moves the valve stem against the force of the valve’s resilient element, causing the valve to open. Additionally, the resilient element contributes to a safe lock of the locking element when in engagement with the counterlocking element. According to a further exemplary embodiment, the actuator element is pivotably coupled to the spray gun main body, in particular to the channel body, via an actuator element hinge arranged at or close to a first end section of the actuator element. Additionally or alternatively, the actuator element may be operably coupled to the valve in a second end section of the actuator element. The first end section may be arranged closer to a fluid inlet (or: an upstream end) of the spray gun than the second end section. The first end section of the actuator element may be coupled to the channel body of the spray gun main body in an upstream end region of the channel body, wherein the second end section of the actuator element can be arranged close to the fluid outlet or a downstream end region of the channel body and / or at least partially enclose the valve, in particular the valve stem. In this configuration of the actuator element, the index finger and the middle finger of a hand holding the spray gun can contribute more force and sensitivity to the actuation of the actuator element, com- pared to an actuator element that is pivotably coupled close to the downstream end of the spray gun. If the actuator element is coupled close to the downstream end, index finger and middle finger would be placed close to the pivot hinge and a hand holding the spray gun could use only ring finger and little finger for actuating the spray gun. Ring finger and little finger are the fingers with considerably less finger power than index and middle finger. Additionally advantageously, the locking structure may be arranged between the actuator element hinge and the valve, in particular wherein the locking element is pivotably coupled to the actuator element adjacent to an area where the actuator element is or comes in contact with the valve. Thus, the locking element realizing the locking function for locking the valve open is located close to the valve and thus, the actuator element does not become subject of bending due to the forces necessary for holding the valve open. In a further exemplary embodiment, the locking element comprises a swivel bracket pivotably coupled to the actuator element, in particular wherein the biasing element is arranged relative to the swivel bracket and the actuator element such that it exerts a biasing force on the swivel bracket that urges the swivel bracket from a biased position in which the swivel bracket is engaged with the counterlocking element into a non- biased (or: neutral) position in which the swivel bracket is disengaged with the counterlocking element. In that way, when the actuator element is in the first position and actuated by a user’s hand, the swivel bracket moves into a position in which it can disengaged from the counterlocking element. In this position, the biasing force urges the swivel bracket fully out of the engagement position such that the actuator element can move into the second position. Thus, automatic release of the actuator element from the counterlocking element is achieved by a simple manual operation of the actuator element in its first position. Further advantageously, the counterlocking element comprises a heart-curve structure forming a travelling path for a guiding pin of the swivel bracket, in particular wherein the heart-curve structure is arranged relative to the swivel bracket and the biasing element in such a way that, when the guiding pin is engaged with an en- gagement recess of the heart-curve structure, the biasing element exerts a force on the swivel bracket urging it out of the engaged position into a non-biased position. A heart-curve structure, heart-curve contour or heart-curve formed path is particularly advantageous when used in combination with a swivel bracket being subject to a biasing force. Thus, the swivel bracket is forced into engagement with the engagement recess provided by the heart-curve structure. Further, the swivel bracket is always supported without backlash as the biasing element pushes the swivel bracket upwards and into the engagement recess. Furthermore, an exemplary embodiment includes that the counterlocking element comprises a base plate, a first guiding element comprising a heart-curve contour and a second guiding element forming a stopping structure, and / or in that the base plate and / or the first guiding element and / or the second guiding element is / are fixedly attached to the spray gun main body, in particular to a first channel body forming at least a section of the fluid channel, preferably wherein base plate and / or the first guiding element and / or the second guiding element is / are formed integrally with the first channel body. The base plate and the first guiding element and the second guiding element can be directly moulded to the first channel body, all of those elements can be made of a plastic material suitable for injection moulding. This results in a simple and cost- efficient production of the spray gun. In this sense, the locking structure can be understood as including locking and guiding functions into the same structure. Additionally or alternatively, the swivel bracket comprises a bracket body to which two hinge pins are attached and which are coupled to corresponding hinge supports attached to the actuator element, such that the swivel bracket is pivotably movable relative to the actuator element, in particular wherein a hinge axis drawn up by the hinge pins and the hinge supports is substantially transverse to a longitudinal axis defined by a longitudinal extension of the actuator element and / or defined by a longitudinal extension of a portion of the channel body, preferably of the first channel body. As the swivel bracket is directly coupled to the actuator element and is subject to the force provided by the biasing element, backlash of the swivel bracket is pre- vented when it engages with or disengages from the counterlocking element. Additionally, such a solution consumes only few space within the actuator element. In a further exemplary embodiment, the swivel bracket comprises a bracket body and two bracket arms extending from the bracket body, wherein the bracket arms at least partially encompass the channel body, in particular the first channel body, and wherein each bracket arm comprises a guiding pin, the guiding pins facing each other and being configured to travel through travelling paths provided by the counterlocking element fixedly attached to opposing sides of the channel body, in particular the first channel body. Providing two bracket arms which encompass the channel body result in a reliable guiding of the actuator element and symmetrical forces acting on the swivel bracket and the actuator element which prevents undesired jamming of the swivel bracket. Additionally advantageous, the spray gun main body further comprises a spray gun casing which at least partially encloses the channel body, in particular the first channel body, and / or the valve body, wherein the spray gun casing and the channel body are arranged relative to each other such that the guiding pins are guided at least partially between the spray gun casing and the base plate of the counterlocking element, in particular integrally formed to the channel body, when travelling through the travelling paths provided by the counterlocking element. By guiding the guiding pins not only in the guiding path provided by the counterlocking element, but also between the spray gun casing and the base plate of the counterlocking element, the guiding pins are prevented from slipping out of the travelling path when travelling and simultaneously being subject to the force pro- vided by the biasing element. According to a further exemplary embodiment, the biasing element is supported at a distance to a bottom wall of the actuator element and the swivel bracket is cou- pled to the actuator element in a position relative to the biasing element such that the biasing element is preloaded by the swivel bracket, in particular wherein the swivel bracket comprises a bottom surface having at least two opposing edges which is in contact with the biasing element and wherein the swivel bracket can be in a position relative to the biasing element in which both edges are in contact with the biasing element and which is a non-biased (or: neutral) position of the swivel bracket and wherein the swivel bracket can be in a position relative to the biasing element in which only one of the edges is in contact with the biasing element and which is a biased position of the swivel bracket. Alternatively, the biasing element is supported at a distance to a bottom wall of the actuator element and the swivel bracket is coupled to the actuator element in a position relative to the biasing element such that the biasing element is not preloaded by the swivel bracket and therefore in a neutral position, wherein the swivel bracket can be in a position relative to the biasing element in which both edges are in contact with the biasing element and which is a non-biased (or neutral) position of the swivel bracket, and wherein the swivel bracket can be in a position relative to the biasing element in which only one of the edges is in contact with the biasing element and which is a biased position of the swivel bracket. Thereby, a functionality of the locking mechanism is fully functional and usable. By preloading the biasing element with the swivel bracket, manufacturing tolerances may be compensated. Thereby, a functionality of the locking mechanism may be ensured. The arrangement of the swivel bracket including two opposing edges which are in contact with the biasing element result in an almost constant restoring force of the biasing element on the swivel bracket over the entire swivel range. Additionally or alternatively, the bottom surface of the swivel bracket may be a plane surface. Additionally or alternatively, the biasing element may be arranged below the hinge axis of the swivel bracket. If the contact area between swivel bracket and biasing element is located below the hinge axis of the swivel bracket, the biasing element needs to be bent only to a minimal extent to fulfil its purpose. Additionally or alternatively, the swivel bracket may be coupled to the actuator element by hinge pins coupled to hinge support hooks attached or integrally formed to a bottom wall of the actuator element. Further, due to the accuracy of the swivel bracket and the zero backlash of the hinge support, a very low overstroke of the guiding pins and consequently of the actuator element can be achieved. In a further exemplary embodiment, the biasing element is made of a stainless material, in particular stainless steel, and / or in that the biasing element is a rod spring or a leaf spring or a compression spring, and / or in that the biasing element is directly attached, in particular integrally formed, to the locking element. Using a stainless-steel material is particular advantageous as the biasing element is operated in a maximum wet environment. A rod spring or a leaf spring allow for a minimum overstroke as only minimal bending of the spring achieves the necessary force of the biasing element. Attaching the biasing element directly to the locking element, in particular moulding it directly to the locking element would provide for a very simple and cost-efficient structure. Furthermore, it may be advantageous, to form the guiding pins with a circular or oval-shaped or rectangular or triangular cross section. Particularly a rectangular cross section allows for a small overstroke as the edges of the guiding pin and the corresponding locking edges of the counterlocking element require only a small overlap to provide for a reliable engagement. It may be also advantageous that the channel body comprises at least one first channel body and one second channel body which are connected by a valve body, wherein the first channel body provides a first channel section, the second channel body provides a second channel section and the valve body provides a valve section fluidically interconnecting the first channel section and the second channel section, wherein the first channel section is arranged non-parallel and non-rectangular relative to the valve section, in particular in an angle between 45° and 80°, preferably between 50° and 65° and / or wherein the second channel section is arranged rectangular relative to the valve section. The actuator element and the locking structure are particularly advantageous when applied to a spray gun in this specific configuration. This allows to directly operate the valve by the actuator element without the need of lever elements or the like. The resilient element of the valve stem can be used to provide the resetting force for resetting the actuator element from the first position in which the spray gun is open into the second position in which the spray gun is closed. Furthermore, it may be advantageous when the valve stem is arranged movably back and forth within the valve section and has an end section with an actuation surface being in contact with a corresponding support surface of the actuator element, in particular wherein the support surface is inclined relative to a bottom wall of the actuator element such that a longitudinal axis of the valve stem is oriented substantially rectangular to a tangent of the support surface touching the point of contact between the actu- ation surface and the support surface, and / or wherein the support surface is substantially plane or slightly curved such that the actuation surface can slide on the support surface when the actuator element is actuated into the first position or from the first position into the second position. In this way the direct operation of the valve by the actuator element is optimised by providing specific contact surfaces on the actuator element and the valve. This allows for a smooth and reliable operation of the valve by the actuator element. According to an exemplary embodiment of the present invention, the locking element further comprises a swivel bracket, wherein the swivel bracket comprises a first edge and a second edge, wherein in a non-biased (neutral) position of the swivel bracket, the swivel bracket touches the biasing element at the first edge and at the second edge. In particular, the swivel bracket is preloaded by the biasing element at a contact of the first edge and the biasing element and at a contact of the second edge and the biasing element. Hence, the swivel bracket is centring itself through a two-point contact. Further, the swivel bracket is mounted without play at substantially all times because the preloaded biasing element pushes the swivel bracket into the bearing seat. Thereby, manufacturing tolerances may be compensated. Further, due to a precise switching behaviour of the automatic locking mechanism a minimal overstroke may be necessary. Additionally, the preload of the biasing element produces a hearable clicking sound when the guiding pins are engaging respectively impacting the first guiding element. The object of the invention is further solved by a method with the features of claim 15. Such a method is provided for manufacturing a spray gun, in particular a spray gun according to any one of the claims 1 to 14, wherein the method comprises the following steps: - providing a spray gun main body comprising at least one channel body that pro- vides a fluid channel for the passage of fluid from a fluid inlet to a fluid outlet of the spray gun and a valve for selectively opening and closing the fluid channel, wherein a counterlocking element is attached, in particular integrally formed, to the channel body; - providing an actuator element for causing the valve to open and close the fluid channel; - attaching a biasing element to the actuator element; - pivotably coupling a swivel bracket to the actuator element so that the swivel bracket is in contact with the biasing element and so that the biasing element is preloaded by the swivel bracket; - pivotably coupling the actuator element with the biasing element and the swivel bracket to the spray gun main body so that the swivel bracket is coupled with the counterlocking element. In this way, the swivel bracket is mounted to the actuator element without back- lash, because the biasing element pushes the swivel bracket into its intended operation position. Also, an advantageous spray gun is manufactured in very few assembling steps. An exemplary embodiment of the invention may comprise the following step: - coupling at least one stopping element of the actuator element with a corresponding counterstopping element of the spray gun main body, in particular of a spray gun casing. In this way, the spray gun can be easily manufactured with defined stops for the actuator element in the first position and in the second position. Novel and inventive features of the present invention are set forth in the appended claims. The present invention will be described in further details with reference to the ac- companied drawings, in which Figure 1 illustrates a schematic sectional side view of spray gun according to an embodiment of the present invention, Figure 2A illustrates a schematic sectional side view of an isolated actuating element of the spray gun of Figure 1, Figure 2B illustrates a schematic sectional side view of the isolated actuating element of Figure 2A with a swivel bracket in a pre-assembled state, Figure 2C illustrates a schematic sectional side view of the isolated actuating element with the swivel bracket as in Figure 2B in an assembled state, Figures 3A to 3E illustrate a schematic sectional side view of the spray gun of Figure 1, in which the spray gun casing and the spray head have been removed, and show the trajectory of the swivel bracket in different states during operation of the actuating element, Figures 4A to 4C illustrate schematic views of alternative embodiments of guiding pins to be used in a spray gun of Figure 1. Figure 1 illustrates an irrigation spray gun 10 comprising a spray gun casing 12 that encloses a fluid channel extending from a coupling section 44 for coupling the spray gun 10 with a water hose, to a spray head 14 for the outlet of water. The spray head 14 may be of the type that can be set to spray in different spray patterns. The spray gun casing 12 is made of a shell that might include two-half shells in which a structure comprising the fluid channel, can be placed. The coupling section 44 de- fines the upstream end of the spray gun 10, wherein the spray head 14 defines the downstream end of the spray gun 10. More specifically, a first channel body 34 and a second channel body 70 are provided. The first channel body 34 forms a first channel section 16 of the fluid channel and the second channel body 70 forms a second channel section 18 of the fluid channel. In this specific embodiment, the second channel body 70 is formed integrally to a valve body 22 of a valve section 20 of the spray gun 10 and the first channel body 34 is coupled onto a connector piece of the valve body 22. The first channel body 34 and the second channel body 70 can be coupled to the valve body 22 in suitable alternative ways. The valve section 20 enables to selectively open and close a passage between the first channel section 16 and the second channel section 18 that is formed by the valve body 22. For this purpose, the valve section 20 forms a passage configured to fluidically connect the first channel section 16 with the second channel section 18. In said passage, a valve stem 24 is located which can move back and forth within the passage and which can be placed in a first position in which the passage be- tween the first channel section 16 and the second channel section 18 is closed, thus interdicting the passage of water from the first channel section 16 to the second channel section 18, and a second position in which the passage between the first channel section 16 and second channel section 18 is open and in which water can pass from the first channel section 16 to the second channel section 18. In this embodiment, the passage provided by the valve body 20 may have a cylindrical cross-section and the valve stem 24 may have a corresponding cylindrical cross-section so that the valve stem 24 can smoothly move within the space provided by the passage. In a first position of the valve stem 24 in the passage formed by the valve section 22, a closing section 26 of the valve stem 24 is disposed in a location in that the valve stem 24 prevents the passage of water. More specifically, the closing section 26 is disposed in the passage in front of the inlet leading from the passage into the second channel section 18. The closing section 26 further includes two sealing rings arranged circumferentially around the valve stem 24 which are distanced from each other to such an extent that the inlet leading from the passage into the second channel section 18 is water-tightly sealed when the closing section 26 is located in the first position as it is shown in Fig 1. In order to open the valve for letting water through the passage from the first channel section 16 to the second channel section 18, the valve stem 24 moves along the passage until the second position is reached in which an opening section 28 of the valve stem 24 is disposed in front of the inlet leading from the pas- sage into the second channel section 18. In the opening section 28, the valve stem 24 comprises recesses that allow the passage water from the outlet of the first channel section 16 to the inlet of the second channel section 18. These recesses might be formed by a reduction of the diameter of the valve stem 24 in the opening section 28 compared to the diameter of the valve stem 24 in the closing section 26. Alternatively, these recesses might be formed as one or more through openings provided within the valve stem 24. Also, the opening section 28 is delimited by two sealing rings that are distanced from each other so that the passage formed by the opening section 28 is sealed to such an extent that water passing through the opening section 28 is prevented from leaking out of the valve section. Selectively opening and closing the valve by opening and closing the valve stem 24 is enabled for the user by providing a manually operable actuator element 32 that can be operated by opening and closing a hand holding the spray gun 10. The actu- ator element 32 is formed as a hollow shell structure that encompasses an interior space 76 (illustrated in Figure 2A). Further, the actuator element 32 is hinged to the first channel body 34 by an actuator element hinge 36 that enables a pivotal movement of the actuator element 32 relative to the spray gun casing 12 which provides the hand- held part of the spray gun 10. More specifically, the actuator element hinge 36 comprises a knuckle 46 (illustrated in Figure 2A) integrally formed to a wall of the actuator element 32 that partially encompasses an actuating element hinge pin 72 (illustrated in Figure 3A) integrally formed to the first channel body 34. Further, the actuator element 32 is arranged at the spray gun casing 12 in a way that a hand holding the spray gun casing 12 can actuate the actuator element 32 with one or more fingers and cause a pivotal movement of the actuator element 32 relative to the spray gun casing 12. In a closed state of the spray gun 10, i.e., in a state in which the valve stem 24 is in the first position in which the passage of the valve section 20 is blocked by the closing section 26 of the valve stem 24, a lower end of the valve stem 24 projects from the valve section 20 into the space 76 formed by the actuator element 32. The lower end of the valve stem 24 comprises a disc-like portion that abuts on a sup- port surface 50 (illustrated in Figure 2A) formed inside of the actuator element 32. Furthermore, a resilient element 30, e.g. a spiral spring, arranged around the valve stem 24 is attached to the valve body 22 and to the valve stem 24 such that the resilient element 30 urges the valve stem 24 out of the passage formed by the valve section 20 and thus urging the valve stem 24 into the first position in which the closing section 26 is disposed in the passage in a location in that the valve stem 24 prevents the passage of water through the valve section 20. The resilient element 30 that urges the valve stem 24 out of the passage, and at the same time urges the actuator element 32 into a position in which the actuator element 32 is pivoted relative to the spray gun casing 12 to such an extent that a stopping element 58 (illustrated in Figure 2A and Figure 2B) that is formed to the actuator element 32 engages with a corresponding counter stopping element of the spray gun casing 12 (not shown) and where the pivotal movement of the actuator element 32 is stopped at a maximum allowed pivotal position of the actuator element 32. For this purpose, the actuator element 32 partially encloses the first channel body 34 and comprises stopping elements 58 on both sides. The maximum allowed pivotal position represents the default position of the actuator element 32 in which the valve of the spray gun 10 is closed. If the user actuates the actuator element 32 by moving respectively rotating it closer to or into the spray gun casing 12, the valve stem 24 is moved against the force exerted by the resilient element 30 further into the passage formed by the valve body 22. At the same time the actuator element 32 is moved further into the spray gun casing 12. The valve stem 24 can be moved up until the second position is reached in which the passage between the first channel section 16 and the second channel section 18 is open, and in which water can pass from the first channel section 16 to the second channel section 18. An automatic locking mechanism is provided on the spray gun 10 that is explained in more detail with reference to Figures 3A to 3E. The locking mechanism enables to lock the actuator element 32 in a position in which the valve stem 24 is located in the second position, i.e., in a position in which the spray gun 10 is in an open or water spraying state. The locking mechanism comprises a counterlocking element 42 and a swivel bracket 40, the movement of the latter being guided on the counterlocking element 42 when the actuator element 32 is pivotably moved relative to the spray gun casing 12. As illustrated in Figure 2B, the swivel bracket 40 comprises a bracket body 62 from which two bracket arms 64 extend parallel to each other. The bracket body 62 includes two hinge pins 68 which extend from opposing sides of the bracket body 62. Each of the bracket arms 64 includes a guiding pin 66 which extend towards each other. As illustrated in Figure 2C, the hinge pins 68 can be hung or clipped into corresponding hinge support hooks 54 that are integrally formed to the actuator element 32 such that the swivel bracket 40 can pivotably move about the hinge pins 68. When the actuator element 32 is mounted to the spray gun casing 12, each of the guiding pins 66 is engaged with respective guiding structures provided by two counterlocking elements 42 (only one can be seen in the perspective of Figures 3A to 3E) that are fixedly attached on opposing sides of the first channel body 34. Furthermore, as illustrated in Figures 2A and 2C, the actuator element 32 comprises side walls that have recesses 52 that are formed such that the swivel bracket 40 can protrude into the recesses 52 for allowing its swivel movement around the hinge pins 68. As illustrated in Figure3A, the counterlocking element 42 has a base plate 86 that is integrally formed to the first channel body 34. The base plate 86 has a surface that is averted from the first channel body 34 and upon which a first guiding element 78 and a second guiding element 80 are attached, e.g., by integrally forming the guiding elements 78 and 80 to the base plate 86. The first guiding element 78 and the second guiding element 80 are formed to define a heart-curve formed path which the guiding pins 66 of the swivel bracket 40 follow when the actuator element 32 is pressed by manual force and brought closer to or into the spray gun casing 12. Furthermore, the actuator element 32 comprises a bottom wall 82 which includes a biasing structure for exerting a biasing force onto the swivel bracket 40 in its mounted position. The biasing structure comprises two struts 48 integrally formed to the bottom wall 82 onto which a biasing element 38, such as a stainless-steel rod spring or leaf spring or flat spring, is supported at a distance to the bottom wall 82 of the actuator element 32 such that the biasing element 38 can bend towards the bottom wall 82. Securing structures 56 prevent the biasing element 38 from being displaced and maintain it in its position on the struts 48. Additionally or alternatively, a securing and reinforcing element may be integrally formed to the actuator element 32 that provides structural rigidity to the actuator element 32 and simultaneously prevents the biasing element 38 from moving out of its mounted position. The position of the hinge support hooks 54 relative to the biasing element 38 sup- ported on the struts 48 is selected such that, when the swivel bracket 40 is attached to the hinge support hooks 54 by its hinge pins 68 mounted to the hinge support hooks 54, a bottom surface 84 of the swivel bracket 40 is arranged in a position such that it touches and bends the biasing element 38 towards the bottom wall 82 of the actuator element 32. Thus, the biasing element 38 exerts a biasing force onto the swivel bracket 40. Figures 3A to 3E in synopsis show a sequence of movement of the actuator element 32 interacting with the swivel bracket 40 and the valve stem 24 when operated by manual force exerted by a user’s hand. FIG 3A shows the default position of the spray gun 10, when no manual force is exerted on the actuator element 32. The actuator element 32 is at its maximum allowed pivotal position due to the force exerted by the resilient element 30 via the valve stem 24 on the support surface 50 of the actuator element 32. The stopping element 58 engages a corresponding element of the spray gun casing 12 (not shown) and prevents the actuator element 32 from moving beyond the maximum allowed pivotal position. In this position of the actuator element 32, the swivel bracket 40 is in a position substantially perpendicular to a position the biasing element 38 would assume if it would be unloaded. Due to the contact of the swivel bracket 40 with the biasing element 38, the biasing element 38 bends out of the position it would assume if the swivel bracket 40 would not load it. The swivel bracket 40 contacts the biasing element 38 with its substantially planar bottom surface 84. Since the biasing element 38 is bent by the swivel bracket 40, the bottom surface 84 is not in plane contact with the biasing element 38, but a first edge 74A and a second edge 74B of the bottom surface 84 of the swivel bracket 40 are in contact with the biasing element 38. Further, the portion of the bottom surface 84 between the first edge 74a and the second edge 74B is distanced from the biasing element 38. Further, the first edge 74A and the second edge 74B are positioned on either side of the hinge provided by the hinge pins 68 coupled to the hinge support hooks 54 at the same respective distance to the hinge axis drawn up by the hinge pins 68 and hinge support hooks 54. In this configuration, the loaded biasing element 38 exerts substantially equal forc- es onto the first edge 74A and the second edge 74B which results in an equilibrium of the swivel bracket 40, keeping it in a relatively stable and stationary position relative to the actuator element 32 and the first channel body 34. As illustrated in Figure 3B, when the actuator element 32 is operated by manual force, and moved towards or into the spray gun casing 12, the position and form of the first guiding element 78 of the counterlocking element 42 interacts with the guiding pin 66 of the swivel bracket 40, causing the guiding pin 66 to slide along a sliding surface of the first guiding element 78 for guiding the guiding pin 66 upwards. This movement tilts the swivel bracket 40 relative to the position the biasing element 38 would assume if it would be unloaded. Therefore, the first edge 74A of the bottom surface 84 of the swivel bracket 40 loses contact with the biasing element 38 and only the second edge 74B maintains contact with the biasing element 38. As illustrated in Figure 3C, in the uppermost position of the guiding pin 66, which corresponds to the most retracted position of the valve stem 24 relative to the valve body 22, the guiding pin 66 slides around an upper corner of the first guiding element 78 and into a recess formed by the first guiding element 78. The movement of the guiding pin 66 around the upper corner of the first guiding element 78 is facilitated by the force exerted by the biasing element 38 on the second edge 74B of the bottom surface 84 of the swivel bracket 40 which urges the swivel bracket 40 to pivot towards the position shown in Figure 3A in which the swivel bracket 40 is in a position substantially perpendicular to a position the biasing element 38 would assume, if it would be unloaded. In this position the spray gun 10 is open and, if the manual force is released from the actuator element 32, the resilient element 30 urges the actuator element 32 away from the spray gun casing 12. However, the actuator element 32 is prevented from moving into the default position of Figure 3A, since the guide pin 66 is located within the recess of the first guiding element 78 and, thus, prevents further movement of the actuator element 32 away from the spray gun casing 12 or the first channel body 34. Therefore, the position shown in Figure 3D represents the open and locked position of the spray gun 10. To release the actuator element 32 from the locked position, manual force may be applied to the actuator element 32 causing it to move towards or into the spray gun casing 12. The guiding pin 66 is moved upwards out of the recess and is forcedly guided by the second guiding element 80 towards a sliding surface of the first guiding element 78 for guiding the guiding pin 66 downwards. The force exerted by the resilient element 30 causes the actuator element 32 to move towards its maximum allowed pivotal position, wherein the guiding pin 66 slides along the first guiding element 78 until it reaches the lowermost tip of the first guiding element 78 (position shown in Figure 3E). After passing the lowermost tip, the swivel bracket 40 is urged by the biasing element 38 which is now only in contact with the first edge 74A of the bottom surface 84, but not with the second edge 74B, to move towards the position substantially perpendicular to a position the biasing element 38 would assume if it would be unloaded. The opening and closing cycle of the spray gun 10 is finished when the default position as shown in Figure 3A is reached in which the swivel bracket 40 is in its non-biased or neutral position in which both edges 74A and 74B are in contact with the biasing element 38. Figures 4A to 4C illustrate schematic views of alternative geometries of guiding pins 66 to be used in a spray gun 10 of Figure 1. The cross-section of the guiding pin 66 can vary as it can be a circular cross section, a rectangular cross section as of guiding pin 66.1 (shown in Figure 4A), an oval cross section as of guiding pin 66.2 (shown in Figure 4B) or a triangular cross section as of guiding pin 66.3 (shown in Figure 4C). A rectangular guiding pin 66.1 allows a small overstroke as both edges of the pin 66.1 require only a small overlap. Furthermore, the height of a pin 66 may increase the rigidity and thus the holding force of the swivel bracket 40. In the exemplary embodiments of Figures 4A to 4C, the height of the recess of the first guiding element 78 is l2 = 0,7mm. The distance between the upper edge of the guiding pin 66.1 and the second guiding element 80 is l1 = 0,3mm. The height of the guiding pin 66.1 is l3 = 2mm. Therefore, the guiding pin 66.1 has to be lifted only slightly more than 0,7mm to disengage with the recess of the first guiding element 78. Thus, an overstroke of less than 1mm can be achieved. It is, of course, possible to provide the second guiding element 80 with a triangular contour as shown in Figures 3A to 3E instead of a rectangular as shown in Figures 4A to 4C. Furthermore, the rounded oval contour of guiding pin 66.2 or the triangular contour of guiding pin 66.3 may facilitate disengagement of the guiding pins 66.2, 66.3 as these can smoothly slide upwards along the contour of the second guiding element 80.

[0002] Reference Numerals 10 spray gun 12 spray gun casing 14 spray head 16 first channel section 18 second channel section 20 valve section 22 valve body 24 valve stem 26 closing section 28 opening section 30 resilient element 32 actuator element 34 first channel body 36 actuator element hinge 38 biasing element 40 locking element / swivel bracket 42 counterlocking element 44 coupling section 46 knuckle 48 strut 50 support surface 52 recess 54 hinge support hooks 56 securing structures 58 stopping element 62 bracket body bracket arms guiding pins hinge pins second channel body actuating element hinge pin A, 74B edges of bottom surface of swivel bracket space first guiding element second guiding element bottom wall of actuator element bottom surface of swivel bracket base plate

Claims

Claims 1. Spray gun (10) with an automatic locking mechanism comprising: - a spray gun main body comprising at least one channel body (34, 70) that provides a fluid channel (16, 18, 20) for the passage of fluid from a fluid inlet to a fluid outlet of the spray gun (10); - a valve (22, 24) for selectively opening and closing the fluid channel (16, 18, 20); - an actuator element (32) operably coupled to the valve (22, 24) in such way that the valve (22, 24) can be caused to open and close the fluid channel (16, 18, 20) by manual operation of the actuator element (32), wherein the actuator element (32) can be actuated into a first position in which the actuator element (32) causes the valve (22, 24) to be in a state in which the fluid channel (16, 18, 20) is open and wherein the actuator element (32) can be actuated from the first posi- tion to a second position in which the actuator element (32) causes the valve (22, 24) to be in a state in which the fluid channel (16, 18, 20) is closed; - a locking structure (38, 40, 42) for releasably locking the actuator el- ement (32) in the first position, wherein the locking structure (38, 40, 42) comprises: • a locking element (40) that is engaged with a counterlocking element (42) to lock the actuator element (32) in the first position and which is disengaged with the counterlocking el- ement (42) when the actuator element (32) is in the second position; • a biasing element (38) that exerts a force on the locking el- ement (40) when the actuator element (32) is actuated into the first position so that the locking element (40) is urged to engage with the counterlocking element (42) and that exerts a force on the locking element (40) when the actuator ele- ment (32) is actuated from the first position to the second position so that the locking element (40) is urged to disen- gage with the counterlocking element (42).

2. Spray gun (10) according to claim 1, wherein the valve (22, 24) comprises: - a valve body (22) providing a valve section (20) as a part of the fluid channel (16, 18, 20),- a valve stem (24) arranged at least partially within the valve section (20) andconfigured to leave open the valve section (20) in a first stem position and to close the valve section (20) in a second stem position; and - a resilient element (30) exerting a force on the valve stem (24) to urge the valve stem (24) out of the first stem position into the second stem position; in particular wherein the actuator element (32) is operably coupled to the valve stem (24) so that the valve stem (24) is pushed against the force direction of the resili- ent element (30) towards the first stem position when the actuator ele- ment (32) is actuated into the first position and wherein the force of the re- silient element (30) transferred by the valve stem (24) acts on the actuator element (32) such that the actuator element (32) tends to be pushed from the first position into the second position and can be fixed in the first posi- tion by the locking element (40) engaging with the counterlocking element (42).

3. Spray gun (10) according to any of the preceding claims, wherein the actuator element (32) is pivotably coupled to the spray gun main body, in particular to the channel body (34, 70), via an actuator element hinge (36) ar- ranged at or close to a first end section of the actuator element (32), and wherein the actuator element (32) is operably coupled to the valve (22, 24) in a second end section of the actuator element (32), wherein the first end section is arranged clos- er to a fluid inlet of the spray gun (10) than the second end section.

4. Spray gun (10) according to claim 3, wherein the locking structure (38, 40, 42) is arranged between the actuator ele- ment hinge (36) and the valve (22, 24), in particular wherein the locking element (40) is pivotably coupled to the actuator element (32) adjacent to an area where the actuator element (32) is or comes in contact with the valve (20, 22).

5. Spray gun (10) according to any of the preceding claims,wherein the locking element (40) comprises a swivel bracket (40) pivotably coupled to the actuator element (32), in particular wherein the biasing element (38) is arranged relative to the swivel bracket (40) and the ac- tuator element (32) such that it exerts a biasing force on the swivel bracket (40) that urges the swivel bracket (40) from a biased position in which the swivel brack- et (40) is engaged with the counterlocking element (42) into a non-biased position in which the swivel bracket (40) is disengaged with the counterlocking element (42).

6. Spray gun (10) according to any of the preceding claims, wherein the counterlocking element (42) comprises a heart-curve structure forming a travelling path for a guiding pin (66) of the swivel bracket (40), in particular wherein the heart-curve structure is arranged relative to the swivel bracket (40) and the biasing element (38) in such way that, when the guiding pin (66) is en- gaged with an engagement recess of the heart-curve structure, the biasing element (38) exerts a force on the swivel bracket (40) urging it out of the engaged position into a non-biased position.

7. Spray gun (10) according to any of the preceding claims, wherein the counterlocking element (42) comprises a base plate (86), a first guid- ing element (78) comprising a heart-curve structure and a second guiding element (80) forming a stopping structure, and / or wherein the base plate (86) and / or the first guiding element (78) and / or the second guiding element (80) is / are fixedly attached to the spray gun main body, in particular to a first channel body (34) forming at least a section of the fluid channel, preferably wherein base plate (86) and / or the first guiding element (78) and / or the second guiding element (80) is / are formed integrally with the first channel body (34).

8. Spray gun (10) according to any of the preceding claims, wherein the swivel bracket (40) comprises a bracket body (62) to which two hinge pins (68) are attached and which are coupled to corresponding hinge supports (54) attached to the actuator element (32), such that the swivel bracket (40) is pivot- ably movable relative to the actuator element (32), in particular wherein a hingeaxis drawn up by the hinge pins (68) and the hinge supports (54) is substantially transverse to a longitudinal axis defined by a longitudinal extension of the actuator element (32) and / or defined by a longitudinal extension of a portion of the channel body (34, 70), preferably of the first channel body (34).

9. Spray gun (10) according to any of the preceding claims, wherein the swivel bracket (40) comprises a bracket body (62) and two bracket arms (64) extending from the bracket body (62), wherein the bracket arms (64) at least partially encompass the channel body (34,), in particular the first channel body (34), and wherein each bracket arm (64) comprises a guiding pin (66), the guiding pins (66) facing each other and being configured to travel through travelling paths provided by the counterlocking element (42) fixedly attached to opposing sides of the chan- nel body (34, 70), in particular the first channel body (34).

10. Spray gun (10) according to any of the preceding claims, wherein the spray gun main body further comprises a spray gun casing (12) which at least partially encloses the channel body (34, 70), in particular the first channel body (34), and / or the valve body (22), in particular wherein the spray gun casing (12) and the channel body (34, 70) are arranged relative to each other such that the guiding pins (66) are guided at least partially between the spray gun casing (12) and the base plate (86) of the counter- locking element (42), in particular integrally formed to the channel body (34, 70), when travelling through the travelling paths provided by the counterlocking element (42).

11. Spray gun (10) according to any one of the claims 6 to 10, wherein the guiding pins (66) have a circular or oval-shaped or rectangular or tri- angular cross section.

12. Spray gun (10) according to any of the preceding claims, wherein the biasing element (38) is supported at a distance to a bottom wall (82) of the actuator element (32) and the swivel bracket (40) is coupled to the actuator element (32) in a position relative to the biasing element (38) such that the biasing element (38) is preloaded by the swivel bracket (40),in particular wherein the swivel bracket (40) comprises a bottom surface (84) hav- ing at least two opposing edges (74A, 74B) which is in contact with the biasing el- ement (38) and wherein the swivel bracket (40) can be in a position relative to the biasing element (38) in which both edges (74A, 74B) are in contact with the biasing element (38) and which is a non-biased (or: neutral) position of the swivel bracket (40) and wherein the swivel bracket (40) can be in a position relative to the biasing element (38) in which only one of the edges (74A, 74B) is in contact with the bias- ing element (38) and which is a biased position of the swivel bracket (40).

13. Spray gun (10) according to any of the preceding claims, wherein the channel body (34, 70) comprises at least one first channel body (34) and one second channel body (70) which are connected by a valve body (22), wherein the first channel body (34) provides a first channel section (16), the sec- ond channel body (70) provides a second channel section (18) and the valve body (22) provides a valve section (20) fluidically interconnecting the first channel sec- tion (16) and the second channel section (18), wherein the first channel section (16) is arranged non-parallel and non-rectangular relative to the valve section (20), in particular in an angle between 45° and 80°, preferably between 50° and 65° and / or wherein the second channel section (18) is arranged rectangular relative to the valve section (20).

14. Spray gun (10) according to claim 13, wherein the valve stem (24) is arranged movably back and forth within the valve section (20) and has an end section with an actuation surface being in contact with a corresponding support surface (50) of the actuator element (32), in particular wherein the support surface (50) is inclined relative to a bottom wall (82) of the actuator element (32) such that a longitudinal axis of the valve stem (24) is oriented sub- stantially rectangular to a tangent of the support surface (50) touching the point of contact between the actuation surface and the support surface (50), and / or wherein the support surface (50) is substantially plane or slightly curved such that the actuation surface can slide on the support surface (50) when the actuator ele- ment (32) is actuated into the first position or from the first position into the sec- ond position.

15. Method for manufacturing a spray gun (10), in particular a spray gun (10) according to the preceding claims, wherein the method comprises the follow- ing steps: - providing a spray gun main body comprising at least one channel body (34, 70) that provides a fluid channel (16, 18, 20) for the passage of fluid from a fluid inlet to a fluid outlet of the spray gun (10) and a valve (22, 24) for se- lectively opening and closing the fluid channel (16, 18, 20), wherein a coun- terlocking element (42) is attached to the channel body (34, 70); - providing an actuator element (32) for causing the valve (22, 24) to open and close the fluid channel (16, 18, 20); - attaching a biasing element (38) to the actuator element (32); - pivotably coupling a swivel bracket (40) to the actuator element (32) so that the swivel bracket (40) is in contact with the biasing element (38) and so that the biasing element (38) is preloaded by the swivel bracket (40); - pivotably coupling the actuator element (32) with the biasing element (38) and the swivel bracket (40) to the spray gun main body so that the swivel bracket (40) is coupled with the counterlocking element (42).

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