Technical Field

The invention relates to a controller for controlling the function of a valve actuator, and in particular to a connector for connecting the controller to a valve actuator. The invention also relates to an assembly of a valve actuator and a controller connected by a connector, and to a valve assembly including such an assembly.

Background Art

It is common to operate valves by valve actuators. Typically, a valve actuator has a pneumatically driven piston operatively connected to the valve for opening and closing the valve. In some solutions, a controller is attached to the valve actuator that controls the function, or some of the functions, of the valve actuator.

In some solutions, a piston rod that is connected to the piston protrudes from the valve actuator and the position of the piston rod changes with the position of the piston inside the valve actuator. The controller typically has a sensor for controlling the position of the piston, and possibly also for determining the position of a valve member in the valve. In some solutions, the sensor is an integral part of the controller. Thus, the position of the controller relative to the actuator is important for controlling the function of the valve actuator.

The above described type of controllers typically encloses the piston rod and it is important that the controller is centered correctly on the piston rod. In known solutions, the controller has a set of screws, where each screw has a screw axis that is oriented radially with respect to the piston rod. When tightened, the tips of the screws move towards the piston rod and engage the valve actuator, for example protrusions specifically intended for locking to the screws. However, if one screw is tightened more than the other screws, there is a significant risk that the controller will shift in the direction of the screw. This in turn causes a radial misalignment between the sensor in the controller and the piston rod, and the control accuracy is reduced.

Additionally, there is also a need for a strong coupling between the controller and the valve actuator. For example, if a valve actuator with a mounted controller is installed in a horizontal relationship, or upside down, the connection is subjected to significant forces by the weight of the controller. This may cause the controller to shift relative to the piston rod, or even the controller to break. In particular, there is a need for a connector that has screws that can be tightened hard, without risk of damaging the controller. There is also a need to reduce the risk of mistakes in the installation process of a valve actuator and its controller, and to make the installation process simple.

Summary

It is an object of the invention to overcome the above described limitations and disadvantages of the prior art. In particular, it is an object to improve the accuracy of the mounting of a controller on a valve actuator, and in particular to avoid a radial misalignment between a controller and a piston rod of a valve actuator. It is a further object to provide a strong coupling between a controller and a valve actuator, in particular a coupling with a reduced risk of damaging the controller and that is easy use in an installation procedure.

To solve the above objects, an assembly comprising a valve actuator and a controller for controlling the function of the valve actuator is provided. The valve actuator comprises a housing having a first support surface and a first knob protruding from the first support surface. The valve actuator further comprises a piston and a piston rod connected to the piston, wherein the piston rod protrudes from the first support surface. The controller comprises a connector for connecting the controller to the valve actuator. The connector comprises: a base plate having a first side and a second side, a first aperture extending from the first side to the second side, and a first edge extending from the first side to the second side. The second side has a second support surface that contacts and conforms to the first support surface. The first knob extends through the first aperture and the first edge faces the piston rod. The connector further comprises: a first lock attached to the base plate and located on the first side of the base plate and at the first aperture for locking the connector to the first knob. The first lock comprises a first screw having a first screw axle, wherein the first screw is configured to engage the first knob and oriented with the first screw axle transverse to a line between the piston rod and the first knob.

In another wording, the above objects are solved by an assembly comprising a valve actuator and a controller for controlling the function of the valve actuator. The valve actuator comprises a housing having a first support surface and a first knob protruding from the first support surface. The valve actuator further comprises a piston and a piston rod connected to the piston, wherein the piston rod protrudes from the first support surface. The controller comprises a connector for connecting the controller to the valve actuator. The connector comprises: a base plate having a first side and a second side, a first aperture extending from the first side to the second side, and a second aperture extending from the first side to the second side. The second side has a second support surface that contacts and conforms to the first support surface. The first knob extends through the first aperture and the piston rod extends through the second aperture. The connector further comprises: a first lock attached to the base plate and located on the first side of the base plate and at the first aperture for locking the connector to the first knob. The first lock comprises a first screw having a first screw axle, wherein the first screw is configured to engage the first knob and oriented with the first screw axle transverse to a line between the piston rod and the first knob.

With this orientation of the screw, it will cause the connector and controller to rotate relative to the piston rod when tightened, thus avoiding or reducing the risk for radial shifts or misalignments.

The base plate may be a common base plate or the base plate may be a first base plate. In case of a first base plate the connector may comprise a second base plate having a first side and a second side. The second side may have a second support surface that contacts and conforms to the first support surface. In case of a common base plate the common base plate may comprise a second edge extending from the first side to the second side or in case of a first and a second base plate the second base plate may comprise a second edge extending from the first side to the second side. The second edge may face the piston rod. The valve actuator may further comprise a second knob protruding from the first support surface in the same direction as the first knob. In case of a common base plate the common base plate may further have a third aperture or in case of a first and a second base plate the second base plate may further have a third aperture. The third aperture may extend from the first side to the second side and the second knob may extend through the third aperture. Further, the connector may also comprise a second lock attached to the base plate, i.e. to the common base plate in case of a common base plate or to the second base plate in case of a first and a second base plate, for locking the connector to the second knob. The second lock may be located on the first side of the base plate and at the third aperture. The second lock may comprise a second screw having a second screw axle, wherein the second screw is configured to engage the second knob and oriented with the second screw axle transverse to a line between the piston rod and the second knob.

In another wording, the valve actuator may further comprise a second knob protruding from the first support surface in the same direction as the first knob. The base plate may further have a third aperture extending from the first side to the second side and the second knob may extend through the third aperture. Further, the connector may also comprise: a second lock attached to the base plate and located on the first side of the base plate and at the third aperture for locking the connector to the second knob. The second lock may comprise a second screw having a second screw axle, wherein the second screw is configured to engage the second knob and oriented with the second screw axle transverse to a line between the piston rod and the second knob.

Here, and throughout these specifications, a screw axle being transverse to a line between the piston rod and a knob is understood to encompass the screw axle being transverse to, or at a right angle to, a line between the center of the piston rod and the center of the knob and parallel to the first support surface and/or the second support surface. It is further understood to encompass the screw axle being transverse to, or at a right angle to, a line between the center of the first aperture and the center of the second aperture and parallel to the first support surface and/or the second support surface, and the screw axle being transverse or perpendicular to a line between the first knob and the second knob or between the first aperture and the third aperture, or the centers thereof. It is also understood to encompass the screw axle being oriented tangentially or circumferentially with respect to the piston rod and/or the second aperture, or the centers thereof.

The first screw axle may be parallel to the base plate or the second support surface at the first aperture. Similarly, the second screw axle may be parallel to the base plate or the second support surface at the third aperture. Alternatively, the first screw axle may define a first angle relative to the base plate or the second support surface at the first aperture, wherein the first angle is less than 30°. Similarly, the second screw axle may define a second angle relative to the base plate or the second support surface at the third aperture, wherein the second angle is less than 30°. The second angle may be equal to the first angle. Additionally or alternatively, the second support surface may be planar.

The piston rod may protrude from the housing of the valve actuator directly between and equidistantly from the first knob and the second knob. This means that the piston rod is at the center between the first knob and the second knob, and that all three are aligned. The first screw and the second screw may be oriented to move in opposite directions when tightened. This is a particularly advantageous arrangement for avoiding misalignments. Alternatively, the first screw and the second screw may be oriented to move in the same direction when tightened. This makes installations easier, since both screws are accessible from one side of the controller. Even so, a good alignment is readily achievable

The first knob may have a proximal portion and a distal portion with the distal portion connected to the proximal portion and forming an overhang. The first knob and the second knob may be circular symmetric and the maximal diameter of the proximal portion may be smaller than the maximal diameter of the distal portion. The knobs described here allows for a strong coupling between the controller and the valve actuator.

The first lock may comprise: a first protrusion extending from the first side of the base plate and located at the first aperture, wherein the first protrusion has a distal end facing away from the base plate for engaging the overhang of the distal portion of the first knob. The first protrusion may be located on the opposite side of the first aperture from the first screw. This allows for a strong coupling between the controller and the valve actuator.

The distal end of the first protrusion may have a first contact surface for contacting the overhang, wherein the first contact surface is slanted with respect to the second support surface at the first aperture for forcing the base plate away from the distal portion of the first knob when the overhang is pressed against the distal end of the first protrusion for pressing the first support surface against the second support surface. Alternatively or additionally, the overhang may have a second contact surface facing the first side of the base plate, wherein the second contact surface is slanted with respect to the first support surface for forcing the base plate away from the distal portion of the first knob when the second contact surface is pressed against the distal end of the first protrusion and pressing the first support surface against the second support surface. These features all contribute to a strong connection between the controller and the valve actuator.

The first lock may comprise a second protrusion extending from the first side of the base plate and located at the first aperture on the opposite side of the first aperture from the first protrusion, and wherein the screw is operationally connected to the second protrusion for allowing the screw to move in the direction of the first protrusion when tightened.

The first screw may have a flat tip with a third contact surface facing and engaging the distal portion of the first knob. This allows for a reproducible and accurate engagement of the first screw, thus reducing the risk of misalignment of the controller due to the tightening of the screw. The piston of the valve actuator may be configured to be operatively connected to a valve for controlling the function of the valve.

The above objects are also achieved by a connector for connecting a controller to a valve actuator having a first support surface, a first knob protruding from the first support surface, and a piston rod protruding from the first support surface, wherein the connector is configured to be connected to the controller. The connector may comprise a base plate having a first side and a second side, a first aperture extending from the first side to the second side for receiving the first knob from the second side, and a first edge extending from the first side to the second side for facing the piston rod. The connector further comprises a first lock attached to the base plate and located on the first side of the base plate and at the first aperture for locking the connector to the first knob. The first lock comprises a first screw having a first screw axle, wherein the first screw is configured to engage the first knob and oriented with the first screw axle transverse to a line between the first aperture and the first edge, or alternatively between the first aperture and the second aperture, or alternatively between the piston rod and the first knob. The first edge may be arranged to face the piston rod.

In another wording, the above objects are also achieved by a connector for connecting a controller to a valve actuator having a first support surface, a first knob protruding from the first support surface, and a piston rod protruding from the first support surface, wherein the connector is configured to be connected to the controller. The connector comprises: a base plate having a first side and a second side, a first aperture extending from the first side to the second side for receiving the first knob from the second side, and a second aperture extending from the first side to the second side for receiving the piston rod from the second side. The connector further comprises a first lock attached to the base plate and located on the first side of the base plate and at the first aperture for locking the connector to the first knob. The first lock comprises a first screw having a first screw axle, wherein the first screw is configured to engage the first knob and oriented with the first screw axle transverse to line between the first aperture and the second aperture, or alternatively between the piston rod and the first knob.

As for the assembly above, with the specified orientation of the screw, it will cause the connector to rotate with respect to piston rod when tightened, thus avoiding or reducing the risk for radial shifts or misalignments.

The first screw may be oriented with the first screw axle transverse to, or at a right angle to, a line between a center of the first aperture and a point on the first edge having the shortest distance to the center of the first aperture. The first screw axle may be parallel to the first support surface and/or the second support surface.

The base plate may be a common base plate or the base plate may be a first base plate. In case the base plate is a first base plate the connector may comprises a second base plate having a first side and a second side. In case of a common base plate, the common base plate may comprise a second edge extending from the first side to the second side for facing the piston rod. In case of a first and a second base plate the second base plate may comprise a second edge extending from the first side to the second side for facing the piston rod. The valve actuator may further have a second knob protruding from the first support surface in the same direction as the first knob. In case of a common base plate the common base plate may further have a third aperture or in case of a first and a second base plate the second base plate may further have a third aperture. The third aperture may extend from the first side to the second side for receiving the second knob from the second side. The connector may further comprise a second lock attached to the base plate, i.e. to the common base plate in case of a common base plate or to the second base plate in case of a first and a second base plate, The second lock may be located on the first side of the base plate and at the third aperture. The second lock may comprises a second screw having a second screw axle, wherein the second screw is configured to engage the second knob and oriented with the second screw axle transverse to a line between the third aperture and the second edge, or between the third aperture and the second aperture, or between the piston rod and the second knob. The first edge may be arranged to face the piston rod.

In another wording, the valve actuator may further have a second knob protruding from the first support surface in the same direction as the first knob, wherein the base plate further has a third aperture extending from the first side to the second side for receiving the second knob from the second side. The connector may further comprise: a second lock attached to the base plate and located on the first side of the base plate and at the third aperture for locking the connector to the second knob. The second lock may comprises a second screw having a second screw axle, wherein the second screw is configured to engage the second knob and oriented with the second screw axle transverse to a line between the third aperture and the second aperture, or between the piston rod and the second knob.

The second screw may be oriented with the second screw axle transverse to a line between a center of the third aperture and a point on the second edge having the shortest distance to the center of the third aperture. The second screw axle may be parallel to the first support surface and/or the second support surface.

The second aperture may be located directly between and equidistantly from the first aperture and the third aperture. This contributes to reduce radial misalignment between a controller and a valve actuator with an equal tightening of the first and second screws. The first screw and the second screw may be oriented to move in opposite directions when tightened. Alternatively, the first screw and the second screw may be oriented to move in the same direction when tightened.

The first knob of the valve actuator may have a proximal portion and a distal portion, and the distal portion is connected to the proximal portion and forms an overhang. The first lock may comprise: a first protrusion extending from the first side of the base plate and located at the first aperture, wherein the first protrusion has a distal end facing away from the base plate. The distal end may be configured for engaging the overhang of the distal portion of the first knob. The first protrusion may be located on the opposite side of the first aperture from the first screw.

The distal end of the first protrusion may have a first contact surface, wherein the first contact surface is slanted with respect to the second support surface at the first aperture. The first contact surface may be configured for contacting the overhang, and for forcing the base plate away from the distal portion of the first knob if the overhang is pressed against the distal end of the first protrusion and pressing the first support surface against the second support surface.

The first lock may comprise a second protrusion extending from the first side of the base plate and located at the first aperture on the opposite side of the first aperture from the first protrusion, and wherein the screw is operationally connected to the second protrusion for allowing the screw to move in the direction of the first protrusion when tightened. Additionally or alternatively, the first screw may have a flat tip with a third contact surface facing and engaging the distal portion of the first knob.

The connector described here may comprise any of the features of the connector described in relation to the assembly above. The features of the connector have the same effect as the corresponding features of the assembly above. Further, in the assembly and connector described above, the second lock of the connector may comprise any of the features of the first lock and the second knob may comprise any of the features of the first knob, thus allowing for similar interaction and function.

The above objects are also solved by a controller for controlling the function of the valve actuator, wherein the controller comprises a connector as described above. The above objects are also solved by a valve assembly comprising a valve and an assembly as described above. The piston of the valve actuator in the assembly may be configured to be operatively connected to the valve for controlling the function of the valve.

Still other objectives, features, aspects and advantages of the invention will appear from the following detailed description as well as from the drawings.

Brief Description of the Drawings

Embodiments of the invention are described, by way of example, with reference to the accompanying schematic drawings, in which

Figs. 1 a-c are a side view, a top view, and a perspective view of an embodiment of a connector.

Figs. 2a and 2b are perspective views of an embodiment of a valve actuator without and with a connector attached to valve actuator,

Figs. 3a-d are side views of an embodiment of a knob and a lock,

Figs. 4a-d are side views of another embodiment of a knob and a lock,

Figs. 5a and 5b are perspective views of an embodiment of a connector and a controller illustrating how the former is attached to the latter, and

Fig. 6 is a perspective view of an embodiment of a valve assembly.

Figs. 7a-d are a first side view, a top view, a perspective view and a second side view seen from a direction perpendicular to the first side view of another embodiment of a connector.

Detailed description

An embodiment of a connector 26 is shown in Figs. 1 a-c. The connector 26 has a base plate 28 with a first side 30 and a second side 32. A first aperture 34, a second aperture 64, and a third aperture 56 extend between the first side 30 and the second side 32. Each of the first aperture 34 and the third aperture 56 can receive a knob, and the second aperture 64 can receive a piston rod, as will be further explained below. The connector has a flat second support surface 36 on its second side 32.

The connector 26 has a first lock 38 and a second lock 58 attached to the base plate 28. Both locks are located on the first side 30 of the base plate 28. The first lock 38 is located at the first aperture 34 and the second lock 58 is located at the third aperture 56. The first lock 38 has a first screw 46 with a first screw axle that is at a right angle to a line between the first aperture 34 and the third aperture 56. Similarly, the second lock 58 has a second screw 66 with a second screw axle that is at a right angle to a line between the third aperture 56 and the first aperture 34. The second aperture 64 is located directly between and equidistantly from the first aperture 34 and the third aperture 56.

The first screw 46 and the second screw 66 are set screws with flat tips 50.

Each flat tip 50 has a planar third contact surface 52. They are oriented to move in opposite directions when tightened. In an alternative embodiment, the first screw 46 and the second screw 66 are oriented to move in the same direction when tightened. This is achieved by reorienting the second screw 66 to point in the opposite direction and position it on the other side of the third aperture 56.

The first lock 38 has a first protrusion 40 and a second protrusion 44 that extend from the first side 30 of the base plate 28 and are located on opposite sides of the first aperture 34. The second protrusion 44 has a threaded bore by which the first screw 46 is operationally connected to the second protrusion 44. The threaded bore orients the first screw 46 to move in the direction of the first protrusion 40 when tightened. The second lock 58 has corresponding protrusions as the first lock 38.

In the embodiment of Figs. 1 a-c, the base plate 28 is manufactured from sheet metal and formed by punching and stamping. The first protrusion 40 and the second protrusion 44 are formed by bending portions of the sheet metal. The base plate 28 has four conical holes 70 going from the first side 30 to the second side 32 that can be used to attach the connector 26 to a controller, as is further discussed in relation to Figs. 4a and b.

Fig. 2a is a perspective view of an embodiment of a valve actuator 12, and Fig. 2b is a corresponding perspective view with the connector 26 described in relation to Figs. 1 a-c attached to valve actuator 12. The valve actuator 12 has a housing 14 with a flat circular top defining a flat first support surface 16. Thus, the second support surface 36 of the connector 26 can conform to the first support surface 16.

A first knob 18 and a second knob 54 protrude from the first support surface 16. The connector 26 is placed on the valve actuator 12 with the second support surface 36 planar with and touching the first support surface 16, and with the first knob 18 extending though the first aperture 34 and the second knob 54 extending through the third aperture 56, as is illustrated in Fig. 2b.

The valve actuator 12 has a piston rod 62 that is connected to a piston inside the housing 14 and move together with the piston. The piston rod 62 protrudes from the housing at the center of the first support surface 16 and extends through the center of the second aperture 64. The centers of the first knob 18, the second knob 54, and the piston rod 62 are positioned in line.

The base plate 28 is a common base plate 28. The base plate 28 comprises the first aperture 34 and the third aperture 56. The base plate 28 also comprises the second aperture 64. The first lock 38 and the second lock 58 are attached to the base plate 28.

The base plate 28 comprises a first edge 81 facing the piston rod 62 and a second edge 82 facing the piston rod. The first edge 81 extends from the first side 30 to the second side 32 of the base plate 28. The second edge 82 extends from the first side 30 to the second side 32 of the base plate 28. The first edge 81 is curved. Also the second edge 82 is curved. The first edge 81 and the second edge 82 are curved such that the second aperture 64 is circular or partially circular. The second aperture 64 is at least partially circular. The at least partly circular second aperture 64 is centered around the piston rod 62.

The first edge 81 comprises a first point 81 1 having the shortest distance to the center of the first aperture 34. The first point 81 1 is the point on the first edge 81 having the shortest distance to the center of the first aperture 34. The first point 81 1 is located on the first edge 81 where the distance from the first edge 81 to the first aperture 34 is at its minimum. The second edge 82 comprises a second point 821 having the shortest distance to the center of the second aperture 56. The second point 821 is the point on the second edge 82 having the shortest distance to the center of the second aperture 56. The second point 821 is located on the second edge 82 where the distance from the second edge 82 to the third aperture 56 is at its minimum.

The first edge 81 as well as the first point 81 1 is located on a line between the first knob 18 and the piston rod 62. The first edge 81 as well as the first point 81 1 is also located on a line between the center of the first aperture 34 and the center of the second aperture 64 as well as the center of the third aperture 56. The first screw axle is transverse to a line between the first aperture 34 and the third aperture 56.

The second edge 82 as well as the second point 821 is located on a line between the second knob 54 and the piston rod 62. The second edge 82 as well as the second point 821 is also located on a line between the center of the third aperture 56 and the center of the second aperture 64 as well as the center of the first aperture 34. The second screw axle is transverse to a line between the third aperture 56 and the first aperture 34. Figs. 3a-d are side views illustrating an embodiment of a lock and a knob that can be implemented in the embodiments described in relation to Figs. 1 and 2 as well as the embodiments described in Figs. 7a-d. Here, the description will refer to a first knob 18 and a first lock 38, but the described features and functions are also applicable for the second knob 54 and the second lock 58.

The first knob 18 has a proximal portion 20 attached to the housing 14 of the valve actuator 12. The first knob 18 also has a distal portion 22 attached to the proximal portion 20. Both portions are circular symmetric and the diameter of the proximal portion 20 is smaller than the diameter of the distal portion 22, thus forming an overhang 24 or an overall mushroom shape, as is illustrated in Fig. 3a.

The connector 26 is oriented and moved in position so that the first support surface 16 and the second support surface 36 are parallel and the first knob 18 enters the first aperture, as is illustrated in Fig 3b. The second support surface 36 is brought in close proximity of the first support surface 16, and the first screw 46 is tightened so that the third contact surface 52 of its tip 50 touches the proximal portion 20 of the first knob 18 and pushes the first protrusion 40 to touch the overhang 24, as is illustrated in in Fig. 3c.

The first protrusion 40 has a first contact surface 48 that is slanted with respect to the second support surface 36 at the first aperture. The first contact surface 48 engages the overhang 24 and when the first screw 46 is further tightened, as is illustrated in Fig. 3c, the connector 26 is forced by the slanted first contact surface 48 towards the valve actuator 12 and the second support surface 36 is pressed against first support surface 16. This way a strong and stable coupling to the valve actuator 12 is achieved.

Figs. 4a-d are side views illustrating another embodiment of a lock and a knob that can be implemented in the embodiments described in relation to Figs. 1 and 2 as well as the embodiments described in Figs. 7a-d. Only the differences with respect to the embodiment described in relation to Figs. 3a-d are described here. Features having the same function have been given the same number indexing. Those differing, but having a related function, have been primed.

As is shown from Fig. 4a, the first knob 18 ^' has a proximal portion 20 attached to the housing 14 of the valve actuator 12. The first knob 18 ^' also has a distal portion 22 ^' attached to the proximal portion 20. Both portions are circular symmetric and the diameter of the proximal portion 20 is smaller than the diameter of the distal portion 22 ^' , thus forming an overhang 24 ^' . The distal portion 22 ^' has a conical shape where it connects to the proximal portion 20, thus forming an overhang 24 ^' with a second contact surface 68 facing the first side 30 of the base plate 28 that is slanted with respect to the first support surface 16.

Subsequent to the first knob 18 entering the first aperture and the first screw 46 being tightened so that the third contact surface 52 of its tip 50 contacts the distal portion 22 of the first knob 18, as is illustrated in Fig. 4b, the distal end 42 of the first protrusion 40 engages the second contact surface 68 when the first screw 46 is further tightened, as is illustrated in Fig. 4c. The connector 26 is forced by the slanted second contact surface 68 towards the valve actuator 12 and the second support surface 36 is pressed against first support surface 16.

The two alternative embodiments of a knob and a lock disclosed in relation to Figs. 3 and 4 both allows for a contact between the first support surface 16 and the complete second support surface 36, which gives a stable support of a controller.

Figs. 5a and 5b are perspective views of an embodiment of a controller 4 with a connector 26. Four screws 72 are inserted in the conical holes 70 of the connector 26 and receiving holes 74 of the controller 4. When tightened, the screws 74 attach the connector 26 to the controller. The screws 74 have flat cone-shaped heads so that they sink into the conical holes 70 when tightened. The controller 4 has access holes 76 through which the first screw 46 and the second screw 66 can be reached and tightened. It has been shown here that the connector 26 is configured to be connected to the controller 4. As an alternative or supplement to the screws 72 and the holes 70, the connector 26 may be integrated in the controller 4 e.g. during molding of the controller 4. In this case, the holes 70 may be omitted. For example, the connector 26 can be placed in the mold when molding a controller 4 made of e.g. a polymer.

Fig. 6 is a perspective view of an embodiment of a valve assembly 8. The valve assembly 8 has a valve 6. The valve is operated by an assembly 10 of a valve actuator 12 operatively connected to the valve 6 and a controller 4 that controls the function of the valve actuator 12.

Another embodiment of a connector 26' is shown in Figs. 7a-d. The connector 26' shown in Figs. 7a-d is identical to the connector 26 shown in Figs. 1 a-c, 2b and 5a- b with the exception that the common base plate 28 of the connector 26 in the connector 26' is divided into two base plates, i.e. a first base plate 28' and a second base plate 28". The same reference numerals denote like elements in the connector 26' as in the connector 26. The first lock 38 is attached to the first base plate 28'. The second lock 58 is attached to the second base plate 28".

The first base plate 28' comprises the first edge 81 facing the piston rod 62. The second base plate 28" comprises the second edge 82 facing the piston rod. The first edge 81 extends from the first side 30 to the second side 32 of the first base plate 28'. The second edge 82 extends from the first side 30 to the second side 32 of the second base plate 28". The second side 32 of the first base plate 28' has a second support surface 36 that contacts and conforms to the first support surface 16. The second side 32 of the second base plate 28" has a second support surface 36 that contacts and conforms to the first support surface 16.

The first base plate 28' comprises the first aperture 34. The second base plate 28" comprises the third aperture 56. The first aperture 34 extends from the first side 30 to the second side 32 of the first base plate 28'. The second aperture 56 extends from the first side 30 to the second side 32 of the second base plate 28".

The second aperture 64 is formed between first base plate 28' and the second base plate 28". The second aperture 64 is located between the first edge 81 of the first base plate 28' and the second edge 82 of the second base plate 28".

The common base plate 28 of the embodiment shown in Figs. 1 a-c, 2b and 5a- b corresponds to that the first base plate 28' and the second base plate 28" shown in Figs. 7a-d are integrated, i.e. are integrally formed, such as formed from one piece, such as formed from one piece of sheet metal.

From the description above follows that, although various embodiments of the invention have been described and shown, the invention is not restricted thereto, but may also be embodied in other ways within the scope of the subject-matter defined in the following claims.

Item list

4 controller

6 valve

8 valve assembly

10 assembly

2 valve actuator

14 housing

16 first support surface

18 first knob

20 proximal portion

22 distal portion

24 overhang

26, 26' connector

28 base plate/common base plate 28' first base plate

28" second base plate

30 first side

32 second side

34 first aperture

36 second support surface

38 first lock

40 first protrusion

42 distal end

44 second protrusion

46 first screw

48 first contact surface

50 tip

52 third contact surface

54 second knob

56 third aperture

58 second lock

62 piston rod

64 second aperture

66 second screw

68 second contact surface 70 conical bore

72 screw with conical head 74 receiving holes 76 access hole

81 first edge

82 second edge

81 1 first point

821 second point