Patent Publication Number: US-2021172781-A1

Title: Interface for connecting a fluid measurement point and a modular fluid measurement system

Description:
The invention relates to an interface for connecting a fluid measurement point and to a modular fluid measurement system comprising the interface and a fluid measurement point connected thereto. 
     In laboratories, in which properties of media, such as, for example, density or viscosity, are to be determined by means of fluid measurement systems, fluid measurement points are connected to an interface, via which a medium to be investigated is supplied to the fluid measurement point and then drained away. 
     The manufacture of a mechanical connection between the interface and the fluid measurement point is complicated in the state of the art. Thus, sometimes screws are led through an interface body and engage in corresponding screw threads in a fluid measurement point housing. This requires a manual maneuvering of the interface and the fluid measurement point relative to one another. Moreover, the provision of screw threads in a fluid measurement point housing results in openings to an inner space of the housing, whereby a contamination of the fluid measurement point in the inner space and a fluid measurement point failure become more probable. Additionally, clamping forces transmitted by means of the screw thread from the screws to the fluid measurement point can disturb measurement operation of the fluid measurement point. 
     An object of the invention, consequently, is to provide, first, an interface for connecting a fluid measurement point and, second, a modular fluid measurement system comprising the interface and the fluid measurement point, wherein manufacture of a robust and sealed mechanical connection is simplified and fluid measurement point safety is increased. 
     The object is achieved by an interface as defined in independent claim  1  as well as by a modular fluid measurement system as defined in independent claim  15 . 
     An interface of the invention adapted for connecting a fluid measurement point comprises:
     a body, which has at least two connection locations,   wherein the body has fluid ducts, each of which has a connection location, wherein the fluid ducts have at their connection locations first duct axes, wherein the connection locations are especially coplanar,   wherein the connection locations are adapted for connecting process connectors from a connection direction for sealed communication with the fluid ducts,   wherein the fluid ducts are adapted via the process connectors to supply, and drain, a medium, respectively, to and from the fluid measurement point,   wherein the interface has at least one holding element for releasably securing at least one process connector to the body, wherein the holding element has at least one process connector seat,   wherein the holding element is adapted to be moved into an end position effecting the securing.   

     In an embodiment, the body includes for each connection location a first support and a second support on an opposite side of the connection location,
     wherein the first support and the second support are adapted to support the holding element at least in the end position,   wherein the first support and the second support are adapted to provide a hold in the connection direction against movement away from the body.   

     In an embodiment, the first support includes at least a first support surface, against which an opposite surface of the holding element is kept in its end position by shape interlocking,
     wherein the second support includes at least a second support surface, against which an opposite surface of the holding element is kept in its end position by shape interlocking.   

     In an embodiment, the first support includes at least a first projection having at least a first cantilever, wherein the first projection extends above a first surroundings at least in certain regions, and wherein the first cantilever covers the first surroundings at least in certain regions, wherein the first cantilever defines the first support surface,
     and/or   wherein the second support includes at least a second projection having at least a second cantilever, wherein the second projection extends above a second surroundings at least in certain regions, and wherein the second cantilever covers the second surroundings at least in certain regions, wherein the second cantilever defines the second support surface.   

     In an embodiment, the first support is arranged between the connection locations. 
     In an embodiment, the first support includes for the holding element a first rotation axis of the holding element extending perpendicularly to the connection direction,
     wherein the holding element is adapted by means of a rotational movement around the first rotation axis to be moved from the starting position into the end position.   

     In an embodiment, the second support includes at least a first bore for receiving a screw, by means of which the holding element is secureable, wherein the holding element has at least a second bore for receiving a screw. 
     In an embodiment, the cantilever includes on a body facing surface a rib, which is adapted to establish the rotation axis,
     wherein a cross-sectional profile of the rib is, for example, triangular, semicircular or semielliptical.   

     In an embodiment, the first support is a radial support, wherein a radial support axis is in parallel with the connection direction, wherein the radial support secures the holding element against movement in the direction of the radial support axis by shape interlocking.
     wherein the holding element is adapted by means of a rotary movement around the radial support axis to be moved into the end position.   

     In an embodiment, the holding element is adapted to be moved into the end position by means of a linear movement perpendicularly to the connection direction. 
     In an embodiment, the holding element is at least sectionally wedge shaped in its end position in the region of the process connection seat, wherein in the wedge-shaped region a surface of the holding element facing toward the body is inclined in the connection direction. 
     In an embodiment, the interface includes a seal, for example, a sealing ring, for at least one connection location. 
     In an embodiment, the connection location includes a counterbore, which has a seal seat. 
     In an embodiment, the holding element is disc shaped or plate shaped. 
     In an embodiment, the body comprises at least two body elements, wherein each body element has at least one connection location and an associated fluid duct, wherein the body elements are separately connectable with the fluid measurement point. 
     A modular fluid measurement system of the invention comprises:
     a fluid measurement point having at least two process connectors; and   an interface as described in one of the variants above,   wherein the at least one holding element is adapted to press at least one process connector against an associated connection location;   

     wherein the at least one process connector seat of a holding element is adapted to be connected with an associated process connector by shape interlocking. 
     In an embodiment, the holding element is adapted to contact at least one bearing surface of the process connector. 
     In an embodiment, a shape of the counterbore is at least sectionally complementary to an external shape of the process connector,
     whereby a tight seating of the process connector perpendicular to a connection direction of the process connector is assured.   

     In an embodiment, the fluid measurement point comprises a Coriolis measurement device, which is adapted to measure a mass flow and/or a density of a medium flowing through a measuring tube of the Coriolis measurement device. 
    
    
     
       The invention will now be described based on examples of embodiments presented in the appended drawing, the figures of which show as follows: 
         FIG. 1  a front view of a modular fluid measurement system according to the state of the art; 
         FIG. 2  a front view of an example of the modular fluid measurement system of the invention; 
         FIG. 3  by way of example, sections through a first support and second support taken with a cutting plane shown in  FIG. 8 ; 
         FIG. 4  an example of a section through a first support and second support taken with a cutting plane shown in  FIG. 8 ; 
         FIG. 5  an example of a section through a first support or second support taken with a cutting plane shown in  FIG. 8 ; 
         FIG. 6  an example of a section through a first support taken with a cutting plane shown in  FIG. 8 ; 
         FIG. 7  sections through terminal openings of fluid ducts; 
         FIG. 8  by way of example, orientations and embodiments of first supports and second supports of an interface of the invention relative to corresponding fluid ducts; 
         FIG. 9  by way of example, a holding element of an interface of the invention; 
         FIG. 10  by way of example, a holding element of an interface of the invention; 
         FIG. 11  by way of example, process connectors of a fluid measurement point of a modular fluid measurement system of the invention; and 
         FIG. 12  examples of assembly of a holding element with a process connector in a modular fluid measurement system of the invention. 
     
    
    
       FIG. 1  shows a front view of a conventional modular fluid measurement system  300 , in the case of which a fluid measurement point  200  is connected to an interface  100  from a connection direction CD, in order by means of fluid ducts  112  to supply, and drain, a medium, respectively, to and from the fluid measurement system via process connectors  210 . The process connectors can, for example, in the case of flow measurement devices or Coriolis measurement devices for measuring the density and/or the mass flow of a medium, be connected with at least one measuring tube, which is adapted to lead the medium to be measured through the flow measurement device, or through the Coriolis measurement device. For securing the fluid measurement point to the interface, screws are led through bores in the interface and engage in bores provided therefor in a housing wall of a housing of the fluid measurement point. Such is unsatisfactory for at least two reasons. The manual maneuvering of the fluid measurement point into connection with the interface is cumbersome, and the introduction of bores into the housing wall of the fluid measurement point is undesirable, since this risks contamination of an inner space of the fluid measurement point. Moreover, clamping forces resulting from the screwed assembly can sensitively disturb measurement operation of the fluid measurement point. For example, in the case of a Coriolis measurement device, oscillation characteristics of a medium-containing measuring tube are measured and under action of clamping forces they can change in a difficultly predictable manner. 
     A goal of the invention is to provide an interface  100  and a modular fluid measurement system  300 , by means of which the discussed problems are solved, and, for example, such as shown in  FIG. 2 , no screws need to pass through the interface into a housing of the fluid measurement point. 
     The solution of the discussed problems is shown in  FIGS. 3 to 12 , wherein at least one holding element  120  (see  FIGS. 9, 10 and 12 ) of the interface is adapted to press the process connectors  210  of the fluid measurement point against terminal opening regions of the fluid ducts. The holding element is, for its part, supported at least in an end position by means of a first support  114 . 1  and by means of a second support  114 . 2  against movement counter to the connection direction. 
       FIG. 3  shows possible embodiments of the first support and the second support, which are arranged on opposite sides of a fluid duct  112 , wherein the views show sections taken according to cutting planes S 1  of  FIG. 8 . Thus, such as shown in the upper view, the first support  114 . 1  can have a first projection  116 . 1  having a first cantilever  117 . 1  providing a first support surface  115 . 1  for the holding element, and, correspondingly, the second support  114 . 2  can have a second projection  116 . 2  having a second cantilever  117 . 2  providing a second support surface  115 . 2  for the holding element. 
     Alternatively, such as shown in the middle view, the second support  114 . 2  can also have a first bore  118 . 1  in the body  110 , or in the body element  110 . 1 , wherein a screw  118 . 3  of the interface is adapted to engage in the first bore and secure the holding element  120 . 
     The first cantilever  117 . 1 , or the second cantilever  117 . 1 , can, such as shown in the lower view, have a rib  117 . 3 , which defines a stop. The rib can, such as shown here, have a triangular cross-sectional profile. Alternatively, the cross-sectional profile can also be semicircularly shaped or semielliptical. 
       FIG. 4  shows an alternative embodiment of the first support and the second support in a view taken with the cutting plane S 3  of the right lower view of  FIG. 8 , wherein the first support  114 . 1  is arranged centrally between two second supports  114 . 2 . The first support is embodied as a radial support RS, which is adapted to support a holding element movable rotatably about a radial support axis RSA, wherein the holding element  120 , as shown in  FIG. 10 , has, in this case, two seats  121  for receiving process connectors. 
       FIG. 5  shows another embodiment of the first support and the second support in a view taken with the cutting plane S 3  of the left lower view of  FIG. 8 , wherein the first support  114 . 1  is arranged centrally between two second supports  114 . 2 . 
     The first support defines support surfaces for two holding elements, which, such as, for example, shown in  FIG. 12 , are supported by the first support  114 . 1  and a respective second support  114 . 2 . 
     At least one second support can, alternatively, also have a first bore with a screw according to the middle view of  FIG. 3 . 
       FIG. 6  shows an alternative embodiment of a first support  114 . 1 , or second support  114 . 2 , in a view taken with a cutting plane S 2  of  FIG. 8 . The first support, or second support, includes two first projections  116 . 1 , or second projections  116 . 2 , with, in each case, a first cantilever  117 . 1 , or second cantilever  117 . 2 , which are opposite one another in the cutting plane S 1 . In such case, a holding element can be pushed along the cutting plane S 1  through a tunnel defined by the cantilevers. 
       FIG. 7  shows examples of sections through a body  110 , or body element  110 . 1 , through terminal openings of fluid ducts  112 , wherein, in a first case, the body  110  has no counterbore, and a process connector must be pressed accurately against the region of the terminal opening. 
     In a second case, the body can have in the region of the process connector location  111  a counterbore  111 . 3 , which forms a seal seat  111 . 4  for receiving a process connector. 
     Arranged in the counterbore can be a seal  111 . 1 , e.g. a sealing ring  111 . 2 . Shape of the counterbore  111 . 3  is, for example, at least sectionally complementary to an outer shape  212  of the process connector, in order to assure a tight seating of the process connector perpendicular to a connection direction of the process connector. 
       FIG. 8  shows by way of example orientations and embodiments of first supports  114 . 1  and second supports  114 . 2  on interfaces of the invention relative to fluid ducts, about which they are arranged, wherein the supports are arranged on a body  110 , or a body element  110 . 1 , of the interface on opposite sides of an associated terminal opening of a fluid duct  112 . 
     In a first embodiment, see left upper view, the body has two fluid ducts  112 , about which are arranged, in each case, a first support  114 . 1  and a second support  114 . 2 , wherein the supports are arranged along a line, wherein the first supports are arranged between the terminal openings of the fluid ducts. In a second embodiment, orientations, in each case, of a first support and a second support are in parallel with one another along different lines, see right upper view. 
     Alternatively thereto, it is possible to associate two second supports with one first support, such as shown in the lower views of the drawing. In the left lower view, the first support  114 . 1  has a first projection  116 . 1  with two first cantilevers  117 . 1 , such as shown in  FIG. 5 , wherein each first cantilever provides a first support surface for a holding element, thus two holding elements are used. 
     The right lower view shows an interface, in the case of which a first support  114 . 1  defines a radial support axis RSA, about which the holding element  120  is rotatably supported, as shown in  FIG. 4 . 
       FIG. 9  shows an embodiment of a holding element  120 , which has a second bore  118 . 2  for passage of a screw  118 . 3 . The holding element includes on a side away from the bore a seat  121  for receiving a process connector, such that the end of the holding element is fork shaped and a process connector is surrounded in an inserted state by means of two tines  124 . 
     In a side view, the holding element  120  can have a rectangular profile, such as shown in the middle view, or such as shown in the lower view, be wedge shaped in the region of the seat  121 . For the case, in which the second support has no screwed assembly, the holding element can also be embodied without a second bore  118 . 2 . 
       FIG. 10  shows an embodiment of a holding element  120 , which has a central bore  123 , in order to accommodate the first support  114 . 1 . In the region of ends of the holding element, the holding element includes second bores  118 . 2 , in order to be able to be secured by means of screws. The holding element includes two seats  121  for receiving separate process connectors, wherein by means of a rotary movement of the holding element around the radial support axis RSA, the process connectors can be pressed, in each case, against a connection location  111 . In the region of the seats, the holding element can have an at least sectionally wedge shaped cross section, such as shown by means of the section viewed according to the cutting plane S 4 . 
     The holding element shown in  FIG. 10  can also be embodied without second bores  118 . 2 . In such case, those skilled in the art will choose second supports according to the upper view of  FIG. 3 . 
       FIG. 11  shows two schematic, side views of process connectors  210 , wherein the process connectors have bearing surfaces  211 , by means of which a shape interlocking connection between process connector and holding element is producible. An external shape  212  of the process connector can, in such case, have a projection  213  or an indentation  214 , or recess  214 , as the case may be. 
       FIG. 12  shows by way of example two securements of process connectors according to the invention by means of holding elements  120 . The upper view shows a securement, in the case of which a holding element is kept in a second support  114 . 2  by means of a screw  118 . 3 , which engages in a first bore  118 . 1 . The first support  114 . 1  on a side of the fluid duct  112  opposite to the second support includes a first projection  116 . 1  with a cantilever  117 . 1 , which defines a first support surface  115 . 1  for the holding element. The pressing of the process connector  210  against the interface can be achieved, for example, by introducing the holding element with the process connector in its seat such that the holding element is placed in shape-interlocking contact with the cantilever  117 . 1  of the first support  114 . 1 , and then an end of the holding element far from the first support is moved in the connection direction toward the body  110 . This corresponds to a rotary movement of the holding element around a first rotation axis D 1  defined by the first support surface  115 . 1 , wherein the first rotation axis D 1  extends perpendicularly to the connection direction CD. This manner of assembly can be advantageous, when the second support  114 . 2  is not covered by a housing of a fluid measurement point, such as indicated by the outline connected with the process connector, and, thus, a free access to the screw  118 . 3  is assured. 
     The lower view of an assembly shows a first support  114 . 1  having a first projection  116 . 1  and a first cantilever  117 . 1  and a second support  114 . 2 , which is embodied, for example, as shown in  FIG. 6 . The holding element has sectionally a wedge shape, wherein in the region of the wedge shape a surface of the holding element  122  facing the body is inclined from the connection direction. The wedge shape enables engaging of the process connector by means of the tines of the seat of the holding element of  FIG. 9  and loose contacting of the first support by the holding element. A further pushing in, such as indicated with the arrow, then lessens, firstly, a clearance of the process connector in parallel with the connection direction and leads, finally, to a compression of the process connector against a seal in the seal seat  111 . 4  of  FIG. 7 . 
     In corresponding manner, the process connectors of a fluid measurement system with an interface can also be pressed with a holding element of  FIG. 10  against connection locations. 
     Those skilled in the art can combine the embodiments shown in  FIGS. 3 to 12 , in order to adapt to desired requirements. 
     LIST OF REFERENCE CHARACTERS 
     
         
           100  interface 
           110  body 
           110 . 1  body element 
           111  connection location 
           111 . 1  seal 
           111 . 2  sealing ring 
           111 . 3  counterbore 
           111 . 4  seal seat 
           112  fluid duct 
           113  first duct axis 
           114 . 1  first support 
           114 . 2  second support 
           115  hold 
           115 . 1  first support surface 
           115 . 2  second support surface 
           116 . 1  first projection 
           116 . 2  second projection 
           117 . 1  first cantilever 
           117 . 2  second cantilever 
           117 . 3  rib 
           118 . 1  first bore 
           118 . 2  second bore 
           118 . 3  screw 
           120  holding element 
           121  process connector seat 
           122  body-facing surface of the holding element 
           200  fluid measurement point 
           210  process connector 
           211  bearing surface of the process connector 
           212  external shape of the process connector 
           300  modular fluid measurement system 
         CD connection direction 
         SP starting position 
         EP end position 
         D 1  first rotation axis 
         S 1  cutting plane 
         S 2  cutting plane 
         S 3  cutting plane