Metering pump with diaphragm attachment to the drive by hooking it on

Abstract

The present invention relates to a metering pump comprising (i) a diaphragm return device comprising a pull rod and (ii) a diaphragm package comprising a mechanically driven elastic diaphragm with a flexible area between the clamping surface at the edge of the diaphragm, which serves to seal the pumping chamber, and a diaphragm core, which serves to transmit force, generate pressure and to connect to the pull rod. characterized by the fact that The membrane package and the pull rod are connected by means of a hook coupling, or a plug coupling, or a clamp connection.

Description

[0001] The present invention relates to the fastening of the diaphragm of metering pumps to their drive.

[0002] In the state of the art, various types of pumps are known under different names, which are designated according to their technical structure or function, e.g. piston pumps, metering pumps, diaphragm pumps, etc.

[0003] A reciprocating piston pump, for example, uses a mechanically driven piston that rotates within a cylinder. This piston is combined with an inlet and an outlet, each closed by a valve. In the first stroke, during intake, the piston moves in such a way that the volume in the cylinder increases, allowing fluid to flow into the cylinder when the inlet valve is open. Subsequently, the inlet valve is closed and the outlet valve is opened, and the piston moves within the cylinder in such a way that the volume decreases again, allowing fluid to flow out of the outlet valve.

[0004] Hydraulically operated diaphragm pumps, on the other hand, have a discharge chamber with a suction port and a pressure port, as well as a hydraulic chamber separated from the discharge chamber by a diaphragm. To deliver a medium, the diaphragm oscillates back and forth between a first and second position. The hydraulic chamber is filled with hydraulic fluid, which is subjected to oscillating pressure by a piston. The two positions of the diaphragm are usually referred to as the discharge stroke position and the suction stroke position.

[0005] Typically, the pressure port is connected to the delivery chamber via a pressure valve designed as a check valve, and the suction port is connected to the delivery chamber via a suction valve, also designed as a check valve. When the diaphragm moves from the first to the second position, the so-called suction stroke, the volume of the delivery chamber increases, causing the pressure in the delivery chamber to drop. As soon as the pressure in the delivery chamber falls below the pressure in a suction line connected to the suction port, the suction valve opens and the medium to be pumped is sucked into the delivery chamber via the suction port. As soon as the diaphragm moves from the second position back towards the first position (the so-called pressure stroke), the volume in the delivery chamber decreases and the pressure in the delivery chamber increases. The suction valve is closed to prevent the medium to be pumped from flowing back into the suction line.As soon as the pressure in the pumping chamber exceeds the pressure in a pressure line connected to the pressure connection, the pressure valve is opened so that the pumped medium in the pumping chamber can be pushed into the pressure line.

[0006] The application of an oscillating pressure to the hydraulic fluid thus leads to an oscillating movement of the diaphragm and thus to an oscillating pumping process of the conveying fluid from the suction line into the pressure line.

[0007] Hydraulically operated diaphragm pumps are preferably used for conveying fluids under high pressures, as the hydraulic fluid places an even load on the diaphragm, thus ensuring a long service life.

[0008] The diaphragm may have a diaphragm return device in the form of a pull rod which acts as a support in the direction of the suction stroke position.

[0009] In hydraulically driven diaphragm pumps, the term "pull rod" has become established for the diaphragm return mechanism. In mechanically driven diaphragm pumps, the term "push rod" is usually used for the corresponding component, since the diaphragm is pushed during the discharge stroke.

[0010] The membrane itself usually comprises several layers, usually two polytetrafluoroethylene (PTFE) layers, which enclose a fabric layer in a sandwich construction.

[0011] The diaphragm also includes a diaphragm core, which has a mount for the tension rod. The diaphragm core is usually made of metal, but can also be made of a suitable plastic.

[0012] Usually, a so-called membrane package is formed together with a membrane holding disc attached to the front side of the pull rod and a clamping screw that fixes the previously mentioned layers.

[0013] Various solutions for connecting the diaphragm assembly to the pull rod (or push rod) are described in the prior art. For example, it is known that the diaphragm assembly has a threaded extension that is screwed into the pull rod until it reaches a fixed stop. A key prevents the pull rod from rotating.

[0014] The disadvantage of this solution is that improper installation can lead to thread breakage. Furthermore, it requires special tools, which can damage the diaphragm itself during installation. Another disadvantage is that an additional component is required to prevent the tie rod from rotating. Furthermore, metal thread pairs (shaft / core) can corrode in aggressive pump environments, making them difficult to remove.

[0015] The reverse variant of a screw connection is also known from the prior art. In this case, the diaphragm assembly does not have a threaded extension; instead, the threaded extension is provided by the tie rod. However, this known embodiment does not overcome the disadvantages of the screw connection formed by the diaphragm assembly. Here, too, special tools are required to screw the diaphragm assembly onto the threaded extension.

[0016] Publications in which the fastening of the membrane package to the tension rod by means of a screw connection is disclosed are, for example, DE 10 2019 109283 A1, DE 3931516 C2, DE 10 2005 039772 A1, DE 10 2011 105000 A1 and WO 2011 / 101118 A1.

[0017] Furthermore, the prior art involves attaching the metering diaphragm to the connecting rod using a coupling (DE 1653586 C3). An additional coupling increases the pump's cost.

[0018] Another option is to connect the metering diaphragm to the tie rod using a ball, hook, or T-slot connection integrated into the tie rod and the diaphragm core. However, this type of connection is very expensive due to the high precision requirements. Furthermore, the diaphragm must be mounted laterally. However, with many feed units, lateral diaphragm mounting is not possible due to the small recess in the drive housing.

[0019] Alternatively, it is known from the prior art that the membrane layers are held directly by the membrane disc and the tension rod, without the membrane assembly including a clamping screw. In this case, the tension rod also performs the function of the clamping screw. This solution requires that when replacing the membrane, either the tension rod must be replaced, or the membrane assembly must be professionally clamped, bonded, and treated with a release agent on-site.

[0020] Furthermore, plug-in, rotary, or bayonet connections between the membrane and the tension rod are known from the prior art (for example, from DE 10 2004 035651 A1). Angular positioning of the membrane is difficult to achieve in these cases. Furthermore, high component precision is required.

[0021] Furthermore, clamp connections are widely used in technology. Application examples are disclosed in the publications DE 20 2015 103406 U1 and EP 3660380 A1. Disadvantages of prior art connections include their complexity, high space requirements, and complicated assembly.

[0022] Further technical solutions for connecting the membrane and the membrane return device are disclosed in DE 10 2015 205061 A1, DE 10 2018 109086 A1, DE 10 2007 005736 A1, DE 10 2015 205060 A1, EP 2528637 B1 and US 2008 / 0292477 A1.

[0023] The object of the present invention is therefore to overcome the disadvantages of the prior art and in particular to provide a secure connection of the membrane package and the tension rod which does not require screwing, does not require complex assembly, allows easy angular positioning of the membrane and in which the risk of damage to the membrane during assembly is minimized.

[0024] This object is achieved by a diaphragm pump with a diaphragm package and a diaphragm return device comprising a pull rod, wherein the diaphragm package and the pull rod are connected by means of (i) a hook coupling, or (ii) a plug-in coupling, or (iii) a special clamp connection, wherein in the case of a connection of the membrane package and the tension rod by means of a hook coupling, the membrane core (2) is provided in the direction of the tension rod (3) with a preferably cylindrical connecting piece (4) which preferably carries two mutually placed tabs (5) at the end, the tie rod (3) is provided on the front side with an axial recess (6) for receiving the connecting lugs (5), and the drawbar (3) is equipped with a coupling sleeve (7) having a radial transverse groove opening (8), wherein the opening serves for the insertion and subsequent rotation of the connecting lugs and the coupling sleeve (7) is connected to the drawbar (3) by flanging, or in the case of a connection of the membrane package and the tension rod by means of a plug-in coupling, the membrane core (2) is provided with a preferably cylindrical coupling element (12) in the direction of the tension rod (3), the coupling element having a groove (13), the tie rod (3) is provided on the front side with a first - axial - opening (14) for receiving the coupling member (12), and the pull rod has a second - radial - opening (15) which is used to fix the coupling member (12), and to fix the coupling member (12) in the pull rod (3) a displaceable component (16) is arranged, which engages in the groove (13) of the coupling member (12) in a lock-like manner by the pressure of a compression spring (17).

[0025] The membrane is coupled to the pull rod by axial or oblique lateral insertion and rotation.

[0026] In a first embodiment, the membrane package and the pull rod are connected by a hook coupling.

[0027] The subject of the invention is therefore, on the one hand, a metering pump comprising a mechanically driven elastic membrane with a flexible area between the clamping surface at the edge of the membrane, which serves to seal the pumping chamber, and a membrane core, which serves for power transmission, pressure generation and connection to the drawbar, wherein the membrane core is provided with a preferably cylindrical nozzle in the direction of the tie rod, which preferably has two tabs placed against each other at the end, the tie rod is provided with an axial recess on the front side to accommodate the nozzle lugs, and the drawbar is equipped with a coupling sleeve having a radial transverse groove opening, wherein the opening serves for the insertion and subsequent rotation of the nozzle tabs and the coupling sleeve is connected to the drawbar by flanging.

[0028] By rotating the diaphragm, the tabs of the screw-in socket are locked to the coupling sleeve and are connected in a non-removable manner.

[0029] Hook couplings typically have up to 0.05 mm of axial play between the connecting parts. A tapered (1° - 3°) plate surface allows for the connection to be tightened and thus free from play. This freedom from play is necessary for proper diaphragm function and to prevent stroke length losses in the pump. At the same time, the play-free connection ensures that there is no movement between the two surfaces relative to each other, thus preventing wear.

[0030] The permanent attachment of the coupling sleeve to the draw rod can be achieved not only by flanging but also by clinching (forming), pressing, pinning, screwing, welding, or gluing. During pump operation, the coupling sleeve may become loosened. Therefore, it is particularly preferred that the draw rod and coupling sleeve be manufactured as a single piece, either from metal by machining or from a suitable plastic by injection molding.

[0031] In one embodiment, the coupling sleeve and pull rod are manufactured as a single piece (embodiment 1a). Production is preferably carried out by machining from metal, preferably from heat-treated steel (e.g., material number 1.7225), case-hardened steel (e.g., material number 1.7147), or stainless steel (e.g., material number 1.4462, 1.4122, or 1.4305). However, the one-piece combination of coupling sleeve and pull rod is particularly preferably made of plastic or a composite of steel and plastic. In such a composite, the pull rod is preferably made of metal, preferably one of the aforementioned steels, and the coupling sleeve is made of plastic. A typical plastic used here is glass fiber reinforced polyphenylene sulfide (PPS), with the glass fiber content typically accounting for approximately 40% of the total plastic mass. The plastic is preferably processed by injection molding.However, other processing techniques are also possible.

[0032] In a further embodiment, the coupling sleeve is connected to the pull rod by flanging (embodiment 1b).

[0033] In a further embodiment, the coupling sleeve is screwed directly to the pull rod (embodiment 1c).

[0034] In a further embodiment, the coupling sleeve is attached to the pull rod with screws (embodiment 1d).

[0035] The force is transmitted to the diaphragm core in the pressure stroke via the end faces of the pull rod and coupling sleeve, and in the suction stroke via the surfaces of the nozzle tabs facing the pull rod and the shoulder of the coupling sleeve.

[0036] When a diaphragm is coupled with a sensor area (tab) for rupture signaling, such as diaphragms according to EP 2180185 A2 or EP 1384891 A1, the exact correlation of the angular position of the diaphragm tab to the nozzle tab can be easily ensured during diaphragm manufacturing. The diaphragm tab is positioned precisely and easily under the sensor during pump assembly. The hooked diaphragm core can compensate for a larger radial angular error of the diaphragm tab than is the case with directly screwed diaphragms, thus facilitating angular positioning of the diaphragm.

[0037] Since the diaphragms are connected by axial insertion and rotation, they no longer need to be mounted laterally, as is the case with conventional hook connections. This means that this invention can also be used with small conveying units and small diaphragm retaining plates. A diaphragm retaining plate is an adapter disc attached to the drive (pull rod) to accommodate diaphragms of different sizes.

[0038] In a further embodiment, the membrane package and the pull rod are connected by a plug-in coupling.

[0039] A further subject of the invention is therefore a metering pump comprising a mechanically driven elastic membrane with a flexible area between the clamping surface at the edge of the membrane, which serves to seal the pumping chamber, and a membrane core, which serves for power transmission, pressure generation and connection to the drawbar, wherein the membrane core is provided with a preferably cylindrical coupling element in the direction of the tension rod, wherein the coupling element has a groove, the drawbar is provided on the front side with a first (axial) opening for receiving the coupling element, and the pull rod has a second (radial) opening which is used to fix the coupling link, and to fix the coupling member (12) in the pull rod (3) a displaceable component (16) is arranged, which engages in the groove (13) of the coupling member (12) in a lock-like manner by the pressure of a compression spring (17).

[0040] During the compression stroke, force is transmitted to the diaphragm core via the end faces of the tension rod, and during the suction stroke, via the laterally hooked surface of the coupling element. The hooked diaphragm core can be rotated radially, thus enabling the angular positioning of the diaphragm.

[0041] “Old” membranes with threaded holes can also be equipped with the coupling element and these can also be fed into the coupling technology according to the invention.

[0042] The coupling element is preferably connected to the membrane core by screwing. However, it is also possible to manufacture the membrane core and coupling element in one piece.

[0043] To disassemble the diaphragm, the coupling element is released. The coupling element and diaphragm core can then be pulled out.

[0044] According to the invention (embodiment 2a), the coupling link is secured by means of a movable component arranged in the pull rod, which engages "lock-like" into the groove of the coupling link due to the pressure of a compression spring. The force of the compression spring continuously moves the movable component upwards. Once the component has engaged, the coupling link is locked. Any sensor area (tab) for break signaling on the diaphragm is then aligned by rotating the diaphragm. Disassembly occurs in the reverse order: using a pin, which the technician inserts from the outside through a hole in the diaphragm holding plate (or in the drive housing), the movable component is moved downwards; the coupling link is released and can be pulled out.

[0045] In a preferred embodiment (embodiment 2b), the coupling element is secured using a clamp coupling consisting of two spring-loaded clamp halves. The clamp coupling is mounted on two parallel transverse grooves of the pull rod. Any sensor area (tab) for break signaling on the membrane is then aligned by rotating the membrane. To disassemble, a flat-blade screwdriver is inserted into the slot of the clamp coupling and rotated approximately 90° to open the clamp coupling. The diaphragm package is then pulled out of the pull rod. The clamp coupling remains on the pull rod.

[0046] In a further preferred embodiment (embodiment 2c-1), a spring-loaded ball, such as a spring-loaded pressure piece according to Ganter standard, is arranged in a radial transverse bore of the drawbar ®inserted, preferably screwed in. The coupling link has a slanted transverse groove of variable depth. The coupling link and the pull rod are connected by inserting them into one another and then turning them in opposite directions. During rotation, the ball enters the groove until it engages in its final position and the coupling link is secured. To disassemble, the coupling link and the pull rod are turned in opposite directions, pushing the ball into its push piece (spring) and reversing the locking.

[0047] In an alternative preferred embodiment (Embodiment 2c-2), the pressure piece (spring) is not incorporated into the pull rod but into the coupling member, and the pull rod, instead of the coupling member, has a wide transverse groove. The functionality of this embodiment corresponds to that of Embodiment 2c-1.

[0048] In a further preferred embodiment (embodiment 2d), a grub screw (threaded pin according to DIN 913) is screwed into one or more radial transverse bores of the pull rod. The coupling link has a radially circumferential groove to accommodate the screw tip. For assembly, the coupling link is inserted into the push rod as far as it will go, and any sensor area (tab) for break signaling on the diaphragm is aligned by turning the diaphragm. The grub screw(s) are then tightened, e.g., using an Allen key, with the tip(s) of the screw(s) tightening the diaphragm core to the pull rod without any play. Disassembly is achieved by removing the grub screw(s).

[0049] The zero-backlash connection provided by this design 2d is beneficial for proper diaphragm function and prevents stroke length losses of the pump. The zero-backlash connection also ensures that there is no relative movement of the clamped surfaces, thus preventing wear.

[0050] In a further embodiment, the membrane package and the tension rod are connected by a special clamp connection.

[0051] A further subject of the invention is therefore a metering pump comprising a mechanically driven elastic membrane with a flexible area between the clamping surface at the edge of the membrane, which serves to seal the pumping chamber, and a membrane core, which serves for power transmission, pressure generation and connection to the drawbar, wherein the membrane core is provided with a screw-in clamping socket in the direction of the pull rod, and the pull rod is provided with a clamping connection which has a first and optionally a second clamping hub, wherein the first clamping hub is incorporated into the pull rod itself, and the optional second clamping hub, depending on the embodiment, forms a separate part which is preferably fastened by screwing.

[0052] The clamp connection is preferably designed according to DIN 32676 (so-called Tri-Clamp clamp connection). This makes the connection less complex and cost-effective.

[0053] The force is transmitted to the diaphragm core without play; during the compression stroke, it is positively connected via the end face of the tension rod, and during the suction stroke, via the clamp connection. The hooked diaphragm core can be rotated radially before being clamped, thus enabling the angular positioning of the diaphragm.

[0054] The clamping sleeve is either manufactured as a part with the membrane core, or it can be inserted, preferably screwed, into existing membranes as an “adapter bolt” with a sleeve.

[0055] The clamp connection preferably has a clamping angle of approximately 20° (according to DIN 32676). Therefore, although the membrane must be inserted from the side, it can only be inserted at a slight angle, unlike conventional hook couplings. Thus, the clamp connection according to the invention can also be used with small membrane holding plates.

[0056] In a preferred embodiment (embodiment 3a), the clamping connection has a radially movable second clamping hub. To mount the diaphragm, the diaphragm core equipped with the clamping socket is inserted into the clamping groove of the tension rod, the diaphragm is aligned, and then the second clamping hub is moved in the groove until it stops and secured with a screw (clamping screw). To disassemble, the clamping screw is loosened, thereby decoupled from the clamping connection, and the diaphragm can be removed.

[0057] In a further preferred embodiment (embodiment 3b), the clamping connection has an axially displaceable coupling sleeve which, when displaced toward the membrane core, clamps the clamping piece in the clamping groove machined into the tie rod. A spring-loaded ball, such as a spring-loaded thrust piece according to the Ganter standard, is also located in a radial transverse bore of the tie rod. ®inserted, preferably screwed in. The coupling sleeve has a corresponding recess for receiving the ball. To install the diaphragm, the diaphragm core equipped with the clamping socket is inserted into the clamping groove of the pull rod, the diaphragm is aligned, and then the coupling sleeve is pushed into the recess until the ball clicks into place, thus securing the connection. To disassemble, the coupling sleeve is pushed back, thereby disengaging the clamping connection, and the diaphragm can be removed.

[0058] Further features and advantages of the invention will become apparent from the following embodiments, in which the invention is explained by way of example using schematic drawings.

[0059] It shows: Fig. 1a-1 to 1a-3: the perspective view of embodiment 1a of a metering pump according to the invention; Fig. 1b, Fig. 1b-A and Fig. 1b-B: the perspective view of embodiment 1b of a metering pump according to the invention; Fig. 1c: the perspective view of embodiment 1c of a metering pump according to the invention; Fig. 1d: the perspective view of embodiment 1d of a metering pump according to the invention; Fig. 1e: the perspective view of a membrane according to one of the embodiments 1a-1d Fig. 2a-1 to 2a-6: the perspective view of embodiment 2a of a metering pump according to the invention; Fig. 2b and 2b-1: the perspective view of embodiment 2b of a metering pump according to the invention; Fig. 2c-1: the perspective view of embodiment 2c-1 of a metering pump according to the invention; Fig. 2c-2: the perspective view of embodiment 2c-2 of a metering pump according to the invention; Fig. 2d: the perspective view of embodiment 2d of a metering pump according to the invention; Fig. 3a: the perspective view of embodiment 3a of a metering pump according to the invention; and Fig. 3b: the perspective view of embodiment 3b of a metering pump according to the invention.

[0060] Fig. 1a-1 to Fig. 1a-3 show, by way of example, a combination of coupling sleeve (7) and draw rod (3) manufactured as a single piece according to embodiment 1a of the metering pump according to the invention. The draw rod is provided on its end face with an axial recess (6) for receiving connecting lugs. The coupling sleeve (7) is made of plastic and is injection-molded onto the draw rod. Alternatively, the coupling sleeve and draw rod are manufactured in one piece, e.g., by machining from metal or by injection-molded machining. The coupling sleeve is equipped with a radial transverse groove opening (8) through which the connecting lugs can be inserted and subsequently rotated. Fig. 1a-2 shows an enlarged top view of the coupling sleeve. Fig. 1a-3 shows an example of a perspective view of a tie rod-coupling sleeve combination according to embodiment 1a. The radial transverse groove opening (8) for inserting and subsequently rotating the connecting lugs (5) can be seen at the end of the component.

[0061] Fig. Figure 1b shows an example of embodiment 1b of the metering pump according to the invention. The coupling sleeve and pull rod are firmly connected by crimping. The crimping process creates the fold (9).

[0062] The Fig. 1b The cross sections of the structure marked AA and BB are shown in Fig. 1b-A (cross section AA) and Fig. 1b-B (cross section BB) is shown schematically.

[0063] Fig. Figure 1b-A shows a cross-section of the transverse groove opening (8) of the coupling sleeve (7). It shows the axial guidance of the nozzle (4) and a schematic view of the nozzle tabs (5) after rotation of the diaphragm (1) and diaphragm core (2).

[0064] Fig. 1b-B shows a cross-section through the coupling sleeve (7). Also shown are the nozzle (4) and the nozzle tabs (5). The surfaces of the nozzle tabs (5) facing toward the diaphragm are inclined by 1°-3°, which ensures axial clearance (not shown).

[0065] In Fig. Figure 1c shows an exemplary embodiment of the metering pump according to the invention. The coupling sleeve (7) and the connecting rod (3) each have a thread (10) on their outer and inner sides, respectively, and are directly screwed together.

[0066] In Fig. Figure 1d shows an exemplary embodiment of the metering pump according to the invention. The coupling sleeve (7) and the connecting rod (3) are connected by screwing (11).

[0067] In Fig. Figure 1e shows an example of a perspective view of an assembled membrane according to one of the embodiments 1a-1d. The membrane core (2), nozzle (4), and nozzle tabs (5) are visible.

[0068] In Fig. 2a-1 and Fig. 2a-2 show exemplary cross sections, designated AA, of embodiment 2a of the metering pump according to the invention, wherein the diaphragm core (2) is provided with a preferably cylindrical coupling element (12) in the direction of the pull rod (3), the coupling element having a groove (13). The pull rod is provided on its end face with a first (axial) opening (14) for receiving the coupling element (12) and has a second (radial) opening (15) which is used to receive the component (16) intended for fixing the coupling element (12). The coupling element (12) is fixed by means of a displaceable component (16) which, under the pressure of a compression spring (17), engages in the groove (13) of the coupling element in a "lock-like" manner with a crescent-shaped hook (44).

[0069] Fig. 2a-1 shows the construction, and Fig. 2a-2 shows the construction after the coupling link (12) has been engaged.

[0070] In Fig. 2a-3 and Fig. 2a-4 are schematic representations of Fig. 2a-1 or Fig. 2a-2 shows cross sections through the longitudinal axis of the tie rod (3) and coupling link (12) marked CC, DD, and EE. It is also visible that the coupling link is disassembled using a pin (18) that is inserted from the outside through a hole in the diaphragm retaining plate (or in the drive housing) (hole not shown) by the fitter. The movable component (16) is then moved downwards, freeing the coupling link (12) and allowing it to be removed. Also shown in Fig. 2a-3 and in Fig. 2a-4 shows that the structure includes a cylindrical pin (40) to align the movable component (16) parallel to the pull rod axis. The cylindrical opening (41) of the component (16) must be aligned with the axis of the pull rod (3) to enable axial insertion of the coupling element (12). In the absence of the cylindrical pin (40), the position of the opening (41) in the component (16) would be indeterminate.

[0071] Fig. 2a-5 shows schematically the perspective view of an assembled membrane according to embodiment 2a of the metering pump according to the invention.

[0072] Fig. Figures 2a-6 show various perspective views and corresponding cross-sections, labeled AA and BB, of the movable component (16) according to embodiment 2a of the metering pump according to the invention. The opening (43) for the pin (40) can be seen.

[0073] In Fig. 2b shows an exemplary embodiment 2b of the metering pump according to the invention, wherein the diaphragm core (2) is provided with a cylindrical coupling element (12) in the direction of the tension rod (3), the coupling element having a groove (13). The tension rod (3) is provided at its end with an axial opening (14) for receiving the coupling element (12) and with two radial grooves (22) for receiving a clamp coupling (19). The coupling element (12) is fixed by means of a clamp coupling (19) secured against rotation.

[0074] The Fig. 2b, AA marked cross section of the construction is in Fig. 2b-1 shown schematically.

[0075] Fig. Figure 2b-1 shows that the clamp coupling (19) consists of two clamp halves clamped together by a spring (20). The clamp coupling (19) is mounted on two parallel transverse grooves (22) of the tie rod (3). The surfaces (21) of the two transverse grooves serve as anti-twist devices for the clamp coupling (19).

[0076] In Fig. 2c-1 shows an exemplary embodiment 2c-1 of the metering pump according to the invention. The connecting rod (3) has a radial transverse bore (23) into which a spring-loaded ball (24), such as a spring-loaded thrust piece according to the Ganter standard, is inserted. ® , is inserted. The coupling link (12) has an inclined transverse groove (13) of variable depth. The coupling link (12) and the pull rod (3) are connected by inserting them into one another and then turning them in opposite directions. During rotation, the ball (24) enters the groove (13) until it engages in its final position and the coupling link is fixed.

[0077] In Fig. Figure 2c-2 shows a variant (embodiment 2c-2) of the previously described embodiment 2c-1 of the metering pump according to the invention. Here, the coupling member (12) has a radial transverse bore (23) into which a spring-loaded ball (24), such as a spring-loaded thrust piece according to the Ganter standard, is inserted. ® , is inserted. The pull rod has a transverse groove (25). The functionality of this embodiment 2c-2 corresponds to that of embodiment 2c-1. The ball engages in the groove (25). The width of the groove (25) determines the angle of rotation for aligning the membrane.

[0078] In Fig. Figure 2d shows an exemplary embodiment of the metering pump according to the invention. The connecting rod has one or more radial transverse bores (26), into each of which a grub screw (27) (threaded pin according to DIN 913) is screwed. The coupling element (12) has a radially circumferential groove (28) for receiving the screw tip.

[0079] In Fig. 3a shows, by way of example, embodiment 3a of the metering pump according to the invention, comprising a diaphragm (1) and a diaphragm core (2), wherein the diaphragm core (2) is provided with a screw-in clamping socket (29) in the direction of the pull rod (3), a clamping groove (35) is machined into the pull rod (3), and the end face of the pull rod (3) is provided with a clamping connection (30) which is driven by a compression spring (39). The clamping connection has a first (31) and a second (32) clamping hub, wherein the first clamping hub (31) is machined into the pull rod itself, and the second clamping hub (32) is radially displaceable and fixable. Fixing is preferably effected by means of a screw (33) with a thread (42).

[0080] In Fig. 3b shows an exemplary embodiment 3b of the metering pump according to the invention, wherein the diaphragm core (2) has a screw-in clamping piece (29) in the direction of the tie rod (3) and the front side of the tie rod (3) has an axially displaceable coupling sleeve (34) which, when displaced in the direction of the diaphragm core, clamps the clamping piece (29) in the clamping groove (35) machined into the tie rod. A spring-loaded ball (37), such as a spring-loaded thrust piece according to the Ganter standard, is also accommodated in a radial transverse bore (36) of the tie rod (3). ® introduced. In the coupling sleeve (34) there is a corresponding recess (38) for receiving the ball.

Claims

[1] Dosing pump comprising (i) a diaphragm return device comprising a pull rod (3) and (ii) a diaphragm package comprising a mechanically driven elastic diaphragm (1) with a flexible area between the clamping surface at the edge of the diaphragm, which serves to seal the pumping chamber, and a diaphragm core (2), which serves to transmit force, generate pressure and to connect to the pull rod, where the membrane package and the pull rod are connected by means of a hook coupling, or a plug-in coupling, or a clamp connection, characterized by , that in the case of a connection of the membrane package and the tension rod by means of a hook coupling, the membrane core (2) is provided in the direction of the tension rod (3) with a preferably cylindrical connecting piece (4) which preferably carries two mutually placed tabs (5) at the end, the tie rod (3) is provided on the front side with an axial recess (6) for receiving the connecting lugs (5), and the drawbar (3) is equipped with a coupling sleeve (7) having a radial transverse groove opening (8), wherein the opening serves for the insertion and subsequent rotation of the connecting lugs and the coupling sleeve (7) is connected to the drawbar (3) by flanging, or in the case of a connection of the membrane package and the tension rod by means of a plug-in coupling, the membrane core (2) is provided with a preferably cylindrical coupling element (12) in the direction of the tension rod (3), the coupling element having a groove (13), the tie rod (3) is provided on the front side with a first - axial - opening (14) for receiving the coupling member (12), and the pull rod has a second - radial - opening (15) which is used to fix the coupling member (12), and to fix the coupling member (12) in the pull rod (3) a displaceable component (16) is arranged, which engages in the groove (13) of the coupling member (12) in a lock-like manner by the pressure of a compression spring (17). [2] Dosing pump with hook coupling according to claim 1, characterized by that the coupling sleeve (7) and pull rod (3) consist of one piece. [3] Dosing pump according to claim 2, characterized by that the coupling sleeve (7) and pull rod (3) are made of metal. [4] Dosing pump according to claim 2, characterized by that the coupling sleeve (7) and pull rod (3) are made of plastic or the coupling sleeve is made of plastic and the pull rod is made of metal. [5] Dosing pump with hook coupling according to claim 1, characterized by that the coupling sleeve (7) is directly screwed to the pull rod (3) via a thread (10). [6] Dosing pump with hook coupling according to claim 1, characterized bythat the coupling sleeve (7) is attached to the pull rod (3) with screws (11). [7] Dosing pump with plug-in coupling according to claim 1, characterized by in that a clamp coupling (19) is arranged to fix the coupling member (12) on the pull rod (3), said clamp coupling consisting of two clamp halves braced by a spring (20) and being mounted on two parallel transverse grooves (22) of the pull rod (3). [8] Dosing pump with plug-in coupling according to claim 1, characterized by in that, for fixing the coupling member (12), a spring-loaded ball (24) is introduced, preferably screwed, into a radial transverse bore (23) of the pull rod (3), and the groove (13) in the coupling member is an obliquely extending transverse groove of variable depth. [9] Dosing pump with plug-in coupling according to claim 1, characterized byin that a grub screw (27) is screwed into one or more radial transverse bores (26) of the pull rod (3) in order to fix the coupling member (12) and the coupling member has a radially circumferential groove (28) for receiving the screw tip. [10] Dosing pump with clamp connection according to claim 1, characterized by in that the membrane core (2) is provided with a screw-in clamping socket (29) in the direction of the pull rod (3), a clamping groove (35) is machined into the pull rod (3) and the end face of the pull rod (3) is provided with a clamping connection (30) which has a first (31) and optionally a second (32) clamping hub, wherein the first clamping hub (31) is machined into the pull rod (3) itself, and the optional second clamping hub (32) forms a separate part which is preferably fastened by screwing. [11] Dosing pump according to claim 10, characterized bythat the clamping connection (30) has a radially displaceable second clamping hub (32), wherein the second clamping hub (32) is fixable. [12] Dosing pump according to claim 10, characterized by that the clamping connection (30) has an axially displaceable coupling sleeve (34) which, when displaced in the direction of the membrane core (2), clamps the clamping nozzle (29) in the clamping groove (35) machined into the pull rod, a spring-loaded ball (37) is introduced, preferably screwed, into a radial transverse bore (36) of the pull rod (3), and there is a corresponding recess (38) in the coupling sleeve for receiving the ball (37). [13] Dosing pump according to claim 8 or 12, characterized by that the spring-loaded ball (24, 37) is a spring-loaded thrust piece according to Ganter standard ® is.

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