US3659969A

US3659969A - Control device for metering pumps

Info

Publication number: US3659969A
Application number: US869475A
Authority: US
Inventors: Lev Nikolaevich Britvin; Vitaly Andreevich Sergeev; Konstantin Semenovich Spassky; Igor Nikolaevich Smirnov; Gennady Mikhailovich Scheglov; Alexandr Alexandrovi Shtelmakh; Boris Moiseevich Prudovsky; Vladimir Karpovich Karakhanian; Viktor Vasilievich Ivanov; Mikhail Ivanovich Semenov
Original assignee: Individual
Current assignee: Individual
Priority date: 1969-10-27
Filing date: 1969-10-27
Publication date: 1972-05-02
Anticipated expiration: 1989-05-02

Abstract

A control device for metering pumps is provided with a setter connected via at least one intermediate element with the pump delivery control mechanism, which latter ensures a directly proportional relation between the pump delivery and the movement of said intermediate element. The connection of the intermediate element with the setter is effected by means of a pivoted element installed at an angle to the intermediate element, the pivoted element interacting with the setter and provided with provision for adjusting the distance between the axis of its hinge and the point of its kinematic connection with the intermediate element. The angle of turning of the pivoted element is set by an additional setter.

Description

United States Patent Britvin et al.

[541 CONTROL DEVICE FOR METERING PUMPS [22] Filed: Oct. 27, 1969 [21] App1.No.: 869,475

[52] U.S. Cl ..417/440, 417/499 [51] Int. Cl ..F04b 23/00, F04b 41/00 [58] Field of Search ..417/499, 440, 441

[ 51 May 2,1972

FOREIGN PATENTS OR APPLICATIONS 204,138 12/1967 U.S.S.R.

Primary Examiner-Carlton R. Croyle Assistant Examiner-Richard E. Gluck Attorney-Waters, Roditi, Schwartz & Nissen [5 7] ABSTRACT A control device for metering pumps is provided with a setter connected via at least one intermediate element with the pump delivery control mechanism, which latter ensures a directly proportional relation between the pump delivery and the movement of said intermediate element. The connection of the intermediate element with the setter is effected by means of a pivoted element installed at an angle to the intermediate element, the pivoted element interacting with the setter and provided with provision for adjusting the distance between the axis of its hinge and the point of its kinematic connection with the intermediate element. The angle of turning of the pivoted element is set by an additional setter.

18 Claims, [3 Drawing Figures Patented May 2, 1972 3,659,969

10 Sheets-Sheet 1 Patented May 2, 1972 FIB. 5

1O Sheets-Sheet 5 Patented May 2, 1972 3,659,969

10 Sheets-Sheet 5 Patented May 2, 1972 3,659,969

10 Sheets-Sheet 6 Patented May 2, 1972 10 SheetsSheet 7 m QR Patented May 2, 1972 10 Sheets-Sheet 8 Patented May 2, 197

10 Sheets-Sheet 9 Patented May 2, 1972 3,559,969

10 Sheets-Sheet l0 CONTROL DEVICE FOR METERING PUMPS The present invention relates to control devices for metering pumps.

The delivery of known pumps is controlled by means of a setter.

The setter is usually either a screw mechanism, or a servocylinder and is connected with the delivery control mechanism, for example, a slide-valve type flow distributor of a piston pump via at least one intermediate element.

The flow distributor is installed on the piston rod and its purpose is to control the degree of opening of the drain channels from the compression chamber and, consequently, the quantity of liquid flowing from this chamber into the discharge line (see, for example, USSR Pat. No. 204,138, Cl. 59a, 19, 1967).

It must be understood that in controlling the pump delivery only one controlling action is employed. At low deliveries, for example up to percent of the total capacity, in the case of a single controlling action the controlling error is relatively large. Therefore, for small deliveries, the usual practice is to employ another pump of low capacity.

If the metering pumps handle difierent liquids simultaneously in a certain proportion, the operating conditions of these pumps are controlled by a relatively complex speed variator installed between the motor and the pump drive.

However, when the pump speed is reduced at small deliveries, the control error increases due to increased leakage of liquid through the seals.

The main object of the invention resides in providing a relatively simple and reliable device for the control of metering pumps which will ensure a sufficiently accurate delivery control of either one pump or several pumps simultaneously at a required interrelation of deliveries and under any operating conditions.

This object is achieved by providing a control device for metering pumps wherein the setter is connected, via at least one intermediate element, with the pump delivery control mechanism which ensures a basically directly proportional relation between the pump delivery and the movement of said intermediate element and in which, according to the invention, the intermediate element is connected with the setter by a pivoted element articulated at an angle to the intermediate element interacting with said setter and constructed with provision for adjusting the distance between the axis of its hinge and the point of kinematic connection of said pivoted element with the intermediate element, the angle of turning of the pivoted element being set by an additional setter which controls the maximum delivery of the pump.

It is practicable that the kinematic connection between the intermediate and pivoted elements be effected by means of a flat contact surface on the pivoted element aligned with the axis of its hinge and interacting with the intermediate element.

This connection can be effected through an auxiliary hinge movable along guides in the pivoted element so that the axis of this hinge and that of the pivoted element hinge lie in one and the same plane.

The hinge of the pivoted element can be mounted on a movable element connected with the setter and installed in guides which are arranged at an angle, preferably at a right angle, to the direction of movement of the intermediate element.

In order to ensure independent movements of the main and additional setters when the pivoted element hinge is located on the movable element, it is practicable that the pivoted element be connected with a contact pivot located at a certain distance from the pivoted element hinge, and to ensure interaction of said contact pivot with a guide arranged parallel to the guides along which the movable element moves.

The guide for the contact pivot can be made in the progressively movable element of the additional setter whereas the guides for the movable element are made in the body of the device.

The guide for the contact pivot can also be located in the body of the device, and the hinge of the pivoted element can be connected with the movable element by means of a progressively movable element of the additional setter, the latter said element being articulated to the movable element.

It is no less practicable to make the guide for the contact pivot in the body of the device and the guide for the movable element, on the progressively movable element link of the additional setter.

For especially precise regulation of pump delivery it is practicable that the axis of the pivoted element hinge be immovable, the element proper being kinematically coupled with the intermediate element via at least one additional link, connected to the setter.

To ensure independent motion of the main and additional setters it is practicable that the additional link be connected with the progressively movable element of the setter via guides installed parallel to the direction of movement of the intermediate element. In this case the pivoted element is connected with the progressively movable element of the additional setter via a contact pivot, located at a distance from the hinge of the pivoted element.

To control the movement of the additional setter by means of a linear scale, it is practicable that the axes of rotation of the contact pivot, pivoted element hinge and the point of kinematic coupling between the pivoted and intermediate elements be located in one and the same plane.

The control device for metering pumps can be installed remotely from the pump by connecting the intermediate element with the articulated pivoted element via a remote transmission and an additional intennediate element which interacts with said pivoted element.

To ensure simultaneous metering of several different liquids by a number of metering pumps operating in synchronism, it is expedient that the pivoted element of the device be made with provision for its kinematic connection with the pivoted elements of other devices for synchronous changing of the angle of inclination of said elements.

With the same purpose in view, it is also practicable that the additional setter be made with a provision for kinematic connection with the additional setters of the other device for synchronous drive with these additional setters.

To preserve a constant relation between the amounts of different liquids metered by several pumps, this relation being set by the setters, it is desirable that the pivoted element of the device of zero delivery of the pump be installed at an angle, preferably a right angle, to the direction of movement of the intermediate element, said angle being equal to the installation angle of the pivoted element of the other device, connected to said intermediate element.

In order to make it possible to use control devices with different maximum angles of inclination of their pivoted elements, it is expedient to provide at least one transmission ratio adjusting device in the connection between the pivoted elements of said devices.

The same purpose can be served by introducing at least one transmission ratio adjusting device into the connection between the two devices.

Now the invention will be described in detail by way of example with reference to the accompanying drawings, in which:

FIG. I is a side view (longitudinal section) of a control device for a diaphragm metering pump, according to the invention, connected to a delivery control mechanism;

FIG. 2 is a side view (longitudinal section) of another embodiment of the device;

FIG. 3 is a side view (longitudinal section) of an embodiment of the device with a pivoted element located in the slide;

FIG. 4 is a side view (longitudinal section) of another embodiment of the device with a pivoted element located in the slide;

FIG. 5 is a diagram of still another embodiment of the invention;

FIG. 6 is a diagram of an embodiment of the invention, wherein the guides of the movable element are located in the progressively moving link of an additional setter;

FIG. 6 is a side view (longitudinal section) of an embodiment of a device wherein the hinge of the pivoted element has an immovable axle;

FIG. 8 is a diagrammatic illustration of still another embodiment of the device with an immovable axle of the pivoted element hinge;

FIG. 9 is a diagrammatic illustration of an embodiment of the device, wherein the intermediate element is connected with an additional intermediate element;

FIG. 10 is a diagrammatic illustration of several devices with interconnected pivoted elements;

FIG. 11 is a diagrammatic illustration of several devices with interconnected additional setters;

FIG. 12 is a diagrammatic illustration of several devices with synchronized additional setters whose synchronizing linkage incorporates a device for adjusting the transmission ratio; and

FIG. 13 is another embodiment of the same arrangement. 7

The device for controlling a metering pump 1 comprises a setter 2 (FIG. 1) connected with a mechanism 3 controlling the delivery of the pump 1 via a pivoted element 4 articulated inside the body 5 and interacting with an intermediate element 6. The setter 2 is intended to change the distance from the axis of the hinge 7 of the pivoted element 4 to the point A of its engagement with the intermediate element 6. An additional setter 8 is provided for changing the inclination angle of the pivoted element 4.

The delivery control mechanism 3 comprises a slide valve 9 covering the bypass channels 10 at intervals governed by the positions of the intermediate element 6.

The kinematic engagement of the intermediate element 6 with the pivoted element 4 is effected by bringing the element 6 to bear at point A against the Contact surface 1 1 of the pivoted element 4.

The setter 2 interacts With the pivoted element 4 and moves it up or down by means of the hinge 7 thereby changing the distance between the hinge 7 (the hinge axis is designated by letters OO) of the pivoted element 4 and point A where the intermediate element 6 contacts the pivoted element 4.

The value of this distance CA at a constant inclination angle of the pivoted element 4 determines the position of the intermediate element 6 and of the delivery control mechanism 3 connected with it, thus controlling the delivery of the pump 1.

The guide 12 of the thrust block 13 is a part of the progressively movable element of the additional setter 8 which sets the inclination angle of the pivoted element 4. This guide interacts with the pivoted element 4 via a contact pivot 14 which has a cylindrical surface and is located at a distance from the axis of the hinge 7 of the pivoted element 4.

The thrust block 13 is moved by the nut 15 of the additional setter 8.

The flat contact surface 1 1 of the pivoted element 4 is aligned with the axis of the hinge 7 and the axis B-B of the contact pivot 14.

The hinge 7 of the pivoted element 4 is secured in a movable element which, in this embodiment of the device, is made in the form of a slide 16 installed in the body 5 with provision for moving in the guides 17 located in said body perpendicularly to the direction of movement of the intermediate element 6. The guides 17 can also be arranged at a different angle to the direction of movement of the intermediate element. However, this will increase the overall dimensions of the device.

The slide 16 is connected with, and moved by, the setter 2.

The setter 2 comprises a progressively movable element in the form of a screw 18 connected with a hand wheel 19.

Said hand wheel can be connected by means of a toothed rim 20 thereof with the actuating elements of a remote or antomatic control system of conventional design (these elements are not shown in the drawings).

The guide 12 is installed parallel to the guides 17 of the slide 16 thus ensuring independent functioning of the setter 2 and additional setter 8.

The axes of rotation of the contact pivot 14, hinge 7 of the pivoted element 4 and point A are located in one and the same plane. The additional setter 8 is installed in the body 5 so that the longitudinal axis of its progressively movable element (thrust block 13) is parallel to the longitudinal axis of the intermediate element.

This ensures the linear dependence of the movement of the intermediate element 6 on the movement of the progressively movable element, i.e. thrust block 13 and screw 18 and independent functioning of the setter 2 and additional setter 8.

In another embodiment of the device the pivoted element 4a (FIG. 2) is made in the form of a hollow cylinder with a longitudinal slot 21, accommodating a movable slide 22 connected by a hinge 23 with the output intennediate element 6.

The inner walls of the cylinder function as guides. The pivoted element may be made in the form of a rod with a shaped slot of, e.g., dovetail configuration, which will ensure movement of the slide 22 along the pivoted element (this and similar forms of the device are not shown in the drawings).

The axle of the hinge 23 lies in plane parallel to the longitudinal axis of the pivoted element and passing through the axis 0-0 of the hinge 7 of the pivoted element 4a. The setter 2a or additional setter move the axle of the hinge 23 in this plane.

The additional setter 80 comprises a worm 24 installed in the movable element and connected by a key 25 with a sprocket 26 which connects the additional setter with the actuating elements of the remote or automatic control system or with an identical element of another device.

The worm 24 turns the toothed quadrant 27 connected with the pivoted element 40.

In another embodiment of the additional setter 8b (FIG. 3) the screw 18a is simultaneously connected with both the setter 2b and the additional setter 8b. In this case the hand wheel 19a is connected by a strip 28 with the screw which latter is connected with the movable element 16b. The thread of the hand wheel 19a interacts with the screw 29.

During rotation of the hand wheel 19a the movable element 16b and, consequently, the axle of the hinge 7 will move in the guides 17a with respect to the intermediate element 6b.

During rotation of the sprocket-26a, the screw 18a con nected with the strip 28 will rotate, moving the additional slide 30 in the guides 31 (one guide is shown) located in the movable element 16b.

During its movement, the slide 30 actuates the pivoted element 4b via the contact pivot 14a, thereby changing the angle of inclination of said element.

Thus, the additional slide 30 performs the same functions as the progressively movable element of the additional setter, i.e. the thrust block 13 in the device shown in FIG. 1.

The angle of inclination of the pivoted element 40 (FIG. 4) can be changed when the additional setter 30a moves in guides 31a located perpendicularly to the guides 17b of the movable element 160 made in the fonn of a rod, moved by the setter 2c.

In this case the axis OO of the hinge 7 of the pivoted element 40 can be connected directly with the additional slide 30a whose position with relation to the rod 16c is determined by the additional setter 8c.

The contact pivot 14b of the pivoted element 4c interacts with the guide 12!; in the body 50 which is parallel to the guides 17b of the rod 16c. Here the slide 30a performs the same functions as the progressively movable element of the additional setter, i.e. the thrust block 13 illustrated in FIG. 1. The movement of the slide 30a changes the angle of inclination of the pivoted element 44': and, consequently, moves the intennediate element 60 connected with said pivoted element via the slide 220 and hinge 230.

It must be understood that the linkages of the pivoted element with the setter, additional setter and movable intermediate element may inc crporate hinge-slides of any known designs.

For example, in the device shown in FIG. 5 the pivoted element 4d is made in the form of a spindle which serves as a guide for the slide 22b connected with the output intermediate element 6d, the outer surface of said slide 22b constituting a part of a sphere or cylinder, said guide interacting with the hinge 23b of the intermediate element 6d.

The contact pivot 14c is likewise connected with the pivoted element 4d by a hinge 32 and moves over the flat guide surface 120 of the thrust block 13a which serves as the progressively movable element of the additional setter 8d.

In this device the movable element 16d is made in the form of a screw 18d so that the guide 17c of the movable element 16d is constituted by the thread in the body 5d of the device. The thrust block 13a of the additional setter 8d is also made as a screw, the guide 120 of the contact pivot 140 being arranged perpendicularly to the longitudinal axis of the thrust block 13a.

Thus, the axes of the progressively movable elements of the screw 18d of the setter 2d and of the additional setter of the thrust block 13a are perpendicular to each other.

In other embodiments of the invention (not shown in the drawings) these axes may be located parallel or at any angle to each other.

In the embodiment of the device illustrated in FIG. 6 the guide 12d can be connected with the pivoted element 4e by means of the contact pivot 33 made in the form of a hingeslide (FIG. 6) of any known design. A portion of the movable element 16a of the setter 2e has the shape of a screw l8e whose guide 17d is located in the progressively movable element 34 of the additional setter 8e which latter is connected with the body 5e of the device by means of a nut 15. The hinge 7 of the pivoted element 4e is connected with the movable element l6e by a bushing 35 and with the intermediate element through the hinge 230, respectively. The screw l8e moves parallel to the guide 12d which is rigidly connected with the body 5e.

The movable intermediate element 6f (FIG. 7) can also be moved by the pivoted element 4f interacting with the setter 2f and additional setter 8f when the hinge 7 of the pivoted element 4f is rigidly fixed in the body 5 f of the device. In this case the pivoted element 4f is connected with the intermediate element 6f by the additional link 36 which is connected with the progressively movable element of the setter 2f, i.e. with the screw 18f.

The screw 18f is connected with the additional link 36 by means of the guide 37 which is parallel to the direction of movement of the intermediate element 6f. The additional link 37 is connected kinematically at point A with the flat contact surface 11b aligned with the axis of the hinge 7 of the pivoted element 4f.

The turning angle of the pivoted element is changed by the additional setter 8f via the thrust block 13b and contact pivot assembly 14d, located at a distance from the axis 0-0 of the hinge 7. The additional setter 8f has a micrometer head 38 which is movable in relation to the scale 39, and a built-in piston 40 which can be moved independently of the head 38 when gas under controlled pressure is fed in through the hole 41.

For accurate adjustment of the angle of inclination of the pivoted element 4f with the setter 2f or additional setter 8fimmovable, the axle of the hinge 7 can be moved by changing the position of the bearing 42 connected with the hinge 7 of the pivoted element 4f.

Said angle can also be adjusted by changing the length of the output intermediate element 6f by means of known devices (not shown).

It is obvious that this adjustment can be made at any point of the linkage between the delivery control mechanism 3 (FIG. 1) and the hinge 7 of the pivoted element 4.

The guides 37a (FIG. 8) can also be made directly in the progressively movable element of the setter 2g, i.e. in the screw 18 and connected with the additional link 360 via the thrust block 43.

Here, the additional link 36a is connected with the intermediate element 63 by the bushing 44 while with the pivoted element 43 it is connected by the hinge 23d. The pivoted element 4g is connected with the additional setter 83 via the thrust block and contact pivot 45 which is made in the form of a hinge located in the same guides 21c of the pivoted element 43 as the hinge 23d. The axes of the contact pivot 45, hinge 23d and hinge 7 lie in one and the same plane.

The longitudinal axis of the thrust block 13c and the guide 37a are parallel to the direction of movement of the intermediate element 6g. This ensures linearity of the scales of the setter 2g and of the additional setter 8g. These scales can be made like the

scales

46 and 39 of the main setter 2 and additional setter 8, respectively, in the device shown in FIG. 1.

The intermediate element 6 is so connected with the delivery control mechanism 3 of the pump 1 that when the point A of kinematic linkage of the intermediate element 6 is aligned with the axis 0-0 of the hinge 7, the pump delivery becomes equal to zero. For this purpose the linkage of the hinge 7 with the slide valve 9 of the delivery control mechanism 3 usually incorporates an adjusting device 47 (FIG. 1) consisting of a screw, nut, and lock nut. This device can change the position of the slide valve 9 independently of the position of the pivoted element 4.

For mounting the control device outside the metering pump, the intermediate element 6): (FIG. 9) is connected with the articulated pivoted element 4h by a remote control transmission 48 made, for example, of synchronized selsyns 49 and 490 which are connected with the corresponding intermediate elements 6h and 6k by gear drives 50 and 50a.

For controlling the pump delivery, the setter and additional setter may comprise, or be connected with, any known actuating mechanism of the manual, remote or automatic control system.

In case of simultaneous control of several metering pumps provided with a synchronized drive (FIGS. 10-13) the pivoted elements 4 of the devices are interconnected for the purpose of simultaneously changing the total delivery of all the pumps, while retaining the preset proportions between the deliveries of difierent pumps, set by the setters 2 of the control devices of said pumps.

With this purpose in view, the pivoted elements are designed so as to allow for a rigid synchronized connection between them.

Shown schematically in FIG. 10 is rigid synchronization of two pivoted elements 4g of the control device used with two pumps 1 and 10, said pumps being provided with a drive shaft synchronized by a rigid coupling 51, said shaft being rotated by a motor 52.

Here, the pivoted elements 4g of the devices are directly coupled with each other and set at the same angle to the direction of movement of the corresponding intermediate elements 6g and have a common mechanism 8e for changing their angle of inclination.

Said connection is made by the use of spindles 53 and 53a connected with the hinges 7 of the pivoted elements 4g.

If in the devices for controlling the pumps 1 and 1a the pivoted elements 43 have different turning angles corresponding to the entire range of deliveries from maximum to zero, the linkage between the pivoted elements 43 is provided with an adjusting device 54, i.e. a reduction gear which changes the transmission ratio between the pivoted elements 463 of the pumps 1 and 10.

If the turning angles of the pivoted elements 4g in the control devices for the pumps 1 and 1a are the same, the pivoted elements may be interconnected by a common spindle 55 (FIG. 7). All the pivoted elements may be made as a single part which is common to all the devices (not shown in the drawing).

During joint operation of the pump control devices, mainly of different sizes and designs it is practicable that the additional setters be synchronized for simultaneous changing of the angle of inclination of the pivoted elements.

For this purpose, the synchronizing drive 56 (FIG. 11) has guide blocks 57 interacting with the thrust blocks 13.

The drive 56 is moved by a screw mechanism 58.

Shown in FIG. 12 is the synchronizing drive 56a made in the form of a chain drive.

In another embodiment of the synchronizing drive each additional setter 8d (FIG. 13) is provided with an electric servodrive 59, all servo-drives 59 turning through the same angle on receiving a control signal through electric mains 61.

If the maximum turning angle of the pivoted elements in different control devices is also different, these devices are then provided with adjusting devices in the form of gear drives 60 (FIG. 12) and 600 (FIG. 13) with different ratios.

The function of adjusting devices can also be performed by guide blocks 57 (FIG. 11) installed at different angles of inclination to the axis of the drive 56.

It must be understood that the same function can be fulfilled by the additional setters 8d (FIG. 12) whose screws 13a have different thread pitches.

To ensure the possibility of changing the total delivery of all pumps provided with a synchronized drive (as shown in FIG. 12 this synchronization can be achieved by a chain drive 62, while in FIG. 13 by synchronous motors 63) and a synchronized interconnection of the additional setters, at zero delivery of the pumps, the pivoted elements are set at the same angles of inclination relative to the direction of movement of the intermediate elements.

It is evident that the above-described means can be used for synchronizing three and more pumps.

It is also evident that the body of the device may be made integral with the pump casing, and the pumps themselves may have a common casing.

The delivery control device, according to the invention, functions as follows.

When the hand wheel 19 (FIG. 1) is rotated clockwise, the movable element 16, rotatable in case of RH. thread of the screw 18, goes down and so does the pivoted element. The intermediate element 6 moves to the left, displacing the slide valve 9 of the mechanism 3 in' the same direction. This reduces the delivery of the pump 1 owing to an increased amount of liquid by-passed through the channels 10.

When the hand wheel 19 is moved counter-clockwise, the intermediate element 6 moves to the right, thereby increasing the delivery of the pump 1. With the hand wheel 19 immovable, the delivery of the pump 1 can be reduced or increased by shifting the thrust block 13 to the left or right, respectively, by means of the nut 15.

If, at zero delivery of the pump 1 the pivoted element 4 is set perpendicularly to the longitudinal axis of the intermediate element 6 (e.g. by means of the device 47) the length AC will, to a certain extent, determine the pump delivery.

In this case the maximum possible value of AC will be determined by the inclination of the pivoted element 4, i.e. by the position of the nut with relation to the scale 39. Thus, the additional setter 8 determines the maximum possible delivery of the pump.

At the maximum allowable inclination angle of the pivoted element, i.e. with the nut 15 in the extreme right position, the pump may be operated at a maximum delivery determined by the length of stroke of the piston 64, by its area, and by the r.p.m. of the pump shaft 65. It is clear that the maximum delivery will be obtained with the hinge 7 of the pivoted element 4 in the uppermost position, The setter 8 can ensure changes in the pump delivery from the minimum, usually zero, value to a maximum, covering the entire scale 46 from its lowermost to its uppermost division.

It is likewise clear, that the range of the pump deliveries is set by the additional setter 8 which limits the maximum delivery of the pump 1. Within the limits of this range, the pump delivery is changed by the setter 2.

It is evident that the relative error of the pump delivery is always the same, regardless of the delivery range. Thus, the control device ensures a high accuracy in adjusting the delivery of the pump I in any range, the maximum value of which is set by the additional setter 8 on the scale 39, while the pump delivery in the given range is set by the setter 2 on the scale 46.

Functioning similarly is the device, shown in FIG. 2, where the angle of inclination of the pivoted element 40 is changed by the quadrant 27 and worm 24 meshing with the sprocket 26 which latter is rotated by any known actuating mechanism, or by an analogous element of the adjacent pump. The position of the intermediate element 16a is changed by the screw 66 of the setter 2a. The position of the intermediate element 16a determines the position of the pump delivery control mechanism (the mechanism and pump are not shown) and consequently, the pump delivery.

A reduction of the angle of inclination of the pivoted element 4b (FIG. 3) is efi'ected by lowering the additional slide 30 which is achieved by rotating the sprocket 26b. When the hand wheel 19a is rotated on the screw 29 connected with the sprocket 26b, the movable element 16b goes down or up with respective displacement of the intennediate element 6b to the right or left. The devices illustrated in FIGS. 4, 5, 6 operate analogously.

In the device shown in FIG. 7, when the supporting screw 18f is rotated clockwise along a RH. thread, the additional link 36 goes down, the intermediate element 6f moves to the left and reduces the pump delivery (the pump is not shown in the drawing).

If, at zero delivery, the pivoted elements of the pumps I and la (FIGS. 10 to 13) are set at equal angles to the intermediate elements, due to rigid synchronization of the pivoted elements, their angle of inclination will also change simultaneously, but the similarity of triangles OAC (FIG. 1) in the pumps 1 and la will be retained. Thus, the interrelation between the lengths AC (FIG. 1) set earlier by the setters will remain unchanged and so will the previous interrelation between the deliveries of the pumps 1 and la.

At ditferent angles of inclination of the pivoted elements, corresponding to a maximum pump delivery, the adjusting devices will ensure changing of these angles to the value of the angle corresponding to zero delivery of the pumps, with the same stroke of the piston 40a (FIG. I0) of the setter 8e and with the same number of revolutions of the screw mechanism 58 (FIG. ll), handle 67 (FIG. 12), or servodrives 59 (FIG. 13).

In this case the interrelation of the deliveries of the pumps 1 and la which has earlier been set by the setters 2 remains unchanged.

According to the invention, the device ensures setting of the pump delivery with an error which does not depend on the delivery range, which makes it possible to reduce the number of modifications of the metering pumps and increase the metering accuracy at deliveries which are considerably lower than the maximum delivery of a given pump.

The device ensures control of the pump delivery by means of independently functioning setter and additional setter, producing two controlling eflects on the control mechanism, said effects determining various parameters of the system in which the pump is used, for example the liquid level and pressure in a closed vessel.

Additionally, the device ensures joint operation of several pumps handling difierent liquids and allows changing total delivery of the jointly operating pumps while preserving the predetermined relation between the deliveries of individual pumps without the use of complicated mechanical or hydraulic variable speed drives. The pumps can be mounted at any distance from one another.

What we claim is:

1. A control device for a metering pump comprising an adjustable mechanism for controlling the delivery of the pump in accordance with the position of said mechanism, a setter and an additional setter operatively coupled with said mechanism to control the position thereof, said additional setter setting the maximum delivery and said setter regulating the delivery within the limit of said maximum delivery, a pivotal member operatively coupled with said setter and additional setter for being relatively moved thereby, at least one intermediate element operatively coupled between said mechanism and said pivotal member to follow the movement of the latter and control the position of the adjustable mechanism thereby, and a hinge for said pivotal member, said intermediate element being kinematically coupled to said pivotal member at a point which is spaced from said hinge by a distance which is adjustable by the operation of said setter, said pivotal member being coupled to said additional setter for being pivoted thereby.

2. A device according to claim 1 wherein the kinematic coupling between the intermediate element and said pivotal member is constituted by a flat surface on said pivotal member aligned with the axis of said hinge and in contact with the intermediate element.

3. A device according to claim 1 wherein the kinematic coupling between the intermediate element and said pivotal member comprises an additional hinge guidably supported on the pivotal member for movement therealong, the axes of said hinges being in one and the same plane.

4. A device according to claim 1 comprising a movable element connected to said setter, the hinge of the pivotal member being connected to said movable element, and means guidably supporting said movable element at an angle with respect to the direction of movement of said intermediate element.

5. A device according to claim 4 wherein said pivotal member includes a contact pivot located at a distance from said hinge of the pivotal member, and a guide extending parallel to the direction of movement of the movable element, said contact pivot resting against said guide.

6. A device according to claim 5 wherein said additional setter includes a progressively movable member, said guide of the contact pivot being connected to said progressively movable member of the additional setter.

7. A device according to claim 5 comprising a body containing the setters, pivotal member and intermediate element, said guide for the contact pivot being in said body, said additional setter including a progressively movable member, said hinge between the pivotal member and said movable element being connected via said progressively movable member of said additional setter, said progressively movable member of said additional setter being articulated to said movable element.

8. A device according to claim 5 wherein said additional setter includes a progressively movable member, said guide for the contact pivot being stationary, the means guidably supporting the movable element being provided in the progressively movable member of said additional setter.

9. A device according to claim 1 wherein said hinge is fixed, the kinematic coupling between said pivotal member and said intermediate element including at least one additional member connected with the setter.

10. A device according to claim 9 wherein said setter includes a progressively movable member connected to said additional member and comprising guides for said additional member extending parallel to the direction of movement of the intermediate element.

11. A device according to claim 9 wherein said additional setter includes a progressively movable member, said pivotal member being connected with said progressively movable member of said additional setter at a distance from said hinge of the pivotal member.

12. A device according to claim 6. wherein the axes of rotation of the contact pivot, the hinge of the pivotal member and the point of kinematic coupling between the pivotal member and said intermediate element lie in one and the same plane.

13. A device according to claim 1 wherein the kinematic coupling between said intermediate element and said pivotal member comprises a remote transmission and an additional intermediate element interacting with said pivotal member.

14. A device according to claim 1 wherein at zero delivery of the pump said pivotal member extends at a right angle relative to the direction of movement of said intermediate element.

15. A device according to claim 1 wherein said pivotal member comprises means for the connection of said pivotal member with the pivotal member of a second control device to provide synchronous change of the pivot angle of such pivotal members.

16. A device according to claim 15 wherein the connection between the pivotal members includes at least one device for adjusting the transmission ratio.

17. A device according to claim 1 wherein said additional setter includes means for the connection of said additional setter with the additional setter of a second control device for synchronous operation of such additional setters.

18. A device according to claim 17 wherein the connection between the additional setters includes at least one device for adjusting the transmission ratio.

Claims

12. A device according to claim 6 wherein the axes of rotation of the contact pivot, the hinge of the pivotal member and the point of kinematic coupling between the pivotal member and said intermediate element lie in one and the same plane.