Apparatus for delivering and metering fluid substances

Abstract

 An apparatus for authomatically delivering metered quantities of mixable substances in a fluid or fluidisable state from storage tanks (12). The apparatus comprises a plurality of delivering heads (11) having control valves connected to respective storage tanks (12). The delivering heads (11) are aligned along a linear path for a trolley (20) supporting a receiving container (22); sensing means (24) are positioned along the path to provide control signals indicative of the positions of the trolley (20) in respect to the delivering heads (11); drive means (25, 26) are provided to reciprocate the trolley (20) along the path, and a programmable control unit (33) to selectively move and stop the trolley (20) and to actuate the delivering heads (11).

Description

[0001] The present invention relates to an apparatus for authomatically supplying and metering fluids or fluidisable substances which are to be delivered in metered quantities in a loose state and which are to be mixed, for example in the dye stuffs batching and auxiliary agents, for preparation of colouring and painting substances, as well as for metering and mixing chemical materials, food stuff or for other applications. For the scope of present application, "fluid substance" means a liquid, party and/or fluidisable powdered or granulate material.

[0002] During the preparation of mixtures from fluid substances, for example for preparation of dyeing materials in the textile industry, or the preparation of paints and colouring agents for various applications, whereby various substances in a loose or fluid state must be delivered and mixed in metered quantities, there exists the problem of providing automatic metering apparatus comprising control means capable to ensure selectively controllable movements and stoppage in appropriate delivering positions of a carriage or trolley supporting a receiving container. Carefully controlled speeds are futherly requested so as to avoid sudden movements and inappropriate stoppages which could create problems affecting, a weighing system or to prevent the container itself from overturning and causing the partial overflow of the fluid substances contained therein. There also exists the need for apparatus or automatic installations particularly suitable for small or medium-size users, which, in addition to having a system effecting translations or movements at controlled speeds, also have an economical design and can be easily maintained; this is particularly important to avoid the long-distance and costly transfer of technical personnel for carrying out the necessary operations of maintenance and/or replacement of parts of the plant.

[0003] Therefore, the main object of the present invention is to provide an automatic apparatus of the kind referred to above, capable to deliver metered quantities of stored fluid substances and to overcome the abovementioned drawbacks; in particular, the invention relates to an apparatus for automatically delivering metered quantities of fluid substances into a receiving container, provided with a programmable drive system for controlling the translational movements and the positioning of the container, designed to avoid sudden stoppages and start-ups, owing to the possibility of providing translational movements subject to a substantially trapezoidal movement law resulting in linear accelerations and decelerations which allow a gentle start-up and stoppage of the carriage supporting the container.

[0004] A further object of the invention is to provide a robotized installation for batching liquid dyestuffs, comonly called "colour shop", having high batching rhythm to increase production requirements.

[0005] A further object of the present invention is to provide a pneumatically actuated apparatus or insatallation of the abovementioned kind which is particularly suitable for being used in dangerous environments or for dangerous substances, i.e. which is such that it possesses flameproof characteristics.

[0006] Presently no apparatus are known for satisfying the objects referred above.

[0007] The above objects can be obtained by means of a delivering and metering apparatus according to the invention comprising the characteristic features of claim 1.

[0008] The invention will be described in more detail hereinbelow, with reference to a preferential embodiment used for the dyestuff batching in the textile industry.

[0009] In the drawings:

Fig. 1

is a general diagram of the apparatus according to the invention;

Fig. 2

is a front view of an ambodiment of the apparatus according to Figure 1;

Fig. 3

is an enlarge view of the left-hand side of the apparatus of Figure 2;

Fig. 4

shows the diagram of a pneumatic control circuit for a pneumatic connector of the apparatus according to Figure 1.

Fig. 5

is a partial view of the pneumatic connector, according to line 5-5 of figure 4;

Fig. 6

is a partial view according to line 6-6 of figure 4;

Figs. 7 and 8

are enlarged cross-sectional details of figure 4.

[0010] The apparatus according to the invention, denoted overall by 10, substantially comprises a plurality of delivering heads 11 having automatically operable valve members 11', 11'' for supplying metered quantities of fluid or powdered substances, for example dyeing liquid substances stored in corresponding tanks 12 provided at a predetermined level on a supporting structure 13. Each head 11 comprises therefore one or more valve means operated for example by pneumatic or electrical actuators to open and close the same valves to control the flow of the fluid substances from storing tanks 12 to the head 11 into a container or from an outer fluid source, such as water for head washing purpouse.

[0011] The controlled and selective coupling of each delivering head 11 to a pressurised air source 14, in the example shown, is performed by means of a pneumatic connector comprising a movable connector element 15 and a plurality of fixed connector elements 16 each associated with a respective delivering head 11. The movable connector element 15 is supported by a slider 17 movable along guide rails 18; the slide 17 is connected to drive means such as an hydraulically operated control cylinder 19 of the rodless type, by a per se known magnetic coupling; or different connecting device.

[0012] The control cylinder 19 is a double-acting cylinder actuated by a combined air/oil control system shown in figure 1 which allows an adequate control of accelerations, decelerations and speeds of the piston member of said control cylinder 19 and hence of the entrained load.

[0013] The slide 17 via an arm 20' is connected to a carriage 20 or trolley provided with an electronic scale 21, or similar weighing device, supporting a container 22 (Fig. 3) for receiving metered quantities of fluid substances supplied by the delivering heads 11. The trolley 20 may be of any suitable type; for example may comprises a lifting device to lift the scale 21 to an appropriate level. A microprocessor or logic unit 33 controls the apparatus and particularly the heads 11 to be actuated, as well as the quantities of fluid substances to be delivered and metered at each batching. In the various figures, 23 denotes solenoid valves for selectively controlling the supply of pressurised air to the delivering heads 11 via connector elements 15, 16, while 24 denotes a position sensing means for the slider 17 and trolley 20, respectively, which in the specific case of Figure 2 consists of a plurality of pneumatic limit switchs 24' provided in corrispondence of each delivering head 11, to define an absolute type encoder; the limit switchs 24' are actuated in sequence by the movement of the slider 17 so as to provide pneumatic position signals to the logic unit 33 controlling the entire apparatus as described below.

[0014] As previously mentioned, the hydraulic control cylinder 19 for driving the trolley 20 along the linear path defined by the longitudinally aligned delivering heads 11, is actuated by a pneumatically powered source 14 via air/oil power transducers 25 and 26 in the manner shown in Figure 1. More precisely, each side of the cylinder 19 is connected to the oil side of a respective air/oil power transducer 25 and 26 via control valves 27, 28 and via flow modulating valves 29, 30, respectively, which make it possible to control with extreme precision the flow of oil in the hydraulic part of the circuit, and consequently the speed, accelerations and decelerations of the piston of the control cylinder 19. Correspondingly, the air side of each air/oil power transducer 25 and 26 is connected to the pressurised air source 14 vi a respective air feeding and venting valves 31, 32, as shown.

[0015] The apparatus is completed by a programmable logic unit or microprocessor 33 to which the solenoid valves 23 of the pneumatic connector element 15 and the actuating valves 27, 28, 29, 30, 31, 32, respectively, in addition to the pneumatic limit switchs 24' are connected via an electro-pneumatic signal transducer or interface 34. The signal transducer 34 has the function to recognize the pneumatic signals of the device and to convert the electric signals emitted by the logic control unit 33, into corresponding pneumatic signals for operating the various valves.

[0016] In the context of pneumatic connection systems it is furthermore known to use connectors comprising male and fermale elements in which the end of a first male element, connected to a pressurised-fluid source, is introduced into the cavity of a second female element connected to an apparatus or to a point utilising the pressurised fluid. These known systems require a high degree of positioning accuracy which can only be ensured using extremely complex and costly solutions which adversely affect the working cycle. According to the invention, the use of mobile connectors, in place of stationary connection devices for simultaneously and/or selectively operate several apparatuses, is extremely advantageous in that it reduces the number of connections required, resulting in considerable simplification from a design and functional point of view.

[0017] Within the context of the proposed invention, it is therefore desiderable to have a type of fluid connector which, in addition to allowing a large number of connection points, does not require a high degree of positioning accuracy and is extremely simple from a functional and structural point of view, whilst being very reliable during working.

[0018] As previously stated and as shown in Figure 4 to 8, the connector device according to the invention comprises the first movable element 15 and a set of second spaced apart elements 16, in which the element 15 is suitably supported by slider 17 and operated so as to move away from and towards each stationary element 16, as well as to displace along a linear path to be selectively positioned in respect to stationary connector elements 16.

[0019] In the example shown, the movable connector element 15 is supported by two pneumatic actuating cylinders 35, 36 so as to be moved towards and away from each fixed connector element 16; in turn, the assembly consisting of the movable connector element 15 and the actuating cylinders 35, 36 is mounted on the slider 17, so as to be moved along the previously referred path. In the example of Figure 4, 37 denotes moreover a third pneumatic cylinder for pressing the front flate surface of the movable connector element 15 against the facing flate surface of a stationary connector element 16 so as to form an air-tight connection; however, it is obvious that, in place of the actuating cylinders 13, 14 and 16, any other solution or any other actuating device suitable for the proposed scope may be used.

[0020] As previously mentioned, the connector elements 15 and 16 have the function of selectively connecting the actuating cylinders of each of the delivering heads 11 to the pressurised air source 14. Therefore, the stationary connector element 16 is provided with one or more through-ducts 47 which, in the case of plate connector elements, as shown, open out on opposite flat surfaces 16a and 16b so as to be connected to a delivering head 11 and to a corresponding number of ducts 48 of the connector element 15 (figure 5), opening out towards the flat surface 15a facing the flat surface 16b of a stationary connector element 16, as shown.

[0021] In turn, the ducts 48 of the movable element 15 of the connector are connected to the pressurised-air source 14 via ducts 50 and the set of solenoid control valves 23, which may be actuated in succession or in a programmable manner, by unit 33.

[0022] The pneumatic connector elements 15 and/or 16 are provided moreover with air-tight means for ducts 47 and/or 48, as schematically shown in Figures 5 and 7 of the accompanying drawings. In the example shown, said air-tight means are in the form of an annular gaskets or O-Rings 52 provided in a seat 53 on the flat surface 15a of the movable connector element 15.

[0023] Figures 7 and 8 of the accompanying drawings show a typical feature of the connector; if Figure 7 is compared with Figure 8, it can be seen that connection of ducts 47 and 48 is assured either when the exact alignment of said ducts occurs (Figure 7) and when ducts 47 and 48 are slightly misaligned (figure 8), without affecting the correct operation and feeding of pressurised air. Thus precise positioning of the two connector elements is no longer requested, resulting in a high degree of functional and constructional simplification.

[0024] According to the proposed solution, the connector device is also provided with suitable sensing means for controlling the position of the movable connector element 15, in respect of the fixed element 16. According to an extremely simple and advantageous embodiment, shown in figure 4, these control means comprise plugging sensors 42, 43, 44 designed to cutt-of or allow the passage of a flow of pressurised air providing a pressure signal depending on the position assumed by the movable connector element 15 with respect to the stationary connector element 16. In particular, in the example shown, a first plugging sensor may consist of a duct 44' opening on the flat surface 15a of the movable connector element 15 which duct, in the advanced condition of connector element 15, is plugged or closed by the flat surface 16b of the stationary element 16 when the movable connector element 15 has been moved up against the stationary element 16 so as to form an air-tight connection.

[0025] Similarly, in order to control the retracted condition of the movable connector element 16, at least one stationary plugging sensor 42 may be provided on the side having the face 15b of connector element 15 which is opposite to the side 15a facing the connector element 16; a fluid duct 42' is therefore provided in the sensor 42, which is plugged or closed by the flat surface 15b in the retracted position of the element 15 (Figure 4). In both cases, the plugging, that is closing and opening of the ducts 42' and 44' interrupts or allows a flow of air which may be suitably sensed and interpreted as a signal indicating a correct positioning of the movable connector element 15; this will be now described in more detail with reference to Figure 4.

[0026] Figure 4 of the accompanying drawings shows the pneumatic circuit for the plugging sensors and the cylinders operating the connector device 15, 16. As shown, the connector element 15 is connected to two double-acting cylinders 35, 36 so as to be moved from and towards a facing stationary connector element 16; the connector element 15, moreover, is pushed up, so as to formed a air-tight connection, against a stationary connector element 16 by a single-acting pneumatic cylinder 37. The cylinders 35, 36 and 37 are connected to the pressurised air source 14 via flow regulators 38, 39, 40 and a slide valve 41 in the manner shown. In Figure 4, references 42, 43 and 44 denote moreover the pneumatic plugging sensors for controlling the advanced and retracted positions of the movable connector element 15 with respect to a stationary connector element 16; the plugging sensors 42 and 43 and the plugging sensor 44 are connected to the electro-pneumatic transducer 34 and respectively to the pressurised-air source 14 via throttling devices 45, 46 in which a main duct 45a and 46a is branched out to form a direct duct 45b, 46b connected to unit 34, and throttling duct 45c and 46c connected to the pressurised air source 14 via flow regulators and slide valve 41, as shown.

[0027] The working mode of the apparatus is described briefly below. It is assumed that the logic unit 33 has been programmed to control the metering and mixing of a certain quantities of substances in the container 22. The direction of translational movement of the trolley 20 is determined by the logic unit 33 via opening of one of the two venting valves 31 and 32. Subsequently the starting signal is emitted by unit 33 so as to perform the translational movement of the carriage 20 in the prechosen direction, by operating the control valve 27 or 28 and the flow modulating valve 29 or 30, respectively, according to the desired direction of movement. This latter valve controls the transfer of oil from the cylinder 19 to the air/oil power transducer 25, 26, and viceversa, which is located on the side towards which the slider 17 is performing its movement. During the movement of the slider 17, the logic unit 33 receives from the position transducer 24 informations relating to the position of the carriage 20 with respect to the delivering heads 11. The logic unit 33 will correspondingly control modulation of the valve 27 or 28 so as to obtain the required acceleration, speed of translational movement and positioning. When a programmed position is reached by the trolley 20, which in this case may occur with a movement speed of the trapezoidal type, the logic unit 33 will operate again the control valves 29, 30, 31 and 32 so as to stop the cylinder 19 ensuring that the trolley 20 is positioned, at a standstill, exactly underneath a required delivering head 11. At this point the sliding valve 41 will be actuated so as to supply pressurised air to the cylinders 35, 36 and 37 of the pneumatic connector element 15 which will be coupled with the respective stationary connector element 16 of the prechosen delivering head 11. The movement of the connector element 15 towards the stationary connector element 16 will result in closure of the duct 44' of the pneumatic plugging sensor 44, thus interrupting the outflow of pressurised air. This condition will be detected by the logic unit 33 as a signal that positioning and engagement of the connector elements 15 and 16 have been correctly performed.

[0028] At this point the logic unit 33 will actuate the solenoid valves 23 in the desired sequence so as operate the valves 11', 11'' of the head 11 to pour into container 22 on the carriage 20. After supply and metering of the substance contained in the respective tank 12 has been completed, the weighing device 21 on the trolley 20 will send a control signal to the logic unit 33, enabling it for a new metering step. Therefore the connector element 15 will be retracted until the plugging sensors 42, 43 provide the logic unit 33 with a disengagement signal, and the cylinder 19 will again be actuated so as to drive and position the trolley 20 supporting the receiving container 22, underneath a new prechosen delivering head 11. After the batching or delivering operation has been effected, the trolley 20 is moved to a delivery point for the container 22.

[0029] From the above description and illustrations it will be unlestood that a new and usefull apparatus for authomatically supplying and metering fluid and/or fluidizable substances has been provided; furthermore, according to the example shown, by using a air/oil power operating system in combination with a linear position transducer, and a connector device for connecting the delivering heads in a controlled manner by a programmable logic unit, it is possible not only to provide a completely automatic and extremely simplified apparatus for metering and mixing fluid substances, but also to use pneumatically operated components, thus increasing significantly the realiability and safety of the entire apparatus; furthermore, as a result of the combined air/oil operating system, it is possible to control with extreme precision the positioning and speed of translation of the trolley or carriage which supports the scale and the receiving container for the substances, preventing sudden movements and jolts which could result in the overflow of the substance from the container 22 or in the loss of equilibrium and overturning of the container itself.

[0030] Lastly, figures 6 and 7 shown the use of a cavity or open chamber 47' on one 16 of the connector elements, to congiuntly connect one or more ducts of a connector element with one or more ducts of the other one 15 of said connector elements.

[0031] It is obvious that the pneumatic solution illustrated in Figure 1 could be replaced with any other suitable solution, by providing electrically controlled valves and/or drive apparatus, or a different type of sensors or position transducers, such as an absolute or incremental type of encoder. The same delivering heads or drive means to selectively delivering metered quantities of fluid substances to be mixer, may by of different type without thereby departing from the innovative principles of the claimed invention.

Claims

1. An apparatus for authomatically delivering metered quantities of fluid or fluidisable substances from storage tanks (12) characterised by comprising a plurality of delivering heads (11) having control valve means (11', 11'') connected to respective of said storage tanks (12), the delivering heads (11) being aligned along a linear path for a trolley (20) supporting a receiving container (22) to be positioned under said delivering heads (11); sensing means (24) positioned along said path to provide control signals indicative of the positions of the trolley (20) in alignement with the delivering heads (11), actuable drive means (25, 26) being provided to reciprocate said trolley (20) along said linear path, and a programmable control unit (33) to control said drive means (25, 26) and to selectively actuate the control valves (11', 11'') of the delivering heads (11).

2. Apparatus for delivering metered quantities of fluid substances, according to claim 1, characterised by comprising:

- a supporting frame (13) and storage tanks (12) for storing the fluid substances, each of said storage tanks (12) being connected to a respective delivering head (11) by valve means, each of said head (11) comprising pneumatically actuated valve means (11', 11'');

- a trolley (20) for supporting a receiving container (22), said trolley (20) being movable along said path beneath said delivering heads (11), and a programmable control means (33) to selectively actuate the delivering heads (11) respectively to move and to stop said trolley (20) with said container (22) under programmed ones of said delivering heads (11),

- said control means comprising a pneumatic connector device (15, 16) to connect pneumatic valve means (11', 11'') of each of said delivering heads (11) to a pressurised air source (14),

- said connector device comprising a first connector element (16) for each of said delivering heads (11) and a second connector element (15) provided with air-flow control valves (23), one of said connector elements (15) being movable between an advanced and retracted positions in respect to the other one (16) of said connector elements;

- a slider (17) movably supporting said second connector element (15) to and from each of said first connector elements (16), said slider (17) being connected to said trolley (20) and reciprocable drive means (19) to move said slider (17) and said trolley (20) along said path;

- said drive means (19) comprising a double-acting hydraulic cylinder, each of the double-acting cylinder (19) being connected by a respective air/oil power transducer (25, 26) and air-oil flow control valves (27 - 32) to said pressurised air source (14), said control valves (27 - 32) comprising oil flow modulating valves (29, 30);

- position sensing means (24) actuated by said slider (17) to provide control signals for said trolley (20) when the receiving container (22) is in alignment with selected ones of said delivering heads (11);

- and a programmable control unit (33) operatively connected to the control valves (23) of second connector element (15) , to said position sensing means (24), and respectively to oil flow modulating valves (29, 30) to control the working speed, acceleration and deceleration of the translational movements of the slider (17) and trolley (20) mentioned above.

3. Apparatus according to Claim 2, characterised in that said control valves (27 - 32) for said air/oil power transducers (25, 26) and said position sensing means (24) comprise pneumatically working valves, and in that said pneumatic valves are connected to the logic control unit (33) via an electro-pneumatic transducer (34).

4. Apparatus according to Claim 2, characterised in that said first and second connector elements (15, 16) comprise opposite flat surfaces (15a, 16b); at least one duct (47, 48) on said first and second connector elements opening in axially alignable positions on said flat surfaces (15a, 16b) ; fluid-tight means (52) being provided to encircle the openings of said ducts and control means (35 - 37) to move one (15) of said connector elements (15, 16) between advanced and retracted positions in respect to the other one (16).

5. Apparatus according to Claim 4, in which said first and second connector elements (15, 16) comprise a set of fluid ducts (47, 48), characterised in that at least one of the ducts (48) of a connector element is connectable with at least two ducts (47) of the other connector element via a cavity connection or chamber (47') on the flat surface.

6. Apparatus according to Claim 4, characterised by comprising double acting control means (35, 36) to move one of said connector elements (15, 16) between an advanced and retracted positions in respect of the other one of said connector elements, and additional thrust means (37) to press said one connector element against the other one in a fluid-tight condition.

7. Apparatus according to Claim 4, characterised by comprising sensing means (42, 44) for providing control signals in said advanced and retracted positions of said one connector element.

8. Apparatus according to Claims 3 and 7, characterised in that said sensing means (42, 44), comprise pneumatic plugging sensors (42, 44) positioned on apposite sides of the movable connector element (15), said plugging sensors having duct means (42', 44') opening toward a flat plugging surface of said connector elements, said plugging duct means being directly connected to the electro-pneumatic transducer (34) of the logic control unit (33), respectively being connected to said pressurised air source (14) through branched out throttling ducts (45c, 46c)

Drawing