Mixing apparatus
A control system for mixing materials in a container. A screw-driven pressure plate clamps the container during mixing. Current of the clamping motor driving the screws is monitored and control circuitry allows multiple speed, multiple current draw, automatic switch-over operation of the clamping motor. Circuit components are automatically checked, and control over a mixing or clamping operation is assumed if necessary.
| Inventors: | Hellenberg; Leen (Katwijk, NL) |
| Assignee: | Fluid Management Limited Partnership (Wheeling, IL) |
| Appl. No.: | 07/795,515 |
| Filed: | November 21, 1991 |
| Current U.S. Class: | 318/114 ; 318/460; 366/209; 366/605 |
| Current International Class: | B01F 15/00 (20060101); B01F 11/00 (20060101); B01F 011/00 () |
| Field of Search: | 366/108,109,110,111,128,216,217,251,605,208,209 318/114,128,460 |
| D254973 | May 1980 | Abrenskou-Sorensen |
| 835846 | November 1906 | Blalock |
| 1448446 | March 1923 | Hulbert |
| 1463626 | July 1923 | Marrazzo |
| 1755763 | April 1930 | Barber |
| 2797902 | July 1957 | Buegler |
| 2894309 | July 1959 | Brzowski |
| 3018092 | January 1962 | Johnson |
| 3229964 | January 1966 | Wiseman |
| 3284057 | November 1966 | Duguette |
| 3421053 | January 1969 | Rinard et al. |
| 3542344 | November 1970 | Oberhauser |
| 3609921 | October 1971 | Foster et al. |
| 3735962 | May 1973 | Pagano |
| 3880408 | April 1975 | Karjalainen |
| 4134689 | January 1979 | Abrenskou-Sorensen |
| 4235553 | November 1980 | Gall |
| 4281936 | August 1981 | Schotter et al. |
| 4568194 | February 1986 | Gargioni |
| 4588302 | May 1986 | Pizzi et al. |
| 4706443 | December 1972 | Oberhauser |
| 4789245 | December 1988 | Morbeck |
| 4842415 | June 1989 | Cane et al. |
| 5066136 | November 1991 | Johnson |
| 5094541 | March 1992 | Nelson |
Primary Examiner: Ro; Bentsu Attorney, Agent or Firm: Fitch, Even, Tabin & Flannery
What is claimed is:
1. Mixing apparatus for mixing contents in a container comprising:
container contacting means including a support plate and a pressure plate which is movable toward and away from the support plate;
actuator means operable in response to a plurality of driving signals to move the pressure plate toward and away from the support plate at a first, faster speed and at a second, slower speed;
circuit means coupled to said actuator means for producing said plurality of driving signals;
said circuit means responsive to input signals;
inputting means for inputting user-defined input signals, relative to parameters of the pressure plate travel, to said circuit means;
said circuit means responding to said user-defined input signals to result in said first and second speeds of movement of said pressure plate travel, said circuit means including programmable computer means and annunciator means coupled to said programmable computer means;
said inputting means includes switch means coupled to said programmable computer means; and
said programmable computer means presents a sequence of messages to said annunciator means and processing respective operations of said switch means as a sequence of different user-defined input signals.
2. The apparatus of claim 1 wherein:
said apparatus further comprises pressure monitoring means for monitoring the pressure applied by said pressure plate to said container;
said user-defined input signals include at least one signal indicating a preselected pressure limit; and
said apparatus further comprises pressure control means for comparing the monitored pressure to said preselected pressure limit and for altering the driving signals so as to alter the pressure applied to said container by said pressure plate and said support plate.
3. The apparatus according to claim 2 wherein said pressure monitoring means includes means for monitoring the power consumption of said actuator means.
4. Mixing apparatus for mixing contents in a container comprising:
container contacting means including a support plate and a pressure plate which is movable toward and away from the support plate;
actuator means including an electric motor, said actuator means operable in response to a plurality of driving signals to move the pressure plate toward and away from the support plate at a first, faster speed and at a second, slower speed;
circuit means coupled to said actuator means for producing said plurality of driving signals, said circuit means responsive to input signals;
inputting means for inputting user-defined input signals, relating to parameters of the pressure plate travel, to said circuit means;
pressure monitoring means for monitoring the pressure applied by said pressure plate to said container including power monitoring means for monitoring the power consumption of said actuator means;
said user-defined input signals including at least one signal indicating a preselected pressure limit;
pressure control means for comparing the monitored pressure to said preselected pressure limit and for altering the driving signals so as to alter the pressure applied to said container by said pressure plate and said support plate; and
the power monitoring means comprises means for monitoring the electrical current inputted to said electric motor.
5. Mixing apparatus for mixing contents in a container comprising:
container contacting means including a support plate and a pressure plate which is movable toward and away from the support plate;
actuator means operable in response to a plurality of driving signals to move the pressure plate toward and away from the support plate at a first, faster speed and at a second, slower speed;
circuit means coupled to said actuator means for producing said plurality of driving signals, said circuit means responsive to input signals;
inputting means for inputting user-defined input signals, relating to parameters of the pressure plate travel, to said circuit means;
pressure monitoring means for monitoring the pressure applied by said pressure plate to said container including power monitoring means for monitoring the power consumption of said actuator means;
said user-defined input signals including at least one signal indicating a preselected pressure limit;
pressure control means for comparing the monitored pressure to said preselected pressure limit and for altering the driving signals so as to alter the pressure applied to said container by said pressure plate and said support plate; and
means for generating a discontinuous driving signal when the power consumption of said actuator means exceeds the preselected limit.
6. Mixing apparatus for mixing contents in a container comprising:
container contacting means including a support plate and a pressure plate which is movable toward and away from the support plate;
actuator means operable in response to a plurality of driving signals to move the pressure plate toward and away from the support plate at a first, faster speed and at a second, slower speed;
circuit means coupled to said actuator means for producing said plurality of driving signals, said circuit means responsive to input signals;
inputting means for inputting user defined input signals, relating to parameters of the pressure plate travel, to said circuit means;
pressure monitoring means for monitoring the pressure applied by said pressure plate to said container;
said user-defined input signals include at least one signal indicating a preselected pressure limit; and
said apparatus further comprises pressure control means for comparing the monitored pressure to said preselected pressure limit and for altering the driving signals so as to alter the pressure applied to said container by said pressure plate and said support plate, said pressure control means being coupled to said circuit means and sending signals to said circuit means, causing said circuit means to produce driving signals so as to reverse the direction of travel of said pressure plate, so as to displace the pressure plate a preselected distance in the reverse direction and resume the pressure plate travel toward the support plate.
7. The apparatus of claim 6 wherein said circuit means causes a change in the speed of travel of the pressure plate when pressure plate travel toward the support plate is resumed.
8. The apparatus of claim 6 further comprising reverse distance input means for inputting a user definable reverse distance signal proportional to the distance of pressure plate travel in the reverse direction.
9. The apparatus of claim 8 wherein said apparatus further comprises lead screw means threadingly engaged with said pressure plate so as to move said pressure plate, rotation monitoring means which monitors the rotation of said lead screw means, and wherein said user definable reverse distance signal is proportional to a preselected amount of rotation of said lead screw means.
10. The apparatus of claim 8 wherein said apparatus further comprises lead screw means threadingly engaged with said pressure plate so as to move said pressure plate, said actuator means includes a motor coupled to said lead screw means for rotation thereof in opposite directions, and said user definable reverse distance signal is proportional to a preselected time duration during which the motor is operated in a reverse direction.
11. Mixing apparatus for mixing contents in a container comprising:
container contacting means including a support plate and a pressure plate which is movable toward and away from the support plate;
actuator means operable in response to a plurality of driving signals to move the pressure plate toward and away from the support plate at a first, faster speed and at a second, slower speed;
circuit means coupled to said actuator means for producing said plurality of driving signals; and
speed switching means responsive to pressure plate movement for altering the drive signals to said actuator means to cause a change in the speed of pressure plate travel, said speed switching means coupled to said circuit means and sending an alert signal to said circuit means when said pressure plate passes a preselected position.
12. The apparatus of claim 11 wherein said apparatus further comprises lead screw means threadingly engaged with said pressure plate so as to move said pressure plate, said actuator means includes a motor coupled to said lead screw means for rotation thereof in opposite directions, and said speed switching means includes rotation monitoring means for monitoring the rotation of said lead screw means.
13. The apparatus of claim 12 wherein said rotation monitoring means comprises an optical coupler adjacent said lead screw means and coupled to rotation counter means for monitoring the rotation of the lead screw means.
14. The apparatus of claim 12 wherein said rotation monitoring means is coupled to said circuit means and sends signals to said circuit means causing said circuit means to reverse the direction of travel of said pressure plate, to displace the pressure plate a preselected distance in the reverse direction and to resume the pressure plate travel toward the support plate.
15. Mixing apparatus for mixing contents in a container comprising:
a pair of spaced container contacting plates including a support plate and a pressure plate which is movable toward and away from the support plate;
actuator means operable in response to a plurality of driving signals to move the pressure plate in opposite directions toward and away from the support plate;
contact sensing means for sensing contact of the pressure plate with a container located between the pressure plate and the support plate, including contact sensing signal means for generating contact sensing signal for indicating such contact;
circuit means for producing said plurality of driving signals, coupled to said contact sensing means so as to receive said contact sensing signal, said circuit means responsive to said sensing signal to change the driving signals to said actuator means, so as to change the movement of said pressure plate in response to said driving signals; and
said driving signals including signals for moving the pressure plate toward a container on the support plate, moving the pressure plate in a reverse direction in response to the contact sensing signal, and resuming movement of the pressure plate toward the support plate so as to apply pressure to said container.
16. The apparatus of claim 15 wherein said circuit means, in response to said contact sensing signal, sends signals to said actuator means causing said actuator means to reverse the direction of travel of said pressure plate, to displace the pressure plate a preselected distance in the reverse direction and to resume the pressure plate toward the support plate.
17. The apparatus of claim 16 wherein said actuator means responds to at least some of said driving signals to move said pressure plate at different rates of speed.
18. The apparatus of claim 17 wherein the pressure plate is initially moved toward the container at a first, faster speed and is moved toward the support plate at a second, slower speed when travel toward the support plate is resumed after a direction reversal.
19. Mixing apparatus for mixing contents in a container comprising:
a pair of spaced container contacting plates including a support plate and a pressure plate which is movable toward and away from the support plate;
actuator means operable in response to a plurality of driving signals to move the pressure plate in opposite directions toward and away from the support plate;
contact sensing means for sensing contact of the pressure plate with a container located between the pressure plate and the support plate, including contact sensing signals means for generating contact sensing signal for indicating such contact;
circuit means for producing said plurality of driving signals, coupled to said contact sensing means so as to receive said contact sensing signal, said circuit means responsive to said sensing signal to change the driving signals to said actuator means, so as to change the movement of said pressure plate in response to said driving signals;
position sensing means for sensing the position of said pressure plate relative to said support plate and for sending a position signal in response thereto,
said circuit means including comparing means coupled to said position sensing means for comparing a position signal to a predefined position from said support plate corresponding to the size of a container to be mixed, and
said comparing means coupled to said circuit means to cause driving signals to be received by said actuator means when said position signal indicates pressure plate position away from the predefined position and to cause driving signals to said actuator means to be discontinued when said position signal indicates pressure plate position close to said predefined position or between said predefined position and said support plate.
20. The apparatus of claim 19 wherein said actuator means includes lead screw means threadingly engaged with said pressure plate so as to move said pressure plate and a motor coupled to said lead screw means for rotation thereof in opposite directions, and said position sensing means monitors the rotation of said lead screw means.
21. The apparatus of claim 20 wherein said position sensing means comprises an optical coupler adjacent said lead screw means and coupled to a rotation counter means for monitoring the rotation of the lead screw means.
22. Mixing apparatus for mixing contents in a container comprising:
a pair of spaced container contacting plates including a support plate and a pressure plate which is movable toward and away from the support plate;
actuator means operable in response to a plurality of driving signals to move the pressure plate in opposite directions toward and away from the support plate;
contact sensing means for sensing contact of the pressure plate with a container located between the pressure plate and the support plate, including contact sensing signal means for generating contact sensing signal, for indicating such contact;
circuit means for producing said plurality of driving signals, coupled to said contact sensing means so as to receive said contact sensing signal, said circuit means responsive to said sensing signal to change the driving signals to said actuator means, so as to change the movement of said pressure plate in response to said driving signals; and
said circuit means including pressure level setting means for defining the contact pressure at which contact is indicated by said contact sensing signal.
23. The apparatus of claim 22 wherein said pressure level setting means comprises pressure level input means for inputting a user defined pressure level setting.
24. The apparatus of claim 23 further comprising a second user defined input means for specifying a second pressure level setting at which said actuator means initiates discontinuous pressure plate travel toward the support plate.
25. Mixing apparatus for mixing contents in a container comprising:
a pair of spaced containers contacting plates including a support plate and a pressure plate which is movable toward and away from the support plate;
actuator means operable in response to a plurality of driving signals to move the pressure plate in opposite directions toward and away from the support plate;
contact sensing means for sensing contact of the pressure plate with a container located between the pressure plate and the support plate, including contact sensing signal means for generating contact sensing signal for indicating such contact;
circuit means for producing said plurality of driving signals, coupled to said contact sensing means so as to receive said contact sensing signal, said circuit means responsive to said sensing signal to change the driving signals to said actuator means, so as to change the movement of said pressure plate in response to said driving signals; and
said contact sensing means including power monitoring means for monitoring the power consumption of said actuator means.
26. The apparatus according to claim 25 wherein the actuator means includes an electric motor and the power monitoring means comprises means for monitoring the electrical current inputted to said motor.
27. The apparatus according to claim 25 further comprising means for generating a discontinuous drive signal when the power consumption of said actuator means exceeds a preselected limit.
28. Mixing apparatus for mixing contents in a container comprising:
a pair of spaced container contacting plates including a support plate and a pressure plate which is movable toward and away from the support plate;
lead screw means threadingly engaged with said pressure plate;
actuator means operable in response to a plurality of driving signals to move the pressure plate in opposite directions toward and away from the support plate, said actuator means including a motor coupled to said lead screw means for rotation thereof in opposite directions;
rotation monitoring means for monitoring the rotation of said lead screw means and for generating a rotation signal indicative of the rotation; and
circuit means for producing said plurality of driving signals, including means for receiving said rotation signal and for changing the driving signals to said actuator means in response thereto so as to change the movement of said pressure plate.
29. The apparatus of claim 28 wherein:
said apparatus further comprises means for inputting at least one user defined input signal in said circuit means, relating to a parameter of pressure plate travel; and
said circuit means includes means for comparing said rotation signal to said input signal and for producing a driving signal in response thereto.
30. The apparatus of claim 29 wherein said circuit means responds to said at least one user-defined input signal and to said rotation signal so as to result in first and second speeds of movement of said pressure plate travel.
31. The apparatus of claim 30 further comprising user defined canceling means for canceling driving signals which result in said first and second speeds of movement of said pressure plate travel.
32. The apparatus of claim 28 further comprising window generating means for generating a consecutive series of time interval windows, said circuit means including means for producing a rotation counter estimate for each time interval window, for comparing the rotation counter estimate to said rotation signal and for generating an error signal if the comparison lies outside of a preselected value.
33. The apparatus according to claim 28 wherein said driving signals include a discontinuous drive signal produced in response to a preselected amount of rotation of said lead screw means.
34. Mixing apparatus for mixing contents in a container comprising:
a pair of spaced container contacting pressure plates movable toward one another so as to apply pressure to a container clamped therebetween and away from one another so as to release the container;
driving means operable in response to a plurality of driving signals to move the plates toward and away from one another;
circuit means for producing said plurality of driving signals in response to an input signal indicative of container size;
means for inputting an input signal in said circuit means, indicative of container size; and
said driving signals including a first signal for initially moving said pressure plates at a first, faster speed and a second signal for moving said pressure plates at a second, slower speed as said pressure plates engage the container.
35. The apparatus according to claim 34 further comprising means for setting a preselected pressure limit imparted by said driving means to said container, and means for monitoring the pressure applied to said container and for comparing the monitored pressure to said preselected pressure limit.
36. The apparatus according to claim 35 wherein said pressure monitoring means comprises means for monitoring the power consumption of said driving means.
37. The apparatus according to claim 36 wherein the driving means includes an electric motor and the means for monitoring the power consumed by said driving means comprises means for monitoring the current inputted to said electric motor.
38. The apparatus according to claim 37 wherein the magnitude of current inputted to said electric motor is monitored.
39. The apparatus according to claim 37 wherein the rate of change of current inputted to said electric motor is monitored.
40. The apparatus according to claim 37 wherein said circuit means stops sending said driving signals to said electric motor when the power consumption of said electric motor exceeds the preselected limit.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention pertains to apparatus for mixing liquid and pulverulent materials, and in particular, to automatic mixing systems.
2. Description of the Related Art
Paint shakers and other apparatus for mixing paint and the like products in a sealed container have been in wide spread use for some time. One common use for such apparatus is to mix paint products in familiar standardized containers such as quart and gallon sized cans and five gallon plastic pails. Oftentimes, paint is mixed at a store location, one container at a time. After adding colorants and other ingredients, the container is put into a shaker machine for thorough mixing of the ingredients.
However, paint and paint products are also prepared commercially, on a much larger scale, with large numbers of containers being pelletized for shipment to remote locations. At times, pallets of paint containers are stacked one on top of another, with considerable pressure being applied to the lower most row of containers on the bottom pallet. Even if the bottom containers are not ruptured, they may become seriously weakened and may even be partly crushed.
Paint shakers impart a considerable force to a container and its contents, and the container is moved back and forth in a series of short, rapid movements. It is important that the paint container be securely held in the shaker machine. In some paint shaker machines, a band is clamped about the girth or circumference of a paint can, or a series of small clamps are spaced about the periphery of the can lid. Such clamping arrangements, which are typically employed for mixing quart or gallon-sized cylindrical containers, are unsuitable for use with five gallon containers which typically are tapered from top to bottom. Because of the size, weight and asymmetric nature of five gallon containers, it is usually expedient to clamp such containers in an upright position, between a pair of horizontal clamp members. Such clamping arrangements, if made of larger size clamping plates, may also be employed to shake several containers, simultaneously. Five gallon containers of paint products, especially those with masonry fillers are quite heavy, weighing up to 70 pounds or more. A substantial clamping force is required to retain such containers during a mixing or shaking operation and, under normal conditions, adequate clamping force can be achieved without risk of damage to the paint container. However, damaged paint containers, such as those weakened during shipment, prior to a mixing operation, present an abnormal condition which may not be detected upon their loading in a paint shaker machine. Such abnormal containers may even rupture during mixing operation, if care is not taken when clamped in the shaker machine.
With present shaker machines it is not always possible to adequately clamp such weakened containers with pressure sufficient to adequately retain the container during mixing, while limiting the pressure so as not to aggravate the previously compromised integrity of the container. A clamping arrangement which is reliable and easy to use, and which offers a greater precision in the application of pressure to a container is still being sought.
Paint and paint formulations are a worldwide industry and with increasing frequency, larger paint handling operations are encountering different-sized containers, with an increasing number of containers being of an unusual size or proportion and not constructed according to domestic or foreign standardized dimensions. It is important that the paint shaker be readily adaptable to such containers. Further, in the manufacturing environment, it is important that the paint mixers be capable of rapid operation in loading and unloading containers therefrom.
SUMMARY OF THE INVENTION
It is an object according to the present invention to provide mixing apparatus suitable for use with containers, such as paint containers of various sizes and proportions.
Another object according to the present invention is to provide a mixing apparatus which precisely applies an accurately calibrated pressure to the container being mixed.
Another object according to the present invention is to provide a mixing apparatus having a clamping arrangement which can sense abnormal conditions during operation on a container and which can make appropriate responses to such indications.
A further object according to the present invention is to provide a mixing apparatus having decision-making capabilities, and which is flexible so as to respond to a number of different, easily programmable instructions.
These and other objects according to the present invention which will become apparent from studying the appended description and drawings are provided in mixing apparatus for mixing contents in a container comprising:
container contacting means including a support plate and a pressure plate which is movable toward and away from the support plate;
actuator means operable in response to a plurality of driving signals to move the pressure plate toward and away from the support plate at a first, faster speed and at a second, slower speed; and
circuit means coupled to said actuator means for producing said plurality of driving signals.
Other objects of the present invention are attained in a mixing apparatus for mixing contents in a container comprising:
a pair of spaced container contacting plates including a support plate and a pressure plate which is movable toward and away from the support plate;
actuator means operable in response to a plurality of driving signals to move the pressure plate in opposite directions toward and away from the support plate;
contact sensing means for sensing contact of the pressure plate with a container located between the pressure plate and support plate including contact sensing signal means for indicating such contact; and
circuit means for producing said plurality of driving signals, coupled to said contact sensing means so as to receive said contact sensing signal means, said circuit means responsive to said signal means to change the driving signals to said actuator means, so as to change the movement of said pressure plate in response to said monitoring means output signal.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings, wherein like elements are referenced alike;
FIG. 1 is a schematic cross-sectional view of mixing apparatus according to principles of the present invention;
FIG. 2 is a legend showing the arrangement of FIGS. 2A and 2B;
FIGS. 2A and 2B together comprise a schematic block diagram of a control system according to principles of the present invention;
FIG. 3 is a legend showing the arrangement of FIGS. 3A-3D;
FIGS. 3A-3D together comprise an electrical schematic diagram of the control system according to principles of the present invention;
FIG. 4 is a legend showing the arrangement of FIGS. 4A-4C;
FIGS. 4A-4C together comprise a flow diagram indicating operation of the mixer apparatus, including control system, according to principles of the present invention: and
FIG. 5 is a schematic diagram of an interface portion of the control system .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is directed to electromechanical systems for mixing containerized materials, such as liquid and pulverulent materials shipped in cans, pails and the like containers for use at locations remote from the material's supplier. The present invention has found immediate commercial acceptance in the paint industry and provides increased flexibility in paint mixing operations for containers of a wide variety of sizes. For example, one commercial embodiment of the present invention is employed in mixing containers used in the paint industry, both domestically and abroad. As will be appreciated by those skilled in the art, there is no set standard for such containers worldwide, and paint materials are being transported in containers of varying sizes and physical qualities. As will be seen herein, control systems according to principles of the present invention provide improved control over a paint mixing operation, and are able to automatically sense and adapt to a wide variety of different containers.
Referring now to FIG. 1, mixing apparatus 98 having electronic control is illustrated. An electronic control system generally indicated at 100 is coupled through Various conductors to motors and output sensing equipment of a mixing mechanism generally indicated at 102. The mixing mechanism 102 includes an outer frame 1 which is adapted to be supported on a floor or other horizontal support surface. An intermediate frame 2 is suspended in the outer frame 1 by means of springs 3. Means for applying a mixing motion to an inner frame 7 is located at the bottom of mechanism 102. A shake motor M2 drives a transmission belt 8. A crank 4 is supported by frame 2 via bearing means 5. The crank 4 has two eccentric pins 6 connected to frame 7.
An eccentric weight 30 is fastened to crank shaft 4, being displaced 180.degree. relative to pins 6, so as to be arranged to counter-balance a weight loading of the inner frame 7 in combination with a receptacle or container 11 to be mixed by apparatus 98. The upper part of inner frame is connected to frame 2 by links 9. When motor M2 is energized, the inner frame is subjected to a vibration of a particular configuration, which has been found effective for the mixing of liquid or pulverulent materials in a container 11. Such mixing is commonly referred to in the art as "paint shaking."
It is important that containers 11 be securely clamped to a table 10 carried by inner frame 7, during a mixing operation. Screw fasteners or nuts 13 are fixed to a pressure plate 12 and are displaced by an actuator means which includes lead screws 14. The lower ends of screws 14 are mounted at 15 to a support plate or table 10 in such a manner that the screws are rotatably mounted, but are not axially movable. Together, the plates 10, 12 comprise container contacting means. If desired, either one or both plates 10, 12 could be made movable. An upper cross member 16 of the inner frame is provided with bearings to guide the lead screws 14 for rotational movement. A pulley 18 is fastened at the upper end of each lead screw 14, and an endless belt 19 drives the pulleys in synchronism.
A transmission mechanism 21 is coupled through a drive shaft 20 to one lead screw 14, which in turn drives the other lead screw 14 through the pulleys 18 and belt 19. Transmission 21 preferably comprises an angle-gear and an electro-optical coupler which is coupled through conductors 21C to the control system 100.
A clamp motor M1 is mounted on frame 2 and is coupled through electrical conductors M1C to control system 100 and a shake motor M2 is coupled to control system 100 by conductors M2C. An output shaft 26 of motor M1 is coupled through a pulley 23 to an input shaft 22 of transmission mechanism 21. The clamp motor M1 can be positioned in-line with input shaft 22, but in the preferred embodiment is horizontally displaced therefrom. Accordingly, an endless belt 24 may be employed to couple the shafts 26, 22 together. Alternatively, as mentioned, shafts 26, 22 can be directly connected together with pulleys 23 and belt 24 being omitted, if desired.
The mixing mechanism 102 has met with widespread commercial acceptance in part, because it is very compact while providing a substantial clamping gap between table 10 and upper cross member 16 of the inner frame 7. Further details of the mixing mechanism 102 may be found in commonly owned U.S. Pat. No. 4,134,689, the disclosure of which is incorporated by reference as if fully set forth herein.
Referring now to FIGS. 2A-2B, a schematic block diagram of control system 100 will now be described. The schematic block diagram of FIG. 2 is divided into two parts, one shown in FIG. 2A and one shown in FIG. 2B. The various electrical circuits broken at the page boundaries between FIGS. 2A, 2B are identified by reference numerals 2.01-2.14 for ease of reference. As mentioned, the control system 100 is coupled to shake motor M2, clamping motor M1 and an opto-coupler or shaft encoder in transmission mechanism 21. The opto-coupler is of a known type which senses the angular displacement and revolutions of lead screw 14 and transmits electrical driving signals through conductors 21C to the control system 100. The control system 100 includes a transformer TRSF and a power supply circuit 110 and 112 to provide electrical energization for various components of the control system.
With additional reference to FIG. 5, electrical components such as the clamp motor M1 and a shake motor M2 associated with mechanism 102 are coupled to control system 100 through electrical terminals 1'-15', which together comprise a first connector designated CON1 which is also shown in FIG. 2A. For example, clamp motor M1 is coupled to control system 100 through terminals 3', 4'. The aforementioned transformer TRSF is coupled through terminals 1', 2' to the power supply circuits 110, 112. The shaker motor M2 is coupled through a shake relay 114 to terminals 5', 6' and an indicating lamp 116 is coupled through terminal 8' to control system 100.
Operating switches are provided on mechanism 102, including push button switches S2' and S3' which, as illustrated in FIG. 2A, receive power from terminal 10'. Switch S2' is coupled through terminal 9' to indicate the start of a mixing operation. Switch S3' is coupled through terminal 13' to control circuit 100, to indicate that upward motion of clamping plate 12 is called for. As will be seen herein, the electrical power and in particular, the current drawn by clamping motor M1 and hence the pressure applied to a container is closely monitored by control system 100. Components monitoring the motor current are calibrated by current simulation equipment which can be coupled to the control system through terminal 14'. Terminal 15' provides a ground for various electrical components of the control system 100 as well as components associated with the mixing mechanism 102. The preferred actuator means includes an electric motor, although air-driven motors would also be used, with power being monitored using conventional techniques.
As shown in FIG. 5, but not in FIG. 2A, permissive switches are connected to break the electrical circuits to the shake relay 114, shake indicator lamp 116 and the start switch S2'. The permissive switches include a safety switch 222, and a front door switch 224 for sensing opening of a front door of a cabinet which surrounds the mixing mechanism 102.
Referring now to FIG. 2B, the operating conditions of these permissive switches are investigated at start up, by a microprocessor controller 120. The microprocessor controller 120 receives input from an A/D converter 124 and also from I/O expander circuit 126. The I/O expander circuit 126 is coupled through level converter means 128 to terminals A-G located at various points throughout the control system. The I/O expander circuit 126 is also coupled through a display interface 130 to an annunciator or visual display 132.
As mentioned above, the transmission mechanism 21 includes an opto-coupler which supplies electrical signals to the control system 100. The opto-coupler is connected through connector CON3 to microprocessor controller 120. The third electrical connector CON2 provides optional coupling of an external interface to microprocessor controller 120. The external interface can be used to perform software diagnostics and/or to alter the software program stored in the microprocessor controller 120.
The control system 100 also includes a plurality of user inputs. For example, potentiometers P1-P3 (See FIG. 2A) are coupled to the A/D converter 124. The program loaded in microprocessor controller 120 guides a user to the correct potentiometer at a given time in a set up program routine. Three LED's, LD1-LD3 are associated with the potentiometers P1-P3, respectively for this purpose. The LED's are driven by signals routed through an address decoder 136.
A potentiometer 140 is mounted on the mixer mechanism, and is coupled through terminals 11', 12' to control system 100. A current source 142 provides a reference signal for the potentiometer 140, with the potentiometer developing a reference voltage fed into the A/D converter 124.
As will be explained in greater detail with reference to FIG. 3, the upper left corner of FIG. 2A, shows that the clamp motor M1 is driven by signals routed through an arrangement of switches T4-T8, which are operated by electrical signals routed through terminals A-D. As will be seen herein, the preferred switch is a FET transistor with gate signals applied through terminals A-D, coupled through the level converter 128 to the I/O expander circuit 126. The control signals originate in microprocessor controller 120 in a manner to be described herein.
Associated with the switching circuit that controls clamp motor M1 is a voltage switching means controlled by signals to terminal E, one of the outputs of power supply circuit 110. As indicated schematically in FIG. 2A, control takes the form of a switching operation and, as will be seen herein, provides motor control signals at one of two different operating voltages as determined by signals from microprocessor controller 120. Associated with the control of clamp motor M1 is a high speed reset circuit 149 which is coupled to microprocessor controller 120 and I/O expander circuit 126. The current draw to the clamping motor M1 is sensed by an operational amplifier 150 which has an output coupled to microprocessor controller 120 through A/D converter 124.
With appropriate software, microprocessor controller 120 is programmed to alter the driving signals to the clamping motor so as to selectively change the voltage level of the drive to clamp motor M1, to thereby operate the clamp motor at different speeds, as desired. Other arrangements for changing motor speed could also be employed. The microprocessor controller 120 also controls the direction of current flow through clamp motor MI and hence, its direction of rotation, thus being able to selectively clamp and release a container held in mixing mechanism 102.
The power consumption of the clamp motor is monitored by operational amplifier 150 which forwards an output signal to the microprocessor controller, as explained above. The distance of travel and the absolute position of the clamping plate 12 is monitored by microprocessor controller 120, through a rotation monitoring signal received from the shaft encoder or opto-coupler within the transmission mechanism 21. As mentioned, the control system 100 includes user inputs to define various aspects of a mixing operation and compares these inputs to sensed operating conditions of the mixing system, including various parameters of pressure plate travel such as speed, position, friction forces (due to paint spill on the lead screws), for example. As will be seen herein in greater detail, the user inputs include a determination where speed switching should occur (if this option is available); a higher pressure setting for the clamping plate; and a lower pressure setting for the by potentiometers P1-P3.
Turning now to FIG. 3, a detailed electrical schematic diagram of control system 100 is divided into four figures, 3A-3D, one on each page. The various circuits extending between FIGS. 3A and 3B have been broken, with end points identified by numbers 3.00-3.11, for ease of reference. The circuits extending between FIGS. 3A and 3C have been broken at the page boundary, within ends identified by numerals 3.20-3.32, for ease of reference. The circuits between FIGS. 3C and 3D have ends at the page boundary identified by reference numerals 3.41-3.49. Finally, the circuits between FIGS. 3B and 3D, broken at the page boundary, are identified by reference numerals 3.60-3.77.
FIG. 3 is a detailed schematic diagram of the control system 100, described in the block diagram of FIG. 2. For example, FIG. 3A includes a voltage doubler circuit 160 having terminal E as a control point. The voltage doubler circuit 160 receives power from a full wave rectifier bridge 162 comprised of diodes D1-D4 and capacitors C1-C4. The rectifier bridge 162 in turn receives power from transformer TRSF coupled to the rectifier bridge 162 through terminals 1', 2', located adjacent resistor R1. Together, the full wave rectifier bridge 162 and voltage doubler circuit 160 roughly comprise the power supply circuit 110 of FIG. 2A. The output of transformer TRSF is fed to a second transformer, designated TR1, which in turn feeds power to various components comprising the second power supply circuit 112 of FIG. 2A. Included is a second full wave rectifier bridge 166 comprised of diodes D14-D17 and capacitors C14-C17. The second power supply circuit is coupled by shunt capacitors C18, C19, resistors R21-R23, capacitor C20 and diode D10 to voltage regulator circuit IC1, preferably of a device type 7805.
As can be seen in FIG. 3A, voltage doubler circuit comprises capacitors C5-C7, diodes D5-D9 and D15, resistors R2-R9, bipolar transistors T1 (preferably of a type BF393) and FET transistor T2 (preferably of a type IRF9640). The voltage divider resistors R6, R7 provide a reference signal output on terminal L which is fed to pin 30 of microprocessor controller 120, as can be seen in FIG. 3B. A control signal is coupled through base resistor R5 to transistor T1 to switch the level of the applied motor voltage, in response to a control signal inputted through terminal E, outputted on pin 1 of I/O expander circuit 126 which preferably comprises a device type PB243, as can be seen in FIG. 3D.
Referring now to FIG. 3A and the upper left-hand portion of FIG. 3B, a first motor controlled circuit, or motor drive circuit 170 receives a voltage feed from voltage doubler circuit 160. The motor drive circuit 170 includes output switching transistors T4, T5, T7 and T8 (preferably of device type XIRF9640 for transistors T5 and T8, and XIRF740 for transistors T4 and T7). As will be seen herein, transistors T5 and T7 cooperate to form one current path for feeding clamp motor M1 and transistors T8, T4 form a second, reverse direction current path for the clamp motor. Transistor T5 is biased by diode D20, capacitor C9 and resistor R13, and is switched through resistor R12 by transistor T3 (preferably of device type BF393 which pulls down the voltage input to transistor T5). Switching transistor T3 receives a base control signal through resistor R10, fed into terminal D, outputted from I/O expander circuit 126, as can be seen in FIG. 3D.
Transistor T4 is biased by resistor R11, capacitor C8 and diode D21, and receives an input control signal through terminal B, outputted from the top module of IC8, (see FIG. 3D) coupled to pin 3 of I/O expansion circuit 126. The level converter integrated circuit IC8 is preferably of device type HCF40109 and includes four modules, with output terminals 5, 4, 13 and 11, respectively, coupled to output terminals B, C, F, and G, respectively.
Output transistor T8 is biased by resistor R15, capacitor C11 and diode D19, and receives control signals through resistor R16, outputted from transistor T6 (preferably a device type BF393). Transistor T6 pulls down the reference voltage at the input to transistor T8, and receives its control signal through base resistor R18, coupled through terminal A to terminal 2 of I/O expander circuit 126.
Transistor T7 is biased by capacitor C10, diode D22 and resistor R17, and receives its input control signal through terminal C coupled to output terminal 4 of level converter integrated circuit IC8. Diodes D12-D15 protect the output portions of transistors T4, T5, T7 and T8. Clamping motor M1 is coupled to motor drive circuit 170, through terminals 3', 4' located between output diodes D14, D15 and D12, D13, respectively.
The high speed reset circuit 149 is comprised of transistor T9 (preferably of device type BSS89, resistor R20 and capacitors C12, C13).
Referring to the bottom left corner of FIG. 3B, shunt resistor R24, capacitors C21, C22 and diode D11 are located at the output of voltage regulator IC1. Microprocessor controller 120 is coupled to an A/D converter circuit 124, which is preferably of device type ADC08008. Output terminals 23-25 of A/D converter 124 are coupled to microprocessor controller 120 through terminals N, O and P which are connected to an LED driver circuit IC10, preferably of device type 74HCT138. IC10 is identified by reference numeral 174, and drives LED(s) LD1-LD3, through resistor R51, in response to signals fed through terminals N, O and P. Capacitors C24, C25, C41 and C33 are located at the power inputs to LED driver circuit IC10, A/D converter 124 and microprocessor controller 120.
As mentioned, three user input potentiometers are provided by control system 100, the potentiometers designated P1-P3. Resistors R25, R26 provide a voltage divider input to terminal 2 of A/D converter 124, and are connected across the input to potentiometer P1, which provides an output signal to terminal 26 of the A/D converter circuit 124. Potentiometers P2 and P3 provide input signals to terminals 27 and 28 of the A/D converter. Capacitor C23 is located at pin 12, providing a reference signal to the A/D converter circuit 124.
Referring again to FIG. 3B, an external interface is provided at pins 2, 3 and 39 of microprocessor controller 120. An associated interface circuit includes an invertor IC7: crystal XTALL: capacitors C26-28, (38 and(39, resistors R27, R28 and R50. Temporary connection is conveniently made at connector CON2.
The shaft encoder or opto-coupler of transmission mechanism 21 is coupled to microprocessor controller 120 through connector CON3, invertor IC7, resistors R29, R30 and capacitors C40, C42.
As mentioned, the mixing mechanism 102 is preferably enclosed within a cabinet having an access door provided to the user for loading and unloading containers to be mixed within the mechanism. A conventional switch is mounted to the access door to indicate when the door is opened so that safety precautions such as terminating a mixing operation can be taken on a selective basis, if desired. The door switch is connected through connector CON4 for coupling to microprocessor controller 120, through invertor IC7C, resistors R57, R58 and R59, and capacitors C43 and C28 (shown in FIG. 3B).
Capacitors C29, C30 are located at the respective 12 volt and 5 volt power inputs to the level converter circuit IC8. A push switch SI and option selection switches S2-1 through S2-4 are connected to terminals 27 and 31-34 of microprocessor controller 120, as shown in FIG. 3B. As will be explained herein, the option switches S2-1 through S2-4 comprise additional user input settings for the microprocessor controller.
Referring to FIG. 3D, a resistor bank R49 having eight individual resistor elements is coupled to terminals 1-5, and 21-23 of I/O expander circuit 126.
Referring to FIGS. 3C and 3D, three 71/2 segment output displays U1-U3 are provided to inform the user of various operating conditions of control system 100. The output displays U1-U3 are controlled by signals on terminals 13-20 of 1/0 expander circuit 126, and display drivers IC5 and IC6, along with capacitors C31, C32 and resistor banks R46, R47 and discrete resistors R41, R42, R45 and resistor bank R43 are employed to drive the output displays U1-U3. Display drivers IC5, IC6 are preferably of device type HEF4511.
Referring to FIGS. 3A and 3B, a mixing drive circuit 180 includes a bi-polar drive transistor T10 (preferably of the type BD241C) and diode D16. The transistor is operated by control signals received at terminal F (see FIG. 3C) and coupled to the transistor through resistor R32. The collector of the transistor is connected to a relay which energizes the mixing or "shake motor" M2. A lamp driver circuit 184 includes a drive transistor T11 (preferably of the type BD241C) and diode D17. Control signals received at terminal G are coupled to the base of the transistor through resistor R33. Transistor T11 completes the lamp circuit, illuminating lamp 116.
The drive transistor T10 provides a current path for the "shake relay" 114 which in turn energizes the mixing motor M2.
The terminals F and G are coupled through IC8 to pins 22, 21 of I/O expander circuit 126, respectively. The start button S2' of FIG. 2A is coupled through voltage divider resistors R35, R34 and invertor IC7 to terminal I. Referring to FIG. 3B, terminal I is connected to pin 3 of A/D converter circuit 124, ultimately providing input to microprocessor controller 120.
Referring also to FIG. 3B, terminal K is connected to pin 4 of A/D converter 124 and provides an input signal from the timer setting potentiometer 140, shown in FIGS. 2A and 3C. Referring to FIG. 3C, capacitor C37 is connected across the potentiometer 140. The terminal 11' of connector CON1 is connected to terminal K and through resistor R31 is coupled to voltage doubler circuit 160. A push button for raising the clamping plate 12 is coupled to terminal H through an invertor IC7 having an input circuit comprised of voltage divider resistors R37, R36 and capacitor C44. Terminal H is in turn connected to pin 29 of microprocessor controller 120.
A motor sensor circuit 200 is coupled to the motor drive circuit 170 through resistor R24 (see FIG. 3A). The resistor R24 couples the motor drive current signal to pin 3 of operational amplifier IC9, preferably of type CA3130. Resistors R38-R40 and R60, and capacitors C34-C36 provide feedback and bias for the operational amplifier circuit. The output of the operational amplifier is coupled to terminal J, connected to pin 5 of A/D converter circuit 124, to ultimately provide an input signal to microprocessor controller 120, which is proportional to either the magnitude of the current drawn by clamping motor M1 or the rate of change of that circuit. As those skilled in the art will appreciate, it is sometimes desirable to calibrate a control circuit under simulated operating conditions. Accordingly, terminals 14', 15' are provided to couple a current simulation generator to IC9 through resistor R44.
Referring now to FIG. 5, a schematic diagram of a portion of the control system, connecting sensors on the mixing mechanism to the electronic circuitry, is shown. The relay coil 114 operates a pair of relay points 214 to energize shake motor M2. A circuit breaker 216 and an on/off switch 218 interrupt power to the control system. As can be seen in FIG. 5, a number of switches interrupt current to the relay coil 114, running lamp 116, and start switch S2'. These switches include safety switch 222, and front door switch 224 which detects opening of the access door in the cabinet surrounding the mixing mechanism. These switches interrupt the flow of power received from terminal 5' of connector CON1. Interruption of power is detected at connector CON4. The switches 222, 224 are connected in series, and if either switch is open, power to the relay running lamp and start switch is interrupted.
Referring now to FIG. 4, a block diagram indicating microprocessor control of the electronic circuitry will now be described. As will be seen herein, FIGS. 4A-4C together comprise a flow diagram usin
