Abstract:
A method for automatically cleaning and lubricating conveyor belt systems is disclosed. A microprocessor controlled control unit senses the movement of the conveyor belt and the presence of items, for example bottles, on the conveyor. The control unit initiates the application of lubricant, detergent and rinse water onto the conveyor according to the speed of the conveyor, the presence of items and the time passed since the previous application. If the conveyor is stationary, that is, is not in motion, no lubricant or cleaning solution is applied. If the conveyor is moving but no items are on the belt, a reduced amount of lubricant is dispensed onto the conveyor system. The conveyor cleaning and lubricating process may be carried out during normal production operations.

Description:
FIELD OF THE INVENTION 
     The invention relates to a new and improved apparatus and method for cleaning and lubricating conveyors using a microprocessor controlled control system. The control system senses the activity of the conveyor and the presence of items on the conveyor, and in return lubricates and washes the conveyor as needed. This automated system also reduces the amount of cleaning labor needed, as well as reduces the amount of wasted cleaning and lubricating supplies. 
     BACKGROUND OF THE INVENTION 
     Conveyors commonly used in the food and packaging industries (in particular soft drink manufacturing facilities, breweries, fruit juice manufacturing facilities, dairies, etc.) generally require periodic cleaning in order to maintain the conveyor in a sanitary condition. This cleanliness requirement in turn requires the application of various cleaning ingredients such as detergents, sanitizers, bactericides, slimicides, etc. A simple, yet very time and labor intensive practice is to apply these cleaning ingredients to the conveyor system manually, either by high pressure hot water, steam, or other methods. Additionally, there is a tendency in manual cleaning to over-apply and waste the cleaning products. This manual practice is both expensive, cumbersome and dangerous and may not provide an adequately clean conveyor belt. The art recognizes a need for improved methods and apparatus. U.S. Pat. No. 5,372,243 provides an alternative to the above described cleaning method. King teaches a pneumatically controlled cleaning and rinsing system for conveyors. The valves for providing cleaning and rinsing ingredients are pneumatically actuated, as are the timers and sequencer valves. Pneumatically controlled and actuated equipment is stressed because of the desire to eliminate corrosion of electrical equipment and components in wet environments. 
     Others have provided alternate conveyor cleaning and/or lubricating systems to replace systems that include electrical equipment. U.S. Pat. No. 5,129,481 describes an apparatus and method for lubricating conveyors and belts used in the food industry comprising a device including valves which are alternately opened and closed by an actuating device driven from the conveyor movement. The valves supply a lubricant which is fed to output nozzles for spraying onto the conveyors for lubricating purposes, and the valves will only feed lubricant when the conveyor is moving. Alternately, U.S. Pat. No. 5,289,899 teaches an air-driven delay valve or relay, which is driven from the conveyor system, and which connects to a counter which controls the valve that passes lubricant in a pulsating or intermittent fashion. 
     However, pneumatically controlled systems, such as those described above, can be inaccurate, for example, in their time measurement and fluid dispensing, leading to ineffective cleaning and/or lubricating of the conveyor and wasted supplies. A substantial need exists for a cleaning and lubricating system for conveyors that is simple, accurate, versatile, reliable, and is easy to maintain. 
     SUMMARY OF THE INVENTION 
     The present invention relates to a new and improved apparatus and method for cleaning and lubricating conveyor systems using a microprocessor controlled control system. The control system senses movement of the conveyor belt and the presence of any items, such as cans, bottles, or food products, on the conveyor belt, and in return either cleans or lubricates the conveyor as needed. This automated system reduces the amount of labor needed to perform these critical tasks, as well as reduces the amount of wasted cleaning and lubricating supplies. 
     In particular, the present invention relates to a conveyor system that includes the combination of a conveyor system, a washing system, and a lubrication system. The conveyor system is for transporting an object, with the conveyor system including a conveyor belt having a front side and a back side, and a drive mechanism for providing movement to the belt. The washing system is for rinsing and washing the conveyor belt and includes a water source, a detergent source, a mixing chamber to mix the water and the detergent to form a cleaning solution, and an applicator for application of the cleaning solution onto the belt. In some embodiments, the applicator is a spray nozzle. The application of the cleaning solution onto the belt is controlled by a control system, which comprises a microprocessor adapted to provide a signal to open the applicator to provide rinse or cleaning solution onto the belt. The lubrication system is for lubricating the conveyor belt to improve belt tracking and to extend the useable life of the belt. The lubrication system includes a lubricant source and an applicator for application of the lubricant onto the belt. In some embodiments, the applicator is a spray nozzle. The application of the lubricant onto the belt is controlled by a lubricant control system that includes a first sensing system to sense movement of the belt, a second sensing system to sense presence of items on the belt, and a control system comprising a microprocessor that receives signals from the sensing systems and sends signals to open the applicator to provide lubricant onto the belt on a predetermined, timed basis. 
     The amount of lubricant applied to the belt is dependent on the signals from the first and second sensing systems. In particular, if the first sensing system confirms movement of the belt and the second sensing system confirms an object, the microprocessor provides a signal to provide lubricant so that a first amount of lubricant is fed from the lubricant source and is applied onto the conveyor. If the first sensing system confirms movement of the belt but the second sensing system does not confirm the presence of an object, the microprocessor provides a signal to provide lubricant so that a second amount of lubricant is fed from the lubricant source and is applied to the conveyor, the second amount of lubricant being less than the first amount. If the first sensing system does not confirm movement, whether or not items are present on the belt, the microprocessor does not provide a signal to apply lubricant. 
     In a further aspect of the invention, the washing system comprises a microprocessor to provide a signal to apply a rinse or cleaning solution to the conveyor belt for a predetermined time interval. Typically, this washing process occurs after any production run on the conveyor system is complete. The washing process generally includes a first rinse step, a cleaning step, and a second rinse step. 
     The invention will be further described in relation to the included drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic perspective view showing an apparatus of this invention, including a conveyor system; 
     FIG. 2 is a simplified schematic diagram in top view of a conveyor system having multiple zones; and 
     FIG. 3 is a block diagram illustrating the logic used by the apparatus of this invention to provide the method for the lubrication and cleaning of the conveyor system. 
    
    
     DETAILED DESCRIPTION 
     The invention relates to a new and improved apparatus and method for cleaning and lubricating conveyors using a microprocessor controlled control system. The control system senses the activity of the conveyor and the presence of items on the conveyor, and in return either cleans or lubricates the conveyor as needed. If the control system only senses movement of the conveyor but no item on the conveyor, only a small amount of lubricant is applied to the conveyor sufficient to keep the conveyor belt properly lubricated. 
     Referring now to the Figures, wherein like elements are represented by like numerals throughout the various views, FIG. 1 shows a general arrangement of a conveyor maintenance system  100  that has a lubrication system  200  and a washing system  300 . The apparatus  100  is used for lubricating and washing a conveyor system  110 , although not necessarily simultaneously. 
     Conveyor system  110  includes a conveyor belt  120  having a front side  122  and a back side  124 , and a structure  115  to support belt  120 . Front side  122  of belt  120  is the side on which items, such as bottles or cans  50 , are carried. Back side  124  is the inner side when belt  120  is formed as a loop (as shown in FIG.  1 ), and back side  124  typically contacts a drive mechanism (not shown). Conveyor systems, such as those designated as conveyor system  110 , are well known. 
     Washing system  300  has a water source  302 , a detergent source  310 , and a device in which the water and the detergent are mixed. In FIG. 1, such a mixing device is shown as mixing chamber  320 . Water source  302  is typically a potable water source and is generally supplied at about 5 to 20 gallons per minute at a pressure of about 60 to 125 psi, although other volumetric rates and pressures could be used. Detergent source  310  can be a drum  312 , such as a 55 gallon drum, or a larger storage tank. The detergent may be any solution, mixture, component or the like used for cleaning, disinfecting, degreasing, etc. A low level alarm  316  may be used within detergent source  310  to warn of low detergent supply. A controller  305  is used to control valves  304 ,  314  which allow feed from water source  302  and detergent source  310 , respectively, to flow to mixing chamber  320 . Once the water and detergent are mixed in a mixing device, for example, mixing chamber  320 , the cleaning mixture or solution is applied to the conveyor belt. In FIG. 1, the solution is supplied via delivery pipe  330  to a detergent applicator, shown as spray nozzle  350  (shown in phantom in FIG.  1 ). Spray nozzle  350  applies cleaning solution to back side  124  of conveyor belt  120 . Optionally, the cleaning solution could be applied to front side  122  of conveyor belt  120  or other areas of conveyor system  110 , such as structure  115 . 
     In some steps during the washing procedure, it may be desired to provide a water-only rinse of the conveyor system  110 ; that is, no detergent is used. The process of waterwashing is considered to comprise rinsing. Rinsing is performed in the same manner as washing, except that typically no detergent is added to provide the solution. There may, however, be additives provide to the water source to produce a rinse solution. Often, a three-step process is used: a first rinse step, a washing or cleaning step, and a second rinse step. 
     The washing process, which includes the steps of applying rinse and/or cleaning solution, may be applied to conveyor belt  120  at predetermined intervals, for example, a one to three minute rinse after every hour of operation. Rinse and/or cleaning solution may also, or alternately, be applied at the end of the production run that uses conveyor system  110 , for example, at the end of the work day or shift. The conveyor belt  120  may continue to run (i.e., move) during the cleaning operation or may be stopped. 
     Generally, no sensors are needed in washing system  300  if it is desired to rinse and/or washing conveyor belt  120  after its use. The washing may be activated by, for example, a manual switch after the production run has been completed. 
     Lubrication system  200  has a lubricant source  210  and a lubricant applicator, such as spray nozzle  250 , to apply lubricant to front side  122  of conveyor belt  120 . Optionally, the lubricant could be applied to back side  124  of conveyor belt  120 . In accordance with the present invention, the amount of lubricant applied to belt  120  is dependent on both the movement of conveyor belt  120  and the presence of items, such as cans  50 , on belt  120 . If belt  120  is in motion and items are present on the belt, a first amount of lubricant is applied to front side  122  of belt  120 . If belt  120  is in motion and no items are present, a second amount of lubricant is applied, with the second amount of lubricant being less that the first amount. If no movement of belt  120  is sensed, whether or not any items are present on belt  120 , no lubricant is applied. This series of inquiries and resulting actions is illustrated in FIG. 3, which is a block diagram of the logic used to determine the application of the lubricant. 
     Movement of belt  120  is sensed by a sensor  220 , which in FIG. 1 is positioned to monitor back side  124  of belt  120 . Presence of items, such as cans  50 , is sensed by sensor  225 . FIG. 1 shows two sensors  225 ,  225 ′ on opposites sides of belt  120  and mounted on structure  115 . Although only one sensor  225  for monitoring the belt and two sensors  225 ,  225 ′ for monitoring presence of items are shown, any number of sensors can be used. Sensors  220 ,  225 ,  225 ′ may be any sensors capable of sensing movement and/or presence of items; usable sensors include well known devices such as motion or vibration detectors, or laser, IR or other sensors. In another embodiment, the sensor may be directly wired or otherwise connected to the conveyor system&#39;s motor. 
     Sensors  220 ,  225 ,  225 ′ are connected to a control system  205  which includes a microprocessor (not shown) therein. Signals from sensors  220 ,  225 ,  225 ′ are processed by the microprocessor, which then sends a signal to valve  204  which controls supply of lubricant from source  210  to nozzle  250 . 
     The microprocessor usable in the control system  205  of the present invention may be a programmable general purpose microprocessor, also known as a “PLC” or a programmable logic controller. ‘Ladder logic’ is typically the format used when programming this microprocessor. The microprocessor is incorporated into the control system  205  and may be attached to equipment such as a monitor, touch screen, keyboard, or a mouse. The microprocessor is then also connected to the sensors and valves. 
     If sensor  220  provides a negative signal to control system  205  indicating that belt  120  is not moving, control system  205  provides a signal to close valve  204  so that no lubricant is applied to belt  120 . If sensor  220  provides a positive signal indicating that belt  120  is in motion, and sensor  225  provides a positive signal indicating that items such as cans  50  are present on belt  120 , control system  205  provides a signal to open valve  204  so that a first amount of lubricant flows to nozzle  250  and is applied to belt  120 . If sensor  220  provides a positive signal indicating that belt  120  is moving, but sensor  225  provides a negative signal indicating that no items are present on belt  120 , control system  205  provides a signal to open valve  204  partially so that a second amount of lubricant flows to nozzle  250  and is applied to belt  120 . The second amount of lubricant allowed through valve  204  and applied by nozzle  250  is less that the first amount, because no lubrication is need between items and the belt if no items are present. The lubrication desired, when no items are present, is a minimal amount, simply to reduce friction and maintain flexibility of the belt. 
     Lubricant source  210  can be any container such as a drum, a large storage tank, or can be supplied by a delivery pipe from a remote location. Valve  204  is preferably a pneumatic (air actuated) valve and is controlled by signals from control system  205 . An air injection tee  214  may be included in lubricant system  200  to provide a stream of air to be mixed with the lubricant before it is applied to belt  120 . 
     Referring now to FIG. 2, a conveyor system  500  is typically divided into multiple zones, generally at least two zones, often more than two zones. FIG. 2 shows conveyor system  500  with four zones. A “zone” is a region or length of conveyor and each zone typically has its own conveyor belt, support framework, conveyor track, and drive mechanism for the conveyor belt. Often, a zone may have multiple conveyor belts that may or may not have their own drive mechanism. 
     FIG. 2 is a top simplified schematic diagram of conveyor system  500  divided into four zones. Conveyor system  500  includes a filler station  520  where a container, such as a can or bottle, is filled. Conveyor belt  510  moves the container from one station, such as filler station  520 , to the next station. From filler  520 , the container progresses along conveyor belt  510  to seamer station  530  where the container is sealed, e.g., capped. From seamer  530 , the container progresses through a warmer station  540 . After warmer  540 , the container progresses to accumulation area  550 , where multiple containers are stored until they are ready to be sent to caser station  560 . At caser  560 , the containers are packaged for delivery and distribution, for example, cans may be packaged in plastic 6-pack rings, or in paperboard boxes for  12  and  24  packs. 
     Conveyor system  500  is divided into four zones I, II, III, and IV, which extend from seamer  530  to caser  560 . Zone I extends from after seamer  530  to warmer  540 , but could optionally start at filler  520 . Zone II extends from after warmer  540  to accumulation area  550 . After accumulation area  550 , conveyor system  500  is divided into two zones, III and IV, which extend to caser station  560 . In accordance with the present invention, each zone may include a system for controlling the lubricant and a system for controlling the rinse and cleaning solutions, the systems may, however, be shared with one or multiple additional zones. In a preferred embodiment, a single control system is capable of controlling all lubricant systems, without the need for an individual control system for each lubrication system. 
     It should be noted that although FIG. 2 is schematically drawn showing a single conveyor belt  510  extending the length of conveyor system  500 , conveyor belt  510  actually may include multiple belts. Typically, each bend or turn in the system requires a new belt. For example, conveyor belt  510   a  extends from filler station  520  to seamer station  530 . From seamer  530 , two belts  510   b ,  510   c  extend to warmer  540 . Both belts  510   b ,  510   c  are within zone I. From warmer  540 , belts  510   d ,  510   e ,  510   f  and  510   g  in zone II extend to accumulation area  550 . Belt  510   h  in zone III and belt  5101  in zone IV extend to caser station  560 . Each belt  510   a ,  510   b , etc., may have its own drive mechanism (not shown), or multiple belts may share a drive mechanism. 
     A single control system with a microprocessor can be used to control all lubricant systems that apply lubricant to belts  510   a ,  510   b , etc. Similarly, a single control system with a microprocessor can be used to control all washing systems. 
     The above-captioned drawings, explanation and specification describe the elements of the conveyor system lubrication and washing system and its method of use. While a variety of embodiments can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.