Patent Publication Number: US-2023135154-A1

Title: Empty conveyor speed limiter

Description:
TECHNICAL FIELD 
     The present disclosure generally relates to a milling machine. More particularly, the present disclosure relates to a conveyor system of a cold planer. 
     BACKGROUND 
     Cold planers are powered machines used to remove at least part of a surface of a paved area such as a road, bridge, or parking lot. Typically, cold planers include a frame, a power source, a milling assembly positioned below the frame, and a conveyor system. The milling assembly includes a cutting rotor having numerous cutting bits disposed thereon. As power from the power source is transferred to the milling assembly, this power is further transferred to the cutting rotor, thereby rotating the cutting rotor about its axis. As the rotor rotates, its cutting bits engage the hardened asphalt, concrete, or other materials of an existing surface of a paved area, thereby removing layers of these existing structures. The spinning action of the cutting bits transfers these removed layers to the conveyor system which transports the removed material from a primary conveyor to a secondary conveyor and then to a separate machine such as a haul truck for removal from a work site. 
     At times the secondary conveyor on a cold planer is left on while the machine is not milling or the secondary conveyor does not have material on it. This unnecessary running of the secondary conveyor can waste fuel and add wear and tear to the conveyor components. 
     U.S. Pat. No. 10,287,104 discusses a conveyor control system where the speed of the speed of the secondary conveyor can be independently adjustable based on operator input. 
     SUMMARY 
     In an example according to this disclosure, a cold planer can include a frame; a milling assembly including a drum housing and a cutting rotor located within the drum housing, the drum housing including a discharge port; a primary conveyor coupled to the frame, wherein the primary conveyor is positioned near the discharge port so as to receive material through the discharge port; a secondary conveyor positioned to receive material off an end of the primary conveyor; a sensor associated with the secondary conveyor to sense a load on the secondary conveyor; and a controller configured to receive information from the sensor regarding the load and to control a speed of the secondary conveyor based on the information. 
     In one example, a system for controlling a speed of a secondary conveyor of a cold planer can include a sensor associated with the secondary conveyor to sense a load of a material on the secondary conveyor; and a controller configured to receive information from the sensor regarding the load and to control a speed of the secondary conveyor based on the information. 
     In one example, a method of controlling a secondary conveyor of a cold. planer can include providing a sensor on the secondary conveyor to sense a load of a material on the secondary conveyor; the sensor sending information regarding the load to a controller; and the controller controlling a speed of the secondary conveyor based on the information. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings, which are not necessarily drawn to scale, like numerals may describe similar components in different views. Like numerals having different letter suffixes may represent different instances of similar components. The drawings illustrate generally, by way of example, but not by way of limitation, various embodiments discussed in the present document. 
         FIG.  1    shows a side view of a cold planer, in accordance with one embodiment. 
         FIG.  2    shows a schematic of a control system for a cold planer, in accordance with one embodiment. 
         FIG.  3    shows a method of controlling a secondary conveyor, in accordance with one embodiment. 
     
    
    
     DETAILED DESCRIPTION 
       FIG.  1    shows a side view of a cold planer  10 , in accordance with one embodiment. The cold planer  10  includes a frame  12 , and a power source  14  connected to the frame  12 . The power source  14  may be provided in any number of different forms including, but not limited to, Otto and Diesel cycle internal combustion engines, electric motors, hybrid engines and the like. 
     The frame  12  is supported by transportation devices  16  via lifting columns  18 . The transportation devices  16  may be any kind of ground-engaging device that allows to move the cold planer  10  in a forward direction over a ground surface, for example a paved road or a ground already processed by the cold planer  10 . For example, in the shown embodiment, the transportation devices  16  are configured as track assemblies. The lifting columns  18  are configured to raise and lower the frame  12  relative to the transportation devices and the ground. 
     The cold planer  10  further includes a milling assembly  20  connected to the frame  12 . The milling assembly  20  includes a drum housing  28  holding a rotatable cutting rotor  22  operatively connected to the power source  14 . The cutting rotor  22  can be rotated about a drum or housing axis extending in a direction perpendicular to the frame axis. As the rotatable cutting rotor  2 . 2  spins about its drum axis, cutting bits on the cutting rotor  22  can engage hardened materials, such as, for example, asphalt and concrete, of existing roadways, bridges, parking lots and the like. As the cutting bits engage such hardened. materials, the cutting bits remove layers of these hardened materials. The spinning action of the cutting rotor  22  and its cutting bits then transfers the hardened materials to a primary conveyor  26  via a discharge port  32  on the drum housing  28 . 
     The primary conveyor  26  can be coupled to the frame  12  and located at or near the discharge port  32 . The primary conveyor  26  is driven at an operating speed as set by the operator, for example. In some embodiments, the speed of the primary conveyor  26  can be automatically controlled by a controller  48 . The primary conveyor  26  transfers the material up to a secondary conveyor  34  positioned to receive material off an end of the primary conveyor  26 . The secondary conveyor then transfers the material to a dump truck positioned to receive the material off of the end of the secondary conveyor  34 . 
     The cold planer  10  further includes an operator station or platform  30  including an operator interface for inputting commands to a control system for controlling the cold planer  10 , and for outputting information related to an operation of the cold planer  10 . A controller  48  can be provided for electrically controlling various aspects of the cold planer  10 . For example, the controller  48  can send and receive signals from various components of the cold planer  10  during the operation of the cold planer. 
     As noted above, at times the secondary conveyor  34  on a cold planer is left on while the machine is not milling or the secondary conveyor  34  does not have material on it. During this time the cold planer machine could be saving fuel and extending conveyor component life by running the secondary conveyor  34  at lower speeds. 
     The present system utilizes a conveyor material load system that senses weight or volume of material on the secondary conveyor  34 . Using this material load information, the controller  48  can determine if the secondary conveyor  34  is loaded or not and can reduce secondary conveyor speed during unloaded times to save on fuel/life etc. 
     For example, the cold planer  10  can include a sensor  40  associated with the secondary conveyor  34  to sense a load on the secondary conveyor  34 . The controller  48  can be configured to receive information from the sensor  40  regarding the load of a material  68  on the second conveyor  34  and to control a speed of the secondary conveyor  34  based on the information. For example, if the sensor  40  detects no load then the controller can be configured. to slow down or stop the secondary conveyor  34 . This saves operational costs and wear and tear on the secondary conveyor  34 . 
     In one example, the secondary conveyor  34  can be controlled independently relative to the primary conveyor  26 . Accordingly, the primary conveyor  26  continues to operate normally, at a normal operating speed, when the secondary conveyor  34  slows down (or stops). Thus, if the cutting rotor  22 . begins cutting again and delivers fresh material  68  to the primary conveyor  26 , the primary conveyor  26  will deliver the material  68  to the secondary conveyor  34 . The sensor  40  can sense the increased load on the secondary conveyor  34  and the controller  48  can determine that the load has increased and thus, increase the speed of the secondary conveyor  34  up to the normal operating speed. 
     In one embodiment, the sensor  40  can sense a material weight on the secondary conveyor  34 . For example, the sensor  40  can include a strain gauge or a load cell sensor to determine the amount of material weight on the secondary conveyor  34 . When the sensor weight information is delivered to the controller  48 , the controller  48  can determine from the material weight whether the secondary conveyor  34  is loaded or not. 
     In one example, the sensor  40  can include a material volume sensor. For example, the sensor  40  can include a smart camera, or radar, or lidar sensors positioned to sense the presence of the material  68  on the secondary conveyor  34 . This information is delivered to the controller  48  which is configured to control the speed of the secondary conveyor based on the information. In another embodiment, the sensor  40  can include a light beam sensor that can be directed across a surface of the secondary conveyor  34  to determine the presence of the material  68  on the secondary conveyor  34 . 
     In one embodiment, the sensor  40  can include a strain gauge that can be coupled to one or more pulleys  42  or other structures of the secondary conveyor  34  to determine a load on the secondary conveyor  34 . For example, if the pulleys  42  have a high strain on them, the controller  48  can determine that the secondary conveyor  34  is loaded, and if there is a relatively light strain then the controller  48  can determine that the secondary conveyor  34  is unloaded. 
     As noted, after the secondary conveyor  34  has been slowed down, the primary conveyor  26  remains at its normal operating speed and begins to deliver the material  68  to the secondary conveyor  34  after the cutting rotor begins cutting again, the controller  48  determines that there is a material load on the secondary conveyor  34  and speeds up the secondary conveyor  34 . Thus, when the cutting rotor  22  begins turning and cutting again, the cutting rotor  22  will feed the material  68  to the primary conveyor  26  which will then deliver the material  68  onto the secondary conveyor  34 . The sensor  40  will pick up the increased load and the controller  48  can determine that a material load is on the secondary conveyor and speed the secondary conveyor  34  up to the proper operating speed. 
     Referring now also to  FIG.  2   , which shows a schematic of a control system for a cold planer in accordance with one embodiment. The control system generally includes the sensor  40  associated with the secondary conveyor  34  to sense a load of a material on the secondary conveyor  34 , and the controller  48  configured to receive information from the sensor  40  regarding the load and to control a speed of the secondary conveyor  34  based on the information by sending speed control instructions to secondary conveyor speed mechanism  50 . The secondary conveyor speed mechanism  50  can be any components on the cold planer  10  used for operating the speed of the secondary conveyor  34 , such as hydraulics, gears, belts, and other drive components. 
     In utilizing the present system, the secondary conveyor  34  slows down or stops when the controller  48  determines there is no load on the secondary conveyor  34 . The secondary conveyor  34  can be controlled independently relative to the primary conveyor  26  of the cold planer,  10  so that the primary conveyor  26  continues to operate at a normal operating speed when the secondary conveyor  34  slows down. Then, if the primary conveyor  26  begins to deliver material to the secondary conveyor  34  again, the controller  48  can determine that there is a material load on the secondary conveyor  34  and speed up the secondary conveyor  34 . 
     INDUSTRIAL APPLICABILITY 
     The present system is applicable to a conveyor system for a cold planer. In these applications unnecessary running of the secondary conveyor can waste fuel and add wear and tear to the conveyor components. 
       FIG.  3    shows a method ( 70 ) of controlling a secondary conveyor, in accordance with one embodiment. The method ( 70 ) can include providing a sensor on the secondary conveyor ( 72 ) to sense a load of a material on the secondary conveyor; the sensor sending information ( 74 ) regarding the load to a controller; and the controller controlling a speed ( 76 ) of the secondary conveyor based on the information. 
     As discussed above, the secondary conveyor can be slowed down or stopped when the controller determines there is no load, as determined by material weight or volume, on the secondary conveyor while the primly conveyor will continue to operate at a normal operating speed (as set by the machine operator) when the secondary controller slows down. When the primary conveyor begins to deliver a material to the secondary conveyor again, the controller determines that there is a material load on the secondary conveyor and speeds up the secondary conveyor. 
     Overall, the present system concerns an empty conveyor speed limiter. According to the system, a conveyor material load sensor can sense weight or volume of material on the secondary conveyor. Using the sensed information, the controller can determine if the belt is loaded or not and can reduce secondary conveyor speed during unloaded times to save on fuel/life and extending conveyor component life. The primary conveyor can remain at the speed set by the operator. In the case of the machine starting in a cut again the primary conveyor would still load the secondary conveyor at the same pace as usual, which would then trigger the secondary conveyor to run after the sensor and controller determines weight or volume present on the second conveyor. 
     Various examples are illustrated in the figures and foregoing description. One or more features from one or more of these examples may be combined to form other examples. 
     The above detailed description is intended to be illustrative, and not restrictive. The scope of the disclosure should, therefore, be determined with references to the appended claims, along with the full scope of equivalents to which such claims are entitled.