Abstract:
A material transfer system including a first vehicle and a second vehicle. The first vehicle has a pressurized compartment maintaining a first air pressure therein. The ambient air outside of the pressurized compartment is at a second air pressure, with the first air pressure being different than the second air pressure thereby defining a pressure differential. The second vehicle has a material discharge device. The material discharge device is capable of delivering material to the first vehicle. The second vehicle having a reservoir for receiving the material. The material passing from the reservoir into the pressurized compartment without substantial loss of the pressure differential.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a material transfer system, and, more particularly, to a material transfer system that maintains pressure in a pressurized compartment. 
     BACKGROUND OF THE INVENTION 
     Some agricultural devices have pressurized compartments, such as an agricultural planter. A planter is an agricultural farm implement typically towed behind a tractor that is used for planting crops in a field. The planter, air seeder or a grain drill lay the seed down in a predetermined precise manner along a series of parallel rows. The seeds that are planted are distributed through numerous row units that are generally spaced evenly along a portion of the planter. Planters vary greatly in size, from 2 rows even up through the 48-row John Deere DB120. 
     Historically, on smaller and older planters, a marker stick extends from the side of the planter to half the width of the planter. The marker stick has some element that drags in the soil causing a line to be drawn in the field so that the operator of the tractor knows hoe to position the tractor for the return trip across the field. On larger modern planters, a GPS navigation system as well as autopilot type steering is used to guide the planter across the field to maintain proper row spacing. 
     Older planters typically had a seed bin for each row, with each seed bin generally would have plates with a predetermined number of teeth with predetermined spacing depending on the type of seed to be sown and the desired spacing of the seeds in the soil. Modern planters generally have one or more large seed tanks with the seeds being distributed to each row unit. The row units perform the final task of seed metering and placement. The seed delivery process may rely on a hydraulically-driven fan to move the seed from the seed tanks to the row units. A flow control valve and gauge allows for the proper tank pressure setting based on seed type. Air from the fan pressurizes the seed tanks and delivers seed to the seed hoppers. Airflow enters the seed tanks through a nozzle in the manifold, which pressurizes the tank. The air then picks up seed and moves it out the other end of the nozzle into seed delivery hoses. These hoses route the seed toward the hopper. A small amount of seed is traveling in the delivery hoses only when needed. The hopper fills with seed until the delivery hose is covered. Once the opening is restricted, seed flow through the hose stops. Air flowing to the row unit travels into the hopper and out through a vent. As the seed is picked up by the meter and planted, the seed pool shrinks until the end of the delivery hose is uncovered. At that time, the airflow and seed delivery resume and the seed pool in the hopper is replenished. 
     It is important to maintain air pressure in the seed tank while planting is underway in order to maintain consistent planting. If the fill lid of the planter is opened the air pressure is lost and with it the ability to transfer the seeds therefrom. 
     What is needed in the art is a method and apparatus to transfer material in the form of seeds into a pressurized compartment while the machine is functioning without the loss of pressurized air in the compartment in an efficient economical manner. 
     SUMMARY 
     The invention in one form is directed to a material transfer system including a first vehicle and a second vehicle. The first vehicle has a pressurized compartment maintaining a first air pressure therein. The ambient air outside of the pressurized compartment is at a second air pressure, with the first air pressure being different than the second air pressure thereby defining a pressure differential. The second vehicle has a material discharge device. The material discharge device is capable of delivering material to the first vehicle. The second vehicle having a reservoir for receiving the material. The material passing from the reservoir into the pressurized compartment without substantial loss of the pressure differential. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a schematical top view of a two vehicle system utilizing an embodiment of a material transfer system of the present invention; 
         FIG. 2  is a schematical rear view of the material transfer system of  FIG. 1 ; and 
         FIG. 3  is a block diagram outlining the steps carried out by a method using the material transfer system of  FIGS. 1 and 2 . 
     
    
    
     Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates one embodiment of the invention and such exemplifications are not to be construed as limiting the scope of the invention in any manner. 
     DETAILED DESCRIPTION 
     Referring now to the drawings, and more particularly to  FIG. 1 , there is illustrated a material transfer system  10  that includes vehicle systems  12  and  14 . Vehicle system  12  includes a tractor  16  and a towed material source  18  towed thereby. Vehicle system  14  includes a tractor  20  and a towed material receiving device  22  towed thereby. Although vehicle systems  12  and  14  are depicted as tractors and wagons, these are general depictions and are generally representative of agricultural, construction, industrial and foresting equipment, for example, towed material receiving device  22  may be an agricultural seed planter. 
     Now additionally referring to  FIG. 2 , there is shown another view of vehicle systems  12  and  14 . Granular material  24 , which may be seeds are transferred from vehicle system  12  to vehicle system  14 . Towed material source  18  includes a discharge device  26 , a meter  28 , a communicative controller  30 , an operator interface  32 , a spout aimer  34  and a spout outlet  36 . Communicative controller  30  and operator interface  32  may be associated with either towed material source  18  or tractor  16 . Towed material receiving device  22  includes a pressurized compartment  38 , a material level sensor  40 , a reservoir  42 , an airlock  44 , a reservoir level sensor  46 , and a communicative controller  48 . 
     Discharge device  26 , which may include an auger, moves granular material  24  from towed material source  18  to reservoir  42 . Granular material  24  moves by gravity while in a tank of towed material source  18  and the amount of granular material  24  that moves through meter  28  is measured thereby and sent to communicative controller  30 . Spout aimer  34  may autonomously aim spout outlet  36  or be in communication with communicative controller  30  for the control of spout outlet  36 . Additionally, information from spout aimer  34  is used by communicative controller  30  to position discharge device  26  and/or towed material source  18  relative to reservoir  42 . In a preferred embodiment, spout outlet  36  and reservoir  42  are not in physical contact with one another. 
     Towed material receiving device  22  may have additional functions, which are not shown, such as distribution elements that distribute granular material  24 . As granular material  24  accumulates in reservoir  42  reservoir level sensor  46  detects the level of granular material  24  therein and passes this information to communicative controller  48 , which in turn communicates this information to communicative controller  30  to alter the flow of granular material  24  from spout outlet  36 . The flow of granular material  24  is thereby controlled by this interaction between communicative controllers  30  and  48 . 
     An air pressure  50  is maintained in pressurized compartment  38  which is different from an ambient air pressure  52  that exists outside of pressurized container  38 . Airlock  44  is operated to move granular material  24  from reservoir  42  into pressurized compartment  38  without a significant loss of the pressure differential between pressures  50  and  52 . Airlock  44  opens an upper opening allowing some of granular material  24  to fall from reservoir  42  into an intermediate compartment  54  of airlock  44 . This upper opening then closes and a lower opening of airlock  44  opens allowing granular material  24  to fall into pressurized container  38 . Airlock  44  may continue to operate in this manner in a batch mode as the upper and lower openings are repeatedly opened in closed in such a way that they are never both open at the same time. One way of doing this it to have two sets of disks with hole in them such that the upper set is open as the lower set is closed and the sets of disks are then rotated so as to alternately be open at the top and then the bottom of airlock  44 . Another contemplated method is to have a small opening  56  with a mechanical device moving granulated material  24  rapidly through the small opening to thereby control the movement of air through the small opening. When the transfer of granular material  24  from reservoir  42  to pressurized compartment  38  is completed the small opening is closed. Other airlock methods are also contemplated. 
     Material level sensor  40  detects the level of granular material  24  in pressurized compartment  38  and passes this information to communicative controller  48 . Communicative controller  48  wirelessly communicates this information to communicative controller  30  so that the end of the operation of transferring granular material  24  is detected and communicated to operator interface  32 . If vehicle system  12  is autonomous, operator interface  32  may not be physically located on vehicle system  12 , and may exist as a controllable interface on a display unit. 
     Now additionally referring to  FIG. 3 , there is shown a method  100  with steps  102 - 110  for the transferring of a granular material  24  from one vehicle system  12  to another vehicle system  14  while bolt vehicle systems  12  and  14  are moving and while maintaining an air pressure differential as indicated at step  102 . At step  104  a metered amount of granular material  24  is moved from vehicle system  12  to reservoir  42 . Once sufficient granular material  24  is in reservoir  42 , then at step  106  granular material  24  is passed through airlock  44  into pressurized compartment  38  while substantially maintaining the air pressure differential between pressurized compartment  38  and the outside air. The material level is detected at step  108  by material level sensor  40 . If the material level is above a predetermined amount then method  100  is done. Otherwise if granular material  24  is not up to the predetermined level method  100  continues. 
     The flow of granular material  24  to reservoir  42  and through airlock  44  is conjunctively controlled by communicative controllers  30  and  48  based on information received from meter  28 , reservoir level sensor  46  and material level sensor  40 . Additionally, communicative controllers  30  and  48  may be used to coordinate the travel of vehicle system  12  so as to coordinate the positioning of spout outlet  36  relative to reservoir  42 , under the direction of an operator by way of operator interface  32 . If vehicle system  12  and/or vehicle system  14  are autonomous or semi-autonomous, coordination of travel of vehicle system  12  and/or vehicle system  14  may not require human involvement. 
     Advantageously, the present invention allows the filling of pressurized compartment  38  while the material receiving device  22  is performing its function, which may be the distribution of seeds or fertilizer or other granular material from the compartment without the loss of air pressure in pressurized compartment  38 . 
     While this invention has been described with respect to at least one embodiment, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.