Apparatus and Methods for Servicing 3D Printers

Abstract

The invention relates to apparatus and methods for producing three-dimensional objects and auxiliary systems used in conjunction with the aforementioned apparatus and methods. The apparatus and methods involve 3D printing and servicing of the equipment used in the associated 3D printer.

1 . A service station for maintaining a plurality of printheads in a three-dimensional printer, the service station comprising:
 a cleaning station;   a discharge station; and   a capping station.   
   
   
       2 . The service station of  claim 1 , wherein the cleaning station comprises:
 at least one receptacle for receiving a printhead;   at least one nozzle for spraying a cleaning fluid towards a printhead face of the printhead; and   a wiper disposable in close proximity to the printhead face for removing excess cleaning fluid.   
   
   
       3 . The service station of  claim 2 , wherein the cleaning station further comprises a splash guard for isolating the printhead face and preventing the cleaning fluid from migrating beyond the printhead face. 
   
   
       4 . The service station of  claim 3 , wherein the splash guard comprises an open position and a sealed position, where the splash guard is biased open and is actuated from the open position to the sealed position by contact with a printhead. 
   
   
       5 . The service station of  claim 4 , wherein the splash guard includes a sealing lip that circumscribes the printhead face when in the sealed position. 
   
   
       6 . The service station of  claim 5 , wherein the sealing lip is generally rectangular in shape. 
   
   
       7 . The service station of  claim 6 , wherein the wiper is formed by one side of the sealing lip. 
   
   
       8 . The service station of  claim 7 , wherein the wiper includes a notched portion configured and located to correspond to a location of a jet nozzle array on the printhead face to prevent the wiper from contacting the jet nozzle array. 
   
   
       9 . The service station of  claim 2 , wherein the wiper is capable of movement relative to a printhead. 
   
   
       10 . The service station of  claim 2 , further comprising a fluid source for providing the cleaning fluid to the at least one nozzle under pressure. 
   
   
       11 . The service station of  claim 2 , wherein the cleaning fluid is provided to the at least one nozzle via a manifold. 
   
   
       12 . The service station of  claim 2 , wherein the at least one nozzle comprises an array of nozzles. 
   
   
       13 . The service station of  claim 2 , wherein the at least one nozzle is positionable to spray the cleaning fluid across the printhead face. 
   
   
       14 . The service station of  claim 1 , wherein the printheads are disposable within a carriage capable of moving in at least two directions relative to the service station. 
   
   
       15 . The service station of  claim 1 , wherein the discharge station comprises a receptacle defining an opening that generally corresponds to a printhead face of a printhead. 
   
   
       16 . The service station of  claim 15 , wherein the receptacle defines a plurality of corresponding openings. 
   
   
       17 . The service station of  claim 15 , wherein the receptacle comprises a tray for at least one of capturing and directing discharged fluids. 
   
   
       18 . The service station of  claim 17 , wherein the discharge from the printheads is directed into a standing pool of waste liquid. 
   
   
       19 . The service station of  claim 1 , wherein the capping station comprises:
 a printhead cap carrier; and   at least one printhead cap disposed on the carrier for sealing a printhead face of a printhead, wherein the cap is moved between an off position and a capped position by the printhead contacting the carrier.   
   
   
       20 . The service station of  claim 19 , wherein the capping station comprises a plurality of caps disposed on the carrier. 
   
   
       21 . The service station of  claim 19 , wherein the carrier is biased to maintain the at least one cap in an off position. 
   
   
       22 . The service station of  claim 1 , wherein the discharge station and the capping station are combined. 
   
   
       23 . The service station of  claim 22 , wherein the discharge from the printheads is directed into a standing pool of waste liquid. 
   
   
       24 . The service station of  claim 23 , wherein the discharge from the printheads is constrained in a cavity defined by a printhead face, a printhead cap, and the standing pool of waste liquid. 
   
   
       25 - 47 . (canceled) 
   
   
       48 . A method of determining a condition of a printhead in use in a three-dimensional printer, the method comprising the steps of:
 acquiring a data value for at least one operational parameter of the printhead; and   comparing the data value to a threshold value, the relationship of the data value to the threshold value indicative of the condition of the printhead.   
   
   
       49 . The method of  claim 48  further comprising the step of initiating a service routine on the printhead if the data value exceeds the threshold value. 
   
   
       50 . The method of  claim 48 , wherein the operational parameter is selected from the group consisting of time elapsed, number of droplets dispensed by the printhead, number of layers printed, droplets dispensed over previously printed powder, droplets dispensed over previously unprinted powder, and combinations thereof. 
   
   
       51 . The method of  claim 48 , wherein the data value is compensated during acquisition to account for an operational environmental factor of the three-dimensional printer. 
   
   
       52 . The method of  claim 51 , wherein the operational environmental factor is selected from the group consisting of temperature, humidity, binder material, and build material. 
   
   
       53 . A method of determining a condition of a printhead in use in a three-dimensional printer, the method comprising the steps of:
 counting droplets dispensed by the printhead; and   determining a percentage of the droplets that were dispensed over previously unprinted pixels.   
   
   
       54 . The method of  claim 53  further comprising the step of initiating a service routine on the printhead if the percentage exceeds a threshold value.