# US 11,298,879 B2 · Methods and devices for automatically clearing a print head of a three-dimensional printing device

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- Number: US 11,298,879 B2
- Document ID: US11298879B2
- Status: Granted
- Kind: B2
- Application number: 16/546,545
- Filed: 2019-08-21
- Published: 2020-02-27
- Granted: 2022-04-12
- Earliest claimed: 2019-07-27
- Applicants: Krzysztof Wilk; Przemyslaw Wolnicki; Filip Turzyński; Szymon Kostrzewa
- Inventors: Krzysztof Wilk; Przemyslaw Wolnicki; Filip Turzyński; Szymon Kostrzewa
- Web page: https://patentgrep.com/patent/US11298879B2

## CPC

- B29C 64/35: Cleaning
- B29C 64/209: Heads; Nozzles
- B29C 64/227: Driving means
- B29C 64/393: for controlling or regulating additive manufacturing processes
- B29C 64/118: using filamentary material being melted, e.g. fused deposition modelling [FDM]
- B29C 64/321: Feeding
- B33Y 30/00: Apparatus for additive manufacturing; Details thereof or accessories therefor
- B33Y 40/00: Auxiliary operations or equipment, e.g. for material handling
- B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00)
- B33Y: ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING

## Abstract

Methods and devices for automatically cleaning a print head within a three-dimensional (3D) printer are disclosed. The methods generally include operating a measurement system (of a 3D printer) to measure an amount of material delivered to a print head of the 3D printer (on a per unit of time basis); detecting a disturbance in the material being delivered to the print head; and retracting the material and then re-introducing the material to the print head. The methods include having a first drive system and a second drive system being used to retract the material and, once the print head is cleaned, to re-introduce the material to the print head with increasing speed from zero to a pre-defined end point speed.

## Claims

### Claim 1

A three-dimensional (3D) printer that is configured to automatically execute a method that cleans a print head of the printer, wherein the printer comprises:
(a) a measurement system that is configured to (i) measure an amount of printing material delivered to the print head by a propulsion system of the printer, on a per unit of time basis, and (ii) detect a disturbance in the printing material being delivered to the print head; and
(b) a first drive system and a second drive system that are configured to retract the printing material, upon the measurement system detecting the disturbance in the printing material, and then re-introduce the printing material to the print head with increasing speed from zero to a pre-defined end point speed, wherein:
(i) the measurement system is configured to be deactivated prior to the re-introducing the printing material to the print head; and
(ii) the measurement system is configured to be activated after the printing material reaches a speed that is 1% to 40% of the pre-defined end point speed, whereupon the first drive system and the second drive system are configured to gradually increase the speed at which the printing material is delivered to the print head until the speed reaches 100% of the pre-defined end point speed.

### Claim 2 (depends on 1)

The three-dimensional (3D) printer of claim 1, wherein the measurement system is configured to be deactivated immediately upon detecting the disturbance in the printing material being delivered to the print head.