Granted Patent B2

US 8,500,345 · App. 12/650,057 · Granted Aug 6, 2013

Abstract

Claims (42)

1. A method of aligning a printer in an item handling system, comprising a transport system defining a transport plane, a printer assembly defining a printer plane, and a printer alignment system supporting the printer assembly, wherein the printer alignment system comprises a plurality of drive elements configured to move the printer assembly, the method comprising:

moving the printer assembly to a limit position of the printer alignment system distal from the transport system using the drive elements by performing the following substeps;

driving each drive element at a first level to move the inter assembly away from the transport system to a travel limit stop on the printer alignment system;

driving each drive element at a second level higher than the first level to apply a predetermined force on the travel limit stop; and

driving each drive element at a third level lower than the second level to maintain the printer assembly at the travel limit stop;

moving the printer assembly to a limit position of the printer alignment system proximate to the transport system using the drive elements by performing the following substeps:

driving each drive element at a fourth level to move the printer assembly towards the transport system so that a portion of the printer assembly engages a portion of the transport system;

driving each drive element at a fifth level higher than the fourth level so that the drive element applies a predetermined force on the portion of the transport system; and

terminating a drive signal to the drive element; and

driving each of the drive elements at a respective predetermined level to place the printer plane in a substantially parallel orientation with respect to the transport plane.

2. The method of claim 1 , further comprising:

detecting a position of a portion of the printer assembly associated with each drive element; and

storing the positions as reference values in a processing device.

3. The method of claim 2 , further comprising controlling the drive elements with a substantially identical signal to position the printer assembly at a desired distance from the transport system.

4. The method of claim 3 , wherein the desired distance is based on a thickness of an item being transported by the transport system.

5. The method of claim 1 , wherein driving each of the drive elements at a respective predetermined level applies a substantially uniform pressure between the portion of the printer assembly and the portion of the transport system.

6. The method of claim 1 , wherein the respective predetermined level is based on at least one of a weight of the printer assembly and a location of a center of gravity of the printer assembly.

7. The method of claim 1 , wherein the transport system comprises:

a base; and

a transport element disposed on the base configured to transport items along a transport path, the transport element having a first surface adjacent to the base and a second surface opposite to the base, and

wherein the second surface of the transport element defines the transport plane.

8. The method of claim 1 , wherein the printer assembly comprises a crash plate having a first surface facing a printer element and a second surface facing the transport system, and wherein the second surface of the crash plate defines the printer plane.

9. An item handling system, comprising:

a transport system defining a transport plane;

a printer assembly defining a printer plane;

a printer alignment system supporting the printer assembly, wherein the printer alignment system comprises a plurality of drive elements configured to move the printer assembly; and

a controller configured to:

control the drive elements to move the printer assembly to a limit position of the printer alignment system distal from the transport system by driving each drive element at a first level to move the printer assembly away from the transport system to a travel limit stop on the printer alignment system; driving each drive element at a second level higher than the first level to apply a predetermined force on the travel limit stop; and driving each drive element at a third level lower than the second level to maintain the printer assembly at the travel limit stop;

control the drive elements to move the printer assembly to a limit position of the printer alignment system proximate to the transport system by driving each drive element at a fourth level to move the printer assembly towards the transport system so that a portion of the printer assembly engages a portion of the transport system; driving each drive element at a fifth level higher than the fourth level so that the drive element applies a predetermined force on the portion of the transport system; and terminating a drive signal to the drive element; and

drive each of the drive elements at a respective predetermined level to place the printer plane in a substantially parallel orientation with respect to the transport plane.

10. The system of claim 9 , further comprising a processing device operatively connected to the controller, wherein the controller is further configured to:

detect a position of a portion of the printer assembly associated with each drive element; and

store the positions as reference values in the processing device.

11. The system of claim 10 , wherein the controller is further configured to control the drive elements with a substantially identical signal to position the printer assembly at a desired distance from the transport system.

12. The system of claim 11 , wherein the desired distance is based on a thickness of an item being transported by the transport system.

13. The system of claim 9 , wherein the controller is configured to drive each of the drive elements at a respective predetermined level by applying a substantially uniform pressure between the portion of the printer assembly and the portion of the transport system.

14. The system of claim 9 , wherein the respective predetermined level is based on at least one of a weight of the printer assembly and a location of a center of gravity of the printer assembly.

15. The system of claim 9 , wherein the transport system comprises:

a base; and

a transport element disposed on the base configured to transport items along a transport path, the transport element having a first surface adjacent to the base and a second surface opposite to the base, and

wherein the second surface of the transport element defines the transport plane.

16. The system of claim 9 , wherein the printer assembly comprises a crash plate having a first surface facing a printer element and a second surface facing the transport system, and wherein the second surface of the crash plate defines the printer plane.

Assignments (8)