Ink supply system for a jet ink printer

Claim 2

A recirculating ink supply system for a jet drop printer comprising: 1. an ink collection receptacle connected for collection of excess ink from said jet drop printing system, 2. a supply line connected for recirculating reception of collected ink from said ink collection receptacle, 3. means for supplying fresh ink to said supply line, 4. means for withdrawing the fluid content from said supply line at a controlled volume rate, 5. pressurizing means for pressurizing the fluid withdrawn as aforesaid from said supply line and delivering the pressurized fluid to said jet drop printer, and 6. means for mixing a depletion correcting replenishment fluid with the recirculated ink delivered as aforesaid to said jet drop printer.

Claim 3

Apparatus according to claim 1 further comprising means for sensing a depletion state of said recirculated ink and controlling said mixing means in response thereto.

Claim 4

a supply line connected for recirculating reception of collected ink from said ink collection receptacle,

Claim 5

a supply line connected for recirculating reception of collected ink from said ink collection receptacle,

Claim 6

input and output connections to said vessel,

Claim 7

input and output connections to said vessel,

Claim 8

a standpipe mounted within said vessel and connected for drainage to said supply line,

Claim 9

a standpipe mounted within said vessel and connected for drainage to said supply line,

Claim 10

Apparatus according to claim 2, said mixing means being connected to said supply line, and said sensing means being connected for sensing the depletion state of fluid at the output side of said withdrawing means.

Claim 11

means for supplying fresh ink to said supply line,

Claim 12

means for supplying fresh ink to said supply line,

Claim 13

means for withdrawing the fluid content from said supply line at a controlled volume rate,

Claim 14

means for withdrawing the fluid content from said supply line at a controlled volume rate,

Claim 15

Apparatus according to claim 2, said sensing means comprising a conductivity sensor.

Claim 16

a diaphragm for covering the entrance to said standpipe, and

Claim 17

a diaphragm for covering the entrance to said standpipe, and

Claim 18

means for urging said diaphragm against said standpipe whereby said input connection receives ink at the delivery rate of said withdrawing means, and said output connection delivers pressurized ink at a rate as required by said jet drop printer, with surplus ink exiting the ink pressurizing vessel via said standpipe.

Claim 19

means for urging said diaphragm against said standpipe whereby said input connection receives ink at the delivery rate of said withdrawing means, and said output connection delivers pressurized ink at a rate as required by said jet drop printer, with surplus ink exiting the ink pressurizing vessel via said standpipe.

Claim 20

Apparatus according to claim 1 further comprising means for controlling the flow of fresh iNk into said supply line in accordance with the back pressure created therein by said withdrawing means.

Claim 21

pressurizing means for pressurizing the fluid withdrawn as aforesaid from said supply line and delivering the pressurized fluid to said jet drop printer, and

Claim 22

pressurizing means for pressurizing the fluid withdrawn as aforesaid from said supply line and delivering the pressurized fluid to said jet drop printer, and

Claim 23

means for mixing a depletion correcting replenishment fluid with the recirculated ink delivered as aforesaid to said jet drop printer.

Claim 24

means for mixing a depletion correcting replenishment fluid with the recirculated ink delivered as aforesaid to said jet drop printer.

Claim 25

Apparatus according to claim 5 said fresh ink supply means comprising a fresh ink supply vessel and a feed line connecting said vessel with said supply line, and said means for controlling the flow of fresh ink comprising a check valve in said feed line.

Claim 26

Apparatus according to claim 6, said mixing means comprising a replenishment fluid supply vessel connected to said feed line and a mixture control valve for selectively admitting fresh ink or replenishment fluid into said feed line.

Claim 27

Apparatus according to claim 7, said pressurizing means having an overflow line connected to said supply line.

Claim 28

Apparatus according to claim 8 further comprising a check valve between said ink collection receptacle and said supply line, the cracking pressure for said valve being less than the cracking pressure for the check valve in said feed line whereby said withdrawing means selectively withdraws from said supply line; first the overflow ink from said pressurizing means, next the ink from said collection receptacle, and lastly fresh ink or replenishment fluid depending upon the position of said mixture control valve.

Claim 29

Apparatus according to claim 9 further comprising a conductivity sensor for sensing the conductivity of the fluid withdrawn from said supply line and a solenoid for receiving a sensing signal from said sensor and positioning said mixture control valve in response thereto.

Claim 30

Apparatus according to claim 1 said pressurizing means comprising:

Claim 31

Apparatus according to claim 11 said means for urging said diaphragm against said standpipe comprising a gas chamber and means for delivering a pressurized gas thereto.

Claim 32

Apparatus according to claim 12 wherein the pressurized fluid flowing from said pressurizing means to said jet drop printer passes through a surge tank comprising a surge cell for pooling said pressurized fluid under an entrapped pocket of air and input and output connections thereto.

Claim 33

In a system for marking with individual drops of ink, including a supply reservoir of aqueous base marking ink containing normally solid dissolved materials, the liquid portions of such ink being volatizable in use whereupon the proportion of solids to liquids changes sufficiently to cause a material change in the flow characteristics of the ink, a drop generator arranged to receive liquid from said reservoir and to project a stream of discrete drops along one trajectory, means for deflecting selected individual drops into anther trajectory, catcher means arranged to intercept drops following one of the trajectories and permitting drops following the other trajectory to proceed toward a receiving surface; and a return connection from said catcher means to said reservoir; the improvement comprising means sensing the relation of volatizable to nonvolatizable portions of the liquid in the system, means controlled by said sensing means for replenishing volatizable components of the marking liquid which are lost in the liquid system, means for combining the replenished marking liquid with fresh marking ink, means for circulating the combined fluid toward said drop generator at a controlled volume rate, and means for returning to said circulating means a portion of said combined fluid in variable amount as Required to maintain a regulated pressure in the fluid received by said drop generator.

Claim 34

In a system for marking with individual drops of ink, including a supply reservoir of aqueous base marking ink containing normally solid dissolved materials, the liquid portions of such ink being volatizable in use whereupon the proportion of solids to liquids changes sufficiently to cause a material change in the flow characteristics of the ink, a drop generator arranged to receive liquid from said reservoir and to project a stream of discrete drops along one trajectory, means for deflecting selected individual drops into anther trajectory, catcher means arranged to intercept drops following one of the trajectories and permitting drops following the other trajectory to proceed toward a receiving surface; and a return connection from said catcher means to said reservoir; the improvement comprising means sensing the relation of volatizable to nonvolatizable portions of the liquid in the system, means controlled by said sensing means for replenishing volatizable components of the marking liquid which are lost in the liquid system, means for combining the replenished marking liquid with fresh marking ink, means for circulating the combined fluid toward said drop generator at a controlled volume rate, and means for returning to said circulating means a portion of said combined fluid in variable amount as Required to maintain a regulated pressure in the fluid received by said drop generator.

Claim 35

A system as defined in claim 14 including a filter in said return connection to remove contaminants entering the open part of the liquid system between the drop generator and the catcher means.

Claim 36

A system as defined in claim 14 wherein said sensing means includes a conductivity sensor.