Automatic coffee maker with inlet water control means in response to cold water and hot water levels

Claim 2

In brewing apparatus comprising, a cold water basin, an inlet water line for supplying cold water to said basin from a source under pressure, a valve in said inlet water line, means for opening said valve to cause cold water to flow into said basin, means for closing said valve when said cold water basin is filled to a predetermined shutoff level, a hot water tank under said basin, means for heating water in said tank, a cold water inlet from said tank to brew coffee extract, and means for closing said valve in the event that the water in said tank rises to a predetermined level therein, the improvement wherein said cold water inlet includes siphon means arranged to start when said shutoff level is reached by water supplied at or above a predetermined pressure and likely to start when water is supplied at a pressure below said predetermined pressure and said shutoff level is not reached whereby water continues to flow into said tank, said means for withdrawing hot water from said tank includes siphon means, and said means for closing said valve includes probe means adapted to be energized by water in said basin and water in said tank respectively.

Claim 3

Coffee brewing apparatus according to claim 1 wherein said probe means includes a vertical insulating sleeve extending from said basin into said tank, a conducting collar on said sleeve the elevation of which determines said shutoff level, and a conducting rod extending through said sleeve the elevation of the lower end of which determines said predetermined level in said tank.

Claim 4

Coffee brewing apparatus according to claim 1 wherein means close said valve when the level of the water in said basin reaches a level above said shutoff level to prevent overflow of said basin.

Claim 5

Coffee brewing apparatus according to claim 3 wherein said means for closing said valve when the level of the water in said basin reaches a level above said shutoff level includes normally closed contacts arranged to be opened by a float in said basin.

Claim 6

Coffee brewing apparatus comprising: a cold water basin, an inlet water line for supplying cold water to said basin from a source under pressure, a valve in said inlet water line, means for opening said valve to cause cold water to flow into said basin, means for closing said valve when said cold water basin is filled to a predetermined shutoff level, a hot water tank under said basin, means for heating water in said tank, cold water inlet siphon means connecting said basin and said tank, hot water siphon means for withdrawing hot water from said tank to brew coffee extract, said cold water inlet siphon means being characterized by not starting until the level of the water in said basin reaches a predetermined level as long as said pressure is above a predetermined value and being likely to start when said pressure is below said value whereby the cold water in said basin does not reach said shutoff level whereupon the level of the hot water in said tank rises above the siphon-out level of said hot water siphon means, and means for closing said valve in the event that the water in the tank rises to a predetermined level above said siphon-out level of said hot water siphon means.

Claim 7

Coffee brewing apparatus comprising: a cold water basin, an inlet water line for supplying cold water to said basin from a source under pressure, a valve in said inlet water line, means for opening said valve to cause cold water to flow into said basin, means for closing said valve when said cold water basin is filled to a predetermined shutoff level, a hot water tank under said basin, means for heating water in said tank, cold water inlet siphon means connecting said basin and said tank, hot water siphon means for withdrawing hot water from said tank to brew coffee extract, said cold water inlet siphon means being characterized by not starting until the level of the water in said basin reaches a predetermined level as long as said pressure is above a predetermined value and being likely to start when said pressure is below said value whereby the cold water in said basin does not reach said shutoff level whereupon the level of the hot water in said tank rises above the siphon-out level of said hot water siphon means, and means for closing said valve in the event that the water in the tank rises to a predetermined level above said siphon-out level of said hot water siphon means.

Claim 8

Coffee brewing apparatus according to claim 5 wherein cold water is supplied from said basin to said tank by said cold water inlet siphon means at a rate greater than the rate at which hot water is withdrawn by said hot water siphon means.

Claim 9

Coffee brewing apparatus according to claim 5 wherein means close said valve when the level of the water in said basin reaches a level above said shutoff level to prevent overflow of said basin.

Claim 10

Coffee brewing apparatus according to claim 7 wherein said means for closing said valve when the level of the water in said basin reaches a level above said shutoff level includes normally closed contacts arranged to be opened by a float in said basin.

Claim 11

Coffee brewing apparatus according to claim 5 wherein said means for closing said valve includes probe means adapted to be engaged by water in said basin and tank respectively.

Claim 12

Coffee brewing apparatus according to claim 9 wherein said probe means includes a vertical insulating sleeve extending from said basin into said tank, a conducting collar on said sleeve the elevation of which determines said shutoff level, and a conducting rod extending through said sleeve the elevation of the lower end of which determines said predetermined level in said tank.

Claim 13

Coffee brewing apparatus according to claim 10 wherein said collar is adjustable vertically to change the elevation of said shutoff level.