Automatic bypass coffee brewer

#The quality and taste with brewed coffee depends upon numerous factors such as the price or quality of the beans, the control exercised in roasting the beans, the proportions of the particles of different size obtained in grinding the roasted beans for brewing, freshness of use after grinding, and the extraction of the correct amount of soluble solids from the coffee during brewing.

#Many different automatic coffee brewers have been designed for brewing and dispensing coffee in wide variety of quantities varying from single cup, ten cup (50 oz.), to one gallon and as large as ten gallon sizes. These are intended for use in homes, restaurants, factories and the like. Although these operate in a generally satisfactory manner, they are subject to the defects and disadvantages of passing all of the measured amounts of hot water through the coffee grounds and continuing to heat the coffee after brewing is completed, resulting in coffee which tastes astringent and bitter initially and worsens in taste with time of heating after brewing.

#In "Facts About Coffee" published by the Pan-American Coffee Bureau it is stated, referring to brewing 1 pound of coffee:

#The novel features which are considered characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and its method of operation, together with additional objects and advantages thereof, will best be understood from the following description of specific embodiments when read in connection with the accompanying drawings, wherein like reference characters indicate like parts throughout several figures, and in which:

#FIG. 1 is an end elevation of an automatic coffee brewer according to the invention in which parts have been broken away to reveal internal details;

#FIG. 2 is a sectional view taken on line 2--2 of FIG. 1 and looking in the direction of the arrows;

#One embodiment of the invention will be described below, first with regard to its similarities with conventional coffee brewers and later with regard to the differences in structure and operation involved in the present invention.

#The brewer illustrated in FIGS. 1-5 and 8 is similar to that described in U.S. Pat. No. 3,034,417 issued on May 15, 1962 to G. R. Bunn. A reissued patent has been granted under U.S. Pat. No. 25663. Briefly, the present machine 10 similarly comprises a base 12 with feet 14 supporting a beaker 16 on the base under the holder 18 for coffee grounds. Within a housing 20 at one side of the brewer is a tank 22 for receiving cold water and heating the same. A siphon device generally indicated at 24 serves to deliver heated water in measured amount through a spray head 26 to the upper part of the grounds holder 18. Other similar parts of the conventional machine are not shown in structural detail but are indicated diagrammatically in FIG. 8. These parts include a cold water inlet pipe 28 having a filter F, incorporated therein, and controlled by valve V operated by a solonoid S to control the intake of cold water into tank 22. An electric heater 30 under control of a timer 32 heats the water in tank 22, when the Off-On switch 34 is closed. A thermostat head is shown within the upper portion of the tank connected to a thermostat switch 36. Also a conventional pressure switch 38 is utilized. The power lines are shown at 40 and 42. It should be noted that the timer connects the heater and pressure switch in series across the power lines 40, 42 in a circuit including the lines 44, 46 and junction point 48. The timer also connects the thermostat switch 36 and the solonoid S in series through lines 50, 52 to the same junction point 48.

#In briefly describing the operation of the automatic coffee making machine 10, it will be assumed that a measured quantity of ground coffee has been placed in the filter in the bottom portion of the holder 18 and that the water pressure of water in tank 22 is sufficient to hold the contacts of the pressure switch 38 closed. Under these assumed conditions the thermostat will function to close and open the contacts of the back of the tank thermostat switch 36 for the purpose of maintaining the water in the water tank at the desired temperature which is at least 195.degree. F. The operating cycle can be initiated by the operator depressing the switch button 34 to start the timer 32. This connects the heater 30 and pressure switch 38 across the power lines 40, 42 and heats the water in the tank. The pressure switch 38 is provided to insure that the tank heater 30 is not energized in the event that the pressure of the water is below a predetermined value. In addition to energization of the heater winding, the water supply valve solenoid S is energized to open the water supply valve V and permit the flow of water to the water tank 22 upon activation of the timer. Upon reaching elevated temperatures above 195.degree. F the pressure in the upper part of the tank 22 will serve to force the hot water through the siphon device 24 to the spray head 26 in a measured amount. The heated water passes through the coffee grounds in the holder 18, extracts the soluble solids therefrom and discharges into the beaker 16. The timer serves to activate the described circuits for a sufficient interval of time to properly heat the water and discharge the measured quantity into the siphon device.