Coffeemaker with automated interlocks

An apparatus for preparing coffee comprises a chassis engaging an electronic power and control circuit, a water heater, a coffee brewing tray adapted for receiving a coffee packet, a coffee pot supporting shelf, a control panel adapted for receiving manual selections for operating the apparatus, an electrical interlock adapted for sensing the presence of a coffee pot on the coffee pot supporting shelf. An electrical interlocking scheme is adapted for sensing when the coffee pot is present and when it is full, the temperature and level of water in the water heater, and when a restraining handle is in place.

BACKGROUND OF THE INVENTION
 1. Field of the Invention
 This invention relates generally to an apparatus for preparing beverages,
 and, more particularly, to a coffee maker that includes interlocks to
 assure automated operation, safety, quick maintenance and reliability of
 operation.
 2. Description of Related Art
 The following art defines the present state of this field:
 Dal Tio, U.S. Pat. No. 5,896,806 describes a machine for preparing coffee,
 white coffee or similar infused beverages, on single or multiple doses
 thereof, utilizes waffles (40) packed in advance, applied in a continuous
 band (41), in a number sufficient to prepare various coffees or other
 infused beverages. The machine has guide and feeding device (43)
 associated to the infusion units (35), (36) and the filters (97), (98)
 thereof, to determine the advancement of the band (41) through the
 infusion units (35), (36), by stopping each waffle in correspondence
 thereto for performing the related infusion operation. The machine may
 contain also a mixer-emulsifier (52) with conduits (105) communicating or
 not communicating with the infusion units (35), (36) through a switching
 valve member (106), for preparing the white coffee or other infused
 beverages mixed with milk.
 Knepler, et al. U.S. Pat. No. 5,375,508 describes a control system for a
 beverage brewing apparatus that includes a programmable control module and
 a separate input device. The control system is used with a beverage
 brewing apparatus of the type having an infusion assembly for retaining
 and filtering a brewing substance, a heated water source and a water
 distribution system for transporting water from the heated water source to
 the infusion assembly. The programmable control module controls numerous
 adjustable functions associated with the brewer and stores at least one
 function limit for each of the functions that it controls. The separate
 input device is selectively attachable to the control module for
 manipulating the function limits of the programmable function retained and
 controlled by the control module. Function controls are associated with
 the input device for selecting a function to manipulate and for
 incrementing and decrementing the limit or limits of the selected
 function. The control module and input device allow selection of control
 limits that affect a valve for controlling water flow from the heated
 water source to the infusion assembly. These control limits establish a
 dispensing cycle that periodically dispenses water from the heated water
 source through the water distribution system to the infusion assembly to
 prevent overflowing the infusion assembly.
 Rudewicz, et al. U.S. Pat. No. 5,975,348 describes a vending machine
 includes a number of failure control devices that monitor and control the
 functioning of the various components in the vending machine to ensure
 uniform quality of food products to be sold to a customer. One specific
 embodiment includes plurality of oven failure control devices, a freezer
 failure control device and a power failure control device. When a
 microcontroller in the vending machine determines the occurrence of a
 failure, the microcontroller displays a failure message on a customer
 display and discontinues vending food until the failure is corrected, for
 example, by an operator. In another aspect of this invention, the vending
 machine includes a mechanism for operating a door of a refrigeration
 compartment of the vending machine. The mechanism includes a motor driven
 rotary link coupled to a roller that moves in a slot of the door.
 Lassota, U.S. Pat. No. 5,953,981 describes a twin brewer system (30) with a
 pair of brewers (30A, 30B) each with a controller (158) for controlling
 the application of electrical power to a hot water heater, disables the
 application of electrical power to the heater (154) of one brewer (30A,
 30B) in response to actuation of a start brew switch of the one brewer
 (30A, 30B) while electrical power is being applied to the heater (154) of
 the other brewer (30A, 30B). The controllers also respond to a hot water
 quantity sensor (164, 168) and a responsive delay circuit for disabling
 dispensing of hot water in response to actuation of the brew start switch
 (50) until a sufficient quantity of hot water is in a hot water dispenser
 tank (152) needed for the brew cycle. Indication lo lamps indicate when
 the brew cycle is being delayed and when brewing is not being performed.
 Actuation of a single emergency stop switch (138) stops hot water
 dispensing of both brewers (30A, 30B).
 Warne, U.S. Pat. No. 5,704,275 describes a control system for a coffee
 brewer having a microprocessor in which the water heated in the heater
 tank must be a predetermined temperature before brewing. A double brewing
 cycle is prevented. Upon the system not being activated for a period of
 time, i.e., the water temperature is allowed to drop a greater magnitude
 for energy saving and component protection.
 Ugolini, U.S. Pat. No. 5,713,214 a machine for cooling and dispensing a
 product substantially behaving like a fluid, such as beverages or
 water-ice, comprises a base (11) and a tank (12) for treatment of the
 product to be dispensed. The tank is positioned on the base in a removable
 manner and heat exchange means (14) and a powered stirring element (15)
 are inserted thereinto. Also arranged in the tank (12) is a level probe
 (19) connected with control means (25) of the product level in the tank.
 The probe (19) has one detecting end (20) within the tank and an
 electrical-contact area (23) disposed on an external wall of the tank
 (12). Additionally, the base (11) bears an electricalcontact element (24)
 connected to the control means (25). On mounting of the tank (12) on the
 base (11), the contact area (23) of the probe (19) comes into electrical
 contact with the contact element (24) on the base so that the probe (19)
 is automatically connected in a detachable manner to the control means
 (25). Further means (43) disables a filling-up action controlled by the
 level sensor, in case of lack or improper positioning of the sensor and/or
 the tank.
 Ford, U.S. Pat. No. 5,676,040 describes a sensing assembly that includes a
 sensing device. The sensor assembly is constructed for use with an
 automatic beverage apparatus. The sensing assembly is attached to a
 beverage reservoir and senses, by physical contact, a quantity of beverage
 retained in the reservoir. The sensing assembly provides information about
 the quantity of beverage retained in the reservoir. When coupled to a
 beverage brewing apparatus, the beverage brewing apparatus will
 automatically produce a predetermined quantity of beverage in response to
 conditions sensed by said sensing assembly.
 Allington, et. al. WO 99/23888 describes an apparatus and method of
 roasting foodstuff such as coffee beans employ a roasting chamber for
 roasting the beans. An air circulation system operatively coupled with the
 chamber flows heated air over the beans and thereby roasts the beans, and
 an air cleaning arrangement is operatively coupled with the air
 circulation system and located downstream of the chamber for removing
 substantially all particulates, smoke and volatiles entrained in the used
 air as it flows through the container and into the air cleaning
 arrangement to provide substantially pollutant-free used air. The
 circulation system uses atmospheric air and heats, cleans and cools within
 as little as 1/4second. Sensors and an electronic controller are provided
 to monitor various parameters in the roasting apparatus and control the
 roasting characteristics. The darkness or color of the beans during
 roasting in roasting machines at a plurality of geographically separate
 locations is controlled by equipping each roasting machine with a computer
 with memory and providing a central control station for downloading
 control signals to the computer to control roasting.
 Liverani, U.S. Pat. No. 5,738,001 teaches a control device which processes
 simultaneously, the signals received from a temperature sensor, and from a
 water delivery counter means, to control, instant by instant, the pump
 delivery and the electricity feeding the machine heat exchanger, so as to
 maintain a reference temperature of the water exiting the heat exchanger.
 The prior art teaches a range of coffee making devices with various
 capabilities including automation features and controls. However, the
 prior art does not teach the safeguards and interlocked controls of the
 instant invention, and especially a coffee making apparatus particularly
 designed for airline use wherein a coffee pot is pinned in place and a
 coffee making process fully interlocked for automated safe operation and
 having modular construction for improved diagnostics based maintenance.
 The present invention fulfills these needs and provides further related
 advantages as described in the following summary.
 SUMMARY OF THE INVENTION
 The present invention teaches certain benefits in construction and use that
 give rise to the objectives described below.
 The present invention is an apparatus for preparing coffee designed for use
 in airplanes or other vehicles subject to movement. The apparatus
 comprises a supporting shelf for supporting a coffee pot; a coffee brewing
 tray adapted for receiving a coffee packet; a chassis engaging an
 electronic power and control circuit; and a water heater, among other
 components. An electrical interlock is adapted for sensing the presence of
 the coffee pot on the coffee pot supporting shelf and provides a physical
 restraint for ensuring that the coffee pot cannot be dislodged during
 aircraft movements. The electronic power and control circuit includes
 interlocks for sensing when the coffee pot is full and the water level in
 the water heater. A control panel provides manual selection of operational
 modes and control of the coffee brewing process. The apparatus includes
 several other advanced features, such as diagnostic circuitry, easily
 changed components and modules and adjustable flow control. Locking
 mechanisms are provides for securing the filter tray as well as for
 locking the system chassis securely in place on a rail-support assembly.
 The apparatus also provides a warmer pad that turns on when the brewing
 cycle is initiated and its temperature is factory set according to
 customer requirement.
 A primary objective of the apparatus is to provide a coffee-preparing
 apparatus having advantages not taught by the prior art.
 Another objective of the apparatus is to provide a means for securing the
 apparatus against movement of the aircraft.
 A further objective is to provide such an apparatus with subassembly
 components contained in modular form so that they are easily replaceable
 for maintenance purposes.
 A still further objective is to provide such an apparatus containing a
 sensor within the coffee pot component itself which causes a circuit to
 stop delivering coffee when the coffee pot is full.
 A still further objective is to provide such an apparatus with an
 electrical interlock so as to prevent the delivery of coffee when the
 coffeepot is not in place on a coffee pot supporting shelf.
 A still further objective is to provide such an apparatus with a pot
 restraining handle electrically interlocked with machine operation.
 A still further objective is to provide such an apparatus with a rail
 system adapted for supporting the apparatus, the apparatus adapted for
 sliding engagement with the rail system; and a locking means for removably
 engaging the apparatus with the rail system.

DETAILED DESCRIPTION OF THE INVENTION
 The above described drawing FIGS. 1-11 illustrate the invention, most
 specifically, a coffee maker for airline use. The apparatus comprises a
 chassis 10 engaging with, and enclosing: (a) an electronic power and
 control circuit 20, a plug-in module comprising and interconnected with
 certain electrical elements, as shown generally in FIG. 9; (b) a water
 heater 30 including a water canister 32 and its electrical heaters 34,
 sensors, etc.; (c) a coffee brewing tray 40 (FIGS. 1 & 2), adapted, as
 will be described below, for receiving a commercially available coffee
 packet 50 (not a part of the instant invention); (d) a coffee pot
 supporting shelf 60, located at the front of the chassis 10, as seen in
 FIGS. 1-4; and (e) a coffee pot 70 (FIGS. 4 & 5) adapted for resting on
 the coffee pot supporting shelf 60 in a position below the coffee brewing
 tray 40 and accessible for insertion and removal from the supporting shelf
 60 by flight attendants or others.
 Preferably, the power and control circuit 20 is enclosed within a modular
 housing 80, the modular housing being adapted for plug-in connection with
 the chassis 10 so that it is easily replaceable should a failure occur.
 The chassis 10 further comprises a control panel 90, located at the front
 of the modular housing 80 (front panel) and adapted with switches 91-96
 for receiving manual selections for operating the apparatus. Below the
 control panel 90 is a tray access port 42 for receiving the coffee brewing
 tray 40 in sliding engagement. A tray locking means 44, a pivoted sheet
 metal partition, is positioned and enabled for moving downwardly into a
 locking position, as shown in FIG. 6, for engaging the tray 40 so that it
 cannot be removed from the front panel when the apparatus is in operation.
 This locking function is accomplished by handle 170 which also bars
 removal of the coffee pot 70 when in the extended (down) position as best
 seen in FIG. 6.
 Critical to the novelty of the instant invention are certain interlocks
 providing controlled automated and safe use of the apparatus, a primary
 concern. Referring now to FIGS. 5 and 6, a first electrical interlock 110
 is a switch adapted for sensing the presence of the coffee pot 70 on the
 coffee pot supporting shelf 60; the coffee pot 70 pressing against this
 switch when the pot 70 is properly positioned on the shelf 60. The control
 circuit 20 prohibits brewing operations when interlock 110 is not made. A
 second electrical interlock 120 is a probe adapted for sensing when the
 coffee pot is filled to an appropriate level (full). This is accomplished
 when the water or coffee liquid level reaches the interlock 120 and thus
 grounds a circuit by electrical conduction through the liquid to the pot
 and thus to the chassis 10. Note that conducting band 122 positioned on,
 and insulated from pot 70 is electrically interconnected with probe 120
 and touches switch 110 to complete the circuit when the pot 70 is in
 place. A third electrical interlock 130 is adapted by use of thermistors
 located in the water heater canister 32 for sensing the temperature of
 water therein and for controlling the heating process to a set
 temperature. A hot water level sensing means 140, a float, senses the
 water level in the water heater canister 32 and is interlocked to the
 circuit 20 wherein a selected water volume must be present for operation.
 Preferably, the apparatus further comprises a faucet 160 extending
 outwardly from the front of the apparatus (FIG. 1) and adapted by water
 circuit interconnection, shown in FIG. 10, for dispensing hot and cold
 water on demand. Water inlet and drain connections are made when the
 chassis 10 is fully engaged with the rail system as shown in FIG. 8. In
 FIGS. 7 and 8, the receiving fixtures and hardware that are mounted in the
 rail system bracket 206 are not shown for clarity.
 Inventively, the apparatus further comprises a movable coffee pot
 restraining means or handle 170 for restraining the coffee pot 70 on the
 coffee pot supporting shelf 60. This restraining handle 170 is
 positionable in a retracted (or up) position, as shown in FIGS. 1, 3 and 5
 and alternately, in an extended (or down) position as shown in FIGS. 2, 4
 and 6 wherein the coffee pot cannot be physically removed or be forced out
 of its position in the chassis 10 due to inertial or other forces. The
 restraining handle 170 must be in the down and locked position for the
 brewing process to take place. A pair of spaced apart fingers 202, as
 shown in FIGS. 3-6, are enabled by the mechanism 200, driven by the
 restraining handle 170, for engaging the rim of the coffee pot 70 when the
 restraining handle 170 is in the extended position. This is best seen in
 FIGS. 5 and 6. An electrical interlock 180 is interconnected with the
 mechanism 200 for preventing the brewing process from starting, if the
 restraining handle 170 is not down. Therefore, coffee brewing is not able
 to start until the coffee pot is in place, the handle is down and locked
 and the liquid level within the coffee pot, if any, is below the defined
 full level.
 Inventively, the water heater 30 comprises an over-temperature sensing
 means 130 as shown in FIG. 7, preferably a pair of thermisters positioned
 within the water heater 30 for redundant assurance that an
 over-temperature condition in the water heater 30 will not go unnoticed.
 These sensors communicate with the power and control circuit 20, as shown
 in FIGS. 9 and 11, and are configured so that the heaters 34 are
 automatically shut down should an over-temperature condition occurs. A
 relief valve 36 provides for pressure relief should pressure in the water
 heater exceed 100 psi. The level sensor 140 (float), a vent 134 for
 draining the water heater, and an over temperature switch 132 in the water
 heater 30 are illustrated in FIG. 7.
 Inventively, the apparatus further comprises a rail system 205 adapted for
 engaging and supporting the chassis 10 in place in an airline kitchen or
 similar location. The chassis 10 is adapted for sliding engagement with
 the rail system, as shown in FIG. 7. Preferably, the chassis 10 may be
 locked in place on the rail system 205 by a locking means 210, shown in
 FIGS. 3 (unlocked) and 5 (locked). Locking means 210 is preferably a
 bolt-action type lock with a spring loaded sliding pin which engages a
 hole in the rail system. Unless this lock is placed manually in a
 withdrawn (up) position, the spring forces the sliding pin to engage the
 rail system 205. Therefore, the rail system and the chassis are engaged by
 default. The chassis is thus proactively prevented from being displaced
 from its operational position on the rail system where its utilities are
 engaged.
 In operation, the coffee pot 70 is placed onto coffee brewing tray 40 and
 tray locking means 44 is moved to the down and locked position. Hot water
 is prepared to a selected temperature in water heater 30 and is then
 delivered, upon command, to drip onto the coffee packet 50 from above. The
 hot water percolates through the coffee packet so as to brew into coffee
 which then runs off a stainless steel coffee packet support 46, upon which
 the coffee packet 50 rests, and downwardly through a coffee access hole
 (not shown) in brewing tray 40, through a shelf access hole 49 and into
 coffee pot 70. When the pot has filled, as indicated by the second
 electrical interlock 120, filling stops and a ready light is illuminated.
 The coffee packet 50 may now be discarded by raising locking means 44 via
 handle 170 which allows the coffee packet tray to be removed. With handle
 170 in the raised position, the coffee pot 70 is able to be removed from
 the apparatus for service.
 While the invention has been described with reference to at least one
 preferred embodiment, it is to be clearly understood by those skilled in
 the art that the invention is not limited thereto.
 Rather, the scope of the invention is to be interpreted only in conjunction
 with the appended claims.