Coffee Machine Comprising a Continuous Heater

Abstract

A coffee machine for preparing coffee, especially based on coffee pads, said coffee machine comprising a continuous heater provided with a water-guiding tube that is thermally connected to at least one heating rod by means of at least one contact surface, and a pump for transporting water through the continuous heater. The aim of the invention is to provide a simple and cost-effective solution for a continuous heater, and to ensure good heat transfer. To this end, the at least one contact surface is embodied in such a way that it is flat between the tube and the at least one heating rod.

Description

The invention is now explained in detail with reference to the accompanying drawings using particularly preferred embodiments. In the figures:

FIG. 1 is a sectional view of a coffee machine to explain the invention; and

FIG. 2 is a perspective view of a housing part as well as components arranged in the housing to explain the invention; and

In the following description of the drawings the same reference numerals denote the same or comparable components.

FIG. 1 shows a sectional view of a coffee machine to explain the invention. FIG. 2 shows a perspective view of a housing part as well as components arranged in the housing to explain the present invention. The coffee machine 10 comprises a flat front portion 12 and a columnar rear assembly 14. Cups for removing coffee via an outlet 16 can be arranged on the front portion 12. A water container 18 is inserted in the rear assembly 14. The rear assembly 14 further comprises a brewing chamber 20 formed by a coffee pad retainer 24 which can be supplied with a drawer and an elastic retainer cover 28 as the upper portion of the brewing chamber 30. A lever mechanism is provided with a lever 26 in order to seal the coffee pad retainer 24 and the retainer cover 28 with respect to one another after inserting the drawer 22. In the state shown the lever mechanism pulls the coffee pad retainer 24 towards the retainer cover 28. If the lever 26 is shifted backwards by 90°, the coffee pad retainer 24 is lowered so that it can be removed from the coffee machine 10 together with the drawer 22.

Components for supplying water, for heating water and for controlling these processes are provided inside the housing formed by the front portion 12 and the rear assembly 14. Located in the lower housing area at the boundary between the front portion 12 and the rear assembly 14 is a pump 32 to which water is supplied from the water container 18 via a hose 34. The pump 32 is connected to the continuous heater 38 by means of another hose 36. Important components of this continuous heater 38 are a pipe 40 used to carry water and two heating rods 42, 44, These heating rods 42, 44 each have two electrical connections 46, 48 to which the heating voltage is applied. Provided on the front portion 12 of the coffee machine 10 is a keypad 50 which is connected to a printed circuit board 52, said printed circuit board 52 preferably controlling all the functions of the coffee machine, especially the functions with regard to the conveyance and heating of the water. Starting from the printed circuit board 52 there is provided a cable run 54 which combines the electrical leads via which the electronic controller delivers its control commands and receives input information. This input information particularly relates to the temperature of the continuous heater detected by a temperature sensor 56 and preferably further temperature information which is recorded by temperature sensors at measuring points 58, 60 downstream or upstream from the continuous heater 38 in the direction of flow. A reed switch 62 is further provided in the rear assembly 14. The task of the reed switch 62 is to electrically detect a minimum filling level in the water container 18. For this purpose a float comprising a magnet is located vertically displaceably in the water container 18. When the water falls below a minimum filling volume in the water container 18, the magnetic float is located near to the reed switch 22 and makes this switch on, closing a circuit which transmits a signal to the electronic controller that the level is too low. If the level in the water container is lower than the minimum filling volume, the coffee machine cannot be operated. The continuous heater 38 can also have a sensor which prevents any running dry during the heating process.

Contact surfaces 84, 86 of the heating rods 42, 44 are constructed as flat and are connected to corresponding contact surfaces or flattened sections of the pipe 40. Thus, good abutment and consequently good heat transfer can be achieved between the heating rods 42, 44 and the pipe 60. The contact surfaces 84, 86 preferably extend over the entire or almost the entire length of the continuous heater 38, a radial position of the contact surfaces 84, 86 being shown by the broken lines in FIG. 1 as an example. The arrangement of pipe 60 and heating rods 42, 44 is held together by a sleeve 64 which can be made of heat-resistant plastic or metal. The temperature sensor 56 is located in the area of this sleeve 64. Flexible tube connecting pieces 66, 68 are attached to the ends of the pipe 60. In the present exemplary embodiment, these are inserted in the pipe 60 and fitted with a circumferential seal 70, 72, for example, an O-ring. Securing means 74, 76, 78, 80 are moulded onto the flexible tube connecting pieces 66, 68 made of heat-resistant plastic, only some of the securing means being identified with reference numerals as an example here. These securing means 74, 76, 78, 80 are used to secure and centre the continuous heater 38 in the housing and also provide receiving elements for additional components, for example, a receiving element for the reed switch 62 in the securing means 78. A safety valve 82 is furthermore built into the flexible tube connecting piece 68. The continuous heater 38 can thus be mounted as a complete unit with the flexible tube connecting pieces 66, 68 and the hoses placed thereon and can easily be inserted in the housing as a result of centring properties.

The features of the invention disclosed in the preceding description, in the drawings and in the claims can be important for carrying out the invention both individually and also in any combination.

Reference List:

• 10 Coffee machine
• 12 Front portion
• 14 Rear assembly
• 16 Outlet
• 18 Water container
• 20 Brewing chamber
• 22 Drawer
• 24 Coffee pad retainer
• 26 Lever
• 28 Retainer cover
• 30 Brewing chamber upper portion
• 32 Pump
• 34 Hose
• 36 Hose
• 38 Continuous heater
• 40 Pipe
• 42 Heating rod
• 44 Heating rod
• 46 Electrical connection
• 48 Electrical connection
• 50 Keypad
• 52 Printed circuit board
• 54 Cable run
• 56 Temperature sensor
• 58 Measurement point
• 60 Measurement point
• 62 Reed switch
• 64 Sleeve
• 66 Flexible tube connecting piece
• 68 Flexible tube connecting piece
• 70 Seal
• 72 Seal
• 74 Securing means
• 76 Securing means
• 78 Securing means
• 80 Securing means
• 82 Safety valve
• 84 Contact surface
• 86 Contact surface
• 88 End
• 90 End

Claims

1-9. (canceled)

10. A coffee machine for preparing coffee using coffee pads, which comprises a continuous heater provided with a water-guiding pipe that is thermally connected to at least one heating rod by means of at least one contact surface, and a pump for transporting water through the continuous heater, wherein the at least one contact surface between the pipe and the at least one heating rod is embodied such that it is flat.

11. The coffee machine according to claim 10, wherein at least two heating rods are thermally connected to the pipe by means of the at least one contact surface.

12. The coffee machine according to claim 11, wherein the at least two heating rods are provided on opposite sides of the pipe.

13. The coffee machine according to claim 10, wherein the pipe and the at least one heating rod are held together by a sleeve.

14. The coffee machine according to claim 13, wherein a temperature sensor is disposed adjacent the sleeve.

15. The coffee machine according to claim 10, wherein the pipe has ends into which hose-like connecting pieces of a water supply and a water exit can be inserted.

16. The coffee machine according to claim 15, wherein the connecting pieces are provided with seals.

17. The coffee machine according to claim 15, wherein the connecting pieces are made of plastic and comprise securing means for securing the continuous heater on a housing of the coffee machine.

18. The coffee machine according to claim 17, wherein holders for further components are provided on the securing means.