Coffee brewing apparatus and method of brewing coffee by the apparatus

• US 5,911,810 A
• Filed: 06/09/1998
• Issued: 06/15/1999
• Est. Priority Date: 06/23/1997
• Status: Expired due to Fees

• Current Assignee: Sanden Corporation (Hisense Home Appliances Group Co., Ltd.)
• Original Assignee: Sanden Corporation (Hisense Home Appliances Group Co., Ltd.)
• Inventors: Kawabata, Akio
• Primary Examiner(s): ALEXANDER, REGINALD
• Application Number:
  US09/094,113
• Time in Patent Office: 371 Days
• Field of Search: 99/302 P, 99/302 R, 99/289 P, 99/289 T
• US Class Current: 99/302.00P
• CPC Class Codes: A47J 31/34 with hot water under liquid pressure
• CPC Class Codes: A47J 31/3652 the tape including only filtering means, i.e. not including brewing material

Abstract

A coffee brewing apparatus has a first cylinder, having a top opening and a bottom opening. A vertically movable second cylinder containing ground coffee, having a top opening and a bottom opening, is disposed below the first cylinder coaxially therewith. A vertically movable upwardly urged plunger, having a top head and a bottom head, is disposed through the bottom opening of the first cylinder, coaxially therewith, in a manner that the top head is sealingly and slidingly fitted in the first cylinder and the bottom head is adapted to be sealingly and slidingly fitted in the second cylinder through the top opening thereof. The plunger has a hot water exit channel vertically therethrough and a pressure-operated hot water release valve disposed in the channel. When water is provided in the first cylinder on the top head of the plunger and pressurized, the plunger is pressed down so that the ground coffee in the second cylinder is compacted by the plunger before the valve opens and pressurized hot water in the first cylinder is released through the hot water release channel to be poured onto the ground coffee.

Claims

1. A coffee brewing apparatus, comprising:

(a) a cylindrical hot water container, said container having a bottom opening;

(b) means for pressurizing said container internally;

(c) a vertically movable cylindrical ground coffee holder, disposed below said container coaxially therewith, having a top opening and a bottom opening;

(d) a vertically movable plunger having a top head and a bottom head, said plunger being disposed coaxially with said container and said holder through said bottom opening of said container in a manner that said top head is fitted in said container sealingly and slidingly and said bottom head is adapted to be fitted in said holder sealingly and slidingly through said top opening thereof, said plunger having a hot water exit channel vertically therethrough;

(e) a hot water release valve disposed in said hot water exit channel; and

(f) means for upwardly urging said plunger.

2. A coffee brewing apparatus according to claim 1, wherein said hot water container has a top opening and said means for pressurizing said hot water container internally is a vertically movable piston, disposed coaxially with said container, that is adapted to sealingly and slidingly fit said container internally through said top opening thereof.

3. A coffee brewing apparatus according to claim 1, wherein said means for upwardly urging said plunger is a compression coil spring disposed internally of said container coaxially therewith.

4. A coffee brewing apparatus according to claim 1, wherein said hot water release valve is a pressure-operated valve.

5. A coffee brewing apparatus according to claim 1, wherein a diameter of said top head of said plunger is greater than a diameter of said bottom head thereof.

6. A coffee brewing apparatus according to claim 1, wherein said top head of said plunger has a funnel-like sink on top thereof.

7. A coffee brewing apparatus according to claim 1, wherein said bottom head of said plunger has a hot water spreading chamber in a bottom part thereof, said chamber being diameterically widened with respect to a diametrical dimension of said hot water exit channel and communicated with said hot water exit channel when said hot water release valve is open.

8. A coffee brewing apparatus according to claim 1, the apparatus further comprising:

(g) a vertically movable, horizontally rotatable filter support block having a plurality of filter support block sections, said filter support block sections being disposed angularly evenly spaced about an rotational center of said filter support block at an even level and a radially equidistance from said rotational center, each of said filter support block sections having a strainer and a coffee outlet under said strainer, each of said filter support block sections being adapted to support a filter thereon in a manner that said filter is sandwiched between said ground coffee holder and said filter support block section.

9. A coffee brewing apparatus, comprising:

(a) a first cylinder for containing a quantity of hot water therein, said first cylinder having a top opening and a bottom opening;

(b) a vertically movable piston for pressurizing hot water in said first cylinder, said piston being disposed coaxially with said first cylinder and being adapted to sealingly and slidingly fit said first cylinder internally through said top opening thereof;

(c) a vertically movable second cylinder for holding ground coffee therein, said second cylinder being disposed below said first cylinder coaxially therewith, said second cylinder having a top opening and a bottom opening;

(d) a vertically movable plunger having a top head and a bottom head, said plunger being disposed coaxially with said first and second cylinders through said bottom opening of said first cylinder in a manner that said top head is fitted in said first cylinder sealingly and slidingly and said bottom head is adapted to be fitted in said second cylinder sealingly and slidingly through said top opening thereof so as to compress ground coffee in said second cylinder when said second cylinder is at an elevated level and hot water in said container is pressurized, said plunger having a hot water exit channel vertically therethrough;

(e) a pressure-operated hot water release valve disposed in said hot water exit channel which opens when hot water in said first cylinder is pressurized to a predetermined pressure by said piston;

(f) means for upwardly urging said plunger;

(g) a vertically movable filter support member disposed below said second cylinder; and

(h) a filter disposed on said filter support member in a manner that said filter is sandwiched between said filter support member and said second cylinder so that said filter covers said bottom opening of said second cylinder when said filter support member is at an elevated level.

10. A coffee brewing apparatus, comprising:

(a) a hot water container;

(b) a ground coffee holder having a bottom opening;

(c) means for introducing hot water in said container onto ground coffee in said holder; and

(d) a vertically movable, horizontally rotatable filter support block having a plurality of filter support block sections, said filter support block sections being disposed angularly evenly spaced about an rotational center of said filter support block at an even level and a radially equidistance from said rotational center, each of said filter support block sections having a strainer and a coffee outlet under said strainer, each of said filter support block sections being adapted to support a filter thereon in a manner that said filter is sandwiched between said ground coffee holder and said filter support block section.