AU2010101197A4 - Espresso Coffee Making Device - Google Patents

Description

AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION INNOVATION PATENT ESPRESSO COFFEE MAKING DEVICE The following statement is a full description of this invention, including the best method of performing it known to me: - 1 ESPRESSO COFFEE MAKING DEVICE Background of the Invention Both traditional and modern espresso machines are relatively large thus rendering them impractical to transport. Additionally, these machines are typically powered by electricity 5 thus requiring the user to access an electrical power supply. This invention has been specifically designed to provide a small, manually operated, portable espresso making device for the purpose of producing quality espresso coffee anywhere that boiling water can be accessed. Brief Description of the Drawings 10 Figure 1 shows the side view, top view, and cut-away side view section of the invention and identifies the main components. Figure 2 shows the side view and cut-away side view section of the cylinder assembly of the invention and identifies the subcomponents of the cylinder assembly. Figure 3 shows the cut-away side view section of the spindle and piston assembly of the 15 invention and identifies the subcomponents of the spindle and piston assembly. Figure 4 shows the cut-away side view section of the basket holder and outlet assembly of the invention and identifies the subcomponents of the basket holder and outlet assembly. Figure 5 shows the operating procedure of the invention. Description of the Present Invention 20 An espresso coffee making device in accordance with this invention comprises an insulated hollow cylinder with a piston driven by a manually operated spindle to drive the piston along the centreline of the cylinder with the piston sealing against the bore of the cylinder to press hot water through ground coffee contained in a perforated basket attached to the downstream end of the cylinder (See Figure 1). The basket is secured in a housing that screws into the 25 cylinder. The rim of the basket seals against a rubber seal recessed into the cylinder. The downstream end of the basket housing is tapered to funnel the espresso into an outlet hole in the centre of the basket housing.

-2 During operation, the cylinder is held by hand. To provide insulation, a sleeve made from plastic or other such insulating material is fitted over the outside diameter of the cylinder and extends up the lower end face (See Figure 2). The upper end of the sleeve is raised to prevent the operator's hand from sliding upward. Insulation of the sleeve is obtained by an air gap 5 between the sleeve and the cylinder. As shown in Figure 2, the sleeve is undercut along its bore to provide the said air gap. The outside diameter of the sleeve has a gripping surface, such as a knurled finish, to provide grip during operation. The insulating sleeve is secured to the cylinder to prevent it from spinning by lugs fitted into the cylinder lower end face. The lugs may also be cast or machined into the cylinder parent 10 material. As shown in Figure 2, the lugs fit into mating holes in the sleeve. The sleeve is secured to the cylinder by a screwed end cap. As shown in Figure 2, the end cap is screwed onto the top of the cylinder. The centre of the end cap has a female screw thread in which the spindle fits. A series of vent holes is drilled through the face of the end cap. 15 The spindle screws into the end cap. The spindle rotation is driven by manually turning a crank handle assembly (See Figure 1). The crank arm is secured to the spindle with a screw and washer (See Figure 3). The attachment between the crank arm and spindle is made secure by a female hexagon or square in the crank arm that fits onto a mating male hexagon or square on the spindle. The end of the crank handle has a knob fitted to enable it to be 20 turned. As shown in Figure 3, the knob is secured to the arm with a screw assembly consisting of a screw that fits into a male axle. The axle fits through the knob, and the screw fits into the axle through the arm. With the screw fastened, the knob rotates freely on the axle. The spindle extends through the end cap to drive a piston assembly attached to the end of the 25 spindle inside the cylinder (See Figure 1). The piston assembly is mounted onto the spindle and is secured by a shoulder screw fitted into the spindle end (See Figure 3). As shown in Figure 3, the piston is comprised of two halves: the lower half and the upper half. The lower half of the piston has a male spigot on which a piston seal is positioned. The two piston halves are screwed together to form the piston assembly. The seal provides a seal -3 between the male spigot and the cylinder bore to provide a pressure seal between the piston and the cylinder. A thrust bearing assembly is mounted above the piston to provide smooth rotation between the spindle and the piston. As shown in Figure 3, the thrust bearing assembly consists of a 5 thrust plate and a thrust washer. The thrust plate fits on the end of the spindle and seats against a shoulder. The thrust washer fits between the thrust plate and the piston. As shown in Figure 4, the filter basket is secured into the basket housing with a wire spring located in a groove in the inside diameter of the basket housing. The spring applies pressure to the sidewall of the filter basket to secure the said filter basket in the basket housing. 10 The outside diameter of the basket housing has a gripping surface, such as a knurled finish. As shown in Figure 4, the basket housing screws into the cylinder. The outer rim of the filter basket seals against a rubber seal recessed into the cylinder. The downstream end of the basket housing is cone shaped to funnel the espresso into the centre outlet hole. The preferred material for the device is brass. However, it may also be manufactured from 15 stainless steel or a suitable heat resistant plastic material. To operate the device, the piston is screwed into the cylinder to an extent necessary to provide sufficient volume in the cylinder chamber. With the device held in the inverted position, the cylinder chamber is filled with water heated to sufficient temperature for espresso extraction. The filter basket secured in the basket housing is filled with ground 20 coffee and screwed into the cylinder. The device is returned to the upright position and the crank handle is turned to drive the piston downward against the water to produce water pressure on the ground coffee. The handle is turned continuously until the desired volume of espresso is extracted from the outlet of the device (See Figure 5).

Claims (5)

1. An espresso coffee making device comprising a hollow cylinder with a piston driven by a manually operated spindle to drive the piston along the centreline of the cylinder with the piston sealing against the bore of the cylinder to press hot water through 5 ground coffee in a perforated basket contained in a basket housing screwed into the downstream end of the cylinder.

2. An espresso coffee making device as claimed in Claim1, wherein an insulated sleeve made from plastic or other such insulating material is fitted over the outside of the said hollow cylinder. The upper end of the said sleeve has a raised lip. The outside 10 diameter of the said sleeve has a gripping surface, such as a knurled finish.

3. An espresso coffee making device as claimed in Claim1, wherein the said piston is comprised of two halves that screw together to retain the piston seal.

4. An espresso coffee making device as claimed in Claim1, wherein the outside of the said basket housing has a gripping surface, such as a knurled finish. 15

5. An espresso coffee making device substantially as herein before described with reference to Figures 1 - 5 of the accompanying drawings. ROSS SPENCER 3 NOVEMBER 2010 www.portaspresso.com