A MACHINE AND METHOD FOR TREATING EDIBLE MATERIAL
FIELD OF THE INVENTION
The present invention relates to a machine and method for treating edible material, and in particular for roasting or caramelising edible particulate materials.
BACKGROUND OF THE INVENTION
Nuts and other edible particulate materials are often caramelised or roasted as part of foodstuff preparation. Such particulate material is usually caramelised in the following manner. Water, sugar and other ingredients or additives, such as powdered coating, are placed into a bowl which is continuously heated. These ingredients are brought to boil and then nuts or edible particulate material are added into the bowl. The contents are heated so that a dry sugar coating is formed on the nuts or edible particulate material. This mixture is then heated until caramelised.
One machine for caramelising nuts has a bowl which sits upright and a vertical arm extending downwards into the bowl. The bowl is rotated in its upright position about its longitudinal axis and the arm assists caramelising the nut mixture. One disadvantage of this machine is that it can only produce limited quantities of nuts (about 5 kilograms) and thus has a poor efficiency. In addition, the machine can be difficult to load and unload as the ingredients and mixture must be loaded into and unloaded from the bowl by hand.
SUMMARY OF THE INVENTION
Accordingly, one aspect of the present invention provides a machine for roasting or caramelising edible particulate material, said machine including: a drum assembly having a drum for receiving edible particulate material, drive means for rotating the drum about its longitudinal axis, heating means for heating the drum to heat the edible particulate material, and
means for mounting the drum assembly for tilting movement about an axis generally transverse to the longitudinal axis of the drum for movement of the drum between an operative position, in which rotation of the drum induces tumbling of the edible particulate material as the drum is heated by said heating means to promote caramelisation or roasting of the edible particulate material, and a discharge position in which the drum assembly is tilted so as discharge the contents of the drum.
Another aspect of the present invention provides a method for roasting or caramelising edible particulate material, the method including the steps of: loading the edible particulate material into a drum; rotating the drum about its longitudinal axis to induce tumbling of the edible particulate material as the drum is heated to promote caramelisation or roasting of the edible particulate material, and tilting the drum so as to discharge the contents of the drum.
Rotation of the drum containing the edible particulate material in its operative position encourages a tumbling effect, thereby promoting roasting or caramelisation without the need for a mixing arm and results in a more efficient roasting or caramelisation process.
Furthermore, the tilting movement of the drum assembly between the operative and discharge positions assist loading and unloading edible particulate material into and out of the drum.
Preferably, the heating means is connected to the drum assembly and has one or more burners for heating the exterior of the drum, the drum being rotatable relative to the or each burner.
Preferably, in the operative position the longitudinal axis of the drum is inclined upwards relative to the drum base to tumble the edible particulate material. There may be more than one operative position. In particular, in a second operative position the longitudinal axis of the drum is substantially vertical for bringing other ingredients to boil before rotation of the drum to roast or caramelise the edible particulate material. It is preferred
that the drum has at least one vane on its inside surface so as to assist tumbling of the edible particulate material. In the discharge position, the longitudinal axis of the drum is preferably inclined downwards relative to the drum base. A container is preferably located beneath the drum in the discharge position for receiving the contents of the drum.
The drum assembly preferably includes a mounting member pivotally connected to the drum assembly to provide tilting movement of the drum assembly. The mounting member may extend partially around the drum. In a preferred embodiment, the mounting member is U-shaped and extends around the base of the drum.
It is preferred that a handle is provided for tilting the drum assembly between its operative and discharge positions. Alternatively, a fluid actuated cylinder may be provided for tilting the drum assembly between its operative and discharge positions. The fluid actuated cylinder permits adjustment of the drum assembly between its operative and discharge positions. This allows the operative position to be varied as required.
The drum assembly may include means for shielding an operator or user from injury by the heated drum. The shielding means may be provided at the front and rear of the drum. A shroud may be provided at the front of the drum and a 'shroud at the rear of the drum.
Preferably, one or more stops are provided so as to limit tilting movement of the drum assembly between its operative and discharge positions.
The drive means may include a motor connected to the drum base via a shaft.
Edible particulate materials suitable for roasting or caramelising by the machine and method of the present invention include nuts, corn kernels, seeds, grains, and like edible materials.
Although the present invention primarily applies to the roasting or caramelising of edible particulate material, the present invention may have broader application to the treatment of
edible material, such as candy, nougat, chocolate, confectionery and other food items.
Accordingly, a further aspect of the present invention provides a machine for treating edible material by heating and tumbling, said machine including: a drum assembly having a drum for receiving edible material, drive means for rotating the drum about its longitudinal axis, heating means for heating the drum to heat the edible material, and means for mounting the drum assembly for tilting movement about an axis generally transverse to the longitudinal axis of the drum for movement of the drum between an operative position, in which rotation of the drum induces tumbling of the edible material as the drum is heated by said heating means, and a discharge position in which the drum assembly is tilted so as discharge the contents of the drum.
In addition, another aspect of the present invention provides a method for treating edible material, the method including the steps of: loading the edible material into a drum; rotating the drum about its longitudinal axis to induce tumbling of the edible material as the drum is heated, and tilting the drum so as to discharge the contents of the drum.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the present invention will now be described, by way of example only, with reference to the drawings of which: Figure 1 is a front view of a machine for roasting or caramelising edible particulate material according to a preferred embodiment of the invention; Figure 2 is a side view of the machine of Figure 1; Figure 3 is a perspective view of the machine of Figure 1; Figure 4 is a top view of the machine of Figure 1 ; Figure 5 is a close-up view of a modified reinforcing plate; and
Figure 6 is a side view of another embodiment of the invention.
BEST MODE FOR CARRYING OUT THE INVENTION
Figures 1-4 illustrate a machine according to a preferred embodiment of the invention. The machine 1 has a drum assembly 3. The drum assembly 3 includes a drum 5 having an open end 7 for receiving edible particulate material, for example, nuts. The drum assembly 3 also includes a drive system in the form of a variable speed motor and gear box 9 and drive shaft 11 for rotating drum 5 about its longitudinal axis 13. A heating system 15 is located beneath the drum 5, which in this embodiment is a gas burner having multiple jets. The drum assembly 3 also has a shroud 17 fitted to the drum 5 at its open end 7, while another shroud 19 is located at the rear of the drum 5. The shrouds 17, 19 shield an operator and the components of the machine 1 from heat released from drum 5 during operation of the machine 1. The shrouds 17, 19 also act to trap heat in the drum 5. A gap is provided between shrouds 17, 19 to allow any excess heat to escape.
The drum assembly 3 including drive system, heating system, and shrouds is mounted to a support frame 21 for tilting movement about a horizontal axis generally transverse to the longitudinal axis 13 of drum 5. For this purpose, the drum assembly 3 also includes a U- shaped mounting member 23 having arms extending around the drum 5. The mounting member 23 is pivotally connected to the upper ends 25 of support posts of support frame 21 by pins 27. The motor and gear box 9 is mounted to the member 23 so that the drum is cantilever mounted by the drive shaft 11 extending forwardly to the base of the drum. A reinforcing plate 31 is also provided at the base of drum 5 to assist supporting of the weight of drum assembly 3.
The reinforcing plate 31 may also have ribs 33, as shown in Figure 5. The ribs 33 extend radially beyond the plate 31 along the outer surface of the drum 5 to provide additional support to the drum assembly 3. Each of the ribs may have a taper towards the open end 7 of drum 5.
The burner 15 is connected to the mounting member 23 by a connecting arm 29, and the
shroud 19 is also connected to the mounting member 23. A handle 30 is fitted to mounting member 23 so as to allow an operator to pivot or tilt mounting member 23 (and thus drum assembly 3) relative to support 21 about the horizontal axis described above.
The support frame 21 has a screen 34 for preventing contact with the drum assembly 3 as it moves between the operative and discharge positions. The screen may also have its own shroud to further protect the operator from the heat of the drum. In addition, the support 21 has wheels 35 mounted to its base so as to render the machine 1 portable and easily transportable as required.
A control box 37 is provided on one side of the support frame 21. In this embodiment, the control box 37 includes a standard variable speed controller connected via leads 39 to motor 9, and controls for the gas burner. The support frame 21 is also provided with an adjustable stop 41 mounted to each of the posts to engage the mounting member 23 and to define the operative position of the drum assembly.
The drum assembly 3 is in its operative position, as shown in the Figures, so that the longitudinal axis 13 of drum 5 is inclined upwards relative to the drum base and the open end 7 faces upwards. The drum 5 is loaded with the initial ingredients via open end 7, and the burner 15 is activated so that the ingredients are brought to boil. Nuts are then loaded into drum 5 and drum 5 is heated so that a dry sugar coating is formed on the nuts. The operator then activates the drive system so that the drum 5 is rotated about its longitudinal axis 13, the drum 5 also being heated in this mode. Due to the inclined position of the longitudinal axis 13 of drum 5, rotation of the drum 5 induces the coated nut mixture contained within the drum 5 to undergo a tumbling effect. This tumbling effect promotes caramelisation of the nuts and ingredients as the burner 15 heats the nut mixture.
Once caramelisation or roasting of the mixture is finished, the motor 9 and burner 15 deactivated. The operator then uses handle 30 to tilt the mounting member 23 and therefore drum assembly 3 to a discharge position (not shown). In the discharge position, the longitudinal axis 13 of drum 5 is inclined downwards relative to the drum base so that
its open end 7 is facing downwards. A trough or other container (not shown) is provided beneath the open end 7 in the discharge position so as to receive the caramelised or roasted nut mixture from the drum 5.
In an alternative configuration, the drum assembly 3 may have a second, additional, operative position in which the longitudinal axis 13 of the drum 5 is positioned substantially vertical so the drum 5 sits upright with open end 7 facing upwardly. An additional stop may be provided to secure the drum assembly 3 in this operative position. In this second operative position, the drum 5 is loaded with the initial ingredients and the burner 15 is activated to bring the ingredients to boil. Nuts are then loaded into drum 5 in this operative position and the drum 5 is heated so that a dry sugar coating is formed on the nuts. The drum assembly 3 is then tilted to the operative position as described above to roast or caramelise the coated nut mixture. In practice, this alternative configuration with the second operative position is the preferred configuration of the machine 1.
Generally, the components of the machine 1 are mostly made of stainless steel, such as the drum assembly 3 and support frame 21. The drum 5 is preferably made of copper, as is reinforcing plate 31, while the ribs 33 can be made of brass.
A further embodiment of the invention is illustrated in Figure 6. In this embodiment, the handle 30 has been replaced with a cylinder 32, which can be pneumatic or hydraulic. The cylinder 32 is connected to mounting member 23 via an arm. The arm has a laterally extending portion to engage the mounting member 23 and a downwardly extending portion to engage the piston via a pin. The cylinder 32 is activated so that the piston moves the mounting member 23 and tilt the drum assembly 3 relative to support 21 about the horizontal axis. The use of a cylinder 32 allows infinite adjustment of the drum assembly 3 between its discharge position and its maximum tilt position. Thus, the operative position can be varied as required.
In this embodiment, an intermediate shroud 18 can be provided between shrouds 17, 19 for additional protection.
The drum 5 may also be provided on its inside surface with vanes (not shown) to further promote tumbling of the nut mixture. These vanes generally extend lengthwise of the drum. The drum 5 can have a diameter of between 500 to 900 mm.
In addition, the drum assembly 3 may have a blade (not shown) to "sweep" the inside surface of the drum 5 so as to remove any small or residual particles (nuts, etc.) that may have become stuck to the drum. This prevents burning of the small or residual particles during use. The blade is shaped to complement the contour of the inside surface of the drum. The blade can be made stationary with the drum moving relative to the blade or the blade can rotate relative to the drum.
It has been found that caramelised nuts can be produced by the machine more efficiently and are of enhanced quality. The ability to tilt drum assembly and so move drum allows for convenient loading and unloading of the ingredients and caramelised mixture. Therefore, caramelised nuts of good quality can be produced more efficiently and in greater quantities.
While the preferred embodiments of the invention have been described in relation to the processing of nuts, the invention may be used to process corn kernels, seeds and grains. In addition, the present invention may have a broader application to other edible material, such as candy, chocolate, nougat, confectionery and other food items.
The foregoing describes only one embodiment of the invention and modifications can be made without departing from the scope of the invention.