Roaster oven with air circulation

Abstract: A roaster oven with whirlpool circulation comprising an oven housing (3) and a whirlpool circulation device (4), the oven housing having two heating tubes (31) for heating up air therein, an air inlet (32) and two air outlets (33) in a front wall. The whirlpool circulation device has a fan (41), a fan housing (40) and a power source (42). The fan is positioned in the fan housing to be rotated by a motor in the power source to blow air in the fan housing, said fan housing having two whirlpool circulating tubes (4030) bent backward extending from the fan housing to lead hot air from the oven housing through the air inlet into the fan housing and then through the air outlets (33) of the oven housing into the oven housing to circulate as a whirlpool around a material placed in the roast chamber, roasting it thoroughly and evenly.

Description: This invention concerns a roaster oven with air circulation. So far, most roaster ovens generally use heat transmission by means of hot air flowing in convection, comprising an electric heating tube and a blower placed under the heating tube so that hot air generated by the heating tube may be blown into the oven and circulates in a convection manner to roast a material placed in the oven. However, the convectional flow of hot air can hardly make every place in the oven thoroughly and evenly heated, and thus the material roasted may not be evenly done, with Places near the heating tube well done, but the farthest place from the heating tube not well down. One kind of roaster oven shown in Fig. 1 comprises two separating plates 10, 10 respectively at a left and a right side in the oven to form two air passageways 11. 11, and a blower 12 to suck the hot air in the oven 1 to flow into the air passageways 11, 11 to flow back in the oven 1 through another side of the oven, forcing the hot air to flow in a convectional way. But the temperature near the bottom of the oven is higher than the upper side thereof, a material placed therein for roasting may get more well done at the right and the left side than other parts, which are not thoroughly nor evenly done. Another kind of roaster oven shown in Fig. 2 comprises an air blowing device 20, which sucks hot air generated by an electric heating tube 21 out of the oven and then blows it back into an upper part of the oven for better circulation of the hot air. But a material may he roasted with its upper and lower parts well done and with the rest parts still half done. So its work performance is not considered to be ideal. A further example of a roasted oven is described in DE-A-3501135 (Eplag AG) and comprises an oven housing having a roasting chamber for receiving a material to be roaster therein, electrical heating means and an air circulating device which comprises a fan located in a housing having a central air current chamber which communicates with air openings in the walls of the roasting chamber and, in use, said fan acts to blow hot air from said air current chamber into said roasting chamber, said hot air current coming out of the air openings becoming an air current which circulates in said roasting chamber around a material placed therein. This invention has been devised with an object of offering a roaster oven with air circulation, intended to overcome the defects of conventional roaster ovens mentioned above. In accordance with the present invention there is provided a roasting oven comprising an oven housing having a hollow roasting chamber for receiving a material to be roasted therein, heating means, and an air circulating device having air current openings comprising an air inlet and two air outlets provided in a wall of the roasting chamber, the air circulating device comprising a fan housing, a fan positioned in the fan housing, and a power source, said fan housing have a centre air current chamber, openings communicating with said air inlet and air outlets of said oven housing respectively, and, in use, said fan acting to blow a strong hot air current from said air current chamber into said roasting chamber of said oven housing, said hot air current coming out of said air outlets becoming an air current which circulates in said roasting chamber around a material placed therein to be thoroughly and equally roasted and characterised in that said air openings are provided in an internal vertical partition wall extending in parallel to a side wall of the roasting chamber and in that said air circulating device is fixed to said internal partition wall outside the roasting chamber and that said air outlets are provided at discrete positions from said inlet and that said air current chamber has two bent-backward whirlpool circulating tubes extending respectively from said current chamber to said discrete outlet openings whereby said two whirlpool circulating tubes create an air current circulating as a whirlpool in said roasting chamber. The power source of the whirlpool circulation device comprises a motor which rotates the fan to blow the hot air sucked in from the oven housing to circulate in an air current chamber of the fan housing to flow out of two whirlpool circulating tubes to enter again in the oven housing to circulate in a whirlpool way. The present invention will now be described, further, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a cross-sectional view of a known conventional roaster oven, Figure 2 is a cross-sectional view of another known conventional oven, Figure 3 is an exploded perspective view of a roaster oven with whirlpool circulation according to the present invention, Figure 4 is a cross-sectional view of the roaster oven of Figure 3, Figure 5 is a cross-sectional view of line B - B' in Fig. 4, showing the whirlpool direction of hot air produced in the roaster oven with whirlpool circulation in the present invention, Figure 6 illustrates the air flow direction of the hot air current coming out of a whirlpool circulating tube of a fan housing in the roaster oven with whirlpool circulation in the present invention Figure 7 is a cross-sectional view of the roaster oven with whirlpool circulation in the present invention, showing how whirlpool circulation is directed inside the oven. A roaster oven with whirlpool circulation in the present invention, as shown in Fig. 3, comprises an oven housing 3, and a whirlpool circulation device 4 combined together. The oven housing 3 has a hollow roasting chamber 30 defined by the housing 3, two electric heating tubes 31, 31 respectively fixed horizontally in an upper portion and a lower portion of the chamber 30, an air inlet 32 (conveniently compirsing a net or fine mesh) provided in a front wall of the oven housing 3, two air outlets 33, 33 respectively provided at a right upper side and at a left lower side of the air net 32, and several rivet holes around the air inlet 32 and the two air outlets 33, 33. The whirlpool circulation device 4 comprises a fan housing 40, a fan 41 and a power source 42 combined together, being fixed with rivets with the front wall of the housing 3 on the air inlet 32, and the two air outlets 33, 33, with the rivets going through the rivet holes 34. The fan housing 40 is shaped as illustrated, having an air current chamber 400 at the center portion and extending to a right side, a shaft hole 401 at the center of the bottom wall of the chamber 400, four rivet holes 402 around the shaft hole 401 for rivets P, two whirlpool circulation tubes 403, 403 respectively provided to extend bending backward from a right upper side and a left lower side of the wall of the chamber 400, a bending portion 4030 respectively formed in the two tubes 403, 403, a flange 404 provided respectively with the wall of the chamber 400 and the two tubes 403, 403 and having rivet holes 405 spaced around in the flanges 404. The fan 41 is to be positioned in the air current chamber 400 of the fan housing 40, having a center shaft sleeve 410 with a center shaft hole 411, a sideway screw hole 412 and a plurality of leaves 413 extending radially from the center, each leaf 413 having an air pushing portion 4130 for pushing air and an air emcircling portion 4131 for letting air to circulate. The power source 42 has a motor 421, a transmitting shaft 420 with one end connected with the shaft of the motor 42 and the other end firmly fixed with the shaft sleeve 410 of the fan 41 after passing through the shaft hole 401 of the fan housing 40 and in the shaft hole 411 of the shaft sleeve 410, two supporting plates 422 provided to sustain two ends of the motor 412, and several rivet holes 423 in the two supporting plates 422. In assembling, referring to Figs. 3 and 4, firstly, the power source 42 of the whirlpool circulating device 4 is combined with the fan housing 40 and the fan 41, with the transmitting shaft 420 made to pass through the shaft hole 401 of the fan housing 40, through the shaft hole 410 of the fan 41 and then fixed firmly with a screw N engaging the screw hole 413 of the fan 41. After that, the power source 42 is firmly fixed together with the fan housing 40 with rivets P1 riveted after passing through the holes 423 of the power source 42 and the connecting holes 402. Then, the whirlpool circulating device 4 combined together is combined together firmly with the housing 3 with rivets P1 riveted after passing through the flange holes 405 of the fan housing 40 and the small holes 34 around the airinlet 32 and the two air outlets 33, 33 of the front wall of the housing 3, finishing assemblage of this roaster oven with whirlpool circulation. In using, referring to Figs. 5, 6 and 7, a material A to be roasted is put in the chamber 30 on a grill B and a door is closed. Then electricity is turned on to let the two electric heating tubes 31, 31 to generate heat. The whirlpool circulating device 4 is also started, with the fan 41 rotated to suck in hot air in the roast chamber 30 from the right side, driving hot air to flow through the airinlet 32 into the fan housing 40, with the hot air pushed by the pushing portions 4130 of every leaf 413 and flowing in the air current chamber 400 and then becoming a circulating air current between the fan leaves 413 and the air current chamber 400 by means of the encircling portions 4131, as shown in Fig. 5. Then the circulating hot air current continuously flows through the two whirlpool circulating tubes 403, 403, which have the bent portions 4030 to force the hot air current to swirl like a whirlpool and then to flow through the air outlets 33, 33 into the chamber 30 as whirlpool current moving around in the chamber 30, as shown in Figs. 6 and 7. Therefore, the material A can be roasted by the hot air whirlpool current, with every part of it receiving the hot air for complete roasting as if the material A were rotated for 360 degrees during roasting.

Claims: A roasting oven comprising: an oven housing (3) having a hollow roasting chamber (30) for receiving a material to be roasted therein, heating means (31) and an air circulating device (4) having air current openings comprising an air inlet (32) and two air outlets (33) provided in a wall of the roasting chamber, the air circulating device comprising a fan housing (40), a fan (41) positioned in the fan housing, and a power source (42), said fan housing have a centre air current chamber (400), openings communicating with said air inlet and air outlets of said oven housing respectively, and, in use, said fan acting to blow a strong hot air current from said air current chamber into said roasting chamber (30) of said oven housing (3), said hot air current coming out of said air outlets (33) becoming an air current which circulates in said roasting chamber (30) around a material placed therein to be thoroughly and equally roasted and characterised in that said air openings (33) are provided in an internal vertical partition wall (32) extending in parallel to a side wall of the roasting chamber (30) and in that said air circulating device is fixed to said internal partition wall (32) outside the roasting chamber (30) and that said air outlets (33) are provided at discrete positions from said inlet (32) and that said air current chamber (400) has two bent-backward whirlpool circulating tubes (403) extending respectively from said current chamber (400) to said discrete outlet openings (33) whereby said two whirlpool circulating tubes (403) create an air current circulating as a whirlpool in said roasting chamber (30). A roasting oven as claimed in claim 1 in which there is a centre shaft hole in a bottom wall of the air current chamber (400), said power source (42) is fixed on an outer side of said fan housing (40), and has a motor (421), a transmitting shaft (420) with one end connected with the shaft of said motor (421) and with the other end passing through the shaft hole (401) of said fan housing (40) and then fixed firmly with the shaft sleeve (410) of said fan (41). A roasting oven as claimed in claim 1 or 2, wherein said fan housing (40) of said whirlpool circulation device (4) has a flange (404) at its inner side and rivets holes (405) spaced around in said flange (404), and said air inlet (32) and said air outlets (33) of said partition wall of the roasting chamber (30) also have rivet holes (34) around them in the corresponding locations of said rivet holes (405) of said fan housing (40) so that rivets (P1) may fasten firmly together said whirlpool circulation device with said oven housing. A roasting oven with whirlpool circulation as claimed in claim 1, 2 or 3, wherein said fan (41) has a centre shaft sleeve (410) and a plurality of fan leaves (413) extending radially from the outer side of said centre shaft sleeve (410), each of said fan leaves (413) having a pushing portion to push air and an encircling portion for forcing air to circulate. A roasting oven as claimed in any one of the preceding claims in which the heating means comprises two electric heating tubes (31) respectively fixed at an upper portion and a lower portion of the roasting chamber (30).

Inventors: WANG CHING-HSIANG, WANG, CHING-HSIANG
Applicants: WANG CHING HSIANG, WANG, CHING-HSIANG
Application year: 1995
Main classification: F24C15
IPC codes: F24C15