The present invention relates to an oven wherein the noise generated by the fan motor is reduced.
In domestic type ovens, for example in built-in ovens, fans are used for circulating the hot air in the heating chamber for maintaining homogeneous temperature distribution and heat transfer by forced convection and to cool the electronic devices in the oven. The fan, circulating hot air in the heating chamber, is mounted on the rear wall of the chassis surrounding the cooking chamber situated in the main body of the oven, is driven by a fan motor and the high amplitude vibrations during the operation of the motor result in the generation of noise. The fan motor is secured on a motor mounting plate fastened on the rear wall of the chassis and the vibrational motion of the fan motor is transmitted to the motor mounting plate and to the chassis from there. The high amplitude vibrations of the fan motor cause the rear wall of the chassis to act like a diaphragm and generate a noise of structural origin.
In the state of the art, generally rubber vibration attenuators are used for obviating the fan motor noise at the rear of the oven, however the rubber dampers occupy much space and can be harmed by melting due to high temperatures in the oven and lose their dampening properties.
In the state of the art Japanese patent document no JP60000225, a heating cooker is explained wherein the stability of the rotary body containing the food to be cooked thereon is improved against vibration and shock.
In the state of the art Japanese patent document no JP59027136, a heating cooker is explained wherein the noise generated by the fan motor is reduced. The fixing fitment, securing the fan motor is fixed to the rear wall of the insulating board through an elastic cushion provided with the space for absorbing the vibration.
In the state of the art United States of America patent document no U.S. Pat. No. 5,990,467, in a microwave oven, the explanation is given how the motor driving the blower for cooling the microwave devices are mounted on the rear panel of the body by means of a fixing rod.
The aim of the present invention is the realization of an oven wherein the noise generated by the fan motor circulating hot air is reduced.
The oven realized in order to attain the aim of the present invention is explicated in the claims.
The oven comprises a fan that circulates the hot air in the heating chamber wherein the cooking process is performed. The fan is driven by a motor not affected by the temperature inside the heating chamber by being mounted outside the rear wall of the heating chamber. The lugs supporting the motor extend outward from the motor in different directions and each motor lug is secured on the mounting plate on the rear wall of the heating chamber for fastening the fan motor.
The oven of the present invention comprises a first spring arm, mounted between each lug and the mounting plate, secured to the lug, a second spring arm fastened to the mounting plate and more than one leaf spring having at least one curve that joins the spring arms.
The spring arms extend in the direction of the lug whereto it is fastened and the curve is in the vertical direction to the lug. The leaf spring stretches in the direction the lug extends and attenuates the vibrations of the fan motor in the parallel direction to the mounting plate.
The leaf springs are produced of metal, preferably of spring steel.
In an embodiment of the present invention, the leaf spring is configured as a hollow closed curve made by joining the two ends of a metal band. In this embodiment, assembly elements such as bolts are welded on the upper and lower surfaces of the leaf spring and the leaf spring is secured to the motor lug and the mounting plate by means of the assembly elements on its upper and lower surfaces.
In another embodiment of the present invention, the leaf spring is configured by bending a metal band in a U form and the spring arms are joined by a single curve. The curve that joins the spring arms is situated on the side of the leaf spring facing the shaft axis of the fan motor. One arm of the U shaped spring is fastened to the motor lug and one arm to the mounting plate, one under the other and at the same level.
In another embodiment of the present invention, the arm of the leaf spring seated on the mounting plate is longer than the arm seated on the motor lug, providing ease of assembly. In this embodiment, a screw hole is provided on the longer spring arm seated on the mounting plate for screwing thereof on the mounting plate and an opening again on the longer spring arm, just opposite the shorter spring arm for fastening the shorter spring arm to the motor lug easily. Since the distance between the shorter spring arm and the longer spring arm is not much, the opening just opposite the shorter spring arm is utilized for fastening the shorter spring arm to the motor lug by inserting a screwdriver or similar assembly tool to screw the shorter spring arm to the motor lug. The leaf spring furthermore comprises a barrier on its arm seated on the motor lug for preventing turning during the assembly.
The leaf spring of the present invention attenuates the vibrational motion of the fan motor in the radial directions in the short distance between the motor lugs and the mounting plate, the motor is prevented from contacting the outer wall of the oven and ease of assembly is provided as well.
The oven realized in order to attain the aim of the present invention is illustrated in the attached figures, where:
FIG. 1—is the schematic view of an oven.
FIG. 2—is the schematic view of the motor lugs supporting the fan motor and the leaf springs fastened to the motor lugs in an oven.
FIG. 3—is the schematic view of a leaf spring fastened between the fan motor lug and the mounting plate in another embodiment of the present invention.
FIG. 4—is the perspective view of a leaf spring in another embodiment of the present invention.
FIG. 5—is the perspective view of a fan motor fastened to a mounting plate and the leaf springs mounted between the fan motor lugs and the mounting plate.
FIG. 6—is the perspective view of detail A in
The elements illustrated in the figures are numbered as follows:
1. Oven
2. Heating chamber
3. Fan
4. Rear wall
5. Fan motor
6. Lug
7. Mounting plate
8. Leaf spring
9. 109. Spring arm
10. Curve
11. Assembly element
12. 112. Screw hole
13. Barrier
14. Opening
The oven (1) comprises a heating chamber (2) wherein the cooking process is performed, a heater disposed in the heating chamber (2), a fan (3) for circulating the hot air in the heating chamber (2), a rear wall (4) covering the rear side of the heating chamber (2), a fan motor (5) mounted outside the rear wall (4) such that the shaft axis (E) thereof is vertical to the rear wall (4) for rotating the fan (3) in the heating chamber (2), more than one lug (6) supporting the fan motor (5) and helping the assembly thereof, each one vertical to the shaft axis (E) of the fan motor (5) and extending in different directions (D1, D2, D3, . . . ) outward from the fan motor (5), and a mounting plate (7) secured outside the rear wall (4), whereto the lugs (6) are fastened (
The oven (1) of the present invention comprises more than one leaf spring (8),
The spring arms (9, 109) are configured to be flat shaped, and the lug (6) contacts with the upper surface of the first spring arm (9) and the mounting plate (7) contacts with the lower surface of the second spring arm (109).
The leaf spring (8) under each lug (6) stretches in the radial direction (D1, D2, D3, . . . ) the lugs (6) extend by the vibrational motion of the fan motor (5) and attenuate the vibrations of the fan motor (5) in parallel directions to the mounting plate (7) and the noise level is reduced.
The leaf spring (8) is produced of a metal material, such as spring steel and is not affected by high temperature.
In an embodiment of the present invention, the leaf spring (8) is configured as a hollow closed curved line made by joining the two ends of a metal band and the spring arms (9, 109) join to each other from both ends by two curves (10) (
In this embodiment, the oven (1) comprises more than one assembly element (11) such as bolts, screws or pins fastened vertically by welding method on the upper surface of the first spring arm (9) and the lower surface of the second spring arm (109). The leaf spring (8) is secured to the lug (6) by means of the assembly element (11) welded on the upper surface of the first spring arm (9) and to the mounting plate (7) by means of the assembly elements (11) welded on the lower surface of the second spring arm (109) (
The leaf spring (8) attenuates the vibrations of the fan motor (5) particularly between the lug (6) and the mounting plate (7) wherein there is insufficient distance, and the fan motor (5) is prevented from contacting the outer body of the oven (1) by moving backwards.
In another embodiment of the present invention, the leaf spring (8) is configured by bending a metal band in U form and the spring arms (9, 109) are joined by a single curve (10). The spring arms (9, 109) extend one under the other between the lug (6) and the mounting plate (7) at the same level and in the direction (D1, D2, D3, . . . ) of the lug (6). In this embodiment, the curve (10) is situated on the side of the spring arms (9, 109) facing the shaft axis (E) of the fan motor (5) (
In a version of this embodiment, the leaf spring (8) comprises a second spring arm (109) longer than the first spring arm (9) that extends in the direction (D1, D2, D3, . . . ) of the lug (6), projecting from the lug (6) outwards (
In this embodiment, the leaf spring (8) furthermore comprises a screw hole (12) on the first spring arm (9) for fastening thereof to the lug (6) and a second screw hole (112) on the portion of the second spring arm (109) extending forward from the level of the lug (6) for fastening thereof to the mounting plate (7) (
The leaf spring (8) furthermore comprises a barrier (13) disposed on the first spring arm (9), extending from the first spring arm (9) and bearing against the side wall of the lug (6) thereby preventing thereof from turning while screwing to the lug (6) and an opening (14) on the second spring arm (109), aligned with the screw hole (12) on the first spring arm (9), big enough for the screw head to pass that is fastened to the lug (6) from the screw hole (12) for easily screwing to the motor lug (6) in the vertical direction by a hand tool like the screwdriver (
While the leaf spring (8) is mounted to the lug (6), a screw passed through the opening (14) is screwed on the lug (6) by means of the screw hole (12) with a screwdriver inserted again through the opening (14). The barrier (13) prevents the leaf spring (8) from turning while the leaf spring (8) is screwed on the lug (6). The screw hole (112) on the second spring arm (109) is not covered by the lug (6) since it is disposed in the portion of the second spring arm (109) extending outwards from the lug (6) and can be easily screwed on the mounting plate (7) by a screwdriver held vertical to the mounting plate (7).
In the oven (1) of the present invention, the vibrations transmitted from the fan motor (5) to the mounting plate (7) and to the rear wall (4) of the heating chamber (2) from the mounting plate (7) are reduced and improvement is provided in the noise generated by the fan motor (5).
Number | Date | Country | Kind |
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A2007/09111 | Dec 2007 | TR | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP08/66379 | 11/27/2008 | WO | 00 | 10/2/2010 |