GB2177880A - A heating device for a fan - Google Patents
A heating device for a fan Download PDFInfo
- Publication number
- GB2177880A GB2177880A GB08518070A GB8518070A GB2177880A GB 2177880 A GB2177880 A GB 2177880A GB 08518070 A GB08518070 A GB 08518070A GB 8518070 A GB8518070 A GB 8518070A GB 2177880 A GB2177880 A GB 2177880A
- Authority
- GB
- United Kingdom
- Prior art keywords
- heating device
- fan impeller
- connecting element
- fan
- stationary
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 238000010438 heat treatment Methods 0.000 title claims abstract description 73
- 229910052751 metal Inorganic materials 0.000 claims description 7
- 239000002184 metal Substances 0.000 claims description 7
- 239000004020 conductor Substances 0.000 claims description 4
- 239000012772 electrical insulation material Substances 0.000 claims description 4
- 229910052709 silver Inorganic materials 0.000 claims description 4
- 239000004332 silver Substances 0.000 claims description 4
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 claims 3
- 241000252203 Clupea harengus Species 0.000 claims 1
- 235000019514 herring Nutrition 0.000 claims 1
- 239000000615 nonconductor Substances 0.000 claims 1
- 239000010445 mica Substances 0.000 description 2
- 229910052618 mica group Inorganic materials 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000010292 electrical insulation Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B3/00—Ohmic-resistance heating
- H05B3/20—Heating elements having extended surface area substantially in a two-dimensional plane, e.g. plate-heater
- H05B3/22—Heating elements having extended surface area substantially in a two-dimensional plane, e.g. plate-heater non-flexible
- H05B3/26—Heating elements having extended surface area substantially in a two-dimensional plane, e.g. plate-heater non-flexible heating conductor mounted on insulating base
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24H—FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL
- F24H3/00—Air heaters
- F24H3/02—Air heaters with forced circulation
- F24H3/04—Air heaters with forced circulation the air being in direct contact with the heating medium, e.g. electric heating element
- F24H3/0405—Air heaters with forced circulation the air being in direct contact with the heating medium, e.g. electric heating element using electric energy supply, e.g. the heating medium being a resistive element; Heating by direct contact, i.e. with resistive elements, electrodes and fins being bonded together without additional element in-between
- F24H3/0411—Air heaters with forced circulation the air being in direct contact with the heating medium, e.g. electric heating element using electric energy supply, e.g. the heating medium being a resistive element; Heating by direct contact, i.e. with resistive elements, electrodes and fins being bonded together without additional element in-between for domestic or space-heating systems
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K11/00—Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection
- H02K11/20—Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection for measuring, monitoring, testing, protecting or switching
- H02K11/21—Devices for sensing speed or position, or actuated thereby
- H02K11/23—Mechanically-actuated centrifugal switches
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B1/00—Details of electric heating devices
- H05B1/02—Automatic switching arrangements specially adapted to apparatus ; Control of heating devices
- H05B1/0227—Applications
- H05B1/0252—Domestic applications
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B2203/00—Aspects relating to Ohmic resistive heating covered by group H05B3/00
- H05B2203/002—Heaters using a particular layout for the resistive material or resistive elements
- H05B2203/003—Heaters using a particular layout for the resistive material or resistive elements using serpentine layout
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Structures Of Non-Positive Displacement Pumps (AREA)
Abstract
The present invention discloses a heating device for a fan which has a fan impeller (2) and a driving motor (5) connected to the fan impeller (2) through its driving shaft to drive the fan impeller (2), and comprises a length of heating element (1) thereon mounted on the fan and in the air delivery path of the fan, and adapted to be coupled to an electrical power source; and means (17; 17') for switching on the heating element (1) when the rotational speed of the fan impeller (2) exceeds a predetermined speed, and switching off the heating element (1) when the fan impeller (2) drops below the predetermined speed, the switching means (17; 17') secured on the fan impeller (2) for being rotated with the fan impeller (2). <IMAGE>
Description
SPECIFICATION
A heating device for a fan
The present invention is related to a heating device for a fan, and more particularly to a heating device which can be switched on when the rotational speed of the fan impeller of the fan exceeds a predetermined speed, and shut off when the rotational speed of the fan impeller drops below a predetermined speed.
The conventional heating device used by the electric fan generally includes a fixed frame adapted to be mounted on the housing around the fan impeller, and a heating element wound on the fixed frame. The external surfaces of the fixed frame are covered by an electrical insulation material, such as mica, having heat-resistant characteristics. One type of the conventional electric fan has two individual switches for controlling the fan impeller and the heating device respectively, whereas the other type has only one switch for simultaneously controlling the fan impeller and the heating device. Apparently, the former is more advantageous than the latter.
However, during the operation of the former, it is often the case that the switch for controlling the fan is opened and the switch for controlling the heating device is closed due to the user's carelessness. This will quickly raise the temperature in the fan, and may result in the melting of the fan impeller, which is generally made of plastic material.
For solving the above problems, a temperature controlling switch is utilized to automatically shut off the heating device when the temperature around the fan reaches a predetermined height. However, the predetermined temperature is usually preset at-a relatively high value for preventing the temperature controlling switch from prematurely shutting off the heating device. In the event that the wrong operation occurs, e.g. the switch for controlling the fan impeller is opened while the switch for controlling the heating device is improperly closed, the electrical power will not be interrupted untii the increasing temperature of the heating device reaches the predetermined temperature. Therefore, it is still inadvantageous that the heating device cannot be immediately turned off in response to the situation that the heating device is not needed.
A heating device in accordance with one preferred embodiment of the present invention intends to solve the problems described above.
The object of the present invention is to provide a heating device for a fan which utilizes means for switching on a heating element of the heating device when the rotational speed of the fan impeller exceeds a predetermined speed, and switching off the heating element when the fan impeller drops below the predetermined speed.
In accordance with the present invention, the heating device for a fan which has a fan impeller and a driving motor connected to the fan impeller through its driving shaft to drive the fan impeller, comprises a length of heating element having a breaking gap thereon mounted on the fan and situated in the air delivery path of the fan, and adapted to be coupled to an electrical power source; and means for switching on the heating element when the rotational speed of the fan impeller of the fan exceeds a predetermined speed, and switching off the heating element when the fan impeller drops below predetermined speed, the switching means connected on the breaking gap and secured on the fan impeller for being rotated with the fan impeller.
The present invention will be more fully understood from the following detailed description, taken in connection with the accompanying drawings which form an integral part of this application and in which:
Fig. 1 is a perspective view illustrating that the heating device is mounted on the fan blades in accordance with one preferred embodiment of the present invention;
Fig. 2 is a side elevational view of a part of the fan with a cross-sectional portion illustrating the way by which the heating device is coupled to an electrical power source;
Fig. 3 is a perspective view of a stationary disc and two fastening means as shown in Fig. 2;
Fig. 4 is an enlarged perspective view of the switching means in accordance with the first embodiment of the present invention;
Fig. 5 is an elevational view of the switching means of Fig. 4;;
Fig. 6 is a perspective view of the switching means of Fig. 4 incorporated with an adjusting means;
Fig. 7 is a perspective view of the switching means incorporated with an adjusting means in accordance with the second preferred embodiment of the present invention.
Referring now to the drawings, it should be noted that a like member is designated with a like reference number. In Fig. 1,there is shown a heating device provided in the fan impeller 2 of a fan by the way that a length of heating element 1 of the heating device is serpentined on the surfaces of the fan blades 3 of the fan impeller 2, and a plurality of securing members 18 are positioned on the heating element 1 and fastened to the fan blades 3 respectively for affixing the heating element 1 firmly on the fan blades 3. Two free ends 1 a and 1 b of the heating element 1 are respectively fixed on the fan impeller 2 by two fastening means 7 and 8, e.g.
threaded connectors, which are coupled to an electrical power supply source. This will be further described in detail below.
On the surfaces of the fan blades 3 an electrical insulation coating, such as mica, having heatresistant characteristics, may be provided beforehand. Alternatively, the fan blades 3 may be made entirely of an electrical insulation material having heat-resistant characteristics.
Along the length of the heating element 1 there is at least one breaking gap 20 thereon, and in Fig. 1 there are shown three breaking gaps. Further, at least one means 17 for switching on the heating element 1 when the rotational speed of the fan impeller 2 exceeds a predetermined speed, and for switching off the heating element when the fan impeller 2 drops below the predetermined speed, is connected on the corresponding breaking gap 20.
Referring to Figs. 1,4,5, and 6, one preferred embodiment of the switching means 17 includes a stationary connecting element 17a having one end fastened to the heating element 1 at one side 20a of the breaking gap 20, and a resilient connecting element 17b having one end fastened to the heating element 1 at the other side 20b of the breaking gap 20. The resilient connecting element 17b is separated with the stationary connecting element 17a by a small distance. This distance determines the predetermined speed. Both of them are arranged vertical to the direction of the centrifugal force generated due to the rotation of the fan impeller 2, wherein the resilient connecting element 17b is closerto the center of the fan impeller 2 than the stationary connecting element 17a.
Therefore, when the fan impeller 2 rotates at the predetermined speed, its generating centrifugal force is then sufficient to urge the resilient connecting element 17b against the stationary connecting element 17a as shown in Fig. 5. As a result, the length of the heating element 1 is formed in a conductive loop for the electrical power. When the rotational speed of the fan impeller 2 drops below the predetermined speed, the generating centrifugal force is no longer sufficient to urge the resilient connecting element 17b to contact the stationary conenecting element 17a. As a result, the resilience of the resilient connecting element 17b will return it back to the original position, and the length of heating element 1 forms a nonconductive loop.It should be noted that a weight ball 17e may be provided on the place near the free end of the resilient connecting element 17a for increasing the centrifugal force. Also, the switching means 17 may include means 17d for adjusting the distance between the stationary connecting element 17a and the resilient connecting element 17b, mounted adjacently to the resilient connecting element 1 7b as shown in Fig. 6. By means of the adjusting means 17d, the predetermined speed to turn on the switching means 17 can be easily changed.
Referring to Fig. 7, the other preferred embodiment of the switching means 17 according to the present invention also includes a stationary and a resilient connecting element 171 and 172.
However, in this embodiment both of them are arranged vertical to the rotational direction A of the fan impeller 2, and the resilient connecting element 172 is placed in front of the stationary connecting element 173, if viewing from the rotational direction
A. Similarly, the switching means 17 will be turned on by the air resilience generated due to the rotation of the fan impeller 2 when the fan impeller 2 rotates up to the predetermined speed, in contrast to the centrifugal force described above, and be turned off when the fan impeller 2 rotates at the speed below the predetermined speed. Further, the structures of the adjusting means 173 and the weight ball 174, and the fastening means ofthe connecting elements 171 and 172 to the heating element 1 are all the same as those in the first preferred embodiment.
Referring now back to Figs. 1,2, and 3, the central portion of the fan impeller 2 is a cup connector 4 around the outer circular surface on which the fan blades 3 are secured. The cup connector 4 is engaged to the driving shaft 5a of the driving motor 5 at its rear hollow part 6. The two fastening means 7 and 8, eg. threaded connectors, are electrical conductors, and they respectively fasten the two free ends 9 and 10 of the heating element 1 on the front surface 4a of the cup connector 4 by screwing from the front surface into the rear hollow part 6 of the cup connector 4. A stationary disc 13 made of an electrical insulation material is secured on the casing of the motor 5, and has a central bore 13a for the driving shaft 5a to extend through.On the stationary disc 13 two concentric circular grooves 13b and 13c are provided, and two openings 13d and 13e respectively extend from the bottom of the grooves to the rear surface of the stationary disc 13.
The surfaces of the grooves 13b and 13c are all preferably formed in an arched shape. The circular grooves 13b and 13c are separated, and respectively have a metal layer covered thereon. Two power supply lines 14 and 15 are inserted into the openings 13d and 13e and then fastened on the metal layers of the grooves 1 3b and 13c, respectively.
Two connecting elements 11 and 12 which are electrical conductors respectively have one end connected to the respective fastening means 7 or 8, and the other end slidably abutted against the respective groove 13b or 13c. When the fan impeller 2 rotates, the connecting means 11 and 12 will rotate and slide along the respective grooves 13b and 13c without detachment following the rotation of the fastening means 7 and 8. Therefore, the electrical power can be supplied to the heating element 1 through the metal layers on the grooves 13b and 13c, the connecting elements 11 and 12, and the fastening means 7 and 8, in the event that the switching means 17 is on due to the rotation of the fan impeller 2.Further, the connecting elements 11 and 12 are preferably constructed from resilient plates, e.g. leaf springs, so that they can bias their free ends to firmly contact the grooves 1 3b and 13c.
At the free ends of the connecting elements 11 and 12 there are two abrasive contacts 11 a and 12a. The abrasive contacts 11 a and 1 2a are preferably in a ball shape in correspondance to the arched surfaces of the grooves 13b and 13c, and are made of silver.
According to the above-described structure of the heating device of the present invention, the power sourr.es respectively supplied to the driving motor 5 and the heating device are advantageously separated. The electrical power is supplied to the heating element 1 only when the fan impeller 2 rotates at the speed higher than the predetermined speed. It should be noted that the heating element 1 can be alternatively fastened on the housing of the fan and in the air delivery path, and the switching means is arranged on the place where it will rotate with the rotation of the fan impeller to properly perform its function.
Claims (15)
1. A heating device for a fan which has a fan impeller and a driving motor connected to the fan impeller through its driving shaft to drive the fan impeller, comprising:
a length of heating element having a breaking gap thereon mounted on the fan and in the air delivery path of the fan, and adapted to be coupled to an electrical power source; and
means for switching on the heating element when the rotational speed of the fan impeller exceeds a predetermined speed, and switching off the heating element when the fan impeller drops below the predetermined speed, the switching means connected to the breaking gap and secured on the fan impeller for being rotated with the fan impeller.
2. A heating device as claimed in 1, wherein the switching means includes a stationary connecting element having one end fastened to the heating element at one side of the breaking gap, and a resilient connecting element having one end fastened to the heating element at the other side of the breaking gap, separated with the stationary connecting element by a small distance, and adapted to be urged to bend toward and contact the stationary connecting element by a pushing force generated due to the rotation of the fan impeller.
3. A heating device as claimed in claim 2, wherein the stationary and resilient connecting elements are arranged vertical to the direction of the centrifugal force generated due to the rotation of the fan impeller, and wherein the resilient connecting element is closer to the center of the fan impeller than the stationary connecting element.
4. A heating device as claimed in claim 2 or 3, wherein the resilient connecting element is provided with a weight ball thereon near the free end thereof.
5. A heating device as claimed in claim 2, wherein the stationary and resilient connecting elements are arranged vertical to the rotational direction of the fan impeller, and the resilient connecting element is placed in front of the stationary connecting element along the rotational direction for being urged to bend back to contact the stationary connecting element by the air resistance generated due to the rotation of the fan impeller.
6. A heating device as claimed in any one of claims 1 to 5, wherein the length of heating element is serpentined on the front surface of fan blades of the fan impeller, which has been clothed with an electrical insulation material having heat-resistant characteristics.
7. A herring device as claimed in any one of claims 1 to 6, wherein the central portion of the fan impeller is a cup connector which secures the fan blades around the outer circular surface thereof, and is engaged to the driving shaft at its rear hollow part, and wherein the heating device further comprises two fastening means which are electrical conductors for respectively fastening two free ends of the heating element on the front surface of the cup connector; a stationary disc which is an electrical insulator, and has two concentric circular grooves respectively covered with a metal layer thereon, secured on the casing of the motor and coupled to an electrical power source at the metal layer on the circular grooves; and two connecting elements which are electrical conductors, and which respectively have one end connected to the respective fastening means, and the other end slidablyabutted against the respective groove, whereby the electrical power is supplied to the heating element through the metal layers, the connecting means, and the fastening means when the switching means is turned on.
8. A heating device as claimed in claim 7, wherein each end abutted against each groove of each connecting element has an abrasive contact thereon.
9. A heating device as claimed in claim 8, wherein each abrasive contact is made of silver.
10. A heating device as claimed in claim 9, wherein each silver abrasive contact is in the form of a ball, and each groove is formed with an arched surface.
11. A heating device as claimed in claim 9 or 10, wherein each connecting element is a resilient plate which biases the silver abrasive contact firmly against the arched surface.
12. A heating device as claimed in any one of claims 7 to 11, wherein the stationary disc has two openings extending from its rear surface to the bottom of the grooves, respectively,fortwo power supply lines to insert thereinto and then fasten to the metal layers ofthe grooves, respectively.
13. A heating device as claimed in any one of claims 7 to 12, wherein each fastening means is a threaded connector which has a part extending through the front surface of the cup connector, and connecting to the connecting element.
14. A heating device as claimed in any one of claims 7 to 13, wherein the resilient connecting element includes means for adjusting the distance between the stationary connecting element and the resilient connecting element mounted adjacently to the resilient connecting element in order to preset the predetermined speed.
15. A heating device substantially as hereinbefore described with reference to any one of Figures 1 to 7 of the accompanying drawings.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB08518070A GB2177880A (en) | 1985-07-17 | 1985-07-17 | A heating device for a fan |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB08518070A GB2177880A (en) | 1985-07-17 | 1985-07-17 | A heating device for a fan |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB8518070D0 GB8518070D0 (en) | 1985-08-21 |
| GB2177880A true GB2177880A (en) | 1987-01-28 |
Family
ID=10582434
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB08518070A Withdrawn GB2177880A (en) | 1985-07-17 | 1985-07-17 | A heating device for a fan |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2177880A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2003086018A1 (en) * | 2002-04-11 | 2003-10-16 | Valeo Climatisation | Electric heating device, particularly for a heating or air-conditioning unit in a vehicle |
| EP1363383A2 (en) * | 2002-05-17 | 2003-11-19 | Cosmos Italia S.R.L. | Control circuit equipped with heating or cooling devices, particularly for direct current fans |
-
1985
- 1985-07-17 GB GB08518070A patent/GB2177880A/en not_active Withdrawn
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2003086018A1 (en) * | 2002-04-11 | 2003-10-16 | Valeo Climatisation | Electric heating device, particularly for a heating or air-conditioning unit in a vehicle |
| FR2838599A1 (en) * | 2002-04-11 | 2003-10-17 | Valeo Climatisation | ELECTRIC HEATING DEVICE, PARTICULARLY FOR VEHICLE HEATING AND AIR CONDITIONING APPARATUS |
| EP1363383A2 (en) * | 2002-05-17 | 2003-11-19 | Cosmos Italia S.R.L. | Control circuit equipped with heating or cooling devices, particularly for direct current fans |
| EP1363383A3 (en) * | 2002-05-17 | 2006-07-12 | Fandis S.p.A. | Control circuit equipped with heating or cooling devices, particularly for direct current fans |
Also Published As
| Publication number | Publication date |
|---|---|
| GB8518070D0 (en) | 1985-08-21 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |