US 2472039 A
Description (OCR text may contain errors)
May 31, 1949. E. zAcHARlA l 2,472,039
ELECTRIC FAN Filed DeC. 9, 1946 /9 ATTORNEY Patented May 31, 1,949`
UNITED STATES PATENT OFFICE ELECTRIC FAN Erhard Zacharias, New York, N. Y.
Application December 9, 1946, Serial Nc. 715,090
5 Claims. 1
My invention relates to an electric fan and more particularly to a fan of this kind which is operated electromagnetically.
My principal object is to provide a noiseless, simple and inexpensive fan of novel construction and capable of developing a strong torque and high relative speed.
With such subjects in View, and others which will appear as the description proceeds, the invention comprises various novel features of construction and arrangement of parts which will be set forth in the following description and claims, reference being made to the accompanying drawings which form part of the specification and which illustrate one embodiment of the invention.
rhe fan according tc the invention is provided with an armature comprising metallic blades attractable by magnetic force arranged as usual; an electromagnet attracting and thereby revolving the blades of said armature when the electromagnet is supplied with electric current; means for interrupting the electric current temporarily at certain positions of the revolving armature; and detent means to fix the blades of the armature in a certain position when the fan is out of action.
In the accompanying drawings in which similar characters of reference indicate corresponding parts- Figure 1 is a front view 0f an embodiment of my improved fan.
Fig. 2 is a side view of the same, partly in section.
Fig. 3 is a back view of the fan with the element box-cover removed.
Fig. 4 is an enlarged showing of the detent holding means.
Fig. 5 is similar to Fig. 4 except that the fan shaft has been slightly revolved.
Fig. 6 is a section along line B-B of Fig, 4, showing the detent means in greater detail.
Fig. is a wiring diagram.
The fan armature I comprises several metallic blades 2, mounted as usual on a revolving shaft 3. A circular stationary Wire frame 9 of known construction protects the revolving armature I. A center disc I located in the front part of frame 9 is centrally perforated to form bearing 1 receiving the front journal 4 of the revolving shaft 3, as shown in Fig. 6.
An opening 8 is provided in the wall of a boX 2l, arranged adjacent to the back part of frame 9 for receiving and bearing the back journal 5 of shaft 3. Journal is provided with a stub 6 2 of square cross-section, said stub extending into box 2 I.
The armature will be actuated by a fixed electromagnet il disposed below the blades in order to attract the same, thereby causing rotation of the armature. The electromagnet comprises coils I6 and a core cf soft iron l5. Electric current is supplied to the electromagnet through circuit wires I8 and i9.
The current will be intermittently opened and closed by the means disposed in box 2l, as shown in ligsl 3 and 7, and described below. Circuit wire l@ is connected with a metallic block 23 to which spring 22 is fixed. Said spring 22 is provided at its upper end with a Contact point 25 and opposite to it, with a cam member 24. Said cam member consists of non-conducting material, preferably rubber. Member 24 is disposed to engage with the square-shaped stub 6. Circuit wire i3 is connected with a metallic block 28 to which a metallic spring 2 is attached, said spring being provided at its lower end with contact point 26. When the armature comprising shaft 3 and stub E, connected to said shaft, moves from the position of stub E3 shown in dotted lines in Fig. 3 to the full line position, spring 22 Will be bent back, contact point 25 will engage contactl point 21, and the circuit will be closed. If springs 22 and 21 as well as stub 6 are in the position shown in Fig 7, the circuit is interrupted. That means that the circuit is always closed when an edge of stub 6 engages with cam member 24 and bends it back, and that it is interrupted when one of the bases of stub 6 contact cam member 24. The electromagnet will be thereby energized and deenergized synchronously with the rotation of the armature. Clockwise the armature moves under magnetic action to the position in which the current is interrupted, and then it moves by momentum to a position Where contact is made again. In this manner the circuit is intermittently made and broken.
In order to regulate the electromagnetic action during the make and break periods, condenser 20 is inserted in the circuit.
The magnetic action of core i5 is improved according to this invention by providing the same with a specially shaped top or surface ll adapted to fit the shape of the outer ends of blades 2 to be attracted by said surface. This is shown in Fig. 1
Blades 2 are shaped in a manner to produce.
In order to insure that the blades are always under magnetic inuence when the fan is to be started, that is, when a closed circuit is in existence when the current is supplied to the electromagnet at the start, detent means are provided to x stub 6, `together with the amature, in proper position when the fan stops.
Means of this kind, as shown in Figs. 4, and 6, are provided partly in journal 4 of shaft 3 and partly in Kdisc, IfIl 'belonging to the ,wire lframe 8. Said means .comprise a .bore I2 provided in and revolving with shaft-journal 4 and in line with said revolving bore I2 four stationary bores lll, provided in disc I0. A spring loaded ball .L3/.I4 inserted in bore I2 is adapted to engage with bores I I. It is evident that ball I3 tvillgbe pressed into bore I2 by wall 'l of disc IQ when shaft 3 is revolving quickly. In this case -there will be -no possibility for ball I 3 to engage with one of `bores Ii. When, however, rotation is slowing down thesnrineloaded .ball will eventuallyengage .with one of the bores II as shown in Fig. 4, thereby xine Shaft withhledes .Zine desired .position- Thie .position is determined .hy .the arrangement of blades z .onshait .Bin relation lto `the arrange ment .of :bore L2 ,inshait Journal .-4. When Shaft 3 .stops.rotating-thesbladeshave to hein n .nesition as vshown .in .F-ig- .1, .where .they are under Tthe influence of the electromagnet I'I in order to Start rotation immediately when the Current is turned .011.
While I have described `the principle l.of .the operation, .together .with :one .embodiment of my invention, .I `desire ,to have Iit understood that the device shown iS merely .illustrative and 4that such changes may .be .medewhen'desired ,ee fell within the scope of the appended claims. For instance, the blades may he'shapedend arranged on the .shaft in `order to provide an exhaneter or a .ventilatorineteedof .e fen .ii So `desired- I claim:
1. An .electroernegnetie lien .eomnrisine .e selient .pole magnetic stator `provided with .an ener,- gizing winding; yaine.enetierotor forzeooneratine with thestatoneeid .rotoreonsisting of .e revolvine armature comprising .a revolving Shaft lorovided with l`fan,blades eskrotor poles, said blades made ofamateriel that is .attreeted .by thermenetic forces,l generated inSaid-stator ;a malte-.andbreak vdevice connected in series .relation with Saidienereizing vvirldilng of the. stator: operated `by rotation of. said, rotor for energizing and de-,energizingsaid stator v and thereby. opening andclosing said make-.and-breal device; .and detent means likewise oneratedby yrotation of the rotor for automatically positioning the rotor in an unbalanced magnetic relation to the stator as the circuit is broken and the rotor is brought to a standstill, whereby the fan becomes selfstarting if switched on again.
2. An electro-magnetic fan as dened in claim 1, in which said make-and-break device comprises a stub of square cross-section, provided at and revolving with the shaft of the armature; and a contact device comprising acontact spring, contact being rclosed when .the .spring is pressed by one of the edges of the revolving stub and being interrupted when the spring is engaged by `the base of said stub and thereby released.
3. A fan as deiined in claim 1, in which said ydetent meansomprises a stationary bearing carrying the vrotatalzile shaft of the armature provided with the fan blades; and a number of bores symmetrically located in a circle inside said bearing; a spring loaded ball provided in a bore of the shaft in a,positioncorrespqnding tothe Icirele of bores inside the bearing', said yspring loaded ball being adapted to 4 engage in one of Athe tignes of the bearing .when rotation of the shaft slows down, said bore being arranged Tina manner to fix at standstill one yof .the -fdll .bladesfactingias rotor poles in proper position to the magnetic stator to startthe fanand run up to speed if ,the contacts are closed. y
t. In e ienne ldefined infelelrn l, en elettro: magnetic salient pole .having a top surface adapted to tthe shape o f the outer end of the blades of the armature to .be attracted .bysaid core when energized.
.5. In a fan 4es dened lin Gleim 1l tOiQf PQleS' consisting of fan blades, the outer edgesof which are -bent at right angles, .said v.fain blades `being symmetrically arranged at the .revolving shait in orderto produce vthe highestpossible kwhirling motion .when irl-rapid rotation.
REFERENCES CITED The following/,references are of ,record in -the fiie ofv this patent:
UNITED STATES PATENTS Number Name Date 550,042 iDiehl 'Nov. A19,-1895 1,005,572 Parkerson Oct. 10,119.11 1,212,282 .-Titeny Jan. 11:6., 119.17 2,063,773 Warnick et al ,D.ec. ,8,l19,3,6 2,233,933 Anderson et al Mar.,.4,g.l9,41