Pitch adjustment for blades of ceiling fan

• US 4,396,352 A
• Filed: 07/17/1981
• Issued: 08/02/1983
• Est. Priority Date: 07/17/1981
• Status: Expired due to Term

• Current Assignee: Hunter Fan Company
• Original Assignee: TRW Limited (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Pearce, Richard A.
• Primary Examiner(s): Hornsby, Harvey C.
• Assistant Examiner(s): Bian, Shewen
• Application Number:
  US06/284,319
• Time in Patent Office: 746 Days
• Field of Search: 416/205, 416/206, 416/207, 416/5
• US Class Current: 416/206
• CPC Class Codes: F04D 29/36 adjustable flexible blades F04D29/382

Abstract

Two position fan blade attachments or blade iron assemblies for sealing fans provide for the individual adjustment of the paddle-type blades into two preselected angular positions providing for either a downward or upward flow of air. The blade attachments provide detents or interengaging locking cams which are maintained in either one of the preselected positions by a spring and by the centrifugal force applied to the blade. In one embodiment, the interengaging structure includes a leaf spring which has two recesses or openings engageable with a ball. In another embodiment pairs of inclined ramps are mutually engageable with corresponding pairs of camming recesses. Pushing the blade inwardly releases the engagement and permits rotation of the blade iron into the other of the preselected positions and release thereof permits movement into a second interlocking and camming position under the influence of the spring and centrifugal force to maintain a noise-free and vibration-free connection between the blade iron and the blade iron support.

Claims

1. A two-position blade attachment arrangement for attaching and securing the paddle wheel fan blades of a ceiling fan at two selectable angular positions on a rotating fan blade support member comprising:

a fan blade bracket adapted for mounting to a rotating fan blade support member, such as to a motor shaft or armature element,

said fan blade bracket having a radially outwardly extending blade bracket support member,

a blade bracket having one end adapted for connection to a paddle-type blade and having another end adapted to be received in interfitting relation to said blade bracket support member providing for translational axial movement thereon while providing for limited angular movement generally about a radial center line of said blade between two defined angular positions,

detent means mutually engageable between said blade bracket and said fan bracket for retaining said blade bracket and the associated paddle blade thereon in either of two predetermined angular positions, said detent means including

means in said blade bracket defining a pair of radially spaced grooves, and

means on said blade bracket support member defining a groove-engaging cam receivable selectively in one of said radially spaced grooves, said grooves and cam being provided with an inclination to said transverse axis whereby centrifugal force tends to cause engagement therebetween.

2. A two position fan blade support attachment for ceiling fans comprising a fan bracket adapted to be mounted to a rotating fan drive member such as a rotor cage,

said fan bracket having a generally radially outwardly extending, generally cylindrical blade iron support portion,

a blade iron adapted for mounting to a paddle-type blade and having an end adapted to be received in partially encircling relation to said support portion,

a clamp member proportioned to be received over said support portion on said blade iron end,

means for retaining said clamp member on said blade iron end,

inclined ramp means formed on said blade iron support portion,

means in said clamp member defining a pair of inclined recesses, said clamp member being selectively engageable with said ramp means at one or the other of said recesses with axial outward movement of said blade iron to define a pair of preselected blade positions,

clearance means on said clamp member adjacent said recesses into which said ramp means may move with limited inward axial movement of said blade iron and clamp member on said bracket providing for limited rotational movement of said blade iron on said bracket for selecting either of said positions, and

spring means urging said blade iron axially outwardly assuring the engagement of said ramp means with one or the other of said recesses and in the direction of the application of centrifugal force during rotation of the fan, for positively maintaining a selected position with a minimum of free play.

3. The blade support attachment of claim 2 further comprising locator means on said cylindrical support portion,

a pair of selectable groove means in said blade iron selectively engageable by said locator means in each of said selected positions,

clearance means in said blade iron adjacent said locator means providing for rotational movement of said locator means with rotation of said blade iron and defining the limits of rotation,

said locator means assuring the alignment and engagement of said ramp means with the selected one of said recesses with axial return movement of said blade iron on said blade bracket.

4. The blade support attachment of claim 3 further comprising a locator tab on said cylindrical support portion,

means in said blade iron end defining a pair of selectable grooves selectively engageable by said locator tab in each of said selected positions,

means in said blade iron end defining a clearance recess opening into said grooves and providing for rotational movement of said locator tab with rotation of said blade iron and having walls defining the limits of rotation,

said locator tab assuring the alignment and engagement of said ramps with the selected one of said recesses with outward movement of said blae iron on said blade bracket under the influence of said spring.

5. A fan blade support attachment for ceiling fans providing for the selection of two pitch positions of the fan blade, comprising a fan bracket adapted to be mounted to a rotating fan drive member such as a rotor cage,

said fan bracket having an outwardly extending blade iron support portion,

a blade iron adapted for mounting to a paddle-type blade and having an end adapted to be received in partially encircling relation to said support portion,

a clamp member proportioned to be received over said support portion on said blade iron end,

means for retaining said clamp member on said blade iron end,

a pair of inclined ramps formed on said blade iron support portion in axially spaced relation,

means in said clamp member defining a pair of inclined recesses for each of said ramps, said recesses being selectively engageable with the associated said ramp with outward movement of said blade iron to define a pair of preselected blade positions,

a clearance relief on said clamp member adjacent said recesses into which the associated said ramp may move with limited telescoping inward movement of said blade iron and clamp member on said bracket blade iron support portion providing for limited rotational movement of said blade iron on said bracket for selecting either of said positions,

a compression spring between said support portion and said blade iron urging said blade iron outwardly assuring the engagement of said ramps with selected one of said recesses and in the direction of the application of centrifugal force during rotation of the fan, for positively maintaining a selected position with a minimum of free play.