Fan with air directing grille

• US 4,123,197 A
• Filed: 02/04/1977
• Issued: 10/31/1978
• Est. Priority Date: 02/04/1977
• Status: Expired due to Term

• Current Assignee: Kemtron International Limited (TE Connectivity Limited)
• Original Assignee: Allware Agencies Limited
• Inventors: Graham, James, Keem, Phillip W., Kaimins, Laimons
• Primary Examiner(s): Croyle, Carlton R.
• Assistant Examiner(s): Holland, Donald S.
• Application Number:
  US05/765,764
• Time in Patent Office: 634 Days
• Field of Search: 415/123, 64/30 E, 192/41 S, 192/56 C, 417/423 R, 188/82.77, 188/82.3
• US Class Current: 415/123
• CPC Class Codes: F04D 25/10 the unit having provisions for automatically changing direction of output air
• CPC Class Codes: F16D 7/022 with a helical band or equivalent member co-operating with a cylindrical torque limiting coupling surface

Abstract

A clutch mechanism suitable for connecting a rotatable member to an output shaft of a motor, which mechanism comprises a body which is attachable to the output shaft and a resilient arm, one end of which is fixed to the body the other end of which is capable of engaging the rotatable member or part thereof, wherein the body is capable of gripping the output shaft in secure frictional contact to transfer rotational drive from the output shaft to the rotatable member only when the rotatable member is not restrained against rotation.

Claims

1. A fan comprising a casing;

a cylindrical wall defining an air passage through said casing, said air passage having an air inlet and an air outlet;

a fan blade assembly mounted within said casing at the inlet end of said air passage;

a motor mounted within said air passage for driving said fan blade assembly;

an air directing grille mounted for rotation in the path of air flow downstream of the fan blade assembly at the air outlet;

speed reducing means driven by the output of said motor opposite said fan blade assembly;

a clutch mechanism coupling said speed reducing means to said grille for rotating said grille at a speed less than that of the fan blade assembly, said grille including a plurality of louvers arranged to direct the air flow in a substantially gyratory distribution pattern, said clutch having means permitting the output of said speed reducing means to continue rotation without imparting rotational movement to said grille when a predetermined restraint of rotation of said grille is applied thereto, said grille being movable axially of said casing and said casing having an annular portion engageable by an outer annular portion of said grille upon axial movement of said grille toward said casing annular portion; and

retaining means operable to hold said grille annular portion against said casing annular portion by applying at least said predetermined restraint to said grille to permit locking of the grille without switching off said motor.

2. A fan according to claim 1 wherein said retaining means includes releasable locking means comprising a coaxially mounted ring and a plurality of axially extending resilient prongs connected to said hub, said prongs having beads to their free ends and being disposed to cooperate with said ring to effect the releasable locking action.

3. A fan comprising a fan blade assembly, a motor for driving the fan blade assembly, means to render the air flow from the blade assembly more axial, and an air directing grille mounted in the path of the air flow from the fan blade assembly and said means, a clutch mechanism operable to couple a first member which is, in use of the motor, axially rotatable thereby, and a second coaxially mounted member in the form of a hub carried by the grille for rotating or allowing rotation of the grille at a speed less than the blade assembly speed, said grille including a plurality of louvers arranged to direct the air flow in a substantially gyratory distribution pattern;

said clutch mechanism including said members, and a drive transfer element in the form of a helical spring coaxially mounted over an axially extending portion of said first member, the inner surface portion of the spring element being frictionally engaged with the outer surface of said axially extending portion for transfer of rotational movement of the first member to the spring, the helical spring having an end portion which extends radially outwardly of the axis of the first member, the second member having an abutment positioned to be engaged by said end portion of the spring, during rotation of the first member and spring, to cause or permit rotation of the second member therewith, the frictional coupling between the spring and said axially extending portion being such as to permit said first member to rotate, in a given direction of rotation of said grille and first member, without imparting rotational movement to the spring when a predetermined restraint of rotation of the second member is applied, the grille being movable axially of said first member and the fan having an annular casing portion which is engageable by an outer annular portion of the grille, upon axial movement of the hub in one direction from a position in which the clutch mechanism is free to drive the grille;

releasable locking means being provided operable to maintain said annular portion and casing portion so engaged to apply at least said predetermined restraint to the first member to permit locking of the grille without switching off said motor.