Epicyclic change-speed mechanism and model clock incorporating same
OwnerEdward H. Harveyinventor
Life of this patent
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Abstract
The invention provides an epicyclic change-speed mechanism comprising a fixed outer ring having an inwardly directed running surface, a spider member mounted within the outer ring and rotatable about an axis concentric with the axis of the outer ring, the spider member having a hollow output shaft concentric with said outer ring, an input shaft concentric with the outer ring, and at least one planet wheel contained within an aperture in the spider member, the or each planet wheel being in driven engagement with the input shaft and in rolling engagement with the running surface of outer ring. The invention also provides a model clock incorporating the change-speed mechanism, the face of the clock being formed from interfitting pieces of a constructional toy.
Claims20
An epicyclic change-speed mechanism comprising a fixed outer ring having an inwardly directed running surface, a spider member mounted within said outer ring and rotatable about an axis concentric with the axis of said outer ring, the spider member having a hollow output shaft concentric with said outer ring, an input shaft concentric with said outer ring and at least one planet wheel contained within an aperture in said spider member whereby the only driving engagement between the at least one planet wheel and the spider member is through the outer periphery of the at least one planet wheel, said at least one planet wheel being in driven engagement with said input shaft and in rolling engagement with said running surface of said outer ring.
A model clock comprising:
- (a) an epicyclic change-speed mechanism consisting of a fixed outer ring having an inwardly directed running surface, a spider member mounted within said outer ring and rotatable about an axis concentric with the axis of said outer ring, the spider member having a hollow output shaft concentric with said outer ring, an input shaft concentric with said outer ring and at least one planet wheel contained within an aperture in said spider member whereby the only driving engagement between the at least one planet wheel and the spider member is through the outer periphery of the at least one planet wheel, said at least one planet wheel being in driven engagement with said input shaft and in rolling engagement with said running surface of said outer ring;
- (b) the diameters of the running surface of said outer ring, the outer circumferential surface of said at least one planet wheel and the outer surface of said input shaft in contact with said at least one planet wheel being so chosen as to give a reduction ratio of 12:1 between said input shaft and said output shaft;
- and
- (c) a minute hand fast with said input shaft and an hour hand on said output shaft and rotatable therewith.
Dependencies are inferred from the claim text.