Abstract An adjustable ratio transmission mechanism having a variable speed ratio between an input shaft and an output shaft where the speed ratio is varied by changing the effective diameters of a pulley on one shaft having oppositely disposed, coned halves, one fixed and one selectively axially movable along the shaft, and a second pulley on the other shaft having oppositely disposed, coned halves, one fixed on the shaft and one movable axially along the shaft, the movable half being spring biased against the fixed half, the two pulleys being coupled by a belt. Adjusting selectively movable half of one pulley with respect to its fixed half produces the opposite movement of the movable half of the other pulley biased by the spring. The improvement comprising a single cup-like member to both retain the pulley biasing spring and position and provide a means to sensing shaft speed. The cuplike member is perforated to periodically vary the reluctance of the magnetic circuit of a magnetic pickup as the shaft rotates, thereby providing a signal indicative of the speed of the shaft.
A shaft speed sensing device for an adjustable speed drive of the type in which a shaft is surrounded by a compressive spring for biasing an expansible adjustable diameter pulley, said shaft being journalled in a housing and said speed sensing device comprising: a cup-like member mounted on said shaft for receiving said compressive spring, said member having a portion thereof having a periodically variable reluctance as said shaft rotates; and a pick up means mounted in said housing adjacent said member and responsive to the variations in the reluctance in said member for providing a signal corresponding to the speed of said output shaft.
Claim 2
Dependent Claim
105 words
A shaft speed sensing device for an adjustable speed drive of the type in which a shaft is surrounded by a compressive spring for biasing an expansible adjustable diameter pulley, said shaft being journalled in a housing and said speed sensing device comprising: a cup-like member mounted on said shaft for receiving said compressive spring, said member having a portion thereof having a periodically variable reluctance as said shaft rotates; and a pick up means mounted in said housing adjacent said member and responsive to the variations in the reluctance in said member for providing a signal corresponding to the speed of said output shaft.
Claim 3
Dependent Claim
22 words
The speed sensing device of claim 1 wherein said cup-like member has a peripheral flange having circumferentially spaced portions of differing reluctance.
Claim 4
Dependent Claim
29 words
The speed sensing device of claim 2 wherein said flange is metal and has circumferentially spaced portions thereof removed to provide a periodically variable reluctance as the shaft rotates.
Claim 5
Dependent Claim
23 words
The speed sensing means according to claim 2 wherein said peripheral flange is tubular having an axis which is coaxial with said shaft.
Claim 6
Dependent Claim
36 words
The shaft speed sensing device as defined in claim 3 wherein the flange of said cup-like member is provided with a series of apertures, and wherein said pickup means is mounted immediately adjacent said apertured flange.