Machine element or mechanism – Rotary member or shaft indexing – e.g. – tool or work turret – Preselected indexed position
Patent
1974-12-23
1976-02-10
Scott, Samuel
Machine element or mechanism
Rotary member or shaft indexing, e.g., tool or work turret
Preselected indexed position
74865, 74868, B60K 4104
Patent
active
039371077
ABSTRACT:
A transmission having a fluid operated forward and reverse drive gear unit and a three speed gear unit to provide three forward and three reverse speed drives. A one-two relay valve in downshift position provides first speed drive and on upshift functions with a downshifted two-three relay valve to provide second speed drive. The two-three relay valve on upshifts provides third speed drive. The one-two relay valve is upshifted in response to either forward or reverse second pressure and the two-three relay valve will upshift in reponse to either forward or reverse third pressure. Each relay valve will downshift in the absence of such pressure except when output speed is above a predetermined value. A manual selector valve is operative in first, second or third forward drive positions to provide first forward pressure to engage forward drive in all forward positions, second forward pressure in second and third forward positions and third forward pressure in third forward position and similarly operative in first, second or third reverse drive positions to provide first reverse pressure to engage reverse drive in all reverse positions, second reverse pressure in second and third reverse position and third reverse pressure in third reverse position. The second forward or reverse pressure is connected to upshift the one-two relay valve. The third forward or reverse pressure is connected to upshift the two-three relay valve. This system provides manual selection of first, second or third speed in either forward or reverse drive and inhibits downshifts above a predetermined speed.
REFERENCES:
patent: 3013574 (1961-12-01), Breting
patent: 3016769 (1962-01-01), Christenson et al.
patent: 3378119 (1968-04-01), Schaefer
patent: 3459071 (1969-08-01), Schaefer
patent: 3691872 (1972-09-01), Schaefer
patent: 3793906 (1974-02-01), Williams et al.
Chandler Lance W.
General Motors Corporation
Heiter A. M.
Scott Samuel
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