Tecumseh Products Company

Rocky H Page

Roland L Von Kaler

Edward J Koscho, Deceased

The present invention is a front shift arrangement for transaxles of small tractors and riding lawn mowers. In one embodiment, the shifter is a cylindrical rod having arms engaging the shift collar of an in-line transmission. One end of the shifter extends out the front of the transaxle housing and has a square head with a bore for attaching to a lever and linkage. By moving the lever and thereby pivoting the shifter, the shift collar is axially moved to selectively engage gears gear ratios of the transmission, with the shifter being releasably secured in selected positions by a detent biasing mechanism. The shifter is positioned below the central plane of the transaxle in the lower housing by a cover plate. The lever attached to the shifter moves on a vertical arc to pivot the shifter. In a second embodiment, the shifter is a flat piece which is bent to form an arm and a lever portion. The arm portion extends out an opening in the lower housing and is bent to form the lever portion which may be attached to and moved by linkage to an operator lever. A bushing pivotally supports the shifter in the opening and includes a detent biasing mechanism for releasably securing the shifter at positions which correspond to the gear ratios. A wall of the housing is positioned in front of the recesses to retain the bushing within the housing.

Shift lever arrangement for transaxle

A transaxle having five forward speeds and reverse includes a shift shaft on which are journalled for free rotation four forward speed change gears and an input bevel gears which is integrally conjoined with a first speed change gear. A reverse gear is also journalled for free rotation on the shift shaft and a neutral spacer is disposed between reverse gear and the four forward gears. A counter shaft carries five companion spur gears in constant running mesh with the forward speed change gears. One of the companion gears is also in constant running mesh with a reverse intermediate gear which is in constant running mesh with the reverse gear. The reverse intermediate gear is supported by a half-bearing in the transaxle housing. A pair of axially slidable and radially outward biased shift keys on the shift shaft selectively couple the forward speed change gears, the input bevel gear, and the reverse gear to the shift shaft. High gear is provided by coupling the bevel gear directly to the shift shaft and bypassing the counter shaft. A differential driven by a spur gear on the shift shaft drives the output drive shafts of the transaxle. A disc brake is provided on the shift shaft.

Transaxle

The present invention is a clutch assembly used to engage a shaft. It includes a pulley adapted to be driven by a belt, pressure plates disposed on both sides of the pulley for engaging and rotating with the pulley, friction surfaces for selectively coupling the pulley to the pressure plates, and a cam mechanism coupled to the pressure plates for axially pressing one pressure plate into the friction surfaces to engage the pulley. The cam mechanism comprises a rotatable center cam plate bordered by an upper and a lower cam plate, with a plurality of balls disposed between each adjacent plate for axially moving the center cam plate when it rotates. The center cam plate presses the pressure plate by virtue of its axial movement into engagement with the pulley.

Clutch

A two belt drive system is disclosed for lawn and garden tractors and other vehicles especially of the type including a variable speed transmission/transaxle having a constant speed rotational input, a variable speed rotational input, and an output speed dependent on the rotational speed of the variable input. A first drive belt is mounted for rotation in one direction on an engine drive pulley, a first pulley on one of the transmission/transaxle inputs, and one pulley of a variable diameter pulley assembly. A second drive belt is mounted for rotation in the same direction as the first belt on a second pulley on the other transmission/transaxle input and the other pulley of the variable pulley assembly. Shifting the position of the variable pulley assembly with a hand control changes the belt receiving diameters of the variator pulleys such that the rotational speed of the second drive belt, second pulley, transmission/transaxle output, and resulting ground speed of the tractor are all adjustable with the hand control while the engine drives the first drive belt at a constant rotational speed.

Belt drive system for dual input transmissions/transaxles

A transmission/transaxle assembly for vehicles such as lawn and garden tractors which includes a housing, a dual input, a constant mesh planetary gear assembly, differential gear, axle, and output gear which transfer the planetary gear output to the differential gear and axle. The assembly reduces the rotational speed of two power inputs to a single, lower speed output and allows clutchless, infinitely variable forward, neutral and reverse output speeds by varying the rotational speed of at least one of the inputs with respect to the other. The assembly is compact and provides efficient lubrication through emersion of portions of the planetary gear assembly which continuously rotate in an oil compartment. The axes of the input shafts are arranged transverse to the axis of the output axles such that the assembly will easily accommodate vertical drive shaft engines in tractors or mowers. Output gearing transfers the reduced output of the planetary gear assembly first transverse to and then parallel to the input axes. Various differential gearing may be used while variation of the speed of one of the inputs may be made with a variable pulley assembly or other variable drive assembly.

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Tecumseh, MI, United States of America

Rocky H Page