Forage box clutch mechanism

Details Forage box clutch mechanism Forage box clutch mechanism

2001-02-08

2003-05-13

Bucci, David A. (Department: 3682)

Endless belt power transmission systems or components

Pulley with belt-receiving groove formed by drive faces on...

By manual actuator for one or both confronting members

Reexamination Certificate

active

06561935

ABSTRACT:

TECHNICAL FIELD
The present invention relates to a clutch and a shift assembly. More particularly, the present invention relates to a clutch having a driving sheave powering a driven sheave by means of a belt and a shift assembly having first and second actuators, the actuators configuring a transmission for delivering rotational power to a plurality of driven mechanisms.
BACKGROUND OF THE INVENTION
While the present invention is described with particularity as related to forage boxes, it is understood that the present invention has application in numerous other applications requiring coupling a prime mover to a driven mechanism. There are many such applications, particularly in the field of agricultural implements where the prime mover is a tractor driven power takeoff and the driven mechanism is on an implement that is separate from, but powered by the tractor.
Forage boxes are typically towed behind a tractor and are utilized to transport livestock feed from a field where the feed is grown and harvested to a site where the feed is either stored or provided to livestock for consumption.
The forage box typically has a plurality of different mechanisms for unloading the food product that is being transported in the forage box. The first such mechanism is a cross conveyor or auger that operates laterally with respect to the longitudinal axis of the forage box to discharge food product from an opening located in a side of the forage box proximate the front end thereof. Rotating beaters are located generally above the cross conveyor to direct the food product onto the cross conveyor. Additionally, aprons, which are chain-drawn bars that are pulled along the floor of the forage box from the rear to the front of the forage box act to bring the food product forward for interaction with the beaters and cross conveyor. The forage box preferably utilized with the present invention incorporates a separate lever for both engaging the rotatable beaters and for selecting the speed of the aprons.
The unloading mechanisms of the forage box are typically powered by connection to the power take off (PTO) of a farm tractor. The PTO rotates at a selected speed and imparts rotational motion to the unload mechanisms of the forage box through a transmission. A clutch mechanism may be incorporated between the PTO and the transmission of the unload mechanisms in order to provide control of the unload mechanisms from the front of the forage box without recourse to starting and stopping the PTO at the tractor controls.
The clutches utilized on forage boxes and many other implements typically have two sheaves. The driving sheave imparts rotational motion to the driven sheave by means of multiple belts. Clutch engagement and disengagement is controlled by an idler pulley that increases or decreases tension on the plurality of belts as desired. A problem that occurs with current implement clutches is that when the sheaves get rusty during storage or if belt dressing has been used to increase belt traction, the belts do not immediately disengage from the sheaves when the pressure of the idler pulley is removed form the belts. This results in the driven mechanisms, such as the beaters of the forage box, continuing to run on after disengagement has been commanded. The clutch is typically covered by a shield. The shield then has to be removed to free the belts, exposing the operator to the still rotating clutch components. The PTO should also be disengaged before attempting to free the belts. Having to take such actions can be dangerous, time-consuming, and frustrating for the operator.
A related problem is the need for an emergency stop function that will immediately disengage the implement clutch from the PTO and immediately stop the driven mechanisms. The emergency stop function is needed to ensure the safety of operators of the implement. For example, in the event that an operator's clothing or the like becomes caught up in one of the unload mechanisms of a forage box, there is a need to immediately stop the unload mechanisms in order to prevent injury or death to the operator. Accordingly, a clutch that runs on after disengagement of the idler pulley contributes to an emergency situation.
The better forage boxes have provided a mechanism to vary the speed of the aprons so that the speed of delivery of the feed to the auger or blowers that inject the feed into the silo can be changed. Changing the apron speed accommodates the varying rates at which the feed can be conveyed into the silo. The variation in speed is typically achieved through the transmission. Although many types of transmissions can be successfully employed, the transmission usually has a variable speed drive commonly called a variable speed sheave. The sheave system consists of two rotating sheaves spaced apart and connected by an endless rubber belt. Each of the two sheaves has a fixed disc and a movable disc that together form the sheave. The interior face of each disc is angled inward toward the center axial shaft of the sheave. Taken together, the two angled discs form a V-shaped groove with the apex of the V at the center shaft. Varying the spread of the V effectively varies the diameter of the sheave that the belt rides in.
The movable disc is capable of moving laterally with respect to the fixed disc on the common axial shaft such that the movable disc is positionable either very close to the fixed disc or the movable disc can be moved apart from the fixed half. Varying the distance apart of the two discs effectively changes the spread of the V and the resulting diameter of the sheave over which the belt rides. Since the belt is fixed in length, it can be seen that as the movable disc of one of the sheaves moves closer to the fixed disc, the movable disc of the second sheave must move further apart from the fixed portion, thereby decreasing the effective diameter on the second sheave. The two sheaves then function as two gears of variable gear ratio to provide the variable drive speeds for the aprons.
One of the two sheaves, the driven sheave, is driven by the power takeoff (PTO) unit from a tractor through the clutch. When engaged, the clutch supplies power from the PTO to the augers. The driven sheave directly powers the beaters at a constant speed with respect to the speed of the PTO. The second of the two sheaves, the slave sheave, is connected to the aprons in the bed of the forage box. As the two sheave discs of the driven sheave are brought closer together the rotational speed that is imparted to the slave sheave is increased proportionally as a function of the fact that the rotational speed of the driven disc remains constant as determined by the speed of the PTO, while the effective diameter of the driven sheave groove in which the belt rides is increased. This increases the rotational and lineal speeds of the belt. At the same time as the diameter of the driven sheave is increasing, the diameter of the slave sheave is decreasing. The increased speed of the belt and the decreased diameter of the slave sheave results in the slave sheave being driven at a greater rotational speed, in turn resulting in a greater speed being imparted to the aprons.
A shifting mechanism has been provided in the past so that operator of the forage box can engage the feed delivery mechanisms and select the speed of the aprons as desired. These selections were effectively limited only to times when the PTO was engaged. The shift assembly was a bar manually rotated by the operator acting through a lever-like handle affixed to one end of the bar. Through a number of engaging mechanisms, the shift assembly directly controlled the distance of the movable disc of the driven sheave from the fixed disc of the driven sheave and thereby controlled the gear ratio of the variable speed sheave. To achieve a higher speed of the aprons, the shift assembly was rotated to bring the movable disc of the driven sheave closer to the fixed disc of the driven sheave. Conversely, reduced apron speed was achieved by moving the movable disc further from the fixed dis

Affiliated with

Also associated with

Rating

Forage box clutch mechanism does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Forage box clutch mechanism, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Forage box clutch mechanism will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3016684