A swinging-lever type of control used on several cars is shown in Fig. 239, and is designed for right-side control and frame mounting. The change gear lever is pivoted to a hub which is free to turn on the control shafts. On each side of this lever are short levers which are fastened to concentric control shafts, each of which extend to the inside of the frame and carry operating arms. These arms are connected to the sliding shafts of the transmission by rods and clevises. The upwardly extending levers are provided with lugs, between which the control lever engages when it is pressed in the direction of the particular short lever. Some provision must be made for holding the change-gear lever in a natural position, and this is accomplished by the two flat springs fastened to the short levers. When the control lever is moved in one of the slots of the quadrant it is connected with one of the short levers and turns the shaft to which that lever is secured.
Fig. 240 illustrates another type of swinging lever control which was introduced by the Warner Gear Co. for unit power plant mounting. It differs from the above in the method of engaging the control lever with the short levers that turn the concentric shafts. These have small arms hinged to them, which are held in contact with the control lever by spiral springs. The pivoted arms have a lug which engages in a slot in the quadrant and locks each shaft in position. This type of control eliminates the danger of turning both shafts at the same time. It also incorporates a reverse lock controlled by a thumb latch on the control lever.
Center control may also be employed with the transmission located amidships or on the jackshaft. An excellent example of this is shown in the United States control, Fig. 241, in which the support for the gasoline tank is used to support the control.
Fig. 239. Swinging Lever Type of Control.
Fig. 240. Warner Swinging Lever Arranged for Center Control with Right Hand Drive.
Fig. 241. United States Center Control Mounting.
On the Flint delivery cars the center control and pedal mounting is incorporated in a single unit supported from the subframe us shown in Fig. 242. The control set is of the swinging; lever type; however, instead of using a quadrant and concentric shafts, the short arms are connected with two parallel shafts which are provided with plunger lucks. The short levers instead of pivoting from the center of the control lever, slide with the shaft. This construction permits placing the sliding shafts in the transmission directly above the gears, making a direct connection and eliminates the trouble usually experienced with bent connections.
A large bracket extends from one subframe member to the other and has bearings at its rear end to support the control and brake lever, while bearings are provided at the front end of the pedals and their shafts. The service brake connection is made from a small lever cast integral with the brake pedal, while the clutch is connected to the pedal through a yoke and levers, keyed to the shaft. The brake pedal is interconnected with the clutch pedal so that in applying the brake the clutch will also be disengaged.
Fig. 80 depicts a unit power plant transmission with the center control and pedal mountings for left-side drive. The swinging control lever instead of being pivoted at its lower end, has the pivot, which is of spherical shape, a short distance from its end and rests on a bracket incorporated with the transmission cover. The end of the lever engages with the shifter forks in the transmission which have lugs that straddle the lever. This makes a very simple control and eliminates a number of parts. The emergency brake lever is mounted at the side of the transmission and is also pivoted a short distance from the end. The lower end has a connection for the brake rod and a slot through which the quadrant is inserted. The pedals are mounted on an extension of the clutch disengaging shaft. Both of these are free on the shaft, but the clutch pedal is connected to a sector which permits pedal adjustment to take up the wear of the clutch.
Fig. 242. Center Control and Pedal Mounting of Flint Delivery Cars.
In the progressive type of transmission it is necessary to progress from one speed to another and for this reason it is necessary to provide a control which has a lock for each speed and the neutral position. The Mogul heavy duty trucks are equipped with a progressive type transmission which is built in a unit with the jackshaft, while the operator's seat is placed over the engine. This makes it difficult to arrange a neat control; however, in the Mogul trucks the control levers and pedals are supported from a single bracket. Both gear and brake levers pivot from the same center and are mounted upon concentric shafts. Since a lock is required for both levers, these are equipped with spoon type latches. The pedals also pivot from a center common to both, but this is somewhat below the center of the levers as shown in Fig. 243.
The position of the control levers also makes it difficult to obtain a direct connection to the sliding shaft in the transmission. In this case it is quite simple as an extra long lever is pivoted from the seat support which connects with the control lever near its pivot end, while the other end is connected to the sliding shaft.
Fig. 243. Mogul Drake. Clutch and Progressive Type Gear Control.