Transmission Control Mechanism

This invention relates to controls for transmissions and like mechanisms in which shift changes between selected operating conditions are actuated by pivotally mounted levers, and particularly those employing such a lever having universal pivotal movement to accommodate rocking thereof in a multiplicity of different directions or planes.

Many agricultural and industrial type machines include a transmission whose gear settings are actuated by a universally pivotable lever which must be manipulated in different planes through suitable linkage under the control of the operator from a station somewhat remote from the transmission. It is also frequently desired to incorporate therewith either a second transmission in series with the first for modifying the speed ratios obtainable, or a power take-off device, and to closely associate the operator's control thereof with the control of the first transmission.

The invention has particular advantage in applications requiring both a control for selecting between a first series of shift settings by manipulation of such a universally pivoted actuating lever, and selecting between another series of shift settings by pivotally swinging a second such lever about a fixed axis. In its broadest aspect, however, the control of such a universally pivotal acutating lever is carried out in accordance with the invention by suitably supporting a shaft for both axial rotation and translational movement along its axis, and providing both a connection between the shaft and the lever for transmitting to the lever both rotational and translational movements of the shaft and an operating handle for directly rotating and axially moving the shaft. In applications requiring the second series of shift settings a second shaft is employed which is supported for axial rotation only, and is provided with an operating handle and a connection to the second lever for pivoting the latter in response to rotation of the second shaft. Preferably such second shaft is arranged in coaxial and mutual journaling relation with the first shaft.

In the prior art U.S. Pat. No. 3,274,842 a transmission control shaft is shown which has both axial rotation and translational movement, but the shift actuating means and its connection to the shaft are entirely different. Also, U.S. Pat. Nos. 2,854,088 and 3,500,697 disclose axial rotation and translation of shifter shafts, but employ therefor numerous links, bell cranks and associated hardware which my invention makes unnecessary.

A better understanding of my invention and its advantages over all such prior art will be better understood from the following description of the preferred embodiment, selected for illustration, having reference to the drawings, wherein:

FIG. 1 is a side elevational view of a control mechanism constructed in accordance with the invention, with portions thereof cut away and shown in section;

FIGS. 2 and 3 are sectional views taken substantially along the lines 2--2 and 3--3, respectively, of FIG. 1;

FIG. 4 is a sectional view taken along the line 4--4 of FIG. 3; and

FIG. 5 is a diagrammatic illustration of the various shift settings obtainable with the mechanism of FIGS. 1-4.

Referring now to the drawings, and first to FIG. 1, two shift actuating levers 1 and 2 are shown which are pivotally mounted in fixed bearings 3 and 4, respectively. It should be understood that the bearing 3 is mounted on or forms part of the housing of a transmission gearbox (not shown) and that the bearing 4 is likewise associated with the housing of a second transmission or accessory control device (not shown). The actuating lever 1 is universally pivotable about the point 5 within the bearing 3 so that its lower end 6 may be moved laterally from its solid line position to either of the dotted line positions shown in FIG. 1, as well as from its solid line position numbered "N" to either of the dotted line positions numbered "1", "2", "3", shown in FIG. 3. Although the bearing 4 would also accommodate universal pivotal movement of the other actuator lever 2, in the arrangement employed this lever 2 has pivotal movement only about a single axis for movement of the lower end 7 of the lever between its solid position designated "N" and its two dotted line positions "L" and "H" shown in FIG. 2.

Such movements of the actuator levers 1 and 2 are responsive to axial rotation and axial shifting or translation of a first shaft 8, and axial rotation of a second shaft 9. As shown in FIG. 1, suitable supporting means accommodating such movements of the shafts 8 and 9 include a fixed bracket consisting of a base plate 10 to which are rigidly fixed, as by welding, two upright wall-like supports 11 and 12. These supports have aligned apertures 13 and 14, respectively, the aperture 14 being substantially larger than the aperture 13 and having journaled therein a bearing sleeve 15 closely embracing the larger shaft 9 and secured for rotation therewith as by a setscrew 16. The bearing 15 rotatably abuts the inner surface of support 12 and is held against axial displacement in the aperture 14 as by a flange 17 which abuts the outer surface of the support 12. The shaft 9 extends through the support 12, and rigidly connected to its outer end is an operator's control member in the form of a lever 18 fitted with a knob 19. Thus, movement of the knob laterally, as viewed in FIG. 2, causes the shaft 9 to rotate about its axis 20. An arm 21 depending from the shaft 9 has its lower end pivotally connected to one end of a link 22 whose other end is pivotally connected to the upper end of the actuator lever 2. Thus pivotal movement of the lever 2 between the various shift settings L, N, H (FIG. 2) is responsive to axial rotation of the shaft 9 by the operator's manipulation of the control lever 18 and knob 19.

The shaft 8 is rotatably journaled and slidably guided in a bore 23 which extends through the shaft 9 concentrically of the axis 20, so that both these shafts are mutually supporting. Rigidly connected to the one end of shaft 8 is a second operator's control member in the form of a lever 24 with a hand knob 25. At its opposite end the shaft 8 extends through the aperture 13 in the support 11. A bearing 26, secured to the support 11, journals that end of shaft 8 for axial rotation and sliding movement. Such axial sliding and rotational movements of the shaft 8 are transmitted to the upper end of the actuator lever 1 by a connection designated generally by the numeral 27. As shown, this connection includes a first element in the form of a U-shaped bracket having its base portion 28 rigidly secured as by bolting 29 to the shaft 8, and two depending arms 30 and 31. A pin 32 extending through both the arms 30 and 31 defines a second axis 33, parallel with the axis 20, about which a second element in the form of a clevis 39 is pivotable. This second element includes a yoke portion 34, best illustrated in FIG. 4, through which the pin 32 also extends, and a shank portion 35. A stud 36, rigidly connected to the upper end of the actuator lever 1, has a part spherical end 37 socketed in the shank portion 35 for universal pivotal movement about the fixed point 38 thereon. Thus, movement of the operator's control knob 25 laterally in either direction from its solid line position shown in FIG. 1 causes the shaft 8 to slide longitudinally within the shaft 9 and bearing 26, causing concurrent translational movement of the bracket arms 30 and 31, as well as the yoke and shank portions 34, 35, with resultant pivotal movement of the actuator lever 1 between its solid line and dotted line positions shown in FIG. 1. Then at either extreme axial position of the shaft 8 the operator may, be swinging the control lever 24 and knob 25 laterally as viewed in FIG. 3, cause the actuator lever 1 to pivot about an axis perpendicular to the axis about which it pivoted during such translational movement.

With reference to FIG. 5, it will thus be apparent that movement of the control knob 19 from the neutral position N to the H or L positions will effect pivotal shifting of the actuator lever 2 to a corresponding position shown in FIG. 2. Also, by shifting the control knob 25 longitudinally of the axis 20 and then imparting rotary movement thereto about the axis 20 so that the knob assumes the position 3, the actuator lever 1 may be swung to either the shift positions 1 or 2, and conversely, when the control knob is shifted axially of the axis 20 to the opposite extreme position and then rotated about the axis 20, the actuator lever may be swung to the shift position 3.

In summary, levers 18 and 24 comprise first and second control levers interconnected with first and second shift actuating levers 2 and 1, respectively, by shift mechanism 8, 9, 21, 27 etc. The shift mechanism is operable to (1) cause the first shift actuating lever to move in a first shifting plane (the plane of FIG. 2) in response to corresponding movement of control lever 18 in a first control plane, (2) cause the second shift actuating lever 1 to move in a second shifting plane in response to corresponding movement of the second control lever 24 in a second control plane, and (3) cause the second shift actuating lever 1 to move in a third shifting plane in response to corresponding movement of the second control lever 24 in a third control plane. The second shifting plane is the plane of rotation of lever 1 shown in full lines in FIG. 1, and is a plane parallel to section lines 3--3 in FIG. 1. The second control plane is the plane of rotation of lever 24 in the position illustrated in full lines in FIG. 1, with the member 8, or motion transmitting rod 8, in a first axial position with respect to supports 11 and 12 shown in full lines in FIG. 1, while the third control plane is the plane of rotation of lever 24 in which member 8 is shifted to the left to a second axial position, which position is shown in phantom lines on the left hand side of support member 11 in FIG. 1. The third shifting plane is the plane of rotation of lever 1 when member 8 is in the latter referred to second axial position. The shift mechanism includes the motion transmitting rod 8 and motion transmitting sleeve 9.

The invention thus provides a compact and simply, but ruggedly, constructed control for a universally pivotable shift lever of a multi-speed transmission, with which may be combined a second control for another transmission or accessory unit having a shift actuating lever pivotable about a fixed axis. It will be appreciated that numerous minor variations in the parts and their assembly as described and shown may be made without departing from the spirit and scope of the invention as hereinafter claimed.