Patent Application
20060070482
The present invention relates to a control lever mechanism, such as a speed control lever for an infinitely variable transmission (IVT).
Production John Deere 20 Series tractors with an IVT include a speed control lever with a rotary wheel, and such a control lever assembly for an IVT is described in U.S. Pat. No. 6,404,187, issued in 2002 to Dieter Ruckert. In this control lever assembly, the rotary wheel projects laterally from a side of the housing and is rotatable about a substantially horizontal axis which is transverse with respect to an axis of the lever. Most of the wheel is exposed and outside of the housing on which it is mounted. The housing must be large enough to allow an operator's hand to grip the housing in the area below the wheel and so that the operator's thumb can manipulate the wheel. But, such a large control lever assembly will be too large for use in more compact control modules, such as an armrest control console.
It is desired to have a knob/wheel design wherein only a portion of the wheel is exposed, thus, reducing the likelihood of an accidental manipulation of the wheel. It would also be desirable to use some existing production parts or components in the design, thus limiting the number of redesigned parts. It would also be desirable to have the wheel position sensor enclosed within a knob housing so as to avoid modifying other parts in order to locate the sensor elsewhere.
Accordingly, an object of this invention is to provide a compact control lever assembly which includes a rotatable wheel coupled to a sensor.
A further object of the invention is to provide such a control lever assembly which can be used in an armrest control console.
A further object of the invention is to provide such a control lever assembly which reduces the likelihood of an accidental manipulation of the wheel.
A further object of the invention is to provide such a control lever assembly which utilizes existing production parts or components, thus limiting the number of redesigned parts.
A further object of the invention is to provide such a control lever assembly wherein a wheel position sensor is enclosed within a knob housing so as to avoid modifying other parts in order to locate the sensor elsewhere.
These and other objects are achieved by the present invention, wherein a control lever assembly has a moveable lever and a knob mounted on an end of the lever. The knob has a hollow housing which is removably attached to a cylindrical base. The housing has a cylindrical side wall which forms an opening which extends into a top portion of the housing. A wheel is coupled to rotary encoder and both are enclosed in the housing. The wheel rotates about an axis which is parallel to an axis of the lever. A portion of the side and the top of the wheel are exposed through the opening.
Referring to
A knob assembly 20, according to the present invention is mounted to the upper end of the shaft 16. Referring now to
Encoder 32 has box-shaped case 34 and a cylindrical sleeve 36 from which extends a rotatable sensing shaft 38 with a flat surface 40. A key slot 42 is formed on one side of sleeve 36. The upper ends 44, 46 of the inner housing pieces 26, 28 form an opening 48 through which extends the shaft 38. A tab 50 projects from end 44 and is received by slot 42 to prevent the case 34 from rotating with respect to the housing pieces 26, 28.
A wheel assembly 52 is coupled to shaft 38 of encoder 32. Preferably, the wheel assembly 52 and the encoder 32 are the same as the wheel assembly and sensor/encoder of U.S. Pat. No. 6,404,187, except that in the present invention the wheel 52 and encoder have their axes oriented parallel to a longitudinal axis of lever shaft 16. Wheel assembly 52 includes a generally cylindrical hollow wheel 70 with a knurled outer surface 72 and a slightly tapered outer profile. An end cap 80 is received in the upper end of wheel 70. The wheel 70 and end cap 80 form a top surface which faces away from the lever shaft 16.
An outer housing 54 is mounted over the wheel assembly 52 and the inner housing pieces 26, 28. Housing 54 is hollow and is fully open at its lower end 55. An opening 56 is formed in the upper portion of housing 54, and extends into a sidewall 58 and a top wall 60 of the outer housing 54. A slot 62 in the lower end 55 receives a tab 64 which projects from an outer portion of inner housing piece 28 to prevent relative rotation between outer housing 54 and inner housing pieces 26, 28. An annular groove 66 on the lower inner surface of sidewall 58 releasably receives rib 23 of the pieces 26, 28 in a snap-fit manner, and the lower end of side wall 58 engages shoulder 25 of pieces 26, 28. As best seen in
Referring again to
Thus, with this design, an operator can rest his or her hand on the surface of the armrest 10 and grasp the portion of housing 54 below the opening 52 and move the lever unit 14 within the slot 12, which reduces the likelihood of an accidental manipulation of wheel 70. This design also uses some parts which are the same as previous production parts, thus limiting the number of redesigned parts. This design keeps the encoder within the outer knob housing and avoids modifying other parts in order to locate the encoder elsewhere.
While the present invention has been described in conjunction with a specific embodiment, it is understood that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, this invention is intended to embrace all such alternatives, modifications and variations which fall within the spirit and scope of the appended claims.
