# US 4,391,158 A · Biased transmission control shaft

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- Number: US 4,391,158 A
- Document ID: US4391158A
- Status: Granted
- Kind: A
- Application number: 06/230,781
- Filed: 1981-01-29
- Granted: 1983-07-05
- Earliest claimed: 1981-01-29
- Assignees: Clark Equipment Company
- Inventors: Theodore A. Malott; Robert W. Wolfe
- Web page: https://patentgrep.com/patent/US4391158A

## CPC

- F16H 63/22: the final output mechanisms being simultaneously moved by the final actuating mechanism
- F16H 2063/202: {using cam plates for selection or shifting, e.g. shift plates with recesses or groves moved by a selector extension}
- Y10T 74/19279: Cam operated
- Y10T 74/20159: Control lever movable through plural planes
- Y10T 74/20165: Spherical mount [e.g., ball and socket]
- F16H: GEARING
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A manual shift transmission having multiple input and output portions is provided with a control having input and output shift rails. A laterally movable control shaft extends axially through cutouts in respective shift rails and carries cams adapted to cooperate with cam follower surfaces on corresponding cutouts to effect rectilinear movement of the shift rails upon rotation of the control shaft. The cams are arranged on the shaft so that the shaft may be positioned to place respective cams in register with the input and output shift rails while all other cams are out of register with the rail cutouts. The shift movement of respective output and input shift rails is overlapped during the rotation of the control shaft to decrease the throw of the shift lever. The control shaft is spring biased to provide variable resistance in response to movement of a control lever to enable the operator to determine his position in the shift pattern of the transmission.

## Claims

### Claim 1

A transmission having a plurality of speed ratios comprising:
a housing;
a shift lever pivotally connected with the housing, the shift lever having a lower end extending through the housing;
a control shaft contained in the housing and operably associated with the shift lever, the control shaft being shiftable in opposed directions in response to pivotal movement of the shift lever, the control shaft having two ends, one of the ends having an internal bore;
a bias assembly operably associated with the control shaft for resisting the shifting of the control shaft in a selected direction past a predetermined point, the bias assembly being mounted in the internal bore and projecting therefrom, whereby a first amount of resistance is provided to enable the operator to sense his position in the transmission shift pattern.

### Claim 2 (depends on 1)

The transmission as claimed in claim 1 wherein the bias assembly includes a spring element and a collar element slidably mounted in the internal bore, an outwardly projecting element integrally connected to the collar element for movement therewith, a retaining element for limiting the extent of sliding movement of the collar element in the selected direction, the spring element spaced between the terminal end of the internal bore and the collar element whereby the spring element is compressed when the projection element encounters an obstruction.

### Claim 3 (depends on 1)

The transmission as claimed in claim 1 further comprising a second bias assembly operably associated with the control shaft for resisting the shifting of the control shaft in the selected direction at a second predetermined point past the first mentioned predetermined point.

### Claim 4 (depends on 3)

The transmission as claimed in claim 3 wherein the control shaft has two ends, one of the ends having an internal bore, the first mentioned bias assembly mounted in the internal bore and projecting therefrom, the second bias assembly including a spring member encompassed on the control shaft for sliding movement thereon.

### Claim 5 (depends on 4)

The transmission as claimed in claim 4 wherein the bias assembly includes a spring element, a collar element slidably mounted in the internal bore, an outwardly projecting element integrally connected to the collar element for movement therewith, a retaining element operably associated with the control shaft for limiting the extent of sliding movement of the collar element in the selected direction, the spring element spaced between the terminal end of the internal bore and the collar element whereby the spring element is compressed when the projection element encounters an obstruction, the second bias assembly including a wall member relatively fixed on the shaft, a collar member slidably mounted on the shaft, a spring member spaced between the wall member and the collar member, a retaining member operably associated with the control shaft for limiting the extent of sliding movement in the selected direction of the collar member, whereby the spring member is compressed when the collar member encounters an obstruction.