Transmission shifting mechanism and position sensor

• US 5,743,143 A
• Filed: 08/09/1996
• Issued: 04/28/1998
• Est. Priority Date: 08/09/1996
• Status: Expired due to Term

• Current Assignee: Eaton Corp. (Wisconsin) (Eaton Corporation PLC.)
• Original Assignee: Eaton Corp. (Wisconsin) (Eaton Corporation PLC.)
• Inventors: Carpenter, Jeffrey L., Huggins, Michael J., Wadas, David L., Lanting, Mark L.
• Primary Examiner(s): Herrmann, Allan D.
• Application Number:
  US08/695,052
• Time in Patent Office: 627 Days
• Field of Search: 74/335, 74/473 R, 74/89.15, 74/DIG. 7, 324/207.16, 324/207.24, 324/207.26, 340/456
• US Class Current: 74/335
• CPC Class Codes: B60W 2540/165 Rate of change
• CPC Class Codes: F16H 2061/2884 Screw-nut devices
• CPC Class Codes: F16H 59/70 dependent on the ratio established
• CPC Class Codes: F16H 61/32 Electric motors actuators or related electrical control means therefor
• CPC Class Codes: Y10S 74/07 Indicators-sensors and meters
• CPC Class Codes: Y10T 74/19251 Control mechanism

Abstract

A transmission shifting mechanism (10) and position sensor assembly. The shifting mechanism includes a member (32) of known flux-conducting or flux-insulating properties movable therewith, which will variably extend (42, 44, 46) into an electric coil (36), which is periodically charged and then allowed to discharge. The rate of discharge is variable with the position of the member in the coil and, thus, provides a signal indicative to mechanism condition (H, N, L).

Claims

1. In combination, a lead screw and nut shift actuator mechanism and nut position sensor assembly, said actuator mechanism comprising a controllable motor for selectively rotating an axially fixed ferromagnetic lead screw, a nut member axially movable on said lead screw to two or more unique axial shifting positions relative to said lead screw, said sensor assembly providing an output signal, the magnitude or rate of change of magnitude of which is indicative of the shifting position of said nut member, said sensor assembly comprising a multiple-winding electrical coil having a bore, a portion of said lead screw passing through said bore, and a magnetic flux insulating tubular sleeve movable with said nut member to a unique sensing position relative to said bore, including at least one unique position wholly or partially within said bore, for each of said unique shifting positions.

2. The combination of claim 1 further comprising means to electrically charge said coil, allow said coil to discharge and, while said coil is discharging, measure the electric charge in said coil, said signal comprising the measured electric charge or rate of change of charge in said coil.

3. The combination of claim 2 wherein said nut is a ball nut.

4. In combination, a single shaft transmission shifting mechanism and position sensor assembly,

said shifting mechanism comprising a shaft selectively rotated to two or more unique rotational shifting positions, each corresponding to a unique transmission ratio selection condition and selectively axially moved to three or more unique axial shifting positions, each corresponding to a unique transmission ratio engagement condition,

said position sensor assembly comprising:

a first multiple-winding electrical coil having a first bore and an extension of said shaft movable with changes in axial shifting positions of said shaft to a unique axial sensing position relative to said first bore, including at least two positions at least partially within said first bore, for each of said axial shifting positions,

a second multiple-winding electrical coil having a second bore and an arcuately movable ferromagnetic member rotationally movable with said shaft to a unique rotational position relative to said second bore, including at least one position within said second bore, for each of said rotational positions, and

means for periodically independently (1) electrically charging each of said coils, (2) allowing each of said coils to discharge, and (3) while discharging, measuring a value indicative of the electric charge in each of said coils.

5. The combination of claim 4 wherein said extension is of a magnetic flux conducting material.

6. The combination of claim 4 wherein said mechanism has at least three unique rotational shifting positions.