Patent Application
20080168861
The present invention relates generally to a starter motor for starting an internal combustion engine. More specifically, this invention relates to an improved shift lever plug mechanism of a starter motor.
Starter motors are provided with a drive assembly and a solenoid contained in a housing. A shift lever extends between the drive assembly and the solenoid, and pivots about a pivot pin inserted through a hole in the shift lever. The pivot pin is held in place by a shift lever plug, which contains a circular hole into which the pivot pin is inserted, establishing a single pivot point for the shift lever. When the shift lever is rotated about the pivot point, a pinion gear of the drive assembly is moved into mesh with a flywheel of the engine.
Statistical variation in the manufacture of the solenoid, the manufacture of the drive assembly, and assembly of the starter motor is not sufficiently taken into account in single pivot point designs, however. The manufacturing variation can cause increased stress on the shift lever not allowing it to meet its useful life requirements, and the variation may cause restriction in movement of the shift lever which can lead to, for example, the pinion gear and the flywheel not meshing correctly.
What is needed is a starter motor pivot that takes statistical variation of starter motor components into account, thereby allowing the starter motor to achieve its life requirements, and preventing malfunction of the starter motor.
The present invention solves the aforementioned problems by providing an improved starter motor with multiple shift lever pivot positions. The improved starter motor includes a solenoid, a drive assembly located at least partially within a housing, and a shift lever linking the drive assembly to the solenoid. The shift lever is in operable communication with a pivot pin. The starter motor includes a shift lever plug that is engageable to the housing and that includes one or more through slot features that are receptive of the pivot pin. The through slot features are configured to provide multiple potential pivot points for the shift lever.
The above, as well as other advantages of the present invention, will become readily apparent to those skilled in the art from the following detailed description of preferred embodiments when considered in the light of the accompanying drawings in which:
Shown in
A shift lever plug 24 is disposed in the drive housing 14. An example of a shift lever plug 24 is shown in
Returning now to
Referring now to
The solenoid end 42 includes two solenoid arms 56 and 58. The solenoid arms 56 and 58 are disposed between annular surfaces 60 and 62 of a shift lever actuator rod 64. In the example shown in
Because the pivot pin 38 is disposed in the slots 32 and 34, there is more than one distinct point at which pivot pin 38 can be disposed along a longitudinal axis 70 of the slots 32 and 34, and thus more than one possible center of rotation of the shift lever 36. An actual location of the pivot pin 38 within the slots 32 and 34 of any one starter motor 10 is determined by, for example, variance in solenoid 68 manufacture, variance in drive assembly 12 manufacture, or variation in manufacture of other subcomponents of the starter motor 10. Allowing the location of the pivot pin 38 to vary depending on a variation in other components of the starter motor 10 allows the starter motor 10 to operate properly by, for example, ensuring proper engagement between the pinion gear 22 and the flywheel. The variance in the solenoid 68 manufacture and the drive assembly 12 manufacture can increase stresses on the shift lever 36, if the pivot pin 38 is restrained in a circular hole. Utilization of the slots 32 and 34 allows for variation in a location of the pivot pin 38 between starter motors 10, based on the variance in the manufacture of each starter motor 10. Allowing variation in the location of the pivot pin 38 reduces static stresses in the starter motor 10 while maintaining functionality of the starter motor 10.
While embodiments of the invention have been described above, it will be understood that those skilled in the art, both now and in the future, may make various improvements and enhancements which fall within the scope of the claims which follow. These claims should be construed to maintain the proper protection for the invention first described.
