Fluid reaction surfaces (i.e. – impellers) – Articulated – resiliently mounted or self-shifting impeller... – Nonmetallic resilient mounting
Reexamination Certificate
2001-05-11
2003-02-25
Look, Edward K. (Department: 3745)
Fluid reaction surfaces (i.e., impellers)
Articulated, resiliently mounted or self-shifting impeller...
Nonmetallic resilient mounting
C416S24500R, C464S182000, C440S083000
Reexamination Certificate
active
06524069
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to propeller assemblies, and in particular, to a propeller assembly for a marine vehicle which incorporates an improved locking structure for maintaining the propeller assembly on the drive shaft of the marine vehicle.
BACKGROUND AND SUMMARY OF THE INVENTION
It is known to propel a marine vehicle utilizing a propeller assembly mounted on a rotatable drive shaft. The propeller assembly includes propeller blades extending radially from a central hub. A motor rotates the drive shaft which, in turn, rotates the propeller blades propelling the marine vehicle through the water.
Typically, the propeller assembly is constructed as a unit wherein the propeller blades and the central hub are mounted or removed from the drive shaft in unison. Alternatively, in order to reduce the time and costs associated with replacing the propeller blades, it has been contemplated to provide a propeller assembly for a marine engine wherein the propeller blades project from a propeller housing that is removable from a central hub. For example, LoBosco et al, U.S. Pat. No. 5,252,028 discloses a marine propeller assembly having a propeller housing which is slidably receivable on a central hub in order to be rotated therewith. The central hub is mounted on the propeller shaft and a retaining disc is threaded onto the propeller shaft to retain the propeller housing on the central hub. It has been determined, however, that the retainer disc does not adequately retain the propeller housing on the central hub such that the propeller housing may become inadvertently disengaged from the central hub resulting in the propeller housing falling from the propeller shaft during use.
Chen, U.S. Pat. No. 5,967,751 also discloses a marine propeller assembly. The propeller assembly includes a central hub secured to the propeller shaft and having three or more axially extending keys on the outer surface thereof. A propeller housing includes an inner surface having three or more pairs of lobes for forming keyways which receive the keys of the central hub. A retainer disc is threaded on a propeller shaft and includes a plurality of angularly spaced ears for engaging with the lobes on the inner surface on the propeller housing in order to prevent the propeller housing from being disengaged from the central hub.
As described, the propeller assembly disclosed in the Chen '751 patent overcomes the limitations of the structure disclosed in the LoBosco et al '028 patent. However, it has been found that the keys extending from the central hub have a tendency to become stuck within the corresponding keyways along the inner surface of the propeller housing. As a result, it may be difficult for an individual to remove the propeller housing from the central hub during maintenance, replacement or the like.
Further, it is highly desirable to retain the propeller housing on the central hub in such a manner as to prevent any unnecessary movement of the propeller housing which may reduce the efficiency of the propeller assembly. The structure disclosed in the Chen '
751
patent includes a retainer disc having a plurality of angularly spaced ears which engage lobes and stops on the inner surface of the propeller housing in order to prevent the propeller housing from becoming disengaged from the central hub. However, due to manufacturing constraints, the ears may not tightly engage corresponding lobes and/or stops along the inner surface of the propeller housing thereby allowing for the possible movement of the propeller housing during use. As such, it is highly desirable to provide a locking mechanism for securely retaining the propeller housing on the central hub.
Therefore, it is a primary object and feature of the present invention to provide a propeller housing which may be securely mounted to a propeller shaft of a marine vehicle.
It is still a further object and feature of the present invention to provide a propeller assembly which is simple and inexpensive to manufacture.
It is still a further object and feature of the present invention to provide a propeller assembly which incorporates a propeller housing which may be simply and easily mounted on a central hub which, in turn, is retained on a propeller shaft of a marine vehicle.
In accordance with the present invention, a propeller assembly is provided for mounting on a rotatable propeller shaft of a watercraft. The propeller shaft extends along an axis and terminates at a threaded end. The propeller assembly includes a central hub mountable on the propeller shaft for rotational movement therewith. The central hub defines a generally cylindrical outer surface having a plurality of circumferentially spaced keys therealong. Each key has a first narrow end and a second wider end. A generally tubular propeller housing is slidable onto the central hub for rotational movement with the propeller shaft. The propeller housing includes an inner surface having a plurality of circumferentially spaced pairs of axially extending lobes therealong. Each pair of lobes defines a corresponding keyway for receiving a corresponding key along the central hub. A locking structure is mountable on the propeller shaft. The locking structure includes a spider washer having first and second ends and aperture therebetween for receiving the propeller shaft therethrough. The spider washer includes a nose portion extending from the first end thereof. A locking washer has an opening for receiving the nose portion of the spider washer therethrough and an outer periphery engaging the lobes and preventing removal of the propeller housing from the central hub. A locking element is mountable on the threaded end of the propeller shaft for retaining the spider washer on the propeller shaft.
It is contemplated to provide a stop member on the outer end of one of the keys. The stop member limits movement of the propeller housing onto the central hub. The inner surface of the propeller housing includes a shoulder formed therein. The outer periphery of the locking washer engages the shoulder to prevent removal of the propeller housing from the central hub. The outer periphery of the locking washer may include a plurality of circumferentially spaced ears.
Each key has a first narrow end and a second wider end, and each keyway of the propeller housing includes a first wide end and second narrow end. The wide end of each keyway receives the narrow end of a corresponding key of the central hub as the propeller housing is slid onto the central hub. As is conventional, the propeller housing includes an outer surface having a plurality of circumferentially spaced propeller blades extending therefrom.
In accordance with a further aspect of the present invention, a propeller assembly is provided for mounting on a rotatable propeller shaft of a watercraft. The propeller assembly includes a central hub mountable on the propeller shaft for rotational movement therewith. The central hub defines a generally cylindrical outer surface having a plurality of circumferentially spaced keys therealong. Each key has a first narrow end and a second wider outer end. A generally tubular propeller housing is slidable onto the central hub for rotational movement on the propeller shaft. The propeller shaft includes an inner surface having a plurality of circumferentially spaced pairs of axially extending lobes therealong. Each pair of lobes defines a corresponding keyway for receiving a corresponding key along the central hub. A locking structure is mountable on the propeller shaft. The locking structure includes a spider washer having a first end directed towards the central hub, a second end and an aperture therebetween for receiving a propeller shaft therethrough. The spider washer includes a nose portion extending from the first end thereof A locking washer has an inner edge defining an opening for receiving the nose portion of the spider washer therethrough and an outer periphery for engaging the lobes and preventing removal of the propeller housing from the central hub.
The inner surface
Boyle Fredrickson Newholm Stein & Gratz S.C.
Edgar Richard A.
Look Edward K.
Turning Point Propellers Inc.
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