Abstract:
A wheel cover for a vehicle wheel with a sprag clutch providing the connection to the cover so that the cover can overrun the wheel. A second clutch of the centrifugal type connects the sprag clutch to the vehicle wheel so that at elevated speeds the cover is not driven by the wheel.

Description:
BACKGROUND OF THE INVENTION 
     1) Field of the Invention 
     This invention relates to wheel covers for the wheels of motor vehicles generally and more particularly to such a cover as is mounted on a wheel so as to be able to spin independently relative to the wheel in certain modes of operation while rotating unitarily with the wheel during other modes of operation. 
     2) Description of the Prior Art 
     Spinable and/or non-rotating wheel covers are well known in the art as exemplified by U.S. Pat. Nos. 3,219,391; 4,929,030; 5,957,542; and 5,490,342. U.S. Pat. No. 3,219,391 in particular shows and describes a wheel cover mounted on a wheel so as to rotate independently relative to the wheel whereby the cover can continue to revolve for at least a short time after the vehicle has come to rest. None of the devices which are the subject matter of these patents relate to a wheel cover which is clutchedly connected to the wheel for unitary rotation when the vehicle is traveling in a forward direction yet when the vehicle stops or travels in reverse is unconnected so as to be able to revolve independently in a forward direction. Additionally, if connected for unitary rotation, do not include a second device for disconnecting the cover from a driving connection at rotational speed above a selected speed so that the cover can again rotate relative to the wheel. 
     SUMMARY OF THE INVENTION 
     The present invention relates to a wheel cover which is mounted on the wheel of a vehicle by a one way sprag (overrunning) clutch so that when the wheel is rotating in a forward direction, the sprags are locked and the cover is connected to the wheel for unitary rotation, since the inner race of the sprag clutch is connected to the wheel for unitary rotation and the outer race of the clutch is connected to the cover for unitary rotation. When the wheel stops, or rotates in a reverse direction, the wheel cover is free to rotate in the forward direction since the sprag clutch will be unlocked. In one embodiment, the inner race of the sprag clutch is mounted on the wheel by a complement of bearings and drivingly connected to the wheel for unitary rotation by a speed sensitive clutch means such as a centrifugal clutch, which latter clutch disconnects the connection of the inner race to the wheel at some preselected rotational velocity of the wheel, and thus at rotational speeds above the selected speed, the inner race of the sprag clutch is free to rotate relative to the wheel and the wheel cover can rotate relative to the wheel even though the sprag clutch may be engaged at such time. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side elevational view in cross section of a wheel with a tire mounted thereon and a spinable wheel cover of this invention mounted on the wheel; 
     FIG. 2 is a view taken like FIG. 1 of a second embodiment of this invention; and 
     FIG. 3 is a front elevational view of the assembly shown in FIG. 2, with the sprag clutch shown in section. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawings, and more particularly to FIG. 1, a wheel and wheel cover assembly is shown generally at  10  conventionally mounted on an outboard end of a driving axle  12 . The hub flange  14  of the axle  12  includes a plurality of circumferentially spaced lugs  15 , which lugs pass through registering openings  16  in a wheel  17 , the latter having a conventional tire  18  mounted thereon. A wheel cover hub  19  has a central opening  20  therein which pilotingly receives the outboard end  21  of the axle  12 , which hub has a n integral flange  22  thereon with the latter having a plurality of openings  23  in registration with and receiving the studs  15 , while a nut  24  is threaded on each stud  15  to thereby secure the wheel  17  and the cover hub  19  to the axle  12  for unitary rotation. 
     Mounted on the hub  19  in a pressed fit relationship for unitary rotation is the inner race  26  of a sprag clutch shown generally at  28 , which sprag clutch has an outer race  30  conventionally spaced from the inner race  26  and having a wheel cover  31  secured thereon for unitary rotation with the periphery of the cover being rotatably spaced from the wheel  17 . A conventional plurality of sprag members  32  is disposed between the races  26  and  30  in a conventional manner. A annularly disposed sprag clutch coiled compression spring  34 , as best seen in FIG. 3, engages the sprag members  32  and urges them into an upright condition whereby they are resiliently biased into a wedging relationship with the inner and outer races  28  and  30  and are drivingly disposed between the inner and outer races when the axle  19  and the wheel  17  are driving forward (clockwise as seen in the direction of the arrow A shown in FIG. 3) to thereby drive the wheel cover  31 , and are overridingly disposed between the inner and outer races when the hub  19  stops rotating or rotates in a reverse direction and the wheel cover  31  can continue to rotate in the direction of the arrow A uninhibited by the sprag clutch  28  since the latter will become disengaged at such time and acts as a rotative connection in the manner of a bearing which provides support while allowing relative rotation. 
     Referring now to FIGS. 2 and 3, a second embodiment of this invention is shown with a sprag clutch  28 A having inner and outer races  26 A and  30 A, and with the inner race  26 A being rotatably mounted on the hub  19  by a roller bearing assembly shown generally at  36 . A speed activated clutch means in the form of a centrifugal clutch is shown generally at  38  and includes a lever  40  with a weight  42  on the radially outer end thereof, with the lever being pivotally mounted by a pivot pin  43  to a support member  46 ; the latter being securely carried by the hub  19 . A compression spring  44  biases the lever to rotate in a counterclockwise direction, as seen in FIG. 2, so that a clutching surface  48  on the radially inner end thereof engages the inner race  26 A of the sprag clutch  28 A, whereby when stationary and at lower speeds the clutch  38  connects the inner race to the hub  19  and the assembly operates as described for the embodiment of FIG.  1 . However, at higher speeds the weight  42  of the centrifugal clutch  38  will cause the lever  40  to rotate clockwise, as seen in FIG. 2, so that the clutching surface  48  will move out of engagement with the inner race  26 A and the sprag clutch, and the wheel cover  31 A carried thereby will be free to rotate relative to the hub  19  and the wheel  17 A carried thereby until such time as the speed of the wheel drops below the speed set for the centrifugal clutch  38 . Thus, while at low and moderate speeds, the wheel cover  31  A will rotate unitarily with the wheel  17 A, at higher speeds above the preset speed, where driving the wheel cover at high rotational velocities could be unsafe, the wheel cover will not be driven and can rotate at whatever speed its energy level dictates. Further, when the wheel stops and the clutch  38  re-engages, the wheel cover can continue to rotate in an attractive manner. While the sprag clutch is shown as an open construction for illustration purposes, it is understood that in actual production, it is contemplated that the clutch would be sealed from the elements in a well known conventional manner. While only preferred embodiments of this invention have been shown and described, it is understood that many changes therein can be made without departing from the scope of this invention as defined by the following claims.