Bearing and bearing mount and tools incorporating same

A bearing and bearing mount comprising an adjustable combined sleeve and thrust bearing which may be adjusted during assembly for endwise positioning which is of generally top-hat configuration having a generally cylindrical sleeve bearing portion and a generally laterally outwardly extending annular rim-like portion providing a thrust bearing face generally perpendicular the axis of the sleeve bearing portion, the rear face of the rim-like portion being provided with a cam or ramp surface which rises progressively relative the front or thrust bearing face in a direction generally parallel the longitudinal axis of the sleeve bearing portion together with a saddle strap having a semi-cylindrical central portion adapted to engage the sleeve bearing portion and so fit against the sleeve portion of the bearing as to prevent it from rotating therewithin and provided with a cam or ramp surface that mates with and is adapted to engage the cam or ramp surface of the combined sleeve and thrust bearing so that relative rotation of the bearing beneath the strap will provide a camming action so as to move the bearing and, therefore, the thrust face thereof longitudinally relative the mounting strap and right-angle sander/polisher incorporating same.

DESCRIPTION 
1. Field of the Invention 
This invention relates to a bearing and bearing mount and, more 
particularly, to a mount arrangement for a combined sleeve and thrust 
bearing which is adjustable in its endwise position during assembly which 
finds particular utility in connection with a beveled ring gear in the 
output drive of a right-angle sander/polisher such as is utilized in 
automotive maintenance. 
2. Background of the Invention 
Right-angle sander/polishers are often used in connection with automotive 
maintenance together with buffing or polishing heads or bonnets for 
applying, buffing and polishing wax or similar finishes, or with abrasive 
heads or discs for example, removing paint, grinding repair materials, 
removing rust, and the like. Right-angle grinders and sander/polishers are 
so designated because they comprise a generally elongated body having a 
hand grip at one end thereof, a generally centrally disposed motor having 
an armature shaft extending generally longitudinally of the longitudinal 
axis of the tool and an output shaft disposed generally at a right angle 
thereto. An auxiliary handle may also be removably associated with the 
gear case end. Affixed to the output shaft there may be provided a rubber 
or similar elastomeric pad to which there may be affixed a sanding or 
polishing pad or, for sanding and grinding, an abrasive disc. Between the 
motor armature shaft and the output shaft is a reduction gear set 
contained within the gear case end to enable the output shaft to be 
rotated at, for example, 1700/1900 revolutions per minute to provide a 
maximum SFPM of the pad of less than or about equal to 3000 SFPM. In the 
right-angle sander/polisher specifically disclosed herein and illustrated 
in the drawing, a double-reduction gear set is included which comprises 
mating beveled pinion and ring gears providing one stage of gear reduction 
driven from the motor armature shaft through a second gear reduction 
stage. 
It is desirable to provide means for enabling the clearance or back-lash 
between the pinion and output ring gear to be adjusted during assembly of 
the tool so that during assembly compensation may be made for variances in 
manufacturing tolerances. With proper adjustment, gear noise and whine can 
be minimized. 
SUMMARY OF THE INVENTION 
In accordance with the present invention, a bearing and bearing mount is 
provided which provides an adjustable combined sleeve and thrust bearing 
which may be adjusted during assembly for endwise positioning which, when 
used in conjuction with a shaft and beveled ring gear carried thereby may 
be utilized to provide for adjustment of the gear in its mating 
relationship with an associated beveled pinion gear to provide smooth, 
quiet, and long life operation. 
A combined sleeve and thrust bearing is provided which is of generally 
top-hat configuration comprising a generally cylindrical sleeve bearing 
portion and a generally laterally outwardly extending annular rim-like 
portion providing a thrust bearing face generally perpendicular the axis 
of the sleeve bearing portion which may, in accordance with one aspect of 
the present invention, bear against a mating face of the hub of a beveled 
ring gear to provide axial positioning thereof. 
Referring to the thrust face or surface of the rim-like portion as the 
"front" face, the rear face of the rim-like portion, in accordance with 
the present invention, is provided with a cam or ramp surface which rises 
progressively relative the front or thrust bearing face in a direction 
generally parallel the longitudinal axis of the sleeve bearing portion. 
Further, the rim portion of the combined sleeve and thrust bearing is 
provided with at least one generally radially extending slot to enable 
engagement thereof, as by a spanner wrench for rotational positioning. 
In accordance with the present invention, a bearing mount is provided 
connected with the housing of, for example, a right-angle sander/polisher 
for supporting the combined sleeve and thrust bearing. Such mount may 
comprise a semi-cylindrical seat within the housing half of a clam-shell 
housing for receiving the sleeve portion of the combined thrust and sleeve 
bearing with the combined thrust and sleeve bearing being retained in 
position thereon and therein by a saddle strap having a pair of generally 
opposed coplanar ears adapted to be attached to the housing half adjacent 
opposite sides of the semi-circular seat, as by means of mounting screws 
and with a semi-cylindrical central portion therebetween adapted to engage 
the sleeve bearing portion generally opposite the semi-cylindrical seat 
and to form therewith a generally cylindrical mounting for the sleeve 
bearing portion. Upon tightening of the mounting screws, the strap should 
so fit against the sleeve portion of the bearing as to prevent it from 
rotating therewithin. 
The generally semi-cylindrical portion of the saddle strap is provided with 
a cam or ramp surface that mates with and is adapted to engage the cam or 
ramp surface of the combined sleeve and thrust bearing so that relative 
rotation of the bearing beneath the strip will provide a camming action so 
as to move the bearing and, therefore, the thrust face thereof 
longitudinally relative the mounting strap and associated housing half 
seat. 
During assembly, a spanner wrench and appropriate tooling such as a 
pressure gauge or feeler gauge may be utilized to provide the desired 
positioning of the beveled ring gear relative the mating beveled pinion 
gear and, when properly positioned, tightening of the saddle strap is then 
effective to lock the bearing in its desired orientation. 
OBJECTS OF THE INVENTION 
Bearing in mind the foregoing, it is a primary object of the present 
invention to provide novel and improved bearings and bearing mounts, 
especially for combined sleeve and thrust bearings having, for example, a 
sleeve portion of generally cylindrical hollow configuration and a thrust 
portion at one end thereof of generally annular configuration having a 
generally flat thrust face generally perpendicular the axis of the sleeve 
bearing portion which may, in accordance with the present invention be 
generally longitudinally adjusted. 
Another primary object of the present invention, in addition to the 
foregoing object, is the provision of such bearings and bearing mounts 
which find special utility in connection with assemblies such as portable 
power tools, for example, a right-angle sander/polisher having a beveled 
ring gear associated with the output shaft and engaged with a beveled 
pinion gear so that adjustment of the combined sleeve and thrust bearing 
effectuates adjustment of the meshing therebetween to minimize noise and 
wear. 
Yet another primary object of the present invention, in addition to each of 
the foregoing objects, is the provision of such bearings and bearing 
mounts, especially for use with such a ring gear having a thrust face on 
the hub thereof slidingly mounted on the output shaft so that adjustment 
of the bearing within the bearing mount in accordance with the present 
invention may provide a desired pre-load or clearance to the ring gear. 
Still another primary object of the present invention, in addition to each 
of the foregoing objects, is the provision within such bearings and 
bearing mounts of mating, cooperating ramp surfaces to enable the bearing 
to be longitudinally adjusted relative the bearing mount during assembly 
so as to position the thrust face at a desired position. 
Yet another primary object of the present invention, in addition to each of 
the foregoing objects, is the provision of such bearings and bearing 
mounts wherein the bearing is further provided with at least one generally 
radially extending slot so as to enable engagement thereof by a spanner 
wrench, or the like, for rotationally adjusting the bearing relative the 
bearing mount so that the cooperating ramp surfaces adjust the bearing's 
endwise position. 
Yet still another primary object of the present invention, in addition to 
each of the foregoing objects, is the provision of such bearings and 
bearing mounts in combination with bevel gear drives of an output shaft 
of, for example, a portable electric power tool such as a right-angle 
sander/polisher wherein the bevel gear is slidable on the output shaft, as 
being keyed thereto, and is provided with a hub having a thrust surface so 
engagement by the thrust face of the bearing to provide adjustment thereby 
of its meshing with a mating drive pinion gear, whereby, during assembly 
the mesh pre-load or clearance can be adjusted quickly, easily and 
inexpensively. 
Another and yet further primary object of the present invention, in 
addition to each of the foregoing objects, is the provision of such 
bearings and bearing mounts which are inexpensive to manufacture and 
assemble but which are yet durable and effective in use. 
The invention resides in the combination, construction, arrangement and 
disposition of various component parts and elements incorporated in 
improved bearings and bearing mounts and in improved portable electric 
tools such as right-angle sander/polishers incorporating the same 
constructed in accordance with the principles of this invention. The 
present invention will be better understood and objects and important 
features other than those specifically enumerated above will become 
apparent when consideration is given to the following detailed 
description, which when taken in conjunction with the annexed drawing 
describes, discloses, illustrates and shows a preferred embodiment or 
modification of the present invention and what is presently considered and 
believed to the best mode of practicing the principles thereof. Other 
embodiments or modifications may be suggested to those having the benefit 
of the teachings herein, and such other embodiments or modifications are 
intended to be reserved, especially as they fall within the scope and 
spirit of the subjoined claims.

DETAILED DESCRIPTION OF THE INVENTION 
With reference now to the drawing, there is shown and illustrated a 
right-angle sander/polisher designated generally by the reference 
character 10 which comprises two housing halves 12 and 14 of clam shell 
construction held together by a plurality of fastening screws 16. The 
sander/polisher 10 further comprises a trigger switch designated generally 
by the reference character 18 adjacent a hand grip portion 20 and there is 
also provided a lock button 22 for cooperation with the trigger switch 
mechanism 18. Yet still further a line cord 24 is provided for powering 
the tool and mounted within the clam shell housing halves 12 and 14 there 
is provided an electric motor shown in broken lines and designated 
generally by the reference character 26 and which includes an armature 
shaft 28 which carries a cooling fan 30 and has formed at one end portion 
thereof gear teeth 32 defining the input of a double reduction gear set 
which comprises the gear teeth 32, and output beveled ring gear 42 and an 
intermediate gear 34 having spur gear teeth 36 in meshing engagement with 
the armature shaft gear teeth 32 and driving pinion bevel gear teeth 38 in 
meshing engagement with the gear teeth 40 of the output bevel ring gear 
42. The intermediate gear 34 is mounted on a gear shaft 44 carried in 
bearings 46 and 48 carried by the clam shell housing halves 12 and 14. 
As heretofore pointed out, the output gear 42 is mounted for rotation with 
an output shaft 50 which extends through a hole 52 provided in the mating 
housing halves 12 and 14. The end portion of the output shaft outward of 
the housing halves 12 and 14 may be provided with screw threads 54 as 
shown, to enable a rubber or other soft, resilient material disc to be 
attached thereto for carrying sand paper, a polishing bonnet, or the like 
as will be readily appreciated by those having skill in this art. Further 
the shaft may be provided with a cross aperture 56 to enable a pin, or the 
like, not shown, to be engaged therewith for holding the output shaft 50 
against rotation to enable the disc pad to be unthreaded therefrom and 
assembly of sanding disc by using a threaded nut and spanner wrench. 
The inward end of the output shaft 50 is journaled in a bearing 58. The 
output gear 42 is provided with a central aperture 60 which is provided 
with a key slot 62. The output shaft 50 and the area within the ring gear 
42 is provided with a milled slot 64 into which a woodruff key 66 is 
inserted. Behind the output gear 42, that is between the output gear 42 
and the bearing 58, the shaft is provided with an annular groove and a 
snap ring 68 is installed which, as will be made clear hereafter, 
positions the output shaft 50 longitudinally. 
The front face of the output gear 42 is provided with a central hub 70 that 
has a thrust face 72 which abuts a thrust face 74 of a combined sleeve and 
thrust bearing designated generally by the reference character 76 and 
which is of generally top-hat configuration comprising a generally 
cylindrical sleeve bearing portion 78 and a generally laterally or 
radially outwardly extending annular rim-like portion 80 providing a 
thrust bearing face generally perpendicular the axis of the sleeve bearing 
portion 76 which may, according to one aspect of the present invention, 
bear against the mating face 72 of the hub 70 of the bevel output ring 
gear 42 to provide axial positioning thereof. 
Hence, the thrust face 74 of the bearing 76 limits outward movement of the 
gear 42. Inward movement of the gear 42 is limited by the snap ring 68. 
Outward movement of the snap ring 68 and, therefore, the output shaft 50 
is limited by the gear 42. Inward movement of the snap ring 68 and, 
therefore, the output shaft 50, is limited by the bearing 58. Both the 
shaft 50 and gear 42 are therefor axially positioned. 
Referring to the thrust face or surface 74 of the rim-like portion 70 as 
the "front" face, the rear face of the rim-like portion 80, in accordance 
with the present invention, is provided with a cam or ramp surface 82 
which rises progressively relative the front or thrust bearing face 74 in 
a direction generally parallel the longitudinal axis of the sleeve bearing 
portion 78. Further, the rim portion 80 of the combined sleeve and thrust 
bearing 76 is provided with at least one generally radially extending slot 
84 to enable engagement thereof by a spanner wrench, or the like, for 
rotational positioning of the bearing. 
In accordance with the present invention, a bearing mount, designated 
generally by the reference character 86 is also provided connected with 
the housing half 12 for supporting the combined sleeve and thrust bearing 
76 and comprises a semi-cylindrical seat in the housing half 12 of the 
clam-shell housing for receiving the sleeve portion 78 of the combined 
thrust and sleeve bearing 76. The combined thrust and sleeve bearing 76 is 
retained in position in the seat by a saddle strap 88 having a pair of 
generally opposed coplanar ears 90 adapted to be attached to the housing 
half 12 adjacent opposite sides of the semi-cylindrical seat, as by means 
of mounting screws 92. The saddle strap 88 further comprises a 
semi-cylindrical central portion 94 adapted to engage the sleeve bearing 
portion 78 generally opposite the semi-cylindrical seat to form therewith 
a generally cylindrical mounting for the sleeve bearing portion 78. Upon 
tightening of the mounting screws 92, the strap semi-cylindrical central 
portion 94 should so fit againt the sleeve bearing portion 78 of the 
combined thrust and sleeve bearing 76 as to prevent it from rotating 
therewithin. 
The generally semi-cylindrical portion 94 of the saddle strap 88 is 
provided with a cam or ramp surface 96 that mates with and is adapted to 
engage the cam or ramp surface 82 of the combined sleeve and thrust 
bearing 76 so that relative rotation of the bearing 76 beneath the saddle 
strap 88 will provide a camming action so as to move the bearing 76 and, 
therefore, the thrust face 74 thereof longitudinally relative the saddle 
strap 88 and bearing mount 86. 
During assembly, a spanner wrench and appropriate tooling such as a 
pressure gauge or feeler gauge may be utilized to provide the desired 
positioning of the bevel ring gear 42 relative the mating pinion gear 
teeth 38 and, when properly positioned, tightening of the screws 92 
holding the saddle strap 88 is then effective to lock the bearing 76 and 
the output shaft 50 in their desired orientation. 
While the invention has been described, disclosed, illustrated and shown in 
terms of a preferred embodiment, or modification which it has assumed in 
practice and herein described, disclosed, illustrated and shown, such 
other embodiments or modifications as may be suggested to those having the 
benefit of the teaching herein are intended to be reserved especially as 
they fall within the scope and breadth of the claims here appended.