External hone

A honing fixture includes a mounting ring 30 carrying a plurality of circumferentially spaced rollers 32. A ring gear 34 rotates about rollers 32 and carries segmented ring segments 40a and 40b for rotation therewith about a honing axis. Ring segments 40a and 40b carry honing stones, the segments being pivotally coupled to one another at one end and biased for closing movement toward one another at the opposite end. A suspension structure supports the honing fixture 14 from a support assembly 12 in a manner to compensate for applied torque loading on the honing fixture and its weight. The suspension structure includes a pair of pivoted arms 72 and 74 carrying the weight of the honing fixture at their distal ends and engaging at their proximal ends a spring 90. The honing fixture 14 is mounted for translation movement along guides 18.

TECHNICAL FIELD 
The present invention relates to an improved hone for conditioning an 
external surface of a workpiece, e.g., a bearing or a ground surface, 
without rotation of the workpiece. 
BACKGROUND 
Most hones are maintained stationary and the workpiece is rotated relative 
to the hone to recondition the workpiece. This requires substantial effort 
to set-up the workpiece relative to the honing fixture. Runout checks on 
the workpiece, particularly for precision honing, additionally require the 
removal of the workpiece from the hone and rotary device. This, in turn, 
necessitates additional and repititious set-ups for further honing to the 
desired surface. Concentricity of the surface to be reconditioned with the 
original axis of the workpiece is also extremely difficult, if not 
impossible, to maintain with a fixed hone and a rotating workpiece. 
Hones adapted to rotate about a fixed workpiece are, of course, well known. 
It will be appreciated, however, that when an external hone rotates about 
a workpiece, a torque is developed, tending to thrust the honing fixture 
laterally in the direction of rotation. In the absence of compensation for 
this applied torque, a non-uniform loading on the surface of the workpiece 
occurs, with the result that the axis of the honing fixture tends to shift 
relative to the axis of the workpiece. Further, if the weight of the 
honing fixture and ancillary equipment are applied to the workpiece during 
honing, the coaxial relation of the workpiece and honing fixture would 
similarly tend to shift. 
DISCLOSURE OF INVENTION 
In accordance with the present invention, there is provided a hone which 
maintains concentricity with the workpiece whose external surface is to be 
honed, i.e., the honing fixture and workpiece axes are maintained during 
honing in a coaxial relation one with the other. To accomplish this, the 
hone support assembly employs a suspension structure which compensates for 
the weight and thrust of the honing fixture. 
According to the present invention, there is provided an external hone 
which compensates for the weight of the honing fixture and the torque load 
applied to the rotating honing fixture whereby concentricity of the 
workpiece and honing fixture and hence a coaxial relation of the axes of 
the fixture and the workpiece are maintained throughout the honing 
process. To accomplish the foregoing, the present invention provides a 
support structure which carries the honing fixture for horizontal 
movement. The honing fixture per se includes a mounting structure, 
preferably a mounting ring, carrying a plurality of rollers 
circumferentially spaced one from the other about the ring, the mounting 
ring defining a honing axis. A rotatable structure including a ring gear 
is mounted for rotation about the rollers relative to the mounting ring 
and carries a plurality of honing stones at spaced circumferential 
positions thereabout. Preferably, the stones are carried by a stone ring 
comprised of a pair of semi-circular ring segments. To drive the stone 
ring about the axis of the honing fixture, a hydraulic motor is mounted on 
the honing fixture, e.g., the mounting structure, and is coupled to the 
ring gear by an endless chain. The hydraulic motor drives the chain and 
ring gear which, in turn, rotates the stones about the axis of the honing 
fixture, honing the surface of the workpiece disposed coaxially within the 
honing fixture. 
A unique suspension structure for the honing fixture is provided connecting 
between the support assembly and the honing fixture and which compensates 
for the weight of the honing fixture and the applied torque load. This 
suspension assembly includes a pair of generally horizontally disposed, 
laterally extending support arms each carried on a discrete horizontal 
pivot intermediate the ends of the support arm by the horizontally movable 
support assembly. The distal ends of the support arms carry rods which, in 
turn, are pivotally connected to hangers secured at their lower ends to 
the mounting ring. These latter pivotal connections form a horizontal axis 
about which the honing fixture may rotate, i.e., a horizontal axis normal 
to the honing axis. The free interior or proximal ends of the support arms 
bear against a spring carried by the support assembly. The weight of the 
honing fixture is transmitted to the distal ends of the support arms by 
the hanger and rod on each of the opposite sides of the honing fixture and 
by the support arms to the spring. The spring effectively carries the 
weight of the honing fixture. Consequently, the honing fixture essentially 
floats and has no weight when applied to the workpiece. 
The suspension assembly also compensates for the torque load applied to the 
honing fixture by the motor which rotates the honing stones. By enabling 
the support arms to pivot in opposite directions as a result of the 
applied torque loading, movement on one side of the honing fixture is 
followed by similar movement of the other side of the honing fixture, thus 
offsetting and counterbalancing the tendency of the fixture to move 
laterally under the applied torque loading. The suspension assembly 
therefore compensates for the weight of the honing fixture and its side 
torque loading to maintain the hone axis coaxial with the original axis of 
the workpiece and the honing fixture concentric with the surface of the 
workpiece. 
Additionally, and in accordance with the present invention, the mounting 
ring for the hones is comprised of a pair of semi-circular mounting ring 
segments, only one of which is secured to the rotatable structure. The 
segments are pivotally connected one to the other at their proximal ends 
at one side of the honing fixture. The non-secured segment is 
spring-biased for movement of its distal end toward the opposite distal 
end of the secured segment. Consequently, a gap may appear at the juncture 
of the distal ends of the two segments, with the segments biased for 
movement toward one another during honing to close the gap. Further, the 
honing stones are carried by the stone ring for radial movement within a 
limited range, i.e., movement toward and away from the honing axis. This 
enables workpieces of different diameters, within the range of movement 
defined by the radially movable stones, to be honed. 
In a preferred embodiment according to the present invention, there is 
provided an apparatus for externally honing a fixed workpiece having an 
axis comprising (a) a support assembly, (b) a honing fixture including (i) 
a mounting structure carried by the support assembly mounting a plurality 
of rollers circumferentially spaced one from the other and defining a 
honing axis; (ii) a rotatable structure carried by the rollers for 
rotation about the honing axis and relative to the mounting structure; and 
(iii) means carried by the mounting structure and coupled to the rotatable 
structure for applying a torque thereto such that the rotatable structure 
rotates about the honing axis, (c) a plurality of honing stones carried by 
the rotatable structure for rotation therewith about the honing axis and 
for engagement with a workpiece for honing the external surface of the 
workpiece and (d) means coupled between the support assembly and the 
mounting structure for compensating for the weight of the honing fixture 
and the torque applied to the rotatable structure such that the workpiece 
and honing axes are maintained coaxial one to the other during honing. 
In a further preferred embodiment according to the present invention, there 
is provided apparatus for externally honing a fixed workpiece having an 
axis comprising a support assembly, a honing fixture defining a honing 
axis and including a mounting structure carried by the support assembly, a 
rotatable structure carried by the mounting structure for rotation about 
the honing axis and relative to the mounting structure, and means carried 
by the honing fixture and coupled to the rotatable structure for applying 
a torque thereto such that the rotatable structure rotates about the axis, 
a plurality of honing stones connected to the rotatable structure for 
rotation therewith about the honing axis and for engagement with a 
workpiece for honing the external surface of the workpiece, support arms 
coupled to the support assembly and the mounting structure on opposite 
sides of the honing axis and independently pivotal relative to one another 
and biasing means enabling the support arms to pivot in substantially 
equal increments in opposite directions in response to an applied torque 
whereby any tendency of the honing fixture to be displaced laterally in 
response to the applied torque is resisted by the biasing means. 
Accordingly, it is a primary object of the present invention to provide a 
novel and improved honing apparatus for externally honing a fixed 
workpiece.

BEST MODE FOR CARRYING OUT THE INVENTION 
Reference will now be made in detail to a present preferred embodiment of 
the invention, an example of which is illustrated in the accompanying 
drawings. 
Referring now to FIG. 1, there is illustrated a honing apparatus according 
to the present invention, generally indicated 10, including a support 
assembly, generally designated 12, for carrying a honing fixture, 
generally designated 14. Support assembly 12 includes a top plate 15 
mounting along its underside a pair of laterally spaced pillow blocks 16 
slidable on longitudinally extending, horizontally spaced bars 18. Bars 18 
are supported at their opposite ends by crossbars 20, in turn, supported 
by uprights 22 which are adjustable in height. The lower ends of uprights 
22 are, in turn, supported by respective pairs of outwardly diverging 
support legs 24. The support legs 24 adjustably carry a strap 25 between 
the legs for securing a workpiece WP between the legs and the undersides 
of the legs. FIG. 1 illustrates the honing fixture 14 in position for 
honing a workpiece WP having an axis A, the workpiece WP being carried by 
the straps 25 between the pairs of legs. It will be appreciated that 
support plate 15 and pillow blocks 16 are slidable horizontally along 
guide bars 18 and that the honing fixture 15 is carried for horizontal 
movement therewith in directions parallel to axis A. 
Referring now particularly to FIGS. 2-5, honing fixture 14 includes a 
mounting structure preferably comprising a mounting ring 30 carrying a 
plurality of rollers 32 at circumferentially spaced positions about ring 
30. Rollers 32 project axially to one side of ring 30 and are mounted for 
rotation about horizontal axes. A rotatable structure, preferably 
comprising a ring gear 34 having external teeth 36, is mounted for 
rotation on rollers 32 about an axis coincident with the axis of mounting 
ring 30 and which defines a honing axis for honing workpiece WP. A 
plurality of honing stones 38 are carried by the rotatable honing 
structure for rotation therewith and about the honing axis. Preferably, 
stones 38 are carried on a segmented stone ring 40 and are preferably 
equally circumferentially spaced one from the other. As illustrated in 
FIG. 4, each stone 38 is mounted on a stone holder 42 which is mounted on 
the stone ring 40 for adjustable radial movement toward and away from axis 
A by means of bolts 44 and 46. Consequently, by adjusting bolts 44 and 46, 
each stone 38 can be moved radially inwardly or outwardly relative to the 
honing axis, i.e., relative to the axes of the mounting ring, ring gear 
and stone ring, whereby workpieces of different diameters within a 
predetermined range can be honed by the honing apparatus hereof. 
Stone ring 40 is formed of two generally semi-circular segments 40a and 40b 
pivoted one to the other at adjoining ends by a pin 48 passing through an 
axially reduced end 49 of ring segment 40a and a pair of plates 51 secured 
to an axially reduced end 53 of segment 40b. The stone segment 40b is 
secured by bolts to ring gear 34 whereas the segment 40a is secured only 
to segment 40b. The opposite end of segment 40a is biased for movement 
toward segment 40b about pin 48 to close the stone ring. To accomplish 
this, a bolt 50 (FIG. 5) is threaded into the end of lower segment 40b and 
is received in a recess 52 formed in the upper segment. A spring 54 
engages between the head of bolt 52 and the base of the recess. The spring 
thus biases segments 40a and 40b for closing movement toward one another 
about pivot pin 48. 
Honing fixture 14 also includes a drive block 60 suitably secured to 
mounting ring 30. A motor mount 62 is connected to drive block 60 and 
mounts a hydraulic motor M. The drive shaft of hydraulic motor M carries a 
sprocket 64 which drives an endless chain 66 which extends about ring gear 
34. An idler gear 68 (FIG. 4) is also carried by drive block 60 and is 
adjustable in a lateral direction to adjust the tension on drive chain 66. 
Consequently, it will be appreciated that operation of motor M carried by 
honing fixture 14 drives chain 66 which rotates ring gear 34. Ring gear 34 
carries the stone ring 40 for rotation therewith by its bolted connection 
with segment 40b and the connections between the opposite ends of the 
segments, i.e., pin 48 and the spring-biased bolt 50. The honing stones 38 
are thus carried for rotation about axis A. 
By applying torque to the drive ring and stone ring through chain drive 66, 
the stones 38 are rotated about the workpiece. This drive also applies a 
lateral thrust to honing fixture 14. To compensate for this lateral thrust 
and also to compensate while honing for the weight of honing fixture 14, 
there is provided a unique suspension structure for coupling honing 
fixture 14 and support assembly 12. More particularly and with reference 
to FIG. 2, the suspension structure includes a pair of laterally spaced 
threaded support rods 70 secured at their upper ends to top plate 15. Rods 
70 terminate at their lower ends in a pivotal connection with a pair of 
laterally extending support arms 72 and 74. The inner proximal ends of 
support arms 72 and 74 are closely spaced to one another but are 
unconnected. Thus, support arms 72 and 74 are carried at the lower ends of 
rods 70 for pivotal movement about discrete horizontal pivotal axes, 
designated 76 and 78. The distal ends of support arms 72 and 74 pivotally 
carry support rods 80 and 82 which pivotally connect at their lower ends 
to hangers 84 and 86. The lower ends of hangers 84 and 86 are secured to 
the mounting ring 30 as illustrated in FIG. 2. Hangers 84 and 86, as 
illustrated in FIG. 3, comprise inverted L-shaped members whereby honing 
fixture 14, including the mounting ring, ring gear and stone ring, as well 
as the drive motor M, are pivotally mounted for movement about a 
horizontal axis B (FIGS. 2 and 3) defined by the pivotal connection 
between rods 80, 82 and hangers 84, 86. 
Turning back to FIG. 2, a helical coil spring 90 is disposed between a 
spring top 92 and a spring bottom 94. The spring bottom rests on the 
proximal ends of support arms 72 and 74. Spring top 92 is carried on the 
lower end of a bolt 93 threadedly and adjustably received in the plate 14. 
Thus, the elevation of the spring top can be adjusted to adjust the 
tension in the spring 92. 
From a review of FIG. 2, it will be appreciated that the weight of the 
honing fixture is carried essentially by spring 90 by the pivoting action 
of support arms 72 and 74 about pivots 76 and 78, respectively. Thus, with 
respect to FIG. 2, the weight of honing fixture 14 tends to rotate support 
arm 72 in a counterclockwise direction about pivot 76 and support arm 74 
in a clockwise direction about pivot 78. Those opposite rotational 
movements are resisted by spring 90 and effectively the weight of the 
honing fixture is thereby transferred to the spring. 
It will also be appreciated that the torque or lateral loading applied by 
the drive motor M to the ring gear and stone ring tending to displace the 
fixture 14 laterally is compensated for by this suspension structure. 
Particularly, when the honing fixture tends to be displaced laterally, 
e.g., to the left in FIG. 2, by its motor drive, support arm 72 will pivot 
clockwise about pivot 76. However, spring 90 will follow that movement at 
the proximal end of support arm 72 and will cause the proximal end of 
support arm 74 to follow that movement. Support arm 74 will thus pivot in 
a counterclockwise direction, tending to raise the opposite side of the 
honing fixture. The tendency of fixture 14 to move laterally in response 
to the applied torque is thus zeroed out by the torque compensation 
provided by the suspension structure. 
While the invention has been described with respect to what is presently 
regarded as the most practical embodiments thereof, it will be understood 
by those of ordinary skill in the art that various alterations and 
modifications may be made which nevertheless remain within the scope of 
the invention as defined by the claims which follow.