US2028648A - Honing tool - Google Patents

Description

HONING TOOL Filed July l5, 1932 ?atenter jan.

'UNITED STATES Maasai Our invention relates to honing tools and particularly to a honing tool of the rigid type which is retained in rigid extension of the driving spindle.

The trend of the art in cylinder grinding andV honing has been toward tools which may be operated at high speed to not only reduce the time of the grinding operation but also provide abetter and finer nish on the wall of the cylinder. When the speed of the conventional. tool was increased, considerable difficulty was experienced because ofthe whipping of the tool relative to the cylinder wall which required the tool to be stopped before it was removed from the cylinder to pre' vent the abrading elements thereof from striking the side wall and destroying its nish.. l

In practicing this invention we provide 4a tool which is employed primarily for high speed opera-4 tion and which is so constructed as to permit the tool to be removed from the cylinder vwall during its high speed operation without there being any danger of the abrading elements ofl the 4tool or other portions thereof striking the cylinder Wall to mar the finish thereof. A rigid spindle is employed on the tool having a connecting portion.- k which is engaged by the driving spindle of the machine in such manner as to forrn arigid yconnection therewith to have the tool retained inl fixed extended relation to the spindle,A The rigid spindleof the tool prevents the whipping of the -grinding end ofthe cylinder and the abrasive elements from contacting with thevside of the cyl-k inder Wall when in contracted position.

To permit the abrading elements to adjust relation of the spindle thereto. `The tool isprovided with a guide plate on its lower end to protect the abrasive elements from striking the top of the cylinder block when the tool is inserted into the bore thereof and springs are utilized for retaining the abrasive elements retracted against their seats adjacent to the spindle. The springs are employed at the top and bottom ends of the abrasive elements and are provided of different strength. The springat the top of theelements is of less strength than the spring employed in the bottom thereof to have the upper end of the abrasive elements move outwardly in case"the conical vadjusting element o f the' tool is -inadvertentlymoved, to thereby permit the lower end of the eiementstoenter the cylinder and tohave K the elements'thereafter moved into parallelaligned relation as the movement into the cylinder progresses. This is made possible by employingY a j point contactbetween the abrasive element hold- 5' v y ers and the adjusting element .tu permit the tilting of the holders relative thereto which is also necessary to permit the complete universal vadjustment of the holders relative to the unaligned` spindle. l ,10

Accordingly, 'the main objects of our. invention Y are; to provide a honing tool with a solidspindle which permits the tool to be operated at a vhigh n speed; to provide an :adjusting element for the abrasive stones which moves thestones laterallyA 15 of thev spindle and which` permits theistones to center themselves relative to a cylinder bore ir.` respective vof a slight voff-center relation of`- the spindle thereto; `to provide springs of relative strength, in the natureofgarter-springs,for re'- 20 taining the abrasive stonesin retrieved position intheir seat; to mount the spring,` of.4 greaterk strengthat the lower end of the 'abrasive elements which will be retained in retrieved .positionwhen v pressure is applied to theexpanding elementsr 25` during the time the hone` is inserted into a cylder; to provide aguide plate at the end` of the tool which preventsthe` abrasiveelement from striking the't'op of the cylinderv wall;v and, in general, to provide a honing tool which may bev op- 30 erated at high speed to rapidly machinethewall of a cylinder and to produce an exceedingly vhigh finish thereto.-

' Other objects and features ofnovelty of `my invention will be veitherv specifically pointed out 35 or will become apparent when referring, for a better understanding ofour invention, to the.

following description in conjunction with the accompanying drawing, wherein: f

j Figure l is a view, partly in section and partly 40 in'elevation, of a honing tool embodying features o f my invention, and l .A .Y Y

Fig. 2 is a sectional viewof the structure illusf Referring to the figures, the honing toolv 5 com- 45 prises a solid spindle 6 supporting'an` adjustable mechanism 1, a pressure exerting device 8 anda cutting head 9 all of which are revolvable jw'ithl the spindle' and movable longitudinally thereof The upper .endv of `the spindle is rigidlyjsecured to afreta'ining `and connectingfhead Ily through PATENT ome;

thereof. A pin |4 extends through the portion I2 in engagementkwith slots in the shank I3 for supporting the tw'o elements against relative lon- The nut |1 is screwed upon a threaded extension I8 of a spring enclosing housing I9 which is retained against rotation relative'to the "spindle 6 by a pin 2| which projects within a slot 22 provided longitudinally of the spindle.

The cam collar I5 is retainedrelative to the member Il on the spindle 6 against downward displacement by a washer 23. The upward bias of the collar I5, effected through the spring enclosingwhousing I9, the nut I1 andthe member I6, is applied to a plurality of ball bearings 24, positioned between the upper surface of the collar |5 and the lower surface of the head The ball bearings 24 reduce the frctional engagement between the two members and permit the ready adjustment of the members I5 for a. purpose which will beexplained hereinafter.v 'Ihe cam carrying washerv I6 is provided with a tongue 25 which projects within the slot 22v to prevent the washer from rotating. A plurality of recesses or notches 26 are provided on both sides of the element I6 to effect a locking engagement with spring biased-plungers 21 provided in the members I5 and I1 which are locked in predetermined position thereby.

The member I1 is provided with a plurality of camming surfaces 28, which as illustrated in Fig. 1 are normally in nested relation with a plurality of 'camming surfaces 29 provided on the member I6. When the adjustable collar |5 is rotated about the spindle 6 relative to the washer I6 the camming surfaces 28 and 29 pass upon each other to effect a downward thrust to the member I6 and therefore to the elements in engagement therewith. These elements include the adjustable nuts I1 and the spring enclosing housing 9 which, when moved downwardly apply a bias to a lspring 3| supported within a cage 32 which is positioned about the spindleA 6.- r.l'he spring herein' illustrated is of preferred construction and is described and claimed in the copending application of F. M. Kern, Serial No. 521,092, filed March 9, 1931, and assigned to the assignee of the present invention. 1 n

The cage 32 limits the expansion of the spring and therefore permits the abrading elements .of the head 9 to be moved a predetermined amount,

- after which the spring stress will be ineffective because of the complete expansion of the spring within the cage 32. A washer 33 is mounted within thehousing I9 above the lspring cage 32 having an annular downwardly extending ange which projects over the cage in position to engage the spring 3| to apply aV predetermined compression thereto. A spring 34 is provided about the spindle 6,`resting on a shoulder 35 thereof, for biasing the washer 33 upwardly out of engagement with the spring 3| when the camming elements 28 vand 29 are in nested `relation as illustrated in the figure. Y

Below the spring cage 32 and in intimate contact therewith is provided an annular washer 36 having extending fingers 31 thereon which are guided in slots 38 in the'sides of the spindle 6 to prevent the fingers from rotating relative to the pindle E; In this construction, the downward movement of the washer 33 stresses the spring 3| which applies apressure through the cage 32 and the washer 36 to the lingers 31 to move them downwardly relative to the spindle 6.

A camming member 4|, of irusto conical shape, is positioned aboutthe lower portion of the spindle 6 for movement longitudinally thereofI effected by the thrust applied to the fingers 31. Above and below the camming member 4I, spiders 42 and 43 are secured in fixed relation to the spindle 6 by keys 44 and 45.

As illustrated in-Fig. 2 the spiders are provided Awith a plurality of slots 46 for receiving the shoes 41 which support the abrading elements 48. The abrading elements are of a form similar to that described in the co-pending application of G. M. Calvert, Serial No. 574,381, iiled November 11, 1931, and assigned to the assignee of the present application and will not be further described. The shoes 41'are provided with cam engaging surfaces 49 by which the abrading elements are adjusted laterally of the spindle 6 when the camming member 4| is moved longitudinally thereby. A spring 5| is provided below the camming member 4| in abuttingrelation to the spider 43 for-moving the member 4| and fingers 31 upwardly when the camming collar I5 is moved to a position yillustrated in the drawing. The camter spring 54, positioned at the bottom of the tool,

is of greater strength than the spring 55 positioned on the upper end of the abrasive elements. When the adjusting nut I1 and the housing I9 are moveddownwardly against the bias of the spring 5|, the camming member 4| is moved downwardly to cause the abrading elements to be moved. radially of the spindle. In the present construction, because of the greater tension in the spring 54than in the spring 55, the upper ends of the abrading elements 48 will be moved outwardly while the lower ends will be retained in substantially their collapsed position. The purpose of this construction is to prevent the lowerend of the head 9 from being expandedv when the tool is inserted within a cylinder bore whenr the adjustable portion of the mechanism has been moved downwardly.

l As a further precaution in preventing the abrading element froml striking the top ofthe cylinder housing when being inserted in a bore thereof, we provide a guiding member 56 which is secured to theend of the tool by a nut 51. l. The guiding member is of a diameter substantial to that of the area encompassed by the abrading elements to thereby prevent the elements from strikingv against the top of the cylinder housing when the honing tool is being inserted within the bore.

.Referring again to'Fig. 1, it will be noted that 4the camming memberV 4I has a greater internal The operation of our tool will now be described. The tool is first assembled on the shank I3 through the insertion of the projection I2 in the recess thereof and turned to have the pin I4 supported within the slots communicating with the shank recess. The cylindrical extension I2 fits snugly within the recess to have the tool positioned as a rigid extension of the spindle. The nut I1 is then adjusted to effect the proper maximum expansion of the abrading elements 48 which will occur when the camming member I5 has been turned to have the cam 28 ride upon the cam 29` The camming nut I5 is then turned to collapsed position, which is that illustrated in Fig. 1, and the shank I3 is lowered to have the abrading elements enter the bore.

The camming member I5 is again operated to have the surface 28 ride upon the surface 29 to expand the abrading elements 48 against the bore to be machined through the downward thrust applied to the adjusting nut I1 and the housing I9, after which the spring 3l is compressed.- The honing tool is then rotated and the abrading elements machine the walls of the cylinder bore. During the machining operation, the bias of the spring 3I eiects a downward thrust to the fingers 31 and the camming member 4|-, to force theabrading elements 48` outwardly of the spindle 6. The expansion of the elements 48 continues until such time as the spring 3| has expanded against the flanges of the spring cage 32 after which no further downward movement of the camming member 4I obtains and the lateral movement of the abrasive elements ceases.

During the operation of the tool at a time when the spindle 6 is in offset relation to the cylinder br c, the clearance between the camming member 4I and the spindle 6 and the ability of the holders 41 to tilt relative to the member 4I permits the abrasive elements 48 to center themselves at all times relative to the cylinder bore, to effect the correct machining of the bore irrespective of the oir-center rotation of the spindle 6 therewith. After the machining operation, the rotation of the honing tool may be stopped and the camming member I5 turned to the collapsed position, illustrated in Fig. 1, and the tool Withdrawn from within the cylinder bore.

By having garter springs of different tension at the ends of the abrading elements, we prevent the accidental expansion of the bottom portion of the abrading elements when the adjustable portion of the -tool is moved downwardly, to prevent the ends of the abrading element from striking against the top of the cylinder block. In like manner the guide plate 56 prevents thev striking of the abrading elementsagainst the top of the cylinder block when the tool is inserted within the cylinder bore, the plate being provided with sloping sides 58 for aiding in guiding the tool therewithin.

While we have described a tool of the manually adjustable type as being provided With the rigid spindle 6, it is to be understood that the same principles embodied therein may be applied to a fll automatic tool in which the expansion and the collapse of the honing elements occurs automatically when the tool is raised or lowered relative to its cylinder bore. Such an automatic tool is illustrated and described in the co-pending application of F. M. Kern, Ser. No. 521,089, led March 9, 1931, and assigned to the assignee of the present invention. It is to be understood that the rigid spindle may be employed with the automatic head provided on the tool described in the above mentioned application and may vbe continuously rotated. When inserted within the bore the honing elements 48 will be in a collapsed position and after penetrating the bore a predetermined distance will be automatically expanded to have the elements moved into contiguous relation to the side of the cylinder bore. After the honing operation the upward movement of the tool collapses the element before they protrude a predetermined distance from the cylinder bore, to thereby prevent the marring of the nish of the bore or damage to the abrading elements. In any application, the abrading elements have an opportunity to adjust themselves relative to the spindle both by tilting about the camming member 4I and by effecting the centering ofthe camming member relative to the spindle which may be slightly 01T center relative to the center of the cylinder bore.

While We have described and illustrated but a single embodiment of our invention it will be apparent to those skilled in the art that various changes, omissions, additions and substitutions may be made therein without departing fromthe vspirit and scope of our invention, as set forth in the accompanying claims.

We claim as our invention:

1. A honing tool including, in combination, a unit spindle, expansible abrading elements tiltably mounted for radial movement on saidv spindle, a spring associated with the lower ends of said elements for biasing them inwardly toward the spindle, and a spring of less tension than said rst spring associated with the upper ends of said elements for biasing them toward the spindle.

2. A honing tool including, in combination, a unit spindle, expansible abrading elements mounted on said spindle, a spring associated with the lower ends of said elements for biasing them inwardly toward the spindle, .a spring of less tension than said rst spring associated with the upper ends of said elements for biasing them inwardly about the spindle, and a guide plate at the end of said spindle of substantially the diameter of said elements.

3. A honing tool including, in combination, a unit spindle, expansible abrading elements mounted on said spindle, a spring associated with the lower ends of said elements for biasing them inwardly toward the spindle, and a spring of less tension than said rst spring associated with the upper ends of said elements for biasing them inwardly about the spindle, and a guide plate having sloping side walls and secured to the end of the spindle for guiding the end of the tool into a cylinder to be bored.

4. A honing tool including, in combination, a driving member, an abrading head supported by said driving member, means for expanding said abrading head, and means for causing one end of said head to expand before the other when the head is unconflned and expanded.

KIRKE W. CONNOR. ALBERT BLEASDALE.

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