US2790278A

US2790278A - Honing tool

Info

Publication number: US2790278A
Application number: US506895A
Authority: US
Inventors: Charles P Smith
Original assignee: Individual
Current assignee: Individual
Priority date: 1955-05-09
Filing date: 1955-05-09
Publication date: 1957-04-30
Anticipated expiration: 1974-04-30

Description

C. P. SMITH April 30, 1957 HONING TOOL 2 Sheets-Sheet 1 Filed May 9, 1955 INVENTOR.

' CHARLES P. s lT ATTORNEY 2 Sheets-Sheet 2 INVENTOR.

CHARLES P. SMITH BY ATTQRNEY April 30, 1957 'Filed May 9', 1955 i 3 W L 6 l wfi kw K w'r 7d w a. 2 2 J q 3 m J FH 'lill 46 u 4 v mm \m 1 3h .q mm. t 3 W Moon mm MM $w m r/ W Z EEC x \K Sm Q 3 w 3 9 w & 3 3 \w m Q g 3 m m H United States Patent HONING TOOL Charles P. Smith, Detroit, Mich. Application May 9, 1955, Serial No. 506,895

12 Claims. (Cl. 51-1843) This invention relates to honing apparatus and particularly to improvements adapted to be embodied in a honing tool for accomplishing such important objects and functions as accurately gauging the diameter of a workpiece bore and interrupting the honing operation immediately upon the finishing of the bore to the desired diameter, controlling the operation of the gauge or sizing means so as to compensate for wear thereof, holding and maintaining the workpiece in proper relation to the honing tool during the honing operation, improving the action of the honing or abrading stones, and improving the construction of the abrading elements so as to prolong materially the life of the stones. These important objects are accomplished by means of honing apparatus which may be constructed in accordance with the embodiments of the invention herein illustrated.

Honing apparatus embodying the present invention may be used for honing the bores of various types of workpieces, such as connecting rods, gears, cylinders etc. for internal combustion engines. The illustrated mechanism is especially adapted for honing relatively small diameter bores or the bores of workpieces, such as connecting rods, which present problems in respect to maintaining the workpiece in a true position relative to the honing tool.

The apparatus comprises a spindle which may be disposed vertically or at an angle to the vertical or horizontally, the spindle being drivingly connected at its inner or upper end to a machine head which is capable of imparting a combined rotative and reciprocating movement to the spindle. The spindle is provided at its outer or lower end with an abrading head having abrading elements or members, such as holders carrying abrading stones, spaced equally around the head and adapted to be moved outwardly or expanded radially against the surface of the workpiece bore by a cone member or wedge i device attached to a rod or shaft extending through the spindle bore and shiftable axially thereof by suitable means, such as hydraulic mechanism conventionally used for this purpose in honing machines. With the abrading elements expanded outwardly against the workpiece bore, rotary and reciprocating movements applied to the spindle will result in honing the bore and the removal of material or stock therefrom.

Another feature of the present invention resides in the provision of guide means mounted on the abradinghead and associated with the abrading members for mounting or holding the workpiece in a true position relative to the honing tool as well as the abrading members. The provision of such guide means is particularly advantageous in honing the bores of connecting rods. The guide means may comprise members adapted to be moved radially and outwardly by wedge or tapered members under spring action so as to yieldingly engage the inner surface of the connecting rod bore during the honing operation, thereby holding the connecting rod against rocking movement and maintaining it true and in proper axial relation to the tool spindle.

Patented Apr. 30, 1957 During the honing operation, the abrading members wear appreciably faster than the, guide members. It is accordingly another object of the invention to provide improved guide operating means for yieldingly urging the guide members radially outwardly against the workpiece bore at substantially uniform pressure independently of the pressure urging the abrading elements radially against said bore.

Another object is to provide on the cone member and guide operating means respectively a ratchet and pawl which are cooperable to enable axial shifting of the cone member in one direction independently of the guide operating means and are engageable to shift the latter in the opposite direction upon retraction of the cone member in said opposite direction. In a preferred embodi- .ment, the cone member is yieldingly urged in said one direction, as for example by conventional hydraulic means, to urge the abrading elements radially against the workpiece bore, and the guide operating means is yieldingly urged in said one direction by resilient means to urge the guide members radially against said bore. Accordingly during the honing operation, the cone member gradually shifts in said one direction in accordance with the wear of the abrading elements and independently of said guide operating means, whereby uniform honing pressure is maintained. Likewise the guide operating means gradually moves in said direction at a lesser rate in accordance with the slower rateof wear of said guide members, whereby constantand substantially uniform guiding pressure is maintained on the workpiece. Upon completion of the honing operation and retraction of the cone member in said opposite direction to release the pressure of the abrading elements against the workpiece bore, the guide operating means is simultaneously retracted in said opposite direction by virtue of the interengaging pawl and ratchet, thereby simultaneously releasing the pressure of the guide members against said bore.

Still another object is to provide improved guide op erating means of the foregoing character having spring means yieldingly urging the pawl into engagement with the ratchet, the pawl being provided with a cam edge engageable with a portion of the spindle which carries the abrading head to cause shifting of the pawl out of said engagement upon retraction of said guide operating means in said opposite direction to a predetermined position. Thus further retraction of said cone member independently of the guide operating means is enabled.

Other objects of this invention will appear in the following description and appended claims, reference being had to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.

Fig. l is a view in longitudinal mid-section illustrating a honing apparatus constructed in accordance with the present invention, taken in the direction of the arrows substantially along the line 1-1 of Fig. 4.

Fig. 2 is an end view taken in the direction of the arrows along the line 22 of Fig. 1 and rotated Fig. 3 is a sectional view taken substantially through line 33 of Fig. 6, looking in the direction of the arrows and rotated 90".

Fig. 4 is an end view taken in the direction of the arrows along the line 4-4 of Fig. l.

Fig. 5 is a view similar to Fig. l, but taken in the direction of the arrows along the broken line 5-5 of Fig. 2. 1

Fig. 6 is an enlarged fragmentary view similar to Fig. 5.

Fig. 7 is an elevational view of the guide means for controlling the position of the honing apparatus with respect to the workpiece.

Fig. 8 is an end view of It is to be understood that the invention is not limited in its application to the details of construction and arrangernent of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

In the drawings there is illustrated a-honing tool-or apparatus which is attachable at its upper or driven end to the conventional machine spindle. The honing tool, depending upon the type of machine with which it is used, may extend either vertically, or at an angle such as 45, or horizontally. In the present instance the tool is shown in a vertical position, although it is understood that this is merely for illustrative purposes.

In accordance with the present embodiment the honing tool is provided with a tubular body or honing tool spindie It} provided at its lower'end with an abrading head 10a which, in the present instance, is formed integrally with the spindle. The upper or machine end of the spindle 10 is indicated at 1%. For the purpose of drivingly connecting the tool to the machine spindle there is provided an attaching collar 11 mounted on the upper end 102) of the tool spindle and provided with internal threads 11a adapted to be screwed onto the nose of the machine spindle (not shown). Also mounted on the tool spindle 10 is a tool spindle driving sleeve 12 having a radial driving flange 1211 having a hole or slot 13 to receive the machine spindle driving pin and by means of which the sleeve 12 is driven. The sleeve 12 is rigidly attached to the spindle 10 such as bymeans of one or more locking pins 14.

Mounted around the body of the spindle 10 is a ball race ring 15 which is keyed or connected to the spindle by means of a bolt 16. A second ball race ring 17 is positioned in juxtaposed relation to the ball race 15. Interposed between these ball races are anti-friction ball bearings, as shown in Fig. lv 7 A compression spring 18 encircles the spindle 10 and has its upper end in engagement with the ball race ring 17. The lowerend of this spring abuts against a bearing sleeve portion 19a which is freely mounted on the spindle. It will be understood that the ball race ring 15 need not be keyed at 16 to the spindle but may have a bearing directly on the spindle and be free thereon for movement relative to the spindle.

In the present instance the sleeve 19a comprises a lower radially inward extension of a trip arm sleeve 19 freely mounted on the ball race rings 15 and' 17 Screwed on the upper end of sleeve 19 is a collar 20 secured in position by a set screw Ztla and having an integral radial limit switch trip arm 21 which, as later described, is shiftable longitudinally with the sleeve 19 but held against rotation in conjunction with the tool spindle. The ball race 15,

. which rotates with the tool spindle, preferably has a hard chrome plated outer surface on which the. non-rotatable sleeve 19 has a hearing. The collar or bearing sleeve portion 190 has a similar bearing on a chrome plated surface 22 of the tool spindle 10 for wear resistant purposes. Mounted on the sleeve 19 is a gauge ring adapter or support sleeve 23 which has internal threads engaging external threads on the sleeve 19. The threaded connection between the sleeves 2t) and 23 provides adjusting means by which the axial position of the adapter sleeve 23 can be varied, thereby varying the axial position of the gauge or sizing ring, hereinafter described. ,The sleeve 23 is held in adjusted position by means of a spanner nut 24 threaded onto the sleeve 19 and is provided at its lower end with an inwardly projecting boss or enlargement 25 having an internally threaded portion 26 into. which is screwed a lock nut or ring 27. The opposed faces of the boss 25 and the lock ring 27 are separated to provide an annular space or channel 28.

- The honing tool is provided with gauge or, sizing means the structure shown in Fig. 7.

comprising a cylindrical body member 29 freely embracing the spindle and shiftable axially relative thereto. This body member, which is in the form of a gauge ring or sleeve, is formed with an upper annular flange 29a freely projecting into the channel 28 between the locking ring 27 and retainer flange 25. The axial width of the annular channel or space 28 slightly exceeds the axial thickness of theflange 29a and is sufiicient to permit the flange to shift laterally or transversely of the spindle without appreciable frictional resistance within the channel 28. The internal diameter of the sizing ring or sleeve 29 is appreciably greater than the external diameter of the spindle at the locality of the sizing ring so as to permit the latter to shift or float relative to the spindle a substantial amount, such as from ten to thirty thousandths of an inch, depending upon the type of work being honed. The amount of float of the sizing device is indicated for illustrative purposes by the float space 39 in Fig. 6 and also the space between the outer edge of the gauge ring flange 29a and the base of the channel 28.

The outer end of the sizing ring or gauge body 29 is machined to provide preferably four equally and annularly spaced longitudinal slots or grooves 31. Cemented or otherwise anchored in these grooves or slots are hardened or wear resisting gauge inserts or gauging elements 32 in the form of carbide tips which project radially a slight distance outwardly of the gauge body and are accurately machined at their outer surfaces to provide arcuate gauging or sizing surfaces. The outer diameter across each pair of opposed gauge inserts corresponds to the desired diameter of the finished bore B of a workpiece W.

For illustrative purposes two workpieces in the present embodiment are shown comprising a pair of internal combustion engine connecting rods having their bearing portions arranged coaxially side by side to permit honing of both workpieces simultaneously. The inserts or gauge elements 32 terminate in tapering lead portions or lead means 32a which progressively narrow in effective diameter and, hence, are adapted to enter in varying amounts the unfinished bore of the proximate workpiece W. From the foregoing construction it will be seen that the gauge or sizing device 29 is entirely free to float or shift a predetermined amount laterally or transversely of the spindle thereby to compensate for uneven stone wear or misalignment of the longitudinal axis of the tool spindle with the longitudinal axis of the bores of the workpieces W being honed.

The abrading head 10a, which forms an extension of the tool spindle, is slotted to receive six annularly spaced abrading elements 33 which project into tapered slots 34 in a cone member 35. The abrading elements 33 and the bottoms of the slots 34 have cooperating tapered faces to provide for expansion or outward radial displacement of the abrading elements upon axial shiftable movement of the cone in the direction toward the workpiece. In accordance with conventional practice the abrading elements are initially projected by the cone a relatively small amount outwardly of the abrading head and thereafter increasing amounts as stock of material is removed from the workpiece bore during the honing operation.

Each'abrading element comprises a stone holder having an abrading stone cemented or otherwise mounted therein. The stone holderin the present instance is in the form of a shell or casing-3t: of thermoplastic material having a tapered inner surface or edge 36a. The body of the stone holder is molded to provide a longitudinal recess or elongate notch 37 intermediate the ends of the shell. This recess has right angularly extending side and inner surfaces and is closed at one side by a relativelythin backing or support wall 36!), see Fig. 2. Firmly cemented within the-recess 37 of each stone holder is a square sided abrasive stone 38. This stone is exposed. at its outer or working face and at one longitudinal side face 38a opposite the wall 36b. The stone holders are installed in the slots 34 of the abrading head so that the exposed face or side 38a faces in the direction of re tation of the tool spindle, as shown in Fig. 2.

By virtue of the cooperating tapered surfaces of the cone or cone member 35 and stone holders 36, downward shifting of the cone will result in expanding the stone holders and contacting the working surfaces of the honing stones with the bore of the workpiece. The cone member 35 is connected by a pin 40 to a cone rod or shaft 41 extending freely through the tool spindle 10. The cone rod is provided at its upper end with a connector member or adapter piece 42 for attachment to the usual hydraulic mechanism of the machine which is operable to shift the cone rod axially of the spindle. The cone 35 is also provided with six non-tapered vertical slots 43 disposed annularly in alternating relation to the slots 34 which receive the abrading elements, Fig. 2. Extending within each of the slots 43 is a guide member 44 longitudinally slotted on its outer face to receive a carbide guide insert 45. Each guide 44 has a tapered inner edge 44a engaged by the tapered outer edge 46a of a guide expander or wedge member 46, one such member being contained within each slot 43 and having an inner vertical edge slidable in guided relation along the vertical base 43a of the slot 43.

Above the cone member 35 and secured coaxially to the cone rod 41 by a pin 47 is an annular ratchet or detent sleeve 48 having a plurality of axially spaced annular pawl engaging teeth 49 engaged by a pair of diametrically opposed pawls or dogs 50. The latter extend axially within a pair of diametrically opposed slots 51a in the body of a generally annular guide operator or retainer 51 and are pivoted thereon intermediate their upper and lower ends by pins 52. The guide retainer 51 is sleeved freely on the ratchet 48 for vertical movement and is urged downwardly by a guide expanding spring 53 coiled around the cone rod 41 under compression between the upper end of the retainer 51 and an annular shoulder 54 of the spindle 10.

A coil spring 55 under compression between the base of each slot 51a and the inner edge of the associated dog 50 above the pin 52 yieldingly urges the lower ratchet engaging end of the dog or pawl 50 firmly into engagement with the teeth 49. In this regard, each tooth 49 has an annular upper surface which comprises a substantially horizontal detent shoulder adapted to engage a mating lower edge portion of each pawl 56 and prevent downward movement of the latter relative to the ratchet 48. The lower surface of each tooth 49 inclines steeply to comprise a cam adapted to engage a correspond- In order to disengage the lower ends of the pawls from the ratchet 48 at a predetermined upper position of the pawls 50 and retainer 51, the upper end of each pawl 50 comprises an arcuate cam edge 50a adapted to engage an inwardly inclined portion 54a of the spindle 10. By virtue of the engagement between the lower ends of the pawls 50 and the teeth 49, it is apparent that upon upward movement of the ratchet 48, the pawls 50 and retainer 51 will also be moved upwardly until the cam 50a engages the portion 541: and swings the lower ends of the pawls 50 radially outwardly from the teeth 49, whereupon the ratchet 48 can continue upwardly independently of the pawls 50.

A lower neck portion 56 of the retainer 51 having a reduced external diameter extends downwardly at a location inwardly of the upper ends of the guide expanders 46 and terminates in a lower radial flange 57. This flange is provided with six radial notches or slots 57a interfitting with notches or slots 58 in the rear ends of the wedges or guide expanders 46, whereby the flange 57 and guide ex- 6 panders 46 are locked together. Thus upon axial or vertical shifting of the retainer 51, the guide expanders 46 are also shifted in the same direction to cause radial shifting of the guides 44 by virtue of the cooperating

inclined surfaces

44a and 46a. Accordingly the interconnected parts 46, 51'comprise guide operators which control operation of the guides 44. The upper portions of the expanders 46 are confined within a generally annular spring clip 59 seating within notches 60 in the expanders 46. Similarly the upper portions of the guides 44 are confined within a generally annular spring clip 61 seating within circumferentially extending notches 62 in the spindle body 10 and notches 63 in the guides 44.

During operation it will be understood that the honing tool is reciprocated by the machine spindle toward and from the workpiece. As the abrading head 10a travels into the boreBbeing honed and the sizing gauge engages the end of the bore, the tapered lead or cam portions 320 of the gauge device, being of reduced efl'ective diameter, will be able to enter the unfinished bore whereas the gauging portions 32 inwardly of the lead portions will not be able to enter the bore until it is finish honed to the desired size. When. the bore diameter is too small to permit entry of the gauging or sizing portions 32 of the gauge, the latter and the

parts

19, 20, 23 and 24 will be forced upwardly relative to the spindle 10 and against the resistance of the compression spring 18. As this occurs the spring will be increasingly compressed between the collar 19a and ball race ring 17. Thus, it will be seen that the action of the spring 18 is to urge the sizing gauge in the direction of its entry into the workpiece bore. The lead portion or portions of one or more of the gauge inserts will, due to the pressure of the spring, engage the end of the bore and will act ineffect to cam or shift the gauge member 29 radially or transversely so as to center the member 29 with the center of the bore. When the bore has been honed to the correct size the action of the spring 18 will force the gauge and its sizing portions fully into the bore, whereupon control means hereinafter described operates to interrupt or discontinue the honing operations.

From the foregoing it will seeen that by mounting of the gauge so as to freely float transversely of the spindle, it is possible to center the gauge with the workpiece bore and, hence, the gauge at the proper time will fully enter the bore when it has been honed to the desired diameter, thus eliminating the disadvantage of honing the bore to any appreciable or objectionable oversize. The floating gauge not only compensates for slight misalignment of the tool spindle with the bore being honed but also for uneven abrading stone wear which frequently occurs owing to the fact that the stones often vary in relative hardness.

During operation, upon axial shifting of the cone 35 to expand the abrading elements 36 against the bore of I the workpiece, the compression spring 53 will force the retainer 51 in a corresponding direction and by virtue of the interlocking connection between the flange 57 and the wedge or guide members 46, the latterwill be shifted simultaneously with the cone and in the same direction. This axial movement of the wedge members 46 to the left in Figs. 5 and 6 will result in the wedge members shifting or expanding the guides 44 outwardly so as to cause the guide inserts 45 to yieldingly engage the bore B of the workpiece. As the honing operation proceeds the guides will be yieldingly urged by the action of the spring 53 into contact with the surface of the workpiece bore, thereby holding the workpiece in proper position.

Thereafter, by reason of the non-tapered edges 43a engaging the non-tapered inner edges of the guide expanders 46, additional downward movement of the cone member 35 will cause additional radial shifting of the abradiug elements 36 without causing radial displacement of the guides 44. Accordingly the rapid wearing of the stones 33 during a honing operation, as compared to the slower wearing of the hardened guide inserts 45 is compensated for by downward shifting of cone 35 under control of the hydraulic rn'echafiis'rii eoh'nected at 42 to rod 41 and urging the latter downwardly. Thus at all times during the honing operation, hydraulic pressure applied to rod 41 is transmitted through cone 35 to the abrading elements 36 to maintain the proper honing pressure on the bore of the workpiece. Simultaneously, pressure from spring 53 is transmitted through the

guide operator

46, 51 to the guides 44 to maintain the proper guiding or centering pressur on the bore.

As the stones 38 wear during the honing operation and the cone 35 moves downwardly, ratchet 48 will also move downwardly freely with respect to pawls 50. After the bore has been honed to the correct size and the honing operation is interrupted by entry of the gauge elements 32. into the bore, the cone rod 41 will be retracted to collapse the abrading elements. Upon retraction of the cone red, the ratchet 48 will engage the pawls G and thus retract the retainer 51 and wedge members 46, thereby collapsing the guide members 49 and releas ing the pressure thereof against the bore of the workpiece.

The gauge

assembly including parts

23 and 29 travels with the spindle toward the workpiece until the gauge elements contact the end of the unfinished workpiece bore, whereupon the gauge assembly backs up against the action of the compression spring 18. Uponfinishing of the bore to size and entry of the gauge element into the bore, the entire gauge assembly is shifted by the action of the spring toward the workpiece and relative to the spindle. The outer end of the trip arm 21 is adapted to ride along the face of a fixed abutment or bracket 64 on the machine, By this construction the trip arm and hence the gauge assembly is held against rotation, yet is permitted axial travel in opposite directions along the abutment in conjunction with the gauge assembly.

The hydraulic mechanism for shifting cone shaft 41 is controlled by a limit switch generally indicated at 65 having a switch actuating member 66in position to be engaged and tripped by the trip arm 21 upon entry of the sizing or gauge elements into the workpiece bore. thereby electrically actuating a suitable solenoid control valve (not shown) to reverse the hydraulic circuit in the hydraulic mechanism and cause the same to retract the cone rod 41 and permit collapse of the abrading elements. Suitable adjusting means is provided, as indi cated generally at 67, for adjusting axially of the tool the position of the limit switch, thereby to vary the timing of the actuation of the switch by trip arm 21.

An important feature of the present case resides in the construction of the guide units or

assemblies

44, 45 by which the life thereof is greatly prolonged while at the same time achieving a high degree of efliciency in operation. Each guide member 44 is preferably formed of hardened bronze or brass, such as the commercial material known as Number 21 Ampco bronze. The guide-inserts 45, on the other hand, are formed of carbide. These inserts are press fitted tightly and snugly into central slots in the guide members 44 and the outer surfaces of the insert and guide member are ground flush on an are having a radius corresponding to the radiusof the bore of the workpiece. When so ground the entire outer working face of the guide presents a uniformly smooth surface with the complete elimination of any protruding edges of the carbide insert which would otherwise cut the steel surface of the workpiece bore. During use the carbide iusert has the advantage of reducing wear of the bronze portions of the guide which embrace opposite sides of the insert while the bronze portions have the advantage of preventing any edges of the carbide insert from cutting or damaging the bore of the workpiece,

In the use of the honing tool it will be understood that a single set of abrading stones 33 will serve, until worn some out, to successively none the bores of a number of workpieces. Upon completion of the honing operation for a given workpiece or pieces, as determined by theentry of the gage elements 32 into the workpiece bore, the cone rod or shaft 41 will be retracted by the hydraulic mechanism so as to retract the cone 35. Normally the cone is retracted in an axial direction approximately one fourth of an inch which is sufiici'ent to collapse the stone holders and release the abrading stones from the finished surface of the workpiece bore. vThis operation is accompanied by termination of the reciprocating and rotative motions of the 1001. Since the pawls 56 will be engaged with the ratchet 48 regardless of the relative axial positions of the cone 35 and

members

46, 51 the retractive movement of the cone 35 will transmit through the ratchet and pawls immediate and positive retractive movement to the member 51 and wedge members 46 thereby releasing the guides 44 from the bore of the workpiece. Although engagement of the cam ends 5% of the pawls with the inclined wall 54a will disengage the pawls from the ratchet, any reverse axial movement of the pawls under the influence of spiing 53 will result in re-engagement of the pawls with the ratchet under the action of the springs 55. Since the ratchet teeth are preferably approximately oneeighth of an inch apart the net retractive movement of the guide wedges 46 will be sufiicient to release the guides 44 from the bore of the workpiece so as to enable it to be removed, a new workpiece installed and the operation of the tool resumed for the purpose of honing such workpiece.

I claim:

1. In a honing apparatus, reciprocable and rotatable spindle means having a honing head mounted thereon, annularly spaced abrading elements and guide elements carried by said head for radially shiftable movement, cone means carried by the spindle means and shiftable axially of the spindle means in one direction for shifting said abrading elements radially to engage a workpiece bore, guide operating means carried by the spindle means and having wedge portions cooperable with said guide elements and shiftable in said direction independently of said cone means for shifting said guide elements radially to engage said bore, and interengaging means for releasably connecting said guide operating means to said cone means for travel as a unit therewith solely upon shifting said cone means in the opposite direction.

2. A honing apparatus according to claim 1 wherein said interengaging means comprises a ratchet on said cone means and a pawl on said guide operating means effective to release said ratchet for axial shifting of the latter independently of said guide operating means in said one direction.

3. A honing apparatus according to claim 2 including resilient means yieldingly urging said pawl into engagement with said ratchet, and means on said spindle means engageable with a portion on said pawl for shifting the latter out of said engagement upon shifting of said operating means in said opposite direction to a predetermined position withrespect to said spindle means.

4. In a honing apparatus having reciprocable and rotatable honing tool means having a honing head, radially shiftable honing and guide elements carried. by said head, operating means carried by said honing tool means and shiftable axially thereof in one direction for moving said honing elements radially to engage a workpiece bore, yieldable means shiftable axially of said tool means for shifting said guide elements into engagement with the workpiece bore, and ratchet and pawl means connecting said operating means and y'ieldaole means for simultaneous retraction as a unit.

5. In a honing apparatus having reciprocable and rotatable spindle means' and a honing head mounted thereon, annularly spaced abrading elements carried by the head for radially shiftable movement, cone actuating means carried by the spindle means and shiftable axially of the spindle means in one direction for radially shifting said abrading elements to engage a workpiece bore, guide elements carried by the head for radially shiftable movement, wedge actuating means shiftable axially to shift said guide elements radially into engagement with said bore, and ratchet and pawl means interconnecting said cone and wedge actuating means for simultaneous retraction as a unit.

6. In a honing apparatus having reciprocable and rotatable spindle means and a honing head mounted thereon, annularly spaced abrading elements carried by the head for radially shiftable movement, actuating means carried by the spindle means and shiftable axially of the spindle means in one direction for radially shifting said abrading elements to engage a workpiece bore, guide elements carried by the head for radially shiftable movement, spring pressed actuating means shiftable "axially of the spindle means to shift said guide elements radially into engagement with said bore, and releasable dogging means for positively connecting both of said actuating means for simultaneous retraction as a unit.

7. In a honing apparatus having reciprocable and rotatable honing tool means having a honing head, radially shiftable honing and guide element-s carried by said head,

operating means carried by the honing tool means and shiftable axially or" the tool in one direction for moving said honing elements radially to engage a workpiece bore, spring pressed guide operating means shiftable in said one direction for moving said guide elements radially to engage said bore, and releasable dogging means for connecting both of said operating means for simultaneous retraction as a unit axially of the tool in the opposite direction.

8. In a honing apparatus having reciprocable and rotatable honing tool means having a honing head, radially shiftable honing and guide elements carried by said head, operating means carried by the honing tool means and shiftable axially of the tool in one direction for moving said honing elements radially to engage a workpiece bore, guide operating means carried by the honing tool means and shiftable in said one direction for moving said guide elements radially to engage said bore, means yieldingly urging said guide operating means in said one direction, and a series of abutments on the first named operating means selectively engageable with a part on said guide operating means for shifting the same in the opposite direction to release the pressure of said guide elements against said bore upon shifting of said first named operating means in said opposite direction.

9. In a honing apparatus having reciprocable and rotatable honing tool means having a honing head, radially shiftable honing and guide elements carried by said head, operating means carried by the honing tool means and shiftable axially of the tool in one direction for moving said honing elements radially to engage a workpiece bore, and guide operating means carried by the honing tool means and shiftable in said one direction for moving said guide elements radially to engage said bore, means yieldingly urging said guide operating means in said one direction, and pawl and ratchet means onthe first named operating means and guide operating means cooperable guide elements against said bore upon shifting of said first named operating means in said opposite direction.

10. In a honing apparatus, reciprocahle and rotatable honing tool means having a honing head, a radially shiftable abrading element and a radially shiftable guide element carried by said head, a cone member carried by said honing tool means and engageable with said abrading element and shiftable axially in one direction for radially shifting said abrading element to engage a workpiece bore, a wedge member enagageabl'e with said guide element and shiftable axially in said one direction for radially shifting said guide element to engage said bore, a guide operator shiftable axially in said one direction or the opposite to shift said wedge means correspondingly in said one direction or the opposite by engagement therewith, and pawl and ratchet means on said done member and guide operator cooperable to any one of a series of axial positions of said cone members for shifting the guide operator in said opposite direction upon corresponding shifting of said cone member.

11. Ina honing apparatus, reciprocable and rotatable honing tool means having 'a honing head, a radially shiftabl'e abrading element and a radially shiftable guide element carried by said head, a cone member engageable with said. abnading element and shiftable axially in one durection for radially shifting said abrading element to engage a workpiece bore, wedge means interposed between and cooperable with said cone member and guide 1 element to shift the latter radially to engage said bore 12. In a honing apparatus, reciprocable and rotatable honing tool means having a honing head, a radially shiftable abrading element and a radially shiftable guide element carried by said head, a cone member carried by said heads and engageable with said abnading element and shiftable axially in one direction for radially shifting said abrading element to engage a workpiece bore, a wedge member engageable with said guide element and shiftable axially in said one direction for radially shifting said guide element to engage said bore, a guide operator shiftable axially in said one direction' or the opposite to shift said wedge means correspondingly in said one di' reotion or the opposite by engagement therewith, cooperpredetermined shifting of said guide operator in said opposite direction. 7

References Cited in the file of this patent UNITED STATES PATENTS 1,487,488 Stimson Mar. 18, 1924 1,883,285 Zimmerman Oct. 18, 1932" 2,102,053 Batzer Dec. 14, 1937 2,581,601 Pedeu ran, 8, 1952 FOREIGN'PA'TENTS 613,962 Great Britain Dec. 7, 19.48' 632,415

Great Britain Nov. 28, 1949