US1978445A - Cylinder grinding tool - Google Patents

Description

Oct. 30, 1934.. H. w. ZIMMERMAN 1,973,445

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H. w. ZIMMERMAN I CYLINDER GRINDING TOOL Filed Feb. 19, 1930 3 Sheets-Sheet 2 j i! z (vz f0)": Herman a! Zimmerman H. w. ZIMMERMA N CYLINDER GRINDING TOOL Filed Feb. 19. 1930 3 Sheets-Sheet 3 Oct. 30, 1934.

Patented Oct. 30, 1934 UNITED STATES 1,978,445 CYLINDER GRINDING TOOL Herman W. Zimmerman, Chicago, 111., assignoz' to Automotive Maintenance Machinery 00.,

Chicago, 111., a corporation of Illinois Application February 19, 1930, SerialNo. 429,618

' 28 Claims. (01. 51-1343) My invention relates to cylinder grinding tools of a character adapted for use either in factory production-work or in the servicing of worn cylinders to bring the surface of the cylinder to true cylindric'ity, accurate diameter and smooth finish.

One of the objects of-my invention is to provide asimple and inexpensive tool of the foregoing character which is capable of fast grinding with high efiiciency, which operates without tendency toward seizing, digging in or increased drag, and which requires less power to operate than tools of this kind which have been used heretofore.

Another object is to provide a cylinder grinding tool which is light in weight and easy to handle, and which is capable of use over long periods 01 time with a high degree of accuracy in performance, notwithstanding wear and the usua1 variations commonly experienced in the forming and machining of tool parts. I

A further object is to provide a cylinder grinding tool having expansible and contractible grinding elements which are mounted along the radius of the tool but with their median line in radial direction offset from the tool radius.

Another object is to provide in a cylinder grinding tool of a type having a plurality of abrading or grinding elements supported in a body or frame for radial expansion and contraction movements, a mounting for the grinding elements which is such that when these elements are set up normally in grinding contact with the cylinder wall surface, the maximum working radius of the tool for that particular setting or adjustment is eil'ective. and, inching or shifting of the grinding element should occur during the grinding: operation, due to abrasive contact with the cylinder wall surface, there will be no tendency toward an increase in that particular setting thereby avoiding tendency toward increase in abrading-pressure which would tend to cause digging in, seizure or increased drag.

Still another object is to mount the abrading elements in the tool in such a way that, if rocking of the same should occur, the tendency will be to rock the cylinder-wall contacting-surface of the elements toward the tool center with a consequent relieving of abrading pressure. Specifically, in carrying out this object, I mount the abrading elements with their median line disposed rearwardly of the tool radius so that, in case of the foregoing rocking of the elements, their median lines will be rocked toward the tool radius.

A further object is to provide an improved and positive acting means for adjusting the ahrading or grinding elements toward and from the cylinder wall surface without the necessity of removing the tool from the cylinder or detaching the tool or parts thereof from the drive mechanism. Provision is made, however, for ready detachment of the tool from the drive when that becomes 0 desirable as in inserting the tool in or removing it from the cylinder.

An additional object of my invention is to provide simple and efficient means for avoiding free adjustment play in the adjusting mechanism by tensionally positioning the same in the tool. My invention further avoids accidental change in an adjustment once made and serves to insure continued cutting or grinding pressure on the abrading means between adjustments. This feature of 7 my invention in conjunction with the offsetting of theabrading carriers, et cetera, insures an exceedingly rapid grinding of the cylinder. Still another object of my invention is to provide an improved support or clamp means for securing the abrading or grinding stone to its carrier. 7

Other objects are to improve the structure of the tool body or frame; to provide an improved drive for the tool including means for compensating for disalignment between the drive and the tool;v to provide a tool which may be readily lengthened as the use requirements make that desirable; and to provide a tool wherein a single set of abrasive or grinding elements will serve for the grinding of a greater number of cylinders, the wearing of the grinding elements being reduced to a minimum.

Other objects and advantages will become ap parent as this description progresses and by ref erence to the drawings wherein,--

Figure l is an elevational view of one form of tool embodying my invention;

Fig. 2is an enlarged vertical section taken substantially on line 2-2 of Fig. l;

Fig. 2a is a plan view of a spring washer for tensioning the movement otthe adjusting dial and adjustment mechanism;

Fig. 3 is a top plan view of the structure as shown in Fig. 2; 1 Fig. 4 is a plan view of one of the frame end plates of Fig. 1;

Fig. 5 is a horizontal section taken substantially on line 5-5 of Fig. 2 and showing the position of the grinding elements with respect to the tool radius or a line drawn through the exact center of a tool;

Fig. 6 is a separated enlarged 'elevational view of one of the abrasive carriers and showing my improved abrasive clamping means;

Fig. 7 is a partial section taken substantially on line 77 of Fig. 6; v

Fig. 8 is a section taken substantially on line 8-8 of Fig. 6; I

- ing mechanism embodying my invention.

Referring to the so-called 5-stone type tool shown in Figs. 1 to 5 of the drawings, it embodies a frame or body of cage-like construction comprising end plates 10 and 11 rigidly secured in parallel spaced relation by a. plurality of tie-bars 12. In this particular form of tool, the tie-bars are sufficient in number and are positioned to provide a center space 13 with five radial passages 14 leading outwardly therefrom, no two of which passages are in diametrically opposite position. It will be understood that my invention is not limited to the S-stone type tool, but is equally applicable to tools having any other number of stones or radial passages corresponding to passages 14. For example, see the tool of Figs. 10 and 11 which will be described hereinafter.

Abrasive carriers 15 are mounted in the passages 14 in such a manner that they are expansible and contractible for varying the working diameter of the tool. Specifically, each of these carriers consists of a blade or body portion which is rectangularly-shaped in cross section and which has a depth, in radial direction, much greater than tits thickness. A head, greater in thickness than the blade, is formed upon the outer edge of the blade and is channeled as at 17' to detachably receive and support an abrading or grinding stone 18 in a manner which will be described more fully hereinafter.

Sole guidance and support for the abrasive carriers 15 is provided by the end plates 10, 11. To that end, each of the end plates is provided with guide-grooves or channels 19 which extend substantially from the center of the end plate (tool axis) to its outer edge thereby providing a long and deep supporting surface. The blades of each of the carriers are of greater length than the distance between the end plates, the carrier heads 17 being of lesser length, thereby providing the carriers with projecting end tongues 20 which are of suitable dimensions to fit snugly, but slidingly, in the end plate grooves 19. The blades 16 and the end plate grooves 19 are of suihcient dimensions, in radial direction and otherwise, to provide a strong and rigid support and guidance for the carriers in all radially adjusted positions.

The abrasive carriers are actuated in their adjustment movement by means located in the tool frame center space 13. Specifically, all of the carrier blades are of suiiicient depth to enter the center space 13 of the cage-frame and their inner edges are suitably shaped for coaction with adjustable wedging means which is actuable to control the diameter of the tool by simultaneously positioning all of the carriers at similar positions with respect to the tool axis. This ad- J'usting means consists of a center stem 21 rotatably mounted on the axis of the tool and screw threaded at.22 to adjustably receive two wedgemembers or cones 23, 24, of identical taper, which cones engage correspondingly sloped wedge-surfaces 25, 26 formed along the inner edges of the carrier blades 16. The cones 23, 24 are each provided with a groove 27 through which a rod 28 carried by the end plates 10, 11 passes to prevent rotation of the cones as the stem 21 is rotated and to insure axial movement of the cones. These cones are arranged in tandem with their small ends upward so that, upon actuation of the center stem to expand the carriers the cones not only act on the carriers to expand them, but also tend to move them in axial direction wedging them firmly into the upper end plate grooves thereby aiding in maximum rigidness of the support at that point. The several abrasive carriers are held in the end grooves, and firmly seated uron the cones, by suitable spring rings 29 which encircle the ends of the carriers and are seated in recesses 30 in the ends thereof, as clearly shown in Fig. 2. The carriers are freely removable from the frame cage by merely removing the spring rings and slipping them from the end plate grooves.

While the general arrangement of the tool so far described is such that maximum rigidity in the support of the slidably-mounted abrasive carriers is initially provided, the necessary slidefit dimensions of the carrier blade and its end plate groove may result in a very slight rocking of the carrier when the tool is inserted in the cylinder and rotates with the abrasive in contact with the cylinder wall surface, may exist, or be amplified, due to slight variations in machining the supporting parts of the tool. It would naturally become more prominent and objectionable as wear due to adjustment, or

otherwise takes place between the carriers and the end plate grooves.

It will be appreciated that, with the inner edge plane surface of the carrier blades resting on the cones and, ii the radial center line of the This condition grooves 19 and carrier blades should coincide with the radius of the tool, any relative rocking of the carriers upon the cone, such as might take place as above explained, would result in bodily tilting the carriers and consequently increasing the working radius of the tool. This would obviously cause a tendency toward the abrasive seizing the cylinder wall surface or such an increased drag condition that the cylinder wall surface might not be accurately ground and there would be a great increase in the power required to rotate the tool.

One of the features of my invention has to do with the prevention of increased drag and tendency toward seizure in case there is a tendency in the operation of the tool toward the above condition. Specifically, the grooves 19 in the end plates 10, 11 are so positioned that the center line (in radial direction) of each of them. is located at one side of, and preferably parallel with, the tool radius or a line passing through the exact center of the tool. In other words, the center line of each of the end plate grooves is offset radially so that the abrading elements or stones and abrasive carriers are positioned with their median lines (in radial direction) offset from, f

and preferably parallel with, the tool radius. One position of the carriers and abrading elements or stones 18 with respect to the tool radius is clearly illustrated by the lines a,-a (carrier median line) and b--b (tool radius) of Fig. 5. Another radially ofi'set position of the carriers and abrading stones which I have found to efficiently serve the purpose is illustrated in Fig. 11 which will be described more fully hereinafter.

The tool is preferably, rotated in the direction indicated by the arrow in Fig. 5, and if rocking I of the carrier should occur during rotation of the tool due .to frictional engagement of the abrasive 18 with the cylinder wall surface, the carrier would rock in a direction opposite the direction of rotation. I, therefore, offset the median line a-a (Figs. 5 and 11) rearwardly (with reference to the direction of rotation) of the tool radius so that, if such rocking should occur, the tendency will be to rock the cylinderwall contacting surface of the abrasive toward the tool center, rather than away from it, thereby avoiding an increase in the frictional engagement or abrading-pressure between the abrasive and the cylinder wall surface and avoiding seizure, increased drag or "digging in. It will be understood that by offsetting the carrier as explained, its inner edge plane surface is engaged at one side with the cone surface and that the greater or normal working dimension of the tool is along a line passing from the center of the tool diagonally through the carrier toward its outer trailing edge portion. In other words, the maximum tool working radius for the particular carrier used is provided .as the normal working radius of the tool, and any rocking tendency of the tilt carrier from thatposition in a direction opposite the direction of rotation will tend to adjust the carrier so that its median line (aa) will move away from and out of parallelism with the tool radius (b-b), thereby adjusting the abrading surface to prevent an increase in the working diameter. Each of the carriers is similarly positioned and, as will be obvious, their median lines extended inwardly lie similarly tangent to a circle,

- the center of which is common to the center of the tool.

The above matter is presented as a possible explanation of the action which actually takes place during the operation of the cylinder grinding tools illustrated and described herein. It may be possible further to explain this action in the following way. If a lead pencil having a rubber eraser on one end of the same is held with the eraser engaging a fiat surface and is inclined in one direction from the perpendicular and moved in the direction of inclination, it will be noted that friction created by the rubber eraser moving over the surface will create a force tend ing to move the pencil axially through the hand and in a direction toward the flat surface. In other words, in dragging the eraser of a pencil over a surface, the resistance to the movement of the rubber has a tendency to pull the pencil out of the actuators hand. If this same pencil is inclined in a direction opposite to the direction of movement, the resistance presented to the rubber eraser moving over the surface will have axis of the tool, as the flat surface is to the penoil moved in a direction parallel to said surface. The cylinder wall and each abrasive element of the illustrated tools, therefore, are comparable with the above referred to pencil and flat surface. This is true since for any given point on the working surface of an abrasive element the radius from the center of the tool frame to that point corresponds to the perpendicular in the pencil analogy while the line extending axially of the abrasive element and its carrier which will intersect the working surface at said given point will correspond to the axis of the penciL. The angularity-of the said axial line with respect to its-radius will correspond to the inclination of the pencil or the angularity of the pencil with respect to the perpendicular. Applying this comparison to a tool, it will be found that for any point on the working surface of an abrasive element positioned in advance of .the tool radius, with respect to the direction of rotation, the axial line for that point will be inclined from its' radius toward the direction of rotation and that radius, the axial line for that point will be in-- clined from its radius in a direction opposite to the direction of rotation. The portions 'of the working surface in advance of the said tool radius, therefore, have a tendency to move radially outwardly toward the cylinder wall. The portions of the working surface of the tool located rearwardly of said tool radius therefore have a tendency to move away from the cylinder wall.

It will be noted that the abrasive elements of the tool shown in Fig. 5 have a major portion of their working surfaces located rearwardly of the tool radius line 12-12 and therefore there will be a major portion of the working surface ofeach abrasive element operating to force each element and its carrier radially inwardly against the rigid surfaces of the adjusting cones. It is believed, therefore, that there will be a resultant force or component which will succeed in holding the abrasive element and its carrier inwardly against the adjusting cones. With the arrangement shown in Fig. 11, with the entire workingsurface of each abrasive element located rearwardly, with respect to the direction of rotation, of the tool radius line 12-12, the entire surface of the abrasive element will be working to force the element and its carrier inwardly toward the axis of the tool.

With this explanation in mind, it will be apparent that when an abrasive eiement rocks, due to wear or the like, this reciting motion will be in a direction opposite to the direction of retation of the tool and will therefore cause an additional portion of the working surface of each abrasive element to be moved rearwardly, with respect to the direction of rotation, of the tool .radius line b-b. Any wear or imperfection developed during manufacture which results in a way that they may be readily and quickly detached; and it is also quite essential that they be desirable features. Specifically, the abrasive or grinding stone 18 is mounted, preferably, in a metal channel-shaped holder 31 and this holder with its stone is mounted in the channel 1'7 of the carrier head. The carrier head, at one side is provided with, preferably, two cut-outs 32 which extend through that side of the head to the channel 17. These cut-outs are each adapted to receive a clamp block 33 which is secured and mounted as follows: The stone carrier just inwardly of its head and adjacent the cut-outs 32 is provided with a boss or clamp-seat surface 34 which is raised above the base of the cut-outs, and upon which the inward edge of the clamp block is adapted to rest and rock. The central portion of the clamp block and the carrier head are provided with aligned openings, the latter being threaded, to receive a screw 35 for drawing the clamp block tightly in place. As will be obvious from Fig. 8, with the inward edge of the clamp block resting on its seat 34 and its outer edges resting against the stone support 31, the clamp block is moved laterally and inwardly, rocking about its seat 34 when the screw 35 is tightened, forcing the stone support 31 toward its seat in the head channel 1'7 where it is firmly held. The screw 35 is of sufficient length to extend a substantial distance through the carrier head so that the likelihood of the screw working loose is reduced to a minimum. With this arrangement, a relatively large diameter screw may be used which further tends to reduce the possibility of the screwworking loose. The head of the screw is also countersunk in the clamp block so that an increased friction-holding surface is provided which further tends to guard against loosening of theclamp means. The use of the large screws enables them to be more readily handled and tends to provide for readiness and ease in the replacement of the stones.

For rapid work, either in factory productionwork or in the servicing of worn cylindersfit is highly desirable that adjustment of the abrasive or grinding stones be accomplished without necessity of removing the tool from the cylinder and without the necessity of making numerous measurements in order to determine when the proper diameter of the cylinder has been reached. To that end. my invention provides an adjusting mechanism which is accessible, and remote from the cylinder, and which provides for readiness and positiveness in the adjustment of the stone carriers so that the work of the operator is greatly facilitated. Specifically, with reference to Figs. 1 to 5, the upper or top end plate 10 is provided with a cylindrical extension 36 disposed along the axis of the tool. This extension has an axial opening 37 through which the center stem 21 passes and finds guidance and bearing support. An extension sleeve-38, which may be of any desired length to meet the requirements of each particular tool and its use, is screwthreaded upon the extension 36. The upper or outer end of the extension sleeve 38 screw-threadedly receives and rigidly supports a dial cage 39 which rotatably supports a cylindrical adjusting dial 40 with its peripheral edge exposed (Fig. 1). The center stem 21 is of sufiicient length to extend upwardly through the extension sleeve 38,.

through a center opening 39' in the .dial-cage39 and through the adjusting dial to which it is fixed by a pin 41. The upper end of this stem, preferably, finds a bearing support in the upper part of the cage 39 so that the adjusting stem is firmly and positively positioned for rotational movement.

Obviously, rotational movement of the dial 40 relative to the dial cage rotates the center stem -21 moving the cones 23, 24 and the carriers in a direction dependent upon the direction of rotation of the dial. The upper part of the dial cage is provided with a horizontal projection 42 serving as a pointer or indicator which cooperates with the dial marks 43 to inform the operator as to the extent of any particular (or the total) adjustment of the grinding stones and the substantially correct extent to which the cylinder wall surface has been ground. In the use of the dial marks 43 (which may represent thousandths). when the tool is first inserted in the cylinder and the stones are set up until they engage the cylinder wall surface. the projection or indicator 42 may register with one of the dial marks. If the operator wishes to remove say five-thousandths from the cylinder wall surface, the dial may be adjusted from time to time until its initiallyregistering mark 43has moved around five points with respect to the indicator 42. The cylinder will have then been ground to the five-thousandth extent, less the amount of the stone wear. The grinding (and adjustments) may be continued to a desired extent to compensate for stone wear.

Since the dial 40 serves to support as well as actuate the center stem 21, there is the probability, unless guarded against, of the dial accidentally being rotated, due to vibration, etc,, of the tool (or its parts) during operation which would result in considerable inconvenience to operator and inaccurate grinding of the cylinder. My invention provides against such a condition by placing the dial under a constant tension so as to frictionally re'slst rotation of the dial. Specifically, the overall width of the dial is slightly less than the depth of the cage opening 39 in which it is positioned; and its hub 40* is of less width than its outer rim 40 providing a space between the dial hub and bottom of the cage opening 39 in which is received a cylindrically-shaped, dished, spring washer 60. This washer is of such size and shape that with the parts assembled as shown in Fig. 2, it is under a slight tension; and it is capable of slight compression so that when the tool is set up in the cylinder the spring washer may be placed under additional tension. Thusly, a constant tension is exerted on the dial to frictionally resist rotation of it and the center stern, thereby insuring that an adjustment once made will be maintained accurately to properly inform the operator. This arrangement takes all adjustment play out of the adjusting mechanism. The dial, stem and cones are tensionally positioned as a unit, thereby tending to hold the grinding stones in abrading contact with the cylinder wall surface under a continued grinding pressure throughout any particular adjustment setting, resulting in a more rapid grinding operation.

li"he tool may be driven by any desired power means which may or may not have a fixed mounting; but in either case it is desirable to provide connecting means between the tool frame and the drive which compensates for disalignrnent of these parts, which insures an accurate and free grinding action and which is readily separable to permit ready handling of the tool and its drive in inserting the tool in and removing it from the cylinder. In the form of Figs. 1 to 9,

inclusive, I provide that as follows: The upper part of thedial cage 39 has an opening 44 in which a short stem 45 is fixed by a pin 46. A parti-spherical head 47 is fixed on the outer end of the stem 45 by a pin 48, the projecting ends of which project outwardly for bayonet-lock engagement in L-shaped slots 49 in a drive socket 50 (Figs. 1 and 2). The upper wall of this socket has an opening which screw-threadedly receives a flat-sided drive shank 51 held in place by a lock-nut 52. It may be desirable to use different shaped drive shanks of different lengths and the detachability of the shank 51 readily provides for that.

The drive shank 51 is adapted to be connected directly to the power means, and its rotation results in rotation of the tool. The arrangement of the drive connection shown in Figs. 1 and 2 is well suited for use with power means which is not fixedly supported as may be the case at times in using the tool for servicing operations and where it is supported by hand. In the use of fixedly-supported power means where disalignment in all directions need be taken care of, as may be the case in factory production-work, I may employ the drive spindle shown in Fig. 9. This spindle comprises a stem 53 having on its lower end a socket 54 (mounted similarly to the socket 50) with L-shaped slots 55 providing a bayonetlock connection, and having on its upper end a parti-spherical head 56 secured by a pin 57, the ends of which pin project from the head for bayonet-lock connection. This spindle is adapted to be inserted between the drive shank 51 and the dial-cage 39 with its socket 54 bayonet-locked to the head 47 and its head 56 bayonet-locked with the drive socket 50. With this connection, slight disalignment between the tool frame and the drive will not hinder free grinding movement of the tool. Further, this intermediate spindle may be used to lengthen the tool as a whole, and

different length spindles may be used as desired.

This arrangement further provides for the use of a more rigid tool' body and adjusting mechanism, and provides for adjustment of the tool from a point remote from the cylinder without the use of joints, or like connections, in the adjusting mechanism or its supporting parts.

In Figs. 10, 11, 12 and 13, I have shown another form of my invention as applied to a socalled 4-stone type of cylinder grinding tool which will now be described. The tool frame or body is constructed similarly to that shown in Figs; 1 and 2, except that four, instead of five, tie bars '70 are employed to rigidly join the end plates 71 and 72 together in spaced relation. These tie bars divide the frame into a center space 73 with four radial passages 74 leading therefrom. The end plates are each provided with four grooves 75 (Fig. 11), each of which is offset radially with its median line disposed'rearwardly (with respect to direction of rotation) of the tool radius. These grooves support and guide the slidably adjustable carrierslfi, each of which comprises a body shaped and mounted similarly to the body of the previously-described carrier. The outer edge of the carrier body is provided with an enlarged, preferably integral, head 106 having a channel 107 in which is carried the grinding stone 108 and its channel support 109. The channel 107 is similar to that of the previously-described form, except that its median line tool radius (Fig. 11note lines a--a and bb) riers, under the foregoing conditions, will not re- (see line c-c, Fig. 11) is oflset with respect to the median line (a-a, Fig. 11) of the carrier body. The median line of the carrier body 105 in the tool is so positioned with respect to the 80 that with the stone-receiving channel'of the head 106 offset as described the radius of the tool passes adjacent the forward edge of the carrier body (compensating for the thickness of the stone channel support 109) and substantially coincides with the leading edge of the abrading stone 108. With this arrangement, the slightest rocking movement of the carrier will not result in increased abrading pressure. This form of carrier and its manner of positioning is well adapted to all of the previously described forms.

The clamp means for holding the grinding stone 108 and its support 109 in place is similar to that shown in Fig. 8. Briefly, the channel head 106 is provided at one side (preferably, the side located nearest the carrier body) with cutouts 110 adapted to receive clamp blocks 111. The base 112 (Fig. 13) of each cut-out is countercut so that its plane is lower than that of the adjacent carrier body surface. The butt or inward end of the clamp block 111 rests on the carrier body surface adjacent the cut-out and when the screw 113 is tightened in place, the unsupported end of the clamp block is rocked toward the stone support 109 forcing the same 105 into its channel-seated position where it is firm-1y held.

It is quite customary in cylinder grinding tools of the 4-stone type to utilize two opposite carriers to support abrasive or grinding stones 108, the 1 0 I other two opposed carriers serving as guides, so to speak, for properly positioning the tool with respect to the cylinder wall surface so that the desired cylindrical finish will be accomplished. Heretofore, the cylinder contacting part of these 15 guide carriers has taken the form of removable guide elements supported by the carriers in engagement with the cylinder wall surface, which elements, in some instances, take the. general shape of the grinding stone and are formed of 0 wood, oil-impregnated cotton belting, fibre and other similar materialsf These prior-used materials are objectionable for the reason, among others, that they do not wear away proportionately to the wear in the abrasive. It has usually been found that the abrasive wears away more quickly with the result that, in the grinding operation, after the abrasive has worn in a single grinding operation, the guides not having worn proportionately are the only part of the tool 3 contacting with the cylinder wall surface as the tool rotates. In tools of a character wherein all of the carriers are simultaneously adjusted to similar extents, further adjustment of the carsult in adjustment of the grinding stones into proper grinding contact with the cylinder wall surface. It becomes necessary, under these circumstances, to remove this tool from the cylinder and dress the guide surfaces before the tool will 4 operate properly. Naturally, such conditions of operation make these prior tools expensive to operate and materially increase the cost to the car owner of the grinding of the cylinders.

I have found that the foregoing objectionable conditions can be overcome by using for guide contact a relatively hard felt material which is preferably (but not necessarily) impregnated with a varnish material of thecharacter used ordinarily in connection withelectrical construction work. This varnish material readily penetrates the felt material and hardens sufilciently to provide a guide element, such as 78, supported by the guide carriers of Fig. 11. A guide element of this character has a sufliciently stiff body to stand up under guide-pressure conditions while, at the same time, having the ability to wear in substantially the same proportion as the cylinder grinding stones. In some instances, I may use a high grade medium-hard felt material untreated, or I may treat only the sides of such material with cement, varnish, lacquer or some similar material to stiffen its side walls sufliciently to support it against free resiliency when in contact with the cylinder wall surface, without interfering with its ability to wear away at the same rate as the grinding stone or other abrasive. With such an arrangement, the grinding may be carried on, in the grinding of a single cylinder, continuously and rapidly without removing the tool from the cylinder to dress the guides.

As shown in Fig. 10, the adjusting mechanism for expanding and contracting the carriers 76 is similar to that of the form first described, except that the structure for supporting and actuating the center adjusting stem 79 is somewhat different. Specifically, (Fig. 10) the end plate '11 has an outward sleeve extension 86) upon which there is secured by screw pins 81 the cylindrical portion 82 of a cage-like drive member 83. 'This drive member is provided with an integral partispherical head as carrying a pin 85 which is adapted to be engaged by a socket part of the drive corresponding with the socket 50, shown in Fig. 2, to provide for universal adjusting aligning movements between the drive and the tool.

The center stem 79 extends outwardly through and finds bearing in the end plate ll and has its outer end secured centrally to an adjusting dial 86 by a pin 87 or other suitable means. As will be noted in Fig. 12, the drive member 83, above its cylindrical bottom part 82 is open, its upper and lower parts being joined by opposed arm sections 88, thereby exposing the peripheral knurled surface of the adjusting dial 8'3 so that the same may be readily grasped to rotate the center stem 79 and move the cones 89 to expand. and contract the carriers '76 as wili be understood from the description given hereinabove.

In this particular term of my invention, the adjusting mechanism is tensionaliypositioned in the tool ior maintaining adjustments and for continued grinding pressure during any one adjustment, as follows: The outer surface or the end plate '11, which is the bottom of the extension 80, is provided with a reduced bore in which there is seated a spring washer 90 similar to the spring washer 60 shown in Fig. 2a. A sleeve 91 is mounted upon the outer end of the stem 79 between the under face of the dial 236 and the washer 90, this sleeve being of sufiicient length to place the washer 90 under slight compression in the normal assembled position of the tool. This structure operates similarly to the tensioning structure shown in Figs. 2 and 2a.

In Fig. 14, I have shown a modified form of drive connection between the adjusting dial 86 and the center stem 79*. More particularly, the dial 86 has centrally secured therein as by pin 92 a short stem or shaft 92, one end of which is seated for guidance and support in a central bore in the upper portion of the cage-like drive member 83. The other end of this stem 92 extends beneath the dial 86 and supports a pin 93, the ends of which project slightly beyond the outer surface of the stem. The adjusting stem extends outwardly through the end plate '71 and has an enlarged head 94 having a central bore for receiving the lower end of the stem 92. The opposite side walls of the head are slotted into its bore to receive the projecting ends of the pin 93 to provide a readily separable but positive drive connection as between the stem 92 and the adjusting stem '79. A spring washer 95 similar to that shown in Fig. 2a is disposed beneath the stem head 94 and the outer surface of the end plate 71 to provide for tensioning of the adjusting mechanism as in the form first shown and described.

With this structure, the tool parts may be readily disassembled by merely removing the screw pins 96 which lock the drive member 83 upon the end plate 71. Other than the above, the operation of this tool is the same as that shown in Fig. 2.

The tool drive structure shown in Fig. 15 is quite similar to that shown in previous figures, except that the end plate 97 of the tool and the cage-like drive member 98 and the parti-spherical universal connection head 99 are all formed as one integral piece. In this form, the adjusting mechanism tensioning means which takes the form of a spring washer 100 is confined between the bottom of the cage opening 101 and the under-side of the dial 102. The under-side of the dial is provided with a shallow bore 103 to readily accommodate the washer 100.

It will be understood that while I have shown and described several embodiments of my invention, other changes in details and arrange ment of parts may be made without departing from my invention as defined by the claims which follow.

I claim:

1. In a tool of the character described, a cageframe having end plates with radial passages therebetween, a plurality of long, deep grooves extending in radial direction in said end plates, corresponding grooves in opposite end plates being vertically aligned, and all said. grooves being so positioned that their median line in radial direction is offset from the tool radius, and abrasive carriers mounted in said radial passages and having their ends slidably seated. in said oriset grooves.

2. In a tool of the character described, a cageframe having end plates with radial passages therebetween, a plurality of long, deep grooves extending in radial direction in said end plates,

corresponding grooves in opposite end plates b..-

said radial passages and having their ends slidably seated in said offset grooves.

,3. In a tool of the character described, a rotatable cage-frame having end plates with radial passages therebetween, a plurality of long, deep grooves extending in radial direction in said end plates, corresponding grooves in opposite end plates being vertically aligned, abrasive carriers mounted in said radial passages and having their ends slidably seated in said grooves, and all said grooves being so positioned that the median line of said carriers in radial direction is offset rearwardly, with respect to direction of rotation, from the tool radius.

4. In a tool of the character described, a cageframe having end plates with radially directed grooves, means dividing said frame into a pinrality of radial passages between said end plates, abrasive carriers mounted in said passages and having body parts with end portions slidably supported in said grooves, said' carrier bodies having plane inner edge surfaces, cone-shaped adjusting devices engaged with the plane inner edge surfaces of said carriers, means for adjusting said cone devices, said grooves being so positioned that the carrier plane edge surface engages said cone surfaces at one side of the median line, in radial direction, of said carrier 5. In a tool of the character described, a cageframe, means forming a plurality of radial passages in said frame, abrasive carriers mounted for expansion and contraction movements in said passages, said carriers having inner edge plane surfaces extending into the central portion of said frame, adjusting devices mounted in the central portion of said frame having surfaces upon which said carrier plane surfaces seat, means for adjusting said devices to expand and contract said carriers, and means for so positioning said carriers in said passages that their inner edge plane surfaces are seated upon said adjusting device surfaces to one side of the radially-directed median line of said carriers. 6. In a tool of the character described, a frame,

abrasive carriers mounted in said frame for toolexpansion and tool-contraction movements, said carriers being of sufficient dimension in radial direction to extend into the central portion of said frame and having inner edge plane surfaces, adjusting means mounted in the central portion of said frame and including elements having surfacesupon which the plane inner edge surfaces of said carriers seat, the mountmg for said carriers being so positioned with respect to the tool radius that the median line in radial directionof each carrier is offset from a line passing through the exact center of the tool.

7. In a tool of the character described, a cageframe having end plates spaced in such a manner as to provide in the frame a center space and radial passages leading therefrom, said endplates having corresponding radially-directed grooves the median lines of which in radial direction are offset from the tool radius, abrasive carriers mounted in said radial passages and each having a bladed body part the ends of which slidably seat in said groov'es, cone-shaped ad usting devices mounted in said frame center space, said carrier bodies being of suchlength as to extendinto the frame center space and being so shaped that plane inner, edge surfaces seat upon said cone devices, the radial offsetting of said end plate grooves positioning said carriers so that they seat upon said cones to one side of the center of their plane surfaces.

8. In a cylinder grinding tool a frame, an abrading element, a carrier for said element mounted to extend in' radial direction in said frame, the

. inneredge of said carrier being fiat, an adjusting member having a cylindrical surface engaged by the inner edge of said carrier, said carrier so engaging said member that upon bodily rocking motion of the carrier in a direction opposite to the direction of rotation of the tool, the surface of said element in contact with the cylinder wall surface is rocked closer to the tool center thereby reducing the working radius of said carrier relieving the abrading-pressure-contact between the abrading element and the cylinder wall surface preventing seizure and increased drag.

9. In a tool of the character described, a stone carrier having a rectangularly-shaped stone-receiving channel therein for receiving a rectangularly-shaped stone-unit, and means for securing said stone unit in said channel comprising a flatface detachable clamp block mounted in one of the channel sides with one end engaging one of the flat sides of the channel mounted stone unit, a seat on said carrier having a seating surface lying in a plane substantially parallel with said flat side of said stone unit and on which the other end of the flat face of said block rests, and a fastening device adjustably engaging said block and carrier to secure the stone in place.

10. In a tool of the character described, an abrasive carrier having a channeled head, an abrading element mounted in the channel of said head, one of the sides of said head channel having a cut-out, a clamp block having a plane surface mounted in said cut-out with one end engaging said element, the base of said cut-out being counter-cut so that it is lower than the carrier surface located adjacent and inward of said head, said block being of such length that its other and rests and rocks upon said carrier surface last-mentioned and fastening means engaging said block and said carrier which rocks the block about its said other end support when it is tightened pressing laterally and inwardly upon said element.

11. In a tool of the character described, a body, abrading means supported in said body, means, including a rotatable stem member extending through said body to be journalled therein and an exteriorly-accessible stem-rotating element, for adjusting said abrading means, and tensioning means acting directly on said stem-rotating element for fricti'onally resisting rotation of'said stem member.

12. In a cylinder grinding tool, a body, abrading elements supported in said body, independent adjusting devices in said body acting on said ele- 13. In a tool of the character described, a frame.

abrasive carriers mounted in said frame for expansion and contraction movements, means for successively adjusting said carriers without removing the tool from the cylinder including a rotatable frame and an exposed rotatable actuator connected to said stem member remote from said frame, and spring means yieldably opposing axial movement of said stem member for tensionally positioning the adjustingmeans in said frame.

14. In a tool of the character described, a rostem member extending through said V tatable cage frame having end plates with aligned grooves, an abrasive carrier extending radially within said frame with its opposite ends slidably mounted in said grooves, an abrading element supported by said carrier, means for expanding and contracting said carrier, said carrier-supporting grooves each having their median line in radial 15. In a tool of the character described, a rotatable frame, an abrasive carrier extending radially within said frame, an abrading element supported by said carrier, and means supporting said carrier with its median line in radial direction offset rearwardly, with respect to direction of rotation, from the tool radius passing substantially parallel therethrough, said carrier supporting said abrading element with the median line of the latter in radial direction oflset rearwardly, with respect to direction of rotation, from. the said median line of said carrier.

16. In a tool of the character described, a rotatable frame having spaced end plates with the grooves extending radially inwardly, a carrier member adjustably supported in said grooves, an abrading element supported by said carrier, .said grooves being so positioned relative to the radius of the tool and said element being so positioned relative to its carrier that the leading edge of said element coincides substantially with the tool radius.

17. In a tool of the character described, a rotatable frame, a carrier member adjustably supported by said frame, a channeled head along one edge of said carrier, the median line of said head channel in radial direction being offset with respect to the median line in radial direction of the carrier, an abrading element mounted in said channel, said carrier being so positioned and said channel being so offset that the tool radius passes through said element adjacent its leading edge with respect to direction of rotation.

18. In a tool of the character described, a frame having end plates with corresponding radially directed grooves therein, all said grooves being so positioned that the median line of each in radial direction is offset from the tool radius, carriers siidably supported at their ends in said grooves, each said carrier having a. channeled head along its outer edge, the median line of each said head channel in radial direction being ofiset from the median line of the respective carrier, and an abrading element supported in the channel of each said carrier head.

19. In a tool of the character described, a frame having end plates with corresponding radially directed grooves therein, all said grooves being so positioned that the median line of each in radial direction is offset rearwardly from the tool radius, carriers slidably supported at their ends in said grooves, each said carrier having a channeled head. along its outer edge, the median line of each said head channel in radial direction being oifset rearwardly from the median line of the respective carrier, and an abrading element supported in the channel of each said carrier head, the arrangement being such that the tool radius passes ap proximately through the leading edge of the abi'ading element.

20. In a tool of the character described, a frame having end plates supported in spaced relation to provide a central space with radial passages leading therefrom, a center stem journalled in said end plates, abrasive carriers mounted in said radial passages, adjusting devices adjustably supported by said stem and engaging said carriers for expension and contraction movements, a hollow extension projecting rigidly from one of said end plates, an exteriorly-accessible adjusting member mounted on and rotatable relatively to said extentherein;

sion and connected to said stem for axial support of the latter, and a universal drive connection associated with said extension outwardly beyond said adjusting member.

21. In a tool of the class described, a frame having spaced end plates with aligned grooves abrasive carriers supported in said grooves for expansion and contraction movements; means for expanding and contracting said carriers including a stem member mounted on the axis of the tool, said frame having a rigid hollow drive extension on one of said end plates through which one end of said stem is projected; an adjusting member supported by and rotatable relatively to said extensiomsaid adjusting member being connected to said stem for support of the latter normally for rotation, and a universal drive connection on said extension outwardly beyond said adjusting member.

22. In a cylinder grinding tool, a cage-like frame having end plates supported in spaced relation, the adjacent faces of said end plates having aligned grooves extending from their periphery to their central portion, abrasive carriers guidingly supported in said grooves, abrasive members supported by said carriers and having their median lines offset from the tool radius, and means for expanding and contracting said carriers.

23. In a cylinder grinding tool, a cage frame having end plates, a plurality of grooves in said plates extending from their periphery to their central portion, corresponding grooves in opposite plates being aligned and each said groove having its median line oflset from a tool radius line passing therethrough substantially parallel with its median line, abrasive carriers having end portions slidably mounted in said grooves, and means for sliding said carriers back and forth in said grooves to expand and contract the tool.

24. In a tool of the character described a cage frame having end plates with radially directed grooves, means forming a plurality of radial passages between said end plates, abrasive carriers mounted in said passages with end portions supported in said grooves, adjusting devices engaged with the inner, longitudinal edges of said carriers, means for adjusting said devices to expand said carriers, said grooves being so positioned that the median line oi the inner longitudinal edges of said carriers is to one side of the point of engagement between said car-- rier edges and adjusting devices.

25 In a cylinder grinding tool, a cage-frame having spaced end plates, grooves in the inner faces of said plates, abrasive carriers having end portions slidably mounted in said grooves for support thereof, abrasive elements supported by certain of said carriers, and means for expanding and contracting said-carriers, said end plate grooves being so located that their median lines a and those of said carriers are offset from the tool radius.

26. An abrasive carrier for tool of the character described which comprises a body portion,

a channelled head supported bysaid body portion, an abrasive unit consisting of an abrasive member and a channel-shaped support therefor mounted in the channel of said head, one of said head channel sides being interrupted to provide openings therethrough, raised seat elements on said carrier aligned with said openings and located inwardly of the base of the channel of said head, a clamp block mounted in said outout with its inward-end resting on said seat, and means engaging said block and carrier for seamaze curing said block in place and for rocking its outer end inwardly against said abrasive member.

27. In a tooi of the character described, a retatable frame, an abrading element having a working face portion engageable with the cylinder wall surface, and means including a carrier member for supporting said abrading element in said frame so that the entire width of said working face will be positioned rearwardly, with respect-to the direction of rotation, of a tool radius passing through said carrier member in parallelism with the central radial plane of said carrier member.

28. In a tool of the class described, a rotatable frame having radially-directed passageways and opposed end members with radially-directed grooves therein, carrier members, having wall contacting elements, mounted in said passageways with end portions thereof mounted in said grooves for expansion and contraction movements, all of said grooves being so positioned that their-median lines in radial direction are offset from the axis of the tool, means located between said and members in engagement with said carrier members and adjustable in-one direction axially of the tool for expanding said carrier members and for limiting contraction movement of carrier members to variable extents, means operable upon adjustment of said first means in an opposed direction for contracting said carrier members, and means foradjusting said first means in both said directions.

HERMAN W.

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