US2856738A - Cylinder hone - Google Patents

Description

Oct. 21, 1958 F. DEUSCHLE CYLINDER HONE Filed Sept. 3, 1957 INVENTOR. Fri/ Deascfi/e H/5 ATIORNEY United States Patent M CYLINDER HONE Fritz Deuschle, St. Augustine, Fla. Application September 3, 1957, Serial No. 681,581 8 Claims. (Cl. 51-187) This invention relates to cylinder hones.

An object of the invention is to provide a simple, inexpensive hone for grinding and polishing cylinders to have a smooth internal surface.

A further object is to provide a hone utilizing readily available and replaceable abrasive cloth, of various grades of coarseness, and having selected spring pressure against the cylinder walls.

Another object is to provide a hone which may be used, even by an unskilled person, by chucking in a hand-held electric drill, or the like driving source, to provide a smooth bore in a pitted, scored or ridged cylinder, without any requirement of careful or accurate alignment 0! adjustment.

Homes in accord with this invention are particularly applicable to the refinishing of automobile hydraulic brake cylinders and to similar cylinders which are. equipped with pistons having neoprene or other elastic sealing cups or rings, although the utility of the device is not restricted thereto. A troublesome problem encountered in, the refinishing of such cylinders is the difliculty of obtaining access thereto for properly positioning the hone and hone-driving motor device in the limited space available in most automobiles.

The device has further specific applicability for use as a deglazing tool for removing or breaking the glaze of gasoline engine cylinders, it being desired, when replacing piston rings, for example, as is well known, to break the glaze that forms on the surfaces of engine cyl' inders thereby to permit the new rings to wear into and seat properly in the cylinder after a short breaking-in period of operation of the engine.

The novel features which are believed to be characteristic of this invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings, in which:

- Fig. l is a side elevation of a hone in accord with the invention with the abrasive sheet removed therefrom;

Fig. 2 is a detail sectional elevation of a ferrule or sleeve element embodied in the device;

Fig. 3 is a top end view of the hone as shown in Fig. 1;

Fig. 4 is a fragmentary perspective view of the head portion of the hone with an abrasive sheet, partially broken away, being applied thereto;

Fig. 5 is a fragmentary perspective view of the head portion, similar to Fig. 3, but showing the abrasive sheet in position for use;

Fig. 6 is a side elevation of the head portion of the device shown as it appears in use in refinishing a cylinder, the cylinder being shown in section;

Fig. 7 is a fragmentary side elevation of the head portion of. a hone device in accord with a modification of the invention, the abrasive sheet being removed; and

2,855,738 Patented Oct. 21, 1958 Fig. 8 is a top end view of the modified device as shown in Fig. 7.

As seen in Fig. 1, the device according to the invention comprises a solid cylindrical rigid metal shank 1 adapted to be received in the chuck of an electric hand drill, for example, and a head portion 2 connected to shank member 1 by means of a flexible spring wire 3 closely coiled into a cylindrical spring 4. The device is constructed by attaching the lower end 5 of the coil por tion of connecting wire 3 to the upper end portion 6 of the rigid shank member 1 by means, preferably, of a brazed connection 7. Thereafter, in assembling the device, a sleeve or ferrule 8 is pressed into position over rigid shank member 1, which fits tightly within reduced diameter portion 9 of the ferrule, with the upper enlarged diameter portion 10 tightly receiving the lower end of the coil.

The ferrule 8 is shown in cross section in Fig. 2 and it will be apparent that the rigid shank member 1 of Fig. l fits tightly within the bore 11 of the smaller diameter portion 9 of the ferrule while the spring member 4 of Fig. 1 fits tightly within the bore 12 of the upper enlarged diameter portion 10 of the ferrule.

It has been found that the ferrule or sleeve 8 remains fixed in position when proportioned to have pressed fit on the rigid shank 1 and on the lower portion 5 of the spring, and the lower portion of the spring 4 is afiixed with sufiicient rigidity and strength to the rigid shank member 1 by insertion of the upper end portion 6 of the rigid member 1 into the spring as shown in broken lines in Fig. l, by providing a single brazed. connection 7 between spring 4 and member 1, and by covering, protecting and further rigidifying the joint by the application of the ferrule. As so connected together, the rigid member 1 and the wire 3 as coiled into spring 4 become a unitary resilient shank for head 2 consisting of a chuckengageable rigid portion 1 and a resilient portion 4 mounting the head.

The head 2, which is connected to the rigid chucken'gageable portion 1 of the shank by means of the resilient spring wire 3, is preferably formed by an extension of the wire, as shown, through a bend 13. The head comprises three legs 14, 15 and 16 joined each to the next by means of resilient wire bends or resilient bridging con nections. Specifically, bend 17 connects leg 14, at the outer or top end 53 of the head, to leg 15 at its outer end 52, while leg 15 is connected at its inner end 51 by meansof a resilient rounded bend 18 to the bottom or inner end 54 of leg 16. The upper or outer end 19 of leg 16 extends into a close or sharp end 20 and thence back on itself at 21 to form a resilient clip portion 22, between leg 16 and the bent back portion 21 of the wire. As later described, clip 22 is adapted to receive a piece of flexible abrasive sheet material. The bend 13 and the bends 1'7 and 18 of the wire are arranged to dispose the head in substantiallycoaxial alignment with the spring shank or connecting portion 4 and, as best seen in Fig. 3, to dispose the individual legs approximately equally laterally spaced one from the other, each leg being thus approximately equally spaced outwardly of the axis and each being generally parallel to the axis and to each other and being substantially coextensive. It will be further apparent that the axis of the rigid portion 1 of the shank is substantially aligned with the axis of the resilient shank portion 4 and, accordingly, substantially aligned with the axis of the head.

The device is adapted to the honing or finishing of cylinders of a range of sizes and, specifically, a device in accord with the preferred embodiment of this invention as shown in Figs. 1 through 6, inclusive, may be designed to operate satisfactorily, for example, in cylinders varying between A: to about 1 internal diameter, or it may be designed for cylinders of between about 1% and 1%" internal diameter. As shown in Fig. l, in solid lines, the device may be appropriate for 1%" cylinders, but by slightly opening the bends 17 and 18, the leg and. 16 may be displaced into the positions indicated in broken lines at 23 and 24, respectively, and in this manner adjusted for cylinders of up to about 1% internal diameter. It has been found that the slight outward bow of the legs, such as shown at 25 for leg 14, permits the head to engage smoothly from end to end the walls of the cylinder being finished whether the legs are in the solid line positions, for a smaller cylinder, or are in the broken line positions for a larger cylinder. The resilient shank or connector portion 4 which connects the chuck-engageable shank portion 1 to the head 2 compensates for any slight misalignment of the head with respect to the rotational axis of the shank, such as may occur from bending of the legs into the proper positions for cylinders of varying diameters or which may result from the disposition of the head in a cylinder to be finished with the driving chuck and rigid shank portion 1 arranged at an angle to the axis of the cylinder. Accordingly, an electric hand drill, or the like, is readily usable as a source of driving power for the hone, the drill being held in the hand without requirement of rigid or accurate mounting, and with the drill not necessarily aligned with the cylinder but being held at an angle to avoid such external objects as may be in the way.

Fig. 4 demonstrates the method of wrapping a piece 26 of flexible abrasive sheet material on the head for the honing or polishing function. One end portion 27 of the abrasive sheet, which is preferably in the form of an elongated rectangular strip as shown, is inserted into the clip 22 and the strip is then Wrapped outwardly as at 28 around leg 16 and thence outwardly around legs 14 and 15 in turn, the opposite end 29 overlapping the portion 28. When the end 29: is pulled snugly into position, the abrasive strip wrappingly encompasses the head 2 as shown in Fig. 5. The device in use is rotated with a right hand twist in order that the abrasive strip will tend to wind around the head as a result of the rotation, and the direction, it will be noted, is such as to tend to cause the coil 4 to become more tightly wound, the coil being formed by twisting the wire in the left hand direction.

The appearance of the device in use in the bore 30 of a cylinder 31 is exemplified in Fig. 6, the device being there shown in inverted position. Each of the three legs is engaged, through the abrasive strip. 26, with the inner walls 32 of the cylinder, and the walls are thus polished as the head is rotated with the abrasive surface engaging the cylinder walls. In use, the hone is moved in and out longitudinally to insure polishing the whole wall of the cylinder substantially equally.

Certain brake cylinders are of slightly reduced internal diameter toward one end, in order that two pistons connected through opposite ends will provide different force on the respective brake shoesof the brake assembly. Thus, cylinder 31 may have a reduced diameter bore portion 33 separated from the larger diameter bore 30 by a shoulder 34. The gentle rounding of connecting bend 17, which arches between and connects legs 14 and 1 5 as previously described, permits the head to be forced downwardly, as shown in Fig. 6, beyond the shoulder 34 and into the reduced diameter bore 33 of the cylinder. The central extreme end portion 35 of bend 17, specifically, lies inwardly of the cylinder walls 3t? engaged by the legs of the head and, accordingly, does not contact the shoulder 34 upon passing the shoulder, and it will be noted, too, that the bend 20 at the outer end of leg 16 curves slightly inwardly causing leg 16 to be deflected inwardly as the hone is forced past the shoulder. With the head. forced completely into reduced diameter portion 33, the bends, such as bends 17 and 18 shown in Fig. 1, resiliently yield. and become slightly more curved, and the legs take up the required positions, slightly closer to the head axis, as required by the smaller diameter.

In adjusting the bends 17 and 18 for a particular diameter cylinder, the bends are manually formed so as to cause the legs originally to define a diameter slightly larger than the diameter of the cylinder involved, whereby upon insertion of the head into the cylinder the legs bear outwardly under the spring force of the wire bends 17 and 18 exerting pressure through the abrasive cloth on the cylinder walls. The amount of pressure is readily adjusted by manually deforming the bends to increase or decrease the angles or radii, of the bends.

The wire of which the head is formed in each embodiment is a wire having suflicieut springiness or resilience to be capable of exerting an outward force of the order of a few pounds, such as from about 1 to about 5 pounds, against the cylinder walls, but at the same time deformable, or formable, under greater force applicable thereto by the hands of the mechanic. Thus, the mechanic can readily deform the head to increase or decrease the radius or angle of any one of the bends which join the legs to one another by supplying force of, for example, six or ten pounds between the legs, such force exceeding the elastic limit of the wire, whereupon the head will resiliently retain its deformed shape and will exert yielding spring force opposing any subsequent forces tending to change the new shape of the head until the elastic limit is again exceeded.

As used herein, the word deformable is intended to cover bending beyond the elastic limit, such as results in plastic change in the rest or unstressed shape of the head. The wire being resilient, or of spring material, the application of bending stress or force not exceeding the elastic limit is opposed by the spring force of the wire and upon relaxation of such force, the head returns to its unstressed shape.

A specific suitable wire is full hard drawn steel wire, of approximately three thirty-seconds of an inch, or five sixty-fourths of an inch, in diameter. The connecting wire 3 which forms the resilient portion 4 of the shank may be of the. same size and material as the wire of the head, being preferably, as shown, a continuous length with the wire of the head, but this wire is coiled into the tight cylindrical spring 4 as shown.

The same wire as described above may be employed both in the head 36 and in the connecting portion 45 of the modification of Figs. 7 and 8, when such modification is to be used for honing or glaze breaking of larger cylinders of about 3 to 4 inches in diameter, for example, although a wire of about 0.12 of an inch in diameter is preferred.

While the device shown in Figs. 1 through 6 has proved desirable for cylinders of less than about two inches in diameter, for cylinders of more than two inches the construction of the head is preferably modified to accord with Figs. 7 and 8, wherein the head 36 is formed of four legs 37, 38, 39 and 40, leg 37 being connected to its next leg 38 by a resilient outer bridging portion or bend 41, corresponding to bend 17 of the first embodiment, and wherein leg 38 in turn joins leg 39 by means of a bend 42 at the inner end of the head, while leg 39 joins leg 40 in a resilient bend 43. A clip 44 is formed on leg 40 corresponding exactly in construction and function to the clip 22 previously described, except that it is disposed toward the inner end of the head. The head 36 of Fig. 7 is arranged on a flexible wire shank portion 45 corresponding to coil 4 of the previously described construction, and it will be understood that a rigid, chuck-engageable shank portion is provided to drive the flexible shank portion 45 which may be in all respects similar to the arrangement shown in Figs. 1 and 2. The legs of head 36 are outwardly bowed, as seen at 46 for leg 39 and at 47 for leg 37, and the legs may be adjusted outwardly, as in the previous embodiment, by opening or closing, i. e. by decreasing or increasing the radii of the bends 41, 42 and 43, thereby to adjust the force of the legs against the walls of a cylinder being honed or to adapt the head for honing a cylinder of larger or smaller internal diameter. The

outward bow of the legs of head 36 causes the head to conform to the cylinder walls in such manner as to provide a smooth and substantially linear honed finish on the cylinder even when the diameter is such that the legs are separated by substantial opening of the bends 41, 42 and 43. When so separated, it will be apparent that the legs will be less nearly exactly parallel but that they will still be generally parallel, even though, for example, legs 38 and 39 will then diverge with distance from bend Z2 and legs 39 and 40 will diverge with distance from bend 43. The slight bowing of the legs, as at 46, prevents the ends of the legs from digging into the cylinder at the ends of the head and from causing uneven grooves in the cylinder even when the legs are considerably spread to adapt the head for use with cylinders as much as about 30% or 35% greater diameter than the smallest cylinder to which the head is adjustable. Accordingly, the heads of Figs. 1 and 7 conform in this as in other respects.

The top view of Fig. 8 shows details of the construction of the device according to Fig. 7 and may be compared therewith better to understand the relative location of the various portions thereof. It is to be noted that head 36 is substantially coaxial with the drive shank 45, except when the device is being used under conditions described above in which the flexible shank will become curved and out of alignment, and the several legs of the head, as before, are substantially equally spaced one from the next and disposed at substantially equal distances from the axis of the device. The broken line 48 indicates generally the direction in which a flexible abrasive sheet material strip is wound about the head, corresponding to the manner of wrapping sheet 26 about the head in the first embodiment as hereinabove described. The head would be rotated in the cylinder in the direction indicated by the arrow 49.

When the device of Figs. l-6 is adjusted for smaller or larger cylinders, reasonable care should be taken to insure that the lower or inner ends 50 and 51 of legs 14 and 15 are separated from each other by substantially the same distance of separation as exists between the upper end 19 of leg 16 and the upper end 52 of leg 15, and approximately the same distance should, then, also separate upper end 19 of leg 16 and upper end 53 of leg 14, as well as lower end 54 of leg 16 and lower end 50 of leg 14.

Similarly, in adjusting the device of Figs. 7 and 8, the lower ends 55 and 56 of legs 37 and 38 should be spaced apart by approximately the same distance as the lower ends 57 and 58 of legs 39 and 40, and the upper ends 59 and 60 of legs 37 and 40 and the upper or outer ends 61 and 62 of legs 38 and 39 should be spaced by approximately this same distance.

It is not necessary in either case that the separation distances be exactly equal, since the Wire of the head is resilient and springy and will afford some automatic correction, but unless the distances are made approximately equal, as described, the grinding of the cylinder will not be even throughout the length of the head. Misalignment, if the leg ends are not spaced as described, may also cause the abrasive strip to wind up or down on the head, rather than in the desired straight direction shown.

While only certain preferred embodiments of this invention have been shown and described by way of illustration, many modifications will occur to those skilled in the art and it is, therefore, desired that it be understood that it is intended in the appended claims to cover all such modifications as fall within the true spirit and scope of this invention.

What is claimed as new and what is desired to secure by Letters Patent of the United States is:

1. A cylinder hone comprising a rigid shank element, a generally cylindrical coil spring having an end fixed to said shank element and extending therefrom in substantially coaxial alignment therewith, a head carried by said spring spacedly from said shank element and in substantial alignment therewith, said head comprising a continuous spring wire formed into at least three leg portions connected each to the next by a respective-resilient bent portion of the wire, said leg portions being approximately equally spaced one from the other and outwardly of said axis, and being generally parallel to said axis, one of said legs having an end portion folded back on itself to form a clip, and a piece of flexible abrasive sheet material engaged in said clip and wrapped about said head.

2. A cylinder hone comprising a rigid shank element, a generally cylindrical coil spring having an end fixed to said shank element and extending therefrom in substantially coaxial alignment therewith, a head carried by said spring spacedly from said shank element and in substantial align ment therewith, said head comprising a continuous manually deformable spring wire bent to form at least three legs connected each to the next by a respective resilient generally arcuately rounded bend of the wire, said legs being approximately equally spaced one from the other and outwardly of said axis, and being generally parallel to said axis, one of said legs having an end portion folded back on itself to form a clip, and a piece of flexible abrasive sheet material engaged in said clip and wrapped about said head, said head being manually adjustable in size by changing the angles of said rounded bends.

3. A cylinder hone comprising three substantially coextensive wire legs, each said leg being substantially equally spaced laterally from and being generally parallel to each of the other two legs, each said leg having an inner end and an outer end, a resilient bridging con nection between the outer end of a first said leg and the outer end of a second said leg and a second resilient bridging connection between the inner end of said second leg and the inner end of the third said leg, supporting and rotating means for said legs and said connections, said means comprising a rotatable shank aligned with an axis centered between said legs and means connecting said shank to said inner end of said first leg, a strip of abrasive sheet material extending outwardly around and encompassing said three legs, and means connected to said third leg clampingly engaged with an end portion of said strip anchoring said strip end portion in predetermined position with respect to said third leg.

4. A cylinder hone comprising a shank having a rear end portion adapted to be engaged in a rotatable chuck and including a flexible spring Wire shank portion joined to and extending forwardly from said near end portion, a head fixed to the forward end of said shank comprising a continuous length of wire with said spring wire shank portion, said wire being formed into a first leg generally parallel to said shank and extending forwardly of and connected at one end to said shank by a connecting arm portion of said wire which extends generally laterally from said forward end of said shank and supports said leg in laterally ofiset relation to said shank, said wire extending from the other end of said leg into an arcuate leg connection and from said leg connection into a second generally parallel leg offset in .a different radial direction from said shank, and further extending from said second leg into a second arcuate leg connection and therefrom into a third generally parallel leg offset in another radial direction from said shank, said legs being approximately equidistant from each other and approximately equally oifset from said shank and being approximately coextensive, a replaceable strip of abrasive sheet material freely wound about said legs, and means removably anchoring one end of said strip to one of said legs.

5. A cylinder hone according to claim 4 wherein said wire of which said legs and leg connections are formed is manually deformable whereby the spacing between said legs is adjustable by selectively opening and closing the are of each said leg connection thereby to adapt the hone to fit cylinders of different diameters, and wherein each said leg has a central portion bowed gently outwardly away from the other two legs.

6. In a, cylinder hone, ahead comprising generally co-' extensive, generally parallel first, second and third legs,

each having an inner and an outer end, a deformable spring connection of approximately arcuate shape conneeted between the outer ends of said first and second legs, and a second deformablespring connection of approximately arcuateshape connected between the inner ends of said second and thirdulcgs, whereby said outer end of said third legend saidinner end of said first leg constitute free leg,,ends,p,cl ipmeans carried by one of said free. ends, a supporting and driving shank connected to the other ofsaidfreeends, said shank having a rotational axis approximately, parallel to saidlegsv and aligned approximately with th;,C6I1tlZ of said head, and a replaceable strip of abrasive, sheet material removably anchored by saidclip means and wrappingly engaged about said legsand encompassing; said; head.

7. The. combination, according to: claim 6 wherein said C p means carried bysaid one; of said free ends comprises a tbird, deformable spring connection of approximately arcuate; shape. and a; fourth leg. connected at one of itsv ends by saidthird connection to said one of said 8 free ends andan opposite end portion of said fourth leg. extending: back-on. itself and forming a spring attachment clip forsaid strip.

8;. Acylinder hone, comprising. a rigid shank element,

a generally cylindrical coil spring having an end fixed to said shank, e-Iementand extending therefrom in substantially 'eoaxialialignrnent therewith, a head carried by saidl springhspacedly. from said; shank element and in substantial alignment therewith, said head. comprising a continuous spring wire formed into at least four leg. portions connected each to the next by. a respective resilient bent portion of the. wire, said leg portions being approximately equal-lyspaced one from the other and outwardly of said axis, and being generally parallel to said axis, one of said legs having an end portion folded back on itselfto:

form a clip, and a pieceof flexible abrasive sheet mate'- rial engaged inv said. clip andv wrapped about said head.

References Cited in the file of this patent UNITED STATES. PATENTS Magaas: Mar. 16, 1926 Grauli Mar. 16, 1937

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