US2229314A - Cylinder ridge grinder - Google Patents

Description

Jan, 21, w41. c..4 soLBRlG 2,229,314

' CYLINDER RIDGE GRINDER Filed Feb. l2, 1940 2 Sheets-Sheet l 11111.21, 1941. SOLBRIG 2,229,314

CYLINDER RIDGE GRINDER Filed Feb. 12, 1940 2 sheets-sheet 2 byu-en or Gusiaz/ .Sblbr Patented Jan. 21, 1941 UNITED STATES CYLINDER RIDGE GRINDER Gustav Solbrig, Cedar Rapids, Iowa, assigner of forty-eight per cent to William H. Dutton,

Minneapolis, Minn.

Application February 12, 1940, Serial No. 318,500

6 Claims.

My present invention relates to an improved tool for grinding or cutting down the annular ridges at the tops of engine cylinders, and may be' hereinafter referred to as a cylinder ridge grinder.

In various types .of engines and pumps employing piston equipped cylinders, the greatest wear on cylinders is produced by the piston rings, which latter are under resilient tension to expand against the cylinder. Since the piston rings are located below the top of the piston and the piston ring travel on the cylinder terminates somewhat short of the top of the cylinder, the cylinder becomes enlarged by piston ring wear throughout the portion traversed by the rings and this leaves an annular ridge above the piston ring travelled portion of the cylinder. When the pistons are removed from the cylinders for the purpose of replacing the piston rings, it be- 20 comes desirable, and in fact in many cases necessary, to cut down this annular ridge near the top of thel cylinder to a diameter equalling that of the ring worn portion of the cylinder therebelow.

An important object of the present invention is the provision of a very simple and inexpensive, but highly eflicient tool by which the ridges left in the top of cylinders as a result of ring wear 3o therebelow can be quickly and accurately cut down to the diameter of the ring worn portion of the cylinder.

Another important object of the invention is the provisionof a tool of the kind described which is adapted to be power operated vfrom a portable hand operated unit such as a conventional motor driven drill driving unit. y

Another object of the invention is. the provision of a tool of the class described that is adaptable without adjustment to operate with equal efficiency on cylinders of different diameter. f

Another important objective of the invention is the provision in a tool of the class described employing a plurality of abrasive carrying shoes that exert pressure on the cylindrical surface being ground as a result of centrifugal action, and wherein the shoes are provided with shoulders that overlap the top of the cylinders and ,50 denitely limit downward movement of the abrasive surfaces of the shoes to a position wherein their outer ends are above the tops of the cylinders.

Another important objective of the invention is 55 the provision in a tool of the class described in- (Cl. 51--184.1) y

corporating centrifugally movable segmental grinding shoes that are faced with removablev strips of flexible abrasive such as emery cloth, of an improved simple and extremely efiicient anchoring medium for such abrasive strips.

'Ihe above, and other and highly important advantages of the invention will be made apparent from the` following, specification and claims together` with the appended drawings. In the accompanying drawings, likecharacters indicate like parts throughout the several views.

Referring to the drawings:

Fig. 1 is a View in side elevation .of one form of the tool .illustrating the same in an operative position in a cylinder that is shown in'section;

Fig. 2 is a view taken on the line 2 2 of Fig. 1, andshowing the tool of Fig. 1 in bottom plan;

Fig. 3 is a detail sectional view taken on the line 3 3 of Fig. 2; Y 20 Fig. 4 is a perspective view of one of the abrasive strips for the shoes of the forms of the tool herein illustrated;

Fig. 5 is a view corresponding to Fig. 2vbut illustrating a slight modification of the tool; and 25 Fig. 6 is a view corresponding to Figs. 2 and 5,

but illustrating still another form of the tool.

With reference first to Figs. 1 to 4 inclusive, an engine cylinder is indicated `as an entirety by l. This cylinder 1 has at its upper end a 30 smaller diameter portion forming an inwardly projecting ridge 8, which ridge is left in the cylinder las a result of piston ring wear therebelow.

The tool of Figs. l` to 3 includes a disc-like head Shaving an axially outwardly, extended shank or spindle I8. Pivo-tally mounted to the underside or face of the head!! at II area pair of shoes each indicated 'as an entirety by I2. The shoes I2 each comprise a flat flange I3 having a segmental outer edge, and a depending seg- 40 mental abrasive carrying flange I4, which latter is also segmental, and is spaced radially inwardly from the outer edge of its respective ilat upper flange I3. The at upper flanges I3 of the shoes are pivotally anchored to-the disc-like head 9 45 at II preferably by rivets Whichhold'the same snugly against'the under face of the head, but

, permit free pivotal movements under centrifugal action. The radius of the are of each segmental flange I4 of the shoes I2 preferably'should be made no greater than that of the smallest cylinder to be operated on.

Of course, the pivoted shoes I2 will-tend'to move Aoutwardly under the action of centrifugal force when the device is rotated in a cylinder,

but this pivotal action of the shoes will be held Within predetermined limits by engagement of shoe carried bolts or the like I 5 with the ends of arcuate slots I6 in the rotary head 9.

These bolts I5 will further aid in holding the shoe flanges I3 snugly against the under side of the head 9. The flanges I3 and I4 of the shoes I2 may be assumed to be integrally formed of cast iron or steel, but may, of course, otherwise -be made or formed of lother materials.

The outer face of each of the segmental shoe anges I4 is faced with a strip of flexible abrasive material such as emery cloth or sand paper; emery cloth being preferred. These facing strips of emery cloth or the like, and which are indicated by I1, are preferably the same depth as the flanges I4, but are longer than said anges and have their ends doubled around the ends of the segmental flanges "I4, and detachably clamped in place by spring clamping devices forming an important phase of the instant invention.

These clamping devices each comprise a normally straight and tightly coiled spring I8 terminating at its opposite ends in an out-turned loop |19 serving as a -nger grip. The normally straight tightly coiled springs I8 are yieldingly bent in two to conform substantially to the arcuate curvature of the inner faces of the shoe flanges I4, and are maintained in this shape normally by engagement with headed anchoring studs 20, which latter are shown as being in the nature of nut equipped bolts. The head acting nuts of the studs 20 overlap the spring anchors I8 cross sectionally, and thereby retain the same against accidental displacement. Of course, the spring anchors I8, due to their resilient nature, and the fact that they are tightly coiled when straight, tend to straighten out and thereby exert a relatively very high degree of yielding pressure against the opposite end portions of the anges I4. To clamp the doubled back ends of the abrasive strips I'l in place, the ends of the spring anchors I8 are bent back as shown by dotted lines in Fig. 2, while the free ends of the abrasive strips are'doubled into engagement with the backs of the anges I4 after which the ends of the spring anchors are released and come into tight clamping engagement with the ends of fthe strips. Retraction of the ends of the spring anchors away from the shoe anges is most readily accomplished by compressing opposite loop ends I9 thereof between the thumb and forenger of one hand.

Operation of device of Figs. 1 to 3 inclusive Preparatory to the grinding operation, the abrasive equipped shoe anges I4 are dropped into a ridged cylinder to the maximum extent permitted by engagement of the radial projecting edge portions of flanges I3 with the top of the cylinder. For the purpose of rotating the tool, the axially disposed stem or shank Ill of the head 9 will usually be clamped in the chuck 2| of a portable power drill unit or the like, not shown. At any rate, it is contemplated that the power driven rotating unit will be of the portable type, which will be held in the operators hands. When the motor of the power unit is turned on, the tool will be rotated at relatively high speed and the shoes will be thrown outwardly into grinding engagement with the ridged portion of the cylinder by centrifugal force. Usually during the grinding operation, the operator will raise the tool slightly so that the projecting edge of flanges I3 will be out of friotional engagement with the top of .the cylinder, substantially as shown in Fig. 1.

Due to the low cost of the abrasive strips and the easy replacement, a stock of such strips with diiferent degrees of abrasive quality may be kept on hand at all times, and new strips of the proper abrasive qualities `for any particular job can be applied for that particular job.

The device of Fig. 5 is like that of Figs. 1 and 2, in all respects except that, whereas the two shoes I2 of Figs. 1 and 2 are pivoted at opposite ends, the two shoes of Fig. 5 are pivoted at like ends. In this respect, it may ybe said that the arrangement of Fig. 5 has some advantage `over the device of Figs. 1 and 2 in that a better balance will be maintained on a rotation and the extent o-f centrifugal action on both shoes will `be the same. The several elements of Fig. 5 are indicated by the same characters as are assigned to corresponding elements in Figs. 1 to 3 inclusive, plus the exponent a.

T'he device of Fig. 6 differs from those of Figs. 1 to 4 inclusive only in the m-anner of mounting the shoes on the rotary head, and all parts in Fig. 6, which correspond to parts in Figs. 1 to 3 inclusive will be indicated by like parts plus the exponent b. The shoes in Fig. 6, in place of being pivotally anchored to the disc-like head of the tool, are anchored to the disc-like head 9b for limited radial movements through the medium `of nut and head equipped bolts 22 that work in laterally spaced slots 23 in the head 9, and are anchored fast in the flanges I3b of the shoes |217.

What I claim is:

1. In a cylinder ridge grinding tool, a rotary head having a substantially circular flat face, an opposed pair of shoes working against the at face of the head and anchored thereto for limited movements toward and from the axis thereof, each of said shoes comprising a radially extended at anchoring iiange lying .against the said face of the head and an axially extended segmental flange projecting from the radially extended flat flange, a primarily iiat strip of flexible abrasive material covering the segmental outer surface of each axially extended shoe flange and having its free ends turned over the ends of said segmental anges and doubled back over the end portions of the inner segmental faces thereof, and means for detachably anchoring the folded back ends of the abrasive strips to their respective flanges, the anchoring means for each shoe comprising a normally straight spring 4anchored to the shoe at its longitudinally intermediate portion in such close relation to the concave inner surface of the segmental Iiange thereof that it will be made to conform normally to the concave contour of said segmental flange and the free ends thereof will be yieldingly pressed toward the segmental ange, said spring being of such length that the free end portions thereof will overlap the folded back ends of the abrasive strip and detachably anchor the same in position.

2. The structure defined in claim 1 in which the said anchoring springs are tightly coiled wire springs.

3. The structure defined in claim 1 in which the said `anchoring springs are tightly coiled Wire springs and in which the ends of said anchoring springs `are provided with outwardly turned finger engaging loops'.

4. In a grinding tool of the kind described, a rotary head, a grinding shoe mounted on said head for movements toward and from the axis thereof, said shoe having a depending abrasive outer surface and a stop ange overlying said abrasive surface and projecting radially beyond the same, and serving as the means for limiting the movement of said tool axially into a cylinder or the like.

5. The structure dened in claim 4 in further combination with yielding means connecting said shoe to said head and exerting force to press the same outward.

6. The structure dened in claim 4 in which there is a plurality of said shoes circumferentially spaced and independently `connecfbed to said head. 5

GUSTAV SOLBRIG.

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