US2864268A - Engine reconditioning equipment - Google Patents

Description

Dec. 16, 1958 v. E. ANDERSON 4,

ENGINE RECCNDITIONING EQUIPMENT Filed July 13, 1955 2 Sheets-Sheet 1 VIII] IIIIIIII IN VEN TOR.

44 TTOANE K VV/PON E. 4N0f/PJON Dec. l6, 1958 v. E. ANDERSON 4,

ENGINE RECONDITIONING EQUIPMENT 7 Filed July 13, 1955 2 Sheets-Sheet 2 fig .5 izgfl .Z'Tj 4 2d 36 I I INVENTOR.

VHF-0N 4/VDEP50/Y United States Patent ENGINE RECONDITIONING EQUIPMENT.

Vyron E. Anderson, Cedar Rapids, Iowa,-- assignor to Cedar Rapids-EngineeringCompany, Cedar Rapids, Iowa, a corporation of Iowa Application July.13, 1955, Serial No. 521,835..

3 Claims. (Cl. 7 72) This invention relates to a reaming fixture, particularly one which is adapted to .be used to rebore valve guides in the head. casting of an overhead valve internal, combustion engine, and containssubject matter related, in part, to my. application Serial Number,488,824 filed February 1 7, 1955, now Patent No, 2,834,233, dated May 13, 1958 for a similar device.

In an overhead valve engine, the .valve guides are vertically bored in thehead casting. Since this casting is relatively inexpensive in ,relation to-the engine block, it is common practice to provide a guide surface by boring openings through the head casting and omitting any type of valve sleeve. As the engine ages and wears, the relatively soft cast iron openings become'worn and irregular, permitting undesirable movement in the valve stem itself.

It is relatively easy-to restore these valve guides by boring out a small amount of metal to secure a straight true opening. It is, however, necessary that boring of this type be donewith extreme accuracy comparable to the accuracy originally obtained by the heavy duty machinery used in manufacture. i i

It is therefore an object of myinvention to provide means whereby a reaming or boring tool may be accurately aligned in relation;to the valve seatv It is a further object of my invention to providea fixture which will permit the original alignment of the valve guide to serve to direct the reboring operation.

It is still another. object of my invention to provide a fixture of the type described which is adaptable to many types and sizes of engines and engine head castings.

It is still a further object of my invention to provide a device in which the opportunities for the misalignment or damage of the fixture, through usage, are held to a minimum.

Other and further features and objects of the invention will be more apparent to those skilled in the art upon a consideration of the accompanying drawings and following specifications, wherein is disclosed a single exemplary embodiment of the invention, with the understanding, however, that such changes may be made there in as fall within the scope of the appended claims without departing from the spirit of theinvention.

In said drawings:

Figure 1 is a view in perspective showing an automotive engine head with the reaming fixture in position for operation.

Figure 2 is an enlarged cross-sectional view taken at 22 of Figure 1 showing the reaming fixture and alignment arbor in operative position.

Figure 3 is a side view of the alignment arbor, particularly showing the taper on one end thereof.

Figure 4 is a side view of the boring bar.

Figure 5 is an end view of the cutting end of the boring bar to show the arrangement of the cutting surface.

7 Figure 6 is a top view of the bushing holder showing the transverse slots therein, and

ice

2 Figure 7 is a view of, the chuck end of the boring bar taken at 7-7 of Figure 4.

Referring now to the drawings, and particularly Figure 1; the engine head casting is indicated generally at 11.

Afiixed to the top of this casting is a relatively long rectangular bar 12 having a slot 13 throughout the length thereof on the upper surface. This bar is the main alignment portion of the fixture and is heldin position on the head casting by set screws 14, and 15. It willbe understood that several openings are provided in this bar to permit the bar to fit a variety of standard head castings.

Slidably engaged on this bar is an adjustable bushing holder 16 which, is adapted ,to receive a bushing 17 which in turn holds the alignment arbor 18 or the boring bar-36.

Power to drive this boring .bar is provided by means of a common fractional horse power electric drill or a manually operated brace, not shown. Theactual connection between the drill or brace and the boring bar being made by a rubber chuck 19 which will permit some lateral movement of .the drill or brace without actually causing any side forces to be applied to the boring bar itself.

Referring now to Figure 2 in which the structure is shown in greater detail; the main alignment bar is again shown at 12 and is bolted to the head casting 11 by .a socket head set screw 15, of which there are two or more. In connection with this bar, it is necessary that it be machined'to a high accuracy as to squareness, and have a polished and ground surface, particularly on the upper and lower faces thereof.

The bushing holder or casting 16 carries the pair of vertical bolts 20 and 21. These in turn-are threadedly connected to a T-shaped holding dog 22 .on the lower end. This holding dog is adapted to fit into the slot 13 of the alignment bar.

The bushing 17 is positioned in this casting 16 in a vertical relation and is held rigidly therein by reason of set screw 23.

The bushing itself contains two sized inner sleeves or bearings 24 and 25, these being positioned at the upper and lower ends of the bushing. In this connection, it is to be noted that these bushings will be varied in size corresponding to the desired bore to be achieved in the valve guide itself.

In Figure 2, an alignment arbor 18 is shown in position in the guide bushing 17. I will now describe in detail the purpose of this alignment bar. In operation, a mechanic would first firmly bolt the main alignment bar 12 to the head casting. He would then position the bushing holder on the upper surface of the alignment bar, permitting the dog to interfit into the slot 13. The bushing holder would then be moved into a relative position to the valve guide to be bored.

While the bushing holder is still loosely held in position, the mechanic would insert the alignment arbor throughthe bushing into the valve guide. This arbor 18 is tapered at the lower end 35, as shown in Figure 3. Since the wear in the valve guideis generally equal in all directions circumferentially, and since there will be a point along the length of the guide, generally near the center where wear is at a minimum, the arbor will take the same alignment position as was achieved at the factory in boring the guide.

Once the bushing 17 and the bushing holder 16 are pulled into position by the alignment arbor and firmly seated, the mechanic will then tighten the two bolts 20 and 21, rigidly fixing the bushing holder in relation to the alignment bar. The mechanic is now ready to remove the arbor 18 and insert the boring bar 3g and begin the actual bori g p rati n.

nature of the boring tool used is of considerable importance.

Figure 4 is a side view of the boring tool 36. It will be seen that the actual cutting edge 27 of the tool constitutes approximately one-fourth of the length of the entire tool. A single cutting edge is employed. In addition to this cutting edge, there are three grooves 28, 29 and 30 positioned radially on the boring bar 36 for approximately the same distance as the cutting edge. These grooves of course permit chip clearance for the material removed by the cutting surface. Actual practice has indicated that employing a boring bar of this type in the applicants invention prevents drifting of the of considerable variance can be made.

In order to achieve this, it is important that the mating surfaces between the alignment bar and the bushing holder be accurately machined and ground. It is further important that the bushing itself be of sufficient length to contain a considerable portion of the boring bar between the two bearings. Practice has indicated that the bushing should be approximately half the length of the boring tool exclusive of the portions contained in the chuck itself. In addition to that, the bushing holder must be of relatively substantial size. In this connection it is also to be noted that referring to Figure 1, the bolts 20 and 21 are contained in two transverse slots 31 and 32 to permit the bushing holder to be positioned outwardly at varying distances from the alignment bar itself, this again to accommodate the different automotive heads presently used.

From the foregoing description it will be apparent that I have provided a substantial and versatile reaming or boring fixture. In practice, a number of different sized bushings, boring bars and alignment arbors would be provided to permit all types of engine heads to be reworked and the gradual increases in size by thousandths when a second or third reworking might be required in the same head casting.

Although I have described a specific embodiment of my invention, it is apparent that modifications may be made by those skilled in the art. Such modifications may be made without departing from the spirit and scope of my invention as set forth in the appended claims.

I claim as my invention:

1. In engine reconditioning equipment of the type described, a rectangular alignment bar of substantial length having a longitudinal slot on the upper face thereof, a bushing holder casting positioned on said bar, a bushing extending a substantial distance above and vertically positioned in said holder and having a pair of spaced-apart bearings in the upper and lower end thereof, a pair of parallel transverse slots in said holder, said slots being bar to such an extent that, if desired, an off-center bore at a right angle to said rectangular alignment bar, means including sald transverse slot and said longitudinal slot for locking said holder in position in relation to said alignment bar, an arbor, one end thereof being tapered said arbor being positioned in said bushing holder and being of sufficient length to extend therethrough, whereby alignment of said bushing holder in reference to the work piece may be secured before said holder is locked in relation to said alignment bar.

2. In a device of the type described for use with an automotive engine head, a rectangular bar having a longitudinal slot therein, means for bolting said bar to said engine head, a bushing holder adapted to be positioned on the upper surface of said alignment bar, means for rigidly positioning said bushing holder in relation to said alignment bar, said means including a pair of parallel slots in said bushing holder adapted to be positioned at right angles to the aforementioned longitudinal slot in said rectangular bar, a bushing adapted to be carried in said bushing holder, said bushing comprising a tubular member extending a substantial distance above said holder, having bearing surfaces at the extreme outer ends thereof, an arbor, one extremity thereof being tapered, said arbor being of substantially greater length than said bushing, said tapered arbor being positioned to extend through said bushing into said engine head to cause said bushing holder and longitudinal and said transverse slots to be aligned with reference to said arbor.

3. In a device of the type described for use in boring valve guides in an automotive engine head, an alignment bar, said bar being of substantial length co-extensive with the length of said engine head and adapted to be bolted thereto, a longitudinal slot in said alignment bar on the upper face thereof, a bushing holder positioned transversely of said alignment bar, said bushing holder having a pair of parallel transverse slots positioned at right angles to said first mentioned slot and having bolts therein, the heads thereof slidable in said slots, a tubular bushing member positioned in said bushing holder and extending a substantial distance above said holder and having a pair of accurately sized bearings spaced apart on the outer ends of said bushing, a tapered arbor positioned to extend downwardly through said bushing holders, the tapered portion being positioned in an opening in said engine head, said arbor being of sufficient length to engage both of said spaced-apart bushings simultaneously, whereby movement of said arbor will secure accurate alignment of said bushing member in relation to said engine head, locking means on said aforementioned bolt members, whereby said bushing holder may be firmly locked in relation to said alignment bar once alignment of said bushing holder and the opening in said engine head are accurately secured.

References Cited in the file of this patent UNITED STATES PATENTS 7 589,067 Beard Aug. 31, 1897 710,257 De Leeuw Sept. 30, 1902 1,698,394 Davis Jan. 8, 1929 1,923,177 Tucker Aug. 22, 1933 2,435,256 Whitmore Feb. 3, 1948

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