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United States Patent im
[ii] 3,764,204  Oct. 9, 1973
 VALVE GUIDE BORING FIXTURE
 Inventor: John H. Kammeraad, Holland, Mich.
 Assignee: K-Line Industries, Inc., Holland, Mich.
 Filed: Nov. 19, 1971  Appl. No.: 200,492
 U.S. CI 408/75, 408/93, 408/97,
 Int. CI B23b 41/12
 Field of Search 408/708, 709, 75,
408/80, 81, 82, 103, 97, 1, 94, 93, 115; 90/12.5
 References Cited
UNITED STATES PATENTS
3,674,375 6/1972 Reed et al 408/115
3,157,068 11/1964 Rickert 408/75
Primary Examiner— Gil Weidenfeld
Attorney— Price, Heneveld, Huizenga & Cooper
A portable, U-shaped valve guide boring fixture to be
mounted on and supported by a cylinder head for an internal combustion engine in order to guide the reworking of the valve guides in said internal combustion engine. The fixture comprises a support post on which are mounted two guide arms normal to the axis of said post. The second arm is fixedly mounted at one end of the post and includes spring seat engaging means. The first guide arm is slideably mounted and spring biased toward the second guide arm intermediate the ends of said post and includes valve seat engaging means comprising a pivotally mounted ball swivel guide having an axial bore to guide said reworking operation. The fixture is clamped over the spring seat and valve seat on the cylinder head, and a tapered alignment pin is inserted through said engaging means and said valve guide to bring the fixture into axial alignment with the valve guide by means of the pivotal action of the ball swivel guide. The fixture is then tightened into said aligned position and may be used to guide the boring and reaming operations, accomplished by means of hand tools, resulting in a reworked valve guide in accurate axial alignment with said valve seat.
17 Claims, 8 Drawing Figures
VALVE GUIDE BORING FIXTURE
This invention relates to tools for the reworking of valve guides in combustion heads for internal combustion engines, and more particularly, to portable fixtures for guiding the reworking operations accomplished by means of hand tools.
BACKGROUND OF THE INVENTION
In the past, valve guide reworking operations have been accomplished by using either large, immovable machines requiring the precise mounting of cylinder heads on the machine at an angle in order to produce the proper reworking alignment, or small tools which could be mounted on the cylinder head. The large machines typically include a heavy base on which is mounted a drill press or other boring tool, thus necessitating the mounting of the cylinder head in a precise position to provide the proper alignment with the drill press. The cylinder head mounting on these machines is a tedious operation and one which, of necessity, must be repeated for each valve guide since the intake and exhaust valve guides in modern engines are often formed at opposing angles. See, e.g., U. S. Pat. No. 3,333,487.
The smaller tools, which could be mounted on the cylinder head when the cylinder head was in any position, were based on alignment principles which often produced inaccurate results. One such smaller tool utilized the principle of aligning the guide tool with the valve guide by means of the valve spring seat on the side of the cylinder head opposite the valve seat. However, since spring seats are cast roughly in the cylinder head casting process, and are normally not concentric with the valve guide axis, the alignment, which keyed on the location of the spring seats, caused the reworking operation based thereon to be extremely inaccurate. Other small tools for the reworking operations were devised but necessitated the mounting of the guide fixture on the cylinder head by means of one of the many holes provided in the cylinder head to mount the head on the engine block. Thus, the accuracy of these tools depended on the ability of the operator to firmly attach the guide tool to the cylinder head by means of these holes. If the mounting hole was in any way deformed or injured, the capability of aligning the tool properly was thereby reduced. See, e.g., U. S. Pat. No. 3,157,068.
The Applicants have conceived of a novel valve guide boring fixture which retains the portability attributes of previously available fixtures and, yet, eliminates the inaccuracies which have been encountered with this type of valve guide boring fixture. One of the important features of Applicants' novel invention is the capability of mounting Applicants' valve guide boring fixture rapidly on the cylinder head by means of a unique clamping action which secures the fixture by means of the valve seat and the spring seat, yet retains the alignment accuracy to produce an exact reworking of the valve guide. It is, therefore, an object of this invention to provide a small, compact, portable valve guide boring fixture which clamps on the cylinder head by means of the valve seat and spring seat, and yet may be aligned by means of a pivotally movable valve seat engaging means and locked in the aligned position to guide the subsequent boring operation. It is another object and feature of this invention to provide a valve
guide boring fixture adapted to be aligned with the valve guide by means of the least worn portion of the valve seat and the least worn portion of the valve guide. It is yet another object of this invention to provide a 5 valve guide boring fixture having the capability of accommodating all sizes of valve guides in all sizes of cylinder heads for internal combustion engines.
SUMMARY OF THE INVENTION
10 These and other objects and features of the present invention are accomplished by providing a portable tool for the reworking of valve guides for internal combustion engines, adapted to be mounted on and supported from a cylinder head from said engine during
15 said reworking, comprising a support post, and first and second guide arms mounted on the support post, said arms extending from the post so as to form in combination with the post a generally U-shaped structure. The first guide arm includes means mounted at a distance
^° spaced from the post for engaging a valve seat on the cylinder head, the valve seat engaging means including an axial bore adapted to guide various valve guide reworking tools. The valve seat engaging means is also
25 pivotally mounted and movable with respect to the first guide arm in order to permit the axial bore to be moved into axial alignment with the valve guide to be reworked. In addition, the valve seat engaging means also include means for locking the valve seat engaging
3q means in position with respect to the cylinder head and the valve guide once the bore has been axially aligned with the valve guide.
The second guide arm also includes means mounted at a distance spaced from the support posts which
35 means are provided to engage the spring seat corresponding to the valve seat engaged by the valve seat engaging means on the first guide arm. Also included in the portable tool are means for altering the distance between the valve seat and spring seat engaging means on
40 the first and second guide arms, respectively, in order to allow the portable tool to be clamped into engagement on the cylinder head prior to its alignment with the valve guide and the locking of the tool in the aligned position.
45 This invention will be readily understood by those skilled in the art from a study of the following description taken in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
50 FIG. 1 is a perspective view of the valve guide boring fixture locked in place in alignment with a valve guide on the cylinder head;
FIG. 2 is a partially exploded, perspective view of the valve guide boring fixture with the boring guide, valve 55 seat adaptor, spring seat adaptor, and wrench shown in exploded positions;
FIG. 3 is a fragmentary, cross-sectional view of the valve guide boring fixture clamped in place on the cylinder head during the alignment step but prior to the tightening and locking step of the method;
FIG. 4 is a fragmentary, cross-sectional view of the valve guide boring fixture guiding the reaming operation;
65 FIG. 5 is an enlarged, fragmentary, cross-sectional view of the valve seat adaptor as supported by the valve seat, with the valve seat being shown in both its worn and original conditions;