Valve grinding apparatus
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to apparatus for metal grinding and more particularly to apparatus for grinding valves within the valve seats of internal combustion engine. 
     2. Background Art 
     Proper operation of internal combustion engines requires seating or sealing of the inlet and outlet valves for the appropriate time duration in the cycle of operation. Failure to properly seal may not only result in inefficient engine operation, but may also result in damage to the engine itself. 
     Proper maintenance of an internal combustion engine requires periodic reseating of the engine valves. This is normally accomplished by rotating the valve while in contact the valve seat in the presence of an abrasive valve grinding compound. Numerous apparatus have been developed to perform such valve grinding operations. The prior apparatus presently known to Applicant is considered below. 
     U.S. Pat. No. 2,576,333 to Earll discloses a valve and seat grinding device for an internal combustion engine. A rotatable pulley rotates the valve and operates the two compression springs 26 and 27 which actually move the valve either into grinding engagement with the seat or space the valve from the seat to permit visual inspection. The direction of valve rotation controls the direction of axially movement of the valve and therefore the direction of grinding is not reversible. The non-rotating spring housing formed by the cylinder 16 and cap 17 is held against the manifold flange during operation to properly align the valve and seat. 
     Jensen U.S. Pat. No. 2,908,120 discloses a grinding apparatus for flow control valves in which the spring force may be adjusted. The grinding wheel is rotated either by hand or a drive motor. A mounting bracket is used to secure the apparatus to the valve house. 
     German Pat. No. 717,470 also discloses a manually operated valve grinding device having a chuck for securing with the valve stem. 
     U.S. Pat. Nos. 1,502,005 to Bishir and 1,951,796 to Kulp et al. disclose valve grinding apparatus. 
     The Bishir apparatus is designed for use on overhead valves and requires removal of the valve and seat case from the engine. The Kulp apparatus provides a guide bearing for centering the valve during grinding. 
     SUMMARY OF THE INVENTION 
     The present invention relates to an apparatus for grinding the valve and valve seats for internal combustion engines. The apparatus is adapted for attachment to a chuck of a conventional handheld electric or pneumatic drill which rotates the engine valve member connected to apparatus. A tubular housing operably positions the apparatus adjacent the valve and seat to be ground. Rotatably disposed within the tubular housing is the valve securing member. An adjustable spring biases the valve securing member relative to the fixed housing to provide the suitable valve grinding force. A portion of the valve securing member is formed by a bias spring to compensate for axial misalignment of the electric drill and the tubular housing during operation. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side view, partially in section of the valve and seat of an internal combustion engine with the valve grinding apparatus of the present invention operably positioned therewith; 
     FIG. 2 is a view taken along line 2--2 of FIG. 1; and 
     FIG. 3 is a view of an alternate embodiment for securing the apparatus with the valve. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The valve seat grinding apparatus of the present invention, generally designated A in FIG. 1, is illustrated positioned for operation with an internal combustion engine E. The reciprocating engine valve V is illustrated in the closed or seated position for sealing with the fixed annular seat S formed by the block or engine E. Movement of the valve V from the seat S enables communication between the cylinder (not illustrated) and either the inlet or outlet manifold M. The valve V includes an enlarged circular head H which seals with the seat S and an rod-like stem Q which extends through a reciprocating movement guide opening G formed in the engine E. An annular recess R is formed in the valve stems Q exteriorly of the engine E. 
     The valve grinding apparatus A of present invention includes a tubular outer housing 10 having a first end 10a disposed adjacent the engine E and a second end 10b. The first end 10a provides an annular shoulder for engaging the internal combustion engine to operably position and guide the operation of the apparatus A relative to the valve B and Seat S during the valve grinding operation. 
     The apparatus A further includes an elongated central member 12 which is concentrically disposed within the tubular housing 10 and extends therefrom beyond the second end 10b of the housing 10. The elongated central member 12 is provided with a first end operably disposed within the tubular housing 10 and a second end 12b disposed outwardly of the tubular housing 10. The portion adjacent the second end 12b of the elongated central member 12 is a rod like portion 12c adapted to be secured within a chuck (not illustrated) of a conventional hand held electric or pneumatic powered drill. Such hand held power drills are well known and commercially available from local hardware stores. 
     Located adjacent the chuck securing portion 12c is a flex stiff spring portion 12d which is secured, preferably by welding, to the chuck gripping portion 12c. The spring 12d compensates for axial misalignment between the hand held drill and the valve stem Q during valve grinding operations. Adjacent the flex spring portion 12d and secured thereto by welding is a helically threaded portion 12e. For purposes of assembly, the threaded portion 12e extends to the first end 12a of the central member 12. Mounted on the thread portion 12e is a finger adjustable spring retainer 14. A coil spring 16 is concentrically mounted about the central member 12 between the adjustable spring retainer 14 and the outer housing 10. In the illustrated embodiment, a retainer washer 18 is utilized for transmitting the urging of the spring 16 to the outer housing 10 with it being understood that the spring size may be selected to fit tightly around the central member 12 and thereby avoid the need for the spring flange 18. The force of the urging of the spring 16 between the adjustable flange 14 and the flange 18 is of course controlled by the position of the adjustable retainer 14. 
     The threaded portion 12e of the central member 12 is preferably a tubular member adapted to concentrically fit about the protruding part of the valve stem Q. 
     As best illustrated in FIG. 1, the outer housing 10 is provided with an elongated slot 10c adjacent the first end 10a. The slot provides clearance to enable longitudinal movement between the inner or central member 12 in the housing 10. Disposed within the slot 10c is conventional nut 20 which is secured to the inner member 12. The nut 20 has conventional opening 20a for receiving a valve stem securing threaded bolt 22. 
     As best illustrated in FIG. 2, the nut 20 is secured to the central member 12 by suitable means such as brazing or welding at 20b. Rotational movement of the threaded bolt 22 will move the valve engaging latch 24 from the recess R of the valve stem Q when desired. Likewise, tightening of the threaded member 22 will secure the valve stem Q with the apparatus A. To maintain the valve stem in concentric relationship with the apparatus A a centering guide 26 may be employed. 
     An alternate form of the valve stem latching mechanism is illustrated in FIG. 3. In this embodiment, reference characters have been increased by a factor of 100 to show identical parts. The housing 110 is provided with a pair of slots 110c and 110d which provide for relative longitudinal movement between the housing 110 and the inner member 112. Disposed within the elongated opening 110c is an outwardly extending mounting lug 112a which is secured to the outer surface of the inner member 112. A pivot pen 128 secures the pivot mounting lug 112 to a lever 130. The lever 130 has an inwarding projected valve locking portion 130a which is received within the radial annular recess R of the valve stem Q for securing the apparatus A with the valve V. 
     To secure the lever arm in the lock position a threaded bolt member 132 is secured to the inner member 112 and extends outward through opening 110d. A suitable wing nut 134 is used to retain the lever arm 130 in a locked position during grinding operations. 
     Use and Operation 
     In the use and operation of the present invention, the apparatus A is assembled in the manner illustrated. A small handheld motorized drill is attached by a chuck to the portion 120 of the rotatable inner member 12 for effecting its rotation. A valve grinding compound is applied to the valve V and the valve seat S with the valve located in the seat S of the engine E. 
     The valve stem Q is then locked to the apparatus A using the securing mechanism for securing the valve stem Q with the inner member 12 for rotation of the valve stem Q. With the valve stem Q attached, the spring retainer 14 is rotated on the threaded port to adjust the spring force for urging the inner member 12 towards the drill and pulling the valve head H into engagement with the seat S. With proper spring 16 tension urging of the valve V on the seat S, the drill motor is operated to rotate the valve for grinding the valve and seat. 
     After rotating for approximately 45 seconds the rotation should be stopped and the valve seat inspected for proper seating. Preferably, the direction of rotation is reversed or alternated for the next 45 second cycle of operation which is sequentially repeated until the valve V is properly seated. 
     The apparatus A is used to polish or grind the annular seat S during engine repair or maintenance operations without the necessity of removing the engine E from the vehicle engine compartment. The apparatus A is relatively inexpensive to make and is easy to use. The disclosed valve and seat grinding apparatus is portable, compact and may be employed with the valves and seats of almost any type of internal combustion. The apparatus A also quickens the grinding operation by compensating for angular misalignment and in providing a constant urging of the valve V on the seat S. 
     The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the size, shape and materials, as well as in the details of the illustrated construction may be made without departing from the spirit of the invention.