US2698615A - Valve safety holder - Google Patents

Description

Jan. 4, 1955 J. DITTMANN 2,698,615

VALVE SAFETY HOLDER Filed April 7, 1952 IN V EN TOR. e/O fl/f/mam? United States Patent Office Patented .Fan. 4, less VALVE SAFETYHOLDER Joe Dittmann, Frontenac, Kans. Application April 7, 1952,'Serial No. 281,015

2 Claims. (Cl. 123-188) This invention relates to attachments for mushroom type valves, for example, such as those used as exhaust and/or intake valves in the conventional internal combustion engine, and refers more particularly to an attachment for valves of this type which is designed to prevent the valve from slipping into the cylinder should a structural failure in the conventional valve holding mechanism occur.

In most conventional internal combustion engines, the intake and exhaust valves each consist of a generally circular head disposed within the cylinder and seating outwardly against the margin of the valve port, and a relatively elongate stem which extends centrally from the head outwardly through the valve port and exhaust or intake duct to a point external of the cylinder head. Each stem is slidably received in a valve guide section so that the valve head may be reciprocated between open and closed position, and that end of the stem projecting outside the cylinder head is connected to a spring assembly which continually urges the stem outwardly to maintain the valve head seated. Heretofore, this connection with the spring assembly has served as the sole means holding the valve and preventing it from falling or being sucked into the cylinder. Frequently, it has proved incapable of sustaining the burden which the engine designer has assigned to it, with the result that considerable destruction to the cylinder, piston and remaining parts of the engine takes place, to say nothing of the loss of time involved in making suitable repairs.

It is a primary object of this invention to provide a simple though extremely valuable device which supplements the holding mechanism briefly described above and serves to limit the entry of the valve into the cylinder past a predetermined point should there be a structural failure in the holding mechanism.

Another object of the invention is to provide a'device of this nature which is adapted for use in existing engines, which is easily installed and removed, and which is designed to accomplish its functions with minimum interference in the eflicient flow of gases through the intake or exhaust manifolds.

A further object is to provide a device which is simple and economical to manufacture, and can therefore be obtained at a low cost to the public.

Other and further objects, together with the features of novelty. appurtenant-thereto; will appear during the course of the following description.

in the accompanying drawings which form a part of the specification and are to be read in conjunction therewith, and in which like reference numerals are used to indicate like parts in the various views:

Fig. 1 is a cross-sectional view taken through a portion of a typical engine in which is employed one embodiment of my invention;

Fig. 2 is an enlarged perspective view of the embodiment of my invention shown in Fig. 1, with the parts in exploded relation;

Fig. 3 is a perspective view of a modification of my invention;

Fig. 4 is a view showing another modified form of my invention and the means for attaching it to a valve stem, the device being shown in longitudinal section;

Fig. 5 is a perspective view of the lower portion of the valve shown in Fig. 4, showing in detail the pins and spring keeps for attaching the device to the valve stem; and

Fig. '6 is a perspective view of the modification of the device shown in Fig. 4.

Referring to the drawings, 1 have shown in Fig. 1 a portion of a typical internal combustion engine in which my invention finds primary utility. Reference numeral 10 indicates generally the engine block, the cylinder wall being shown at 12 and the upper portion of the piston at 14. A removable cylinder head 16 is mounted on the top of the engine block; the interior of the cylinder head is provided with an exhaust or intake duct 18 which communicates at one end with the interior of the cylinder through a port 20 and at the other end with a manifold 22. As is conventional in mostengines, both the engine block and cylinder head are provided with water jackets 24 through which coolants may be circulated during operation.

Positioned within the cylinder and seating upwardly against the beveled lower margin of the port 26 is the head 26a of a conventional mushroom type valve having an upwardly extending elongate stem 26b which extends above the top of the cylinder head 16. The stem 26a is slidably received in a valve guide 28 mounted within the upper portion of the cylinder head as shown, which serves to maintain the valve in axial alignment with the port 20 during reciprocation between its open and closed positions. That portion of the valve stem 26b extending above the top of the cylinder head 16 is encircled by a coiled spring 30 which bottoms against the upper surface 16a of the cylinder head 16 and exerts a continual upward thrust on the valve 'stem 26b to maintain the valve head 26a in its normally seated position.

The upward thrust of spring 30 is transferred to the valve stem 26b by means of a cup-shaped retaining collar 32 encircling the upper end of the valve stem and receiving in its tapered cup section a pair of diametrically opposed similarly tapered valve keeps 34. Each of the keeps is provided on its inner surface with a pair of circumferential ridges which engage with annular grooves 260 formed in the upper end of the valve stem. The tapered construction of the retainer cup and keeps insures that the latter will be continually urged radially inward against the valve stem 26b to maintain the ridges within the grooves 26c.

The depression of the valve head 26:: against the action of spring 30 to open the port 20 is' accomplished by means of a rocker arm 36 pivotally connected at 38 with a rigid support 40 mounted on top of the cylinder head 16. One end of the rocker arm overlies and engages the upper end of the valve stem 26b, and the other end is fitted wtih a bolt 41 having a ball-like head 41a which seats in a socket 42a formed in the upper end of a reciprocating push rod 42. A cam shaft (not shown) cooperates with the lower end of the push rod 42 in the conventional manner to rock the rocker arm 1% to the position shown in the dotted lines and 'thus depress the valve." The entire valve actuating mechanism is covered by a protective cover 44 in the usual manner.

The above description has been made in some detail to create sufiicient background for explaining the features and advantages of the present invention. It will be understood, however, that the principle of the invention, as hereinafter set forth and described, is applicable to any similarly arranged valve system,'fo'r example such as might be used in piston-type air compressors, or other machinery having a like construction. However, it is in internal combustion engines'that I have found it to be of primary utility.

As earlier noted, in a typical engine such as that illustrated in Fig. l, the valve is retained in its operative position by means of the'spring 30, retainer cup 32, and valve keeps 34, the latter having ridges which engage with the annular grooves 26c at the upper endof the valve stem 26b. Therefore, should the ridges or grooves become worn to the point that they fail to engage with one another, or should there be a structural failure in the retaining cup 32, the valve would be free to slip longitudinally downwardly through the valve guide 28 into the cylinder when the piston 14 is near the bottom of its stroke. Once the upper end of the valve stem 26b passes below the lower end of the valve guide 28, the valve stem is free to depart from axial alignment with the valve guide with the result that on the upstroke of the piston, it will be driven against the walls of the duct 18. In most cases, under these circumstances, not only is there severe damage to the walls of duct 18, but also the valve stem 26b breaks under the strain and the valve head 26c together with a fragment of the stem, under the repeated impacts of the rapidly reciprocating piston 14, creates havoc within the cylinder proper.

The above difficulties are overcome by my invention in that an auxiliary holder is attached to the valve stem 26b above the port 29 to serve as a safety stop for limiting the axial movement of the valve into the cylinder should the holding mechanism previously described suffer a structural failure. In one preferred embodiment as shown in Figs. 1 and 2, the holder comprises a sleeve element 46 slidably fitted on the valve stem 26b and provided with a lateral set screw 48 adapted to be adjusted radially with respect to the sleeve. An annular groove 26d is machined into the periphery of the valve stem 26b,

and the inner end of set screw 48 is provided with a nipple or point 48a adapted to be received in groove 26a! for fixing the holder in position on the stem. A lock nut 49 is also provided on the set screw for preventing the loosening of the set screw under the influence of engine vibrations. The stop means, preferably made integral with sleeve 46, consists of a ring 50 having a diameter slightly greater than the' diameter of port 20 and connected to the lower end of sleeve 46 by a plurality of spider-like legs 52 extending outwardly around the periphery of the latter. interference with the gas flow through duct 18, the sleeve 46 is located as far up on the valve stem 26b as is possible Without interfering with the normal operation of the valve. Moreover, the legs 52 are inclined downwardly to position the ring 50 only far enough above the port 20 to allow for the free depression of the valve head 26a to its open position, as shown by the dotted lines in Fig. 1. Thus, should the normal retaining means fail, the valve will drop only a short distance until the ring 50 strikes the upper margin of the port 20 and prevents further movement of the valve into the cylinder. It will be understood that while a solid fiange or skirt-like element could be utilized in place of ring 50 and legs 52, the latter construction is preferred for the reason that it ofiers considerably less interference to the flow of gases through duct 18 and will therefore have little or no effect on the efficiency of the engine.

In Fig. 3 is shown a modification of the holder of Figs. 1 and 2, which comprises a sleeve 54 identical in construction with that in the previously described embodiment and adapted to be secured to the valve stem in the same manner. In this modification, however, the ring has been eliminated, the legs or prongs 56 projecting outwardly and downwardly from the lower portion of the sleeve serving as the stop means.

A further'modification of the invention is shown in Figs. 4, and 6. Here the safety holder comprises a sleeve 58 slidably mounted on the valve stem 60 and provided with diametrically opposed bracket members 62 which extended longitudinally down the sides of the stem toward the valve head. Each of the brackets 62 is provided near its lower end with an aperture 62a (see Fig. 6) which is adapted to be engaged with a dowel or pin 64 projecting from and fixedly secured to the valve stem. The outer portions of dowels 64 are grooved to receive hairpin keepers 66 which serve to hold the brackets 62 in place. As is also true in the embodiment shown in Figs. 1 and 2, a ring 68 is carried by the sleeve 58, being secured thereto by downwardly inclined legs 70. It will be understood that the location of the pins 64 and length of the brackets 62 relative to the over-all construction of the valve and engine is such as to allow the valve to reciprocate freely during the normal course of operation.

It will be noted that in all the modifications described,

For the purpose of preventing undue provision is made for detachably securing the holder to the valve stem, by means of a sleeve connection. The particular advantage in thisarrangement lies in the ease of assembly afforded. Normally, the assembly of the valves with the cylinder head takes place prior to the mounting of the latter on the engine block. The valve is inserted stem first through the bottom of the port, directed into the valve guide and pushed into its seated position after which the connection with the spring assembly is made. To mount the safety holder on the stem, the holder is first placed within the duct 18 in substantial alignment with the port 20, and the valve stem inserted therethrough prior to directing it into the valve guide 28. Once the valve is in its final position, the sleeve is secured to the stem; in the case of the embodiment shown in Figs. 1, 2 and 3, this is accomplished by tightening of the set screw 46 into engagement with the groove 26d, and in the embodiment of Figs. 4, 5 and 6 by flexing the brackets outwardly and slipping the apertures 62a into engagement with pins 64.

From the foregoing it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth together with other advantages which are obvious and which are inherent to the structure.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, I claim:

1. A safety holder for valves of the type having a valve head adapted to close a valve port and a stem of smaller diameter extending from said valve head outwardly through said valve port, comprising a member encircling said stem and normally slidable thereon, means i or detachably securing said member to said stem on the opposite side of said port from said valve head, leg members projecting outwardly from said member and away from said stem, the ends of said legs being spaced outwardly from said stem a distance greater than the-radius of said valve port, and a ring member of greater diameter than said port secured to the outer ends of said legs in coaxial relation with said stem.

2. A safety holder for valves of the type having a valve head adapted to close a valve port and a stem of smaller diameter extending from said valve head outwardly through said valve port, comprising a member encircling said stem and normally slidable thereon, means for detachably securing said member to said stem on the opposite side of said port from said valve head including a lateral set screw threadedly connected with said member, the inner end of the screw being received in an annular groove formed in the valve stem, and leg members projecting outwardly from said member and away from said stem, the ends of said legs being spaced outwardly from said stern a distance greater than the radius of said valve port.

References Cited in the file of this patent UNITED STATES PATENTS 187,022 Loughridge Feb. 6, 1877 487,673 Ienks Dec. 6, 1892 507,901 Grist Oct. 31, 1893 592,434 Niebling Oct. 26, 1897 860,608 Schwehm July 16, 1907 1,577,242 Anderson Mar. 16, 1926

Images