US2797676A

US2797676A - Valve guide assembly

Info

Publication number: US2797676A
Application number: US419472A
Authority: US
Inventors: Guy F Van Skike
Original assignee: TRANS WORLD AIRLINES Inc
Current assignee: TRANS WORLD AIRLINES Inc
Priority date: 1954-03-29
Filing date: 1954-03-29
Publication date: 1957-07-02
Anticipated expiration: 1974-07-02

Description

y 1957 GUY F. VAN SKIKE 2,797,676

' VALVE GUIDE ASSEMBLY Filed March 29, 1954 INVENTOR. 62y V077 5/066 United States Patent Ofiice 2,797,676 Patented July 2, 1957 VALVE GUIDE ASSEMBLY Guy F. Van Skike, North Kansas City, Mo., assignor to Trans World Airlines, Inc., Kansas City, Mo., a corporation of Delaware Application March 29, 1954, Serial No. 419,472

1 Claim. (Cl. 123188) This invention relates to improvements in valve construction and more particularly to an assembly for guiding the valve in its reciprocable movement to and from a position engaging a seat formed in the valve body.

It is the most important object of the present invention to provide a guide assembly for valves which includes parts that may be readily and quickly removed for replacement when such becomes necessary because of wear, all Without requiring re-boring or other machine tool operations as has heretofore been necessary particularly in the case of internal combustion engines.

Another important object of the present invention is the provision of a valve guide assembly having the aforesaid advantageous features and including additionally, a proper type of fit between interrelated parts such as to diminish wear, increase heat dissipation, and provide better seating of the valve itself through long periods of use and with decreased pitting, scarring and similar damage to the valve and its seat.

A further important object of the present invention is the provision of a valve guide assembly which may be initially installed as a repair unit and subsequently serviced simply by changing a guide sleeve for the valve stem, which sleeve may be removed and a new sleeve inserted without force as is sometimes required in similar parts in other structures.

Another important object of the instant invention is the provision of a valve guide assembly including a rigid bushing within which is movably mounted a sleeve that is spring-loaded toward one end of its path of travel and within which the valve stem is free to reciprocate and rotate, all for the purposes aforementioned.

Additional objects include important details of construction, all of which will be made clear as the following specification progresses, reference being had to the accompanying drawing, wherein:

Figure l is a cross-sectional view through a valve supporting body illustrating the valve guide assembly forming the subject matter of the present invention; and

Fig. 2 is a fragmentary, detailed, cross-sectional view taken on line II--II of Fig. l.

The particular nature and purpose of the valve with which the guide assembly forming the subject matter of the instant invention is adapted to be used, is of no consequence to the principles hereinafter set forth, and for purposes of illustration only, there is shown a body for valve 12 taking the form of an internal combustion block.

Valve 12 is reciprocably carried by the body 10 for controlling the flow of fluid through a passageway 14 in the body 10 and accordingly, body 10 has a seat 16 adapted to complementally receive head 18 of valve 12 when the latter is yieldably held in the closed position shown in Fig. l by double-coil spring 20. When valve 12 is used in connection with an internal combustion engine, it is normally actuated or moved to an open position relative to the valve seat 16 against the action of spring 20 by a rocker arm 22 shown fragmentarily in Fig. 1, as is well known.

Rocker arm 22 bears against that end of stem 24 opposite to the head 18, and spring 20 coiled about the stem 24 is held in place by a releasable retainer ring 26 on the stem 24. Stem 24 extends upwardly from the head 18 through a bore 28 in the body 10, and there normally is provided a sleeve (not shown) within the bore 28 that slidably receives the stem 24. Such sleeves are held in place in various ways such as by press-fit within the bore 28 and/ or by use of releasable retainers. Each time repairs are to be made, it is necessary to forcibly remove the sleeve from within the bore 28 and before a replacement sleeve is inserted, the block 10 must be re-bored, necessitating a great amount of work, time and expense.

In accordance with the principles of the present invention, after removal of the aforementioned sleeve from within bore 28, a bushing 30 is inserted into the bore 28 and positioned as illustrated in Fig. l. The outside diameter of the bushing 30 is substantially the same as diameter of bore 28 to the end that bushing 30 must be forced into place providing a pinch fit.

As a still further means for positively retaining the bushing 30 in place, one end thereof is flared outwardly into a flange 32 which cooperates with a flange 34 on the opposite end of the bushing 30 to positively hold the bushing 30 against all movement with respect to the body 10.

Thereupon, a sleeve 36 is inserted into the bushing 30 and held in place by the spring 20 through the medium of a ring or washer 38 directly underlying the spring 20. Sleeve 36 is provided with a continuous outturned flange 40 that is held against the block 10 by the washer 38 which is also yieldably held against the block 10 by the spring 20. The inside diameter of the sleeve 36 is substantially the same as the diameter of the stem 24 for free reciprocable and rotative movement of the stem 24 with respect to the sleeve 36. Additionally, the outside diameter of the sleeve 36 is less than the inside diameter of bushing 30, to the end that the sleeve 36 is free to reciprocate and rotate in the bushing 30 as limited only by the stop means or flange 40 in one direction and yieldably by the spring 20 in the opposite direction.

Notwithstanding the fact that normally, spring 20 not only maintains the head 18 yieldably biased against the seat 16, but holds the flange 40 of sleeve 36 biased tightly against the block 10, it can be appreciated that during reciprocation of the stem 24 by the action of rocker arm 22, there will be a tendency for sleeve 36 to reciprocate relative to the bushing 30 because of the frictional engagement of the stem 24 with the sleeve 36 internally thereof.

Additionally, both sleeve 36 and stem 24 are free to rotate with respect to body 10 and bushing 30 and such rotation will naturally occur as the valve 12 reciprocates rapidly during normal use.

It is well known that permitting a valve such as at 12 to rotate during its reciprocation, is advantageous because of reduction in pitting and other damage to the head 18 and its seat 16. In other Words, the head 18 does not always strike the seat 16 in the same place and, therefore, wear on these parts is distributed evenly throughout the periphery of the head 18 and the seat 16.

In accordance with the principles of the present invention, this freedom of rotation of the valve 12 is enhanced because of the fact that the sleeve 36 may also rotate relative to the bushing 30 with, or with respect to the valve stem 24.

Accordingly, by virtue of the construction forming the subject matter of this invention, all parts of the valve structure become long-lasting since not only do the head 18 and the seat 16 last appreciably longer, but less wear takes place between the stem 24 and the sleeve 36. In

any event, it becomes necessary for repairs to be made from time to time and through use of the valve guide structure shown in the drawing and above described, it is a simple matter to provide the necessary replacement in sleeve 36. The operator need merely remove the retainer 2e, whereupon spring 20 and valve 12-, as well as the sleeve 36, may be removed without use of any tools. After dressing the stem 24, a new sleeve 36 of lesser inside di'arn'eter may be inserted in the bushing 30 and reassembly 6f the valve unit can immediately take place with little time consumed.

To this end, therefore, all of the supply sleeves 36 will have the same outside diameter and vary internally only to the extent that wear takes place on the valve stem 24 necessitating slight machining during the repair operations.

It is 6f still further importance to note that extensive tests have proved that the valve guide assembly of the instant invention develops appreciably less heat or is capable of dissipating such heat of friction more efiicieritly than has heretofore been made possible through use of guide structures of conventional character.

The principles 'of the instant invention are particularly adapted for use in aircraft engines wherein it is extremely important that all of the valves be properly and accurately guided and wherein it is important that repairs be made quickly and inexpensively.

As above indicated however, the valve guide assembly is not limited in its use to aircraft engines and, therefore, such uses and applications as fairly come within the spirit of the invention are contemplated hereby and it is desired to be limited only by the appended claim.

Having thus described the invention what is claimed as new and desired to be secured by Letters Patent is:

In an assembly of the kind described, a block having a passageway therein, a port for placing the passageway in communication with the exterior of the block, a valve seat defining the outer extremity of the port, and a straight, elongated, cylindrical bore extending from a face of the passageway opposite the port to a surface of the block remote from the port and the passageway, the axis of the bore being aligned with the port; an elongated, cylindrical bushing of uniform inner diameter tightly fitted in the bore and provided with an outturned, annular flange at one end thereof engaging said face; an elongated, cylindrical sleeve of lesser outer diameter than the inner diameter of the bushing loosely fitted in the bushing for reciprocation and rotation relative to the latter, said sleeve being provided with an outturned annular flange at the end thereof opposite said one end of the bushing, said flange of the sleeve being adapted to engage said surface when the sleeve is fully reciprocated in one direction, said sleeve extending through said bushing when the sleeve is fully reciprocated in said one direction; a valve having a head engageable with said seat and an elongated stem extending from the head through the port, the passageway and the bore, said stem being received within the sleeve for reciprocatory and rotative movement therebetween; a spring retainer element on the stem adjacent the end thereof opposite the head; and compression spring means between the element and the flange of the sleeve and operably biasing same in opposite directions to yieldably urge the head toward the seat and the flange of the sleeve toward the surface.

References Cited in the file of this patent UNITED STATES PATENTS 1,746,927 Burgmann Feb. 11, 1930 2,046,255 Fisher June 30, 1946 FOREIGN PATENTS 202,028 Great Britain Aug. 10, 1923 682,448 Great Britain Nov. 12, 1952