US2742689A

US2742689A - Valve lock replacer

Info

Publication number: US2742689A
Application number: US271735A
Authority: US
Inventors: Evenor A Rocha
Original assignee: Individual
Current assignee: Individual
Priority date: 1952-02-15
Filing date: 1952-02-15
Publication date: 1956-04-24
Anticipated expiration: 1973-04-24

Description

April 24, 1956 E. A. ROCHA 2,742,689

VALVE LOCK REPLACER Filed Feb. 15, 1952 2 Sheets-Sheet l F/G. i.

INVENTOR. EVENOE 4. 200194,

April 24, 1956 E. A, ROCHA VALVE LOCK REPLACER 2 Sheets-Sheet 2 Filed Feb. 15. 1952 R w M V v ma 0 Q. 2 M070, z m N w E a, M

Q M w 5 a ATTOENEY'S.

2,742,689 VALVE LOCK REPLACER Evenor A. Rocha, Eureka, Calif.

Application February 15, 1952, Serial No. 271,735

2 Claims. 01. 29-249 gines, said replacer being simple in construction, involving only a few parts, being easy to manipulate, and greatly facilitating the replacement of the locking keys on the valve stems of internal combustion engines of the poppet valve type.

A further object of the invention is to provide an improved implement for replacing the locking keys on the valve stems of poppet valves in internal combustion engines, the improved tool beinginexpensive to manufacture, saving a substantial amount of time in the process of replacing the locking keys on the poppet valves of internal combustion engines, being easy to manipulate, and

greatly reducing the hazards of injuries to the fingers of the mechanics reassembling the valves.

Further objects and advantages of the invention will, become apparent from the following description and claims, and from the accompanying drawings, wherein:

Figure 1 is a top plan view of an improved valvereplacing tool constructed in accordance with the present invention;

Figure 2 is a side elevational view of the valve-replacing tool of Figure 1;

Figure 3 is a bottom plan view of the valve-replacing tool of Figures 1 and 2;

Figure 4 is a vertical, cross-sectional view of the tool of Figures 1 to 3;

Figure 5 is a perspective view showing a typical set of valve-locking keys which may be replaced by use of the tool of the present invention;

Figure 6 is a bottom plan view similar to Figure 3, but showing the set of locking keys of Figure 5 installed in the tool preparatory to replacing the keys in a poppet valve assembly of an internal combustion engine;

Figure 7 is a vertical, cross-sectional view showing the upper portion of a poppet valve in which the keys of Figure 5 are to be replaced and showing the keys and the key retainer in the key-replacing tool in position for insertion in the valve assembly,

Figure 8 is a view similar to Figure 7, but showing the intermediate stage of the key-replacement process wherein the valve-retainer disc has been forced downwardly by the tool of the present invention and the valve-locking keys are about to be engaged against the recessed valve stem;

Figure 9 is a fragmentary vertical cross-sectional view taken through the upper portion of the poppet valve assembly showing the valve retainer disc in its final position, wherein the valve-locking keys are housed in the cavity provided therefor in the valve-retaining disc and wherein said keys are locked in engagement with the recessed portion of the valve stem.

Referring to the drawings, the improved valve keys nited States Patent 0 v, 2,742,689 Patented Apr '24, 1956 2 replacing tool is generally designated at 11 and comprises a sleeve-like, tubularcore 12 on the top end'of which is threadedly engaged a cap 13. Secured to the cap 13 is a relatively soft coil spring 15 which is received in the core 12, the top turns of the spring being clamped between the top rim of the'sleeve12 and the top wall of core 12 by abutment with the bottom flange 18 ofsaid,

core.

Designated at 21 is a large disc member formed with a central sleeve portion 22 slidably engaged on the bushing 19. Bushing 19 is formed at its lower rimwith an externally projecting, annular flange 23 which is received in an annular seat 24 formed in the bottom of disc member 21, whereby said disc member is retained against downward movement relative to the bushing 19 beyond the position thereof shown in Figure 4. Designated at 25 is 'a coil spring which surrounds the core 12 and which bears at its lower end on'the annular shoulder 26 of guide disc member 21 and which bears at its top end on the bottom rim of the cap 13.. As shown in Figure 4, the coil spring 25 tapers upwardly and has a generally conical configuration. Said spring acts as a guide and stabilizer for disc member 21. Under normal conditions, the spring 15 positions plunger member 17 substantially as shown in Figure 4, wherein an annular space is defined between the plunger 17 and the inside wall surface of bushing 19. V r

The bottom of the disc member21 is formed with a circular recess 27 which is shaped to receive the retaining disc 28 of a conventional poppet valve assembly with the valve stem of the assembly positioned in alignment with the plunger 17 of the tool. The valve assembly may be of a conventional type wherein a set of locking keys, such as are shown at 30 in Figure 5, are employed to lock the valve retainer 28 to the valve stem 29, said valve stem being formed with an annular recessed portion 31 in which the key segments 39 are receivable. When the valve is assembled, the poppet valve spring 32 exerts an upward force on the valve retainer 23, the key segments locking the valve retainer 28 to the valve stem 29 and defining abutments at their lower edges which engage the bottom wall 33 of the valve retainer 28 to resist the upward force of the valve spring 32 and to maintain their locking relationship with the valve stem by their wedging cooperation with the upper portion of the recess 31.

As shown in Figure 7, the valve retainer 255 has a cavity 34 surrounding the valve stem 29 and is beveled at the top edge of said cavity, as shown at 35.

in using the improved locking key-replacing tool, the key segments 38 are first disposed in the bushing 19 around the plunger 17 in the manner shown in Figures 6 and 7, the tool being held in an inverted position in 7 order to facilitate the insertion of the keys 3t into said bushing 19. The valve retainer 23 is then seated in the recess 27 and the tool is then inverted with the retainer 28 held by one hand while the tool is moved to a position over the valve stem 29. The retainer 28 with the tool ii is then lowered as suggested in Figure 7 so that the retainer 28 encircles the valve stem and rests on the spring 32. A downward force is then applied to the cap 13, said force being transmitted to the valve retainer 28 by the core 12 and the key segments 30, causing the valve retainer 28 to be moved downwardly to the position of Figure 8, the plunger 17 being forced upwardly into the hollow core 12 due to the relative yieldability of the coil spring 15. This brings the valve locking keys 30 into the position shown in Figure 8, wherein the lower ends of the keys are disposedon the beveled portion 35 of the valve retainer. At this position the keys 30 are disposed adjacent. the recessed portion 31 of the valve stem 29, as shown in Figure 8, and by the application of a slight additional downward force on the cap 13, the key segments 30 are cammed by the beveled portion 35 against the recessed portion 31 of the valve stem. The tool is then released, allowing the retainer 28 to move upwardly, whereby the keys 30 are received in the cavity 34 of the valve retainer until finally the bottom ends of the keys engage the bottom wall 33 of the valve retainer, whereby the valve assembly is completed.

The chief purpose of spring 25 is to serve as a guide and stabilizer for the bottom disc 21, which itself acts mainly as a guide. Spring 25 has the added function of acting as a shock absorber when the tool is freed and the disc 21 is momentarily subjected to the pressure of valve spring 32 during the completion of the movement of the key segments into locking positions.

While a specific embodiment of an improved split key-replacing tool for poppet valves has been disclosed in the foregoing description, it will be understood that various modifications within the spirit of the invention may occur to those skilled in the art. Therefore, it is intended that no limitations be placed on the invention except as defined by the scope of the appended claims.

What is claimed is:

l. A tool for preserving the relationship of a key retainer with the key segments of a segmental key during the positioning of the retainer on a stern, said tool comprising a body having a bore opening through one end, a plunger mounted in said bore ,to move longitudinally adjacent the open end thereof, a sleeve mounted on the body to move longitudinally adjacent and in spaced concentric relation to the plunger, said sleeve and plunger defining an annular key segment receiving chamber, and a guide carried by the sleeve for movement therewith in concentric spaced relation to the key segment receiving chamber for engaging a key retainer and holding it in proper relation to key segments in the chamber during the positioning of said retainer on a stem, yielding means carried by the body and bearing on the plunger for holding the plunger projected beyond the body, and yielding means carried by the body and engaging the guide for holding the sleeve projected beyond the body and the plunger and sleeve in chamber defining relation.

2. A tool for preserving the relationship of a key rctainer with the key segments of a segmental key during the positioning of the retainer on a stem, said tool comprising a body having a bore opening through one end, a plunger mounted in said bore to move longitudinally adjacent the open end thereof, a sleeve mounted on the body to move longitudinally adjacent and in spaced concentric relation to the plunger, said sleeve and plunger defining an annular key segment receiving chamber, a guide disk carried by the sleeve for movement therewith, a flange carried by the guide and projecting from the side thereof remote from the sleeve in concentric spaced relation to the chamber and defining a seat for receiving a key retainer and retaining it in proper relation to key segments in the chamber during the positioning of said retainer on a stem, a compression coiled spring carried by the body and engaging the plunger for holding said plunger projected relative to the body, an outwardly extending annular shoulder carried by the body adjacent the end thereof remote from that through which the bore opens, and a compression coiled spring encircling the body and bearing on the guide disk and on the shoulder for holding the sleeve projected relative to the body and in chamber defining position relative to the plunger.

References Cited in the file of this patent UNITED STATES PATENTS 2,177,232. Tinnerman Oct. 24, 1939 2,422,549 Hogin June 17, 1947 2,601,639 Schneider June 24, 1952 FOREIGN PATENTS 266,149 Switzerland Aug. 16, 1950