US3392434A - Collet lock removal tool - Google Patents

Description

July 16, 1968 w. s. GILES COLLET LOCK REMOVAL TOOL x W w Z fi f 3 a Z aw a a in an u 2 1 2 9 d 3 a 2 a 0 2 1 #4 z Z a w 'uwunwwh flvw 1 l F 1 a w w w I N VEN TOR.

x 4 ATTORNEYS United States Patent 01 lice 3,392,434 COLLET LOCK REMOVAL TOOL William S. Giles, Highland Heights, Ohio, assignor to TRW Inc., Cleveland, Ohio, a corporation of Ohio Original application Aug. 5, 1964, Ser. No. 387,591, now

Patent No. 3,314,136, dated Apr. 18, 1967. Divided and this application Oct. 20, 1966, Ser. No. 588,091

2 Claims. (Cl. 29-249) ABSTRACT OF THE DISCLOSURE A manually operated tool of hollow frusto-conical configuration for spreading and frictionally engaging the fingers of a valve stem retainer lock for removing the valve spring retainer and retainer lock from a valve stem.

This application, a division of my copending application Ser. No. 387,591, filed on Aug. 5, 1964, now US. Patent No. 3,314,136, generally relates to valve stem retainer lock tools and more particularly relates to a manual valve stem retainer lock tool that frictionally engages the spread fingers or segments of a retainer lock for removal of the lock from the valve stem.

In conventional engine poppet valve assemblies, the tip end of the poppet valve stem has a spring retainer locked thereon to form the bottoming means for the valve ClOSing spring. For this purpose the stem is provided with a peripheral groove near its tip end for receiving the ribs or beads of a valve spring retainer lock. The lock may be a one-piece tubular lock that is wedge tapered and has a plurality of expandible and contractible fingers which are internally ribbed. The lock when positioned around the valve stem has a wedge fit in the tapered bore of the valve retainer with the locking ribs or beads projecting within the valve stem groove. The tool of this invention is especially suited for unlocking a retainer assembly having this type of one-piece tubular lock by providing means for frictionally engaging the expanded portion of the retainer lock and disengaging the lock from the valve stem. It will be understood however, that the tool is also useful in unlocking retainer assemblies with multi-piece locks.

It is, therefore, an object of the present invention to provide a manual retainer assembly removal tool.

It is another object of the invention to provide a retainer assembly removal tool which has means to expand a retainer lock and to frictionally engage the expanded retainer lock; and retainer lock to remove the lock from engagement with a valve stem.

Another object of the present invention is to provide a manual retainer lock tool having a tapered lock engagin g portion.

Still another object of the invention is to provide a manual retainer lock tool having a removing portion with a tubular body having an inner diameter equal to the outer diameter of the valve stem and having a slightly tapering thickness and a handle portion connected to said removal portion.

Many other features, advantages and additional objects of the present invention will become manifest to those versed in the art upon making reference to the detailed description which follows and the accompanying sheets of drawings, in which preferred structural embodiments incorporating the principles of the present invention are shown by way of illustrative example only.

On the drawings:

FIGURE 1 is a perspective view of a manual valve stem retainer lock assembly removal tool constructed in accordance with the principles of the present invention;

FIGURE 2 is a fragmentary longitudinal cross-sectional 3,392,434 Patented July 16, 1968 view of a conventional valve spring retainer and lock as sembly mounted on the tip end of a valve stem of a conventional engine poppet valve assembly with the valve stem shown in elevation;

FIGURE 3 is similar to FIGURE 2 but shows the positions of the parts of the retainer assembly after the retainer has been pushed inwardly on the valve stem in the direction of arrows of FIGURE 2 and after the nose of the tool shown in FIGURE 1 has been inserted into the lock;

FIGURE 4 is similar to FIGURE 3 but shows the positions of parts as the tool removes the retainer assembly from the valve stem.

As shown on the drawings:

The portion of a conventional engine poppet valve assembly shown in FIGURE 2 and indicated generally at reference numeral 10 comprises a cylindrical valve stem 11, a valve spring 12 which biases the valve member of the stem 11 into engagement with the valve seat, a valve spring retainer 13 against which the top end of the spring 12 bottoms and a retainer lock 14 which locks the spring retainer 13 on the valve stem 11.

The valve spring retainer 13 has a central tapered bore extending axially therethrough and indicated at 16 to receive the lock 14. The lock 14 has a cylindrical bore 17 just slightly oversized with respect to the diameter of the valve stem 11 so that it may slip over a tip end 18 of the valve stem and down over the body of the stem.

Although the lock 14 is shown in one piece it could be in two or more pieces. The lock 14 comprises a plurality of longitudinally extending fingers as at 19 eX- tending upwardly from a lower tubular body portion 20. An annular head or rib 21 is formed on the inner wall 17 of each of the fingers to extend into a groove 22 formed near the tip end of the valve stem.

The top end of the groove 22 comprises a fiat radial wall 23 whereas the bottom end forms an oblique wall 24. correspondingly, the top end of each of the ribs 21 comprises a fiat radial wall 26 and the bottom end comprises a Wall 27 which is inclined at about the same angle as the bottom wall 24 of the valve groove 22.

An outer wall 28 of the lock 14 is also tapered complementarily to the shape of the bore 16 of the spring retainer 13 to provide a wedging action therebetween which urges the ribs 21 of the lock 14 into the stem groove 22 as the retainer is urged upwardly by the spring 12.

A bottom end 29 of the lock 44 is flared outwardly after the lock is assembled on the retainer 13 in a manner whereby the lock is able to move axially relative to the retainer 13 but cannot be removed from the bore 16 of the retainer.

A manual retainer assembly removal tool constructed in accordance with the present invention comprises a plug indicated generally at reference numeral 30 in FIGURE 1 which includes an enlarged diameter handle portion 31 and a reduced diameter finger-engaging or lock removal portion 32 projecting axially from one end 33 of the handle portion 31.

In order to facilitate handling of the tool the enlarged portion is cylindrically shaped and may be knurled as at 34 across a portion or the entire length thereof to provide a better grip and to prevent slippage.

The reduced finger-engaging portion 32 comprises a cylindrical base 36 concentric with the axis of the handle portion 31 and a tapered or frusto-conically shaped nose 37. An outer end 38 is bored centrally at 39 to a diameter only slightly greater than the diameter of the valve stem- 11 whereby the tip end 18 of the stem can be telescoped snugly into the bore 39.

An outer wall 40 of the nose 37 is tapered from the 3 base 36 such that the diameter thereof at the outer end 38 is only slightly greater than the diameter of the bore 39, whereby the outer end 38 comprises a narrow annularly shaped lip. The bore 39 extends into the nose 37 a distance sufiicient to receive a substantial portion of the tip end 18 of the valve stem 11.

In using the tool 30 to remove the retainer assembly the first step is to apply by any suitable means a downward force on the retainer 13 in the direction of the arrows as indicated at reference numeral 41 in FIGURE 2. The retainer 13 is pushed down against the bias of the spring 12 until a bottom wall 42 thereof abuts the flared end 29 of the lock 14. In this position of the retainer 13 the fingers 19 of the lock are no longer wedged radially toward the valve stem 11.

The retainer 13 is then pushed even further downwardly to force the lock 14 itself downwardly on the steam 11. In doing so the inclined wall 24 of the valve stem groove 22 serves to cam the oblique wall 27 of each of the lock fingers 19 outwardly to spread the fingers and enable the ribs or beads to expand radially outwardly to the diameter of the valve stem 11 and downwardly thereon. In this position the various parts of the assembly 10 are disposed in the manner shown in FIGURE 3.

The next step involves pushing the nose 37 of the plug 30 downwardly over the tip end 18 of the valve stem a distance sufiicient such that the lip 38 is moved between an outboard valve stem engaging surface 43 of each of the fingers 19 and an outer wall 44 of the valve stem. At this point in the removal operation the relative disposition of the tool 30 and the assembly 10 is as shown in FIG- URE 3.

In this position of the tool 30 the fingers 19 of the lock 14 are held in a spread position. Further there exists a frictional relation between the outer wall 40 of the tool nose 37 and the outboard stem engaging surface 43 of each of the fingers 19.

The next steps are, in order, to release the downward force on the retainer 13 and then to lift the tool 30. The spring 12 acting on the retainer 13 tends to urge the retainer upwardly to assist the frictional pulling effect of the nose 37 acting on the spread fingers 19.

As the spread lock 14 is pulled upwardly across the groove 22 of the valve stem 11, in the position thereof shown in FIGURE 4, the ribs 21 pass across the groove without interference therewith because of the spread condition of the fingers of the lock. The assembly 10 is then raised upwardly completely off of the tip end 18 of the stem 11 and the nose of the tool 30 pulled out of the lock 14.

To briefly summarize, then, in removing a retainer and lock assembly 10 the retainer 13 is first pushed downwardly to a point whereby the ribs 21 of the fingers 19 are cammed out of the groove 22 and the lock slid down to a position shown in FIGURE 3, then the nose 37 of the tool 30 is pushed down on the valve stem 11 and into the top end of the lock 14, then the downward force on the retainer 13 is released and then tool raised off of the valve stem, carrying the retainer and lock assembly 10 with it.

Although minor modifications might be suggested by those versed in the art, it should be understood that I wish to embody within the scope of the patent warranted hereon all such modifications as reasonably come within the scope of my contribution to the art.

I claim as my invention:

1. A retainer assembly removal tool for valve spring retainer assemblies mounted on the valve stem of a poppet valve and having a tubular spring retainer with a tapered bore and a radially expansible-contractible retainer lock therein, with said lock having a bore therethrough of a diameter slightly greater than the diameter of the valve stem and an upper portion being divided into a plurality of radially expansible and contractible fingers each having a radially inwardly extending lock rib for projecting into a groove of the valve stem when the retainer assembly is assembled on the stem and outboard and inboard valve stem engaging surfaces and said expansible-contractible fingers being tapered externally to form a wedge fit in said retainer bore, comprising:

a plug being divided into an elongated handle portion and a tubular lock finger-engaging portion projecting from one end of the handle portion,

said finger-engaging portion having a cylindrical bore extending inwardly from the outer end thereof and having a frusto-conically shaped outer wall that increases in diameter from the outer end of said finger-engaging portion in the direction of said handle portion,

the diameter of said bore being slightly greater than the diameter of valve stem to receive the tip end of the stem in telescoping relation, the taper of said outer wall being such as to frictionally grip the outboard valve stem engaging surfaces of the lock fingers when the lock ribs of the fingers are expanded to the diameter of the stem to enable the retainer and lock to be pulled off of the stem.

2. A retainer assembly removal tool for valve spring retainer assemblies mounted on the valve stem of a poppet valve and having a tubular spring retainer with a tapered bore and a radially expansible-contractible retainer lock therein with said lock having a bore therethrough of a diameter slightly greater than the diameter of the valve stem and an upper portion being divided into a plurality of radially expansible and contractible fingers each having a radially inwardly extending lock rib for projecting into a groove of the valve stem when the retainer assembly is assembled on the stem and outboard and inboard valve stem engaging surfaces and said expansible-contractible fingers being tapered externally to form a wedge fit in said retainer bore, comprising a plug having a cylindrical handle portion and an axial- 1y aligned retainer lock finger-engaging portion extending from one end of the handle portion,

said finger-engaging portion comprising a frustoconical outer wall which decreases in diameter in the direction of the outer end thereof, and means forming a coaxial cylindrical bore in said finger engaging portion opening to the outer end thereof for receiving the tip end of the valve stem,

the diameter and taper of said outer wall being such as to enable the outer wall to spread the lock fingers when the finger engaging portion is pushed down over the tip end of the valve stem and to slide between the valve stem and the outboard valve stem engaging surfaces of the lock fingers to move the lock ribs radially outwardly sufiiciently to clear the valve stem and to frictionally engage the outboard valve stem engaging surfaces for removal of the spring retainer and the retainer lock from the valve stem along with the finger engaging portion of the plug.

References Cited UNITED STATES PATENTS 3,284,887 11/1966 Tauschek 29249 3,314,136 4/1967 Giles 29249 MILTON S. MEHR, Primary Examiner.

Images