US2884914A - Means for controlling and indicating the adjustment of rotatable members - Google Patents

Description

y 1959 H. B. MOTTERSHAW 4,

MEANS FOR CONTROLLING AND INDICATING THE ADJUSTMENT OF ROTATABLE MEMBERS Filed Oct. 25, 1957 lVIEANS FOR CONTROLLING AND INDICATING THE ADJUSTMENT F ROTATABLE MEMBERS Harold Bell Mottershaw, Astwood Bank, near 'Redditch, England Application October 25, 1957, Serial No. 692,401

Claims priority, application Great Britain October 27, 1956 2 Claims. (Cl. 123-90) This invention has reference to means for controlling the adjustment of rotatable members and for giving an audible indication of the degree of any adjustment effected. Whilst the invention is applicable to a wide range of different types of rotatable members, it is particularly applicable to screw threaded members which, as a consequence of rotary adjustment within a tapped carrier, are also adjusted axially. For example, the invention is applicable to the adjustment bolts fitted in the valveactuating rocker arms of internal combustion engines.

The principal object of the present invention is to provide simple and economical means for controlling the adjustment of rotatable members.

A further object of the invention is to enable a rotatable member to be adjusted quickly, easily and accurately within fine limits.

Another object of the invention is to enable an audible United States Patent indication to be given to an operator of the extent of the adjustment being made to a rotatable member.

Still another object of the invention is to insure that when a rotatable member has been adjusted, it will remain in its adjusted position.

Yet another object of the invention is to enable fine adjustments to be made to a rotatable member by hand and with certainty when once an operator is aware of the degree of adjustment required.

The above and other objects of the invention will be apparent from the following description and claims and may more readily be understood by reference to the accompanying drawing which, by way of example, shows one preferred embodiment of the invention.

In the drawing:

Figure 1 is an elevation of a valve-actuating rocker arm of an internal combustion engine;

Figure 2 is a plan of the rocker arm shown in Figure 1; and

Figure 3 is a perspective view of a component part of the said rocker arm.

As shown in Figures 1 and 2, the rocker arm 1 comprises a transversely bored hub 2 whereby it is adapted to be rotatably mounted upon a shaft (not shown) and a lug 3 which projects substantially tangentially to one side of the hub in alignment with an ear 4 which projects to the opposite side of the said hub, a reinforcing rib 5 being provided along the top of the hub and the ear. When installed in an engine, the free end of the ear 4 is adapted to abut the stem of a spring loaded valve of the engine and the arm is adapted to be rocked about a shaft to open the valve against spring action and to enable the valve spring to reclose the valve, by a cam-actuated push rod which engages the domed tip 6 of the shank of a bolt 7 screwed into a tapped hole in the lug 3, and projecting upwardly and downwardly of the said lug.

The bolt head 3 is circular in plan and a number of V-shaped notches 9 are formed in and around the periphcry of the said head, the said notches being pitched apart by a common and predetermined uniform angular distance. A cruciform :slot 10 formed in the crown of the 2,884,914 Pa'ten'ted May 5, 1959 ice head is adapted to be engaged by a suitable tool whereby the bolt may be rotated about its axis relative to the lug and consequently, due to the engagement of the threaded shank 7 with the tapped hole in the lug, adjusted axially relatively to said lug.

The mounting arm 13 of a V-shaped blade spring 12 is so seated upon the lug 3 that the other and control arm 14 of the said spring extends away from the lug to and beyond the bolt head, the two arms being stressed in the direction which enlarges the angle included between them so that the control arm is urged into resilient contact with the notched periphery of the bolt head.

An aperture 15 is formed in and between the free end and the root of the mounting arm 13, the said aperture being in register with the tapped hole in the lug 3 and being engaged by the bolt shank 7. A coil spring 16 disposed around the said shank between the mounting arm 13 and bolt head 8, is maintained in compression so that the said arm is clamped between the spring and the lug. The mounting arm is at such an angular relationship to the control arm 14 that when the former arm is so clamped by the coil spring 16, the blade spring 12 is stressed thereby urging the control arm into its resilient contact with the periphery of the bolt head. A jaw 17 formed in the edge of the free end of the mounting arm, embraces and makes a positive engagement with the reinforcing rib 5 thereby preventing the blade spring from rotating about the axis of the bolt relatively to the lug 3.

A longitudinal slot 8 in the control arm of the blade spring, extends from the free end towards the root of the arm. The slotting of the arm provides two spaced tongues 19 of which the adjacent edges are urged into contact with the notched periphery of the bolt head at opposite ends of an arc of the said periphery so that, in effect, the said control arm is located in the plane of a secant of the periphery, the slot being of a width such that both the said adjacent tongue edges engage simultaneously with different notches in the said periphery.

Since the pitch of the threads on the shank of the bolt is known, or, if not known, is capable of being ascertained without difficulty, the pitch of the notches in the periphery of the bolt head is determined so that by turning the bolt about its longitudinal axis through an angular distance sufficient to take the head-contacting edge of each tongue 19 out of engagement with one notch 9 into engagement with a next adjacent notch, a predetermined unit of axial adjustment is imparted to the 'bolt relatively to the lug 3 of the rocker arm. Consequently, if it is desired to adjust the axial setting of the bolt relatively to the lug by a distance equal to any whole multiple of the said unit, then the adjustment is eifected quickly, easily and accurately, merely .by turning the bolt about its longitudinal axis in the appropriate direction to cause a number of notches equal to the said multiple, to travel past each of the head-contacting edges of the tongues. 19. Moreover, since re-engagement of each tongue edge with a fresh notch is accompanied by a click, and since both edges engage fresh notches simultaneously, an audible signal is given each time the bolt is adjusted axially by a distance equal to a unit of adjustment. Therefore, when it is desired to adjust the bolt axially by a distance equal to one unit or a desired multiple of units, such adjustment may be effected exactly merely by counting the numiber of clicks created as the bolt is rotated by, for example a manually operated tool inserted into the slot 10.

For example, if the pitch of the screw-thread on the shank of the bolt is such that there are twenty-five threads per inch, then, by forming forty equally-spaced notches in and around the periphery of the bolt head (that is by pitching the notches at 9 apart around the said periphery) the unit of axial adjustment of the bolt is one thousandth of an inch and axial adjustment of the bolt through,

for example, five thousandths of an inch, is effected by rotatablememberssince the spring may be employed for controlling and giving audible indication of angular adjustment of a peripherally notched member which is capable of making simple rotary movements only; the control armof the blade spring may. make only a single edge movement with the notched periphery or the two tongues. may be relatively inclined so that they do not lie in. the, plane of the secant which passes through the ends of" the are between the said tongues; again, alternative means may be provided for clamping the blade spring in position and for preventing it from rotating about the axis of the adjustable rotary member; thus, for example, in the rocker arm described and illustrated, instead of providing the jaw 17 in the free end of the mounting arm 13 and engaging the said jaw with the reinforcing rib 5,, the rib may be formed with a recess into which a projection from the arm extends.

I claim.

1. In an assembly for controlling and indicating the periphery, and spring means on said carrier andengaging said. serrated periphery for retaining said memiber in adjusted position relative to said carrier, the improvement in said spring means comprising an angled blade spring having a mounting arm and a control arm extending generally perpendicularly from said mounting arm and having a portion for engaging the serrated periphery of saidhead, said mounting arm being seated on said carrier and having an opening therein through which said member extends, means on said mounting arm engageable with a, portion of said carrier to prevent rotation of said blade spring upon rotation of said member, and a coil adjustment of a control member rotatably mounted in a carrier, said control member having a head with a serrated between said member*head'and' said "mounting arm "for constantly urging said mounting arm against said carrier with said control arm extending substantially parallel to the rotary axis of said member with said portion biased toward the serrated periphery'of said head, said portion comprising; means on said toontrol: arm engageable with the' serrated periphery of saidiheadzto prevent rinadverent movement of said member while permitting manual movement thereof;

2. In combination witlra rockerarm having a lug on one side of itspivotwithwan internally: threadedbore in :said lug and a bolt threaded in said bore and having a head with a serrated periphery; ananglecl'" blade spring having a mounting arrn'andacontrol arm, said mounting arm being seated. 011* saidlug andhaving an opening therein through which said bolt extends, a bifurcated portionon the free end of said mounting armengaging opposite sides of a portionof saidf rocker arm to prevent turningtmovement ofIsaid mounting arm upon rotation ofsaidbolt, a coil springdisposed about saidbolt and intermediate said. bolt 'headandlsaid mounting arm for constantly urging the latter against said lug; said bolt head having a plurality of alternate equispaced V-shaped furrows and'ridges formed in the periphery thereof, said control arm having a. tongue engaging the periphery of said bolt head. and disposed in a plane defining a secant with respect to said head, a degree curved joint portiondisposedbetween andconnecting the armsof'said blade spring for resiliently urging said'tongue into one of. said furrows to prevent said bolt from turning from vibration, yetpermitting movement ofsaid bolt when turned manually by the camming of said tongue along the walls of.the furrows and ridges .to remove the tongue from engagement with saidone furrow.

References Cited in the file 'of' this patent UNITED STATES PATENTS 1,212,980 Manning Jan. 16, 1917 1,503,463 Amos-ct a1. Aug. 5,.1924

1,520,208 Pielstick Dec; 23., 1924 FOREIGN PATENTS 503,105" Great Britain Oct. 28, 1937 530,110 Great Britain May 2, 1939

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