US1411387A

US1411387A - Valve-silencing mechanism

Info

Publication number: US1411387A
Application number: US484812A
Authority: US
Inventors: George A Suffa
Original assignee: Individual
Current assignee: Individual
Priority date: 1921-07-14
Filing date: 1921-07-14
Publication date: 1922-04-04
Anticipated expiration: 1939-04-04

Description

G. A. SUFFA.

VALVE SIL'ENCING MECHANISM.

APPLICATION FILED JULY 14,1921.v

1,411,387. Patented Apr. 4, 1922.

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Mechanisms, of which the following is a specification.

My invention relates to the means for actuating the valve mechanisms of motors, more especially those of the internal combustion types, and has as its particular object to provide a construction which w1ll serve to take up the lost motion. in the said mechanism,and in that manner to eliminate theclicks and similar noises commonly noticed in valve mechanisms of'the prior types.

My invention is described in the specification, having reference therein to the accompanying drawings, forming a part of this application.

In the said drawings, wherein 1 have shown my invention in several of its preferred forms; 4

Figure 1 is an elevation, partly in longitudinal section, showing my invention as the same is applied. to a motor having the socalled overhead type of valve, which is operated through a rocker'arm.

Figure 2 is a plan view of the underside of the rocker arm which forms a part of the valve mechanism shown in Fig. 1, with the shoe support attached thereto.

7 Figure 3 is a view of the hinge side of the shoe forming a part of my invention.

Figure 4: is an elevation, partly insection, showing my invention a the same is applied to the valve mechanism of a motor having cylinders of the so-called L- or T-head type.

Referring to the drawings; the valve 1 is arranged to lift with respect to its valve seat 2 formed in the valve chamber wall 3; the said valve being guided and. centered by its stem 4: which is arranged to slide longitudinally within the guide-bushing 5 mounted upon said wall castin 3'. A. valve sprlng 6, maintained in a state 0 compressmn, hold said valve 1 closed upon its seat 2, except as the same is raised against said spring 6 by the action of the valve mechanism Said valve spring 6, in its usual embodiment encircles the valve stem 4:, and is confined between an inner plate or washer 7, lying ad jacent the inner end of the guide bushing 5, and a plate 8 fixed longitudinally with re- Specification of Letters Patent. Patented Apr. it, 1922,

Application filed. July it,

met. Serial No. eaters.

spect to the valve stem 1; as by a pin 9., or other approved means of attachment.

The valve actuating mechanism may be of any approved type. As shown in F igures 1 and a it includes a cam 10 rotating with the cam shaft 11, and engaging a roller 12 carried in the forked'end 13 of a valve tappet 13 which is longitudinally slidable in a guide 14 mounted in the motor frame 15.

The foregoing descriptive matter, although more especially directed to the construction shown in Figure 1, will apply with equal pertinence and descriptive effect to the construction which is shown in Figure 4. In both said Figures 1 and a similar parts are identified by similar numerals; it being noted, however, that in Figure l the valve is shown in a closed position, whereas in Figure ithe valve i shown. raised or unseated.

The chain of connections by which the valve actuating means transmits its valve unseating movements to the valve, includes a rod 16 which engages at its lower, (as viewed in Figure 1) end, the tappet 13, and at its upper end carries the ball or spherical knob 16*. Said knob 16 is adapted to engage within a recess 17 provided in the lower end of an adjustable set screw 17 carrying the check-nut 18, which is mounted by a threaded engagement in one end of the rocker arm 19. Said recess is formed with a contour which substantially conforms with that of the knob 16 so that the engagement between the rod 16 and said rocker arm end through the said screw 17 is essentially of the ball and socket type.

The said rocker 19, which is mounted upon the journal or pivot 20 carries in its other arm the shoe support 21 and the shoe 22, in the form and cooperative functioning of which reside the more essential features of my invention. Said shoe support 21 comprises a, stud portion 21 (which engages within a hole formed in said rocker arm end, and is secured therein as by the nut 23) and a lower portion formed with a convexly curved face 21' which is preferably substantially of the form of a portion of a cylinder extending along the width of said lower portion; the axis of said cylinder being in the line of vision of the observer looking at said Fi ure 1.

aid lower portion carries,'attached thereto, by a hinge connection lying substantially parallel with the axis of said cylindrical face 21", the shoe 22 having the characteristics hereinafter described. Said shoe 22 is attached to said shoe support by means of the resilient arm or spring 22, which is preferably formed separately of the shoe and is attached at one end to the upper portion of the shoe by any approved means of attachment, as by the screw 24. If desired, however, said spring arm 22 may be formed as an integral part of said shoe, as it is shown in Figure 4.

The other end of said spring arm 22 is attached to said shoe support y an easily engaged but secure connection, preferably" one in the nature ofa hinge. To that end the free end of said arm is fashioned so as to combine with a suitable projecting portion of the shoe support in forming a hinge ofwhich the hinge members are held together by the hinge pin 25. Such connection of the hinge type is not, however, essential and said arm 22* may be fixedly at tached at its end to the shoe support in any other approved manner.

The said spring arm 22 is of curved form, as shown in the figures, with its upper surface closely approximating the curvature of the face of the cylindrical portion of the shoe support, to which it is arranged to lie closely adjacent. Further the hinge pin 25 is so located that the adjacent surfaces of said spring arm 22' and of the said cylindrical portion 21 come into contact with one another at a point adjacent said hinge pin, but with a gradual separation of the same as the distance from said pin increases. In the drawings such separation is shown in exaggerated degree in the interest of clarity of the drawings, but in practice the separation is very slight and the said surfaces lie I very closely to each other.

The lower face 22 of said shoe is preferably in the form of a cylindrically convexed surface which is arranged to make contact, in the assembled valve mechanism, with the plate 26 carried upon the end of the valve-stem, in the construction shown in Fig. 1, or withthe upper face of an adjustable cap-screw head 27 carried upon the valve tappet in the construction shown in Figure 4; the point or line of such contact lying to the left of the axis of the valve stem as shown in the figures. B turning respectively the set-screw 17 (of igure 1) or the cap-screw 27 (of Figure 4) the said shoe is caused to bear correspondingly against the said plate 26 or said cap-screw 27 with a force calculated to flex said arm 22" insufficient degree to produce a pressure, resiliently exerted through said shoe 22 upon said plate or cap-screw head, by which all lost motion in the valve mechanism is taken up.

While the spring arm 22 should possess makes contact.

of said shoe are so coordinated that when that degree of stiffness which is requisite to producing the pressure necessary to the taking up of the lost motion, at the same time it must be of a weakness calculated to be dominated by the valve spring; that is, said spring arm must bend, as the valve mechanism actuates to raise the valve, prior to the yielding of the valve spring 6. Owing to the close correspondence of the curvature of the upper surface of the spring arm and of the adjacent face of the cylindri-. cal portion 'of the shoe support, the bending of the spring arm will cause the closing together of the same, at first'in the vicinity of the hinged'end of the said arm and then at points or lines which gradually increase in distance from the hinged end of the arm 22; and such bending of said arm and'the closing of the same together and into contact with said shoe support is arranged to continue until the point or line of contact between the same comes into the plane which substantially lies coincident with the axis of the valve stem.

During the bending of said spring arm 22 such change in the inclination and posi-- tion of the said shoe carried thereon as may result iscared for by a rolling or sliding action between the lower convex surface of the shoe and the surface of the plate 26 or the head of the cap-screw 27 with which it The conformation of said adjacent surfaces of said arm and said cylindrical portion, and of the convex surface the flexing of said spring arm has proceeded to the stage where the line or point of contact of the same'with the shoe support substantially reaches and coincides with the plane lying at the axis of the valve stem the change of position of said shoe causes its lowersurface to make contact with the adjacent surface of the plate 26 or the capscrew head 27 along a point or line which lies substantially in the same plane. In con- 1 0 sequence the motion imparted to the shoe support by the valve actuating mechanism is communicated by a direct thrust through said shoe to the valve.

It will be'noted that in the construction 5 shown in Figure 4 the shoe support 21 is carried upon the end of the valve stem 4;

' the same being attached thereto-in any apmines? and said arm having surfaces arranged, as said arm is initially flexed, to contact for a portion of the length of said arm adjacent the point of its attachment with said support, and as a further flexing of said arm occurs arranged to effect a shifting of said shoe into a position wherein it becomes operative to transmit the further valve opening movement of the actuating means to the valve.

2. In valve mechanism for motors and the like, a valve, valve operating mechanism which includes actuating means and a train of connections for communicating the valve opening motion of the said actuating means to the valve, said train of connections including a shoe supportand a shoe supported thereon through a resilient arm, said shoe being normally carried upon said support with its arm under flexure in a degree suiiicient to take up the lost motion in the train of connections, said shoe arm and said support being so conformed and attached to each other than an additional flexing of said arm causes said shoe to gradually shift into a position wherein it comes into rigid contact with said support and thereafter becomes effective to transmit the further motion of the valve actuating means to the valve.

3. In valve mechanism for motors and the like, a valve, valve operating mechanism which includes actuating means and a train of connections for communicating the valve opening motion of the said actuating means to the valve, said train of connections including a shoe support and a shoe supported thereon through a resilient arm, said arm be ing normally maintained in a condition of 'flexure adapted to cause said shoe to bear against the connections contiguous therewith with a pressure sufficient to take up the lost motion in said train of connections, and means whereby the valve opening motion of said valve actuating means produces an additional flexing of said arm whereby said shoe is shifted into a position in contact with said shoe support wherein it becomes effective to transmit the further motion of the valve actuating means to the valve.

1-. In valve mechanism for motors and the like, a valve, valve operating mechanism which includes actuating means and a train of connections for communicating the valve opening motion of the said actuating means to the valve, said train of connections including a shoe support and a shoe supported thereon through a resilient arm, said arm being so mounted upon said support as to normally maintain said arm in a condition of fiexure adapted to cause the lower surface of said shoe to bear against the connection contiguous thereto with a pressure suflicient to take up the lost motion in said train of connections, the adjacent surfaces of said arm and said support being so formed that the 'further flexing of said arm causes said adj acent surfaces to close together and to gradually bring said shoe into rigid contact with said shoe support,'so that thereafter said shoe serves to transmit the further valve opening motion of the actuating means to to valve.

GEORGE A. SUFFA.