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Sept. 27, 1938. w. M‘ GOODWIN 2,131,507 VALVE OPERATING MECHANISM Filed March 25, 1935 El- 8 % m ' 4/ 45 l3 / / 4 % 4 4 4 / / / / / / 4 / ,é/M 4 / / 4 4 / 4 / / w" / z 4 / 4 i , 4 / / e b2 ’ 4 / / / Z ' lé 29 32 Z 4 ,2 3 “L2 2 724 g5 2 ‘24425 / $9 / F \: 3; 4p 2 29 Q5 R $§ \ £44 ———" . __'___ 32 23. / :\ SE , ’ 5 31- 30 7 Patented Sept. 27, 1938 2,131,507 UNITED STATES PATENT OFFICE 2,131,507 VALVE OPERATING MECHANISM William M. Goodwin, Central Square, N. Y. Application March 23, 1935, Serial No. 12,641 9 Claims‘. This invention relates to a valve operating mechanism and pertains more particularly to the actuating means for the usual spring closed poppet valve of an internal combustion engine 5 of the class set forth in my Patent No. 1,609,711 dated December 7th, 1926. In a'valve operating mechanism of the above mentioned class, it is a well known fact that con siderable di?iculty is experienced in preventing 10 lost motion between the actuating means as a cam and the valve actuated thereby when said .Valve is in the closed position in engagement with its seat. This is due to variations in‘the over-all length of the connecting parts intro 15 duced therein by temperature changes and it is dif?cult, therefore, to prevent tappet noises inci dent to such lost motion. The applicant is ac quainted with many different devices which have been introduced in an endeavor to overcome this 20 defect in the construction of internal combus tion engines but in so far as'he is aware, these devices have either been impractical due to- de fects in mechanical construction or have been so expensive to construct as to render them com, 25 mercially impractical. , It is one of the main objects of this invention to produce an improved valve operating mech anism for an internal combustion engine that will prevent lost motion between the operating 30 cam and the valve actuated thereby and at the same time allow the valve to properly engage its seat over all working conditions. Another object of the invention is to provide a valve operating mechanism adapted to take 35 up any lost motion which may occur therein that is simple, durable and economical in con struction and which is positive, automatic and 'eflicient in operation. In carrying out the above mentioned objects 40 I have provided a motion‘ transmitting mecha nism incorporated in the valve operating mech anism which has relatively movable members for taking up lost motion between the operating cam‘ and the valve stem and at the same time is 45 self-acting to permit variations in the length of the associated parts, particularly the valve stem, (01. 123-90) movement of the members to compensate for any variation in the length of the connections introduced by temperature changes or by other reasons. A still further object resides in pro viding a self-adjusting mechanism for trans mitting motion from a cam to a poppet valve which will remain in the adjusted position dur ing the opening and closing operation of the valve as long as there is no variation introduced in the length of the associated parts and thereby con having a relative movement. Other objects and uses relating to speci?c parts of the mechanism will more fully appear in the 15 following description taken in connection with the accompanying drawing in which: Figure 1 is a vertical sectional view partly in elevation of a poppet valve, the adjacent por tions of an internal combustion engine and my novel mechanism for transmitting motion from ' the operating cam to the valve. Figure 2 is a detail horizontal sectional view on an enlarged scale taken on line 2—2, Figure 1. Figure 3 is a fragmentary sidev elevation part ly in section of the adjacent end portions of the valve stem and my novel motion transmitting and take-up mechanism as viewed from line 3-3, Figure 1. Figure 4 is a vertical sectional view of the 1 upper end portion of the motion transmitting and take-up mechanism partly in elevation as shown in Figure 1 but on an enlarged scale. Figure 5 is a vertical sectional view partly in elevation of the lower end of my novel motion transmission and take-up mechanism and the operating cam therefor taken at right angles to the views shown in Figure 1. Although as will be readily understood, this in vention is not limited in its application to an internal combustion engine and particularly to the valve mechanism therefor, I have illustrated in Figure 1 my novel transmission ‘and take-up mechanism as ‘I in connection with a poppet valve of an internal combustion engine 9 in which the valve 8 is opened and closed to and from due to expansion or contraction thereof caused its seat 10 by means of a cam II and a retract by temperature changes. ing spring I2 respectively. The valve 8 and re tracting spring 12 may be of any well known A further object of the invention is to provide 50 means for locking the relatively movable por tions of the motion transmission mechanism to each other to prevent relative movement there of during the opening of the valve and to unlock said portions as the valve approaches -or is in 55 the closed position to permit necessary relative 10 ‘tribute to a maximum life of the device by re ducing to a minimum the wear incident to parts construction but as shown the valve stem as I3 50 isreciprocally mounted in a vertically disposed guide 14 mounted in an extension I5 of the en gine frame 9 while the'spring I2 is mounted on the valve stem and guide between the engine frame extension 15 adjacent the lower end of“ 2 2,131,507 the guide opening and a retaining washer l6 on the valve stem adjacent the lower end thereof. The cam H‘ is secured to or made integral with a cam shaft l‘! which is journaled in the usual manner in the base iii of the engine. This cam may be of any desirable form capable of lifting the valve 3 from its seat l0 against the action of the spring i2 once during each revolution and as shown is of usual construction except that 10 it is provided with a peripheral cam groove 20 in the lower side thereof substantially mid-way between the sides of the cam. This cam groove '20 is arranged diametrically opposite the high side of the cam in symmetrical relation there 15 with and is of slightly more than 180° in length for the purpose of effecting the operation of the locking mechanism included in my novel motion transmission and take-up mechanism for opera tively connecting the cam with the valve stem in a manner which will hereinafter be more ap parent. be rotated by the action of the spring l2. It will thus be understoood that while the spring 32 functions to produce relative rotation of the tappet screw 29 and the plunger 24 in one ' direction to increase the over-all length thereof, the axial pressure exerted on the tappet screw by the valve spring l2 tends to produce relative 10 rotation of these members in the opposite direc tion to shorten the over-all length-thereof. In order, therefore, that the tappet screw and the plunger may be maintained or locked against relative rotation during the axial movement 15 thereof and particularly when said members are being lifted by the action of the cam II to raise the valve 8 from its seat Ill, I have provided a novel locking mechanism which is controlled by the cam II and cam groove 20 for accom 20 plishing thisresult. The motion transmission and take-up mech anism ‘I as illustrated in the drawing comprises‘ a vertically disposed tubular plunger 24 mounted 25 for reciprocative movement in a guide bearing 25 on the engine frame between the cam II and the valve stem I3 with its axis of movement in alignment with that of said valve stem. This plunger 24 is of considerably less length than the 30 distance between the cam II and valve stem l3 and has ?xedly secured to the lower end there of a foot or contact member 21 to form an in tegral part of the plunger and adapted to contact with the cam ll. range the threads 30 and 3| at an angle some where between 30“ and 45° to the axis of the screw so as to reduce the tendency of said screw to ‘ In the upper end of the plunger 24 is adjust ably mounted a tappet screw 23 which has the lower portion thereof provided with relatively coarse external threads 30 in threaded engage ment with similarly constructed internal threads 40 3| provided in the upper end portion of the plunger 24. The upper end portion of the tap pet screw 29 is reduced in diameter and is main tained in constant engagement with the outer or lower end of the valve stem l3 by a torsional spring 32 coiled about the upper end of the tap pet screw with one end connected as at 33, Fig— ure 2, to the screw to rotate therewith and the other end fixed to the upper end portion of the plunger 24, as at 34, Figures 1 and 3, to rotate with said plunger. The spring 32 is tensioned to constantly urge relative rotation of the plunger 24 and screw 29 in a direction to cause separa tion thereof by the screw threads 30 and 3i to increase the over-all length of said plunger and screw. In other words, the tappet screw isurged by the spring 32 to be rotated in a direction to move the screw axially toward the valve stem l3 and to rotate the plunger 24 in the opposite direction to effect the downward movement thereof toward the cam shaft H for maintain ing said members in constant contact with the valve stem and cam I i respectively. The angle of the screw threads 30 and 3| is preferably as shown substantially 45° to the axis thereof so that relative rotation of the tappet screw and plunger to produce relative axial movement thereof may be readily effected whether axial pressure is exerted at the upper end of the screw or at the lower end of the plunger. While I have illustrated the threads extending 70 at an angle of substantially 45° it is to be un derstood that this angle may be altered as desired so as to interpose whatever frictional resistance is required; that is, if the spring I2 is exception ally highly tensioned, it may be desirable to ar _ This locking mechanism consists of a pair of screw members 38 and 39, one of which as 38 is provided with external threads 40 and is mount ed in a central bore 29' provided in the lower 25 end portion of the tappet screw 29 with the threads 40 in meshing engagement with similarly constructed internal threads 42 provided in said bore. The upper end of the screw member 38 normally terminates some distance below the in 30 ner end of the bore 29’ and an expansion spring 43 is mounted in said bore between the upper end , of the member 38 and the bore 29' as shown in Figure 4 for exerting a constant downward pres sure on the member 38. 35 The other screw member 39 is mounted in a central bore 21' provided in the contact member 21. The screw member 39 is provided with ex ternal screw threads 45 which are in meshing en gagement with similarly constructed internal 40 screw threads 46 provided in the bore 21’. The pitch of the screw threads 40 and 45 as shown in the drawing is substantially 60° so as to per mit the ready relative rotation of the screw mem~ bers intheir associated elements when axial pres 45 sure is applied to either end thereof and to fric ~tionally resist relative rotation of these screw members and the tappet screw 29 and plunger 24 during relative rotation of said screw and plunger to vary the over-all length thereof affected by 60 the screw threads 30 and 3| in the manner here~ inbefore described. However, it is to be under stood that the angle of the threads 40 and 45 may be ‘so selected as to interpose whatever fric tional resistance is required. The screw members 55 38 and 39 are secured together by the tongue and slot connection 49 as illustrated in Figure l to cause said members to rotate in unison and at the same'time permit relative axial movement thereof. The lower end of the screw member 39 60 is somewhat reduced in diameter to form an ex tension 39' projecting below the threads 45‘ for engaging in the cam groove 20. Operation 65 Assuming that the cam shaft I1 is moving in the direction indicated by the arrow X, Figures 1 and-5, and that the high point of the cam is positioned at substantially right angles to the axis of the plunger 24 and valve stem I3 under 70 which condition the valve 8 will be in the closed position in contact with the seat in. The lower end 39' of the screw member 39 will be in regis tration with the rear end portion of the cam groove 20 and may or may not be extended into 75 3 2,131,507 v said cam groove in the manner illustrated in/ Fig ures 1 and 5, Then as the cam H is rotated, if the end 39’ is in the groove 20, the lower end of the screw member 39 will be moved out of the cam slot 20 and will be brought into and main tained in the plane of the lower end of the foot or contact member 21. The engagement of the cam II with the con tact member 21 will, of course, produce upward 10 axial movement of the plunger 24 and the screw member 39 and at the same time the upper ver tical movement of the plunger will be transmitted ' to the tappet screw 29 through screw threads 30 and‘ 3| and thence to the valve stem i3 to lift the valve 8 from its seat l9. Inasmuch as this 'upward movement of the valve will be effected against the action of the spring H the resistance thus produced to the upward axial movement of the tappet screw 29 will tend to produce relative rotation of the tappet screw and plunger 24 against the action of the spring 32 through the medium of the screw threads 30 and 3| to shorten the over-all length of the motion transmitting mechanism 1 and improperly open the valve 8. However, the plunger 24 and tappet screw 29 25 _ will be prevented from relative rotation during the axial movement thereof by the screw threads on the screw members 38 and 39 owing to the frictional resistance o?ered thereby to such turn 30 ing movement by the difference in the pitch or particular relative angular arrangement of the screw threads 40-42 and 30--3l and also to the fact that the screw member 39 is prevented from, downward axial movement relative to the plunger 35 24. This relative axial movement of the screw member 391s prevented for the reason that the end 39' of the screw member 39 is always in con— tact with the high portion of the cam H during the axial movement of the plunger 24 which holds 40 the screw member 39 against being screw thread ed downwardly or toward the cam ll relatively to the plunger 24 and tappet screw 29. In other words, as looking members 38 and 39 are held by cam ll against rotation in the di 45 rection of rotation of tappet screw 29 when the latter is being screw threaded into plunger 24, bers 38 and 39 and will thus cause the lower end 39’-of the screw member 39 to enter the cam groove 20 to a greater or less degree which action is assisted by the spring 43. As the cam groove 20 again passes beyond the screw member 39 the lower end of said member will again engage the high portion of the cam H and be forced up wardly relatively to the plunger 24 and thereby effect a turning movement of the screw member in the plunger and screw thread the screw mem 10 bers 38 and 39 upwardly into the plunger and tappetscrew 29 respectively without affecting the over-all length of the plunger and tappet screw. If, on the other hand, the over-all length of the plunger and tappet‘screw is insufficient to main 15 tain the tappet screw in contact with the valve stem l3 when the valve engages the seat l0 and the low portion of the cam II is in contact with the member 21, the spring 32 will rotate the tappet screw 29 in a direction to screw thread 20 the same outwardly or upwardly from the plunger 24 and thereby increase the-over-all length of these members until the tappet screw again con tacts the valve stem l3. As the over-all length of the plunger and tappet screw is thus in 25 creased, the screw members 38 and 39 will re main practically in their lower position due to the action of the spring 43 as will be readily understood, and when relative rotation of the screw members is produced by the relative to 30 tation of the tappet screw and plunger any axial relative movement of the screw members pro— duced thereby will be permitted by the tongue and slot connection 49 between said members. It is to be understood that when there is an 35 easy sliding ?t between the screw members 38 and 39 and the tappet screw 29 and plunger 24 the spring 43 may be omitted, but when the spring is incorporated in the structure this spring is sufficiently light in structure so that when the 40 over-all length of the plunger and tappet screw remains constant and any relative rotation of these members occurs, the screw members 38 and 39 will remain in ?xed relation thereto during each cycle of movement and will only move 45 downwardly when the lower end 39' of the mem any normal tendency of the tappet screw to ro- ' ber 39 is in registration with the cam groove 20 tate in said direction will be prevented by the upon relative rotation of the plunger and tappet locking members for the reason threads 40 on 50 looking member 38 are of greater pitch than that of threads 38 on tappet screw 29. It will thus be seen that during the vertical axial movements of the valve 8 produced by the cam H and spring I2 the plunger 24 and tappet 55 screw 29 are locked against relative rotation and the over-all length thereof will, therefore. re main constant and will produce a uniform lifting screw in a direction to shorten the over-all ‘length ’ of the valve 8 to open the same upon each revo 60 lution of the cam shaft l1. Now as the high portion of the cam H passes beyond the contact member 21 and said member engages the low portion of the cam, the cam groove 20 is brought into registration with the screw member 39 and if the valve stem l3 has 65 been lengthened during the axial movement thereof due to expansion or other causes, the ac tion of the spring l2 tends to force the tappet screw 29 downwardly and produce relative ro tation of the tappet screw and plunger 24 against 70 the action of the spring 32 to decrease the over all length thereof until the valve has reached the limit of its downward movement by the engage ment thereof with the seat III. This relative ro~ tation of the tappet screw and plunger will pro 75 duce a corresponding rotation of the screw mem of these members. ‘ It will now be understood that the over-all 50 length of the motion transmission mechanism 1 will be automatically adjusted to assure a con tinuous connection between the cam l l and valve stem l3 and thereby prevent lost motion and 55 noise incidental thereto and although I have shown and particularly described the preferred embodiment of my invention, I do not wish to be limited to the exact construction shown as various changes in the form and relation of the 60 parts thereof may readily be made without de parting from the spirit of the invention as set forth in the appended claims. I claim: 1. A valve operating mechanism comprising a plurality of valve operating members having movement relative to each other to increase or decrease the over-all length thereof, a con tinuously operating cam for intermittently -re ciprocating said members to open and close the valve, means for locking said members against said relative movement throughout the recipro cating movement thereof including two holding elements operatively connected to transmit mo tion from one to the other, means for main 75 2,131,507 taining operative connection between each hold ing element and a respective valve operating ing one of the valve operating members for inter member effective upon a decrease in the over means for said valve operating members includ ing a holding element, means maintaining oper ative connection between the holding element and two of the valve operating members whereby all length of the valve operating members to positively produce movement of the holding elements relative to said members toward the cam to bring one of said elements into operative engagement with said cam, a second cam co operating with said one of the holding elements 10 during the inoperative portion of the cycle of movement of said ?rst mentioned cam for re leasing said locking means, and means rendered operative by the release of said locking means for adjusting said valve operating members rela tive to each other. 2. A valve operating mechanism comprising a plurality of axially reciprocating valve operating members, means for maintaining operative con nection between the members so that upon rela tive rotation of themembers their over-all length will be increased or decreased, a cam for inter mittently reciprocating the valve operating mem bers to open and close the valve, co-acting look ing elements arranged in co-axial relation with each other and having'axial movement relative to each other and to thegreciprocating mem bers toward and from the cam, screw means be tween each locking element and a respective one of said members effective upon said relative rota 30 tion of the members to decrease the over-all length thereof to positively move the elements relative to said members toward the cam, said cam having holding engagement with one of the locking elements during said intermittent move I ment only for maintaining said elements and members against said relative axial movement, a second cam for releasing said locking elements at the end of the intermittent movement of the members, and means rendered operative by the 40 release of said locking means for adjusting said reciprocating members relative to each other. 3. In a valve operating mechanism, in com bination, a plurality of axially reciprocating valve operating members, means including screw threads for maintaining operative connection between the members so that upon relative rota tion said‘ members will be moved axially to in crease or decrease the overall length thereof, a cam engaging one of the valve operating mem mittently reciprocating said members, locking relative rotation of said members to decrease the overall length thereof will positively produce movement of the holding element from a re tracted position at one side of the cam to an 10 extended position into the path of movement of said cam, a groove in the cam adapted to register with the holding element for releasing the look ing means at the end of the intermittent move ment of the valve operating members, and means 15 rendered operative by the release of said locking means for rotating the valve operating members to increase the overall length thereof. , 5. A valve operating mechanism comprising, in combination, a plurality of valve operating mem 20 bers having movement relative to each other to increase or decrease the overall length thereof, means including a continuously operating cam engaging one of the valve operating members for intermittently reciprocating said members to 25 open and close the valve, said cam having a peripheral groove in the lower side thereof, lock ing means for said operating members including a holding element mounted in said member en gaged by the cam to be moved by said cam from 30 an extended position beyond the member and within said cam groove to a retracted position within the member engaged by the cam, means maintaining operative connection between the holding element and at least two of said valve 35 operating members effective during a decrease in the overall length of the members to posi tively produce movement of the holding element from said retracted to said extended position, and means yieldingly urging relative movement of the valve operating members to increase the overall length thereof. _ 6. A valve operating mechanism comprising, in combination, a plurality of valve operating mem bers having movement relative to each other to increase or decrease the overall length thereof, means including a continuously operating cam engaging one of the valve operating members for intermittently reciprocating said members to bers for intermittently reciprocating said mem open and close the valve, said cam having a bers, locking means for said valve operating , peripheral groove in the low side thereof, locking members including two, holding elements opera means for said valve operating members includ tively connected to transmit rotary motion from ing two holding elements operatively' connected to one to the other, means including screw threads 55 operatively connecting each of said elements with a respective one of the valve operating members, said latter screw threads being so constructed transmit motion from one to the other, means for maintaining operative . connection between each holding element and a respective one of the valve operating members eifective during a de and arranged relative to the first mentioned crease ‘in the overall length of the members to screw threads that a decrease in the over-all positively produce movement of ‘the holding ele length of the valve operating members will posi ments relative to said members toward the cam, tively produce axial movement of the holdingv one of said holding elements being mounted to elements relative to said members to be engaged alternately register with the cam groove and. to by the cam, a second cam for releasing said hold be engaged by the cam whereby the valve oper ing elements during the inoperative portion of ating members are free to move relative to each the cycle of movement of the first cam, and other when the valve is closed and will be main means rendered perative by the release of said tained against movement relative to each other 65 locking means f r adjusting said operating mem during the opening and closing operation of the bers relative to each other. valve, and means yieldingly urging relative 4. In a valve operating mechanism, in combi movement of the valve operating members to 70 nation, a plurality of axially reciprocating valve increase the overall length thereof. 70 operating members, means including‘ screw 7. A valve operating mechanism comprising a threads for maintaining operative connection be plurality of axially reciprocating valve operating tween the members so that upon relative rotation members having screw-threaded connection with said members will be moved axially to increase or each other whereby upon relative rotation the decrease the overall length thereof, a cam engag over-all length thereof may be increased or de~ 75 2,131,507 creased, a locking element having screw-thread ed engagement with one of the valve operating members, the pitch of the screw-threads of said locking element being greater than the pitch of the screw-threads between said valve operating members, so that when the locking element is held against rotation the valve operating mem bers will be maintained thereby against rotation with respect to each other, and means for recip 10 rocating the valve operating members and for intermittently holding the locking element against rotation. ‘ 8. A device as in claim 7 having means ren dered operative by the release of the locking ele ment for producing relative rotation of the valve operating members. 9. A valve operating mechanism comprising a plurality of axially reciprocating valve operating members having screw-threaded connection with 5 each other whereby upon relative rotation the over-all length thereof may be increased or de creased, a pair of locking elements splined to each other to rotate in unison and to have axial move— ment relative to each other, each of said locking elements having screw-threaded engagement with a respective one of said members, the pitch of the screw-threads connecting said locking elements to said valve operating members being greater than the pitch of he screw-threads 10 connecting the valve operating members to each other, so that when the locking elements are held against rotation the valve operating mem bers will be maintained thereby against rotation with respect to each other, and means for recip rocating the valve operating members and for intermittently holding the locking elements against rotation. WILLIAM M. GOODWIN.