US1972477A - Automatic device for tappet valve adjustments - Google Patents

Description

P 934. H, H. ENGEMANN ET AL 1,972 477 AUTOMATIC DEVICE FOR TAPPET VALVE ADJUSTIENTS I Filed Feb. 3, 1932 s Sheets-Sheet 1 j '!lllIlIIIIlI -IIIIIIIllllllllllII Li a x ext 13%?2 u Spt. 4, 1934. H, ENGEMANN 1,972,477

AUTOMATIC DEVICE FOR TAPPE'I. VALVE ADJUSTMENTS Filed Feb. 3. 1932 3 Sheets-Sheet 2 INVENTORS 5 561? A TORNEYS.

Sept. 4, 1934. H. H. ENGEMANN ET AL 1,972,477

AUTOHAT IC DEVICE FOR TAPPET VALVE ADJUSTHENTS Filed Feb. s, 1952 3 Sheets-Sheet s nuumV/ Illlllllllllll I'I////////// I mumlum Z IIIIIIIIIIIII atented Sept. 4, 1934 UNITED TATES? Herbert H. Engernann and 'H enry 'Bu'r d i ek Application February 3, S erial N o. 100mm. (0.1. 123 -96) The present invention relates broadly to by drocarbon engines and more especially town automatic adjustment device for the valves thereof. i

In the operation of hydrocarbon engines; it is usual to provide a poppet valve and cam operated tappet mechanism for opening the valve, the valve being maintained against the valve seatbyj spring pressure. One of the problems of hydro carbon engine operation is the'maintenance 5 of the adjustment of the relation between the tappet and the valve stem in order that thevalv may be opened and closed at the proper time. 1 v

It is very desirable to maintain a slightclearan'ce between the tappet and the end of the valve stem in order that the entire spring pressure-nthe valve stem may be effective to seat the valve head against the valve seat. The valve parts being made of metal change in length when the parts become heated. Therefore, adjustments {or a cold motor are not proper for the motor when it is heated and vice versaQ -The present invention overcomes the difiiculties above outlined by providing mechanism'to maintain a constant predetermined clearance in the line of valve operating mechanismfand preferably between the tappet and the valvestem regardless of thermal conditions or wear; In a'ccoi dance with the present invention, compensat irig adjustments are made for each cycle of valve operation. These adjustments are brought about bymechanism operated by the same power which reciprocates the valve stem, and the adjustments are maintained while the valve is being'opened but are released when the valve is closed.

f While the present invention in the preferred form is illustrated as associated with an L-head type internal combustion enginefit is to be un .der'stood that the principles of the present in"- vention are applicable to any type of hydrocarbon engine using tappet valve mechanism. It is also to; be understood that while thepreferred form 0; the invention has been illustrated to conform to the patent laws, that the invention may. be embodied in different devices and mechanisms from those specifically illustrated herewith so that the disclosure herewith is to be understood as illustrative and not in the limiting sense.

Fig. 1 is an elevational view of a valve adjusting mechanism according to the presentinvention.

If'ig. 2 is a side view of the adjustmentmechanisin taken on line 2--2, Fig. 1'.

Fig. 3 is a detail view of a part of the mecha: nismtaken on line 3-3, Fig. 1. w r

Fig. 4 illustrates the position of the parts with the valveopentofull'position. I Fig. 5 illustrates the va-lve closeda'nd' the tap'- pet having just release'd the pressure on the-adjusting -mechanism suffi'eient for the --'-parts' to moveto non-adjusted- "position -''just before "the parts are moved to-jad-justing position 'sho' Fjg 6 1- Fig." 6 illustrates the-parts with 'th dju's't; merit completed'and -a;valv'e stemj being readyto be raised]; I 5 Referring to the drawings andimor'e e'specially to Fig. 1,' a-valve I is mounted in the usu'al way .for =reciprocalf-rhovement in an'engin'e head Z 'and the stem of the valve 4 carries on its' lower end a spring collar'ihel'd in-pbsitmn'by across pine extending through "the -"valve steir'i -41 A strong coil spring 7 extendsbetween the spring collar 5 and an abutment which may comprise apart of the engine h'e'ad. f II '5 A cam 9 operates a 't'appe'twhich may comprise a pair of screw threaded' members 10 and'llj adapted to be held in position by a lo'ck nut l2 whereby major adjustments 'may be made during? the assembly ofthe engine. l1

An important feature of the'present -'invention comprises a constant clearance device which preferably= comprises 5 a cup adapted to receive the lower end of the valve'steni 4. Tliis' cup 14'- cafries a spacer p1a'te"l5 through whi'eh p'asssecuring members that in the preferred form' are illustrated-as rivets l6'.- A plate sp ring 17- is" provided with openings through which the rivets 16 pass and is bent in the form of e bow-m such manner as": to tend tos eparate the spacer plate 15-from the b'ottom 'of the-cup 14; "The amount of separation is "determined 'by t'h dis tance the spacer "plate 15'may move on tlie'r'ivets' 16. This operation of the spring 17 provides a"; clearance 18 comprising the distance between'the cup 14 and the s'pacer-Iplate '15 minus'the thick: ness of the: plate sp ring'-'17.'-""I liis clearance is? th'ereiore a constant clearance which'isfinai itained atall times until the plate spring 17 is flattened by -compressive forces, The' coil sprin 7 of 1a 'sufiicirit' initial set- S0 thaFWheI} th'etappet'is raised by the cam-9 the platespri'ng 17 will be entirely flattened"before the spring 7' yields to compression to li ft'thevalye l tr'om' it's:

Ojne purposeof the dev ice of the" present in: vention is tomaintai-n thisconstantclearance the operating line between the operating cam and the valve head.-{ This constant clearance is established by the mechanismpreviously 'de-' scribed comprising the cup 14, the spacer plate 15 and the plate spring 17 and to maintain it, it becomes necessary to compensate for wear and for thermal expansion and contraction of the parts. The preferred mechanism for overcoming play or slack comprises preferably a wedge mechanism operative to compensate for wear and expansion. Preren y, this wedge. mechanism nerates once during each cycle of valve operation so that the adjustment is made just prior to the valve operation whereby the parts are always set in proper adjustment when the valve operation cycle begins. Referring to P28. 1, i, and 3, an extension 19 from the head of the motor may comprise a support for the compensating mechanism. The compensating mechanism is carried on a frame plate 20 which is suitably secured to the extension 19 by bolts or screws 21 suitably locked in place. A pair of arms 22, 24 are pro vided with slots 25, 26 through which extend pivot. studs 2.1, 23. that are riveted into the frame plate 20. The arms 22, 24 are therefore both. pivotal and on the: Pivot Studs. These a m 22 andv 24 are hinged; at their lowerends to compensatmz wedges 29 and 30, which wed es an s id ble between the ii of the impact and. th spac r plate on the c n-- stant clearance cup 14 so that when the com reheating wedges are forcedinwerd. all extranew linen W has. been eonmenseted for or taken up. The arms 22, 24 are provided with, 85 31. 32 thick be!!! flat sprin s ,5. The ironic. plate 2.9 is also provided with less 36 and 3'1 on which are mountedflat sprmss 38. 38 that beer aaeinstthe lugs 31, 32' on the bums 22', 24. The middle portion of, the frame plate i provided a vertical slot 40 par-- and to the axis-of t of. the valve stem 4.. A slide pin." 41 is wanted over this slot 4e and carries an operating pin 42 which extends intothe net-h or movement of the spring collar 5 on the stem 4 of the valve. The upper end of the slide P ate 1 is by a stud; rivet M. A pair of contact. links. 45. 416 are pivotally moimted at their inner ends on; the slide plate: 41 and are mounted to slide on studs 47:. 48 carried. by the frame: plate 28. A return, spring 49 (Fig. 3) is mounted an adjustment segm nt 5e pro-- vided with a segmental slot 51 and a screw 5.2 screw thre ded into the frame pl te 20 so that: the. outer end of the return spring 49: may be adjusted relative to the position of initial contact with. the operating pin 42 carried by the. slide plate 41.

The operation of. the device may be followed more easily by referem to F'ss. 4|, 5 and 6., 4 illustrates the exam 9 at its hiahest lift point with the valve i op n... Under these. com the v dses 29 and .30 are tightly clamp between the upper end, 11, of the tappet and the; pacer 1.5 carried y he can 14. due to the stron resistaneeof the heavy coil sprin '1. The 09- erating pin. 42 has contacted with the collar 5 and been carried. upwardly, there-- hit movie: he slidephte 41 upwenfly and swingthe contact links 45, 4.6. outwardly to place t fl pi p i s 34, 35 under tension. t ick. would tend to swim the arms 22. 24 outwardly and thus. tend: to. carry the compensating wedges 29, outwardly. The tension on: the springs 34. isnot sufliciently great, however, to overcome the friction, holding the wedges in placedue to. the pressure. of the earn a actin the force of the heavy coil. spring 7., Under this. condition, it will be ob erved that the plate spring 17 is flattened and the constant clearance space 18 has been taken up before the valve 1 starts to open.

As soon as the cam 9 has rotated to lower the valve stem to its lowermost position whereby the force of the spring '7 is expended against the spring collar 5 without furtheranovemenhof the valve stem, the wedges 129' and '30Qa'rfnolonger tightly clamped, and, therefore, the tensions on the springs 34, 35 operate to swing outwardly the arms 22, 24 and thereby withdraw the wedges 29, 30 as is illustrated in Fig. 5. In the mean time, when the operating pin 42 was lifted by the valve spring collar 5, the outer end of this pin tensioned the return spring 49 (Fig. 3). The return spring 49, however, is not of sufiieient strength to move the slide plate 41 until after tension on the hairpin springs 34, 35 is relieved. AS, soon as this tension is relieved by the withdrawal of the compensating wedges as illustmted in Fig.5, the return spring 49 operates-to snap the slide plate 41 downwardly-to its lowest position as illustrated in Fig. 6. When this,hap pens, the return fiat readjusting springs 3-33, :33 cerriedon the lugs36,.- 37 on thefiame i-plate 20, ami which-were stressed whenthe-armgn; 24. swung outwardly as illustratedwin Rig-v. now operate toswing the arms 22,24 inwardly sincethese springs 38, 39 are now, the only forces present acting on the arms 22, 24. Consequently the compensating wedges, 29 and- 3p. are.i'o,rcedinto place between the member lief the tappet. and the spacer plate-l5,ca rried,by the oup lfl. The force exertedby the springseii, 39.15 not a heavy force, and, therefore-the. wedges 29 and 30 are not moved together with a, force sufiicient 1y great to flex the plate spring 111. which. is acting at this time tomaintai-n the constant clear;- ance 18.. It will benoted the wedges 29,30 snapout quickly when the cam pressure .on the'tappet is released, and that thesewedges arelimmediateg ly snapped back into compensating. position I by the operation of thereturnspring 49 whichmoves the Links 45, 46 so as. torelease the ei fectiva energy. stored in theflat readiustinglsprings, 3 8, 139 38 to swing the arms 22, 2.4 inward- .1;; From the foregoing, it will appear tha th'e present invention provides first, aconstantsclear -g ance space in the operatingfline between the operating cam and. the. valve, which .spajce.. isi taken up when, the cam functions to operate the valve; second, the present invention rakes. up and eliminates all other extraneous oriindes able slack in the operating linebetween peep-g eratingReam, and the. valve head so that. allthat lag. is left is the predetermined constant clearance. In. this way, a constant operating conditionsis provided for the valve regardless. of. wear .or ther.-. mal expansion and contraction. What we. claim is:- V .1.

I- In a valve operat g mechanism. for "hydro carbon engines, the combination of .power.mealr'is, a. valve, connections betweensaid v powerfmeans and saidvalve whereby .saidfvalve is operatedl said connections. comprising a late, aistbp' td 1 .40 limit. the movement of said plate'and a spring to move said plateagainst said stopto establish a predetermined clearance when the valvis' closed, and means operative during' each valve operating cycle to adjust said connections to'ta'ke i-l up all lost motion therein with'the exception'o'f the predetermined clearance. f 3 2' 2. In a valve operating mechanism for hydro; carbon engines, the combination of -:a v'a1ve', a cam, connections for transmitting motion rromiefi said cam to said valve, means to establish a predetermined clearance in said connections when said valve is closed, a pair of wedges, spring means energized by the cam to withdraw said wedges, and means to insert said wedges to take up lost motion in said connections prior to the action of said cam on said connections to open said valve.

3. In a valve operating mechanism for hydrocarbon engines, the combination of power means, a valve, connections between said power means and said valve whereby said valve is operated, said connections comprising means to establish a predetermined clearance when the valve is closed, wedge means to take up all lost motion in said connections with the exception of the predetermined clearance, spring means to adjust said wedge means to inoperative and then to operative position for each operation of said valve.

4. A valve operating mechanism for hydrocarbon engines comprising a valve, a spring normally tending to hold said valve closed, thrust means to oppose the action of said spring and open said valve, a cam to operate said thrust means,said thrust means comprising a pair of wedge members movable transversely of the line of thrust, a pair of springs energized by the force opening said valve to withdraw said wedges from operative position when the valve is closed, and means to reinsert said wedges into operative'position to take up any lost motion in said thrust means before said valve is opened.

5. Valve operating mechanism for hydrocarbon engines comprising a valve having a valve stem, a valve spring for seating said valve against a valve seat, a tappet rod for opening said valve, spring means to maintain a predetermined clearance between said valve stem and said tappet rod when said valve is closed, wedge means movable at substantially right angles to the line of movement of said tappet rod, spring means operated by the force opening said valve to snap said wedge means to inoperative position when the valve is seated, and additional spring means to snap said wedge means to operative position before the valve is reopened.

6. In a valve operating mechanism for hydrocarbon engines, the combination of a valve, a cam to operate said valve, mechanism for transmitting motion from said cam to said valve comprising means to maintain a predetermined clearance in said mechanism when the valve is seated, and means acting automatically at predetermined periods in the cycle of valve operations to adjust the mechanism between the valve and the cam to introduce excessive lost motion and then to take up lost motion therein to maintain said clearance as the sole clearance between said valve and said cam.

7. In a valve operating mechanism for hydrocarbon engines, the combination of a valve, a cam for operating said valve, connections for transmitting motion from said cam to said valve, means for automatically adjusting said connections prior to each valve opening movement to introduce excessive lost motion in said connections and then to take up lost motion in said connections prior to the action of the same cam on said connections to open said valve, and means to establish a predetermined clearance in said connections when said valve is closed and when said means for adjusting said connections have operated to make said valve adjustment.

8. Valve operating mechanism for hydrocarbon engines comprising in combination a valve, a spring tending to hold said valve closed, thrust means to open said valve, a valve stem against which said thrust means is efiective, wedge means carried by said thrust means and operative to eliminate lost motion of said thrust means, means to render said wedge means inoperative and then operative, and devices for maintaining predetermined clearance between said valve stem and said thrust means when said valve is closed and after said wedge means have become operative to take up said lost motion.

9. Valve operating mechanism for hydrocarbon engines comprising a valve having a valve stem, a valve spring for seating a valve against a valve seat, a tappet rod for opening said valve, wedge means movable at substantially right angles to the line of movement of said tappet rod, devices operated by the force opening said valve to withdraw said wedge means when the valve is seated and to reinstate said wedge means before the valve is opened, and means to establish a predetermined clearance between said valve stem and said tappet rod when said wedge means are seated.

10. Valve operating mechanism for hydrocarbon engines comprising in combination a valve, a spring tending to hold said valve closed, a tappet to open said valve, a valve stem against which said tappet is effective, a cam to operate said tappet, wedge means between said tappet and said valve and operative to eliminate lost motion, means to completely readjust said wedge means for each cycle of operation of said valve, and means to establish a predetermined clearance between said valve stem and said tappet after said valve is closed.

' HERBERT H. ENGEMANN.

HENRY H. BURDICK.

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