The Baker Valve Gear

The Bak er Valv e G ear B V hi h n o e The aker alve Gear , w c is a , impr v ment over what was known as the Baker- Pilliod V n s e. alve Gear , is a out ide radial gear , i . , it has no links or sliding blocks . The movement is de f n rived rom the crosshead and the ecce tric crank . The crosshead moves the valve the amount of the n lap a d lead each way , and the eccentric crank gives the remainder of the movement . In the short cut- offs the actual effect o f the eccentric n cra k is reduced , while the crosshead movement is constant . The bearings are all pins and bushings , the latter being ground inside and out to a standard - u gauge . The pins are case hardened and gro nd to siz e on both the bearing and tapers . The improved gear has ten per engine less bear ings than the old one and the movement of nearly l r a lv h a l has been g e t reduced . T ree bearings or o of the f the joints n each side engine , aside rom h- e reac rod , move when the reverse lev r is changed . No loose oil cups are employed !each bearing has an oil reservoir or cup which is made integral h s ﬁ with t e part . These cavitie can be lled with v waste or curled hair to retain the oil , ob iating the danger o f a bearing running dry on the A longest runs . ll these bearing pins and bolts are e!posed to view so that they can be got at 4 TH E BAK ER VAL VE GEAR o o n o re r t be rem ved by the engi eman r pai man . ns o o n o r mo Three pi , r tw pins a d a b lt, e ve the o o n Th v s hardest piece t be taken d w . e hea ie t e 86 o n s piec , the bell crank, weighs o—nly p u d . Standa rdiz a tion of P a r ts This has b e e n reached to some e!tent in the Baker Gear as all the outside admission gears of this make are alike and all the inside gears are the same , no matter what the type or class of engine upon c whi h used . The yokes and radius bars are also for the same both admissions . The combination lever must suit the stroke of the engine and the S h ff lap and lead . ince there is not enoug di er ence in the power it takes to operate a valve on the different modern engines it does not warrant ff z W o e s di erent si ed gears . ith ther gears th re i not if n ff oss - s c o much , a y , di erence in the cr e ti n f ff area o the same part on the di erent engines . c All parts are interchangeable , and the astings , n f s fo r es includi g the rame , are the ame both sid of the engine e!cept the gear connection rod . f The combination lever has rights and le ts , but - f they are drop orged . f The rame is one piece cast steel , the same casting on both sides of the engine !one type for inside admission and another type for outside o f m a e! admissi n . The ra e is designed with n tension so that the same frame will go on a f n variety o e gines . This reduces to the minimum the number of kinds of frames that any road m So fa r o n of o ay have . tw desig s utside and one design of inside admission frame have been se 1 sho s a n a V ew of a . u d . Fig . w ge er l i the ge r TH E BAK ER VAL VE G EAR 6 TH E BA K ER VA L VE GEAR — Alig nmen t E very part of the gear is sym metrical with respect to the center line of the gear , and all pins are supported on each end . s s Thi makes a straight line motion , and prevent ff the possibility of a twisting e ect on any part . This construction i s claimed to increase the strength of the gear and also the wearing !uality of the bearings . — L ead and P r eadmission The Baker Gear has a constant lead with a variable preadmission . The objections to a constant lead have been that it retarded the engine while running in full gear and did not give compression enough in the short - off cut s . It makes no diff erence what lead there is in full gear so long as there is not preadmission f f cut which is the actor in compression . In ull o ff the Baker Gear has practically no preadmis sion and the indicator cards show a low compres ” sion line . This means a !uick engine . A - off n the s o s the cut is shorte ed , preadmis i n 25 f o 3 increases , and at per cent there is r m 4 - inch to inch preadmission . 2 Fig . shows in a general way the action of the for d Baker Gear outside a mission . On an inside admission gear the bell crank stands ahead of the reverse yoke and point L for the connection of the valve rod is below point K instead of f above . The eccentric crank ollows in both cases . AD of h The circle is the path t e crank pin . C B B ' ircle is the eccentric crank circle . ADK is TH E BAK ER VA L VE GEAR 3 TH E BAK ER VAL VE GEAR DX D e n . o X s th mai rod is Mthe cr sshead . N i o . N u on the cr sshead arm is the ni link. MK L K the combination lever . JG the bell . onn c E E F crank The gear c e tion rod is G O. H e a s . I shows th r diu bar is the reversing yoke . The two movements of the gear are as follows One from the eccentric crank B which follows n t o 90 o the mai pin a ab ut degrees . The ther motion from the crosshead through the combina tion lever . The eccentric crank moves the radius bar and the action the radius bar has on the o o valve is c ntr lled by the reverse yoke . The radius bar and yoke take the place of the link of and block a link motion . The combination lever thnows the valve the amount of the lap and a n Walsch r h lead , the s me as i the ae ts Gear . T is ! makes the lead constant and independent of the - ff H cut o . aving a constant lead the valve should show lead opening in all cut- off s when the engine is on either dead center . - off The cut , release and compression is done by means of the eccentric crank and controlled s o by the rever ing yoke . The yoke contr ls the of - off length the cut and also reverses the engine . The action is as follows : E ccentric crank in ' ' f - going rom B to B moves point C from C l to C" By this movement it moves pin E ' " H o E - of E through t 1 . The particular path ' E - F - is an arc whose radius is 1 1 . Thus it will E F E be seen that causes point to raise . This - rising movement moves G from G 4 to G of s K f which , by means the bell crank , move rom - K K 4 to This it can be seen will move the TH E BAK ER VAL VE GEAR 1 0 TH E BAK ER VAL VE GEAR f valve orward . The valve is moved backward to its original position in the ne!t half turn of of the wheel . The peculiar action the combina As tion lever is not shown . the combination lever does its important work near the dead center of the engine and when the engine is in the position as shown in the diagram the com on s wn binati lever i as sho on the diagram . From the diagram it will be noticed that E has a rising and falling movement caused by the E F If f I radius bar . the yoke is changed rom I to L 2 it would change the center of the radius ' " o E f E - E - F . S that will move rom 2 to 2 in o o f o ther w rds , the rising and alling m vement is - - cut down which would move G from G 8 to G 2 K f o K - K - and r m 3 to z . Thus it will be seen that with the varying position of the yoke I the of f h amount movement o the valve varies . Wen I is in the mid- gear position E would not move up and down at all but simply swing back and f rc If f w orth in an a . I is put in ull back ard motion the same motion of the eccentric crank that caused the rising movement before would cause the falling movement in the back motion " E - and E would go from 4 to The full motion backward is shown by a dotted line and the short cut- off in backward motion by dash and three dots .

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