AN EPICYCLIC CHANGE SPEED GEAR.
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A _Resume of Recently Published Patent.
Simplicity ;in connectiOn with a Motor vehicle, may develop in at least. two directions." The chassis may be easy to control and :operate, or it may be simple in construction. It•apnears to be difficult to contrive that the 'amine machnie shall be both simple as regards its control and also . in respect of its construct-ion. Indeed, it is Olmost axiomatic that the former attribute is 'only gained at the expense of the latter. Various instances, could: be cited in proof ofthis contention, hut one will suffice. There isa 'certain inexpensive car, which for once shall be naniolessl. its simplicity of control is beyond dispute; its construeticin is such that" none but the expert, either amateur.ar professional, can with' safettriattempt any but the most minute and insignificant of adjusarnents or re
plaCements. -•
Now thegearbox .of. a. car, has, from the beginning of the motor movement, been the subject of. considerable attention from the inventor. The:usual construction," inving• the' ;meshing of toothed wheels While they areirevolving at high andldiffstring` speeds, has always een anathema. aLike10 'the engineer and the unfortunate userof a car: The termer tees some!ofi.-his !most cherisliacIAtenets wilfully disregarded„ evert: scented,. in iinekt• xleVice. The. latter, he is thoroughly -master orhis car, has also his moments of agony. There.is no need to dwell ort them. The gearbox of this type however,is easy, to constract and understand, .and these. features have generally carried sufficient Weight, to overrule the academic .abjectionssof the engineer as swell u.S. %the:. Mose,. practical ones of the user of the vehicle. • However, there is one type efl-box whichhas a considerable fa,scmation for= th4 inVentor, particularly:he who aims at providing the car owner with ,mechanism which shalr be easier to*operate than'the usual gearbox ; we refer to-that farm of transmission which incorporates an epicyclic gear or gears..11eret; of.course, the object is simplicity .of control, and it is unfortunately generally gained a the expense, as has been pointed out, of simnlicity-of construction. This criticism applies to the • design patented by A. Ramsey and another, in specification Na. 138,575. The end of the engine or driving shaft carries the. main sun Wheel' of acornpound epicyclie gear. It is hollow, ,and supports within itself the spigot end of the main Or driven shaft.. The latter is surrounded by, as it -were,sleeve 'upon sleeve—there are four—all provided with clutches attheir ends, for engagement with the several components of the compound epicielic gear. Fonr fort:yard speeds arethus provided, as well as a reverse. There is no rieed',, for the ordinary type of. engine clutch, as the gear acts in that capacity. The arrangement also allows of a direct, top gear being provided. • Besides the clutch sleeves to which reference has been made, there are two brakes, the manipulation of which is complementary to that of the sleeves. They can also be used
to retard the motion of the car.
Other Patents of Interest
Specification No. 136,133 illustrates another variation of the • unit construc
tion idea. All the 'important control levers of a car, the Pedals, change speed lever, and side brake lever, are carried on One cross-member of the ira.me which is Ihxibly, not rigidly, connected to the side members of the chassis. The gearbox is in one with the torque and radius member, the front end of which is forked and. attached to the flexible
cross-member aforesaid. The patentee is A. de ,Coninck.
The differential gear patented in No. 138,565, by G. C. Goodhart, an American, has already made its appearance over here, ahead of the publication of the specification which deals with it. Each differential shaft is coupled to its corresponding sun wheel by means partly fine_ tonal and partly positive. The arrangement is such that increased resistance to traction by any one wheel causes more pcisitive operation of the gearwheel which drives it. Lack of resistance, as when one wheel commences lo spin, causes the drive to be transmitted' entirely to the wheel which is in -better -tractive contact With the ground. -Constructions ;of disc "type universal joints wherein special provision is.niado for maintaining the alignment of the two Main portions of the joint are not new. G. IL Savage, in No. 138,485, provides, for the contact between the two bearing surfaces, material which is elastic in its natufs., so that the rattle which is liable to develop where the material -used is metallic is obviated. • . The spuds 'or strakes for tractor wheels, which are described in specification No. 138,578, by J. Bench, are Z-shaped in 'the latter, however, being sadly deformed. The tonand bottom of the
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Z run along the outer and inner edges of the wheel rim. The stem "cros-ses the rim diagonally being laid to the contrary direction, however, to that of the stein of a correctly made letter. The arrangement is such that the Ranges of the Zs overlap tine another, and thus proVicl continuous contact, throughout the hircumference of the wheel. The object is to reduce vibration when travelling on a hard road, without diminishing the effectiveness of the grip when on the land.
Specification No. 138,392 is concerned witligsplash guards, and describeS method of attaching the guard to the wheel rim. The attachment is. flexible, adjustable, and 'may 'quickly: b 'removed
or attached_ The patentee. is T. G. Bebson.
Af guard of a. 'different type is the" sub-. .ject of No. 138,410 by J. Anderson. A segment fitted with bristles is supported on the outiideof the hub cap, which is specially designed to afford -considerable bearing .surface, and provides 'means lubrication. •
Another differential gear is described in No. 138,561. In this..case -worms gears. areincorporated inthe design, instead of the more usual spur wheels.. The patent is mainly concerned with the construction of the gear with the, object of making the -thrusts set up by the worst gears self Contained. This gear "also prevents all the engine torque being ;transmitted to -any One wheel which may
• be spinning on a piece of ground which
• .-does'not afford -the requisite tractive grip.