Medical Society of the State of North Carolina. An.

Cyclopedia of automobile engineering; a general reference work on the construction, operation, and care of gasoline, steam, and electric automobiles, instruction in driving, commercial vehicles, motorcycles, motor boats aerial vehicles, self-propelled railway cars, etc online

. (page 14 of 27)
Online LibraryMedical Society of the State of North Carolina. AnCyclopedia of automobile engineering; a general reference work on the construction, operation, and care of gasoline, steam, and electric automobiles, instruction in driving, commercial vehicles, motorcycles, motor boats aerial vehicles, self-propelled railway cars, etc → online text (page 14 of 27)
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coupling at the flywheel end, the motor drives a large disk, running
parallel to and in the same plane as the flywheel. Another disk or
wheel is mounted to run at right angles to the motor-driven disk,
pressing against the latter and traveling across its face, as con-
trolled by the hand lever shown. This wheel is carried on a counter-
shaft on which is also secured the small or forward sprocket of a
single chain drive. The large sprocket and differential are mounted
on the rear axle, the chain itself being encased to protect it from dirt
and water. This chain drive is mounted to one side of the large disk.



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so that the transmission wheel may be moved across its entire face,
both the speed and the direction of rotation depending upon the
point at which the wheel makes contact with the disk, the center of
the disk naturally representing a neutral point The periphery of
the wheel is equipped with a special friction material, which may be
replaced at a nominal expense when worn. A transmission of this
type provides a wide range of speeds, both- forward and reverse,
with a very gradual and easy increase or decrease, it being possible
to go into reverse while the car is still moving forward, though this
is also a feature of the planetary type of change-speed gear. The
view of the power-plant and transmission also illustrates the con-
struction of the internal expanding brakes and the rear axle.

In operation, all speed changes are obtained by means of the
single hand lever which serves to shift the wheel across the disk.
The car is started or stopped by depressing or releasing a pedal on
the footboard.

Van Dyke. The Van Dyke 1,000-pound delivery wagon rep-
resents another instance in which friction transmission is employed,
but in a totally different manner. The two-cylinder, horizontal,
oppoi^ed motor comprising the power-plant, is placed at the left-hand
side of the chassis, forward, and is carried parallel with the frame
on two transverse members. These cross pieces also serve to carry
two bearings which support a horizontal shaft on which the sliding
friction wheel is mounted. The flywheel of the motor also serves
as the friction disk. Drive is by propeller shaft to a live type of rear
axle, which also embodies the differential. As the car is intended
for low speeds, the gear ratio of the drive at the rear axle is 6 to 1,
which, with the speed changes available in the friction transmission,
permits of driving it at anything from half a mile an hour up to the
maximum, which will probably not exceed 15 miles an hour.

Randolph and Lambert, The Randolph and Lambert vehicles
also employ a friction type of transmission designed on the same
general lines. That of the Randolph 1,500-pound delivery wagon
is illustrated in Fig. 38, the method of sliding the transmitting wheel
on the splines of the countershaft, as well as the manner of fitting it
with a special friction facing, both being plainly evident. The disk,
driven by the motor, which in this case is also of the twin-cylinder,
horizontal type placed transversely across the forward end of the



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chassis, is also apparent. Final drive is by double side chains,
according to standard practice on such vehicles. The friction type
of transmission on the delivery wagons of this size has lately been
discontinued, a gear drive being substituted. The same makers
build a slightly larger vehicle with 2,000-pound capacity in either
the friction or gear drive. The friction transmission does not lend



Fig. 38. Randolph Delivery Chassis Showing Friction Drive.

itself to heavier vehicles and has seldom been employed on anything
much lai^er than a 1-ton or 1^-ton wagon.

Friction Drive, The friction type of transmission is not gen-
erally regarded with favor by engineers, as is shown by the compara-
tively-small number of vehicles in which it is employed. As already
mentioned, this type seldom exceeds one ton in capacity, but in this
r6le the friction transmission appears to bear out to a very large extent
the promise of its very favorable theory. The area of actual contact



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between the disk and the power transmitting wheel is little more than
a short line, and it would accordingly not seem to be capable of trans-
mitting a great deal of power — ^particularly the effort due to starting
a load on a grade or out of a mud hole — but the fact that the Carter-
car vehicles have shown themselves capable of ascending grades as
steep as 50 per cent, and of being stopped and restarted on such a
terrific incline, would appear to dispose of this effectively. In actual
service, grades as bad as 20 per cent are very rarely encountered, as a
15 per cent grade represents an exceedingly steep incline. The
success of the friction-driven cars now on the market makes it appar-
ent that this type is to be reckoned with as a factor, its low cost
and absolute simplicity making it of great importance where the
unskilled driver is concerned.

Most of the vehicles thus far described, with such exceptions as
the Randolph and possibly one or two others, are really nothing more
than pleasure car chassis with a delivery body mounted on them,
but as they have been designed with a view to simplicity of construc-
tion and economy of operation, they have proven effective in both
idles. Doubtless the day is not far distant, when, with the aid of
readily interchangeable bodies, the small merchant will find it prof-
itable to use his car for both business and pleasure, by simply sub-
stituting a touring body in the evening or on Sundays and holidays.
This was proposed in England several years ago, and a system of
interchangeable bodies, permitting of a change from one to the other
in half an hour or less, was devised to make it feasible. There
appears to be no reason why the use of the machine in this double
capacity should not be found entirely practical.

Special Types. For the hard and unremitting service called for
by department stores and other large business houses, it is naturally
quite as much of an advantage to have a vehicle specially designed
for delivery purposes, as is the case with the heavier trucks. Such
cars are run constantly and are, for a large part of the time, loaded
to their rated capacity. It is nothing unusual for them to average
10 to 14 hours a day, practically every working day of the year that
they are in use, and service of this nature does not allow for a great
deal more idle time than is actually necessary for the daily washing
and overhauling required to keep them up to a high standard of
efficiency.



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Autocar. The Autocar open-body delivery wagon. Fig. 39,
affords an excellent example of a vehicle designed especially for the
most severe business conditions. The motor is of the two-cylinder,
horizontal, opposed, four-cycle type, the cylinder dimensions being
4J-inch bore by 4J-inch stroke, and it is rated at 18 horse-power,
according to the standard set by the Association of Licensed Auto-
mobile Manufacturers (A. L. A. M.) controlling the Selden patent
The crank shaft is mounted on imported annular ball bearings which
not only add greatly to the efficiency of the motor as a whole, but do
away with the attention necessary to adjust plain bearings. This
construction, which is far more expensive than plain bearings, also



Pig. 39. Autocar Open Body Delivery Wagon.

reduces the number of parts which are subject to damage should
the driver neglect to provide sufficient oil, the lubrication system
otherwise being entirely automatic. Two flywheels are carried on
the crank shaft, the forward one having its blades cast staggered so
as to set up a strong current of air, thu3 eliminating the necessity
of a belt- or gearniriven fan, while the rear flywheel carries the clutch.
The importance of providing ample weight in the balance wheel
is something to which insufficient attention has been devoted in the
past, its influence upon the starting ability and smooth-running
qualities of the vehicle being extremely marked, especially where
a two-cylinder motor is employed. Both flywheels on the Autocar
motor are counterweigh ted, and this, supplemented by a careful
balance of all the reciprocating parts, makes an extremely smooth



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and quiet-nmning motor with unusual starting and grade climbing
ability for its size.

The crank case is split horizontally into two sections, the lower
half carrying the cylinders, crank shaft, cam shaft, and water pump,
while the upper half carries the push rod guides, the magneto, the
oiler, and a gear for driving the water pump. The magneto and
oiler are both driven through bevel gears and short shafts, reducing
the possibility of failure in these two highly important essentials —
ignition and lubrication — to a minimum. This upper section of
the crank case is readily removable, carrying its parts with it and
thus giving access to the crank-pin bearings without the necessity
of dismantling the m^tor. A Bosch magneto is employed with a fixed
firing point, thus taking this element of control out of the hands of
the driver. Lubrication is by a force-feed oiler delivering oil through
a sight feed to the crank case, from which the pistons, crank pins,
and main bearings are lubricated by splash. Both the magneto and
the lubricator are simply attached to the crank case by wing nuts
so as to be removable without the aid of tools. A hydraulic speed
regulator connected in the circulation of the cooling water, controls
a throttle placed in the intake manifold between the carbureter and
the cylinders, limiting the speed of the motor to 1,400 r. p. m. and
that of the vehicle to 18 miles to 20 miles per hour.

A patented floating ring clutch that has been developed on the
same make of pleasure cars and used for a number of years, constitutes
the first step in the transmission. It consists of a bronze floating
ring, lined with cork inserts on its inner face, and mounted on four
keys on the inside of the rim of the rear flywheel, thus rotating with
the latter. Two cast-iron rings, adapted to clamp the bronze ring
when the clutch is engaged, are mounted on the clutch shaft, which
extends into the transmission case. Engagement is accomplished
by a sliding trunnion and four toggle links, the motion of which is
checked by a dashpot and plunger. This insures gradual automatic
action, entirely free from jerk regardless of the care exercised by
the driver. The addition of small springs to the floating ring elimi-
nates all noise whether the clutch be engaged or not, while the arrange-
ment is such that adjustments can be easily and readily made.

The transmission housing is all one piece, except its cover plate,
and it has been so designed that all the shafts and gears may be



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removed without disturbing the housing itself. The shafts are large
and are carried on adjustable roller-bearings, while the gears have
broad faces and heavy teeth. Three speeds forward and one reverse



F'm. 40. Autocar Engine and Trmnamiasiom Mounted on Separate Sub-Frame.

are provided, lubrication being obtained by covering the shafts and
gears with a bath of semi-fluid oil.

Both front and rear axles have l)een designed especially to meet



FiK. 41. Autocar Enjfine and Transmission — Plan View.

the recjuirements of the heavy senice imposed upon them in carry-
ing the load on solid rubber tires. The front axle is of the tubular
type, with extra heavy yokes for the steering spindles, w^hich are made
integral with the spring saddles. Adjustable roller-bearings are



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employed in the wheel hubs. The rear axle is of the full floating
type with a double gear reduction. A bevel pinion at the end of the
propeller shaft meshes with a large bevel gear on a short transverse
shaft, from which the drive is transmitted to the differential case by
means of a pair of substantial spur gears. The bevel pinion shaft
and the jack shaft both run on adjustable roller bearings.

One of the chief features of advantage of the Autocar delivery
wagon is the mounting of the complete motor and transmission,
barring the rear axle, on an independent subframe, as shown in Fig.



Fig. 42. Autocar Complete Chassis.

40 and Fig. 41. In the illustration of the complete chassis, Fig. 42,
every part of the power plant is seen to be accessible by lifting the
bonnet, while tlie complete unit, as shown separately, may be removed
from the chassis and replaced by another. The plan view of the
chassis, Fig. 43, shows the relative location of all the essential parts^
including the gasoline tank which is placed transversely on the main
frame directly under the driver's seat. The frame is of pressed steel,
perfectly rectangular and heavily reinforced. Two sets of brakes
act on drums attached to the driving wheels, while the suspension
consists of double-elliptic springs in the rear and semi-elUptic springs
placed forward directly under the motor.



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Grabowsky. The Grabowsky power wagon is another specially
designed type having similarly advantageous features of accessibility
and interchangeability, the entire power plant and transmission being



Fig. 43. Autocar C!omplete Chassis — Plan View.

an independent unit which is designed to slide on raib on the chassis
frame, so as to be readily installed or removed. The simplicity of



Fig. 44. Grabowsky Power Wagon, Showing Sliding Mounting for Power Plant.

this operation may be judged from the illustration, Fig. 44, which
clearly shows the channel members upon which the motor and trans-



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74 COMMERCIAL VEHICLES

mission gear are mounted, as well as the rails of similar section placed
in an inverted position on the chassis, on which they are designed to
slide. By means of the horse mounted on casters and shown in the
foreground, the motor and its accompanying essentials may be slid
off the chassis and replaced by another in a very short time. This
is a great advantage to any delivery system employing a number of
vehicles, as with an extra equipment of one complete power plant for
every eight or ten cars in ser\'ice, it is seldom, if ever, necessary to
retire a machine from service to make repairs to the motor or trans-
mission, as the extra unit may be temporarily installed in any one of



Fig. 46. Grabowsky Chassis Showing Simple Construction.

the cars needing attention of this nature. This is on the same prin-
ciple as the keeping of three horses to insure the steady service of
a single two-horse wagon, six for two team wagons, and so on; except
that the percentage of extra motive power necessary in the case of
horse-drawn vehicles is much greater than with power wagons.
The Grabowsky car shown is much heavier than the delivery types
previously illustrated — in fact, it is a truck chassis, but is shown in
this connection following the Autocar as a further example of a special
design involving much the same principles.

Fig. 45 serves to illustrate the ready accessibility of the various
essentials of the motor by merely lifting the short hood. It
may be noticed in this case that the radiator is carried above the
motor. The force-feed lubricator will be seen forward just under
the end of the crank shaft, while the direct-current generator for



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COMMERCIAL VEHICLES 75

supplying the ignition current is bolted to the right-hand rail
of the sliding motor sopport; the ignition timer is mounted vertically,
directly over the crank shaft. The valves and their operating
mechanism, the spark plugs, carbureter, and electrical and water
connections are all within easy reach, most of them being mounted
directly on top of the motor. Fig. 46 illustrates the great simplicity
of the chassis as a whole. The drive from the planetary gearset,
which is shown in part section in Fig. 47, is by shaft to the differential,
mounted at the center of the countershaft near the rear. From this,
the drive to the rear wheels is taken by side chains in the conventional



Fig. 47. Planetary Gearset Shown in Part Section.

manner. Internal expanding brakes are designed to act upon the
drums which also carry the driving sprockets.

Rapid, The Rapid cars, while specially designed in many forms
for commercial service, and in which they have proven unusually
successful, are characterized more by features of design that have
been conventionalized in the two-cylinder pleasure car. Like the
Autocar and the Grabowsky, the Rapid one-ton chassis is equipped
with a two-cylinder motor of the same general type, the cylinders of
which measure 5 inch by 5 inch, giving it a rating of 24 horse-power.
It is placed parallel with the frame and under the body, the crank
shaft carrying a two-speed planetary gearset through which the
power is transmitted by a single chain drive to a countershaft, from
which it is taken by means of side chains to the rear wheels in the
usual way. While placed under the body, the motor is readily



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76 COMMERCIAL VEHICLES

accessible from the side of the car, due to the somewhat greater height
of the frame. The radiator is carried forward and serves as a dash,
while the suspension consists of a half-platform unit composed of
three semi-elliptic springs in the rear, and two straight semi-elliptic
springs forward. Solid axles of If-inch square section are employed,
and it will be noted from this and bther details of the construction
that the vehicle is unusually subtsantial for its size so that its rating
of one-ton capacity is merely nominal. The wheels run on Timken
roller bearings and may be either of the usual artillery type or what



Fig. 48. Chassis of Rapid Delivery Wagon.

is known as an indestriictible wheel, made of heavy, stamped sheet
steel, which not only has the advantage of great strength but is easier
to keep clean than the ordinary spoked type. Internal-expanding
hub brakes are employed on the rear wheels and are operated by a
hand lever, and as is usual with a planetary gearset, the reverse
may be employed as a transmission brake. The wheels are 32 inches
in diameter and are fitted with 3J-inch solid-rubber, endless tires.
By increasing the dimensions of the chassis throughout, and equipping
it with a 5i-inch by 5-inch motor, rated at 30 horse-power, it is listed
as a l^-ton to 2-ton car with a number of different types of bodies.
One of the Rapid cars has the distinction of being the only com-
mercial vehicle to have climbed to the sunmiit of Pike's Peak.
A chassis of the one-ton Rapid delivery wagon is shown in Fig. 48.
Types with Two-Cycle Motor. Owing to its great simplicity
and lack of small parts, the two-cycle type of motor would certainly



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COMMERCIAL VEfflCLES 77

appear to hold great promise for the commercial field. It is far
cheaper to build than the four-cycle type, as, with the exception
of the crank shaft, connecting rods, and bearings, a two-cycle motor
is composed wholly of iron castings. While not quite as economical
in operation as the four-cycle where fuel consumption is concerned,
the difference is hardly of suflBcient moment to have an important
bearing, and may be compensated for, to a large extent, by the lesser
number of cylinders required, owing to the more frequent impulses.
Its entire absence of valves and the numerous small parts which their
operation involves makes it a particularly advantageous type to place
in the hands of the ordinary driver, as, outside of the carbureter and
ignition, there is absolutely nothing in the way of adjustments that
the driver can tinker with. Owing to the fact that the four-cycle
motor had none of the short-comings of the two, the latter was never
considered seriously in the early days and almost entire attention
was devoted to the development of the former, and, except for the
efforts of a few pioneers with the courage of their convictions, it has
not had an opportunity to demonstrate of what it is capable, either
in the commercial or the pleasure-car field.

There are a few makers building two-cycle commercial cars —
the whole field, in fact, both pleasure and commercial, can be
accounted for on the fingers of one hand. Consequently, the two-
cycle motor is still in an unsettled state — ^it has not yet reached that
stage in its progress where it can be regarded as having been placed
on a standard basis, as practically every maker is building a motor
with special features of his own and no two are exactly alike, while
many differ radically. But the promise it holds of future develop-
ment may be gauged from its performance for many years past in
the marine field, as there are thousands of small two-cycle motors
in use in dories, oyster boats, and fishing boats that are put to the
hardest class of business service day after day and in all kinds of
weather. The two-cycle motor is also employed on a very large
and constantly increasing number of motor boats for pleasure use.
While marine sendee demands the sturdiest of construction, the
speed requirements are low, the ordinary two-cycle marine motor
being designed to develop its power at a normal r. p. m. rate seldom
exceeding 600 turns per minute This naturally involves a weight
per horse-power that is prohibitive for automobile use, the usual



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78 COMMERCIAL VEHICLES

6- to 8-horse-power, two-cycle, marine motor weighing quite as much
or more than a 30-horse-power, four-cycle, automobile type. The
reason for this will be apparent upon a consideration of the reference
to the flexibility of the motor and its power output as influenced by
its speed, Page 56. Weight is naturally not as objectionable in
a boat as on a vehicle which must transport itself and its load on rubber
tires. No little difficulty was experienced at the outset in the attempt
to improve the two-cycle motor by increasing its speed in order to
cut down its weight per horse-power, and the action of the motors
under experiment was so erratic and unsatisfactory, particularly
where an increase in their power output at the higher speeds was
concerned, that many of the investigators gave up the task and went
back to the four-cycle type. It is almost beyond the power of the
human mind to grasp the rapidity of the sequence with which the
different functions take place in a four-cycle motor when nmning
at speeds which were thought utterly impossible twenty years ago,
but which are now conMnon. When turning over at 1,800 r. p. m.,
as many small motors do, they are making 30 revolutions per second.
This means that 120 distinct operations mu^t be gone through every
second, i. e,, drawing in of the charge, compressing, firing, and ex-
hausting it. For the accomplishment of each, there is thus allowed
exactly tJt ot sl second. In fact, it has never quite been figured
out how the various operations can follow one another so rapidly
without conflicting — ^just how the burning gas of one chaise can be
so completely expelled as not to ignite the fresh gas of the charge
following it. 1,800 r. p. m. is not an extreme speed by any means,
as motors have been successfully operated at a rate as high as 2,200
r. p. m. or more, though the average automobile motor is not designed
to run much above 1,500 r. p. m. and the tendency is naturally to
lower this rather than to increase it.

When a two-cycle motor is running at 600 r. p. m., it is carry-
ing out as many functions as the four-cycle motor running at double
that speed, so that to design a two-cycle motor capable of a speed of
1,800 r. p. m. it is necessary to so arrange its intake and exhaust that
the gases may be successfully transferred \\ith the small time allow-
ance of Tj-J-g- of a second. This explains why the first attempts were so
disappointing, as the fresh charge was either fired by its predecessor
before reaching the combustion chamber, or was so small as to be



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productive of practically no power, this decreasing, instead of in-
creasing, as the speed became greater. The investigations were
continued, however, with the result that there are now several cars


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Online LibraryMedical Society of the State of North Carolina. AnCyclopedia of automobile engineering; a general reference work on the construction, operation, and care of gasoline, steam, and electric automobiles, instruction in driving, commercial vehicles, motorcycles, motor boats aerial vehicles, self-propelled railway cars, etc → online text (page 14 of 27)