116
MILK DELIVERY CYCLE UNITS
[Vol. XXIV, Part II,
For the three units designed here, standard rickshaw parts were used as far as possible;
they are less expensive than special spare parts which must be imported, and are
usually available locally, some of them actually made in India.
THE TRAILOR UNIT
This unit consists of an ordinary bicycle to which is attached a two-wheeled
trailor. The trailor includes a carrier rack that is mounted on two wheels; the
trailor is attached to the bicycle by means of a handle or tongue. A special mecha
nism which permitted freedom of movement both horizontally and vertically was
used in this attachment (Plate IV, Fig. 5).
Two models of this unit were made and observed under actual route use. The
carrier rack of the first is made from ½ and ¾ inch strap or angle iron, that of the second
from 3/4 inch galvanized iron pipe; otherwise the two are similar. The rack is of
open and welded construction with a wooden floor. The four sides extend 18 inches
above the floor which is 28 inches wide and large enough to hold two five-gallon milk
cans 34 inches long side by side at the rear, and a case of up to a dozen bottles of milk
at the front. The carrier rack is supported on springs fixed to the axel at either
end of which is an ordinary bicycle wheel. The leaf-type springs support either
side of the carrier and absorb much of the road shock when the unit is in operation.
The handle is fixed to the front of the carrier rack and attached to the bicycle from
immediately below the seat and above the rear wheel. Initially this attachment
included a ball and socket joint to give the required freedom of motion, but this
proved unsatisfactory. A double-hinged or universal joint connection has proved
more satisfactory.
Both models were used on the regular routes of the Institute dairy for over three
years. The strap iron carrier rack broke frequently during operation; fractures
being most common in the corners just outside of the welds. The rack made of
galvanized iron piping pipe was more durable and therefore more satisfactory, despite
being a little heavier. Both models placed such a very heavy load on the bicycle
frame at the point of attachment, however, that the fork of that frame, extending
from the seat base to the rear wheel frequently broke. This unit was very flexible
in operation, giving the cycle rider substantially as much freedom of movement as on
an ordinary bicycle without a trailor attached.
THE SIDE-CAR UNIT
This unit consists of an ordinary bicycle and a carrier rack supported mainly
by the rear cycle wheel and an additional wheel to the right of the cycle (Plate IV,
Fig. 6). In the way it is constructed and in the manner in which it is supported on
its axel by two leaf-type springs, this carrier rack is similar to those of the trailor
except that the front of the rack is about eight inches narrower, viz. only 20 inches.
This narrower width is continued backwards for about ⅔ of the length of the carrier,
to make room for unimpaired pedal action by the rider. The rear 1/3 of this carrier
rack is full width.
The inner end of the axel is fixed to the rear axel of the bicycle by means of an
inverted U-shaped bar made of one inch angle iron, the outer end is supported by a
standard bicycle wheel which is on its axel. The front inside corners, top and bottom.