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Original Year
1977
# of pieces
283
Categories
Construction Equipment:
Forklifts
Dimensions
28(L)x14(W)x16(H)
Features
Steering (rear), Lifting forks
More Information

850/950 Forklift

iso 850
Click the image to download the LDraw file of this model.
Model by Owen Dive

Set 850 was released under the "Technical Set" series in 1977 in Europe.  It finally made it to the US in 1979 with the number 950 as an "Expert Builder"set.  This forklift features rear wheel steering as well as forks which raise and lower, both using a rack and pinion system.  Traditional studded construction is used almost exclusively, with a couple of beams used vertically and attached with pins.

This was the least functional of the sets from 1977, but the first in a long line of yellow construction equipment which would dominate Technic releases to the present day.  This is one of the least complicated of the forklifts released by LEGO, but for the time was an excellent example of using the rack and pinion sets for something other than steering, and was an early example of using axles and pins in addition to studs for construction.

Features

Steering
The rear wheels can be steered using a vertical wheel at the driver's position.  As can be seen in the computer generated image, the wheel drives an axle connected to a 24 tooth crown gear.  Torque is rotated 90 degrees by a 24 tooth spur gear (via the crown gear used as a bevel gear).  On the same axle is an 8 tooth pinion which drives a pair of racks.  The steering mechanism itself uses 6 traditional 2x2 swivels with 2 pair allowing rotation of the wheels about the vertical axis and another pair acting as control arms attached to the rack gears.  Simple axles allow the wheels to rotate freely.

steering    steering2
Click for an animation of the steering in motion.
Forks
The forks can be raised and lowered using a horizontal wheel on the front right of the vehicle.  An axle transmits torque all the way to the left side where it is passed into a parallel axle using a set of 8 tooth and 24 tooth spur gears.  Finally, a pair of 8 tooth pinions ride on 6 racks which lift the forks.

When the forks are up, the rack gears protrude above the vehicle, making vertical clearance a problem.

Not much weight can be placed on the forks or they will backdrive the mechanism.  The moment created by the cantilevered weight is reacted by a force couple:  the upper forward load is reacted by the pinion gears, and the lower aft load is reacted by contact of the lower plate against the vertical structural assembly.
forks    forks
Click for an animation of the forks in motion.
Wheels and Tires
This set uses four rubber 17x43 tires and standard old gray wheels.
Wheels
 

Other Views

Side View
side view
Top View
top view
Front View
front view
Computer Render
Render

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