A Built-in Unioader for Timber Lorries
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A:1/4' • ingenious device which facilitates th: Unloadine of timber has beenevolved by an 'ex-U.S. Air Force pilot, Mr. P. Pernberthy.
the normal way, the timber, when it reaches the last roller on the lorry floor, is allowed to crash to the ground unless special external means be employed to lower it under control.
Mr. Pemberthy, who now owns one of the largest retail timber yards in California, . designed an unloading-device, which. being built into the rear of the timber truck. makes it possible for the timber to be: unloaded at any point without consideration .• for :cranes,. hoists or,. other external
mechanical aids. • • . The unloader .comprises two pivotally mounted box. . section arms which carry at their 'upper ends a roller lying on the same level as those fitted in the truck.. •
• The first step in unloading is to roll back the thither until the"centre of the load is over-the rearmost fixed roller: The unloader, which • is hydraulically operated by gear of .25-ton capacity, -comes into use as the load tilts over under the • control of a "snubbing". rope... • .. . As the unloader valve is opened the load is carefollv eased to the ground. • When the rear end makes contact with the ground, the .vehicle is .driyen forward until:tbe . • front half of the load is beating upon the unloader roller. With the vehicle braked,the driver operates a 'control in' the cab; and the load is carefully let down, .either oms to trestles or the ground. . As at present arranged, the device cannot he 'employed " in reverse" for loading, ' but it would not be a difficult matter to arrange for .this. • .
In the case of .comparatively light loads, the Pernherthy., Lumber Co. has built unloaders working on the .saine principle, but with mechanical linkage. Within their 'sphere, these have given complete satisfaction