cable jack is a heavy-duty mechanism that performs the function of raising the cable reel to a certain height.Typically, the value of the lift amount is not very large and is only a few centimeters.It uses this tool as a pay-off at work, or rewind the cable laying.
device
cable jack (DC 5V included) has a very primitive structure, which consists of the following components:
- rack;
- cradle;
- lifting gear and axle.
design features
existing cable jack as follows.Through the central hole in the drum unit bore holes for the axis of the jack, which is mounted on the centering sleeves or cones.This special Platen shoes move on the axis of the spinning drum cheek and locked with the clamp.Racks are mounted on this apparatus on either side.Thus they provide a working air gap between the design of the rack and drum cheek.Usually this value does not exceed the level of 10 centimeters.Why jack cable (DC 5 in particular) can not be set larger gap?The fact that an increase in the distance between the two devices would increase the bending moment of the axis, and this, in turn, can lead to breakage and failure of the entire mechanism.
As for lodgements, they are aligned with the axis of the cable drum and are utilized as a hoist.It does not really matter, it's a pair of screw or hydraulic system.Lifting height of the coil is about 50-100 millimeters.
Species
There are several types of these devices:
- screw;
- lever;
- hydraulic.
Each of these devices has its own principle.To understand the structural characteristics of each, consider all three types separately.
begin with devices that have a screw drive system.Such a cable jack operates on the principle of a screw pair, wherein the coil lifting nut performs rotational movement, and the screw - translational.
Hydraulic devices in their own special.Their design requires a special hydraulic cylinder or jack, which acts as the main hoist.In such instruments the process of raising the coil takes place by reciprocating movements hydraulic jack handle, or hydropower.
lever unit constitute a set of jacks, in which the lifting cable reel is performed by using a special lever.In this part are assigned all the efforts that developed due to the difference shoulders and arms of the cradle relative to the central pivot point.
Thus, cable jack - a mechanism which can carry out lifting of the cable drum by means of different devices to a particular height, but not more than 50 or 100 millimeters.
