ive devices have been introduced to the market, however, no device introduced previously nor now available combines the functions present in the current invention, nor do they offer the innovative features contained therein.
The present invention alleviates this lack of product offering by supplying a device which combines several handy, or in some cases, essential articles into one, and further, incorporates new features not ordinarily seen in such an application, such as voltage converters. These aspects are then packaged into a product having a small footprint and one which is easily portable.

As is well known, the traveling apparatus of the crawler vehicle is required two functions of obtaining a great traction force and reducing a vibration and an impact of the vehicle, at a time of traveling the ground surface having the great rolling plain or the irregularity such as rocks or the like.
In particular, in the crawler vehicle such as a tractor, a bulldozer and the like working on the basis of the traction force, a traction force at a time when a crawler belt of the traveling apparatus slips due to a dozing load or a traction load (hereinafter, refer to as a shoe slip) is a critical traction force of the vehicle. Accordingly, the traveling apparatus of the vehicle is required to be structured such that the shoe slip can be inhibited from being generated as much as possible under a predetermined vehicle mass, whereby a high traction force can be obtained.
In order to solve the problem mentioned above, there has been conventionally considered various kinds of traveling apparatus of the crawler vehicle. As a first example, in Japanese patent document 1: Japanese Unexamined Patent Publication No. 57-107964, there is described a traveling apparatus of a crawler vehicle in which an improved road-hugging property of the traveling apparatus is secured at a time of traveling on the road surface having the great rolling or the irregularity such as the rocks or the like, and both of securing the traction force and cushi