| 摘要 |
<p>COMPACT CRANE A compact truck-mounted towing crane is constructed with a boom pivoted near the center thereof. A tow bar secured at the rear end of the boom is positioned below the boom pivot, and a power cylinder is connected to the forward end of the boom for raising a vehicle which is to be towed. The boom pivot is at the rear of a base secured to the frame of the towing vehicle and the power cylinder is secured to the front of the base. The relative positions of the boom and power cylinder are such that the power cylinder arm is retracted during the power stroke to lower the front end of the boom, thereby raising the tow bar and the load thereon. The tow bar together with the portion of the boom to the rear of the main pivot are removable as a unit by simply withdrawing a pivot pin which connects front and rear sections of the boom together in the vicinity of the main pivot. The rear section is movable about this pivot pin between an extended or working position and a storage position wherein the tow bar is positioned above and to the rear of the main pivot.</p> |
