Hitachi Construction Machinery Co., Ltd.

Manabu Ogasawara

Hideki Akita

Kazuyoshi Hatano

Toshio Hasegawa

Makoto Ota

Atsushi Hoshino

Hideaki Nakatani

Takemasa Kudou

Kazumasa Omotera

Tooru Nabeshima

Junichi Kouda

Keishi Kondou

Minoru Itou

Motohiro Ishii

On the lower surface of a cylinder stay at its fore end portion, a stopper plate is pivotally attached as a safety device for front working equipment by a pin. A rear end portion of the stopper plate is supported to an upper boom to be swung in union with the upper boom. The stopper plate has an outer peripheral configuration having a first curved region which functions as a first stopper, and a second linear region which functions as a second stopper. When a swing angle of the upper boom is within a risky range of possible interference between the bucket and the cab upon the arm being maximally folded, an inner belly portion of the arm strikes against the first region before the occurrence of such interference, whereby further folding of the arm is mechanically limited. When the arm is folded from a condition that the swing angle of the upper boom is within a range in which the bucket and the cab will never interfere with each other and a folding angle of the arm comes within a risky range of possible interference between the bucket and the cab upon the upper boom being further swung laterally toward the cab side, the second region strikes against a side portion of the arm before the occurrence of such interference, whereby further swing of the upper boom is mechanically limited.

Offset boom type construction machine

The improved slide bearing assembly comprises at least a shaft and a bush that is formed of a porous iron-base sintered material and is characterized in that the bush is impregnated with a lubricant oil having a viscosity of 240-1500 cSt. The bearing assembly can be operated in slow- and high-pressure applications without oil refillings for a prolonged period of at least several years. The shaft is preferably formed of an iron or a steel member that have been subjected to a treatment of surface modification. The slide bearing assembly is preferably used in such an environment that the working pressure applied to the sliding surfaces is at least 6.0 kgf/mm.sup.2 and that the sliding speed is in the range 2-5 cm/sec.

Slide bearing assembly

Growing community of inventors

Ibaraki-ken, Japan

Manabu Ogasawara