公开(公告)号：US4093092A

公开(公告)日：1978-06-06

申请号：US669936

申请日：1976-03-24

申请人： Cyril W. Habiger ,  Tom E. Robinson

发明人： Cyril W. Habiger ,  Tom E. Robinson

IPC分类号： B66F9/22 ,  B66F17/00 ,  F15B11/16 ,  F15B20/00 ,  B66F9/20

CPC分类号： B66F17/003

摘要： The invention is concerned with an improvement in a load lifting apparatus which comprises a primary load member pivotally mounted about a generally horizontal axis on a frame, a tilt cylinder and a tilt piston movable relative to one another pivotally connected to the frame and the primary load member to provide impetus for pivotal movement therebetween, a secondary load member movable relative to the primary load member, a lift cylinder and a lift piston movable relative to one another connected to the primary load member and the secondary load member to provide impetus for linear relative movement therebetween, tilt cylinder valve means for controlling flow of pressurized fluid from pump means to the tilt cylinder and lift cylinder valve means for controlling flow of pressurized fluid from the pump means to the lift cylinder. The improvement of the invention provides protection which prevents the apparatus from overbalancing. The improvement operates by sensing a moment created by a load on the apparatus. Most particularly, the improvement comprises a valve sensing simultaneously a lift pressure force proportional to a lift pressure in a head end of the lift cylinder and a tilt pressure force proportional to a tilt pressure in a rod end of the tilt cylinder. The valve blocks flow of pressurized fluid from the tilt cylinder to the tilt cylinder valve means and from the lift cylinder valve means to the lift cylinder responsive to the greater of the lift pressure force and the tilt pressure force exceeding a predetermined value. The improvement of the present invention is particularly useful in the lift trucks wherein the primary load member is a lift truck mast and the secondary load member is the forks of a lift truck.

摘要翻译： 本发明涉及一种负载提升装置的改进，该负载提升装置包括主要负载构件，其围绕框架上的大致水平的轴线枢转地安装，倾斜气缸和倾斜活塞可相对于彼此枢转地连接到框架和主负载 以提供其间的枢转运动的动力，可相对于主负载构件移动的次级负载构件，提升缸和可相对于彼此连接的连接到主负载构件和次级负载构件的提升活塞，以提供用于线性相对的动力 用于控制从泵装置到倾斜缸的加压流体的流动的倾斜缸阀装置和用于控制加压流体从泵装置到提升缸的提升缸阀装置。 本发明的改进提供了防止装置过度平衡的保护。 该改进通过感测由装置上的负载产生的时刻来进行。 特别地，改进包括阀同时检测与提升缸的头端中的提升压力成比例的升力压力和与倾斜缸的杆端中的倾斜压力成比例的倾斜压力。 该阀阻止加压流体从倾斜气缸到倾斜气缸阀装置的流动，并且响应于升高压力和倾斜压力超过预定值的较大值，从提升缸阀装置到提升缸。 本发明的改进在起重车中特别有用，其中主负载构件是升降车桅杆，而次级装载构件是叉车的叉子。