1. Ntiaj teb no Evolution

1940s–1950s: Primitive Temporary RampsTom qab WWII, booming highway freight tsim kev thov rau adjustable loading choj. Factories siv yooj yim ntoo / steel planks tsis muaj log lossis qhov siab hloov kho, tso siab rau ntawm phau ntawv padding, muaj kev nyab xeeb siab.

1960s–1980s: Mechanized First GenerationCov neeg tsim khoom nyob sab Europe & Asmeskas tau pib lub log steel ramps nrog guardrails. Phau ntawv jacks kho gradient; tes hydraulic twj tso kua mis tau qhia nyob rau hauv 1970s rau stepless qhov siab hloov, ua qauv warehouse khoom. Lub peev xwm thauj khoom tau txwv rau 5-8 tons nrog cov qauv kev nyab xeeb yooj yim.

1990s-2000s: Mature Hydraulic TechnologyHigh-tensile manganese steel, anti-slip grating, rub tuav thiab cov log tsheb tau siv dav. Dual-lub tog raj kheej nqa, kev ruaj ntseg chains thiab kev txhawb nqa ob txhais ceg txhim kho kev ruaj ntseg. Modular ntau lawm enabled 6-15 tuj kev cai qauv, thiab CE cov qauv kev nyab xeeb tau tsim thoob ntiaj teb.