| 摘要 |
A scissor jack has a leg having a lower end adapted to bear on the ground, a support arm having a lower end pivoted on an opposite upper end of the leg at an intermediate horizontal axis, and a load-bearing member engageable with the vehicle body and formed on an opposite upper end of the intermediate support arm. Upper and lower links are pivoted together at another intermediate horizontal axis with the upper link also pivotal on the support arm between the ends thereof at an upper horizontal link axis and the lower link also pivotal on the leg between the ends thereof at a lower horizontal link axis. A jack screw is connected between the intermediate axes and can draw the intermediate link axes toward one another to raise the load-bearing member or separate the intermediate link axes to lower the load-bearing member. A foot piece can rock on the lower end of the leg relative to the ground about a lower horizontal foot axis as the leg is raised and lowered. A control brace fixed on the lower link projects therefrom past the leg and beyond the lower horizontal link axis to support the jack in a raised position with the lower link axis above the ground. This brace has an outer end operatively engageable with the ground and forming a lower horizontal brace axis spaced from the other axes such that it always defines with the lower foot axis a plane generally parallel to a plane defined by the intermediate link axes.
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