| 摘要 |
An adjustable stand comprising a base with a pair of upstanding, spaced parallel friction plates having an upstanding arm with a lower end pivotally attached between the friction plates and an upper end connected to a supported load. The lower end of the arm has a friction member adapted to engage the friction plates. A counterbalancing tension spring extends between the arm and the base to substantially balance the weight of the arm and the supported load whereby the counterbalancing spring and the friction member act to ensure that the upstanding arm with its supported load will remain at any position to which the upstanding arm is pivoted. 12 |
