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A hydraulic jackhammer (Fig. i) consists of an impact mechanism, state sensors, a slidevalve distributor, and pressure and overflow lines. The impact mechanism has feedback with the distributor in specific positions of the hammer with respect to the frame. On account of the feedback, specified conditions of impact-mechanism motion exist, and the mechanism is brought into action at a definite value of the force Q applied to the handle. P'=Ppr-AP,.,;P2=Ppr +AP,; ~u='Pov+AP,.3. When x h Z (Zl + xf), the forward path of the hammer begins, i.e, y = i P, = Po* + APs,,; .P, = Ppr --AP,.4. When y 2 lov, the inverse-path chamber is connected to the auxiliary chamber and the overflow line, and the hammer moves slowly to rest, although Xh > 0 Pt = Pov -AP3.

No abstract