Method and apparatus for adapting the operational behavior of a percussion mechanism to the hardness of material that is being pounded by the percussion mechanism

An apparatus for use in a method in which material is pounded using a first operational unit, which receives energy at an input port from a second operational unit, while the operational behavior of the first operational unit is adapted to the hardness of the material being pounded, both operational units having respective internal resistances, the second operational unit being a conveying unit which conveys a hydraulic driving medium to the input port of the first operational unit and the first operational unit being a percussion mechanism having a striking piston which is reciprocated by the driving medium, the method including the steps of (a) determining a measured value, step (a) including measuring the striking rate of the striking piston from outside the percussion mechanism, (b) generating a limit value, (c) supplying the measured value and the limit value to a control system, and (d) adjusting the internal resistance of one of the operational units with an adjustment member in such a manner that the internal resistance is increased if the measured value rises to the limit value, the adjustment member being responsive to a control instruction generated by the control system, wherein said apparatus comprises:

• striking rate sensor means, disposed outside the percussion mechanism, for measuring the striking rate in step (a) of the method, the striking rate sensor means having an output;
• a striking rate controller connected to the output of the striking rate sensor means;
• adjusting member means, responsive to the striking rate controller, for increasing the internal resistance of one of the operational units, in step (d) of the method, if the value of the striking rate measured by the striking rate sensor means rises to the limit value.

An apparatus for use in a method in which material is pounded using a first operational unit, which receives energy at an input port from a second operational unit, while the operational behavior of the first operational unit is adapted to the hardness of the material being pounded, both operational units having respective internal resistances, the second operational unit being a conveying unit which conveys a hydraulic driving medium to the input port of the first operational unit and the first operational unit being an adjustable percussion mechanism having a striking piston which is reciprocated by the driving medium, the percussion mechanism having a stroke whose magnitude can be set, the method including the steps of (a) determining a measured value, step (a) including measuring the striking rate of the striking piston from outside the percussion mechanism and determining the rate at which the operating fluid enters the input port, the measured value corresponding to the ratio of the striking rate to the rate at which the operating fluid enters input port, (b) generating a limit value, the limit value being predetermined as a function of the magnitude set for the stroke of the percussion mechanism, (c) supplying the measured value and the limit value to a control system, and (d) adjusting the internal resistance of one of the operational units with an adjustment member in such a manner that the internal resistance is increased by adjusting the magnitude set for the stroke if the measured value rises to the limit value, the adjustment member being responsive to a control instruction generated by the control system, said apparatus comprising:

• striking rate sensor means, disposed outside the percussion mechanism, for measuring the striking rate in step (a) of the method;
• incoming drive fluid sensor means, disposed outside the percussion mechanism, for determining the rate at which the operating medium enters the input port in step (a) of the method;
• calculating member means, responsive to the striking rate sensor means and to the incoming drive fluid sensor means, for determining the measured value in step (a) of the method by finding the ratio of the striking rate to the rate at which the driving fluid enters the input port;
• a controller connected to the calculator member means, the controller receiving the measured value and the limit value in step (c) of the method;
• and
• adjustment member means, responsive to the controller, for increasing the internal resistance of the percussion mechanism in step (d) of the method if the measured value rises to the limit value.