US 5,177,415 AGranted

Apparatus and method for controlling a vibratory tool

AssigneeCaterpillar Paving Products Inc.

InventorsAlain J. Quibel, Michel M. Aubourg, Michel H. Froumentin, Rene G. Divay

Life of this patent

Estimating the term…

Loading patent…

Abstract

An apparatus 400 and a method are provided for increasing the density of a compactible material 10 while continuously evaluating the density of the material. The evaluation of material density is carried out by calculating the total of the static, dynamic and centrifugal forces applied by a vibrating tool 102 l to the compactible material 10. The total applied force calculation includes measuring the vertical acceleration of the material contacting member 102 and the position of an eccentric mass 206 mounted on the material contacting member 102. The acquisition of these parameters is carried out simultaneously, and the calculation of the dynamic and centrifugal forces is made when the material contacting member 102 is at its lowest position.

Claims15

Dependent claims

A method for controlling a vibratory tool for moving over and compacting compactible material, said vibratory tool having a member eccentrically attached to a rotatable shaft, said eccentrically attached member having a mass and said tool being mounted on a chassis, comprising:

moving the vibrating tool over the compactible material and maintaining said tool in substantive rolling contact with said material during moving;
rotating said eccentrically attached member simultaneously with moving said vibrating tool;
sensing the vertical acceleration of said vibrating tool and producing signals corresponding to the magnitude and direction of said vertical acceleration;
determining the maximum positive value of the vertical acceleration signals during one rotation of said eccentric member;
sensing the presence of the rotating eccentric mass at a predetermined reference position;
calculating the angular position of said rotating eccentric mass responsive to the determined maximum positive value vertical acceleration signal;
delivering said determined maximum positive value vertical acceleration signal;
comparing said calculated angular position of the eccentric member with said predetermined position and producing a signal representative of the angular displacement between said calculated angular position and said predetermined reference position;
producing signals representative of the mass of said chassis, said vibrating tool and said eccentrically mounted member;
producing a signal representative of the distance between the center of gravity of said eccentrically attached member and the center of rotation of said shaft;
producing a signal representative of the rotational frequency of said eccentrically mounted member;
receiving said signals corresponding to the maximum positive value of the acceleration of said vibrating tool, the angular displacement of said eccentrically attached member, the mass of said chassis, said vibrating tool and said eccentrically attached member, and the distance and rotational frequency of said eccentrically attached member;
calculating the static, dynamic and centrifugal forces applied by said vibrating tool to the compactible material;
summing said calculated static, dynamic and centrifugal forces applied by said vibrating tool to said compactible material;
delivering a signal responsive to said summing;
and
stopping the movement of said vibrating tool over the compactible material when said summing signal has a predetermined value.

14 more elements

In an apparatus for controlling a vibratory tool having a chassis, a material contacting member resiliently and rotatably mounted on the chassis, a shaft rotatably mounted on the material contacting member, a member eccentrically attached to the rotatably mounted shaft, and a means for rotating the shaft includes a means for sensing vibratory motion of the material contacting member and producing a signal corresponding to said vibratory motion, and a means for determining the angular position of the eccentrically attached member relative to a preselected position when the vibratory motion of said material contacting member is at a maximum value and producing a signal corresponding to said relative angular position, the improvement comprising:

means for delivering a plurality of set point signals each representative of a respective mass of said chassis, mass of said material contacting member, mass of said eccentrically attached member, and distance from the center of gravity of the eccentrically attached member to the center of rotation of said shaft;
means for sensing the rotational frequency of the eccentrically attached member, developing a signal in response thereto, and delivering said developed signal;
means for receiving said set point signals and said rotational frequency signal, calculating the static, dynamic, and centrifugal forces of said material contacting member, summing the value of said calculated forces, and delivering a signal responsive to said summed calculated forces;
comparing said summed calculated forces signal to a predetermined set point value;
and
delivering a signal for stopping movement of said vibratory tool in response to the comparison of said summed calculated forces signal being at a predetermined magnitude.

3 more elements

Dependencies are inferred from the claim text.