Ground compacting apparatus

Claim 2

IN a ground compacting machine of the type which includes an Operator''s station; vibration producing means cylically movable at selectively variable frequencies; and means including a ground contacting member vibrated by said vibration producing means; the improvement comprising: means on the machine responsive to the phases of said vibration producing means and said means vibrated thereby for producing a signal output independently of the relative vibration amplitude of the vibration producing means and the means vibrated thereby, the signal output being related solely to a phase difference; and, means on the machine adjacent said operator''s station and operatively connected to said responsive means for producing a visual indication from said output.

Claim 3

A ground compacting machine according to claim 1 including means responsive to said signal output for regulating the frequency of said vibration producing means.

Claim 4

In a vibratory compactor of the type including a frame, a ground engaging compacting member resiliently mounted on the frame, and vibration producing means cyclically movable at selectively variable frequencies for cyclically vibrating the compacting member at substantially the cyclic frequency of the vibration producing means to cause the compacting member to engage the ground in compacting relationship, the improvement comprising: first detector means for detecting the cyclic movement of the vibration producing means; second detector means for detecting the cyclic movement of the compacting member; means responsive to said first and second detector means for determining, independently of the relative amplitudes of the detected cyclic movements, the relationship of a predetermined phase difference desired to be maintained during operation of the machine to the existing phase difference between the detected cyclic movement of the vibration producing means and the detected cyclic movement of the compacting member; and means for varying the frequency of said vibration producing means, whereby such frequency may be adjusted to produce the desired correlation of the phase difference between the cyclic movements of the vibration producing means and the compacting member with said predetermined phase difference.

Claim 5

In a vibratory compactor of the type including a frame, a ground engaging compacting member resiliently mounted on the frame, and vibration producing means cyclically movable at selectively variable frequencies for cyclically vibrating the compacting member at substantially the cyclic frequency of the vibration producing means to cause the compacting member to engage the ground in compacting relationship, the improvement comprising: first detector means for detecting the cyclic movement of the vibration producing means; second detector means for detecting the cyclic movement of the compacting member; means responsive to said first and second detector means for determining, independently of the relative amplitudes of the detected cyclic movements, the relationship of a predetermined phase difference desired to be maintained during operation of the machine to the existing phase difference between the detected cyclic movement of the vibration producing means and the detected cyclic movement of the compacting member; and means for varying the frequency of said vibration producing means, whereby such frequency may be adjusted to produce the desired correlation of the phase difference between the cyclic movements of the vibration producing means and the compacting member with said predetermined phase difference.

Claim 6

A vibratory compactor according to claim 3, including means for establishing as said predetermined phase difference a lag of said compacting member about 90* behind said vibration producing means.

Claim 7

A vibratory compactor according to claim 4, including means for controlling said frequency varying means in response to the output from said phase difference relationship determining means to effect an increase in the frequency of said vibration producing means when said compacting member lags behind said vibration producing means less than said predetermined frequency difference and to effect a decrease in the frequency of said vibration producing means when said compacting member lags behind said vibration producing means more than said predetermined frequency difference.

Claim 8

A vibratory compactor according to claim 3, wherein said first detector means comprises means for detecting at least one cyclic position of the vibration producing means relative to the frame; and, wherein said second detector means comprises means carried by the frame for detecting at least one cyclic position of the frame, the cyclic position of the frame being related to the cyclic position of the compacting member.

Claim 9

A vibratory compactor according to claim 3, wherein said first detector means comprises means for detecting at least one cyclic position of the vibration producing means relative to the frame in response to the position of a reference on the vibration producing means relative to the position of a reference on the frame; and, wherein said second detector means comprises means for detecting at least one cyclic position of the compacting member relative to the frame in response to the position of a reference on the compacting member relative to the position of a Reference on the frame.

Claim 10

A vibratory compactor according to claim 7, wherein said second detector means includes light beam producing means and photosensitive means, one of such means being mounted for movement with said compacting member and the other being mounted for movement with said frame at a position such that the light beam contacts said photosensitive means when the relative movement between the compacting member and the frame brings these parts to the relative vertical locations occupied thereby when the machine is at rest.

Claim 11

A vibratory compactor according to claim 7, wherein said second detector means includes magnetic field generating means and electric conductor means, one of such means being mounted for movement with said compacting member and the other being mounted for movement with said frame at a position such that said electric conductor means cuts said magnetic field when the relative movement between the compacting member and the frame brings these parts to the relative vertical locations occupied thereby when the machine is at rest.

Claim 12

A vibratory compactor according to claim 3, wherein said second detector means comprises means for detecting at least one cyclic position of the compacting member at which the vertical component of acceleration of said member is about zero.

Claim 13

A vibratory compactor according to claim 10, wherein said second detector means includes a mass mounted for vibration relative to said compacting member in a vertical direction at substantially the same frequency, and means for generating a marker pulse each time said mass moves in one direction past a center point of its path of vibrating movement.

Claim 14

A vibratory compactor according to claim 11, wherein said mass is supported on said compacting member.

Claim 15

A vibratory compactor according to claim 12, including magnetic field generating means and electric conductor means, one of such means being mounted for movement with said mass and the other being mounted for movement with said compacting member, said conductor means being positioned to cut said magnetic field as said mass moves past a center point of its path of vibrating movement.

Claim 16

A vibratory compactor according to claim 11, wherein said mass is supportd on said frame and the cyclic position of said frame is related to the cyclic position of said compacting member.

Claim 17

A vibratory compactor according to claim 14, including magnetic field generating means and electric conductor means, one of such means being mounted for movement with said mass and the other being mounted for movement with said frame, said conductor means being positioned to cut said magnetic field as said mass moves past a center point of its path of vibrating movement.

Claim 18

In a compactor of the vibratory roller type which includes a frame, rotatable shaft means, means including a resilient element for connecting said shaft means to said frame for rotation and bodily movement relative thereto, an eccentric mass fixed on said shaft means for rotation therewith, a ground contacting compaction roller mounted for free rotation on said shaft means and variable speed drive means for rotating said shaft means to rotate said eccentric mass and produce vibration of said roller relative to said frame, the improvement which comprises: means for producing a first signal when said eccentric mass passes a certain portion of its path of movement and for producing a second signal when said roller passes a certain point in its path of vibrational movement; means responsive to said first and second signals for producing a signal output related to the angular difference between the occurrences of said first and second signals, said signal output being produced by said responsive means independently of the relative amplitudes of said first and second signals.

Claim 19

In a compactor of the vibratory roller type which includes a frame, rotatable shaft means, means including a resilient element for connecting said shaft means to said frame for rotation and bodily movement relative thereto, an eccentric mass fixed on said shaft means for rotation therewith, a ground contacting compaction roller mounted for free rotation on said shaft means and variable speed drive means for rotating said shaft means to rotate said eccentric mass and produce vibration of said roller relative to said frame, the improvement which comprises: means for producing a first signal when said eccentric mass passes a certain portion of its path of movement and for producing a second signal when said roller passes a certain point in its path of vibrational movement; means responsive to said first and second signals for producing a signal output related to the angular difference between the occurrences of said first and second signals, said signal output being produced by said responsive means independently of the relative amplitudes of said first and second signals.

Claim 20

A compactor according to claim 16, including means for automatically adjusting said variable speed drive means to change the speed of said eccentric mass in one diRection when said angular difference is below a predetermined value and to change the eed of said eccentric mass in the opposite direction when said angular difference is above a predetermined value.

Claim 21

A compactor according to claim 16, including means for producing a third signal when said eccentric means passes another point in its path of movemnt; and means responsive to said second and third signals for producing a second signal output related to the angular difference between the occurrences of said second and third signals.

Claim 22

A compactor according to claim 18, wherein said third signal trails said first signal by a predetermined angle in the direction of rotation of said eccentric mass, and wherein means responsive to said signal outputs is provided for automatically aadjusting said variable speed drive means to increase the speed of said eccentric mass when said second signal trails said first signal and for decreasing the speed of said eccentric mass when said second signal leads said third signal.

Claim 23

A compactor according to claim 16, wherein said shaft means includes a first shaft element mounted on said frame for rotation about an axis fixed with respect to said frame, a second shaft element coaxial with said compaction roller, and means rotatably coupling said shaft elements together while permitting bodily movement of said second shaft element relative to said frame; and wherein said means for producing said first signal includes means for generating a signal in response to the roation of an angular segment of said first shaft element past a reference station fixed with respect to said frame.

Claim 24

A compactor according to claim 20, wherein said means for generating a signal in response to the rotation of an angular segment of said first shaft element past a reference station fixed with respect to said frame includes an annular member fixed coaxially to said first shaft element and having an opening therethough; and light source means and photosensitive means fixed to said frame in positions such that light from said source means strikes said photosensitive means when said opening is located between said source means and said photosensitive means.

Claim 25

A compactor according to claim 20, wherein said means for generating a signal in response to the rotation of an angular segment of said first shaft element past a reference station fixed with respect to said frame includes cam and cam follower means carried respectively by said first shaft element and said frame; and switch means actuated by said cam follower means.

Claim 26

A compactor according to claim 20, wherein said means for generating a signal in response to the rotation of an angular segment of said first shaft element past a reference station fixed with respect to said frame includes cylindrical means rotatable with said first shaft element and having an electrically conductive surface portion; and brush means mounted on said frame in position to contact said electrically conductive surface portion during a portion of each revolution of said first shaft element.