Hoeing scraper control system

Claim 2

In a scraper vehicle having a bowl for receiving and transporting material and an apron disposed at the front region of said bowl, and support means for said apron which provides for forward and backward movements of said apron relative to said bowl and upward and downward movement of said apron relative to said bowl to accomplish hoeing motions the combination comprising: motor means coupled to said support means for moving said apron in any of said forward and backward and upward and downward directions relative to said bowl in response to control signals, and circuit means for generating a first predetermined sequence of said control signals for causing said apron to execute a first predetermined pattern of hoeing motion to assist movement of said material into said bowl, said circuit means having means for selectively generating a second predetermined sequence of said control signals to cause said apron to execute a modified pattern of hoeing motion, and manual means for conditioning said circuit means to produce any selected one of said sequences of control signals.

Claim 3

The combination defined in claim 1 wherein said circuit means has means for generating a third predetermined sequence of said control signals for causing said apron to move to a closed position at said forward region of said bowl to retain loaded material therein.

Claim 4

The combination defined in claim 2 wherein said circuit means for generating said third sequence of said control signals has means for causing said apron to move upward and backward simultaneously and then downward and backward simultaneously at least once in the course of movement towards said closed position.

Claim 5

The combination defined in claim 1 further comprising an electrical power source and wherein said circuit means comprises a stepping switch connected between said power source and said motor means and having a plurality of step positions with means for transmitting predetermined ones of said control signals to said motor means at predetermined successive ones of said step positions, said stepping switch further having drive means for stepping said stepping switch through said sequence of step positions, and a pulse generator connected between said power source and said drive means of said circuit means for transmitting a sequence of pulses to said drive means to sequentially progress said stepping switch through said sequence of step positions thereof.

Claim 6

The combination defined in claim 4 further comprising means for delaying the transmission of successive pulses from said pulse generator to said drive means at predetermined ones of said step positions to control the extent of movement of said apron during corresponding portions of said hoeing motion thereof.

Claim 7

The combination defined in claim 5 wherein said pulse generator produces said pulses in response to charging of a capacitor to a predetermined voltage level and wherein said stepping switch transmits a voltage from said power source to said capacitor at said step positions and wherein said time delay means at at least one of said step positions comprises a resistor connected between said stepping switch and said capacitor at said one stepping position to delay charging of said capacitor to said predetermined value for a predetermined time period.

Claim 8

The combination defined in claim 5 wherein said pulse generator produces said pulses in response to charging of a capacitor to a predetermined level and wherein said stepping switch transmits voltage from said power source to said capacitor at each Of said step positions and wherein said time delay means comprises a normally open limit switch connected between said stepping switch and said capacitor at at least one of said step positions of said stepping switch to charge said capacitor to said predetermined value only after said limit switch is closed, and means for closing said limit switch when said apron reaches a predetermined position in said hoeing motion thereof.

Claim 9

In a scraper having a bowl with an opening at the forward end for receiving material and having a pair of bail arms on opposite sides of said bowl which are pivotally attached to said bowl at the lower end of said bail arms and having at least one fluid pressure operated bail motor connected between said bowl and one of said bail arms for pivoting said bail arms forward and backwards and having an apron pivotally carried by said bail arms and having at least one fluid pressure operated apron motor coupled between said apron and one of said bail arms for pivoting said apron upward and downward relative to said bail arms the combination comprising: first electrically controlled valve means for actuating said bail motor to pivot said bail arms forward, second electrically controlled valve means for actuating said bail motor to pivot said bail arms backward, third electrically controlled valve means for actuating said apron motor to pivot said apron upwardly, fourth electrically controlled valve means for actuating said apron motor to pivot said apron downward, an electrical power source, a stepping switch having at least three banks of output contacts and having an input contact for receiving voltage from said power source and having drive means for sequentially connecting said input contact with successive ones of said output contacts at each bank in response to successive step pulses, step pulse generator means for transmitting said step pulses to said stepping switch in response to an input voltage of predetermined magnitude, conductor means connecting predetermined ones of said output contacts of said stepping switch with predetermined ones of said first, second, third, and fourth electrically controlled valves to cause said bail motor and said apron motor to move said apron through a predetermined pattern of movement as successive ones of said output contacts of said stepping switch are energized, and means transmitting said input voltage to said pulse generator through an individual one of said output contacts of said stepping switch at successive ones of said step positions thereof and having means for delaying rise of said voltage to said predetermined magnitude at predetermined ones of said step positions to predetermine the extent of specific movements in said predetermined pattern of movement of said apron.

Claim 10

In a scraper having a bowl with an opening at the forward end for receiving material and having a pair of bail arms on opposite sides of said bowl which are pivotally attached to said bowl at the lower end of said bail arms and having at least one fluid pressure operated bail motor connected between said bowl and one of said bail arms for pivoting said bail arms forward and backwards and having an apron pivotally carried by said bail arms and having at least one fluid pressure operated apron motor coupled between said apron and one of said bail arms for pivoting said apron upward and downward relative to said bail arms the combination comprising: first electrically controlled valve means for actuating said bail motor to pivot said bail arms forward, second electrically controlled valve means for actuating said bail motor to pivot said bail arms backward, third electrically controlled valve means for actuating said apron motor to pivot said apron upwardly, fourth electrically controlled valve means for actuating said apron motor to pivot said apron downward, an electrical power source, a stepping switch having at least three banks of output contacts and having an input contact for receiving voltage from said power source and having drive means for sequentially connecting said input contact with successive ones of said output contacts at each bank in response to successive step pulses, step pulse generator means for transmitting said step pulses to said stepping switch in response to an input voltage of predetermined magnitude, conductor means connecting predetermined ones of said output contacts of said stepping switch with predetermined ones of said first, second, third, and fourth electrically controlled valves to cause said bail motor and said apron motor to move said apron through a predetermined pattern of movement as successive ones of said output contacts of said stepping switch are energized, and means transmitting said input voltage to said pulse generator through an individual one of said output contacts of said stepping switch at successive ones of said step positions thereof and having means for delaying rise of said voltage to said predetermined magnitude at predetermined ones of said step positions to predetermine the extent of specific movements in said predetermined pattern of movement of said apron.

Claim 11

The combination defined in claim 1 wherein said circuit has position sensing means for initiating predetermined ones of said sequence of control signals in response to completion of an apron movement initiated by preceding ones of said control signals, and has timing means for initiating others of said signals a predetermined time after initiation of preceding ones of said signals.