Pedal actuated steering clutch and brake controls for tractors

Abstract

.Iadd.The steering clutches and steering brakes of a tractor are operated by foot pedals. Each of two pedals operates to release its respective clutch and apply the corresponding brake. A third pedal, located intermediate the other two, applies both brakes without operating the clutches. .Iaddend.

We claim: 
     
       1. In a tractor which has steering clutches and steering brakes, the combiation comprising: .Iadd.first and second .Iaddend.actuating members for said clutches and brakes, .Iadd.a fluid-operated clutch disengaging valve associated with each clutch, a .Iaddend.linkage .Iadd.arrangement to operate one clutch disengaging valve and .Iaddend.to release one clutch upon actuation of one member and to apply the corresponding brake upon further actuation of said one member, and .Iadd.a .Iaddend.similar linkage .Iadd.arrangement .Iaddend.between the other clutch and brake and the other member, .Iadd.each of said linkage arrangements including a first linkage from each actuating member to the corresponding clutch disengaging valve and a second separate linkage from each actuating member to the corresponding brake, .Iaddend.a third member and means operable upon actuation of said third member to apply both brakes only .Iadd.and without operating the clutches. .Iaddend. .[.2. The combination of claim 1 in which the linkages between the one and the other members include hydraulic valves and means in said valves to permit the further member actuation for 
     
     
        applying the brakes after release of the clutches..].  3. In a tractor which has steering clutches and steering brakes, the combination comprising: actuating pedals for said clutches and brakes, linkage to release one clutch upon depression of one pedal and to apply the corresponding brake upon further depression of said one pedal, similar linkage between the other clutch and brake and the other pedal, a third pedal .Iadd.disposed between the other two.Iaddend. , .[.and.].  means operable upon depression thereof to .[.apply.].  .Iadd.operate .Iaddend.both brakes only .Iadd., and said means including a member pivotally connected to the third pedal and engaging both linkages to 
     
     
        equalize brake applying pressure.Iaddend. . 4. .[.The combination of claim 3 in which.]. .Iadd.In a tractor which has steering clutches and steering brakes, the combination comprising: two actuating pedals for said clutches and brakes, linkage to release one clutch upon depression of one pedal and to apply the corresponding brake upon further depression of said one pedal, similar linkage between the other clutch and brake and the other pedal, a third pedal, means operable upon depression thereof to operate both brakes only, and .Iaddend.the linkages between the pedals and the clutches .[.include.]. .Iadd.including .Iaddend.hydraulic valves and means in said valves to permit the further pedal depression for applying the brakes after release of the clutches. .Iadd. 5. The combination of claim 1 including means connected to the third member for engaging both said second separate linkages to equalize brake applying pressure. .Iaddend..Iadd. 6. The combination of claim 1 in which each said linkage includes a first linkage to release the corresponding clutch, and a second separate linkage from each pedal to the corresponding brake; and in which the means operable upon depression of the third pedal includes the second separate linkages but not the first linkages. .Iaddend..Iadd. 7. The combination of claim 6 in which the means operable upon depression of the third pedal also includes a member operatively connected to the third pedal for engaging both said second separate linkages to equalize brake applying pressure. .Iaddend. .Iadd. 8. In a tractor which has steering clutches and steering brakes, the combination comprising: first and second actuating pedals for said clutches and brakes, a shaft and means for pivotally mounting the first and second pedals on the shaft, linkage to release one clutch upon depression of one pedal and to apply the corresponding brake upon further depression of said one pedal, similar linkage between the other clutch and brake and the other pedal, a third pedal, means for pivotally mounting the third pedal on the shaft intermediate the first and second pedals and generally colinear therewith, and means operable upon depression of the third pedal to apply both brakes only and without operating the clutches. .Iaddend..Iadd. 9. The combination of claim 8 including a fluid-operated clutch disengaging valve associated with each clutch, and wherein the linkage is arranged to operate one clutch disengaging valve to release one clutch upon depression of one pedal. .Iaddend..Iadd. 10. The combination of claim 8 in which each said linkage includes a first linkage to release the corresponding clutch, and a second separate linkage from each first and second pedal to the corresponding brake. .Iaddend. .Iadd. 11. In a tractor which has steering clutches and steering brakes, the combination comprising: first and second actuating pedals for said clutches and brakes; a shaft and means for pivotally mounting the first and second pedals on the shaft; linkage to release one clutch upon depression of one pedal and to apply the corresponding brake upon further depression of said one pedal; similar linkage between the other clutch and brake and the other pedal; a third pedal; means for pivotally mounting the third pedal on the shaft intermediate the first and second pedals and generally colinear therewith; means operable upon depression of the third pedal to apply both brakes only; each said linkage including a first linkage to release the corresponding clutch, and a second separate linkage from each first and second pedal to the corresponding brake; and each second linkage including a lever pivotally mounted on the shaft at a position intermediate the third pedal and one of the first and second pedals. .Iaddend. .Iadd. 12. The combination of claim 11 in which each lever is separate from but engageable by its adjacent pedal of the first and second pedals. .Iaddend..Iadd. 13. The combination of claim 12 in which the means operable upon depression of the third pedal includes an outwardly-extending equalizer bar pivotally connected to the third pedal about an axis extending crosswise of the shaft and extending outwardly for engaging both levers when the third pedal is depressed to thereby apply both brakes without operating the clutches and without depressing the first and second pedals. .Iaddend..Iadd. 14. The combination of claim 13 including stop means on the third pedal to limit pivotal movement of the equalizer bar. .Iaddend..Iadd. 15. The combination of claim 13 including a fluid-operated clutch disengaging valve associated with each clutch, and wherein each first linkage is arranged to operate one clutch disengaging valve to release one clutch upon depression of one pedal. .Iaddend. .Iadd. 16. In a tractor which has steering clutches and steering brakes, the combination comprising: first and second actuating pedals for said clutches and brakes; means for pivotally mounting the first and second pedals on the tractor at spaced positions; linkage to release one clutch upon depression of one pedal and to apply the corresponding brake upon further depression of said one pedal; similar linkage between the other clutch and brake and the other pedal; a third pedal; means for pivotally mounting the third pedal on the tractor at a position intermediate the first and second pedals; means operable upon depression of the third pedal to operate both brakes only; and said last-mentioned means including a first lever pivotally mounted on the tractor at a position intermediate the first and third pedals, a second lever pivotally mounted on the tractor at a position intermediate the second and third pedals, and a member pivotally mounted on the third pedal for engaging the first and second levers upon depression of the third pedal. .Iaddend. .Iadd. 17. In a tractor which has steering clutches and steering brakes, the combination comprising: first and second actuating pedals for said clutches and brakes; a shaft and means for pivotally mounting the first and second pedals on the shaft; a linkage arrangement to release one clutch upon depression of one pedal and to apply the corresponding brake upon further depression of said one pedal; a similar linkage arrangement between the other clutch and brake and the other pedal; a third pedal; means for pivotally mounting the third pedal intermediate the first and second pedals and generally colinear therewith; means operable upon depression of the third pedal to apply both brakes only; each of said linkage arrangements including a first linkage to release the corresponding clutch, and a second separate linkage from each first and second pedal to the corresponding brake; each second linkage including a lever on the shaft at a position adjacent the pedals; each lever being separate from but engageable by its adjacent pedal of the first and second pedals; a fluid-operated clutch disengaging valve associated with each clutch; and each first linkage being arranged to operate one clutch disengaging valve to release one clutch upon depression of one pedal. .Iaddend. .Iadd. 18. In a tractor which has steering clutches and steering brakes, the combination comprising: actuating pedals for said clutches and brakes; linkage to release one clutch upon depression of one pedal and to apply the corresponding brake upon further depression of said one pedal; similar linkage between the other clutch and brake and the other pedal; each said linkage including a first linkage to release the corresponding clutch, and a second separate linkage from each of said actuating pedals to the corresponding brake; a third pedal located between the other actuating pedals; means operable upon depression thereof to apply both brakes only; and the means operable upon depression of the third pedal including the second separate linkages but not the first linkages, and a member operatively connected to the third pedal for engaging both said second separate linkages to equalize brake applying pressure. .Iaddend.