IE41994B1 - Improvements in multi-furrow ploughs - Google Patents

Abstract

1483834 Multi-furrow trip ploughs RANSOMES SIMS & JEFFERIES Ltd 15 Jan 1976 [17 Jan 1975] 2196/75 Heading A1B The hydraulic cylinder 29 of the foremost plough beam 3 is connected to an hydraulic accumulator 51 by way of valve means 61 which restrict the flow of hydraulic fluid to the accumulator 51 so that the frequency of tripping movements of the foremost plough beam 3 is approximately the same as that of the remaining plough beam or beams. In the case of three or more furrow ploughs, further valve means 61 may be provided so that all the plough bodies trip at the same frequency. The valve means 61 comprise a check valve 63, and a flow restrictor 65 (or spring-loaded pre-set valve). Each beam 3 is pivoted to the head 1 of a frame 50, 60 secured to a tractor, by spindles 7 situated forwards of the front of the plough body 21, one of the spindles 7 being displaced from a respective cup 2 when the beam 3 is tripped. Shear pins 3D shear when the plough body is subject to a force greater than that required to trip the beam 3. The piston 29B is secured to a rod 10 extending through the beam 3 andpivoted at 12 to the head 1.

Description

This invention relates to multi-furrow ploughs.

It is well-known that in such ploughs the front plough body is in operation the most heavily loaded. Accordingly, where, to allow tripping of the plough bodies when they encounter obstructions, the plough body support legs are mounted on respective pivotal plough beams which are provided with respective hydraulic cylinders connected to a common hydraulic system such as an hydraulic accumulator or suitable tractor hydraulics, the front plough body trips more frequently than the remaining plough bodies. This is undesirable. It is, therefore, an object of the invention to provide a multi-furrow plough having plough bodies oarried on trippable plough beams in which, in operation, tripping movement of the plough beams occurs at or approximately at the same frequency.

The present invention consists in a multi-furrow plough, comprising a plurality of plough beams mounted in a frame for pivotal tripping movement in respective vertical planes, a plurality of plough body support legs mounted on the respective beams for supporting respective plough bodies, and hydraulic cylinders connected to a common hydraulic system and adapted upon pressurisation in use of the common hydraulic system to afford resistance to tripping movement of the respective beams, tripping movement of each beam upon encountering of an obstruction by the associated plough body in use causing the corresponding hydraulic cylinder to expel hydraulic fluid to the common hydraulic system so that upon freeing of the obstructed plough body, return of hydraulic fluid from, the common hydraulic system to the hydraulic cylinder corresponding with the obstructed plough body is effected to return the beam corresponding with that plough body to its position relative to the frame prior to tripping movement thereof; wherein between the hydraulic cylinder of the plough beam corresponding with the front plough body in the. direction of operative travel of the plough and the common hydraulic system are provided valve means which restrict the flow of hydraulic fluid to the system thereby to limit during operation - 2 41894 the frequency of tripping movement of the beam associated with the front plough body to, or approximately to, that of the remaining plough beam Or beams.

Suitably, the valve means comprise, connected, in parallel, a check valve which inhibits flow of hydraulic fluid to the common hydraulic system from the hydraulic cylinder whilst permitting reverse hydraulic fluid flow and a flow restrictor which limits hydraulic fluid flow from the cylinder to the system.

If desired, the cylinder associated with the plough body to the rear of the front plough body may also be provided with valve means to limit the frequency of tripping movement of the associated plough beam. In such a case, it will be apparent that the degree of restriction of hydraulic fluid flow from the cylinder to the common hydraulic system is less than for the cylinder of the front plough body.

Preferably, the common hydraulic system comprises an hydraulic accumulator, the hydraulic fluid pressure within which is increased when flow of fluid thereto from a cylinder takes place upon tripping movement of the corresponding plough beam, the increased pressure in the accumulator causing return of hydraulic fluid to the cylinder of a tripped plough beam as soon as the corresponding plough body is free from its obstruction.

The invention will now be described, by way of example with reference to the accompanying drawings, in which:Figure 1, is a plan view of some principal parts of a two furrow reversible plough according to the invention.

Figure 2, is a fragmentary side elevation of the plough illustrated in Figure 1, and, Figure 3, is a diagram of the hydraulic circuit of the plough of Figures 1 and 2.

In the drawings like parts have been accorded the same reference numerals. - 3 41994 The plough shown in the drawing:: comprises for each pair of reversible plough bodies such as body 21 a hollow stub beam 3 with a pair of vertically opposed support blocks which are rigidly attached at the forward end of the beam 3· Each support block 3A is provided with a spindle 7 which extends transversely of the beam and which projects at either end from the corresponding support block.

The projecting ends of each spindle 7 engage within respective coaxial semi-cylindrical cups 2 formed in the head 1 so as to lie, in the working position shown in full lines in Figure 2, on opposite sides of the corresponding support block 3A· In this way the beam 3 can as more fully explained hereinafter, pivot about the axis of either spindle 7, with in each case one spindle rotating within the associated pair of semicylindrical cups and the other spindle being lifted out of its associated cups.

The head 1 of the rear pair of reversible plough bodies is suitably coupled to frame 5θ adapted to be drawn by a tractor whilst that of the front pair of plough bodies is coupled to a lateral extension 60 of the frame 50.

Leg support plates 3B are attached to the rearward end of each stub beam 3 between which, by means of pivot pins 3C and shear pins 3D, are bolted the right hand plough support leg 8 and the left hand plough support leg 9 to which are attached the respective right and left hand plough bodies.

Transversely located in each head 1 is a pivot rod 12 to which is freely coupled the eye-shaped end of a rod 10. 8od 10 passes rearwards and longitudinally through the corresponding stub beam 3· Attached tp the rearward end of each stub beam 5 are ram mounting brackets A retaining trunnions 29A which are integral with a hydraulic cylinder 29 which extends rearwards from the rear end of the stub beam 3· The trunnions 29Λ allow the cylinder 29 to pivot between the ram mounting brackets A in a vertical plane. The piston 29B witiiin each cylinder 29 • is attached to the rearward end of the corresponding rod 10. 419 9 4 The full lines on Figure £ show the operative position of the right hand plough body whilst the dot and dash lines indicate the maximum tripped position the body acquires as a result of contacting an obstruction. After tripping, the body automatically returns to its working position whilst the tractor continues its forward movement. This is more fully explained hereinafter, A gas diaphragm or piston type hydraulic accumulator 51 as seen in Figure 1 is attached to the plough. The hydraulic pipe 52 from the accumulator connects via a pipe 53 with each cylinder 29. The pipe 53 leading from the cylinder 29 of the front pair of plough bodies connects with the accumulator 51 by way of valve means 6l hereinafter more fully described. The hydraulic system is charged with oil and pressurised through a pipe 54 connecting the accumulator 51 to the tractor hydraulics. This pressure can be varied to give different loads on the plough bodies required to operate the trip mechanism.

. An obstruction encountered by a plough body Imposes a load which creates a clockwise turning movement in the vertical plane of the associated beam 3 about the upper spindle in the corresponding cup 2. During this movement the lower spindle 7 separates from Its oup 2. The movement of the beam J causes the rod 10 to rotate about the pivot rod 12 and the distance between '.be axis of the pivot rod 12 and the axis of the trunnions 29Λ lengthens aa a result of which rod 10 causes movement of the piston 29B to discharge a volume of oil from the end of the cylind ,-r 29 adjacent the beam 3· The discharged oil from the cylinder flows into the accumulator 51 further compressing the gas and increasing the .accumulator pressure.

As soon as the obstruction Is cleared, the increased pressure in the accumulator causes return of fluid to the cylinder 29 with the result that the tripped beam 3 is lowered and the plough body 21 re-enters work.

The valve means 6l between the hydraulic cylinder of the front plough body and the hydraulic accumulator are in the form of parallel connected valve elements, namely, a check valve 63 and a flow restrictor 65. The cheek valve inhibits hydraulic flow from the cylinder to the accumulator but permits hydraulic flow in the reverse direction whilst the flow restrictor provides a restricted path for fluid flowing from the cylinder to the accumulator. In the direction of flow from the accumulator to the cylinder, the flow restrictor is by-passed by the check valve whieh is then open. The valve means provide increased flow resistance between the cylinder of the front plough body and the hydraulic accumulator, the effect of such resistance being that the front plough body which otherwise tends to trip more frequently than the rear plough body is caused to trip less frequently. By appropriate dimensioning of the flow restrictor^frequency of tripping of the front plough body is made approximately to be equaT or/equal to that of the rear plough body.

In the case of three or 'more furrow ploughs the cylinders beam beam of /3 other than the front /3 .- may be provided with valve means so to limit the frequency of tripping of the corresponding plough bodies that all plough bodies trip at much the same frequency.

In the embodiments described the flow restrictor alternatively to a restriction may take the form of a pressure relief valve whieh is, for example, a spring loaded differential 'valve pressure-operated/ which opens when fluid pressure in the associated hydraulic cylinder reaches a preselected value upon the corresponding plough body encountering an obstruction. - 6 41994 The assembly of the legs 8 and 9 and the plough bodies is symmetrical about the longitudinal axis of the corresponding stub beam 3 arid the trip mechanism accordingly controls both right and left hand plough bodies.

By locating the centres of the spindles? forward of the plough points, immediate lift from the ground of the plough body is achieved when the body encounters an obstruction. The shear bolts 3D fitted between the leg 8 and the leg support plates 3B and between the leg 9 and the leg support plates 3B give secondary protection to the plough. The point load required to shear the shear bolts 3D Is in excess of the point load required to operate the hydraulic system; therefore, if through any reason the hydraulic system falls to operate, the shear bolt will provide the necessary protection. additionally Known types of disc and skim coulters oan/be attached to the stub beam 3· It will be seen that as the main components of each trip mechanism consist primarily of the rod 10 which is contained within the beam 3, the cylinder 29 which is an enclosed structure, rod 12, the spindles 7 and their cups 2 which, except beam when a / is tripped, are protected by the end of the beam 3 and blocks 3A, the likelihood of the trip mechanism being rendered inoperative by foreign bodies, stones, earth, etc., is minimised.

Claims (8)

1. WHAT WE CLAIM IS:

1. A multi-furrow plough, comprising a plurality of plough beams mounted in a frame for pivotal tripping movement in respective vertical planes, a plurality of plough body .support legs mounted on the respective beams for supporting respective plough bodies, and hydraulic cylinders connected to a common hydraulic system and adapted upon pressurisation in use of the common hydraulic system to afford resistance to tripping movement of the respective beams, tripping movement of each beam upon encountering of an obstruction by the associated plough body in use causing the corresponding hydraulic cylinder to expel hydraulic fluid to the common hydraulic system so that upon freeing of the obstructed plough body, return of hydraulic fluid from the common hydraulic system to the hydraulic cylinder corresponding with the obstructed plough bcdy ie effected to return the beam corresponding with that plough body to its position relative to the frame prior to tripping movement thereof; wherein between the hydraulic cylinder of the plough beam corresponding with the front plough body in the direction of operative travel of the plough and the common hydraulic system are provided valve means which restrict the flow of hydraulic fluid to the system thereby to limit during operation the frequency of tripping movement of the beam associated with the front plough body to, or approximately to, that of the remaining plough beam or beams.

2. A plough as claimed in Claim 1, wherein the valve means comprise, connected in parallel, a check valve which inhibits flow of hydraulic fluid to the common hydraulic system from the hydraulic cylinder whilst permitting reverse hydraulic fluid flow and a flow restrictor which limits hydraulic fluid flow from the cylinder to the system.

3. A plough as claimed in Claim 1 or Claim 2, wherein the common hydraulic system comprises an hydraulic accumulator, the hydraulic fluid pressure within which is increased when flow of fluid, thereto from a cylinder takes place upon tripping movement of the corresponding plough beam, the increased pressure in the accunulator causing return - 8 41994 of hydraulic fluid to the cylinder of a tripped plough body beam as soon as the corresponding plough body is freed from its obstruction.

4. A plough as claimed in Claim 1, Claim 2 or Claim 3, wherein the cylinder associated with the plough body to the rear of the front 5. Plough may also be provided with valve means to limit the frequency of tripping movement of the associated plough beam.

5. A plough as claimed in any preceding claim, wherein the pivotal connections about which the respective plough beams can pivot relatively to the frame on tripping are located each forwardly of the foremost 10 point of the corresponding plough body when the latter is in work.

6. A plough as claimed in any preceding claim, wherein each plough body support leg is connected to its associated plough beam by means of a pivotal connection and a shear pin, the latter being adapted to shear when, in operation, the corresponding plough body is subject to 15 a force in excess of that required to pivot the corresponding plough beam relatively to the frame.

7. A plough as claimed in any preceding claim wherein each hydraulic cylinder is connected by means of a rod passing through the corresponding plough beam with the frame. 20

8. A multi-furrow plough, constructed and adapted to operate substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.