GB2301518A - A machine for preparing and planting cuttings - Google Patents

Abstract

A system (Figure 1) whereby a towed machine for the successive preparation and planting of vegetative cuttings embodied a mechanism driven by a double acting hydraulic cylinder 6 . Such a cylinder is controlled by electrical switches 25, 27, 29 which activate solenoids to operate hydraulic valves 19, 20. From a "dwell" position of the mechanism outward and return motions of the piston rod cause corresponding related motions of a sliding block 4 on which is mounted equipment for the preparation and planting of cuttings and which is driven along constraining slidebars 45 , mounted on an inclined frame 1, in a downwards and rearwards direction followed by return to the "dwell" position. This sequence is initiated by the closure of "trigger" switch 29. The distance travelled by the sliding block depends on the lengths and positions of control rods 26 and 28 fixed to the sliding block and operating electrical switches 25, 27 , such lengths being chosen to give the required distance of travel.

Description

A SYSTEM FOR DRIVING AND CONTROLLING THE MECHANISM OF A MACHINE FOR PREPARING AND PLANTING CUTTINGS.

This invention relates to a machine for the successive preparation and planting of vegetative cuttings which may be towed from the three point linkage of an agricultural tractor or other suitable vehicle.

This machine embodies a mechanism with a sliding block on which is mounted an anvil, guide and shutter plate and which is constrained in linear motion along slidebars mounted on an inclined frame. It is a purpose of this invention to describe means by which the sliding block may be driven in a suitable outward and retum motion along the slidebars for the purpose of preparing and planting cuttings.

A machine having some similar mechanical features but with a mechanism driven in a continuous oscillating motion has been described. (U.K. Published Patent Application No. 9415826.8) According to this invention an alternative driving means is described whereby the sliding block is driven in a sequence of outward and return motion from and to a "dwell" position, and whereby such a sequence is initiated by the closure of an electrical switch acting as an independent "trigger" According to this invention there is provided a double acting hydraulic cylinder with a piston and piston rod actuating a mechanism connected to the sliding block so that there exists some suitable relationship between the linear displacements of the piston rod in the cylinder and of the sliding block in linear motion along the slidebars.

Provision is made for independent adjustment of the outward and return speeds of the piston rod with corresponding effects on the speeds of the sliding block.

The distance travelled from the "dwell" position by the sliding block in outward and return motion depends on the lengths and positions of control rods fixed to the sliding block. The control rods operate electrical switches which, by activating the solenoids of hydraulic valves, control the hydraulic cylinder.

High pressure hydraulic supply and low pressure hydraulic return pipes are connected to the hydraulic cylinder through a suitable arrangement of hydraulic control valves Solenoid operated reversing and bypass valves are operated from a direct current supply such as a 12V battery supply through a suitable electrical switching circuit.

A specific arrangement of the invention will now be descibed as an example with reference to the accompanying drawings in which: Figure 1 shows a general elevation of the sliding block, slidebars, hydraulic cylinder and mechanism mounted on the inclined frame. The arrow shows the direction of tow.

Figure 2 shows, in a part view at right angles to the inclined frame, an arrangement of control rods, microswithches and hydraulic control valves. The slidebars and mechanism are omitted for clarity and the sliding block is shown in the "dwell" position.

Figures 3, 4, and 5 are further part views at right angles to the inclined frame showing the operation of the electrical switches by the control rods during the outward motion, at the extreme point of travel and during the return motion respectively. The arrows show the directions of motion of the sliding block in travel along the slidebars..

Figure 6 shows the electrical circuit diagram.

Figure 7 shows the hydraulic circuit in diagrammatic form.

Figure 8 shows a typical arrangement of the "trigger" switch. The arrow shows the direction of tow.

Referring to Figure 1, there is provided an inclined frame 1 mounted on a chassis 2 at pin 3 and constrained by suitable springs to perform only small rotational displacement about the axis of this pin. A sliding block 4 is constrained to move linearly along the slidebars 45 mounted on the inclined frame. The sliding block is driven to and fro along the slidebars through pin 5 by a double acting hydraulic cylinder 6 acting through a mechanism as shown. The cylinder body is mounted at pin 7 to a bracket 8 attached to the inclined frame. The piston rod ofthe cylinder operates a rocking arm 9 through pin 10, the rocking arm being pivoted onto the inclined frame at 11. The rocking arm is connected at pin 12 to an intermediate rod 13. Roller cam followers 14 are mounted on pin 15 at the lower end of the intermediate rod and engage the cam surface 16.A connecting rod is provided between pin 15 and pin 5 on the sliding block. The profile ofthe cam surface is chosen so that a suitable relationship exists between between the displacement of the piston and piston rod in the cylinder and the linear displacement of the sliding block in motion along the slidebars. Tension springs 42 are provided to act between the end ofthe shutter plate 17 attached to the sliding block and a suitable point on the rocking arm 18 so that the roller is maintained in contact with the cam during retraction of the piston rod and consequent upward motion of the sliding block The machine may be referred to as being in the "dwell" position when the piston rod is retracted into the cylinder and the sliding block is at the upper limit of travel.

Referring to Figures 1 and 2 there is provided a hydraulic reversing valve 19, which is open to flow during switching, and a bypass valve 20. Both valves are connected to the high pressure hydraulic supply pipe 21 and low pressure return pipe 22. Each valve is spring loaded and is operated by separate solenoids 23 and 24 respectively with activation controlled by microswitches. When niether solenoid is activated, the bypass valve remains open and the reversing valve is connected so that the mechanism remains in the "dwell" position.Three microswitches are provided, of which two are mounted on the inclined frame and are operated by motion of the sliding head along the slidebars For this purpose there is provided, for each switch, a metal control rod rigidly mounted on and lying substantially parallel to the sliding head so that the switch is operated by the rod according to the position of the sliding head In particular, switch 25 is operated by rod 26 and activates the reversing valve solenoid 23, switch 27 is operated by rod 28 and activates the bypass valve solenoid 24. Referring to Figures 6 and 8, the third switch 29 activates both solenoids as a "trigger" switch.

To obtain some uniformity in the distance travelled by the machine in tow between each triggered sequence of motions, switch 29 may be mounted to operate from the rotation of a cam 30 mounted on shaft 31 which is driven by ground friction through wheel 32, either directly as shown in Figure 8, or through an intervening drive such as belt, chain or gearing, while wheel 32 is towed along with the planting machine.

Alternatively, switch 29 may be operated manually or by other means.

Referring to Figures 2 and 7, pipes 33, 34 connect the reversing valve to each end of the hydraulic cylinder, the flows in these pipes being interchanged according to the setting of the reversing valve. The flow from the reversing valve to the cylinder passes through a needle valve 35, or other suitable variable restrictor, in combination with a by-pass pipe round the needle valve which is closed in this direction by a one-way valve. The return flow from the cylinder to the reversing valve passes in the opposite direction through a similar valve and by-pass arrangement 36 with the one-way valve open in this direction. Manipulation of the needle valves permits independent adjustment of the out and back speeds of the piston rod and of the corresponding speeds of the sliding block in outward and return motion along the slidebars.

A direct current at a suitable voltage is supplied to a circuit box 37 for the operation of the hydraulic valve solenoids using the circuit diagram shown in Figure 6. The hydraulic circuit is shown in diagrammatic form in Figure 7.

Referring to Figure 2, each microswitch is closed by depression of a spring loaded button 38. This may be depressed manually or by movement of a roller arm 39. In the case of the switches 27 and 29 the roller arm is held against the button by a light spring so that a small movement of the roller arm towards the body of the switch is required to depress the button and close the switch. In the case of switch 25 the roller arm is in the normal position when pointing directly away from the body of the switch and is spring loaded to return to this position. The arm may move from this position by clockwise or anti-clockwise deflection but the spring loaded button is depressed and the switch closed by clockwise deflection only, (as seen in Figure 2) the switch remaining open in the case of the normal position and for anti-clockwise deflection.

Referring to Figures 2, 6, and 7, the operation of the device will now be described.

With the machine initially in the "dwell" position, operation commences when the "trigger" switch 29 is closed under the action of a cam as in Figure 8, or by other means. This switch activates both solenoids, thus closing the bypass valve 20 and operating the reversing valve 19 so that the flows to and from the hydraulic cylinder 6 cause the piston rod to move away from the fully retracted or "dwell" position.

This drives the sliding block 4 in a downward direction along the slidebars so that the rods 26 and 28 move to become adjacent to the microswitches 25 and 27 respectively. These rods impinge on the rollers of microswitches 25 and 27, causing rotations of the roller arms which close both switches as in Figure 3. Once switches 25 and 27 are closed, the triggering function is complete; the solenoids of hydraulic valves 19 and 20 remain activated and the trigger switch 29 may reopen without change to the status of the reversing or bypass valves. Diodes 40 and 41 are included in the electrical circuit to avoid cross connection between switches 25 and 27 so that the hydraulic valves 19 and 20 may be operated independently once the trigger switch is open. This should occur shortly after the closure of switches 25 and 27.The sliding block then continues to be driven in the downward direction by the hydraulic cylinder 6 until the upper end of the rod 26 passes microswitch 25, thereby releasing the roller arm of this switch which returns to the normal position as in Figure 4. With the roller arm in the normal position, microswitch 25 opens and the solenoid of the hydraulic reversing valve 19 is no longer activated. As a consequence the reversing valve reverses the supply to the hydraulic cylinder. During this operation the bypass valve remains closed since the roller arm of microswitch 27 remains deflected by rod 28. With reversed flows to the hydraulic cylinder and the bypass valve closed, the piston rod retracts into the cylinder and the sliding block 4 is now driven upwards towards the "dwell" position as in Figure 5.The control rod 26 again impinges onto the roller of microswitch 25 but the rotation of the corresponding roller arm is now in the opposite direction and the solenoid of the reversing valve 19 is not activated. The sliding head continues in upward motion along the slidebars until the roller of microswitch 27 reaches the end of rod 28 so that the roller arm is released and the switch opens. At this point the solenoid of the bypass valve 20 is no longer activated, the bypass valve opens and the sliding block 4 is no longer driven along the slidebars. The sliding head comes to rest with the machine returned to the "dwell" position. The machine remains in this position until the trigger switch is again closed and the above sequence is repeated.

Several similar machines may be towed together in an abreast formation. In this case the trigger switches of each machine may be operated independently as in Figure 8 but by individual cams mounted on the same rotating shaft. The cams may be arranged in an angular relationship on the shaft so that the machines are triggered in sequence during towing to promote a spatial pattern of planting operations between the machines.

Claims (6)

1. A system whereby a towed machine for the successive preparation and planting of vegetative cuttings has a mechanism driven by a double acting hydraulic cylinder.

Such a cylinder is controlled by electrical switches which operate hydraulic valves by activation of solenoids. From a "dwell" position of the mechanism and with the piston rod retracted into the cylinder, outward and return motions of the piston rod cause corresponding related motions of a sliding block on which is mounted equipment for the preparation and planting of cuttings. During the outward motion the sliding block is driven along constraining inclined slidebars in a downwards and rearwards direction followed by return to the "dwell" position in order to effect a sequence in the successive preparation and planting of cuttings.

2. A system according to claim 1 in which the sequence of outward and return motions of the sliding block is initiated by the closure of an electrical switch.

3. A system according to claim 1 in which the distance travelled from the "dwell" position in outward and return motion of the sliding block depends on the lengths and positions of control rods fixed to the sliding block and which operate electrical switches. The lengths and positions of such control rods are chosen to give a required distance of travel.

4. A system according to claim 1 in which the speeds of the outward and return motions of the piston of the hydraulic cylinder are individually controlled and adjustable as may be required for the preparation and planting of cuttings.

5. A system according to claim I in which the piston, piston rod and mechanism are coupled so that during the outward and return motions of the piston a relationship exists between the displacements of the piston and of the sliding block from their respective "dwell" positions, as required for the preparation and planting of cuttings.

6. A system according to claims 1 and 2 in which, in the case of a number of similar machines being towed together, the switches initiating the outward and return sequence of operation of each machine may each be operated by a separate cam mounted on the same rotating shaft and so arranged that a timed sequence of operation between the machines occurs.