GB2025742A

GB2025742A - Potato Planting Machine

Info

Publication number: GB2025742A
Application number: GB7918193A
Authority: GB
Original assignee: Cramer & Soehne Maschf
Current assignee: Cramer & Soehne Maschf
Priority date: 1978-07-24
Filing date: 1979-05-24
Publication date: 1980-01-30
Also published as: DE2832383B1; FR2433276B1; FR2433276A1; NL7903813A; DE2832383C2; GB2025742B

Abstract

A potato planting machine has vertically conveying scoops 1 arranged on revolving planting belts 2, and a supply bin 11, the bottom of which is formed by a conveyor belt 14 reaching into a scooping space 7, which delivers the potatoes to the planting belts and the drive of which is operatively connected with the drive of the planting belts. The layer of potatoes taken up by the conveyor belt is conveyed on to a rigid slide path 17 following upon the conveyor belt and which guides the potatoes to the scoops. A press key 19 in the unloaded condition forms part of the slide path and has such a large key surface that the loading of the press key is always effected by several. potatoes in the layer of potatoes. The press key is pressed downwards when a specific force exerted by the load of potatoes is exceeded and thereby influences a device, which regulates the conveying performance of the conveyor belt and thus controls the rate of delivery of potatoes to the scooping space 7. <IMAGE>

Description

SPECIFICATION Potato Planting Machine The invention relates to a potato planting machine with vertically conveying scoops arranged on revolving planting belts or the like, with a supply bin the bottom of which is formed by a conveyor belt reaching into a scooping space which delivers the potatoes to the planting belts, and the drive of which is operatively connected with the drive of the planting belts and with a control device which renders possible control of the conveying performance of the conveyor belt through a press key ascertaining the potato weight and arranged to yield vertically, said press key being pressed downwards when a specific force exerted by the load of potatoes is exceeded and thereby influencing the control device.

Potato planting machines of this type are known from DE-AS 25 38 1 88. In these there is arranged at the end of the conveyor belt a rocker arm, the forward end of which is formed as a pickup element for the potatoes arriving on the conveyor belt and the rear end of which is articulated to a circuit breaker. The potato taken up by the pickup element moves the rocker arm owing to the weight of the potato, in that way opens the circuit breaker and stops the conveyor belt. When the rocker arm is swung back into its orignial position, so that the following potato can fall into the pickup element, the conveyor belt is again accelerated to its operating speed. Thus each potato is individually weighed.

In order to render this weighing possible, the potatoes must be fed individually to the pickup element and spaced from one another. These known machines require for this purpose a supplementary singling device, which brings the potatoes issuing from the supply bin individually into a precise aligned file. This takes place in such a way that the tubers pass through a narrow discharge opening which is formed by the conveyor belt and the V-shaped recess in a contrarotating vane wheel with cooperation of oscillating shaker plates. This expensive and unreliable device grips the potatoes roughly, so that damages to and loss of individual sprouts are not precluded, this being a factor of particular importance when sprouted potatoes are to be planted with these machines.

A further disadvantage of these known machines in which the conveyor belt must be brought to a halt and immediately accelerated again during weighing of each individual potato, consists in the occurrence with them of high forces due to inertia. Such a method of operation can only be carried out with low frequency of planting so that such machines cannot approximate the planting speeds of present-day conventional potato-planting machines.

Potato-planting machines are also known from German patent specification 26 36238 and German Gebrauchsmuster 7626 669, in which there is arranged in a scoop space following upon the conveyor belt and to which a rigid slideway leads, a mechanical probing device the purpose of which is to investigate by feel the depth of the layer of potatoes. When, in the event of excessive supply of potatoes the depth of the layer of potatoes exceeds a specific threshold value, the probing member causes stoppage of this 'continuously-conveying conveyor belt, or a reduction in the step length of a step-by-step conveying conveyor belt, until the supply of potatoes had been reduced to an appropriate value.In these known planting machines, difficulties arise for the reason that the probing member does not pass smoothly over the bumpy surface of the tubers lying in part next to one another and in part one above another, but causes a considerable deceleration of the flow of potatoes. Especially when the probing member reaches the threshold position and is to bring about the switching operations it exerts a considerable pressure on the layer of potatoes and decelerates the flow of potatoes so intensely that the potatoes build up and travel over the probing member. The probing member thereby loses its regulating function.

The purpose underlying the invention is to develop potato planting machines of the type described in the preamble in such a way that the automatic regulation of the potato feed not only ensures gentle handling of the potatoes and a high planting speed, but takes place in such a reliable way even with reduction of the cost of production that a previously-necessary assistant operator becomes superfluous.

This purpose is fulfilled according to the invention in that the layer of potatoes taken up by the conveyor belt is conveyed in a manner known per sue on to a rigid slide path following upon the conveyor belt and which guides the potatoes to the scoops, the press key in the unloaded condition forming part of the slide path and having such a large key surface that the loading of the press key is alway effected by several potatoes in the layer of potatoes.

The following advantages result by this means in relation to the known machines with individual weighing: 1. The passage of the layer of potatoes from the supply bin over on to the conveyor belt takes place through a wide discharge opening, so that the potatoes arrive undamaged in a gentle manner at the press key and the machine is particularly suitable for planting potatoes which have already begun to sprout.

2. Besides its scooping equipment, the planting machine according to the invention has no need of any supplementary singling equipment, so that the contrarotating vane wheel and the oscillating shaker plates required in the known machines are superfluous. Thus these costly and unreliable parts are discarded and the machine may be manufactured at considerably less cost.

3. Owing to the weighing of whole groups of potatoes, a smaller number of weighings is required than with individual weighing, so that the planting machine according to the invention operates with correspondingly higher planting frequencies.

Compared to the known machines with a mechanical probing device arranged in the scooping space, there is the advantage that the scooping space is free of built-in parts, so that the potato flow can take place without hindrance and deceleration and breakdowns are avoided. The operative displacement of the press key amounts to only a few millimetres, whereby the checking by weight is extremely sensitive.

In further development, provision is made according to the invention for the press key, on its downward movement, to close an electrical circuit in which is arranged a solenoid the armature of which through a guide rod influences a stepping switch which-rnglates the step length of the conveyor belt.

It is further proposed that the guide roller operating the conveyor belt be rigidly connected with a ratchet wheel on the shaft of which is pivoted a datum disk which can be set in various rotary positions by means of a setting device.

One embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings in which the potato feed is regulated by a stepping switch which influences the step length of the conveyor beit.

In the drawings: Fig. 1 is a longitudinal section through the planting machine, without the stepping switch; Fig. 2 shows on a larger scale a stepping switch with a segmental disk the position of which is determined by a solenoid: Fig. 3 shows on a larger scale, a longitudinal section through a stepping switch.

Fig. 4 shows a cross-section through the stepping switch of Fig. 3, along line A-B of Fig. 3; and Fig. 5 shows the datum disk of the stepping switch.

Planting belts 2 fitted with scoops 1 run over a driving pulley 3 and an upper idler pulley 4. The driving pulley 3 is mounted on a shaft 5 which receives its drive from the ground wheels of the planting machine, which are not shown in the drawings, At the beginning of their ascending path, the scoops 1 enter into the trough-shaped portion 6 of the scooping space 7, remove in each case one of the potatoes available there, guide them by way of the upper idler pulley 4 into the planting chute 8 to the delivery point 9 located near the ground, and at this point allow them to fall into the furrow 10.

The supply bin 11 which contains the commodity to be planted, is divided by the oblique front wall 12 from the scooping space 7.

In the front wall 12 there is the discharge opening 1 3 through which the potatoes pass out of the container into the scooping space, The conveyor belt 14 is so arranged that if forms the bottom of the supply bin. The conveyor belt 14 runs around the guide rollers 1 5 and 16, and reaches in the scooping space 7 as far as the transfer members 17. The guide roller 1 5 is rigidly connected to the shaft 1 8 which is made of steel tubing and effects the motion of the conveyor belt 1 4.

The potatoes, which are forwarded by the conveyor belt 14 to the transfer member 17, arrive at the trough-shaped portion 6 of the scooping space 7 and thence into the zone where they are taken up by the scoops 1. One part of the transfer member 1 7 is in the form of a press key 19 which can tilt about a hinge pin 20 rigidly arranged on the planting machine frame. When the press key 1 9 is not loaded, or is only slightly loaded, it lies flush in the plane of the transfer member 1 7. When the stream of potatoes travelling over the transfer member loads the press key 1 9 in such a way that the load bearing therefrom exceeds a specific threshold value, the press key tilts downwards against the action of a spring 21. The downward displacement of the press key is slight; it amounts to only a few millimetres.The movements of the potatoes travelling over the transfer member are not noticeably influenced thereby. A microswitch 22, the switch lever 23 of which completes a circuit 24 in which the solenoid 25 is incorporated, is situated below the transfer member 1 7.

When the supply of potatoes is too great and the load bearing upon the press key 1 9 exceeds the threshold value, the press key tilts downwards, presses the switch lever 23 downwards and thereby completes the circuit 24, so that the armature 26 of the solenoid 25 is drawn into the magnet coil.

A ratchet wheel 28 is rigidly mounted on the shaft 18. Arranged axially of the shaft 18 is a driving shaft 29 one end of which is supported within the shaft 1 8. Secured on the drive shaft 29 is a sprocket wheel 30 which is connected with the drive of the planting belts 2, in a conventional way by chain drives.

Mounted on the driving shaft 29 is an arm 31 which constantly revolves with the driving shaft.

A ratchet tooth 32 is mounted to be radially displaceable in an oblong hole in the arm 31. The arm 31 is so arranged that the ratchet tooth 32 engages under the thrust of a spring 33 in the toothing of the ratchet wheel 28. When the driving shaft 29 is in rotation from the drive of the planting belts, the arm 31 also continuously revolves with the ratchet tooth 32. When the latter is in engagement with the teeth of the ratchet wheel 28, this latter is also taken along and operates the conveyor belt 14 through the guide roller until, when necessary, the ratchet tooth 32 disengages and interrupts the drive of the conveyor belt 14.

A datum disk 34 is situated next to the ratchet wheel 28. As can be seen in Fig. 5, the datum disk 34 has, on the part 35 of its periphery, a diameter corresponding to that of the ratchet wheel 28, and at the other part 35 of its periphery a greater diameter which nearly corresponds to the external diameter of the ratchet wheel 28. The peripheral parts 35 and 36 merge gradually into one another. The toothing of the ratchet wheel 28 is completely masked laterally entirely covered by the peripheral part 36 of the datum disk 34.

The ratchet tooth 32 is of such a width that it extends not only over the width of ratchet wheel 28 but also over the datum disc 34. The ratchet tooth 32, as long as it is located on the peripheral part 36 of datum disk 34, is thereby prevented from engaging in the toothing. When the driving shaft 29 is rotating, the ratchet tooth 32 slides along the peripheral part 36 of the datum disk 34, so that the conveyor belt 14 is not driven. Only when the ratchet tooth 32 reaches the peripheral zone 35 of the datum disk 34, does it engage under the thrust of spring 33 in the toothing and operates the conveyor belt 14 one step length forward, until the ratchet tooth again moves up on to the peripheral part 36 of datum disk 34.Upon each rotation of the driving shaft 29, the conveyor belt 1 4 accomplishes one step which at most may be as large as is permitted by the peripheral part 35 of the datum disk 34.

A segmental disk 37 is arranged on the driving shaft 29 next to the datum disk 34 and the ratchet tooth 32 likewise reaches across the disk 37. The radius of the segment corresponds to the radius of the crown line of the ratchet wheel 28.

The segmental disk 37 is mounted to be freely rotatable on the shaft 1 8. The segmental disk 37, depending on its position, reduces the toothing region not covered by the datum disk 34 in such a way that the ratchet tooth 32 engages at a later point of time and the conveyor belt 14 accomplishes a shorter step in conformity therewith. The solenoid 25 is secured to the frame of the planting machine. When the circuit 24 carries no current, the armature 26 of the solenoid is held by a pressure spring 38 in a neutral position in which it is fully extended. The armature is hingedly connected with a tie-rod 39 which acts on a pivotal point 40 of the segmental disk 37.

The operation of the potato-planting machine according to the invention is effected as follows: In the most favourable operating condition, in which the conveyor belt 1 4 supplies to the planting belts 2 only slightly more potatoes than are removed by the scoops 1, a stream of potatoes of relatively small layer depth travels over the transfer member 1 7. Only a moderate number of potatoes then dwells in the troughshaped portion 6 of the scooping space 7, and are soon removed. Therefore there is no occasion for turbulence of the potatoes at this position; the sprouts are not damages. In this favourable operating condition, the press key 1 9 is slightly loaded and is in its highest position flush with the plane of the transfer member 1 7. The microswitch 22 remains open, and no current flows to the solenoid 25.The armature 26 of the solenoid is held in the neutral position by the pressure spring 38, and holds the segmental disk 37 in a position in which all of the teeth of the ratchet wheel 28 are released. The constantly revolving arm 31 engages with ratchet tooth 32 in the first free tooth of the ratchet wheel 28 and turns the latter through a large angle of traverse until the ratchet tooth 32 again ascends on to the peripheral part 36 of the datum disk 34. Upon each rotation of the driving shaft 29, the conveyor belt 14 accomplishes a step of maximum length.

In the event that the conveyor belt 14 has taken up considerably more potatoes than corresponds to the most favourable operating condition, the potatoes accumulate on the transfer member 1 7 and the load on the press key 19 is increased to the extent that the latter tilts downwards, thus pressing down the switch lever 23 of the microswitch 22 and thereby closing the circuit 24. The solenoid 25 draws the armature 26 into the magnet coil, so that the segmental disk 37 is turned in the forward direction by the tie-rod 39. The segmental disk then masks a portion of the teeth of ratchet wheel 28.In the subsequent rotations of the driving shaft 29, the ratchet tooth 32 remains engaged only during a smaller angle of traverse; the conveyor belt 14 accomplishes shorter steps in conformity therewith and reduces the potato supply to the transfer member'and thus to the scoops 1. In this way the load on the press key 1 9 is reduced, and said press key is then pushed back by the spring 21 into its highest position. The circuit 24 is thereby interrupted, and the previous favourable operating condition is again established. When planting large tuber potato varieties, the conveyor 14 must accomplish larger steps than when planting small tubers. In order to provide adaptation to potato sizes there is arranged on the datum disk 34 a regulator 41 by means of which the operator can set the datum disk in one of three positions 42 to which it can be turned on the frame of the planting machine.

Claims

1. A potato planting machine with vertically conveying scoops arranged on revolving planting belts or the like, with a supply bin the bottom of which is formed by a conveyor belt reaching into a scooping space, which delivers the potatoes to the planting belts, and the drive of which is operatively connected with the drive of the planting belts and with a control device which renders possible control of the conveying performance of the conveyor belt through a press key ascertaining the potato weight and arranged to yield vertically, said press key being pressed downwards when a specific force exerted by the load of potatoes is exceeded and thereby influencing a regulating device, the layer of potatoes taken up by the conveyor being conveyed on to a rigid slide path following upon the conveyor belt and which guides the potatoes to the scoops, the press key in the unloaded condition forming part of the slide path and having such a large key surface that the loading of the press key is always effected by several potatoes in the layer of potatoes.

2. A planting machine according to Claim 1, in which the press key on its downward movement, closes an electrical circuit in which is arranged a solenoid the armature of which through a guide rod influences a stepping switch which regulates the step length of the conveyor belt.

3. A planting machine according to Claim 1 or 2, in which a guide roller operating the conveyor belt is rigidly connected with a ratchet wheel on the shaft of which is pivoted a datum disk which can be set in various rotary positions by means of a setting device.

4. A potato planting machine substantially as hereinbefore described with reference to the accompanying drawings.