GB2047065A

GB2047065A - Track marker actuator

Info

Publication number: GB2047065A
Application number: GB8007635A
Authority: GB
Original assignee: Amazonen Werke H Dreyer SE and Co KG
Current assignee: Amazonen Werke H Dreyer SE and Co KG
Priority date: 1979-03-07
Filing date: 1980-03-06
Publication date: 1980-11-26
Also published as: FR2450550A1; DE2908953C2; FR2450550B1; GB2047065B; DE2908953A1

Abstract

An actuating device for alternately raising and lowering track markers or scarifiers on seed drills, including a housing (1) in which there are provided a unilaterally impactable cylinder (2) connected with track scarifiers (8,9), a locking member (22) secured to the housing, and two control levers (15,16) of which one is pivotally connected to the cylinder (2) and the other to its connecting rod (3). The control levers (15,16) have guide members (25,26) at their free head ends adapted to be moved past the locking member, but flush with one another, and shoulders (20,21) which, for locking the track scarifiers (8,9) into a raised position, are each abutable against a shoulder surface (23) of the locking member (22). Resilient elements (27) may be provided between the housing and control levers and acting thereon in the direction of the locking member. <IMAGE>

Description

SPECIFICATION Actuating device for displacing track markers or scarifiers The invention relates to an actuating device for displacing track markers or scarifiers of an agricultural apparatus, more especially for their alternative raising and lowering on seed drills, including a housing in which a pressure medium impacted cylinder is located and connected to the track scarifiers, having displaceably located control means for changing over the direction of movement ofthetrackscarifiers and at least one locking member for locking each track scarifier in the raised position.

An actuating device is disclosed in German Patent Specification 2546752 in which a sliding member each is secured on each of the two free ends of the bilaterally impactable (double acting) cylinder or its connecting rod, whereby the sliding members project through four passage-like openings formed in the two side walls of the housing and are reciprocable in these openings and connected via rods, rigid per se, to the track scarifiers. Furthermore, the control lever and the locking member are pivotally mounted on a pin located on a side wall of the housing. Herein, the control lever has a slot formed therein extending in its longitudinal direction and has two hook-shaped stops at its outer ends via which stops during the reciprocating movement of the sliding members it may be slid to and fro in the passage-like openings within the slot.

On the other hand the locking member is provided at its outer ends on the sides averted from each other each with an abutment surface for the alternate locking of the sliding members and hence also the track scarifiers in their raised position. Furthermore, the locking member has an upwardly projecting abutment in its central region in which is located a compression spring acting on the central region of the control lever by which the control lever and the locking member, depending upon the position of the control lever in its slot, may be pivoted to one side or the other for the alternate release or locking of the sliding members and hence the alternate lowering and raising of the track scarifiers.

A disadvantage of this known actuating device chiefly resides in that a relatively costly bilaterally impacted cylinder has to be used. Moreover, it is of considerable disadvantage that the compression spring can exert only a relatively minimum torque on the control lever and the locking member because the minimum spacing of its end on the control lever side from the pin to which the locking member and the control lever are pivotally mounted in the two end positions is determined by the slot of the control lever. Consequently, the function of the whole actuating device is considerably impaired as soon as it exhibits a certain weight. Despite careful manufacture such a weight may quickly be built up in use due to contamination during rough field deployment.An additional aggravating feature is that the known actuating device is mounted relatively low on the frame of a seed drill, so that after a brief period of deployment, the dust-like soil particles raised by the running wheels of the seed drill and the tractor towing it and by the cultivating implements, can penetrate through the passage-like openings and pass into the housing. A correspondingly unfavourable effect on the function of the actuating device results if, when deploying the seed drill on damp soil, clods of earth are thrown by the rear wheels of the tractor towing the seed drill into the passage-like openings of the housing, so that the sliding members during the raising of the track scarifiers cannot be pressed into their outer end positions.In this case the alternate operation is interrupted, so that the same track scarifier is constantly lowered again into the operating position.

It is an object of the present invention to provide a structurally simple actuating device which will reliably function even in rough field deployment.

According to the present invention there is provided an actuating device for displacing track mar kers or scarifiers of a n an agricultural apparatus where- in the scarifiers are to be alternately raised and lowered, said device including a housing, a pressurizable (unilateral) piston-cylinder arrangement located in the housing and connected to the scarifiers and adapted to be pressurized at one end, two control levers for changing over the position of the track scarifiers, and at least one locking member for securing each track scarifier in the raised position is rigidly connected to a wall of the housing and provided with stop or abutment surfaces on surfaces facing each other and provided each with inclined contact surfaces on surfaces averted from each other; wherein one of the two control levers is pivotally mounted on the cylinder and the other control lever is pivotally mounted on the piston or connecting rod thereof, and which control levers are each provided on their side facing the locking member(s) with a shoulder abutable against one of said abutment surfaces and each lever has a guide member projecting outwardly beyond its free end, whereby the shoulders are slidably displaceable over the inclined surfaces of the locking member or members, and whereby the free end of the guide member of the momentarily displaced control lever is located below the free end of the other guide member facing it during the contact of its shoulder against the inclined surface.

From the outset the utilization of a unilaterally impactable cylinder i.e. one pressurizable from one end only results in a substantially simpler and hence favourably priced structure, than in the known actuating device. Furthermore, the control levers and locking members may be kept substantially smaller, whereby the dead weight of the control levers alone is reduced and a functionally more reliable and compulsory alternate locking of the track scarifiers in the raised position is attained. This functional reliability cannot be impaired to any substantial extent by the settling of dust particles on the locking members and the control levers.

In order to prevent the control levers from tilting in their mountings to one side with the unavoiable occurrence of wear during long term use, the control levers are bifurcated on the side of their mounting, whereby they enclose the cylinder or the connecting rod on both sides. Afavourable method of construction results if the control levers each comprise two individual levers, the head or free ends of each are interconnected by the shoulder and that the guide members are located on the shoulders.

The invention provides for two outwardly projecting pins to be provided for mounting the control levers on the cylinder and the connecting rod thereof, the outer ends of which pins are each guided by means of a U-shaped sliding rail. By this means the guidance of the piston and the connecting rod is so relieved that a satisfactory functioning of the actuating device is still ensured even after a long term deployment. Furthermore, for this guidance no passage-like openings are required in the side wall through which dust-like soil components have access to the functional components of the device. A complete protection of these functional components against contamination is obtained in that the housing is closed on all sides, whereby the openings for the connecting conduit of the cylinder and the coupling elements to the track scarifiers are sealable.

In order also for a special machine design to allow installation of the actuating device in any position, i.e. for example pivoted about 1800 without impairing its functional reliability, resilient elements are provided connected, on the one hand to the control levers and, on the other hand, to the housing and which act on the control levers in the direction of the locking member or members. Herewith the resilient elements cause an alternate reliable abutment of the shoulders of the control levers against the abutment surfaces or the locking member or members, even if this locking operation for the track scarifiers has to be effected in their raised position against the dead weight of the control levers.

A further substantial advantage is obtained in that the resilient elements are provided as tension springs and that their length will control levers locked on the locking member or members is at least greater in their untensioned state than the stroke of the connecting rod. This advantage resides in that the springs on their own ensure the alternate function of the actuating device, even if the track scarifier just being lowered makes contact with the ground surface after a brief pivotal movement as may occur in a laterally inclined position of the seed drill or when deployed along a slope.

An alternate function of the actuating device entirely independent of the lowering movement of the track scarifiers is attained in that the connecting elements between the cylinder or its connecting rod and the track scarifiers are displaceable in themselves in a manner known per se from the German Offenlegungsschrift 22 17 302.

Also contributing towards a favourable and specially simple method of construction of the actuating device, is the measure in accordance with which only one locking member is provided connected to the housing and equipped with two upright abutment surfaces. This permits the locking member itself to be formed with maximum simplicity by the fact that a space is provided between the abutment surfaces of the locking member which is greater than the longitudinal extension of the shoulders seen in the direction of movement of the control levers.

The invention will be described further, by way of example, with reference to the accompanying drawings, in which: Figure lisa side elevation of a displacing or actuating device for track markers or scarifiers; Figure 2 is a plan view of actuating device of Figure 1; Figure 3 is a side view on an enlarged scale of the central portion of the actuating device of Figures 1 and 2 and by way of a movement study; and Figure 4 is a similar side view to that of Figure 3 showing the device in the position wherein the track scarifiers are raised.

A displacing or actuating device for track markers or scarifiers is secured in known manner to a seed drill (not shown) and has a housing 1 which is closed on all sides and in which a cylinder 2 is located to be impacted with a pressure medium. The cylinder is adapted as a unilaterally impactable hydraulic cylinder. Furthermore, to the closed end of the cylinder 2 and its piston or connecting rod 3, individually displaceable connecting elements 4 in the form of cables are connected. The elements 4 are conducted through the openings 7 formed in end walls 5 of the housing 1 which are each provided with a seal 6 and the other ends of the elements being secured to two track markers or scarifiers 8 and 9 pivotally mounted on the seed drill.Of these track scarifiers the left-hand scarifier 8 is shown in the lowered working position whilst the right-hand track scarifier 9 is shown in its raised position. As clearly shown in Figures 3 and 4, a connecting conduit 10 of the cylinder 2 passes through an elongate opening 12 formed in the upper outer wall 11 of the housing 1, and this opening is sealed by a plate 13 located on the cylinder 2.

Moreover, control levers 15 and 16 are pivotally mounted on pins 14 which pins are located at an end of the cylinder 2 and an end of piston rod 3 - the free ends of the pins being guided during their movement in U-shaped rails 18 mounted on the side walls 17 ofthe housing 1.

As shown in Figure 2 the control levers 15 and 16 each comprise two individual levers 19 whose free ends are interconnected by a downwardly projecting shoulder 20 and 21 respectively. A control or locking member 22 is secured to the housing 1 below the control levers 15 and 16 and this control member has two abutment or stop surfaces 23 and at its opposite ends the two inclined contact or sliding surfaces 24.

In this case, a space z exists between the two surfaces 23 which is greater than the longitudinal extension A of the shoulders 20,21, seen in the direction of movement of the control levers 15 and 16 denoted by the double arrow R.

Furthermore, guide members 25 and 26 respectively adapted to be moved laterally past the locking member 22 are welded to the shoulders 20,21 and project outwards beyond their head ends. Finally, the housing 1 contains resilient elements 27 which are adapted as tension springs and secured at one end to the control levers 15 and 16 and at the other end to the end walls 5. The length L of the tension springs herein in the locked state of the control levers 15 or 16 is greater by at least the length L exhibited by the tension springs 27 in the untensioned state, than the stroke H of the connecting rod.

The alternate raising and lowering of the track scarifiers 8 and 9 occurs as follows: Proceeding from the view of Figure 1, in which the left-hand track scarifier 8 is in the lowered position and the right-hand track scarifier 9 is in the raised position and has assumed a locked position by abutment of the shoulder 21 against the right-hand abutment surface 23 of the locking member 22, the cylinder 2 is first subjected to pressure by switchingon the hydraulic system. The cylinder 2 is moved thereby to the right against the tension of the left-hand resilient element 27, whereby the left-hand track scarifier 8 is raised from the ground and the left-hand control lever 15 slides over base plate 28 of the housing 1.When the control lever 15 has reached the position shown in Figure 3, in which its shoulder 20 has arrived at the left-hand inclined surface 24 of the locking member 22, the free end of its guide member 25 is located below the free end of the guide member 26 of the locked right-hand control lever 16.

With continued movement of the cylinder 2 and hence of the control lever 15 in the direction of the arrowr(Figure 4) the guide member 26 of the control lever 16 is lifted upwardly by the guide member 25 of the control lever 15 until the shoulder 21 of the control lever 16 is disengaged from the right-hand abutment surface 23 of the control member 22 and the shoulder 20 of the control lever 15 under the additional effect of the left-hand resilient element 27, abuts against the left-hand abutment surface 23 of the locking member 22. In this position as shown in Figure 4 the left-hand track scarifier 8 assumes the raised and locked position, whilst the right-hand track scarifier 9, however, assumes the raised but not locked position.

If the cylinder 2 is then depressurized the connecting rod 3 under the influence of the weight of the right-hand track scarifier 9 and by the tension of the resilient element 27, then moves in the direction of the arrow r. The right-hand track scarifier 9 is thus then lowered into the operating position.

With renewed operation under pressure of the cylinder 2, the connecting rod 3 is again drawin into the cylinder 2 and the right-hand track scarifier 9 thereby raised, until the shoulder 20 of the control lever 15 is lifted-off the guide member 26 of the control lever 16 and out of abutment with the left-hand abutment surface 23 of the locking member 22 and the shoulder 21 of the control lever 16 stopped against the right-hand abutment surface 23 of the locking member 22. During pressureless operation of the cylinder 2, the latter moves into the position shown in Figure 1 in which the left-hand track scarifier 8 again assumes the operating position.

Even ifthetrackscarifiers 8 and 9 in a partly lowered state should make contact with the ground, the movement of the cylinder 2 or the connecting rod 3 occurs due to the influence of the given resilient element 27 up to its outer end position, as illustrated in Figure 1 forthe cylinder 2. Hence, in such special situation the reliable alternate function ofthe actuating device is maintained.

Claims

1. An actuating device for displacing track markers or scarifiers of an agricultural apparatus wherein the scarifiers are to be alternately raised and lowered, said device including a housing, a pressurizable (unilateral) piston-cylinder arrangement located in the housing and connected to the scarifiers and adapted to be pressurized at one end, two control levers for changing over the position of the track scarifiers, and at least one locking member for securing each track scarifier in the raised position is rigidly connected to a wall of the housing and provided with stop or abutment surfaces on surfaces facing each other and provided each with inclined contact surfaces on surfaces averted from each other; wherein one of the two control levers is pivotally mounted on the cylinder and the other control lever is pivotally mounted on the piston or connecting rod thereof, and which control levers are each provided on their side facing the locking member(s) with a shoulder abutable against one of said abutment surfaces and each lever has a guide member projecting outwardly beyond its free end, whereby the shoulders are slidably displaceable over the inclined surfaces of the locking member or members, and whereby the free end of the guide member of the momentarily displaced control lever is located below the free end of the other guide member facing it during the contact of its shoulder against the inclined surface.

2. An actuating device as claimed in claim 1, in which the control levers are bifurcated at the mounting end, one lever enclosing both sides of the cylinder and the other lever enclosing both sides of the connecting rod.

3. An actuating device as claimed in claims 1 and 2, in which the control levers are each comprised of two individual levers, the free ends of which are interconnected by the shoulder, and in which the guide members are located on the shoulders.

4. An actuating device as claimed in any of claims 1 to 3, in which two outwardly projecting pins are provided for mounting the control levers on the cylinder and on the connecting rod thereof, the outer ends of said pins being guided by means of a U-shaped sliding rail.

5. An actuating device as claimed in any of claims 1 to 4, in which the housing is closed on all sides, although openings for a connecting conduit of the cylinder and the coupling elements leading to the scarifiers are sealable relative to the track sca rifiers.

6. An actuating device as claimed in claim 1, in which spring or like resilient elements are provided connected at one end to the control levers and at the other end to the housing and acting on the control levers in the direction of the locking member or members.

7. An actuating device as claimed in claim 6, in which the resilient elements are provided in the form of tension springs, and in which their length (L) in control levers locked at the locking member or members is at least greater by their length in their untensioned state, than the stroke (H) of the connected ing rod.

8. An actuating device as claimed in any of claims 1 to 7, in which the coupling elements between the cylinder or its connecting rod and the track scarifiers are displaceable in a manner known per se.

9. An actuating device as claimed in any of claims 1 to 8, in which only one locking member is provided, connected to the housing and provided with two upright abutment surfaces.

10. An actuating device as claimed in claim 9, in which a space (Z) is provided between the abutment surfaces of the locking member which space is greater than the longitudinal extension (A) of the shoulders, seen in the direction of displacement (R) of the control levers.

11. An actuating device substantially as herein described with reference to and as illustrated in the accompanying drawings.