GB2133268A

GB2133268A - Automatic implement-lifting device for an agricultural device, in particular a mower

Info

Publication number: GB2133268A
Application number: GB8324714A
Authority: GB
Inventors: Jean Pierre Amstutz
Original assignee: Bucher Guyer AG
Current assignee: Bucher Guyer AG
Priority date: 1979-12-07
Filing date: 1983-09-15
Publication date: 1984-07-25
Also published as: GB2133666B; GB2064290A; DE2949335A1; GB2133666A; GB8403074D0; CH655426B; GB2133268B; CH654976A5; GB2064290B; GB8324714D0; FR2471130A1; FR2471130B1

Abstract

Automatic implement-lifting device lifts the implement (for example, a mower) which is mounted on a vehicle (for example, an agricultural tractor) when said implement strikes an obstacle. The implement is carried on a longitudinal carrier 71 mounted at 93 on a deflecting rod 72 pivotal about a horizontal axis 94 in a vertical carrier element 15 connected via framework 12 to a tractor. Rod 72 is releasably held in element 15 by mechanism 73 comprising sphere 75 loaded by spring 74 into a hollow 77 in element 15, the mechanism being released on impact of the implement against an obstacle. Spring 49 acts to lift the implement on impact. In a further embodiment a hydraulic device lifts the implement. <IMAGE>

Description

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SPECIFICATION

Automatic implement-lifting device for an agricultural device, in particular a mower

This invention relates to an automatic implement-lifting device for an agricultural implement, in particular a mower.

Such an implement may be connected to a tractor via a linkage mechanism which, in the event that the implement strikes against an obstacle, allows the implement to be pivoted relatively to a carrier which is arranged on the tractor. In order to provide protection against harmful effects in the event of agricultural implements unintentionally striking solid objects, it is known in connection with mowers to use devices which (as a result of the impact) remove the mower from the obstacle in a pivoting motion contrary to the direction of travel. Some devices functioning in this manner consist of two rods which can be extended parallel to one another, which run in fish-plates and which, by virtue of mutual coupling by means of claw-like cams with the coupling point loaded by a spring, maintain the mower in the operating position offset to one side at the rear of the tractor. Should the mower strike against a stone or another solid object, the rod which is connected to the mower is drawn out of the coupling device so that the mower frees itself from the obstacle by a backwards pivoting motion.

However, devices of this kind are effective only when the mower is attached offset to one side at the rear of the tractor because a backwards pivoting motion is only possible from this position. At the same time, this device offers only a small range of pivoting so that, immediately having noticed the impact, the tractor driver must stop the vehicle in order to prevent the next impact.

This device also only allows the pivot motion to take place in an approximately horizontal plane; therefore, hitherto, damage to the mowers and to their attaching devices and to the tractor could be avoided only insufficiently. For this reason, the mowers and the attaching devices are provided with greater load-bearing components at the structural design stage.

The principal aim of the present invention is to provide a lifting device of the type in question which allows the implement which is arranged offset to one side at the rear or the front of the tractor to be lifted out of its operating position in such manner as to avoid an impact which would give rise to damage.

In accordance with the present invention, this aim is realised by the implement being attached to an implement carrier which can be pivoted about a horizontal axis relative to a device carrier and by the implement carrier being assigned a lifting device by which the implement is lifted from the ground.

This structural design of the lifting device reliably avoids damage to the implement in the event of impact with an obstacle because the carrier is in this case pivoted by the lifting device about a horizontal axis relative to the traction engine and the implement is raised from the ground. This mode of functioning of the lifting device allows the implement to be arranged both at the tail end and at the front $nd of the tractor.

Expedient further developments of the invention are described in the sub-Claims.

The present invention will now be more particularly described with reference to the accompanying drawings which illustrate a few exemplary embodiments of the invention and in which:—

Figure 1 is a side view of a first embodiment of an automatic implement-lifting device, according to the present invention, with a mower attached;

Figure 2 is a side view of a second embodiment of such a device with a mower attached; and

Figure 3 is a side view of a third embodiment of such a device with a mower attached.

An automatic implement-lifting device, which is illustrated in Figure 1 and which in toto is indicated by the reference numeral 11, is connected via a carrier 12 to a tractor (not shown). The carrier 12 possesses at least two hinge or attachment points to the tractor and can be raised and lowered at its front end by means of hydraulic cylinders. At the front end of the carrier 12, which consists of two longerons 13, there is attached a coupling device 14 for the lifting device 11. A disc mower 20 is connected to the lifting device 11 which is attached to the tractor. The connecting element consists of a longitudinal carrier 71 which is mounted on a pivotal deflecting rod 72 so as to be pivotal about a horizontal axis 93. The deflecting rod 72 is itself pivotal about a horizontal axis 94 in a vertical carrier 15 which is rigidly connected to the device carrier 12. The deflecting rod 72 is secured in the vertical carrier 1 5 in such manner that it can be released by a release safety mechanism 73 which is located in the vertical carrier 15 directly adjoining the upper end of the deflecting rod 72. It consists of a sphere 75 which is loaded by a compression spring 74 and which is pressed into a hollow 77 matched to the respective spherical or part-spherical shape at the upper end side 76 of the deflecting rod 72. The sphere 75 is provided with an annular collar 78 on which one end of the compression spring 74 rests.

The release safety mechanism 73 is adjustably attached to the vertical carrier 15; that is to say, the force exerted by the sphere can be modified by means of an adjusting screw 79 which can be locked by means of the nut 80.

At the rear end the longitudinal carrier 71 is provided with a support 81 which contains the mounting of the gripping rod 92. This gripping rod is of telescopic construction or form and can extend in the event of tractional stress. It consists of a fork-like carrier element 82 which is pivotally mounted at its lower end in the support 81 and at the upper end possesses a compression plate 83. Against the compression plate there abuts a compression spring 84 through whose convolutions extends a telescopic rod 85 which is provided at its lower end with a gripping element 86 which abuts externally against the

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compression spring 84 transversely of its longitudinal axis. A cantilever support arm 87 attached to the vertical carrier 15 possesses a stop strip 88 which is arranged at right angles to the rest of said arm 87 and which engages a so-called suspension cam 89 of the gripping rod 92, said suspension cam 89 being provided on the upper end of the rod 85 and abutting the stop strip 88 during mowing. From the upper end of the rod 85, a traction cable 46 leads across a guide roller 90 which is supported on the deflecting rod 72; the cable 46 terminates at the driver's seat position. In order to achieve an improved cable arrangement, a follower member 91 is provided which is connected to the deflecting rod 72 and which possesses a roller or a sliding element. At the front end of the longitudinal carrier 71, there is arranged a tension spring 49 whose second attachment point is to the vertical carrier 15. The spring 49, which exerts its maximum tension force during mowing operation, maintains the device in equilibrium.

If the mower 20 strikes against a solid object, the deflecting rod 72 is brought out of the release safety mechanism 73 via the longitudinal carrier 71 as a result of the reaction force. For this purpose, the carrier element 82 must be telescopic because, when the deflecting rod 72 is inclined forwards, the distance between the stop strip 88 on the vertical carrier 15 and the bearing on the support 81 increases. During this release procedure, the suspension cam 89 of the telescopic rod 85 is pushed by the follower element 91 from the stop strip 88 as a result of which the spring 49 relaxes whilst the mower is raised. With the aid of the cable 46, the deflecting rod 72 then engages the release safety mechanism 73 whereupon the telescopic rod 85 is positioned upon the support 87.

Another embodiment of an automatic implement-lifting device is illustrated in Figure 2. The implement used is a mower 20 corresponding to the previous example which is attached by •means of two lateral carriers 101 and two adjustable spacing means 102 to the carrier 103 of a mobile machine of which only one wheel 104 is shown. The carriers 101 are mounted on the device carriers 103 which each comprise a short pivot arm 105 and a long pivot arm 106. One end of the carrier 101 is articulated to the short pivot arm 105 by means of a horizontal pin or spindle 99. The long pivot arm 106 is attached to a forklike support 107 into which there is inserted a rod 108 which extends through a slot 109 which is formed in the carrier 101 and which extends longitudinally of said carrier 101. In order that the mower may be maintained in a stable position, it is provided with lateral flanges 110 which are connected to the tie-bars 100 of the device carrier 103 by means of the spacing means 102.

As soon as the mower 20 is subjected to a sudden force, the impact is transmitted to the carrier 101 and is transmitted thereby to the arm 105. The resultant torque influences, albeit to a reduced extent, the arm 106 in that the latter is lifted and the mower is conveyed out of the impact area. The lowering of the mower is effected by means of a hydraulic operating cylinder (not shown) which acts upon the device carrier 103.

Figure 3 illustrates yet another embodiment of an automatic implement-lifting device which is provided in particular for a drum mower 111. On account of the construction of this mower, an engine frame 113 thereof which is arranged above the drums 112 requires a device carrier construction which differs from that employed in connection with disc mowers. A device carrier 114 (not shown completely) is permanently connected to the tractor so as to be capable of being raised and lowered. At the tip of the carrier 115 it possesses a fork-like coupling device 14 in which the lifting device, provided with the mower, is attached on one side. A further support element, which is not shown in the drawing, connects the upper end of a vertical carrier 115 and the device carrier 114 in adjustable fashion. Deflecting frames 116 which are screwed to the engine frame 113 and which each consist of a thrust arm

117 and a deflecting rod 118, are mounted at the lower end of the vertical carriers 115 so as to be pivotal about a horizontal axis 124. At the upper end, the deflecting rods 118 are provided with release safety mechanisms 73 which are arranged on the vertical carrier 115 so as to be adjustable and lockable. From the deflecting rod 118a control lever 120 (which is connected to the control element of a directional control valve 119) projects approximately horizontally and contrary to the direction of deflection. The deflecting rods

118 of the deflecting frames 116 are attached to return cables 121 which possess a quite specific length and are connected to the machine. The pipelines 122 and 123 which are connected to the valve 119 lead to the lifting ram of the device carrier and to the tank or reservoir containing the fluid pressure medium. As in the previous exemplary embodiments the two lateral deflecting frames 116 are linked to one another in a rotary connection.

The simple mode of functioning of the device consists in that the mower 111, having come up against an obstruction, directly brings about the deflection of the deflecting frames 116; as a result of and simultaneously with said deflection, the valve 119 is switched over and the device carrier 114 is lifted hydraulically. The highest lifting point of the lifting device and the lengths of the cables 121 are adapted to one another in such a way that the deflecting arms 118 are withdrawn into the release safety mechanism 73, in this position, the valve 119 changes its state and the drum mower 111 can be lowered again.

In contrast to the drawing, the release safety mechanism 73 could also be arranged so as to operate upwards in a vertical or near-vertical direction. This would necessitate an additional deflection of the cable 121 to the front side of the device.

It goes without saying that, in any of the lifting

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devices in accordance with the present invention, a detachable joint is provided between the mower on the one hand and the lifting device on the other hand so that a lifting device can be used for different types of implements.

Claims

1. Automatic implement-lifting device connected via a linkage mechanism to a tractor which, when the implement strikes against an obstacle, allows the implement to be pivoted relatively to a device carrier which is arranged on the tractor, wherein an implement is attached to a carrier therefor which can be pivoted about a horizontal axis relatively to the device carrier and wherein the implement carrier is assigned a lifting device which is such as to ensure that the implement is raised from the ground when the implement strikes said obstacle.

2. Device as claimed in Claim 1, wherein the implement carrier consists of an approximately horizontal longitudinal carrier and an approximately vertical deflecting rod which is connected to said longitudinal carrier so as to be pivotal about said horizontal axis, the implement being attached to the front end of the longitudinal carrier considered in the direction of motion of the tractor, and the deflecting rod being mounted for pivoting movements about another horizontal axis relative to the vertical carrier of the device carrier; the end of the longitudinal carrier remote from said front end thereof being articulated to a telescopic gripping rod which is provided with a suspension cam which can be brought into engagement with a support arm which is arranged on the vertical carrier above said other horizontal axis; the lifting device being formed by a tension spring which acts between said front end of the longitudinal carrier and the vertical strut, an automatically triggerable release safety mechanism being provided which, in the event of a predetermined axial load on the longitudinal carrier being exceeded, allows the deflecting rod to be pivoted about said other horizontal axis relatively to the vertical carrier, the suspension cam disengaging from the support arm in the event of the deflecting rod pivoting as aforesaid.

3. Device as claimed in Claim 2, wherein the release safety mechanism consists of a sphere which is acted upon by the force of a compression spring, resting on the vertical carrier, and which is forced thereby into a hollow which is arranged at the upper end of the deflecting rod.

4. Device as claimed in Claim 3, wherein a traction cable which leads to the seat of the driver of the tractor acts upon the free end of the gripping rod and, when pulled, causes the longitudinal carrier to be pivoted against the force of said tension spring and allows the suspension cam of the gripping rod to be brought into engagement again with the support arm of the vertical carrier.

5. Device as claimed in Claim 1, wherein the device carrier is a bell crank lever which can be pivoted about another horizontal axis relative to the tractor and which possesses one arm pointing upwards and the other arm pointing forwards, the implement carrier being articulated to the free end of the upwards-pointing arm so as to be pivotal about said first-mentioned horizontal axis, and the forwards-pointing arm engaging under the implement carrier.

6. Device as claimed in Claim 5, wherein a forklike support is arranged on the free end of the forwards-pointing arm and bears a transverse rod which extends through an elongate slot which is formed in the implement carrier.

7. Device as claimed in Claim 5 or Claim 6, wherein the forwards-pointing arm of the device carrier is longer than the upwards pointing arm thereof.

8. An automatic implement-lifting arrangement 100 constructed, arranged and adapted to operate substantially as hereinbefore described with reference to and as illustrated in Figure 1 or Figure 2 of the accompanying diagrammatic drawings.

Printed for Her Majesty's Stationery Office by the Courier Press, Leamington Spa, 1984. Published by the Patent Office, 25 Southampton Buildings, London, WC2A 1AY, from which copies may be obtained.

8. Device as claimed in Claim 1, wherein the implement carrier consists of an angle lever which can be pivoted about said horizontal axis relatively to a vertical carrier of the device carrier and which possesses a forwards-pointing arm and an upwards-pointing arm, the implement being arranged at the free end of the forwards-pointing arm, the upwards-pointing arm engaging with a release safety mechanism arranged on the vertical carrier, one arm of the implement carrier having arranged thereon a control lever which actuates a valve which controls a hydraulic lifting device which acts upon the device carrier.

9. Device as claimed in Claim 8, wherein the release safety mechanism consists of a sphere which is acted upon by the force of a compression spring, resting on the vertical carrier, and which is forced thereby into a hollow which is arranged at the free end of the upwards-pointing arm of the implement carrier.

10. Device as claimed in Claim 9, wherein a cable is attached to the upwards-pointing arm of the implement carrier and to the tractor, the length of said cable being matched to the highest lifting position of the device carrier in such manner that the upwards-pointing arm of the implement carrier re-engages with the release safety mechanism and the control lever switches over the valve in order to cause the device carrier to be lowered.

11. Automatic implement-lifting device constructed, arranged and adapted to operate substantially as hereinbefore described with reference to and as illustrated in Figure 1 or Figure 2 or Figure 3 of the accompanying diagrammatic drawings.

12. Any features of novely, taken singly or in combination, of the embodiments of the invention hereinbefore described with reference to the accompanying diagrammatic drawings.

Superseded claims 1—12

New or amended claims:—

1. An automatic implement-lifting arrangement connected to an agricultural tractor and including a work implement fastened to at least one support, said support being connected to a carrier for said arrangement and extending forwards (as

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defined above); said support comprising an approximately horizontally extending longitudinal carrier member and an approximately vertically extending deflecting rod which are connected to 5 one another; the deflecting rod being pivotal about a horizontal pivot axis relatively to the carrier for said arrangement; the implement being attached to the front (as defined above) end of the longitudinal carrier member; and an automatically 10 triggerable release safety mechanism acting on the upper end of said deflecting rod to lock, in a releasable manner, said deflecting rod in its vertically extending attitude; and lifting means associated with said support; whereby, during 15 movement of said tractor in the direction which is customary for utilization of said work implement and in the event of an obstacle being encountered which applies to said implement an axial load in excess of a predetermined value, the lock applied 20 to the upper end of said deflecting rod by said release safety mechanism is overcome and said upper end of the deflecting rod moves forwards (as defined above) in an arc about said horizontal pivot axis with the result that the implement is 25 thereupon lifted clear of the obstacle by said lifting means.

2. An arrangement as claimed in Claim 1, wherein said longitudinal carrier member and said deflecting rod are so connected to one another as

30 to be relatively pivotal about another horizontal pivot axis which is below the level of the first-mentioned pivot axis; the end of said longitudinal carrier member which is remote from said front end thereof being articulated to a telescopic 35 gripping rod which is provided with a suspension cam which is supported by a support arm arranged on an element above the level of said first-mentioned pivot axis; and said lifting means being constituted by a tension spring which acts 40 between said front end of the longitudinal carrier member and said element; whereby, when said upper end of the deflecting rod moves as aforesaid in said arc, the suspension cam is disengaged from the support arm, with the result that the 45 tension spring causes the longitudinal carrier member so to pivot about said other pivot axis as to lift the implement clear of the obstacle.

3. An arrangement as claimed in Claim 2, wherein a traction cable is connected to said

50 upper end of the deflecting rod and extends to the position of the seat for the driver of the tractor; said traction cable, when pulled, causing the deflecting rod to pivot about the first-mentioned axis in order to effect re-engagement of said upper 55 end of the deflecting rod by said release safety mechanism and causing said longitudinal carrier member to be so moved about said other pivot axis as to cause said tension spring to be re-stretched and as to cause the suspension cam to 60 re-engage the support arm.

4. An arrangement as claimed in Claim 1, wherein said longitudinal carrier member and said deflecting rod are so connected to one another as to form an L-shaped lever whose arms are

65 incapable of movement relatively to one another; one arm of said L-shaped lever having arranged thereon a control lever which is operable to actuate a valve which controls a hydraulic lifting/lowering device which constitutes said 70 lifting means and which acts upon the carrier for said arrangement; whereby, when said upper end of the deflecting rod moves as aforesaid in said arc, the control lever actuates the valve to cause the hydraulic device to lift the carrier for said 75 arrangement, with the result that the implement is lifted clear of the obstacle.

5. An arrangement as claimed in Claim 4, wherein a traction cable is connected to the deflecting rod and wherein the length of said

80 traction cable and the greatest height to which the arrangement can be lifted are so matched to one another that, when said greatest height has been reached; said upper end of the deflecting rod engages the release safety mechanism again and 85 the control lever actuates the valve to cause the hydraulic device to lower the arrangement carrier.

6. An arrangement as claimed in any one of the preceding Claims, wherein said release safety mechanism consists of a spring-loaded sphere and

90 a hollow in the free end of the deflecting rod; the locking of the deflecting rod, in said releasable manner, in its vertically extending attitude being effected when said sphere engages said hollow.

7. An arrangement as claimed in Claim 6, 95 wherein the sphere is spring-loaded by a compression spring which is adjustable, as regards the force which is applied thereby to the sphere, by an adjusting screw.