GB2055539A

GB2055539A - Reciprocating mower

Info

Publication number: GB2055539A
Application number: GB8025155A
Authority: GB
Original assignee: Deere and Co
Current assignee: Deere and Co
Priority date: 1979-08-04
Filing date: 1980-08-01
Publication date: 1981-03-11
Also published as: GB2055539B; DE2931731C2; FR2462091B1; DE2931731A1; FR2462091A1

Abstract

Two separate knives 22 and 24 extend over different parts of the length of a single cutter bar and reciprocate out of phase with each other in order to balance lateral forces in known manner. To simplify the drive of the knives, only the in-board knife 22 is driven directly by way of an oscillating lever 54. The adjacent ends of the knives 22 and 24 are coupled by a mechanism 32 which moves the knife 24 in the opposite direction to the knife 22. <IMAGE>

Description

SPECIFICATION Reciprocating mower The invention relates to a reciprocating mower with two knives which reciprocate out of phase with one another so that transverse forces on the mower are counterbalanced.

A mower of this kind is described in US-PS 3 508 388 and has two pitmans at the inboard end of the cutter bar, one connected conventionally to the inboard knife and the other connected by a long sliding link to the outboard knife. This makes the drive relatively expensive.ln DE-OS 2 173, the two pitmans are connected to the adjacent knife ends, midway along the cutter bar, but this is an inconvenient location for the pitman drive.

The object of this invention is to provide a mower with a simpler drive and this objective is provided by the invention as defined in claim 1. The inertia of the moving parts can be kept small with such a construction.

It is advantageous for the knives to overlap each other in the region of the mechanical coupling. By this means a good guiding of the knives is obtained over the whole cutter bar length, even in the region of the coupling. Due to this arrangement and construction of the knives it is possible for the individual parts, especially the knife sections and fingers of the cutter mechanism, to be made all of one kind.

It is further advantageous that, in the region where the knives overlap, one of the knives should cooperate with the upper edge of the fingers and the other knife with the lower edge of the fingers. In this way it is possible without removing the fingers to arrange the knives so that they overlap in a given region.

The first knife can have a knife-back which is stouterthan the knife-back of the second knife. In this way it is possible to make the second knife more economically, especially since it no longer needs to transmit any large forces.

The first knife should then be shorter than the second knife so that the weights of the knives are approximately equal. In this way the inertia forces of the drive mechanism can be equalized.

It is advantageous that the coupling should be provided in the body of the mower. By this means it is possibleforthe linkage to be protected from contamination.

It is further advantageous that the drive mechanism should be drivably connected directly with the mechanical coupling and that the drive mechanism andiorthe coupling should be arranged approximately centrally with respect to the cutter bar as a whole. Accordingly both knives can be driven in a simple manner from one position and the motive power for driving the knives can be reduced.

Two embodiments of the invention will be explained by way of example with the aid of the drawings, in which: Figure 1 shows a cutter bar with two oppositely driven knives in plan view, Figure 2 is a section along the line 2-2 according to Figure 1, Figure 3 is a section along the line 3-3 according to Figure 1, and Figure 4 is a plan view of an alternative mechanical coupling for the two knives.

In Figure 1 a reciprocating mower2 has two knives 4 and 6 which are drivabie in mutually opposite directions. The mower 2 has an inner shoe 8 (Figure 3) which is connected with a frame, not shown in the drawing, of a harvesting device. The shoe 8 has at its front end an angle iron finger bar 10 to which are fixed a multiplicity of fingers 12 arranged side-byside. Openings 14 are provided in the individual fingers 12 under tongues 18 ofthe fingers. Knife sections 20 move through the openings 14, these knife sections being secured to a left (inboard) knife-back 22 and to a right (outboard) knife-back 24.The left knife-back 22 is rigidly secured by a plurality of rivets 26 to an upper knife-supporting member 28, while the right knife-back member 24 is secured to an upper supporting member 30. (Figure 1 is upside down relative to the normal mower altitude).

The supporting mowers 28 and 30 are connected by a mechanism 32 so that the inboard knife 4 can drive the outboard knife 6. The mechanism 32 consists according to Figure 1 of a left-hand lever 34 and a right-hand lever 36. The two levers 34 and 36 are each releasably, but nevertheless non-rotatably, connected by a bolt 35 with a respective toothed segment 40 or 42. The toothed segments 40 and 42 have teeth 44 which mesh with each other. The levers 34 and 36 are pivotally connected by hinge bolts 46 and 48 to the knife-backs 22 and 24 respectively.

The hinge bolts 46 and 48 are rigidly secured to the knife-backs 22 and 24 and extend into bearing bosses 50 and 52 which are provided respectively on the ends of the levers 34 and 36 and form a driving connection between the hinge bolts 46 and 48 and the levers 34 and 36 respectively. The bolts 35 on the other hand are mounted in bearings 39 forming part of the fixed cutter bar.

The inboard or left-hand knife-back 22 is connected to a driving lever 54 which is connected to a drive mechanism not further represented in the drawing. The knife-back 22 is driven via the driving lever 54 and drives the right-hand knife-back 24 via the transmission mechanism 32. The two cutter halves 4 and 6 can thus be driven in mutually opposite directions. As is clear particularly from Figure 2 the knife sections 20 on the left-hand knife-back are so arranged that they overlap the knife sections 20 of the right-hand knife-back in the region of the transmission mechanism 32.In orderthat it should not also be necessaryforthe individual fingers 12 to be offset with respect to each other in the overlapping region, the knife sections 20 on the left-hand knifeback 22 cooperate with upper cutting edges 58 on the fingers 12 and the knife sections 20 on the righthand knife-back 24 cooperate with lower cutting edges 56 on the fingers 12.

In order to ensure a uniform pressure contact between the individual knife sections 20, knife guides 60 are provided between the individual fingers 12 to press the knife sections against the cutting edges 56 of the fingers 12. A guide 60 is shown only in Figure 3 and is secured to the finger bar by means of a screw 11.

A further constructional embodiment of the transmission mechanism 32' is shown in Figure 4, which mechanism has a lever 34' pivotably con nected to the knife-back 22 and a lever 36' connected to the knife-back 24. The lever34' or 36' is pivotably connected via a hinge bolt 46' or 48' with the knife back 22 or 24 respectively and is fixed to a lever 62 or 64 by a transmission bolt 35' in each case. The driv ing connection between the two levers 62 and 64 is provided buy a link 66 which is connected at its ends by a bolt 63 or 70 to the corresponding lever 62 or 64.

The pivot bolt 68 lies between the pivot bolts 46 and 35' whereas the pivot bolt 70 lies beyond the corresponding pivot bolt 35 i.e. the latter pivot bolt lies between the pivot bolts 70 and 48.

Claims

1. A reciprocating mower comprising a cutter bar, first and second knives extending along respective portions of the cutter bar, a reciprocating drive mechanism connected soiely to the first knife, and a mechanical coupling between the first and second knives serving to transform motion of the first knife in either direction into motion of the second knife in the respective opposite direction.

2. Areciprocating mower according to claim 1, wherein the mechanical coupling comprises coupled levers which are pivotally connected to the adjacent ends of the two knives.

3. A reciprocating mower according to claim 2, wherein the levers are pivotally mounted on the cutter bar.

4. A reciprocating mower according to claim 3, wherein the levers are coupled by meshing toothed segments.

5. A reciprocating mower according to claim 3, wherein the levers are coupled by a link pivotally connected to one lever between its mounting pivot and its pivotal connection to its knife, and pivotally connected to the other lever at a point such that the mounting pivot of the other level has between that point and its pivotal connection to its knife.

6. A reciprocating mower according to any of the preceding claims, wherein the knives overlap each other in the region of the mechanical coupling.

7. A reciprocating mower according to claim 6, wherein, in the region where the knives overlap, one of the knives cooperates with upper edges of fingers on the cutter bar and the other knife with lower edge of the fingers.

8. A reciprocating mower according to any of the preceding claims, wherein the first knife has a stouter knife-back than the second knife.

9. A reciprocating mower according to claim 8, wherein the first knife is shorter than the second knife, the weights of the knives being approximately equal.

10. A reciprocating mower substantially as hereinbefore described with reference to and as illustrated in Figures 1 to 3 or Figures 1 to 3 as mod ified by Figure 4 of the accompanying drawings.