GB2073572A - Haymaker - Google Patents

Abstract

In a hay making machine having at least one rake head which is rotatable about an upright axis, control mechanism includes an eccentrically mounted rotating ring (26) carrying radially extending connecting rods (28) which are coupled to arms (35) at the inner ends of tine carriers (23), through the intermediary of a linkage system (30) which includes a swinging link (31) which is pivoted at a fixed point (32), and a connecting link (34) extending between the swinging link (31) and the arm (35). The linkage system (30) converts a smooth rotary motion derived from the ring (26) into an intermittent motion whereby the tines have an extended dwell close to the ground and are lifted upwardly away from the ground sharply. The ring (26) may be rotatable on a collar (25) which is adjustable to vary the eccentricity of the ring relative to the rotational axis of the head. <IMAGE>

Description

SPECIFICATION Hay making machine This invention relates to a hay making machine of the kind including at least one rake head which is driven about a generally upright rotational axis and affords a plurality of tine carriers which extend outer wardly relative to said rotational axis, the rake head having a control mechanism whereby the position of tines on said tine carriers is variable relative to a reference plane perpendicular to said rotational axis.

Such machines are hereinafter referred to as being of the kind specified.

Various designs of machines of the kind specified are known in which the tines are controlled by means of a cam track which is engaged by a follower arm projecting transversely from the inner end of each tine carrier, so that in one range of positions along the circular path swept out by the tines they extend generally perpendicular to said plane, and generally transversely relative to the ground, so that hay or other crop on the ground is engaged and swept along, whilst in another range of positions, the tines are lifted to disengage from the crop and then extend generally in or close to said plane, and generally parallel to the ground.

The cam tracks required for such mechanisms are relatively costly to produce and are also subject two a number of other disadvantages. For example, in order to lift the tines quickly from the crop so that it is deposited in well formed swaths, the cam track requires a steeply rising sector which is subject to heavy wear and itself imposes a substantial, repeated and intermittent resistance to rotation of the rake head as each follower encounters that sector.

Moreover, the form of such a cam track is not readily variable to enable the machine to be adjusted in accordance with different working conditions orto provide different functions.

Previous proposals which have attempted to provide for such adjustments have generally resulted in arrangements which are unsatisfactory for various reasons, including a reduction in the rate at which the tines are lifted from the crop in consequence of a more "smoothed" profile for the cam track.

An alternative approach has suggested the use of an eccentric mechanism, including a ring which is rotatable about a central disc which is eccentrically arranged relative to the rotational axis of the rake head, the ring being coupled to rakes which are pivoted for movement about respective generally vertical axes between positions in.which they extend generally radially relative to said rotational axis and positions in which they extend generally tangentially. The raking action thus provided can be varied by adjustment of the control disc angularly relative to the rotational axis of the rake head, but the raking action is less precise than when the tines are lifted from the ground because crop may not disengage completely while the rakes remain close to the ground.Moreover, there is no sharp change from a raking position to a depositing position, only a continuous adjustment of position, which gives rise to further loss of precision in the raking action.

It is an object of the present invention to provide a hay making machine of the kind specified with an improved control mechanism having one or more advantages as hereinafter pointed out.

According to a first aspect of the invention we provide a hay making machine of the kind specified wherein each tine carrier is pivoted for movement about a respective axis which extends transversely relative to the rotational axis of the rake head, and the control mechanism includes a ring which is rotatably mounted on a stationary collar which is itself eccentrically arranged relative to said rotational axis of the rake head, and each of the tine carriersof that head is operatively connected to said ring through a linkage system including a swinging link which is pivotable on an axis arranged generally parallel to and spaced from the pivotal axis of the tine carrier concerned in a direction transverse to said reference plane, a connecting rod extending between said swinging link and said ring and connected to the swinging link at a point spaced from its pivot, a lateral arm on said tine carrier, and a connecting link extending between, and pivotally connected to, the swinging link and the lateral arm.

In operation, the ring is rotated about the collar (which is held stationary) and each connecting rod oscillates radially as it sweeps through 360 about the rotational axis of the head. Thus, the swinging link, which is preferably arranged above the tine carrier and depends from its pivot, is caused to oscillate angularly. The free end of the swinging link thus moves along an arcuate path including a first portion having a major component which extends generally parallel to said plane (i.e. horizontally) and a second portion having a substantial component which extends generally transverse to said plane (i.e. vertically).During the first portion of the movement of the swinging link, the connecting link pivots about its connection with the lateral arm without significantly moving the latter, however during the second portion of the movement of the swinging link, the connecting link is moved as a whole generally vertically and thus causes the lateral arm to turn about the pivotal axis of the tine carrier. In this way the tines on the tine carrier are caused to swing between positions in which they extend generally perpendicular to said plane and positions in which they extend generally in or close to that plane.

The continuous sinusoidal reciprocatory motion of each connecting rod is, when transmitted to the corresponding lateral arm, converted to one which has a prolonged almost stationary dwell, corresponding to the first portion of the movement of the swinging link, and a more sharply defined excursion, corresponding to the second portion of the movement of the swinging link. This enables the lower ends of the tines to remain close to the ground at substantially constant spacing over a substantial part of their 360" sweep, unlike a simple sinusoidal motion which would give a more restricted low point and a less well defined lift.

By suitable choice of the geometry of the linkage system, the contour of the line swept by the end of each tine can be tailored to suit specific requirements and thereby optimise the performance of the machines various hay making operations.

In accordance with a second feature of this invention, the control mechanism is adjustable to vary the angular position relative to the generally upright rotational axis of the head at which each carrier is rotated to lift the tines thereon. This is achieved by securing the collar fixedly to a shaft which defines said rotational axis, the shaft being mounted on the support member in such a manner as to enable itto be rotated about the axis and held in any selected angular position of adjustment. For this purpose, the shaft may be journalled in a bushing and provided with a control arm which is releasably engageable with a control quadrant or sector in any one of a plurality of positions of adjustment to hold the shaft against rotation, and in any desired setting.Positional adjustment of the shaft angularly about the rotational axis is then effected by releasing the control arm from the quadrant or sector, and relocating it at the appropriate positionS. In this way the angular position at which the tines lift can be adjusted over any desired range up to a full 360 sweep.

In accordance with a further feature of the invention, the collar is adjustable in the radial direction relative to the upright axis to enable the height of lift of the tines to be varied.

This may be achieved by forming the collar as respective inner and outer parts, with the inner part in the form of a circular disc secured to the shaft with its centre point spaced from said rotational axis, and the outer part in the form of a circular disc with a circular opening eccentrically arranged with respect to the centre of the outer disc, and in which opening the inner disc is received, the arrangement being such that on rotation of the outer disc about the inner disc the centre of the outer disc can be adjusted between at least one position where it is spaced from the rotational axis of the head and a further position in which is coincides with that axis.

However, more conveniently, the shaft which defines the rotational axis may be formed or provided with a laterally off-set cranked portion on which the collar is eccentrically mounted, in such a manner as to be angularly adjustable relative to the rotational axis of the head, the arrangement being such that in one angular position of the collar the centre of the collar coincides with the rotational axis of the head so that the ring is rotatable about that axis, whereas in all other angular positions the centre of the collar is spaced from that axis so that the ring is rotatable about an axis which is eccentrically disposed relative to the rotational axis of the head.

The ring may be driven to rotate about the collar by means of a connection fromthe rake head provided in addition to the connecting rods which connect the ring the tine carriers. This is conveniently achieved by means of a pair of driving members, one of which is carried by the rake head and rotates in a circular path centred on the rotational axis of the head, and the other of which is carried bythe ring, one of the members comprising a radially disposed slide so arranged that a driving connection is maintained despite radial excursions of the member car ried by the ring as it rotates about the ring when the latter is eccentrically disposed relative to the rotational axis of the head.

These and other features of the present invention will now be described by way of example with reference to the accompanying drawings wherein:- FIGURE 1 is a part sectional view in side elevation of a rake head incorporating one embodiment of improved control mechanism in accordance with the invention; FIGURE 2 is a sectiqnal plan view on the line 2-2 of Figure 1 which line also indicates a reference plane perpendicularto the rotational axis of the rake head; FIGURE 3 is a plan view of a similar part of a furtherembodiment of control mechanism in one position of adjustment; FIGURE 4 is a similar plan view to Figure3show- ing the mechanism in a different position of adjustment; and FIGURE 5 is a graphical illustration of the controlled movementofthetrnes during each revolution of the rake head.

A hay making machine in accordance with the invention, as illustrated in Figures 1 and 2, includes a rake head 10 having a generally upright rotational axis A, defined by a shaft 11 which carries spaced upper and lower bearings 12 and 13 and is itself supported at its upper end in a bush 14 incorporated in a frame structure, only part of which is shown. A drive shaft 15 isjournalled in a casing 16 and carries a pinion 17 meshing with a bevel gear 18 which is secured to a top plate 19 of the rake head 10 concentric with the upper bearing 12. Where one or more further rake heads are provided any suitable means may be employed to transmit drive from the shaft 15 to such additional head, for example a chain or belt drive from a pulley carried by the bevel gear 18, or a cross-shaft having a pinion meshing with the bevel gear 18 itself.

The rake head 10 houses acontrol mechanism indicated generally at20 and also includes a bottom plate 21 which supports the lower bearing 13. The rake head 10 may, if desired, include a circumferential casing (not shown). In addition, the shaft 11, at its lower end beneath the tower bearing 13, carries a bracket which- is.sppo rted by a ground engaging wheel (not shown) The top and bottom plates 19 and 21 of the rake head 10 are interconnected by a plurality of spacer members 22, eactEofwhich supports a generally tangentially extending tine carrier arm 23. In the illustrated embodiment (see Figures 3 and 4) there are foursuch arms, but there may be any other suitable number, for example between 3 and 7 or 8 could be used. Such arms extend generally in a plane perpendicular to the rotational axis A, of the; head and parallel to the reference plane indicated by the line 2-2 in Figure 1. The arms 23 carry attheir outer ends a number of transversely extending tines (not shown in Figures 1 and 2). Such tines normally extend downwardly from the arms 23 so thattheir tips are in close proximity to the ground, but the arms 23 are supported in the members 22 in such a manner as to be pivotable about their longitudinal axes by means of the control mechanism as hereinafter described.

The shaft 11 includes a cranked part 1 lea which has its longitudinal centre line A2 laterally off-set from the axis A,. A circular plate 24 is fixedly secured on the cranked part 1 la of the shaft 11 and supports thereon a circular collar 25 carrying a spring loaded locking pin 27 which is selectively engageable with different apertures formed in the plate 24. Normally there will be at least two said apertures 27a, 27b at diametrally spaced positions but the re may be a plurality of said apertures arranged in an arcuate row centred on the centre line A2.The collar 25 which is conveniently formed in two parts which are bolted together, is eccentrically disposed with respect to the cranked part 11a of the shaft 11 so that its central axis A2 is radially off-set from the line A2 and from the axis A,.

However, by rotating the collar 25 about the centreline A2 of the cranked part 1 la of the shaft, the radial spacing between its axis A3 and the axis A, can be.adjusted between a maximum value (as shown in Figure 1) and a value of zero where the two axes are coincident.

A ring 26 formed of upper and lower elements 26a and 26b is rotatably mounted on the collar 25.

A fixed length or adjustable length connecting rod 28 (one for each tine carrier arm 23) is pivotally connected at its inner end to the ring 26 by means of a ball joint 29, and forms part of a linkage system indicated generally at 30 for pivoting the associated tine carrier arm 23 about its longitudinal axis as the rake head 10 rotates. The linkage system includes a swinging link 31 which is movable about a horizontal axis by means of a pivot 32 which is spaced above and parallel to the corresponding arm 23, and the outer end of the connecting rod 28 is pivotally connected to the link 31 at its lower end 33. A connecting link 34 is pivotally connected at one end to the lower end 33 of the swinging link 31, and at the other end to the outer end of a lateral arm 35 secured to the carrier arm 23.

The ring 26 is rotated by means of a driving member 36 carried by the top plate 19 of the head 10, which member 36 includes a roller 37 engaging in a radial slide 38 secured to the ring 26. In this way, the ring 26 is positively driven in synchronism with the rotation of the rake head. However, by appropriate design of the linkage system 30 it would be possible to arrange for rotation to be imparted to the ring through such linkage system.

As the rake head rotates about the axis A1, when the disc 25 is set in the position shown in Figures 1 and 2, the ring 26 rotates about the axis A3 which is eccentrically disposed relative to the axis A1 and accordingly each connecting rod 28, as it sweeps through 360 about the axis A1, moves radially inwardly and outwardly in a sinusoidal manner as indicated by curve S shown in Figure 5. As can be seen from Figure 1,the substantially linear sinusoi dal reciprocatory movement of each connecting rod 28 is converted by the linkage system 30 to an angular non-sinusoidal oscillation as applied to the corresponding carrier arm 23. In Figure 1, the one swinging link iilustrated is shown at its extreme outward position.Movement of the connecting rod 28 radially inwardly from position Ato position B will cause the lower end 33 of the swinging link 31 to move along an arcuate path which extends substantially horizontally, i.e.generally parallel to said reference plane, with the result that the connecting link 34 will pivot about its connection with the lateral arm 35 without causing significant angular movement of the latter. However, further radially inward movement of the connecting rod 28 from position B to position C will cause the link 31 to move along an arcuate path which has an increasing vertical component, so that the link 34 is lifted and the outer end of the lateral arm 35 moves along an arcuate path which extends upwardly, i.e. generally transverse to said reference plane.In this way, the angle of the tines relative to the axis A, varies in accordance with curve T shown in Figure 5, in a manner which is non-sinusoidal and affords a prolonged dwell period where the tips of the tines are maintained close to the ground, as ill us- trated most clearly by curve H which represents the height of the tips of the tines above the ground.

The improved control mechanism in accordance with the invention thus converts the smooth and continuous rotary motion of the ring 26 into an almost intermittent motion whereby the tines on the one hand have more extended dwell close to the ground, and on the other hand are lifted upwardly away from the ground more sharply, than would be so in either case if such sinusoidal motion were applied directly to the tines without modification.

In accordance with a further feature of the invention, as mentioned above, the collar 25 may be rotated about the axis A3 of the cranked part 1 la of the shaft by releasing the locking pin 27 and relocating it in a further aperture. Such adjustment serves to vary the radial spacing between the axis A3 of the disc collar and the rotational axis A, of the head. In this manner, the magnitude of the reciprocatory movement of the connecting rods 28 may be adjusted between a maximum value and a minimum value which may be zero. In the latter case, the axes At, A3 and A3 are spaced apart by equal distances so that in one position of adjustment the axes A1 and A3 are coincident In this setting, the collar 25 is centred on the axis A1 and the ring rotates on the axis A1 and not eccentrically.When the control mechanism is set in this position, the tines are maintained in a constant position so that the machine may then serve tedding and other similar operations.

In accordance with a further feature of the invention, which is particularly applicable in machines of the kind including a plurality of such rake heads, the angular position at which the tines lift from the ground (relative to the direction of forward travel), can be varied by rotating the shaft 11 about the upright axis AI. For this purpose, the shaft 11, which is rotatably supported in the bush 14 carries a control arm 39 passing through a diametral hole in the shaft 11 and having one end releasably engageable in any one of a plurality of apertures 41 in a control sector or quadrant 40. By withdrawing the end of the control arm 39 from the quadrant 40, the shaft 11 can be rotated about the axis A, and thereafter the end of the control arm can be secured in a further aperture of the quadrant 40.

Referring now to Figures 3 and 4, there is shown therein part of a modified control mechanism in which the ring 26 is rotatable around a collar 125 which is formed as a split inner part 125a and an outer part 125b. The inner part 125a comprises a disc which is secured to the shaft 11 eccentrically, the shaft then being straight instead of having a cranked portion as in the embodiment shown in Figures 1 and 2. The outer part 125b is similarly formed as a disc which is mounted eccentrically on the inner part 125a. The two parts may be held together buy a locking pin 127 in at least two different positions of angular adjustment. As shown in Figure 3, the central axis of the outer part 12ebb can be off-set from the axis of the shaft 11, whilst by rotating the outer part 125yew aboutthe inner part 125a, to the position shown in Figure 4, these two axes can be made to coincide.

Thus, in the first position the ring 26 rotates about an eccentrically disposed axis, whereas in the second position it rotates on the rotational axis ofthe head.

In this way, the angular movement applied to the tines can be varied between a maximum value and zero, in the same manner as previously described in relation to Figures 1 and 2.

Claims (12)

1. A hay making machine of the kind specified wherein each tine carrier is pivoted for movement about a respective axis which extends transversely relative to the rotational axis of the rake head, and the control mechanism includes a ring which is rotatably mounted on a stationary collar which is itself eccentrically arranged relative to said rotational axis of the rake head, and each of the tine carriers of that head is operatively connected to said ring through a linkage system including a swinging link which is pivotable on an axis arranged generally parallel to and spaced from the pivotal axis of the tine carrier concerned in a direction transverse to said reference plane, a connecting rod extending between said swinging link and said ring and connected to the swinging link at a point spaced from its pivot, a lateral arm on said tine carrier, and a connecting link extending between, and pivotally connected to, the swinging link and the lateral arm.

2. A hay making machine according to Claim 1 wherein the pivotal axis of the swinging link is disposed generally above that of the corresponding tine carrier.

3. A hay making machine according to Claim 2 wherein said connecting rod is pivotally connected to said swinging link at or adjacent to the lower end thereof, the lower end of the swinging link being moved by said rod along an arcuate path which extends in a direction generally parallel to said reference plane.

4. A hay making machine according to Claim 3 wherein said swinging link is pivotably connected to said lateral arm at or adjacentto the outer end thereof, and the outer end is movable thereby in an arcuate path which extends generally in a direction transverse to said reference plane.

5. A hay making machine according to any pre ceding claim wherein said ring is positionally adjust able in a radial direction relative to the rotational axis of the head, between an inoperative position in which its axis of rotation is coincident with the rotational axis of the head and at least one operative position in which the two axes are spaced apart radially.

6. A hay making machine according to Claim 5 wherein a shaft which defines the rotational axis of the head is formed or provided with a laterally off-set cranked portion on which said collar is eccentrically mounted, the collar being angularly adjustable relative to said shaft so that in one angular position the centre of the collar coincides with said rotational axis, whereas in all other angular positions the centre of the collar is spaced from that axis.

7. A hay making machine according to Claim 5 wherein said collar is formed at respective inner and outer parts, with the inner part in the form of a circular disc secured to a shaft which defines said rotational axis, and the outer part in the form of a circular disc with a circular opening eccentrically arranged with respect to the centre thereof and in which opening the inner disc is received, so that on rotation of the outer disc about the inner disc the centre of the outer disc is adjustable between one position in which it coincides with said rotational axis and at least one further position in which it is spaced from said axis.

8. A hay making machine according to any one of the preceding claims wherein a driving connection between the rake head and the ring is provided in addition to said connecting rods.

9. A hay making machine according to Claim 8 wherein said driving connection comprises a pair of driving members, one of which is carried by the rake head and rotates in a circular path centred on the rotational axis of the head, and the other of which is carried by the ring, one of said members comprising a radially disposed slide whereby a driving connection is maintained between the two members despite radial excursions of the member carried by the ring as it rotates when it is eccentrically disposed relative to said rotational axis of the head.

10. A hay making machine according to any one of the preceding claims wherein the control mechanism is adjustable to vary the angular position relative to said upright axis at which each carrier is rotated to lift the tines thereon.

11. A hay making machine according to Claim 10 wherein the control mechanism is mounted on a shaft which defines said rotational axis, and the shaft is journalled in a bushing and provided with a control arm which is releasably engageable with a control quadrant or sector in any one of a plurality of positions of adjustment to hold the shaft against rotation in any desired setting.

12. A hay making machine of the kind specified substantially as hereinbefore described with reference to and shown in the accompanying drawings.