EASY ADJUST TENSIONER ASSEMBLY

Abstract

A tensioning bar assembly for a tensioning assembly of a drive system of an agricultural machine, including a longitudinal bar having a longitudinal axis, a top end and a bottom end, an attachment device attached to the top end of the longitudinal bar, a compression spring having first and second ends, the spring located around a portion of the longitudinal bar, and a first spring retainer for engaging with and retaining the first end of the spring, where the longitudinal bar has a bolt section, and the bolt section has a threaded portion, an engagement head, and a sleeve section, and the sleeve section includes an internally threaded hollow section for receiving the bolt section, and the sleeve section is fixed and rotationally attached to the attachment device.

Claims

1. A tensioning bar assembly for a tensioning assembly of a drive system of an agricultural machine, comprising: a longitudinal bar having a longitudinal axis, a top end and a bottom end; an attachment device attached to the top end of the longitudinal bar; a compression spring having first and second ends, said spring located around a portion of the longitudinal bar; and a first spring retainer for engaging with and retaining the first end of the spring, wherein the longitudinal bar comprises a bolt section, said bolt section comprising a threaded portion, an engagement head, and a sleeve section, said sleeve section comprising an internally threaded hollow section for receipt of the bolt section and further wherein the sleeve section is fixedly rotationally attached to the attachment device.

2. The tensioning bar assembly as claimed in claim 1, further comprising a locking nut fitted on the threaded portion of the bolt section of the bar, wherein the locking nut may be used to lock the bolt section of the bar in place in relation to the sleeve section of the bar.

3. The tensioning bar assembly as claimed in claim 1, further comprising a second spring retainer for engaging with and retaining the second end of the spring.

4. The tensioning bar assembly as claimed in claim 1, wherein the first spring retainer and the engagement head are a unitary item.

5. The tensioning bar assembly as claimed in claim 1, wherein the engagement head of the bolt section of the bar comprising any one or more of: a triangle, square, pentagon or hex head or socket; a posidrive head or socket; a torx head or socket; a slotted or phillips screwdriver receiving socket; a spline head or socket; a pair of locking nuts locked in position on the threaded portion, proximate the bottom end of the bar; and an engagement head device screwed to the bottom end of the bar on the threaded portion.

6. The tensioning bar assembly as claimed in claim 1 wherein the attachment device is a clevis.

7. A tensioning assembly for a drive system, comprising the tensioning bar assembly as claimed in claim 1, further comprising: a tensioning arm pivotally mounted to the machine; a tensioning device mounted to the tensioning arm for contacting the drive system and applying a tensioning force directly thereto; and a bracket mounted to the machine, wherein the attachment device is attached to the tensioning arm at an attachment point and the second end of the spring is in direct or indirect physical contact with the bracket, such that compression of the spring applied by and between the bracket and the first spring retainer provides a resultant force applied to the tensioning arm, via the attachment point, about the pivot mounting point of the tensioning arm, which produces the tensioning force to force the tensioning device into contact against the drive system.

8. The tensioning assembly as claimed in claim 7, wherein the bracket has a facing side facing towards the tensioning arm and a distal side facing away from the tensioning arm; the spring and first retainer are located on the distal side; and the second end of the spring is in direct or indirect physical contact with the distal side of the bracket such that the resultant force acts to pull the attachment point towards the bracket.

9. The tensioning assembly as claimed in claim 7 wherein the tensioning arm has a first end and a second end, the tensioning device being mounted proximate to the first end, the attachment point being proximate to the second end, and the pivotal mounting of the tensioning arm being at a midpoint between the first and second ends of the tensioning arm.

10. The tensioning assembly as claimed in claim 7 wherein the tensioning arm has a first end and a second end, the tensioning device being mounted proximate to the first end, the pivotal mounting of the tensioning arm being proximate to the second end, and the attachment point being at a midpoint between the first and second ends of the tensioning arm.

11. The tensioning assembly as claimed in claim 7, further comprising a second spring retainer for engaging with and retaining the second end of the spring and wherein the second spring retainer further engages with the bracket.

12. The tensioning assembly as claimed in claim 11 wherein the second spring retainer and the bracket are a unitary item.

13. The tensioning assembly as claimed in claim 7 wherein the tensioning device is an idler wheel and the drive system is a belt drive system or a chain drive system.

14. The tensioning assembly as claimed in claim 7 wherein the tensioning device is an idler gear and the drive system is a chain drive system.

15. A drive system for an agricultural machine comprising the tensioning bar assembly as claimed in claim 1.

16. A drive system for an agricultural machine comprising the tensioning assembly as claimed in claim 7.

17. An agricultural machine comprising a drive system as claimed in claim 15.

18. An agricultural machine comprising the tensioning assembly as claimed in claim 16.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The invention will now be described in more detail by reference to the attached Figures.

[0042] FIG. 1 shows a typical prior art drive system from a combine harvester. It shows a drive system which provides drive power to a straw chopper at the rear end of a combine harvester.

[0043] FIG. 2 shows a cross-sectional view through a portion of the prior art tensioning assembly giving more detail of some of the items of FIG. 1.

[0044] FIG. 3A shows a schematic view of elements of a tensioning bar assembly in accordance with aspects and embodiments of the present application.

[0045] FIG. 3B shows a schematic cross-sectional view of a sleeve section of a tensioning bar, unitary with a clevis attachment device, in accordance with aspects and embodiments of the present application.

[0046] FIGS. 4A and 4B show alternative schematic arrangements of bar, bracket, spring and tensioner arm in accordance with embodiments of the invention4a where the overall configuration is similar to that of FIGS. 1, and 4b where the tensioner arm is mounted in an alternative manner.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0047] FIG. 1, as described elsewhere herein, and FIG. 2 show:

The drive system 60 comprises a driving wheel 61 and a driven wheel 62 connected by a belt 63. Tension in the belt is applied by a tensioning system 1. Tensioning system 1 includes an idler wheel 47 which presses against the belt and is mounted on a tensioning arm 41.

[0048] The idler wheel is rotationally mounted on a first end 41a of the tensioning arm, and the tensioning arm is pivotally mounted on a pivot 41p, at a midpoint 41m, to the combine harvester (not shown). To the second end of the tensioning arm 41b is connected a tensioner assembly 1, which applies a force Fa to the end 41b of the arm 41.

[0049] The tensioning assembly 1 comprises a longitudinal bar 2. At a first, or top end of the bar 2t is a clevis assembly 3 which is connected to the second end of the tensioning arm 41b by a clevis pin 36 at an attachment point 3p. In this prior art arrangement, the longitudinal bar 2 is fixed to the clevis assembly 3 such that in effect the bar and clevis are a unitary item. A portion of the bar 2a is provided with a screw thread. Fitted over this threaded portion of the bar is a spring 4s, having first end 6b and second end 6t, and also a first spring retainer 4b and a second spring retainer 4t which together keep the spring in place.

[0050] When in position on the combine harvester (or machine), the second spring retainer 4t butts up against a bracket 20 which is attached, ultimately, to the combine harvester. Bracket 20 has a facing side 20f facing towards the tensioning arm 41 and a distal face 20d facing away from the tensioning arm. The first spring retainer 4b is kept in its position on the bar by a pair of locking nuts 5a, 5b fitted onto the screw thread of bar portion 2aa first locking nut 5a for adjustment of spring compression and the second locking nut 5b for locking the nuts in place.

[0051] When in position on the machine, the spring is effectively compressed between the facing side 20f of bracket 20 and the locking nuts 5a, 5b via the action of the top and bottom (second and first) retainers 4t, 4b on ends of the spring 6t, 6b respectively. The action of the spring on the second retainer, and thus the bracket face 20f, acts to push the first retainer, and thus the locking nuts, away from the bracket. As the locking nuts are threaded onto and thus mechanically joined to the longitudinal bar, this provides an axial force Fa along the bar which in turn, through the clevis and clevis pin, produces a sustained pulling pressure on the second end of the tensioning arm. As the tensioning arm is pivotally mounted, this produces a torque T around the pivot point 41p, such that the idler wheel 47, mounted on the first end 41a of the tensioning arm 41, is pressed against the belt and thus provides a tensioning force Ft on the belt.

[0052] FIG. 3A shows a tensioning bar assembly in accordance with aspects and embodiments of the invention of the present application, for use as a replacement or alternative for the prior art tensioning bar assembly shown in FIGS. 1 and 2. FIG. 3B shows a cross-sectional view through sleeve portion 122.

[0053] There is provided a longitudinal bar 102 having a first, or top end 102t which is attached to (or unitary with) an attachment device, in this case a clevis 103 and which is formed in two parts: a sleeve portion 122 which is hollow and has a threaded internal diameter along a portion of its length; and a bolt section 121 which in this embodiment is very simply in the form of a long bolt having a hexagonal engagement head 102h and a threaded portion 102a which extends the full length of the bolt. The bolt section 121 is screwed into the sleeve portion 122 and is locked in place with a lock nut 105a which is also threaded onto the bolt portion. A tool, preferably a power tool, can clearly be applied to hex head 102h. Spring 4s with ends 6b and 6t and first and second spring retainers 4b and 4t are also fitted around the threaded portion 102a of the bolt section of the bar, at either end of the spring.

[0054] As described hereinbefore, the arrangement shown in FIGS. 3 and 3a allows for the simple adjustment of the tensioning assembly by means of engaging a tool at locking nut 5a, which can then be slackened off, whilst bolt section 121 can then be rotated by application of a tool (advantageously potentially a power tool) to the hex head 102h, thus rotationally moving bolt section 121 relative to sleeve section 122 and hence either shortening or lengthening the bar 102. Locking nut 105a can then be rotated/screwed along the bar until it butts up against the bottom end 102d of the sleeve portion, locking bolt section 121 and sleeve section 122 into position relative to each other. A final tightening operation with a wrench on nut 105a may be required to fully lock the nut into position. Such an operation will be familiar to one skilled in the art.

[0055] FIG. 4A shows an embodiment where a tensioning bar assembly and tensioning assembly according to embodiments of the invention is in place in relation to a drive system in a configuration generally similar to that of prior art FIG. 1.

[0056] FIG. 4B shows an alternative embodiment where force Fa is a pulling force on tensioning arm 241 and tensioning arm 241 is pivoted about its second end 241b with clevis 103 attached at a pivot point 103p to a midpoint 241m. In this embodiment, spring retainer 204t has an arm 204ta which is bolted by nut and bolt assembly 27 to bracket 20. In this way, the spring 4s acts indirectly against the distal face 20d of the bracket 20. Also in this embodiment, bolt section 121 is a simple length of threaded bar. Engagement head 202h is threaded onto the end 102b of the bolt section and locked in place with further locking nut 105c.

[0057] Clearly the skilled person will recognise that various aspects, embodiments and elements of the present application, including as illustrated in the figures, may be arranged in differing combinations, any and all of which may be considered to fall within the ambit of the inventive concept. The invention will be defined by the following claims.