U.S. patent application number 11/757636 was filed with the patent office on 2008-12-04 for combine header belt tensioning apparatus and method.
This patent application is currently assigned to Claas Selbstfahrende Erntemaschinen GmbH. Invention is credited to Adam Lee Haworth, Craig Kaster, Cristoph Nathan, Jens O. Petersen, Steve Tippery.
Application Number | 20080296131 11/757636 |
Document ID | / |
Family ID | 39940714 |
Filed Date | 2008-12-04 |
United States Patent
Application |
20080296131 |
Kind Code |
A1 |
Tippery; Steve ; et
al. |
December 4, 2008 |
COMBINE HEADER BELT TENSIONING APPARATUS AND METHOD
Abstract
A belt tensioning apparatus for a combine or harvester header
has a frame with two spaced apart longitudinal support members and
at least one transverse member attached to each of the longitudinal
support members. An end roller support bracket has two bracket
extensions extending longitudinally and disposed to slidingly
engage with bracket extension receivers attached to the
longitudinal support members. A push rod is longitudinally oriented
and slidingly mounted on the transverse member intermediate to the
longitudinal support members. The push rod is attached to the end
roller support bracket and mounted to have a retracted position and
an extended position. An actuator is attached to the longitudinal
support members and exerts a substantially uniform force to the
push rod along a range of travel of the push rod between the
retracted position and the extended position. The actuator may be a
scissors assembly or a hydraulic cylinder.
Inventors: |
Tippery; Steve; (Gretna,
NE) ; Nathan; Cristoph; (Missouri Valley City,
IA) ; Kaster; Craig; (Omaha, NE) ; Haworth;
Adam Lee; (Louisville, NE) ; Petersen; Jens O.;
(Omaha, NE) |
Correspondence
Address: |
HUSCH BLACKWELL SANDERS LLP
190 CARONDELET PLAZA, SUITE 600
ST. LOUIS
MO
63105-3441
US
|
Assignee: |
Claas Selbstfahrende Erntemaschinen
GmbH
Harsewinkel
DE
|
Family ID: |
39940714 |
Appl. No.: |
11/757636 |
Filed: |
June 4, 2007 |
Current U.S.
Class: |
198/813 |
Current CPC
Class: |
A01D 61/02 20130101;
A01D 57/20 20130101 |
Class at
Publication: |
198/813 |
International
Class: |
B65G 23/44 20060101
B65G023/44; A01D 57/20 20060101 A01D057/20 |
Claims
1. A belt tensioning apparatus for a combine or harvester header
comprising: two spaced apart longitudinal support members; at least
one transverse member attached to each of said longitudinal support
members; an end roller support bracket, said end roller support
bracket having two bracket extensions, said bracket extensions
extending longitudinally and being disposed to slidingly engage
with bracket extension receivers, said bracket extension receivers
each being attached to said longitudinal support members,
respectively; a push rod, said push rod being longitudinally
oriented and slidingly mounted on said transverse member, said
sliding mount of said push rod on said transverse number being
intermediate to said longitudinal support members and said push rod
being attached to said end roller support bracket; said push rod
being mounted to have a retracted position and an extended
position; and an actuator, said actuator being attached to said
longitudinal support members and said actuator exerting a
substantially uniform force to said push rod along a range of
travel of said push rod between said retracted position and said
extended position and a substantially uniform force along the width
of an end roller.
2. The tensioning device in claim 1 wherein said actuator exerts
force along a single axis, said axis being substantially parallel
with said push rod.
3. The tensioning device in claim 1 wherein said actuator is a
scissors assembly.
4. The tensioning apparatus of claim 1 wherein said actuator is a
hydraulic cylinder.
5. The tensioning apparatus of claim 1 wherein said attachment of
said push rod to said end roller support bracket is substantially
at a transverse center of said end roller support bracket.
6. The tensioning apparatus of claim 1 further comprising a spring,
said spring being disposed to bias said end roller support bracket
towards maintenance of a selected position.
7. The tensioning apparatus of claim 6 wherein said spring is a
compression spring.
8. The tensioning apparatus of claim 6 wherein said spring is
mounted on said push rod.
9. The tensioning apparatus of claim 6 wherein said spring is
mounted on said push rod at a position adjacent to said end roller
support bracket.
10. The tensioning apparatus of claim 1 wherein said end roller
support bracket supports a drive roller.
11. The tensioning apparatus of claim 1 wherein a distance between
a fully retracted position of said end roller support bracket and a
fully extended position of said end roller support bracket is
within a range of about 0.1 to about 0.3 times the width of a belt
supported by said tensioning apparatus.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention is in the field of support and
tensioning apparatuses for combine and harvester header transport
belts.
[0003] 2. Related Art
[0004] Combine or harvester headers cut a wide swath of crop and
transport it to a central feeder house for threshing. Conveyor
belts are one of several means for transporting crops from the
outer side portions of the header towards the feeder house in the
center of the header. Belted headers are sometimes known as
"drapers" on agricultural machines. The belts move crop in a
direction transverse to the direction of travel of the combine or
harvester and from the outside in. Advantageous designs for these
belts and their support and drive systems maximize speed,
throughput, efficiency, and a robust response to variations in crop
density and volume, crop types, variation in terrain and potential
impacts to the machine during use.
[0005] In order to achieve these overall design goals, as well as
to realize the advantages of economy, simplicity, durability and
ease of repair that are a constant need in the industry, it is
desirable to maintain tension on the belts within a certain
preconfigured range. Support systems for the belts should
advantageously apply tension in a uniform manner across the width
of the belt. It is advantageous if the tensioning force applied to
the end roller of the belt does not substantially vary when the
longitudinal position of the roller is adjusted. They should allow
for adjustments of the tensioning system by an operator. There is a
need in the industry for improvement in these areas.
[0006] It is also advantageous if the support structure and
tensioning apparatus allows for the release of tension and
retraction of the apparatus to a degree sufficient to allow repairs
to be done to the belt or header. A useful design would minimize
binding, gaps between the belt and its adjacent parts and slackness
or slippage of the belt. When the drive system for the belt is a
friction roller, maintenance of belt tension within a prescribed
range is also advantageous.
SUMMARY OF THE INVENTION
[0007] The present invention is a belt tensioning system for a
combine or harvester header. It is comprised of two longitudinally
extending support members, at least one transverse bar between the
support members, an end roller, an end roller support bracket, two
support bracket extensions corresponding to each of said
longitudinal support elements and disposed to engage said
longitudinal support elements by sliding in and out of them. The
end roller and end roller support bracket are extended and
retracted relative to the overall frame by a push rod. The push rod
is attached to the end roller support bracket and supported by the
transverse member. The push rod is attached to the end roller
bracket at a position intermediate to the longitudinal support
elements. In the depicted embodiment, the push rod is attached
substantially in the center of the end roller bracket.
[0008] The push rod may be adjusted to extend or retract
longitudinally, that is, in the direction of the length of the
belt. In the depicted embodiment the amount of force exerted by the
push rod is substantially equivalent in an extended position as the
amount of force applied by it in a more retracted position of the
end roller.
[0009] In one embodiment, the force applied to the push rod is
applied by a scissors device. The mechanical scissors extender is
symmetrical around the push rod, supported by a second transverse
bar and extended or retracted by turning a transverse screw member.
Optionally, a compression spring may be mounted with the scissors
tensioning device in order to exert a longitudinal force on the
push rod. In one depicted embodiment, the spring is disposed at an
end of the push rod nearest its attachment to the end roller
bracket.
[0010] In a second embodiment depicted herein, the push rod is the
rod of a hydraulic cylinder. The hydraulic cylinder is in turn
mounted on one or more transverse elements within the plane defined
by the longitudinal support elements.
[0011] Further areas of applicability of the present invention will
become apparent from the detailed description provided hereinafter.
It should be understood that the detailed description and specific
examples, while indicating the preferred embodiment of the
invention, are intended for purposes of illustration only and are
not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The present invention will become more fully understood from
the detailed description and the accompanying drawings,
wherein:
[0013] FIG. 1 is a schematic top view of a combine.
[0014] FIG. 2 is a top perspective view of a belt tensioner with a
scissors actuator.
[0015] FIG. 3 is a top perspective view of a belt tensioner with a
scissors actuator.
[0016] FIG. 4 is a top perspective view of a belt tensioner with a
hydraulic actuator.
[0017] FIG. 5 is a top perspective view of a belt tensioner with a
hydraulic actuator.
[0018] FIG. 6 is a bottom view of an alternate embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] The following description of the preferred embodiment(s) is
merely exemplary in nature and is in no way intended to limit the
invention, its application, or uses.
[0020] Referring now to the drawings in which like reference
numbers indicate like elements, FIG. 1 is a schematic top view of a
combine 2 having a header 4 with conveyors or "drapers" 6 disposed
to convey cut crop towards a feeder house 8 where the combine takes
the crop in for threshing. Each belt 6 is supported by a frame and
oriented to turn such that the top surface of the belt rotates
towards the center of the header and the feeder house.
[0021] In FIGS. 2 and 3, a frame for a combine or harvester header
belt is depicted with the supporting header structure and belt
removed for clarity. The frame 10 is comprised of a first
longitudinal support number 12 and a second longitudinal support
number 14. At least one transverse bar 16 spans the distance
between them. In the depicted embodiment the belt and transverse
members are about 40 inches wide. Together with end roller 18,
these structures provide an overall frame which the belt will
rotate around. Cut crops will be transferred on the top surface of
the belt, which will run over the top surface of the frame 10
toward or away from end roller 18. The tensioning apparatus may be
at either or both of the lateral and medial ends of the belt.
[0022] End roller 18 is supported by end roller bracket 20. End
roller bracket 20 has at its transverse ends an end mount 22 and an
opposing end mount 24. End mount 22 is pivotally attached to a
transverse end of the end roller support bracket at pivot pin 26.
Opposing end mount 24 is similarly attached and is slidingly
engaged with extension 28 which extends longitudinally from lateral
support number 14. The opposing end mounts 22 and 24 affix end
roller bracket extensions 30 and 32 to the end roller bracket 20.
Extensions 30 and 32 are longitudinally oriented. They are disposed
to slidingly engage extension receivers 34 and 36. Extension
receivers 34 and 36 are attached to or integral with an inner
aspect of each of said longitudinal support members 12 and 14,
respectively. Extensions 30 and 32 may slide in and out of
extension receivers 34 and 36, and thereby provide support and
stability to the end roller 18 and end roller support bracket 20
through a range of longitudinal positions.
[0023] A push rod 40 is disposed in a longitudinal orientation at a
position intermediate to the longitudinal support numbers 12 and
14. In the depicted embodiment, the push rod is attached
substantially in the center of the end roller support bracket 20.
The push rod is supported by a transverse member 16 and disposed to
slide through it. The push rod 40 is attached to the end roller
support bracket 20 with a push rod fork 42 that is pivotally
attached to the end roller support bracket at pin 44. Optionally,
push rod 40 may travel through an extended bushing for further
stability, as depicted in FIG. 2.
[0024] The push rod 40 is extended and retracted by the action of
scissors assembly 50. Scissors assembly 50 includes two back arms
52 and two lever arms 54. Each back arm 52 is pivotally attached to
hinge nut 56 and each hinge nut is correspondingly pivotally
attached to the forward arm 54. Likewise, lever arm mount 58 is
attached to the inner aspect of push rod 40 and is pivotally
attached to the outer aspect of each lever arm 54. The back arms 52
are further pivotally attached at mount 60 to a second transverse
number 62, which provides rigid backing support for the action of
the scissors assembly 50 in extending and retracting the end roller
support bracket 20 and end roller 18. A transverse rod 64 is
threaded and engaged to the internal threads of a through hole on
each of hinge nuts 56. The opposing end portions of rod 64 are
threaded in opposing directions such that rotation of rod 64 urges
travel of both hinge nuts 56 simultaneously towards or away from a
center line of rod 64 and also the centerline of the overall frame.
The rod 64 is mounted with bolts 66 in slots 68 and 70 in the
longitudinal support elements and extension receivers respectively.
Slots 68 and 70 are elongated to allow the rod 64 to travel as
necessary longitudinally in order to follow the extension or
retraction of the push rod by operation of the scissors assembly
50. The rod 64 may be turned by a crank or power drive unit [not
shown] which would engage an extension of rod 64 from the back side
of the header.
[0025] In operation, the tension applied via the push rod to the
end roller 18 through the end roller bracket 20 may be adjusted by
turning rod 64 in a first rotational direction for extension and in
a second direction for retraction. The scissors assembly 50 exerts
leverage on the push rod 40 and thereby actuates longitudinal
travel of push rod 40. In this manner, the end roller 18 and end
roller bracket 20 can be moved to a more retracted position,
allowing a looser mounting engagement of the belt, or to a more
extended position, allowing a tighter mounting engagement of the
belt. By mounting the push rod intermediate to the two longitudinal
support members 12 and 14, which in the depicted embodiment is
substantially in the center between the longitudinal supports,
pressure is exerted on the end roller evenly across its lateral
extent, thereby reducing binding effects that may be put on the
belt by an uneven application of pressure. It will be apparent to
those of skill in the art that in both the scissors jack embodiment
above and a hydraulic embodiment discussed below, the mechanism for
exerting force on the end roller support bracket is aligned with or
symmetrical to the push rod substantially centered on the end
roller support racket 20, thus promoting an even application of
pressure along the width of the roller. These embodiments also
apply substantially even pressure through an extended longitudinal
range of motion of the end roller assembly.
[0026] As is shown in FIG. 3, a compression spring 80 may be
mounted on the pressure rod 40 in order to exert a supplemental
tensioning bias on the end roller 18. In this manner, the end
roller 18 and support bracket 20 may flex in order to absorb the
shock of an impact, or may flex in order to accommodate downward or
eccentric pressure on the belt itself in response to variations in
the crop load traveling over it, may flex in response to eccentric
or upward forces placed on the overall head due to its interaction
with uneven ground. The spring 80 may be mounted on the push rod 40
with a fixed stop 82. The stop 82 may optionally be adjusted itself
to adjust the tension exerted by spring 80.
[0027] A second embodiment of the present invention uses a
hydraulic actuator. As depicted in FIGS. 4 and 5, the frame of this
embodiment also consists of longitudinal support members 112 and
114. At least one transverse member 116 connects the longitudinal
support members 112 and 114. The end roller 118 is supported by an
end roller support bracket 120. On its transverse ends, end roller
support bracket 120 has end mounts 122 and 124 which are pivotally
attached to the transverse end portions of end roller support
bracket 120 at pins 126. Support bracket extensions 130 and 132 are
attached to the end roller support bracket 120 at end mounts 122
and 124. Bracket extensions 130 and 132 are longitudinally disposed
for sliding engagement with extension receivers 134 and 136.
[0028] A push rod 140 is attached to the end roller support bracket
at fork 142 and held there with pin 144. Push rod 140 is the piston
rod of a hydraulic cylinder and extends from the cylinder 150. The
hydraulic cylinder 150 is longitudinally oriented and maintained in
its position by transverse bracket 116 and at least one other
bracket 162 and/or 164. Optionally, the hydraulic cylinder may be
further mounted under a longitudinal belt guide 166. The hydraulic
cylinder in the depicted embodiment is single or double acting and
may optionally include a pressure gauge. Optionally, the hydraulic
assembly may include a simple hand pump (represented schematically
at 170 in FIG. 5) which may also serve to relieve pressure,
increase pressure or relax the hydraulic cylinder's tension applied
to the belt which is useful for repair and maintenance or selective
adjustments.
[0029] As will be readily apparent to those of skill in the art,
the apparatus can apply a uniform force to the end roller at any
position along its range of retraction and extension. A uniform
tension is applied to the belt, thus achieving the same uniform
pressure on the end roller and tension on the belt as was achieved
by the mechanical scissors applicator of the first embodiment.
Tensioning adjustment also allows for accommodating belt splice
inaccuracies for belt tracking.
[0030] As is also apparent to those with skill in the art, the
extension members 130 and 132 and their receivers 134 and 136 have
a relatively long stroke length that is sufficient for removing the
belt for purposes of repair or maintenance when the end roller is
in a retracted position. For repair and maintenance purposes, the
stroke length of the depicted embodiment is 8 inches. The belt is
40 inches wide. Although various belt widths are within the scope
of the invention, the depicted stroke is within the range between
0.1 and 0.3 times the width of the belt, or the distance between
the longitudinal support members 32, 132 and 34, 134.
[0031] In operation, pressurizing the hydraulic cylinder in a first
direction extends push rod 130, thereby causing the end roller 118
on its end roller bracket 120 to travel outwards, carrying the belt
to an extended position and placing greater tension on the belt.
Pressure in the other direction on the hydraulic cylinder retracts
the push rod 140, thereby retracting the end roller 118 on its end
roller bracket 120 and shortening the belt and slacking the tension
on the belts. The internal pressures of the hydraulic cylinder are
available to dampen shocks to the belt or end roller. Optionally,
an accumulator may be added to hydraulic system to act as a
cushion.
[0032] In the depicted embodiments, the end roller 18 is a drive
roller, driven by a hydrostatic motor 180. It is within the scope
of the present invention that end roller 18 may be a static or
idler roller.
[0033] FIG. 6 depicts another alternate embodiment of the present
invention. A front longitudinal member 212 and a rearward
longitudinal member 214 together with transverse members 216 and
262 comprise a frame. An end roller 218 and end roller support
bracket 220 are disposed at an end of the frame. End rollers may be
drive rollers or idler rollers, but in FIG. 6, the end roller 218
is a drive roller driven by hydrostatic motor 280. As before end
mounts 222 and 224 are pivotally mounted to an end of end roller
support bracket 220. End mounts 222 and 224 support end roller
support bracket extensions 230 and 232 which are in turn slidingly
engaged with the longitudinal members 212 and 214. As can be seen,
the bracket extension receivers 234 and 236 in FIG. 6 are
integrally formed with the longitudinal members 212 and 214. Also,
the end roller support bracket extensions 230 and 232 are not
cylindrical but elongated flat pieces of metal having flanges on
either end that are formed to slidingly engage corresponding
receiving indentations in receiving portions 234 and 236 of
longitudinal members 212 and 214.
[0034] The scissors assembly in FIG. 6 is as described hereinabove
with respect to FIGS. 2 and 3. The bulk of the push rod and then
extended bushing or sheath 240 surrounding it is disposed
underneath a longitudinal center piece 290 of the frame which
serves as a support for the draper conveyor belt that will be
mounted over the frame. Again in the embodiment depicted in FIG. 6
a spring 284 is disposed at an end of push rod 240 nearest its
attachment to end roller support bracket 220. A mounting bushing,
such as attached to transverse member 216 in the depicted
embodiment may form a rear stop or string 284. Optionally, mounting
bushing 286 may include an adjustable ring 288 for further
adjustment of the compression strength of the string 284. A
longitudinal belt support 290 is over the scissors assembly.
[0035] As various modifications could be made to the exemplary
embodiments, as described above with reference to the corresponding
illustrations, without departing from the scope of the invention,
it is intended that all matter contained in the foregoing
description and shown in the accompanying drawings shall be
interpreted as illustrative rather than limiting. Thus, the breadth
and scope of the present invention should not be limited by any of
the above-described exemplary embodiments, but should be defined
only in accordance with the following claims appended hereto and
their equivalents.
* * * * *