US20030154633A1

Movatterモバイル変換

Info

Publication number: US20030154633A1
Application number: US10/239,519
Authority: US
Inventors: Jean-Philippe Lassonde
Original assignee: Bombardier Inc
Current assignee: Bombardier Recreational Products Inc
Priority date: 2000-03-22
Filing date: 2001-03-21
Publication date: 2003-08-21

Abstract

A snow tiller (10) suitable for grooming ski hills, trails, or other areas, provides an adjustable snow housing assembly. A snow chamber (70) is formed between a ground shaping element (48) that has a rotatable drum (50) and a trailing finishing element (62) that is supported by a trailing bar bracket (84, 110, 130). The shape and/or volume of the snow chamber (70) can be adjusted by activating a finisher positioning mechanism (72), such as a hydraulic cylinder, to pivot the trailing bar bracket (84, 110, 130). A pair of connecting bars (98and100) from a pivot point about which the trailing bar bracket (84, 110, 130) pivots in an arc with respect to the snow surface, thus providing for precise positional control of the snow chamber (70).

Description

This application is a continuation-in-part application of International application No. PCT/CA00/01501 filed Dec. 15, 2000, the contents of which are hereby incorporated by reference.[0001]

FIELD OF INVENTION

This invention relates to ground working devices, particularly snow grooming devices. More specifically, this invention relates to tillers for use with snow grooming vehicles for ski slopes.[0002]

BACKGROUND OF THE INVENTION

Ground working devices have long been used in agriculture to break up and till earth. Such devices, known as tillers, typically include a trailing assembly that has a rotating ground loosening unit and a smoothing or leveling board. The loosening unit can be subdivided into subassemblies connected by joint(s) to accommodate the changing contours of the ground.[0003]

This general concept has been adopted and modified to groom snow, especially ski slopes. Snow making and snow grooming has become an essential part of any successful ski center due to increased skier traffic, longer ski seasons, and variable weather conditions. As a result, snow groomers are becoming more sophisticated. Typical snow grooming vehicles are tracked vehicles, which provide traction across the snow and up and down hills. These vehicles are equipped with a number of attachments or devices to help in the snow grooming process.[0004]

Generally, a tracked snow vehicle has an inverted V-shaped or U-shaped plow on the front of the vehicle that collects snow from areas where there is too much and moves it to areas which are worn. The front implement can also rip up icy and encrusted slopes to create or renew trails and remove glacier surface ice. The front implement can include a toothed bar that is lowered by a pivoting ram to break up hard, icy slopes into large lumps. The tracks of the vehicle assist in breaking up the lumps. Attached to the rear of the vehicle is a snow tiller that grinds the lumps and surface and then smoothes the surface of the snow to restore it to skiing condition.[0005]

Snow tillers are frequently equipped with a drum formed as a rotating blade and a finishing member that trails behind the rotor. A snow chamber or housing is formed immediately behind the drum and under and in front of the finishing member to hold a volume of snow so that it can be worked more extensively by the tiller. The finishing member is usually a flexible mat or mats having grooved finishing elements provided at the rear of the tiller assembly to provide the final snow surface conditioning by smoothing or, alternatively, to provide a “corduroy” texture to the surface of the tilled snow.[0006]

By controlling the angle at which the finishing member is supported, the volume of the snow chamber can be changed. Accordingly, the amount of snow held in the snow chamber during tilling can be controlled and varied based on current snow conditions. For example, if the snow chamber is enlarged, snow held within the chamber can be worked by the tiller for a longer period of time. An example of a variable snow chamber is disclosed in U.S. Pat. No. 5,067,263, in which the angle of the trailing bar mounted on the flexible membrane that forms the outer bounds of the snow chamber is varied to retain more or less snow within the snow chamber. The disclosure of U.S. Pat. No. 5,067,263 is incorporated into this application by reference.[0007]

A prior art assembly similar to U.S. Pat. No. 5,067,263 is shown in FIGS. 11 and 12. A[0008]

tiller

200 is typically driven by a vehicle such as a snow groomer (not shown). Tiller200 includes amain frame238 that is supported by the vehicle. Main frame supports a pair ofcross beams244 that hold aground shaping element248 that has acutting drum250 and acover252. Cuttingdrum250 is driven to rotate thereby breaking up ice chunks, hard pack and other lumps of snow or ice to produce a softer, more desirable and uniform surface. Afinishing element262 extends fromground shaping element248 and is formed as a flexible mat that smoothes out the ground ice and snow. Asnow chamber270 is formed between theground shaping element248 and thefinishing element262 in which snow and ice is held while thecutting drum250 works the ice and snow. Finishingelement262 has atrailing bar280 that is supported by apositioning mechanism272 that includes ahydraulic cylinder278 and asupport bar276. As seen in FIGS. 11 and 12, trailingbar280 can be tilted backward and forward by actuatinghydraulic cylinder278 within a limited range of movement.

Known variable geometry snow tillers produce acceptable, and at times even outstanding, snow surface finishes over a wide range of snow conditions. However, moist to wet snow conditions pose special considerations and handling requirements. In particular, it is difficult to process wet or moist snow effectively once it has been through the cutting drum, resulting in an unacceptable snow surface finish.[0009]

The inventor of this application believes that the poor performance results when snow is held too long in the variable geometry snow chamber. Since moist to wet snow is the ideal type of snow to make snowballs, snow tumbling in the snow chamber, defined as the area between the cutting drum and trailing bar, begins to agglomerate into lumps. These lumps continue to increase rapidly in size until the entire chamber section is filled with lumps. After initially filling the snow chamber, the lumps continue to become more and more compacted and correspondingly harder. The trailing bar tends to retain the lumps until they reach a high degree of compaction, producing lumps of almost rock-like hardness. The growing volume of these hard lumps of compacted snow eventually forces the lumps to pass under the trailing bar and be pressed into the groomed snow surface. The presence of these hard lumps, which may be of substantial size, results in a groomed snow surface that is not satisfactory for most snow sports. Therefore, there is a need to better control the assembly under such snow conditions to address the problem of forming hard lumps during snow conditioning.[0010]

SUMMARY OF THE INVENTION

An aspect of this invention is to provide a tiller that can be modified in response to snow conditions.[0011]

Another aspect of this invention provides a tiller having a snow chamber in which the volume and/or geometry can be varied.[0012]

A further aspect of this invention provides a snow chamber that can be finely adjusted.[0013]

An additional aspect of this invention comprises providing a controller that allows an operator to selectively change the chamber shape for grooming.[0014]

Embodiments of this invention provide a tiller assembly for shaping a surface, comprising a main frame, a ground shaping element carried by the main frame, and a finishing element supported by the main frame and arranged to trail behind the ground shaping element over the surface. A chamber having a volume is formed between the ground shaping element and the finishing element. A bracket is secured to the finishing element, and a driven member connected between the main frame and the bracket that moves the bracket in an arc with respect to the surface to thereby change the volume of the chamber.[0015]

This invention also provides a tiller assembly for shaping a surface, comprising a main frame, a ground shaping element carried by the main frame, and a finishing element supported by the main frame and arranged to trail behind the ground shaping element over the surface. A chamber having a volume is formed between the ground shaping element and the finishing element A pivot arm extends outwardly from the ground shaping element, and a bracket is secured to the finishing element. A pivoting connector is pivotally attached between the bracket and the pivot arm. A driven member is connected between the main frame and the bracket that causes the bracket to pivot with respect to the pivot arm.[0016]

This invention additionally provides a tiller assembly for shaping a surface, comprising a main frame, a ground shaping element carried by the main frame, and a finishing element supported by the main frame and arranged to trail behind the ground shaping element over the surface. A chamber having a volume is formed between the ground shaping element and the finishing element. A bracket is secured to the finishing element. A pivoting connector has two ends with one end pivotally attached to the bracket. A driven member is connected between the main frame and the other end of the pivoting connector that causes both ends of the pivoting connector to pivot and swing the bracket, thereby changing the volume of the chamber.[0017]

The invention further relates to a method of working the surface of the ground, comprising providing a tiller assembly having a ground shaping element and a finishing element with a chamber defined therebetween, wherein the finishing element is supported by a bracket. The method includes tilting the finishing element to change the volume of the chamber by moving the bracket in an arc with respect to the surface of the ground. The ground shaping element is operated to grind the surface, and the tiller assembly is driven across the surface to drag the finishing element over the surface and provide a finished texture to the ground.[0018]

It is to be understood that the invention described herein can be varied in a number of ways and is not restricted to the particular embodiments described herein. The invention is intended to generally include a variety of equipment arrangements wherein the volume and shape of the snow housing can be selectively set and controlled.[0019]

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described in greater detail in conjunction with the following drawings wherein:[0020]

FIG. 1 is a side view of a tracked vehicle with a tiller in accordance with an embodiment of the invention attached thereto;[0021]

FIG. 2 is an enlarged partial side view of the tiller shown in a first position in accordance with an embodiment of the invention;[0022]

FIG. 3 is an enlarged partial side view of the tiller of FIG. 2 shown in a second position;[0023]

FIG. 4 is a schematic view of the tiller of FIG. 2 showing the change between the first and second positions;[0024]

FIG. 5 is a partial perspective view of a support assembly for the tiller in accordance with an embodiment of the invention;[0025]

FIG. 6 is a partial perspective view of another support assembly for the tiller in accordance with an embodiment of the invention;[0026]

FIG. 7 is a partial perspective view of the preferred support assembly for the tiller in accordance with another embodiment of the invention;[0027]

FIG. 8 is a side view of the tiller in the first position according to the embodiment shown in FIG. 7;[0028]

FIG. 9 is a side view of the tiller in the second position according to the embodiment shown in FIG. 7;[0029]

FIG. 10 is schematic side view of the tiller moving between the first and second positions in accordance with the preferred embodiment of FIG. 7;[0030]

FIG. 11 is a partial side view of a tiller in accordance with the prior art in which the tiller is in a first position; and[0031]

FIG. 12 is a partial side view of the prior art tiller of FIG. 7 in a second position.[0032]

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

The invention is described with particular reference to a snow groomer including a snow tiller. The detailed description of the snow groomer as the vehicle with which the tiller is used is provided for purposes of illustration only and is not intended to be a limiting embodiment.[0033]

FIG. 1 shows an assembly[0034]1 including aground working vehicle12 with atiller10 attached thereto in accordance with an embodiment of the invention.Ground working vehicle12 in this case is a tracked vehicle, commonly called a snow groomer, that functions as the power source fortiller10.

[0035]

Vehicle

12 has acab14, in which an operator can sit and drive the vehicle and operate the controls for the various implements connected to the vehicle. The drive mechanism forvehicle12 is a pair ofrotatable tracks16 with onetrack16 disposed on each side of the vehicle body.Vehicle12 has a front implement18, in this case a hydraulically controlledplow20, and a rear implement, which in this case istiller10.Vehicle12 is especially adapted for driving on snow, but of course could be any type of vehicle. Additionally, a variety of accessories and attachments may be used with the vehicle either on the front or rear, including for example a front digger rather than a front plow. Further, if desired, only a rear implement could be used.

[0036]

Vehicle

12 is equipped with

appropriate attachment mechanisms

22 and24 on the front and/or back of the vehicle, respectively, to provide power and structural connections to such front and/or rear implements.Cab14 includes acontrol panel26 connected to a controller, shown schematically in FIG. 1, to control operations of the vehicle and its implements. Of course, if desired or if a different type of vehicle is used,control panel26 could be provided elsewhere on the vehicle, on the tiller itself, and/or at multiple locations. Thecontrol panel26 can be of any known form suitable for actuating the implements and selecting various functions for the implements. The controller can be implemented in any known type of operating control system. For example, the control logic could be hard wired into the central logic system of the vehicle or implemented as a plug-in or through software installation.

[0037]

Attachment mechanism

24 is an articulated joint for connectingtiller10 to a power source, in thiscase vehicle12, and can be a threepoint hitch26 and a hydraulically controlledlifting mechanism28. Thehydraulic lifting mechanism28 includes amain tow bar30 and a drivenhydraulic cylinder32 that can be controlled to raisetiller10 from the surface of the ground. Ahydraulic tilt cylinder34 is provided to change the depth at whichtiller10 works the surface. Any other suitable connecting mechanism could also be employed and could optionally include the lifting mechanism, if desired. Other desired connections could be used including electric, pneumatic, optical or communication connections to control and operate different operating functions of the tiller.

[0038]

Tiller

10 includes asupport frame36 connected to thelifting mechanism28. Thesupport frame36 has a mainhorizontal frame38 in the form of a box beam, I beam, channel beam or any strong structural beam type member. Anupper snow guard40, typically two separate panels, is attached tomain frame38 to prevent snow from blowing from thetracks16 over thetiller assembly10 onto the finished snow surface. A pair of cross beams, of which only onebeam44 is shown, extend rearwardly frommain frame38 and support aground shaping element48.

[0039]

Ground shaping element

48 includes arotatable drum50 with cutting teeth and acover52.Cover52 creates a housing forrotatable cutting drum50 and includesend caps51.Cover52, which is best seen in FIG. 7, can form a single housing or a series of housings along the length ofground shaping element48.Ground shaping element48 has a longitudinal axis about which drum50 rotates and is oriented perpendicular to a direction in whichtiller10 is driven. A drive train, in this case in the form of a gear box, is connected torotatable drum50 to selectively rotatedrum50 to grind or otherwise shape the ground or material beneathdrum50.Drum50 rotates to break up ice chunks, hard pack, or other undesirable types of snow, or ice as the case may be, to produce a softer, more desirable surface.

Extending from[0040]

cover

52 ofground shaping element48 is a finishingelement62. Finishingelement62 includes a flexible mat, for example a rubber or heavy polymeric sheet, that is positioned to drag behindground shaping element48. The design, surface, and weight of the mat as it being drawn across the surface, smoothes the ground out behindground shaping element48 after the ground has been cut or shaped. It is preferred that the trailing mat be flexible at anticipated operating temperatures so that it may more closely follow the contour of the surface of the ground.

The outer edge of finishing[0041]

element

62 can be shaped, for example with serration, and/or can include finishingformations66, which are blocks or strips attached to the lower surface of or molded into the flexible mat, both of which create texture in the finished surface whentiller10 is driven across the surface of the ground. Finishingelement62 may also be formed as a board or membrane that optionally has rows of finishing elements, preferably formed of polyethylene or plastics but may also be formed of steel, fiberglass, or other suitable materials in a variety of profiles. The texture formed in the snow surface by finishingelement62 is known as a “corduroy” surface, especially in the snow grooming field, and includes a series of striations formed on the surface of the snow. The texture can be varied, of course, by varying the type and/or shape of edge64 of finishingelement62 and/or the shape, type and size of finishingformations66.

A[0042]

snow chamber

70 is defined beneathcover52 and betweenrotating drum50 and finishingelement62. Snow is retained withinsnow chamber70 and worked by rotatingdrum50 before being smoothed by finishingelement62. As described below, the shape, and hence the volume, of thesnow chamber70 can be varied in accordance with this invention.

A[0043]

finisher positioning mechanism

72 is provided to rotate finishingelement62 relative to the ground and to adjust the shape of finishingelement62 so as to control the volume of thesnow chamber70. Preferably, twofinisher positioning mechanisms72 are provided on each side oftiller10. However, there is no specific number of mechanisms required, and any number from one or more than two is possible.Finisher positioning mechanism72 extends fromcover52, or as an extension of cross beams44, and is secured to finishingelement62 by a trailingbar80, which is preferably semi-rigid so as to conform to the terrain over which the tiller passes.

As described in detail below,[0044]

finisher positioning mechanism

72 includes a drivenmember78, such as a hydraulic cylinder, and a trailingbar bracket84 that is pivotally attached to an extension ofmain frame38 so as to allow trailingbar80 to pivot with respect tomain frame38. As described herein, trailingbar bracket84 is preferably supported by apivot arm76, which is attached to housing or cover52, and adjusted byfinisher positioning mechanism72.

As seen in FIGS. 2 and 3, trailing[0045]

bar

80 is secured to finishingelement62 on one side of the mat with a smoothingboard82 secured to the other side of the mat. It is possible to use only the trailingbar80 without smoothingboard82. It is also possible to use only smoothingboard82 as the attachment point through the mat forfinisher positioning mechanism72.

In this embodiment, trailing[0046]

bar

80 is supported by trailingbar bracket84. As seen in FIG. 5,bracket84 preferably includes a generallyhorizontal bracket bar86 and a pair of

angled support legs

88 and90, respectively.Bracket bar86 can be formed as a box beam for strength or can have any conventional structural shape, including an I-beam or plate. Similarly, support

legs

88 and90 are shown as plate-like brackets, but can be formed of any known structural shape. As seen in FIGS. 2 and 3,finisher positioning mechanism72 is secured tobracket bar86. (In FIG. 5,finisher positioning mechanism72 is removed to more clearly show the trailingbar80 support structure.)

As noted above,[0047]

bracket bar

86 is also secured to pivotarm76 that extends outwardly fromground shaping element48. In this case,pivot arm76 extends fromcover52 and is secured to crossbeam44, which is supported bymain frame38. As seen in FIGS. 2 and 3,pivot arm76 is secured at two

fastening points

92 and94 to crossbeam44 so thatpivot arm76 extends rigidly outward and cannot move.Pivot arm76 is coupled tobracket bar86 with asupport bracket96 that extends from belowbracket bar86, as seen in FIG. 5, and rotatably supports a pair of rigid connecting

98 and100 are arranged in longitudinal alignment with respect to the front to back direction of the tiller.

Connecting rods

98 and100 are rotatably supported at each end. For example, connectingrod98 is rotatably supported bysupport bracket96 at one end and bypivot arm76 at the other end.Connecting rod100 is similarly supported.Pivot arm76 is configured with a pair of spaced,

parallel support fingers

102 and104 at its outwardly extending end to support the ends of connecting

rods

98 and100 therebetween. Of course, any secure form of attachment can be provided at any point on trailingbar bracket84 that allows relative pivotal movement betweenpivot arm76 and trailingbar bracket84.

As seen in FIGS.[0049]2-4, the lower ends of connecting

rods

98 and100 are secured to pivotarm76 adjacent to each other while the upper ends of connecting

rods

98 and100 are secured to supportbracket96 spaced from each other. By this, connecting rods are not arranged parallel to each other along their length. As seen in FIG. 2, connectingrod98 is also longer than connectingrod100. However, the connecting rods could be the same length or connectingrod100 could be longer than connectingrod98. By any of these arrangements, the four ends of the connecting

rods

98 and100 define the corners of a trapezoid. Ideally, the trapezoid is shaped to minimize the amplitude experienced by the trailingbar80 when it is adjusted.

Alternatively, as seen in FIG. 6, the trailing[0050]

bar

80 support structure can be aU-shaped bracket110 with

upstanding side walls

112 and114 and a connectingweb116 that is directly secured to trailingbar80. In this case, pivot pins118 and120 are provided to support the upper ends of connecting

rods

98 and100. The lower ends of connecting

rods

98 and100 are secured at pivot points to achannel bracket122.Channel bracket122 is used in place ofpivot arm76 and is directly secured tofinisher positioning element72. The relative relationship between connecting

rods

98 and100, as described above with respect to FIG. 5, remains the same.Bracket110 can be used alone or in combination withbracket84. When used in combination,bracket110 can be used as a stabilizer. In this case, for example, a pair ofbrackets84 can be secured to trailingbar80 along with threebrackets110 alternated at each side ofbracket84 to provide a consistent shape tosnow chamber70.

In operation,[0051]

finisher positioning mechanism

72 is operated to selectively move trailingbar80 with respect to themain frame38 oftiller10. First, drivenmember78 is actuated. Any driving force member is suitable for use in this invention, for example a gear driven rod or ratchet assembly, pneumatic cylinders, motor driven devices or rotating devices, used singly or in combination. However, in this embodiment, a hydraulic cylinder is used as the drivenmember78. So,hydraulic cylinder78 is actuated using any suitable control system and hydraulic assembly.Cylinder78 can be driven using a separate hydraulic system or can be driven using the hydraulic system in place in the snow groomer. For example, parent PCT application PCT/CA00/01501 describes several suitable hydraulic control schemes that vary from manual to automatic.

To change the volume and/or shape of the[0052]

snow chamber

70, the operator of thevehicle12 actuateshydraulic cylinder78 to move between a first position, shown in FIG. 2, and a second position, shown in FIG. 3, and vice versa The terms first and second are used only as relative terms and do not imply a particular order. The first position is the open or fully extended position in which the rod of thehydraulic cylinder78 is fully extended The second position is the closed or filly retracted position in which the rod of thehydraulic cylinder78 is full retracted.

Referring to FIG. 4, the finisher positioning mechanism is shown moving from the first position (in dotted lines) to the second position. As can be seen in FIG. 4, because of the arrangement of connecting[0053]

rods

98 and100, with the trapezoidal configuration and four pivot points, retractinghydraulic cylinder78 causes bracket bar86 (to which the end of hydraulic cylinder is connected) to move in an arc α. This causes trailingbar80 to also move in an arc with respect to the surface of the ground, in this case snow. Moving trailingbar80

causes finishing element

62 to change shape. As seen in FIG. 4, finishingelement62 changes from a relative straightened profile to a convex profile with respect to the snow surface, thus reducing the volume ofsnow chamber70. Pivoting trailingbar80 in an arc allows a greater scope of control in controlling the volume ofsnow chamber70. By the arrangement described above, trailingbar80 in effect swings aroundpivot bar76 in response to movement ofhydraulic cylinder78.

The embodiment shown in FIG. 6 works in the same way in that trailing[0054]

bar

80 swings frombracket110 in response to movement ofhydraulic cylinder78.

Referring to FIGS.[0055]7-10, which show the preferred embodiment of this invention, trailingbar80 is supported by an arch shapedrigid bracket130.Bracket130 is formed of a metal rod or tube, for example, bent into an arch shape with each end of the arch secured to a

channel bracket

132 and134, respectively. Any number ofbrackets130 may be used along the length of trailingbar80. For example two to four brackets may be used. At the apex of thearch bracket130, asupport bracket136, similar to supportbracket96 in the embodiment shown in FIG. 3, is provided that connects arch130 to drivenmember78 andpivot arm76. Betweenpivot arm76 andsupport bracket136, connecting

rods

98 and100 extend. As described above, each connecting

rod

98 and100 is rotatably supported at its respective ends, which are arranged to define a trapezoid.

FIG. 8 shows the driven[0056]

member

78 in the fully extended position, which moves thefinisher positioning mechanism72 into the first position. Due to the trapezoidal arrangement of connecting

rods

98 and100, trailingbar80 is tilted with respect to the snow surface. FIG. 9 shows the drivenmember78 in the fully retracted position, which moves thefinisher positioning mechanism72 into the second position. As seen in FIG. 10, actuation of drivenmember78

swings support bracket

136 in an arc, pivoting drivenmember78 with respect to crossbeam44 and causing connecting

rods

98 and100 to rotate with respect to pivotarm76. As a result,bracket130 swings andtilts trailing bar80.

To help maintain the shape of[0057]

snow chamber

70, apressure plate140 is used in this embodiment to press the end of finishingelement62 down and reduce bulging in thesnow chamber70.Snow chamber70 is shown with a relatively flat upper surface in FIG. 8, which is an ideal shape. However, in practice,chamber70 typically has an upper concave shape that bulges upwardly due to snow accumulation withinchamber70.Pressure plate140 extends from housing or cover52 and can optionally be biased downwardly as seen in FIG. 9. A conventional biasing mechanism can be used, such as a spring hinge, that allowspressure plate140 to pivot upwardly when trailingbar80 is tilted upward andsnow chamber70 is enlarged and then return to a downward oriented position. Of course,pressure plate140 can be used with any of the embodiments disclosed herein.

A tiller designed and controlled in accordance with any of the above schemes can be used to groom surfaces, for example ski trails, in controlled profiles and be responsive to variable snow and weather conditions. The degree of work that the tiller does on the snow can be controlled by controlling the shape and volume of the snow housing. By this, snow grooming can be controlled in different areas of the trail and at different times by the operator during grooming.[0058]

In addition to the snow housing adjustments, the tiller may be provided with a range of other adjustments to address differing snow conditions on the same hill on the same day in different areas. Preferably, the operator would be able to activate all of the controls to move the various cylinders or make other adjustments to the operation of the tiller from the security of the cab. It is possible to arrange the system so that an operator would only need to glance in the rear view mirror to discern if the correct quantity and quality of snow is being left behind.[0059]

Further, this invention can be used in combination with the profile adjustment system disclosed in parent PCT application PCT/CA00/01501 by using the same or a different control scheme.[0060]

It is to be understood that the essence of the present invention is not confined to the particular embodiments described herein but extends to other similar devices that employ a variable snow housing assembly to control snow conditioning[0061]

Claims

What is claimed is:

1. A tiller assembly for shaping a surface, comprising:

a main frame;

a ground shaping element carried by the main frame;

a finishing element supported by the main frame and arranged to trail behind the ground shaping element over the surface, wherein a chamber having a volume is formed between the ground shaping element and the finishing element;

a bracket secured to the finishing element; and

a driven member connected between the main frame and the bracket that moves the bracket in an arc with respect to the surface to thereby change the volume of the chamber.

2. The tiller assembly ofclaim 1, wherein the driven member causes the bracket to pivot about a point spaced from the bracket.

3. The tiller assembly ofclaim 1, further comprising a pivot arm supported by the main frame, wherein the bracket is connected to the pivot arm and pivots with respect to the pivot arm.

4. The tiller assembly ofclaim 3, further comprising a connector having one end pivotally connected to the bracket and another end pivotally connected to the pivot arm.

5. The tiller assembly ofclaim 4, wherein the driven member is movable between a first position and a second position thereby swinging the bracket with respect to the pivot arm.

6. The tiller assembly ofclaim 4, wherein the connector includes a pair of connecting rods both arranged to pivot about pivot axes substantially parallel to the ground shaping element.

7. The tiller assembly ofclaim 4, wherein the connector includes a pair of connecting rods aligned with the driven member.

8. The tiller assembly ofclaim 4, wherein the connector includes a pair of connecting rods connected between the bracket and the pivot arm with four pivot points arranged to define a trapezoid.

9. The tiller assembly ofclaim 1, wherein the bracket includes an arch shaped rod.

10. The tiller assembly ofclaim 1, wherein the bracket includes a bar spaced from and substantially parallel to a top surface of the finishing element.

11. The tiller assembly ofclaim 1, further comprising a connector disposed between the bracket and the driven member.

12. The tiller assembly ofclaim 1, wherein the bracket includes a pair of side walls and a pivot member extending therebetween, wherein the driven member is pivotally attached to the pivot member.

13. The tiller assembly ofclaim 12, further comprising a connector disposed between the pivot member of the bracket and the driven member.

14. The tiller assembly ofclaim 13, wherein the connector includes a pair of connecting rods and the pivot member includes a pair of pivot pins, each connecting rod pivotally connected between a pivot pin and the driven member.

15. The tiller assembly ofclaim 14, wherein each connecting rod has opposed ends, the ends arranged to define a trapezoid.

16. The tiller assembly ofclaim 1, further comprising a trailing bar connected to the finishing element, wherein the bracket is coupled to the trailing bar.

17. The tiller assembly ofclaim 1, further comprising a plurality of brackets and a plurality of driven members.

18. The tiller assembly ofclaim 1, further comprising a power connection on the frame for connection to a power source, the power connection attached to the driven member.

19. The tiller assembly ofclaim 1, wherein the driven member is a hydraulic cylinder.

20. The tiller assembly ofclaim 1, further comprising a controller in communication with the driven member that controls movement of the driven member and thereby controls the volume of the chamber.

21. The tiller assembly ofclaim 20, wherein the controller includes a hydraulic system connected to the driven member.

22. The tiller assembly ofclaim 1, wherein the ground shaping element includes a rotatable drum with cutting teeth.

23. The tiller assembly ofclaim 1, wherein the tiller assembly is a snow tiller and the ground shaping element is a rotatable drum with a cover.

24. The tiller assembly ofclaim 1, wherein the finishing element is a flexible mat with finishing formations that create a texture in the surface.

25. The tiller assembly ofclaim 1, in combination with a vehicle.

26. The tiller assembly ofclaim 25, wherein the vehicle is a tracked vehicle and the tiller is a snow tiller.

27. A tiller assembly for shaping a surface, comprising

a main frame;

a ground shaping element carried by the main frame, wherein the ground shaping element has a longitudinal axis;

a pivot arm extending outward from the ground shaping element;

a bracket secured to the finishing element;

a pivoting connector pivotally attached between the bracket and the pivot arm; and

a driven member connected between the main frame and the bracket that causes the bracket to pivot with respect to the pivot arm to thereby change the volume of the chamber.

28. The tiller assembly ofclaim 27, wherein the pivoting connector includes a pair of connecting rods.

29. The tiller assembly ofclaim 28, wherein the connecting rods are aligned in a direction substantially perpendicular to the longitudinal axis.

30. The tiller assembly ofclaim 28, wherein each connecting rod has a first end and a second end, wherein the first ends of adjacent connecting rods are spaced apart at a first distance and the second ends of adjacent connecting rods are spaced apart at a second distance different from the first distance.

31. The tiller assembly ofclaim 27, wherein the bracket includes an arch shaped rod.

32. The tiller assembly ofclaim 27, wherein the bracket includes a generally horizontal bar and a pair of support legs that space the bar from the finishing element, the driven member being attached to the bar.

33. The tiller assembly ofclaim 27, further comprising a trailing bar connected to the finishing element, wherein the bracket is coupled to the trailing bar.

34. The tiller assembly ofclaim 27, further comprising a power connection on the frame for connection to a power source, the power connection attached to the driven member.

35. The tiller assembly ofclaim 27, wherein the driven member is a hydraulic cylinder.

36. The tiller assembly ofclaim 27, further comprising a controller in communication with the driven member that controls movement of the driven member and controls the volume of the chamber.

37. The tiller assembly ofclaim 27, wherein the finishing element is a flexible mat with finishing formations that create a texture in the surface.

38. The tiller assembly ofclaim 27, further comprising a plurality of brackets and a plurality of driven members.

39. The tiller assembly ofclaim 27, wherein the tiller assembly is a snow tiller and the ground shaping element is a rotatable drum with a cover.

40. The tiller assembly ofclaim 27, in combination with a vehicle.

41. The tiller assembly ofclaim 40, wherein the vehicle is a tracked vehicle and the tiller is a snow tiller.

42. A method of working the surface of the ground, comprising:

providing a tiller assembly having a ground shaping element and a finishing element with a chamber defined therebetween, wherein the finishing element is supported by a bracket;

tilting the finishing element to change the volume of the chamber by moving the bracket in an arc with respect to the surface of the ground;

operating the ground shaping element to grind the surface; and

driving the tiller assembly across the surface to drag the finishing element over the surface and provide a finished texture to the ground.

43. The method ofclaim 42, wherein tilting the finishing element includes driving a hydraulic cylinder by selectively energizing a hydraulic fluid in the hydraulic cylinder.

44. The method ofclaim 42, wherein tilting the finishing element includes moving the bracket about a pivot point spaced from the bracket.

45. The method ofclaim 42, wherein driving the tiller includes towing the tiller assembly from a vehicle.