U.S. patent number 3,794,122 [Application Number 05/234,512] was granted by the patent office on 1974-02-26 for snow conditioning machine.
Invention is credited to Dennis L. Rohrer.
United States Patent |
3,794,122 |
Rohrer |
February 26, 1974 |
**Please see images for:
( Certificate of Correction ) ** |
SNOW CONDITIONING MACHINE
Abstract
A snow conditioning machine for conditioning snow at ski areas
to give it a proper texture for skiing even after it has become
packed hard or become icy including a rotating member having radial
teeth that intermesh with stationary teeth on the machine and
through which the snow passes to be reduced in particle size to an
acceptable level. The unit includes means for breaking hard packed
snow into large chunks which are then passes into the intermeshing
teeth of the rotating member and the stationary member. Support
rollers for the unit are provided, this makes the unit usable for
compacting newly fallen snow when the rotating member is not in
use.
Inventors: |
Rohrer; Dennis L. (Burnsville,
MN) |
Family
ID: |
22881664 |
Appl.
No.: |
05/234,512 |
Filed: |
March 14, 1972 |
Current U.S.
Class: |
172/66; 172/68;
172/142; 172/149; 172/174; 172/473; 172/120; 172/146; 172/180;
172/482; 37/222 |
Current CPC
Class: |
E01H
4/02 (20130101) |
Current International
Class: |
E01H
4/00 (20060101); E01H 4/02 (20060101); A01b
009/00 (); A01b 005/00 () |
Field of
Search: |
;172/23-24,45,49-52,55,63,65-71,118-120,122-123,133,142,145,146,148-151,170
;37/10 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
|
|
|
|
|
1,248,085 |
|
Aug 1967 |
|
DT |
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1,195,996 |
|
Oct 1964 |
|
DT |
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25,357 |
|
Dec 1919 |
|
DK |
|
Primary Examiner: Wright, Jr.; Ernest T.
Assistant Examiner: Eickholt; Eugene H.
Attorney, Agent or Firm: Dugger, Johnson & Westman
Claims
What is claimed is:
1. A snow conditioning apparatus comprising a vehicle having a main
frame adapted to be moved over the surface of snow including front
support means at a front portion of the vehicle, and a subframe
assembly pivotally mounted to said main frame to the rear of said
front support means, rear support means mounted on said subframe
assembly at the rear of said vehicle, a snow conditioning section
mounted on said subframe assembly comprising a rotor, means to
rotatably mount said rotor to said subframe assembly about an axis
substantially transverse to the direction of movement of said
vehicle, said rotor including a plurality of axially spaced
radially extending rotor teeth along the axial length thereof,
power means to rotate said rotor at a desired speed to comminute
snow coming in contact with said teeth as the rotor is rotated, a
transverse support and feed bar member narrow in front and rear
direction, means to mount said feed bar member on said subframe
assembly in fixed position with respect to said rotor and below
said rotor, said rear support means being mounted to said subframe
assembly rearwardly of said rotor in direction of normal movement
and on the opposite side of the pivotal mounting of the subframe
assembly to the main frame from said rotor, power means to pivot
said subframe assembly about its pivotal mounting to said main
frame to selectively move said rotor away from said snow and
support the rear portions of said main frame on said rear support
means, and alternately to lift said rear support means from said
snow and move said feed bar member into engagement with said snow
to push snow toward said rotor as said vehicle is moved while
supported by the snow.
2. The combination specified in claim 1 and a plurality of upright
teeth mounted on said feed bar member and positioned to pass
between the radially extending teeth of said rotor, whereby snow
engaged by said feed bar member is contacted by said rotor teeth
and forced between said upright teeth by the teeth of said
rotor.
3. The combination specified in claim 2 and removable means for
mounting the upright teeth to said feed bar member.
4. The combination specified in claim 2 wherein said rotor has a
central shaft, and said rotor teeth comprise individual axially
narrow tooth assemblies drivably mounted onto said central shaft,
means to retain said tooth assemblies in position on said central
shaft, said means to retain said tooth assemblies on said central
shaft being removal to permit replacement of tooth assemblies on
said central shaft.
5. The combination specified in claim 1 wherein said front support
means from said main frame comprises a rotatable front roller of
substantial diameter to provide flotation over a snow surface.
6. The combination specified in claim 2 and spring tooth means on
said main frame movable to engage the snow ahead of said rotor and
to break said snow into chunks prior to engagement of the snow by
said rotor.
7. The combination specified in claim 1 wherein said means to mount
said rotor and feed bar member includes a rotor housing comprising
a formed plate overlying said rotor, end plate members fixed to
said formed plate, said end plate members extending from said
formed plate downwardly to support said feed bar member and said
rotor as a unit.
8. The combination specified in claim 2 wherein at least some of
said rotor teeth are offset in an annular direction from others of
said rotor teeth.
9. The combination specified in claim 4 wherein each of said rotor
tooth assemblies have four radially extending teeth, and wherein
some of said rotor tooth assemblies are annularly offset from
others of the rotor teeth assemblies.
10. The combination as specified in claim 1 wherein said rear
support means comprises a tubular roller member, disc plate means
at the ends of said tubular roller member, said disc plate means
being fixed to said tubular roller member and projecting radially
outwardly beyond the outer surface of said tubular roller member a
short distance to provide lateral stability when the tubular roller
member engages the snow.
11. The combination as specified in claim 1 and a plurality of
spaced planar members extending downwardly from said feed bar and
fixed to said feed bar, said planar members extending in fore and
aft direction with respect to direction of movement of said machine
to form narrow vertically depending guide blades extending
downwardly from said feed bar.
12. The combination specified in claim 6 and separate hydraulic
cylinder means for alternately raising said spring tooth means away
from the surface of said snow and forcing said spring tooth means
into the snow.
13. The combination specified in claim 1 wherein said main frame
includes means to permit said main frame to be towed behind a
vehicle towing, a power source on said main frame, and wherein said
power source supplies the power means for rotating said rotor and
for pivoting said subframe relative to the main frame.
14. A snow conditioning machine comprising a main frame member
having front and rear ends, a first transversely extending
elongated roller rotatably mounted on said main frame member in
position to support the front end of said main frame member, a
subframe assembly positioned at the rear end of said main frame
member, said subframe assembly being pivotally mounted to said main
frame member about a first axis extending transverse to the normal
direction of movement of said machine in use, a rotor, means to
rotatably mount said rotor to said subframe assembly, said rotor
comprising an axial shaft rotatable about a second axis transverse
to the normal direction of movement of said machine, a plurality of
substantially radially extending teeth spaced axially along said
shaft, a second transversely extending elongated support roller
rotatably mounted to said subframe assembly to the rear of said
rotor, means to mount said second support roller at a position in
respect to the first axis so that when said subframe assembly is in
a first pivotal position with respect to said main frame member
said rotor will be in position to engage snow as the main frame
member is moved along snow being conditioned, and said second
support roller will be spaced from the snow to the rear of said
rotor, and in a second position of said subframe assembly said
second support roller will be engaging the snow to support the rear
portions of said main frame member and said rotor, and said rotor
will be spaced from said snow, means to direct snow into the path
of rotation of said rotor, power means to rotate said rotor, and
power means to control movement of said subframe assembly between
its pivotal positions.
15. The combination specified in claim 14 wherein said means to
direct snow into the path of said rotor comprises a transverse bar
member fixedly mounted on said subframe below said rotor and
engaging and being supported by snow over which the main frame
moves when the subframe is in its first pivotal position with the
second roller spaced from said snow.
16. The combination specified in claim 15 and a plurality of
substantially uprightly extending teeth mounted on said transverse
bar, said upright teeth being positioned to pass between teeth on
said rotor as said rotor rotates.
17. The combination specified in claim 16 and means teeth mounted
on said main frame to engage snow ahead of said rotor in the
direction of normal travel of said main frame to break said snow
into chunks prior to the time snow engages said rotor.
18. The combination specified in claim 16 and removable means to
mount a plurality of said upright teeth and means to mount said
removable means onto said transverse bar member.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to machines for conditioning snow for
skiing purposes.
2. Prior Art
Most snow conditioning machines presently in use are generally
rotary hoes or spring tooth cultivators that are normally used for
cultivating the earth or some combination of the two devices.
Specialized equipment for grooming snow or conditioning snow for
skiing is shown in U.S. Pat. No. 3,368,292 and U.S. Pat. No.
3,478,827.
A rotating earth working tool that conditions the ground, and
reduces particle size or comminutes the ground is shown in the U.S.
Patent to Staats, U.S. Pat. No. 2,785,613. A rotating flail type
beater is shown for conditioning soil. Also, the Richey U.S. Pat.
No. 2,667,022 shows a flail type device for shredding stalks of a
corn field or the like, and the U.S. Patent to Cohen, U.S. Pat. No.
3,008,526 shows a soil conditioning apparatus which utilizes three
separate flail type beaters for engaging the soil with hammers for
pulverizing soil.
Another form of a flail type device is shown in the MacDonald U.S.
Pat. No. 2,986,841.
All of these earth working devices do not have the intermesh teeth
for obtaining a desired particle size, and of course in the
conditioning of snow it is important that the particle size be
maintained at a relatively controlled level so that it isn't so far
in that it packs immediately, and is not so coarse so that it
interferes with proper skiing.
SUMMARY OF THE INVENTION
The present invention relates to a snow conditioning or grooming
apparatus which includes a rotating member (rotor) having radially
extending teeth spaced along the transverse length thereof. Means
are provided for moving a layer of snow into the path of the rotor
teeth. As shown the teeth of the rotor intermesh with stationary
teeth on a transverse bar that engages the snow. The bar pushes
snow ahead of it so the upper 2-3 inches of snow has to go over the
bar and into the rotor teeth. The snow conditioning machine also
includes a spring tooth harrow type device for breaking up packed
snow into usable chunks, which then pass over the transverse bar
and through the intermeshing teeth of the unit.
The entire comminuting or pulverizing apparatus including the rotor
having the radially extending teeth, and the transverse support or
bar having the stationary teeth is mounted in a subframe assembly
with a large flotation support roller. The subframe assembly is
pivotally mounted to the main frame and can be tilted relative to
the main frame of the unit so that the large rear roller is
supporting the rear of the unit with the rotor and transverse bar
spaced off the surface of the snow, or the subframe can be moved to
a position wherein the transverse bar rides along the surface of
the snow and the rear roller is spaced off the snow surface. The
unit can be used as a snow compactor for compacting newly fallen
snow when the rear roller is contacting the snow and the rotor is
spaced from the snow.
A large roller rotatably mounted at the front of the main frame
supports the unit without severly compacting the snow.
The intermeshing teeth of the rotor and transverse bar are made to
be replaceable either in sections, or individually, so that if a
foreign object passes through the teeth and one of the teeth breaks
it can be replaced without completely changing the entire machine.
The power unit for operating the machine components is mounted on
the main frame. The machine is shown as a towed vehicle but it
could also be self propelled, if desired.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of the snow conditioning machine
made according to the present invention;
FIG. 2 is a top plan view of the machine of FIG. 1;
FIG. 3 is a fragmentary side elevational view showing the snow
conditioning machine in a position with a rear roller engaging the
ground to support a snow comminutation rotor portion spaced from
the snow;
FIG. 4 is a fragmentary front elevational view of the snow
comminutation portion of the present invention;
FIG. 5 is a sectional view taken as on line 5-- 5 in FIG. 4;
DESCRIPTION OF THE PREFERRED EMBODIMENT
A snow conditioning machine illustrated generally at 10 includes a
main frame assembly 11 that has a pair of longitudinally extending
main side frame members 12,12 joined together with a front cross
member 13 and a center cross member 14, and any additional cross
members that may be necessary to hold the frame in a rigid assembly
for the loads encountered. The frame assembly 11 can be bolted
together, or can be welded if desired within the requirements of
being able to assemble the unit. The frame assembly 11 has a hitch
pole 15 mounted to the front cross frame member thereof, and this
hitch pole includes the usual clevis or other attaching means for
connecting the unit to a towing vehicle such as the usual tractors
that have large tracks for flotation over the snow.
A large flotation roller 20 is rotatably mounted on suitable
bearings 21 at the foward end of the frame 11, and extends between
the side members 12,12. The roller 20 can be made of a hollow metal
tube, such as of a conventional metal culvert approximately 30
inches in diameter, with discs 20A welded at the ends of the tube,
and having stub shafts extending from the discs into the bearings
21. The roller will merely rotate and roll along the ground when
the frame is pulled.
The frame has a support carriage 23 mounted adjacent the forward
end, over the roller 20, that supports an internal combustion
engine illustrated schematically at 24, and a hydraulic fluid
reservoir R or the like. The engine 24 provides the power for
operating powered components of the snow conditioning machine 10.
The engine 24 drives a hydraulic pump 25, which takes fluid from
the fluid reservoir and pumps it under pressure to a valve assembly
shown schematically at 26 that controls flow of fluid under
pressure to the various components. The pump and valve can be
mounted in any desired manner in order to obtain the power control
necessary for operating the snow conditioning machine. The control
valve can be mounted on the towing vehicle, if desired.
The snow conditioning machine is thus supported by the forward
roller 20. Immediately to the rear of the forward roller 20 there
are a pair of cross shafts 28, each of which is square in cross
section except at their ends, which are turned round and are
rotatably mounted in suitable supports 29 at the opposite frame
members 12,12. The shafts 28 are used for mounting a plurality of
conventional spring harrow teeth 31, that are mounted onto the
shafts 28 with suitable U bolts or clamps, in a usual manner.
Pivoting of shafts 28 is controlled through the use of a hydraulic
cylinder 32 having an extendable and retractable rod 33. The rod 33
acts through a torque arm 34 attached to the rear shaft 28. A link
35 is pivotally connected to arm 34 and to an arm 35B mounted on
the front shaft 28 so that when the rear shaft 28 is pivoted
through movement of the torque arm 34, both shafts 28 will pivot.
The harrow teeth 31 will be raised when the rod 33 is retracted and
will be lowered into the snow when the rod 33 is extended as shown
in FIG. 1. The harrow teeth are used for breaking up firmly packed
snow, or icy snow into chunks that will be readily reduced in size
when they pass through the snow comminution assembly.
The snow comminution assembly is part of a subframe illustrated
generally at 40 and includes a large housing 41 that has a formed
transverse top plate member 42 extending across the machine which
has end plates 43 on the opposite ends thereof. The end plates 43
in turn rotatably support a toothed rotor indicated generally at 44
(see FIG. 4) that is rotatably mounted in suitable bearings 45
attached to the opposite end plates 43. The rotor 44 is made up of
a central square tubular shaft 46 (see FIG. 5) and at the ends of
the shaft 46, round stub shafts 47 are welded in place for
rotatable mounting in the bearings. Each of the shafts 47 has a
threaded section 48 of larger diameter than the portions mounted in
the bearings on which nuts 49 are threaded. The nuts 49 are
securely locked in place with set screws to keep them from
loosening once the rotor is assembled. The rotor is made up of a
plurality blade like teeth assemblies indicated generally at 55.
The rotor teeth assemblies, as perhaps best shown in FIGS. 4 and 5,
have central hubs 56 that have square openings that slide over the
square tube 46 and closely fit the tube and each tooth assembly has
four radial blades or teeth indicated at 55A, 55B, 55C and 55D for
the end tooth assembly shown in FIG. 5. The hubs 56 are welded to
the actual tooth plate which is made from a plate having the four
blades formed by cutting out portions of the plate and which are
spaced 90.degree. apart. The desired number of tooth assemblies are
slid onto the square shaft 46 and are held on the shaft by the nuts
49 at each end of the shaft to form the rotor made up of individual
tooth assemblies stacked together. The openings in hubs 56 are
positioned so that some of the blades or teeth have a different
angular position than blades of other tooth assemblies when mounted
on the shaft. For example, as shown in FIG. 4, a series of
identical tooth assemblies 57 are adjacent each other and then a
stack of tooth assemblies 58 are mounted on the shaft 46. The
blades of tooth assemblies 58 are angularly offset from the blades
of tooth assemblies 57 by a desired amount, for example 15.degree..
The next stack of tooth assemblies 59 are offset another 15.degree.
to stagger the blades so the loads on the shaft when breaking up
snow are equalized. If desired, adjacent teeth can be offset from
each other so the blades actually spiral around the rotor rather
than having several identically positioned blades in a row or
stack. As shown, there are a plurality of rotor sections with the
teeth in each section oriented identically, but which are annularly
offset from the other adjacent sections.
The blade offset insures that the forces on the rotor are
relatively balanced so that all of the blades don't contact snow at
the same time and cause excessive loads on the rotor itself. The
individual teeth or blades of the rotor assembly are spaced apart
in axial direction of shaft 46 as shown in FIG. 4, and these spaces
are approximately one half inch as shown. The hubs 56 provide for
the spacing.
The snow conditioning machine is provided with a bottom snow
engaging and feeding cross bar assembly 60 that supports a
plurality of spaced triangular shaped upright teeth 61. The teeth
61 are attached as shown to individual U-shaped mounting sections
62 which fit onto the cross bar 60, and can be bolted in place. The
sections 62 can be made up with any desired number of teeth 61
fixed thereto, for example sixteen teeth in a section. Then if any
of the teeth 61 break out, the section 62 can be replaced. The
teeth 61 may be made of a spring steel, and individually bolted or
fastened directly in place onto the cross bar 60 with a suitable
bracket, so that individual teeth 61 can be replaced if they break.
The teeth 61 are triangular plate blades as shown and have
uprightly extending edge portions facing in the direction of
movement of the snow conditioning machine. The rotor blade teeth
pass between two adjacent fixed teeth 61 to provide a breaking or
grinding or comminuting action for any material that is engaged by
these teeth.
The cross bar 60 can be attached between the end plates 43 in any
desired manner, but should be removable. For example, end brackets
64 can be provided which bolt to the end plates 43, and which are
welded to the cross bar. The cross bar 60 can be removed by
removing of the cap screws holding the brackets 64. The end plates
43 are slotted from the bottom to permit the rotor and cross bar 60
to be removed. Braces 65 from the housing to the cross bar 60 can
be provided if desired. The rotor teeth are spaced to miss the
braces.
The bar 60 also may have edge mounted planar guide blades 60A
welded to the bottom thereof. The blades 60A travel below the
surface of the snow and stabilize the frame from lateral
shifting.
The end plates 43 extend rearwardly even with the rear end of the
top plate 42 of housing 41. A pair of side frame members 66 are
attached to the side plates 43 so they move as part of the subframe
40. The side frame members 66 are provided with stub shafts 67
which are rotatably mounted in hubs 68 that are attached with
brackets 68A to the main side frame members 12. The shafts 67 can
be pinned at their outer ends (outside hubs 68) to keep the main
frame members 12 from separating. The frame members 66 include
rearwardly extending portions 69 that are angled upwardly and which
are connected together with a rear cross piece 70.
The frame portions 69 support bearings 71 that in turn rotatably
mount stub shafts 72 fixed to the end plates of a support tube or
roller 73. The support roller 73 is constructed similar to the
roller 20, but the end discs 73A extend outwardly beyond the
periphery of the roller a small amount to give the machine
stability when the roller 73 is on the snow.
The pivoting of the subframe 40 which includes housing 41, and the
roller 73, is controlled through use of a pair of hydraulic
cylinders 75 that are attached at the first ends to brackets 75A on
upright mast or arm members 76 which are fixed to the subframe
member 66 and therefore fixed to the housing side plates 43. The
hydraulic cylinders 75 have extendable and retractable rods 75C
that are attached to brackets 75B fixed to side frame members 12.
Movement of the cylinder rods 75C therefore determines the position
of the subframe assembly about its pivot shaft. When the rods are
retracted the cross bar 60 is riding on the snow and the roller 73
is off the snow, as shown in FIG. 1. However, by extending the rods
of cylinders 75 under hydraulic pressures through controlling the
valve 26, the entire housing 41 is lifted off the snow surface, and
the roller 73 contacts the snow surface as the subframe pivots
about the axis of the shafts 67. The roller 73 can be used for
compacting the snow if desired.
The toothed rotor assembly 44 is driven with a hydraulic motor 80
that is mounted onto a bracket 81 adjustably attached to one of the
end plates 43. The output shaft of motor 81 has a sprocket 82
drivably mounted thereon which in turn drives a chain 83 to drive a
sprocket 84 on the corresponding end shaft 47 of the rotor. The
hydraulic motor 80 is controlled through valve 26, (which has a
sufficient member of individual valves for operating these
hydraulic components), and when driven the motor will rotate the
rotor in direction as indicated by the arrow 86, to cause the rotor
teeth 55 to pass between the fixed teeth 61. Any snow that is in
front of the lower teeth 61 will be pulverized or reduced in size
by the intermeshing teeth on the rotating rotor. The bar 60 pushes
snow ahead of it as shown in FIG. 5. As the frame is moved along
the snow the rotor breaks the snow up and forces it through the
fixed teeth 61. The size of the snow particles when it has passed
through the intermeshing teeth will be approximately "pea" size
which is a good size for giving good control in skiing conditions,
but is not so fine that it will readily pack again. The rotor is
rotated at about 750 rpm with an outer diameter of teeth of about
12 inches.
Thus when the unit is to be used, the spring harrow teeth 31 are
lowered into the snow by operating cylinder 32 and as the frame
moves over the snow the harrow teeth break up the hard snow into
chunks of moderate size. Then the bar 60 pushes snow ahead of it as
it moves along and the chunks and other snow will be engaged by the
rotor assembly 44 and the teeth 55 thereof, and it will be
comminuted or pulverized as the teeth 55 pass between the
stationary teeth 61. The bar 60 rides along the surface of the
snow, and insures that any loose snow is pushed up ahead of it, and
has to pass through the intermeshing teeth from the rotor 44 and
the stationary teeth 61. The bar 60 actually forms a snow feeding
means for feeding snow into the rotor.
The bar 60 can have suitable central supports, if desired, as shown
in FIG. 4 which support the bar from the housing plate 42 for added
strength. Guide wings 90 are mounted ahead of the rotor housing to
guide snow into the rotor from the sides and prevent ridges from
forming. These guide wings are pivoted to the frame members 12 at
their leading ends and ride on the snow.
The teeth 55 of course are replaceable by loosening the nut 49 on
one end of the rotor assembly 44, after the rotor has been removed
from the housing by taking off the bearings, and then merely
sliding off the teeth 55 until the broken one is removed. New teeth
can be substituted and the rotor reassembled.
The pivoting subassembly controlled by hydraulic cylinders 75 make
the unit easy to operate and give it dual usage. The rotor housing
assembly is of sufficient weight so that it will ride firmly on the
snow. The bar 60 is supported by the snow slightly below the
surface of the snow so that chunks and loose snow are pushed ahead
of the bar and then pass into the rotor.
The use of the harrow teeth for breaking the snow up into chunks
which will pass through the rotor insures that an adequate job of
pulverization or snow grooming is achieved.
The configuration of the corrugated culvert rollers is shown only
partially in FIG. 2. Both rollers are made of the corrugated
material, because when used for compacting snow the small, gentle
ridges left make a better skiing surface than a smooth roller.
The carriage or frame 23 is supported an the side frame members 12
and has cross members extending above roller 20 all the way across
the frame to support the engine and other components. There are
also fore and aft braces 23A extending from cross member 14 to the
carriage cross members, and braces 23B from the front cross member
to the carriage for strengthening purposes. One end of cylinder 32
is mounted on a bracket connected to braces 23A.
It should also be noted that the rear portion of the top plate 42
serves to deflect snow thrown rearwardly by the rotor to cause the
pulverized snow to drop back down onto the snow into an even layer
and form a new skiing surface.
* * * * *