Cutting arrangement for a snow blower

A snow blower is provided with cutting devices which are housed within, but project beyond, a housing provided for the blower's auger. As the cutting devices engage snow during the blower's advance, the cutting devices move in a direction which tends to urge the forward portion of the blower downwardly.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a snow blower provided with an arrangement 
for cutting compacted snow so as to facilitate operation of the blower's 
operation. 
2. Prior Art 
A problem experienced in operating a snow blower is that which occurs when 
the blower is advanced in a path through snow which has a crusted surface 
or which has been compacted. The dense, hard snow impedes penetration of 
the blower into the snow. One must repetitively drive the blower into the 
snow mass until forward progress stops, back the blower and then move it 
forward. 
The problem of dealing with compacted snow has previously been addressed. 
For example, in U.S. Pat. No. 5,398,431 an arrangement is disclosed 
wherein a pair of plates are positioned outwardly of the ends of a housing 
which encloses the snow blower's auger. When the auger is driven, the 
plates rotate so as to break up crusted snow and ice and assist in 
propelling the snow blower forward. 
Another example of a snow blower provided with cutting elements for 
compacted snow is disclosed in U.S. Pat. No. 5,101,585. This patent 
discloses an arrangement similar to that described with respect to U.S. 
Pat. No. 5,398,431. However, the corrugated cutting plates employed in 
U.S. Pat. No. 5,101,585 are mounted within the housing which encloses the 
auger. 
SUMMARY OF THE INVENTION 
The present invention overcomes deficiencies found in known devices. More 
particularly, according to the present invention, cutting members, in the 
form of toothed chains, are mounted within the auger's housing in such 
positions as to comply with ANSI standards concerning exposure of movable 
parts of a snow blower. Moreover, the cutting members are driven so as to 
move in a sense opposite that of the snow blower's auger. As the cutting 
members advance into the snow to be displaced by the blower, the cutting 
members move upwardly relative to the snow cover's surface. The upward 
motion of the chain cuts two paths through the crust allowing the side 
frame of the auger clearance to move forward. This action also tends to 
hold the forward portion of the snow blower down as it advances into the 
snow. By contrast, the direction of rotation of the cutting members in 
previously known snow blowers with such a feature rotate in the same 
direction as the auger. This tends to lift the forward portion of the snow 
blower when compacted snow is encountered thereby decreasing the operating 
efficiency of the blower.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION 
The present invention pertains to a feature incorporated in a conventional 
snow blower, a feature which can be described without completely 
describing the snow blower itself. Consequently, for convenience of 
illustration and description, a full snow blower is not illustrated in the 
accompanying drawings. 
Referring to FIG. 1, a first embodiment of the invention is shown. A 
conventional snow blower auger housing is designated as 10. An auger drive 
shaft is partially illustrated as 12. Shaft 12 extends substantially the 
entire length of the housing. Each end of the shaft is provided with a 
sprocket 14, only one of which is shown. As the auger is driven by shaft 
12 in the counter-clockwise direction indicated by the arrow, sprocket 14 
is similarly rotated. 
A chain guide bar 16 is mounted at each end of the housing. Again, only one 
such guide bar is shown. The housing 10 supports two chain idlers 18 and 
20 positioned adjacent the guide bar. A toothed chain 22 is guided by each 
guide bar 16. Each chain passes over idlers 18 and 20 and is directed 
around its sprocket 14, as indicated, whereby when shaft 12 is rotated in 
a counter-clockwise sense, chain 22 is moved in a clockwise direction 
about the guide bar 16. 
The principal longitudinal axis of guide bar 16 is oriented in a vertical 
sense. Consequently, as each chain 22 moves relative to its guide bar, the 
teeth at the leading edge of the chain move upwardly. The guide bar 16 is 
so dimensioned, and is mounted to housing 10 in such a fashion, that the 
upwardly moving teeth of chain 22 project forwardly of the housing 10 by 
an amount not exceeding ANSI standards limiting the acceptable projection 
distance of a snow blower auger. The remainder of each chain is protected 
by the housing. 
As the upwardly moving teeth of chain 22 engage compacted snow and/or a 
crusted snow surface, the resistance encountered tends to hold the forward 
portion of the snow blower down thereby contributing to the efficiency of 
the blower's advance into the snow which is being displaced by the blower. 
Additionally, the teeth cut through the compacted snow and crust which 
otherwise resists the advance of the snow blower. This permits the 
blower's auger to more efficiently move the snow to the snow blower's high 
speed impeller which displaces the snow via the blower's chute. If 
extremely solid areas of snow are encountered, the moving chains tend to 
lift and move them out of the way. Additionally, the close proximity of 
the chains and their supporting structure to the ends of the housing 10 
assist in removing support for any crust on the snow. 
When the crusted snow's resistance overcomes the traction of the snow 
blower's wheels, forward motion stops, and the cutting chains attack the 
crust. The augers chew up the cut snow, and it is discharged through the 
chute until such time as wheel traction is reestablished to move the snow 
blower forward. 
FIG. 2 illustrates an alternative arrangement for supporting and driving 
the toothed chains 22. Instead of sprockets 14, each end of the shaft 12 
is provided with a gear 24 which meshes with a gear 26 mounted on a 
generally triangular shaped chain guide bar 28. The bar 28 is a three 
piece lamination (FIG. 3). A sprocket (not shown) is provided between the 
outer layers of the lamination and is mounted on a shaft fixed to gear 26. 
The sprocket engages the teeth of chain 22 whereby when gear 26 is 
rotated, the chain moves about the guide bar 28. The chain is supported by 
bar 28 in conventional fashion, as also is illustrated in FIG. 3. 
When gears 24 are rotated in counter-clockwise direction, as indicated by 
the arrow in FIG. 2, the respective chains at opposite ends of the 
housings are moved clockwise. Inasmuch as a major axis of the chain bar 
guide 28 is vertically oriented, the same results are achieved as 
described with reference to the embodiment illustrated in FIG. 1.