SNOW PLOW

CHASSE-NEIGE

English Abstract

ABSTRACT OF THE DISCLOSURE
A snow plow adapted to be installed in front of a
propelling vehicle is disclosed. The snow plow comprises a frame, e
moldboard mounted on the frame and having forwardly projecting side
wings, wheels mounted on the frame for supporting the moldboard, and
resilient means mounted on the frame and permitting the moldboard to
slide rearwardly and upwardly on the frame when it strikes a hard
obstruction, so as to clear the obstruction and prevent damage to the
moldboard, while the moldboard remains sufficiently parallel to itself
so that the front lower corners of the side wings will clear the ground.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY
OR PRIVILEGE IS CLAIMED, ARE DEFINED AS FOLLOWS


1. A snow plow comprising a moldboard, a supporting frame
adapted for attachment to the forward end of a propelling vehicle, said
moldboard having forwardly projecting side wings, rigid links articulating
said moldboard to said frame, said rigid links extending rearwardly end
downwardly from the upper portion of said moldboard, straight guideways
secured to said frame and rearwardly and upwardly inclined, guide members
secured to the lower portion of said moldboard and engaging said guide-
ways for rectilinear movement along the same, spring means connecting
the moldboard to the frame and biasing the lower edge of the moldboard
towards the ground, so constructed and arranged that, when the lower edge
of said moldboard strikes a hard obstruction, the entire moldboard moves
upwardly and rearwardly with respect to said frame and remains suffi-
ciently parallel to its previous position, so that the front lower
corners of said side wings will clear the ground.


2. A snow plow as claimed in claim 1, wherein said guideways
make about a 45° degree angle with the ground.


3. A snow plow as claimed in claim 1 or 2, wherein said
guideways include stop means against which said guide members abut to
define the foremost and lowermost limit position of said moldboard
relative to said frame, said spring means being connected between
said guide members and said guideways.


4. A snow plow comprising a moldboard, a supporting frame
adapted for attachment to the forward end of a propelling vehicle,
ground-engaging means carried by said frame for maintaining said
frame at a determined level above the ground, said moldboard having
a scraping blade rigidly secured to the lower longitudinal edge
thereof and further having side wings projecting forwardly of the
moldboard from the ends of the same and rigidly secured to said mold-
board, rigid links articulating the upper portion of said moldboard
to an upper portion of said framework, said links extending rearwardly


and downwardly from said moldboard, straight guideways secured to said
frame below said rigid links and rearwardly and upwardly inclined, guide
members secured to the lower portion of said moldboard and mounted in
said guideways for rectilinear movement therealong, stop means in said
guideways against which said guide members abut in a foremost and lower-
most limit position of said moldboard relative to said frame, with
said scraping blade adjacent to the ground, spring means mounted between
said guide members and said guideways and biasing the moldboard to said
limit position, so constructed and arranged that, when said scraper blade
strikes a hard obstruction, the entire moldboard moves upwardly and rear-
wardly with respect to said frame and remains sufficiently parallel to
its previous position, so that the front lower corners of said side
wings will clear the ground.


5. A snow plow comprising a moldboard, a scraping blade rigidly
secured to the lower longitudinal edge of said moldboard, forwardly pro-
jecting side wings rigidly secured to the ends of said moldboard, a support-
ing frame for said moldboard adapted for attachment to the forward end to
a propelling vehicle, said frame including a transverse beam adapted to
extend just above the ground and having an upwardly and rearwardly inclined
flat surface and rigid posts located behind said transverse beam, first
brackets extending rearwardly from the lower portion of said moldboard
and spaced from each other along said moldboard, wheels carried by some
of said first brackets and in rolling engagement with said inclined
flat top surface of said transverse beam, guide blocks secured to said
top surface of said transverse beam and each having a straight guiding
slot extending above, across and parallel to said top surface of said
transverse beam, a pin extending through said slot and carried by others
of said first brackets to be guided by said slot, a rod secured to the
rear end of each guide block and extending rearwardly therefrom, a spring
retainer in the form of a sleeve slidable on said guide block pivotally
attached by said pin to said others of said first brackets at its lower
front end, a second spring retainer secured to the free end of said rod,
a compression coil spring surrounding said rod and extending between said


first and second spring retainers, second brackets extending rearwardly
from the upper portion of said moldboard, rigid linkage members pivotally
connected to said posts and to said second brackets, the pivotal
connections of said linkage members to said posts being at a lower
level than the pivotal connections of said linkage members to said
second brackets, said spring biasing said pin in a limit position against
the lower and of said slot with said scraper blade and moldboard at a
predetermined level relative to said transverse beam and permitting
movement of the entire moldboard upwardly and rearwardly along said top
surface of said transverse beam, while the moldboard pivots slightly
forwardly about said pins under the action of said linkage members, but
insufficiently for the front lower corners of said side wings to contact
the ground.


6. A snow plow as claimed in claim 5, further including push
bars pivotally attached to said frame and extending rearwardly of the
same for detachable connection to the front of a propelling vehicle and
means to adjust the vertical angle of said push bars relative to said
frame.

Description

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s This lnvention relates to snow plows, and more particularly

to snow plows adapted to be attached to the front of a tractor or a
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truck.
The moldboard assemblies of snow plows designed for the removal
of snow and ice on city streets, parking lots and elsewhere, are normally
provided with a scraping blade which is secured to the ground engaging
edge of the moldboard. These scraping edges are often damaged by hard
obstructions such as manhole covers~ crubs, water plugs and others when
these obstructions are hit during plowing of the snowO Some safety de~
vices enabling the moldboard to be tripped to a safe out-of-the-way
position when hitting an obstruction have been designed~ However, the
known safety devices are generally complex and costly.
It is the object of the present invention to provide a snow
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plow with simple~ non~costly resilient mPans which allow the snow plow

to yield when hittlng an obstruction on the ground or pavement.
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The snow plow, in accordance with the invention, comprises a

, frame, a moldboard mounted on the frame, wheels mounted on the frame
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for supporting the moldboard and resilient means mounted on the frame

and permltting the moldboard to slide rearwardly and upwardly when it
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';~ 20 strikes a hard obstruction so as to prevent damage to the moldboard.
In a preferred embodiment of the invention, the resilient
means comprises a pair of rods secured to the frame one at each end
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of the moldboard at an angle sloping rearwardly and upwardly, a spring


surrounding each rod and having one end retained by the outer end of
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;~ the rod~ and a spring compressing member connected to the moldboard
adapted to contact the other end of each spring to compress it when the
moldboard strikes a hard obstruction.
The invention wlll now be disclosed~ by way of example~
with reference to a preferred embodiment illustrated in the accompanying
~ 30 drawings in which:
; Figure 1 illustrates a perspective view of a snow plow in
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accordance with the invention;
igure 2 illustrates a side elevation and cross-se~tion view
of the snow plow shown in Figure 1~ Figure 2 being taken along line
2-2 of Figure 3;
Figure 3 illustrates a plan view of the snow plow shown in
Figure l;
Figure 4 illustrates a cross-section view taken aLong line
4-4 of Figure 3;
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Figure 5 is a side view, partly in longi~udinal section of the

resilient means and its connection to the moldboard; and

Figure 6 is a front view~ partly in cross-section of the
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means of Figure 5.
.~ Referring to the drawings, there is shown a moldboard assembly
comprising a moldboard 10 having a replaceable scraping blade 12, and
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side wings 14 rigidly connected to the moldboard by means of braces 16.
;; The moldboard ls mounted on a frame which consists of a main transverse
beam 18 which is ~oined to a shorter transverse beam 20 by diagonal ;

beams 22. E~tending upwardly from each end of beam 20 are vertical

~i posts 24 which are joined attheir upper ends by transverse member 26.

Each post 24 is braced sideways by a plate 28 and ~oined to the main
~ beam 18 by a diagonal beam 30. A vertical post 32 is welded to each
ii end of main beam 18 and a shaft 34 is secured to each post for mounting
wheels 36 which support the frame. A skate 38 is also mounted on each post
32 by menas of pla~e 30 and ad~usted at a predetermined distance above


ground so as to momentarily support the frame when a wheel falls into
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a cavity in the ground.
Main transverse beam 14 is of L-shaped cross-section and has
a main flange 13' which defines an upwardly and rearwardly inclined
surface for guiding the moldboard rearwardly and upwardly.
The back of the moldboard is provided with a plurality of
reinforcing ribs and some of these ribs are used to connect the

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moldboard to the frame while allowing rearward movement of said mold-
board. Thus, two spaced brackets 42 and 42' are welded to the base of
ribs 44 and 48 respectively (see Fig. 3) and two additional spaced
brackets 46 welded slightly above the middle of the ribs 48 (see Figs.
3 and 4).
Referring more particularly to Figures 2, 4 and 5, there is
shown resilient means for preventing damage to the scraping blade when
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it hits an obstruction~ A pair of spaced rods 50 are secured to the
rear end of guide blocks 52 in turn secured to flange 18l of beam 18
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and reinforced by brackets 54. A spring 56 is positioned around each

rod and slightly compressed in position between a washer plate 58
and a washer plate 66 secured to a hollow spring retainer 60 slidably
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enclosing guide blocks 52. Washer plate 58 is held to the outer end of
rod 50 by nut 62, while spring retainer 60 is connected at one end to
brackets 42 by a pin 64 which is allowed to freely move within an
elongated slot 52~ of guide block 52.
Turning now to Figure 2, a pair of spaced screw ad~usting
linkages 68 are pivotally connected at one end to post 24 and at their
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` other end to brackets 46. Linkages 68 permit to adjust the aogle of

",!~ 20 the moldboard. A lifting chain 70 is also attached to each bracket 46

; for raising the moldboard by the ~ractor whenever required.
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~ It will be easily seen from the above description that if the
; moldboard hits an obstruction, the spring retainer will slide rear-
wardly and upwardly on the guide blocks 52 secured to beam 18 against
the action of spring 56 until the obstacle is clear. As shown in
Figure 2~ it will be noted that beam 18 is conveniently installed
with its flat surfaces 18~ at an angle corresponding to the angle of

rod 50~ for instance an angle of 45 relative to the ground. However,
; other means of mounting the resillent means so that they will slope
rearwardly and upwardly are also envisaged. During its rearward and
; upward movement, the moldboard will remain substantially parallel to

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its previou~ poqition, as 8hown in dot-and-dash line in Figure 2,
due to the lower po~itions nf the pivotal connection~ of linkage~ 6
on post 24 than the position3 o~ the pivotal connections of linkage
24 on bracket8 46. Therefore~ tha front lower cornHr~ of side
wing~ 14 olear th~ ground during movement of the moldboard. Whesls
72 arB mounted on brackats 42~ of rib~ 48 of the moldboard for
oontscting be~m 18 to help in supporting the moldboard during its
- upwsrd and resrw~rd movemsnt. When the ob3truction i9 olear, the
moldboard will return to it~ ground engaging position under the
action o~ the springs 56. Thi~ position i8 delimite~ by pins 64
~ abutting against the end of guide ~lots 52' of blocks 52 (see
Figure 5).
The snow plow ig pushëd by mean~ of pu~h b~r~ 76 which ~re
pivotally connacted at one end to brackets sscured to bnam 18 by pins

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7~ and joined ad~ucent their othsr end by tr~nsver~e member 80 pivoted

to push bars 76. A vertical bar ~2 is secured bet~e~n be~m 20 and
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transv~rse member 26 and tran~verse member 80 i9 ~d~u~t~bly secured
to vertical bar ~2 by mesn~ of bolt 84. Several hole~ ars msde through
b~r 82 fo~ adju~ting the height of pu~h bars 76 to suit the height
: 20 o~ the moldbo~rd attachment mesn~ of the tractor or truck.
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Although the inv~ntion has been disclo~ed with reference to
~ preferred embodiment, it i~ to be understood th~t it is not limited
:~ to such embodim~nt, but by the scope of the olaimn only. For example,
. . other types of resilient mean~ may be provided for permitting the
moldboard to slide rearwardly ~nd upwardly when it strikeo a hard

obstruction to prevent damage to the moldboard.

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