US 3883965 A
A snow plow supporting frame mounted on a vehicle in any convenient manner. The frame has a pair of pivot brackets on which the plow is mounted so that the plow can pivot on a horizontal axis transverse of the vehicle upon striking an obstacle. Air bags are provided to cushion the swiveling action, the air bags being provided with safety valves and also with a resupply air source.
Description (OCR text may contain errors)
United States Patent 11 1 Poirier, Sr. et al.
[ SNOW PLOW FRAME  inventors: Real J. Poirier, Sn; Real J. Poirier,
In, both of 5 Bridges Rd., Brimfield, Mass. 01010  Filed: Oct. 9, 1973  Appl. No.: 404,593
 US. Cl. 37/42 R; 172/801; 293/71 P  Int. Cl A0lb 61/04  Field of Search 37/42 R, 42 VL; 280/481; 293/71 P; 172/276, 801
 References Cited UNITED STATES PATENTS 1,833,859 11/1931 Robinson et al. 37/42 VL 2,144,357 1/1939 Booharin 293/71 P 2,643,470 6/1953 Kaeser 37/42 R 2,775,830 1/1957 Kenyon 37/42 R 2,841,894 7/1958 Valois 37/42 R 3,022,587 2/1962 Greeley 280/481 X 3,238,647 2/1966 Hall et 37/42 VL 1451 May 20, 1975 3,332,562 7/1967 Kokott 280/481 x 3,650,054 3/1972 i-lanson........ 37/42 v1. 3,689,054 9/1972 0611113110 293/71 1 3,808,? 14 5/1974 Reissinger 6! a1. 37/42 VL FOREIGN PATENTS 0R APPLICATIONS 471,288 5/1969 Switzerland 37/42 R 1,425,809 3/1965 France 280/481 Primary Examiner-E. l-l. Eickhoit Attorney, Agent, or Firm-Charles R. Pay
[5 7] ABSTRACT 8 Claims, 4 Drawing Figures WJENTED M29195 SHEET 2 OF 2 FIG. 2
SNOW PLOW FRAME BACKGROUND OF THE INVENTION Conventional snow plows are usually mounted to yield under pressure. the yielding action being resisted by springs. Most spring mounts cause the plow to pivot forwardly and this usually results in a great deal of damage to the plow where obstructions are encountered. resulting in a rough edge and dents in the blade. It is the object of the present invention to provide a pivotal action of the plow so that the blade thereof yields or retracts against the action of a new and improved air bag construction, resulting in better automatic control of the plow when obstructions are hit and in less damage to the blade.
SUMMARY OF THE INVENTION A rigid frame which may be of conventional construction is applied to a vehicle as usual in a vertical relation. At the low end of the frame there are provided plow support brackets which can pivot on a horizontal axis transverse of the vehicle. The plow is mounted on these brackets and the usual plow lifting mechanism etc.. can also be used.
An air bag construction is set to resist the rearward pivoting of the bracket but the air bags are set so that they allow the pivot action to take place when an obstruction is encountered, but when the obstruction is removed. the air bags move the plow back to its original plowing operational position.
The effect of this is that when an obstruction is hit. force is transmitted through the plow frame to the pivoted brackets which then pivot i.c., to the rear. This has the effect of allowing the plow to swing to the rear. retracting or yielding. The plow blade is therefore enabled to retract under conditions of hitting an obstructionv This in turn results in less damage to the plow blade as compared with conventional types of plow blades which are mounted for spring action to pivot in the opposite direction when the lower edge or working edge at road level strikes an obstruction.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a view in side elevation illustrating the invention'.
FIG. 2 is a front view of a plow frame; and FIG. 3 is a plan view of the air bag construction.
PREFERRED EMBODIMENT OF THE INVENTION A frame of any convenient description, such as those which are used in the prior art. is indicated at I and this is mounted in any way desired to the truck chassis which is shown at 12. This frame may have the usual plow lifter 14, I6, etc.. if desired.
At the lower end of frame II] it is provided with a pair of vertical legs 20. and conveniently pivoted thereon by pins or bolts 22. 22 are a pair of brackets generally indicated at 24. 24. Brackets 24 extend forwardly and are provided with a pair of apertures 26, 26 for the reception of pins holding the plow frame 28. the plow blade being shown at 30. It is to be understood that the plow and the plow frame 28 may be of any description but of course it should be liftable as by the lifter struc ture l4, l6 pivoting with the frame 28.
The brackets 24, 24 can pivot about their pivot pins 5 22, 22 to the dotted line position in FIG. I, in which case of course the plow blade 30 as a whole will retract and therefore when an obstruction is encountered at the road level the plow blade 30 will not be damaged to any extent because it retracts and does not resist the obstruction. as does the usual plow. which tends to pivot over towards the obstruction.
Brackets 24, 24 are mounted on a crossbeam 32 each having a rearwardly extending portion carrying pins 34 pivoting the air bag support structure 36 which in turn is pivoted at 38 to a cross-support 40 attached to the front axle or other part of the vehicle. As the brackets 24 turn counter clockwise. FIG. 1, they cause pressure plates 40 to start to compress the air bags 42 and the structure 36 tends to pivot clockwise. When the obstacle is removed or the plow lift over it. the air bags bring the plow back to operating positionv Frame 36 carries the telescoping guide member 44 which is pivoted at 46 to the beam 32 which connects brackets 24.
The air bags are provided with a pressure release valve 48 which in turn is connected as at 50 to a source of air under pressure not shown so that the air bags absorb the rearward motion of the brackets 24. 24 and return the plow to normal operating position holding it there in normal operation for plowing except when an obstruction is hit.
I. A snow plow and a snow plow frame for a vehicle. comprising a bracket pivoted on the frame. means mounting the snow plow on the pivoted bracket. the pivot axis of said bracket being horilontal and transverse of vehicle. direction and fielding. resilient air bag means resisting motion of the bracket in a rearward direction under impact from an obstruction encountered by the plow. the resilient means yielding to allow the plow to relatively yield from the obstruction.
2. The device of claim I including a support for said air bag means, said support being mounted on the vehicle on which the plow is mounted.
3. The device of claim 2 wherein said frame is pivoted with respect to the vehicle and with respect to the brackets.
4. The device of claim I including a relief valve for said air bag means.
5. The device of claim 4 including a source of air under pressure for replenishing said air bag means in the event of loss of pressure through relief the release valve.
6. The device of claim 1 including a pressure plate in contact with the air bag means. the bracket being connected to the pressure plate.
7. The device of claim I wherein the point of attachment of the plow to the bracket is below the pivot axis of the bracket.
8. The device of claim 2 wherein the air bag support is pivoted relative to the vehicle.