US 3432946 A
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Description (OCR text may contain errors)
March 18, 1969 PE L 3,432,946
LIFTING AND PRESSURE UNIT FOR SNOWPLOWS AND THE LIKE Filed Nov. 9, 1965 Sheet of 2 IO N INVENTOR. J O 8 EF PE ITL ATTORNEYS J. PEITL .March 18, 1969 LIFTING AND PRESSURE UNIT FOR SNOWPLOWS AND THE LIKE Filed NOV. 9, 1965 m on o N QE INVENTOR. JOSEF PEITL Mega, 7M 61 89:14;
ATTORNEYS 2 Claims ABSTRACT OF THE DISCLOSURE A lifting and pressure apparatus for vehicle mounted snowplows wherein the snowplow is movable between an upper transporting position, a normal plowing position, and a lower pressure applying scraping position. Upper and lower links connect the snowplow to the sprung portion of the vehicle, the lower link being oriented in a downward and forward direction when the plow is in its normal plowing position, the upper link being shorter than the lower link so that the plow when raised is moved upwardly with the lower part of the plow moving upardly and forwardly relative the upper part of the plow. A substantially horizontal lever separate from the links raises and lowers the plow, and a reciprocating double acting fluid operated piston is operable in a substantially vertical direction against the lever to raise the plow and also press the plow downwardly to its lower scraping position, to transfer some of the vehicle weight to the plow.
This application is a continuation-in-part of my copending US. Patent application Ser. No. 459,568, filed May 28, 1965.
The invention relates to snowplows, scrapers and other ground engaging equipment for cleaning road surfaces.
More particularly the invention relates to an improved means for mounting such equipment on the front end of a wheeled vehicle for raising the equipment to a transporting position and also for using vehicle weight to press the equipment against a road surface such as when a snowplow blade is used as a scraper. Such equipment may include, in addition to snowplows, ice scrapers, rotary snowplows and pulverizers, road brushes, rollers, etc.
In earlier filed application Ser. No. 459,568, there is shown a snowplow blade mounted on the front end of a propelling motor vehicle in such a manner that it can be moved vertically between a raised transporting position and one or more operating positions. When the blade is carried in its transporting position it must have a suitable road clearance to avoid contact with low objects. Also it is necessary with a blade having two plowing edges to raise the blade high enough so that it can be rolled over to reverse the angle of attack on the snow. To accomplish this, the blade is swung upwardly through a relatively large arc with a swinging movement rather than a direct vertical lifting action, thus a. smaller and less cumbersome lifting unit may be used.
Another pertinent feature shown in earlier filed application Ser. No. 459,568 is a provision for transferring part of the weight of the motor vehicle to the cutting edge of the snowplow blade when the blade is used as a scraper for removing ice and compacted snow. In this way the unit pressures of the blade edge against the road surface are increased substantially beyond that supplied by the weight of the plow blade and its supporting mechanism alone.
The lifting and pressure unit used to provide these capabilities includes a mounting member attached to the front of a propelling vehicle and a carrier member to "nited States Patent 3,432,946 Patented Mar. 18, 1969 which the snowplow blade is attached and which is adapted for vertical movement relative to the mounting member. During the raising of the snowplow blade to a transporting or rollover position, the lower portion of the carrier member moves both upwardly and outwardly to swing the snowplow blade upwardly through a relatively large arc and thus raise the blade to a sufficient height to provide the desired clearance.
The movement of the carrier member is guided by means of upper and lower links pivotally connected between the mounting member and the carrier member. The upper links are horizontal when carrier member is lowered to its operating position. The lower links are longer than the upper links and extend downwardly and outwardly from the mounting member when the carrier member is in its operating position. Thus when the carrier member is raised to lift the snowplow blade, the lower portion of the carrier member moves both upwardly and outwardly to provide the desired levering action which swings the snowplow blade through a relatively large arc to its transporting position. On the other hand, when the unit is used to transfer vehicle weight to the blade the lever portion of the carrier moves both downwardly and rearwardly to provide a forward tilting of the carrier member and the plow blade.
The means for operating the lifting and pressure unit, shown in prior application Ser. No. 459,568, consisted of a hydraulic cylinder pivotally connected to the upper portion of the mounting member and to the lower portion of the carrier member. With this arrangement the piston strokes work directly on the movable carrier member and in some instances are not in a direction parallel to the direction of movement of the lifting and pressure unit.
For this reason the cylinder force is not always used to best advantage. Also a relatively long stroke is required for raising the equipment to a transporting position. Inasmuch as space is at a premium, this raises problems.
The lifting and pressure unit of the present invention eliminates the objectionable features of the construction discussed above and affords advantages heretofore not realized.
In accordance with the present invention a hydraulic cylinder unit cooperates with a lever connected at one end to the mounting member attached to the front end of the vehicle to provide a fulcrum. The opposite end of the lever is connected through a flexible arrangement such as a pivot link to the movable carrier member which supports the ground-engaging equipment. Thus the lever is operable to move the carrier member through a path of travel between a transporting position, intermediate position such as for plowing snow, and a pressure applying position such as for scraping.
The carrier member is guided for movement through a path of travel corresponding to that shown in application Ser. No. 459,568 to provide the desired amount of lifting.
The piston rod of the hydraulic cylinder unit is pivotally connected intermediate the ends of the lever so that the piston stroke may be relatively short and still provide the necessary degree of movement for the carrier member. The connecting point may be selected to fit the stroke of a standard cylinder unit and to provide the desired operating pressures. The cylinder unit may be driven, for example by a hydraulic system located in the vehicle.
With this construction, the operating force of the cylinder unit is applied in a direction corresponding more closely to the desired direction of application of the vehicle weight to the equipment and thus provides improved operating capability for transferring vehicle weight to provide increased unit pressures for the snowplow blade. Also it will be apparent that only a relatively short piston stroke is needed to obtain a maximum amount of lifting of the equipment.
It is among the objects of the invention to provide an improved lifting and pressure unit for snowplows, scrapers and other ground engaging equipment which may be operated by a standard fluid cylinder unit and in which the force of the cylinder unit is applied in a direction substantially parallel to the direction of relative movement of an equipment-carrying member.
It is also an object of the invention to provide an improved means for transferring part of the weight of the front end of a wheeled vehicle to a scraper block or other ground engaging equipment mounted on the front end thereof.
Another object of the invention is to provide an improved lifting and pressure apparatus for snowplows, scrapers and other equipment which is operable by a fluid cylinder unit wherein a relatively short piston stroke is operable to lift the equipment through a maximum vertical movement to a suitable transporting position.
Other uses and advantages of objects will become apparent from the detailed description and claims.
The invention may take physical form and certain parts and arrangement of parts; a preferred embodiment of which will be described in detail in this specification and illustrated in the accompanying drawings which are a part hereof and wherein:
FIGURE 1 is a side view partly in cross section of the forward end of a motor vehicle, having a snowplow mounted on the front end thereof shown in the normal plowing position showing the lifting and pressure unit raised to a transporting position in dashed lines; and
FIGURE 2 is a view similar to FIGURE 1 but showing the blade in a scraping position wherein a part of the weight of the vehicle has been transferred to the plow blade by the lifting and pressure unit.
Referring more particularly to the drawings which illustrate a preferred embodiment of the invention and are not for the purpose of limitation, FIGURE 1 shows a motor vehicle A having a snowplow B mounted on the front end thereof for vertical movement relative thereto through means of a hydraulically actuated lifting and pressure unit C.
The vehicle A forms no part of the present invention and is shown relatively schematically. Such vehicle A includes the usual front rubber-tired wheels mounted so as to be steerable on an axle 11 which in turn supports the chassis 12 through a conventional spring mechanism such as the leaf springs 13. Obviously, the springs can be coil springs, hydraulic springs or the like. The wheels 10 may be power driven as is conventional in large vehicles of this type. The principal cooperating feature of the vehicle A is that the chassis 12 be spring mounted relative to the wheels 10 such that when an upward force is applied to the chassis 12, the chassis 12 may move upwardly relative to the earth or road surface 15 on which the wheel 10 rolls, the springs 13 flexing to permit this movement. When the plow is not in engagement with the ground 15, the entire weight of the plow B, its supporting bracket mechanism and the front end of the vehicle is transferred to the wheels and ground through the springs 13.
The plow blade B per se forms no part of the present invention and is shown somewhat schematically. The plow consists of the usual curved, forwardly facing, concave mold board reinforced by brackets 21 welded to the back surface thereof, which brackets in turn are welded to a supporting plate 22. The lower or cutting edge of the plow B is, in accordance with the invention, formed from a plurality of fiat fingers 25 which form a forward and downward extension of the lowermost portion 25 of the mold board 20. Each finger 25 is supported in the plow B so as to be retractable in an upward and rearward direction and is biased forwardly and downwardly by means of a helical coil spring or springs 27 bearing at the forward end against the rearward end of the finger 25 and at the rear end against the base of a cylinder welded to one of the reinforcing brackets 21. The specific construction of the mechanism for urging the fingers 25 forwardly forms no part of the present invention.
The fingers may have any desired width, but the narrower that such fingers are, the greater sensitivity they will have to obstructions which they encounter and the more readily will they be able to conform to transverse curvatures in the roads surface. A width of seven to ten inches has been found quite adequate in practice.
The leading edge of the fingers 25 will, of course, be angled relative to the fore and aft axis of the vehicle A as is conventional.
Skids or runners 30 are provided for controlling the clearance of the leading edge of the fingers 25 from the road surface 15. These skids 30 may take any desired form including wheels, but in the embodiment shown, comprise shoes adjustable to a desired height. Obviously, any means of adjustably supporting the skids behind the cutting edge of the plow may be employed.
The plow B is mounted on the front end of the vehicle A by means of a lifting and pressure unit C embodying the present invention. Thus, a plate is welded to the front end of the frame 12. A mounting member 41 forming a part of the unit C is mounted on this plate 40 by any suitable means such as the studs 43 welded to the plate 41 and extending through suitable openings in the plate 40. Nuts 44 complete the fastening action.
The unit C also includes a carrier member 45 having a plane spaced forwardly from and generally parallel to the mounting member 41. The member 45 is mounted for vertical movement relative to the member 41 by means of a pair of upper links 46 and a pair of lower links 47, both the upper and lower links being pivoted at their forward ends to a rearwardly extending flange 48 integral with the carrier member 45 and at their rearward end to a forwardly extending flange 49 integral with the mounting member 41.
The upper links 46 have a generally triangular form and one edge 51 thereof engages the forward face of the mounting member 41 when the unit C is in its ultimate pressure applying position as shown in FIGURE 2. This provides a stop limiting the downward movement of the carrier member 45.
When the unit C is moved to its highest transporting position the upper edges of the links 46 engage stops 52 thus limiting the upward travel of the carrier member 45.
In accordance with the invention, the connection of the carrier member 45 to the mounting member 41 is such that when the member 45 is moved vertically relative to the member 41, its angle will change relative thereto and in particular so that when the member 45 moves upwardly relative to the member 41, its lowermost edge will move in an upwardly and outwardly extending arc. To accomplish this, the upper links 46 are shorter than the lower links 47 and normally extend generally horizontally while the lower links 47 extend generally forwardly and downwardly.
In accordance with the invention, the unit C includes means for forcefully moving the plow B or other ground engaging equipment not only in an upward direction for transporting the equipment above the pavement 15 as shown in dashed line in FIGURE 1, but also so that the equipment may be pressed downwardly into pressure engagement with the pavement 15 as shown in FIGURE 2, in such a manner that at least some of the sprung weight of the motor vehicle A may be transferred to the equipment and thus to the pavement 15, such as when the plow B is used as a scraper for compacted ice and snow.
The unit C is operated by means of a fluid cylinder unit pivotally connected at its upper end to the mounting member 41 by means of a transversely extending shaft 61 rigidly fixed at its ends to the plates 49.
A piston 63 is slidably supported inside of the cylinder unit 60 and has a downwardly extending piston rod 64 which cooperates with a lever 65 adapted to translate the piston strokes into upward and downward movement of the carrier member 45 relative to the mounting member 41. The lever 65 has a link 66 pivotable at each end connecting the lever to the carrier member 45 as shown. It will be apparent that the link 66 or some equivalent flexible connection is essential in order that the carrier member 45 be movable in response to the raising and lowering of the lever 65. The piston rod 64 is pivotally connected to the lever 65 intermediate the ends thereof as shown in the drawings.
The reciprocating movement of the piston 63 thereby operates the lever 65 to drive the carrier member 41 through a path of travel controlled by the links 46 and 47. The cylinder unit 60 is generally vertically mounted so that the force exterted thereby during the movement of the carrier member 45 to its pressure applying position will be substantially parallel to the relative movement of the members 41 and 45 thus providing optimum leverage.
Thus, as the piston 63 moves upwardly and downwardly, the carrier member 45 will move upwardly and downwardly with the upper end moving in an arcuate path tangent generally to the vertical plane and the lower end moving in an arcuate path tangent to a plane extending downwardly and rearwardly generally at an angle of approximately 45 The upper and lower ends of the cylinder 60 are connected through hydraulic conduits 70, 71, respectively, through a valve 72 to a hydraulic pump 73. The valve 72 is relatively conventional in construction and has an up, a down and a neutral position. The pump 73 is also connected to an oil reservoir 74.
The valve 72 is preferably arranged so that when in the neutral position, hydraulic fluid can neither flow into nor out of either the upper or the lower end of the cylinder 60. This in effect locks the vertical position of the plow B or other equipment relative to the vehicle A.
To initially place the plow B or other equipment in operation, it is mounted on the front end of the vehicle A with the hydraulic piston 63, being in such a position that the equipment is either just in engagement with the road surface or has a slight clearance therefrom. In this position, the piston 63 is preferably midway between each end of its stroke.
In the event that the snow is hard packed or has turned to ice, however, it has been the experience that the normal plow blade as so operated is unable to remove all of this hard packed snow or ice and this is so even though the entire weight of the blade itself is allowed to press downwardly.
The mechanism described herein, however, enables a large part of the unsprung weight of the vehicle A to be transferred to the ground engaging equipment so that the pressure exerted thereby on the road surface can be enormously increased.
It is, of course, to be appreciated that if the vehicle A is of the fore and aft drive type, some of the drive traction of the forward wheels will be lost, but practice has shown that this is in no way detrimental, it being noted that almost vehicles employed for the purpose of driving plows and similar equipment have a relatively large and very heavy motor normally located over the front wheels 10. Thus, there is always ample or even excessive weight to obtain driving traction on these front wheels and a slight transfer of weight to the plow B is not in any way detrimental.
As is shown in FIGURE 2, when the plow B is forcefully moved downwardly by transferring some of the weight of the vehicle A to the plow B, the sprung weight on the wheels 10 is reduced and the springs 13 flex so that the frame 12 moves slightly upwardly.
The invention has been described with reference to a preferred embodiment. Obviously, modifications and alterations will occur to others upon a reading and understanding of this specification and it is my intention to include all such modifications and alterations insofar as they are included within the appended claims.
Having thus described my invention, I claim:
1. A lifting and pressure apparatus for vehicle mounted snowplows and the like comprising a mounting member attachable to the front end of a vehicle; a substantially vertically aligned carrier member for supporting ground engaging equipment; connecting means connecting said carrier member to said mounting member comprising spaced apart upper and lower links pivotally connected to both said members wherein the upper link is shorter than the lower link and is substantially horizontally oriented and the lower link is downwardly and forwardly oriented when the carrier member is in a plowing position whereby said carrier member is movable vertically between a transporting position, and operating position and a lowermost pressure applying position and whereby when said carrier member moves upwardly to said transporting position the lower portion thereof moves upwardly and forwardly relative to the upper portion thereof; a substantially horizontal lever separate from said connecting means pivotally connected at its rearward end to said mounting member; a link pivotable at each end connecting the forward end of said lever to said carrier member; a double acting fluid operated cylinder unit having a reciprocating piston and rod operable in a substantially vertical plane, said unit being pivotally connected at one end to said lever intermediate the ends thereof and at the other end to said mounting member; whereby said cylinder operates said lever to lift said carrier member to said transporting position and to press said carrier member downwardly to said pressure applying position to transfer vehicle weight to said ground engaging equipment.
2. In combination a snowplow and scraper assembly and a lifting and pressure applying apparatus therefor comprising a mounting member attached to the front end of a vehicle to the sprung portion thereof;
a substantially vertically aligned carrier member for supporting said snowplow and scraper assembly;
connecting means connecting said carrier member to said mounting member whereby said carrier member is movable between a transporting position, a plowing position and a lowermost pressure applying scraping position, said connecting means comprising spaced apart upper and lower links pivotally connected to both said members wherein the upper link is shorter than the lower link and is substantially horizontally oriented and the lower link is downwardly and forwardly oriented when the carrier member is in the plowing position; whereby when said carrier member moves upwardly to said transporting position the lower portion thereof moves upwardly and forwardly relative to the upper portion thereof;
a lever means which is substantially horizontally oriented and separate from said connecting means pivotally connected at its rearward end to said mounting member;
a link pivotable at each end connecting the forward end of said lever means to said carrier member;
a double acting fluid operated cylinder unit having a reciprocating piston and rod operable in a substantially vertical direction, said unit being pivotally connected at its upper end to said mounting member and its lower end to said lever intermediate the ends thereof, whereby said cylinder operates said lever to lift said carrier member and said assembly to said transporting position and to press said carrier member and said assembly downwardly from said plowing position to said scraping position when desired to transfer vehicle weight to said snowplow and scraper assembly.
(References on following page) References Cited UNITED STATES PATENTS Soule et a1. 37-42 Bywater et a1. 97-47 Cook et a1. 3742 HD1111 37-42 Gjesdahl 3742 Malvese 37 -42 Riedy 3742 8 3,150,884 9/1964 Drott 37-42 3,165,842 1/1965 Holopainen 3742 3,296,721 1/1967 Coontz 37-444 5 WILLIAM B. PENN, Primary Examiner.
E. H. EICKHOLT, Assistant Examiner.
U.S. C1. X.R.