US 3775877 A
A conventional snowplow attachment for the front of a small vehicle is provided with controllable means for overcoming the springs of the attachment's conventional safety-release mechanism, which permits at least the lower edge portion of the blade to pivot to the rear when it encounters an obstacle, to retain the blade's lower edge portion in such rearwardly and downwardly-inclined position for backplowing purposes.
Description (OCR text may contain errors)
United States Patent 1 1 1111 3,775,877
Gove, Sr.  Dec. 4, 1973 BACKPLOWING SNOWPLOW 3,307,275 3/1967 Simi 37/42 R ATTACHMENT 1,561,368 11/1925 Staley 172/808 X  Inventor: Ernest J. Gove, Sn, Rt, 151, FOREIGN PATENTS OR APPLICATIONS Newington, N.H. 03801 168,983 1 1951 Austria 37 42 v1. 103,657 3 1964 Norway... 172/806  Sept 1972 653,231 12/1962 Canada 37 42 v1.
 Appl. No.: 292,940
Primary ExaminerEdgar S. Burr Assistant ExaminerEugene H. Eickholt  US. Cl. 37/42 VL, 172/264, 172/414,
172/463, "2/808 AttorneyJohn W. Malley et al.  Int. Cl E0111 5/04  Field of Search 37/41, 42 R, 42 VL,  ABSTRACT 37/50 141 R; 172,276 A conventional snowplow attachment for the front of 264 a small vehicle is provided with controllable means for overcoming the springs of the attachments conven-  References Cited tional safety-release mechanism, which permits at UNITED STATES PATENTS least the lower edge portion of the blade to pivot to 1,195,271 8 1916 Ruth 172 806 x h r r wh n it encounters an obstacle, to retain the 2,614,344 10/1952 Rust..... blades lower edge portion in such rearwardly and 2,775,830 V1957 y downwardly-inclined position for backplowing pur- 3,007,265 11/1961 Harris poses 2,867,921 1/1959 Brown 3,528,509 9/1970 Bleyker 172/802 6 Claims, 6 Drawing Figures 78 '1 a a 1 a2 "MENIEUBEB 4197s SHEET 1 BF BACKPLOWING SNOWPLOW ATTACHMENT BACKGROUND OF THE INVENTION This invention relates to an improvement in a snowplow attachment for vehicles. More especially, this invention relates to an improved snowplow attachment which can be used to backplow sucessfully.
Snowplow attachments of the type under consideration are well known and usually involve a frame detachably connected at its rear end to the front of a jeep or a small truck. The rear end of the frame normally is pivotally connected to the vehicle for vertical swinging movement while its forward end supports a snowplowing moldboard or blade. Power-operated means, usually hydraulic, normally are provided for lifting and lowering the forward end of the frame in order to lift the blade into an inoperative position or to lower it into operative position for plowing snow on forward movement of the vehicle. The blade of such attachments usually is mounted on the forward end of the frame for pivotal adjustment about a vertical axis. This adjustment normally is remotely controllable from the vehicle so that the angle of the blade, relative to the direction of its forward movement, can be changed. Thus, as the snow is plowed it can be selectively moved to either the right or left of the plowing vehicle.
The front surface of the blade of such snowplow attachments normally is concavely curved in vertical section to roll the snow ahead, while the blade is tilted somewhat to the vertical so that its lower scraping edge portion has a downward and pronounced forward inclination. Such downward and forward inclination of the lower edge portion of the blade results in a downward component of the plowing reactive force on the blade to maintain the latter in its effective plowing position against the surface of the ground underlying the snow.
Snowplowing by small vehicles using attachments of the aforedescribed type usually is confined to relatively small areas like driveways and parking lots. Most such areas do not lend themselves to so-called throug plowing, i.e., plowing snow by a continuously forwardly moving vehicle. Instead, plowing of such areas usually is accomplished by dexterously maneuvering the vehicle and also the blade in order to clear such areas of the snow. While conventional snowplow attachments of the aforedescribed type are satisfactory for their intended purpose, they lack the ability to backplow satisfacton'ly, i.e., to plow snow effectively while the vehicle is backing up. Backplowing with such conventional attachments is successful, in fact, only when the snow is relatively light, fluffy, and not too deep. Effective backplowing, however, would be a most useful maneuver for clearing small areas of snow.
The lack of successful backplowing by conventional snowplow attachments is due to the fact that the lower edge portion of the blade normally is downwardly and forwardly inclined, so that when the vehicle backs up there is an upward component of the backplowing reactive force on the blade which causes it to move upwardly and thus override the snow. Not only is such overriding most unsatisfactory as respects clearing the snow, but also tends to pack the snow, thus making it more difficult to remove by the only remaining method of removal, namely shoveling by hand. As a result, backplowing with conventional snowplow attachments usually is avoided.
Conventional snowplow attachments of the aforedescribed type also are usually provided with a safetyrelease arrangement for avoiding damage when the blade encounters a relatively immovable obstacle. Such an arrangement enables at least the lower edge portion of the blade to move from its forwardly and downwardly inclined forward plowing position to a rearwardly and downwardly-inclined position. This rearwardly-inclined position results in an upward component of the plowing reactive force on the blade to cause the latter to move upwardly and to override the obstacle. In some such safety arrangements the entire blade is mounted for pivotal movement about a substantially horizontal axis and maintained in its normal plowing position by springs connected to the blade and to parts of the blade-carrying frame. Other conventional snowplow attachments include an arrangement wherein the blade has an upper main section and a lower scraping edge section connected to the upper section for pivotal movement about a substantially horizontal axis. This lower scraping section of the blade normally is maintained in its normal plowing position by springs connected to the upper and to the lower blade sections. All of such springs will yield, however, if the blade encounters an obstacle in order to enable either the entire blade of the first described construction or only the scraping section of the last described construction to move to its rearwardly-inclined obstacle-overriding position.
Accordingly, it is an object of this invention to provide an improved arrangement for a snowplow attachment of the aforedescribed type which will enable such attachment to be used to backplow snow effectively.
It is another object of this invention to provide a simple and inexpensive modification for snowplow attach DESCRIPTION OF THE DRAWINGS FIG. 1 is a somewhat diagrammatic side elevational view of a snowplow attachment embodying this invention showing the plowing blade in its normal plowing position.
FIG. 2 is a fragmentary view corresponding to FIG. 1 showing the plowing blade moved into a position for effective backplowing.
FIG. 3 is a perspective view of the rear of the snowplow attachment shown in FIG. 1.
FIG. 4 is a view corresponding to FIG. 1 but showing the application of the invention to a modified type of snowplow attachment.
FIG. 5 is a fragmentary view corresponding to FIG. 2 of th snowplow attachment shown in FIG. 4.
FIG. 6 is a perspective view of the rear of the snowplow attachment shown in FIG. 4.
Referring now to FIGS. 1 to 3 of the drawings, there is shown a conventional snowplow attachment which includes a frame 10 carrying a moldboard or blade 12 at its forward end and having rearwardly divergent arms 14 adapted to be supported, at their rearward ends, on the front of a small vehicle 16, such as a Jeep or a small truck. Mounted on the vehicle 16 adjacent the rear end of the frame is the usual upright post 18 to which is connected one end of a vertically swingable lever 20. Connected to the outer end of the lever 20 and to the outer end of the frame 10 is a chain 22. A reciprocating hydraulic motor 24 is pivotally connected to the vehicle 16, adjacent the lower end of the post 18, and to the outer end of the lever 20. The arrangement is such that when the motor 24 is extended the outer end of the lever 20 will swing up and thus raise the forward end of the frame 10 and the blade 12 to an inoperative position. When the motor 24 is retracted the blade 12 is lowered into an operative plowing position.
Carried for pivotal movement on a vertical axis on the forward end of the frame 10 is a semicircular frame part 26. Since the details of the pivotal connection between the part 26 and the frame 10 are unimportant to this invention, such details need not be further described. The blade 12 is carried on the forward straight crossbar 28 of the frame part 26. The front surface of the blade 12 is concavely curved in vertical section while the marginal portions of the upper and lower edges of the blade are reinforced by horizontal back flanges 30 interconnected by vertical stiffening ribs 32. The blade 12 is mounted to the frame part 26 for pivotal movement on a horizontal axis by pivot pins 34 secured to the rear side of the blade and projecting into bushings 36 secured at opposite sides of the crossbar 28.
The blade 12 normally is retained in a plowing position, in which the back of the blade engages a suitable stop (not shown) on the top of the crossbar 28 and the lower marginal edge portion of the blade is downwardly and forwardly inclined, by coil tension springs 38 connected between the upper edge of the blade and to a bracket 40 attached to the top of the frame part 26. Conventional snowplow attachments of this type also usually include reciprocating hydraulic motors 42 connected between the blade 12, on opposite sides of its vertical pivot axis, and the frame arms 14 in order to adjust the angular position of the blade about its vertical pivot axis, so that when the vehicle 16 is moved forwardly and the blade is in plowing position the snow will be moved off to the left or to the right of the vehicle as desired.
Mounted at the midpoint of the crossbar 28, on a bracket 44 secured thereto, is the cylinder 46 of a reciprocating hydraulic motor 48 having an upwardly projecting piston rod 50. Chains 52 are secured to the upper end of the piston rod and to brackets 54 extending rearwardly from the lower horizontal flange 30 on the blade 12. The motor 48 is supplied with hydraulic fluid through a hose connection 56 from an appropriate source (not shown) on the vehicle 16. Such supply preferably is controlled from the vehicle 16 by conventional means.
When an operator desires to use the snowplow attachment for backplowing purposes, the motor 48 is extended to lift the chains 52 and thus to move the blade 12 from its forwardly inclined plowing position to its rearwardly inclined obstacle-overriding position against the tension force of the safety-release springs 38. With the blade 12 retained in this position by the motor 48 the attachment can be used for backplowing purposes without the possibility of developing an upward component of reactive plowing force on the blade which would cause it to raise and override snow while backplowing. When it is desired to use the attachment for forward plowing, the supply of high pressure fluid to the motor 48 is diverted and the springs 38 will thereupon return the blade 12 to its normal forward plowing position.
Referring now to FIGS. 4 to 6 of the drawings, there is shown another type of a conventional snowplow attachment wherein the blade 58 has an upper main section 60 and a lower scraping edge section 62 pivotally mounted to the upper section. This lower section 62 usually has a rearwardly extending horizontal stiffening flange 64 at its upper edge while its lateral sides are provided with upwardly extending cars 66 that are pivotally connected to vertical stiffening ribs 68 at the opposite ends of the upper blade section 60. Coil compression springs 70, interposed between horizontal brackets 72 on the rear side of the upper blade section 60 and the horizontal flange 64 on the lower scraping section 62 maintain the latter in a normal plowing position constituting a continuance of the front concave surface of the blade 58. In this position the lower edge of the upper section 60 constitutes a stop engageable by the upper edge of the lower section 62.
It will be seen, however, that should the lower scraping section 62 of the blade 58 encounter a relatively immovable obstacle, the springs will yield and enable the lower section to pivot to a rearwardly and downwardly inclined position, as shown in FIG. 5, so that, again, there will be an upward component of reactive plowing force exerted on the blade to cause it to rise and override the obstacle.
In this embodiment of the invention it will be seen that the main blade section 60 is carried on the forward end of a plow frame 74 for pivotal movement about a vertical axis, and that a pair of reciprocating hydraulic motors 76 are connected between the rear ends of the frame, at its opposite sides, and to the rear side of the upper blade section to permit the entire blade 58 to be selectively angled to the right or to the left as desired. The frame 74 can be lifted to raise the blade 58 to an inoperative position by a reciprocating hydraulic motor 78 mounted on the vehicle 80 and connected to the frame in the same manner as the embodiment shown in FIGS. 1 3.
This embodiment of the invention also includes an upright reciprocating hydraulic motor 82 having the lower end of its cylinder 84 supported on a bracket 86 extending rearwardly of the main portion 60 of the blade 58 at about the midpoint thereof. One end of each of a pair of chains 88 is secured to the end of the vertically projecting piston rod 90 of the motor 82, while the other ends of the chains are secured to the ends of brackets 92 secured to and projecting rearwardly of the horizontal stiffening flange 64 on the scraping edge section 62 of the blade 58. Normally, when the motor 82 is retracted, the lower blade section 62 will be retained by the springs 70 in the forward effective plowing position shown in FIG. 4. When an operator supplies the motor 82 with hydraulic fluid under pressure, however, the piston rod 90 will be extended and the chains 88 will exert a force on the lower scraping edge section 62 of the blade 58 to cause it to pivot rearwardly to the position shown in FIG. 5. In this position the snowplow attachment can be used for backplowing, as described with respect to the embodiment shown in FIGS. 1 to 3, without resulting overriding of the blade 58 on the snow.
It thus will be seen that the objects of this invention have been fully and effectively accomplished. It will be realized, however, that the specific embodiment shown and described is susceptible to modification without departure from the principles of invention. For example, the hydraulic motors used to overcome the springs of the safety-release arrangements could be replaced with other operating instrumentalities, such as a mechanical toggle linkage, a screw or scissors mechanism, etc., any one of which could be operated manually at the plow attachment or operated by an electric motor controllable remotely from the vehicle. Hence, the invention encompasses all modifications included within the spirit and scope of the following claims.
1. A snowplow attachment for a vehicle comprising:
a blade supporting frame mountable to a vehicle at its rearward end for vertical swinging movement; laterally elongated plowing blade means carried by the forward end of said frame and having at least a lower scraping edge portion movable between a downwardly and forwardly-inclined position for forward plowing without snow-overriding upward movement of said blade and a downwardly and rearwardly-inclined position for obstacleoverriding upward movement of said blade; means operatively associated with said blade means for urging said edge portion into said plowing position, said urging means being yieldable when said edge portion encounters an obstacle; and
controllable means carried by said attachment and operatively associated with said blade means for selectively moving said edge portion into said rearwardly-inclined position to enable backplowing without snow-overriding upward movement of said blade.
2. The structure defined in claim 1 in which the controllable means includes a linear hydraulic motor.
3. The structure defined in claim 1 in which the entire blade means is movable as a unit for movement of the lower edge portion thereof and the controllable means is mounted to the frame and connected to said blade means.
4. The structure defined in claim 3 in which the controllable means includes a linear hydraulic motor having a cylinder and piston and flexible means connecting said piston to the blade means.
5. The structure defined in claim 1 in which the blade means includes an upper main portion movably carrying the lower edge portion and the controllable means is mounted to said upper main portion and connected to said lower edge portion.
6. The structure defined in claim 5 in which the controllable means includes a linear hydraulic motor and flexible means connecting said motor to the lower edge portion.