Method and apparatus for maintaining level plow when angling

Abstract

A support assembly that includes first and second frame components may be used to support a plow blade to a vehicle. The first frame component may have a first end defining a first pivot axis about which the plow blade pivots when it is moved side-to-side. The second frame component may have a first end that defines a second pivot axis about which the second frame component, the first frame component and the plow blade pivot when the plow blade is raised or lowered. A second end of the first frame component may be pivotally attached to a second end of the second frame component about a third pivot axis. The first frame component and the plow blade may automatically pivot together about the third pivot axis to maintain the plow blade in a level orientation even when the plow blade is both raised and moved side-to-side.

I/we claim: 
     
         1 . A plow assembly comprising:
 a plow blade assembly comprising: a plow blade having a plow surface that is suitable to contact and plow an associated plowable substance; and,   a support assembly that supports the plow blade assembly to an associated vehicle, the support assembly comprising:   (1) a blade support structure that is attached to the plow blade assembly and that supports the plow blade assembly to the support assembly;   (2) a blade height adjustment mechanism that is operable to raise and lower the blade support structure and the plow blade assembly with respect to an associated ground surface; and,   (3) a blade side-to-side adjustment mechanism comprising: (a) a first frame component comprising: a first end attached to the blade support structure and defining a substantially vertical first pivot axis about which the blade support structure and the plow blade assembly are pivotal together with respect to the first frame component; and a second end; (b) a second frame component comprising: a first end defining a second substantially horizontal pivot axis about which the second frame component is pivotal with respect to the vehicle when the blade height adjustment mechanism operates to raise and lower the blade support structure and the plow blade assembly; and a second end; (c) at least a first power device that is operable to cause the blade support structure and the plow blade assembly to pivot together about the first pivot axis; and, (d) wherein the second end of the first frame component is pivotally attached to the second end of the second frame component about a substantially horizontal third pivot axis so that the first frame component, the blade support structure and the plow blade assembly are automatically pivotal together about the third pivot axis to maintain the plow blade in a level orientation when: (i) the blade height adjustment mechanism is operated to raise the blade support structure and the plow blade assembly with respect to the associated ground surface; and. (ii) the first power device is operated to cause the blade support structure and the plow blade assembly to pivot together about the first pivot axis.   
     
     
         2 . The plow assembly of  claim 1  wherein:
 the second end of the first frame comprises one of a first tab and a first contact surface; 
 the second end of the second frame comprises the other of the first tab and the first contact surface; and, 
 the first tab contacts the first contact surface to limit the pivotal motion of the first frame component, the blade support structure and the plow blade assembly about the third pivot axis. 
 
     
     
         3 . The plow assembly of  claim 2  wherein:
 the second end of the first frame comprises a first plate having a first hole and first and second ends; 
 the second end of the second frame comprises a second plate having a second hole and first and second ends; 
 the first plate is juxtaposed to the second plate with the first and second holes being substantially concentric and receiving a pivot pin that defines the third pivot axis; 
 a first bracket having a first opening is positioned on one of the first end of the first plate and the first end of the second plate, a first surface of the first bracket defining the first opening defines the first contact surface and a second surface of the first bracket defining the first opening defines a second contact surface; 
 the first tab is positioned on the other of the first end of the first plate and the first end of the second plate; 
 the first tab is received in the first opening; 
 the first tab contacts the first contact surface to limit the pivotal motion of the first frame component, the blade support structure and the plow blade assembly about the third pivot axis in a first rotational direction; and, 
 the first tab contacts the second contact surface to limit the pivotal motion of the first frame component the blade support structure and the plow blade assembly about the third pivot axis in a second rotational direction that is opposite the first rotational direction. 
 
     
     
         4 . The plow assembly of  claim 3  wherein:
 a second bracket having a second opening is positioned on one of the second end of the first plate and the second end of the second plate, a first surface of the second bracket defining the first opening defines a third contact surface and a second surface of the second bracket defining the first opening defines a fourth contact surface; 
 a second tab is positioned on the other of the second end of the first plate and the second end of the second plate; 
 the second tab is received in the second opening; 
 the second tab contacts the third contact surface to limit the pivotal motion of the first frame component, the blade support structure and the plow blade assembly about the third pivot axis in the first rotational direction; and, 
 the second tab contacts the fourth contact surface to limit the pivotal motion of the first frame component, the blade support structure and the plow blade assembly about the third pivot axis in the second rotational direction. 
 
     
     
         5 . The plow assembly of  claim 4  wherein the second pivot axis is substantially perpendicular to the third pivot axis. 
     
     
         6 . The plow assembly of  claim 5  wherein the first and second frame components together form an A-frame. 
     
     
         7 . A plow assembly comprising:
 a plow blade assembly comprising: a plow blade having a plow surface that is suitable to contact and plow an associated plowable substance; and,   a support assembly that supports the plow blade assembly to an associated vehicle, the support assembly comprising:
 (1) a blade support structure that is attached to the plow blade assembly and that supports the plow blade assembly to the support assembly; 
 (2) a blade height adjustment mechanism that is operable to raise and lower the blade support structure and the plow blade assembly with respect to an associated ground surface; and, 
 (3) a blade side-to-side adjustment mechanism comprising: (a) a first frame component comprising: a first end attached to the blade support structure and defining a first pivot axis about which the blade support structure and the plow blade assembly are pivotal together with respect to the first frame component; and a second end; (b) a second frame component comprising: a first end defining a second pivot axis about which the second frame component is pivotal with respect to the vehicle when the blade height adjustment mechanism operates to raise and lower the blade support structure and the plow blade assembly; and a second end; (c) at least a first power device that is operable to cause the blade support structure and the plow blade assembly to pivot together about the first pivot axis; and, (d) wherein the second end of the first frame component is pivotally attached to the second end of the second frame component about a third pivot axis so that the first frame component, the blade support structure and the plow blade assembly are pivotal together about the third pivot axis. 
   
     
     
         8 . The plow assembly of  claim 7  wherein:
 the first pivot axis is substantially vertical with respect to the associated ground surface; 
 the second pivot axis is substantially horizontal with respect to the associated ground surface; and, 
 the third pivot axis is substantially horizontal with respect to the associated ground surface. 
 
     
     
         9 . The plow assembly of  claim 8  wherein the second pivot axis is substantially perpendicular to the third pivot axis. 
     
     
         10 . The plow assembly of  claim 7  wherein the first and second frame components together form an A-frame. 
     
     
         11 . The plow assembly of  claim 7  wherein:
 the second end of the first frame comprises one of a first tab and a first contact surface; 
 the second end of the second frame comprises the other of the first tab and the first contact surface; and, 
 the first tab contacts the first contact surface to limit the pivotal motion of the first frame component, the blade support structure and the plow blade assembly about the third pivot axis. 
 
     
     
         12 . The plow assembly of  claim 11  wherein:
 the second end of the first frame comprises one of: first and second brackets defining the first contact surface and a second contact surface; and, the first tab and a second tab; 
 the second end of the second frame comprises the other of: the first and second brackets defining the first and second contact surfaces; and, the first and second tabs; 
 the first tab contacts the first contact surface to limit the pivotal motion of the first frame component, the blade support structure and the plow blade assembly about the third pivot axis in a first rotational direction; and, 
 the second tab contacts the second contact surface to limit the pivotal motion of the first frame component, the blade support structure and the plow blade assembly about the third pivot axis in a second rotational direction that is opposite the first rotational direction. 
 
     
     
         13 . The plow assembly of  claim 11  wherein:
 the second end of the first frame comprises a first plate having first and second ends; 
 the first tab is positioned on the first end of the first plate; 
 the second end of the second frame comprises a second plate having first and second ends; 
 a first bracket having a first opening is positioned on the first end of the second plate; 
 a first surface of the first bracket defining the first opening defines the first contact surface and a second surface of the first bracket defining the first opening defines a second contact surface; 
 the first plate is juxtaposed to the second plate; 
 the first tab is received in the first opening; 
 the first tab contacts the first contact surface to limit the pivotal motion of the first frame component, the blade support structure and the plow blade assembly about the third pivot axis in a first rotational direction; and, 
 the first tab contacts the second contact surface to limit the pivotal motion of the first frame component, the blade support structure and the plow blade assembly about the third pivot axis in a second rotational direction that is opposite the first rotational direction. 
 
     
     
         14 . The plow assembly of  claim 11  wherein:
 the second end of the first frame comprises a first plate having first and second ends; 
 the first tab is positioned on the first end of the first plate; 
 a second tab is positioned on the second end of the first plate; 
 the second end of the second frame comprises a second plate having first and second ends; 
 a first bracket having a first opening is positioned on the first end of the second plate; 
 a first surface of the first bracket defining the first opening defines the first contact surface; 
 a second bracket having a second opening is positioned on the second end of the second plate; 
 a second surface of the second bracket defining the second opening defines a second contact surface; 
 the first plate is juxtaposed to the second plate; 
 the first tab is received in the first opening; 
 the second tab is received in the second opening; 
 the first tab contacts the first contact surface to limit the pivotal motion of the first frame component, the blade support structure and the plow blade assembly about the third pivot axis in a first rotational direction; and. 
 the second tab contacts the second contact surface to limit the pivotal motion of the first frame component, the blade support structure and the plow blade assembly about the third pivot axis in a second rotational direction that is opposite the first rotational direction. 
 
     
     
         15 . A method of maintaining a plow blade in a level orientation comprising the steps of:
 (A) providing a plow assembly comprising: (I) a plow blade assembly comprising: a plow blade having a plow surface that is suitable to contact and plow an associated plowable substance; and, (II) a support assembly that supports the plow blade assembly to an associated vehicle, the support assembly comprising: (1) a blade support structure that is attached to the plow blade assembly and that supports the plow blade assembly to the support assembly; (2) a blade height adjustment mechanism; (3) a blade side-to-side adjustment mechanism comprising: (a) a first frame component comprising: a first end attached to the blade support structure and defining a first pivot axis; and a second end; (b) a second frame component comprising: a first end defining a second pivot axis; and a second end; (c) at least a first power device; and, (d) wherein the second end of the first frame component is pivotally attached to the second end of the second frame component about a third pivot axis;   (B) operating the blade height adjustment mechanism to pivot the second frame component about the second pivot axis and to raise the blade support structure and the plow blade assembly with respect to an associated ground surface;   (C) operating the first power device to cause the blade support structure and the plow blade assembly to pivot together about the first pivot axis with respect to the first frame component; and,   (D) maintaining the plow blade in a level orientation by automatically pivoting the first frame component, the blade support structure and the plow blade assembly together about the third pivot axis with respect to the second frame component.   
     
     
         16 . The method of  claim 15  wherein step (A) comprises the steps of:
 providing the first pivot axis to be substantially vertical with respect to the associated ground surface; 
 providing the second pivot axis to be substantially horizontal with respect to the associated ground surface; and, 
 providing the third pivot axis to be substantially horizontal with respect to the associated ground surface and substantially perpendicular with respect to the second pivot axis. 
 
     
     
         17 . The method of  claim 15  wherein:
 step (A) comprises the steps of: providing the second end of the first frame to comprise one of a first tab and a first contact surface; and, providing the second end of the second frame to comprise the other of the first tab and the first contact surface; and, 
 step (D) comprises the step of: limiting the pivoting of the first frame component, the blade support structure and the plow blade assembly together about the third pivot axis with respect to the second frame component by contacting the first tab with the first contact surface. 
 
     
     
         18 . The method of  claim 17  wherein:
 step (A) comprises the steps of: (1) providing the second end of the first frame with one of: first and second brackets defining the first contact surface and a second contact surface; and, the first tab and a second tab; and, (2) providing the second end of the second frame with the other of: the first and second brackets defining the first and second contact surfaces; and, the first and second tabs; and, 
 step (D) comprises at least one of: (1) contacting the first tab to the first contact surface to limit the pivotal motion of the first frame component, the blade support structure and the plow blade assembly about the third pivot axis in a first rotational direction; and, (2) contacting the second tab to the second contact surface to limit the pivotal motion of the first frame component, the blade support structure and the plow blade assembly about the third pivot axis in a second rotational direction that is opposite the first rotational direction. 
 
     
     
         19 . The method of  claim 17  wherein:
 step (A) comprises the steps of: (1) providing the second end of the first frame with a first plate having first and second ends; (2) providing the first tab to be positioned on the first end of the first plate; (3) providing the second end of the second frame with a second plate having first and second ends; (4) providing a first bracket having a first opening that defines the first contact surface and also defines a second contact surface on the first end of the second plate; (5) juxtaposing the first plate to the second p)ate; and, (6) positioning the first tab in the first opening; and, 
 step (D) comprises at least one of: (1) contacting the first tab to the first contact surface to limit the pivotal motion of the first frame component, the blade support structure and the plow blade assembly about the third pivot axis in a first rotational direction; and, (2) contacting the first tab to the second contact surface to limit the pivotal motion of the first frame component, the blade support structure and the plow blade assembly about the third pivot axis in a second rotational direction that is opposite the first rotational direction. 
 
     
     
         20 . The method of  claim 17  wherein:
 step (A) comprises the steps of: (1) providing the second end of the first frame with a first plate having first and second ends; (2) providing the first tab on the first end of the first plate; (3) providing a second tab on the second end of the first plate; (3) providing the second end of the second frame with a second plate having first and second ends; (4) providing a first bracket having a first opening that defines the first contact surface on the first end of the second plate; (5) providing a second bracket having a second opening that defines a second contact surface on the second end of the second plate; (6) juxtaposing the first plate to the second plate; (7) positioning the first tab in the first opening; and, (8) positioning the second tab in the second opening; and, 
 step (D) comprises at least one of: (1) contacting the first tab to the first contact surface to limit the pivotal motion of the first frame component, the blade support structure and the plow blade assembly about the third pivot axis in a first rotational direction; and, (2) contacting the second tab to the second contact surface to limit the pivotal motion of the first frame component, the blade support structure and the plow blade assembly about the third pivot axis in a second rotational direction that is opposite the first rotational direction.