US 4,495,754 AGranted

Trailing wing mower with hydraulic breakaway system

OwnerJack O. Cartnerinventor

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Abstract

A hydraulic wing mower includes a central section (A) to which a left wing section (B) and a right wing section (C) are pivotally connected. A first hydraulic cylinder (100) is operatively connected between the central section and left wing section for selecting its angular position and a second hydraulic cylinder (100') is operatively connected between the central section and the right wing section for selecting its angular position. A hydraulic circuit provides hydraulic fluid under pressure from a reservoir (120) to a wing angular position control valve (170). The wing angular position control valve selectively directs hydraulic fluid under pressure to the first and second cylinders to select an angular orientation for the left and right wings. A pressure relief valve (180) is selectively connected between the hydraulic cylinders and the reservoir. When an upward force occurs on one or both of the wing members, e.g. when a wing member engages an upward incline or the central section moves into a depression, the hydraulic fluid flows from the cylinders through the relief valve to the reservoir. This allows one or both wing sections to yield or breakaway under an upward force. In the preferred embodiment, the wings do not yield or breakaway under a downward force such that they may be cantilevered over a ravine or the like.

Claims18

Dependent claims

A trailing wing mower comprising:

a first mower section including supporting means for movably supporting the first section above and substantially parallel to the ground immediately thereunder and a first motor means operatively connected with the first section for providing motive power to a first cutting means;
a second mower section including support means for movably supporting the section above the ground and means operatively connected with the second section for providing motive power to a second cutting means;
a first hinge means extending above and substantially parallel to the ground immediately thereunder operatively connecting the first and second sections such that the second section is angularly displaceable relative to the first section about the first hinge means;
and,
a first angular position controlling means for limiting the angular position of the second section relative to the first section to a selected angular displacement range, the angular displacement range extending between a generally perpendicular angular position and a selected limit angular position, the first angular position controlling means including a first hydraulic cylinder operatively connected between the first and second sections, hydraulic fluid supply means for selectively supplying hydraulic fluid to the first hydraulic cylinder to control the relative extension of the first hydraulic cylinder, and first hydraulic pressure relief means for relieving hydraulic fluid pressure a preselected force such that the relative extension of the first hydraulic cylinder is altered, the first hydraulic cylinder and the hydraulic fluid supply means select the limit angular position, such that the first hydraulic cylinder is adapted for selectively fixing the second section cantilevered over the ground when the ground thereunder is lower than the ground under the first section by an angle outside of the angular displacement range, and the first hydraulic pressure relief means allows the extension of the first hydraulic cylinder to be altered to permit the first and second sections to be angularly displaced between the perpendicular and limit angular positions as the sections follow the contour of the ground thereunder, such that the first section remains substantially parallel to the ground thereunder, whereby the first hinge and a portion of the first section thereadjacent are not lifted further above the ground and out of the parallel relationship therewith by the second section when the ground under the second section is higher than the ground under the first section.

2 more elements

A trailing mower comprising:

a central mower section including supporting means for movably supporting the central section a preselected distance above and substantially parallel to the ground immediately thereunder and a first motor means operatively connected with the central section for providing motive power to a first cutting means;
a left wing section including supporting means for movably supporting the left wing section above the ground and means operatively connected with left wing section for providing motive power to a second cutting means;
a right wing section including supporting means for movably supporting the right wing section above the ground and means operatively connected with the right wing section for providing motive power to a third cutting means;
a first hinge means having a first axis extending generally a preselected distance above and parallel to the ground thereunder, the first hinge means being operatively connected with the central and left wing sections such that the left wing section is angularly displaceable upward and downward relative to the central section about the first hinge means axis;
a second hinge means having a second axis extending generally a preselected distance above and parallel to the ground thereunder, the second hinge means being operatively connected with the central and right wing sections such that the right wing section is angularly displaceable upward and downward relative to the central section about the second hinge means axis;
a first double acting hydraulic cylinder means operatively connected between the central and left wing sections for controlling the angular position of the left wing section relative to the central section;
a second double acting hydraulic cylinder means operatively connected between the central section and the right wing section for controlling the angular position of the right wing section relative to the central section;
and,
a wing attitude control means for independently limiting the angular displacement of the wing sections relative to the central section to a selected angular displacement range, the attitude control means including a hydraulic control circuit for selectively providing hydraulic fluid to the first and second cylinders for selecting the lowermost angular position of the angular displacement range of the left and right wing sections relative to the central section and holding the left and right wing sections cantilevered over ground thereunder which is lower than the ground under the central section by an angle outside the angular displacement range, the hydraulic circuit including pressure relief means operatively connected with the first and second cylinders for permitting each wing section to be angularly displaced upward toward a more vertical position when at least one of the wing section supporting means is urged upward by changes in contour of the ground, such that each wing section follows the contour of the ground over rises and remains cantilevered above depressions at the selected lowermost angular position.

6 more elements

A hydraulic trailing wing mower comprising:

(a) a central mower section having ground engaging wheels and a first hydraulic motor for providing motive power to a first rotary cutting blade, the central section being adapted to be pulled by a prime mover;
(b) a left wing section including at least one ground engaging wheel and a second hydraulic motor for providing motive power to a second rotary cutting blade;
(c) a right wing section including at least one ground engaging wheel and a third hydraulic motor for providing motive power to a third rotary cutting blade;
(d) hinge means operatively connecting the central section with the left and right wing sections such that the left and right wing sections are angularly displaceable relative to the central section;
(e) a first hydraulic cylinder operatively connected between the central section and the left wing section, the first hydraulic cylinder including a left wing raising chamber and a left wing lowering chamber which are separated by a slidable first piston;
(f) a second hydraulic cylinder operatively connected between the central section and the right wing section, the second hydraulic cylinder including a right wing raising chamber and a right wing lowering chamber which are separated by a slidable second piston;
and,
(g) a hydraulic circuit comprising:
(i) a hydraulic fluid reservoir;
(ii) pump means for supplying hydraulic fluid from the reservoir under pressure;
(iii) hydraulic motor control valve means operatively connected with the pump means for selectively directing hydraulic fluid under pressure to the first, second, and third hydraulic motors;
(iv) heat exchanger means operatively connected between the first, second, and third hydraulic motors and the hydraulic reservoir for cooling hydraulic fluid returning to the reservoir from the motors, the heat exchanger means being operatively connected with at least one of the central, left wing, and right wing sections;
(v) a wing angular position control valve means for selectively supplying hydraulic fluid under pressure from the pumping means to the left and right wing raising chambers and the left and right wing lowering chambers for limiting the angular position of the left and right wing sections relative to the central section, each to a lowermost angular position which is selected by the supplied hydraulic pressure, such that when the ground under one of the wing sections is sufficiently lower than the ground under the central section, the corresponding hydraulic cylinder holds the corresponding wing cantilevered over the ground thereunder;
(vi) relief valve means operatively connected between the left and right wing lowering chambers and the hydraulic fluid reservoir for allowing hydraulic fluid to pass from the wing lowering chambers to the reservoir in response to the central section being urged downward relative to at least one of the wing sections, such that the left and right wings move upward from the lowermost angular position to follow rises in the ground;
and,
(vii) check valve means operatively connected between the hydraulic fluid reservoir and the left and right wing raising chambers for allowing hydraulic fluid to be drawn from the reservoir into the left and right wing raising chambers in response to at least one of the wings being moved upward relative to the central sectiion, such that above the lowermost angular position each wing is permitted to be angularly displaced relative to the central section to follow contours of the ground.

13 more elements

A trailing wing mower comprising:

a central mower section including supporting means for movably supporting the first section above the ground and a first motor means operatively connected with the first section for providing motive power to a first cutting means;
a left wing section including supporting means for movably supporting the left wing section above the ground and means operatively connected with the left wing section for providing motive power to a second cutting means;
a right wing section including supporting means for movably supporting the right wing section above the ground and means operatively connected with the right wing section for providing motive power to a third cutting means;
a first hinge means operatively connected with the central and left wing sections such that the left wing section is angularly displaceable relative to the central section about the first hinge means;
a second hinge means operatively connecting the central and right wing sections such that the right wing section is angularly displaceable relative to the central section about the second hinge means;
a first hydraulic cylinder means pivotally connected with the central section;
a second hydraulic cylinder means pivotally connected with the central section;
a first kinematic chain operatively connected with the first hydraulic cylinder and the central and left wing sections for converting changes in the extension of the first hydraulic cylinder into corresponding changes in the angular position of the left wing section, the first kinematic chain including:
a first drive link pivotally connected at one end with the central section and pivotally connected closely adjacent its other end with the first hydraulic cylinder,
a first floating link pivotally connected at one end closely adjacent the first drive link other end and pivotally connected at its other end with the left wing section such that the floating link connects the first hydraulic cylinder with the left wing to exert lifting forces thereon,
the first hydraulic cylinder and the first floating link being connected with the first drive link such that the first drive link spaces the first hydraulic cylinder from the central section without providing a mechanical advantage between the first hydraulic cylinder and the first floating link;
a second kinematic chain operatively connected with the second hydraulic cylinder and the central and right wing sections for converting changes in the extension of the first hydraulic cylinder into corresponding changes in the angular position of the right wing section, the second kinematic chain including:
a second drive link pivotally connected at one end with the central section and pivotally connected closely adjacent its other end with the second hydraulic cylinder,
a second floating link pivotally connected at one end closely adjacent the second drive link other end and pivotally connected at its other end with the right wing section such that the floating link connects the second hydraulic cylinder with the right wing to exert lifting forces thereon,
the second hydraulic cylinder and the second floating link being connected with the second drive link such that the second drive link spaces the second hydraulic cylinder from the central section without providing a mechanical advantage between the second hydraulic cylinder and the second floating link;
and,
a wing attitude control means for independently limiting the relative angular displacement of the wing sections relative to the central section to a selected angular displacement range, the angular displacement range extending between a generally perpendicular relative angular displacement and a lowermost angular displacement, the attitude control means including a hydraulic circuit for selectively controlling the extension of the first and second hydraulic cylinders to select the lowermost angular displacement at which each wing section is held cantilevered over ground which is sufficiently lower than the ground under the central section that the wing section is unsupported thereby, the hydraulic circuit including pressure relief means for releasing hydraulic fluid from the first and second hydraulic cylinders in response to a force which urges the left and right wings, respectively, upward relative to the central section toward a more vertical orientation such that the wing sections are movable through the angular displacement range.

14 more elements

A trailing wing mower comprising:

(a) a central mower section having ground engaging wheels and a motor for providing motive power to a first rotary cutting blade, the central section being adapted to be pulled by a prime mover;
(b) a left wing section including at least one ground engaging wheel and means for providing motive power to a second rotary cutting blade;
(c) a right wing section including at least one ground engaging wheel and means for providing motive power to a third rotary cutting blade;
(d) hinge means operatively connecting the central section with the left and right wing sections such that the left and right wing sections are angularly displaceable relative to the central section;
(e) a first through-rod-type hydraulic cylinder operatively connected between the central section and the left wing section, the first through-rod-type hydraulic cylinder including a left wing raising chamber and a left wing lowering chamber which are separated by a slidable first piston mounted on a first rod which extends through both the left wing raising and lowering chambers;
(f) a second through-rod-type hydraulic cylinder operatively connected between the central section and the right wing section, the second through-rod-type hydraulic cylinder including a right wing raising chamber and a right wing lowering chamber which are separated by a slidable second piston mounted on a second rod which extends through both the right wing raising and lowering chambers;
and,
(g) a hydraulic circuit comprising:
(i) a hydraulic fluid reservoir;
(ii) pump means for supplying hydraulic fluid from the reservoir under pressure;
(iii) a wing angular position control valve means for selectively supplying hydraulic fluid under pressure from the pumping means to the left and right wing raising chambers and the left and right wing lowering chambers for selecting a pressure differential across the first and second pistons to bias the left and right wing sections to a selected lowermost angular positions at which each wing section is held cantilevered over ground thereunder which is too low to support the corresponding wing second ground engaging wheel when the corresponding wing section is in the lowermost angular position;
(iv) first relief valve means connected between the left wing lowering and raising chambers for allowing hydraulic fluid to pass from the left wing lowering chamber to the left wing raising chamber in response to the pressure in the left wing lowering chamber exceeding a preselected left wing upward breakaway pressure, whereby the left wing is angularly displaced above the lowermost angular position to follow contours in the ground thereunder and limited in downward movement to the lowermost angular position;
and,
(v) a second relief valve means connected between the right wing raising and lowering chambers for allowing hydraulic fluid to pass from the right wing lowering chamber to the right wing raising chamber in response to the pressure in the right wing lowering chamber exceeding a preselected right wing upward breakaway pressure, whereby the right wing is angularly displaced above the lowermost angular position to follow contours in the ground thereunder and is limited in downward movement to the lowermost angular position.

11 more elements

Dependencies are inferred from the claim text.