WO2012027658A2

WO2012027658A2 - Breakaway guard for a mower

Info

Publication number: WO2012027658A2
Application number: PCT/US2011/049322
Authority: WO
Inventors: Philip D. Stam; Kent L. Thompson
Original assignee: Forage Innovations B.V.
Priority date: 2010-08-27
Filing date: 2011-08-26
Publication date: 2012-03-01
Also published as: WO2012027658A3; EP2608651A2; EP2608651A4

Abstract

A mower is suspended from a frame and includes a header with a cutter with a main guard over the header and cutter. An outer guard is attached to the main guard at a front connection point and a rear connection point so that if the outer guard strikes a fixed object like a fence post it will fall off. The front connection is designed to separate slightly before, or at the same time as the rear connection to prevent damage to the main guard. This functionality is provided by allowing the outer guard to slide relative to the main guard, while the outer guard includes a spring loaded mounting plate that is part of the mounting structure, that contacts a fulcrum on the main structure, when the outer guard slides relative to the main guard, the spring loaded mounting plate contacts the fulcrum, continued movement of the outer guard results in the mount plate being pried away from the main guard, separating the connection in a controlled and reliably repeatable manner.

Description

BREAKAWAY GUARD FOR A MOWER

CROSS-REFERENCE TO RELATED APPLICATIONS

Not Applicable

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to crop harvesting equipment and more particularly to mowers with main safety guards and safety guards on the outer wings of the main safety guards.

Background of the Invention

U.S. Patent No.7,726, 109 shows guards on the extreme outside of each of two disc mowers, for example in Fig. 5b of the Ί09 patent. The reason for these guards are so that if a person is adjacent to or even having a leg pressed against one of the guards, it keeps that person spaced far enough from the outermost disc cutter nearest to the guard that it would be difficult if not impossible for such person's leg or foot to get close enough to such outer disc cutter to endanger the person's leg or foot. Prior art guards of this type can typically pivot about a mostly horizontal axis that is mostly parallel with the forward direction of the mower, to provide access to the end disc mower, for example so that the blades thereof can be changed or removed for sharpening.

However, when the mower is actually moving forward the guard needs to be down, such as while being operated to cut a crop or transported from place to place, there is a danger that the guard will come in contact with something such as a fence post. If being transported into or out from a field, contact of the guard with a fence post could occur while passing through a narrow gate. And during a mowing operation, farmers and ranchers are typically trying to mow as close to fences as possible to get as much of the growing crop as can be cut. So it is not uncommon that the guard will inadvertently come in contact with a fence post or other object that will damage the guard. If the guard is damaged, there is a danger that the user will just remove the guard in order to finish mowing a field, rather than repairing or replacing it.

Also, while most mowers have flexible main guards that sort of look like a blanket draped over the mower for preventing the blades of the mower from throwing rocks or broken cutter blade pieces outside of the guarded area, at least one innovation by the inventors' employer is to mold a main guard out of a semi-rigid plastic material such as high density polyethylene, instead of using flexible material. This semi-rigid plastic main guard is relatively expensive so that care needs to be taken not to damage it. If the outer guard is damaged by striking a post or the like, the main guard can be easily damaged. For instance as the outer guard is being ripped off it may also damage the main guard to the point of needing to replace the main guard as well.

Accordingly, there is a need to provide an end safety guard that is not destroyed or damaged when it comes in contact with a stationary object such as a fence post. There is also a need to prevent damage to relatively expensive semi-rigid main guard for mowers.

BRIEF SUMMARY OF THE INVENTION

The present invention relates to a machine having an outer guard attached to the main guard with a breakaway feature with a front connection point and a rear connection point. Although it could be used on a variety of machines, this invention is particularly useful for a mowing and/or conditioning machine, to protect the integrity of the guards in the infrequent instances when the outer guard strikes an obstacle while the machine is travelling in a forward direction. In these instances it is critical for the front connection to separate slightly before, or at the same time as the rear connection. The present invention is intended to protect the main mower structure, including the main guard, to allow the outside guard fall to away when an obstacle is struck, while travelling at a relatively high rate of speed. The dynamic characteristics of these situations, the speed of travel of the machine, results in the possibility for damaging the machine. The potential for damage is increased if there is a slight delay in releasing the front connection. With such a delay the outer guard would remain attached at that the front connection point which could lead to damage to the main structure or main guard. Thus, it is critical that the front releases with the following critical characteristics:

1) controlled timing of the release, as described above, the front connection point of the outer guard breakaway feature will release slightly before or at the same time as the rear connection point;

2) consistent break away force, so that the outer guard breakaway will release when striking an obstacle, but that it will not release too easily. This invention provides the possibility to adjust the breakaway force so that it can be set as high as possible to minimize the probability that the guard will break-away, while at the same

time preventing damage of any components.

The breakaway capability is provided by allowing the outer guard to slide relative to the main guard when it strikes an obstacle. The outer guard includes a spring loaded mounting plate that is part of its mounting structure. The spring mounted plate pivots to allow this sliding motion and that contacts a fulcrum on the main structure. As the outer guard slides relative to the main guard, the spring loaded mounting plate contacts the fulcrum, and continued movement of the outer guard results in the mount plate being pried away from the main guard, separating the connection in a controlled, reliable , and repeatable manner.

Another important aspect of the present invention is that once the breakaway guard falls off, there are no loose parts, so because it is intact, it can be simply put back on without the use of tools. Other objects, advantages, and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a perspective view of a mower having a preferred embodiment of the present invention on it;

FIG. 2 is a perspective view of the preferred embodiment of a main guard that goes on top of a mower with a breakaway guard pivotally attached thereto looking rearwardly from a towing prime mover, at the front of the mower;

FIG. 3 is a perspective view like Fig. 2, but showing a plate removed to show an adjusting bolt for a spring and a fulcrum;

FIG. 4 is a partial elevational view looking from the rear of the mower at the right side of the main guard and breakaway guard;

FIG. 5 is a cross-sectional view taken along line A-A of Fig. 4;

FIG. 6 is is a cross-sectional view taken along line B-B of Fig. 4;

FIG. 7 is is a cross-sectional view taken along line C-C of Fig. 4;

FIG. 8 is a perspective view of the preferred embodiment of a main guard that goes on top of a mower with a breakaway guard pivoted upwardly thereto looking rearwardly from a towing prime mover and shown with a plate removed to show a spring biasing structure; FIG. 9 is a perspective view of the preferred embodiment of a main guard that goes on top of a mower with a breakaway guard pivoted upwardly like Fig. 8, but with a spring mount plate attached to keep debris out of the spring compartment;

FIG. 10 is an enlarged bottom view of the main guard and breakaway guard in dashed lines to show how the two parts are attached to each other, the front of the guard being down in the operative position thereof and showing how the front plate pivots about a fulcrum when the breakaway guard hits an object with sufficient force to cause it to break away from the main guard;

FIG. 11 is an enlarged bottom view of the main guard, the same view shown in Fig 10 with the breakaway guard in dashed lines and the spring plate removed to show how the spring is attached;

FIG. 12 is a simplified bottom view of the main guard and breakaway guard and how they are attached together during a mowing operation;

FIG. 13 is a simplified bottom view of the main guard and breakaway guard like Fig. 12, but showing what happens when a force F is applied to the breakaway guard such as the force of the breakaway guard hitting a fence post as the mower is moving forwardly;

FIG. 14 is a simplified bottom view of the main guard and breakaway guard like Fig. 13, but showing what happens just after a force F of Fig. 13 is applied to the breakaway guard to cause complete separation of the breakaway guard from the main guard;

FIG. 15 is a simplified bottom view of the breakaway guard like Fig. 12, but showing a front plate biased to the position shown in this Fig. 15, illustrating the functional components that are attached as integral components of the outer guard;

FIG. 16 is front view looking along line 16-16 of Fig. 15;

FIG. 17 is a simplified view like Fig. 12, but showing only the main guard and a shaft that extends through the main guard producing stub shafts on the front and rear thereof for making it possible to attach the breakaway guard thereto;

FIG. 18 is front view looking along line 18-18 of Fig. 17;

FIG. 19 is front view like Fig. 18, but showing the breakaway guard attached thereto and pivoted upwardly, Fig 19 also showing that the fulcrum is ineffective when the guard is in the raised position; and

FIG. 20 is a front view showing how the breakaway guard can easily be reattached once it has fallen off by engaging a stub shaft of the main guard with an opening in the breakaway guard and then pivoting the breakaway guard down on the right side shown in Fig. 20 until a hole in the front bracket extends over a stub shaft extending out of the front of the main guard.

FIG. 21 is a front view looking along line 21-21 of Fig 14

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, FIG. 1 shows a mower 10 with a frame 11 having wheels 12 operatively attached thereto for permitting the frame 11 to be towed from place to place, though this invention would apply to non-towed mowers as well, such as those mounted directly to a tractor instead of using the tractor to tow the mower. This invention could be used for machines other than mowers. For the sake of clarity, the following description will focus on the application for a mower, while not intending to suggest that its application is limited to mowers.

A header 13 is operatively attached to the frame 11 by top links 14 and bottom links 15 for example in the way shown in Figs. 8-12b of U.S. Patent No.7,726, 109, which is incorporated herein by reference in its entirety. Hydraulic cylinders 16, attached to the frame 11 and the header 13, are used to raise or lower the header 13 with respect to the frame 11.

Cutters (not shown) are operatively rotatably attached to the header 13 in the way shown in Figs. 5a and 5c of the ' 109 patent mentioned above for cutting plants off a short distance above the ground.

A tongue 21 is operatively pivotally attached along a first substantially vertical axis C as shown in Fig 1 and is adapted to be attached to a prime mover (not shown) at the other end thereof by use of a hitch 24.

Still looking at Fig. 1, a main guard 101 has a flexible skirt 101s attached thereto at the bottom thereof and an outer breakaway guard 103 has a flexible skirt 103s attached thereto at the bottom thereof for preventing objects such as rocks from being thrown by the cutters under the guards. Looking to Fig. 2, the main guard 101, preferably molded from a semi-rigid plastic such as high density polyethylene, is pivotally attached to the mower frame 11 using a hinge 17. The breakaway outer guard 103 is pivotally attached to the main guard 101 by a front side pin 104a, formed as part of a rod 104, the rod 104 extending through the main guard 101 and having a rear stub shaft portion 104r as can be seen in Figs. 12-14, for example.

Still referring to Fig. 2, a front plate 102 is pivotally attached along a vertical axis about a hinge 106 and has an opening 107 therein that extends over and around front stub shaft 104f. Front plate 102 is pivotally attached to the outer breakaway guard 102 at vertical pivot pin 108. Plate 102 has a hole in it large enough for bolt 109 to extend loosely through it. This bolt 109, with a bolt head 109h, is attached to one end of tension spring 110 and is threaded where adjusting nut 111 is located so that turning the bolt 109 with respect to the nut 111 in one rotary direction increases the force of the spring 110 to make it harder for the breakaway guard 103 to fall off and rotating the bolt 109 with respect to the nut 111 in an opposite rotary direction decreases the force of the spring 111 to allow the breakaway guard to fall off easier. The end of the spring 110 with a hook on it hooks into a flange 112 rigidly attached to plate 120 that is bolted to the breakaway guard 103 as can be seen in Fig. 6.

The main guard 101 has a fulcrum 113 as can be seen in Figs. 7, 11, 14 and 17, for example.

In operation, the outer breakaway guard 103 is attached to the guard 101 as shown in Figs. 2-12, for example. When in use, while mowing, the outer breakaway guard 103 will be pivoted to the down position as shown in Figs. 2, 3 and 12 for example. The mechanical elements that cooperate to allow the shield to pivot between a raised position, while being properly oriented in a down position, are illustrated in Figs 14 and 21. The main elements of main guard 101 include a front pivot pin 104f, rear pivot pin 104r and surfaces 105a, 105b and 105c. The main elements of breakaway guard 103 include a rear aperture 117, front aperture 107 and surfaces 115a, 115b and 115c.

Surfaces 105 and 115 abut when the breakaway guard is in the lowered position and installed on the main guard, and are oriented parallel to the direction of travel to allow the breakaway guard to slide relative to the main guard. As illustrated in Fig 21 the abutting surfaces are offset vertically from the pivots. This offset determines the position of the breakaway guard in its lowered position. Alternative arrangements are possible. For instance a single adjustable arm could be fixed to the break away guard to contact an alternate surface of the main guard. The key functional requirement is that there is a surface on either the main guard or the breakaway guard that is parallel to the direction of travel, or to an axis that passes through the front pivot pin 104f and the rear pivot pin 104r, with a cooperating component on the opposite guard that abuts that surface to position the breakaway guard in its operating position, while allowing it to slide as required for the breakaway hinge to function as described below.

If the mower 100 is moving in the forward direction as shown by the arrow in Fig. 13, and it hits an object like post 150, a force F, will cause the outer breakaway guard 103 to move from the position in Fig. 12, to the position in Fig. 13, noting that the front plate 102 will contact the fulcrum 113, causing the plate to pivot about vertical axis 108, overcoming the bias of the spring 110, thereby causing the left end of the front plate 102 to move off of the front stub shaft 104f. This situation is also shown in Figs 10 and 11, where the front plate 102 is in contact with fulcrum 113. It is important to note in Fig 13 that the position of the fulcrum 113 will affect the timing of when the front plate 102 will slide off of the front stub shaft 104f as compared to the timing of when aperture 117 in the outer breakaway guard 103 will slide off the rear stub shaft 104r. The position of the fulcrum, the length of the front stub shaft 104f, and the length of the rear stub shaft 104r are designed so that the front of the outer breakaway guard 103 will drop off at the same time or before the rear of the outer breakaway guard 103 falls off of the rear stub shaft 104r. If the rear of outer breakaway guard 103 dropped off before the front of the outer breakaway guard 103 it could shift forward and remain engaged with the front stub shaft 104f, which would result in damage to the main guard 101, which is extremely expensive to replace compared to replacement of the outer breakaway guard 103.

Fig. 10 shows a removable plate 120 attached to the breakaway guard 103. The biasing member, extension spring 110, although not visible in this figure, is connected to plate 120 on one end by the tab 112 that is fixed to plate 120 as shown in Fig 6. Fig. 11 illustrates the position of spring 110, with plate 120 hidden, with the second end connected to front plate 102.

Fig. 14 shows the outer breakaway guard 103 completely separated from the main guard 101.

Figs. 15-16 show details of the outer breakaway guard 103 in a simplified form, illustrating the main integral components including the front plate 102 with aperture 107, spring 110, adjustment bolt 109, and rear aperture 117. Figs. 17 -18 show details of the main guard 101 in a simplified form including the front pivot pin 104f, rear pivot pin 104r, and fulcrum 113.

Fig. 19 shows that the fulcrum 113 as designed in this embodiment is ineffective when the guard is in the raised position.

It is important to note that once the outer breakaway guard 103 falls off, there are no loose parts so because it is fully intact it can be simply put back on without the use of tools.

Fig. 20 shows how the outer breakaway guard 103 is re-installed, i.e. that the outer breakaway guard 103 could be put onto the rear pivot or stub shaft 104r, and then snapped over the front pivot of front stub shaft 104f. The front bracket 102 is bent out on the bottom 102b to allow it to be forced out to the right as shown in Fig. 20 as the front plate of the outer breakaway guard 103 is moved down against the front pin, stub shaft 104f of the main guard 101. One aspect of the present invention is that when the 103 is rotated into the upper position, the front pivot plate does not contact the fulcrum 103. The fulcrum 103 only becomes effective when the outer breakaway guard 103 is lowered into the lower/operating position shown in Figs. 1-7 and 12 for example.

Obviously many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

Claims

1. A mower comprising:

a frame adapted to be movable in a forward direction;

a header operatively attached to the frame;

cutters operatively attached to the header for cutting plants;

a main guard operatively pivotally attached to the frame along a first mostly horizontal axis, the main guard extending over the cutters in an operative downward position thereof and pivoted up in an upper position to allow ready access to the cutters when the mower is not being operated;

an outer guard operatively pivotally attached to the main guard along a second mostly horizontal axis when the main guard is in an operative downward position, the outer guard having a down operational position and an up access position;

a front stub shaft extending forwardly from the main guard about the second mostly horizontal axis;

a rear stub shaft extending rearwardly from the main guard about the second mostly horizontal axis;

a front plate pivotally attached to the outer guard about a first mostly vertical axis when the outer guard is in the down operational position and the main guard is in a downward operational position thereof;

a front opening in the front plate, the front stub shaft extending into the opening in the front plate when the outer guard is operatively pivotally attached to the main guard;

a rear opening in a component of the outer guard, the rear stub shaft extending into the rear opening in the front plate when the outer guard is operatively pivotally attached to the main guard; a fulcrum operatively attached to the main guard at a position between the front opening of the plate and the mostly vertical axis of the front plate for permitting the plate to pivot about a second mostly vertical axis at the fulcrum; and

a biasing member operatively attached to the outer guard and to the plate for biasing the plate towards the front stub shaft to thereby keep the outer guard attached to the main guard during normal operation of the mower.

2. The mower of claim 1 wherein the biasing member is a spring that is adjustable in biasing force.

3. The mower of claim 2 wherein the biasing member is a tension spring.

4. The mower of claim 1 wherein the biasing member is a tension spring operatively attached to the outer guard at one end there of and operatively attached to the plate at the other end thereof.

5. The mower of claim 4 wherein the tension spring is disposed around a threaded member having a threaded adjusting nut thereon for adjusting the biasing force of the tension spring, the threaded member extending slideably through a hole in the plate, an enlarged portion being disposed on the threaded member forwardly of the plate so that the force of the tension spring pulls the plate rearwardly.

6. The mower of claim 5 wherein the enlarge portion is either a threaded nut or a bolt head rigidly attached to the threaded member.

7. The mower of claim 1 wherein the frame includes wheels operatively attached thereto for permitting the frame to be towed from place to place.

8. A method of attaching an outer guard of a mower to a main guard of a mower comprising:

allowing the outer guard to slide relative to the main guard, using a spring loaded mounting plate on the outer guard that is part of the mounting structure to contact a fulcrum on the main structure so that when the outer guard slides relative to the main guard, the spring loaded mounting plate contacts the fulcrum and whereby continued movement of the outer guard results in the mount plate being pried away from the main guard, separating the connection in a controlled and reliably repeatable manner.